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m7g6ey | what actions fulfill the statement "by continuing to use our site, you accept our use of cookies"? | Technology | explainlikeimfive | {
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"Cookies are small bits of text sent in the HTTP headers with the response. When you received that page, there are probably cookies. Those cookies may not be permitted to be stored on your system, which is to say that your browser shouldn’t remember them. This is done by not sending expiration values with the cookie, to tell the browser it should forget after it closes. If you continue to other pages, they may take that as implied permission and send cookie headers with expiration values that allow your browser to store the cookies. They aren’t really installed, and they don’t do things by themselves, they’re just blobs of text, some of which can be used to identify you on return requests. Curiously, the only way to remember whether you accept cookies is to store a cookie. So if you decline, or ignore the acceptance, it may prompt you every time you visit. If you do accept, at least the cookie that notes that will be stored, and likely other cookies to remember you later."
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m7gf2r | Is there still missing links in Darwin's theory? | Biology | explainlikeimfive | {
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"The concept of a missing link is not really a thing anymore. The idea assumes evolution is a linear process when it really isn't. Lines of creatures branch off from each other and a lot of them go to dead ends. We aren't descended from chimpanzees for example, we did share a common ancestor long ago, but we branched off into different lines since then, we didn't actually evolve from chimps. This chart may explain it better visually:[ URL_0 ]( URL_0 )",
"The term “missing link” was more of a phrase termed by those who did not want to believe evolution could be a viable predictive model. In science, there are always “missing links”. That doesn’t mean a model doesn’t work, it just means we do not currently have the data or technology to define that gap. As we learn, we find there are new gaps and the scientific method moves on the define those. As for the theory of evolution, yeah, there are a ton of gaps, and more are created every time we learn something new. As a model, there are volumes of data supporting the model and the model holds very strong predictive power, hence it being termed a “theory” and not a “hypothesis”. For context, “theory” in biology means a mode is extremely strong and has a ton of evidence; it’s often misused as “having an idea” or posing a hypothesis.",
"As long as we don't have every single skeleton, there will always be missing links. Scientist these days don't even bother calling their finds \"the missing link\" They're just another example of an early hominid. They've found more links like [Homo heidelbergensis]( URL_0 ) and some more of our cousins like the [Denisovans]( URL_1 ) But the work is on going and will never be 100% done."
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m7gnwm | the difference between a chromebook and a normal laptop | Technology | explainlikeimfive | {
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"Basically, a Chromebook's main function is to run the internet and cloud-based programs. As the name suggests, a Chromebook is integrated with Google's browser and apps. Since it's meant to be an internet machine, it has low-grade specs. It doesn't need a heavy graphics card since you're not installing games, it doesn't need much RAM since you're not running intensive programs, and--most importantly--it doesn't need much of a hard drive because you're not going to be installing and saving much to it. Again, since it's browser-based, it saves stuff to your Google drive. So there's actually very little disk space. A normal laptop is essentially supposed to be a portable computer. A Chromebook (or, more generically, a netbook) is supposed to be for internet and internet apps. Actually, you can think of your Chromebook as a smart phone with a keyboard, except it doesn't call or text.",
"A chromebook has more in common with a Smartphone or an iPad that fully fledged PC. It uses a simplified operating system that can only run mobile and web browser based apps like those you get on your phone, vs the more complex x86 apps on a PC. The advantage of a Chromebook is the hardware is simpler and cheaper, and costs a lot less. If all you're doing is surfing the web, using basic apps, and playing mobile games it's ideal. Chromebooks and Mobile tablets are good enough for 90% of non-business users or gamers these days. They cost less, weigh less, have less parts to break, and the batteries last longer. If you want to play PC games, or need to run stuff for work chances are a fully fledged PC will be better. But the line between the two is blurring more and more every year."
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m7govv | How come two pictures that are the same size and taken with the same camera can have different file sizes? | Technology | explainlikeimfive | {
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"Compression. The camera saves storage space by compressing the image, and how well that works depends on how detailed and sharp the image is. The more information there is in the image, the harder it is to shrink down in size.",
"Different amount of detail in the picture. A picture of some white animals on snow is going to have a lot less detail (and a smaller file size) than a picture of a bunch of cosplayers standing in front of a Tokyo neon-lit street. The way images (a JPEG, for instance), are saved, more detail = larger file size. [This is a pretty good breakdown of the how and why.]( URL_0 )"
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m7h1ob | Why do our ears canals not fill up when we swim? | Biology | explainlikeimfive | {
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"They do, as far as your eardrum. Your eardrum is sealed and airtight so the water can't get past that. Normally it runs right back out again when you get out of the water but sometimes you get some water stuck and it deadens your hearing on that side until you can jostle the water enough to get it to drain. If you perforate your eardrum you \\*can\\* get water (and air and smoke and whatever's in the environment) into your inner ear...that's bad."
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m7h8xs | Why is a professional diagnosis always required prior to treatment and/or prescribed therapy, when multiple self-diagnosis tolls are available that mimic/are similar to tolls used by psychiatric professionals? | Other | explainlikeimfive | {
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"Personal biases affect the way you perceive things about yourself and can affect the reliability of a self diagnosis. That's not to say you'll misdiagnose yourself for sure, but it's much more likely.",
"If the professional is out of their depth, you are going to be even more out of your depth. Going to an expert doesn’t guarantee that you will get a correct answer, but trying to self-diagnose means your chances of getting it wrong are very, very, very high, and insurance isn’t going to fork out money based on the word of someone who almost certainly doesn’t know what they’re doing.",
"A diagnosis (or V Code) is just a way to describe whats wrong, and figure out the best kind of treatment to address it (or justify why a kind of treatment will help, and why an insurance company should pay for it). Self assessments can help narrow down possible diagnoses, but professionals go through years of training to recognize, understand, and rule out diagnoses. Even then, clinicians, and psychiatrists can still be wrong sometimes and miss a diagnosis they don't specialize in, or mistake a diagnosis for something they DO specialize in.",
"More than just getting a diagnosis, which in psychiatry is a lot more than just checking off symptoms, a lot of these meds have serious side effects and adverse reactions that require monitoring. Additionally, if one medication isn’t working dosages need to be adjusted (of which there are maximums) or a combination of medications are needed and some can be deadly when combined. Doctors don’t go to school for 15 years to learn to check boxes, they are in essence detectives that learn to see people as a whole. The reason sometimes it takes a while to get a proper diagnosis is not ineptitude of the physician but a lack of complete information."
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m7hafr | What causes a computer's software to "stop responding", and why is it specific to certain tasks? | Technology | explainlikeimfive | {
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"Software operates like baking a cake. You pull together all the ingredients. You find a bowl to mix everything in. And after everything is prepared, you fire up the oven to bake the cake. When you open up a Save As / Open dialogue box, the operating system these days shows you a snapshot of the file system. This is like you trying to put some silverware back in the silverware drawer. Instead of everything in the silverware drawer being saved anywhere, when you open the drawer, it first loads up the drawer, then it loads up everything inside, one at a time. Now imagine that you're standing in the kitchen again, working on baking that cake. When you're focused on preparing everything, life is good. If you suddenly divert your attention to washing the dishes, the cake process stops while you figure out what you need to wash the dishes. Now imagine that you started washing the dishes but decide to make a sandwich. The cake process and dish washing process are still active and taking up space in your kitchen which means less space to work with while making a sandwich. Likewise, after you open up a few programs, there will be less space (memory) available for additional actions. Once you run out of space either in the kitchen, or if you see that you're trying to do too much in the kitchen and mentally break down, that's the same thing as the software's message of it not responding. As for the second half of your question for why it's specific to certain tasks, think about everything you do in the kitchen. Some tasks take lots of prep and work like baking a cake. Others are nice and simple like pouring a glass of water. You can pour yourself a glass of water all day and have no issues pouring a glass of water. If you try to prepare a complex recipe, you'll need to dig all over to pull all the necessary ingredients together for that recipe. If you try to prepare a complex recipe on another day, you'll still be stuck pulling ingredients and supplies from all over."
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m7hb5x | What actually happens in our brains/eyes/auditory nerves when we imagine sights and sounds? | What I mean is, do the same things/areas of the brain get stimulated? How are we able to imagine a sound and "hear" it but differently than an actual noise? Same for imagining sights. | Biology | explainlikeimfive | {
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"Different parts of the brain, called lobes, have different jobs. For example the occipital lobe at the back of the brain processes vision, the temporal lobes process hearing, and so on. All brain activity is a system of \"emergent behavior\" of a bunch of neurons either activating or not activating electrically, and sending or not sending various chemicals between each other. As to the nature of consciousness itself, well, that's a big philosophical discussion. Over the course of evolution the brain developed more sophisticated layers. Our frontal lobe, the most recently evolved part, processes abstract thinking tasks like planning and language. The most primitive part, the brain stem, controls things like breathing and your heart beating."
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m7hf77 | Why is waking up earlier than usual so difficult no matter what time you fall asleep? | Biology | explainlikeimfive | {
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"Your body has an internal clock that it keeps sync’d through a combination of routine and sunlight/darkness cycles. Thus your body “knows” what time it is, and attempts to keep to a rough schedule by getting tired and waking up around the same time each day, based on when you’ve been going to sleep and waking up most recently. When you wake up is thus a combination of both how much rest you have gotten and also what time you have been waking up for the last several days/weeks/months. It is easiest to wake up when you fulfill both of these triggers and get adequate rest during the regularly scheduled sleep period. It is hardest to wake up when you aren’t hitting both of these targets. So trying to wake up early with inadequate sleep is very difficult. Trying to wake up early after going to bed earlier is better, because you are getting adequate sleep, but still harder than if you were keeping to your regular sleep schedule."
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m7iftc | How does camouflage work in reptiles, spiders, etc? How do they know what color to turn? And how do they turn that specific color? What happens biologically there? | Biology | explainlikeimfive | {
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"Animals don’t know what color to turn. Natural selection is at work. Let’s say a lizard lives in a desert full of beige sand. If the lizards are all green, then predators will have a much easier time spotting and catching them. Through random genetic mutations though, some lizards will be beige. Therefore, they camouflage much better in the beige sand. Beige lizards will be harder for predators to catch, so they’ll live longer than the green ones and have more chances at procreation. Then there are more and more lizards with the beige gene in that desert. This is what survival of the fittest is. The beige lizards are more fit to survive in that desert than green lizards. So, given enough time, all the lizards end up being beige, and whenever there’s a mutation, say a black lizard appears, it is quickly eliminated by predators because it’s an easier target than a beige one. On the flip side, predators rely on camouflage to catch prey (rather than avoiding predators) so it works the same way... the better the camouflage, the better the hunter. Poor camouflage leads to starvation."
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m7ih1h | Why does military communication quality suck while my mobile can produce actual sounds? | Technology | explainlikeimfive | {
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"Your mobile would suck if someone shot a missile at your cell tower. Also you probably wouldn't get mobile reception in the middle of an active warzone (possibly due to missiles/mortars/insurgents with hammers). Military coms often can work without cell towers, but you're stuck talking radio to radio rather than having a big tower full of electronics equipment to help out. Also there's encryption to prevent the enemy from listening to what you say and sending you incorrect orders. Finally, the radio was probably designed in the 1980's and never updated because they couldn't find a mobile that could take the punishment while being cheap enough."
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m7iifi | If mitochondria are small even through microscopes, how do we know how they work?? How do we "know" how body cells function?? | Biology | explainlikeimfive | {
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"Much of what we know about cells comes from a) direct observation under electron microscopy and b) knock-out mutations/disease in people and animal subjects. Some structures we can see under electron microscopes, and we have a saying in physiology of “form follows function.” Basically, the way something looks can inform what it does. So we look at mitochondria and see the double membranes, and then we make hypotheses. What’s the double membrane for? Is it for energy production? (It is—it’s for the electron transport chain) Then we look at what happens if there are no mitochondria at all. What happens to the cells? If they don’t have mitochondria, they don’t seem to make any energy, and they die. Some people have mitochondrial disorders, too, and what happens in their bodies can inform us of what the purpose of the structure is. Finally, animal experiments where genes are artificially silenced or enhanced can prove or disprove our hypotheses. Biochemistry can be frustrating because we don’t normally see exactly what is going on. We have to use surrogates sometimes to make a theory about what is happening, and—when it comes to physiology—sometimes when something goes wrong, we can try to find what is missing and determine the function from there.",
"in addition to r/freethinking375 comment, we can also study mitochondrial function by measuring various processes that involve even more than the electron transport system (btw it's not a linear chain, which is a common misconception). my lab studies skeletal muscle function and to assess the mitochondria, we use a multiplexed assay platform that can measure oxygen consumption, membrane potential, reactive oxygen species production, redox state (NADH/NAD+ ratio), and other key aspects of mitochondrial processes. it's also important to note that certain players upstream of the mitochondrion can affect its function. for example, when you consume food (fuel), the dehydrogenase system will pull electrons from the fuel and carry them to either the first or second complex of the ETS. any lesions within the dehydrogenase system will by default impair mitochondrial respiration. there are also ways to assess individual complex activities through the introduction of substrates that are specific to each complex. we use these data collectively to make inferences about mitochondrial function just as mentioned in the above comment. hope this helped a bit !"
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m7iycj | How do unprofitable businesses fund themselves & their activities? | A lot of big companies like Uber, Lyft, Snapchat, Tesla, etc are unprofitable & lose money year after year. Besides taking on new investors & using that money, how do these businesses fund their yearly budgets? | Economics | explainlikeimfive | {
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"It's mainly taking on new investors and going into debt. Right now, and for the past several years, interest rates on business loans have been almost nothing, which makes going into debt pretty cheap. If this doesn't make sense, that's because it is still a bonkers system.",
"I think that these companies take on low-interest debt. Sometimes it is better to be in the negatives overall with healthy cash flow. I invest in rental properties and although I might put money down AND take on a mortgage to purchase a property which would technically put me financially in the negatives for an undetermined amount of time, this would provide a large monthly income boost that will go on for as long as I have the property. So while companies may take on debt and lose money in the short term, investors often think about the long-term outcomes of their investing."
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m7izcr | Why does it feel really cold when the air conditioner is set to 68 degrees in the summer, warm when the heat is set to 68 degrees in the winter, and extremely cold swimming in 68 degree water on a 68 degree day? | Earth Science | explainlikeimfive | {
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"Expert on heat transfer and thermodynamics here. The reason is because your HVAC system does not push out air at 68ºF. If the heater is on, it only has one temperature: HOT. They usually have an outlet limit of around 170°F. So the furnace works by sucking in supply air through your return, using natural gas flame or electrical resistance coils (or coal, or oil, or a boiler, etc) to raise the temperature of the air by around 40-70°F and then the fan blows it back into your home through the vents. The air coming out of the vents is quite hot, and it's doing that because your rooms are losing heat to the surrounding environment. Cracks in doorways, drafty windows, poor insulation, etc. It'll keep blowing hot air until the average temperature as measured at the thermostat hits 68°F, and it accomplishes that by blowing air much hotter than 68F until the temperature comes up. The opposite is true in the summer time. Your A/C isn't blowing 68°F air. The air coming out of the evaporator coil is typically 40°F. Except this time it's fighting against heat coming in from outside. It's the same physics though. Same philosophy. To bring the average temperature in a room down from 75 to 68, you blow 40° air in until the average drops to 68°F. So if you're standing anywhere that you can feel air coming through the vents, you'll feel far hotter or far colder than the 68°F temperature the thermostat is set at. Now, your body can't sense absolute temperature. You can only feel heat flux, or the rate of heat transfer into or out of your body. It's why grabbing a pizza in a cardboard box out of the freezer doesn't feel as cold as grabbing a piece of ice. The two are at identical temperatures, it's just that the cardboard is a very poor conductor of heat. They're at verifiably the same temp, but touching them you'd notice a difference and that's because your body perceives heat transfer *rates* and not absolute temperature. This is the primary reason why 68°F air is completely comfortable and 68ºF water can actually kill you from hypothermia. They both have different densities, specific heats (thermodynamic property), and heat transfer coefficients. Water can transfer heat away from your body roughly 25 times faster than air at the same temperature. So you can actually get hypothermia in water that's at what you would assume was room temperature.",
"There are lots of things that make your body feel like “it’s nice outside” - the actual temperature is just one of those things. Have you ever been outside and moved from a sunny area to a shaded area, or vice versa? The sunny area would seem warmer than the shaded area, even though the air temperature is the same. The energy from sunlight will make you warmer - it’s what warms the earth and the air to begin with. Have you ever been outside and moved from a windy area to a non-windy area, or vice versa? Cold air feels colder when it’s windy and hot air feels hotter. This is because there are more molecules of air rubbing against your skin. Air movement matters. Air contains lots of things - oxygen, carbon dioxide, other stuff, and even a little bit of water. Sometimes there is more water in the air and sometimes there is less water in the air. Our bodies feel the temperature of air with more water quicker than when there is less water in the air, just like we feel it more when it’s windy. When it’s hot, things are even worse because our bodies sweat to cool off. We cool off when the sweat evaporates into the air, but this happens slower when the air has more water in it than when there is less water in the air. Humidity - the amount of water in the air - matters. In fact, the air conditioners in our cars and houses make us more comfortable because they lower the air temperature and also remove water from the air - this is why water drips from the bottom of cars on hot days... the water is what the air conditioner removed from the air."
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m7j1v8 | What is an alternate reality game defined as? (ARG's) | And how does it different from augmented reality? | Technology | explainlikeimfive | {
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"Augmented reality is augmented or changed/added to. Typically it involves a layover by looking througj some kind of glasses or tablet or such, where computer graphics will overlay against a real life background. Pokemon Go is a good example. You can see the pokemon against a real world background using technology. Alternate reality is akin to roleplaying where the game takes place using the real world. For example, it may involve solving a puzzle where clues are posted through sources like radio signals or websites that appear to be legitimate, not just \"part of a game\". In this sense, you're \"changing\" the reality we experience, altering it to make it something else. Often times its not initially explicitly stated to be an ARG and the air of mystery is what makes it interesting. Clues will be left for people to pick up and be curious about, leading them on a hunt for more. It'll just he this weird thing and they don't know what it is till the stumble through it. Its often used as a form of viral marketing."
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m7jiog | What does it mean to borrow against oneself? How does it work? | Economics | explainlikeimfive | {
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"It looks like you’re borrowing from yourself but you’re really borrowing from the market. Most employers don’t let money be added to your retirement when you borrow from yourself so if the market is on an upswing you’d be missing out. On the opposing side if the market crashes you could have to sell assets to maintain an account minimum of the agreement. If you lose the job or quit you could have to pay the loan back in full in a short period"
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m7jqq9 | How did tea become a cultural alternative to coffee? | I did a google search and searched the sub but found nothing. I don't want to say a universal alternative but it seems to be that way. I've usually seen folks (including myself) go for teas rather than coffee if they want an alternative warm drink. Why is this? What kind of cultural history made this a normal thing? EDIT: Sorry about the super dumb wording. It's very late where I am. You'd think I'd remember that tea has been much more prominent and significant for a much, much longer time in eastern countries, especially since I've been to Japan and I study the language. | Other | explainlikeimfive | {
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"Tea has been around way longer than coffee. And spread throughout Asia. Its possibly been around 10000 but at least 5000 years. Coffee has only been around 1 to 2 thousand years. So if anything coffee is the alternative. The US switched from tea to coffee around the time of the revolution as an anti british sentiment. In many parts of the world tea is still more popular but America's switch and other things led to the western world adopting coffee.",
"The Eastern countries have historically had tea. Tea has been part of the Chinese and Indian cultures thousands of years before the USA even existed.",
"Your statement is, taken at a global level, likely untrue or at least hardly universal. At the very least, it depends on which culture or society you belong to. Tea is probably more popular globally than coffee. India and China (40% of the world's population) are, on the whole, considered tea drinkers. And of course the stereotypical view of the British is still true. Tea is still the more popular drink in the UK. Coffee, relative to tea, is a newcomer (\\~1000 years). In terms of dollar sales, it definitely outsells tea. But that is because coffee costs per cup is much higher than tea. (Coffee requires much more processing)",
"Dear OP, ignorance is easily remedied!! You asked the right question, and now you know. It’s why we have these subs. Go forth and enlighten!",
"I can ask same question by flipping up tea and coffee. The same reason coffee became alternative to countries where tea is the most grown beverage but rest of the world introduced coffee to them."
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m7jr2l | why does it matter if air is in the bloodstream? | I know that it can like cause you to die, but I don’t understand why, your blood has oxygen in it already. It always seems like they waste some when they’re about to inject (insert drug here) | Biology | explainlikeimfive | {
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"Oxygen and air bubbles are not the same thing. Think of it like a car engine. If the gas is flowing through the engine properly then the engine works fine, but if there's an air bubble in the gas line, then it causes the engine to \"miss\" and sputter. When the heart \"misses and sputters\" - that's a heart attack",
"Air bubbles can physically prevent bloodflow. Preventing bloodflow to a small part of, say, your brain, can kill you."
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m7jxoz | How does ownership of TV air time work? Do the broadcasting channels like ABC, CBS, or FOX own the specific channels? What would prevent me from having my own channel to broadcast whatever I wanted over the air? | Technology | explainlikeimfive | {
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"In the US, control over broadcasting frequencies is through the FCC. Each broadcaster is awarded a certain frequency to broadcast on. You will be prevented from broadcasting over the air. It would be impossible to broadcast and not be detected and the location triangulated very easily.",
"Broadcasters are licenced to use certain bands of the broadcast spectrum. They pay the Govt for such licences. When detected, penalties in law would be used to prevent the unlicensed broadcaster from continuing. How would they know? Well, if you were to broadcast at exactly the same frequency as an established brand, it won't take long for their regular viewers/ listeners to complain about the interference with their regular programming...."
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m7md89 | How do our brains visualise past visions from memories? | What allows us to see these sights so readily, say when we close our eyes? | Biology | explainlikeimfive | {
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"Scientists don’t know exactly. But they have scans that show where the brain is active at the time. When we remember stuff visually, the same part of the brain lights up as when we actually look at something. So, to your brain, you actually are looking at this memory!"
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m7n3kg | If our body replace our skin every 7 years, why does our skin start to look aged? | Biology | explainlikeimfive | {
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"Your skin consists of 3 layers. Outside is the epidermis, these cells are indeed replaced, not even every 7 years, but every single month, so no problems there. The layer under the epidermis is called the dermis. The dermis has cells, these are also replaced, not quite as fast as the epidermis, but still fast enough, still no problems. However, surrounding these cells are loads of filaments, the most important for the ageing effect are the elastic fibers. These cannot really be replaced, they were all formed when we were an embryo or in the first years of our lives and that's more or less it. So it is the loss and/or damage of these elastic fibers that gives us wrinkles and not the cells themselves. (the 3rd layer is the subcutis, which is more or less the fat under the skin, but is also not really involved in ageing) Contrary to some other comments, it's really not because of DNA damage or cell division.",
"Skin is held tight and smooth by collagens, like rubber bands they deteriorate over time. While the upper layers are replaced the lower layers of skin aren’t as much...",
"Each time our skin is replaced (or anything in our body, really), it does a slightly worse job each time. You can almost think of it like a really long game of chinese whispers. Each replication, the same instructions are given to the new cells, but sometimes there's some slight errors in communication. With enough of these happening throughout the years, the cells aren't able to create skin as good as they used to, because the instructions the new cells have are a bit different to how it was originally done.",
"Something I'm not seeing here mentioned, is that the SUN does a lot of damage to our skin, and if you regularly use sunscreen in sunny weather, you will stay looking (or even improve, if coupled with other skin care) much younger than your age would suggest.",
"Your body is not just made up of cells, there are parts outside of cells. A good example is bones. Bones can be healed. But most of the “extra cellular matrices” cannot be repaired by your body. Elastic fibers in your skin are one such part that your body can’t repair or replace."
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m7nosi | What's REM and NREM sleep and which one is considered deep sleep? | Chemistry | explainlikeimfive | {
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"Both. REM is rapid eye motion, NREM is non-REM, a similar deep sleep phase. REM is a dreaming phase, NREM is a non dreaming phase. Both are deep sleep, perhaps arguably NREM is deeper. NREM appears to be more important - you get NREM phases earlier when you're more tired then REM later.",
"REM is deep sleep. It is the last phase of the sleep cycle. The NREM sleep actually consists of 4 phases and starts from a light sleep then going deeper until you reach REM. During REM you dream. Every night you go through the cycle several times. You are most easily woken up during NREM. If you wake during REM sleep you will actually feel as a truck hit you - very irritated, very tired. This is why sometimes when you slept 3-4 hours and wake up you might feel refreshed but if you slept 10 hours you might feel terrible. Depends on what phase you woke up. Tip: If you feel terrible every morning when the alarm goes off, change your alarm to be 20-30 minutes earlier to avoid waking up during REM (considering you go to sleep approximately the same time every night)."
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m7ox5w | why do different areas of the face develop different types of pimples? | for example, why do i find mostly blackheads on my forehead and mostly whiteheads near my chin? | Biology | explainlikeimfive | {
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"Skin thickness plays an important role, and related to that is the depth at which the sebum gland sits. Iirc blackheads are black because they contain melanin, which is produced for the same reason we get tanned in the sun; light exposure. A deep pore may not be exposed to light as much and will therefore be paler. The forehead has thin skin and very little subcutaneous fat, so the glands will be closer to the surface there. Edit: Yeah the color is from oxidation from air exposure, not light exposure, but mostly same answer regardless."
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m7pkpm | What is the purpose of a rubber duck? | Other | explainlikeimfive | {
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"It's super useful for programming because you can explain your problem to it (helps thinking it over in its entirety) without having to chase it down and tie it up like you'd have to do with colleagues. Also children like them in baths? I think?",
"To create elaborate scenes in the bathroom to annoy your roommate with progressively more ducks. Then, when they demand the littlenducks be removed, you get larger ducks to annoy them. Finally, when you compromise and are only allowed one duck, you get a massive inflatable duck that takes up the whole bathroom.",
"According to Wikipedia, they were originally made and designed to be chewtoys but then someone had the revolutionary idea to make a duck float and the rest is history."
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m7pqpv | why does a physical trauma (car crash,bad fall, etc) start the flare response in people with autoimmune diseases? What is the body responding to? | Biology | explainlikeimfive | {
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"The role of the immune system is not limited just to fighting off infectious pathogens, although that is a major aspect of the work that it does. The immune is also generally responsible for cleaning up around wounds and stimulating the repair of injuries. Anytime anything damages or kills cells in the body — be it a cut, a bruise, a broken bone, a cancerous growth, or an infection — it’s the immune system’s job to clear out any foreign material and remove any damaged, infected, or dead cells, so that new healthy cells can divide and replace them. In other words, the immune system is not *just* the body’s police force, it’s also the body’s fire department and garbage collection. Traumatic physical injuries activate the immune system and stimulate immune cells to start killing and eating damaged cells. In people with autoimmune disorders, this process of killing and eating cells can run wild and off-target."
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m7q2ak | Schizophrenia vs Tulpa vs Plurality (dissociative) | I came across this topic recently and tried to read some of the articles online. But many consists of vague definitions and some made me even more confused than I was previously. & #x200B; So if someone could help me understand this differences a little bit more will be greatly appreciated! | Other | explainlikeimfive | {
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"Schizophrenia - A person has delusions and hallucinations, creating a distorted view of reality. She may see and hear things that don't exist, such as people, but does not know they are not real. Dissociative personality disorder, once called plurality- Person has more than one distinct personality. The personalities may or may not be aware of each other. Note that a person can have the disorder but have no delusions or hallucinations. Tulpa -- Person creates a voice in her head through a conscious effort. The person has no delusions or hallucinations.",
"Schizophrenia, despite the common portrayal in the media, has nothing to do with having a split personality. The defining symptoms of schizophrenia are delusions and hallucinations. A delusion is a firmly held false belief. A common delusion is that you're being followed by the government, or that someone is trying to kill you (it's only a delusion if they believe it in the complete absence of evidence to support it, if you believe you're being followed because you actually are being followed, that's not a delusion) Plurality is essentially another term for Dissociative Identity Disorder, which is about having distinct personalities. It can be comorbid with schizophrenia but a split personality isn't on its own a symptom of schizophrenia"
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m7re64 | How does your eye get longer to cause myopia? | Biology | explainlikeimfive | {
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"Your eyeball is squishy and your eyeball hole is not necessarily round. Sometimes growing up your eyeball hole gets even less round, due to genetics and/or up-close activities like reading and screen time.",
"Ophthalmologist here. There is no easy way to ELI5 because... we don't really know why it happens. In some people it is genetics. We do know however that increased accommodation (smartphone use) for prolonged periods and not being exposed to UV light may lead to that."
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m7s6ru | What actually happens when one of our body parts "falls asleep"? | Also, is there a more professional term for this? | Biology | explainlikeimfive | {
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"You compress one of your nerves. This stops those nerves from working correctly. Since the signals can't get past the compressed area, it can't get to your brain and you can't feel it. It's called Obdormition.",
"Typically a nerve fiber gets pinched in a way it’s not really supposed to. This causes all the nerves along that fiber to go a little haywire, which your brain interprets as that pins and needles sensation going along that area. This awkward pinching is also why it often happens if you’ve been laying or sitting in a weird position for too long. And the technical term for it is paresthesia"
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m7sku0 | why do fake laughs sound fake? | what makes them sound fake? how can we distinguish them from a "genuine reaction" so easily? | Other | explainlikeimfive | {
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"You don't hear the body resonating. It's similar to a fake smile with the mouth, but missing the eyes part of the smile.",
"Often, they are too breathy. Folk will take a big breath and then try to laugh. Just doesn't sound right. The key is to breathe out and then laugh. It sounds much more convincing, especially after some practice.",
"It’s basically because they’re not good enough actors. For an actor to believably convey an emotion, there’s a way in which they’re controlling their body to actually experience/embody that emotion (in some form). So, since laughter is an emotional response, such as smiling or crying, it’s impossible to do it honestly without feeling it honestly."
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m7sypw | Why does the age of who we’re attracted to grow older as we get older, is it a human trait? | Biology | explainlikeimfive | {
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"Depends what you mean. I’m 35 now. I still find 22 year olds generally more physically attractive than 35 year olds. But I wouldn’t want to be in a relationship with one anymore. So physically attractive? I think this post is definitely wrong. But attracted to on a more meaningful level? Of course we would be more deeply attracted to people who have more in common with us.",
"Because we’re also attracted to people who have experienced as much life as us if we’re actually aging healthily, sometimes younger people have emotional maturity but people that are ONLY attracted to people 20+ years younger than them are usually very into controlling and manipulating people less knowledgeable than them whether they know it consciously or not.",
"Attraction at it's core is about survival. Best chances for your attraction to pan out successfully is to be attracted to those who are relatively equal to you in terms of attractiveness. So as you age, your attraction tends to age because unless you have something that offset your age cough*a fat fucking wallet*cough you have really low odds of successfully pairing with someone significantly younger than you. This is the same reason that when you see wide age gap relationships, you can safely place a bet that the older individual has money. Rich young people aren't attracted to older people (probably some out there but they're rare exceptions) because what's the survival gain? Nothing. It's a net loss.",
"It doesnt. Studies have shown for men the age they are most attracted to stays 21-23 their entire lives. Women tend to like older men until they hit about 50 and then prefer slightly younger (4-5 years). & #x200B; [ URL_0 ]( URL_0 )",
"What alternate reality are you living in where old people aren't attracted to young people?",
"Sorry ,but we don't The actual \"trait\" is to be attracted to individuals of fertile age. Unfortunately that can be taken in many different ways",
"I'm 31/m. Would I bang an 18 year old hottie if given the chance? Without a second thought. Would I date one? No, because they are immature and have different life goals. I find younger women more physically attractive but older women more mentally and emotionally stimulating. I think half the problem is they stop caring about their appearance once they hit 30 and pop out 2 kids.",
"If you look at it purely visually, we would definitely find someone younger 'attractive'. However, attraction is not only visual - I for example might not get along with or be able to carry on an interesting conversation with someone 20 years younger than me (I'm 40). Someone in a similar age group has much more in common and therefore understands you better than someone much younger would.",
"So at least [based on day from the online dating website OkCupid]( URL_0 ) this isn’t actually true...for men at least. Throughout their entire lives men report finding women in thei low 20s to be of peak attractiveness whereas women tend to find men their own age to be the most attractive. However this isn’t to say that most men end up with women in their 20’s—just who they prefer. On average the age gap between men and women is roughly 3-4 years (women being younger). Reason as to why men are attracted to younger women is pretty simple from an evolutionary prospect—they’re also the most fertile and have the most child bearing years left."
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m7tgq3 | Why would eliminating the filibuster hold senators accountable? | Other | explainlikeimfive | {
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"Because it would force them to vote on difficult issues. Currently the filibuster allows Senators to just never vote if they don't want to. Without it they'd be forced to take a position, and a lot of them don't want that because what their voters support is different from what their financial backers support.",
"The filibuster was not a designed or intended thing. It was initially just a consequence of the rules. There is no means to stop someone talking nor was their a time-limit, you can only vote when everyone had their say, hence as long as you keep talking no one can ever vote on any law. Cause this created utterly unworkable solutions, Means of stopping people from talking have been introduced. This generally involved just using a larger majority than 50.1% (like 60% or 70%) to force a vote Can congress be rid of it? Sure, congress itself sets the rules for the filibuster, so lowering the vote required to force a vote to a simple majority kills the filibuster. What are the effects? More legalization will be passed, for better or worse. Republicans in power with 1 seat? they can now pass bills without any stray democrats. Democrats in power? they can pass bills without stray republicans."
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m7ucbo | How do scientists cryogenically freeze people without knowing the process of unfreezing them? How can they say that revival is possible if they haven’t been able to do it? | Biology | explainlikeimfive | {
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"The idea is that the revival technology will be developed in the future. People who have done this left instructions to be frozen immediately after their death from terminal illness, on the offhand chance that a way to revive and cure them is eventually discovered. The companies that handle this process make no guarantees that you’ll ever actually come back, only that they’ll do their best to maintain your mummy for as long as the trust funds last.",
"They just do it and trust that one day in the future the technology will exist to thaw them without the cellular damage (or at least the ability to correct it). It is junk science.",
"Currently , we can't freeze anyone alive because of the legal reasons. To cryogenically freeze a person, the person must be considered legally dead before being frozen. In the future , I am not sure what can science do to a dead body. I think necromancy would be a bigger possibility than scientifically revive some dead frozen person.",
"The companies are lying when they say that the revival is possible, not \"the scientists\". It's part of the sales pitch.",
"At least when they started doing it, the idea was that the people being frozen would be dying of some disease with no cure. The whole premise is that they are passing the buck down the road hoping that in the future someone figures this stuff out.",
"They simply do their best, leaving undiscovered techniques of resuscitation for future generations to employ. Sadly, any successfully cryogenically frozen people are far more likely to be used for scientific study in the future than resuscitated to live a new full life. (that's my opinion anyway)"
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m7umfw | Do we perceive bad smells (i.e rotten food) as bad smells because they are potentially harmful to us? | Biology | explainlikeimfive | {
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"Generally yes. Chemicals that we find particularly noxious are rarely present randomly on their own, they’re sulfurous compounds that decomposing bacteria release as waste. The various sulfides aren’t necessarily toxic on their own, but their presence indicates a high likelihood of nearby decay - or active volcanoes. Animals that actively seek out decomposition like flies find the horrific scent of hydrogen sulfide quite attractive.",
"Yes, but it's a two-way street: microbes also make the smells and toxins _because_ they ward you away from food. Microbes rotting food are actually competing with large animals for access to that food. If you eat it, they can't grow on it anymore. So some microbes on rotting foods produce toxins (and smells that signal the presence of those toxins) in order to deter larger predators from eating their food (and them along with it).",
"we are really good at detecting decaying food. A couple examples: Onions have a very distinctive smell, now when an onion starts to decay you will smell it, even if it just started. Same goes for most vegetables. Especially the human, who is an omnivorous, has a \"smelling system\" where we categorize things to unpleasent and good. There are nearly no animals that do that, because they have other senses to tell them that food is good or bad. Like vision, Frogs have very bright colors, so predators think they are not good to eat. Nettle hurt when eating, so animals remember the look of them. But also do we perceive smells as bad when we connect it with a bad experience. Cheese is a good one, there are many people that dont like cheese and really hate the smell. This can happen when your parents force you to eat certain things, i.e. cheese, when you are small. So you connect it with a bad experience, this is also the reason why wwe chaneg our taste every couple of years or so, we try to reset these bad experiences and connect them with new ones. I hope that makes sense to you, my english is not the best ngl.",
"Omg this just brought back memories. I was like 8 years old and at my friends house and it was Easter. They had a bowl of intricately painted Ukrainian style Easter eggs in a bowl. I picked one up to look at it closely and it suddenly exploded. POP! Teal green slime everywhere. I remember the color vividly it was like neon fucking teal. It was everywhere, all over me and the surrounding area and the smell was horrendous. Instant gag. Normally when you make these kind of eggs you pierce them and drain the contents. This one was not empty and who knows how long it was festering....years?!",
"Same goes for why many don’t like bitter. As i heard it, we taste salt because it’s essential for the cells. We like it, so an extent. Sweet, the taste of carbonhydrate. Sour, can’t remember what that was. Bitter, most often poisonous stuff. Umami: taste of protein. I’m not 100% about if i remember it right, but bitter is certainly ly like this",
"A lot of things we fear or find disgusting are perceived as such due to evolutionary avoidance. We are disgusted by animals like rats and rotting smells and bad tastes because we learned to fear things that transmit disease as those who didn't were more likely to get infected and die. Potatoes taste bitter to us because until very recently they were deadly poisonous and our palates remember that and still try to warn us \"NO! THIS THING CAN KILL ME!\""
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m7utq8 | If water is clear and colorless, then why is it blue? | Earth Science | explainlikeimfive | {
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"Water is blue because it absorbs red, yellow and green light, but scatters blue light. The reason a small amount of water appears clear is because not much light is scattered. In larger bodies of water there are more water molecules for light to collide with, resulting in more blue light being scattered.",
"It is very slightly blue. So when you don't have very much water it doesnt look blue at all but when you look through a bunch of water it will look blue."
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m7vd0p | How do predators that swallow their prey whole prevent getting hurt from the panicing animal in their stomach? | Biology | explainlikeimfive | {
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"Sometimes they do, but not very often, obviously. Prey animals panic, get exhausted, and go limp. Also There's no air to breath in an animal's stomach and it's highly muscular and constricting so the prey rapidly dies of asphyxiation. However it's not entirely impossible for prey to escape from a stomach and it's been documented occasionally. Here's an eel pulling a chestburster [ URL_0 ]( URL_0 ) A pigeon is a pretty wimpy animal, though, it doesn't have a sharp strong beak or sharp claws.",
"Snakes in particular will usually strangle their prey first. While it might not fully kill them, they’re not alive enough to fight back. Pelicans will sometimes scoop up water to drown their prey before consuming. Once inside, the prey doesn’t really have a whole lot of room to move about so it’s hard to get a good peck or scratch in.",
"Wildlife biologist here: being a predator is dangerous and many predators do eventually get injured or killed by their prey. Check out this gruesome (but cool) photo of a heron flying around with an American eel that burst out of its neck. It's a tough world out there. & #x200B; [ URL_0 ]( URL_0 )",
"The pelican traps the food in its large beak until it is physically exhausted (so the pelican's throat isn't torn up by the animal kicking and fighting), and once swallowed, the animal (i.e. a pigeon!) will pass out from lack of air, then perish.",
"While not a nice thought, consider how difficult it is to use a weapon in a limited space. Imagine that space becoming so tight you can barely move. Now imagine the same space has poor air quality and you're struggling to breathe. Now imagine that it's dark and you can't even see. If you're lucky, blind panic might knock or cut something loose. More likely, you're just going to tire yourself out, use up all your air, and die. On top of this, consider that most prey animals that are typically swallowed alive are also the same ones designed not to snag. Mice fit through all kinds of small spaces, as do snakes, while fish are hydrodynamic. Any defenses designed to make them harder to swallow could also impede their ability to navigate their environment, and might ironically get them eaten faster.",
"Most prey animals that get eaten alive are weak and small. Evolution has weeded out animals that try to swallow porcupines and badgers alive.",
"The truth is sometimes they do get pecked and clawed. Obviously they do what they can to hurt/exhaust/kill the prey before hand and you can bet the the animal getting swallowed isn't given much room to move or breath which leads to the death of prey that might not already be dead. But given all of that, sometimes the prey will still find a way to fight back and this can seriously injure the predator and might even kill it while the prey dies anyway. Nature, you scary.",
"gizzard. > The gizzard has a number of important functions, such as aiding digestion by particle size reduction, chemical degradation of nutrients and regulation of feed flow, and responds rapidly to changes in the coarseness of the diet.",
"The snake that swallowed a porcupine, didn't survive. URL_0 .",
"Read the comments as I was curious myself. Satisfied, I move on. Scroll down and immediately see the pelican swallowing the pigeon video. Felt smug watching, like I’m some sort of pelican nutritionist.",
"Hi, squirrel rehabber here. I can’t explain exactly why that happens. My experience with feeding live mealworms to squirrels is that they swallow them whole, so they’re a choking hazard. We can’t feed them to young baby squirrels because they tend to crawl back up in the back of their throat and cause them to gag 🤢🤢"
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m7vm9s | One reason we try not to contact uncontacted tribes today is we might spread disease killing the tribes people, but is there any significant risk that a uncontacted tribe could expose the world to a deadly disease that was isolated with them if they were ever contacted? | Biology | explainlikeimfive | {
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"Sure, but the risk is much, much smaller. Because of the shear scale of the 'developed' world, we have all been exposed to or vaccinated against a myriad of diseases. Trade caused those groups to come into contact with one another and let otherwise isolated diseases spread to new populations, which developed immunity over time. A small, isolated group might have a disease that could infect us, but _we_ have hundreds of diseases that could infect them.",
"In addition to what other people have said, the most deadly diseases were really only able to develop in an urban environment because if a disease was deadly enough it would kill people faster than they could be born (prior to modern medicine that is) essentially wiping itself out. But urban areas constantly had enough people moving in to maintain the population. So there's already a really low chance a small isolated group of people ever even be able to support a super deadly disease in the first place.",
"It’s possible, but we don’t have evidence of that happening yet. We do have a ton of evidence the other way around, in the case of Native Americans for example.",
"CGP Grey has a great video on youtube that talks about why there was no America Pox to kill the European colonists which relates closely to your question.[ URL_0 ]( URL_0 ) Edit TLDW: human viruses are good at not killing humans. The deadliest plagues come from animals of which, most have been domesticated. Any uncontacted tribes are unlikely to carry any animal diseases that would affect the rest of the world.",
"No for the same reason that native Americans didn’t bring many diseases to the table: major diseases and viruses generally come from domestication of animals. Domestication leads to close contact where we get animal viruses like smallpox which comes from cows and originates this whole thing. So unless an undiscovered people group was also advanced enough to domesticate wild animals, we don’t have much to worry about."
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m7w8l6 | Worksheet that is "Illegal to post on Internet" | Technology | explainlikeimfive | {
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"You can’t post the entire text of Harry Potter online for people to download because it’s covered by copyright laws. This section of a digital math textbook likely is as well. You can’t own math of course, but you can copyright specific text of questions and answers that you have written.",
"if not human decency then in this case at least copyright law. while you cant copyright the problems themselves, you can get a trademark/copyright for the composition.",
"Copyright law is what's preventing you. Technically, it prevents you from posting it anywhere. You're not allowed to make a copy unless you have a license. You could be sued for copyright infringement."
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m7wsng | why do you feel the urge to take a dump when you’re nervous/anxious? | Biology | explainlikeimfive | {
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"Its a flight/fight response, you will notice it in animals too. The quick evacuation of the bowels lightens the body incase you need to haul ass. Its essentially panic-shit.",
"In Psychology they said the brain shuts off pissing/shitting urge a lot in fight or flight cause your body puts its energy elsewhere."
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m7wvag | Why does Australia have so many weird creatures compared to everywhere else? | What is it about their geography or other factors that makes them so attractive to the scariest bugs and other creatures? | Biology | explainlikeimfive | {
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"One reason is Australia is completely isolated. All the rest of the world is or was recently connected (in a evolutionary time frame). Since they were all connected, many thing evolved or developed on a similar path. Australia disconnected from the others on a much earlier timeline and had longer to evolve animals in a different way.",
"Oh, they been isolated for so long & was discovered couple of hundreds of years after Americas plus the fact that it’s resource poor, hence survival traits were maxed out by animals in its evolution tree.",
"Australia has been separated from the other countries for a long time so different animals had the opportunity to diversify into many niches. Like for example, placental mammals never made it to Australia, so the marsupial and monotreme mammals didn't have them to compete against, they had the opportunity to become established. Same for the surrounding islands, many had different animals filling out the niches that would usually be filled by placental mammals, such as small running birds that took the niche usually filled by rodents. The Kakapo is a heavy, flightless nocturnal parrot from New Zealand that was very successful before European humans introduced mammalian predators. The bird is well camouflaged and it's natural predators were all birds of prey that hunt by sight, so when it feels threatened, it freezes to be harder to spot. When cats, ferrets and other placental mammals were released on the island, the kakapo's defence mechanism was useless because those mammals hunt largely by smell. There are now very few kakapo left alive. This is an example to show how a completely unique ecosystem of birds filling in what we know as mammalian niches had developed on New Zealand and was very successful until invasive species were introduced. Plants are different in Australia for the same reasons animals are- there was a long period of time where Australia was isolated, so the living things there had time to evolve independently of the rest of the world. The life on Australia when it became isolated was the entirety of the Australian gene pool, and the traits that evolved in Australian nature were limited to that pool and the mutations that happened on the island (so that's why no placental mammals evolved there, they were not part of the available gene pool). Other continents had different gene pools and mutations. Over millions of years, evolution occurred differently based on these different starting conditions. \"Scariest\" is not a real descriptor for animals, but if you're talking about venemous animals being found on Australia- they're also found in Asia and Africa etc. That is not something unique to Australia, nor is having many invertebrates. If you're talking about the *potency* of venom found in Austalia, then it could be an evolutionary arms race situation. All the snakes in Australia are elapids, which are venemous. So the gene pool for snakes contained venom from the start. More potent venom is advantageous to a snake because it means it can bring down larger prey and ensure they don't get away before the snake can eat them. If the more potent snakes are better at survival than the less potent snakes, you will see a trend of venom becoming more potent as weaker snakes are selected against. The result is that all the remaining snakes are highly potent. This type of situation is also applicable to invertebrates, reptiles and mammals- it is common for venemous or poisonous species to become more potent over evolutionary history especially when their neighbours are using the same tricks. All in all, Australia is unique because it has been evolutionarily isolated for so long that it built up ecosystems out of completely different animals and plants as we have in the rest of the world. Traits like very potent venom evolved because they provide a fitness advantage, just like birds evolving to become ground dwelling, or plants evolving to be drought resistant etc."
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m7y711 | how does motion capture work? | Like when an actor does things, does the animating team have to still animate it, idk how to explain it. | Technology | explainlikeimfive | {
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"For most professional mocap, the actor wears a suit with special markers at key points on the body. As the actor moves, a camera records them and feeds it to a program. The program then creates a 3D 'skeleton' of the actor moving around - the markers help the program identify keep points on the body. The animators can then layer textures on top of that skeleton so that the end result is animated, but it has realistic motions (because the skeleton is a recording of the actual motion)."
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m7ysq9 | How do baby animals know what to do | Like when a kangaroo is born it knows to climb to the pouch. How does it know that | Biology | explainlikeimfive | {
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"This is a huge topic in animal psychology. The truest explanation is that they kinda don't. They know how to move their bodies and they know they want to move someplace warmer. They learn about the pouch along the way. Come to think of it, I'm pretty sure kangaroos place their newborns in the pouch before they're mobile. So they learn about the pouch BEFORE they start moving around.",
"The same way our heart and organs function without us doing anything but yeah it's amazing. Watch Planet Earth 2 when the lizards hatch in sand but take off for high ground right away because they know they're in danger.",
"How does a human baby know when to cry. It’s just embedded with the organism’s brain function. It’s simply nature. There is literally no other explanation for a definitive answer."
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m7z9uo | How do recycling centers work? | What happens to my milk jug? I also hear how a lot of items sent there can’t actually be reused. How can we help this problem? | Other | explainlikeimfive | {
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"I hate to disillusion you, but generally the vast majority of stuff sent to be \"recycled\" is actually just thrown back into the regular trash, probably to end up in a landfill. Recycling centers usually only recycle stuff that's economically feasible to recycle. That means glass, aluminum cans, and a small amount of clean plastic. Other types of materials like paper and most plastic aren't recycled unless they're part of a bulk deal where the provider (usually a business) can guarantee that they're clean and properly sorted. Furthermore, recyclable materials often can't be recycled back into their original form. Instead, they're recycled into other forms where consistency is less strictly required, like those park benches made of recycled plastic, or glass being added to asphalt. So the recycling process isn't really the fully complete loop you see in educational cartoons. That's why reducing waste and reusing what you can are so important. One way to greatly increase the amount of recyclables that can be recycled is to switch to \"multi-stream\" recycling instead of \"single-stream\". This means that instead of having one recycle bin that you throw all your stuff into, there are three or more bins, each with a very specific type of recyclable (e.g. cleaned glass bottles without tops). That way there's much less cross-contamination, and the expensive pre-sorting process can be skipped. Of course, you'll need to either get your local waste pickup to support that system, or take them to a recycling plant yourself."
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m7zafp | Tax write offs | Can someone please explain what tax write offs are about and why people save receipts for gas and stuff? | Economics | explainlikeimfive | {
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"You change (lower) your taxable income. In short, taxes are meant to be paid out of your \"profit\" or income. But if your money for a business comes in but then is spent right away on business things, or other things that get privileged in the tax code, you don't pay taxes on it. So if you can write off $500 in gas expenses (because you have a job that makes you drive around alot), and you made $5,000 from your job, you will \"write off' the gas expenses and be taxed for $4,500 of income, not $5,000. Less income, less taxes you pay on that income. also, I can't help but think of: Jerry : How is it a write off ? Kramer : They just write it off . Jerry : Write it off what ? Kramer : Jerry all these big companies they write off everything Jerry : You don't even know what a write off is . Kramer : Do you ? Jerry : No . I don't . Kramer : But they do and they are the ones writing it off .",
"at a basic level, tax write-offs or deductions are a way of people to limit or reduce the amount of tax they have to pay. for a simple example. if you made $100,000 in a year. assuming you had no tax write-offs or deductions. Based on that income, you'd have to pay about 20,000 in federal taxes. But, if you can prove that you did certain things with that money, you may not have to pay all of those taxes. If you donated 10,000 to charity, then you can take $10,000 deduction, which basically means you pay taxes as if you only made $90,000, rather than the full $100,000. This means you'd maybe only pay $18000 in taxes. This is the deduction process. There are various deductions or write offs, and tax credits that all apply different ways. In my home town, you can donate up to $1000 to a school charity, and then you can take $1000 off of the amount of taxes you owe, this would be called a tax credit.",
"Its somewhat complicated, but let me see if I can explain it pretty simply. At a basic level, a tax write off is an expense that you can subtract from your income, so that you pay less taxes. But there are specific rules as to when you can do it, and it can get very complicated, and some people like to break the rules and hope they don't get caught by the IRS. Here are some examples: 1 - You work for a company, you don't use your personal vehicle for anything work related, just to get to work and back. But you keep the receipts, and then claim on your taxes that the gas is a work expense. That is not allowed. If you get caught, you get in big trouble. 2 - You work for a company, but you need to use your personal vehicle for company based travel. So you keep your receipts for gas and oil changes and a journal of how many miles you drive for work related stuff. When you file your taxes, you subtract the gas/oil/mileage charges (there is a rate for mileage allowed by the IRS) from your income, reducing your income, which reduces your taxes. This is allowed and legal. So you need to keep those receipts. There are a lot of grey areas when it comes to taxes though. And it gets very complicated if you try to itemize your taxes, have business related expenses, etc. And, you open yourself up for the possibility of being audited. If they find something during the audit that you are doing incorrectly, then you get in trouble or if it was an honest mistake, you get to pay the money owned with penalties and interest."
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m80g6q | What is a transformer? How does it work? | Physics | explainlikeimfive | {
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"An electrical component that basically lets you trade current for voltage or vice versa. They work by electricity in the input wire causing induction in the output wire; they're like mini generators that run on electricity instead of steam or wind or solar. One reason you might want to do this is that the more current goes through a wire, the hotter the wire gets, so the more energy gets wasted as heat. So if you need to transport electricity over long distances, you can use a \"step-up\" transformer to trade high current, low voltage for low current, high voltage. The lower current wastes less energy so it's more efficient for transport, but then you need to bring it back down a usable voltage on the other end, so you use a \"step-down\" transformer to trade low current, high voltage for high current low voltage.",
"Are you at all familiar with gears or pulleys? Transformers are kind of the electrical analogue to those. If you have a very large gear up against a very small gear and both are rotating, you have a similar system to a transformer. The small gear will be spinning very fast, but will have very little torque. The large gear, on the other hand, will be turning very slowly, but have a large amount of torque. The gears in this system let you \"exchange\" rotational speed for rotational force (which is torque). Transformers work in much the same way, but instead of \"exchanging\" speed for torque, they lets you exchange voltage for current. To extend our gear analogy Voltage is sort of like force and current is sort of like speed (this is an oversimplification, but you get the point). How transformers work is a lot more complicated. A property of electricity is that any electrical current creates an associated magnetic field, and always at a right angle to the direction of the current. In a similar way, magnetic fields can create, or induce, an electrical current. By wrapping wires in coils in very specific ways we can have a current create a strong magnetic field in one direction, then capture that magnetic field in a separate set of coils to create a new current. The two different coils are like the two different gears in our original analogy, instead of having more teeth on the gear, you have more wire in your windings.",
"Two separate coils of wire wound on, usually, a common axis with an iron core, although geometries vary. The driven current in the primary coil creates a magnetic field in the core. The magnetic field in the core induces a current in the secondary core. If the driving current is continually alternating in direction (AC current), a corresponding alternating current can be drawn from the secondary coil. The voltage across the secondary coil differs from that in the primary by the ratio of the number of turns of wire in each. So you can step up the voltage but get a lower current, or step down the voltage but increase the current.",
"A wire carrying current produces a magnetic field. If you coil that wire in a loop multiple times, the strength of that magnetic field will grow. And just like electric current produces a magnetic field, a magnetic field produces an electric current in a wire brought into that field. So if you coil a current carrying wire into multiple loops, it will produce a magnetic field. If you bring another wire into that magnetic field, current will then be produced in that wire. You can loop the second wire into a coil as well. The first coil's magnetic field will induce a voltage in the second coil. *That voltage will be a result of the ratio between the number of loops in each coil.* Imagine a transformer where the primary coil takes 120v, and the secondary coil outputs 24v. 120/24=5. So this type of transformer, 120v to 24v, needs to have 5 times as many loops in the primary coil as it does in the secondary coil."
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m80gqq | How does cellular data work? | Ok I get it sends a signal to my device, but how does it know the specific data I want? Also, how does it find my specific phone when I receive calls? | Technology | explainlikeimfive | {
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"The cell tower doesn't know what specific data you want, any more than the post office knows what's inside your mail...it just knows it's got a \"packet\" addressed to you and it delivers it. Your phone is the one making the requests and processing the receipts. As far as knowing where your phone is, as long as you're connected to your network, you've got an active radio connection to the \"nearest\" cell tower (\"nearest\" because it's really the one with the strongest signal, not necessarily physically closest). When someone calls you that request goes into your phone company's network. The network says \"Right, which tower is talking to number XYZ?\". If you're on the network, one of the towers will say, \"Me!\" and the cell network routes the call to that tower. Then the tower sends a radio signal to your phone saying, \"Call for you.\" The tower already knows where you are (in a \"which antenna\" sense) because your phone is always maintaining a connection."
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m80w7i | How does food get delivered through the umbilical cord? | Biology | explainlikeimfive | {
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"Through blood, the same as it's delivered to anywhere in your body. The mother doesn't literally pass food to the developing fetus; she passes the nutrients floating around in her blood.",
"Literal food doesn't go through the umbilical cord, just as literal food doesn't flow through your veins. When food is digested, it is broken down into smaller molecules that cells can utilize, and this is transported by your blood. The same goes for babies, but since they can't eat they get a nutrient-rich blood tube directly to their arteries.",
"To get benefits from the food it needs to be metabolised to its simplest form, (carbs to glucose) (fats to triglyceride) (proteins to amino acids) then all this stuff go to your blood stream to be used by the body. So basically your blood contain all nutritions that your body need. Thats how the fetus get his food. It's already processed and ready to be used.",
"Food doesn't get delivered through the umbilical cord, blood does which carries in nutrients through the placenta which is attached to uterus to allow it get rid of waste and pick up nutrients."
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m80y0k | Unbiased explanation of Critical Race Theory? | Most of the ones I found through the search were not ELI5 at all, like they didn't even make an attempt at explaining in a simple fashion. Some others were obviously biased. | Other | explainlikeimfive | {
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"Critical Race Theory is the theory that most, if not all, aspects of modern society have racism baked in, which is why it’s been so hard to get rid of racism. For example, we tend to assume that our laws are written to be race-neutral, but critical race theorists point to the fact that people from different racial backgrounds can have wildly different outcomes while dealing with similar legal issues in the same legal system. The explanation, according to CRT, is that the laws and legal system are actually designed (consciously or not) to perpetuate racism. It’s important to note that CRT isn’t really one theory, but rather is a collection of different ideas that challenge a wide swath of intellectual and political traditions. The common thread is that they all agree that race is one of the important factors in creating and maintaining inequalities in society.",
"It's a legal theory that arose in the 1980s with two core principals: > White supremacy exists in the US and exhibits power maintained over time, and, in particular, that the law plays a role in this process. > Transforming the relationship between law and racial power, as well as achieving racial emancipation and anti-subordination more broadly, are possible. The supporters of this theory were reflecting on the effects of the 1968 Civil rights act, which seemed to have not completely eliminated racism in the US. Some lawyers in the 80s saw black civil rights as a \"legally solved\" problem, implying more application of existing laws was the answer to racism. The CRT folks disagreed. As a result of CRT, the lawyers that support it argue for things like special treatment for minority races in laws. This leads to black empowerment zones and provisions in pot legalization statutes that favor minority communities in licensing to compensate for disproportionate incarceration for pot crimes. The opposition is that fixing white supremacy with black preferences is the \"two wrongs make a right\" sort of thing that the Law disapproves of, in general. While the concept of rules that shift to get a desired outcome is common in ordinary life, the legal community likes to consider the law permanent and unchanging perfection."
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m81s3u | If give and take are opposites, why is a caregiver the same as a caretaker? | Other | explainlikeimfive | {
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"Because English is a super weird language that isn't based on logic whatsoever. The same word can have the exact opposite meanings. \"Cleave\" for example, can mean to separate or to unite."
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m81yi9 | Why does coffee make me feel tired? | Biology | explainlikeimfive | {
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"If your brain is understimulated, stimulants, like the caffeine in coffee, bring it up to a baseline of stimulation, which causes it to relax and makes you sleepy. At least, thats how my dr explained it to me when I was diagnosed with ADHD and we were discussing how stimulant medications work.",
"Coffee contains caffeine. Caffeine when absorbed by the body will trigger production of a tiny amount of adrenaline. Everyone will react differently to adrenaline, depending on their current state. You may feel more awake, and more alert. This is common because adrenaline triggers the flight or fight reflex. But you might feel more tired, especially if you are already feeling tired as you consume the caffeine."
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m82bh5 | How do some electronic devices (phone chargers, e.g.) plugged into an outlet use only a small amout of electricity from the grid without getting caught on fire from resistance or causing short-circuit in the grid? | Technology | explainlikeimfive | {
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"Electrical engineer here: Low powered devices do the opposite of a short. They have such high resistance that they only let a small amount of electricity through.",
"Devices only take the power they need. Like a firehose, you could use a whole lot of water if you open it all the way, but your phone charger only needs a little bit of Power, so it's like opening it up a tiny bit. A trickle comes out. Even through there's plenty of water pressure available. The fire hose is the main power to your house. Your outlets are like garden hoses, they each can't let out nearly as much power as the main power line, but they're all connected to the same main location (your fuse box)",
"My (non-electrical engineering) understanding is that newer alternating current (AC) to direct current (DC) transformers (which change the voltage of wall current to something lower voltage that digital devices can use) work by only using a little bit of current from the short period of time when the voltage is starting to go up and down in the AC cycle. As such, they don't use resistance (which would make heat) to change voltage. A part of the device called a rectifier switches the positive and negative parts of the cycle so the current is only running in one direction (DC). Then capacitors smooth out the current so it's basically constant.",
"Electricity is like a water supply in a closed loop (from live to neutral, or positive to negative, say). Voltage is a \"pump\" pushing water through that loop. The wires are pipes. If the pipe is small and constricted, only a small amount of water can travel through it. If the pipe is large, a larger amount of water can travel through it. Low voltage devices, by the design and nature of being low voltage, are all very thin pipes. High voltage devices are very fat pipes. Now if you push hard enough, obviously the small pipes would burst first, but that's not how electricity works in practical contexts. We push at a very standardised pumping rate (voltage). The items we design are designed to always cope with that \"pressure\" without bursting (otherwise everything would be on fire!). Given that we know that pressure, and design all our pipes to cope with it, our pipes cannot burst. They might get very, very thin or very fat, but they're designed to cope with the pressure of 110V or 220V. However, if you make a pipe like that, and its very narrow and thin, there's only so much water that can pass through it every second (the power). If you make a pipe fat, more power can go through it, even though you're only pushing with the exact same pressure. The size of the pipe you make determines the power that the device gets / uses. And you never design it such that a pipe is so weak that it could \"burst\" (e.g. a wire burning out) or put more pressure down a pipe than it's designed to handle (e.g. 440V down a 110V cables) because then that's a fire hazard. But it's the size of the pipe that matters. And phone chargers only have a tiny pipe, and the electricity company only ever pushes with a certain amount of pressure, so only a tiny amount of power ever goes through them. So long as that pressure stays the same, the pipe never bursts, but less water goes through the little pipe than through the bigger one that's fed from the same supply pressure (the same way that you can run a dribble from your tap and your neighbour can run a huge hose from the same water supply, and it doesn't BURST out of your tap when he does that)."
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m82vmm | How can magicians guess the exact number I am thinking? | Or how can they guess who my first crush was, or who my first best friends name was? I’ve seen a magician do this kind of thing and unless they make a deal with the devil I don’t know how they make this happen lol. And they always get it right... Tell me! | Other | explainlikeimfive | {
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"While I can't comment on the specific trick without actually seeing it, most magicians use a technique called [cold reading]( URL_0 ) for their 'amazing' guesses. They use vague statements, informed by information they can see about a person or crowd, and combine that with statistically likely events to 'guess' things correctly. This technique is particularly useful for larger groups, as it ups the odds of success dramatically. So, for example, if I were to have a group of middle aged people and say, \"I'm sensing someone here has recently lost a maternal figure - a grandma, and aunt, a mother - to something in the chest - breast cancer, heart disease, lung cancer...\" _Someone_ is going to think, \"wow, he knew that my aunt died a few months ago from breast cancer!\" Well, no - I didn't. I knew that people who are middle aged have statistically lost older relatives, that those three diseases are the most common causes of death for women, and named all of the possible 'maternal' figures you could have. It was a shot in the dark, but I knew it would hit _someone_ because of the odds. If it missed, I'll quickly change to another tactic to get a hit, and people will forget about my last miss. **EDIT**: I'll also add that they tend to make use of Barnum statements, named after P. T. Barnum. Barnum statements are statements that _seem_ personal, but are actually quite generic. Think horoscopes. So, for example, I might say \"I can sense you are a confident person around your close friends, but you can get insecure when you meet new people.\" Seems personal, but almost everyone shares that trait.",
"For the case of things like numbers this sort of trick is often done using what's known as a \"force\", \"magician's choice\", or \"the illusion of choice\". They structure the situation so that what appears to be choice on your part is actually under their control. A simple example would be to offer you the choice of two face down cards where they have managed to set them up so they know which is which. Then if you picked the one they want, they turn it over, but if you picked the other one they discard the one that you picked, and turn over the other one. There are more complicated and subtle ways of doing this sort of thing. For things like personal history, it's usually done by some form of cold reading where they fish with broad guesses to get you to reveal more specific information in a way that tricks you into thinking you were merely confirming specific things they said. Or there's the Peter Popoff method where they just have someone looking up information about the marks and reading it to the performer via a hidden radio earpiece.",
"There's a pretty broad range of different things that can be done. The simplest is with a tool called a \"nail writer\" which is basically a pencil lead taped to a nail or finger. They pretend to write something, then comes time for the reveals and you tell them your answer, they subtly write that answer on a pad with their nail behind their back, and then they reveal it as though they knew all along, possibly doing some slight of hand to make it seem as if it was in a sealed envelope the whole time. Other options might be to get that info from you by someone else ahead of time without you realising it, then feeding it to the \"magician\" via earpiece. This was famously done by televangelist Peter Popoff as a way to make it seem like God was giving him the information, when his wife had taken surveys of the audience ahead of time."
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m82wd5 | Why is crude oil, coal, and natural gas found so deep within the earth? | If natural gas, crude oil, and coal are the result of decomposing plants, microorganisms, and animals, how did it get so deep beneath the earth’s surface and the sea floor? Why is there thousands of feet of rocks and soil between the earth’s surface and the oil/gas/coal deposits? | Earth Science | explainlikeimfive | {
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"Seams of coal are essentially ancient forests. When the first trees evolved there was no bacteria or insects that could decompose them yet so the plant material just piled up higher and higher creating thick soil saturated with wood. Over the eons dirt, sand, volcanic activity, rivers, tectonic movements, etc piled up layers of rock over the ancient forests and the combination of compression and fossilization result in them become coal seams. For oil it's a similar story, but with single celled micro organisms like plankton that piled up on the ancient sea floor"
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m84egn | How does regenerative braking work? | Technology | explainlikeimfive | {
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"Electric or hybrid cars have electric motors and batteries. Electricity flows from the battery into the electric motor to make the car move. The opposite also works. The electric motor can convert motion into electricity that is put back in the battery. So regenerative braking does exactly this. It converts the energy of the car's motion into electricity. As it does so, it slows the car down, because that motion energy is being consumed to generate the electricity."
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m852qh | What do each of the greeks mean in financial markets? | (This is not a request for financial advice) Can someone please explain what each of the greeks mean in money markets? The ones I am aware of are: Delta Gamma Theta Vega (I think there are others) & #x200B; Thanks in advance | Mathematics | explainlikeimfive | {
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"Delta represents the rate of change between the option's price and a $1 change in the underlying asset's price. Theta represents the rate of change between the option price and time, or time sensitivity - sometimes known as an option's time decay. Gamma represents the rate of change between an option's delta and the underlying asset's price. Vega represents the rate of change between an option's value and the underlying asset's implied volatility. Rho represents the rate of change between an option's value and a 1% change in the interest rate. URL_0 .",
"A question I am qualified to answer. These Greeks are used in option markets and other less used derivatives. Delta is the rate of change of the option value with respect to the underlying security Ex. If you have the $BRO 420c(call) with a delta of 0.25. your theoretical value or theo for short will increase by 0.25 every dollar $BRO increases, but if it decreases, it will go down 0.25. Theta is measured in how many dollars the option will lose per day. if the $BRO 420c has a theta of -2, then your option loses $2 of value per day. Vega measures sensitivity to volatility Gamma measures the rate of change in the delta with respect to changes in the underlying price. Gamma approaches its max near ATM options. This is what's called a second order Greek, it is the second derivative of the function(Black Scholes) used to valuate the price of the option. Rho measures how an option will change with changes in the interest rate."
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m85ga4 | Dishwashers | How come a restaurant's stainless steel dual door dishwasher is done in 30 seconds while a house's undercounter dishwasher takes an hour and a half? | Physics | explainlikeimfive | {
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"A commercial dishwasher uses an extreme amount of water and pressure to get dishes clean quickly. It’s like the difference between you with a garden hose vs you with a pressure washer.",
"For one, most dishwashers (the people) scrub all the stuff off the pans before they go through the machine, the machine is basically just to sterilize"
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m85j19 | What is happening in our brains during the phenomenon known as "semantic satiation"? | Biology | explainlikeimfive | {
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"words are not exact things in the brain. they are also a bit of similar words, and a bit of what you feel about them, and a bit of when you last heard it, and even a bit of where you first learned it. brains are very good at finding the strongest links and recognising how they connect, but they get tired too, so when a word keeps on arriving then the connection isn't as strong and one of the other links seems to be the strongest instead. eventually the most significant thing about the word might just be how the sounds feel like an interesting rhythm in the mouth, or how it could mean something else if it was a different shape, or even the weather on the day you first learned it."
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m860in | If we're all made up of atoms that just banded together, how did we get life and consciousness? | I was thinking of our DNA as maybe a starting point then gets executed over time like how automated computer logic works. Looking for a scientific answer. Thanks! | Biology | explainlikeimfive | {
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"The life part of that is simple. Well, relatively speaking. So, you know about chemical reactions, right? Molecules (groups of bound atoms) doing things together that result in different outcome molecules. A really simple chemical reaction to demonstrate this would be the [burning of hydrogen]( URL_0 ). Here, Hydrogen (as H2 molecules) react with Oxygen in the atmosphere (as O2 molecules) to make water (H2O - two hydrogen atoms stuck to an oxygen atom), a process that releases energy that we see as fire. You may also know about catalysts - materials that make a specific chemical reaction more likely to happen (all chemical reactions have a tiny chance of happening spontaneously provided the right reagents are assembled, but catalysts increase the likelihood of that happening to something a little faster than \"once in a trillion years\"). Organic molecules are the molecules of life - carbons and hydrogens and oxygens stuck together, with some nitrogen and phosphorous and other stuff thrown in for good measure. A lot of organic molecules, even quite complex ones, can arise naturally in high energy environments, such as around geothermal vents at the bottom of the ocean (where a bunch of heat is pumped out from the deep earth). These happen naturally and they're found all over the place. Some organic molecules are catalysts - they make specific chemical reactions more likely to happen. So likely to happen in fact that it's easiest to describe catalysts as just \"doing\" the reaction - it wouldn't happen on any feasible or observable scale without them so we attribute these organic molecules agency even though that's kind of unscientific and all they're *really* doing is passively existing next to some reagents. Now, the really interesting bit is when an organic molecule catalyses a reaction that produces more of the same molecule. If a catalyst makes other molecules, and those molecules are also the catalyst, then what you have is a self-replicating catalyst. As long as it's got reagents and enough energy, it'll keep creating copies of itself automatically. That's just chemistry. But it's also the core prerequisite for life. Replication like this occasionally creates mistakes (mutations) and some of those mistakes increase the chance of the molecule creating copies of itself, for example by speeding up the time it takes to make a copy or making the molecule more stable so it can make more copies of itself before disintegrating. That mutation process, over a very long time, is evolution. All life is is a bunch of organic molecules catalysing reactions where the end product is that the entire bunch of organic molecules has been copied, and life neatly packages these groups of molecules up inside cell membranes (which occur naturally and automatically when you put the fat molecules they're made off into water) so we can look at specific bubbles of molecules and say \"this is a frog cell\" or whatever. Life is nothing more than a bunch of automatic chemical reactions that happen to produce copies of themselves, thereby continuing their own existence through offspring. Evolution naturally shapes these automatic chemical reaction bubbles into forms that can improve their ability to replicate, such as by collecting extra energy from sunlight (photosynthesis) or by having defense mechanisms that prevent other cells attacking them (poison or something). There is no hard line between \"life\" and \"not life\", and defining \"life\" is one of the biggest problems in biology. We all know when something we look at is life, but it's really hard to define exactly what makes it life. Life is really just a bunch of chemical reactions that *evolved*. Now, the matter of consciousness is a separate matter, and the short answer is \"fuck knows\". They're still working on that one.",
"It is one of the dirty secrets of science that we don't really have a great idea of how life came about the first time. There have been theories about this for many decades, and they are along the lines of, \"if you get the right chemicals together, maybe they'll just sort of start spontaneously acting like this.\" But we've never actually been able to make anything like that happen in a lab, and we're not really sure what those conditions are. There are hypotheses, but none of them are really firm. The best we can do is say, \"well, maybe if you have the right proteins and some catalysts and maybe a spark of lightning you end up with something that sort of acts like a virus and from there it evolves into cells and the like.\" (Viruses are on the line between \"life\" and \"non-life\" and so a very interesting thing to consider in this context.) But that's very hand-wavy. This isn't a slander against science. It just means we don't really know, yet. It is murky enough that many scientists actually lean towards the idea that somehow life on Earth came from another planet (e.g., hitched a ride on a comet, or something), which is really about as close as you get to them just giving up on the problem. Maybe someday we'll know. Right now, we don't. (Scientists and science-enthusiasts like to hand-wave over this question because they are afraid that if they can't answer it, it'll make people more interested in alternatives to evolution. There really isn't any doubt that once life exists, natural evolution explains how it got to be in its present forms. But we don't actually have a great sense of how it came to exist on this planet in the first place. I have faith there is an entirely naturalistic answer to it. But I'm willing to acknowledge that this is a form of faith.) We don't really know what consciousness really \"is\" and so we don't know the answer to that one, either. None of the theories are very satisfying, though they can be very interesting. They range from \"something quasi-mystical\" (quantum theories, religious theories, whatever) to \"consciousness isn't really a thing\" (which goes against our individual experiences of it). The most compelling idea I've heard is that consciousness is what we call the sensation that the brain generates in order to make sense of a lot of different kinds of sense-data, and it evolved as a sort of \"hub\" for coordinating eyes, ears, mouths, limbs, etc. But that doesn't really explain what it \"is\" and so it is still pretty unsatisfying. So anyway. These are great questions. But the answers are currently mostly unknown to science. That doesn't mean that science won't someday know the answer to either of them, or perhaps both (there are some who are betting we will never wrap our heads around \"consciousness\" in a satisfying way, because maybe our brains are just not capable of understanding it). I suspect the answer to the first one will be figured out well before we answer the second one, if we ever answer the second one.",
"Consciousness could just be the next step from instinct. Lots of animals have emotions and moods which could be considered consciousness. We shouldn't think that our form of consciousness is all that special just because our large brains allow for speech and innovative technology. How did humans become conscious? The same way dozens of animals did. Being a bit smart and evolving the traits that we associate with consciousness (emotion, intelligence, etc)",
"There isn't really a good answer. Certain combinations of atoms just so happen to replicate themselves with minor chances of mutation which kicks off the process of evolution. There are certain atomic configurations that can sense, that data is hooked up to certain actions, like if you sense a green light to propel towards and chomp your mouth. Over time these senses and actions get really complex and detailed. As the level of sense complexity rises, sense data gets processed. You can only do so much with photons hitting an eye, so you start to model the outside world by sense processing. Instead of seeing a mess of light, you see a fish swimming across a backdrop. It kind of divides the sensual experience into different entities. As those entities get more and more accurately modeled, they become perceptions and there is some decent mapping between the outside world and the inner world. Like there is a perception of a fish, of water, and different forms. The brain\\* is essentially running a low level simulation. As with perception of the outside world, there is also perception of self. If you are trying to sneak up on your prey, it is pretty important to perceive the amount of noise you are making. As perceptions get more complex, you start to approach consciousness. I think a big feature of consciousness is that it incorporates a lot of different senses and coordinates them with a sense of time. A purely perceptual being wouldn't really account for time all that well and is just in the moment. At the heart of it, everything is physics. A level above the mechanical, everything is sensation. Perceptions are just processed sensations, but still sensations. Consciousness I would say is processed perceptions, so essentially still sensations, but mixed together and multi-layered. A few tangents.. There's not anything pushing evolution into a certain direction, it is just kind of how it happened. Conscious or perceptual beings are not any better evolutionarily than others, it is just a different survival strategy. Since consciousness evolved, all the lines are blurry. Most mammals we could put somewhere on the perceptual to being semi-conscious line, but its tough. Insects are kind of on that sensation to perceptual line. Bacteria is purely sensational. What is most confusing is that though I presented this on a line from lifeless to conscious, that there is no actual line like that. Aliens or AI could still be put on that line because the concepts are high level, but that wouldn't mean that an alien would be conscious in the same way that we are. None of this addresses the concept of the philosophical zombie, which is kind of a different problem. Although I believe the answer above is mostly correct, it's not really that satisfying."
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m865k7 | How do password manager work? What is the best one and does it work on mobile as well? | Technology | explainlikeimfive | {
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"Password managers are a secure vault to store your passwords and other sensitive information in. They work by storing your usernames and passwords in a way that can be retrieved easily, provided you remember the master password. The master password is used to decrypt the vault so that the information within it is accessible. It is recommended to have a two-factor authentication method configured as well. This means that you’ll need both the password and a code that is generated by an app or physical token. When the code and your password are paired together, the vault is unlocked. There are many options available. You can read a non ELI5 explanation on them at URL_0 They recommend Bitwarden as a solution. There are Bitwarden apps for MacOS, Windows, Linux, iOS and Android, plus a web interface. Bitwarden is open source, which means anyone is able to review the source code and determine if there are flaws. In summary, a password manager enables you to have very complicated and unique passwords for all of your accounts without you having to remember each one."
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m86bcf | what does an over and under mean in sports betting? | Other | explainlikeimfive | {
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"Whoever the bookie or house is will give a number of total combined points they think both teams will score? So they may say it's 52.5 in football which means they think if you add up both teams scores at the end will be 52.5. You bet whether you think the total will be over or under that amount. So if you bet over on 52.5 and the final score is 26-21, you lost as the total is 26+21, so 47 which is under 52.5. If the score is 35-29, you won as the final total of 64 is over 52.5.",
"Say imagine a football match between Real Madrid and Barcelona. The most common market is 2.5. So if you bet under 2.5 you win in case 0, 1 or 2 goals are scored, while with over 2.5 you win in case 3 or more goals are scored. Example: Real Madrid 1-1 Barcelona, only 2 goals, so under 2.5 wins Real Madrid 1-2 Barcelona, 3 goals so over 2.5 wins. This also applies to basketball, American football, etc."
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m86mjl | how do you get “good” at poker if it’s almost completely a game of luck? | Other than the obvious poker faces and reading other players, how do these high stakes players get to the point of basically knowing what each player has in their hand? How do they know percentages, odds, when to fold etc.? | Other | explainlikeimfive | {
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"They know statistical probabilities to the T. Now whether or not they play that probability is determined by other factors within the game like you mention, tells, and how the hand has been played to this decision point. The purpose of the dealer button rotating around the table after each hand is because based on you turn to make a decision, you are either in an advantageous or disadvantaged situation because you have to make your move with less pieces of information than the others have that will make their decision later in the round of betting. Additionally, people will act a certain way when they have certain ranges of hands, and based on what cards flop",
"\"In poker you never play your hand, you play the man across from you\" - James Bond Poker isn't just about what cards you get, it's being able to read and play the people at the table. A good poker player studies human behavior and can figure out when players have a good hand or if they are bluffing just by studying their behaviour. They also try to manipulate players into betting too much, by making them think they have the advantage. At a high level seldom does the player with the best hand win the round. It's not like the cards are meaningless, but it's not just about having the best hand.",
"A lot of it is avoiding mistakes. When one player in a game makes a mistake the rest of the players gain from that. The ones who makes the fewest mistakes will win the most.",
"Think of betting as a form of communication. When you bet, you aren’t just randomly dropping money out there, you are speaking to the other players. What you bet, as well as the context which is determined by the cards, determines your message.",
"poker is a game of skill with randomized components. poker as I know it in general is not a \"solved\" game but there is theory out there people often talk about \"playing the opponent\" maybe some people can understand others enough to reach a high level but that's not a tangible skill so I'll ignore that factor at present. I'm super rusty but essentially given three variables stack size pot size and the likelyhood of winning there is a amount you \"should\" bet (the expected value of your hand plus oh what's it called \"fold value\" (the value you get from folding your hand)) so if you're a computer or a high level player perhaps you can see two of those variables stack size and potsize and use those to infer based on the amount bet how \"likely\" they think they are to win and given the cards on the table roughly predict the hand they're going for. to be clear I'm not saying that this is what poker players are necessarily thinking I'm saying that this is a mechanic players can learn to infer through experience and training as well as quick metrics like pot odds and others."
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m86ra2 | How do split hairs happen, and why do some hairs have multiple splits while most others have none? | Biology | explainlikeimfive | {
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"So - split hairs aren’t *actually* “split”. Under a microscope, they look a lot more like a rope that has frayed/come undone at the end. Technically, every hair has splits - all the way up the hair shaft, not just the ends. Hair shafts look kinda like roof shingles, the cells overlapping, and at the outer edge, they lift up slightly. The healthier and more hydrated the hair, the less the edges lift up. The less healthy and dryer, the more they lift up. They are more brittle at this stage, so very small tears are likely to happen, all up and down the shaft. The reason why hairs ‘split’ at the ends more than up the shaft, is that the end is both the least healthy part (it has been exposed to the elements the longest), and, like a rope fraying, there’s nothing below it it keep the momentum of the cell’s organization going downwards. It’s just and end that gets tossed about, etc. And, like how cutting a rope above the fray makes it nice & clean edged, that’s why regularly cutting above the split can actually make the hair “grow faster” - the fray is more likely to continue to unravel, causing breakage - so severing it before it does that gives that strand more time, before it starts it own fraying process again."
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m86urf | Why do mothers experience postpartum depression? | Just recently read this shorty story called “The Yellow Wallpaper” about a woman experiencing this condition who eventually falls into psychosis and it got me wondering as to why it occurs. | Biology | explainlikeimfive | {
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"If I remember correctly it's because of a chemical imbalance that occurs due to building a baby. Your body throws all these resources into making it then once out, the body doesn't know how to handle it and then it throws off your happy chemicals and you are not the same for a little while."
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m87lcv | How do some pregnant women go an entire pregnancy without realizing they are pregnant | Biology | explainlikeimfive | {
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"She has no hallmark symptoms of pregnancy, she’s overweight, she’s uneducated about the signs of pregnancy, her period is irregular so she thinks nothing of it. Usually all the above"
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m87u3y | How do computers and phones keep track of the date and time, even when they're completely shut off? | Technology | explainlikeimfive | {
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"They're not completely shut off. Computers will have a small battery called a CMOS battery. It keeps the clock running, among other things. I don't know about phones, but I imagine they pull a tiny amount from the battery to keep the clock running.",
"On PCs, on the motherboard, there is a small battery called a CMOS battery that provides a small amount of power even if the pc is unpowered :)",
"They are never completely shut off. A dedicated circuit, the Real Time Clock or RTC is always powered on, usually through its own dedicated battery. The RTCs only job is to keep track of the time.",
"One correct answer is that they are not completely off, which has already been said. Another correct answer here is that smartphones and computers use the internet to tell time. So as soon as it connects to wifi or a cell phone tower or something like that, it will adjust it's clock accordingly. This can happen for some cell phones before they even display the time. So it has already been corrected before you see what it thought the time was when it was off.",
"Cell phones are connected to your providers network. Atomic clocks at the local phone office keep time for the entire network. [What You Should Know About Stratum System Levels ( URL_1 )]( URL_0 )"
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m88dsa | The Doppler effect, and red and blue shift | Edit 1: My grammar looks like it’s from a five year old. | Physics | explainlikeimfive | {
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"Sound is made up of waves of air pressure changes. Picture a car driving towards you - these waves are \"squished\" closer together by the motion. You hear this as a higher pitch. Or driving away, the opposite happens - the waves are \"stretched\" out. You hear a lower pitch. Blue and red shift is just this principle applied to light waves. Something comes towards you - higher frequency or \"bluer\" light. Going away - lower frequency or \"redder\" light. We just don't notice it with light in our day to day lives because we never interact with anything fast enough to have a noticeable effect, since light travels about a million times faster than sound in air."
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m88jqt | Why do French fries get “chalky” after being cold and reheated? | Other | explainlikeimfive | {
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"It’s called retrogradation. When starch is heated during cooking it looses its normal structure. When the starch cools down new hydrogen bonds form and the structure is again different. In short, the molecular structure of starch is directly related to its perceived texture"
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m88t18 | How do we know the voice we are hearing is from a male or a female? | Whether you are hearing someone’s voice in person or over the phone how can we distinguish if it is coming from a male or a female? Both males and females can have high or deep voices but it is still possible to distinguish which sex is talking to us. (Male or female in regards to the anatomy they are born with) | Biology | explainlikeimfive | {
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"Trans person and voice actress who has thought a lot about this kind stuff and done a lot of voice training. A lot of what genders a voice is resonance and intonation. Feminine voices(stereotypically speaking) resonate more near the head, and intonation is a bit more sing song or curious sounding. Masculine voices resonate more from the chest, and in terms of intonation, lowers at the end or a sentence more. Regardless of pitch, those mannerisms can absolutely change how it's perceived."
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m88vq6 | peanut allergies | I grew up in the 90’s and I don’t remember a single kid I knew with a peanut allergy. It wasn’t a thing in our lunchrooms. How did they become so prevalent? | Other | explainlikeimfive | {
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"There was a documentary that looked into this recently... peanut allergies have been on the rise in the last 30 years. One part is medical identification of allergies, or perhaps more awareness, but our western culture has also propagated the issue too. Less exposure to microbes to build immune systems in early ages seems to do more harm than good in the long term. One of those repercussions, overreactions- in this case a deadly immune response to proteins found in peanuts.",
"Healthcare triage are a channel run by a group of doctors and medical researchers which help to collect and summarise medical research. Here is their 5 minute summary (with all sources included) on this: URL_0"
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m88yg4 | Why is it impossible to pack an opened pack of cigarettes to the same degree as you can pack an unopened pack? | Is there some magical seal that the tobacco fairies put on every pack that wards the smokes against being packed once the seal has been broken? | Other | explainlikeimfive | {
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"It’s not impossible, just very difficult. They have machines that squeeze in the cigarettes tight so it’s thinner and they can put more packs on each truck. When you open it air gets in and they puff back out a bit.",
"You mean the packing of the tobacco by banging the pack against you palm, or whatever? In an unopened pack, there is no empty space; the cigarettes themselves cannot move, only the tobacco can. Once you've torn the wrapper, or god forbid removed a cigarette, there's enough space that the cigarettes can move, absorbing most of the energy, and carrying the tobacco with them, so the tobacco will not pack down."
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m8ah8s | How do animals that don't have parents around learn to survive? | Biology | explainlikeimfive | {
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"Instinct. Humans are born with basic instinct to suckle, cry, crawl (when strong enough) etc. We only have those because we evolved to learn from our parents, our brains are plastic (moldable) so we can learn many different things. Simpler animals have everything they need already built in to their brain",
"Some animals are precocial and some are altricial. Precocial animals are born almost completely developed and are able to move around and find their own food almost immediately (Horses, giraffes, ducks, hare) Altricial animals are born underdeveloped and require constant care from the parent(s) to survive to independence. (Songbirds, cats, dogs, humans)"
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m8b2qb | What is a plasma tv and why were they so popular but have now been forgotten? | Technology | explainlikeimfive | {
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"Plasma TVs work by using panels made of millions of small gas cells (think mini fluorescent light bulbs). These panels are relatively difficult to manufacture. They were very popular because they had superior performance than comparable LCD TVs at the time -- with deeper blacks, more accurate colors, wider viewing angles, and less motion blur. But over time, LCD TVs became much simpler (thus cheaper) to manufacture than Plasma TVs. Plasma TVs also required more electricity to run on. So Plasma TVs began losing in popularity to the cheaper LCD TVs. What finally killed Plasma TVs was the introduction of 4K \"Ultra High Definition\". Turns out, making 4K Plasma panels for 50-60\" TVs would have been incredibly expensive. Because of this high cost, TV manufacturers decided that they would be better off selling 4K LCD TVs instead of Plasma, and invest in newer technologies like OLED.",
"A plasma tv is tv that uses little gas cells that light up when you flow electricity through them as pixels. Imagine neon (and xenon, and argon, but everyone just calls them all neon) lights, those tubes of gas that like up colorfully when electricity flows through then. Now take those, shrink them down super duper small, making little gas cells, and that is how you make a plasma tv pixel. It’s hard to say exactly why the disappeared. The true reason is because the companies that made plasma TVs announced that they were going to stop making them in 2014. While we probably won’t know exactly why those companies made those decisions exactly, it’s safe to say that they found reasons to prefer making LED TVs over plasma ones.",
"Plasma TVs produced a slightly better picture, but the quality difference wasn't worth the downsides for most consumers. So the sales figures never matched LCD screens, eventually leading manufacturers to abandon the technology.",
"They are what others described. The reason they were discontinued is because of the cadmium ban, which made good quality phosphors, and CRT/Plasma screens impossible. The CRT and Plasma screens were still sold in \"third world\" countries for some years afterwards.",
"They came right in the transition to big (32\" or more) and there weren't much LCD of that size Contrast and grey scale was far **superior** (LCDs were dim and no so good for B & W content) Still you can spot'em on tv news shows (small local) they have a **black stripe all around** inside the panel... so they competed and LCDs won for price , size (eventually) and life expectancy.",
"I miss the great blacks and refresh rates of the old plasmas. And the glass screens made the picture look better. I guess plasmas were the last flat screens available before LED made TVs cheap and disposable. Happens with a lot of products I guess."
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m8b87i | How does gas collect so much that it creates an entire planet? | Physics | explainlikeimfive | {
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"Time. And gravity. Let’s go even bigger than planets into Stars. Before a Star is born, it is just a cloud of mainly hydrogen and helium gas. This gas over millions of years will slowly pull itself closer and closer, making the cloud denser and denser. And as grows larger and denser it’s gravitational effects will pull even more gas in. Until eventually the cloud gets to the point that it’s so dense that a fusion reaction kicks off in the dense core, creating a bright burning massive star. All from nothing but gas, gravity, and time.",
"If you're talking about gas giants like Jupiter, the chances are that its core is a mix of rock and metallic hydrogen. Back when the planets were forming, all the planets probably started from a quite similar solid core (albeit the ones further from the sun could use water and other stuff that would be liquid in the inner system as part of that core), and as the gravity of those solid masses increased, they attracted other materials in the area, including gasses. In the inner planets, most of the gas was gone already, blown away by the solar wind, but there was plenty left to be gathered in the outer system, so the planets there just kept building up thicker and thicker envelopes of gas until they got to the size we see today.",
"There are four forces in our universe. You've probably heard of two of them (gravity and electromagnetism). (The other two forces are called the \"strong force\" and the \"weak force,\" and they operate over very short distances. The strong force and weak force are mostly interesting to nuclear scientists.) At large scales, gravity and EM are the two most important forces. But electrical charge can be + or -, and both kinds of charge occur in equal numbers. Which means the + and - EM forces tend to cancel out over huge distances. That leaves gravity. We use the word \"mass\" to refer to \"gravitational charge.\" Unlike electrical charge, mass can only be positive. So unlike other forces, it's easy for gravity to add up over long distances. If you have a giant planet-sized spread-out cloud of gas or dust or rocks or any kind of matter, each little bit feels gravity pulling it toward each other little bit. These little pulls don't totally cancel each other out. All the little bits end up getting pulled toward the average position of the bits. (That average position is called the \"center of mass\" or \"center of gravity\".) Over a long period of time, often a whole bunch of little bits end up all clumped together in a single object. When the clumps get big enough, interesting stuff starts happening. A big enough lump of hydrogen gas will start turning into helium, a process that releases huge amounts of heat and light -- that's what a star is. Smaller lumps feel the pull of the star's gravity. A lot of lumps simply get sucked in and become part of the star. The remaining lumps go into orbit around the star following a circular path (or sometimes elliptical) due to the balance between the lump's velocity and the pull of the star's gravity. If an orbiting lump is big enough, its gravity will be strong enough that any nearby lumps either get sucked into it and become part of it, or get flung away from it. Over the decades, astronomers studied a bunch of space lumps, and at some point they decided they needed to think about how to classify them. So in 2006, astronomers decided that, in order for a lump to officially be declared a \"planet,\" it had to be big enough to clear all the other lumps out of orbit this way. Pluto failed the requirement, so its \"planet\" status was revoked, which made a lot of Pluto's fans sad."
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m8bf4u | What is biological purpose of male nipples | Biology | explainlikeimfive | {
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"Developing embryos form very similarly regardless of gender up until a point where they start to develop gender specific traits. The nipples form on all embryos and then after about 6 weeks, sex chromosomes (x and y) kick in to action and differentiate us. In females, this includes forming the tissue and glands that will allow for milk to be excreted. Theres no use for nipples, they just form in case we end up as females and would need them.",
"The basic issue with nipples, is that in the womb, the gender doesn't actually begin to affect physical development until after breast tissue began developing, which is why men have nipples and breast tissue. The reason we still have those, is more because it has not yet been mutated out, of the DNA, and it's not harmful to our survival or sexual prowess."
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m8cale | Why are generally exoplanets and planets that are farther from their star large? | Physics | explainlikeimfive | {
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"Detecting small exoplanets at a distance from their star is harder. Maybe there are many of them that are beyond our detection capability; we don't know."
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m8cg0h | () What does it mean to remove a mol of electrons? | Im not sure what it means by removing a mol of electrons, as this is the definition for first ionisation energy | Chemistry | explainlikeimfive | {
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"> this is the definition for first ionisation energy It’s the definition of the first ionization energy *per mol*. They talk about moles a lot in chemistry because it’s the link between single atoms and single molecules (which are super tiny) and an amount of things which is measurable in grams. You *can* talk about the ionization energy of a single atom/molecule. You just have to use a correspondingly small unit like an electron volt (eV). A physics class would talk about single atom ionization problems in terms of electron volts. A chemistry class would talk about ionization in terms of kiloJoules per mol.",
"If you turn a mole of Na into a mole of Na^+, you removed a mole of e^- from the Na. We usually look at such processes per mole, not per atom, because it gives us more usable numbers. Or, at least, more convenient ones."
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m8cgms | I know that creatures like dart frogs get their venomous skin due to eating a species of ants (correct if I'm wrong) so how come a snake for example get their venoum if their diet is mostly rodents? | Biology | explainlikeimfive | {
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"Poison dart frogs aren't venomous, they're poisonous. That means the toxin is harmful through ingestion rather than entering the bloodstream. The frog just has developed an immunity to the ant toxin and the ability to store it. The snake, meanwhile, has glands that produce the toxin directly rather than just scavenging it from their diet"
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m8cpjm | why do computers get slower over times even if properly maintained? | I'm talking defrag, registry cleaning, browser cache etc. so the pc isn't cluttered with junk from the last years. Is this just physical, electric wear and tear? Is there something that can be done to prevent or reverse this? | Technology | explainlikeimfive | {
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"It’s not really really getting slower, it’s mostly the fact that new software is developed for never faster computers, so they will run slower on older computers, and as apps get updates over time, they will run slower and slower As an analogy if your computer is a car and the road is the software, it’s not your car getting less powerful, it’s the road getting steeper",
"They don't, they run at the same speed throughout their operational lifetime. You're just making them do more that they weren't doing before. As an IT professional, programmer and system admin please: \\- Stop defragging. It does basically nothing nowadays, certainly nothing worth the disk wear or the time it takes. Defragging is a handover from the days of 20Mb hard drives on older filesystems on slow-latency hard drives. Just stop it. Especially if you have an SSD - you're literally just wearing the SSD away, for no reason. If you want to avoid the need to defrag, don't run your hard drives more than 90% full, that's when things start to fragment to jam them into the gaps. If your drive isn't more than 90% full, it'll sort itself out and likely will never fragment in the first place. And modern PCs will basically not noticeably slow (even on a benchmark measurement) just because they're slightly fragmented. \\- Registry cleaning - again, does nothing. The registry on an average machine is maybe 50Mb-100Mb or so? Pathetic by modern standards. Cleaning it does nothing. You can remove services and auto-start entries, but use a proper tool for that, not some pay-for junk off the internet, or in the registry itself because if you cock it up, your computer won't boot properly. Sysinternals has Autoruns available to you for free, but pretty much most of what it does you can do with Windows 10 task manager, etc. on its own. \\- Browser cache - again, does nothing. You're just making the problem worse. Modern browsers manage their own cache and clearing it out makes nothing faster, just the opposite. Unless the page you are loading is not the page you expected (i.e. it's not up-to-date), cleaning your browser cache is entirely the wrong thing to do. What you want to do: \\- Make the computer do less. Have less programs installed (no, it doesn't matter how full your disk is, it's to do with how much stuff is running all the time). Get rid of anything you don't need to be running 24/7 (e.g. get it off your taskbar, stop it running with Windows, or stop it staying around all the time - it'll still work when you actually need to use it). Steam, for example, does not need to be in your taskbar 24/7. Stop it, using the options in the program or Autoruns. Then when you want to play a game, you run Steam. Personally, about 4-5 taskbar icons (by the clock) I find annoying. I work to get rid of them. Almost all of them can go. The Intel display one (unless you think you need to use it), nVidia icon, Java, Steam, printer monitors, etc. etc. Get rid of them. The screen will still work, your games will still work, your printer will still work. But you're not constantly running them 24/7. There are also dozens of services, programs that run on startup, and other junk that's always running that don't need to be. Almost all third-party program services (e.g. game launcher services) can be changed to manual startup (and then they will start if they're needed, but won't if they are not). Uninstall stuff you don't use. Your machine is no slower than the day you bought it. It's just running all the shit you installed on it for the last few years and never removed and which is running 24/7 even though you don't realise or don't even use it any more.",
"It's a combination of factors: More tasks / software bloating - The strongest of these is that normally you are asking your computer to do more tasks than before - some of this is subtle stuff brought in with Windows Updates and especially Chrome updates. Chrome started nice and efficient and a hell of a lot faster than Internet Explorer but has slowly gotten fatter and fatter. But it's not solely the browser's fault. As PC Processing Power, PC Memory, Browser Stability and internet speeds have all generally increased so websites have gotten more and more resource intensive (especially with the copious amounts of various advertising they force on you). The same holds true for a lot of software out there - that as PCs become more powerful so the software changes to leverage more of that power. Security, security, security - A HUUUGE part of OS, browser and software updates is security based. It's very, very seldom that security updates result in increased speed or performance. Failure Rates - RAM, CPUs, GPUs, HDDs, SSDs all have failure rates and these tend to get worse over time especially if there's significant heat in your system. I not talking total failure I'm talking bad sectors, I'm talking memory parity errors. Modern day OS and firmware do an immensely good job at handling this invisibly. Often you may not be aware that you have bad sectors at all. The sector has been discretely marked off limits and a replacement sector has been allocated. But when that happens it's basically introducing a permanent fragmentation onto your drive. OS / Registry scarring - Back in the good of days of Windows 98 it was a pretty regular thing to reformat your system at least once a year - sometimes due to a complete OS crash - but often wanting to have a clean version on because over time you add and remove programs, you get the occasional virus, you run registry cleaners and you install a ton of updates and well as any tinkering you may have done yourself in the registry. This all leads to the registry and system files not functioning as well as it should. Registry cleaners are a mixed bag - they spot a lot of problems but their solution is to delete the problems. Top Recommendations: Antivirus - check that you only have one anti-virus on your system and that's it's not McAfee. Multiple antivirus apps will interfere with each other. These days Windows Security is an excellent choice for your antivirus needs. Switch to an SSD - If you haven't switched yet and you can afford it I would highly recommend it. It's faster and doesn't suffer from fragmentation (assuming you don't live with your system drive 99.95% full). HDDs are still good for storage drives by your system and games should be running off an SSD. Clean install - Especially if you've upgraded between windows versions or even between major builds you will be surprised how much better your PC will run on a fresh system. This goes well with upgrading to an SSD. Download the USB installer from Microsoft's website and get a completely fresh version of Windows with no manufacturer bloatware on it. Do make sure tht you've backed up EVERYTHING you need: files, passwords, websites. Remove software that you're not using - especially any software that installs it's own services. I try where possible to use portable versions of applications - that way you know that they're not cluttering up your registry, system files and services. Also always check if there isn't a windows app that does what you want already. Hosts file - Use your hosts file to block advertising sites - this is fairly technical and I don't recommend for the average user but it's preferable to using ad blocker software. It's a fast, nasty but uncomplicated firewall essentially. What I do when I find a website that's running slow it I analyze that particular website on [ URL_1 ]( URL_0 ) \\- I identify the external links which are causing delays and block those via my hosts file. Upgrade you memory - definitely these days if someone has only 4gigs my instant recommendation is upgrade, upgrade, upgrade. Running Windows 10 you want 8gigs minimum.",
"Another good one nobody seems to have mentioned. Dust. Give your old pc a good Hoover out occasionally. Make sure it has good air flow, clean the fan and the filters if it has them.",
"PC's can slow down only a few ways. 1. Electronic failure. Parts can break, but on a PC most components that break will prevent it from working at all. The exception is a hard drive or a fan, which are the only two parts that can slow down over time. 2. Hard drives. Hard drives can slow down as they fill up, get erased, and rewritten. Your computer knows where files are, but imagine reading a book where each word is on a different page in random order. You have to flip back and forth to read it. This problem with hard drives can be fixed with a format and reinstall. A drive known as a \"SSD\" can also help prevent this from happening as much. 3. Heat. With the death of fans, your computer can overheat. Your computer tries to prevent this by using less electricity, and running slower. This can be fixed by cleaning, or replacing broken fans. Sometimes other measures like new paste under the cpu cooler can be required. 4. Software. Software can be added and added, slowing down your computer just like the car weight analogy. Sometimes removing the program leaves behind traces which still slow down computers. Most techies call this \"bloat\" or \"bloatware.\" A format and reinstall can fix this. This is the most common way PC's \"slow down\" over time. Edit: it's important to note that generally PC components like processors and ram never slow down. It just seems like it over time because of other factors. A good clean, a new SSD, and your PC will run just as good as new, at least for the vast majority of cases.",
"Newer versions of software is written for newer faster hardware, so sometimes it asks to do a lot more stuff at once, which can be taxing on older systems. Unfortunately, there's not a lot you can do about that other than trying to tell it to stop running so many background. So even if your computer hasn't physically degraded at all, it's slower than it used to be.",
"Check your task manager and see are any programs hogging cpu, memory and disk. Check the temperature of the hard drive, SMART data and temperature of the onboard components. If it is a laptop and things are hot swap out it's thermal paste and clean it.",
"5400 rpm hard drives. Companies love to install them in inexpensive computers. If it doesn’t have an SSD, don’t bother. Win10 updates on a spinning disk is the “death” of a computer.",
"The thermal paste drys out, and heat fins clog up with dust. That makes the chips run hotter, and they slow themselves down to produce less heat.",
"Take a look at [Bill and Andy's Law]( URL_0 .) Basically, software gets more complex over time to take advantage of new hardware. If you don't upgrade the hardware, the new software will just take longer to run.",
"Windows user profile is a big cause. It stores all the user customizations, and basically loads it all up whenever that user logs in. The way windows works, there is no easy way to reset an old profile back to new. So create and use a new profile on that \"slow\" computer. Voila! Much faster now~",
"The only real answer is that your computer does not get slower. It can't. Aside from some actual hardware problem. It's just becoming less capable. It's the equivalent of thinking a pocket calculator would become slower over time. Follow up question. Who on earth is still using a computer with a HDD? I just bought a 1TB Samsung SSD on Amazon for $109. You can get a 250GB for $30 tomorrow. More than enough to run your OS and frequently used programs. Also. All third party Anti-Virus software is worthless for a single user home PC. Worthless. They just steal CPU crunch time and RAM with zero ROI. Windows defender is enough.",
"Computers don't get slower. They stay exactly the same speed. What changes is the software. Software continues to use more and more resources. which means older hardware takes longer to run newer versions. These days the amount of resources things use is a little crazy. Just opening up a web browser and surfing the web for half an hour will take up like 1-3 GB of RAM depending on what web pages you go to. For reference the computers that NASA used to do the calculations for moon landings had 32 KB of RAM.",
"Registry cleaning and other stuff doesn't solve all problems completely. Some errors still remain, some junk still accumulates, more software is installed/updated over time and this new software is often \"heavier\" and slower-working than older versions. If you format a drive and do a clean reinstall of the system with (optionally) only the old versions of the software it had at the start, it should work faster again.",
"In general, the answers here are correct but a big mistake is assuming it to be true. Computers can get slower with time. SSDs get slower by lack of trim or by the aging cells. Processors also get slower as time pass because the cooling gets inefficient with time, by dust, old motors or even old thermal paste. But in general, what makes a pc old is the new software who is programmed with more resources in mind.",
"It's mostly a Windows issue in my experience. When W10 was forced on my very old low end i5 laptop it took 5-10 mins from button press to chrome displaying a white page with no content. I installed Manjaro Linux and it was faster and more responsive than my developer-grade i7 work laptop. I rescued repeated this again with Ubuntu Studio Libux on another laptop with the same result. That being said, when talking about application performance, they keep getting bigger and more complex. You also adjust to your new pc's performance, making that the new normal for you.",
"If you do a clean install of Windows it will be as fast as the day you bought it. But after you've downloaded all the updates and installed all your software again, you'll pretty much be back to square one. As others have noted, it's the software getting bloated, not your PC getting slower.",
"I just want to add a quick comment about framentation. It will make your harddrives with spinning disks get data slower. This is because of the read head inside has to move more to access all the parts of files. In solid state media there is no read head, therefore it doesn't care about fragmentation.",
"Mostly, it’s not slower. There are three major points to consider: -The software side, if you keep installing more and more programs that do stuff when the computer turns on or while it’s running - this will effect performance (which is why a clean install of your operating system will often offer a tangible performance boost). -For hardware, clean the dust from your pc so that thermal throttling doesn’t occur. Most of the components will have suffered negligible performance degradation. But if they’re unable to maintain the temperature they were manufactured to operate they will throttle themselves so that errors and damage does not occur. -hardware is constantly evolving and software becoming more and more complex with it. What was good ten years ago is mediocre at best now. A top of the line system back in 2011 is about as powerful as an entry level system is now. So relatively speaking, the old computer will feel slow.",
"Some of it is perception, but a lot of it is due to mechanical hard drives. I can guarantee that if you replace the mechanical hard drive with a solid state drive, you will experience an immediate 3-5 times boost in performance for the system booting, programs loading, and so forth. , Also memory requirements gradually climb over time so that more and more installed memory is needed for the system to run smoothly. If you do not have enough installed memory then Windows is forced to do something called paging which involves moving infrequently used data out of memory and onto the disk so that programs have enough free memory to function. Even back in the days of Windows XP, 256 meg of memory was just not enough and the system would regularly run horribly slow because it was constantly paging out what little memory was available to the slow mechanical hard drive, to try to shoehorn everything into a tiny amount of live memory. * Around 2000, about 512 meg of memory was enough. * Around 2005, about 1 gig of memory was a good amount. * Around 2010, about 2 gig of memory was enough. * Around 2015 about 4 gig was enough, and people started moving to 64-bit operating systems. * Now around 2020, about 8 gig is the expected minimum, and 64 bit is the standard for operating systems. I am expecting this to continue, and it may accelerate towards 2015 that 12 to 16 gig will be the expected minimum. Any new computer that I buy now will have a minimum of 16 gig installed, AND at least 1 expansion slot open to grow this to 32 gig by 2030. , A similar minimum growth is occurring with the Windows boot drive for an average work computer where someone is doing minimal or no video editing. Back in about 2015, 128 gig was an acceptable size for a boot drive for a typical business desktop or laptop, but this has gradually grown to about 256 gig now. Part of this is related to the increase in memory storage, because Windows generally likes to have both a virtual memory page file and hibernation file that are both about as large as all of your installed memory. * Windows 10 by itself wants about 30 gig of storage. * If you have 16 gig of memory, then except to have at least 16 gig used for the page file. * And another 16 gig for the hibernation file. * Windows Update likes to hold onto a cache of installed updates so that they can be removed if there's a problem. * When Windows Update does a \"release upgrade\" it is essentially installing an entire new copy of Windows and the previous version hangs around for at least a month, consuming 10-20 gig. All of this plus a few installed company desktop programs rapidly ends up consuming 75-100 gig of storage, so a 128 gig solid state drive just doesn't cut it anymore."
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m8dgnh | ... How can a infection like chicken pox trigger alopecia? | Biology | explainlikeimfive | {
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"Imagine your body is a city that you have to protect from invaders. You have the city walls (the innate immune system) and the city guards (the adaptive immune system). Each of these city guards has been trained to look for a particular characteristic that no normal person in your city has, say brown hair with a ponytail (this could be something like the spike protein in COVID-19). Now suppose this guard arrests an intruder with brown hair and a ponytail. They are now on much higher alert than before, so much higher that they start arresting anyone with brown hair, or anyone with a ponytail, even if they are innocent citizens. This is how an infection in your body can cause autoimmune disorders. The T-cells in your body are sensitive to particular antigens but are also mildly sensitive to many other antigens, sometimes even self-antigens i.e. your body's own cells. What can happen is that during an infection like chickenpox, the T cell that is specific to a chickenpox antigen will be activated making it much more sensitive overall. It can then react to self-antigens that it was only mildly sensitive to before and begin attacking the body's own cells.",
"The body has an immune system that fights off germs like chicken pox. Usually the immune system is really good at telling the difference between your body and germs. But, sometimes the immune system gets confused and accidentally damages parts of your body that are healthy while it fights off germs."
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m8euhe | Psychiatric medication | Other | explainlikeimfive | {
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"If sanity is a recipe, some people have the wrong ingredients or amounts. The medicine is an ingredient fix.",
"Most issues with the brain (schizophrenia etc) are a result of a chemical imbalance in the brain. The drugs used to combat these issues attempt to regulate these imbalances. Sometimes they suppress one naturally produced chemical, other times they're designed to replace one. Other times, they increase the body's production of a *different* organically produced chemical. All of this is done to achieve a kind of balance in the brain."
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m8flat | How do people discover planets and galaxies millions of light years away? | By this, I mean celestial objects that are so far away you would have to travel faster than the speed of light to reach it (eg. Andromeda? im not sure on this but its an entirely different galaxy so it should be right?). so then what kind of methods do scientists use to gain such precise knowledge of planets and galaaxies so far away? | Physics | explainlikeimfive | {
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"They’re millions of light years away, but they’re *billions* of years old. The light has had an eternity to cross that gap. When you look at a picture of the Andromeda galaxy, you’re seeing the 2.5 million year old light that has just recently arrived. We can see galaxies from this far away because they’re incomprehensibly large beacons of light. Planets are neither large nor bright, and they’re much harder to spot from afar. Most are detected from their gravitational effects on their star, and usually these stars are dozens of light years away, not thousands.",
"The short answer is really, really, really good telescopes. And math. The longer answer is, anything that emitted light that was within about 14 billion light years of us at the time is, or will be, visible to us. I.e., light travels one light year per year (hence the term), the universe is around 14 billion years old (give or take), and by no coincidence, the visible universe is around 14 billion light years in radius. The further away you get though, the harder it is to pick something out, for the exact same reason that it's really hard to read a book from across the room. Individual planets get nearly impossible to spot directly after just a few light years. So all of them that we know about, we found by how they effect the star they orbit. If the star wobbles in a particular way, or its brightness varies in a particular way, that indicates planets orbiting it. Individual stars get hard to pick out even with the best technology after a few million light years. Similar indirect methods can be used for spotting stars and/or galaxies that are too small or dim to see at their distance."
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m8fs5i | How do they represent whole population in statistics? | Hello, recently I saw an ig post regarding the #notallmen movement and it read that 97% of women in the UK have been sexually harassed. Could someone explain what is the process of how they research this and come to that number? (Does not have to be this particular research) I am not questioning the number i am just using it as an example. This post is not meant for a #notallmen debate, i was just interested in the problematic of making that statisic. :) Many thanks! | Other | explainlikeimfive | {
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"[Not a statistician, please correct me if I'm wrong] A study typically takes a sample and extrapolates this onto the whole population. For instance, if you have a (random) sample of 1'000 women and 970 have been harassed, then there's a high likelihood that in the population 97% of the women will actually be harassed (to take your example). You can check this at home by throwing a coin and noting every time it lands on heads or tails and you'll see that after 20 throws you will likely be close to 50%, so it is important to note that the higher the sample the better, since a higher sample gives more accurate results (Not that it matters but the precision scales up to the square root of the sample #)",
"Ideally, you want to ask the question “have you ever been sexually harassed” to all female UK residents, but that’s not possible. To solve that, you need to ask it to a smaller number of women and extend the results to all women. But that can’t be just your co-workers, or your neighbours, or the women that order a coffee on starbucks on a particular morning. If you do so, you’re asking only a particular kind of woman, women that have something in common. Therefore, you need a representative sample of the UK women. One way to do that is to check the demographics of the UK and have the same demographics in your sample. With demographics I mean (I’ll make up the data): in the UK, 30% people live in rural areas, 70% urban. 15% women are unemployed, 15% care of the household, 70% work. You want to have a selection of women (let’s say 2000) in which the percentages are the same as in the whole of the UK. You should also include the right percentages of age, socioeconomic status, ethnicity, single/married women. Then is when statistical analysis takes place. There are some calculations to know how large your sample needs to be in order to be able to make solid conclusions about the whole population (in this case, UK women). Once you do your analysis, you also obtain a margin of error, or an estimate of how confident you can be about your result. It’s important not to extrapolate your results to a different population. What you obtain in the UK might not apply to a different country. Also, if you do the study with women of (for example) London only, it’s not right to apply it to for example Norwich or to the whole UK. This is how you do it properly, but bear in mind that some crappy journals would actually ask the women at starbucks and publish it as if it was a proper study! Always check the sources.",
"Thank you all for your answers! :) you have been very helpful",
"Data collectors do this by collecting data from a \"Representative Group\". They would like to survey all women in this case, but that would be too expensive, so they ask a smaller number, as ressources allow and extrapolate to the entire population. This does require some considerations - that would be the \"representative\" part of this. You might have seen the famous picture of then-presidential candidate Dewey holding up a newspaper saying \"Dewey beats Truman\". This picture is pretty famous statistically, because while the newspaper had surveyed a fairly large population, they had only surveyed their own readership - and their readers predominantly voted for Dewey. They created a bias, and thus were not \"representative\" of the whole population. Today we have various tools and rules of thumbs to make sure the groups we survey are representative, but we still need to think about it, as we may introduce biases that we were not aware of.",
"You collect a sample that is large enough and diverse enough to be statistically representative. If you’re asking about women in the UK, that means your sample will have to include 19 year olds in Wales and 70 year olds in Scotland. A good band of ages and ethnicities, urban and rural, rich and poor. This typically requires a sample size of several thousand. The study *should* cite their methodology. If a study doesn’t cite the methodology, or they do and you find that they surveyed nine women on a bus in Liverpool at 7:26 AM on a Friday and then extrapolated that data set to the entire country... then the statistic is suspect. Collecting data in these types of studies can be difficult. Some chunks of the population are harder to reach than others, and some types of people simply don’t want to respond to surveys. How you word the questions can also change how people respond. If you see a statistic, check the methodology. There’s a lot of bullcrap “studies” passed off as absolute truth in the media these days."
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m8he6w | How long can blood banks store blood? | Biology | explainlikeimfive | {
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"Whole blood and red blood cells are actually only kept for up to 42 days before it's discarded. Platelets last for 5 days. Plasma can be frozen for up to a year."
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m8hpj3 | Why do liquor bottles sometimes have those thing that make it pour really slow? | Technology | explainlikeimfive | {
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"They are to measure the fluid. Barkeepers need to measure a lot of fluid in as short of an amount of time as possible. I don't know the exact figure, but they pour at around 1cl per second, so if the drink asks for 2 cl you pour for 2s. That is much more accurate than having an open bottle and just guessing how much you pour.",
"It that has to do with being able to control the pour, so you don't have the giant air bubbles (since a lot of those bottles have long narrow necks) and not filling the glass too full. Since most hard liquor is meant to dolled out in fractions of an oz to maybe 2 oz. I can't remember the exact size of the jigger and pony.",
"This is a bit broad. Are you referring to pour spouts as seen in bars and restaurants, or the plastic built into the opening of large bottles?",
"Posi-pours have a ball bearing that stops flow after a specific measure is poured. These can help insure consistent mixtures, and speed up service.",
"If you're talking about those whitish plastic things, they can be popped out pretty easily with a knife in my experience.",
"All these comments talking about measuring are either thinking of something else (spout) or just wrong. The plastic thing is an anti-tamper protection so nobody can tamper with the drink, like dilute it with water or fill it again with moonshine to sell as the real deal. Cheers."
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m8hzvx | How do we know that photons have no mass and not just a really small mass that we can't measure yet? | Basically the title. I was thinking about whether or not our understanding of photons is limited by our technology to measure them. Is it possible that they have a mass, but it's simply too small to measure with our modern technology? | Chemistry | explainlikeimfive | {
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"Simply, we calculate it based on things we can measure or are observed to be constant. The equations only work, provided that they have no mass. It's never going to be a case that someone puts them on a scale, it's all derived mathematically.",
"Basically here is how it works. We observe the universe. We create a model for what we observe. We use that model to make predictions. We make additional observations and see how they match our predictions. Currently, our models set the mass of a photon at 0 and there haven't been any observations that contradict the predictions of those models. Yes, our observations are limited by our technology, but that is true for every single scientific observation ever; no need to give light any special treatment.",
"Yes, it is possible. In fact, it has already happened once with another particle - the neutrino - whose mass must be non-zero because of its behavior but is also too small to currently measure. (It's at least a million times less massive than the electron, and possibly much smaller). That being said, we understand photons pretty well and our current physical models work just about perfectly on the assumption that photons have no mass. So they're pretty widely believed to actually be massless. In either case, experiments have put a [very low]( URL_0 ) limit on their mass - in fact, that limit is much lower than the limit even on neutrino mass."
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m8i0d3 | Why do some plants tend to lose their vibrant color when the environment conditions aren't optimal (eg pinkish plants becoming green or fading) | Biology | explainlikeimfive | {
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"Dietary needs not being filled. You loose color in your face if your not eating well pretty much.",
"Plant nutrients are important: besides Sunlight, CO2, Oxygen and Water plants need a particular combination of nitrogen(N), phosphorus(P) and potassium(K). If any of these nutrients are lacking in the soil your plants may not grow, bud, bear fruit or be as colorful as they're supposed to be. Fertilizers and plants foods that you buy contain a particular ratio of these nutrients and this is shown on the packaging as the fertilizer grade. Roots are essential for plant development so typically if you're having this with store bought plants it'll be because you haven't repotted to a larger pot which is absolutely essential with any nursery plant - it's roots when you buy it will already be too confined. Fungi, mold and pests also effects plants. Check closely for signs, be aware though this can be a hidden problem when it's the roots that are being attacked. Always remember with plants too much can often be as dangerous as not enough - be it water or sunlight or any other factor. Overwatering can result in leaching nutrients, poor nutrient absorption or disease."
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m8i807 | Dividends, yield, and bonds | I’ve recently gotten into stocks and I’ve started investing in my 401 k through fidelity and bought some stocks through them. I know I have a lot more to learn but I’m still confused on a few things like dividends, stocks, and bonds | Economics | explainlikeimfive | {
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"Dividend = the company pays a percentage of its earnings to shareholders. It is a way to make owning the stock more attractive to shareholders, and it's also a sign that the company feels comfortable with where it's at (they're not going to pay dividends if they're consistently losing money). It helps build confidence in an investor. They generally pay out on a quarterly (every three month) basis, but sometimes it's every month, just depends on the schedule of the company. More stocks means you get more dividends. If a company is paying 20 cents per share, and you own one share, then you get 20 cents. If they pay 20 cents per share but you own five shares, then you get a full dollar. Yield is a combination of *realized* (when you sell) gain or loss on the investment and it factors in any dividend payouts. For instance, if you have a stock that you bought at $100, and get a total of $2 in dividends from that stock over the year, then the one year yield would be 2% (2 / 100 = 0.02). If you sell it at $20, and had a dividend of $2, then it would be 22% (20 + 2 / 100 = 0.22). If you sell at a loss then you can have a negative yield. Stock = share = a portion of ownership in a company. If a company is entirely publicly owned and sold 100 shares on the market and you buy one of those shares, then you own 1 of the 100 and you are a 1% shareholder. If you owned 50 you would own 50% of the company. Bear in mind... companies sell *thousands and thousands* of stocks, and they usually do not sell anywhere near 100% of their total stock. Bond = a government issued security. Easy example is municipal (city) bonds. Say your local city wants to build a new bridge across a river in town - they might fund half of that project through bonds. You buy a bond for $500, that $500 helps pay for the bridge, and then when the contract/term of the bond is up, you get paid the $500 back plus interest. Historically bonds are considered low risk since the government does *not* want to default on loans, but they also don't pay *too* much in interest, either.",
"Dang, lots of long winded answers here. Stocks represent fractional shares of ownership of a company. Dividends are cash paid to shareholders. \"Yield\" is a general term easily explained by a formula: Cash Received / Value of Investment. A bond is an investment that generally pays interest for a certain amount of time, and has a maturity date which then pays the original principal back. Let's start there and let me know if you want examples.",
"Dividends are (typically) quarterly payments some companies pay to shareholders from profits. Each quarter, the company announces the amount, the date on which one must own the stock to get the dividend, and the payment date. Most companies are pretty stable in their dividend payments, raising them slightly year to year and rarely suspending them. They are typically only a small percentage of the share price on an annual basis, like 1-3%. For example, Apple pays $0.205/sh per quarter (was $0.82/sh before 4-for-1 split). Stock is a fraction of ownership in a company. You buy a share of Apple, you own 1/17,000,000,000 of the company. Bonds are basically loans. By buying a bond, you are lending a government or company money. You receive interest payments for the duration of the bond's terms, and at the end you get your initial money back. Bonds can also be bought and sold on the secondary markets between investors."
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m8ij3m | Why can you throw a Frisbee faster vertically? | Physics | explainlikeimfive | {
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"A frisbee is shaped as an airfoil, with a convex curved top surface. This allows it to generate lift as it flies through the air horizontally, keeping it in the air for longer. The thing is that generating lift always results in creating drag. This drag is imaginatively called lift-induced-drag, and by definition acts in the opposite direction to travel, slowing down the frisbee.If you throw a frisbee on its side then the lift generated by the foil is horizontal, so is not opposing gravity. You therefore get less lift, or the frisbee accelerates to the side. Less lift means less drag, and so the frisbee can go faster. The downside is that with no vertical lift it will drop more and so have a shorter flight time.",
"The frisbee is designed to convert forward motion into lift. It uses it's weight to maintain the angle of attack, maximizing this effect so it stops and then gently floats down for your dog to catch. If you throw is at too steep an angle of attack, like straight up. This balance effect doesn't work as well, so it falls like a disc."
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m8ik8o | How can a head injury spark a new ability in someone? | I've heard of people who became amazing at sculpting, others at drawing, others at maths, others at visualising mathematical equations... and so on. How does this happen? | Biology | explainlikeimfive | {
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"A stroke can injure the dominant side of the brain, creating the necessity to use the less-dominant side. It can be frightening, but can also open up new thinking patterns, along with skills. Jill Bolte Talor wrote a book about it and also did a TED talk. My Stroke of Insight was excellent.",
"The brain is very complex. It controls everything from balance to IQ and interests. When an injury occurs to the head, some of these areas may become damaged. Because of this, the brain has to from new “pathways”. Neurons can redirect to other areas and figuratively exercise that area of the brain. Head injuries can also be physically debilitating, so it isn’t uncommon for somebody who isn’t able to walk to pick up a hobby like painting, if that makes sense."
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m8ipxw | How did different races cone to existence if at first we were all of the same race? | Biology | explainlikeimfive | {
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"Two main factors - distance, and inbreeding. For most of prehistory, humans were very nomadic. There was no incentive to settle down in one place until the advent of agriculture, which occured a few times in different places around the world around 10,000-4,000 years ago. Before that, you had to move with the food - once the prey animals moved on and/or the fauna was over-foraged, human groups had to move on to a new area. Over time, distance increased between different human groups. Eventually, several groups uncovered the techniques for agriculture, began settling down, and started the very first civilizations. With this vast distance between populations, inbreeding was fairly normal. Not brother-sister or parent/grandparent-child, but cousin-cousin was fairly frequent. Today, we often scoff at anecdotes of people like Albert Einstein or Edgar Allen Poe marrying their first cousins. But for most of history, this was a fairly normal practice (and one that tends to avoid the damaging genetics of closer inbreeding). Populations were simply too small and too distant for everyone to be able to mate with someone they weren’t closely related to. Eventually, this began strongly concentrating certain traits - some of which arose through chance mutation and others which arose by environment. Those populations in Europe developed lighter skin to attain adequate vitamin D, while those in Africa maintained darker skin to protect from excess harmful UV light, and some developed the genes for sickle cell anemia to stave of malaria. Another adaptation, the eye fold characteristic to far northern populations and populations in east Asia, may have been developed to protect the eye from UV light and snow blindness. These differences are very largely superficial - not enough time has transpired for any living human population to diverge into a different species - internal organs and cognitive capabilities have remained the same (although genetics and contagion exposure over time have played a role in epidemiology) Since these populations were concentrated amongst themselves for so long, those traits eventually became definitive in those areas, to the point where such traits can identify ethnicity and ancestral origin. It wasn’t until about 600-700 years ago that interactions between these previously distant populations became relatively common, and it wasn’t until the past few hundred years that the intermingling of these populations became common (e.g. interracial marriage in the United States was illegal until 1967). The globalization of all world populations may introduce something equally revolutionary in our genetic pool in the future - a single, unified ethnicity. Because almost every population has access to almost every other population, traditional ethnic traits will likely converge over time.",
"People who moved to colder climates had no need for super dark skin but did need to make more vitamin d from sunlight since they got less of it, so they slowly evolved to have lighter skin.",
"If the question is about humans then the answer is that race is a social construct. What is included in what groups is not the same in different places. It also changes in the same location over time. There is no biological concept that matches the social definitions. There is also no district groups of humans biologically but a continuum between all groups so there is no biological base of something that would divide humans into groups like that.",
"Restrictions on gene pools and interbreeding. Humans started in Africa. A small group of those African humans moved out of Africa. When small groups of people do things like that, you get something called a population bottleneck - a new pool of genes that don't have any gene flow from the original larger population is made, which means mutations have a bigger influence. Then those small group of humans that moved out of Africa met other human sub-species like Neanderthals, and they had a pretty good idea: Have sex with them. The humans spread out across the world. The ones that went to Europe and that area had sex with the neanderthals and made European people - human-neanderthal hybrid people (although the influence of neanderthal DNA has been averaged out a lot now, so white people nowadays are almost entirely human but with less genetic diversity than Africans, and some neanderthal genes). Another population of humans moved East through Asia and it's thought that they met and had sex with a group of another human subspecies called Denisovans, creating the kinds of humans found in Melanesia and aboriginal Australia. There are likely other groups of human subspecies involved in race evolution too but those two are the most prominent ones in known evolutionary history. You've got that combined with natural mutations within populations as well.",
"Until quite recently, populations of humans that lived far apart couldn't mix together very much. They could only get around on foot, so they lived apart from each other and mostly stayed apart. Since different groups of people couldn't mix very much, they started adapting to their own home environments, which is different all over the world. Today, we have a huge variety of humans in the world who have characteristic features of their pre-historic origins. Note that I didn't say \"race\". The idea of race isn't even strictly about physical traits; it's something that people made up to wield power over each other and has no firm basis in science at all.",
"Evolution is the results of small changes over very long periods of time, with local populations not mixing with others so that the changes get emphasized. As far as skin and hair conditions go - which is all that \"race\" is, for the most part - humans left Africa about 300,000 years ago. That's a decent amount of time for some mild changes. For a smaller population subset, humans came to the Americas only around 23,000 years ago (give or take). Then, the ice ages would cut some people off from mixing again due to ice blockages, while also opening land bridges due to lower sea levels - allowing greater dispersals. There were some major ice fluctuations around 16,000 years ago, which would serve to isolate some populations for a time, allowing for divergences. Then when the ice ages ended at the start of the Holocene, sea levels went up significantly, further cutting some people on islands or in the Americas off. These types of actions would repeatedly isolate small groups of humans, who would then interbreed and it would enhance certain common features and genetic quirks of that group. And then over time these small populations would grow much bigger when weather changes led to more resources and then agriculture, and then agricultural neighbors would bump into each other and start mixing once again."
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m8jiti | Why are Φ and Φ transliterated differently? | A Greek Φ (phi) is always transliterated into English as "ph" in loanwords, yet a Russian Φ (and Cyrillic Φ's across the board?) are usually brought into English as an "f". Why the discrepancy? Is it just tradition/convention or is there some reason for it? | Other | explainlikeimfive | {
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"You can use F for the Greek letter, as well. It's because transliteration is an imprecise science based on approximating sounds and there's always multiple ways to transliterate different characters. Even for Cyrillic transliteration there's like half a dozen different acceptable ways of doing things - the ending -ый on Russian adjectives can be \"-yy\" or \"-yj\" or just \"-y\", for instance. Sometimes soft and hard signs are transliterated, sometimes they're not. Just depends on the style guide you're using.",
"It originated as a convention to transcribe *Ancient* Greek. Unlike in Modern Greek, we're pretty sure Φφ wasn't pronounced /f/ in Ancient Greek, but rather /pʰ/ - a \"p\" sound except \"aspirated\", meaning it was pronounced with an extra puff of air, sort of. In fact, we think Ancient Greek had 3 such aspirated stop consonants, to also include Θθ /tʰ/ and Χχ /kʰ/. If you had to be able to systematically distinguish an unaspirated /p/ from an aspirated /pʰ/, like Ancient Greek did with Ππ vs. Φφ, in an alphabet like Latin that doesn't have dedicated letters for that... what do you do? The solution was to represent aspiration with an extra \"h\" - since that's sort of all /h/ is, anyway, just exhaling. However, language changes, and the pronunciation of Φφ is thought to have shifted to [ɸ] in Koine Greek around the turn of the millenium, and from there /f/ in Byzantine Greek. But when you've already got a transcription schema for a language... why invent a new one every time a sound changes?",
"The same symbol is being used for two different sounds in two different languages. When we pull them into English we keep the sound it was being used for in wherever it came from. Cyrillic cribbed most of its symbols from other alphabets (maybe all?) but remapped some of the sounds. When you see Φ in Greek (or in engineering, where we assume it's Greek), we mean the Greek letter \"phi\" and pronounce it appropriately. When you see Φ in a Cyrillic language, like Russian, we mean the sound \"f\" (I don't know the name of the letter itself) and pronounce it that way."
],
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8,
8,
3
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m8k8om | Can someone explain the theory that the mind exists outside of the body? | Other | explainlikeimfive | {
"a_id": [
"grhpt8i",
"grhs3u4",
"grhqytz"
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"text": [
"Sure. It's pretty simple, actually. We don't fully understand the mind yet. Therefore, it must be spooky magic. QED.",
"It's basically: * Blobs of goop can't think; * I can think; * My brain is a blob of goop; * Therefore: I must be using something \"outside\" of my brain to think. I'm not sure that we could disprove it since we don't really know how consciousness works...but we also can't prove it either since we don't really know how consciousness works. So, it's mostly something to \"blow your mind\" in a Philosophy 101 course and generate a lot of discussion.",
"No, not even the people that believe it. One question and their argument goes into a tailspin."
],
"score": [
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4,
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m8l7nl | Why do multivitamins have calcium and iron in them when calcium inhibits iron absorption? | Chemistry | explainlikeimfive | {
"a_id": [
"grhw8k2",
"grhwy2h",
"grhxtp4"
],
"text": [
"In my personal opinion a multivitamin is way more about marketing than it is effectiveness.",
"Because it’s a way to claim “100% complete” marketing message. Calcium won’t completely prevent iron absorption, since you anyway take both while you eat, so you’d not completely deprived of either.",
"Because when people compare labels in the grocery store they'll say, \"Oooh, this one has more calcium.\""
],
"score": [
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m8lo2t | - Could we add some type of air compressor and blower system to clear solar panels and extend the life of planetary probes? | Technology | explainlikeimfive | {
"a_id": [
"grhze7v",
"grhzspx"
],
"text": [
"Yes. However the degradation of the panels is planned for during the engineering design phase, and it's cheaper (and less launch weight) to simply oversize the solar panel than it is to add a complicated mechanism (~~air~~ atmosphere pumps don't have infinite lifetimes, and abrasive dust is also a problem: you can't just add a dust filter to the pump intake because it would eventually clog). A brush on the solar panel would seem like a good compromise to me, but perhaps it would eventually erode the surface of the cell (again due to the abrasion from dust).",
"In theory: yes. If there's anything to compress you could do it. In practice, so far it's been deemed not worth it. On Mars it turns out there's enough wind to keep the panels somewhat clean anyway. So why not go the easier way and just make a bigger solar panel instead? This way you avoid all the fiddly moving parts of a compressor, and don't run a risk of it say, blowing up. Also a rover has a weight and energy budget, and using that on the compressor may well mean passing on something else that could be more useful. Opportunity was planned for 90 days and lasted 15 years. Spirit lasted for 6 years until it got stuck. Curiosity and Perseverance are nuclear powered and don't have solar panels. All in all it just doesn't seem to be a problem that needs solving."
],
"score": [
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m8lr1n | How come when you have an allergic reaction your body/face swells up super quickly, but it takes days for the opposite to happen (to go back to normal)? | Biology | explainlikeimfive | {
"a_id": [
"gri2u42"
],
"text": [
"The [complement system]( URL_0 ) proteins involved in these really severe reactions are present everywhere in your blood, and can respond *very* quickly to recruit/activate immune cells when triggered. The mechanisms that shut down inflammation are not nearly as fast, or are just passive processes (like pro-inflammatory signaling molecules being drained away from the affected area via the lymph)."
],
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5
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"https://en.wikipedia.org/wiki/Complement_system"
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|
m8muin | Why are mammals not more colorful? | Why are mammals universally shades of brown/grey/white/black/red and never the rest of the color spectrum? Birds/reptiles/amphibs/insects, etc. can ROYGBIV with reckless abandon, why not us furry creatures? | Biology | explainlikeimfive | {
"a_id": [
"gri8slg",
"gri9iim"
],
"text": [
"Most super colorful insects or reptiles use it as a [warning sign]( URL_0 ) that they are not good to eat. Mammals don't produce poison so we don't need this. Only male birds (usually) are colorful as a mating sign. It's also easier for them to escape than it would be for a mammal, so this is not a hindrance for survival. Mammals are confined to the ground and have different selection pressures. They need to blend in with the environment, which tends to be green or brown. Many prey animals can only see in the green/blue(?I think) spectrum, which is why many cats will be orange/yellow. More simply, because being any other colors than brown/gray/black/etc did not have evolutionary advantages over being a bright color.",
"well, all animals have an interest in being hard to see; I think colors that blend in are more common across the board than bright colors. Why does it seem like birds and reptiles are more colorful than mammals? I'm not an expert, but I do know that reptiles and birds, across the board, tend to have better daytime color vision than mammals. Reptiles and birds have mostly been daytime animals for the last few hundred million years, whereas mammals have been mostly small, nocturnal burrowing animals for most of our existence. Even today, most mammals are active when it's dark. So, mammals tend to have pretty bad color vision, and better senses of smell and hearing than reptiles and birds. So, it maybe makes sense that bright colors would matter less to the animals who can't see them very well."
],
"score": [
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5
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"text_urls": [
[
"https://en.wikipedia.org/wiki/Aposematism"
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m8my7p | Why Do Babies Get Fevers When Teething? | Fevers are an immune response. Teeth aren't foreign invaders. So what gives? | Biology | explainlikeimfive | {
"a_id": [
"gridazv"
],
"text": [
"Not a doctor or medically trained, so take this with a pinch of salt. But what I know from my old college classed is babies immune systems are weak. They’re still figuring out how to fight so many illnesses and the best way to do it. On top of that, when babies are teething, they put everything they can in their mouth. Which also includes dirt and bacteria. So add dirt and bacteria to an open wound (the gum where the tooth is pushing through) and you get super mild infection. In an adult, the body would barely register this. In a baby though, the immune system kicks in and caused a fever."
],
"score": [
3
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m8my8u | how do potatoes and onions keep growing green stems while in dark and dry places after a week while other plants quickly die from lack of light and water? | Biology | explainlikeimfive | {
"a_id": [
"gri76rc"
],
"text": [
"Root vegetables like onions and potatoes have their own source of nutrients and water stored in the root. When conditions are right, the sporting process begins. If it starts in a dark room, the shoots will search for light and a place to plant their roots until the nutrients and water are depleted."
],
"score": [
5
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m8myrj | If getting pregnant can happen accidentally so easy, why is it difficult for people to get pregnant? | Biology | explainlikeimfive | {
"a_id": [
"gri71k5",
"gri8kuc",
"gri9kro",
"gri7kog"
],
"text": [
"It's easy when both the male and the female are fertile. But that's not always the case. Sometimes the male has low sperm count, poor sperm mobility or other factors that prevent the sperm from even reaching the egg. Other times the female can have issues with the zygote implanting into the uterus, or simply non-viable eggs. There are a ton of different causes. But when two people have fully-functioning reproductive systems, it's very easy to become pregnant.",
"It’s not that it happens accidentally so easily. Nor that it’s so monumentally difficult to do it on purpose. But you’ll hear a lot of both stories because they’re both distinct, life changing, and out of the norm. If someone’s trying for a baby and gets pregnant within a reasonable time frame, they’re not gonna drum up drama about how long they’ve been trying or how they didn’t want to be pregnant. If someone accidentally gets pregnant, it’s probably pretty out of the ordinary for them, even if they’ve been having unprotected sex for a while. Conversely, if someone’s been trying to get pregnant for two years without success, it’s so out of the ordinary that it will be distinctly dramatic for them. [Pregnancy is actually statistically pretty difficult in the first place]( URL_0 ). Most people trying to get pregnant and having *sex twice a week* will have just a 50 percent success rate after 3 months, and 95% after 2 years. Variance from that in either way can be pretty shocking, so you’ll hear more about it.",
"Because the people getting accidentally pregnant are typically younger, which typically means more fertile.",
"The people who keep trying get pregnant without success is not the same people who get pregnant easily. And it's about the couple too. Usually the couple who is trying is older then the couple who get it accidentally, and fertility decrease with age. Also older woman sometimes take the pill for longer times, so the body must take time to adjust to \"normal\". Younger couples do more sex , and do more mistakes too, and no method is 100% bulletproof ."
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m8notc | Why is almost boiling water louder than rapidly boiling water? | Put water on the stove, turn up the flame, wait for it to boil. It get's really loud....but it's not boiling yet. Wait another minute, it gets quieter and is boiling. WHY? | Chemistry | explainlikeimfive | {
"a_id": [
"gribztr"
],
"text": [
"Before the entire pot boils, only the water at the bottom closest to the burner will be at the boiling point. So, tiny bubbles of steam will be created at the bottom which then almost immediately pop. This popping sound is what you're hearing. When the whole pot is at boiling temperature then the bubbles will make it all the way to the top before they pop which is quieter."
],
"score": [
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m8p13g | what Net Zero Emissions means exactly? | When climate change scientists say we need to be at Net Zero Emissions by X date what does that mean? | Earth Science | explainlikeimfive | {
"a_id": [
"grijw5x",
"grijnpo"
],
"text": [
"Net zero means that the sum total of everything being added and subtracted from the system cancels out, hence the net addition is zero. Net zero emissions functionally means both reducing emissions, and using carbon capture and storage techniques to recapture whatever carbon you still end up emitting.",
"The more CO2 that humanity puts into the atmosphere the more the Earth will heat up. In order to avoid catastrophic changes to the climate we need to limit just how much CO2 we put into the air. But, the relevant number isn't just how much CO2 we emit, but rather the amount we emit minus the amount we capture. There are a number of ways to capture CO2 out the air. The most straightforward is to plant trees in a place that doesn't currently have trees. Those trees will take CO2 out of the air and turn it into wood. So, we need to get to a point where the amount of CO2 we put into the air is equal to or less than the amount that we take out so that the total CO2 in the atmosphere stops going up."
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