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ny4yqe | How did snakes develop venom as a way of killing when no other reptiles did (and so few animals have)? How did the variations in kinds of venoms come about? Did constricting snakes lose their venom? | Other | explainlikeimfive | {
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"Venom is an extremely advantageous trait. It takes a lot of muscular power and body adaptations to mechanically capture and subdue prey, which expends a lot of energy. So being able to do it chemically would allow an animal to kill prey with less risk to itself. The prevailing theory is that venom first evolved in early reptiles as simple modified salivary glands that produced digestive proteins. Reptiles with this trait presumably fared better than those without, and continued to develop a fanged injection system and more powerful venom as time went on. Correspondingly, many more reptiles lost their venom or fangs, but still carry the genes in their DNA. Variations in venom are often prompted by prey gradually evolving resistance to it, as some venom mechanisms can be defeated by biological adaptations."
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ny54vn | Why and how do knots form in trees? | Earth Science | explainlikeimfive | {
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"Something to note beforehand: Wood has a “direction” to it, that is that the grain goes along the length of the trunk or branch. As the tree grows branch grow out from the trunk. The grain orientation of the trunk is vertical, whilst the branch grain follows the branch. When the tree continues growing and upper branches develop, lower branches become useless and die off leaving their stump. As the tree grows further this stump becomes incorporated into the trunk, becoming the knot. This stump had the original branch grain direction and that’s why when cutting though wood, encountering a knot can be hard to deal with."
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ny5g66 | When you stand in hot water, why is it cooler if you stay still? | Physics | explainlikeimfive | {
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"If you stand still you cool the water directly around you. Once you move you exchange that layer of cooler water for new hot water. Same effect as moving air cooling better than still air."
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ny5tni | Why is the recommended brushing time the same regardless of the type of toothbrush? | My 10 year old basically asked me this when I replaced his manual toothbrush with an electric one, and I had no answer. If a powered toothbrush does more brushes per second than a manual one then shouldn't you have to bush your teeth for less time? Or if 2 minutes is recommended for the electric one then shouldn't you need more time with a manual? | Technology | explainlikeimfive | {
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"One of the useful things that toothpaste usually contains is fluoride, which can fill microscopic holes in your tooth enamel and stop them from growing into larger and more problematic holes. The two minute thing is more about letting the fluoride have time to be in contact with your teeth and do it’s thing, and less about a particular amount of mechanical action from the tooth brush bristles. This is also why mouthwashes say not to eat or drink for a while after using them. They usually contain fluoride as well, and if you don’t eat/drink/ rinse with water after the mouthwash, it leaves some fluoride on your teeth and gives it longer to work.",
"Although the fluoride is important, the conditions necessary for fluoride to do its thing means that it's more important to expose your teeth *often* rather than for a single long time. The recommended 2 minutes is more about making sure that you brush *all* of your teeth for enough time to scrub off the plaque. Consider how you brush: you hit different \"zones\" in your mouth, focusing on a couple teeth at a time. Two minutes of brushing across your whole mouth works out to be only a little bit of brushing on each tooth."
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ny625c | What exactly does it mean to Direct a movie or a film? What role do they technically play and what exactly do they do? | Because I always see that the directors of movies are given much more significance. | Other | explainlikeimfive | {
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"I suppose you know what shooting a movie is like right? Everything there is the choice of the director, including: * Actors, where do they stand, how do they move, how do they act. The directors keeps on telling the actors to change it this way or that way, until they get the shot that they want. * Camera, where are they, how they move, which lenses to use, etc. The cameraman just follow the director's direction. * The above is also true for other elements in the scene, such as lighting. * Locations, props, and costumes. The director tells the location scout, what kind of setting they are looking for. The scouts then look for places and come back to the director with a short list of locations. Then either the director pick a location from the list, or tells the scout to look for more. The same idea is true for props and costumes. * Post-production, the above is also true for any other process, like editing, sequence, the sound, the songs, color grading etc. Basically, nearly all the creative process AFTER the screenplay UNTIL the movie is there, have to be ran through the director, and the director have the final say in everything. So what is it the director are not in charge of? Director usually work for producer, and producer are in charge of the money. Such as, what is the budget, how much will everyone get paid, WHO is the director, making the trailer, the marketing, deals with cinema etc2.",
"The director is the creative vision that is the final say on most, if not all, aspects of the film. They are the person who has the job of taking a script and turning it in to a movie. Naturally they will delegate some of their authority to other directors and departments because \"implementing a creative vision\" is a really large task that is hard for just one person to do properly, but in general if there is a decision to be made the director or someone the director appoints will make it. It's in the name: the director directs. They are in control, and they are the person giving everyone orders what to do and when, how, and to do it again if it's not right."
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ny6cen | How is it possible that my apartment is 26c when it's 17c outside? All my windows are open. | Physics | explainlikeimfive | {
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"You, your lights, your computer, and most notably your refrigerator, all produce heat. A good breeze would bring it closer to outside temperature sooner, but it's a lot like you have several heaters running in your house.",
"All that heat is stored inside... in everything. Including your furniture. Now it's radiating out of your walls and stuff towards the cooler air."
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ny6pz0 | Why are vitamin pills not a replacement for a balanced diet? | Biology | explainlikeimfive | {
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"Vitamin pills are fine but you still need fibre, protein, carbs and good fats etc which pills are unlikely to provide so pills alone cannot sustain you",
"Some people who can't eat may be on enteral feeds (tube feeding), which essentially means they meet all their nutrition needs (carbs, fat, protein, vitamins, minerals) from a nutritional supplement drink/formula. Sometimes people can't eat but also can't be tube fed, so they require parenteral nutrition (IV nutrition). This basically means carbs, fat, protein, vitamins, and minerals are infused directly into their bloodstream. So yes, it is possible to live off of nutrition \"supplements\" - not necessarily vitamin pills like you asked about, but formulas and specially made mixtures. For those of us who can eat, we also know that there are health benefits to eating \"real\" food that you can't get from supplements. For example, eating a well-balanced diet will also provide fibre and phytonutrients, such as antioxidants. There is a lot that we still don't understand about the thousands of compounds we find in fruits and vegetables beyond just vitamins and minerals, but we know that we don't get the same health benefits when we isolate these compounds in pill form, compared to eating food as a whole with all the components they contain. And let's not forget that food isn't just about nutrition! Eating foods that are satisfying to us and enjoying meals is also good for our health :)",
"If vitamin pills only contain vitamins like I'm led to believe, then it's not enough nutrients. You need carbonhydrates, proteines, fats and such to survive. If you eat all of these in moderation, everything should be alright ( unless I'm misunderstanding the question, which is very likely).",
"[The guy]( URL_0 ) who helped popularize vitamin supplements was a Nobel prize winner, he thought vitamin C would help cure cancer and he could live forever. Needless to say he's dead. And smart people are rarely always smart all the time.",
"Just because you put a vitamin or mineral in a pill, does not mean your body will absorb and use it the same way if it was in food. You might require another mineral or substance in the food to actually trigger the absorption of the vitamin your interested in.",
"What we eat can affect the way in which the nutrients of those things are absorbed. This means that the same amount of vitamins eaten are often absorbed more efficiently when eaten as part of food, compared to when eaten just in pure pill form. Another aspect of this is the fact that vitamins can be dangerous in high quantities. It's usually recommended to prioritise a balanced diet over supplements because you need to eat every day anyway (so you may as well make it balanced) and because you can't easily account for the vitamins in what you eat. If your diet is unbalanced, you may already be getting too much of a particular vitamin, but still be taking multivitamins for convenience, which would mean you always had too much of that particular vitamin in you. Depending on the vitamin that can cause various issues, but beta-carotene for example has been linked to increased risk of lung cancer.",
"If you wanted a \"pill\" for fat, it would just be a spoon full of lard. The required quantities of various nutrients are more than would fit in a pill.",
"Another aspect to this is we don’t really know what nutrients are needed to maintain health.",
"URL_0 > In 1965 a ‘grossly obese’ man survived without eating for 1 year and 17 days. He lived entirely off his copious body fat and vitamins, and ended up losing 125kg [276 lb] of weight with no adverse effects. (Standard disclaimer)",
"ELI5 answer: A balanced diet includes a lot more than just vitamins. You also need to intake proteins, carbohydrates, fats, minerals, fibres, in addition to vitamins. There are in fact, meal replacement powder/formula, so you can replace a balanced diet with just formula if you want to. The volume of nutrients is much more than what can be contained in pills (you'll get either one huge pill the size of an orange or you split that into 50 regular sized pills but that's annoying to swallow every meal). So the idea of an \"all in one\" meal replacement exist, it's usually a bottled drink or a cup of powder that you mix with water, not a pill.",
"Vitamins don't provide energy while macronutrients like carbohydrates, fat, and protein do. Also, when we're talking about how a well-balanced diet contributes to wellness, vitamins are only one part of the equation (albeit a very important one). There are other things like fiber, minerals, zoochemicals (found in animal products), and phytochemicals (found in plants and vegetables) that contribute to wellness. Another interesting aspect of wellness is how our gut microbiome (an ecosystem of microorganisms living in our gut) plays a role. The microbiome affects immune system function, appetite control, mental health, and various other physiological processes. It's a very hot field of research right now and a lot is being figured out, but to put it short, vitamin pills alone don't really \"feed\" our microbiome. A healthy, well-balanced diet does in such a way that the benefits the aforementioned physiological processes."
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ny7b9s | Why not just kill all mosquitoes? | Earth Science | explainlikeimfive | {
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"We *are* trying to do exactly that. Experiments have run in several countries in which genetically modified mosquitos are released to mix with natural mosquitos, they mate, and the result is no viable offspring. URL_0",
"We have developed techniques to do just that. And there have been a few experiments with the goal of seeing how easy it is to eradicate mosquitoes. There is currently one such large scale experiment taking place in Florida. The criticism against this is that there might be unknown consequences. We think we have a good idea about the role that mosquitos have in the ecology but there might be something we have overlooked. We have done mass eradication before which have ended in catastrophe. We do not think this will happen if we kill all the mosquitos but we can not be quite sure until we do, and then it will take time to reverse it. But just to be on the safe side the experiments which are being done now is taking place on mosquito species which are able to spread malaria. As far as I know nobody have seriously suggested killing all the mosquitos, only those which can transmit dangerous diseases to humans and animals. Not all mosquitos are of these species.",
"We don't understand mosquitos' ecological niche. Driving each and every mosquito extinct because they're inconvenient to us could have horrifying consequences that we simply can't appreciate from our current perspective."
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ny7t56 | what is the purpose of the value e? | Mathematics | explainlikeimfive | {
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"The mathematical constant e is referred to as representing natural growth. Unlike other popular constants like pi, e does not have a handy visual to explain it. Instead it can be thought of using banks and interest: (For true ELI5, interest means \"the bank will add 'this much' to your money at the specified time) If we have a bank that generously offers 100% interest every year, and you give them $1, then after a year you will have $2. But wait! A rival bank wants to offer 50% interest TWICE a year if you bank with them. At first, you may think that 50% twice = 100% once, but that isn't the case. After 6 months with this bank, your total + interest will be $1.50. Then another 6 months later it would be $2.25, getting $0.75 from 50% of the $1.50. So it would seem that even if the % interest adds to the same 100%, getting it more often leads to giving you more money! So what about a bank that offers 25% interest every 3 months? Or 8.3% every month? How about an inconceivablely small percentage interest at every fraction of a millisecond throughout the year? You'll find that the final amount tends toward the value of e if you were able to gain interest at a \"natural\" rate of growth. 100% once a year: $2 50% twice a year: $2.25 25% four times a year: $2.4414 8.3% twelve times a year: $2.613035 Every possible moment in a year: $2.71828 (approaching the value of e) e is also important in Calculus and the natural log, but those are waaaay beyond a 5 year old.",
"It’s the value of C where the gradient of the curve C^x is equal to C^x . In other words at e^x the rate of growth/decay is equal to the size of the population/sample. For other values of C^x there are modifiers you have to do to calculate the gradient. In practical terms this makes e inherent to any sort of equations that relate to growth/decay where the growth/decay is continuous (eg radioactive decay/bacterial growth) rather than calculated incrementally (eg compound interest calculated monthly) It also crops up in more complex and less intuitive applications, like the solutions to differential equations.",
"In algebra, you learn about functions and you’re mainly concerned with what the output is (y) for any given input (x). In calculus, you are now concerned with the rate of change of the output (dy/dx) for any given input (x). In calculus, dy/dx is called “the derivative of y with respect to x”. Mathematically speaking, it is the slope of the function’s tangent line for any given input (x). So what if we could make a function f(x) whose rate of change was the same as its output for all inputs? Well experimentally we can find that this is true of some specific number raised to the x power. That number is e (2.71.....). For example: consider again the function y=e^x. let’s plug in 2 for our input x. This gives y = 7.39. What makes our function unique is that our output (y) is the same as our rate of change (dy/dx). So y= dy/dx = 7.39 This pattern will continue for all possible inputs. So to recap, what we have created is a function whose rate of change increases exactly as its output does. In math terms, e^x is a function that is its own derivative. As the other commenters have pointed out, that has extremely important applications in compounding interest and estimating all sorts of cool stuff. Calculus sounds much more intimidating than it is, and if you’d like a very very well explained and animated version of what calculus actually accomplishes, check out [this video ]( URL_0 ). Good question OP."
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ny8mnn | Why diseases get "stronger" at night? | Most times when i'm sick, i don't feel any symptoms at morning or noon, a commom cold for example won't show symptoms at morning but when the night falls, specially late at night, i get fever, clogged nose, coughing etc. Is it because the immunologic system is fighting the disease more at night, and the symptoms are the result of the "fight"? | Biology | explainlikeimfive | {
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"Symptoms are the body’s method of fighting disease. They make us miserable, but they work when the disease is minor. Like a fever makes your body less hospitable. We have less stress hormones at night so our immune systems kick into action.",
"Yep, you have it exactly right. There a *lot* of things that affect how the immune system works, both in terms of ramping it up and dampening it down. One of those things that can dampen it is steroids, namely Cortisol, which your body makes on its own for a variety of reasons. Your Cortisol production dips at night and pops up again in the morning (Cortisol also affects wakefulness, so toning it down lets you sleep better and bumping it up helps wake you up). So to your point, when Cortisol is low (night), its dampening affect on the immune system is also low. The immune system ramps up and, as you said, your symptoms are a result of that fight. That's one of the reasons we prescribe steroids sometimes: inflammatory symptom control. And we typically recommend taking it in the morning so it can help you function better throughout the day but recommend against taking it at night because it can *really* interfere with sleep. We know its limiting your body's ability to fight the infection (and may actually prolong the illness by a little bit as a result in some cases) but it makes folks more comfortable/functional during the day through the process."
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nya8wm | Why are billionaires to blame for not paying taxes when the feds/irs know full well but do nothing about it? | Economics | explainlikeimfive | {
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"Legally, not all billionaires are not guilty of tax evasion. However, that means that the FBI/IRS are similarly not at fault; if they're not guilty of something, then law enforcement can't do anything about it. The substantive issue is how the tax code is written. In order to change the tax code, you need legislators on board to propose/vote for changes/reform. The best way to do that is to draw voters' attention to the issue, since they will pressure their legislators to reform the tax code. One way to draw voter attention is to highlight/blame the billionaire's relatively tiny tax burden compared to middle-/lower-class people's tax burden.",
"Simply put, it's easier to go after the little guy who can't afford a lawyer. They go for the low-hanging fruit. The IRS needs a lot more resources to audit the rich tax cheats and prosecute them in court.",
"The rich use lawyers and lobbyists to insert rules in the tax laws which allow for specific moneys to be tax free or tax deductble. These loopholes are available to everyone, but most regular people cannot make use of them because they have far less money than rich people (it is not worth the trouble) For example, advertising is tax deductible. it is how businesses find new customers, it increases business/profits, thus will be an investment in the future where the business will pay more tax. that is how it is presented. in reality, a company can repaint and decal their vehicles, call that advertising, and write it off (which reduces the amount of taxes they have to pay) A political donation is tax deductible. if a business or rich guy wants to support a candidate (because that candidate promises to enact policies that will benefit their business) the business donates a huge sum of money, which is deductible on their taxes. when all these deductions are added up, it can be that the corporation or rich person will owe very little in taxes. It gets even better if a business has operations in 2 countries. they will move the profitable parts of the business to the country with the low tax rate. the unproductive part (HR, management, offices) will stay in the country with the higher tax rate. since money is generated in the cheap country, most profits get reported and taxed there at a lower rate. the unprofitable parts are taxed at a high rate, but since they can show that they actually lost money (sales are all out of the low tax country, all the expensive parts of the business are in the high country, such as HR, IT) the part in the high tax country lost money so might actually get a refund from the government) & #x200B; Also, a rich person, such as the CEO of a big company, might be paid in stocks or options. their paycheque is very small, they get paid food, lodging, travel at work, so low expenses, not really income. the stock options are not taxed at the same rate as a cash paycheque."
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nyaukn | Can someone explain how the higher units of the US Army are organised? | What is a command? A field army is made of 2-3 corps, but the only active field army has just 1 division and some other stuff in it and a bunch of other confusing stuff like divisions not being part of corps contrary to what the official US Army site suggests. Why is it all so confusing? | Other | explainlikeimfive | {
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"There is organization as it could/should be, and there's organization as it is. In general, there are divisions, then corps, then field armies, then army groups, then theaters. In practical usage, those levels can be skipped if needed. If there is a single division deployed in Elbonia (far from any other US forces) as part of peace-keeping operations, you don't need those intermediate levels of organization; it can report directly to the Europe theater commander. There's no reason to have the divisional commander report to a corps commander who reports to a field army commander who reports to the army group commander who then reports to the theater commander. The \"could/should be\" organization is sort of the worst-case scenario: \"if you have a massive army fighting a complex war, it should be organized like this.\" Divisional commanders reporting to a corps commander makes sense if there are tons of divisions on the field; that way, the field army commander doesn't have to deal with 20 different divisional commanders giving him reports, only 5-7 corps commanders. It also makes command easier; the field army commander can order 1st Corps to take X region, and the details are up to them. They don't have to order 1st Division to secure Y City, 2nd Division to advance to the Z river and hold against a counterattack, 3rd Division to detach their artillery support for 1st Divisions attack, etc.",
"Units can be administrative or field. Field unit are a bit more standardize because a commander can't control effectively too many units, but administrative unit can vary a lot more in organisation. In time of war 2-3 Corps will form an Army and 2-3 Armies will make an Army Group, but right now the US Army rarely need Corps or Army level of command on the field. When they need it, it's usually for an operation and so they organize it specifically for that operation and don't worry about standardization. Most of the Corps and Army currently in the US Army are administrative and Command is also just an administrative unit, they are responsible to keep the US army trained, equipped and ready to be deployed when needed. Any unit are not necessarily under the command of the directly bigger unit (Division under Corps, Corps under Army, etc). Why sometime it doesn't follow that logic? Well because sometime it's not needed. Why add a level of command, when you don't need it. For example a Corp could have a Military Intelligence directly subordinate to it, because it's a small role that don't need to be delegated."
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nyb007 | How does an executive order carry the weight of law? | I'm flying today and see and hear the announcement that refusing to wear a mask is a violation of federal law. This is in accordance to the Feb. Executive order requiring face masks on all public transport. Without getting into the facemask debate, how is it possible to prosecute someone under "federal law" for an executive order that wasn't passed through the legislative process? | Other | explainlikeimfive | {
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"Basically, the legislative branch (congress) passes laws, and the executive branch (president) executes them. Theoretically, executive orders are the president's interpretation of implementing existing laws. Imagine your boss tells you to get his car washed. You could go buy a hose and some soap, or go to the car wash, or go to your home and wash it. All of those would be implementing what he wants in completely different ways.",
"The fact that you're flying is the key there. The FAA has broad authority and control over how passengers in the air, and violating FAA policy is where you'll end up breaking the law. Since the FAA is a federal entity, it can be directed via executive order. So not following the executive order isn't really the breaking the law part, it's not doing what the FAA told you to do, and the FAA does what the executive order tells them to do.",
"Federal laws give the authority for regulation-making over to government bodies. The actual regulations they make can be guided by executive orders. For example there could be a federal law that says you must listen to TSA or FAA rules when you fly in order to maintain health and safety on planes. But that original law does not specify exactly what the rules will be, the FAA and TSA are free to make and change the rules they think are appropriate. They can, and do, change them in response to perceived risks, such as the requirement to take your shoes off for inspection after somebody hid a bomb in their shoe. Because the President and executive branch are ultimately in charge of those regulatory bodies, they don’t exactly write every rule, but they can instruct the staff who are in charge on what rules they should make.",
"Executive Orders are issued based on the bounds set in law. It is frequently politically argued that EOs go beyond the law that it claims allows it. However, it is rare that an EO is found to be unconstitutional through either the judicial or legislative process. Most laws provide enough flexibility that the fight against EOs usually fail."
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nybcxm | Why can’t you kill a fly by punching it out of the air? | Am I just weak? | Biology | explainlikeimfive | {
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"If you're moving your fist fast enough to kill them you're also moving enough air to shove it out of the way."
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nybyzt | Does sunscreen actually cause cancer? If it does, how do you avoid getting cancer from the sun then? | Biology | explainlikeimfive | {
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"Sunscreen simply doesn't cause cancer, thats pure nonsense. Ultraviolet radiation from the sun does though, and sunscreen is made to block some of that wavelength. UV radiation damages the DNA of skin cells, which in turn can cause then to become cancerous. People with darker skin have more melanin, which is a pigment that helps absorb UV light and protect the cell from damage.",
"I'm assuming you are talking about the recent news of benzene contamination in major sunscreens. Benzene is not an ingredient if sunscreen. This is unintentional, they have been recalled (and it affected mostly sprays). This is no different than your veggies getting contaminated. Return/destroy contaminated products, get new ones and use those",
"Prolonged/chronic exposure to unfiltered sunlight (which is composed of, among other things, UV radiation)can increase the risk of cancer; that is absolutely true. Different people may have different \"resistance\" (for lack of a better word) to sunlight due to genetics. For instance, people who have dark skin have more melanin in their skin. Melanin protects the skin from UV radiation, so they are less likely to develop skin cancer compared to someone who has the same level of sun exposure but less melanin; this is absolutely true. Sunscreen is a topical ointment/cream that is designed to protect you from UV radiation just like melanin does. However, it is not 100% protection from UV radiation. And since someone who applies sunscreen is more likely to spend more time outside than someone in the same situation without sunscreen, they may both end up with similar rates of skin cancer. So it's not a matter of \"sunscreen causes cancer\" or \"sunlight does/doesn't cause cancer\"; since cancer is highly tied up in probabilities, there are tons of factors that can influence whether someone gets skin cancer, some of which interact with each other."
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nyc1yg | Why does Serotonin make you happy? | Biology | explainlikeimfive | {
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"Serotonin regulates your mood, so its less likely to make you happy but rather make you stable. Dopamine is what effects happiness, especially when it floods. Othertimes its similar to serotonin in regulation in both emotional and physical symptoms. While too much causes various mental/physical ailments. This is part of the reason therapy is just as or more important than medicine in terms of certain mental illnesses. I know when I've taken SSRIs, which increase serotonin, the doctor has always stated it will never directly make me happy, but rather regulate my hormones in conjuction with therapy to make changes in my life that can make me happier. I hope that makes sense, this is the easiest way i could think of to explain it."
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nycio6 | What determines an organisms lifespan? | I’ve tried looking this up on my own - and the only real answer I seem to get is “how large the animal is” The internet says *the smaller the animal, the shorter the lifespan* However, this leaves me with more question.... Why do humans average 70-90 years, but giraffes average 26 years, blue whales average 80-90 years, **and the giant tortoise which is smaller than all of them averages 150 years** ??? | Biology | explainlikeimfive | {
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"It has to do with metabolism, evolution, and predation. _In general_: •the slower an organism’s metabolism, the longer it lives. This is mostly because organisms release cancer causing chemicals (like oxygen free radicals) as part of their metabolism, and because their cells wear out faster •evolutionarily, organisms that care for their young live longer. If they didn’t, fewer young would survive and they would be selected against. This seems to be part of the reason people live so long once they make it through childhood. •predation means that some animals are evolutionarily selected to live fast and die young. Because evolution has selected them to procreate early, they don’t have genetic defenses against aging. Size correlates with metabolism in mammals, so that’s what you’re probably thinking of. Predation is why bats live about 10x longer than mice, even in captivity. And R vs S selection is why apes live longer in general than other mammals. Edit: of course, there’s some imbalance now due to medicine."
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nycx0e | Hesienberg’s Uncertainty Principle | I understand the math of the equation — mathematically speaking, the more certain you are of electron location, the less certain you are of velocity, and vice versa. But why? Do we know why this is a thing for electrons? Is here any hope of resolving this or does it appear to be an immutable characteristic of particle physics? I’m tagging it Chemistry, because I’m primarily trying to understand it in terms of chemistry principles rather than physics principles because that’s how I need to apply it. | Chemistry | explainlikeimfive | {
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"You can't understand it with chemistry alone, because it's physics, plain and simple. Chemistry is physics too, but at the slightly higher scale of interacting atoms. The Heisenberg Uncertainty Principal is a property of waves and wave pulses. Anything that has wave properties will have a similar phenomenon electrons included. Imagine that you have a perfectly periodic wave. You know the ~~amplitude~~ frequency, not sure why I said amplitude (energy/momentum) exactly, however, there's no information about the location of your wave, as it exists along the entire line. Now imagine the reverse, you have a single, infinite peak at your origin. You now know exactly where your wave pulse is, but no information about the energy. Then, you can smoothly transition between these two extremes, and you'll find a tradeoff between how much you know about position and momentum, or time and energy, or other Heisenberg relations.",
"Heisenberg's principle really isn't all that complicated nor unusual. It is a very simple observation about the nature of time and waves. Let's take the example of the momentum/position pair. Momentum is the description of movement. Time is required to make sense out of any movement. The position is the opposite: when describing the position of a moving object you need an exact point in time. Together they are contradictory - if there is no time, there is no movement. If there is a perfect position, there is no time. Similarly for the energy/time pair. Energy is derived from the wavelength of the object. But without time the very idea of a wave simply doesn't make any sense at all. Therefore, if you reduce time to zero for perfect precision, there are no waves, and without waves the idea of energy stops making sense. It isn't just quantum physics, it applies to normal life as well. For example, if you take a photo of an object at a very short exposure time you have no idea about its movement. It looks completely still. If you increase the exposure time you can see the object moving, but the photo is smeared so you can't really say where the object was during the shot."
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nydo11 | Why can’t gravity be blocked or dampened? | If something is inbetween two objects how do the particles know there is something bigger behind the object it needs to attract to? | Physics | explainlikeimfive | {
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"The other explanations here are not really getting at the heart of your question (which isn't any different for gravity - other forces do the same thing). Your error is in going \"this is a solid object and nothing can go through it\". But what you think of as \"solid objects\" are not completely impenetrable. As an everyday example, light has absolutely no trouble going through glass. [EDITED to clarify: this part is here to explain to OP how their idea of 'solid' is inaccurate. It's not directly about how forces can go through things] ~~'Solid' objects don't fill up all the space in the region they occupy (in fact, they're not even *close* to filling up all the available space). They seem solid on human scales because electrons repel one another, so once two atoms get even somewhat close, they're pushed apart by the repulsion of the electrons in each atom.~~ On an even more fundamental level, fields (like the electromagnetic field or, if you set aside some of the weirder aspects of relativity for a sec, the gravitational field) aren't different things from the physical objects around you. Objects are \"made of\" these fields, in the same way that a wave in the ocean is made of water. What we think of as a particle is just a place where these fields take on different values from other parts of the field, in the same way that a wave is just a place where the water is a little bit higher. And so your question becomes, roughly, \"how can water travel through a wave?\". If this seems strange, well, it is. There's a reason it took fifty years and some very surprising experiments for the most brilliant minds in physics to figure it out.",
"A good analogy for gravity is putting a bowling ball on the center of a trampoline URL_0 the bowling ball sinks into the 'sheet' and any other balls you put on will roll towards it. No matter where you put other balls - near to the bowling or farther away - they'll always roll towards the bowling ball. and also if you have lots of balls inbetween the bowling ball and the edge of the trampoline, they all still roll towards the bowling ball at the center. so - with the huge sun at the center of our solar system, all the planets are affected by it no matter whats in between.",
"What we perceive as the Force of Gravity is actually a warping of Space-Time produced by the presence of \"*Things*\". \"Things\" in this context are Matter, Energy, and *maybe* some other things we don't know about yet. If it **occupies** Space-Time, then it warps Space-Time. Space-Time is the Space and Time that *Things* can occupy in this universe. When Space-Time is warped by the presence of *Things*, a *bias* is introduced into how *Things* move through that warped Space-Time. Objects will move towards the *Thing* that is warping Space-Time, unless they have reason *not to*. You experience this as Gravity. --- The warping of Space-Time has some funky properties. The Warping is at its most intense where the Thing is, and falls off relatively quickly... but never ceases to have an effect. This is the reason we have Ocean Tides on Earth. There are three sources of Gravity that are strong enough *on Earth* to affect the oceans: Earth, our Moon, and The Sun. When the Moon or the Sun is overhead, the gravitational bias changes enough that the oceans are \"stirred up\" by the small change in their weight. The Warping produced by multiple *Things* located in the same place will \"combine\" to produce an aggregate effect larger than any one *thing* could manage. That's why celestial bodies have Gravity Wells. The weight of any one grain of sand isn't much, but the weight of the entire Earth and everything on it creates a Gravity Well that holds the whole thing together (and forces it to a roughly spherical shape). > Weird Side Note: Gravity goes *weird* at the center of a Celestial Body. It you stand at the Center of Mass for a Planet... you'd probably experience something similar to Zero Gravity if it weren't for the intense pressure of everything *else* being pulled towards you. --- With that groundwork in place, we can answer your question. > If something is inbetween two objects how do the particles know there is something bigger behind the object it needs to attract to? This is the weirdest thing about Gravity to wrap your head around. Every other Fundamental Force has what are known as \"carrier particles\" that move information around. Gravity, as far as we can tell, *does not have a Carrier Particle*. Gravity-Related Information is not directly shared between Particles... it is instead indirectly shared through the aforementioned warping of Space-Time. The particles don't need to communicate, because the information is stored in the medium (Space-Time) they occupy. The only way to affect the strength of a Gravitational Field is to either shove more *Things* into a space, intensifying the aggregate warping effect of that mass; or you need to take *Things* out of a space... spreading that effect out.",
"Gravity isn’t pulling on stuff like magnets or a vacuum. It bends space and time. To block gravity, you’d need to bend space the other way. To do so would require an absolutely incredible scientific discovery, and is the basis for the hypothetical warp drive.",
"Well, particles don`t really \"know\" to attract to other particles. What happens is that matter bends space in such a way that makes other matter fall into it. This goes both ways of course, so objects with mass keep falling towards each other. A great and simple way to imagine this is through this video URL_0 The video shows this happening in two dimension, but basically the exact same principle applies to three dimensions.",
"You'd need something theoretical like negative-mass that pushes outward rather than inward to counteract gravity. The thing is, something like that would require a lot of energy even if we somehow had negative-mass readily available. Then you have the problem of being unable to control the direction of this mass. For example, if you wanted a hovering anti-grav car, nothing is stopping the anti-grav from pushing normal objects around it in every direction. It would be kind of like when a helicopter pushes everything away with the rush of air from its blades, but worse, because it's also pushing up and to the sides in all directions instead of just down. The best we can currently do is magnets, which is a different force that can locally push up against gravity. Thing is that's limited to rails, so the future is electric maglev cars on rail unless we discover some new physics breaking technology.",
"We actually don't understand gravity that well. We think we do because of how well we can generate calculations and predict the movement of planets. But what exactly generates the gravitational force? What is it about mass, or atoms, that generates the force as a natural byproduct? How can it have infinite range? These questions are still a mystery and prevent us from doing things like reproducing real gravity in a lab setting. So in reality we can't measure gravity directly or even sense/detect it. Everything we do involving gravity is either an indirect measurement of it's effects (like a scale) or a calculation based on mass and distance. It's pretty much impossible to create something to counter a force that you can't even detect. All we can do for now is generate forces to cancel out it's calculable strength.",
"I feel like a lot of the answers are presenting great theories, that are ultimately unproven and largely are just describing how we know things act. The truth is, we don't fucking know. We just don't know a lot about gravity, what it 'is' and how it functions. We know it has a pulling force, it acts broadly based on size of object. And there's theories it fits nicely into for equations and working things out by maths. But there's a whole lot more we don't know about gravity...yet...",
"If someone in this reddit really knows why, he would get a nobel prize. We know less about gravity than most people think. People can explain how it works but not why.",
"I like how not even proper scientists have figured out the answer to the the GRAVITY QUESTION and \"The effects of Force Damping\"... But here we have 1.8k \"Redditors\" already answering it and at the same time, dumbing it to ELI5. Absolute genius!",
"Gravity isn't one larger object attracting a smaller one. Everything puts a dent in the same fabric of space. It's a two way street. If you put our sun next to another sun of the same mass, both stars will orbit the space in-between it. When you change the mass of one object up or down, it just moves the fulcrum, or center of gravity. Both are still interacting. Earth, for example, is just so small it orbits a space VERY NEAR the center of the sun. Jupiter, for example is so big, and so far away, that it and the sun actually orbit a point outside the surface of the sun, meaning technically that Jupiter doesn't orbit the sun. To dampen or \"block\" gravity you have to change the mass of something or the distance from other objects. The trampoline example many are giving is perfect. You can imagine a cluster of many small balls making a huge dent in the trampoline. Add a bowling ball much bigger than each individual small balls, but with a smaller dent than the small balls combined, and the bowling ball with orbit the small balls (until it collides and joins the pack).",
"Well, depends on what you mean by blocked or dampened. Let's look at heat here. Heat, just like gravity, is type of energy. It behaves a bit differently when it comes to exact science, but for our purposes it works fine. How do we dampen or stop heat? We put something between heat source and what we want to stop from getting heated up. Heat dissapear? No, it gets absorbed into the material we used as a heat shield. Same with removing heat from object. We coat it in something that has low heat and well tranfers heat itself like water. The heat dissapears, it's just divided between more matter, so original matter has less of it. Similarly is with gravity. We can damper it by putting a force between two object that attract themself by gravity. That's how we achieve flight. We create enough force to stop gravity. Like heat before, gravity doesn't dissapear, it just is counteracted. The only major difference is that we cannot really stop creation of gravity like we can put out the fire. Cause fire is a chemical reaction that generates heat. We can stop that reaction. But gravity is generated by existance of matter itself. And removing matter from existance is way harder. But to shortly answer your question: we can damper gravity. That's what wings and engines on planes do. That's what you do for a short moment when you jump. Or even when you just stand. Your legs damper gravity enough so you aren't crushed into the earth beneath you. There's just a lot of gravity created non-stop."
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nyduix | Why Do Doctors Hesitate To Increase Voltage While Applying Electroshock to the Heart? | I guess I'm talking about defibrillation. Is it just the movies, or is it how defibrillation actually works in real life ? I mean, you are trying to revive someone, trying to bring them back to life. What's the worse thing that can happen ? Why do they start from low voltages and increase it slowly, and get more and more anxious and dramatic every time they say "Go up to 350" or whatever. I mean, the person is already dead. What's the risk ? Why do they act so hesitant ? What's there to lose ? | Biology | explainlikeimfive | {
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"At what point does it stop becoming a life-saving effort and become a barbeque? The currents needed are miniscule in comparison to what we can actually muster",
"I feel it’s important to understand that defibrillation is trying to *stop* the heart from beating ineffectively (“fibrillation”). This allows the autonomous pace-maker trigger the heart to beat rhythmically. I’m no expert but I suspect that increasing the voltage doesn’t really help this stopping in the most real-world cases.",
"The general thought is that using the lowest level of energy to convert the heart from ventricular fibrillation, ventricular tachycardia or atrial fibrillation to a normal rhythm is best. The idea is that the greater the shock, the greater the risk of creating a parasympathetic nervous system discharge that can theoretically prevent the heart from restarting. When portraying these types of situations, TV and movies often take liberties with medical accuracy in attempt to create tension or drama. Cardioversions for certain abnormal arrhythmias are very routine procedures that aren’t particularly dramatic. Cardiac arrests however can be quite dramatic, extremely emotional events when we are working hard to save someone’s life. Factor in things like a patient’s youth, an unexpected negative event, or an emotional connection you have with the patient or their family and the adrenaline gets pumping rapidly. So yeah- we will not hesitate to escalate the shock energy when indicated and tv doesn’t always show things the way they happen in real life.",
"Defibrillators aren’t used when your heart stops, so there is no reviving someone with one. The only thing that will start your heart pumping is someone slamming your chest (trying not to break your ribs) doing CPR. Nowadays they use automated external defibrillators (AEDs) that are used in conjunction with CPR and actually talk to let the rescuer know when to start, stop, and clear so that it can apply a jolt safely to get the victim’s heart beating regularly. The paddles being rubbed together and then placed on the patient while the doctor yells, “CLEAR!” is Hollywood theatrics. Source: Entered cardiac arrest and revived 3 times in a short span of time in the ER. Fun fact: The rhythm they teach someone doing CPR is “Stayin Alive” by the Bee Gees."
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nye87e | Why do eyes sometimes go out of focus and stare into the emptiness? Why do we have to concentrate to focus again? What is happening to the eyes in that moment? | Biology | explainlikeimfive | {
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"Eyes muscles get tired and take a breather cos focusing needs muscle power. A teeny tiny power but still",
"It takes effort to focus, when you don't need to focus on something you just don't. Why bother your muscles staying focused if you're not paying attention to what you're looking at anyway?",
"A little more simple: One thing is to see and other is to process the image. One part of the brain processes the action of seing, plane and simple Other part of the brain allows you to process the image and let you know what it is exactly. This Translates in some illness allow you to see a person and knowing is a person, but you are not able to know if that person is a random person or your mom. So, when you stare into the vacuum, you lose your mind and you are SEEING, but your brain does not processes what you are seing, and when you come back from your trip, your brain again uses energy to understand what you are seeing. P. D. Sorry for the bad English, that is the best I can do.",
"Tear film evaporates. Its less the eye muscles changing (inner \"eyes muscles\" should be relaxed when looking in distance & #x200B; if we are talking looking at near object then the eye will stop accommodating",
"Anyone else's eyes started going out of focus after reading the first out of focus?"
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nyf8jo | How are qbits read and useful? | Technology | explainlikeimfive | {
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"From what I understand, they are both a 1 and a 0 at the same time *until* they are read. At that point, they resolve into either one or the other. But there will be another bit entangled with it, such that once one of the qbits is read, the other is known instantly.",
"n entangled qubits can be in a superposition of all 2^n states. When they are measured you only get 1 state. Quantum Computers use quantum logic gates to manipulate the probabilities of which state is output upon measurement. The goal is to use constructive and destructive interference so that the wrong answer are cancelled out and the right answers are amplified.",
"I'm not the most knowledgeable on quantum computers, so take this with a grain of salt... But Qbits are in both states until read. When read, you only get one answer. As to why it is useful: think if you were solving a problem, with a number of variables. All those variables could change and your outcome could change. In a normal computer, you'd have to calculate every possible combination of variables one at a time to get an answer. In a quantum computer, since everything exists in both states, to oversimplify you can have every combination existing in the same space at once, and you simply need read the outcomes. This can make problems, like brute forcing cryptography, very simple as you can test everything at once and only read the correct output."
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nyf9yu | why 3G is basically useless now? | I've noticed among myself and my friends that the 3G technology doesn't work as well as it used to, or not at all. When I say not at all, i mean if our phones drop from 4G to 3G there will be little to no service available. Phone isn't connected to the interwebs. | Technology | explainlikeimfive | {
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"More physical assets and infrastructures are being adjusted to 4g and 5g now, which leaves very limited resources left to handle 3g signals and data. This slows any 3g applications down immensely to the point of non- function.",
"> or not at all. Verizon turned 3G off completely last year, AT & T is planning to in February of 2022, and T-Mobile will turn off their 3G and Sprint's old 3G around the same time.",
"Can somebody explain ELI5 what 3G, 4G and 5G exactly mean? Are these frequencies? Volume of data?",
"Your phone drops to 3G when there is no 4G reception. So 3G will only be used when the signal is possible to be received correctly but 4G is not. So it is not that 3G is worthless, it is that the phone only uses it automatically when the reception is very bad and 4G do not work. If you instead force your phone to use 3G when there is a good signal it works fine. It is likely a lot faster than it was in the past for you because relatively few used is and there is a limited amount of bandwidth per cell. I have no idea if you can force a iPhone to use 3G but for android it is possible, On my phone, it \"SIM card & mobile data\"/click on one of the two sim cards/\"Preferred network type\" and not you can force it down to 3g/2g or just 2g On my previous phone, it was under \"addition network setting\" in the main setting. Exactly where it depends on the phone. If you do that 3G works fine because you use it when the reception is good. The extra speed with 4G and 5G is not primary to increase the speed to an individual user but to increase the amount of data all users in a single cell share. So the network does not slow down when many use it at the same time. If there only was a single user in a cell the bandwidth is enough for normal phone usage.",
"Fewer towers are providing it and everything is using more data. Even basic webpages run code that is far too advanced for 3g to load quickly/properly.",
"Useless can be subjective. I still use iPhone 4s with 3G and my speeds are 6 megabits per second. Some people call that useless but for many people even in the developed world that is very useful. Whether 3G is being decommissioned or not often depends on the locality. Often regions are designated specific licenses to operate some bands have most use for 3g wheras other bands have more than one mode being used. For example, in many places in Ohio AT & T is authorized a certain chunk of the 800 MHz spectrum depending on the part of the state. My understanding is the way this is authorized in these parts doesn't make it always easier for them to light up 4g on 800 MHz so it's more economical to just keep 3g here consequently 3G is ok in many parts of Ohio. Some frequencies used for 3G are better able to go over obstructions or go through them. As a result, whether a tower gets turned off or not can make a great deal of influence whether your service goes out. It's possible your area was never that great for the used 3g frequencies by your carrier in your locale. So when they turned off a single tower then that ruins your service quality"
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nyg31l | How can edible things have zero calories? For example: mustard. | Chemistry | explainlikeimfive | {
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"It does not have zero calories. The energy content is 66 Calories/100 grams. Labeling law allows that food that contains less than 5 calories per serving. 5 calories would be 7.5 grams of mustard but when I looked at single-serving packaging online the size I found was 5.5 grams. So less than 5 calories and can be labeled as zero. & #x200B; It is possible that the stuff you can consume has zero calories. Water is an example. You can't metabolize it for energy, it is in fact the result of normal metabolism for food alongside carbon dioxide. There is other stuff like dietary fiber that have zero calories for human and is a part of the food we eat. The fibers are too long for us to break down and extract the sugar so they pass trou us. Other animals like cows can break it down with the help of bacteria. They can live on grass but you can not.",
"There is also the fact that if it is less than 5/calories per serving, they are allowed to round down to zero. This is why some packages that have both per serving and per container facts on it may say 0 calories per serving but 15 calories per box.",
"Calories are a count of how much energy your body can extract from the food. There's plenty of things you can safely consume that your body isn't capable of extracting any energy from, like water. Or in the case of something like mustard, there's some stuff you can get energy from but not a ton so they can round the calories per serving down to 0 if they use a small serving size.",
"I hear that celery is a negative calorie food. From what I've heard, you burn more calories eating it than you gain from eating it.",
"Tic tags apparently have zero cals of you eat one because of the less than 1 cal. Eat all 75 of them and you have consumed 73 cals… it is a minders day mystery."
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nyh6k4 | What's happening when a charging battery is full, but still keep receiving power ? (Smartphone stay plugged all night for instance) | Technology | explainlikeimfive | {
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"Smartphones have small circuits that turn off the power when the battery is full, even if it’s still plugged in. Overcharging a battery can damage it and possibly cause it to explode. Just being near 100% charge damages it.",
"When a battery hits full, the charger stops charging. This is built into pretty much all batteries/chargers, either by the nature of how the battery works or by a circuit that exists solely to do disconnect the battery when full. If this doesn't happen, then the battery is overcharged and can quickly overheat or even explode.",
"The battery itself stops being charged. Putting more energy in would damage it, or could even start a fire -- it's like putting too much air into a balloon. But, the phone itself needs electricity too. So the charger keeps giving enough electricity so that the battery doesn't have to do any work until you unplug the phone."
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nyhsg5 | If it takes more muscles to frown than to smile, why do we 'default' to frowning? | The expression "It takes more muscles to frown than to smile" if that is true, why do we seem to frown more than smile, considering it takes fewer muscles to smile? | Biology | explainlikeimfive | {
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"Let your face relax. Use a mirror if it helps. Now frown by pulling the corners of your mouth down. You can do it, right? So your resting face isn't a frown, because it's different. Now smile, because you learned something new. :-)",
"Because it takes less energy to frown because the muscles aren’t contracting. The energy expended in contracting your cheek muscles is greater than the energy of those muscles at rest. For an example, consider your average fresh corpse. Very few smiles because there is no way to maintain the energy expenditure to keep the cheek muscles contracting to pull the lips and cheeks into a smile.",
"\"Number of muscles used\" isn't really the deciding factor in whether we do things. People have all sorts of idle actions that use muscles, such as tapping your foot, drumming your fingers, or jiggling your leg while sitting down. Another question to be asking is, is it *actually* true that people overall frown more than smile? It probably varies a lot from person to person."
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nyiilh | . Salt melts ice. Glaciers sit in an ocean of salt. Glaciers don't melt. | Earth Science | explainlikeimfive | {
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"I think you mean icebergs? Glaciers are rivers of ice. They don’t touch salt water as a general rule, except where the river meets the sea. Icebergs are giant hunks of ice floating in the ocean. Salt lowers the freezing point of water, which is why it can cause ice to melt. But it does not remove the freezing point altogether. At about 28.4F, saltwater will freeze. That is the point at which salt will no longer melt ice, and that is the temperature at which icebergs can survive in saltwater.",
"Salt doesn’t necessarily melt ice, it just lowers the freezing point of the water that composes the ice, meaning that water has to reach a lower temperature in order to freeze. My guess is that the oceans in the Arctic and Antarctic are so cold, that it negates the effect of the salt on the ice, but I’m not a scientist or anything",
"Only the very edge of glaciers touch ocean water. Glaciers are constantly melting into the ocean and forming farther up on land.",
"Salt is a solute, which when added to water (ice in this case) lowers its freezing point. The freezing point of water is 0 degrees on Celsius scale. Addition of salt will lower its freezing point, to some negative temperature. The geological locations where Glaciers exist, the temperatures are way below 0 degrees. So even though the freezing point of ice is lower, the temperature is still lower than the final freezing point of the salt-water solution, hence it tends to remain in the solid state.",
"Glaciers sit on land, not the ocean. When the end of a glacier reaches the ocean, parts of it break off and become icebergs, which eventually melt."
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nykgob | How does fluoride prevent cavities? | Chemically, Sodium Fluoride seems like it should be very similar to the sodium chloride we know and love, what's big deal with flouride? | Chemistry | explainlikeimfive | {
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"The enamel on your teeth is made out of a mineral called hydroxyapatite. It's hard and durable, but becomes soft when acids are present. Bacteria produce acids as they eat the sugars in your mouth, which soften the enamel and cause it to erode away. Your saliva contains dissolved minerals that slowly rebuild small bits of damage, but with a modern diet, the bacteria erode your teeth faster than your saliva can rebuild them. When fluoride is present, it reacts with the minerals in your saliva to form a closely related mineral called fluorapatite, which is then deposited into the minerals on the surface of your teeth. Fluorapatite is very similar to hydroxyapatite in most of its properties, but it's more resistant to acid, so it doesn't wear away as easily when bacteria grow on it. As a side note, if fluoride was in your drinking water when you're a kid, your whole tooth contains traces of fluorapatite (because fluoride was present in small amounts in your body when your teeth were being formed). This makes your teeth more resilient for life, and is why we add fluoride in small amounts to drinking water."
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nykl4g | Why do we have seedless fruit but not pitless stone fruit (e.g., peaches, plums, cherries)? | Biology | explainlikeimfive | {
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"Stone fruit grows on trees, which take a *long* time to mature. The process of selecting a tree that produces fruit with *small* pits, then growing a bunch of descendants of that tree, then selecting a descendant with *smaller* pits, etc.... takes way too long to be financially viable."
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nykmlr | Where does wealth originate? | Economics | explainlikeimfive | {
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"Adam Smith famously wrote, \"Labour was the first price, the original purchase - money that was paid for all things. It was not by gold or by silver, but by labour, that all wealth of the world was originally purchased.\"",
"Goods like natural resources for example. Originally people traded and then currency came about to make that trade more efficient and easier. Just give everything a dollar/peso/yen value and we no longer need to trade that actual thing, just the amount of money it is worth.",
"Money comes from the usable goods and services of a population. You work a day to design and build a wooden chair? That made some wealth. You gave 10 people an oil change? That made some wealth. This wealth can be represented by the money distributed by the government, as it is a usable vehicle to exchange those goods and services."
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nylha8 | Why do kids car seats expire? | Is there any reason why car seats have an expiration date? Is it just BS or are there legitimate safety concerns? Btw I don't have kids, so I'm not basing any decisions on this post. | Other | explainlikeimfive | {
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"Frequent use and sunlight can cause the plastic to degrade or warp. Ultimately making it not safe to use. So, just a way for people to know they need to replace it so they ensure the safety of the child using it.",
"Car seats are primarily plastic components and are designed to absorb a lot of energy in the event of a car accident Over time with changes in temperature and UV exposure the physical properties of plastics change. You don't want to find out *during* a crash that your seat went through a few too many thermal cycles and isn't quite up to the loading anymore so there are expiration dates on them to make sure they get swapped out every 5-10 years which is generally 2-3x as long as a single kid can actually use them for Car seats are probably most similar to helmets which are also recommended to be replaced every 3-5 years even if you don't have an impact with it",
"German here. Just checked my car seats, and there is no expiration date on them. However, we have (European) safety norms that are updated every few years. Seats with a certification before 1995 can no longer be sold or used. The pre 2005 models are not recommended but still pop up on Ebay. To actually add an answer: here, seats „expire“ because they no longer meet the updated safety norms.",
"Plastic is a cheap material that absorbs impact well. But like all soft materials, plastic degrades over time becoming more brittle.",
"I've looked into this claim a number of times, and my conclusion has always been that it was a concern raised by some safety advocates that the industry then happily jumped on. But there are basically zero studies confirming what is essentially a hypothesis. [This article]( URL_1 ) goes into the lack of evidence. The biggest concern for me, as noted in the article, is the environmental cost of tossing used carseats that are otherwise in working condition. Obviously, carseats that have been in an accident should never be used again, but there are plenty of carseats that will never see anything remotely close to an accident. [This article]( URL_2 ) explains why carseats *do* expire. The two reasons given are that the technology of carseats becomes out-of-date and that the materials degrade. These are both concerns that would apply to the car itself. It's one reason I would be wary of buying a car that is, say over 10-12 years old. But just five or six years old? Similarly, the plastics, straps and other materials that make up a carseat are largely the same as those used in the car itself. Again, no one is worried about a car's control knobs degrading through light exposure. [This study]( URL_0 ) is sometimes cited by these articles to note that degradation of polystyrene over time through sunlight exposure. Again, polystyrene is [used in other car components]( URL_3 ) as well. And that study talks about degradation over \"decades or centuries\" as opposed to thousands of years. I would also note that polystyrene in carseats wouldn't ordinarily be exposed directly to sunlight. It's material covered by or embedded within other layers (same as your car). The article I linked about why carseats expire doesn't otherwise cite any other evidence. Instead it just casually says to look at how poorly your lawnchair sitting in the backyard has fared. Not exactly scientific proof. Years ago, probably about 10 or so, I found an early article discussing the expiration dates, and one manufacturer flatout admitted that there was no reason a carseat not in involved in an accident would degrade simply through time. On a final note, the \"baby junk\" industry is, IMO, one of the most shameless pushers of products that most parents don't need. Any parent can tell you how ridiculous, unnecessary and over specialized many baby products are. The companies know that they can brew concerns over safety, well being, and child development into profit-margin gold."
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nymgr2 | the relationship between the double slit experiment/string theory/superposition and the multiple universe theory | I have a basic understanding of what is happening during the double slit experiment and what we know it entails, same deal with string theory and superposition in general. My question is how they justify the existence of a multiverse. Maybe there’s a super simple explanation and I’m just missing it, or maybe the multiverse theory is independent of that other stuff. Please help me understand | Physics | explainlikeimfive | {
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"What you seen to be asking about is the Many Worlds interpretation of quantum mechanics, which is somewhat close to the sci-fi idea of a multiverse though with some differences. The idea comes from the fact that when we measure quantum objects, they seem to somehow change in nature. Before the measurement they evolve smoothly like a wave, this is what causes the interference pattern in the double slit experiment, however when we measure them they appear to have a single definite position, not spread out like a wave is. The most common explanation is that the wavefunction (the quantum mechanical thing which describes the state of a system) collapses upon measurement. It goes from being a spread out wave to a single spike. The problem is we don’t really know why this would happen, and we don’t know at what point in the process it actually does. The Many Worlds interpretation rejects wavefunction collapse and considers what would happen if instead the wavefunction just continues to evolve like normal. This is where you need to bring in entanglement and superposition. When a particle is measured, it becomes entangled with what you used to measure it. The state of one depends on the state of the other. For example if you have an electron and a device which detects its spin, when you make a measurement the electron and the detector become entangled. The state of the system is now a superposition of two states, either the electron was spin up and the detector measured spin up, or it was spin down and the detector measured spin down. Many worlds applies this principle all the way up to the scale of the universe. We all become entangled with the system when the measurement is made, and so the wave-function which describes the system of the whole universe becomes a superposition of the two possible results. These two possible results are both real and a part of the wavefunction of the universe, but they behave like different branches and evolve on their own. Many worlds says that every time any things interact with each other, the possible results of those interactions split into new branches of the universal wavefunction, into new worlds effectively."
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nymhd1 | How do ISPs work? | Technology | explainlikeimfive | {
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"The internet works like roads do. You home connects to smaller roads (your ISP) which in turn connects to major streets (Tier 2 ISPs) which in turn connect to major highways (Tier 1 ISPs). Those major highways connect to one another, creating a large web of roads/streets/highways that connect every house in the country (or in this case, the World Wide Web). You **must** get connected to the web somehow by finding someone to connect you to the larger infrastructure- you have to connect to another ISP at some point. You could bypass your local ISP and connect directly to a Tier 2, but that would require them laying dedicated cable to you home and would likely be cost prohibitive. Long story short, you really can’t get around your ISP. There are different ISP options available (wireless ISPs - or WISPs - are becoming more common) but you’ll need one no matter what you do."
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nymk0l | Why is X multiplied by 0 is still zero? | Mathematics | explainlikeimfive | {
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"Imagine you have 3 cartons of eggs. Each carton has 12 eggs. How many eggs do you have? Answer: you have 36 eggs. Imagine you have 3 cartons of eggs. But now you don’t know how many eggs are in each carton. We represent that unknown number with X. So you have 3 cartons of X eggs, or 3X eggs. Now imagine you have zero cartons of eggs. How many eggs do you have? It doesn’t matter how many eggs are in each carton, because you don’t have any cartons at all. Zero eggs.",
"If you have nothing and multiply it by something. You still have nothing. You cannot multiply what doesn’t exist. You have nothing to begin with. Multiplying doesn’t change that.",
"Imagine that you have 0 candy bars. Now imagine that I give you 0 candy bars a day, or in other words, I don't give you any candy bars each day. Assuming you don't get candy bars from outside sources, after one day, you'll have 0 candy bars, since I didn't give you any. After 2 days, you'll still have 0 candy bars, since I still didn't give you any. After 7 days, or 10 days, or 100 days, you'll still have 0. No matter how many days pass, you'll have 0 candy bars. The number of days that have passed, X, times 0, will always equal 0 candy bars."
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nymv7i | Ok but like what is calculus | Mathematics | explainlikeimfive | {
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"Calculus is the study of the *instantaneous* rates of change. In other words, it looks at how the value of a function changes when one of the variables is changed just a teeny tiny bit.",
"It’s a mathematical shorthand way of calculating two weirdly opposite things. The first is the area of irregularly-shaped objects. If you can describe the object as an equation, you can calculate the area inside it. The other is the ability to calculate the rate of change of something happening. It ends up having many uses in things like finding the best solution to a multi variable problem, the flow of fluids or electronics, the area of an oil spill, the change in weather."
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nyn2pz | Why does wind blow in gusts? | Earth Science | explainlikeimfive | {
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"Ok so this is a complex question and it boils down to a lot of different factors are controlling the winds, from convection cells to jet streams, even the fucking moon plays a role in it. High and low pressure especially though, basically the high and low pressure winds are competing and clashing so they are pushed up and down, wind doesn’t stop blowing it just moves up TLDR- wind go up",
"While others might give long and good answers, I'll put a smaller thing to think about. Wind gusts just like waves bob on the ocean. For a lot of complicated reasons that others may go into more detail about, you have lower points of wind, and higher points of wind. They're just usually not as frequent or in such an even pattern as waves are. It also doesn't help that wind will usually have a lot more to work through, like trees and buildings, where as waves are usually undisturbed for miles and miles and miles."
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nynegy | How does a SAM distinguish different targets? | How does the SAM (surface to air missile) not fire on friendly aircraft and only on enemy aircraft? | Technology | explainlikeimfive | {
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"As others have mentioned IFF exists to identify aircraft. But it's also worth pointing out the launcher isnt operating alone, it's linked to a detector, usually radar. This is the eyes, it has a computer brain and the iff coming off the contact is part of the information set that makes decisions. Some missiles then themselves have smaller detector/decision setups and can change their minds after launch All these things together make them pick legitimate threats out and stop them whacking flocks of birds etc etc"
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nyopoj | Why people with O-Negative blood can only receive O-Negative blood? | Biology | explainlikeimfive | {
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"It's not only the A & B antigens. O- people are also unable to accept O+ blood because it's missing the Rh factor or D antigen. O- is also known as Rh negative Apart from the four major blood groups, A, B, AB and O, there is another surface antigen called D or Rh, the presence or absence of which makes a blood group positive or negative - these are known as sub-types or sub-groups. O- is the universal donor as the absence of all three surface antigens (A, B, and D) makes it the least capable of arousing an immunological reaction in the recipient, whatever the blood group of the recipient might be. Since the positive groups are much larger in the general population, among the positive groups, O+ is as good as universal donor. However, O+ cannot be given to a person who is Rh negative as the anti-D antibodies in the recipient will react with the transfused O+ blood. Edit: Since you are O- will you consider donating blood? The blood bank is constantly low on O-Negative. It's the red blood cells that is most use during emergencies when there is literally no time to test the patient for his blood type. They will just grab O negative Red blood cells and transfuse."
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nyp3pn | How are feminised seeds produced? Is this done through natural means or does it involve genetic engineering? | Biology | explainlikeimfive | {
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"Female plants, under the right circumstances, can be induced to produce male flowers. If this happens, the pollen produced by these flowers will not contain any male chromosomes, so 100% of the seeds produced with this pollen should have female genetics. Normally, a male plant will produce pollen with both chromosomes so the resulting seeds could be either sex.",
"It's done by \"masculinizing\" a female plant - which is when you get a female plant to produce male parts (specifically pollen) which is then used to pollinate a female plant and produce seeds. Because the masculinized plant and the target plant are still both genetically female the seeds that get produced are female (i.e. feminised) It can be done naturally by waiting until late in the budding cycle and hoping some male parts develop or it can sometimes be brought on by stressing the plants by fucking around with their light cycles, temperature, etc Nowadays though it can also be done with certain chemicals that will induce male flowers - not really sure of how the science behind that actually works but certain chemicals like silver nitrate will get female plants to produce male flowers."
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nypon6 | In an atom what is keeping the proton and electron apart? | They're of opposite charge and in makes sense that that just form a neutron but they don't. Why? | Physics | explainlikeimfive | {
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"Electrons in the atom do enter the nucleus. It's not intuitive, but when we get into the realm of quantum physics, things are not like what we experience on a macro scale. Particles aren't physical objects with defined shapes or sizes or locations. Electrons aren't little balls with a shape or volume that can fall into the nucleus under electrostatic attraction like a golf ball falling into the hole. Electrons are kind of fuzzy wave-like areas called wavefunctions that spread out in space and can sometimes act like particles in limited ways. An electron also doesn't have a definitely location, but exists in a probability cloud of where it might be found, and these clouds are determined by the electron's energy. All of these clouds overlap with the nucleus, so the concept of an electron \"falling into\" or \"entering\" the nucleus does not really make sense. Electrons are always partially in the nucleus because they exist in this probability cloud that overlaps with the nucleus. If the question was supposed to ask, \"Why don't electrons in the atom get localized in the nucleus?\" then the answer is still \"they do\". Electrons can get localized in the nucleus, but it takes an interaction to make it happen. The process is known as \"electron capture\" and it is an important mode of radioactive decay. In electron capture, an electron is absorbed by a proton in the nucleus, turning the proton into a neutron. The electron starts as a regular electron, with its wavefunction spreading through the atom and overlapping with the nucleus. In time, the electron reacts with the proton via its overlapping portion, collapses to a point in the nucleus, and disappears as it becomes part of the new neutron. Because the atom now has one less proton, electron capture is a type of radioactive decay that turns one element into another element. If the question was supposed to ask, \"Why is it rare for electrons to get localized in the nucleus?\" then the answer is: it takes an interaction in the nucleus to completely localize an electron there, and there is often nothing for the electron to interact with. An electron will only react with a proton in the nucleus via electron capture if there are too many protons in the nucleus. When there are too many protons, some of the outer protons are loosely bound and more free to react with the electron. But most atoms do not have too many protons, so there is nothing for the electron to interact with. As a result, each electron in a stable atom remains in its spread-out wavefunction. Each electron continues to flow in, out, and around the nucleus without finding anything in the nucleus to interact with that would collapse it down inside the nucleus. It's a good thing too, because if electron capture was more common, matter would not be stable but would collapse down to a handful of nuclei.",
"Nothing. They effectively *do* touch, at least as waves of probability. They cannot combine or equalize their charges, however. The static energy of the electromagnetic force keeps the electrons probability uncertain enough that it cannot be effectively “stuck” to a particular area."
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nypxmh | Why is there a higher danger threshold for acids than bases, if most of our body is slightly basic? | Acids only become dangerous once you get lower than two on the pH scale, which is about the acidity of lemon juice, but ammonia is poisonous and it's only 11, four steps away from neutral. If you look at diagrams like [this]( URL_0 ), it feels like acids become a problem a lot more "abruptly" than bases do. Is there a reason for this? | Chemistry | explainlikeimfive | {
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"Your body uses acid to digest food, so it has a pretty high tolerance for acidic things when you eat it. You'll notice that most of the stuff on that chart you put up is food on the acid side. You've got a lot of systems in your body for dealing with acids (Especially ones you eat). So it just seems like they aren't as strong from that chart."
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nyqmnp | Why is it necessary to get up after a 2-hour surgery to avoid blood cloths, but lying in bed for 8 hours + sitting still for 8 hours at work is okay? | Biology | explainlikeimfive | {
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"Because sleeping =/= unconscious/anaesthetised You fidget and move about in your sleep, especially if you lie in a funny position/squash a limb. You will move the affected body part without waking. If you fidget during surgery the anaesthetist gives you more drugs to keep you sedated. Anaesthetics are a cocktail of drugs including strong muscle relaxants. Your pretty much totally immobilised, not the same as sitting still/sleeping Edit to add: for leg surgery the patient is still encouraged to sit up and move about with crutches or a wheelchair. Other things you need to do after day surgery is have something to drink, then eat and go to the toilet. If you can do those things without a problem (being slower or using an aid is not a problem) then you can safely be discharged home",
"Blood clots are caused by three things (this is called Virchow’s triad): 1. Venous stasis: if your blood isn’t moving, it’s more likely to clot. If you’re anesthetized for surgery you move less than if you’re sleeping naturally, and if you're tired, in pain, or sedated to any degree after surgery you may move less than you would normally unless pushed to move around. 2. Hypercoagulability: surgery is a major stressor on the body and it results in a lot of metabolic changes as well as a pro-inflammatory / pro-coagulability response. So basically, among other changes, your body responds to surgery by making blood clotting happen more easily. 3. Endothelial damage: undamaged blood vessels act to prevent clotting, but when they are damaged they help start clots. Blood vessels can of course be damaged at the site of surgery, but blood vessel damage can also be caused from being under general anesthesia because it can cause veins to relax too much and become distended. As you can see, there are several ways surgery makes clots more likely, making moving around afterwards (and frequently the use of anti-clotting medications) more important. The anti-clotting medications can of course be used after leg surgeries, but still patients are usually pushed to get up and move (in safe ways) as soon as possible after leg surgeries. Early mobilization is very big in hip and knee replacements.",
"Your heart pumps blood around the . is kind of false. Your heart pumps blood around the arteries in your body. After this the blood enters the venous system (veins). This blood is not pumped around the body by the heart. Instead, it is moved through the veins via muscular contractions. Due to gravity blood will pool in your legs. If you don't move your legs around this blood will sit in your legs. Blood which isn't circulating is at a higher risk of clotting. Depending on the circumstances after surgery they may even give you anticoagulants to help prevent clots from forming. They may do this if the type of surgery has a higher risk of blood clots forming and/or if you have certain predispositions to developing clots. I've had surgery. I've had a blood clot in my leg. I've had a pulmonary embolism (blood clot in the lung).",
"When you're opened, your blood is exposed to the air and can start clotting. If a clot moves to a thin enough vein then it can block the flow completely and cause severe issues. These thinner veins can be found more in the extremities of your legs/feet. Walking around is kind of like shaking a bottle of ketchup to help liquefy it and to help breakup any small clots before they become a problem"
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nyqu5g | How does charcoal filter out stuff from water? | Physics | explainlikeimfive | {
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"Besides normal old filtering by catching big stuff like a net, activated charcoal has tiny pores in it. The tiny holes grab up stuff in the water and entrap it. Eventually the holes get filled up and it doesn't work so well so you need a new filter. One gram of the stuff can have a surface area of 3,000 square meters according to wikipedia. That's nearly half a football field. Lot's of little holes for stuff to get caught in.",
"Charcoal is very porous, meaning it has a large surface area that the water can come in contact with. This then means that impurities can react and bind with the charcoal, removing them from the water. After some time all the charcoal surface will be occupied by the impurities and the filter has to be replaced."
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nys64s | How do 48- and 72-hour deodorants work? | Chemistry | explainlikeimfive | {
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"You have holes under your arms that sweat comes out of. The sweat is stinky so you rub a lotion under your arms that smells nice and has tiny bits of metal in it that block the holes and make you stop sweating."
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nysdvq | Why does the body give up on producing scabs and leaves you with a plain scar if you keep removing the scabs? | Biology | explainlikeimfive | {
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"The body doesn’t “give up.” Scabs are materials from the blood. When the skin is partially healed, there’s no more blood flow to the surface to make the scab. But if you remove the scab to soon, it will damage the surface of the skin, sometimes enough to make blood flow out so it will form another scab. But of course, sometimes it won’t since the skin beneath healed enough.",
"Because every time you pick a scab you are damaging the skin cells, eventually the cells become so damaged it forms scar tissue.",
"Hemostasis / haemostasis from the flushing of the wound to the platelets bonding with fibrin to create a barrier and the new skin cells covering up the wound site. - URL_0"
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nyt832 | why somes species don't have their own body heat (like reptiles) and rely on the environment's temperature when the combustion of sugar in the blood releases energy and heat (and allows us to have our own body temperature)? | Biology | explainlikeimfive | {
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"There's more to body heat than producing energy. You are right, \"cold\" blooded animals do produce body heat. However, they don't retain it. There are a few reasons for this. They don't regulate their production of body heat. They don't produce more when they're cold by doing things like shivering. They don't constrict blood vessels to move blood away from their skin to reduce the loss of body heat to the environment. The reason they don't is that cold blooded came first. Warm blood animals evolved to be warm blooded instead of being cold blooded. There are disadvantages to being warm blooded. One is that it requires a lot more food. Warm blooded animals have to eat a lot more food to maintain their body temperature. A lot of cold blooded animals can go very long periods without eating. Warm blooded animals have to be more active so that they can be, well, more active. They're always closer to starving to death than cold blooded animals. In fact, some smaller warm blooded animals are in constant danger of starving to death if they don't keep eating all day.",
"This is basically asking why some animals are more evolved/specialized than others. It’s just how we developed over time. Cold blooded animals live in environments that they thrive in, and having to regulate their own temperature would cost way too much energy that wouldn’t be as “fit” in that environment. For example a reptile living in the desert would not benefit from being forced to ingest copious amounts of water + food to regulate their own temperature. That amount of food and water doesn’t exist in that environment, and so it would be disadvantageous to develop those traits."
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nytiqk | With prime colors blue and red makes violet, but when light is split with a prism it makes secondary colors between prime ones, except violet is on the very end and not in contact with red light, only blue. Why is this? | Physics | explainlikeimfive | {
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"Hi :-) Our eyes have three types of color receptors for red, green and blue. (And some for just brightness.) Kind of like printers make up all the colors mixing ink / combining ink dots close next to each other. But it's not as simple as that. The receptors for red are also a bit sensitive in the other range. When the receptors for red and blue detect something, but not the receptors for green, our brain perceives violet.",
"First of all there is - somewhat - of a misconception in your question. As you named Blue and Red to be primary colors you're probably talking about additive coloring. That is when one uses light. But Blue and Red doesn't 'make' Violet, it 'makes' magenta. (subtractive would yield purple) Both magenta and purple are entirely made up by the brain, they are no spectral colors. However as you mentioned yourself violet is actually part of the visible spectrum of electromagnetic waves. Thus it is a color that corresponds to a particular wavelength. Also called a spectral color. Violet is at the blue end of the visible spectrum, thereby there is no red in it (as you yourself pointed out). So technically they are all different colors, magenta and purple are \"fake\" and violet is \"real\", in the sense of electromagnetic waves. However: The human eye has 3 different color-receptors that each correspond to a certain range in the blue, green and red area of the visible spectrum. The blue cones do encompass violet as well, not just pure blue. In fact the blue receptors peak at around 450nm which is the boundary between violet and blue. Also in the case of violet, the red receptors actually do fire as well, making the brain interpret some form of red even though there is none in violet itself. So given the right mixing it should indeed be possible to trick the brain into thinking something is violet when it's actually a real mix of blue. TL;DR: Blue and Red doesnt \"make\" violet, it at best approximates something the brain interprets as violet, so it's just as \"unreal\" as purple or magenta. The real violet however is a spectral color without red in it but the L-receptor (red) of the human eye fires anyway. So one is a \"trick\" and one is the real deal."
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nyu9ca | what determines if a food makes you feel full or not? | If I eat yoghurt or oatmeal I’ll usually still be hungry but let’s say I eat a pizza, a burger or a steak, I’ll feel full. What determines this? | Biology | explainlikeimfive | {
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"The foods you're describing vary significantly in size. Typically fiber and complex carbs will make you feel full longer. Comparing a yoplait yogurt cup to eating a burger is silly. One is a 4-8oz meat patty with buns & toppings and the other 6oz of yogurt.",
"AFAIK foods with complex fibers or starch makes you feel full easily compared to foods without.",
"Protein, fat, and fiber take longer to digest. Drop a cracker (carbs) in a glass of water and watch it disintegrate. Now drop a bite-sized piece of steak in there and watch it just sit there. Stomach acid is more powerful than water, but the concept is similar. That harder to digest food will keep you feeling full longer. Low carb foods also don’t create an insulin spike (the crash is really the problem, but you can’t have a crash if you don’t have the spike), so hunger is more gradual than sudden, so you don’t notice it as much."
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nyum8j | Why do wall sockets only have 1 or 2 plugs? | I've always wondered why there were only two. Can't we add more? | Technology | explainlikeimfive | {
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"There is typically a code (for safety) regarding electrical wiring. There is always the option of running more wires to more outlets, but there is a limit to how many sockets can be wired for a single pair of wires (by code). Also a outlet boxes are very standard items - they are low cost because they are made in large volumes and made to common specification. Anything custom will be very expensive. More outlets means more circuits, means more wires, larger distribution boxes and more circuit breakers. Lots of things can be done (within the electrical code for homes) but it is a matter of paying a lot more. Most households don't bother with the added expense.",
"Completely normal in Norway to install quadplex (4 plugs) behind Tv/media. 6 plugs, where max 2 can be europlug, are required in areas where tv/media is planned to be installed.",
"Builders usually want to spend the minimum amount on materials and labor to make a saleable house. If they could include even fewer outlets, they would. If they could have rooms without heaters, they would. But the electrical codes and building codes stipulate a minimum, and that's what gets built. I use the 2- > 6 outlet expanders basically everywhere. There is no harm in that.",
"4 plug outlets are a thing I have plenty like that. Google “double gang” or “double duplex” outlet.",
"Technology connections did a great video explaining why breakers protect the wires in the walls. If we had more outlets then we'd need more dedicated wires and thus more breakers. It is pretty full as it is. URL_0",
"Houses built long ago (say 30s) had one plug per room. Modern homes have a duplex plug every 12’ of wall or closer (many devices come with 6’ cords). I have changed 6 of my duplex plugs out for quadplex due to all the chargers, etc.",
"Yes, we can add more. My wife sells new houses and those things have tons of electrical plugs. However, what if your house was built 50 years ago? How many things were you going to plug in *back then*? In your living room you probably had a television, and maybe record player or radio. And... what else? You could have a few lamps as well, but those probably wouldn't sit right next to your TV. Today we have a lot more stuff that uses electricity, that we expect to use at the same time. But houses even 30 years ago might just expect to have a TV and VCR on the same outlet. If you wanted to add a Nintendo or something you could use a power strip."
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nyuv7g | Why is it harder to breathe if there is air being blown into our face? | Biology | explainlikeimfive | {
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"Your body's respiratory system does not just suck air in and push air out, it also regulates the amount of flow on those two activities because your air filtration system is only efficient at certain flow rate, so if you inhale while air is being blown at you your body will try to limit the speed of air flow proportional to the speed of the air being blown at you by involuntarily resisting how fast you suck air and it will make you feel as if inhaling is hard.",
"Your diaphragm contracts and relaxes to let air in and out of your lungs. Ambient air pressure is what allows air to be driven into your lungs. According to the Bernoulli principle, air moving with speed has a decreased static pressure, so the faster the air is moving, the more your diaohragm has to work to inhale.",
"Mammalian Dive Reflex is a set of body responses that happen when the body thinks it's going underwater. Part of this reflex is stopping you from inhaling so you don't drown. The air blown on your face briefly fools your brain into thinking you are going underwater."
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nyv30k | Why are luxury fashion and jewelry brands worth more than tech giants? | I was surprised to see Bernard Arnault as the richest man in the world, above Jeff Bezos, Elon Musk, and Bill Gates. He owns an empire of fashion and jewelry brands like LV, Givenchy, Tiffany Co. etc. as well as luxury booze companies like Moet and Hennesey. How are fashion and jewelry businesses worth more than tech and innovation in the year 2021? Are there really masses out there spending all there disposable income on 500 dollar t shirts and 6 thousand dollar bags? Flexing on Instagram and popping bottles in the club. I've seen the type on Instagram, but I thought surely they must be a minority, and not large enough a market to top giants like Elon Musk and Amazon. I must be really out of the loop. | Economics | explainlikeimfive | {
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"Amazon and tesla(among many other companies) are worth a good bit more than his. But he owns a larger share. Did not need as many investors to get where he is.",
"The top comment is the best answer but I feel I have to address > Are there really masses out there spending all there disposable income on 500 dollar t shirts and 6 thousand dollar bags? Flexing on Instagram and popping bottles in the club. Yes Yes there are",
"Everyone is missing the vary obvious answer here. Tech giants are worth more than luxury fashion companies. Louis Vuitton, which is the largest company Bernard Arnault owns, is only worth [$47.2 Billion]( URL_1 ). Where as for example Amazon is worth over [$1 Trillion]( URL_0 ). The reason Bernard Arnault is worth so much money is not because fashion is more valuable than tech. It's because the super wealthy tech giant owners mostly only own one company. 80% of Jeff Bezos net worth is from his ownership in Amazon. Where as Bernard Arnault owns over 70 companies. That is why he is the wealthiest man in the world.",
"These brands are *affordable* luxury. URL_0 The price of the highball glasses is lower than the price of AirPods.",
"Correlation does not mean causation. Arnault has more money and Arnault owns an empire of luxury does not mean luxury is worth more than tech. For starters, Bezos, Musk and Gates don’t own 100% of Amazon, Tesla and Microsoft.",
"The tech companies are worth more, but a founder’s ownership stake matters most in terms of determine personal wealth. Apple and Amazon are worth way more than LVMH, but it’s founder could and does own a much larger percentage of the company.",
"He owns/operates quite a bit more than fashion brands: *Arnault is a familiar name to many fashion obsessives, as LVMH owns many exalted brands in the industry, including Christian Dior, Celine, Givenchy, Loewe, Fendi, Bulgari, Tiffany & Co., Sephora, and Fenty, briefly, in addition to the aforementioned Louis Vuitton and Moët Hennessy. The company also controls several wine and spirits brands (including Veuve Clicquot, Chandon, and Belvedere) as well as the luxury yacht company and the high-end hotel brands Cheval Blanc and Belmond.* Luxury yacht company? CHECK High-end hotel chain? CHECK Booze companies? CHECK",
"Not masses. Tech giants have a huge market, but sell lots of less expensive things. Their profits balloon due to sales volume. Exclusive fashion has a much smaller market, and much higher production cost (mostly labour), but the markup is absurd because of exclusivity. And lets be realistic, once you have enough money to buy top quality versions of the things the masses buy, the next step is buying things no one (or very few others) will have. Luxury brands do production items, but also limited editions and single editions. Add a few zeroes to the price with every level of exclusivity."
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nyvbsn | Is there a scientific reason why many young girls like like pink more than any other colour? | Other | explainlikeimfive | {
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"I don't think that they do. I *think* that this 'predisposition' towards pink is a direct result of old thinking that 'blue is for boys, pink is for girls', one that's pushed on children by their parents. If you're raised thinking pink is 'your' color, you'll gravitate towards it. It's a learned behavior, like racism.",
"Purely cultural. In many Asian countries it is black for boys and yellow for girls. Most people vastly underestimate how much cultural traits are transfered very early in a person's life.",
"There is a scientific reason! But it's not what you might think. Sociology is a science, and therefore the effects of socialization should be considered scientific. Young girls get socialized in many different ways to love pink. Advertisements tell them that toys made for them tend to be pink. Their parents will buy them pink clothes and tell them they look cute in pink. Their friends will also like pink for the same reasons which reinforces it. They will hear again and again through so many different people that pink is girly. It all adds up to making pink part of their identity.",
"I'm also curious. It's my son's (2 year old) favorite as well. I don't think we encouraged that in any way but didn't discourage either. He's pretty isolated due to the pandemic and doesn't have many pink toys or clothes. Yet pink was the first color he could identify and he still loves it today.",
"They aren't. It's just that, in America, at least, pink is for girls, blue is for boys, and the mass marketing for such imprints on them. It's kind of like how my ex-wife always wanted her hamburgers plain and didn't like ketchup, and since I was away a lot during my son's early development he imprinted that \"ketchup is nasty.\" It took me *years* to get that out of his head. He wouldn't eat anything that had the color red on it, because it might be ketchup. Kid didn't like burgers because he insisted on them being plain, because that's how his mother liked them. Wouldn't eat pizza, any red sauce pasta, etc. *Finally* managed to trick him one time, and he realized that tomato sauce wasn't the devil (doesn't help that he is autistic) and now he eats \"normally,\" although he still prefers a white sauce pizza. Anyway, got off topic. Young children are *extremely* impressionable, and imprint on things so fast it'll blow your mind. And since modern American marketing covers little girls in pink from the day they're born (a lot of hospital nurseries will put a pink knit cap on a girl and a blue one on a boy) it ends up being a familiar and comforting color."
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nyvdny | How can you freeze in space, when there is no matter to exchange temperature with? | Does a body really freeze as fast as the movies make it seem? Suggestions for “the following object’s behavior in space would be…”: 1 cubic meter of 30C warm water 1 human within a good winter jacket for insulation 1 can of your favorite soup | Physics | explainlikeimfive | {
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"There are 3 methods of heat transfer: conduction, convection, and radiation. Conduction and convection require some medium of transfer. Radiation however, does not, because it's the emission of infrared radiation, which is part of the electromagnetic spectrum, so heat does absolutely transfer in space, just only via radiation. And no, it's no where near as fast as in the movies because radiation is the slowest of the 3 methods. As for how long it would take for specific things to freeze, that depends on if they're directly exposed to vacuum or inside some sort of container or space suit because water behaves very differently in a vacuum. It also depends on how far they are from the sun or whether they're in sunlight or not.",
"Yeah it’s a fairly common misconception that you would freeze. Although the end result is similar it’s caused by the blood and other bodily liquids to boil due to the negative pressure (vacuum) which lessened the required energy needed to change phases.",
"No, it doesn't. Radiation is the major means that transport heat to/from a body. Radiation is the slowest of the three, so it will take a lot for a body to lose enough heat to freeze. For the suggestions (considering deep space without other bodies near the subject): 1 - a thin layer of the water sphere will boil creating a gas coat on the surface of the object, after some days a icee shell is covering the remaining liquid mass and after some months/years all the waters is turned to ice. 2 - Dead for asphyxia then same as water example (1) above 3 - Same as water example (1) above, without gassification of the outer layers For deep space the equilibrium temperature is near 0°K. If the object is near a star or a planet it will receive some heat from them and the times to freeze will be longer. With the paradox of the side of the object facing the sun boiling up while the side facing the space freezing."
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nyvm48 | how come when it gets cold we get sick more often? | How come when the weather is colder people get sick more often? | Biology | explainlikeimfive | {
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"When the weather gets colder people tend to spend more time indoors and in enclosed spaces. Just like you've heard countless times over the past year due to Covid. Social distancing basically breaks down when people huddle for warmth and lots of bodies breathing/sweating/shedding/ and just existing that close together become a breeding ground for new bacteria and very useful vectors for viruses to spread. Basically, there's more sharing of personal space with strangers when the weather is colder due to trying to stay warm and diseases and pathogens take advantage of this to jump around a lot more."
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nyvz6u | What actually is a headache? | Biology | explainlikeimfive | {
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"As far as I know, there are not solid answers to this as of yet. Correct me if Im wrong, reddit. Some head pain is believed to be caused from a swelling of the brain and is relieved when the pressure decreases. Other times head pain is thought to be caused by a lack of the proper amount of water in your brain and your circulation is lacking because of it.",
"built into your brain is a map of your body, its the same part of the brain that enlightenment is supposed to turn off and on. So the brain has an abstract understanding of itself, but the brain is not terribly good at talking to itself. When you \\*feel\\* your arm, the brain connects to the nerves in the arm, the nerves send a message, the brain listens to the message and decides what to do about it. Although there is a lot of back and forth, the sender and receiver are different. But when the brain tries to talk to itself, the brain is simultaneously broadcasting and self-assessing. So the brain broadcasts its own self-assessment. Then it broadcasts that its broadcasting its self-assessment to itself. Ad infinitum. Its like feedback when a microphone gets too close to its speaker. So when your brain tries to communicate with itself about pain, you get this weird abstraction of pain rather than something local and acute because the brain is going through 50,000 iterations of interpreting the pain and most people don't know how to shut out pain signals to control the feedback. You can feel different headaches like a dehydration headache or a stress headache because this abstraction process produces the same result given the same starting point, but different results with different stimulus, even though it seems weirdly abstract and detached from the original cause. That weird detachment is because your pain receptors are pretty much all on the outside of your skull instead of inside with the brain; the brain is trying to abstractly guess how to represent the pain accurately in the part of the body that it knows (because of the map) that you don't have proper pain receptors. And the reason why its very difficult to study is because scientists haven't figured out intentionality/that feeling the mind can focus on a thing and think about it. So paying attention to head pain is on the other side of that obstacle they call \"the hard problem of consciousness,\" which means basically figuring out how the brain produces intentionality and abstraction. disclaimer: I have no credentials or sources, this is just how I understand it. I don't think science has really locked down an answer on its own so I'm drawing on some philosophy and meditation brain science stuff. Take it with a grain of salt.",
"I'm a neurologist. Basically - headaches are *never* from the brain itself, because the brain doesn't have pain receptors. Most headaches are caused by tension on the linings of the brain (the meninges) or by trauma, engorgement, or clots in blood vessels of the brain."
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nyw3ar | Is the blood in your lower legs forcefully pushed back up your leg or is it a knock on effect from having more blood pushed down behind it? How does blood manage to flow against gravity? | Biology | explainlikeimfive | {
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"As well as the above responses, the veins in your legs also have valves that allow the blood to flow in one direction. The pressure needed to provide the movement comes from constriction of muscles in the legs and around the veins. In people who have less than ideal health, prolong, inactive sitting such as aboard a long airline flight, blood can pool in the lower extremities resulting in blood clots that can become dislodged when they start to move again. This is why it is a good idea to get up and walk the length of the plane every hour or hour and a half if flying on a long journey.",
"You have a venous plexus in both your feet. As you walk, it pumps a bolus of blood back up to your calf area where the muscles there help the blood back up towards the heart. For people who are bed bound there are machines that go over your foot to “pulse” under the foot. There are also “sleeves” that go over your calf muscles to help pump blood back up when you’re horizontal.",
"This sounds very weird but the your leg muscles (especially the calf and thigh muscles) play a vital role in pumping blood back to your heart. The vessels that bring blood back to the heart are called veins and they have one-way / non return valves in them after every some distance. As you walk and move about - the muscles contract and relax thereby sqeezing the veins and hence pushing the blood upwards towards the heart. The non-return valves prevent the blood from the veins to flow down to the feet (the wrong direction). Hence if you want to support your heart and get your ciculatory system going - walk. Even if its a slow pace walk - it will still help your heart immensely. And this is also why a sedentary lifestyle stresses your heart..."
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nywcaz | why do houseflies get stuck in a closed window when an open window is right beside them? Do they have bad vision? | Earth Science | explainlikeimfive | {
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"Flies have very simple brains. Through their evolution it has been enough to fly towards light; then along came us tricky humans and put transparent glass in their way. In a similar situation we can observe, learn and devise a strategy to escape. Flies can't, so this is less an issue of vision and more one of brainpower.",
"The concept of transparent glass does not exist to insects. The flies are just trying to fly towards the light source they see. Whether or not they are capable of seeing the glass as different from air, they don't understand the concept of having an object they can see through but cannot fly through. To the insect, if they see the light then they just fly towards it. They are incapable of understanding that they cannot fly through glass. Therefore they won't \"know\" too look for an open window. They just keep trying until they accidentally hit the opening.",
"Houseflies (and most other insects) have rather specialized eyes adapted to navigate in flight. A fly primarily sees what's known as \"optical flow\", i.e its movement relative to stuff around it, which it uses to navigate. It's not adapted to handle transparent barriers like glass (because such barriers just don't exist in a fly's natural environment). Most animals have significantly worse eyesight than humans - when it comes to generalized daytime vision, humans are among the best, only a few birds of prey have better eyesight.",
"Top comment by u/atomfullerene when a similar question was asked 6 months ago: \"Flies get into houses because they are searching for food. Flies find food by smell. Smell diffuses through air. So imagine a fly trying to get into your house. If it comes to a closed window, it can't smell food through the window so it ignores it. If there's an open crack at the bottom of the window or an open door or something, it can smell the food and will follow the scent through the opening, which will actually let it get inside, because usually where the smell is going out there is an actual passage for the fly going in. The exception here is screen doors and windows, and sometimes you will see flies buzzing all around those trying to get inside and failing, because they can't follow the smell. Flies bump into glass windows but can't escape because flies, when not following a scent towards food, are attracted to light. Flies aren't very smart, so they usually just home in on the brightest light source. Inside a house, the light source is usually the window. The fly doesn't really understand glass, so it keeps banging against it trying to fly toward the light. It's not smart enough to realize it isn't making progress and search around for another way out. To sum up: Flies following the light to leave a house tend to run into an impassible barrier (glass) while flies following smells to get into a house tend to find actual openings (open cracks, open doors). So they get in more easily than they get out.\"",
"Flies don't plan or analyze. They are simple beings that respond to simple instinctual cues. They pretty much have simple little \"if - then\" loops going on in their heads. They move toward a light. They react to nearby movement. Pro-tip: Exploit their simple brains by slowly approaching with a fly swatter from behind them. Then swing fast and hard aiming for a few inches in front of them. They see the object coming (huge field of vision), launch forwards, die. They're not tracking an objects trajectory and actively dodging it. They're just reacting and moving.",
"Part of it, is an issue of scope. They’re only really considering their surrounding vision, in their general vicinity. Imagine you’re on a mountain range, and it’s super foggy, so you can’t see much around you. You’re trying to get to the highest point. You can tell when you’re going up and down, but you can’t see the other mountains in a distance. If you’re at the top of one mountain peak, you can’t guarantee you’re on the *highest* mountain peak. And simultaneously, any direction away from where you are, is an immediate negative from where you are. The fly sees freedom. It doesn’t see the window next to him. And traveling away from the closed window, is a step away from the goal. Moving one step back, to move two steps forward is a pretty complicated strategy for any animal that isn’t a human.",
"Flies have like a hundred eyes, but each eye basically sees if it's light or dark in the direction it's facing, beyond having barely any brain to think about things they have not tons of visual sense.",
"This is pretty much a variation of a similar but common question URL_0",
"Others have offered very good explanations, but I’ll try to combine those into one as ELI5 as possible. First, their eyes. Flying insects don’t have eyes like we do, their vision system is wildly different and hard for us to understand. First, their two big compound eyes can be thought of as thousands of individual eyes, each with one or a small number of “pixels” pointed in different directions. When combined these form an almost 360° panoramic view in all directions, but it’s a very *very* low resolution view, their total visual field in all directions might only have as much image information as a 240p YouTube video depending on the species. So while they can get a good feel for their surroundings and recognize certain targets or threats they don’t have sharp detailed vision in any direction. But flies don’t just have two eyes. Many also have a set of three “simple eyes” on the top of their head, arranged in a triangle pattern. Each of these isn’t so much an eye as a light detector, and it’s believed that these are for orientation, like aligning the sun with one of these eyes to ensure they keep traveling in the same direction. Then as others have said flies have very simple brains. They don’t appear to *think* so much as they react to stimulus. When moths fly in circles around a porch light it’s because their brains are wired to keep the moon in a certain part of their visual field to guide them, but when they come across an artificial light they can’t tell that it’s not the moon so they’ll try to follow it the same way, which means looping around and around forever. A simple insect brain can be replicated with a basic computer program, if the light isn’t in this part of the sky reorient yourself until it is, if you see a flower or whatever go towards it. They don’t really reason or plan like more advanced animals do. And of course, no animal is capable of intuitively understanding the concept of windows because that is not a situation that exists in nature, if you can see through it you can move through it. More advanced animals can figure out windows from experience, a cat only has to try to jump through one a couple times before they understand they’re impenetrable, but insects generally aren’t capable of that kind of reasoning and learning. If they weren’t able to fly through it the first time they’ll just try again, because in a sense they aren’t even capable of realizing that they didn’t succeed the first time. And because their vision and brans are so simple insects tend to follow other senses like smell, so houses can mess with that too. If they don’t have a sense to follow their brains will just default to cruise control until they either pick up on something or some other impulse need takes over and causes them to land or return to home base.",
"Flies don't have bad vision, just different vision. Their eyes take in light and send it to their brains in the way that helps them survive. It's more like what an almost blind person might see than than what we normally see--light and dark, movement, blobs of colors. If they had fancier eyes, they would need bigger brains to take all the images and make sense of them. But a fly with a bigger brain would be too heavy to fly and fall to the ground and die. We have different eyes and bigger brains that can do more with everything the eye sends to it. We tell ourselves that what we see is what's really there, but people walk into glass doors all the time. We don't do it more because we learn that if something looks like it should be a door or a window, it probably is and there is probably a piece of glass there if we can't see it. Flies just don't know what doors and windows are. If we could really see what's really there, we would be able to see bacteria and maybe even viruses and maybe we would see who is breathing out viruses and avoid getting sick. But that would take much bigger, fancier eyes and much, much bigger brains. And we wouldn't be able to hold our heads up and we would fall over and die.",
"There are 2 reasons to that 1. They have mosaic vision so it's really not of great help as a sensory organ with really poor precision which mainly just works with detecting light and movement. 2. Because of how little information they have and even lesser capabilities of comprehending it, they get stuck with an open window beside them.",
"Its like when you get stuck in a job or relationship you dont like for years, because you cant see further than the next hour or day.",
"There has to be more to this though than it's just a dumb fly, I mean I get that it's brain isn't thinking ok, let's try something else. But at the same time when given a choice and I see the fly going towards my window and open door beside it, it lines up for the window every time. I'm wondering if the fly maybe feels a breeze or something from the open door and doesn't like that and is why it flies to the closed window instead. I mean considering complete random chance, it's quite astonshing how often it picks the closed window as opposed to the open door long before it has reached the wall so to speak. There has to be something to this.",
"Flies only know how to fly :) in the direction of light, wich was enough to survive untill we made windows and other transparent objects.",
"I think they’re not interested in what you think is inside or outside. They don’t know freedom or being trapped. They just buzz buzz buzzzzzz",
"Yes! Most insect eyes are actually pretty terrible! There are a lot of reasons for this, but the simplest of those reasons is that the smaller the eye is the less light can enter it, so the less it can see. A little telescope sees fewer stars than a big one. For creatures with small eyes, the world is always dimly lit and poorly focused - it's like looking through a first generation cellphone camera. The resolution is terrible, the lens is terrible, and the sensor is half the size of a grain of rice. So really, flies and many other insects (though, not all) visually just react to strong sources of light or things with high visual contrast, and often can't see more than a few feet.",
"Okay, so most of the answers I have seen here do a pretty good job of explaining why flies don't see glass (like birds and a lot of other animals, including the occasional human!) but I haven't seen anyone yet explain why they won't fly out an open window (at least I haven't bothered to scroll down that far yet!) and the answer has to do with air flow; an open window will tend to have air flowing through it which affects the direction the fly can fly in and, as most people have a window open to let air in, the air flow will tend to push against a fly attempting to fly out through it, so it will instead try to fly out the closed window near by because there is less air resistance. The trick to get a fly to fly out a window is to open another window on the other side of the house, or room, so that the air can flow in one and out the other; eventually the fly will find the open window where the air is not pushing against them to easily fly out."
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nyweh0 | What is an “amp” link? | Posted a link to clarify an AMA and was asked not to post “amp” link. Please explain. Much appreciated! | Technology | explainlikeimfive | {
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"What is AMP? AMP is an open-source web component framework developed by the AMP Open Source Project, first announced by Google in 2015 as a reaction to Facebook’s Instant Articles and Apple News. While it was originally aimed at accelerating mobile pages (hence AMP), it’s now a much broader project aimed at improving the UX of websites, stories, ads and mail. The AMP framework consists of three components: AMP HTML, which is standard HTML markup with web components; AMP JavaScript, which manages resource loading; and AMP caches, which serves and validates AMP pages. In plain English: AMP is Google’s attempt at making pages (and more) faster. They did a good job, pages built with the AMP framework will normally load faster. However, as this article explains, you won’t notice much of a difference unless the AMP library is served using the AMP cache, but more on that later. You can read more here: URL_0"
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nyx2ev | How are certain songs recorded so that some sounds can only be heard through one earphone and not the other? | Technology | explainlikeimfive | {
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"Most songs are recorded with all the instruments separated. Each instrument records a separate track and someone mixes them together later. Stereo formats have the left and right separate so the can adjust what sounds come into each ear.",
"When you listen in stereo you're actually listening to two different tracks in mono - one in each ear.",
"A stereo recording is two entirely separate tracks. Theoretically, one could be a hummingbird drinking nectar and one could be a Concord at 104% of maximum thrust. Basically, if the mixer wants you to hear a sound in one ear only, they put it on one track and not the other. One method of recording stereo is to have a model of a head and a microphone in each ear, so you can capture the sound exactly as a person would hear it. But that's not the only way. Art, ya know)"
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nyxmhk | How were game cartridges copied back in the NES and Atari days? | After the main game is made, how are the backup copies of the game manufactured, back when computers weren't as common as it is now. | Technology | explainlikeimfive | {
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"A normal user wouldn't make a copy of it. As for manufacturing them, I believe most of them were masked ROM, so the contents would be built into the chip as it was manufactured. You couldn't erase them and put something else on them. There were EPROM and EEPROM chips that you can write to after manufacture, but you'd need a purpose built programmer to read the cartridge and write the copy. I expect anyone selling such a device commercially would have been sued for enabling piracy."
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nyxp7n | Archimedes and the crown. | The logic behind this continues to escape me. If the pure gold crown is equal in dimensions to the possibly half gold half silver crown, would they not displace the same amount of water? Since it's based off volume? I just don't get how say one inch cube of pure gold would displaced more water than a 1 in cube of gold silver because they both are have the same dimensions and therefore size. | Mathematics | explainlikeimfive | {
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"I think an important piece were omitted when you were told the story. It is very hard to calculate the volume of a crown. So they did not make a cube based on the volume of the crown. Instead they made the gold cube based on the weight of the crown. That is an important difference. Then they compared the volume of the crown and the gold cube by measuring their water displacement.",
"You've gotten halfway there A 1 inch cube of gold and a 1 inch cube of 50% gold/50% silver would displace the same amount of water because they're both 1 cubic inch and too heavy to float (this is important) But they wouldn't weigh the same! A 1 inch cube of 100% gold weighs in at 316 grams. A 1 inch cube of 100% silver weighs in at just 172 grams. A cube that's a mix of gold and silver would be less than 316 grams but more than 172 grams, and the ratio determines where in that range it falls. If you know how many cubic inches of water the crown displaces, you divide its weight by that to figure out its density and then you can compare to the density of pure gold and pure silver to figure out what percent gold it is. Since both metal blocks sink, the cube of gold doesn't displace more water, but it is heavier when placed on a scale. With the combination of \"volume of water displaced\" and \"weight on a scale\" you can figure out density and do a lot with that.",
"It will displace the same amount of water. But they will not weigh the same. Archimedes is using the water to get the volume of the crown. After that you can get that same volume of Gold and then test the weight of that against the crown."
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nyy4og | Why is it so difficult for software to give an accurate amount of time remaining for an install? Isn’t the install process relatively discrete? | Technology | explainlikeimfive | {
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"There are always other programs running on your system. If some of them decide to use memory or the drive right now, your install can be delayed for an unpredictable amount of time.",
"Your assumption is that internet speed and hardware speed stays the same throughout the entire install process. You need to consider the fact that these speeds constantly change and can change several times within a second. Having a perfect countdown will rarely be the case if at all."
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nyynmy | Are all photons the same, or are there different types according to age and source? Do the ones travelling through the universe for millions of light-years undergo any changes during the journey? | Physics | explainlikeimfive | {
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"As a physicist-in-training, I thought I could add to the discussion here. We can tell photons apart, but only if they have different energies. Two photons of the same energy are indistinguishable, however, consistent with other elementary particles like electrons and protons. Now, that is not to say they are different \"types\" of photons, since they are still the same thing (excitations of underlying B and E fields, but that's a bit more than ELI5), just with different characteristics. It would be a bit like saying two pieces of quartz are different things because they are different sizes. They are clearly the same, just with different mass/volume. Photons travelling through empty space (that is, between galactic superclusters, not so much travelling in our own galaxy) do indeed change. They redshift (become longer in wavelength) according to the amount of empty space in between source and observer, and the energy they lose goes into the expansion of the universe itself^1 . Measuring this redshift is actually one of the ways deep space cosmologists can determine the distance to different stars and galaxies. Tldr; photons are all the same, except when they are different in energy, but they still are kind of the same. Photons do change as they travel through the universe, but only over really big distances. Physics is difficult and weird. Ps I am only a senior undergrad so if anyone with more expertise would like to correct anything here, please do! ^1 ( URL_0 )",
"I'm not a physicist, but I think things traveling at the speed of light do not experience time.",
"They lose energy as they travel long distances through space (red-shifting). Photons can also have different spins (up/down) or polarization (left/right) when observed."
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nyz1gh | How are deserts growing? Where is the new excess sand coming from? | Earth Science | explainlikeimfive | {
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"There’s a well known process called *desertification* in response to climate drying, overgrazing and/or too intense agriculture … possibly with migrating sand dunes (did measurements on the latter for a major US Army base). Richer soil has a fungi component giving it a structure based on hyphae … and fungi need water. The hyphae act as molecular “cages” to trap more nutrients that plants love. Even in richer soils, sometimes it needs to be replenished. Debris (plant and animal) falling on the surface gets attacked by hyphae and incorporated into the soil in wetter environments. In drier ones it may be unavailable however or blow away in the wind. What were agricultural fields in Northern Africa during the Roman Empire are now part of the northern Sahara, so there’s been a bit of “terraforming” (in a negative sense) already.",
"There isn’t necessarily any new sand. A desert is defined as an area that receives less than 250mm (10in) of precipitation in a year. Desert growth usually happens in places that already have little rain, but still aren’t at a point where they get classified as deserts. It can be caused by extended droughts, human activities like urbanization, overusing groundwater, and deforestation, and overgrazing.",
"Deserts aren't about sand though they can have sand in them, the definition is rainfall, if there is very little rain in an area it is a desert. URL_0"
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nyzc2a | How are human corpses recovered and not eaten in large bodies of water, sometimes after weeks of being out there? Do animals generally not like human flesh? | Other | explainlikeimfive | {
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"if a corpse that has been in the water for that long still resembles a full sized human that's likely because there are no significantly sized lifeforms in those waters to scavenge it or the body wasnt there for long enough.. Scavenging corpses is A VERY common practice in aquatic Biomes but often you got the pecking order where smaller species have a small window before larger ones also come and could eat them..",
"Human corpses are often scavenged. The longer they are in the water the more likely they will be nibbled on, if not outright consumed. Some corpses are recovered but they are often not completely intact."
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nyzf05 | How come lightning strikes over the ocean aren't massively lethal to aquatic life? Or are they? | Biology | explainlikeimfive | {
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"Apparently lightning spreads over the surface of the ocean when it strikes it (doesnt go down in a straight line path to the ocean floor). So it does electrocute the surface fish (because there is millions of volts being discharged for every lightning strike). If the lightning strikes a fish / shoal of fish on the surface it sure will pass through it into the water beyond it and \"earth itself\". So yes - it is lethal to aquatic life if it strikes the aquatic life directly (or if aquatic life is near the strike area). What is happening is that electricity is using water as a conductive medium to \"earth\" / \"ground\" itself (dissipate the energy). Watch this video to understand how electricity behaves in a body of water [ URL_0 ]( URL_0 ) You will learn in the video, that at the place where the electricity is entering the water (in your example the lightning strike location) the voltage is maximum. As you move away from that \"electricity entering\" location the voltage keeps reducing. The same logic is applicable for a lightning strike - just that instead of 120 Volts - its maybe 12 Million volts.",
"Before a lightning strike, a charge builds up along the water's surface. When lightning strikes, most of electrical discharge occurs near the water's surface. Because water is a good conductor, it encourages the electrical current to travel over its surface rather than delve underneath similar to a Faraday Cage, so most of the fish swimming below the surface and are unaffected.",
"Lightning does not strike in the way you might think it does. Charge is gathered from a vast area and concentrated, and at the very point of contact, the current delivered makes for something unbelievable, but that is on its path between the charge carrying areas. Once it reaches the charged area, it is back to not being current. Here's an example of divers basically right underneath a lightning strike: URL_0 Couple quick notes: It struck the metal ladder they were right in front of. And instantly dissipated. Both the divers and the fish were fine. The diver's reaction was exactly the wrong one: they surfaced, and then climbed right onto the metal staircase, which would have killed them if the lightning struck there, because they would be part of the pathway the charge was trying to cross to get to the water. If they had been on the surface, they might have been the path the current took to get to ground.",
"The same reason they aren't massively lethal to land life. The ocean is huge, and if you pick one spot at random you won't generally find a huge clump of fish and marine life sitting near the surface. To paraphrase Douglas Adams: The ocean is big, really big. You just won't believe how vastly hugely mind-bogglingly big it is."
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nyznp9 | How do allergies develop? | How is it that some allergies only develop over time? For example: I only got allergic to a certain kind of hair dye when I was 15, didn't have problems before. Another example is my mum's hay fever which only developed in her late 20s. How does that work? Why does the body suddenly decide "Oh, by the way, I'm allergic to that now!"? | Biology | explainlikeimfive | {
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"When something is introduced to the body that the immune system detects to be foreign, antibodies are produced. Your fighter cells latch onto some of that foreign material and become like specifically geared to attack/respond to it. When you have an overload of whatever it is that you're allergic to, a ton of those cells that bind to it take that information in and start multiplying and copying themselves. So now you have a cache of self-replicating cells that have the only job of trying to fight this one thing your body is recognizing as a threat. It also chemically signals your body to release stuff like histamines and cortisols etc. I think allergies are kind of glitchy because when you're allergic to something it's not usually particularly harmful... Like pollen or cat hair or whatever. Your body just overreacts to some things and throws all of its defense mechanisms at it on first contact."
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nyzpqa | What gives turtles a long life span compared to other life forms? | Biology | explainlikeimfive | {
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"Cold blood and a slow metabolism means the burn energy slower and age accordingly. Well, that is in theory at least."
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nz02d9 | When does our brain choose our dominant hand? | Biology | explainlikeimfive | {
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"It’s not entirely clear exactly what causes someone to be left or right handed, but it’s probably genetic. So it’s not really your brain choosing, it’s just how the chips fall when you’re conceived. The current theory is that basically the left side of your brain handles language and also controls the right arm. So as we developed written language, it became beneficial to basically have the hand you write with be controlled by the part of the brain deciding what to write. So a gene that made people right hand dominant became favorable. There isn’t actually a similar left handed gene. You either have the right handed gene, or a different gene that could wind up going either way. You could have this second gene and still be right handed.",
"It doesn't choose. As far as we're currently aware, handedness is a product of the way structures in the brain develop. Normally, the human brain has two separate halves, right and left. These are connected and share messages between themselves, but it's thought that the processing of particular tasks is handled in particular halves. The brain is flexible and can adapt, but it prefers to do particular things in the right and other things in the left if it can. One of the things it prefers to do in the left is process the fine motor skills involved in writing, and because the body is weird and flips over left and right when it comes to controlling the body, this means most people end up right-handed - the left brain, which controls the right side of the body, is doing most of the fine motor skills processing. There's no one gene or decision point for being left-handed. Rather, it seems that left-handedness and ambidexterity are associated with increased connection between parts of the brain. These connections aren't normally supposed to be there, and they result in many tasks being processed more evenly across both halves of the brain. Sometimes (but not always) this manifests in people being left-handed or ambidextrous. Both of these traits are a lot more common in people with certain brain structure abnormalities like autism and ADHD, and current theory is that these things all arise from unusual connections between areas of the brain. Incidentally, this is also implicated in ASMR and \"musical chills\". Both of these are physical sensations felt as a result of non-physical stimuli and it's thought they occur because signals in the brain that normally process audio and visual stimuli are unusually connected to the parts of the brain that handle physical sensations and emotions."
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nz0lg5 | how is June bug not endangered? | June bugs seem barely functional. They fly into objects bounce off of walls and windows. They get stuck in grass or hair. I've never seen one and thought "ohhe is doing this useful thing" like eating or drinking or making a nest. How do they not die off of stupidity? | Biology | explainlikeimfive | {
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"text": [
"June Bugs, as we are familiar, are only short-lived. They spend most of their lives in the “grub” stage where they feed. They emerge as adult June Bugs, mate and die. They don’t have to be super agile.",
"Evolution don't give a shit if you're *good* at stuff, only that you're *good enough* to pass on your genes. June bugs are good enough to make babies, and that means there's little pressure to get better at stuff.",
"June bugs are the final stage of their lifecycle. The grubs live underground for 11 years before they pupate and emerge as junebugs whose only purpose is to find a mate, reproduce and lay eggs before they die. The beetles only live for a few days. It also means that when you see a junebug, there's a good chance its energy is already spent and it's lethargic and dying."
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nz0z1v | When pouring a liquid out of a cup, why does it often run along the outside of the cup instead of just flowing out? | Other | explainlikeimfive | {
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"h1n28ks"
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"text": [
"The water wants to stick to the surface it’s running along, this is called surface tension. If your cup has a rounded edge, which it probably does to make it comfortable to drink from, this will be more likely to cause it running down the side. The best thing to do it to tip the cup quickly towards what you’re trying to pour the water into. If you hesitate, or don’t tip it far enough, the water will always run down the sides."
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nz1dns | The Watergate Scandal | Other | explainlikeimfive | {
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"text": [
"Nixon and his team of manics (like a young Roger stone) did \"dirty tricks\" one of which was bugging the democratic national headquarters in DC at the Watergate office building. They were caught in the act of bugging the headquarters, and in the course of the investigation, it came out a few of them knew Nixon, were former CIA etc. Nixon said he had no idea, when he knew the entire time (and it was on tape), so impeachment charges were brought but he resigned. (I am probably forgetting some things, but iirc thats basically it)"
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nz2479 | Why is a plane boarded from front to back? Wouldn't it be more efficient to board back to front? | Other | explainlikeimfive | {
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"With the exception of elderly, first class and active military, today most airlines are loading back to front due to Covid and have become aware of how much smoother the boarding process has become",
"Back to front **is** more efficient, but that would make all those special upcharge options board last. They're just milking the money out of people willing to pay for upcharges like first-class, club cards, etc, etc.",
"Great video explaining it and other better methods URL_0",
"Overhead bin space and carry-on bags. If you let the peons board first, they will surely consume all the space for my bags!",
"Window to aisle would be more efficient. And board from both ends like some planes do. The main reason boarding is so slow is that no-one wants to check bags any more and people hand carry too many and too bigger bags."
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nz4oof | Why do animals like to be petted? | Biology | explainlikeimfive | {
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"text": [
"Most wild animals do not like to be petted. Domesticated animals however have been bred to work and live in close relationship to humans. Thus they trust humans more and in most cases depend on us to survive. Domesticated animals have thus learned to socialise with humans, and petting is a social interaction. I guess it is similar to us humans talking, but since animals can't speak we need to communicate in other ways. Petting is a way in which we can express love, affection and trust. With that said you should never pet an animal which you don't know or have the permission to pet as they can be dangerous or don't like humans and get scared.",
"Animals that are familiar with humans and trust them probably like being petted because it feels similar to being groomed for parasites. Many if not most animals appreciate groomers, of their own species or others. Animals that are not familiar with humans will generally tear you up or risk everything to get away if you dare to touch one. The more you know."
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nz5yhf | Why do mothers crave certain foods during pregnancy? | Biology | explainlikeimfive | {
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"text": [
"Sometimes its based on certain things shes lacking in her diet. Other times its just because hormones, lol. For example if shes low on salt, her body will have her crave salty foods. Or low sugar, sweet foods and etc.",
"To guarantee nutritional necessities are met for the babies development. There are a lot of vitamins and such that are lacking in the average persons diet, many of which are very, very, important for babies. Folic acid is important, for example. My sister hates mushrooms, but craved them during her pregnancy. Never has again after that."
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nz61zy | seven come eleven | Other | explainlikeimfive | {
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"text": [
"The first time a shooter rolls the dice, it's called a \"come-out roll.\" On this roll, ideally the shooter wants the dice to come up showing seven or eleven, because that's the simplest and quickest way for him to make money. \"Seven-come-eleven\" is a superstitious message to the dice, asking them to come up showing either of those numbers."
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nz6350 | Why do radio stations have acronyms before the number? | Technology | explainlikeimfive | {
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"h1nv8o7",
"h1nvnyc"
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"text": [
"In the US all broadcasters are assigned a series of call letters as an identifier when they get their license from the FCC.",
"That's a call sign. It's a unique alphanumeric code that identifies all radio and television broadcasters. In the US such things are regulated by the FCC. Stations east of the Mississippi start with W and stations to the west start with K. A station can request a specific call sign as long as it's unique, but otherwise they are assigned randomly or sequentially."
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nz74xq | What can't anti-tick-and-flea meds be made for humans? | Biology | explainlikeimfive | {
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"text": [
"The kind that are applied to the body of the animal use the fur to distribute the 'medicine'. The kind that is taken internally is not FDA approved for humans."
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nz7hn8 | How do lock companies produce so many unique lock key combinations through a standardized production methods? | Technology | explainlikeimfive | {
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"text": [
"The unique combinations for a lock depend on the number of pins in the lock and the number of possible positions. When the key is inserted it pushes up on the pins based on the shape of the key, and based on how high the pins are pushed it can unlock the door. So if you have 7 pins, with 5 different possible heights each that's 7 ^ 5 = 16,807 possible combinations. They make a fair number of duplicates as well, so your specific lock combination might get made a whole bunch of times. But distribute it coast to coast and the chances of your key working in any other lock in your neighborhood or town is slim to nil. Different lock types also use different shapes of keys, so your key won't fit into a different brand or type of lock. If you're worried about the chances of your door key being duplicated, don't be. To be perfectly frank if someone is sufficiently motivated it's much easier to sledgehammer down a door or break a window than copy a key or pick a lock... There are much easier ways to break into your house than copying a key, get an alarm instead."
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nz8uj5 | why is boarshead roasted chicken 30 calories per ounce but standard chicken breast is 47 calories per ounce? | Other | explainlikeimfive | {
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"text": [
"Chicken breast is often injected with a mix of saltwater, flavoring, and sugar to make it juicier and tastier.",
"> What am I missing? It isn't just pure meat. One way meats are commonly manipulated is to inject brine into them, loosening the muscle fibers and adding flavorings. This brine is basically free of calories and so will reduce the calories for a given weight of the meat. Take a look at the sodium content, chickens aren't generally a salty bird."
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nz8wfq | Why are movies rated R if they say "fuck" twice, but Youtube videos can say it all the time and anyone can watch them? | Other | explainlikeimfive | {
"a_id": [
"h1oac7z",
"h1oaler"
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"text": [
"Movies are rated by the MPAA, a non-government industry organization that rates movies. Youtube videos aren't rated by anyone.",
"The ratings on movies are from the MPAA, a trade association involving the movie industry. It's a self-imposed system, not a legal one. They set the rules entirely by themselves, and give ratings based on those rules. Nothing like that exists for Youtube."
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nz98rf | What is the difference between well made plastics and ones that break easily? | Chemistry | explainlikeimfive | {
"a_id": [
"h1odjv4",
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"text": [
"Picking the right plastic for the job (there's tons of types), spending the extra money to add in glass-fiber reinforcement (if you look on the inside of a drill clamshell where it says like PA6 GF20 that means it's 20% glass fiber), engineering the design to be of a proper thickness and have good reinforcement, having the right mix and settings for the melt/extrusion. A lot of stuff can make the difference. Most of it is related to, no surprise, being willing to spend the money.",
"You can reinforce plastic by adding fiberglass into it. It makes it more expensive because it wears out the moulds faster. Moulds cost tens of thousands of dollars to make so plastic manufacturers want to keep track of how long they last. That's why you'll often see a circle with 1-12 printed around it and an arrow pointing towards a number and another circle next to it with some numbers corresponding to a year. Those numbers don't represent when the plastic item was made, but when the mould was made so they can keep track of how long it lasts."
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nz9orz | During a shuttle launch, what happens at T-6.6 seconds vs. what happens at 0 seconds? | At T-6.6 seconds, you see a huge fireball come out of the rockets, but the shuttle doesn’t actually lift off until 0 seconds. What happens at 0 seconds that isn’t happening at T-6.6 seconds? I think I found a Wikipedia article, but it’s way over my head. | Technology | explainlikeimfive | {
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"At T-6.6s they begin firing up the three Space Shuttle Main Engines underneath the Orbiter. These are liquid-fueled engines that pull fuel from the big orange External Tank. The SSMEs are *extremely* mechanically complex and things could go very wrong very quickly if an engine fails during launch, so NASA lets them run for a few seconds to make sure they’re working properly. Once the SSMEs have stabilized, the two Solid Rocket Boosters strapped to the side of the tank are ignited and the Shuttle lifts off. Unlike the liquid-fuel engines, there’s no way to shut the SRBs down after they’re lit, so they wait until the last possible second.",
"They stagger start the liquid engines (to limit stress), as the engines come up to full power. As they start the main engines, the thrust has rocked the shuttle forward. When it rocks back into the original position, they start the solid fuel engines. This is timed perfectly to account for the slight rocking. Anytime before they light the solid fuel booster, they can shut down the main engines and abort the flight. Once the solid fuel engines are ignited there is no turning back, it's going to fly.",
"In addition to what people have here's the actual countdown starting at 6 hours: [ URL_1 ]( URL_1 ) Here's the site with pretty much everything you'd need to learn to be an astronaut and fly the shuttle (training materials, cue cards, etc). It's amazing that all of this is now online: [ URL_0 ]( URL_0 )",
"At T-6.6 seconds, the 3 main engines on the shuttle ignite, one at a time staggered by 120 milliseconds. It takes a few seconds for the engines to spool up to full thrust, and the control computers check to make sure each engine is at the correct thrust and all other sensors are nominal. Assuming that's the case, at T-0, simultaneously, the SRBs are ignited and the bolts that hold the shuttle down the launchpad are released and the shuttle lifts off. The 3 main engines are ignited first because they can be shut down if something is wrong, but once the SRBs are lit, there's no way to turn them off, so they make sure the 3 main engines are burning normally before igniting the SRBs and committing to liftoff.",
"The fireball is hydrogen burning off. Just after that, the RS-25 main engines slowly spin up to full power, which can be seen as the exhaust gets clearer and the mach diamonds more pronounced. It can also be seen as the full stack leans forward. Assuming startup went well, the SRBs are ignited, explosive bolts detonated, and the vehicle leaves the pad."
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nz9pxe | Explain the Critical Race Theory and its controversy related to school systems. | Other | explainlikeimfive | {
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"text": [
"CRT says that social problems are created by social structure, not the individual or culture. At the core of this is white supremacy, with its structural racism. Essentially, the root of all problems is whites have the power and have arranged society for other races to fail.",
"CRT is the inclusion of non-white TRUTHFUL HISTORY taught in school that is more than 3 paragraphs long in chapter of your school's history book. It shows how racism has benefited the USA and the power stucture of white supremacy. Opponents are trying and unfortunately successfully banning it because they feel it's unbiased against white people. So like racists are saying anti-racist teaching is racist towards racist."
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nza3mh | How do flies see things so much faster than us? | I’m out here trying to swat a fly and I swear it starts moving the millisecond I begin my swing, it’s crazy. | Biology | explainlikeimfive | {
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"text": [
"We are much bigger than flies. Even our brains are orders of magnitude bigger than them. So the time it takes for signals to travel from their eyes to their brains are much shorter because they're literally millimeters (or less) away. Also, because their eyes and brains are much simpler, they need less time to process information before making a decision. And because they're so small, they've evolved to watch out for pray far larger than them going after them, hence their big, protruding eyes that can see in all directions.",
"Aside from what's already been said, flies are also covered in hairs that can detect movement in the air. It doesn't have to see you to know something is coming for it and from what direction it's coming. And they don't spend any time analyzing what's happening or how to deal with it. It's just an instant reaction. Something coming my way > dodge.",
"In terms of *how*, smaller creatures in general will have faster reaction times because the electrical signals that carry the \"get out of the way!\" signal don't have to travel as far. So their \"ping time\" is lower. Also the locomotion they have to put into actually carrying out the command is tiny in comparison. In terms of *why*, it's because their survival utterly depends on it and so evolution has done its thing over millions of generations to make them super-specialists. A fly has to have fast reflexes or die. Compared to, say, humans, while reflexes are certainly one component to being able to deal with external threats, we also have other options that benefit from other traits, like being strong or smart or social."
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nza4lu | Why is some rain little droplets and some rain are big old fat drops? | Earth Science | explainlikeimfive | {
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"text": [
"Rain forms when little particles of dust start getting water stuck to them in the cloud. When they get heavy enough, they fall. Sometimes, the wind is blowing upwards and the drops have to be heavier before they fall; this is how hailstones are made, too. Sometimes there's no wind blowing upwards, but the raindrops form way high up in a really thick cloud and keep collecting water as they fall. They don't fall very fast, so they have time to pick up a lot sometimes. When they form close to the ground they don't have enough time to pick up much extra water. Edit: huh, needed a semicolon for once."
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nza5bd | Why do you feel sore after exercising the day after and not right after? | Biology | explainlikeimfive | {
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"text": [
"It's called DOMS, delayed onset muscular soreness, and the tiny fibers in your muscles are breaking down, then healing from enzymes 'recruiting' inflammatory mediators to help repair the muscles, which makes you stronger. The fun thing is that science knows what's going on, since those mediators stimulate pain receptors, called nicoceptors, but there is no one accepted reason to why it takes 24-48 hours after a particular nasty workout. No one knows for sure. I personally think it simply takes that long for the muscles to recognize they were ripped up by heavy lifting or exercise, and time for the nicoceptors to react to the healing process. That's a guess."
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nzaigx | How do bodies know to "stop growing"? What tells the body to only grow your bones, organs etc to a certain size? | Biology | explainlikeimfive | {
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"text": [
"When the fetus grows, it turns on programs of genes, including triggers to stop. These programs can in turn trigger other programs until all the necessary programs have been executed. Some of these programs are kept open into our infancy, adolescence or even adulthood. This system of genetic control is fairly well characterized in Drosophila flys, c. Elegans flatworms and plants like arabidopsis, but much less understood in humans. What we do know is that the group of genes known as homeobox (Hox) play a critical role in triggering gene programs related to body architecture and therefore also height. Interestingly, twin studies show a heritability of body size in the order of 60-70%, but attempts at pinpointing this to specific genes (in genome-wide association studies, GWAS) have largely failed. It is just, very, very complex.",
"Your dna basically. Like there’s more too it but basically your dna is blueprints for the building that is you and just like with an actual building it’s meant to be a certain size no more no less. Now mind you sometimes weird things can happen and you can grow to be gigantic or just be stunted to a less than average size but that’s definitely not normal or common.",
"There are hormone clocks wired into our DNA; a hormone activates this part of growing while also activating a second hormone that slowly stops the last from working and starts the next part which activates a third etc. This allows puberty and maturation processes to happen sequentially Nutrition also has a massive role to play; good nutrition while young allows those stages to occur optimally, which means faster in this case. As the stages are timed; better nutrition means bigger people. Average height of the world drastically increased after the industrial revolution as better nutrition was more widespread. Also why heigh is looked upon favourably still as you used to have to be rich to grow tall kids reliably.",
"When your mama goes \"stop, now you cant grow anymore, I want you to remain my baby boy\" your body knlws it's time to stop growing",
"Your body's growth is influenced by several hormones throughout the years. These hormones affect your long bones' growth plate, which makes the bones grow in length. From birth, thyroid hormone is involved with your bone growth. From around 9 months old, Insulin-Like Growth Factor (IGF) and Growth Hormone (GH) are involved. Just before puberty, glucocorticoids from your adrenals start playing a role. And finally, in puberty, sex hormones (estrogens and androgens such as testosterone) start playing a role. These sex hormones finally close the growth plates as well, which means they won't grow any further. During the whole window of growth, nutrition naturally plays a vital part as well."
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nzaotj | Since it rains diamonds on Saturn and Jupiter, do the diamonds just pile on each other? Do they evaporate? | Other | explainlikeimfive | {
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"text": [
"The gas giant planets are incredibly hot inside. They have an enormous, rocky core, the surface of which is closer to a volcano than the earth's crust. It's covered with an ocean of liquid gas that consantly boiling away then raining down again. Anything that falls to the surface is boiled and returns to the upper atmosphere. The problem with the diamond rain is that it's theoretical. The presence of it depends on how convective the lower atmosphere and oceans are. If they're highly convective then the diamonds will mix with oxygen and burn to create Co2. Eventually, all the carbon will be burned this way and there'll be no diamond rain. If they're more evenly layered, or if a thick layer of hot gas is preventing the liquid ocean from coming into contact with the molten surface, then the diamonds will fall into the lava and boil away without getting the chance to bond with any oxygen. AFAIK, we don't know which of these is true. We don't even know how thick the atmospheres are or how big or hot the rocky cores are.",
"actually because of the heat in jupiter and saturn causes that diamond to melt and evaporate into the atmosphere which then turns into solid pieces of diamond which is formed due to the coldness in these gas giants's upper atmosphere ............causing the rain of diamond again and again & #x200B; & #x200B; so to answer your question ....no it doesnt piles up"
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nzbcjn | Why do loud sounds and noisy environments give people headaches? | Biology | explainlikeimfive | {
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"text": [
"For people who are sensitive to noise, loud noise is a stressor. This increases blood pressure, making the blood vessels surrounding your skull expand. This may activate “trigeminal sensory nerve fibres”, which is responsible for giving feeling to your face and controlling motor skills like biting and chewing. This releases proteins that worsen brain inflammation and pain."
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nzbk68 | What happens to oxygen in space? Would it be possible to get oxygen into space? What would happen to it? Even if it’s a small amount, does it just vanish? | Earth Science | explainlikeimfive | {
"a_id": [
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"text": [
"In our atmosphere oxygen molecules have an average speed of around 1000mph. They're constantly bouncing up against other molecules and changing direction. In space there's nothing else to run into so oxygen released there would quickly disperse at high speed in every direction.",
"I'm not quite sure what you mean. Nothing \"happens\" to oxygen in space, it's just oxygen. Did you mean to ask what happens to some volume of a gas in space? There's vast amounts of oxygen already in space, it's just extremely spread out. Yes, you can of course bring oxygen to space. Just put an oxygen tank in space and then open it. The oxygen will just rush out of the tank and disperse. If you're near some body like a planet, the atoms or molecules will spread out but stay gravitation ally bound to that body. If you're in deep space, the atoms or molecules will just spread out forever."
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] |
|
nzbpds | Why does heating steel up to a certain temperature cause it to become non-magnetic? | Chemistry | explainlikeimfive | {
"a_id": [
"h1oqa17"
],
"text": [
"Magnetism comes from the alignment of the atoms ( they all face one direction). When you heat up the steel, the atoms heat up making them move around. This changes the alignment of the atoms to be in all different directions, making it loose it’s magnetism."
],
"score": [
8
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
nzbsu4 | What are those moving patterns we sometimes see when we close our eyes? | Biology | explainlikeimfive | {
"a_id": [
"h1ormzh"
],
"text": [
"They are called phosphenes. I don't know if the science is 100% settled, but it seems that it comes from the normal activity from cells in eyes. It registers as light on our retinas and our brain makes sense of it as shifting patterns."
],
"score": [
5
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
nzcueg | Anselm’s Ontological Argument for the Existence of God | As much as I try learning about it, I don’t get it. What is the ontological argument, and why is it special? | Other | explainlikeimfive | {
"a_id": [
"h1oy9y8"
],
"text": [
"His proof goes something like this. 1. God is greatest possible thing. 2. Everything is imaginary and/or real. 3. Something is better when it is real than when it is imaginary. 4. If God is only imaginary, then he wouldn’t be the greatest possible thing, because a real God would be better. This would contracts God as the greatest possible thing. 5. God must exist by proof of contradiction. In short, the guy thought he was really smart, when in reality, he was going in circle."
],
"score": [
12
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
nzcwo8 | why bar soap makes you feel sticky and liquid soap does not. Do you get clean by just using bar soap and no wash cloth? | Other | explainlikeimfive | {
"a_id": [
"h1oy11l"
],
"text": [
"i've never experienced this phenomena as a bar soap user myself. are you rubbing off soap in chunks? you're only supposed to rub it lightly to get a lather going. my skin is actually super dry after i shower. i moisturize it after. i definitely do not feel sticky."
],
"score": [
10
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
nzcz7w | How do deep sea aquatic organisms get oxygen? | Oxygen is abundant near the surface of the ocean since it can freely dissolve from the atmosphere. I've always assumed that the deeper you go, the less oxygen is available. But how do deep sea organisms like blobfish and anglerfish thrive in such low-oxygen environments? I'm discounting whales and the such, cause I mean... They got lungs, they just hold their breath. | Biology | explainlikeimfive | {
"a_id": [
"h1oyoew"
],
"text": [
"You are correct that there are areas of the ocean that have very low amounts of dissolved oxygen, but it's not as simple as deeper = less oxygen. These so called oxygen minimum zones vary by depth at different places in the world, and are almost never actually at the sea floor. Oxygen concentration tends to be the lowest around 200-1000 meters, at which point oxygen concentrations rise again as you descend. Anyway, it's important to remember that sea creatures that live in these zones evolved there, so they have the necessary adaptations to live in very low oxygen environments. These creatures tend to have a very high concentration of oxygen transport proteins and also extremely efficient gills with large surface areas relative to their bodies for maximum oxygen extraction. They also tend to have low metabolic rates that minimize oxygen consumption."
],
"score": [
14
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
nzdyll | How do mosquitos (and other bugs that bite) distinguish me from an inanimate object when I’m not moving? | Biology | explainlikeimfive | {
"a_id": [
"h1p1ohn",
"h1p1ws1"
],
"text": [
"You stink. Literally, they go by smell, particularly your sweat. Interestingly enough, some people’s aroma attracts mosquitoes better than others. They hardly bother me, but attack my wife like crazy. Same with our kids, one of them is a skeeter magnet and the other isn’t.",
"Your smell most likely. They smell your sweet smelly sweat and land on you, and their hypothesis is confirmed when they feel your warmth and how soft and supple your skin is. Then they stick it in, er uh the needle that is if they’re a mosquito. And if it goes in easily and they can get some blood then that added to the proof that you’re an animal they can drain."
],
"score": [
13,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
nzepax | Why does a fresh cut feel better after you put it in your mouth? | Biology | explainlikeimfive | {
"a_id": [
"h1p9j3n",
"h1p89y8"
],
"text": [
"Opiorphin - When we put the cut in our mouths, there is a natural chemical in our saliva called opiorphin. This chemical is a really strong pain killer - even stronger than morphine. [Source / More Information ]( URL_0 )",
"I once read that our spit (and mammals in general) have some sort of weak anesthetic. I'm not sure how legit this is but it does make me wonder why it does feel slightly better and why dogs always lick their injuries."
],
"score": [
9,
5
],
"text_urls": [
[
"https://www.google.com.au/amp/s/www.newscientist.com/article/dn10514-natural-born-painkiller-found-in-human-saliva/amp/"
],
[]
]
} | [
"url"
] | [
"url"
] |
|
nzf88l | how did a cloud form inside the garage with the dryer running? | I only saw it once. Was a small cloud in midair. I am assuming it had something to do with the dryer and the humid air coming out. Dryer was running, garage door closed but has vents in the garage door. Dryer located at one end of the garage, vent hose not connected to the outside but vents to the other side of garage. | Earth Science | explainlikeimfive | {
"a_id": [
"h1p8a5y"
],
"text": [
"A cloud indoors is possible but you need PERFECT EXACT proportions of everything from temp, light, humidity and some other factors to be able to achieve it. It's been done before by some artist who took the time to create a cloud inside of a building(I believe it was a church)"
],
"score": [
10
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
nzft2c | why a bathroom mirror or window fogs up with steam during a warm shower if water only boils at 100 degrees. | Chemistry | explainlikeimfive | {
"a_id": [
"h1pasjt"
],
"text": [
"Water always evaporates. It is more inclined to be a vapor as it gets hotter, until 100 degrees where it is essentially obligated to be a vapor. Hot air by a cool mirror means that the water in the air cools off and liquefies on the mirror."
],
"score": [
16
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
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