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How is a space rocket's weight supported while on the launch pad?
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"Any rocket can support it's own weight many times over by design. The reason is that on the pad, only gravity is affecting the rocket, but once launched, the acceleration will typically be 10 to 20 times bigger than gravity. \n\nSo if a rocket can handle the launch, than it can handle being on the pad without support.",
"All rockets have some sort of attachment system on the side of the rocket at base holding it up from the pad. [Here's a gif showing the clamps for the Falcon 9 moving](_URL_2_) and [here's a video showing the massive hold-down arms on the Saturn V swinging out of the way as it lifts off](_URL_0_). Some rockets have clamps that swing away by hydraulics or springs when the rocket lifts off, and other have explosive bolts that separate. The Soyuz is somewhat unique in that it doesn't have any hold-down system at base, rather it has support arms that attach midway up the rocket and essential suspend it over the flame trench. [Here's a video where you can see them swinging outward at the moment of liftoff](_URL_1_).",
"There are spots near the engine that actually sit on points that extend up on the pad. For the spaceX rockets they use [hold down clamps](_URL_4_), which is basically raised metal pads, and part of the motor support structure (the octoweb) just sits on top of them. They have hydraulic tops to lock it into place. [You can see more](_URL_3_). There are additional points that help stabilize it somewhat on the tower, but they don't hold the weight.",
"It doesn't sit on the engines as you need the engine bells open or instead of your rocket being a controlled explosion, you'll just have an explosion\n\nThe rocket is supported at the base of the engines but above the engine bells on many. This point is super strong because the force is applied in roughly the same spot during flight (expanding gasses push against the combustion chamber and engine bells before bouncing out the back)"
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What makes some allergies more severe than others?
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"In the simplest terms, an allergic reaction is an overreaction to certain chemicals that are basically harmless. Your body's initial defenses are triggered.\n\nThe problem is that your cells are *really* dumb. Sure, with all the complex mechanisms that you have and the finely-tuned balancing act between them, you can get a really powerful adaptive defense. But any single component? It's purely a \"receive specific stimulus, do single task.\" So, you have an overreaction, and parts your immune system sets off other part, which set off other parts, and so on. Furthermore, if you set off the *wrong* parts first, you're body's not prepared to counteract itself; you have systems to stop your immune system from killing itself, but if you \"glitch\" past that with allergies or autoimmune diseases (which is similar to being allergic to yourself), your body won't be able to hold itself back.\n\nDifferent allergens get into your body in different ways and set off different parts of the immune system, causing different reactions."
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What happens in our brains when we cry?
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"I'm fairly sure crying is just a symptom of intense emotion. It's not just tears but your sinuses in general that start overproducing.",
"I think it’s a way of your brain to utilize your body to signal to others that you’re in distress. Basically an anatomical “help me please!”"
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- Is there any truth to the expression, “Beer before liquor, never been sicker, liquor before beer, you’re in the clear”?
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"If you drink beer before liquor, you are gradually ramping yourself up to an unknown BAC, therefore when you take shots, they hit you exponentially harder which could lead to getting drunker quicker. However, if you drink liquor first, you will ramp up exponentially from a 0% BAC to a possible tipsy or drunken state, but you can now gently stay at the same level of BAC with beer, therefore not getting sick quickly unless you down a bunch of beer in a short amount of time.",
"It's not true because of something chemical that's going on inside of you or anything like that. It's just a matter of pacing yourself.\n\nIf you start the night with a few shots or mixed drinks and then limit yourself to beer, you're not going to get too much drunker, because beer is low alcohol per volume and you'll need to drink a lot of it. Unless you're really chugging, you're not going to get yourself to the point where you get sick.\n\nIf you start with a couple of beers, though, and then switch to liquor, it's a different story. Number one, liquor is higher alcohol per volume, so you're taking in the alcohol faster. And number two, you've already been drinking, which means your inhibitions are lowered. Which means you're more likely to do something dumb, like take too many shots too fast, getting yourself very sick.\n\nSo the expression is only true in the sense that switching to beer almost forces you to slow down and exhibit a little more self-control. But if I were to have one beer, then one shot, while my friend has one shot, then one beer, the two of us won't feel too different and neither of us will feel any sicker - it's more about when you hit your limits and how easy it is to go past that limit.",
"We in Russia have an entirely opposite folk wisdom: Градус понижать нельзя (You don't lower the proof). Which means you drink the less alcoholic things first, the more alcoholic later."
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When using sign language - is there a way to indicate you are just making a gesture as opposed to signing? Or is it just obvious?
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"Quick note for those who may not know: there is not one sign language. Most countries have their own sign languages (ASL - American Sign Language; BSL - British Sign Language; Auslan - Australian Sign Language; Chinese Sign Language, etc.). This is because sign languages developed naturally over time, just like spoken sign language, and they are different for all of the reasons that no one uses a universal spoken language.\n\nThere are two ways to kind of think of gestures in sign languages. One way is to consider that gestures have their own \"meanings\" that are not a part of language, and are used by everyone, whether you're hearing or not. For instance, when you point at something, that conveys *something*. Usually it means \"look this direction\" or \"I'm indicating this thing\". But it's not grammatical. There's no sentence, there's no formal structure or meaning, and although pretty much everyone knows what you're trying to convey, it can convey a lot of things. So a gesture \"in sign language\" is still just a gesture, and it conveys whatever meaning it has in the culture that's using it.\n\nAnother good example would be the middle finger in America. A lot of people say that the middle finger is a sign, but it isn't (in ASL). It's a gesture. It doesn't \"mean\" anything in sign other than that you've given someone the middle finger. That gesture certainly has meaning within the culture of America, and you can roughly translate that to \"fuck you\" or something, but it still doesn't *mean* that. It doesn't *mean* anything except that you're giving someone the middle finger, with all of the connotations attached to that. Incidentally, ASL *does* have signs both for \"FUCK YOU\" as in \"to have sex with\", like \"[I want to] fuck you\" or \"[I] fuck[ed a coconut]\"; and, \"FUCK-YOU\" as in, well, yelling \"Fuck you!\" to someone - which obviously doesn't mean you want to have sex with them, you just want to express that you are upset with them.\n\nAlternatively, if you want to consider random gestures that aren't associated with anything, you can kind of think of them like random noises people make that aren't words. Consider \"meh\" which isn't a word but still carries some meaning. Or laughing, which isn't a word but still indicates that you are amused. ASL does kind of have a sign for laughing, which is essentially spelling H-A-H-A... rapidly. (It's hard to explain but easy to show, go figure.) But signing \"H-A-H-A\" is kind of like *saying* \"Haha\" which isn't the same as laughing.\n\nThe point is, users of various sign languages understand the difference between a gesture and a sign in the same way that a hearing person understands the difference between a word and a noise. One is a commonly accepted part of the language, which follows its grammar and is known among users of that language as a word or sign. The other is not a part of the language - although it might convey some meaning in the context of the culture around it, it doesn't follow the grammatical rules of the language, and people don't think it's a word or sign or use it like one. You can even just make up signs, just like you can make up words. If it follows the rules and acts like a sign, someone using a sign language would take it for an unfamiliar sign but it would still otherwise be nonsense.",
"As you said. It is obvious. Its much like if someone who actually speaks saying one or two words that dont relate to something. You wouldnt assume they are actually trying to form a sentence ."
] |
Clinical depression vs depression vs Major depression disorder what is difference?
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"Clinical depression and Major Depressive Disorder are different ways to say the same thing. Both are defined by the crieria in the DSM-5. MDD is the formal name whereas clinical depression is the informal name.\n\nDepression just refers to an emotional state. You can be depressed without having a mental illness (like if a loved one dies). Depression turns into an illness when it lasts a long time and/or becomes more intense."
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Why does throat “burn” after drinking water with minty mouth?
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"You ever see that internet joke that mint is just cold spicy? That's why. Specifically, it activates a protein called TRPM8, which is used by nerve endings to sense cold (similar to how capsaicin activates VR1 to simulate \"hot\"). Of course, unlike your mouth, your throat doesn't really have a concept of cold -most of your body doesn't-, just agitated and not agitated.\n\nGuess what kind of feeling you get when the nerve endings in your throat give the agitated signal?"
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Why do pushrod engines have to be so much bigger than a dohc to make similar power, for instance the DOHC Ford 5.0 vs Pushrod 6.2 Chevy vs Pushrod 6.4 Mopar?
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"The main issue with pushrod engines is that due to the weight of the valvetrain they have issues with floating valves at high engine speeds. Basically the spring is not able to accelerate all the cams and rods fast enough to close the valve in time. So pushrod engines have a lower redline then other technologies like overhead camshaft or pneumatic valves. The lower engine speed have the effect of reducing the effective size of the engine. In order to produce power an engine have to suck inn as much air and fuel mixture as possible into its cylinders. The volume of an engine is how much air and fuel mixture it will suck into the cylinders per revolution. But if you have lower speed you also suck inn less air and fuel mixture even if you have a big volume engine.\n\n & #x200B;\n\nYou will find that if you multiply the volume of the engine with the ideal RPM of an engine and its boost pressure you get how much air and fuel mixture it goes through every minute which should roughly correspond to fuel consumption and power production."
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Why can’t you open a plane door mid flight?
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"Except that airplane doors open *inward* you have it correct. \n\nThe pressure is much much greater inside the plane so the force required to overcome the internal pressure is simply too great. The pressure inside is what keeps the door closed.",
"Most airplane doors open inward.\n\nWhen the plane is at cruising altitude, the pressure inside the cabin is greater than that outside the airplane. Assuming the locks were compromised or otherwise non-functional, you would still have to combat ~4-8 p.s.i. of differential pressure to ***pull*** open the door (consider the fact that a door is comprised of *many* square inches and this is a crazy amount of force).\n\nYou can think of it like a drain plug. The plug is pushed down onto the drain by the water on top of it. To pull the plug out, you have to combat the accumulated pressure caused by the weight of the water. Depending on how deep the water is, this can be very difficult.",
"[The aircraft’s pressurization system makes it possible. Here’s how the magic works…](_URL_0_)"
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why does crying make your nose run?
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"when you cry your tears come out of the tear glands and also drain through the tear ducts that empty through your nasal passage. it makes the mucus in your nose more liquid and thus making it run. everything in that region is all connected."
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How do shows produced by streaming services like Netflix and Hulu make money? How does viewer count come into play?
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"Subscription services, be it Netflix or or your mobile phone, or Ball Fondlers monthly all care about the exact same two things: \n\n(1) Getting new customers, and \n\n(2) Keeping the ones you have\n\nGetting new customers you need a reason for them to subscribe. Maybe its a new show, maybe its good service, maybe its something cool, maybe its just great marketing and word of mouth.\n\nKeeping customers you continually need to give them something of value. Maybe they want new content, better speeds, more razors, whatever. You need a reason for people to continue paying you.\n\n\"new\" shows keep people paying (so they can watch new content) and draws in new customers to watch it too.\n\nNow... this is a bit outside of your question, but the original content shows on Netflix and Hulu aren't made by them. They buy the rights to show the shows from production companies. So thats how the \"show\" makes money, by selling rights to Hulu/Netflix. Hulu and Netflix make money on subscriptions.",
"The shows themselves don't make money. Netflix or Hulu simply pay for all the costs and then own all the rights which allows them to stream as much as they want for 'free'. These services just want a big roster of different shows to attract and keep as many paying subscribers as possible. In the end the cost of these shows are just one point of expenditure for Netflix that is balanced by its income from subscriptions.\n\nThe shows Netflix produces are like the fuel a taxi driver buys to make his money shuttling passengers around.",
"Same way that any content makes a streaming service money... they draw subscribers in who want to watch the content. When they produce the shows in-house, Netflix, etc. don't have to pay licensing fees to the production companies who own the shows' rights like the would with other shows or movies."
] |
Can you make a brand new internet, like it would be completely empty with no data, no website no anything?
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"Yes. And you'll have to keep it from connecting to current internet. Otherwise it'll just be part of the current internet.\n\nYou'd have to get people to rerun millions of miles of cabling independently of all current connections. \n\nNot very cost effective",
"You certainly can. And in fact this is exactly what happens if you plug some computers into a router but don't connect that router to the public Internet — you just created your own tiny private Internet.",
"I suppose so, but it doesn't make sense.\n\nThe internet is a network of connected computers. You could in theory create all the infrastructure to transfer data between computers without actually connecting it to anything but that isn't really an \"internet\", it is just a geographically large network.\n\nYou could connect a bunch of blank servers to that big network but I don't know why people would do such a thing. Usually you add a server to actually host something."
] |
How does gum have calories if we don’t actually eat it?
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"Pour a bunch of sugar on a piece of paper. Put the sugar and paper in your mouth and chew it. Once you don't taste any more sugar, spit the paper out. Do you think you just consumed some calories even though you didn't eat any paper? The answer is yes. Same concept applies to gum.",
"The calories on food stuffs are the total, not the portion you swallow. \n\nSugars in the gum are desolved in saliva and swallowed or absorbed directly through the mouth tissue. So even if you don't swallow the gum, the primary calories in it you typically would.",
"You're getting calories from the flavoring and sugar that you swallow and absorb through the area underneath your tongue"
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Why do our fingers naturally curl up at rest?
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"You have muscles to extend them and muscles to retract them into a fist, when not doing either intentionally those muscles meet in the middle."
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Why doesnt the fire of a light lighter not go back in the lighter?
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"To ignite, fire needs a mix of oxygen and fuel. The lighter works because the fuel is sprayed and mixed into the air, giving the right combination to keep the flame lit. However, the tube connecting to tank of the lighter to the outlet doesn't have oxygen and thus won't combust."
] |
When you have a small chunk of skin removed, say you cut your fingertip off, how does the body know how much skin to replace to get it looking like it did before the injury?
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"Basically every cell in your body has an internal set of instructions to follow. For skin, one of the primary jobs is to either grow or not. So each skin cell is sitting there and constantly going over a checklist of if it's time to divide or not. \"Ok, has it been a while since the last time I divided? Yup. Am I big enough? Yup. Is there room for another cell next to me? Nope...dang. Start over.\" So, if you have a wound your skin cells recognize that there's not skin cells next to them and start dividing to fill the gap. Once they're surrounded by skin cells they stop.\n\n\nA \"fun\" fact is that this is pretty much what cancer comes from. Basically something (radiation, chemicals, copy error, dumb luck) damages the \"check list\". Most of the time when the list is damaged it will be unintelligible and the cell will just sit idle until it dies, but once in awhile the list is damaged in such a way that it most of the conditions that would trigger a stop get ignored. \"Ok, has it be awhile since I last divided? Who cares. Am I big enough to divide? Your mom thought I was big enough. Is there room next to me? Fuck it, it's go time!\" So the cell divides like crazy making a bunch of cells that divide like crazy.\n\nedit: welp, thanks for all the replies and metals, but now I'm gonna be late for work. Thanks jerks ;) ! Also, a couple of people have said I'm wrong which honestly doesn't surprise me much. Don't, like, make any serious medical decisions based on some rando on reddit in a sub based on explaining things as if to children, k?",
"Seeing a lot of answers here that kind of answer the question. I’m a wound care nurse so my studies include this specific topic.\n\nTypically your skin cells (made up of multiple layers) grow vertically to maintain your intact skin barrier. When you have a wound the body’s reaction to this “breach” is to essentially notify the skin cells surrounding the damaged skin. When the cells get this signal they stop growing vertically and start growing horizontally from the wound edges inward.\n\nWhen the skin cells meet in the middle (so the wound is no longer open) they re-program themselves to start growing upward again instead of side to side. In doing so, they start to strengthen the skin to return it back to its normal elasticity and protective ability.\n\nDepending on how many layers of skin are affected (how deep the wound is), the body will either be able to make a pretty smooth skin cover with all surrounding tissue structures intact (hair follicles, nerves, etc) or it will rely on scar tissue to do the best it can to get everything closed up. The deeper the wound, the more likely it will heal with scar tissue (which isn’t as strong and uniform as regular skin). When scar tissue is involved, damaged structures within the skin layers can not be preserved or repaired.",
"If you chop a chunk of your finger there is no way your body regenerates a new fingertip.\nIf you get a small cut then skin Bridges itself and starts to reproduce as always \"pushing\" any damage out. For a deep cut or a chopped limb the body just produces an ugly fiber which closes the wound in the shortest way possible.\n\nObviously not a doctor nor is English my first language.",
"Basically, the cells will continue duplicating endlessly until they are touching other cells of the same type, which triggers a stop function in them.",
"As an embryo growing from a single cell, different parts of the genome get activated in order to tell certain cells to take on different roles. As they grow to become functional parts, each segment of your finger has slightly different genetic activations which tell it “where” it is in your finger and how it is supposed to act and develop. When part gets cut off and regrows, the gradient of activated or deactivated genetic segments can be recreated and therefore “know” what type of tissue should be created and how much of it (roughly) from the patterns laid down during embryonic development for cell differentiation at the very beginning.\n\nObviously for larger injuries, the replacement might be too far away for this simple trick to work, but that’s how it does it on the small scale.\n\nYou might enjoy [this fun video on evolutionary development](_URL_0_) which focuses on how these changes evolve and were laid down in the first place, but also has some famous examples on how differentiation and “cells knowing what to be” works and how that can go wrong if you mess with it (like flys that grow eyes in their ass or legs on their faces if you inject different proteins into different segments during development).",
"The human body really doesn't heal itself by any sort of overall plan.\n\nInjuries heal as fast as the body can heal them, using the least energy, and taking into account physical activity.\n\nA deep but narrow cut will heal cleanly if it is sutured, or somehow kept from moving. If a deep, narrow cut is stressed and stretched, it will heal with much more scar tissue. This is not due to the body following any sort of inherent growth/repair plan. It is simply a result of the body healing as quickly and efficiently as possible, impacted by physical activity.\n\nThe rest of the body works the same. Larger wounds frequently heal with odd shapes of scar tissue because there is no biological 'blueprint' that the body can access to reconstruct the proper shapes of the missing flesh.\n\nAnimals which have true regeneration seem to have bodily repair functions which can draw 'plans' from genetic code. Humans mostly cannot do this, though there is one example of a human body part with true regeneration. The liver.\n\nWhy the human liver can regenerate, but the rest of the body cannot is way beyond a simple answer.",
"Basically your body generates skin by generating cells at a base layer pushing them up. As they are pushed up they die, and eventually slough off (get brushed off). When you remove a chunk of skin in an injury, you expose a lower layer of your skin. Your body heals the wound, but your body continues as per usual with the base layer creating cells underneath and pushing them up until the wound bed sloughs off. This reveals a new layer of skin that will also sometime in the future die and get sloughed off. The only reason the skin at your wound doesn't overgrow is because your regular skin doesn't overgrow everyday!",
"Each layer of your limb that got cut will reconstruct until the injury is gapped over. It's possible to do with small injuries because the multiple layers (muscle, fat, dermis and epidermis) all take care of themselves. Larger injuries may have certain layers not heal entirely before another does, leaving indents or disfigurement. Bone obviously does not regenerate when severed, although the layers of fat and skin can still typically regenerate around it.",
"One time I had MRSA on my arm... My skin opened up exactly where I have a mole, and it ended up being completely gone. No more mole. When it healed, however, my skin grew back the mole! There's a little scar right next to it, but it's back as if it had never left. Our body's a insane, what they're programmed to do. Giant machines encoded with our unique DNA.",
"The skin on the end of your finger is much thicker than you think it is. Most cuts don't go all the way through the skin. If it does you will regrow smoother scar tissue. If there are some of the lower skin layers left, the end will grow back complete with fingerprints.",
"Imagine you made a clay pot, then a bit gets chipped, but you know what it looked like and so you think you can do a pretty decent job of repairing it. \nYour body is like this, it made you once, it can make you again.",
"Your DNA carries explicit blueprints for the shape and design of your body. If it’s repairable, the body will follow those instructions to recreate the lost flesh.",
"Bone doesn't grow back, skin does. Sure fractures heal, but the bone isn't regrowing, it's just fusing with some of the fragments with the help of some special enzymes in the blood. Blood regenerates itself all the time, but it always seems like the closer to liquid a bio-structure is the easier it is to regenerate. Plants are really wild in that part, because plant's always grow back. It is probably because plants have very few genetic instructions in comparison to animals; grow. Yeah some plants do it differently, but it usually depends on the plant's range. Tall trees are more likely to be inhabited by animals so they usually have fruit that the animal would like to eat(and poop it's seed somewhere). Plants with fruit that grow in the ground don't have to worry much about that because if the fruit gets eaten my worms or insects, the seeds would be left wide open to all the nutrients of the soil and would just grow again. Some pests kind of ruin that by eating the seeds but there's a balance, if the plant growth reduces, the pests population also decrease, another way of balance showing itself is the typical \"circle of life\" where the insect eats the fruit, the bigger insect eats the insect, the bird eats the bigger insect, snake eats the bird, and bla bla bla reducing the chances of the plant growth reduction. What am i talking about again? \n\nOh yeah plants grow wounds pretty well, but it's usually because their bodies don't really have any instructions, other than grow and spread seeds. Kinda like hair.",
"So this might not completely answer your question, but disclaimer this is my limited non scientist understanding, \n\nFrom what I have read, they have found that when you are first growing your body and frogs bodies (you’ll see why frogs matter momentarily) sends electrical impulses to your finger tip in this case and say hey cells y’all need to make a finger tip.\n\nNow what they have done is listened to the electrical impulses and tried to mimic some of their own and in a lab setting they have taken a frog, cut off its tail and then gave the frog a shot.\n\nI was surprised by this being a shot I had visions of this frog with little electrodes all over it but no it’s a shot and I could use an ELI5 on this one.\n\nAfter they gave the frog a shot it then regrew a leg where it’s tail should’ve been because that’s what the scientists wanted it to do after that they cut off the leg and gave it another pill to make it regrow the tail again. \n\nSo TLDR: your body sends electrical impulses to the cells which tell it to regrow back to the way it was before. We have studied flatworms and they can regenerate their head with memories and all still in tact. BIOLOGY IS EXCITING.\n\n[link to an article](_URL_2_) \n\n[link to article](_URL_2_)\n\nNinja edit: wrote pill rather than shot",
"People seem to be completely overlooking scar tissue; if you lose an actual \"chunk\" of skin, i.e. several layers deep, it will never grow back the same.\n\nIf you lose too much skin from one area, it grows back in *roughly* the same shape in the form of scar tissue. Note the lack of sensation in scar tissue compared to standard skin; it's a comparatively \"simple\" replacement to fill the gap, mostly lacking nerve endings and finer details like finger prints and hair follicles.\n\nBurn victims, for example, are capable of growing back a lot of their skin but it grows incorrectly because it's mainly scar tissue trying it's best to \"fill the gap\". Severe burns that damage deeper layers of growing, fresh skin require skin grafts to look relatively normal again, though this obviously causes the site the replacement skin's taken from to scar.\n\n(Such skin is usually taken from areas that are easy to cover up.)",
"This is really well studied and defined by biology/medicine.\n\n & #x200B;\n\nBasically this process will only be (near)perfect as long as the deepest layer of skin (basement membrane) is intact. It will act as the foundation on which to build up the next layers of epithelium (skin). That process will be called regeneration since it created new skin. \n\n & #x200B;\n\nOn the other hand, if the basement membrane was damaged, no new skin will be created, since there is no foundation to guide such growth. Then scar tissue will be formed. That process is called repair, since it replaced damaged tissue with collagen (fiber).\n\n & #x200B;\n\nI think this might do it for ELI5. For more specifics you should read about regeneration & repair on a pathology textbook/web article.",
"This property is called **contact inhibition**. It is one of the factors helping in suppression of uncontrolled growth and multiplication of cell in a tissue. If a cell comes in contact with the surrounding cells its multiplication recedes.\n\nFor skin, its more than that. The contact inhibition works in the layer of germination. The cells in *stratum germinativum* then start multiplying towards their outside surface. As the skin keeps forming it also keeps shedding hence a balance is maintained.\n\nAfter getting wounded, some factors help in increasing the rate of cell multiplication for the time till it heals to some extent. So after it is healed the balance between multiplication and shedding holds importance.",
"The skin is composed of different layers. The surface of your skin is actually composed of dead cells. The layer of skin below that is alive. If you get a cut which then heals until it's as good as new, it's because that living layer of skin was unharmed. It continues to grow normally, with new cells dying and then forming a new outer layer of skin.\n\nThe living layer can regenerate if it has sustained some damage. If it sustains too much damage, scar tissue forms instead, which does not heal back normally.",
"Also curious how bones know to grow back into one piece. I broke my collarbone in 2 points and a middle part fell out. It's too small to be put back with the plate so they just plated the bigger two pieces together leaving a gap in the middle. Every few weeks we'd take an x-ray and I'd see the two ends of the bone growing closer, then finally touching, then fused together, then for denser. It's magical that it just knows what to do once put in the position.",
"It doesn't. Your skin is constantly replacing itself. Your body is basically shoving aging cells further and further out until it simply flakes off. Most of the dust in your house is actually just really tiny skin flakes. Eventually, the healing skin will look just like the rest of your skin, however, both are actually the same \"age.\"",
"You haven’t been badly cut or abraded if you think it grows back exactly as before. Every scar that covers a large area of damaged skin on my body is smaller than that originally. My fingertip and nail were avulsed a few years ago, and although I have a nail and fingertip again, they are smaller/shorter.",
"Speaking as someone who cut the tip of his finger off as a kid...it is entirely possible it will not grow back, and if it does it will not be exactly the same. My injured finger is shorter and shaped different than the rest of my fingers, and the fingerprint is misaligned in a noticeable way.",
"The no excess part is also largely thanks to the process of contact inhibition wherein if the dividing cells have basically patched up and have closed up then the cells stops making more. This functionality is the one that is lost during cancer that’s why they just continue to divide like cray cray.",
"Your cells have signals that are released when the skin reconnects. I apologize I cannot give a more in depth answer. It's been awhile since I took biology. But this is one of the causes of cancer. When the cells dont say stop and keep dividing.",
"To my understanding, I think it has something to do with cell-cell communication though cell-cell contact. Also probably something to do with your cells' ability to detect cells which have died but remain in contact with living ones that were not damaged during the cut.",
"Normal cells have a thing called \"inhibition-dependent density.\" It means they multiply only up to a point necessary to fill a space, then stop. Cancer cells, which are literally just cells that multiply without stopping, lack inhibition-dependent density.",
"It doesnt. I cut my fingertip off and now it has grown back but it's not the same and my fingerprint is messed up. It doesn't even register as a fingerprint on my phone anymore.",
"Imagine a giant building made of self assembling bricks. Now imagine that every brick contains the blueprints for the entire building.",
"The skin grows from the edges in until it run into skin then it stops.\n\nThis is called contact inhibition.",
"If the body knew how to do it in the first place. Why would it forget?"
] |
Many of the Japanese anime are adapted from light novels or manga. Why is there so few Western cartoons adapted from books?
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"1. Manga are already cartoons/illustrations. And the USA has had lots of animated superhero shows based on comic book stories & characters.\n2. In the USA, animators like Dreamworks and Disney are given a lot of creative freedom to create original work, which takes particular advantage of the animation medium."
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How was 16-bit music created on different consoles?
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"For those of us in the United States, the “Megadrive” is what the rest of the world (except South Korea, where it's the “Super Aladdin Boy”) calls Sega's “Genesis” console.\n\nCarry on.",
"The **S**NES music chip was based on using tiny recordings of sounds and playing them back at different speeds to get different notes. Since it only had 64kB of memory on the sound chip, these *samples* needed to be really tiny.\n\nThe Megadrive, OTOH, used an FM synthesis chip. FM is pretty hard to explain to the layman because the math involved is pretty unintuitive. In short, you give the synth chip a handful of numbers that define how to make a sound & it does a bunch of complex math to actually make the sounds from scratch every time."
] |
so is it or is it not okay to eat raw eggs? I have heard of people who do this every day but some say it's bad.
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[
"Like with most things in life, there is no easy one off answer. Raw eggs can contain diseases such as salmonella, which can be real nasty to whomever consumes it. The CDC says about 1.1 million people in America will get salmonella each year, and about 450 of those will die. Most deaths are attributed to severe dehydration, and those susceptible to fever etc. All in all, it seems like salmonella presents symptoms similar to most food poisoning, diarrhea, vomiting, and just general feeling like shit for a few days. If you're willing to risk that, and are a reasonably healthy person otherwise, you more than likely will not die from salmonella, if you even get the infection.\n\nNow some people may say it is safe and others say that it isn't, and neither of these people are truely wrong. In other countries, Japan as an example, have had raw eggs in their diet for much longer than over here in the west, resulting in much stricter health codes concerning eggs. This better treatment leads to a lower risk of salmonella outbreaks. On the flip side, it is impossible to completely wipe out salmonella, and there will always be some risk in developing the infection. In America, the health codes are considered lax compared to Japan or the EU, and comparatively the infection rate is higher. Infact, the CDC states that out of an estimated 1.2 million cases per year globaly, the vast majority will occur in America because of the laws surrounding the handling of eggs before they arrive to market. \n\nTl;dr Raw eggs in America are more dangerous than raw eggs from other countries which is why some people disagree. Eating raw eggs can be dangerous if you are already susceptible to infection, otherwise no reason to fear it anymore than you fear food poisoning."
] |
How does our brain determine the amoumt of pain we feel when we hurt or break a certain part of our body?
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[
"It's about the number of nerve cells that are able to send messages to the brain.\n\nIf you have a small burn, then that's a small area, which means a small number of nerves.\n\nIf you have a small burn, but it is deep, then you get all the area inside and underneath the burn too, and that's more nerves, more messages, and more pain.\n\nBut that also means that areas of your body that have higher numbers of nerves, like your finger tip and arm pit, send more pain signals for the same size wound.\n\nIt also means that if you broke your foot and also broke your neck, you only feel the pain in the neck. The foot can't communicate with the brain because of the break in the neck, so you don't feel that injury.\n\nIt also means that you can interrupt the nerve messages, and if the brain doesn't get the message it doesn't know it is in pain. That's how numbing agents and pain relievers work.\n\nIt also means that you can overload your brain with messages, and it can't process all of them. If you have pain in your tooth, and then you stub your toe, it will feel like your tooth hurts less."
] |
why do you only feel the touch on one finger when you rub two fingers on the same hand together
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[
"This is like those optical illusions where you can see two things in the picture, but only one at a time. [Which direction is this train going?](_URL_0_) \n\nWhen you pinch your fingers together, you *can* feel both of them, but your brain focuses on only one.\n\nYou can see this in action, too. If you make the OK sign with your thumb and pointer, it feels like only one finger. \n\nUse your thumb to press up harder; you will feel with the thumb.\n\nThen use your pointer to press down harder; you will feel with the pointer."
] |
Sometimes I get a sudden really loud high pitched ringing in one ear, (can be any one) that fades away quickly. What is it and why does it happen?
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[
"sounds are electrical impulses interpreted by your brain, and sometimes the tiny hairs deep inside your ear canal responsible for sending impulses get tripped (from air pressure changes, for example, which your inner ear is particularly sensitive to) resulting in neurological 'feedback.' sometimes this feedback lasts a long time or is permanent, due to a condition that's probably caused by these hairs dying. it's called tinnitus, as other comments have covered. but many people get the occasional ringing in their ear(s).\n\n\\*clarity",
"I had this happen to me every day and was worried it was tinnitus. Being only 20, that would suck. I went to my doctor and turns out it's likely because my nose has been so blocked it's caused my ears to be blocked without me realising. A round of steroids and it's gone completely. \n\nSo, it could be tinnitus but it's unlikely since it's not all the time and changes ears. Still, definitely ask a doctor especially if you've been exposed to loud noises or are young.",
"Here is a wonderful tip for tinnitus or ringing of the ear. Put your palms over your ears with your fingers interlaced on the base of your skull. Get your pointer and middle finger on both hands and tap the base of your skull for 15-30 seconds. Makes it go away like magic.\n\nYou're welcome.",
"I get something like this happenening, I have tinnitus, but this is kinda different... it's like suddenly all sound dulls and this high pitch ring takes over, for 3-4 seconds and slowly fades and usually it's only in one ear. It's like tinnitus and I don't have the expertise to say it's not tinnitus, but being that I have tinnitus already and this happens infrequently and it takes a much more pronounced form when it does happen. With tinnitus I've gotten used to it and hardly notice it unless it's silent, this however will over take any and all sounds almost like a cotton ball was just shoved in my ear with a speaker outputting a high frequency sound.",
"There's a really good chance you have Tinnitus. Schedule an appointment with your primary care doctor tell him/her what's going on, and he/she can refer you to an audiologist. I've had it since Iraq, shit sucks man. But it's not a disease only soldiers get. Headphones, using power tools without proper hearing protection, hunting without ear protection, these can all do it! Get a professional opinion from a doctor, though.",
"You might have tinnitus if you’ve been exposed to loud noises. Go to enough rock shows and the ringing will continue all the time.",
"It’s called Sudden Onset Ringing Tinnitus. It happens to everyone.\n\nEssentially, your ears have two different types of hairs. Inner hairs, and outer hairs. The inner hairs pick up sound vibrations and pass them onto the auditory nerve. The outer hairs pick up quieter sounds, and amplify them. Essentially acting like a bullhorn for quieter sounds. This drastically increases our hearing sensitivity (especially in higher frequencies) when it’s working correctly. \n\nBut these outer hairs work in an odd way. They pick up a vibration, then amplify that vibration into the inner ear membrane so the inner hairs can send it to your auditory nerve. SORT is what happens when two outer hairs get stuck in a feedback loop - One causes the other to vibrate, which causes the first to vibrate again, which travels back to the first, on and on very rapidly. Now instead of amplifying quiet sounds, the hairs are amplifying their own vibrations. This causes a sudden ringing sensation, as the hairs in question vibrate back and forth against each other.\n\nThe body has ways to stop this, eventually. It can basically send a reboot signal to the hairs in question. But this takes anywhere from 15-30 seconds to kick in, which is why the ring happens suddenly, then slowly fades.",
"Ringing in the ears can be caused by many things. Sometimes they’re little things that aren’t bad and sometimes they’re the beginning of things that can get really bad over time. \n\nIf it doesn’t pulse with your heart, stick to one ear specifically, or keep you from working or sleeping then you’re probably in the green or yellow zone. You should always tell your doctor cause it can be the first sign of many of things that need to be monitored or treated. \n\nNon 5 year old comments: Am an audiologist. Ringing or tinnitus can be caused by hearing loss, growths/tumors, migraines, blood pressure changes, medications, stress, TMJ, etc. Let your primary care physician know so they can further evaluate.",
"This happens to me too and it’s probable bc someone turned on an old tube tv 10 miles away."
] |
What happens to the cells of meat when they are cooked? are they still the same or totally different? Like If I take a piece of paper and burn it, does the makeup of paper before it was burned transformed into carbon by the fire? Thanks
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[
"Meat is mostly muscle fibers. Heating them up slowly will cause the fibers to contract and firm up. This contraction will also squeeze moisture out. This is why meat that has cooked for a long time tends to be dry and tough. Some cuts of meat also have a lot of fat and connective tissue. These will break down under a low heat, but it takes a while. Cooking meat well can often be a balancing act between breaking down the connective tissue but not drying out the muscle fibers. \n\nThis is all independent of the Maillard Reaction, which is what happens when meat (or other things) \"browns\". Applying very high heat to the surface of the meat causes complex reactions between the sugars and amino acids (proteins) in the meat. I encourage you to look up the details if you're curious."
] |
Why do heatwaves cause massive power outages?
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[
"Air conditioning draws a lot of power. The grid stability is challenged, and once one part starts to fail e.g. brownouts, all the loads kicking back on at once when re-connected causes bigger disturbances. This is mitigated by having more capacity within the grid, and the ability to load follow (add electricity as needed on demand.)",
"It’s hot, everyone cranks their AC to 12. That’s a massive draw on the power grid, often more than it can sustain. Even the houses where the people set their thermostats to 80 when they leave have the AC units cycle on constantly because it’s just that damn hot. \n\nAnd as another poster said, equipment can fail at high temperatures. The power grid is always run at point where the loss of one big circuit can cause a chain reaction of outages.",
"The biggest issue is air conditioning. Air conditioners actually use a lot of power. When you have thousands of people turning on air conditioners in a relatively short time span, it can overdraw from the power grid and cause major issues.",
"Three reasons. Other people have mentioned a big one: people use more electricity in heat waves to run air conditioning. But also:\n\nPower plant turbines, like all engines powered by heat, become less efficient when the air or water used to cool the engine becomes hotter, so their output is smallest during the summer. Most power plants are rated for a certain \"summer capacity\": their [winter capacity](_URL_1_) is a few percent greater.\n\nTransmission line capacity is limited by temperature: the more current the line carries, the hotter it gets, and too much heat will cause the wires to lose their strength or droop. The hotter the air temperature is, the less current can be carried safely. Even worse, as the wires get hotter their resistance increases, which causes them to heat up even more. Summer heat can reduce the power a transmission line can carry by [20-30% or more.](_URL_0_) Even [global warming](_URL_2_) can make a significant difference!",
"Overheating electronics can cause plastic coverings of wires to melt, which fucks with shit."
] |
How do Height Increasing Powders work?
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[
"Oh, this is an easy question. They don't. \n \nUnless they contain Human Growth Hormone (which is generally available only by prescription), anything that promises to increase your height is a scam."
] |
When the human eye sees a flat image, say a landscape photograph, and there is an apparent depth of field, does the human eye/brain try to bring into focus the flat image?
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[
"Your eyes WANT to see the same image in both eyes. So when you look at a flat photo, because it's NOT actually a 3 dimensional scene, nor is it a composite of two images laid on top of each other taken at different angles (they way your two eyes ACTUALLY perceive the world), both eyes are already seeing the same thing and your brain says \"ahh, this is in focus and I can tell that mountain I'm seeing isn't ACTUALLY 3 miles away from me\".\n\nThis also explains why sometimes your eyes will focus on a patterned surface at the wrong focal point making it look like it's closer or further away than it actually is. (this used to happen to me all the time with a certain trapper keeper cover I owned as a child). \n\nAs you naturally look around a room your eyes are constantly changing focus (essentially pivoting more/less cross-eyed depending on how far away the thing you're looking at is). When you turn your gaze to that patterned image, sometimes your eyes aren't quite at the right focal point for the distance the object actually is at, and yet the images are seemingly the same at the center of your field of view, so your eyes lock in that focal point and your brain says \"ahh, this object is 3 feet away from me\". \n\nBut SURPRISE! the object is actually 2 feet 6 inches away from you because your eyes layered the wrong parts of the repeating pattern on top of each other. As you try to grab the object (trapper keeper folder, in my example) your hand reaches in the wrong place, either in front of or behind where it really is, and then your brain notices on the edge of your field of view the border of the folder is not in focus as in one eye the pattern has ended, but in the other eye, there's one more row.\n\nSo you close your eyes and shake your head and reopen them allowing your eyes to re-focus on the correct focal point.\n\nIncidentally, this is also how Magic Eye images work, to some degree, you trick your eyes to focus in front of or behind the physical surface of the picture, and the two superimposed printed patterns are in focus behind the physical surface giving the illusion of a 3D object where there actually isn't one.\n\nEDIT: grammar",
"We do, sometimes. Normally, we learn not to. Otherwise your eyes get sore. However, when we do something our brains aren't used to (such as seeing a 3D movie), we can trick ourselves into trying to focus on things that are blurry even while in focus. This is one reason why people can get headaches and eye aches from 3D movies."
] |
How can the price of food, school, cars, and consumer goods in general outpace inflation? Isn't that the definition of inflation?
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[
"Rising prices can't outpace inflation, because they \\*are\\*, as you say, inflation. They can outpace the purchasing power of a dollar (or whatever monetary unit.) They can outpace income, or specifically the minimum wage, which is often a topic of discussion.\n\nPeople often use the word 'inflation' to mean 'the whole problem caused by rising prices without a similar rise in income'. But this is, as you point out, not strictly correct usage.",
"Inflation is an average increase of price. Usually it is measured on many items over a large area and over a long time.\n\nWhen talking about a single good, there are many factors that come into play. Brocolli may seem like a simple commodity, but by the time it gets to the store it has been affected by: the price of gas to transport it, the price of electricity to cool it, the price of water to grow it, the price of labor to tend it, and the price of pesticides and farm equipment.\n\nSo if a regulation or law passed that changed pesticide use, that will affect the price of broccoli in a significant way. It will not affect the price of glass, gas, or houses though.\n\nOne sector of the economy might see faster price changes than another, but inflation is the average of all sectors."
] |
The U.S. debt ceiling, how it can just be raised willy nilly and how if it's not, what would happen?
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"The US Debt Ceiling is one of the dumber (which is saying something) aspects of the US Government's Finances.\n\nBasically, the US is the only country in the developed world that places a limitation on how much money its government can borrow. In any other country the government borrows as much as it needs to pay its obligations.\n\nBut in the US Congress says that you can take no more than X debt. Which is fine... except that Congress ALSO controls how much is spent. So here's the kicker - Congress will spend Y amount of money which will require borrowing more money than the X allowed by the ceiling AND THEN THEY FREAK OUT ABOUT IT. It's like your mother telling you to buy the school lunch for $5 and then beating you because she only gave you $4 and you spent $5 because she told you to spend $5 or she would beat you for not buying the lunch. It makes no sense and is absurd.",
"The debt ceiling is a restriction on how much debt the US federal government is allowed to issue. It's set in absolute terms. i.e. the government is not allowed to borrow more than X dollars. Even if you're not a fan of government debt, this is kind of silly. Due to inflation, what you might consider a reasonable level for the debt ceiling in 1970 would be incredibly restrictive today. Therefore, Congress just increases it as necessary, whether the increase was necessary because of inflation or because of more debt-financed spending. This prevents the debt ceiling from accomplishing its stated purpose (reining government debt). It's a good object lesson in why passing an extreme regulation can backfire when nobody wants to actually enforce it, making it like you passed no regulation at all. \n\nThe main reason why Congress would be incredibly foolish to not raise the debt ceiling is because one of the things the government spends money on is honoring its debts. A bunch of people took out 30-year savings bonds in 1989, and now they'd like their money. If the debt limit was allowed to actually bind, the treasury would eventually have to start turning these people away. This would cause a sovereign debt meltdown the likes of which the world has never seen. Likely consequences include a global recession and a severe downgrade in the credit rating the the United States. This second consequence would make it more expensive for the government to borrow in the future, meaning that even if the government started borrowing under the debt limit, it would have to spend more than if it just kept increasing it. In the end, it would be like losing weight by cutting off your feet.",
"> how it can just be raised willy nilly ... ?\n\nThe US debt ceiling *can't* be raised willy-nilly.\n\nFrom the [Government Accountability Office](_URL_0_):\n\n > \"the debt limit does not control or limit the ability of the federal government to run deficits or incur obligations. Rather, it is a limit on the ability to pay obligations already incurred.\"\n\nThe debt ceiling is reached when the US runs out of credit trying to pay existing expenditures. Since only Congress can borrow against the US's credit, when the Treasury runs low on funds they inform Congress that unless another bill is passed appropriating more funds, the Treasury will run out of funds to pay existing bills. Congress then must find a way to bridge that gap, usually by a combination of budget reductions and a debt-ceiling increase.\n\nThe term is in the news a lot right now because Congress approved a large budget *and* a huge tax break for big companies, resulting in less money in the US Treasury. But despite how much they might *want* to raise the debt-ceiling 'willy nilly', they can't. When Obama signed the Budget Control Act of 2011 into law it raised the then-current debt ceiling by 900 billion but cut spending by 917 billion over 10 years; it also placed limitations on further debt-ceiling increases for 10 years, and established mandatory across-the-board budget cuts if Congress failed to do its job of establishing a reasonable budget. The current Congress has these limits in place, and those members who want to fix the current budget problem by simply raising the debt-ceiling are not able to do so."
] |
What's the difference between sorting by best and sorting by hot?
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"Hot means they’re very active right now; best means they’re highly upvoted.\n\nControversial means they’re highly up AND downvoted.\n\nAnd New means they’ve recently arrived."
] |
How does aloe vera gel help heal sunburns?
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"There's a compound in the clear gel of the liquid that has been shown to reduce the healing time of burns, as well as open wounds, and has antibacterial, fungal, and viral properties when applied to the area. These are from compounds that help the plant to heal itself after damage, also work on human skin. It has been used for well over 6000 years.\n\n & #x200B;\n\nThe yellow part of the plant is also a great laxative.\n\n & #x200B;\n\nNo other uses have been researched effectively or thoroughly enough to say its effectiveness."
] |
Why is it when skin is wet, it makes dry skin conditions like eczema worse than if the skin was dry?
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[
"Skin conditions like eczema are not the result of dry skin. They are an auto immune disease where your body is literally attacking itself. This can be aggravated by various things. Being too dry, being too wet, getting too much sunlight, being exposed to various chemicals such as chlorine from a pool, etc. \n\nAdditionally water on the skin does not help hydrate it. Water on the skin washes away the protective oils that the skin produces, which in turn cause the skin to lose more moisture than it could gain via osmosis in having water on it. This effect is often more extreme in people who have eczema as the disease means they are less efficient at producing said protective oils.",
"So it looks like water strips the skin of it's natural moisturizering factors (nfm). NFM is what's responsible for keeping your skin hydrated."
] |
what is the difference between white meat and dark meat in a chicken?
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[
"Breast is white because the fuel for these muscle fibers comes primarily from a carbohydrate called glycogen and doesn’t require as much oxygen from the blood. Glycogen is useful for short bursts of activity.\n\nDark meat get their fuel primarily from fat, which provides a more sustainable energy (for the prolonged activity of standing, walking, and running). Dark meat is made dark by two proteins involved in the process of converting the fat into energy for the muscles.\n\nBasically a chicken uses its leg and thigh muscles a lot more than its breast muscles.",
"The difference is basically how often the animal uses the muscles.\n\nThe legs and thighs of the turkey are used constantly, so the muscle adapts to be used on a constant basis; these muscles are fast oxidative muscles. Which means the muscle has more myoglobin. The breast muscles of turkeys don't get used as much, so they are slow oxidative muscles, which have less diameter on average and less glycogen to use."
] |
Why Nipples are sometimes erect and sometimes not
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[
"The nerves in the nipple react to stimuli, both physical and psychological. So an arousing thought, change in temperature, or something as simple as the fabric of your shirt brushing against your skin can cause one or both of your nipples to become erect.",
"Erect nipples facilitate nursing, which, afterall, is their primary purpose. They are heavily innervated to respond to the stimulus of a baby suckling. Of course, this means that they respond to just about any stimulus. Same thing applies to the penis."
] |
why is turbulence no big deal for an aircraft the vast majority of the time, even though it feels like a big deal inside of the plane?
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[
"Planes are designed with a substantial safety factor, where its wings can hold some multiple of its normal weight. Normally, we experience one gee of acceleration due to gravity, so planes are designed to withstand 5,6,7 gees in order to cope with turbulence and other unexpected phenomena. Not only this, but we as humans don't mind acceleration itself (anything between 0.5 and 1.5 gees feels okay), but sudden changes in acceleration startle and scare us. This is why many car drivers apply the brakes slowly, instead of suddenly; it makes the ride feel smoother even if the peak acceleration is higher. Planes, meanwhile, don't really mind sudden changes in acceleration - it makes no difference to the plane what direction it is being thrown, so long as it isn't being thrown too hard.",
"Because the plane is built to tolerate much stronger shaking than the human body's comfort level. Basically, no wind less than flying into a tornado should break the plane up."
] |
Why does our body temporarily cease managing its own temperature when we enter REM sleep? Why leave it up to the environment?
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[
"The way I read it, it is the other way around: it's not that REM sleep turns thermal regulation off, it's that sleeping where we don't have to worry about thermal regulation (or predators) enables REM sleep. REM sleep is the effect, not the cause.\n\nREM sleep only occurs when we sleep in a warm-enough, safe-enough, cozy-enough place. From an evolutionary standpoint, if those conditions aren't met it is in our best interests to not sleep too deep, so we can consciously maintain thermal regulation (tend the fire, arrange the blankets) and keep our fight-or-flight circuitry online. If those conditions \\*are\\* met and we no longer have to worry about survival issues, we sleep deeper and this new state occurs: REM sleep. We wake up feeling healthier, so we develop an association between sleeping in a warm safe place and feeling rested and energetic the next day.",
"No, your body never stops thermoregulation. The statement from your source:\n\n > …it’s interesting that during rapid eye movement (REM) sleep, your brain’s temperature-regulating cells switch off and let your body temperature be determined by how warm or cool your bedroom is.\n\nappears to have been made up. Fanciful but wrong inventions like this are pretty common in psuedo-science sites like you reference that sell essential oils and other nonsense.\n\nThere is a decent [summary of sleep processes at the National Institutes of Health](_URL_0_)."
] |
Why do toddlers yell when they’re having fun?
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[
"It isnt a matter of age. Its a matter of society. As adults we choose/learn that screaming is annoying, especially every time we are having fun. But some still scream whooo at appropriate times like at a party or amusment park.",
"Adults absolutely scream when they're having fun, or you've never been at a club/concert/theme park. But most of the time we retrain, as it's quite annoying.",
"They don't have the words to describe how much fun they are having so they do a yell about it. Plus social conditioning hasn't set in to make them feel weird about being vocally excited."
] |
- How does creatine work?
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[
"Creatine is a compound that turns ADP back to the usable ATP. \n\nATP is the fuel your body uses to do everything. It’s called ATP for short, or adenosine tri phosphate . Once used turns into ADP, adenosine Di phosphate. So it losses a phosphate ( tri 3, Di 2)\n\nATP is what your heart uses to pump blood, how muscles move. It involved in nerve signalling and everything else\n\nYour body uses oxygen to make ATP. So your not really burning oxygen, but burning ATP. I hope that shows how important ATP is, and why creatine helps."
] |
Brillouin Scattering
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[
"Disclaimer: Not an expert, just doing my best to translate the wikipedia article. The refractive index of a material changes when that material is put under different conditions. This includes physical force, electric charge, and magnetic polarity. The result is that phonons (physical vibrations quasiparticles), polarons (electric charge displacement quasiparticles), and magnons (magnetic oscillation quasiparticles) can interact with an oncoming photon by changing the refractive index of the material they're in. Quasiparticles are like... Things that aren't technically particles but often behave like particles.. This interaction can cause the photon to give some of its energy up to the phonon/polaron/magnon that interacted with it, and results in the photon losing some energy (dropping in frequency) and scattering."
] |
Why do spiders make such a special effort to never be seen in the day, but bite me while I'm asleep? Wouldn't they be better off spending all day hunting bugs?
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[
"Yeah but every night this giant mountain of meat just stomps through their turf and then splays out asking to be eaten for 8 hours!"
] |
why when you scratch a bug bite it becomes more itchy.
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[
"Your body releases a chemical wr.call histamines when it takes damage, like a scratch or a bug bite. Histamines cause inflammation (swelling) and redness, as well as itchiness.\n\n So when you get a bug bite, it itches, and scratching it is seen as damage by your body, causing it to release more histamines."
] |
How can enlisted soldiers in the US get a degree while on active duty? For example, the U.S. Navy?
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[
"The GI bill, part of the agreement they get for enlisting, pays for college tuition (or most of it) and many colleges offer online courses in modernity that you can take via the internet. This allows soldiers to take one or two classes at a time during their free time."
] |
How do panic attacks manifest from seemingly nothing at all?
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[
"Not sure this is really BIO so much as PSYCH, and the answer I have is more anecdotal than scientific, but hear me out: Often times, when things scare us, we think about them. This is rather reasonable, since thinking about problems usually helps us fix em. However, sometimes thinking about them makes them more scary. Of course, this happens all sorts of times, and it doesn't usually result in a panic attack. Panic sets in when our minds don't know how to respond to a situation, and I would describe it as the \"drop your bag and run\" response. When we panic, we stop processing. This all means that we keep picturing the problem in our heads, but we can't actually do much *thinking*. We just have this mental image of the problem, and we can't do anything to get rid of it because we aren't really thinking. This often combines with things like hyperventilating and sobbing, which left unchecked usually lead to chemical imbalances in our blood (too much co2, for instance), which drives our brains into super-ultra-panic mode, since suddenly our brains are being subjected to something they shouldn't be (acidic blood from too much co2). All of this happens in the span of a minute or so, and boom."
] |
My parents hate each other, but are staying married for us kids. Is there a peer-reviewed study that can help them decide the best course of action?
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[
"I don't have any peer reviewed journals but I do have the horrible firsthand experience of growing up with parents who hated each other but remained together: they need to split up asap. If they hate each other and are fighting every day it's only unnecessary stress on themselves and their children. It teaches kids to sacrifice their health and happiness for the sake of others and a whole heap of unhealthy arguing techniques and anger. There's nothing worse than knowing your parents are unhappy because of you, even if they think they're staying together \"for the sake of the family.\" It just makes kids feel guilty and it's unfair on them too. Ask anyone who had parents remain in a loveless relationship, they'll tell you the same I did"
] |
If you own a small business and have paid your employees, taxes, and other costs. Are the money left (profits?) considered your income? And do you pay tax on that? Or do you assign yourself a salary and what is left belongs to the business and does it get taxed?
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[
"Depends on if your business is a sole proprietorship, single member LLC, multi member LLC, an LLC with the “S” tax election, an S Corporation, or a C Corporation. \n\nSole Proprietorship: All profits and losses pass to you individually. You’re also personally liable for anything that goes wrong. Pro Tip: form an LLC or go get a free consultation with a business attorney.\n\n\nSingle Member LLC: Profits and losses pass through to you personally, but your liability is limited to the Company’s assets. You also have to pay self employment tax.\n\nMulti-Member LLC: Profits and losses are split in proportion to each members ownership interest in the company. You also pay self employment tax.\n\nLLC with “S” election: You pay yourself a reasonable salary, and that salary is not subject to the self employment tax. Remaining profits and losses are passed through to you and any other shareholders in proportion to each shareholders percentage interest in the corporation. Whether or not you get taxed on any distributions depends on your basis, but this is where is gets complicated and I can’t ELI5 (just let the CPA worry about this) \n\nS Corporation: see above\n\nC Corporation: The corporations profits are taxed at the corporate tax level and then any dividends made to shareholders are taxed as well. This is called double taxation and it’s why C Corporations are not ideal for small business owners.\n\nUnethical Life Pro Tip: Want to live a lavish lifestyle, completely tax free, and without much hard work!? Start a non-profit seed faith mega church, go on TV, and convince all the sheeple to send your church money, because god will take the little “seed of faith” they send and will “sow” the seed into 10x the amount they sent.",
"It depends on how your company is set up. The easiest way is for the company to give you a paycheck that is taxed like you're a regular employee and the rest of the money gets put back into the business.",
"It depends on your type of business. \n\nIf you're a sole proprietor, you pay personal income taxes on 100% of the profit made (after all the expenses and employee salaries, not yours). You and the business are 1 entity.\n\nIf you start a business coporation, then the business has it's own income taxes to pay after all expenses, and you's have to pay yourself in either salaries or dividends or both. The amount of personal income tax you pay depends on the amount of dividends/salaries you receive. \n\nYou can deduce your salary from your company's taxable income but not your dividends, so there are different strategies out there to minimize your and your businisses taxes.",
"Small businesses will generally pay the owners dividends. This is taxed.\n\nLarger businesses will usually put the money back into the business. Better equipment, debt repayment, or sometimes a share buyback if there are a lot of shares. A shareholder will sell the shares to the company. Those shares essentially no longer exist, and all remaining shares are now worth more."
] |
How are we able to see planets through the naked eye like we see stars? They don't shine or glow, so are we just seeing a reflection?
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[
"Yup. Reflections from the sun\n\nThey're much closer than stars (except our own sun of course)",
"Light bounces off of everything. Even [VANTA black](_URL_0_) reflects *some* light. This is how we are all able to see stuff - it reflects light, and the amount of light it reflects, and the wavelength of that light, determines the brightness and colour of the object. The same is true for planets. If they had no stars shining on them, they would not be visible. They would just be black. But our Sun shines on all of the planets, not just Earth. And the planets reflect some of that light back to us, enabling us to see it",
"We can see planets with the naked eye for two reasons:\n\n* **They reflect light from the Sun.** This is the same reason why we're able to see the Moon. Our satellite emits no natural light of its own; instead, it reflects sunlight which bounces from its surface towards Earth, where it's received by our eyes.\n* **They're very close to Earth.** Compared to stars, which are millions of light-years away and enormous in size, the planets of our system are relatively small but close. That's why they appear about the same size as stars, and can sometimes be mistaken as such. If the planets were farther away, it's likely we would require instruments (e.g. a telescope) to be able to view them.",
"There are two main types of bodies. Luminous and iluminated. Planets are part of the second one.\n\nThe Moon, for example, only glows because the sun is reflecting off it."
] |
How do you immigrate to the United States of America?
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[
"Since it may be a while before you get a *serious* answer that goes into real detail, I'll give you what I know: You have to file for citizenship, take a test, pass a background check, and pay substantial fees every step of the way. This is a short explanation, but in reality the process takes many months and often years. The agency(ies) that process applications and application-related information are slow and understaffed, and the process itself is anything but streamlined. When and if you are approved, then congrats! You're a citizen!"
] |
When a large ship is launched into a body of water does it raise the water level? What about when that ship enters a new body of water ? Is it possible to calculate? Is it the same principle as sitting in a tub of water?
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[
"it will raise the water level. the volume of the ship that is beneath the water is \"added\" to the water by displacing it. in total it raises the water level by the same amount as if you would add water of that volume. \n\nwhich happens to be the amount of water which weight is equal to the weight of the whole ship.",
"It would raise the water but because the volume of a ship is such insignificant compared to all the water on earth the amount the water will raise is pretty much unnoticible. I do belief that I read something some where that all ship together did raise the water to a noticible amount but i dont remember by how much."
] |
If drums produce sounds that correspond to certain frequencies (e.g., C#, F), how is it that drums, when played, do not clash with the songs in different keys?
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"They do, it's called frequency masking. Mix engineers put a lot of effort into dealing with it, both live and in recordings. Cymbals are a particular nuisance. \n\nThey don't necessarily clash harmonically however. That's because tuning the drums with a drum key is necessary, but only for the more tonal pieces of the kit (snare, tom, kick). Pieces of the kit that can't be tuned usually come in different keys/pitches, like triangles, claves, cowbells, etc. Not everyone uses the correct pitch for a piece, or tunes for every tune, but our ears are accustomed to listening to it (unless you're really anal retentive about it). \n\nA compounding factor here is that drums, even pitched ones, have much more complex modes of resonance than other instruments. Even if it's tuned, you can get enharmonic frequencies, and our brains don't really deal with that well so we just hear it as cool noise, especially when it decays fast, as in a drum. We have less time to latch on to the fact it isn't in key. \n\nThere's also the fact that when you get into physical acoustics (sound through solids) it gets weird. The speed of sound isn't constant in a solid for example, so internal reflections actually change the resonant modes as the system resonates. That and solids don't vibrate in nice ways like air in a woodwind, a string fixed at two points, or a membrane (same thing as a string, but the tension applied is in two dimensions). If you see a video of a bridge collapse due to resonance you can actually see the bridge twists, rather than moving just up/down and side to side. Same thing happens in say, a woodblock or some claves.",
"A two-dimensional surface like a drum skin doesn't give out a single note or series of simply related harmonics of a note (2 x frequency, 3x, 4x, etc) like a vibrating string or air column.\n\nThere are a much more complicated set of vibrations that give out a mishmash of frequencies simultaneously. It also depends where the stick hits the drum. Here is an article with some animations of the way the skin can oscillate, you can ignore the scientific language of you want.\n\n_URL_0_",
"I don't know of a drummer that tunes their drum to a note. They all go for sound and punch.\n\nThe sound is too short for thetmre to be a note in them. This is why things like steel drums and tuned steel percussion are tuned with a special tuner, that repeats the sound in their circutry. \n\nBut you can end up getting clashing sounds if your drums have long echo. But generally you always tune and set membranes so you don't get the echo."
] |
Why do people automatically stick out their arms when frustrated or confused (AKA universal WTF hand gesture) and why is it universally done and understood?
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[
"are you referring to shrugging, showing the palms of the hands? I don’t know if it really is universal but if it is, it feels as though the gesture were a way of showing: hey, look, i am NOT in control here. it is literally out of my hands. and that equates to: don’t blame me for this shit"
] |
How do so many space artifacts end up orbiting Earth and endangering us, instead of falling into Earth or off somewhere else?
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"They don't have enough energy to go off somewhere else. The escape velocity for the Earth is about 11 km/second. Anything going less than that will stay in some sort of orbit, maybe circular, maybe very eliptical. The only way that won't continue is if the orbit intersects\nwith the Earth or the orbit dips low enough to be slowed down by air resistance to make the orbit intersect, and then they crash land or burn up."
] |
Aerospace has never been this big since Apollo, and rocket launches have never been this frequent,, How do nations not mistake another nation's rocket launches for a hostile action? And also, do nations conceal their "true intent" behind commercial launches?
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"To answer your last question first, yes, sort of. Governement space launches often have classified payloads. It may be a satellite with an unknown or classified mission, or even a classified payload or system on board an otherwise known about satellite. Your open source example here is GPS, which is owned an operated buy the government but it is well known that there are at least two different location resolutions and many different sensors on board the crafts. \n\nAs to your first question, they have to tell someone, so everyone knows. When a scheduled launch is planned, flight paths have to be closes and the FAA notified. Other countries must do the same. So when a civilian or government launch is planned, pretty much everyone knows. So when a launch outside that area or window occurs, it gets some special attention. This is not addressing rouge states such as North Korea and the like, who don't typically make pre-launch press releases unless it is to be used for propaganda. Often times, satellite imagery can simply confirm build up of machinery and launch equipment at known launch sites however, so even without warning, they pretty much know what's going to happen.",
"All nations publicly list whenever they're going to have a rocket launch, and that information is readily available to everyone that's concerned with detecting missile launches. You can't launch a space vehicle stealthily, so there's no point in trying to be coy about it, and it's in everyone's interest that nobody mistakes a space launch with a hostile action.\n\nThe payload for the launch will be hidden if it's important, though it's not common nowadays. Basically the only concealed payload is spy satellites anyway, so the US even lists them as carrying a \"classified NRO payload\". The NRO is the National Reconnaissance Office, the US agency that runs the nation's spy satellites.",
"Launches are planned and announced in advance, even military satellites. While I would not at all be surprised if there was the occasional military satellite concealed as a civilian satellite, by and large they are publicly announced as military satellites. For example, this friday, three chinese military satellites will be launched on a long march 2C rocket.\n\nThere is the minor issue of surface to satellite missiles, however. These missiles are occasionally shown off by different militaries, usually unannounced, and with no plan to mitigate debris.",
"Looks like the question has already been thoroughly answered but let me ELY5:\n\nIf we want to shoot our rocket, we have to tell all the other kids at the park before we launch it so they don’t get surprised. Those are the rules, and all the good kids play by the rules.",
"By hostile action I assume you mean a missile launch? Well, a bunch of reasons. The first is that only a handful of countries have the capability to launch rockets or missiles large enough to be confused for rockets, and most of these countries are on friendly terms with each other, and a bunch even actively cooperate in space, so we're aware of all of their space-related activities. Countries take great pains to *avoid* any chance of other countries thinking their rockets might be missiles. One of the reason's Russia launches rockets the way they do is so they don't overfly China, so China can track the launch and know very quickly it's not going near them. Rocket launches are, aside from North Korea, essentially public knowledge well beforehand. These things are made know well in advance so there's no confusion.\n\nLaunching a missile disguised as a rocket is also pretty dumb because it can still be traced back to it's source for retaliation. If a space-faring country is going to launch a missile attack, they're not gonna launch one missile disguised as a rocket, it's going to be hundreds of ballistic missiles, with only a few notable exceptions. Also, rockets going to specific orbits have predictable trajectories. A launch from Cape Canaveral to the ISS is always going to have the same trajectory, so any country is gonna instantly know what it is.\n\nAs for concealing the \"true intent\" behind commercial launches, that's just paranoid conspiratorial thinking. Do countries launch classified military stuff into space? Of course. Do they pretend it's something else? No, and why would they? What would they have to gain from that? And who are they hiding it from? The US has launched classified military payloads before on SpaceX rockets. They just say upfront that it's a classified payload. Think about all the people involved who would have to be either in on it or silenced. Hundreds of people build the payload, and hundreds more integrate the payload into the rocket. Then there are all of the people in the company that paid for their satellite to be launched, all of whom would have to be in on this conspiracy.",
"Short answer is aerospace projects are so expensive that they can't really be kept quiet so everybody knows when a rocket will be launched.\n\nIt is also beneficial for countries to know about launches for your reason so countries don't keep it quiet.\n\nNow the second part is a little trickier. It really depends on what you mean by \"hostile action\".\n\nIf you refer to a direct attack, then the rockets often look completely different to a trained eye and follow different trajectories so its virtually impossible to disguise commercial launches as such.\n\nIf you refer to spy satellites, then they absolutely do. Most satellites are dual use so they have a \" civilian\" function and a military function. The benefits here are twofold: there is less cost because you're launching fewer satellites, and if a satellite somehow survives reentry then upon inspection it looks innocent.\n\nThe obvious example here is GPS. Though the GPS technology itself is both military and commercial, each satellite will typically have another function built into it. Since there's a lot of GPS satellites which are user controlled, there's a large platform for military tech."
] |
Why does thunder in the distance sound like a low-pitched but long duration kinda "rumble" akin to the sound of a jet overhead as opposed to the "CRACKBOOM" experienced when it's close?
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[
"The lightning super heats the air ss it strikes. This causes a turbulent air column to collapse on itself, creating a sonic boom.\n\nBut each branch and fork of the lightning is like its own mini sonic boom.\n\nWhen you are close, those are all so close together in happening, that you hear them all at once. \n\nFar away, though, the difference in their initial starting positions, and how the sound travels through the air, makes them at hit your ears at different times. \n\nImaging throwing five rocks into a pond at the same time, in roughly the same location. \n\nThe initial waves would all look like one wave ring, but after that, you would see a large variation on the wave pattern, the further you were away from the splash.",
"High frequency sounds create the \"crack\" and the rumble is lower frequencies. The former are more attenuated by air and material objects in the pathway to you than the lower ones. Just the same as if you hear someone in the next room talking, you can often tell they are speaking but not make out the actual words due to the loss of the high end sounds."
] |
Why do insects like flies rub their eyes/heads with their legs ? What purpose does it serve ?
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"They cannot blink so they clean their eyes with legs. Their legs also have brushy hair called setae which are very sensitive and inform the insect if anything is on them (mold, dust, whatever). They also have little hair on their entire body that acts as an advanced sensory organ. This also has to be clean."
] |
How does blinking moisturise/hydrate eyes?
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"Your tear ducts secrete tears, which lubricate the eyes and keep them moist. Blinking spreads the tears around so they create a protective/lubricating/moisturizing film on the whole surface of your eye."
] |
With the history of large ships being taken over by "Somali pirates" or whatnot, why aren't those vessels outfitted with mounted machine guns, and a couple GTFO rocket launchers?
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[
"They aren't legal - even the USA doesn't allow non-military ships to have such weapons. The age pf piracy made sure all nations signed up to this. The high seas would be chaos if any ship could be armed to the teeth.",
"Most of these ships are civil. You'd need military personal for that and the approval of a country and the international community. And probably you can't just kill everybody just like that.",
"Some of them have armed ex commandos on board for security. A friend of mine used to run one of these companies. Moving the weapons around was quite tricky but it was quitel lucrative."
] |
If I buy a 5 kwh solar system and the efficency of the panel is 20% do I only get 1khw?
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[
"A 5kW panel will generate up to 5kW of electricity. Due to the sun rising and setting and the weather, you’ll only average about a seventh of that, even if the panels are ideally positioned. So 5kW times 24 hours divided by 7 gives around 17kWh per day, on average. In the summer it could be more than double and in winter less than half; much depends on the climate where you live, orientation of the panels, and any shading from things like trees and houses.",
"You buy the panels based on the output you need / what they actually produce, and that's how they are marketed.\n\nThe theoretical efficiency is of interest to people designing the next generation of panels, not to the consumer buying panels right now.\n\nYour Camry would get 100mpg if it was perfectly efficient in internally combusting gasoline and converting it into forward motion. But they aren't allowed to say it gets 100mpg.",
"20% efficiency means that converting 100J of light yields 20J of electricity, so 20% of the energy is retained in the conversion."
] |
Why don’t we, as passengers, feel the speed of a plane whilst it is flying?
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"The plane is cruising at a constant speed. You feel the accelaration at take off but once the speed of the plane (and your speed too) is constant you wont feel it just like in a car too.",
"You actually partly answered your own question. We are only able to feel the acceleration but not the constant movement.",
"It's important to remember that objects don't change speed or direction unless something makes them (i.e. a force is applied to the object).\n\nAs a vehicle (e.g. a car or plane) accelerates, initially you don't move at the same speed as the vehicle. Don't forget - a force has to be applied to you in order to make you speed up. It takes a moment for the speeding up plane seat to apply its forces to you to speed you up. \n\nThis is why you feel acceleration - it's a change of speed and the seat is 'pushing' you to go faster and to match the speed of the car.\n\nSo, when the car is travelling at a constant speed and when you are travelling at the same speed as the car, you carry on moving at the same speed and in the same direction. No force is needed, so you don't feel anything.",
"We human usually anticipate the idea of speed by either visual of relative movement or wind blowing in our face, which is why you might think a car on the highway is still when it is travel at the same speed as yours and why we cannot feel the Earth rotating at a crazy speed when the atmosphere we are in rotates together with us.\n\nIn the case of airplane flight, we do not feel the speed since everything is so far from us and move so slowly in our eyes, in turn make us feel like we are moving slow. Trust me, if you fly pass a floating Superman you will be able to tell how fast you are travelling.",
"Probably the most fundamental of all the laws of physics is:\n\nForce = Mass \\* Acceleration\n\nAcceleration, not speed. So, if you are in a car that accelerates, the seat pushes against your back in order to accelerate you, which you feel as a force on your body. But once you and the car have reached a constant \"cruising speed\", and nothing accelerates any more, there are also no longer any forces involved."
] |
why do some antidepressants have "suicidal thoughts" as a side effect? Is'nt it counterproductive to take these drugs and still have those tendencies?
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"Nobody AFAIK has invented drugs to block specific types of thoughts.\n\n The problem as I understand it is that sometimes, in some people, the first lift in mood (from say, an SSRI starting to take effect) gives the person the energy/motivation to actually carry out a suicidal plan, whereas beforehand they couldn't make themselves do it.\n\nBut \"suicidal thoughts\" is shorter to put in the black box, and gets the idea across.",
"Conditions such as depression, PTSD, Panic attacks and so on are often aftershocks of a series of events or trauma. They are the residue of moments long past.\n\nIn order to treat these conditions, one has to stabalise the effects of the condition, such as lack of sleep, severe anxiety, somatic pain, rage, delerium and other more serious symptoms.\n\nThat's where antidepressants and other such medications come in.\n\nHowever, these medications come with their own set of problems- weight gain/loss, drowsiness, behaviour issues, fainting, hallucinations, sleep paralysis and a host of other side-effects. \n\nSuch side effects can add more pressure on top of the treatment itself to an already prevailent condition.\n\nWhen we're treating cancer with chemotherapy, for example, the treatment will make us more sick and cause the body to recess. But, if we want the cancer tumors to go away forever, we have to go through with it. It's the only medical option so far.\n\nUnlike chemotherapy, no-one can predict a patient suffering a mental condition will respond to the known side-effects of antidepressants.\n\nOne person may respond negatively to the weight-gain. Another may not be able to function with day-to-day needs from the drowsiness.\n\nImagine you're somebody suffering from anorexia, weight loss will have a negative effect. But for another suffer of a different condition but on the same medication, it may not be an issue. \n\nNow, suicide is often an ideation, something the mind plays yet there is full awareness of the consequences and the measures taken, which prevents us from going forward with it.\n\nThis is normal.\n\nIt's like standing a cliff-edge and feeling the impulse to jump off.\n\nWhen you have the pressures from the mental condition, the treatment *AND* the medication itself, the impulse to harm yourself becomes much stronger.",
"You'll notice that there's many brands of antidepressants, and they're all or almost all different formulas and can affect you differently. Sometimes negatively. So if the particular med is giving you that kind of stuff you're supposed to consult with whoever prescribed them and get switched.",
"I think some of these remove impulse control or anxiety that would come with these thoughts. Thus your brain thinks its no different than thinking about what you will eat for lunch."
] |
Heron's Formula
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[
"Heron's Formula is that the area of a triangle is sqrt(s\\*(s-a)\\*(s-b)\\*(s-c)), where a, b, and c are the sides of a triangle and s = (a+b+c)/2. I don't think there's really an intuitive way to understand *why* it works, but you can prove that it does work.\n\n[One way](_URL_0_) to do it is to split the triangle you're looking at into two right triangles by starting at one vertex and drawing a line to the opposite edge. Right triangles are easier to work with because you can use the Pythagorean Theorem to relate the sides to each other. Do some algebra and you can get to Heron's Formula."
] |
why does matter bend space?
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"Since Newton we know that mass correlates with gravity. Which is only half of the truth.\n\nFor example, take an apple. Measure it's weight. \n\nNow, shrink the apple. It's weight is the same as before. But since the apple is now only half as big as before, the ant crawling the apples surface feels a much stronger gravity pull. Shrink the apple even more, you get a black hole.\n\nEinstein realized that to make sense of this and to be in accordance with the data from experiments, mass, gravity and space/ time had to be related to each other. And once he got the mathematics straight (he himself said he had deficits in math), he realized that indeed, gravity is nothing but curvature of space and time.\n\nAs to WHY mass bends space and time... As I said before, no one knows."
] |
why can we control some things our body does subconsciously like blinking and breathing. But why can we not control other things like making our hearts beat faster?
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"We cannot directly control our heart beat because the heart only has autonomic nerves. These are involuntary. Breathing, blinking, swallowing all have muscles that have somatic nerves, meaning we can voluntarily move them. They are also autonomic responses, however we can control certain muscles that allow us to resist this.",
"In a just world, catchy educational vids like these would still be shown to children in lieu of sham-wow infomercials....\n\n[School House Rock - The Nervous System](_URL_0_)\n\nCan't really get any more ELI5 than that."
] |
why does a hot day or hot room make you so tired and weak?
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"Scientists say that energy from the sun transfers heat to the body through electromagnetic radiation in the form of photons. This radiation causes body temperature to increase. When your body temperature changes more than .5 degrees, your body reacts by being sleepy, grump, or tired."
] |
How do ‘bad’ carbs cause increased inflammation in your body?
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"Glucose in the blood causes inflammation\nWhat's so bad about sugar and refined carbs is that it is absorbed very fast and spikes your blood sugar because there are no fibers and other nutrients due to the refinement process."
] |
What is the academic reasoning behind believing we live in a simulation?
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[
"IMHO, (layman here) is that there is not a \"belief\" that we live in a simulation. It is a philosophical position that we cannot rule out by our reasoning that we are not living in a simulation. There is nothing we know of (by observation or reasoning) that contradicts this position. This does not imply belief or support - simply it is something that cannot be ruled out.",
"In short, there are 3 possibilities: \n1: humanity (or any other species for that matter) never decides to run simulations of reality because either they decide it’s too cruel or we never achieve the computing power. \n\n2: humanity or other does run simulations but we are the real ones. In this situation the world we live in is the one that in the future will run simulations of reality and thus we still live in reality.\n\n3: we are living in a simulation run by humanity or other \n\nThe idea is that when these simulations are run, there will be lots of simulations run and the ‘realities’ within these simulations will also run simulations, and then those realities will run simulations etc etc. This means that if simulations are run then there will soon become millions if not billions of different simulations. \n\nSo if we go back to our 3 possibilities the first possibility is still possible, simulations of reality require huge computing power we don’t have yet and may never have. The second possibility requires that we live in the one real ‘reality’ out of millions of simulations, this means that this possibility is incredibly unlikely. This leaves the last possibility which is that we live in a simulation."
] |
How does Olaplex No.3 Work?
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[
"As it is proprietary, I'm guessing the best you can do in understanding the motivation is reading the relevant patent [here](_URL_0_). It gives specific chemical interactions among other things."
] |
Why does China use two currencies CNH and CNY?
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[
"China does not have two separate currencies. Rather, the Chinese government treats Renminbi (yuan) differently dependingbon whether it is currency that is within China, or outside of china. \n\nLets say use an easier example, lets say you are a US citizen and have some Canadian dollars (CAD). If you go to a seller here in the US with your CAD, they may not be very appealing, and the shop owner might want to charge a higher price. If you instead go to Ontario, and offer to buy the same product, you will may get a better deal.\n\nThis is basically what happens with every currency all the time. There may be different exchange rates between different parties (banks, sellers, buyers), but in practice it should more or less equal out to the market rates because one player is directly manipulating exchange rates.\n\nIn China, the case is a bit more complicated. China considers currency within china (CNY) differently than currency outside of china (CNH).\n\nIf you hold any Chinese currency outside of china, you will likely be converting it at rates driven by market forces, the same as any other major currency. \n\nhowever, if you hold Chinese currency inside China, the central bank of China will directly dictate what the exchange rate is. This results in a difference between the two exchange rates, and causes t the two different ticker symbols, even though all the currency is the same. \n\n_URL_0_",
"basically a domestic currency and one for international trade. Foreign trading isn't controlled as tightly as the domestic currency."
] |
How does fiber-optic internet work?
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[
"We are next door neighbours and I have a red laser pointer. Whenever I bake cookies I want to invite you over to eat them. So I shine the red laser pointer at your house.\n\nYou have a blue laser pointer. If you are busy and can’t come over to eat the bookies, you can shine the blue laser pointer and I will know to save cookies for you.\n\nFibre-optic Internet is like that, we shine lights at each other through glass cables. We can tell each other many things by shining lights into the cables. We can tell each other what’s the weather like, recipes for good cookies, watch YouTube videos and so on."
] |
Why is it so hard to find a reading position that doesn’t become uncomfortable after five minutes?
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[
"Because you're straining a particular set of (small) muscles continuously. Holding a small object still for a long time is not something humans evolved to do particularly.",
"It's because books aren't designed to be read! I swear, I have this problem! And, I've concluded its because we keep making books in way that have to awkwardly pulled open with two hands"
] |
Why do politicians resign from their government as a protest? Do they not have more power staying in their post to fight against what they don't like? [UK example inside]
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[
"Like you say, jumping before he is pushed.\n\nThe PM decides who's in the cabinet and what roles they have. If he fundamentally disagrees with the PMs approach, then he would be fired anyway.\n\nChances are the new PM will change up who's in the cabinet anyway.\n\nHe remains an MP and a member of the Conservatives. He has simply resigned as a minister. So he still gets to vote in Parliament, and can vote against Johnson.\n\nHe could be expelled from the party if he keeps voting against the government, but even then he would still be an MP and still get to vote.",
"He, and others, are resigning from the government, not the party or as an MP. The government is the squad of people chosen by the Prime Minister from amongst MPs of (usually) their own party to head departments and other functions. MPs of the majority party who are not chosen sit on the \"backbenches\" in the House of Commons while government ministers sit at the front and introduce and defend the laws and other measures they want to introduce. \n\nBackbenchers are expected to vote along party lines but have more latitude to argue against matters that they have strong opinions about. On the other hand there is a concept of \"collective responsibility\" amongst members of the government. They may argue **in private** as to what policies should be, but once decided they are all expected to support it, or resign and return to the backbenches."
] |
How can domesticated animals change when in the wild?
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[
"Generally speaking, when domesticated animals escape into the wild their chances of survival are not high due to their domesticated nature. \n\nWith regards to some farm animals escaping, the rapid change in their physical appearance would be down to one of two reasons. Firstly, some farmers will trim horns or tusks to prevent injury to other livestock and potentially themselves. The livestock is their livelihood and if they are injuring each other its going to cost them. When these farm animals escape into the wild there is no farmer to trim their horns/tusks so they simply grow back. \n\nSecond reason would be the need for survival. Most livestock are typically speaking prey animals and when kept in safe pens with food on tap they will have had little to fear. When in the wild and faced with potential predators they need to adapt to survive. However, as I mentioned above, as they are not used to having to fend for themselves and find food, most domesticated animals would not last long in the wild if they could not adapt quick enough."
] |
Why light and the rest of electromagnetic waves don't interfere with each other?
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[
"All your questions can be answered by understanding the concept of wavelength.\n\nBasically speaking, once you know what the wavelength of every radiation is, you can predict how it will interact with other things.\nI'll give you an example you probably didn't think about:\nWhy do car radios start to have bad reception in muntain tunnels? Well, the wavelength of radiosignals is pretty big, but the width of the mountain walls is bigger, therefore you start getting white noises and such.",
"This basically comes down to photons and energy, as well as diffraction. A photon is the smallest unit of energy that light of a certain frequency can carry. If light hits something, it does so with photons. This means that if light is absorbed by an object, only exactly one photon can be absorbed at a time (rarely, more than one are absorbed at a time). Now, imagine a photon of radio waves; it contains orders of magnitude less energy than a photon of visible light. This energy is too *small* to be absorbed by singular atoms, or even molecules, but can be absorbed by movement of valence electrons (electricity), and so things that are just slightly conductive of electricity tend to absorb radio waves well. Microwaves and infrared, meanwhile, usually carry roughly the right amount of energy to cause molecules to start jiggling in a specific way (I can't really describe it without pictures). This jiggling has a few different types, and its energy varies between molecules, which is why certain things heat up in a microwave while others don't. Visible light carries the right amount of energy to jiggle molecules, but only rarely. This is why most things look mostly white/gray/black. Now, scattering. Scattering is what makes things appear white. When light hits them, it gets scattered off in all directions. This tends to happen when the light wavelength is roughly similar to the size of particles, or when the particles bend light like glass does. This is why powders often appear whiter than their solid forms, and why glass powder looks white instead of transparent. As far as why waves of different frequencies don't interfere: Things like radios and phones are designed to use very specific frequencies, and so they only listen to those frequencies. Therefore, they don't pick up interference from other frequencies. Microwaves (as in the device - not the frequency of light) tend to emit a broad spectrum of radio frequencies that overlaps with radio and phone communication frequencies. The result is that microwaves can emit \"loud\" chaos over the frequency that your phone is trying to use."
] |
What happens in your body when you’ve been constipated for days?
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[
"It's [not good](_URL_1_). \n\nPoop is where everything your body doesn't want goes. If your intestines are packed too full of shit, they'll begin to rupture and leak poop into your blood stream which is life-threateningly-bad. \n\nIf you haven't shit in a couple of days, drink some coffee until you do. If you're lactose intolerant, maybe it's a good time to see what milkshakes are all about. \n\nIf you haven't shit in a week, it's time to get some laxatives (not stool softeners) from the store. Milk of Magnesia or [Colon Blow](_URL_0_) or something. \n\nIf THAT doesn't work, it's time for a trip to the Doctor. They've got the good stuff that may require a IV for dehydration because it cleans you out so well. \n\nIf THAT doesn't work, you've probably got a blockage and someone's got to roto-rooter your ass out to get things going. The good news there is that you're usually riding that Kracken out high on pain meds, so you've got that going for you.",
"If you haven't pooped in days then the poo gets backed up which can cause diverticulitis, but more commonly bloating and abdominal pain. Not pooping for weeks can cause ruptures, leaky gut or an impacted bowel. I have IBS-C. Which is chronic constipation. I have gone 2 weeks without pooping, with minimal problems (but I have an illness so don't take that as even remotely normal). It was only this year that I found out pooping every day was normal lol. If you don't normally have trouble pooing than any kind of laxatives will probably clear you out. Although I wouldn't take anything with bisacodly unless all other options fail. And if you do, probably stay home from work.",
"18 months ago I looked at my daughter on a sat night and thought “hmmm, her tummy looks big”. Didn’t really think anything else because of her growth pattern. She had been acting ‘off’ all day but we were at an intense sport convention and I thought she was tired. \n\nSunday morning: we are all set to start day two and as we are walking out of the hotel room I notice a ‘grimace’. Asked her what’s wrong. She responds “I have to go poopy and I can’t”. Hmmmm.....ok. Nbd. But it was. When I asked “when was the last time u went poopy” she responded “at disney” which was THREE WEEKs prior. Ah hell. I know what’s coming. Send my husband immediately for adult enemas. \n\nAn hour later. One enema in. She literally cannot go. Per our doctor, gave her a second. ALL HELL BREAKS LOOSE. Kid proceeds to poop out 10+ LOGS or compacted poop. My guess? Each one was in excess of a pound. No joke. Like bricks. \n\nFirst ‘log’ clogs hotel\nToilet. Shit. Call maintenance. Put her in tub. Proceeds to poop remainder in tub. Of a hotel room. Stench makes ur eyes water and gag. I am surprised they didn’t evacuate our floor. \n\n45 min later, maintenance and housekeeping comes. Husband and I are literally throwing 20’s at them as them help clean it up (we had done the majority of the heavy lifting but there was that toilet and the 20 towels we had gathered). We pack kid up, throw her in the car and have never returned to said Hotel. \n\nMoral of the story. One, said kid is prone to constipation. two, when your kids tummy is abnormally large, it may be a problem and three, that poop just builds and builds and builds.",
"Are you eating enough fiber? Most people don't get enough fiber in their diet. Fiber is your friend if you have this problem on a regular basis. Fiber moves things along at the correct pace. So whether you're going too much or not going enough, fiber will help."
] |
Why doesn’t water go up your butt if you jump in a pool?
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[
"Something tells me you just might not be a real doctor!\n\nIt’s all to do with your anal sphincter"
] |
How a bunch of moving electrons can power homes?
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[
"A moving electrical current produces a magnetic field--so while the electrons aren't directly striking the rotors inside a fan, they *are* creating a magnetic field that is pushing against the rotors.\n\nThat's the basis of any motor: a moving electrical current causes a magnetic field. If you put some pieces together in the right ways and shapes, you can make it so that this magnetic field causes a central shaft to spin. In the case of a fan, that shaft is just hooked up to the blades, making the fan spin.\n\nLight from a bulb is a little different. In incandescent bulbs, the electricity flowing through the filament makes the filament so hot that it produces light. In fluorescent bulbs, the electrical current electrically charges a gas inside the bulb; the gas produces light when it jumps down from one energy level to another. And in a LED bulb, LEDs produce light in a similar way to the fluorescent bulbs, except they're solid instead of gas."
] |
Why are civilians targeted by militias in the Democratic Republic of the Congo?
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[
"Ultimately that is a question that depends on the nature of the specific militia, its terminal and instrumental goals^1 , the attacks and who the people targeted were beyond just 'civilians'. Without that knowledge all I can really do is speak generally.\n\nGenerally a terrorist group (with political goals, most do but some dont) if they attack civilian populations do so as they view that population as either complicit in or representative of what they have issue with. They probably don't think their actions will have a direct effect at achieving their endgoal, but rather it can be a show of power against state government to rally support, reduce the legitimacy of government and its ability to protect them in the eyes of the population and to sow general fear which might serve the groups political goals in some way.\n\nLouise Richardson's *What Terrorists Want* is a good book to read on this topic.\n\nA militia though is different in nature to a terrorist organisation, its goals, structure and methods are more akin to a conventional army than a terrorist group. They might attack a civilian population in a counter-terrorism effort as terrorist groups usually derive most of their material support from civilian communities, though efforts like this usually backfire. They could be using the civilians as an exploited labour force, which in Central Africa is not uncommon due to conflict resources. They could be acting in a terrorist capacity themselves and doing it for all the same instrumental goals.\n\nReally it just depends. Conflicts like this are messy, there is no easy universal answer especially since your question is quite broad.\n\n1. A Terminal goal is your final goal, an Instrumental goal is a goal you want to achieve in service of achieving the terminal goal. If being a doctor is your terminal goal, going to medical school is a likely instrumental goal of yours.",
"Because the militias are manned by people who want an excuse to hurt others, and their cause gives them the justification they need to do so. It’s horrifying what humans will do to each other when they think they can get away with it."
] |
Sex workers in modern times have acces to many forms of birth control. It is also a well know fact that sex work is one of the oldest professions in the world. How did people prevent pregnancy before the invention of modern birth control methods? Was birth control even used?
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[
"There are plants that can induce abortion/miscarriage; a woman could consume those. There were also medicines/mixtures/potions (whatever you want to call them) that would have the same affect.\n\nThey couldn’t really ‘prevent’ it beyond not having sex when they were fertile; but they could end a pregnancy",
"London prostitutes back in the day used copper tuppence inserted in vagina to kill sperm, as copper is pretty effective spermicidal.",
"One of the oldest forms of birth control is nursing, some women would nurse not just their own babies, but other people’s \n\nSome ancient women used paste made of acidic or anti microbial things (crocodile dung, fruit juice, honey, acacia ) to put in their vagina before sex. Lemon soaked sponges are mentioned as birth control in the Talmud \n\nAncient Egyptian women used animal dung to make a flexible disc called a “pessary” to block sperm from the cervix. \n\nLysol as douche was common (and awful) not very long ago",
"While there were methods of birth control sometimes they just ended up \"throwing them away\".\n\nJust think of examples of babies being left in monasteries/temples and such.\n\nI think there was an example of a Roman brothel/bathouse where it turned out there was a pit round the back that was just full of baby [bones.](_URL_0_)",
"Didn't people use the intestines of certain animals as birth control? Or am I remembering that from a novel?",
"It’s also worth noting that in Ancient Rome, babies weren’t considered people until they were about a month old, that’s why there’s so many myths and stories about babies being left in the mountains, because if you had a kid you didn’t want you just threw it away."
] |
Why is staring at a solar eclipse deemed to be dangerous and what is the difference from just staring at the sun?
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[
"When you look at the sun your eye goes \"Damn that's bright, I better do something\". This causes your pupil to shrink down REALLY small to not let much light in, and also causes a reaction to flinch away. Both of these protect your eye from damage. \n \nIf you look at a not-quite-total eclipse your eye goes \"This is pretty dark\" and makes your pupil big to let lots of light in and doesn't trigger those protective reflexes. But any part of the sun \"peeks\" around the eclipse is just as bright as it was before, which means it can cause damage to the light sensitive bits in the back of your eye.",
"The vast majority of people are smart enough not to look directly at the Sun normally.\n\nDuring a solar eclipse, the desire to see something cool and relatively uncommon can override people's common sense aversion to looking directly at the sun, so they need to be reminded that this is still a bad idea, as it is still harmful, even though an eclipsed Sun is technically still *less* harmful than an uneclipsed Sun.",
"It's not any more or less dangerous than looking directly into the sun.\n\nThe danger comes from people assuming that because the sun is blocked, that they can look into it.\n\nThat's why you hear warnings not to look into it.",
"When you look at the Sun, it hurts because of light overload.\n\nWhen the Sun is 50% eclipsed, it still huts, but only 50% as much.\n\nWhen the Sun is 95% eclipsed, if might not hurt enough to make you look away, but the brightness per unit area might be so high that it damages the few sense cells that it falls on."
] |
Why is some ice completely clear while other ice is opaque?
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[
"A lot of it is dependant on how the water was frozen, where water that is slowly frozen will be more clear, as less air and impurities will be caught in the ice. This is why icicles are usually really clear",
"Cloudy ice is full of gases (air) that come out of solution as the water freezes. If water freezes slowly enough, the gas is able to escape the solution before being trapped in ice. Alternatively, there are ice makers out there that shake the water while freezing it quickly that form clear ice."
] |
How does the open refrigerator at the store with cheese, butter, etc. not spoil the food, but our refrigerators at home need to be closed?
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[
"Fluid dynamics!\n\nThe refrigerators at a store rely on something called \"laminar flow.\" There are fans at the top of the fridge that blow air along a straight path where all particles are moving in straight lines (\"laminar flow\", as opposed to \"turbulent flow\" where all the particles are moving in different directions).\n\nThis creates an effective curtain of air that pushes warmer air out of the way, creating an invisible door made out of air. \n\nIt's not as good as a real door, of course, but it's more than good enough for a dairy case.",
"The refrigerator in the store has a substantial airflow that forms a \"door like\" region, trapping cold air close to the food. This consumes much, much more electricity, so you can't have something like this in your house. Even stores are moving towards physical doors when remodeling to reduce energy use.",
"In addition to what's been posted, most cheeses and butter are safe at room temperature so they don't need to be refrigerated to the temperatures you would have in your home fridge.",
"It's also only used for stuff that is somewhat shelf-stable. Cheese and butter have always been a way of storing dairy beyond its expiration, especially before pasteurization was around. \n\n & #x200B;\n\nThere is actually a lot of tech and nuance that goes into things like grocery stores. The supply chains for some of them are just ridiculous.",
"Also- different foods are more or less likely to spoil. At my store milk is in a cooler with a door. But yogurt and cheese and butter are in an open cooler.",
"It’s a question of energy use. It takes more work to cool things that are rapidly rising in temperature due to an open container. Keeping it closed slows the heat transfer to the food from outside temperature. So it saves energy and speeds up cooling process. Stores, however, make enough money to afford leaving their containers open. (They also have more powerful, commercial coolers made to keep cooling while open). Your home fridge isn’t powerful/fast enough to keep everything cool while open and you run your home electric bill up.",
"Not sure on the specifics/ mechanics but yes there are fans that pump air from bottom to top and then the cold air falls down (because density) from vents at the top edge and into vents at the bottom edge creating a wall of cold air inside which milk and stuff can stay cool.",
"There are fans that blow cold air around, creating an air curtain. As far as I am aware, they’re not efficient but they do the trick."
] |
why is it more devastating to detonate a nuclear bomb at a distance above ground, as opposed to directly at ground level (upon impact) ?
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[
"If you detonate a bomb at ground level then a lot of the energy is spent digging a hole which is useless. You want the bomb to have a clear line of site to a large area for effective destruction\n\nIt's also important to note that if a 10 PSI overpressure will collapse most reinforced concrete structures then there isn't much value in hitting them with a 50 PSI overpressure, they're collapsing either way. Nuclear bombs are generally detonated at a height that maximizes the range of their 5 PSI overpressure which will knock down most structures and is almost universally lethal\n\nThere's also an interesting effect where the shockwave hits the ground and then bounces back up still expanding. This means that the edges of the shockwave are extra strong because they're the combination of the initial shockwave coming outward from the bomb and the shockwave reflecting off the ground. This results in extra damage and increases the radius of the 5 PSI overpressure.",
"Pop (without going mad) a water balloon that's on the floor.\n\nNow do the same over your head.\n\nWhich has the greater \"splash zone\"?",
"A good question! To help understand, when the bomb explodes it pushes out it every direction evenly to create a big sphere. If you detonate it in the air you can pick the distance above the ground where the widest point of the sphere touches the ground so it covers the most area. If you waited and let it explode once it hits ground level a lot of energy is wasted pushing dirt out of the way and digging into the ground instead of traveling above it like in the air burst detonations.",
"Think about shouting in a pillow, most sound is absorbed by it. \n\nThe ground does the same thing, if you explode a nuke at ground level, most of the force will go into the ground. If you explode it in the air, it will have a larger reach.\n\nOf course, a ground level nuke would have more devastating effects on the impact point, but even a fraction of a nuke power is enough to kill and destroy, so you just spread that force over a wider area.\n\nSide note, in the past they built some massive nuclear bombs (Castle Bravo, Tsar Bomb), but they ditched the idea because they were uneffective. Multiple smaller bombs are more effective than a huge, single bomb.",
"I gotchya.\n\nImagine a soap bubble on a flat, smooth surface. This is the shape a nuclear explosion takes detonated on the ground.\n\nNow if you put a straw within that soap bubble and blow to make it bigger, that would mimic the appearance of the explosion over time. \n\nConsider how the bubble grows. It grows both taller and wider at the same time. That’s just like the explosive force in a blast. It moves outward and upward in every direction. But not downward, (the ground is in the way.)\n\nNow consider the target. We don’t target flat, smooth surfaces. So imagine a little city that the walls of the soap bubble is trying to expand through and between.\n\nAll the buildings get in the way of the soap bubble’s growth, slowing it down, and maybe even popping it. The city’s buildings reduce the ability of the bubble to grow outward. The buildings closest are gone, but each building gets a little protection from the building between it and the bubble’s expansion. \n\nThis means the path of least resistance is upward, the bubbles walls are having trouble growing outward, so it will grow upward. But we aren’t targeting anything upward.\n\nNow consider that same soap bubble floating down on a city. Imagine just before it lands, you put in the straw and blow and it rapidly expands.\n\nAs the bubble grows, each building of the city it lands on is directly hit by the bubble’s walls as it grows. Because the bubble is getting larger as it comes down on the city, each building is being struck from above, where there’s nothing between the building and the ‘blast.’\n\nBefore, the ‘blast’ on the ground was striking each building from the side, which allowed each building to protect the one behind it. But from above, each building is the ‘first hit’ by the part of the bubble expanding toward it.\n\nLastly, imagine being an ant in the bubble-city experiment. The bubble growing on the ground may pass over you if you’ve found a good crevice to hide in or have a particularly strong group of pebbles (buildings/hills/ cover) between you and the bubble.\n\nBut if the bubble lands on you from above, no crevice can hide you and few pebbles can directly protect you. When the bubble lands, you’re trapped between it and the ground.\n\nTLDR: That’s why a blast is more effective from above, no protection (cover) from that direction and being trapped between the blast and the ground is crushing.",
"There are two main reasons.\n\nThe first is that a bomb directly on the ground will direct a lot of energy into the ground, and also run into line-of-sight issues (buildings will absorb a lot of the energy that is released along a straight line). So even raising it a little bit (say, just higher than the buildings) would mean the effects would go significantly further. \n\nThe second is more complex. At certain heights of detonation, the blast wave can reflect off of the ground. This reflected wave travels faster than the original wave, because the original wave has lowered the air pressure in the affected region. This means the reflected wave can \"catch up\" to the original wave. When they meet, they amplify each other, increasing the destruction at that point. So if you know the power of your bomb (the yield), and you know what blast pressure ring you'd like to amplify, you can calculate the height of detonation that will expand that blast range by a significant fraction (nearly twice as much in some cases). \n\nSome illustrations relevant to this:\n\n* [This graph](_URL_2_) shows how different heights of burst correspond to different maximum ranges. Notice the \"knees\" — those are the maximum ranges of a given pressure line. So you can see, for example, that for a 1 kt burst, setting it off on the ground will get you a 1 psi blast range of a little under 4,000 feet, but if you set it off at 1,500 feet, you expand that to over 7,000 feet. These differences scale with yield.\n\n* [Diagram showing how the blast wave reflects](_URL_1_)\n\n* [Photograph of a test where you can actually see the blast wave reflecting](_URL_0_)\n\nAt Hiroshima and Nagasaki, the scientists calculating heights of burst meant to amplify the area of 5 psi overpressure, which is to say, the blast pressure necessary to destroy houses. In fact, there were people who argued that flimsy Japanese houses really only needed 3 psi, in case you have any doubts about what they were trying to destroy with that choice of height of burst.\n\nNote that in terms of actual weapon targeting, there are sometimes very good reasons to detonate a weapon on the ground. If you detonate a nuclear weapon on contact, you are putting just a devastating amount of blast pressure wherever that is. So your total area of damage is decreased, but your damage to whatever you hit is increased. If you're attacking something underground, or \"hardened,\" or something you need to put a crater in (like an airport runway), you're going with a surface burst.",
"Non-shaped charges explode in a sphere so at most about 50% of the shock wave, aka kill potential, will reach a target. Now if you put that explosion in contact with a surface, 50% of the kill potential goes directly into the ground. The remaining kill potential goes into the sky and a small ring radiates outward and thus about 15-25% of the power of the bomb actually reaches the intended targets. You also have to take into account the light emissions of a nuclear weapons because that flash can also kill. When you detonate it on the ground the surrounding structures will occlude anything behind them thus further reducing the destructive power of the weapon.\n\nIf you take that same explosion and put it at a moderate height, 50% of the kill potential reaches the target area and increases the effective yield by greater than 2x vs a ground detonation. This is obviously far more devastating. In addition to increasing the direct impact of the shockwave and flash, both will bounce off of the ground further increasing the kill potential ( by a small margin ).\n\nThus air bursts are far more deadly than surface detonations.",
"There's a documentary on Hiroshima on netflix that goes over this quite well and it's really interesting highly recommend giving it a watch",
"Also airborne detonation maximizes reach of EMP damage to critical electrical/electronics and related infrastructure which causes all kinds of lingering negative effects.",
"The blast goes in all directions. Why waste half of it on the ground?",
"If it wasn’t summer, I’d think this thread just wrote somebody’s term paper. (Assuming this is northern hemisphere) \n\nThe other type of explosion is the subsurface burst which has the least amount of fallout generally speaking but would obliterate Navy bases and city’s with lots of water based infrastructure. It’s the least powerful but that’s a bubble you don’t want to be above. \n\nThe air burst shockwave referred to in this thread is 3 to 10x more powerful where the waves meet more than the original shock based on ground composition (if I remember my Nuke plotting courses correctly).",
"There are a lot of variables involved. What kind of damage are you looking for, thermal or shock wave? What kind of target are you aiming at, city or bunker? Target geography and geology has a lot to do with shock wave propagation, so is it mountains or open sea?"
] |
Why can we see light reflections from an angled surface? How are photons getting back to us?
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[
"You're following the old axiom from physics class of \"the angle of incidence = the angle of reflection\". Physics class almost always modeled the world with a level of perfection of surfaces and materials rarely or never really found - e.g. the frictionless surface, and in this case \"the perfect mirror\".\n\nTo that point, in your example were it reflecting _perfectly_ as a sign it would _be a mirror_ and you'd not be able to see it was there other than that the world would look strange in the spot occupied by said \"sign-mirror\" (e.g. you'd see a tree trunk start at 10 feet of the ground and end at 12 for that 2 foot tall sign and an lots of sign poles with seemingly non-existance signs!).\n\nSo...we don't build signs as mirrors, we build them as ... signs, and their surfaces are so imperfect that that they bounce light back in nearly all directions. In fact, the surfaces of these signs are designed to have the reflecting surfaces be nearly omnidirectional. Imagine pasting sand on top of a sign and each grain of sand is pretty reflective. Each grain of sand would be oddly shaped and at least a lot of surfaces/edges of sand would be bouncing light back in the direction from which it came, not using the orientation of the face of the sign.\n\nTL;DR: Light does work that way, but surfaces of materials on signs aren't flat and parallel to the face/orientation of the sign."
] |
Why are animal sounds different in different languages? How did their spellings originate?
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"Different languages use different sets of sounds, and different ways of stringing sounds together, to make words. For example, the way an American would say the 'r' in \"red\" doesn't exist that way in Japanese. Another example, the way a Francophone would say the 'r' in \"rouge\" doesn't exist in English. \n\nThe sounds that things make, such as animals, are described differently based on the sounds of the language being used. We think cats say \"meow\" because that makes sense by the standards of English. Japanese people think cats say \"nyan\" because that makes more sense when you're working from Japanese sounds. Nyan doesn't make as much sense in English, and meow doesn't make as much sense in Japanese.",
"My Hungarian father in law argues with me that ducks say mack and not quack. This comes up often.",
"in case you're interested: \nthe russian word for meow is also meow, while for woof it's \"gahv\". \nchirp is chirik, ribbit is kvak, quack is kryak... \nmoo is moo.",
"I think we associate the sound as it was when we grew up because that’s what we were told. \n\n“Arf arf!” Or “ruff ruff” both sound good to me but when I think about it “wan wan” works too. When I first heard that I was like hell no a dog doesn’t sound like that but now I hear it. I think it’s like those videos where it’s like “I hear this person saying all ten of these phrases” and you can hear it too if you’re told that’s what they’re saying."
] |
Why does Jupiter look black / invisible from this picture?
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[
"That picture is taken from the shadow of Jupiter. You're seeing the \"night\" side of Jupiter, except for a tiny curve of \"twilight\" Jupiter.",
"Because you're looking at the night side of the planet. Look at where the sun is in the photo; it's on the other side of Jupiter."
] |
How was Amazon able to pay $0 of Federal income tax on over $11 billion of profit
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[
"Your parents give you $20 to start a lemonade stand, under the condition that for every dollar you make, you have to give them $0.10. \n\nAfter a full day of successful lemonade selling, you made $10 profit. This usually implies that you owe your parents $1, but instead, you use those $10 to buy a bigger pitcher, make your stand a bit prettier, and buy more lemons for the next day. You used up all of your profit, leaving you with $0 total profit for the day, and $0 owed to your parents.",
"Businesses are allowed to carry over losses for tax purposes. Amazon had $11B in losses in past years they were able to apply to reduce this year's tax obligation.",
"I assume, without knowing specifically, that Amazon had massive net operating losses in prior years which it used to offset it's taxable income."
] |
Two headed creatures
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[
"Polycephaly is caused by the same thing as conjoined twins. Basically, during very early development, one of the cells of the initial foetus goes \"Freedom!\" and starts to form as its own baby. Then it changes its mind and goes \"Actually, do you mind if I just creep back in here?\". This makes the cells very very confused, so you tend to end up with two brains sharing the same organs to a certain degree (often, they'll have their own set of some organs, such as the spine, heart or arms). \n\nControl is often a complicated matter. Each brain tends to control its own related organs, but one head may be anencephalic (a condition in which the neural tube doesn't close properly so the majority of the brain never forms, leaving the animal extremely primitive and incapable of most emotions or higher thought), and often an organ may be controlled by both nervous systems simultaneously. Enervation in this kind of animal is something I don't know very much about, and I don't think *anyone* knows much about it. \n\nIt happens more frequently in reptiles because reptiles are highly susceptible to environment. Development is an incredibly complicated process that's very sensitive to stimuli such as temperature. Reptiles don't incubate their eggs, they just put them down and get on their way, so temperature fluctuations, among other things, mean reptile eggs are much more likely to undergo deformity-causing processes. It happens sometimes in fish too, although temperatures in the ocean are much more stable so fluctuation doesn't have anywhere near as much of an effect.",
"Abby and Brittany Hensel would probably both say, in unison, \"I am.\"\n\n_URL_0_"
] |
How does food end up in your stomach even if you eat or drink upside down?
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"Muscles in your esophagus squeeze it “down” the tube to your stomach. Kinda like trying to squeeze that last bit of toothpaste out of the tube.",
"There is a series of muscles in your esophagus that contract in sequence to push food towards your stomach. These contractions can push the food against gravity and into your stomach. Once in your stomach there is a opening that can open and close at the end of the esophagus that will keep the food in your stomach.",
"As the food travels into the throat and you swallow, it causes muscles to kind of grab and squeeze the food towards the stomach. When it reached the wall of the stomach, there is a thing similar to a butt hole. It sort of swallows the food into it with more muscles but keeps a firm grip on the stuff. It opens for food juice to flow in while on the other side, inside the stomach, locks shut so that the stuff already inside it doesnt flow out... or, down...while youre hanging from a tree."
] |
How is the British Prime Minister selected by such a small group of individuals?
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[
"The conservative party are in power, and the conservative party members elect the leader of the party. It's that simple.",
"The simplest explanation is that as a whole, the UK voted for the Conservative party to be in power, meaning that that party has the vote on who runs the Parliament.\n\n & #x200B;\n\nIt's also key to know, that the general public have again got a PM that wasn't voted for, we got May due to Cameron throwing his toys out the pram about Brexit and leaving, despite saying he wouldn't."
] |
Why is particle movement considered random?
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[
"You're mixing up two different things.\n\nYou can \"move your hand\", because muscles connected to your rigid bones are articulated in a useful way. Your brain (where your \"will\" lives) can control those muscles to a certain extent.\n\nEach atom that makes up your hand moves randomly. This is usually called \"heat\" and is motion in a very small region of space. If an atom moves this small distance, it hits another atom and bounces off, so the net effect of this motion is too small to see. This is not a function of your \"will\", the atoms in a steel bar on your desk are doing this and steel bars have no free will (I claim).",
"Individual particles move randomly because of the Heisenberg Uncertainty Principle. However, it's not entirely unpredictable. The Principle says that the more precisely you define a particle's location, the less accurately you can define its velocity, and vice versa. If you perfectly define one, the other is completely indefinable. But, you can know one a little bit and the other a little bit, just not both. And the more particles you have, though, the more \"smoothed out\" the randomness becomes. \n\nThink of it this way: if you roll one six sided die, it could be any possible number between 1 and 6. You can't predict the value any more precisely than that. But what if you rolled ten dice? The average of a d6 is 3.5 (that's 1+2+3+4+5+6=21, ÷6=3.5). So the value of 10d6 is *probably* going to be *around* 35. It might not be, sure, but it should be close. \n\nAnd it is very unlikely that all of them will be 1 for a total of 10. It could happen, technically, but it almost certainly won't. The total probably of all possibilities will make a Bell curve, and almost every time you roll the dice it'll be closer to the middle. For every die that lands on 1, you expect another to land on 6, on average. \n\nSo, what if you rolled several billion billion billions of dice? What are the odds that all of them will roll a 1? So remote that it might as well be impossible. It's not, technically, but... if you rolled dice every second of every day waiting for that perfect all-1s roll you'd experience the heat death of the universe before you had any real chance of seeing that roll. \n\nSo when you move your hand, with billions of billions of particles, yes, you can't know the position and momentum of any *single* atom in your hand. But you can add up all of the momentums and all of the positions and get the average of both. Any single atom will end up way outside of the average, randomly zipping out of you. For every one that does, on average you'll also get another randomly zipping into you. \n\nBut most will stay exactly where *on average* you expect them to be. Since you're measuring the position of your entire hand, that's all that matters, since your hand is essentially the combined average position of all of the particles in it."
] |
since when and why do seagulls eat small animal, I recently saw a video of a seagul eating a small rabbit whole like a snake really freaked me out is that actually a seagulls normal diet? why do they eat small animals?
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[
"They’ll eat anything, they are greedy greedy bastards. There’s a town called Whitby in the UK where they’ll just attack anyone who has food.",
"This isn't really an ElI5 question. You could just Google \"Seagull diet\" and come up with the answer. They eat rodents and a lot of other things, they always have. It's not hidden information, or a topic that's hard to grasp."
] |
Why do humans have dominant hands? Why aren't we all ambidextrous?
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[
"The neurons that control your left hand are not the same as the ones that control your right hand. If you taught one to write and not the other, then you made yourself one-handed as a writer. It's a parlor trick to teach yourself to write with both hands, but it takes hours that most people aren't willing to commit. Plus, when you write with both hands at the same time on the board in class, it leads to anti-intellectual jokes which are not pleasant.\n\nFun Bonus Fact: James Garfield, 20th president of the US, could write Greek with his left hand and Latin with his right hand simultaneously. Oh, the things you could learn in the 1850s due to the extra time on your hands. (pun intended)",
"The broad phenomenon you’re referring to is Laterality. This is the tendency of most humans to have a dominant hand (or foot or eye or ear), which you prefer to use for most tasks. In the few humans that are not right-dominant the remainder are left-dominant apart from very few that are ambidextrous.\n\nThe reasons for this are unclear, but one rather neat idea is that it has to do with language. Within the sounds that we all recognise as speech, there are rapidly changing parts (like the sound of the consonants and vowels pa, ba, ki, to, called phonetics) and more slowly changing parts (like the pitch and intonation, called prosody).\n\nBecause language is a very complex skill to learn, we have evolved so that we only train one side of our brain to do the quickly changing part, and the other side to deal with the slowly changing part.\n\nUsually the left hand side specialises in high frequency phonetic decoding and production, and the right side on decoding and production of the low frequency information.\n\nBecause of a crossover near the base of your brain, the right hand side of your body is controlled by the left hand side of your brain, and vise versa. Since the left hand side of your brain is doing the high frequency audio work, it also specialises in the fine (ie precision) motor skills. And this is a potential reason that most human beings are left-lateralised for language, and are right hand dominant for motor tasks.\n\nThis is just an idea though - there are people who have language spread across both sides, truly ambidextrous people, and right-language, but right-handed, people.",
"Efficiency. It's takes more brain cells dedicated to doing something like writing with both hands. Our brains prefer to commit as few brain cells to accomplishing a task as possible, allowing more other things to use that freed up \"space\"",
"Fun fact. Horses have dominate sides. \n\nThey prefer that “lead” (leg that moves forward first) when cantering and have to be taught how to use both sides. So it isn’t limited just to humans?"
] |
why can animals drink out of a lake or body of water and be okay and we can't?
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[
"well, you can, you just have to get used to it. BTW, if you've drunk clean water your whole life, drinking water in India or Mexico will usually make you very sick at first, but once you have developed the right gut bacteria from drinking that water, you'll be fine. Truth be told, some people never get to \"fine\"..."
] |
Is there any purpose of nipples on men? How are they created?
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[
"In the womb, we don’t start as male and female separately. We have a single starting template, that’s mostly female like, and then differentiate as we grow. Ovaries migrate downwards to become testicles, for example, and the genital ridge (the precursor to vaginas and penises) expands and grows into a penis. \n\nNipples are simply part of the starting template, and males do not develop in a way that makes them go away. They’re not strictly intended to do anything, but there’s not really a reason to get rid of them either. \n\nSince the breast and nipple is a complex design, with alveoli (little tubes) lined with milk production cells, males just never activate these structures. They’re still there, but inactive. It would be a lot more work to try to absorb and alter them for no particular gain. \n\nFun fact: males can lactate, or produce milk, under the right circumstances. Some men have taken the hormone prolactin, which activates these structures, and breastfed their children.",
"There is no purpose of nipples on men. However, through the use of hormones they can be made to be functional. The reason men have nipples to start with is because all embryos start out female amd the splitting of chromosomes eventually determines the real sex. The same applies to other mammels.",
"There is no \"purpose\" for nipples on men, but evolution isn't driven by \"purpose\". There is no grand plan. There is no significant biologic pressure against nipples on men, so men haven't evolved to be nipple-less (nipple-free?)."
] |
Why aren't there planes with solar panels on their top?
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[
"Planes use fuel engines, not electric ones, so it wouldn't help generate more fuel. It might help powering the electronics without using the alternator or similar, but planes burn a lot more energy than would possibly be generated by solar panels of its size. For reference, a modern car might go 40 miles with 1 gallon of fuel. A commuter plane uses something like 1 gallon per second, at 500 mph this gives something like 0.15 miles per gallon of fuel."
] |
why are insulated metal containers always hand wash only? What harm would the dishwasher do to metal?
|
[
"Some are simply because the dishwasher can damage the finish on the metal if it's colored/powder coated, etc. But the heat, etc. of a dishwasher can also break the vacuum seal on insulated contrainers, rendering them a lot less effective at keeping things hot/cold.",
"I assume by insulated you mean vacuum insulated or \"thermos\" style containers. Like Yeti and rtic \n\nThe main reason is dishwashers use fairly strong detergents, stronger than dish soap that you'd use to wash them by hand. These can damage the silicone seals on the lids, discolor or crack the paint/powder coating and the polycarbonate lids. Plus the high heat can damage the seal on the vaccum chamber, which would make it no longer insulate. \n\nTo avoid that, not using the dishwasher is recommended. Most of those insulated containers are stainless steel, so the metal itself won't get damaged. Aluminum on the other hand will become discolored in the high phosphate detergant."
] |
Why sometimes we only remember how to do something when we start doing it?
|
[
"Brains are associative: for singing you strongly learn the word before leads to the word after, and with a given pitch. You can also learn muscle movements instead of what exactly you are moving to: for example close your eyes and tell me the left-to-right, top-to-bottom order of your keyboard without using your fingers.",
"In short the brain has only so much capacity for short/long term memory, so something like a “forgotten” memory can resurface due a trigger like doing something or looking at a picture. As you haven’t thought about it enough the memory (synapse) isn’t that strong so when presented with a trigger or similarity it causes the memory to resurface.",
"Memories are not stored as single things. Rather, our brain basically shreds our entire perception and stores different parts in different places, and then when we remember something, we reassemble those pieces in such a way that it feels like we're re-living those moments. The problem is, your brain stores more complex memories as chains of related parts, and you need one part to remember the next.\n\nThis means that it can be very difficult to recall a memory until you are prompted by circumstance. Doing step 1 of a task is thus a fantastic way to remember how to do step 2.\n\nIt also applies to other circumstances. Were you always in the same place when you did X? It'll be easier to do X if you're in or thinking of that place. Did you learn about something while drunk? It'll be easier to remember it again while drunk again.\n\nFunnily enough, this same phenomenon also relates to the Laurl-vs-yanny thing, the black/blue or white/gold dress, the vase-vs.-face illusion, etc. If you prompt your brain with a certain stimulus or expectation, when you see something ambiguous, you'll tend to see what you were prompted to see - even if you are just \"seeing\" the noise of thoughts within your own head. And hallucinations/dreams? You're just being over-prompted by general background noise.\n\nSo much of human cognition/consciousness can be understood as our brains working as pattern-matching machines that breaks down data into tiny pieces to look for patterns.\n\ntl;dr you only remember things when prompted because your brain is obsessed with patterns and similarities."
] |
How does seeing a crush or a SO cause the feeling of lightheadedness and 'butterflies' in the stomach? What are the butterflies?
|
[
"I always associate it with anxiety. Similar to performance anxiety. Butterflies aren't a positive experience for me, but the attraction and excitement associated with a crush also combines with this anxiety making it a wonky feeling.",
"Nerves. Your body is in a fight or flight kinda state which causes the stomach muscles to get extra sensitive.",
"Being around your crush puts you in a heightened state of self-consciousness. You're nervous about embarrassing yourself in front of them, and this fear activates the sympathetic nervous system, also known as \"fight or flight\" mode. Essentially, your body responds in the same way it would if you were in real, physical danger.\n\nWhen this happens, your digestive system temporarily shuts down to conserve energy, which causes the \"butterflies\". Also, your circulatory and respiratory systems prioritize the flow of blood and oxygen to your muscles, reducing the amount of each available in your brain, which can cause lightheadedness.",
"Its an fight or flight response. your body gets ready to do something, it redirects blood from the stomach to muscles and brain and releases some cocktail of chemicals causing you to perceive reality differently. the butterflies specifically are like the white noise feeling when you sit on your hands for an while and then get off them. its your body getting ready to do physical exercise. the blood in intestince is less important at that point, because it isn't needed for the physical exercise. so its moved to the muscles that move joints and the brain.",
"LPT: When this happens, immediately walk up and say hello, don't hesitate or hold back at all. Show your nerves that whatever they're freaking out about isn't that bad.\n\nBest case: It goes well and you maintain the friendship/get a date with your crush. Great!\n\nWorst case: It's incredibly awkward, there friends all laugh at you. Big fucking deal. You never get the chance to befriend/date this person, but you deffinetly would have neer gotten the chance standing their nervously.\n\nThe more you do this the easier it gets, it builds your confidence.",
"I think I know this one! It's because the longest nerve in the body goes from your brain all the way down to your stomach/bum. It's called the vagus nerve. It sends signals up to your brain, and vice-versa. \n\nThat's why when you're nervous, you can feel it in your throat, torso or stomach. \n\nAt least that's what my therapist briefly explained to me.",
"We usually feel cocoon towards regular people. A crush will cause these to turn to butterflies.",
"It's the activation of the basal ganglia in the brain, which is associated with dopamine production. The activation of this pleasure zone causes an immediate physiological response. The heart beats fast, your hands will get cold and sweaty and you’re super-focused on that person. It can also be related to the fight or flight reflex in humans, which means in a way you are super nervous about this person you care for. That activates your adrenaline glands and can make you feel excitable as if you're on a roller coaster."
] |
Why do speakers get blown out when you play them too loud?
|
[
"The voice coil in a speaker is an electromagnet, it vibrates back and forth against a permenant magnet. The voice coil can overheat due to too much power being sent to it. Or damage from moving too far forward/back.",
"Beside the coil burnout discussed here, cheap consumer and bad home build enclosures mess with the throw and can damage the cone, tear it up or bang the coil. I have a book on building speaker enclosures, it used to be popular and some still do it for custom car builds and at home. \nCheaper speakers can let the cone overextend, tearing it, or bang the voice coil and change the response because of the change in shape."
] |
Why was JFK assassinated?
|
[
"Because Oswald was a mentally disturbed idiot. A psychiatrist in his childhood suspected he had a disturbed, schizoid personality. He was a pathetic loser who tried to compensate for it by seeking out counter-culture, such as Marxism. In this way, he was really not that different from someone who claims the Earth is flat. They're just pathetic little morons who want to feel special. Anyway, Oswald made trips to Russia and was a communist wannabe. \n\nTo quote the Warren Commission: \n\n > It is apparent, however, that Oswald was moved by an overriding hostility to his environment. He does not appear to have been able to establish meaningful relationships with other people. He was perpetually discontented with the world around him. Long before the assassination he expressed his hatred for American society and acted in protest against it. Oswald's search for what he conceived to be the perfect society was doomed from the start. He sought for himself a place in history — a role as the \"great man\" who would be recognized as having been in advance of his times. His commitment to Marxism and communism appears to have been another important factor in his motivation. He also had demonstrated a capacity to act decisively and without regard to the consequences when such action would further his aims of the moment. Out of these and the many other factors which may have molded the character of Lee Harvey Oswald there emerged a man capable of assassinating President Kennedy.\n\n & #x200B;\n\nTLDR: Oswald was a pathetic loser who wanted to get attention by killing someone important. I'm sure that if he lived in the 2000's, he would have been an active shooting spree or one of those ISIS wannabes."
] |
Why are smaller blueberries significantly sweeter than larger blueberries
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[
"There are lots of varieties of blueberries.\n\n* Some are sweeter than others\n\n* Each has a different maximum size\n\n* Mature at different times on the summer calendar\n\nThe most common store varieties are large, have good shelf life, box well without damage, but don't have much flavor. Instead of letting them sweeten, they pick early to minimize time to market and minimize crop loss. Fortunately customers don't know what they are supposed to taste like.\n\nYour sweeter berries were of a naturally sweeter type and were picked later to let the bush pack them full of sweetness. All varieties will be super sweet if left on the bush long enough. By the time the store variety gets sweet the birds have eaten them all.\n\nSource: Have about 5 blueberry varieties in the garden."
] |
how are some flying animals (e.g - sparrows and house flies) able to fly at such a high speed without bumping into anything?
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[
"The brains of flying animals are specifically evolved to handle the calculations and processes needed for flight. Humans bump into things when they move at ridiculous speeds because we evolved to move at medium and low speeds, dedicating more of our brainspace to things like language. When your entire brain is fly, eat, don't die and have babies, it turns out you can actually dedicate quite a lot to not bumping into things. Also, flying insects *do* bump into things all the time, they're just small enough and tough enough they don't really care. Meanwhile, the brains of birds are just tiny miracles which do way more than they should be able to.",
"How are you able to drive a car at such high speed without hitting anything? You drive a lot faster than t can fly.\n\nAnd who says they don't bump into anything? Have you never had a flying bug smack you in the face when you're just standing there minding your own business? And birds hit windows, though that might be because they don't see it."
] |
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