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eli5_category

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{ "a_id": [ "h34miz5", "h34nyy9" ], "text": [ "Chemistry, but each one has a different synthesis process. For instance strawberry flavor is called 2-méthylpropanoate ethyl, it's made with alcohol and carboxylic acid.", "The base materials have to come from natural sources. The \"artificial\" part refers to how they're put together. In nature, materials are converted into the desired molecule by organic catalysts inside cells. In industry, materials are converted into the desired molecule by catalysts (sometimes organic, sometimes inorganic) that are sometimes located in cells and sometimes not. A catalyst is something that causes particular reactions to happen that wouldn't normally occur. The way this works is very complicated and involves a field of physics related to magnets called \"magic\". An organic catalyst is simply a catalyst produced by biological processes. They typically take the form of proteins called enzymes, which are really quite remarkable. In industry, some chemicals can be made using inorganic catalysts, like platinum or nickel, and very specific materials and environmental conditions. Others are made by extracting the gene that codes for an enzyme from its original organism and implanting it into bacteria to produce huge quantities of the enzyme very efficiently, without having to grow an entire plant/animal. Also, many artificial flavourings are actually not the same chemical used in the natural form, but a chemical that was produced coincidentally from another process and that people thought tasted a bit like a particular thing." ], "score": [ 3, 3 ], "text_urls": [ [], [] ] }

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{ "a_id": [ "h34uvel" ], "text": [ "The neurovascular theory of migraines suggests that there is some trigger that activate a neuron system. After that, there will be vascular changes, with dilation of brain vessels which will cause pain. As you know, people that have strokes are usually only affected on one side of the body. That's because the vascular system is very well divided between the left and right brain hemisphere. For the migraine is the same. Only one side will suffer the change of perfusion, thus you only feel pain on one side." ], "score": [ 16 ], "text_urls": [ [] ] }

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{ "a_id": [ "h3532u6", "h353r7p" ], "text": [ "Weight is a unit of force, the SI unit for it is Newton. A bit simplified it is the force of gravity on a mass on the surface of the earth. Because gravity depends on the location on earth, the difference is on the surface of Earth is 0.7% The result is the weight of an object depends on where you are on earth. The mass has the SI unit of the kilogram, weight is mass \\* gravitational acceleration. Calibration weights that you use to calibrate a scale are made to have a specific mass, not a specific weight because weight is location-dependent. The same way density is not weight/volume but mass/volume. Between 1889 and 2019 the kilogram was defined as the mass of the [ URL_1 ]( URL_0 ) All other masses were derived as a comparison to it. There is always a level of accuracy so not two-kilogram prototype had the exact same mass. There was a small change in mass over time because if you use them they need to be clean and there was a drop of around 1micro gram per cleaning, which is a change of 1 in one billion. Any good calibration weight will have documentation so you can trackback what is was compared to and when. That way any errors and inaccuracies can be tracked. Because of problem like this the kilogram was redefined in 2019 as > \"The kilogram, symbol kg, is the SI unit of mass. It is defined by taking the fixed numerical value of the Planck constant h to be 6.62607015×10\\^−34 when expressed in the unit J s, which is equal to kg m\\^2 s −1, where the metre and the second are defined in terms of c and ∆ν\\_Cs.\"\\[1\\] Today mass is determined by a physical constant. So any real physical object will not have a mass that is exact. The object made with higher accuracy will cost more. Any density measurement of material will have one accuracy limit and I assume it is the volume that is harder to determine than the mass.", "Calibration weights are correct by definition, within a known tolerance. Unlike a lot of other basic units, mass is annoyingly difficult to quantify in any absolute terms that we can usefully employ. Saying \"1kg is equal to 1 cubic decimeter of water at such and such temperature and pressure\" (the original definition) is perfectly rigorous but really hard to implement, because you've just turned the problem into one of measuring volume instead of mass. So in the late 1890s they switched to a physical artifact...they made a platinum iridum bar and \\*defined\\* it to be 1kg. Later that got replaced by a cylinder that was used to calibrate everything else. It can't be wrong, because it's the definition. Then you just compare other weights to \\*the\\* kilogram and keep track of the tolerances of your measuring devices to make calibration weights for general use. The problem with this approach is that if your reference mass changes you get into a fight about which one is right. Very recently (2019) we redefined the kilogram in terms of the Planck constant, the second, and the meter (which all have really vigorous definitions that don't depend on a physical artifact). This lets us check reference weights against other things we can directly measure." ], "score": [ 7, 3 ], "text_urls": [ [ "https://en.wikipedia.org/wiki/International_Prototype_of_the_Kilogram", "https://en.wikipedia.org/wiki/International\\_Prototype\\_of\\_the\\_Kilogram" ], [] ] }

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{ "a_id": [ "h353x36", "h3525nu", "h3533wz", "h36em6w" ], "text": [ "Water doesn't really have a taste. What makes certain water taste good and others not as good is how similar the dissolved mineral content is to your saliva. That also means the taste isn't universal since everyone is a little different. Unless there's something really off about it, asking someone to describe the taste of water is basically asking them to describe how flavorless it is. There might be one language which has a lot of specific words for different types of flavorless but English isn't one of them.", "Because taste, color and other such experiences can only be expected when comparing it to another experience.", "Our tongues can taste sweet, sour, salty, fatty and bitter. Each of these tastes is a different taste receptor detecting different nutrients - sugars, salts, acids, proteins, fats, etc. There's tons of variations of all of these that produce very complex tastes, but pure water has none of them.", "Follow up: Why do cold water, lukewarm, and hot water taste differently?" ], "score": [ 23, 12, 7, 3 ], "text_urls": [ [], [], [], [] ] }

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{ "a_id": [ "h35havr" ], "text": [ "Are you not allowed to say North Korea?" ], "score": [ 8 ], "text_urls": [ [] ] }

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{ "a_id": [ "h35l7o4", "h35jr6x", "h35p8bs" ], "text": [ "Antidepressants, depending on what kind, do not give you an immediate feeling of getting better. I take zoloft which is an SSRI and the way that it works is that it continuously builds in the body to provide a more stable/consistent production of serotonin. If anything it makes you feel worse at first for a little bit, im just a patient so im not entirely sure why other than the introduction of something altering my chemical composition. Ive been on Zoloft for about 5 years now and i’ve stopped having daily panic attacks that last a couple hours. It doesn’t necessarily stop you from being depressed but it makes the chemicals your braiin produces more stable and consistent. They’re more mood stabilizers if anything, to prevent the extreme lows of depression and similar conditions.", "It's not like antidepressants are straight up injections of those hormones. Even if they were, it doesn't work that way: hormones aren't drugs. Antidepressants tend to try to affect the *receptors* for those hormones for better regulation (and sometimes work with other mechanics entirely). Psychiatric medicine has come a long way but it's still a complex, emerging science, and it never boils down to simple 'make the brain feel better by rewarding it.'", "SSRI is a reuptake inhibitor- meaning that there is actually more serotonin available because it’s essentially not letting the body reabsorb those chemicals. The older antidepressant meds TCAs were more dopamine and norepinephrine targeted in nature but the key with understanding depression is that each persons underlying chemical imbalance is unique. There’s no test that can tell you which chemical the body is lacking. Keep in mind there are some medications that are considered serotonin or dopamine “agonists” used for things like Parkinson’s or migraines. The issue is that as these can effect mood but also come with side effects those chemicals. This is why the antidepressant mechanisms focus on the reuptake inhibitors- milder in effect sometimes but also comes with safer and less side effects." ], "score": [ 9, 5, 4 ], "text_urls": [ [], [], [] ] }

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{ "a_id": [ "h364ap6", "h36p3i2" ], "text": [ "When we are surprised our body reacts by taking in a deep breath of air so we have enough oxygen to prepare for the next move we may need to defend ourselves or react to the event that caused us to be surprised, or scream/yell with our mouths open sometimes in fright. When we take that deep breath in, we also open our mouths- and inherently we may be either trying to: A. Hide the fact we are shocked, after we realized there may actually be no harm and it was a close call, because we might feel embarrassed B. Being in a surprised state with our mouths open to take in that breath to take on a defensive posture, instinctively we will cover our mouths to protect our mouth as well.", "Where are you from? Here in Austria (and a lot of other places in Europe I’ve been to) I’ve never seen anyone doing this. I know the gesture and I’ve seen people doing it as a joke. Edit: Or in movies/videos to convey surprise (because how else would you show it?). Or by women/girls when they intentionally overreact (accompanied by a lot of giggling and girlish screaming)." ], "score": [ 4, 3 ], "text_urls": [ [], [] ] }

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{ "a_id": [ "h365f47", "h3666h4" ], "text": [ "A movie can make money and still be a flop because it is fundamentally an investment. The investors took a huge risk in paying for the production of the movie, and expect to be rewarded in a manner proportional to the risk, just like any other investment. So, breaking even or making a small amount is certainly better than losing money, but could still be considered a failure, since that money could have been used elsewhere and made a much larger return, or achieved the same return in a much safer way.", "Three reasons: 1. Marketing costs are generally counted separately from production costs and can be enormous. A movie may have “broken even” on its $100 million budget with $100 million in box office receipts, but that doesn’t cover the $50 million in ads they spent. 2. The theaters keep a portion of the box office. It’s obvious, once you think about it, but just because a movie made X dollars at the box office doesn’t mean the coming that made it gets X dollars, so they need to make substantially more to cover the theaters’ share. 3. Opportunity cost. This is a big one. Even if a movie does actually make a tiny profit, even after the other expenses I mentioned, there are only so many movies that can be put out a year. Money invested in a movie that ended up making only $5 million in profit is a waste when the same effort could have gotten $500 million. And this is why you see an endless series of sequels and franchise films: *reliably* large profits." ], "score": [ 19, 16 ], "text_urls": [ [], [] ] }

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{ "a_id": [ "h365nnl", "h365rfs", "h365su0" ], "text": [ "It’s not really a test and isn’t about a specific diagnosis. The abstractness or the blots is intended as a tool for the psychiatrist to find out what’s on your mind. If every picture looks like some sort of battle, they will get a different idea about your internal self than if you see every blotch as a couple making out.", "The cards are standard, so the idea was that you could compare a person's response to a given card to the responses that other people with known histories/disorders gave. They aren't generally used anymore because the comparison was largely interpretation by the test performer, so reliability was never very high. Plus, all you ever got was a correlation of responses with backgrounds, and if you really want to know something about someone's psyche, you can just ask if you know how.", "They aren't some kind of exact science. It's not as if you show someone a particular ink blot, and ask him what it looks like, and if he says, \"a dragon.\" then he's definitely a psychopath. They can, however, be used as a tool to kind of gain entrance into a person's psyche. For example, if a person is shown an inkblot and says it looks like his father, the tester might then ask, \"And what do you see your father doing?\" If the person responds, \"He's hitting my mother with an axe,\" then there is a pretty good indication that that person has some kind of psychological issues, possibly relating to his parents. So, to answer your question, it's impossible to actually render a psychological diagnosis, simply by administering an ink-blot test. But, it can be a useful tool." ], "score": [ 13, 12, 11 ], "text_urls": [ [], [], [] ] }

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{ "a_id": [ "h379cgu" ], "text": [ "They aren't really born with two heads, it's rather twins fused together and born with one body. That said the extent of the balancing of functions between the brains truly depends on how they are fused together and the extent of the malformation. Generally speaking, in humans, in the vast majority of scenarios, each brain has separate thoughts and is responsable, feels and coordinates one side of the body with very little overlap. Neural activity has only been observed to be shared, if the skulls are connected" ], "score": [ 5 ], "text_urls": [ [] ] }

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{ "a_id": [ "h36af3q" ], "text": [ "Downstream effects where G proteins congregate in lipid rafts, in the brain, and cannot access cAMP, is the leading theory. Just because something binds to a receptor doesn’t always elicit a desired effect right away since further events must take place once the ligand is bound. ELI5: binding to a receptor requires further steps in the cell to reach the desired effect and there is a problem with the second messenger system" ], "score": [ 4 ], "text_urls": [ [] ] }

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{ "a_id": [ "h36kigj", "h36fcqv", "h36kvba" ], "text": [ "Why would I be explaining this to a 5yo?", "I believe it's because water doesn't handle friction as well as oils. Same reason we use oil in an engine instead of water", "Because water isn't a good lubricant. Normally when you interact with things there's no lubricant. When you're walking, picking things up, whatever, it's dry on dry. Water fills the gaps between things so it makes things more slippery than nothing, but water is a pretty sticky liquid. Now vaginal lubrication is mostly water, but it's got a lot of other proteins and stuff that make it extra slippery. That's why you can have skin sliding against skin without causing friction burns. Unfortunately since it's water based, water will wash away any natural lube it comes into contact with, leaving you with skin pulling on skin and no fun at all. If you want proof get your fingers wet then rub them together. Then try it with oil. Then with natural lube. You'll see that while water is better than nothing, it's a pretty poor lubricant." ], "score": [ 14, 11, 8 ], "text_urls": [ [], [], [] ] }

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{ "a_id": [ "h36g1r3", "h36ir19" ], "text": [ "My understanding: Like most failures of this type, it’s many things that aligned together to cause a failure. Texas wanted to keep from being regulated by the federal government, so the majority of the grid is isolated to within the state. Therefore they can’t easily call on supplies from other states during over demand (El Paso is connected to New Mexico, and was fine). Demand was high as Texas doesn’t typically get that cold for that long, so lots of heating systems there rely on electricity (cheaper systems to buy, more pricy to run) rather that oil or gas which is more typical in colder climates. Combine that with the cold weather that the grid was not hardened against and chronic lack of investment (and probably several other factors) and poof… no power for a while…", "Readily available electricity is something that societies count on….hospitals, police, our military, fire departments, etc…. Texas wants to increase profits for private power suppliers by doing away with pesky “regulations” that require minimum standards in materials, safety and such. If Texas companies can buy cheaper, less reliable materials that would be substandard in any regulated power plant, but will increase their profit , then that’s what they’ll do. It’s stupid and short-sighted, but there it is. Another example of why, if I owned Texas and Hell, I’d rent out Texas and live in Hell." ], "score": [ 9, 4 ], "text_urls": [ [], [] ] }

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{ "a_id": [ "h36hixg", "h36lb4x" ], "text": [ "Plants have certain processes that keep them alive and help them grow, and different types of plants can have different processes. Weed killers and herbicides can be made to target processes that happen in weeds and not in common grass. Edit: not all weed killers are like this. They can also be non specific and kind of just kill everything. If you're buying just be careful on what brand you buy and do some research before you destroy your lawn", "One method is used on broadleaf weeds and another method on crabgrass. Lawn grass has a narrow leaf. Lawn weeds such as dandelions are broad leaf. (Crabgrass is not a broadleaf.) Broadleaf weeds absorb water through their leaves. Grass doesn't. So, the herbicide used to combat broadleaf weeds is effective only on plants which absorb water though crabgrass. Broadleaf herbicides are actually growth hormones, which cause the plant to grow very quickly. Crabgrass is a significant problem. Herbicides that kill crabgrass also kills lawns. So, the usual plan to deal with crabgrass is to dig out the plants. Then, a pre-emergent herbicide is applied. The pre-emergent coats seeds and stops them from germinating. Most lawns have a perennial grass, and thus don't rely on seeds for spreading. The key to effective crabgrass control is to apply the pre-emergent at the correct time of the year." ], "score": [ 10, 3 ], "text_urls": [ [], [] ] }

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{ "a_id": [ "h36of8j", "h36ob60", "h36rnr6", "h36xcfd", "h36s1rf", "h375qnd" ], "text": [ "I feel very old having to explain this. In the 1950s-1970s, there was no 911. If you didn't know the phone numbers to your local ambulance service, police department, and fire department, you were SOL. (Well, you could probably call the operator and hope that got you somewhere.) If you bought a (landline) phone in the 1970s to mid-1990s it usually had a little card with a clear plastic cover, with a blue police car or shield symbol, red fire or fire truck symbol, and red cross symbol, for writing down phone numbers for police/fire/ambulance. When you bought a new phone you were supposed to fill these things out. In the 1960s-1990s, 911 service was rolled out throughout North America. The idea was that when you dialed 911, your call would be automatically routed to whatever local authority (often a police station) agreed to service the block of phone numbers that includes yours. No need to memorize numbers - no matter where you lived, you dialed 911 and got someone who could either help or direct you to help. The rollout was very slow. Emergency phone number cards and stickers were still a big thing for decades. By the late 1980s, 911 service was almost everywhere, and it was no longer necessary to call your local FD/PD/EMS directly. The 911 system was great - you made a call, and you got a 911 center assigned to your phone number. The ubiquitous emergency stickers with police/fire/ambulance next to every phone slowly disappeared. Then cellphones became a thing. They operated in the same system - you called 911 and got a 911 center assigned to your phone number. That might be on the other side of the continent if you were traveling. Enter Enhanced 911, or E911. Under this system, the 911 system was improved, so that 911 calls weren't blindly sent to whatever police department claimed that block of numbers, but instead went to Public Safety Access Points (PSAP) with equipment and operators that could make sure the caller was physically in the region, determine what sort of emergency response was required, and redirect the caller if necessary. For cellphone users, the tower used to make the call was encoded as metadata, and used to redirect the 911 call to the PSAP associated with the tower, *not* the PSAP associated with the phone number. E911 has some additional features, such as the ability to poll your phone for location data, if your phone has GPS/AGPS enabled. This of course only works if your phone has an active and accurate location fix at the time of the call, and the PSAP has the equipment to poll that information.", "The other answer, while not wrong, doesn’t really answer this question, so: When you call 911, your service provider looks up the “Emergency Service Number”, which is a regular 10 digit phone number, that connects to the 911 call center physically closest to you. Every area has one of these, and they look up which one is closest to your area based on your billing address or cell tower. They redirect your call to this 10 digit number, and from there it’ll ring at your local 911 call center.", "To make the reasoning short and non-technical, Your phone operator is at all times aware of where you are. When your phone is on, it talks to the cellphone towers. To make it possible to call you, it's required that the cellphone tower that you are currently communicating with knows that you are supposed to be there. For any of it to work, the tower ALSO needs to share that information with a centralised control system. The first thing the phone system does when it tries to forward a call to you, is that it asks the centralised system \"alright, who is it that talks to that phone right now?\" so that the actual phonecall can be forwarded specifically to that cell tower that is tasked with maintaining the phonecall. There are some more fiddling that occurs when a phone moves out of convenient reach of a cell-tower, and hooks up to another instead in a fashion that appears seamless. But those are not relevant for this explanation, besides that you need to know that when the phone moves, the centralised system gets an updated summary of where you are instead. When you make a 911 call, the phone operator is forced by law to look at this information and make a sensible assumption on which emergency call centre to forward the call to. Generally speaking, this is a manually assigned decision on each and every cell tower, when it's erected. To top it off, many cell towers are \"divided\" into several cells. One antenna in each direction, so to speak. And that also offers an ability for the cell-tower to distinguish your rough direction relative to the cell-tower. And that information is also passed along to the call centre, together with the cell towers physical location. (It still gives a lot of guesswork since the information is something like \"I am at 2200 Main Street, and my westward pointing antenna can hear this phone. It ought to be somewhere within a mile or so in that general direction.\" But at least it's something.) In some places, regulations are pushing for cell towers to be able to force phones to activate their GPS and track themselves. In some places, cell towers already force phones to activate their GPS occasionally. But there are still phones on the market that has absolutely no GPS in them, and the technical information from the cell tower always works, which makes it a convenient start.", "When you make a phone call, it has to be routed through the phone system - so your mobile will connect to a specific cell tower, and your landline will be physically wired through a specific phone exchange. When you phone 911 the phone system recognises you are calling an emergency number, and it notes which tower or exchange your call is coming from - this lets it route your phone to the appropriate dispatcher for your area who will then organise the response.", "imagine you are in one of a large number of adjacent rooms (phone network) . each room also has a manager (call router) , that knows the managers of the other rooms. usually when you want to make a call the manager would transfer you to the other rooms until you me the person you want to speak with. but in an emergency you need that help locally. so the manager also knows where the first-aid kits are located in his room an can send you there directly", "I’m a 911 dispatcher and can answer this. The way 911 works, it routes your call to whatever center is in charge of the first cell tower your phone hits. Once that happens the 911 system keeps refreshing and working on pinging the next 2 closest towers to get a very accurate location (I’ve seen as close as on the physical building to about 50 meters away). Now it’s very common for that first tower that your phone hits to not be in the actual jurisdiction that you’re in, that’s where the triangulation comes in, you’ll then be transferred to the correct agency/center. Now with landlines this is different. Landlines are programmed to ring to the proper agency when they are set up. I hope this answer helps." ], "score": [ 1443, 38, 26, 5, 4, 3 ], "text_urls": [ [], [], [], [], [], [] ] }

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{ "a_id": [ "h36jlc1", "h36kl5i", "h36kegz" ], "text": [ "Bat. Most broken bats have probably been used multiple times and several likely have cracks, however big or microscopic, before finally breaking.", "They work together to do it. Both objects experience the same force (Newton’s third law) during the collision. But we could determine which one brings more energy to the event. A baseball is 0.15kg and is going 40 m/s. That’s 120 joules of kinetic energy. The bat is much larger at 1 kg. It’s traveling roughly 30 m/s. That brings about 450 j of energy. So the bat contributes the majority of the energy and an argument could be made that it is the more significant “cause”", "It depends on a variety of things: place the bat was hit, speed of the ball, how much the bat has been used, speed of the swing, etc. I have seen a video of a player breaking the bat while checking his swing. He started swinging but stopped quickly. His hands stopped, but the upper half of the bat didn’t." ], "score": [ 52, 25, 3 ], "text_urls": [ [], [], [] ] }

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{ "a_id": [ "h36r8ht", "h36su6y" ], "text": [ "You go paralyzed for awhile. I’ve been through a 5 month long coma and it took a very long time before I was able to learn to walk or talk again. But now I’m almost back to 100% normal.", "Imagine if your consciousness was like a TV and xbox with a bunch of cords. It isn't until the xbox is on, the tv is on at the same time, electricity is going to them and all the cords are in the right spot, boom now you have Nintendos. BUT if I unplug just one of your precious cords what happens to the system? People have a hard time defining consciousness, What little we do know seems to be that consciousness comes from multiple brain regions working together to create a perception. Bein knocked unconscious means that you have interrupted enough processes to not be able to provide a conscious picture or even keep you upright, attentive. Like another Redditor said our bodies remain relatively the same (and this is probably because all the brain regions are working fine on their own individually, but the mind needs to get back in tandem before it can create a perception again which means it need to realign all the electrical and chemical signals (probably similarly to how you wake up every day) before you regain consciousness. If you have ever seen starts you know that the brain doesn't always come online at once, or if you've ever blacked out due to low blood pressure/sugar you know the senses don't all go away at once so it probably takes a long time to get them all going in unison again. It'd be like if a high school marching choir\\* got sprayed with a firehose and then the conductor was all like hey get back in formation and sing dammit, it'd probably take em a second to get their shit toter and get back in formation" ], "score": [ 15, 11 ], "text_urls": [ [], [] ] }

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{ "a_id": [ "h36rjo3", "h36wk6r", "h372fc9" ], "text": [ "Well it depends. We have only 3 types of cones, so we can't imagine what the world looks like for animals that can see more different colours. But more wavelengths don't require more different colours. If each cone had a wider \"bandwidth\" of wavelengths then we would just see everything we see right now as green, and some normally invisible colours as red or blue. The main difference in the world would be flowers. Many of them that are white to us are actually UV coloured and some even have UV patterns.", "Well, you've seen camera captured IR footage, and you've seen the weird details which emerge sometimes under a black light - those aren't bad ways to think about it. Just imagine always having both on hand, or rather both being blended with your existing vision.", "Some humans don't need to imagine. We have cells in our eyes called \"cones\" that are sensitive to different ranges of wavelengths (which we perceive as colours). Broadly speaking, some detect red light, some green light, and some blue. Combinations of these give all the colours a typical human can see. Ultraviolet light can be detected by the cones, but it is blocked by the lenses of the eyes. Some patients born without lenses (a condition called aphakia) or who have had operations to remove cataracts, in which the lenses are replaced, report being about to see UV light and say it looks whitish blue. As an aside: all humans with regular eyesight can see UV light... sort of. Laundry detergents that contain optical brighteners convert normally invisible UV light to visible light, and so make white clothing literally \"whiter than white\"." ], "score": [ 10, 5, 3 ], "text_urls": [ [], [], [] ] }

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{ "a_id": [ "h36t7np", "h36rkqi", "h36xdx8", "h37cctf" ], "text": [ "So there's a weird thing about chemistry... Any stable compound needs to have energy added to it before it can change to any other stable compound. That's why you have to light explosives or smack them really hard or whatever. So every combination of atoms that form molecules is stable if, and only if, all of the electrons can find basically a tiny lowland valley in their energy chart. So raw petroleum, and coal, All started as plant material, The oil of various algae and plants. They all got buried at once, where at once means over the course of the same million or 100 million years etc, and then the heat and pressure of the Earth basically jammed more and more individual oil molecules into longer and longer chains. So in a refinery what's really happening is that, slowly, crude oil is being pumped into the refinery tower and the application of heat and pressure allows useful molecules to be sorted into different layers and pumped away. The most volatile chemicals are things like acetone, which is very light and rise to the top, and beneath that is gasoline and beneath that is kerosene and so forth. Down at the very bottom just above the ash is where we find things like molten plastics and petroleum jelly. This entire refinery process is called cracking, and it sorts the useful parts from the toxic parts from the dangerous parts from the ashy useless parts. So when virgin plastic pellets of the various grades are made, basically that liquid stack has the particular chemicals they're interested in siphoned off and allowed to cool. In the case of plastics it's usually looks like a whole bunch of little tiny white pellets. And different pellets have different grades, and different grades of pellets will only bond with pellets of similar grades. I mean they'll bond with anything but they'll only bond well and uniformly with similar molecules. The entire field of chemical science is figuring out what bonds with what. The thing we're actually missing is that we have no way to recreate the original petroleum that we got out of the ground. We basically need to take the ash, the chunks of plastic, the Vaseline, the gasoline, the acetone, and just everything else and put it in chamber and supply it with a whole bunch of heat and a whole bunch of pressure for a whole bunch of time in order to recreate the crude oil. And people have tried to do this. There's one process that uses microwaves and wave guides and hydraulic presses and some other stuff to recreate crude oil more or less, but it's not as good as the real thing because we can't take the time and energy necessary to put it back into original equipment position. We also can't do it in bulk (as of yet). So when we're recycling plastic, most of the time we're just taking shreds of plastic, heating it up and jamming it together. A plastic bottle doesn't become a new plastic bottle, on average plastic bottle becomes a bench. The other thing is we have an unpleasant tendency to do things like color our plastics and add things like BPA to keep it flexible instead of letting it get brittle and stuff like that. We're basically polluting the plastic when we make it. So we have no way to get the plastic pollution out, and we have no way to gather up everything we need to make new petroleum out of the old stuff because we do things like burn kerosene and gasoline and throw acetone away and stuff like that. So you're basically trying to unbake a cake when you recycle. Advanced polymer chemistry is sort of like solving millions of individual jigsaw puzzles, and we've got certain ways to work them in one direction, but we don't really have any ways to work them reliably in the other direction. So we've got a very limited number of processes we can use to \"reuse plastic\", but we got something half as good and nowhere near as flexible as the stuff we started with. Unbake a cake, un-boil an egg, turn an adult into a child again Somebody else talked about injection molded versus pressure molded. But that's just the details. The stuff that turns the empty butter tub yellow and leaves it soft instead of brittle is far worse for future recycling the van the means of molding. The means of molding are important, I'm not saying they're not, part of the reason they're important is because of the chemicals we add to it and the different temperatures we use in the various processes. The thing is we used to have the perfect material for doing our soda bottles. We called it glass. Glass can be used again and again, particularly clear glass. And we used to use paper for bags until the plastic industry decided to convince us that we were killing trees and we should really use plastic, and now we've got a garbage patch in the ocean. We simply cannot make the furnace presses necessary to properly recycle any plastic at scale. So even if you think you recycling, a lot of it's just getting thrown away later, and most of the stuff that is getting recycled isn't being turned back into what it was that you just used. A bottle never becomes a bottle, a bottle becomes a parking stop in a parking lot. And then that can't be recycled at all. The sad and simple truth is that most chemical processes are very difficult to reverse, particularly if you've extracted energy in the process of performing them because it's hard to put exactly the energy you took out back in. The entire idea that recycling is the solution to plastic waste is basically blame shifting. If you perfectly recycled everything in your life most of it would still get redirected to the landfill after made you feel good to put it in a little blue bin. I'm not saying it's not worth doing, but it is not the solution, it's the guilt trip run by the industry. If we went to glass bottles and reserved the petroleum products for the rarefied processes and truly important products like medical plastics we could solve a lot of problems. We'd recycle the glass, and yeah we'd burn the medical waste or whatever, but then plastic would be a boutique industry instead of a gold rush. Edit: I corrected some of the mess made by my voice to text app. I'm sure there's much more mess in there. But I got a screwed up right hand right now so I can really do more than dictate into my phone.", "Different kinds of plastics can't be mixed together to be recycled. Plastics must be separated into individual types. Each type is shown by a number on the bottom: 1, 2, 3, 4, 5, 6, or 7. Each number stands for a different resin (a different chemical). Each resin reacts differently when it is reprocessed into a new item, because different resins melt at different temperatures. Factories that make new products out of plastics are set up to take only specific resin types. Even resins with the same number can't always be recycled together. You might wonder why #2 yogurt and margarine tubs can't be recycled in the City's recycling program when #2 milk bottles can. It's because the tubs are \"injection molded\" and the bottles are \"blow molded.\" These two different processes create chemical combinations that react differently when they are melted down for recycling. So they can't be mixed together.", "There are two main types of plastics. Thermal plastics and thermoset plastics. Thermal plastics like the type milk jugs are made out of melt when heated. They are much weaker but easy to work with; it's the same type of plastic you'd use in a 3d printer. They are easily recyclable into the same thing again as long as you don't mix them with other types of thermal plastics and they're clean when you recycle them. If they are mixed with different types of plastics then they lose some of their properties and become a lower grade of plastic like the kind you make carpet out of. Another thing that makes them harder to recycle is, since they are relatively weak, people reinforce it with glass fiber. Thermoset plastics on the other hand are made by a chemical reaction by combining two different types of chemicals. They are much tougher like acrylic. They don't melt when heated; they burn. Most recycling places won't take it because it takes too much effort (money) process it back into a raw material. Technically, everything is recyclable as long as you put enough money into it. The problem is it's not always profitable; especially when it comes to plastics. The reason why it used to be profitable was shipping companies would not want to return to China with empty shipping containers. They want to charge another company to pay to send something back to China. Typically, that thing is either e-waste or things Americans don't want to recycle. A few years ago, China stopped taking American plastics because 1. It lead to environmental issues of their own, 2. Americans are too fucking lazy to clean out their plastic food containers and it generally ruins the whole batch of plastics if it's contaminated. As long as we rely on petroleum based fuels, base stock for plastics will be cheap because it is a byproduct of making gas and as long as the base stock for plastic is cheap, recycling it will be very low profit or unprofitable.", "Technically everything is recyclable, but there's big differences in how much effort, energy and expensive technology it takes. But only a few things are recyclable in a way that takes less effort than making it new. Aluminum metal is commonly recycled because it can simply be melted down and turned into new metal, and because the process of making new aluminum is pretty expensive in comparison. Paper can be dissolved and turned into new paper. The quality isn't as good as new paper and you need to bleach out the old ink, but it's less difficult than making new paper from wood if the paper is already collected and not too contaminated with other trash. Some plastics can also be melted down and turned into new things if available in a mostly pure form. If multiple types are mixed it can still be made into lower quality plastic. The issue with plastic is that it's just too easy to make new plastic from oil, recycling is often more difficult. If you took a bunch of mixed plastic and pumped a ton of energy and hydrogen in you could break up all those molecules and turn it back into a sludge of hydrocarbons and a few other chemicals, but realistically it's just much easier to get the hydrocarbons from the ground." ], "score": [ 80, 47, 5, 3 ], "text_urls": [ [], [], [], [] ] }

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{ "a_id": [ "h36uqjn", "h36xbdc", "h36z3en", "h36ujnp", "h3738or" ], "text": [ "It's kind of the opposite of that. Particles are shot through 2 slits before hitting a wall. If those were large objects, like billiard balls, we would expect the particles to hit around 2 specific spots, directly in line with where the slits are. But what we see on the collision wall is a pattern that is typical of waves, with alternating hit and miss bands. That would means that particles going through one slit are affecting particles going through the other slit. But the weird thing is that this pattern happens even if you shoot a single particle at a time. That sort of implies that the particle gets interference from a phantom particle. Physicists interpret this as the particle going through both slits and interfering with itself, because things keep getting weirder the more you tweak the experiment. Let's say you get a detector and put it in one slit. So if the particle goes through that slit, you would know it. Only now the particle behaves like the billiard balls. The interference pattern is gone. So something in detecting the particle forces the particle to not behave like a wave. It gets even weirder because you can randomly choose to detect or not which slit it goes through after the particle went through and it sort of retroactively acts like billiard ball if you do it. Quantum physics is decisively weirder that our common sense is equipped to deal with.", "It's helpful to note that in successful modern Quantum Field Theory ([QFT]( URL_0 )), the more objective word/concept \"interaction\" is used instead of the word/concept \"observation\". That is to say: the *interaction* of particles is the key point, not any human or machine that participates, observes or records data. Interestingly, in the modern framework of QFT, the word/concept \"particle\" has been redefined. It no longer matches the definition of \"particle\" from the 19th century. (Even though the old definition is still misleadingly taught in schools.) That old definition is responsible for nearly all conceptual obstacles people face when learning quantum mechanics. There's a lot to unpack in the definition of \"particle\" in the Wikipedia QFT link, but the main point is this: non-physical fully-space-occupying fields are considered to be fundamental -- not the particles themselves, which are excited states of those fields. That's why our intuition needs to be retrained, and why most teachers just give up and call it \"weird.\"", "If I showed you a sound wave and asked you \"where is the sound at?\" What would you say? Is it where the biggest peak is? What if it's a pure tone and so there is no \"biggest peak\" and all of the peaks are evenly spaced? This is the conundrum. There are times when things act as though they are a wave where *everything* is all in one big spike/are (i.e. a particle) or times when things are so spread out over space that they act like a pure tone wave. Unfortunately, there isn't a great macroscopic analogue. What I can offer instead is this insight: everything and I mean *everything* is a wave. Everything. Waves are the fundamental building blocks of anything in the universe. What physicists have found time and time again is that sometimes those waves happen to smoosh into spikes or sort of areas where you could look at the wave's biggest peak and clearly say \"ah! there it is!\" and you'd have a particle!", "Think of it as like a bad X boy/girlfriend you can't stop thinking about. You broke up with them and separated yourself but a couple weeks later you're like dang I miss that person I better hit up them dm's, and so a couple hours later you're at their house and you're like Ohhhhhh yea this is why I broke up with this piece of trash....and repeat forever.....ok so enter light & #x200B; Now, imagine if you were magnetic energy and you couldn't Fu\\*kn stand electrical energy. It just repulsed you. The positive forces from magnets repel the positive forces from electricity and vice versa. So, when you have electric magnetic radiation (AKA light) what you really have is a piece of magnetic and electrical energy that happens to get real close, but as it gets close it does what, repel. As it repels that energy gets pushed further apart and as it gets pushed apart, it forgets why it even hates magnets or electric to begin with. No just joshing, in physics all things attract eachother. But since these magnetic electric forces are both positive lets say, they repel each other and get further away, then as the energy gets further apart, that repelling energy fades and the laws of physics predict (rightfully most times) that those two energies will be attracted to eachother and so they fall back towards eachother until they get close enough so that the positive energies begin repelling themselves. This is how light can go on forever creating a \"wave like\" motion where the magnetic force leaves the electric force only to be brought back together by other forces and it does this as it travels forming a wave instead of a straight line since the electric and magnetic energy is moving back and forth while traveling in some direction. The stronger the electromagnetic energy, the more they push away or repel eachother and the larger wave you have. These particles act \"more\" like waves where as the waves with teeny tiny wavelengths (little electicmagnetic repellence) behave more like particles because they don't repel so much and make less of a wave and more of a straight line when moving.", "What your referencing is an unusual example of the ‘observer effect’ and is essentially a bunch of scientists saying “i dunno why its doing that!”. When talking about quantum particles, we expect them to act a specific way. Specifically newtons laws of motion. “An object in motion tends to stay in motion until acted upon by another force”. So shoot a particle from a gun, we expect it to cruise forward until something changes that. If it collides with another particle, we expect it to bounce off, etc. Enter the ‘double-slit experiment’: So we grab a particle gun, fully automatic cus why not, we stand in front of a wall and place another wall in the way, we cut two slits in the wall in the way. When we start firing millions of rounds of particles at this wall, we expect that we will see a bunch hit the nearest wall, and what goes through the slits, will basically reflect the size and shape of the slits on the back wall. I mean, only the ones that went through the slits would hit the back wall right? They cant go through the wall thats in the way, to mark up the area we cant see through the slits, right? ([A visualization of what i mean.]( URL_1 ). If somethings standing in the way, the wall behind that something would not be hit right?) So in the case of the double-slit experiment what we actually saw was more a kin to what would happen if we used water instead of particle bullets. The water would be obstructed by the closest wall, and what funnels through the slits, would bend around the edges and expand outward from each slit. This is called diffraction ([double slit visualization]( URL_0 )). There are finer details then my analogy contains, but the takeaway is; the simple act of setting up the walls to observe how our ‘particle bullets’ would behave, caused them to behave different then what we would expect. We have no explanation for this behavior, so we just say “because we observed it, it acted differently”. The crazy part is, if we change the slightest thing in this experiment, such as firing one particle bullet at a time, or attempting to determine what slit each bullet went through to get where it ended up, the more the results differ, even changing patterns, away from the diffraction patterns (hence, “the more detailed our observations, the more uncertain our results become”). Its theorized that even our consciousness, while firing our particle gun, would have some effect on the particles." ], "score": [ 27, 14, 8, 7, 3 ], "text_urls": [ [], [ "https://en.wikipedia.org/wiki/Quantum_field_theory" ], [], [], [ "https://upload.wikimedia.org/wikipedia/commons/a/a9/Doubleslit.gif", "https://slideplayer.com/16979955/97/images/slide_37.jpg" ] ] }

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{ "a_id": [ "h37h9pr", "h36z1v4" ], "text": [ "You're brokerage keeps track of what you own, much like your bank remembers how many dollars you have. The market maker who processes the trade has an identity, but in most cases, the brokerage is the recorded beneficiary of the trade. They buy and hold the stock on your behalf.", "In 99.99999% of stocks, the company doesn't. When you buy 1 share of apple, you're not buying it from apple but from another shareholder. When a company first trades on the stockarket called the Initial Public Offering, IPO, you're still not buying from the company, but rather from the bank that manages the IPO. The bank is the one that buys the shares from the company and sells to whoever wants to buy the IPO shares. The super rare exception is when company does a direct offering. Which Roblox recently did." ], "score": [ 11, 11 ], "text_urls": [ [], [] ] }

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{ "a_id": [ "h36z0bz", "h37n6fp" ], "text": [ "Carrots do, and they produce tiny black seeds. The flowers are pretty white or yellowish white in carrots. Same with parsley, parsnip and similar. Potatoes also have yellow flowers that can produce seeds.", "Potatoes have a small berry like a tiny green tomato (same family), but they are not edible. They contain more of the toxic chemicals potato tubers produce when they go green or get damaged. Carrots, turnips, radishes, beets, parsnips and sweet potatoes just produce small seed heads (usually at the end of small stalks) that aren't really fleshy like you think of fruit as being." ], "score": [ 13, 5 ], "text_urls": [ [], [] ] }

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{ "a_id": [ "h36z0na", "h36ykc7", "h372427" ], "text": [ "1. It is still within the therapeutic window. The minimum therapeutic dose of paracetamol is 10 mg / kg and is generally safe up to 150 mg / kg. So a starting dose of 1000 mg will be effective for anyone below 100kg, and you’re instructed by the doctor to take more if it doesn’t work, up to a maximum daily dose of 4000 mg (8 tablets of 500 mg). That covers all adults from 7 to 400 kg, which is all humans with maybe a handful of exceptions. 2. Non-linear scaling. The amount of paracetamol which can be processed by your kidneys does not scale 1:1 with body mass. Increasing the dosage to compensate for added body mass may lead to renal toxicity (ie kidney damage).", "Medication dose by weight it predicated by two things. Firstly how much of the drug will get into the blood stream and be effective. Secondly, how much the liver/kidneys can take before they risk damage. So 2 paracetamol is ok for most humans at most weights with normal livers/kidneys. Below a certain weight and your ganna need a lower dose and above a certain weight you might need more to be effective. Most common over the counter drugs have been tested at length for the best dosages that suit the majority of the population. More dangerous drugs such as chemo drugs are completely weight dependant down to the 0.1 of an lb of weight of patient.", "If I were to explain this to a 5 year-old, I would tell them that the medication dose is dependent on your weight and your organs ability to process the drugs. A 150kg person may be way bigger than a 80kg but their organs are a pretty similar size and can only handle a similar amount of a drug as the smaller person." ], "score": [ 34, 20, 19 ], "text_urls": [ [], [], [] ] }

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{ "a_id": [ "h36zn89" ], "text": [ "Because galaxies are very big, so even though they are distant they still appear very large. For example the Andromeda galaxy is 2 million light years away, yet it appears much larger than the full moon in our sky when revealed with long exposure photography. When it comes to imaging distant planets outside the solar system, we really can't. We can detect some (think in the 10s) exoplanets by directly imaging them but they appear just as points of light with no detail." ], "score": [ 7 ], "text_urls": [ [] ] }

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{ "a_id": [ "h37d627" ], "text": [ "The government passes a law that says they're the only people allowed to create the currency. They probably also pass a law that says all bank accounts and mortgages and outstanding loans, that are held in/by that country's banks, automatically get converted to the new currency at a specified date/time. They print a lot of the new currency notes and mint coins, and get them distributed to banks ahead of the agreed switchover date/time. From the agreed switchover date/time, banks and ATMs stop giving out the old currency and give out the new currency instead. Banks will still accept the old currency, at least for a while, but will automatically convert it to the new currency when you deposit it. The government also passes a law that says from the swithchover date/time, workers get their salary paid in the new currency. Shops probably continue to accept both old and new currency for a short while, but give change in the new currency. The shops will convert the old currency to the new currency at their banks; in turn the banks convert it at the (government-run) central bank. The measures above mean that the amount of the old currency circulating will drop rapidly. Everyone will switch to the new currency." ], "score": [ 6 ], "text_urls": [ [] ] }

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{ "a_id": [ "h37ek58", "h37h136" ], "text": [ "it also helps you feel full faster and helps avoid over eating :) the stomach only has one sensor, which is \"im big now stop eating\" so it will respond to it whether it's liquids or solids that you're eating. Drinking a small amount of water throughout the meal will make you feel fuller so you can eat smaller portions, which is a great first step in weight loss!", "I drink something with flavor during my meal, usually a drink that contrasts what im eating so the flavor never dulls. So if im eating something super savory ill have a sweet drink like juice or gatorade and if im eating something sweet ill have a neutral drink like unsweetened iced tea. Then i drink a lot of water after i eat because your body uses the water to digest food. My absolute fav thing is to have a clear soup at the end of my meal." ], "score": [ 57, 4 ], "text_urls": [ [], [] ] }

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{ "a_id": [ "h376n3p", "h376zkn", "h38neft", "h38o0gq", "h377nfi" ], "text": [ "Yes, they go into a form of sleep. The animal's body temperature, heartbeat, and metabolism are reduced, this is why they store fat by feeding heavily to see them through the winter. A similar process, done by animals in hot climates trying to escape droughts or extreme heat is called aestivation.", "Hibernation is when the body essentially puts itself in a coma. Everything slows down including their metabolism, heartbeat, their breathe rate, and even their body temperature lowers so they don't consume energy to heat themselves up. To prevent themselves from dying, the body burns its fat reserves for energy so they don't die of starvation and hyopthermia.", "Okay but I want to know, poop and pee? Do they just go in their sleep? How do hibernating animals retain the necessary fluids the whole time?", "But what keep them from pissing and shitting themselves? Surely the body accumulates waste products.", "They eat a lot before going to hibernation. Animal bodies have two types of Fats, White Fat and Brown Fat. White fat is what makes you obese and is harmful, Brown fat is healthy and it breaks down to give energy. So animals eat a lot and store everything as Brown fat in their body(because their body's metabolism allows it) and then go to hibernation which basically the stage where the body is in a Coma stage where the autonomous functions such as nerves and circulation works and everything is slowed down to almost zero. The energy created from burning of fat keeps the body warm and their heart rate just is slow enough to keep them alive. As this is so risky and complicated only smaller animals are able to do it for a longer time. Bigger animals body is large so they can not store enough fat to keep them alive and warm for a longer time so they go for shorter hibernation. And the Awakening is triggered by temperature change. Body responds to change in temperature. The lack of oxygen is not effective enough because every metabolism is almost switched off and body is dead silent. And fat burning keeps the body warm insulates too. Nature is weird and skilled, they could have build houses and thermostats if their predecessor were apes too." ], "score": [ 38, 10, 8, 5, 3 ], "text_urls": [ [], [], [], [], [] ] }

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{ "a_id": [ "h378xyi", "h37a8n9" ], "text": [ "By moving forward really fast. The forwards movement and the shape of the wings has two effects: 1. The air travels faster over the top of the wing which, in accordance with Bernoulli's principle, causes a lower pressure over the wing. This pushes the wing upwards. 2. The wing is angled so that it pushes air downwards which, in accordance with Newton's third law, causes the wing to be pushed up. Exactly how large a role each of these factors play is still a topic of debate.", "Air is a fluid, so like water you can push it together into a very thick pocket, like water in a cup. You can also spread it out very thin, like when you blow water out of your mouth into a mist. Air also likes to rise up and move. If you push a lot of air together, it will move everything else around it trying to escape into any direction. Wind is a very big example of this. So, the shape of a wing cuts through the air in a way that more air gets pushed under the wing, than on top of it. When there is way more thick air under the wing than over it, it pushes the wing up, like how a piece of thin wood floats on top of water. That causes lift, and if you adjust the angle of the wings right with enough speed, you can use that lift to fly up into the air. ✨✨✨✨✨✨✨ Fun fact, there are pockets of thin and thicker air hanging in the sky, so sometimes when you fly through them, you will rise or fall in the air a little bit. Fun fact extra, there are high speed ultra-light sail boats that can rise up out of the water using similar techniques as planes, but still in the water. The lift generated involves the same fluif physics as air flight: thicker water pushes the foil up and into the thinner air" ], "score": [ 12, 9 ], "text_urls": [ [], [] ] }

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{ "a_id": [ "h37bkov" ], "text": [ "It's fatigue. At a certain point when lifting weights your muscles will be fatigued from either lifting weights again and again and again or you'll lift something that's just on the cusp of your ability to lift. At this point your muscles will start to fail. They'll contract and then stop contracting and then contract again. This causes shaking as when they stop contracting they're not working." ], "score": [ 20 ], "text_urls": [ [] ] }

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{ "a_id": [ "h37gwkf", "h37z0h7" ], "text": [ "ELI5 answer. The hardware actually does physically change. When a picture is saved to memory, the phone does a \"write\" command to the drive. This means the data for picture is physically written on the drive. It no longer needs electricity to maintain the data.", "Imagine that you have an row of switches [like this one]( URL_0 ), that you can turn on or off, and to \"write\" information, you put them in different positions. Those switches need energy (your fingers) only when you want to change them, but if there's no energy they get stuck in their state. At the lower level, the methods of storing data you mentioned need energy to change their state (i.e. writing), but not to keep it, being a disc that is magnetized at different parts (as in a typical HDD), a chemical dye that is heated to change its shape (as in a CD-RW), or little \"switches\" (as in a flash drive)." ], "score": [ 10, 3 ], "text_urls": [ [], [ "https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSnYaNe0JTAf7vBYc0xr_v9639nr3eBvVStffCfdURBeYdbuj2H5YTWYuvcg2xsElw1gPM&usqp=CAU" ] ] }

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{ "a_id": [ "h37hzdk", "h37i167" ], "text": [ "Physics. Conservation of energy. All the methods you described would take more energy than they would produce", "Where would that energy come from? With a turbine, the additional drag would consume more energy than the turbine could generate" ], "score": [ 9, 5 ], "text_urls": [ [], [] ] }

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{ "a_id": [ "h37mmev", "h37me8m", "h37pims" ], "text": [ "Composting results in a lot of chemical reactions going on. These reactions result in a lot of heat being generated. That said, that's usually not smoke. It's steam. While compost piles do get hot they are (supposed to be) really moist. It's certainly possible for that to be smoke, and a compost pile can ignite, but that's rare and means something has gone wrong.", "Compost is actively decomposing thanks to the bacteria and fungi inside it, which generate a lot of heat. That heat can build up, pushing water out and eventually get something within the pile to smolder and eventually burn.", "This also happens to hay barns if the hay isn’t dried out properly before being stored and once that goes it’s gone in a flash" ], "score": [ 16, 5, 3 ], "text_urls": [ [], [], [] ] }

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{ "a_id": [ "h37p5bm", "h380g1g", "h37ml7k" ], "text": [ "As a developer, I can tell you that a web app is not always a good idea, and even a stupid one as even the weakest computer can handle many thing. You don't need Internet for a calculator for exemple", "There are two key reasons. Reason 1 is history: web browsers are newer than many applications, meaning that those applications would have to run \"natively\" (I.E. not in a web browser). Reason 2, is that web applications are not the most efficient, and don't necessarily have access to every feature the hardware provides. And for something like a video game, you'd want every bit of performance and efficiency you can get. Or, for a system app, you wouldn't want to rely on having a full web browser available. I will also note, that many applications are just webpages bundled with a browser. The most common one is Electron, which is just chromium.", "Initially, with iOS, that’s how Steve Jobs envisioned it. But there are different issues that arise from this. One being you’d need constant access to the internet for web apps. Secondly, they honestly wouldn’t look as appealing. ChromeOS runs web based apps, and there are severe limitations with that OS because of it." ], "score": [ 11, 8, 6 ], "text_urls": [ [], [], [] ] }

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{ "a_id": [ "h37n4eb" ], "text": [ "They sweat the same but the socks help absorb the sweat, disperse it across the sock and evaporate quicker because they have a lot of breathable holes for the air to get through. Shoes aren't made to absorb the sweat so much, especially the sole which is normally a rubber and pvc so really doesn't want to absorb" ], "score": [ 251 ], "text_urls": [ [] ] }

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{ "a_id": [ "h37ntsr", "h37wrjj", "h37ort1", "h38lt6i", "h37o2ps", "h3839rw" ], "text": [ "They wait with high-tech zoom cameras under a tarp for days at a time to avoid being detected by animals.", "I have not seen this mentioned yet but, depending on the size of the animals, they sometimes recreate the animal’s environment in a controlled setting which makes it easier for them to control environmental variables for shooting. I’ve seen this done sometimes with insects and aquatic animals.", "They are much farther away than they appear to be. They have really good camera lenses that let them do that.", "They also often stitch together shots from different days, locations and even animals to get the final sequence", "They use long range lenses known as teleobjectives, which are essentially like telescopes mounted on cameras. That way camera dudes can stay at a safe distance from let's say a lion and still capture all the action.", "National Geographic did an interview with the guy that makes cameras for these things. Really cool how they go about assembling off the shelf items into something that animals can be comfortable with. URL_0" ], "score": [ 32, 10, 9, 5, 5, 4 ], "text_urls": [ [], [], [], [], [], [ "https://www.nationalgeographic.com/podcasts/article/episode-6-real-life-macgyver-in-nat-geos-basement" ] ] }

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{ "a_id": [ "h37u8km" ], "text": [ "The yellow-white stuff is known as a \"fibrin membrane\". Fibrin is a blood protein that aids in scab formation, and it will ooze out of shallow wounds easier than red blood cells. Have you ever seen certain road rashes heal? The countless scratches can be big enough to let fibrin flow, but too small to let much whole blood out, resulting in yellow-white scabs." ], "score": [ 3022 ], "text_urls": [ [] ] }

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{ "a_id": [ "h3803zu" ], "text": [ "It's the dollar amount a company pays to buy another company above the book value of the company they are buying. Book value being the dollar value of the assets when the asset was purchased. So things like reputation, logo, client base all add to the value of a company you're buying. But the company you're buying doesn't have this on their balance sheet so you can't add it to yours. In order for your balance sheet to balance, you can't spend money without showing where you spent it. So the placeholder (Goodwill) for this value was created. And the rest of the company you bought goes under the other asset categories like property, buildings, cash, etc." ], "score": [ 5 ], "text_urls": [ [] ] }

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{ "a_id": [ "h37xuk5", "h37sryj", "h37xtdp", "h383u5u", "h37yd05", "h38v6jo", "h38uy1d" ], "text": [ "Everything is either soluble in oil/fat or water. Soap works by consisting of two-ended molecules: one end likes water, the other likes fat. When washing grease off with soapy water, the soap molecules will stick to the grease with their fatty ends, leaving the watery end outside. Voila, now the grease is water-soluble. For viruses such as Corona, soap can even destroy the lipid (fatty) virus shells. It does that by offering stronger, more efficient bonds that the virus shell molecules will like to bind with even more than they like to be bound to the rest of the virus. (In expert's terms, it's because the virus is held together with weak non-covalent bonds, which is kind of like magnets sticking together. Bring a stronger magnet into the game, and you win the game of attraction.)", "Nope, it works by bonding with both water and oil molecules, allowing you to more easily rinse away the oils that germs were sticking to your body with.", "Soap basically destroys or breaks down the cell membrane of bacteria and into small bits that can be washed away. That’s why you need to get your hands soapy for a few seconds before rinsing. AFAIK, hand sanitizer does the same thing using alcohol", "Each soap molecule is like a string with a knot at one end. The string is “oily” (non-polar) and the somewhat polar H-O-H water molecules are not attracted anywhere near as much as the stringy parts are attracted a) to each other and b) to molecules of grease (also non-polar, like attracts like). Meanwhile the “knots” at the ends are polar (hold an electric charge separation) and that makes the ends attractive to water. That attraction is called hydrogen bonding and it is a big part of why life exists on our watery world. . In water, a group of soap molecules self assemble into spheres called micelles. The knotty ends all point outward toward the surrounding water and the oily strings form a gooey center. These micelles soak up bits of grease from the surroundings where oil and water don’t mix (an oily sheen on the surface is a layer of oils preferring their own kind) while the micelles are perfectly happy to disperse throughout the water. So soap is a great way to break up grease, soak it up, make it soluble (dissolvable), and able to be rinsed down the drain.", "Soap forms bonds with stuff on a microscopic level and then sloughs off with water. (Shampoo does too but is the opposite charge to soap. Source: my highschool chemistry teacher) It kills microrganisms by bonding with atoms in their cell wall, breaking them apart, similar to hand sanitizer. But it also removes detritus that isn't microrganisms.", "Your skin is a cliff. The germs are Mufasa. The soap is Scar. The water is the Wildebeasts. Sometimes the soap is Scar-debeasts. If you have no idea what I'm talking about, go watch the original Lion King.", "Soap is good at holding hands with gross stuff, but it also holds hands with water. Water usually isn't all that social, and doesn't like holding hands. So when the soap holds hands with both the water and with the gross stuff, the gross stuff gets pulled away when the water leaves, and goes down the drain with it. Some of the gross stuff ends up on your hand towel too, because not all of the water leaves, until you dry off." ], "score": [ 1249, 165, 12, 8, 6, 4, 3 ], "text_urls": [ [], [], [], [], [], [], [] ] }

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{ "a_id": [ "h37yg59" ], "text": [ "\"Glia\" is a term which comprises different non-nerve cells in the nervous system. The most prominent are astrocytes, which serve a variety of functions, including maintaining blood-brain barrier, disposal of waste products, providing neurons with nutrients, etc... Another one is the microglial cell, which play a part in phagocytosis (uptake/engulfing of foreign matter or micro-organisms in the immune response). Other import ones are Schwann cells, which produce myelin for the peripheral nervous system, which increases transmission speed of the nervous impulse. For the central nervous system, the glial cell is the oligodendrocyte. Ependymal cells are the glia which line the brain's and spinal cord's ventricles (fluid filled cavities). Apparently this is a new avenue of research, but recently researchers are investigating a potential glial, rather than neural, origin in Alzheimer." ], "score": [ 3 ], "text_urls": [ [] ] }

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{ "a_id": [ "h37uhl7", "h393mme" ], "text": [ "In theory both eyes could be moved and focused independently from one another. But our eyes and brain have evolved to give us depth perception, which relies on both eyes working together. So our brains dont know how to work them independently. I believe chameleons have that ability.", "It is not that our eyes cannot focus on more than one thing, they can. It is that only so much of that stimulus can be brought to your conscious perception. Most of what you perceive has cut corners. There is no way for your mind to analyze process and create a perception of the environment that's accurate. So, your mind gives you a conscious to focus on just few things meanwhile, your subconscious is processing more of the environment than you are even aware of . For one, its not evolutionary advantageous to see reality but instead it does our species better if we see what we need to see. Hear what we need to hear etc. Your mind is creating one perception for you. Focusing on different things would likely require multiple conscious perceptions of the same reality to be useful and is too much for the way our brain is set up. Our conscious is already fragile and requires a lot of brain regions cooperation so it would be difficult to create or link two different made up perceptions fo the same reality together." ], "score": [ 4, 3 ], "text_urls": [ [], [] ] }

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{ "a_id": [ "h37wzvt", "h3a4f5m" ], "text": [ "A perfect mirror reflects 100% of all light. But nothing is a perfect mirror. Some seem green because the glass used in them absorbs the color the least, so more green comes back to you than the other colors. Silver, grey and white are both not actually colors as wavelengths of light. They are the perceived combination of all visible wavelengths. So in theory they are just different kinds of all colors being reflected equally. Specific names are then probably down to impurities. So some greys are warmer bc they have more red in them. Silver differs from grey and white not only in the specific impurities but also it refers to the object being shiny. So tldr : a perfect mirror would have no color for itsself but everything absorbs at least a little bit of some wavelengths, giving it a light touch of colour.", "When light interacts with a material, there are two behaviours: whether the light is reflected or absorbed, and whether the reflection is specular or diffuse. An object that reflects all wavelengths of visible light is white. One that absorbs all is black. In between those extremes are shades of grey, if the wavelengths are evenly reflected. If the wavelengths are unevenly reflected, then you get the various shades of red, green, blue, yellow, purple etc. Specular means the light reflects at the exact opposing angle it hit. Diffuse means it goes in an effectively random direction. Specular is what gives a \"glossy\", \"shiny\" or \"mirror\" quality to a surface. Diffuse is what gives a \"matte\" quality, and allows the various wavelengths of light to mix into what you perceive as a colour. A mirror is *mostly* white, meaning it will reflect all wavelengths equally. It is also *mostly* specular, meaning the image is directly reflected. Those leftover bits that aren't covered by the \"mostly\" are why a mirror appears grey. No material is perfect. Some light is absorbed, so it's slightly grey instead perfectly of white. The surface is slightly diffuse, so you can perceive that grey instead of a perfect reflection. There's nothing special about the colour grey, but you want a mirror to have that colour because it means the mirror isn't adding a colour tint to the reflected image." ], "score": [ 27, 4 ], "text_urls": [ [], [] ] }

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{ "a_id": [ "h37xrok", "h37xu24", "h385vv0", "h37y5dt" ], "text": [ "Public companies are listed on the stock market, and raise money from the sale of stocks to the public. Private companies do not. There's more to it, having stockholders adds a set of rules to the company.", "When you start selling shares of your company of the stock market. Basically they are carving up the company ownership into pieces, keeping (for example) 51% of it and selling the rest to make money.", "That when they first offered shares of stock that anybody could buy. Prior to that, shares were held only by founders, investors, employees. In an IPO (initial public offering) brokerage firms help sell shares to customers and then once the shares are placed and trading begins on a stock exchange (like NYSE or NASDAQ) then anybody with a brokerage account can buy shares.", "A publicly-held company is one that makes shares of its stock available to the general public, so that anyone can buy them. A privately-held company also has shares, but they are only offered to the specific buyers that the company wants to offer them to. Many privately-held companies only offer shares to their original owners and a select few executives or board members. When a privately-held company goes public, it simply means they have decided to begin offering their shares to the general public." ], "score": [ 4, 3, 3, 3 ], "text_urls": [ [], [], [], [] ] }

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{ "a_id": [ "h38dcik" ], "text": [ "Hard to ELI**5** SERS, so this is more like ELI**undergrad**: You can, to a rough approximation, think of a molecule as being a bunch of little masses (the atoms) attached to each other by little springs (the bonds). Just like collections of masses on springs, molecules have lots of different ways they can vibrate and what, exactly, those “vibrational modes” are is very dependent on what the masses and springs are and how they are connected to each other. Raman spectroscopy uses the inelastic scattering of light off molecules to tell us about how they vibrate. As the specific vibrational modes are highly dependent on the structure of the molecule, Raman spectroscopy can very quickly give us a lot of information about its structure! Surface-enhanced Raman spectroscopy (SERS) first places our molecules of interest onto a surface of some sort (usually a metal or silica). The surface will either absorb energy from other modes (say, fluorescence) and/or enhance the response from Raman. This means that a weak Raman signal can be radically enhanced, while potentially interfering (and less informative) fluorescent (et al) signals are suppressed. Putting the molecule on a surface can also change how it vibrates a bit, so you have to be aware that the SERS spectrum usually isn’t *exactly* like the free Raman spectrum. There’s also SM-SERS, in which the Raman signal is so enhanced that a spectrum can be obtained from a *single molecule* (“SM”). This is usually accomplished by putting the molecule between two metal nanoparticles that act kind of like antennas for the signal and alter the local electromagnetic properties around the molecule." ], "score": [ 6 ], "text_urls": [ [] ] }

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{ "a_id": [ "h37zvvn", "h380nlu" ], "text": [ "Different stock indexes pick different stocks to include in their average. The S & P500 uses five hundred different companies which the DOW uses just thirty. The actual companies in each changes depending on a number of factors.", "The nasdaq is where companies list. Its a competitor to the new york stock exchange The dow and the s & p 500 are lists of the biggest stocks. They can include stocks from any exchanges in the us (not sure about internationally)." ], "score": [ 4, 3 ], "text_urls": [ [], [] ] }

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{ "a_id": [ "h38ckhv", "h38cqji", "h38brrq" ], "text": [ "There is one dominant male per pride at a time. But there can be other males that are able to mate even though they are not dominant. Especially in larger prides this happens quite a bit. The males also move between the prides so the dominant male is probably not related to any of the females. And it is hard work being dominant so the males tends to be forced out of the pride by younger males fairly often. So there is actually quite a bit of genetic variation.", "It's complicated, since males go off and attempt forming their own pride, and young females may choose to join. Wildlife biologists have a word for when a herd or group reaches a point that it separates into smaller herds/groups. Usually it is due to reproduction, as younger adults members leave to avoid the older dominant reproducing members. There is also young members meeting groups and challenging the older members for leadership. The combination of behaviors causes social species. It's similar to farmers having to select roosters, bulls, and other male animals for breeding, while the female animals are kept for milk and eggs. How many farmers keep the gene pool healthy? If the meat isn't kept healthy, food safety is affected.", "Because this one lion is constantly challenged by other males and eventually killed or driven away. The new male kills the pups most ov the time so he can breed the cats as soon as possible." ], "score": [ 8, 6, 4 ], "text_urls": [ [], [], [] ] }

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{ "a_id": [ "h38uzof", "h38znhr", "h3901d5", "h38zv8a" ], "text": [ "The moon exerts a gravitational force as you’ve noted, and the tides move as a result of (rotational) kinetic energy, kinetic energy and gravitational potential energy are direct equivalents, so the potential energy of Earth’s total ocean mass under a gravitational influence is equal to its maximum kinetic energy, energy is entirely conserved in this system, in other words the amount of kinetic energy a body can experience is entirely dependent on the force of gravity acting on it, as for harvesting energy, only a very small fraction of a fraction of that kinetic energy is transformed into electricity, so the energy loss in the entire system is negligible", "The energy comes from kinetic energy in the earth's rotation. A day 600 million years ago was 21 hours long. The current slowdown is that a day gets shorter by 1.7 milliseconds per century, so it is not a lot on the time scale we are used to but a lot on earth's geological time scale. The same has occurred for the moon but faster because it is smaller then earth. The moon has slowed down so only one side point to earth. That mean the orbital time is the same as the rotational time. This is called today locking and why we can only see one side of the moon. If left undisturbed earth would become today locked with the moon. It would take around 50 billion years and the rotation time for earth would be 47 current days. The problem is that our sun will expand to a red giant in roughly 5 billion years. It will expand and might swallow the earth and the moon, Venus will certainly be swallowed. So if the earth and the moon survive the surfaces will have been remelted and the lightest molecule like water would be below away, So the earth will no longer support life.", "The energy comes from the rotational movement of the earth. This causes the earths rotation to slow, the length of a day increases by about 1.7 milliseconds per century.", "The ultimate energy source is the kinetic energy of the Earth’s spin. Harvesting tidal energy will in fact cause the Earth to turn slower. But not enough to worry about." ], "score": [ 6, 4, 3, 3 ], "text_urls": [ [], [], [], [] ] }

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{ "a_id": [ "h38zfll", "h38z0g0", "h39fgu7", "h39pvl5", "h390ghy", "h39mevo", "h39bi7b", "h395zo2" ], "text": [ "Ok, we have to clarify a few things first. Your body maintains constant temperature, because it's important for your internals. Even if it's a hotter day, your body still tries to more or less keep this proper temperature, that's why it's important to drink a lot, because we need it to cool ourselves. If your body isn't able to cool efficiently enough - you won't feel well and can even end up in hospital. The second thing - it's not that an increase in body temperature makes you ill, it's the other way round. If you contract a disease, your organism rises the internal temperature to mobilize the immune systems to fight, all effort goes into fighting a virus/bacteria and that's why you can feel tired. Of course fever can be dangerous itself if it gets too high (more than 40 C).", "they are just two different things. in a fever, your body is purposely increasing its temperature as an immune system response to attempt to kill off germs that it has detected in your body. on hotter days, the heat it externally generated and your body works to maintain its normal core temp by sweating.", "Just because it's a different termperature outside, doesn't mean its different inside. Your inside temperature is relatively constant, no matter what the outside temperature is, thanks to tens of different mechanisms your body has to either increase temperature production, or decrease it, to compensate for outside temperature. So, if the outside temperature is too warm, the body will start sweating and reduce temperature production, among other things, all of which will make it not heat up. These compensatory mechanisms work both ways. In addition to that, your outside is actually pretty-well insulated. You have clothes, that from closed packets of air, that act as an insulator from the outside environment. Even when you're naked, the air around your body is no the same as air 2 meters from it. The air closer to you will have temperature closer to your body, as opposed to air far away from you, which will have the temperature of an actual environment. This forms another layer of insulation - a layer which is broken when you move, or air moves - which is why a fan blowing air of 28 degrees will feel cooler than if you sit at 24 degrees, without air movement, since the fan will destroy that insulated layer, such that your 37 degree body will always be in contact with 28 degree air, as opposed to if the air didn't move, and it would just be the same air, already warmed up by your body (which would mean your 37 degree body contact 37 degree air) All of the above mechanisms ensure your inside temperature is constant, despite the flactuations in the environment. When your body temperature rises, that's a whole different process. And it's destructive for many, many reasons, too long to write here. So what you really should understand is, that despite fluctuations in outside temperature, mechanism are in place to ensure your body temperature stays the same. When you have a fever, your body temperature actually changes", "Okay, so here is my ELI5: Your body has a thermostat, just like your home does. It is pretty reliable, plus or minus a degree (actually less). Sometimes your body turns that thermostat up because it needs to fight off attackers. But most of the time, it's just chilling at about 36-37°C. Just like your thermostat, it's not just checking the temperature, it's affecting other things. In fact, your thermostat in your house is connected to two or three devices. Your body's thermostat is connected to way more than that. It can move blood towards or away from the core. Away from the core causes more heat to be given off. Towards the core conserves heat. It can increase metabolism. Metabolism increases temperature. This is what shivering is. A way to increase metabolism through muscle movements that increases body temperature. You also have some more active ways to increase temperature. You will often unknowingly do things like rub your hands together. You will close your arms around your body. You will move your feet. There are some animals that even have \"brown fat\" which are little heaters throughout the fat that keep them warm even when their metabolism of their whole body is really, really low (like hibernation). The body also has air conditioning. This is what sweat is. You can sweat a lot, and not realize it. Evaporating water is a great method of getting rid of heat, like AC. In fact, it kinda works in a very similar process. Those are the main ones. I'm sure I've missed some.", "> Why does a small increase in body temperature of 1degree put us into a fever state while we can adapt to higher temperatures on hotter days? Your body maintains the same constant core temperature, regardless of the environmental temperatures. It will do anything to achieve this, cutting off blood circulation to extremities in cold environments and sweating profusely in warm environments.", "It’s like no one in this sub has ever met a 5 year old. Your body is very happy when it’s the right temperature. It’s so happy, that it has special powers to make it stay at that temperature all the time, even when it’s hot or cold outside. But sometimes, when there are germs invading, your body has some special knights who get called in to help beat the germs, but they like the heat so for them were willing to turn up the temperature to make them happy so they work harder until they defeat the bad guys and you’re healthy again.", "Alternate question, how does raising the body's temperature help develop the immune response?", "Fever is your body trying to “cook” the germs, the same way we cook food to make it safe to eat. Sometimes though your body cranks the heat all the way up and burns itself along with the germs." ], "score": [ 2823, 75, 20, 11, 8, 7, 6, 4 ], "text_urls": [ [], [], [], [], [], [], [], [] ] }

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{ "a_id": [ "h391zmj" ], "text": [ "The effect of fluoride on teeth was first discovered by observation. Some places have trace amounts of fluoride in their natural water sources, and those trace amounts both (a) prevent tooth decay and (b) create small visible stains that were interesting enough to investigate. Eventually, it was discovered that the two were both linked to fluroide, and the rest is history." ], "score": [ 4 ], "text_urls": [ [] ] }

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{ "a_id": [ "h399wfz", "h3994lk", "h398z6i" ], "text": [ "Trust me, corporations and government agencies *do* frown on them. A *lot.* (Along people who kiss the asses of said corporations and government agencies.) But they're utterly powerless to do anything about it. Doesn't stop them from trying, though. YouTube automatically deletes any comments from someone using a VPN. CAPTCHAs get a lot more touchy when they're in use. Streaming services try to block VPN users, though they aren't always successful. But the same things that scare these people are the very reasons why VPNs are so important.", "They're countered equally easily if the service provider wants to. VPNs are inherently centralized, so building an index of VPN servers and blocking their IPs isn't hard. The key is understanding who these limitations originate from, and often it's not the content provider themselves. Therefore, they don't care about people circumventing a ban if it doesn't affect them. Example: A US website does not confirm to EU's GDPR, and therefore is geo-blocked in EU countries. Provider doesn't care about Europeans accessing the site via VPN, since the provider doesn't break the law by serving non-conforming content in the EU. From their view, it goes to an American server and from there on, it's not their business.", "Well, there are a few reasons I believe. The law generally takes a while to catch up. The technology advances at a rapid pace, and it takes years for the companies to gather their lawyers, go to a court and fight something this big. Imagine making a case against VPNs for bypassing netflix, for example. Another thing is that it is generally faster and easier for these corporations (Like netflix) to take the matter in their own hands. As far as I know there is a game of cat and mouse when it comes to VPNs and Netflix. They create algorithms that detect VPNs, and the VPN companies bypass them. So basically, I believe there is not much they can do." ], "score": [ 14, 10, 3 ], "text_urls": [ [], [], [] ] }

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{ "a_id": [ "h39asfc", "h39b9bj", "h39b1lw" ], "text": [ "Pretty simple, there are no financial incentives to improve the systems and no financial risks to not improving the systems.", "Scam and span calls have nothing to do with security Thats like saying roads are insecure because criminals use them.", "The ability to phone your number from anywhere is the whole point of phone networks, of course this means that if someone with malicious intent gets your phone number they can spam you, just like with email, it’s not a matter of security of the system, it’s just what you use it for You can’t simply ban spam calls, it’s just any other call for the phone company, and if they banned number after receiving complaints, the scammers will just get a new number" ], "score": [ 6, 5, 4 ], "text_urls": [ [], [], [] ] }

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{ "a_id": [ "h39b7ln", "h3a0he7" ], "text": [ "Surface area! When water is in the glass, it has limited exposure to the cold air. But when you pour it, the surface area is expanded exponentially and it can lose temperature much faster.", "Ice needs a starting point to form. Think of an ice crystal as a maze with you have to draw a line through in order to complete it. If you haven't found the place to start the line in the maze then there's no way for it to freeze. Contamination in water is where freezing first starts when forming ice crystals. In pure enough water there aren't any of these starting points. When you throw water into the air it becomes less dense and there is the Jacob more opportunities for ice crystals to form. Water below the freezing temperature of 32 degrees is called supercooled. Supercooling of water is possible because water needs a small nucleus or seed of ice for the molecules to form crystals and in very pure water “the only way you can form a nucleus is by spontaneously changing the structure of the liquid." ], "score": [ 14, 3 ], "text_urls": [ [], [] ] }

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{ "a_id": [ "h39f6i5", "h39njx0" ], "text": [ "An unfortunate side effect of death is loss of ability to control your body, including actions which were seemingly effortless in the past, such as closing your eyes.", "You use two muscles to move your eyelid- one to open and one to close. When these muscles are active, the neutral state is somewhere in between, where your eye is partially open. That’s why eyes are typically found partially open when a person dies. For the eye to be closed completely, one of the muscles would need to be active to pull it shut." ], "score": [ 22, 3 ], "text_urls": [ [], [] ] }

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{ "a_id": [ "h39hwun" ], "text": [ "A cyst refers to all sorts of things that are formed in different ways for different reasons. Most commonly due to a blockage. Dirt inside you gets trapped and your body covers it with white blood cells, that die and form pus." ], "score": [ 3 ], "text_urls": [ [] ] }

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{ "a_id": [ "h3a5xcl", "h39pbgm", "h39py88", "h39msny", "h39mb4q", "h39siy4" ], "text": [ "Gold is the key one here. Why is gold valuable? Three factors come together: it's pretty, which drives demand for jewelry, etc. It's scarce but not _too_ scarce : demand can easily outpace supply, but there's enough for everyone to know what it is and for it to have cultural significance. It's inert: it doesn't rot or rust, and it can be melted down and reformed over and over again. You can bury it in the ground and dig it up 1000 years later and it will still look the same. All these things come together to explain why gold has been valued as a method for storing wealth for ages. It starts out with people digging up and refining gold in the early days of metalworking, and valuing it for its beauty. But it's rare, so it's extra valuable because more people want it than can get it. This just puts it on part with a huge amount of rare-but-valuable luxury goods that people have valued down through the ages. But because gold doesn't rust away or rot, it's just really convenient as a store of wealth. If you have some gold you can be sure when you come back to it it's still all going to be gold, even if you chucked it in a hole in the ground, even if it got wet, even if it got dropped or otherwise mistreated. There's not a lot of things that work that way. Try to store your iron coins and you may come back to a lump of rust, that's not happening with gold. Another really handy thing about gold is that you can melt and cut and recombine it without losing value. The mass of gold has the same innate value no matter what shape it's in. Gemstones in general are in a similar position as gold...they are relatively rare, pretty, and relatively inert. That gives them some of the same value. But gemstones (and diamonds in particular) are subject to more trends in fashion and supply changes (and monopolies) and they are also not as infinitely dividable and recombinable as gold. They are more of just your standard luxury good that people value because it's rare and pretty. ''' Now as for why we don't put value on useful things: We do put a lot of value on things that are useful...there are a number of metals that are more valuable than gold and have some niche industrial use. But things that are useful tend to not be as good for _stores_ of wealth. For one thing, useful things tend to be too common to make a good store of wealth. You don't build an industry around a super rare material unless you have no other choice. More importantly though, the value of a useful thing depends on how useful it is, and that's variable. Maybe someone finds a new way to make a widget without your expensive material, and the value plummets because that was most of the demand. Maybe widgets just get replaced by some new technology. The value of your useful thing could plummet at any moment due to technological change. Gold, on the other hand, has a few thousand years of appeal to people, it's not likely to lose its demand due to some market shift", "A big part of the reason we put a high value on diamonds is because the DeBeers company a) advertises that diamonds are important and b) hoards piles of them to keep the supply low and the price high. This was one big reason why DeBeers opposed lab created diamonds so strongly - to the point of threatening researchers. If any appropriately stocked lab could crank out diamonds more perfect than the DeBeers diamonds, then DeBeers' vault of diamonds would be worthless.", "Gold is rare and unique. Gold is very useful to convey value. It is not abundant, it takes labor to extract it, it has intrinsic properties that make it hard or impossible to fake or destroy, and of course it looks good. What else could past societies use to track their wealth? You said something useful, so what would it be? Were they supposed to rely on sacks of grain? It's impractical. In the modern world we no longer need to rely on gold to convey value, and we don't. But it still retains its rarity, it's properties, and it's appeal.", "You can look into the historical reasons we value these things but more simply, humans aren’t drive entirely by logic and what’s absolutely the most prudent for survival. We have evolved and developed a society that allows many to live superfluously and values certain material items that don’t serve any practical purpose. We’re social creatures that have evolved to value prestige. It’s also worth mentioning that these things have a value backed by society. In fact, gold was what once gave the US dollar value. These things retain value well over long periods of time so it’s a reasonably good way to store wealth. That being said, there are tons of important uses for gold, diamond, sapphire, silver, etc. in science and medicine. But generally, the quantities needed here are relatively small compared what’s produced so they don’t have a big impact on the market.", "Useful in what way? Those things are valuable as a form of currency.", "Useful things break or wear out, value decreases rapidly. Gold diamonds glass beads etc last longer" ], "score": [ 38, 21, 19, 6, 3, 3 ], "text_urls": [ [], [], [], [], [], [] ] }

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{ "a_id": [ "h39nrxi" ], "text": [ "There's lots of details and particulars, but what it comes down to is that Nixon's people orchestrated a break in at an opposing political party's offices to gather intel and tried to make it look like a robbery. They were caught, and ultimately Nixon participated in the attempted cover up of the crime, using powers of the Oval Office to do so. So we had a sitting president's henchmen attacking political rivals through unambiguously illegal means, followed by strenuous public denials and using presidential powers to try to hide the crime. What led up to it was Nixon's serious and well-documented paranoia and his willingness (some say eagerness) to use unethical (and illegal) means (and some really bad guys) to harm his political opponents, and in fact, just about anyone who wasn't an enthusiastic Nixonite." ], "score": [ 6 ], "text_urls": [ [] ] }

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{ "a_id": [ "h39v10y" ], "text": [ "You're talking about [color temperature]( URL_0 ). If you look at the chart on that page, you'll see a range from fairy deep orange (1700K) to a bright light blue (15,000K+). The physics explanation is that if you have an object that literally gets that hot (1700 Kelvin is ~1425 Celsius or ~2600 Fahrenheit), it'll glow that color. Think about heating a chunk of iron until it's \"red-hot\", and then even hotter until it's \"white-hot\". When you're buying lightbulbs, there's nothing getting that hot - it's just a calibrated scale that manufacturers can use to describe what \"kind\" of white light you'll get. There's all sorts of psychological / mood factors that come into play. Usually, light that is a little more orange is going to feel warm, inviting, or calming - so you'll see lights in that end of the spectrum in hotels, for example. On the other hand, light on the bluer end of the scale is intense, focusing, energetic - perfect for schools or offices." ], "score": [ 4 ], "text_urls": [ [ "https://en.wikipedia.org/wiki/Color_temperature#Categorizing_different_lighting" ] ] }

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{ "a_id": [ "h39x9uq" ], "text": [ "Theres a lot to talk about here: 1- Yes it is true that the brain tissue itself is incapable of feeling pain. However, the tissues surrounding the brain; the meninges, do feel pain. 2- In ischemic strokes: i.e. strokes where there is lack of blood flow, pain isn't a symptom. I mean yes, you can have a feeling of pins and needles or numbness or a total lack of feeling in the affected members, but not pain. 3- there is one specific type of stroke that causes severe pain. The thalamus is a part of the brain that receives all the cognitive sensations in your body (pain, touch, vibrations, pressure, temperature) and relays all that info to specific parts of the brain to be interpreted. A stroke specifically in the thalamus screws up it's ability to properly relay that info and as a result you will feel intense pain triggered by the slightest of touch. 4- Hemorrhagic strokes caused by a berry aneurysm that has ruptured causes a severe headache. Sometimes known as a thunderclap headache. But the pain isn't happening in the brain; it's happening in the blood vessels around the brain and also caused by the inflamed meninges." ], "score": [ 6 ], "text_urls": [ [] ] }

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{ "a_id": [ "h39x386" ], "text": [ "Either they are driven into the soil by rain, covered with soil by wind, or the root can sprout downwards and grow into the soil. There is no rule that seeds must all start underground, the roots of the plant just need to end up in the ground (usually) and the plant needs to get established before it dries out, blows away, etc. Starting under the soil is a good way for the plant to get established before it dries out or blows away, which is why humans plant this way for best results. And some plants in some environments may require that. But for many plants, at least SOME seeds can grow wherever or however they fall. Most plants produce a large number of seeds because it’s not that reliable, though." ], "score": [ 5 ], "text_urls": [ [] ] }

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{ "a_id": [ "h3a12i8", "h3a2len" ], "text": [ "The gas doesn't leave the system and gasses disolve better in liquid at cold temperature. Hence why the fizz crack on a hot soda sounds airier and the drink is flatter", "Henry's Law essentially states that the amount gas above the liquid is proportional to the amount of gas dissolved. When it returns to a liquid, there's no where else for that gas to go. So even if the carbonation comes out of solution (undissolves) when the drink solidifies, it essentially HAS to go back into solution when the drink melts." ], "score": [ 10, 5 ], "text_urls": [ [], [] ] }

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{ "a_id": [ "h3ap6zz", "h3b07a0" ], "text": [ "It's complete BS. Small differences in the pH of your water do not make any difference whatsoever. It's just marketing to make it sound more healthy, when in reality any bottled water is more questionable than filtered tap water due to the plastic particles that seep from the bottle (provided that you live in an area with drinkable tap water)", "Chiming in having studied human physiology on Bachelor's level. What everyone says is true, it is total bullcrap. Your body maintains a REALLY steady pH by itself, keeping it around 7.35-7.45. Anything more or less is a sign of serious illness and potentially life-threatening. For this reason your body actively and passively buffers any attempts to fiddle with blood pH. If your blood's pH changes, you should seek immediate medical help, not drink some \"pH-adjusted\" water. Furthermore, if the water was basic enough to have considerable effect, it'd be life-threatening. Drink one bottle to reach \"optimum pH\"? Good. Drank 3 bottles bit too quickly on a hot day? Enjoy twitching on the ground due to alkalosis. If the water actually worked the way it claims, the bottle would have huge warning labels on it to avoid accidental injuries and/or death." ], "score": [ 13, 7 ], "text_urls": [ [], [] ] }

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{ "a_id": [ "h3a4eml", "h3a4h05", "h3aipyd" ], "text": [ "If solipsism is true, what can one do about it? How does the knowledge of its truth help us one bit? We still have to live and exist and function within this society and reality we find ourselves in, and even if none of it is real at all that in my mind it's real enough. Whether or not the world as we perceive it exists independently or not we cannot escape this perception except by death, so it's best to act as if the world is independent of our minds.", "Well, solipsism would basically be treating the world like a video game, nothing you do matters if nothing is real. The problem is that reality doesn't care whether you believe in it or not, you can't just load a prior save to avoid the consequences of your actions.", "I think the biggest flaw is that it’s unknowable. Subscribing to a solipsistic philosophy requires a certain disregard for how we as individuals can negatively impact the world around us. If solipsism is true, then that’s fine - it doesn’t really matter if we hurt the planet or other people because none of it is “real.” However, since there’s no way to *know* that it’s true, there is a chance that the solipsistic person is causing real damage to a real world with real people in it." ], "score": [ 8, 4, 3 ], "text_urls": [ [], [], [] ] }

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{ "a_id": [ "h3a5zxv", "h3a5xh8" ], "text": [ "The soil! You know how charcoal and sand act as water filters? Basically, the soil around the water plays a large part. This is why lots of northern lakes are very clear, most of the soil is sand and other debris. As the lake water filters in and out of the soil, it leaves behind many of the contaminants that make the water appear murky. This is exactly the reason why Michigan's lakes are known to be so clear, usually. Your local lakes are probably near relatively \"muddy\" soil where the composition has much less sand. This means that the water is keeping many of the contaminants and the water appears more brown and murky. But, you only really see these impurities when you have a large body of water as they need to absorb the light passing through them and light can penetrate pretty far in even murky water.", "I can think of at least two reasons, there are probably others. For a start, even if the water looks transparent when you're looking through a few inches of it in a glass, it won't necessarily do so when you're looking through the entire depth of the lake, so impurities in the water will totally affect its colour. Secondly, there's also whatever is at the bottom of the lake--unless the water is very deep indeed you'll be able to see some distorted image of the lake bottom through the water, and the colour and material of that will affect how the water appears from the top." ], "score": [ 8, 4 ], "text_urls": [ [], [] ] }

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{ "a_id": [ "h3anqjz" ], "text": [ "There are some types of memory which can be filled up very fast, but like RAM in a PC, they are only temporary. So a high speed camera records a huge number of frames per second for a very short burst, then you need to transfer that data off the camera memory before recording the next high speed burst. You can easily need to be storing gigabytes of data per second, so with high end cameras most of the expense is getting the memory and memory controllers right." ], "score": [ 5 ], "text_urls": [ [] ] }

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{ "a_id": [ "h3a9ano" ], "text": [ "It's arbitrary. All of the oceans are a single contiguous body of water. Different organizations have different definitions of where the boundaries are, but the International Hydrographic Organization (IHO) is the main one, along with the National Geographic Society, various national authorities, and others. But none are any more objectively correct than any other." ], "score": [ 4 ], "text_urls": [ [] ] }

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{ "a_id": [ "h3adinx" ], "text": [ "We don't really know. We know that genetics are involved in this because genetics are involved in basically everything, but we don't know much about how they're involved yet. Our best explanation so far is that different types of cells are hyper sensitive to their environments - they can detect a lot of different properties about where they're located, and have \"programs\" for what to do in each environment. To give an example, the cornea is a layer of cells on the surface of the eye. It's made of cornea cells, arranged into a layer a few cells thick. There are no blood vessels in the cornea (because that would obstruct vision), so it's quite a simple structure. The cells on the outer side of the cornea essentially resides in a very, very shallow layer of water, and the open air just on the other side of that water. On the inner side, the cells of the cornea touch the cells of the next layer down, which happen to very closely resemble the cells of the human placenta, for some reason. If you get a bunch of cornea cells and put them in a nutrient fluid or in a petri dish or wherever else you can grow cells, they will grow, but they won't form a cornea - they'll just form amorphous clusters of cells. If you fix a bit of human placenta to the petri dish and soak it in fluid, the cornea cells will stick to the placenta, but they'll still grow amorphous clusters. However, if you get that fixed bit of placenta and then make the pool of nutrient fluid very, very shallow, so that he cells will be *almost* exposed to the air, the cornea cells spontaneously form a cornea, which is even suitable for transplant. So, cornea cells can detect when they're in an environment that they think is the surface of an eye and automatically arrange themselves into a cornea in response to it." ], "score": [ 10 ], "text_urls": [ [] ] }

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{ "a_id": [ "h3aha4g", "h3b1kqo" ], "text": [ "Almost certainly it's the brew time. the solubility of caffeine is not great at low temperatures (thus takes longer to extract), so the tea was probably not brewed for very long. another thing to consider for coffee is that hot water likely doesn't contact the coffee for very long, where tea often is seeped for longer.", "Brewed beverages like these depends on a few factors to extract flavor and other compounds from the tea/coffee. The 3 most important are Contact Time, Surface Area, and Heat, each of which speed up extraction. When you put GROUND coffee in contact with water for 24 hours, you extract pretty much all the caffeine those grounds because you have lots of surface area from it being ground up and lots of time in contact with water. With tea, while it has a long contact time, it does not have the huge amount of surface area that ground coffee does. With hot tea, the heat is doing even more work relative to hot coffee because of the lack of surface area. When heat is removed from both, things like caffeine are extracted more quickly from ground coffee." ], "score": [ 36, 15 ], "text_urls": [ [], [] ] }

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{ "a_id": [ "h3aqh9m", "h3bi0we", "h3aoyoh" ], "text": [ "Liquid water can’t exist for long in a vacuum, so any runny ice cream would start boiling pretty much right away! This boiling isn’t hot, though, like boiling here where there’s more pressure, and the steam that goes away with the boiling will take a lot of heat with it, cooling the rest of the ice cream off until it’s frozen solid. If the ice cream is melty, that boiling might break the scoop apart. If it’s a real cold scoop, then you’d probably see very little happen to it at first. When the sun shines on it, it will warm up a bit and that will cause some of the frozen water in the ice cream to *sublimate*, which means to go directly from solid ice to steam gas, and the gas then flies away in all directions in the vacuum. Eventually, this process will completely dry the scoop of ice cream out, leaving behind something like astronaut ice cream. If the scoop is far from the sun or in a constant shadow, then the scoop could remain frozen with ice still in it for millions of years! There’s other stuff in space, too. High energy light thats bluer than blue (that we cannot see, but is the same sort of light that gives us sunburns) can break down the stuff that makes up the ice cream, so that it turns white or tastes stale. Fast-moving atoms that zip out of the sun may (very slowly) erode the ice cream, even if it’s already dried out, too.", "I feel like this is the set up to a tell me a joke like I'm five and the punchline is something about an ice cream float.", "Depends , with direct line of sight the sun and close enough to it like somewhere around earth would probably melt from the solar radiation since there us nothing protecting from it like our atmosphere. In a \"shade\" or far from a star would probably freeze as it loses all its heat" ], "score": [ 10, 3, 3 ], "text_urls": [ [], [], [] ] }

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{ "a_id": [ "h3ap1ha", "h3aprcm" ], "text": [ "If memory serves the screen is made up of thousands of little Dots that, when pressed, make an adressable electrical connection. To over simplify it think of a grid system like the Battleships game, you press somewhere on the screen, the software in your phone reads it as a coordinate and then checks where that coordinate corresponds to.", "When you touch the screen you complete an electrical connection. This lets the phone (for example) know where your finger is and where it is moving, so it can visually draw the same line on the image. The touchscreen is the laptop track pad, the image is the laptop screen. Just on your phone its all combined into one surface." ], "score": [ 4, 4 ], "text_urls": [ [], [] ] }

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{ "a_id": [ "h3aqq1k", "h3astzt" ], "text": [ "Because there needs to be a way to READ the connections. Your screen is flat and rigid, so it isn’t actually based on pressure. There’s a slight conductivity to skin, which is what allows the phone to detect contact. That’s why it also works with pencils wrapped in foil, but not things like rubber", "There are two very common touch screen types, resistive and capacitive. The resistive screens work by having two conductive layers held a short distance apart by a grid of spacers. When the pressure of an object touching the screen pushes the layers together the electricity that is able to flow between the conductive layers will allow the touch to be detected. This kind of screen can sense touches from any kind of object capable of exerting the required force, but they tend to have relatively low resolution of touch and the layers obscure the screen underneath a bit. Gloves would work with these screens. A capacitive screen works by having a grid of conductors that form an electric field that extends outside of the screen a short distance. When an object which can conduct electricity such as a finger comes close enough it can be detected and the touch registered. Any kind of object that conducts electricity similar to a finger can be detected as that is what it is calibrated to sense, so special conductive stylus' can be used or even weird things like uncooked hot dogs. Cotton or polyester fabric though as would be on the end of a normal glove is not of similar conductivity to gloves though and so they won't work." ], "score": [ 6, 5 ], "text_urls": [ [], [] ] }

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{ "a_id": [ "h3ar6hf" ], "text": [ "Bacteria consume food debris and produce acid. The acid breaks down the tooth enamel, creating cavities." ], "score": [ 5 ], "text_urls": [ [] ] }

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{ "a_id": [ "h3bgjsj", "h3awmac", "h3chinu", "h3bjaau", "h3auxas", "h3cylhr", "h3d9q97", "h3d57kf" ], "text": [ "The ocean also has big animals because they're not fighting against gravity to hold themselves up. Big land animals have to dedicate more work into moving about, which limits how big they can get. Whales, sharks and giant squid don't need to bother with strong legs.", "Larger animals have a slower metabolism, which means they require less energy to function. Food is not abundant in the abyss, therefore deep sea species evolved to become larger. Another reason is that the larger a body is, the smaller their surface to volume ratio is. What that means is that the bigger they are, the less surface there is for their body heat to escape, making them again more adapted to survive with reduced access to food. Nature World Facts' video on [Deep Sea Gigantism]( URL_0 )", "They don't. Blue whales and several other types of whales are far larger than anything deep in the ocean. Same for whale sharks. Most deep sea creatures are in fact quite small. The large ones are actually pretty unusual, and because they are both unsual and rarely seen by humans, we notice them more. Squids are a good example. Giant squids are larger than the squids we normally see, but they are still only a fraction of the mass of the largest whales.", "Bigger animals need less food compared to how much they weigh. Small animals like a mouse might eat food the size of their body every day. Where big animals like an elephant might only eat something the size of their head. Also, big animals can go longer between meals, so the can spend a really long time looking for food. Sometimes weeks or even months! Small animals need to eat very often, and don't do well at the bottom of the ocean, there isn't always enough food. Words and ideas to look up: Metabolism and gigantism", "Megafauna usually survive as megafauna due to the space that they can live in and the abundance of food. It’s why one of the last species of megafauna on land in North America is the Moose. Lots of vegetation and plenty of land.", "Coming from the deepest parts of the ocean when viewed from above is completely different from coming from the deepest parts of the ocean when viewed from the side. Large animals come from the *surface* parts open ocean, *not* from the deep parts of the open ocean. This is because large animals require high amounts of food and need to travel far in order to get it, hence they can't be restricted to a single reef or other coastal area. This isn't exclusive to the very largest animals either, mid sized animals like dolphins and tuna are also found more often in the open ocean, because most of them are constantly travelling. Animals in the actual deep ocean are mostly very small. The largest are animals like six gill sharks or goblin sharks. And even these rare giants are still dwarfed by a great white shark let alone a whale. Even giant squids and colossal squids don't live near the very bottom, it's moreso that they are very elusive living near the poles, and live in the sort of border between the open ocean and deep ocean. Even then their size is anomalous, most creatures there are quite small.", "They don't - whales are the biggest animals in the ocean/world, and they tend to spend time near the surface (by necessity, since they breathe air). The largest shark, the whale shark, rarely explores the depths. The answer is that we are interested by things that come from the unknown depths, and also by things that are very large, and so we are fascinated by giant squid and other creatures that check both boxes.", "It’s also worth bearing in mind that the larger land based animals were hunted to extinction by humans. And this wasn’t even a case of over consumption - A lot of the largest animals tended to have longer pregnancies, so even killing one every few months would negatively impact their population and eventually lead to extinction in a matter of years." ], "score": [ 332, 273, 98, 64, 8, 8, 5, 3 ], "text_urls": [ [], [ "https://youtu.be/jwwBHgl5zJo" ], [], [], [], [], [], [] ] }

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{ "a_id": [ "h3avkri", "h3avoxa", "h3avz8o", "h3b635f" ], "text": [ "I used to work at a plastics factory. More or less melt stuff and stir. Pour and press into whatever mold(typically done by robots but not always). The materials melted depend on what kind of plastic you are making. There are different densities, changes for food safeness, flexibility, etc. Most of the words for the things they use I don't entirely know, but they do smash certain types of rocks into powder for certain mixes. Edit: my position at the factory was not a high one and I wasn't really interested in anything but my paycheck.", "It's kinda weird because plastic is mostly categorized by their plasticity, hence the name. The more specific (but still broad) term for plastics are polymers (long chains of the same units of molecules). Plastics are made by polymerization of monomers, so connecting the individual units into a long chain. The process is called [polymerization]( URL_0 ), and it usually involves a liquid for suspension of the monomers, and a few other things to control the rate of reaction (heat, pressure, UV light, initiator chemicals) So to conclude, plastics are so different from each other because they literally just mean \"long chains of some molecule\". They can be completely different molecules with completely different properties", "As you say there are lots of different types of plastic. In general plastic is made up of polymeres. This is just a fancy way of saying that it is a chain of monomeres. And a monomere can be any number of different types of chemicals, orginic or inorganic which can be chained together. So for example the plastic polyethylene is made up of a chain of ethylene molecules which is made from natuaral gas through a series of chemical reactions. But it can also be made from alcohol. You can get different properties by varying the length of the polyethylene chains, the number of branches in the molecules and by using various different addatives.", "Plastics are composed of long chains of smaller molecules. The chains are called \"polymers\", the basic small units are called \"monomers\". There are lots of possible monomers, from [simple]( URL_0 ) to [complex]( URL_2 ) the main thing they have in common is that they're usually composed of carbon, hydrogen, and a few other elements, and they have some sort of chemical property that makes it easy to link up into chains. While plastics are artificial, living things also produce very similar polymer chains, such as cellulose, lignin, starch, and protein. The connection with oil is that oil is composed of a wide range of molecules containing lots of carbon and hydrogen, so it's a good starting point for creating monomers. But [some plastics]( URL_1 ) can also be made from plant matter such as cellulose or starch. Why's it so cheap? It starts from cheap materials, and we make a LOT of it. It may seem odd to call oil a \"cheap material\", but consider: you probably consume several kilograms of oil in the form of fuel, just to get to work and back every day. But one kilogram of oil in the form of plastic will meet your needs for weeks or a month. A typical ten-gram plastic bottle uses about as much oil as your car uses when it drives 200 meters (600 feet)." ], "score": [ 10, 5, 4, 4 ], "text_urls": [ [], [ "https://en.wikipedia.org/wiki/Polymerization" ], [], [ "https://pediaa.com/wp-content/uploads/2015/12/Difference-Between-Polyethylene-and-Polypropylene-image-1.pnghttps://pediaa.com/wp-content/uploads/2015/12/Difference-Between-Polyethylene-and-Polypropylene-image-1.png", "https://en.wikipedia.org/wiki/Polylactic_acid", "https://d12oja0ew7x0i8.cloudfront.net/image-handler/ts/20190220044337/ri/763/src/images/Article_Images/ImageForArticle_17671(2).jpg" ] ] }

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{ "a_id": [ "h3awl8e", "h3b7agr", "h3crrvi", "h3awgcb", "h3awod3" ], "text": [ "It is the impurities in the water that connect to contact points within a device. If the device is on, the electric current can be sent to places that it shouldn’t go and that causes damage. If those impurities don’t make contact with the connections in your device and create a short then your device may be completely fine. The water does not automatically destroy devices, but it can trigger problems. Even if your electronic device survives a water incident there is a chance of problems in the future. Water can cause corrosion, a chemical reaction, with metal and the circuit board. Electronics can often function with some corrosion, but you may notice issues or complete failure over time.", "water as in pure H20 doesn't really do anything major. its the impurities in most water you see around that causes problems, they are mostly either minerals or salts, both of which are generally conductive to electrical current, so when it gets inside a device that isn't protected it leads to shorts that will likely damage the device. even if the contact itself doesn't do any noticeable damage, you have the issue where these same impurities tend to deposit after the water evaporates and these materials are helpers in generating corrosion in metals by reacting with them and the oxygen around them.whatever corrosion doesnt end up breaking, rust is not conductive so the circuit still gets irreparably damaged.", "ELI5: Electricity is lazy. What I mean by that is electricity will take the easiest, shortest, least resistance path at any opportunity it can get. To only reason we get electricity to do anything we want it to is by giving it fancy little wires for it to travel on a circuit board. Then water comes along and is like \"hey, instead of going through that very complicated circuit...why not just hop a ride through my electrolytes (charged ions that can carry electricity), and take the easy way?\" So electricity, which should have gone one way very slowly, is now dumping everything at full power into something it isn't supposed to and likely breaking it.", "It will erode certain pieces. And although water isn't a great conductor it will conductor and short circuit pieces which can cause damage", "1. Short circuit, water (the less pure, the worse) is conductive, so it will put electricity where it shouldn't 2. Corrosion, water will cause metals to tarnish and corrode, which might break thin metals like component legs and contacts 3. Electrolysis, when there are two or more metals in electrical circuit through the water, they will react with the presence of electrical current, and do unwanted things like generating flammable hydrogen, eroding material and rusting" ], "score": [ 60, 7, 5, 4, 3 ], "text_urls": [ [], [], [], [], [] ] }

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{ "a_id": [ "h3blsy3", "h3az5pv", "h3bap54", "h3ayogd" ], "text": [ "People here are failing to address the main issue - explaining resistors assuming everyone already knows everything about a circuit. Imagine a circuit like a bunch of pipes with water flowing. The water pressure is voltage, and the current is the amount of water flowing through. Now imagine you have something which is powered by water, let’s say a garden hose. When you connect the garden hose, you don’t want the water flying out at a crazy high pressure. It could hurt you, and damage things. This is the same in circuits. The components in the circuit can’t all handle the high voltage, just like how your hose can’t handle the high pressure. So what’s done to fix this? You add a valve to the hose, or a resistor to the circuit. The valve on the pipe will restrict the amount of water that can flow through - protecting whatever the water is being used for. Just like this, a resistor is used in a circuit to protect components that could be damaged otherwise. Of course, there are a lot more applications of resistors. However, protecting components is a common and simple use of resistors.", "Even a direct connection via a copper cable has a resistance. It's miniscule, yet unneglectable. This is why we need thermal circuit breakers in house wirings, because if you draw too much current from a cable it heats up due to its resistance. Resistors to electronics is what drag is to aviation. A plane can only steer via flaps because they alter well-dosed amounts of aerodynamic drag. Same thing with electronics. Any device making use of transistors (transfer resistor) only works by altering the resistance of a certain circuit within.", "One important use of resistors is allow for control within a circuit. For example, volume/tone knobs on musical instruments, tuning knobs on radios, and on/off triggers like smoke/door alarms, thermostats, and light switches. All use various forms of resistors to take an input (a change of resistance) and change the properties of a circuit for a purpose (turn on your air conditioning, or making the volume louder on a guitar, for example). Another use of resistors can be to protect sensitive electronic components. Light bulbs, for example, are essentially resistors that make light, but LED lamps produce light with very small amounts of resistance. If I were to install an LED lamp directly into an electronic circuit, there wouldn't be very much resistance at all and the flow of electricity would damage the LED, so I need to put a resistor into the circuit to limit the flow of electricity and protect the circuit. As an analogy, resistors have the role in a circuit as a load does on a car engine. If I took a sports car and floored the pedal to drive up a hill, the effort of driving up a hill is a \"load\" on the engine and it's ok. If I put the car up in the air on a jack and floored the pedal the wheels would spin without any load and the engine would just accelerate and accelerate to a speed that could damage the moving parts of the car. In a similar way, in a circuit without resistors electricity could flow so freely it could damage the sensitive computer chips and things that don't like tons of electricity.", "This explanation is far from correct, but you might get the idea: Not every component in a circuit is made to handle high voltages/currents, so you will need to limit how much energy flows to avoid breaking those components. Some components produce different results when applying different voltages, in which using a resistor can aid in achieving the result you were aiming for. Also, electricity attempts to go the path of least resistance. If you wanted to power multiple parallel components equally you would have to balance the resistances on each." ], "score": [ 41, 12, 11, 5 ], "text_urls": [ [], [], [], [] ] }

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{ "a_id": [ "h3b1g40" ], "text": [ "URL_0 Everything at finite temperature is undergoing Random thermal fluctuations. These fluctuations tend to move systems towards states that are more common. The tendency for things to go from order to disorder is because of this — disordered states are much more common. For systems of any appreciable size, the less common states are *much much much* less common to the point where it’s almost never going to happen by way of random fluctuations. They figured out how to quantify this degree of commonness/uncommonness into a quantity called “entropy” so they can incorporate it into theories about thermodynamics or statistics or other fields." ], "score": [ 7 ], "text_urls": [ [ "https://old.reddit.com/r/explainlikeimfive/search?q=Entropy&restrict_sr=on" ] ] }

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{ "a_id": [ "h3b6j08" ], "text": [ "Backside: The upper half of your face gets reflected even further up, while the lower half gets reflected even lower. Frontside: The upper half of your face gets reflected DOWN, while the lower half gets reflected UP." ], "score": [ 3 ], "text_urls": [ [] ] }

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{ "a_id": [ "h3b9i4k", "h3b4w5z" ], "text": [ "Your body is a machine, your brain make it work and pain is an information. The one goal of your brain is to ensure you survive. To that extent, pain is an important information. If it hurts, something bad is happening. Usually something you either need to wait the end of, or something you need to act against. But what if you're being chased by a predator and got hurt? You can't \"wait\" and you can't fight back something more powerful than you. Both of the standard way of handling pain are not viable. So usually, your brain goes with the 3rd solution of \"Ignore the pain\". It dull the sensation because the pain is being an hindrance to your survival. Because you need to keep moving and pain is useless. Your body doesn't know that, so it keep sending pain, but your brain try real hard to ignore it. When you get hurt, if you try and force your body to move, there is a good chance your brain goes into emergency mode and dull the pain to allow you to keep going. Brain doesn't really know what is a life threatening emergency and a simple scratch. All it knows is that you're trying to push through the pain. You made the executive decision to work through the pain, the brain doesn't go into details. It just allow you to. Even if it's not the correct decision.", "It’s a distraction technique that can be pretty effective for minor injuries. Obviously, you should never try to “walk off” a major injury like a sprain or a broken bone. Seek medical attention in those cases. But for a bump or scrape where you just need to get through the initial pain it’s fine." ], "score": [ 4, 3 ], "text_urls": [ [], [] ] }

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{ "a_id": [ "h3b80ww" ], "text": [ "If your body gets to hot you do not die of dehydration. Heat can cause dehydration but you can get hot with dehydration too, fall into hot water and the heat will kill you before you have lost water to any significant degree. Lots of chemical and chemical reaction in the body is temperature-dependent. If your body gets too hot proteins denature, that is a change in structure because of heat and you have seen just that if you fry eggs. Sweating is a way your body tries to keep cool, another way is to pump more blood to the extremities where heat can dissipate. So if you are out in the heat you can get into trouble from dehydration that is because you sweat to keep the body cool enough to not die for other reasons Chemical reactions in the body also have a lower temperature limit. Muscles also are less efficient if they get cold. So a decrease in body temperature will reduce the rate the heat can pump around blood and you will die when it can provide enough oxygen that is required cells like your brain needs to survive. Tissue can handle a lot more of a decrease in temperature than a increase. The result is that if you are out in the cold blood flow reduction to keep the core warm or just exposure to cold air can result in tissue temperature drops so water can freeze. Water that freezes expand and form sharp crystals and that will damage tissue. Frostbite is the result of tissue freezing. It is the most common in fingers, toes, nose, ears, cheeks, and chin areas and can kill the tissue. If all of your body would get frozen that would destroy all your cells. That would certainly kill you even if cells did not require oxygen." ], "score": [ 6 ], "text_urls": [ [] ] }

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{ "a_id": [ "h3badry", "h3bm6x0", "h3badv1", "h3be16z" ], "text": [ "Yes. It’s not as simple as you have the high IQ gene though. It’s multi-factorial and lots of genes appear to have correlations with IQ. It’s also important to remember that IQ is not an amazing measurement of how intelligent someone is in the real world or how successful someone will be. Radiolab has a great series of podcasts called G that I would highly recommend to anyone interested in IQ", "There is almost certainly a genetic component to intelligence, but in reality there are a lot of *other* factors that are tied into intellect (and thus, IQ scores). The biggest single factor is likely nutritional and developmental, particularly before the age of 5.", "There is a genetic component. Having high IQ parents gives you a statistically higher chance for having a higher IQ as well. It isn't the full story though. How your brain is stimulated (especially during childhood) plays a big role too.", "Intelligence quotient measures the percent of what the average or typical person your age should know that you know. If a typical 35yo female should know these 100 things and you know 15 more, then your iq would be measured as 115. If you put a four year old in second grade, s/he will struggle a bit but in a relatively short time their IQ will reflect that they know far more than other children their age because their peer group and scholastic exposure is to a dearth of knowledge that would otherwise not be available to others her/his age. Typically it can be said that one's ability to acquire and retain information has many genetic components, but with effort one can improve these abilities. If a person is raised inan environment where they have the nourishment, freedom, time, space and safety to actively work on these skills; then improvement can be made. however, if conditions aren't conducive to exposure to information or the ability to focus on thinking, it stands to reason that one's IQ would be less than what they would otherwise be capable of. I am over-simplifying the measure and the concept. I leave it to others to talk more about how near-impossible it is to nail down where in the alleles and genetic code one's ability resides to form neurons, make permanent their connections and information, and accurately recall as well as one's ability to actively focus and to have endurance with mental strain. There is research into c. elegans that is attempting to nail down where in some genetic code resides the ability to form neurons and whether or not the neuron can endure if certain chunks of genes are knocked out. There's a really surprising study that found that some microscopic worms (I forget the species - sorry) can inherit knowledge trained into another individual when they 'ingest' or more accurately subsume another individual which has been trained. Humans do not have this ability, we have to learn things the hard way and IQ is as much a measure of how much one has had exposure to as well as one's environmental ability to take advantage of the opportunity. I'm very curious OP, what's your reason for wanting to know?" ], "score": [ 21, 7, 4, 4 ], "text_urls": [ [], [], [], [] ] }

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{ "a_id": [ "h3bfuqg", "h3d5ry5", "h3c5a59", "h3bcq0c", "h3ct6mz", "h3door7", "h3dppnk", "h3dewp7", "h3eq9ej", "h3dxszu" ], "text": [ "Ants like many small creatures have tiny hooks on the ends of their legs. They simply hook into whatever they are standing on. Even when a surface looks smooth, at the microscopic level there are scratches and protrusions that your eye just can't see.", "Ants actually have several different ways of holding onto different structures! As others have mentioned, they have hooks/claws at the end of their limbs. This means that for softer surfaces like wood, grass, paint, leather, and so on, they can literally just spike their claws into it- even if it _were_ perfectly flat, they can still grab onto it no problem! And of course, since an ant is something like 1/1,000^th the height of a human, surfaces that might _seem_ smooth to you or me can still give plenty of spaces for an ant to grab onto. Even sheet metal can have grooves or ridges in it that are several micrometers (millionths of a meter) across- relative to an ant's limbs, that might as well be rocks on a climbing wall. But most importantly, ants (and other small insects) also have adhesive pads on their feet. These are literally small footpads that get wet and sticky, and help the insect walk across vertical or upside-down surfaces, just like someone scaling a building with suction cups. So even on perfectly flat, very solid materials, ants can _still_ hold on with very little problem. Between all three of those methods, it can be incredibly difficult to uproot an insect just with wind unless you can catch them off guard. Aerodynamics also helps- wind likes deflecting _over_ obstacles more than it likes pushing against them, which is why dust can collect on the surface of a ceiling fan even when it's on. But overall, ants have several very effective ways of holding onto stuff, no matter how flat it seems.", "Insects are much smaller then people in a way that's hard to understand. Mass and volume scale with the third power of length, so trying to think of them like a \"tiny person\" doesn't work. At their scale, they can see roughness in things we think are smooth. In fact, some insects exploit something called \"van der Waals\" forces, which is like magnetism without magnets. It's so weak we can virtually never observe it ourselves, but it work for certain insects because they're so small. It's kinda like an insect superpower.", "When sensing a wind gust the ants spread their legs and lower their body close to the floor, clutching the surface to resist the wind.", "At a very small level, electric forces are more relevant than gravity. This phenomenon is used in many ways, first being small insects that stick to vertical surfaces. It is also used by lizards that just chill on the ceiling or in glue industries to make effective glues.", "ELI5: glass isn't really smooth when you look at it under a microscope, and ants have tiny feet with even tinier grippy toes.", "Van de vaals forces or something can’t remember exactly how they work but I know it’s how geckos stick to walls though!", "Apart from what others have said about tiny hooks, which is the main reason and correct, there is also the fact that all insects are incredibly strong in proportion. Ants can lift 50-100 times their size. This is because muscles depend (more) on area than on volume, while weight goes the other way around. So, with very small bodies, volume is minimised while the muscle surface ratio is maximised.", "Foe small insects, surface tension is as significant as gravity is for us. Surface tension forces at that size are comparable to the insect’s weight. Exit: a typo", "Natural Velcro hairs. Wondering if they hear tiny ripping noises when lift their feet?" ], "score": [ 4105, 2074, 147, 20, 9, 7, 5, 5, 4, 3 ], "text_urls": [ [], [], [], [], [], [], [], [], [], [] ] }

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{ "a_id": [ "h3bcjzb", "h3bfdlz" ], "text": [ "At the end of a shutdown process, your operating system sets an ACPI command indicating that the computer should reboot. In response, the motherboard resets all components using their respective reset commands or lines, and then follows the bootstrap process.", "It does clean everything (or at least used to. not sure for newer technologies). To start a computer, you push a button, it send an electric signal to the motherboard to start up. Mother board does its thing and computer start. When you push the shut down button (or tell windows to shut down) it send a signal to the motherboard to shut down. Mother board does its thing then shut down. When you order a restart instead of a simple shutdown, there is a very slight change in the \"does it thing\" before shutting down. The last thing the mother board does before shutting down... Is sending a signal to herself to start up. So while everything MB needs done is done, there is a very slight delay before cutting the power to empty the batteries. Well the signal to start comes before these batteries empty and the MB can start the process immediately." ], "score": [ 19, 11 ], "text_urls": [ [], [] ] }

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{ "a_id": [ "h3be2e6", "h3bfewj", "h3bg026" ], "text": [ "It doesn't. But water has to exist for all life on Earth to exist. And space is a really big place. So we rule out places that *don't* have water and focus on places that *do* have water to focus our search for life. That doesn't mean there's life out there that doesn't require water, but for right now it would be kind of a waste of time and resources and money to specifically find life there if we don't have any reason to believe it would be there to begin with.", "Because we're basing our assumptions on what alien life would require to exist upon what Earth life requires to exist. Because going on any other assumption is so far outside the realm of what we consider possible that we can't even fathom it yet.", "Water has to be present for lifeforms we'd recognize to exist. We've (afaik) only ever speculated what non- carbon based organisms would look like, and water is essential for the processes of carbon based life. It would be difficult to search for other life forms when we're not even sure what they are. So we look for water, and things we're familiar with." ], "score": [ 10, 6, 3 ], "text_urls": [ [], [], [] ] }

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{ "a_id": [ "h3bid6r" ], "text": [ "This depends a bit on the animal, but let's talk about bears: During hibernation, their whole metabolism changes and slows down. Bears don't even pee during hibernation, and they don't eat or drink - they live off stored fat and basically recycle their proteins and whatnot. Their bodies adapted perfectly to not lose bone mass or get muscle atrophy. How? It's a very complicated process that has to do with metabolism and re-absorbing amino-acids from their own urine, as well as a nervous system that basically goes ahead and makes their muscles contract while they hibernate (they shiver). These things are studied for the exact reason you stated: to maybe find a way to prevent osteoporosis in humans and to help recovery / prevent muscle atrophy in people who, for example, are in coma or sent to space. So far we haven't found a way to get the human body to do what the bears do, though." ], "score": [ 35 ], "text_urls": [ [] ] }

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{ "a_id": [ "h3bj59l", "h3bj4u0", "h3bj92u", "h3cpm5j", "h3bjewm", "h3bmzsd", "h3btx64" ], "text": [ "The proximity to the sun only matters when you're facing it. The sun makes things hot by shining lots of photons on it. The night side of Mercury is the side facing away from the sun and therefore isn't getting any of those delicious photons. But it should already be hot from being in the sun during the day-time, right? No. Hot things radiate their heat away. Without an atmosphere to trap the heat and keep it there (like a blanket), it just gets rid of all its heat (in the form of infrared radiation) and gets very cold.", "The side facing towards the sun (\"daytime\") will receive a lot of heat from the proximity to the sun. On the other hand, the side facing away from the sun (\"nighttime\") is facing empty space which would be colder than the daytime surface, and with no atmosphere to hold in the heat, the heat escapes quite easily.", "A lack of atmosphere means heat doesn’t get trapped. That is also why Venus is hotter than Mercury. The light side of Earth’s moon is also quite hot compared to earth. Atmospheres are effective heat traps for a couple of reasons. One being the greenhouse effect, which traps heat. The other being that atmospheres are made up of molecules, which collide with one another distributing their energy, which distributes the heat around.", "Imagine boiling a pot of water on a gas stove and then turning off the stove. The water stays hot for a long time. Now imagine turning on a gas burner with nothing on it and then turning it off; within a minute or so, the top of the burner is close to room temp. In these scenarios, the water in the pot is the atmosphere. Without the atmosphere, Mercury's dark side gets pretty cold during its year-long night. Overall, the universe is pretty cold despite trillions of nuclear reactors firing all at once, because it's big. So any surface without insulation (oceans, atmospheres) will lose heat very rapidly without direct sun/starlight on it.", "There's no atmosphere to trap the heat. On earth we have greenhouse gases that do this for us such as CO2. Therefore the temperature of the side facing away from the sun plummets.", "Mercury's day is REALLY long, like half an earth year. This gives plenty of time for the 'night' side of the planet to cool off. There atmosphere matters for two big reasons, first is the fact that an atmosphere can 'catch' heat that is trying to escape (which would keep the night side warmer), a good example of this might be how cloudy nights on earth are often warmer than clear-sky nights. The 2nd thing an atmosphere can do is move heat around, in other words wind. Air can be exchanged between hot and cold areas which can help even out temperatures.", "There is a concept in physics called “black-body radiation” (see [here]( URL_0 )) which states that every object is continuously emitting light. The color of this light depends on the object’s temperature. This is why hot things glow red-yellow, and hotter things glow blue-white. This is also how thermal cameras can see in the dark - the “color” of light which objects emit when they’re not very hot is outside the range which humans can see, but thermal cameras can pick it up. So every physical object is constantly emitting this light, but making light costs energy, and the energy which is used to make this light comes from how warm the object is. As a result, every object everywhere is also constantly cooling down. On earth, this constant loss of heat is balanced out by the fact that every object is also constantly _gaining_ heat by soaking up the light emitted by other nearby objects. But out in space, there are no other nearby objects, so you get cold really fast. You might now wonder why _earth_ doesn’t get cold really fast, if it’s losing heat energy into space all the time. The answer is, we’re gaining heat from the sun as fast as we’re losing it into space. Obviously, this is happening on Mercury too, so why is Mercury’s night side so cold? Earth’s atmosphere catches the light that’s going out into space, absorbs some of it and sends some of it back down to the ground. This is the “greenhouse effect” you might have heard of. This slows down the loss of heat into space. So when a place on earth is away from the sun - when it’s night there - that place doesn’t lose much heat overnight, and then warms back up the following day. On Mercury, without an atmosphere each place on the planet can lose heat much more quickly, so it gets to be a lot colder at night." ], "score": [ 222, 22, 18, 14, 9, 3, 3 ], "text_urls": [ [], [], [], [], [], [], [ "https://en.m.wikipedia.org/wiki/Black_body" ] ] }

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{ "a_id": [ "h3cq3sa" ], "text": [ "Tough question, but I'll try. So according to quantum field theory, subatomic particles are really these unusual objects called fields. The maths of these fields isn't worth getting into, but one thing we can say is that are certain things that we can mathematically do to this field that don't change what outcome we get when we measure a particle. For example, one way we might think of a field (in an extremely simplified way) is as having a complex number associated with each point in the field. If you don't know what complex numbers are, think of these as basically numbers that as well as having a size, also have an angle associated with them. One of the things we can then do to this field is change the angle of each of these complex numbers by the exact same amount. Since the maths of quantum field theory only depends on the difference between angles, and not the absolute value of any particular angle, this won't change the answers we get when we measure a particle. A change like this, that we can make without altering the outcome of any measurement, is called a *gauge transformation*, and if the system doesn't change under a particular transformation, then it's called *gauge invariant*. However, it's a bit more complicated than what I've just described. What I've just described is more accurately described as a *global* gauge transformation - we made the same change everywhere, changed every complex number by the same amount no matter what point of the field they corresponded to. One of the things that we might wonder though, is what would happen if the amount we changed each angle by was itself something that varied from place to place, so, say, we change these angles over here by a little bit, and these angles over here by a different amount, and so on. This would then be called a *local* gauge transformation, because it varies from place to place. Well, if we still want this kind of transformation to leave the results of our measurements unchanged, then we're in trouble, because the maths of quantum field theory is going to give different answers if we change the angles by different amounts in different places. The solution to this, it turns out, is to add a second field, that changes in a different way when we change the angles. In particular, we can construct this second field so that it *exactly cancels out* the difference caused by the changing angles. This second field, that exactly cancels out the changing angles, is called a *gauge field*. For example, if we consider an electron field, and we apply this local angle-changing transformation to it (this particular transformation is more properly called the U(1) group), then we need to add a gauge field that exactly cancels out this angle-changing. This gauge field turns out to be the electromagnetic field, and just like how the electron field corresponds to electron particles, the electromagnetic field corresponds to its own particles, which are photons. Because the photon turns out to arise from this gauge transformation, we say it's a *gauge boson*. There's a lot more to it than that, obviously, and I've skipped over a *lot* of technical details, but that's the gist of it, as simplified as I could make it while retaining the essential details. The only other important thing I'll add is that U(1), the angle-changing transformation, isn't the only important gauge symmetry in modern physics. The Standard Model, in particular, concerns itself with 3 different transformations: U(1), which I've explained here, SU(2), which is associated with quantum spin, and gives rise to the weak interaction, and SU(3), which is associated with the \"colour charge\" of quarks, and gives rise to the strong interaction." ], "score": [ 4 ], "text_urls": [ [] ] }

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{ "a_id": [ "h3btejo", "h3cmf7i", "h3cwdno", "h3bubdw", "h3btfw2" ], "text": [ "The entire radio spectrum is \"noisy\"--there's interference in it from both man-made sources and natural ones (e.g. lightning strikes). If you tune the radio to a dead channel then all it will be picking up is that noise, which it amplifies and turns into the static that you hear. You still get the noise on actual radio channels, but it gets drowned out by the radio station you're tuned in to so you tend not to notice unless it's very bad.", "You hear whatever radio electric waves are around that specific frequency. These are generated by each and every electric device, near of far. Tuning at a frequency means your receiver expects a specific signal (a carrier) at that frequency, with some power level, and it also expects data to be coded in a specific way on that carrier. FM radio means frequency modulation, so you get bits by adding a specific set of frequencies on the carrier for a specific length of time (or oscillations). When there is no emitter, there is no power, but the system will still try to decode the signal like there was a carrier and modulation on it, which produce this noise. Smart receiver systems will try to follow the carrier, as it does move a bit, but when it gets too far from anything it will not \"autotune\" to the nearest, highest powered carrier detected. Fun fact, there can be data in that noise. In fact, when you do not need a lot of bandwidth, say under 1000 bauds, you can transmit with a very low level of power, at noise level power or sometimes even less. It makes it \"invisible\", since to everyone and anything that scans by trying to detect power levels higher than noise, it is drowned in noise. I think the military uses that now (they used to use frequency jumps but that can be spied on now)", "I'm surprised I didn't hear this answer yet. One of the most dominant noise sources is the thermal noise generated from your system. You can think of heat as random motion or vibration of the matter in your antenna (and well...everything). That means the electrons are randomly moving, and moving electrons in a resistor makes small random voltages occur. This noise is multiplied by the effective receiver bandwidth. So cosmic noise maybe 10 dB above the fundamental noise floor.. Electrical storms and other man made noise can contribute, but MOST of the time, you're just hearing a bunch of warm electrons dancing around inside your radio.", "Your radios antenna picking up all the background radio waves/interference from other electromagnetic waves. When you tune a radio to a station number (or more specifically tune it to that specifically frequency) you pick up what the station is broadcasting with that frequency. Typically, the this signal is strong enough to drown out any background static/background radiation/interference. But, when you’re tuned to a station that isn’t broadcasting (that you’re out of range of any station that is broadcasting on that frequency. Your radio antenna is just picking up and playing all that background noise that typically gets drowned out. Edit: to add a source of these waves/background noise that you’re picking up. They can come from things like radio stations that are too far away to receive clearly, or they could come from all the electronics and appliances like microwaves/handheld radios etc we have around in our modern world. Or, for really sensitive equipment (or equipment away from lots of other sources of interference, it could even be radiation from space. The sun, stars, and even cosmic background radiation from the Big Bang all exist and can interact with our equipment.", "[Cosmic background radiation]( URL_0 ) Basically, it’s electromagnetic radiation leftover from the big bang. Same as TV static (does that exist anymore? Lol). Your radio is looking for electromagnetic signals, and it picks that up when it can find anything stronger (like a station’s signal). Edit: erased some redundant wording cause I messed up the link at first" ], "score": [ 383, 65, 29, 23, 21 ], "text_urls": [ [], [], [], [], [ "https://en.m.wikipedia.org/wiki/Cosmic_microwave_background" ] ] }

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{ "a_id": [ "h3btola", "h3bztqd", "h3c5x7n", "h3bxfm0", "h3bzwon", "h3c0emo", "h3cdtru", "h3ccpbi", "h3c727i", "h3ceeh2", "h3caru2", "h3cbcs9", "h3c75z7", "h3cetxe", "h3cdmff" ], "text": [ "Being ridden causes additional wear and tear on their hooves, as well as walking on pavement or gravel.", "In nature, horses run around on grasslands. People like to make roads, and the shoes protect the hooves from the road material (often stone/gravel or concrete).", "Wild horses actually have quite a lot of foot problems. Owners of domesticated horses want to avoid that by taking care of their horse’s hooves and sometimes that means shoeing them especially if they have “soft feet” and crack easily. Shoes also help with grip and other hoof problems. Horse’s feet are very important to their health because they can’t lay down for long periods of time or their weight will crush their lungs and won’t get good enough circulation because their hooves actually help to pump their blood. This is why horses with broken legs are often euthanized because it’s very difficult to save them, even if put in a sling, as they will very likely develop other problems like foundering.", "Other people will surely give some valid answers here about the different demands on a horse's hoof based on the pattern of use. And I think they'll be right. But let me just also note that when we ask these sorts of questions about domesticated animals, we can't always draw a comparison to \"how they were in nature\". Obviously, a horse does certainly resemble its wild ancestors, but if you take this to the extreme, ask yourself what a pug \"ate in nature\" or otherwise how it survived. Why are there no bands of feral pugs or French bulldogs roaming the forests? TL;DR - Domesticated animals are a creation of humans, and may have maladaptive traits that weren't selected out of their gene pool.", "I asked someone who i was friends with who had horses this exact question. They said it improves the life span of the horse. Surprisingly wild horses dont live that long. Mostly due to feet/leg related injuries.", "Do you wear shoes? In nature, humans don't have shoes. Why do we wear them? I would posit that we've given horses shoes for the same reasons. It prevents foot and leg problems. Horses with bad feet or legs are pretty much useless and destined to die.", "I wanted to add to the discussion that not all domesticated horses have or need shoes. I’ve owned horses before that did fine with a trim of the hooves every few weeks, others required shoes due to the level of work (competitive jumping and dressage) I did with them. For horses that we only trimmed, it was to ensure that the hoof stayed “flat” on the ground. Their hooves grow and if they grow unevenly or too long it can cause issues with their leg bones and in cases of severely overgrown hooves can limit movement. For horses that we shod, it was a trim and replacement (or reattachment) of the shoes every 6-8 weeks.", "Hello I own horses. Mine do not wear shoes. There are many horse owners who prefer to let their horses go barefoot and many who only put shoes on the front feet. There are many types of horse shoes. Some work to correct foot problems and others work to give more traction (such as when horses race in mud or run on grass for a jumping competition). The shoes overall also provide protection to the hoof. I want to note that a person trims the hoof before the horseshoe is put on.", "A little googling (who'd a thunk it?) yields a few more details. Hard surfaces and even hard ground are very wearing on the keratin at the ends of horses feet (similar to a large thick toe nail). Added weight and jumping too. If you look at wild ponies they're a lot smaller than racehorses (or draft horses) with similar sized feet. They spend their lives ruminating at a slow pace similar to cattle. When facing potential threats or as part of determining hierarchy they do have a bit of pace on them (as do cattle) but these are usually short bursts. In case you were wondering race horses use aluminium shoes, not steel.", "Hooves are made from what is essentially the same thing as fingernails. So they're pretty hard, but they'll absolutely chip and break if they put too much force on something harder than them, like a rock, or some concrete. They were really made for moving on things like grass, and dirt, and in sandy loam. Unfortunately for the horse, who walks on its fingernails, humans love making paths out of rocks and concrete. Well, it turns out horses have a lot of weight, and the relatively low area of where the fingernail meets the pavement amplifies the force of that weight, so they're prone to breaking in bad ways that can make the horse lame without proper care. Luckily, we can shape metal, which while hard, is also malleable. So if we shape some metal to fit around a hoof, and nail it into the hoof, when the horse steps on the cobblestone path, or the concrete floor of the tin building where Farmer Ted is trying to work on his damn tractor in peace, an errant step isn't going to result in a chunk of horsenail snapping off. Rather, the metal will deform ever so microscopically, and the nail will deform slightly less microscopically, and it'll be a smoother, gentler step for the finger-walking freaks of nature we call horses.", "Humans in nature are barefoot, why do YOU need shoes?", "In nature they also do not have to carry horse girls, ride when they'd rather rest, or run on asphalt.", "Hit ain't the heavy haulin that hurts the hoss's hooves, nor the huntin on the heath. It's the hammer hammer hammer on the hard highway. Pronounce the initial H's as you see fit.", "A shod horse can do more work with less wear, or distributes any pressure so they don’t crack or split or wear. Think like wearing work gloves vs not and having to do some heavy work. Except you get put down f you hurt your hand. They can get infected or even come off like A toenail, and of that happens, they have to be put down.", "My horses don’t wear shoes and I ride them out on roads and rocky tracks. Keeping horses barefoot isn’t as straightforward as just taking the shoes off, the management, feeding, grazing type and lifestyle all need to support the bare hoof. I used to have a thriving business taking horses in and getting them functionally barefoot and can get very boring indeed about this. It’s also a minefield of clashing opinions and zealotry in the horse world." ], "score": [ 452, 357, 185, 149, 43, 34, 9, 7, 7, 7, 6, 4, 3, 3, 3 ], "text_urls": [ [], [], [], [], [], [], [], [], [], [], [], [], [], [], [] ] }

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{ "a_id": [ "h3bwxwo" ], "text": [ "It’s more to do with the height of the ground increasing signal strength than your head acting as an antenna" ], "score": [ 3 ], "text_urls": [ [] ] }

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{ "a_id": [ "h3c22qv", "h3cl5au", "h3cj1jw", "h3d6i4c", "h3d3ozc", "h3ciuh9" ], "text": [ "Generally the difference is light. If the light is hitting objects at different angles, or if it’s not passing through partially transparent objects like skin, your mind will see that something is wrong.", "There are several things that I notice that will clue me in to CGI: * Lighting is off. It looks mismatched with the scene, or it doesn't shift with perspective. * Edge blending is unrealistic. Often the edges of the CGI are too fuzzy or too sharp. They look the same when \"distant\" as when \"close\". * Unrealistic physics. Like when someone is shot into the distance at what would be 50g acceleration. Or, when a Transformer grabs on to a bridge and shoots around in the other direction without destroying the structure or generating enormous exhaust from thrust. Or when something large drops from orbit and doesn't create a crater or shockwave.", "Modern CGI has gotten really good at replicating photorealism, especially with the use of ray tracing which has allowed movie makers to actually simulate how light actually works in the real world. Games do a really bad job of showing how human skin and light interact because it's actually really complex and games (until recently) couldn't use ray tracing. Movies don't have the same limitation so they can spend as much time and money as they want rendering their frames whereas games need to render dozens of frames per second. Basically at this point you really have to know what to look for to spot the CGI, even more so in action scenes where your brain is more focused on the action. Unless of course the studio just does a really bad job of drawing superman's mouth...", "We like to brag about the size of our human brain compared to animals, but a very, very large portion of that is dedicated to visual processing and facial recognition. Compared to most animals which recognize each other by scent, it takes up a lot more space to do visual recognition. This is the essence of the uncanny valley. Our brain is really, really good at human facial recognition and, to a slightly lesser extent, other animals we're familiar with like dogs and horses. We can make pretty darn convincing CGI still images, but making every single frame of a moving sequence convincing enough to fool our brains is much more difficult. The final factor is that CGI is sometimes *too* real. It perfectly models an artificial reality that is neater than actual reality. The light is scattered in a mathematically perfect way rather than a messy, real way, for example.", "movies employ many tricks to avoid you getting too close of a look at a \"fake\" thing. especially fake human things (I mean... whos to say what a fake thanos should look like? but we know what humans should look like, especially famous recognizable ones that were just in the last scene) so they put on masks, and wear outfits that have easy to render textures and minimal \"loose\" fabrics that need to wrinkle. They they shoot the scenes with lots of cuts and bright lights, and distractions, and the rare close ups they will put a real image into a fake scene and just the right shadows so you cant see the cutting line. games on the other hand... have almost no control over how you see them. the angles and lighting are completely uncontrolled, they can do very little to optimize them other than improving everything about them in all circumstances. which is much more difficult.", "We are so used to looking at people's faces that we recognize small details that aren't so relevant. There are different skin textures, hair follicles, shadows, etc." ], "score": [ 285, 64, 41, 9, 9, 3 ], "text_urls": [ [], [], [], [], [], [] ] }

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{ "a_id": [ "h3c8rv7", "h3chobt", "h3e87qw", "h3c8vhq", "h3d3rj9", "h3cvh40" ], "text": [ "Leverage is basically debt. More specifically, leverage is when you borrow money (rather than use just your own money) to undertake an investment, project, or acquisition. If you bought a house via mortgage, then that house is leveraged. Leverage has higher potential gains than only using your own money, but it also has higher risks. If the after-tax profit exceeds the borrowing costs, then leverage is a useful tool. If the asset's value falls or it fails to generate enough income to cover the financing costs, then the leverage can multiply the losses.", "There are all sorts of leverage related to business. Can you be more specific the context? Some examples can be in investing, borrowing money to add to your investment so that you make greater returns -- if you have $100 and borrow $100, make a 25% return, your effective return is 50% since you only have to repay the borrowed amount (plus interest) and keep the gains. Another type might just be having the upper hand in negotiations. If you want to buy something -- say a building -- and you know the seller is distressed (ie. about to get foreclosed on, in legal trouble, etc) you could use that as leverage to offer a lower price that you know they'll accept to get out of their predicament.", "A lemonade stand costs $10 to run. You only have $10 You can spend all of your money to set up 1 stand OR you can borrow from the bank and set up 2 stands If you borrow, you are levered", "You might want to give some context. Leverage is a term used in many areas in business. In any case the broadest possible idea is to use a small amount of resources to influence or control the deployment of a larger amount of resources. In finance, leverage is also used to discuss the debt/equity or debt/capital ratio.", "Imagine you have a magic box. You put 10 sweets in and you get 11 out (10% market apreciation). Congratulatiom you got one sweet. But you are a smart little fella so you borrow (leverage) sweets from other kid, that has 90 of them. So you put 100 in, get 110 out. You return original 90 to the kid (principal) with lets say 2 more for the trouble (interest) and voila you got 8 sweets for free instead of 1. But the box is sad. You did not sacrificed the goat to it, so it will take one for every 10 put in (-10% market depreciation). You do that again with the same numbers. You put your 100 sweets in but take out only 90. Loosing all your own sweets. Other kid now wont lend you his / hers sweets because there is no trust, and forces you to give back all his / hers sweets (margin call). Now you are homeless. Edit: grammar and formatting", "When you borrow money as a business, you pay a premium to a bank or other investor to get that money. However, you're willing to do so because you believe you can do more with that money than the premium you're paying. As you're 5, let's say you want to start a lemonade stand, but need $10 to buy supplies. Someone lends you that but says you'll have to pay them $11 back at the end of the sale. You're OK with that because your options are 1) not have the lemonade stand and make $0 or 2) make $20 selling lemonade, then pay back the $10 you borrowed + $1 premium to have borrowed it. So you can profit $9 by selling lemonade with a loan or $0 from not having the lemonade stand at all. Leverage is the use of borrowed money to pay for a project you want to complete. Analysts look at leverage ratio as an indicator of how risky a business is. But leverage itself is simply borrowing money with the expectation you can make more in profit than you pay to borrow the money." ], "score": [ 13, 12, 3, 3, 3, 3 ], "text_urls": [ [], [], [], [], [], [] ] }

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{ "a_id": [ "h3cfwo1", "h3c25h4", "h3c2b0b" ], "text": [ "The other answers aren't wrong-physiologically, yes, both people work basically the same way. But that doesn't explain why you don't really have to choose between safety and efficacy for those drugs. Especially because some drugs, like some painkillers or anesthetics, have to have really precise dosage. That reason is something called the *therapeutic window*. That's the gap between the lowest effective dose and the highest safe dose. For (most) OTC meds, the therapeutic window is pretty big. That is, you don't need a huge dose to get an effect, and you need way more than that dose to be harmful. So you can base your dose on say the 275 lb man, and its still safe for the 95 lb woman. The woman would have to take multiple doses to have any risk. For other drugs, the therapeutic window is relatively narrow. In those cases, the dose is adjusted to each specific person. Those drugs are usually not OTC then, but are administered by a doctor because it is way easier to give a dangerous dose when all you want is an effective dose.", "Because liver and kidneys are pretty much the same in both. Those are the organs you'll damage if you take too much.", "It would take at least three CVS receipts to list all the possible dosages for all the possible height and weight combinations, and even then different people have different tolerance levels and a 6'8\" 275 lb male might not be able to handle his tylenol as well as a 4'8\" 95 lb female. SO they just err on the side of caution and give a general lower dose than what would realistically cause any sort of damage for most people." ], "score": [ 11, 6, 4 ], "text_urls": [ [], [], [] ] }

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{ "a_id": [ "h3d8mxq", "h3c8h73", "h3ddzzg" ], "text": [ "Every cell in your body has the same DNA (with some exceptions that aren't relevant here). However, the way your DNA works during development to make all the parts of your body is very complex. A developing embryo isn't so much like a \"lego person\" that gets assembled from individual pieces. It's more like origami--as the embryo grows, different tissues and organs have to \"fold together\" to make the final shape. Your face, for example, starts off looking very unlike a face, until it gets folded into it's final face shape ([Here's an article with some images of what this looks like]( URL_0 ).) That's why some people are born with things like cleft lip--the \"folding\" process sometimes gets messed up or doesn't finish completely. Your development, and especially symmetry, isn't just controlled by DNA either. Identical twins, for example, aren't always totally the same. Sometimes one can be right handed and the other left handed, for instance. Even though they have the same DNA, their body symmetry isn't identical. So the reason why one of your feet is longer than the other isn't because its DNA is different. It's because the development of that foot was slightly different from the other foot. (Exactly what caused it to be shorter is kind of impossible to say, though; it could have been a lot of things. We really don't understand human development 100% yet).", "All of your cells have the same DNA. A lot of your DNA codes for things that act like switches to turn on and off different genes on the DNA in different cells. This is why you can have different kinds of cells that have the same DNA overall. During development, when and where certain genes are turned off and on is tightly controlled so that everything ends up in the right place. With regards to arms and legs, there are a bunch of genes called HOX genes that make sure you end up with the right number in the right place, and that they are mirror images of each other", "Your DNA doesn't say to create a foot 10.48\" long or something. & #x200B; Instead, it has plans for how to grow a foot step by step. When to create chemical messengers that say \"grow this part longer\" and when to create chemical messengers that say \"stop growing\" Asymmetry is often caused by injury, maybe even in the womb, that results in one part of the body not responding the same to those chemical messengers as the other. SO one foot ends up slightly larger then the other, even though they get the same set of 'grow now' and 'stop growing' messages." ], "score": [ 35, 5, 3 ], "text_urls": [ [ "https://teachmeanatomy.info/the-basics/embryology/head-neck/face-palate/" ], [], [] ] }

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{ "a_id": [ "h3d3ql6", "h3etsf0", "h3d7zkm" ], "text": [ "Hair is always falling off and regrowing. Eyelashes don't do this as often as the hairs on your head. Hair turning gray is a result of the natural cycle of the hair follicle over your lifespan. As the cycle continues, your hair produces less color, turning gray. This process usually begins after age 35. Other factors such as vitamin deficiency, stress, and genetics also play a role to when your hair starts losing color. In some ways this is similar to cancer being more likely to occur the older you are. As cells divide, they lose a bit of themselves that keep them from turning into cancer. Over time, it accumulates and has a higher chance of turning into a cancer cell.", "I had accidentally pulled out a few lashes with an eyelash curler when I was about 20 years old and they never grew back; so now I have a little gap in between them in one place and it’s been about 12 years since then. I want to know why they’re never grew back.", "...guess I have crap genes...I found grey lashes and brows in my early 20s. But I did start going grey by 15 so...." ], "score": [ 191, 7, 3 ], "text_urls": [ [], [], [] ] }

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{ "a_id": [ "h3c5lgx", "h3cv0cr", "h3cqmkf", "h3edyaz", "h3c94le", "h3ec3g7", "h3en1w8", "h3f1gys", "h3ei8wp", "h3efs4s" ], "text": [ "It’s blocking the ‘reuptake’ of them. Sometimes they don’t get passed on to be used / effective and get reabsorbed back. So the blockers block that and force them to continue forward making you feel them more.", "You're correct, the answer is they inhibit reuptake, not the receptors. But what does that mean? The two communicating cells are next to each other with a physical gap between them. Neurotransmitters are chemicals that act as little \"signal balls\". The sending-cell shoots out the neurotransmitter molecules into this gap between cells, they cross the gap, and then bind to receptors on the receiving cell. However there needs to be a way for that signal to \"end\", for 2 reasons. 1. If the message is \"hey I'm firing and you should fire too\", you don't want the receiving cell just firing constantly forever, so the sending-cell needs to turn off the effect of the neurotransmitters it just released into the gap. 2. The next time the sending cell wants to send a message, it would be great to reuse some of those signal balls rather than having to make completely new ones each time. As a result of those 2 things, there is *reuptake*. Basically, the sending-cell then starts absorbing the neurotransmitter it previously released out of the gap and back into itself. This turns off the message it was sending, and allows it to re-use those neurotransmitters later. Now, depression etc can have many physical causes. Cells not producing or releasing enough neurotransmitters as they should be, receiving cells not having as many receptors as they should have, or having defective receptors, etc. Turns out you can improve all of those different problems by blocking or slowing down the reuptake! It lets whatever neurotransmitter is managing to be released into the gap hang out there longer and build up to higher levels. That way, it can at least partly overcome slow release rates, few receptors etc.", "To add to what others have said, SSRIs don’t always work and if they do take some time to work rather than immediately. So it’s not as simple as just increasing serotonin levels in the brain and you instantly feel better.", "Some good responses here, I'll just throw my analogy into the mix. Imagine your brain as a traffic grid. Serotonin, dopamine, norepinephrine, and other molecules like these (called neurotransmitters) are like green lights, red lights, yield signs, or so on. Happiness (or any subjective component of human experience) isn't a function of a single intersection, it's a function of the entire traffic grid. All the cars and trucks need to be getting to their destinations for your brain to be happy and healthy. For the sake of the analogy, let's say traffic not having long enough yellow lights is causing numerous traffic accidents. A single accident doesn't matter so much in the grand scheme of the traffic grid, but if across the board you are getting many fender benders all over the grid because of these too-short yellow lights, then applying a software patch to all the traffic lights in your traffic brain to lengthen those yellow lights will give your traffic a chance to not get into so many accidents. A drug that blocks serotonin reuptake would be like that software patch: a way to get a certain signal to fire a little longer than it would otherwise. It isn't that yellow lights make the traffic run better; it's that the yellow lights are now letting the cars get to their destination in a way we prefer. Similarly, it isn't that serotonin is a happy molecule; it's that having more of it stay in the synaptic cleft for a bit longer is letting your brain have a greater likelihood of giving you a non-depressed state of being. In other words, the molecules are signals. SSRIs, SNRIs, tricyclics, etc. can be thought (in the brain, at least), as dampening or amplifying certain characters of certain signals. Having more of the signal does not necessarily solve anything, but having more of the signal in the right time and place gives your brain a fighting chance of wiring things differently than it did before.", "So a lot of them block these things called reuptake inhibitors. They block the things that eat up all the extra neurotransmitters, meaning that more neurotransmitters are available to be used by the next cell. Its kinda like when people walk into a room, and some of them go into the next room but many of them go back through into the previous room. The drugs block the doors that let the people go back, which forces them to go through the doors in front.", "In all honesty, we've been treating depression with drugs, rather unsuccessfully since the start. Read \"Anatomy of an Epidemic\" It explains alot of the history and methods used to treat various mental illness. Its tragic, really.", "My understanding is that, at least when this class of antidepressants was introduced, it was very well understood HOW they worked, but not why. E.g., if blocking the reuptake of serotonin was all it took to fix depression, patients should experience results in hours, not the weeks it often takes. Maybe the rest of the cause/effect relationship is understood now; my data is at least a decade old.", "A lot of antidepressants prevent the body from capturing serotonin etc which makes their effect go away. Normally, the body releases them for their effect, then captures them again. antidepressants change that to some degree. Also, serotonin dopamine etc are not what makes a person happy. We don't know what makes a person happy. And we don't know how anti depressants treat depression, because we don't know what depression is on a smaller scale. some depressed people actually have more serotonin than normal. [the theory behind serotonin being the cause of depression is over 50 years old and not thought to be true anymore.]( URL_1 ) not that serotonin and dopamine etc has nothing to do with it, it definitely does. but we don't know what role it plays in depression, just that it does and has to do with signaling. Anti depressants also are very ineffective at their job compared to other medications for illnesses. [they improved symptoms above placebo only in 20% of the cases, and prevent relapse over placebo in 27% of the cases. They probably have no effect on mild depression.]( URL_0 ) its better than nothing for a lot of people, but if your painkillers only had a 20% chance of working, you would want better painkillers because those odds are terrible.", "No one actually knows how antidepressants work. [New Scientist]( URL_3 ) [Science Daily]( URL_2 ) [Dr Neil R Jeyasingam]( URL_0 ) [NHS]( URL_1 )", "The premise of the question is off. There is no widely accepted theory for the mechanism of the desired effect, and efficacy studies are marred by the influence of big pharma on research...depression and other mood disorders are a long way from effectively managed let alone cured..." ], "score": [ 493, 96, 20, 13, 8, 6, 5, 4, 3, 3 ], "text_urls": [ [], [], [], [], [], [], [], [ "https://www.ncbi.nlm.nih.gov/books/NBK361016/", "https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4471964/" ], [ "https://www.ted.com/talks/neil_r_jeyasingam_how_do_antidepressants_work/transcript?language=en", "https://www.nhs.uk/mental-health/talking-therapies-medicine-treatments/medicines-and-psychiatry/antidepressants/overview/", "https://www.sciencedaily.com/releases/2016/07/160728125256.htm", "https://www.newscientist.com/article/mg23931980-100-nobody-can-agree-about-antidepressants-heres-what-you-need-to-know/" ], [] ] }

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{ "a_id": [ "h3c880o", "h3c8hhn", "h3cblxz" ], "text": [ "Incidence: New Cases Prevalence: total cases. Incidence and prevalence are both proportions to the total population, where incidence is new cases that developed during a time period, while prevalence is the total existing cases during that time period. Basically, it isn’t like diabetes is infectious, so just a small group of people develop diabetes at any time. That’s incidence But, because diabetes is largely manageable now, there are a lot of people who already developed diabetes that are still living with it. That’s prevalence.", "The number of people who have diabetes in the world is high; therefore, we say it has high prevalence. However, that number is mainly because people with diabetes live with it for a long time, not because there are constantly tons of new cases. Because the rate of new cases is relatively low, we say diabetes has low incidence.", "True to the above but also this might be due to the type of diabetes as well and the context of the population you’re referring - Type 2 Diabetics make up about 95% of all diabetic patients. To throw a curve ball Type 2 Diabetes has a much higher incidence than Type 1. Type 2 can be acquired through lifestyle (though genetic predisposition is a huge factor) but there can be tricky distinctions to be made even within diabetes itself!" ], "score": [ 150, 20, 8 ], "text_urls": [ [], [], [] ] }

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{ "a_id": [ "h3cn4oq", "h3cowzk", "h3cldc3", "h3d7ibm", "h3coyd8", "h3day9m" ], "text": [ "“One or the other, but not both” True XOR True - > False True XOR False - > True False XOR True - > True False XOR False - > False", "The best advice that I ever got in math is: when in doubt, write it out (for functions, plot it out; for word problems, draw it out). It may take a while at the beginning, but that’s how everybody got started. Eventually you do it enough times that you can do the writing/drawing/plotting in your mind, then everybody else start telling you that you’re “good at math”. In this case, the truth table goes like: TRUE XOR TRUE = FALSE FALSE XOR FALSE = FALSE TRUE XOR FALSE = TRUE FALSE XOR TRUE = TRUE Then, you look at it and try to describe it in your own word… …and it’s a difference detector — the result is TRUE only when the 2 inputs are different. Next, go ahead and write the truth table out for multiple inputs… …and you’ll see that XOR is an even/odd detector — the result is TRUE only if there are even number of TRUE’s in the input.", "Well, its like an OR where it can be A or B , you get a true result with any of: {A, B, A+B} EXCEPT its called EXCLUSIVE OR, which means the case where its BOTH A and B is deliberately excluded A xor B, you get a true result with any of: {A, B} or did you mean like how I'd make this out of diodes or whatever?", "You are having a wedding and are asking guests to choose chicken or steak. They choose chicken? Sure They choose steak? Fine They don't want to eat? Not ok, once that open bar takes effect they're going to be wasted without food They want both chicken and steak? Fuck that noise, you're on a budget and weddings aren't cheap.", "If you have two light switches for a room, they work the same as XOR. If either light switch is in the ON position, the light is ON. If both switches are OFF -- *or* if both switches are ON -- then the light is OFF.", "Ask two girls to prom. If one says yes and the other says no, that’s the girl you take. If they both say yes, you just call in sick and cancel. If they both say no, you don’t go. XOR: only one evaluates true to be true but not both" ], "score": [ 71, 9, 8, 7, 3, 3 ], "text_urls": [ [], [], [], [], [], [] ] }

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{ "a_id": [ "h3ct76y", "h3d5h2z" ], "text": [ "If I want to describe a ball, I could use weight (newton), mass (gram), volume (cubic meters) or shape (meters). Which one I use depends on what I want to describe. So with radiation there are different aspects we may want to talk about. How much radiation is being produced (becquerel), how much radiation is in the environment (C/kg), how much radiation has been absorbed by an object (gray), or how much damage the radiation has caused (sievert) each have their own unit. If I say 60 Gy, then you automatically know I'm talking about radiation that was absorbed. BUT, because all of these units describe the same concept/object we can convert them into each other. With my sphere, I can convert shape (meters) into volume (cubic meters), and then use mass (gram) to calculate weight (newton). With radiation, if I know how much radiation was produced (becquerel) I can figure out how much was in the environment at a specific location (C/kg), then determine how much could have been absorbed (grey), and finally use that to calculate how much damage was done (sievert). And similarly going backwards, if needed. Now if you are an American, you are lucky enough to learn 2 units for each of these. It's the same logic as why feet and meters measure distance. America is currently transitioning into the SI units, so students are currently learning both sets. Eventually all the old practicing doctors will retire and the new ones will be willing to use SI, and then it won't be so confusing. Source: I am a radiation therapist.", "Common units are: - Becquerel: this is the unit of decays per second. - Rōntgen: the unit of ionizing events per second in air. - Sievert: The physiological dose acting on the human body. Different units are for different purposes. All count the rate of radioactive events, but are weighted differently with respect to type of radiation and energy. Becquerel is simply counting events (irrespective the energy). Roentgen is the unit of what the dosimeter will measure (as it measures ionization in air). Sievert will measure the effect on human physiology (different energies incur different amount of damages)." ], "score": [ 23, 3 ], "text_urls": [ [], [] ] }

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{ "a_id": [ "h3dd7vo" ], "text": [ "Vibratory Urticaria is an allergy to vibration. Most people are not affected by this. Some people get an itchy feeling on their skin in response to intense vibration. In rare cases the person will break out with red spots or hives on the affected part of the body, or full allergic reaction. Vibratory urticaria can be caused by a mutation in the ADGRE2 gene which controls normal allergy responses." ], "score": [ 34 ], "text_urls": [ [] ] }

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{ "a_id": [ "h3d2an5" ], "text": [ "For \"something like the kids choice awards\"? Or The Nickelodeon Kid's Choice Awards? For the Nickelodeon Kids Choice awards, the show choose whomever they want for any reason they want. Its not a \"real\" awards show like say the Oscars which have intense criteria or things like that, its a commercial. They want people who will show up and be part of the show and be cool with it. A lot of \"awards shows\" work like this, they talk to a bunch of celebs in their area, see who wants to be a part of it, and if they do they will nominate them and invite them to come and both sides get good publicity. These shows are primarily a commercial/PR thing, not some intense scrutiny criteria for getting an award. It just labeled an \"awards show\". Awards shows are big in entertainment, everyone likes a pat on the back, they aren't quite as a big as they once were, but still a big deal. The best way to win these awards: show up. Awards shows often go through tons of people before they find ones will to participate." ], "score": [ 16 ], "text_urls": [ [] ] }

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{ "a_id": [ "h3d4n55", "h3d47ty", "h3d58xq", "h3dd5yr" ], "text": [ "The problem was that people didn't think far enough ahead. Many early computer programs only used two digits for the year. For example, *1976* was just *76*. However, once you hit 2000, two digits aren't enough. When the data says \"00,\" is that *1900* or *2000*? Any date-related program could go haywire. Imagine a payroll program for example--does it pay you for two weeks or a hundred years and two weeks? Fortunately, as 2000 got closer, computer programmers realized the potential problems and raised the alarm. There was a huge world-wide effort to update programs to deal with four digit years. The effort was so good, 2000 came in with very few serious problems. For more info, see [Year 2000 Problem at URL_0 ]( URL_1 ).", "Dates are used in all sorts of calculations. And a lot of those weren't built to suddenly have the year swap from 99 to 00. Imagine a billing program, calculating your next bill it calculates with the end date of the billing cycle being 100 years earlier. Some pretty weird results for the math. Or, a real example, a medical risk evaluation for pregnant women that used age. Suddenly, their ages are all over the place, and instead of getting the risk information of a mid 20s year old they're getting the risk information of a 70 year old. This actually led to abortions in some countries because the tests came back with wonky results. These were known issues, which was why businesses had mostly upgraded their systems early on. The cost comes from having large teams working on *very* important systems trying to make sure that the old and new data flows seamlessly and doesn't accidentally take down a banking network or power grid. Those emergency fixes are even costlier.", "When computers first started getting used in businesses and governments and banks, making programs as small as possible was important, as they couldn't store giant files. So using 75 rather than 1975 for the year made sense. Those early programmers never imagined that years later, many major systems would still be using those programs, and that when 1999 became 2000, those older programs would get confused and not know what to do as a result. This could have caused major problems for banks, for power plants, for military bases, as a lot of them were still using really old software in many cases. A power plant's computer might go \"You haven't paid your bill in 100 years! We're shutting off the power!\" or a bank computer might go \"We can't give that person a loan, they haven't been born yet.\" This was a real issue, and could have been really bad, but because we knew it was coming, companies were able to hire programmers to go back and update those older programs so that they used 1999 rather than 99, and thus prevent Y2K from causing a lot of problems. It could have been bad, but thousands of programmers all around the world worked hard to fix things ahead of time.", "Often, when we wrote dates, we just write the last two digits. 1945 becomes 45, 1969 becomes 69, 1992 becomes 92, 2010 becomes 10. Often, this is fine. Now, say you want to know how old someone is. Easy method is to take the current date or year and subtract their date of birth. If you're in 1992 and someone was born in 1945, then 1992-1945 is 47. But if you only use the last digits, 92-45=47, so it still works! Now, say we're in 2010. Someone who was born in 1945 is 2010-1945=65. Great. But if you only store the last two digits, you get 10-45=-35. Apparently, this person is -35 years old, i.e. they won't be born for another 35 years. Oops. This is the essence of the Y2K bug. Computers that stored dates as just 2 digits might trip up. The would think someone who's 105 and someone who's just 5 are the same age. To fix it, we just need to use a longer date format to do sums. And it might not just be the ages of people. Software might be keeping track of how long ago a particular thing happened. Maybe there's something that needs to happen every 5 year, for example. So, you need to use more digits to stop the computer from getting confused." ], "score": [ 25, 17, 4, 4 ], "text_urls": [ [ "Wikipedia.org", "https://en.wikipedia.org/wiki/Year_2000_problem" ], [], [], [] ] }

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