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6910rp | Biology | Why isn't it good to have a lot of vitamins at once? I'm specifically talking about gummy vitamins/pills. | There are two types of vitamins: fat-soluble and water-soluble. The water soluble vitamins are more common so if you take too much of these, you'll just pee them out. They do no harm. However, the fat-soluble vitamins are very harmful because they stay in your body and if you have too much, you can get very sick. For example, if you take too much vitamin D you might experience nausea, a loss of appetite, and vomiting. This is because too much vitamin D causes calcium to build up in your blood. Taking too many vitamins can be very harmful, just like most good things. | 3 |
5uz5kd | Biology | Why does going to bed later than usual but sleeping the same amount of hours as you normally would, feel worse when you wake up? | How does having naps during the day affect sleep quality/sleep debt? I'm interested if naps are beneficial or actually disrupt evening sleep quality. | 5 |
o0y3dx | Technology | Why does it take 1+ hours to charge something when electricity is almost instant? | It depends what technology is used to store the charge. Capacitors charge and discharge in a very short time (milliseconds to seconds) but hold a very small charge. All of the common battery systems in household use use chemical reactions to store energy. Those chemical reactions need time to happen. Still there are often specific quick charge routines that cut the time far shorter often at the price of a reduced battery lifetime. | 2 |
kgr8nn | Chemistry | What makes things "sticky" like tape or any kind of adhesive? How do they stick on to smooth surfaces instead of coming off? | Ok let's take this in three parts: Pressure sensitive adhesives such as tape are a mixture of rubber (like your tires) and a type of liquid that is very slow to move but still liquid. When these are pressed against a surface, they squish themselves into the cracks of the material. The liquid material will allow you to compress it and it actually moves better when squished than it does just sitting there meaning it is now stuck in the cracks. From there, it actually resists being pulled on like a Chinese finger trap. This is what we perceived as being sticky. There are also chemical reaction based adhesives. These don't have to be crazy things like vulcanizing rubbers, etc. This can be something as simple as honey coming in contact with your fingers. The structure of honey allows it to absorb water into its system. This means that as it contacts your finger it takes a liking to the water on your finger and gets bound to it. The only way to get it out is to overwhelm the matrix with more water (aka licking your fingers). Finally, when it comes to smooth surfaces (no surface is actually smooth) we go back to the first type of adhesive. The idea for smooth surfaces is to not only fill the cracks, but to make a uniform surface of adhesives that can use the small gaps in the surface to anchor it to the smooth material. For the rest of the area, it is more like a suction cup than like the tape adhesive. | 4 |
9uktr5 | Biology | Why can horses sleep standing up but not humans? | Horses are able to lock their knees so they don’t fall over. As another commenter stated, having 4 legs does help. | 3 |
8bs5m6 | Chemistry | What is in gasoline that makes cars go and why can’t we make artificial gasoline? | Gasoline is a chemical mixture that releases a lot of energy when it is burned. There are many chemical mixtures that can do so but the gasoline mixture is relatively cheap and easy to make from oil found, naturally, in the ground. Chemists **can** make gasoline and other chemical mixtures that produce energy when burned. The problem is that synthesizing gasoline in large quantities, as is necessary, would be very, very, expensive and still result in all the carbon pollution problems that we have with naturally derived gasoline. | 4 |
jstcod | Other | Why do money transfers between bank accounts take many days? | Here is an episode explaining the US system: URL_0 | 4 |
jbl8ty | Biology | How did humans think before language was invented? | Like animals. Without being pedantic - becuase it is relevant - language wasn't "invented", it developed, slowly, over many centuries. (Indeed, it still is developing.) Animals communicate, in ways unique to each, and so did we - signs and grunts to begin with, and the vocal noises developed bit by bit alongside developments in our brain. | 5 |
ni7xzs | Mathematics | Why is a negative times a negative positive? | Actual ELI5: Negatives are like UNO reverse cards. Reversing a reversal puts you back in the original direction. Your logic makes sense for addition (where negatives just "pile on"), but multiplying by a negative is more like a reversal: take whatever you have and negate it. | 2 |
fpwigj | Biology | Why is whistling the exact right notes so easy for almost everyone who knows how to whistle? | Much like singing, it's easier (and a LOT faster) to correct than an instrument. You don't have to push, pull, or stretch anything, just move part of your body, and that can be done quickly enough for most people to not notice the off tune parts of notes, before you hit the note you want. | 4 |
fcxrst | Biology | Why do your hands shake when being nervous? | During periods of extreme stress your body chemically alters the signaling pathways to put your muscles into battle mode - increasing strength and reflex speed but decreasing accuracy and rational thought. This makes the muscles jittery and tense, and prematurely engages sweating before you've started fighting. Really useful when you're fighting a sabre-toothed tiger in 54,000 BC. Not useful at all when you're giving a speech. | 4 |
6sy6jo | Culture | The Body Positivity/Fat Acceptance movement. I have seen a lot of articles lately that are applauding "fat" (their words) people for accepting who they are and not trying to improve their health. Why are they applauded for being unhealthy, over weight, and lacking ambition to improve? | I like your question, but I don't think anyone is being aplauded for lack of health. I think there is some pushback on the health of the ideal healthy weight . Our ideal is miserably skinny. But I also think there is a desire to not use weight as the measure of health. If we looked at blood sugar, cholestoral, and blood pressure, could we find better personal ideal weights and behavior? Just thinking. I'm interested in other opinions. | 5 |
bayynw | Biology | Why does your lip feel so much fatter when it’s numbed, at the dentist for instance? | The brain makes up reality that matches our sensations. In case of a numb lip, you can't move the lip easily and the likely explanation is that it has somehow become heavy. Heavy lips would be bigger, so you feel that lips are bigger. Also you can't feel touch, that would happen if the lips are covered by a thick layer of some substance. So bigger feeling lips. | 6 |
9gdjw2 | Technology | Why was Half Life 2 considered such a milestone in gaming? | This guy has a good few videos on some of the reasons why, might be worth checking out. URL_0 | 11 |
8yewwl | Other | How a citizens arrest actually works? | This depends entirely on the jurisdiction in which you are. It is not the same everywhere, not even necessarily within a single country. Often, it opens a person up to significant legal liability, so it is important to understand the local rules before you attempt it. | 2 |
6rzvk9 | Economics | How was 8 hours/day determined to be a regular work day? | Wait so I can thank unions for the 8 hour word day and the weekend being a thing? | 12 |
6vc78m | Other | Why do people think MSG is bad, and what are objectively it's benefits and drawbacks? | MSG have been thoroughly studied for negative health effects and nobody have been able to prove any of it. We have even found positive health benefits in the form of increased appetite in people with reduced appetite. MSG is present in most everyday food but have only recently been linked to the savory taste and therefore is currently used as an additive. The connection between MSG and diarrhea is a nice cultural subject. MSG found to be responsible for the savory taste in Japan and was therefore first adopted in East Asian kitchens first. It was also at the time when Asian cuisine were spreading throughout the world. Some people would become sick when eating at these new Asian restaurants for various reasons. New restaurants may not have the proper hygienic routines in place. Unfamiliar new ingredients might upset the stomach until you get used to it. And some spices can cause mild diarrhea in some people. This is when the theory that MSG is bad for you came about. And this theory explained a lot of peoples experiences and many therefore though it was true. It could be that places that used a lot of spices were also using a lot of MSG which would further strengthen the theory. Scientists have tried to isolate this effect but have been unable to. People who claim they are affected by MSG will have a placebo effect if you tell them that their food contains MSG but will not exhibit any illness if told that their food does not contain MSG even if it does. And there is no reports of problems after eating meals which is naturally rich in MSG like you get when people eat meals that have added MSG concentrates even though the MSG levels are the same. | 1 |
6zer3a | Culture | why certain cuisines are more famous than others? For example, Italian and French cuisines are much more famous than the German or Scandinavian cuisine. Thai food is famous but it is less famous than Spanish food....etc what is the reason behind that? | This question has a lot of answers, but [this article]( URL_1 ) goes through some key reasons brought up in "Gastronomie Francaise" by Jean-Robert Pitte, A professor at the Sorbonne University in Paris. Being Scandinavian, the cultural reasons stemming from religious pietism resonate with me. While we're probably among the most secular in the world now, we still have that thing in us about needing a bit of pain before we can treat ourself in any way. Poor year-round access to fresh produce and the need to conserve fish and meat can also be seen in our traditional foods. Germany can't really use that excuse to the same extent, but they also had a protestant pietistic movement. I also recommend reading the quite short wiki article on [haute cuisine]( URL_0 ) which includes early history and the codification of modern (i.e. 19th century) French cuisine with people like Escoffier. In short, extravagant feasting became part of the culture and an "art" among the wealthy in 17th century France. | 3 |
alrkr2 | Biology | What happens to the human body that makes it feel like cold isn't cold? Just a couple days ago the "real feel" was -50 F. Now it is 5 F. A couple weeks ago 5 felt like it was unbearably cold. Now 5 feels almost balmy. What happened? | Your body can't actually sense temperature. It feels heat being absorbed or lost. So when you are losing heat your body tells you that your surroundings are cold. The more heat you lose the more you perceive your surroundings as being cold. Also, the greater the temperature differential between two things, the faster heat flows from one to the other. You are asking about how you can feel cold in a cold temperature but then ok in that same temperature later (when you have adjusted). This is the same thing as getting into a cold swimming pool: freezing at first but fine after you've been in it for a while. Your body adjusts by constricting blood flow in the extremities, so your skin is colder than your insides. When your skin was hotter there was a greater heat loss and you perceived it to be colder. When your skin was colder there was a smaller heat loss and your body tells you that means your surroundings are warmer (when it's really that your skin is colder). | 1 |
ls9qsc | Biology | Hoe can E. Coli and other dangerous bacteria live in our body and digestive system but if we ingest them we get very ill? | Your digestive tract is like a bacterial zoo. There’s a huge population of various bacteria in there that break down a lot of what you eat. They assist your digestion, you provide them food and shelter. It’s a great deal as long as they don’t escape. They’re not allowed to wander the rest of your body and digest whatever they feel like, and you don’t want strangers from other zoos coming in and disrupting the carefully managed ecosystem either. | 2 |
aauv31 | Biology | why do ants falling from large heights (like even up to 5m) not die? I've been thinking: if a human falls from a large height, they'll either get injured very badly or just die. If an ant falls from a similar height proportional to his size, he'll usually just carry on like nothing happened. Why does this happen? (I'm sorry if this question is poorly framed). | Really ELI5ing here: The "death" from falling is caused by being smashed against the hard surface of the Earth. And how hard you are being smashed depends on your weight. So, a heavier animal will be smashed much harder than a lightweight one. Now, when it comes to ants, the power behind that "smash" is so small that their bodies can easily withstand it. But when it comes to humans or bigger animals, the power behind that "smash" overcomes the strength of our bones and other tissues so we will be injured. | 5 |
aip80f | Culture | ? Why the passenger seat in a car is called shotgun? | It's related to travel by coach (pulled by horses). The driver is controlling the horses. The person next to them is holding a shotgun to protect the coach from robbers. | 5 |
7ucnlq | Technology | How does steel affect a MRI, or magnetic resonance imaging, while using it? I'm curious since this article about a man who died a couple of days ago in Mumbai, after being sucked into an MRI machine. | The MRI machine is comprised of a large magnet, and just like any magnet will attract metallic objects. Which is why no metallic objects are allowed in the vicinity of the MRI machine. The strength of magnets is measured in Tesla ( 1 Tesla is equal to 10,000 gauss) and most MRI machines in the field are of 1.5T (3T magnets are also seen). To put that into perspective, the earth’s magnetic field is approximately 0.5 gauss. So 1.5 T magnet is equal to 15,000 gauss (approximately 30,000 times the magnetic field of the earth). Once a magnet is engaged, it's quite a task (expensive and time consuming) to stop and start it again. So if a patient is wheeled into the MRI room with a regular wheelchair or an oxygen cylinder, it's simply sucked in and can cause injury or death. | 2 |
8iedgn | Culture | Why does Breast Cancer get almost all focus and support against; while countless other cancers are publically ignored? | better PR. We're all pretty shallow and ignorant in the bigger picture. Breast cancer has by far the most money put into advertising so more people know about it and more people put money into it. Sadly a lot of that money goes into organizations that are really just hangers on to the whole issue. You've got people who contribute nothing or next to nothing to breast cancer treatment and research but do plenty of advertising for it so they can accept donations. | 1 |
kktntr | Mathematics | . How does my drink have 0 calories per serving(12 fl oz) but the whole (33.8) fl oz bottle is 10 calories So I was looking at my drink and got very confused. The bottle is 33.8 fl oz and has a total of 3 serving size per bottle. Its is a flavored carbonated water drink. Here is where I am confused. How can 10 calories split into 3 serving? How many calories would be in each serving then? Pic is of the [nutrition facts]( URL_0 ) | If the calories per serving are less than 5 they can round down to 0 ( this is in the US anyway). So probably you beverage is 3-4 calories per serving | 4 |
6fkwww | Biology | What actually happens when you go through ego death on psychedelics? Some people in high doses of LSD or Mushrooms have experienced a feeling of not being themselves anymore and going through the death of their ego. They then come out of the trip a different person. What happens inside the brain/what makes this happen? | I'm curious to ask if going through ego death without the use of psychedelics is a recorded practice? Such as through meditation? | 8 |
9i0grs | Biology | what would happen if a morbidly obese person starved themselves? Would they live longer than an average weight person who did the same? | Follow up question: Who would survive fasting longer - someone with an extra 50 pounds of muscle, or with an extra 50 pounds of fat? | 11 |
n2j8fo | Biology | how does decaying fruit/veg help soil? Can it restore soil? | I made a [image album]( URL_1 ) of a edible garden I made from 100% recycled/salvaged materials. Built straight on top of previous lawn. [Here]( URL_0 ) is another album of a tiny garden that I built straight from burying raw organic trash. Atoms are not created or destroyed, they can be recycled through 'nutrient cycling'. This also means bags of leaves, and grass clippings people through out are worth hundreds of dollars if you wait a few months and have sunlight and water. | 2 |
6fmxyt | Biology | What prevents our bodies from decomposing while we're still alive? | Decomposition is mostly the work of bacteria and fungi. Our immune system does a pretty good job of keeping them from doing that as long as we're alive. | 4 |
94djni | Physics | if high gears on a manual trasmission are weak , how are they strong enough to further accelerate if used properly? | [Simple machines]( URL_0 ) are mechanical devices that increase the force that you can apply, at the expense of direction, reach, etc. For example, with a lever crowbar, you can lift a very heavy rock 1 inch up in the air, by pressing down with your (weak) hands a foot or two. The transmission in cars does the same thing, converting the high rotation of the engine into the low rotation of the wheels, but with a lot of torque and power applied to the wheels. The transmission is a mechanical device, the gears inside it act like levers. So your engine turns very fast, and all that motion is concentrated into slow turning wheels but with lots of torque / power. Or, your engine turns very fast, and all that engine motion is converted to somewhat-fast but quite weak turning of the wheels. The car can still accelerate because, basically, one person can push a car on a flat level road, it's not that hard. You don't need the 200 horse-power of the engine to accelerate (push) the car. Try to go uphill, though, or try to peel out of an intersection, and you suddenly do need all that power. But if you're at 60 MPH on a flat road and trying to reach 65 MPH over the next minute or so, that doesn't require a lot of torque / power. | 1 |
eo48lu | Technology | Internet Cables on the Ocean Floor All of the world's internet runs in cables on the ocean floor. How is that possible when we know so little about the oceans and when some parts of the ocean are too deep? | May I recommend this magnificent article about undersea cables from Neal Stephenson. Mother Earth, Mother Board: URL_0 I read anything this guy writes. | 5 |
j7bvpr | Other | How does an stenographer/stenography works? I saw some videos and still can't understand, a lady just type like 5 buttons ans a whole phrase comes out on the screen. Also doesnt make sense at all what I see from the stenographer screen, it is like random letters no in the same line. EDIT: Im impressed by how complex and interesting stenography is! Thank you for the replies and also thank you very much for the Awards! :) | I saw a video the other day about this. As others have said, they have a keyboard that looks kind of like a piano. there are 3 sections, with like 10 keys each, and they combine to form difefent base letters. Those letters are then decoded into the actual word. The person giving the example was a student but was about 85% (or better) proficient. said that they are still around because they are actually better at recording than audio recording. If there's a cough/sneeze it could muffle whoever is talking, but the stenographer would be able to hear and correctly reply. Plus they have near instant readback, compared to other recording types. | 22 |
kd2num | Other | Why do people wear a suit and tie when trying to look professional or nice? | Because every society and culture has its idea of what is formal wear. Suit and tie is the European tradition, other cultures have their own. Idea of what is formal wear. Suit,vest, shirt, tie evolved out of a practical need to wear several layers of clothing for half the year in a lot of northern Europe. | 3 |
jlceol | Biology | Why do toenails grow so much slower then fingernails? | Biologically they are the same (i.e. it's not in their DNA or structure), but you're correct that finger nails grow on average about twice as fast as toe nails. Studies show that nails grow faster the more they are stressed. Your fingernails generally undergo more stress than your toenails. | 2 |
i40rfh | Other | What do people without eyes see? | So I'm fully sighted, but I would think the answer to your question is really dependent on if the person was blind from birth, or if they became blind later in life. What you're trying to do is fill in the lack of sight with something that you know and are comfortable with: the black when you close your eyes. But I expect it's completely different for the person who never had sight to begin with, since their brain was just never exposed to that kind of information. They wouldn't necessarily perceive it as a lack or absence, because it was never there to begin with. Just like we don't feel weird that we can't see ultraviolet light. We could never see it in the first place, so our brain doesn't know how to tell us we don't know how to see it, does that make sense? On the other hand, for somebody who went blind grandually, or had a traumatic incident resulting in permanent and total vision loss, I expect it's a different story since their brain did know what to do and now recognizes that loss. Whether they perceive that sensation of black like when you close your eyes or not I don't know, but it's probably going to be a much more noticable thing to them. | 2 |
b0nsbo | Technology | You know those glass windows that can blur at the press of a button? How do those work? | Since we're on the subject, what are they called and can I get some? How expensive would it be? | 7 |
i39y7u | Physics | How can we measure something as far back as the events immediately after Big Bang within seconds to minutes? After seeing the first few minutes of [Veritasium's]( URL_0 ) video on how half of the baryonic matter was yet unobserved until recently, he mentions how the ratio of deuterium and helium and other elements were all formed within the first 20-ish minutes after the big bang but also how with around 10 seconds the universe had cooled significantly. How is that sort of timescale measured accurately when the big bang happened so long ago, especially when even some modern history events cant be traced down to hapening within an exact year sometimes? | Those things he talked about in that video weren't actually measured, they are calculated based on our understanding of physics and our best measurements of the basic characteristics of the universe. In the case of saying when deuterium and helium formed, we know that those elements can't form above a certain temperature, because we can measure in our particle colliders at what temperature those elements break apart into free neutrons and protons. Knowing the rate at which the universe is expanding, and knowing the temperature of the cosmic microwave background radiation, we can calculate how hot the universe was at different times in the process of the Big Bang, so we can calculate about when the temperature was low enough that protons and neutrons could stick together to form deuterium and helium. The reason why the time frame is so short (a mere 20 minutes after the actual "bang"), is that the temperature at which protons and neutrons can start to stick together is really, really high. Put another way, it takes a huge amount of energy to pull them apart. The universe was cooling as it expanding, and it very quickly reached a point where there was not enough energy to keep from sticking together. As for why we can make statements about the first few seconds of the universe's life when we can't say for certain how a modern historical event occurred: the model of the Big Bang is based on some pretty well understood physics, and while there was a lot of matter and energy involved, the important factors really boil down to just a couple of things: mainly the density of matter and energy at any given time. For an historical event, you're dealing with less matter, but the important factors are many times more complicated. You can't predict how a human being will behave in every situation. If you boil off all that human's atoms into a gas and keep that gas in a bottle, a physicist can pretty well predict how that gas will behave as you change its temperature and the volume of the bottle. That's essentially the situation we're dealing with here. That said, cosmology is still a developing science. It's based on our best understanding of how physics works and our best measurements of the basic characteristics of the universe. That said, the fundamental laws of physics aren't completely understood yet, and the gaps in our knowledge become more important in the first fraction of a second. Also, new observations may end up invalidating or tweaking certain aspects of the story that video told. | 2 |
bdvz0b | Economics | How can people in a country with fertile land like Venezuela be having a food crisis? | Edit: Seems like u/lithuim answered your question more directly, I stupidly forgot to read your whole question and only answered the title... I'm not an expert, but as far as my understanding goes it's that no country is currently well enough off to be self-sustainable. So when countries like the US put sanctions (a stop on what Venezuela can export and import, which is how countries in today's society make money), they have to try and stand on their own feet. Which is virtually impossible, given their history of bad infrastructure (lack of system that people can consistently follow to make the cogs turn) and conflict of interest. At least not when the population is split in their opinion on how the country should be run (meaning resources needed for security), outside forces want to influence how the country should turn out (meaning resources needed for military) and a lot of people are acting out of self interest/desperation (hoarding of wealth instead of equal distribution). | 8 |
8cjbep | Repost | Where does fat mass go and muscle mass come from? I’ve lost 75 pounds over the past year and I’m wondering where all the fat mass has gone and all the muscle mass came from | Food, water, and breath go in, pee, sweat, poop and breath go out. What used to be fat mostly left as breath and pee, but you can't track it in detail. | 3 |
6up393 | Physics | Why does everything sometimes look yellow outside after a thunderstorm? We experienced this in Philadelphia yesterday after a severe thunderstorm rolled through. The pictures I took all look like they just have a sepia filter on them, but in reality the only word that could describe it was yellow. In fact it was a little bit disorienting. URL_0 | saw the title, and immediately knew you were talking about philly. that was definitily uniquely weird. | 4 |
8hpq1i | Other | The Iran nuclear deal and why it's so controversial. | Iran as a nation had a TON of money frozen in bank accounts due to sanctions that had been levied against them by other nations. The deal was "we'll release this money if you prove to us you are not gonna make nuclear bombs to attack other people with". This got made into a complicated agreement with all kinds of terms and went into effect. Controversial: Iran is considered a state sponsor of terrorism against other countries. Iran is considered to be a sworn enemy of Israel and dedicated to removing Israel. Some consider it is not any nation's place to say if Iran can or cannot join the ranks of nuclear powers in this world. Some consider Iran to have a bad track record of keeping their promises. Some say that Iran is falsely maligned on all of the above more or less. There are all kinds of opposing opinions on this, thus the controversy. | 1 |
814v3h | Other | . In the big picture what will raising the age to buy a gun from 18 to 21 really accomplish? | To be perfectly honest, young people are dumb, impulsive & have a poor understanding of the consequences of their actions. The general principle behind gun control is to make it harder for impulsive people to get their hands on guns - if something is illegal to purchase and now costs 3x what it did when it was legal, you're less likely to buy it for stupid shit. | 2 |
91iik1 | Other | How come your brain can recognise things when shown but can't come up with it by itself. For example listening to a song you might not be able to think of the title while listening to it but when you read it you know that you knew the title. How does this work? | When something’s shown to you, there’s a stimulus that your neurons and brain can fire off of, sort of like a launching pad. When you’re trying to recall something out of thin air, there’s no launching pad, no foothold, for your brain and neurons to go off. Without that assist, it’s much harder to come up with things. | 1 |
9dtuxb | Biology | Why do humans crack their finger knuckles before they're about to do something? | I would suggest that you ask some of these humans. You may gain a variety of answers or just one. Either way you could advance science. | 6 |
63lw0n | Physics | What was the universe before the Big Bang? | Simply put; either it was, or it wasn't. It's quite possible we'll never know which one is the truth. All we know is that, at a point in time around 13.8 billion years ago, the universe was very tightly packed together. We can't really figure out precisely what it would have been in the few instants in time immediately before this point, mainly because the math and physics that describe that version of our Universe is not entirely known, and the bits we think we've figured out are *weird*. It's at least conceivable that there *wasn't* a "before," and that space and time didn't exist prior to the start of the Big Bang. | 2 |
l7ckr5 | Economics | Stock Market Megathread There's a lot going on in the stock market this week and both ELI5 and Reddit in general are inundated with questions about it. This is an opportunity to ask for explanations for concepts related to the stock market. All other questions related to the stock market will be removed and users directed here. How does buying and selling stocks work? What is short selling? What is a short squeeze? What is stock manipulation? [What is a hedge fund?]( URL_0 ) What other questions about the stock market do you have? In this thread, top-level comments (direct replies to this topic) are allowed to be questions related to these topics as well as explanations. Remember to follow all other rules, and discussions unrelated to these topics will be removed. **Please refrain as much as possible from speculating on recent and current events.** By all means, talk about what has happened, but this is not the place to talk about what will happen next, speculate about whether stocks will rise or fall, whether someone broke any particular law, and what the legal ramifications will be. Explanations should be restricted to an objective look at the mechanics behind the stock market. EDIT: It should go without saying (but we'll say it anyway) that any trading you do in stocks is at your own risk. **ELI5 is not the appropriate place to ask for or provide advice on stock buy, selling, or trading.** | What is preventing gamespot from issuing more stocks? Why can’t they issue more stocks and make money off this chaos? | 489 |
i1od03 | Chemistry | whay my wife keeps telling me Do Not put glass instruments with hot liquid inside the refrigerator? Not necessarily Hermetically closed | While I can't tell you the exact reason your \*wife\* tells you this (she could dislike them for a subjective reason for all I know), it is generally a bad idea because a fridge isn't a very powerful heat pump. It doesn't move heat from the inside of the fridge to the outside very fast, because it relies on the door being closed most of the time, and for the appliance to be well insulated. If you introduce a very hot item to the fridge, it could end up raising the average internal temperature of the fridge from, say, 5 celsius to 10 celsius for over half an hour, even more for items close to the thing you just put in. This doubling of temperature will more than double bacterial activity in the food inside the fridge, possibly cutting a significant amount of shelf life off of whatever's in the fridge. It also uses more energy because it needs to move the excess heat out. If you can, you should put very warm things outside of your house to cool down before refridgerating it, just make sure to seal it so animals or insects can't get in. This assumes that you don't live in an area where the outdoors are hotter than your food, of course. | 5 |
dyxe1u | Biology | Why does hunger come and go in "waves", even if you don't eat anything? | The hunger you feel then isn’t actual hunger. We have a lot of bacteria in our digestive system that is use to regular intake at the same times each day, and are sending message about the lack thereof. It is our innate messaging system, it’s like needing a cigarette when you smoke, even though it’s bad for you. It’s all hormones, chemicals and bacteria. If you follow a intermittent fasting diet, this internal clock will change and ring the bell at the new times you set for intake of food. Same if you want to stop smoking, start ignoring the craving you get, and after a while it will fizz out. Actual hunger feels different, pain in you mouth is one of the symptoms. Our bodies work better on empty stomachs, it takes a lot of energy to digest food, and as most people food habits are several times a day, you never get to feel the full force of your own energy. Just think about all the energy packed in fat storage. For this interested in fasting/intermittent fasting, google autophagy :) | 11 |
8povos | Biology | Why do babies/toddlers scream and cry for a long time when they are tired instead of just going the eff to sleep? | As the parent of a one-year-old, and somebody who has never asked why, I have a theory that just popped into my head. When babies cry, our usual reaction is to comfort them. When they’re overtired, they’re also uncomfortable, so maybe it’s a way for them to ask to be comforted to sleep, in the only language they know how to speak. | 30 |
akfmg6 | Chemistry | What changes happen to any foods that it is generally considered not fresh once frozen? | When you freeze things the ice Crystals in the food cut open the cells when it thaws the texture is mush | 1 |
i8rzf8 | Other | Why are modern wars involving USA not fought on USA soil? (1900-2020) | We are surrounded by oceans and allies. How would a ground force get to us? | 5 |
5n4tul | Culture | Why are the French famous for surrendering? | Because they surrendered in WWII, mostly. Made everyone bail their asses out. Also English speakers generally don't like the French because the French don't like anyone. So on top of them being entitled surrender monkeys they also have a stereotype of being assholes. To be fair I'm an American so my stereotype is "being fake nice" which in my opinion is worse than being an outright jerk. This is only compounded by the fact I'm a Southerner- which means I am both racist and compulsively friendly and welcoming. | 36 |
6z9jq8 | Repost | Why does coming back from somewhere always seem shorter than the trip there? | I heard an explanation for this a while ago, I'll try to do it justice but I don't know all the scientific terms behind it So when you're going somewhere brand new your brain is taking in all the details, and forming your picture of the area. It seems longer because your brain is working harder to perceive everything about it. On the way back through it you already have those details, so your brain is recalling them as opposed to forming the memories, which uses less power, and feels like it takes less time | 1 |
edg7d6 | Economics | When economy of a country goes down, why can't they just print the currency notes and boost the economy? | The more money you print, the less valuable the money becomes. If there's only $100 in the whole economy, each cent becomes worth a lot more. But once you have $1,000,000,000,000, a penny becomes basically worthless. | 3 |
63dtl0 | Culture | What's so great about the Mona Lisa? | Or you could add that this portrait masterfully employed, amongst many other techniques, a technique known as 'sfumato' which essentially means blending and tricks the eye so you cannot perceive where one carefully layered detail ends and another begins, like how smoky eyeshadow can create visually pleasing and strangely captivating eye-candy. The big idea here is that the painting masterfully incorporates and utilizes numerous effects and styles and is representative of pretty much everything a good portrait painting of that period can or should possess. URL_0 | 33 |
is7ik3 | Other | What is the "Just-World Hypothesis"? How is this idea a bad thing? | In addition to what others have said, it's bad because it leads people to blame victims. The rape victim must've dressed slutty, the poor person must be lazy, the person shot by police must have been a criminal. It's an excuse to never try to improve the world, because if bad things only happen to bad people, then it's ok for bad things to happen. | 3 |
m0e71g | Technology | What is the difference between digital and analog audio? | I guess you mean analog and digital recording of audio. Sound is vibration of air (or any medium it travels through). Its properties are frequency (how many oscilations it makes in a second, i.e. how high the tone is) and amplitude (how 'big' are those oscilations, i.e. how loud it is). So, how to record that? In essence, there are three ways: vinyl records, magnetic tapes and digital. Vinyl is the simplest one. Imagine a big membrane that is in the way of those vibration. From the air, the vibrating transfers to the membrane. Now connect a sharp needle to it so it vibrates too. And while vibrating, that needle leaves the marks on a rotating dics. Then you can go reverse and the needle follows the grooves on the record, vibrate, transfer vibrations to the membrane and then to the air so we hear the recorded sound. Sure, this is oversimplified but it shows the important part. Tapes work similarly, but the membrane is not connected to a needle but to an electromagnet. Magnets and elecrticity have a love relationship. When a magnet moves near the wire coil it creates electricity in in. And vice versa, if there is electricity in a coil, the magnet will move. So, as the magnet vibrates it creates a small amount of electric current that magnetizes the small particles of iron oxide on a moving tape. What was a wiggly scratch on a vinyl is now a series of variating little magnets of different strengths. You play the tape by reverting the process: tiny magnets on tape create the electricity in the electromagnet in the tape-player head, which moves the magnet connected to the membrane which creates the sound. Both these systems transfer physical properties of sound into some other physical properties - depth and width of scratch mark on the vinyl or strength of magnets on tape. Now the digital recording... which also goes from the membrane and into electromagnet to transform the vibration into electric current but then that current get measured and stored as a number. As the sound is vibration that changes many times a second (it goes from 16 to 20000 oscilations per second) it has to do quite a lot of these measurements and store a number for each one. For CD it is 44.1 thousand per second, film standard is 48000 and, more often than not, initial recording in profesional environment is 96000 times per second. Difference between this and the previous two ways is that now we don't have one physical property transfered into other but into a series of descrete numbers somewhere in memory of the computer. To store them permanently, you can enrave them into silver foil (CDs and DVDs) or use magnetic disks (hard drives). Magnetic disks use the same mechanism as the audio tapes but they don't record the vibrations directly but the numbers created according to those vibrations. So what's the benefit? (edited this paragraph as it was badly formulated) Magnetic tapes and disks are losing a tiny portion of quality with every reading/listening. Here is the important difference. If you copy analog data from the tape, there will be more and more shhhhhh noise introduced in every new generation of a copy as the electricity makes noise. But the copying of a digital recording is immune to that as each new reading and copying gives the same series of numbers as the original even if the recording is faded or partly damaged. That is because even as the magnetic material wears off, reading of the numbers is the same and when you deal with numbers you have safety mechanisms to check if your reading is ok or even to recalculate a part that is missing (see checksums for more info on this). But eventually the hard disk will fail. | 17 |
knjsdp | Mathematics | How do calculators work? like how do calculators, especially cheap dollar store calculators, store a near infinite number of mathematical solutions? what goea in them to allow them to always correctly determine answers. | They don’t store anything but a few numbers. They...calculate using either circuitry or a logic chip, depending on how old they are. | 5 |
6qtvlp | Engineering | My washing machine has 4 sections: Perm Press, Heavy Duty, Knit and Delicate, and Pre-wash. What's the difference? My mother said something about using perm press for everything, except towels and sheets go on heavy duty. Thirty years later, it occurs to me I know nothing about my washing machine. ELI5? | Pre-wash: clothes are washed a little bit before they enter the main program (use this in case they are full of stains). You need detergent in two of the boxes. Knit and delicate: it doesn't spin as fast, and water is not too warm. I don't know the others. But my gut tells me: listen to your mother. | 2 |
lvf8ft | Engineering | What happen to the detached pieces of the rockets in the air? Is there nota possibility for them to fall down and crush on earth causing major damage? | They just crash. Rockets are usually launched over ocean or deserts^[1] to reduce the risk of debris doing damage when falling down. China is a notable exception and there have been instance of rocket parts crashing near or in villages. One exception is the falcon 9 core which tries to come back and land. (F9 fairing also do) *************** [1] the ESA launch from kourou in south America, going east over the Atlantic. The USA does the same from Florida and has a launch site in Vandenberg, CA. which launches going south over the pacific. Russia launches from Plesetsk or Baikonur (Kazakhstan), going north-east over Siberia & the arctic ocean. | 3 |
k9vwbs | Other | Why can't the government just tell you how much you owe in taxes so you can lay that amount? | If you are the average earner it takes an afternoon & if you make a mistake you generally just get a letter saying "we think you made a mistake, you owe X more/less" There are a number of things you are supposed to volunteer in the process that they don't really have good tracking for along with a number of choices you can make with your tax strategy. Generally, once you get to the career level of job and have a family if you are filing all the defaults you are quite possibly not doing the most financially advantageous thing and you are certainly giving up your chance to correct certain bad outcomes. | 12 |
9wzkb2 | Other | Why do schools care so much about the no hat policy? | Mainly has to do w distractions, because a hat inside is not a necessity but rather a desire. The reasoning is stupid to me as students are allowed to wear bracelets, rings, etc which are far more distracting. | 10 |
hqrzgx | Biology | What are the biological mechanisms that causes an introvert to be physically and emotionally drained from extended social interactions? I literally just ended a long telephone conversation and I'm exhausted. Why is that? | Do we even know of mechanisms that allow someone to be “physically and emotionally drained” in the first place? It is possible that introversion is just people using a word to describe people who they perceive as having certain traits, and does not actually map to a single “feature” a person can have. | 10 |
bmthp9 | Other | Why is it ok to ride some animals, but not others? Horses are ok to ride, but elephants are not. Surely elephants are stronger than horses? | Elephants spinal disks aren’t shaped like most other riding animals, they’re sharp and they point upwards so the weight of even a small person can cause irreparable damage. They’re also not domesticated the way horses are so the training they have to undergo to be willing to tolerate people riding them is often incredibly torturous. | 5 |
69j7ue | Technology | a few short years ago 3G Internet used to be amazing. Why is it now barely functional? | The issue of the data we are consuming being a problem is there. Another reason for the perceived slowdown that I have heard of is that in some areas, mobile networks have repurposed the 3G bandwidth and radio frequencies for 4G. | 4 |
6ls4gm | Biology | Before any languages existed, how did that 'voice inside our head' exist? I don't want to sound stupid, but we all think in our head and talk to ourselves sometimes. For example, you might be sitting down and think 'I need to do that now' or 'I need to eat before I forget'. | You're not stupid at all. Humans have quite literally *evolved* to have language. Before language, we didn't have a voice in our head at all. The phenomenon of talking to yourself in your head is called [sub-vocalization]( URL_0 ), and in fact, you're even moving your throat/mouth muscles ever-so-slightly when you do it, as if you were quite literally talking. Human thought is structured as if a speaker is talking to a listener. This is a fascinating area of research for anthropologists, evolutionary biologists, linguists, and philosophers. | 5 |
l7ckr5 | Economics | Stock Market Megathread There's a lot going on in the stock market this week and both ELI5 and Reddit in general are inundated with questions about it. This is an opportunity to ask for explanations for concepts related to the stock market. All other questions related to the stock market will be removed and users directed here. How does buying and selling stocks work? What is short selling? What is a short squeeze? What is stock manipulation? [What is a hedge fund?]( URL_0 ) What other questions about the stock market do you have? In this thread, top-level comments (direct replies to this topic) are allowed to be questions related to these topics as well as explanations. Remember to follow all other rules, and discussions unrelated to these topics will be removed. **Please refrain as much as possible from speculating on recent and current events.** By all means, talk about what has happened, but this is not the place to talk about what will happen next, speculate about whether stocks will rise or fall, whether someone broke any particular law, and what the legal ramifications will be. Explanations should be restricted to an objective look at the mechanics behind the stock market. EDIT: It should go without saying (but we'll say it anyway) that any trading you do in stocks is at your own risk. **ELI5 is not the appropriate place to ask for or provide advice on stock buy, selling, or trading.** | One thing to add to the other explanations: Options are extremely volatile. If you buy aggressive options on the right day, the option may be up 200-500% the next morning. You can also lose 80-90% overnight. This is why options should be bought very carefully. Instead, some of the autists on wallstreetbets put all their money on in options on one stock. To make it even more unstable, institutions and individuals sometimes invest on margin, or borrowed money. This is how these large $13B losses occurred. Normally in a short squeeze (as others have described), once the shorts start to lose serious money, they bail out and sell at a loss. This time, the shorts held their positions and doubled down, risking even more money, betting they could break the back of the Redditors and eliminate their losses. Rather than just take windfall profits, which is what any sane person would do, wallstreetbets poured even more money into GME calls trying to drive the price into the stratosphere. That is what caused the rise from less than $5 up to a max of $360 yesterday. GME opened up at $400 today and lost 50% by the afternoon, but made up most of those losses by close. So it looks like the Redditors are holding the line at this point. It is astonishing to see [these guys]( URL_0 )^(\*) successfully facing down hedge funds. ^(\*The board is private now but you can see the front page here.) | 489 |
69y07x | Economics | How do credit card reward systems work and why do some people get more points/cashback than others? | There are a lot of detailed answers here, but I don't see any good ELI5 near the top so here's my take: Credit card companies charge stores a fee in order to accept credit card payments. Depending on the type of card, they charge more or less. Cards with reward systems usually end up charging the most. The credit card company gives some of that fee back to the customer as a reward - either points, or cash back. This gives customers an incentive to use that card more, which means more of the money that stores pay goes to that credit card company. Of course, merchants raise prices to compensate, so it's not really "free" money - it's just funded by all the people who buy things and *don't* get rewards. People get more cashback/rewards by choosing to use cards that offer the best rates. Some cards give you better rates on certain categories, like gas or groceries. If you always make sure to use the right card on the right type of thing, you can maximize the reward. Another trick people sometimes use is to buy things like gift cards at grocery stores. Say you want to get something from amazon that costs $100, and your credit card gives you 6% for groceries and 3% for everything else. You could just use the card directly on amazon and get $3 back, or you could buy the card at a grocery store and get $6 back, then use it on amazon to make your purchase. Credit card companies are aware of this tactic, so they often have limits on the amount of purchases you can get rewards for in categories like that. | 12 |
8y00yr | Culture | Why is the red/black, positive/negative paradigm in math and finance have opposite meanings in the electrical world? My assumption is that the colors are arbitrary, so if red/black already had an established meaning in one sector, why didn't the other sector just follow suit? Or are the colors not arbitrary, and it's just an unfortunate coincidence that the results are opposite in meaning? | Besides positive/negative, red can also mean “hot”, or “danger”. In many common electrical circuits, negative is ground or neutral while positive is a different (potentially dangerous) voltage. Other electrical standards fit this philosophy too. While negative voltage often equaled neutral/ground, this isn’t always true. Newer/safer equipment uses *green* for ground... green suggests “good” or “safe” but is independent from positive/negative. So this works even when the old rules of thumb (negative = safe) don’t hold up. | 2 |
fcsmlj | Biology | What causes ne to seemingly "hear" voices or sounds that aren't actually there in total silence? | ok being "fairly certain" is NOT a diagnosis. You need to speak to a medical professional as this indicates a neurological issue. these might not be scizophrenic episodes but could indicate any number of issues that need to be dealt with. | 4 |
i5j2mr | Technology | How is glass an isolator but fibreglass is used for e.g. fast internet? This question popped up while reading this physics article which mentioned that glass is an isolator. Please correct me if my way of thinking is wrong! Admittedly I have super basic understanding of physics and no understanding of how internet access/networks work... looking forward to your responses! | Fiber-optic internet doesn't use electricity, it uses light. A thin glass fiber will keep a beam of light within itself over long distances, and the signal travels at the speed of light. So electric data is turned into flashes of light at one end, transmitted, and re-translated into an electronic signal at the other end. | 3 |
6rsljq | Biology | What is it that brings out a goat's drive for being on top of things and parkour in general? | They're natural, sure-footed climbers. They are driven to get up on rocks and in precarious places like that because it's a defensive position: they know that many of the predators that would like to eat them can't follow, or keep up. It's a safe place to be if you're a goat. | 1 |
dyxe1u | Biology | Why does hunger come and go in "waves", even if you don't eat anything? | For intermittent fasting, the reason hunger comes in waves has to do with how your body changes it’s energy source for metabolism. First, the body breaks down sugars (glucose) for energy in the first wave of metabolism. The brain has the highest demand for, and is optimized for sugar (because of how quickly sugar can be converted to energy) as its main energy source. So, once your sugar levels run low, your body begins to switch to fat burning. The second stage of metabolism is called “ketosis” because of the fat molecules being converted into ketone bodies as an energy source. The third stage is protein breakdown. So, during the transition between stage 1 and 2 metabolism, the brain sends “hunger” signals throughout the body, which causes the stomach to growl. The brain runs more efficiently on sugar than is does on fat, so that is why the brain sends this signal. Once, the transition from stage 1 to 2 is complete and the brain is able to convert the ketone bodies into energy, the “hunger” signals start to die down for a while. Which, is likely long enough to not bother you until your next meal. But just remember, eventually your brain will take over and win that hunger battle because it really wants to run on sugar. | 11 |
e4c9ib | Technology | - What exactly is the "exposure" in photography? Like, for instance, I've seen photos of the night sky with crazy details of the stars and they say that this picture was taken with "12 hours exposure". What does that mean exactly and what does it do? | “Exposure” in photography is a combination of three things: 1) the size of the hole through which the light is being gathered (“aperture”), 2) the sensitivity of the film or electronic sensor (“sensitivity” or “ISO”), and 3) the time that the sensor is exposed to the light (“exposure time” or “shutter speed”). The combination that’s right for a given set of circumstances will depend on various things, such as the amount of light that’s coming off the thing you want to photograph, the amount it’s moving with respect to the camera, and the required distances that need to be in focus. For most everyday photography in daylight, a normal shutter speed (exposure time) would be around 1/30 to 1/500 of a second. Photographing stars would require a much longer exposure time because they’re much dimmer than a normal daytime scene. An exposure time for stars using a normal camera would often be several minutes. Any reasonably advanced camera would support this kind of long exposure, but it would normally require a special setting on the camera. Such a long exposure will require the camera to be locked down on a tripod or similar. (For a sharp picture, the camera has to be still during the exposure and nobody can hold a camera still enough for such a long time.) Because the stars are moving in relation to the camera (the stars are still but the camera is fixed to the Earth and the Earth is rotating under the stars) the stars will often appear to move during the exposure and the resulting image will show the stars as lines (in a “star trail” picture). An exposure time of a few minutes is enough for the stars to move enough to start forming these lines. To have a long exposure of several minutes (edit to add: or hours, as in your example) but still keep the stars as fixed points rather than star trails, the camera can be mounted on a special device that very slowly moves the camera to compensate for the Earth’s rotation and keeps the stars stationary in the view the camera is pointing at. | 3 |
9p8bsk | Biology | Would it take an obese person the same amount of time to die of starvation as a skinny person? | No. There is at least one case study of an obese person living for iirc 10 months on nothing but water and vitamin pills, with no adverse effects. In fact his health improved significantly on account of losing around a hundred kg. Meanwhile very skinny persons will die within weeks if not eating. | 2 |
8e7lxv | Engineering | Is there an upper limit to how tall a building can be? Assume a 50,000 square feet cuboid building on a plain, firm land, in a landlocked area and not on any major earthquake prone areas. How tall can it be theoretically? | The limit is based on the weight the construction can carry. If the construction cannot carry that amount anymore, then it will crush under its own weight. For example, the World Trade Centre towers, you might have heard a little bit about it. They were 400 meters high. The metal and concrete construction were properly specced to hold its heights for the first 35 years: Nothing wrong with it. Now due to an external incident, the metal construction is affected and lost its strength. It then collapsed under the weight of the construction on top of it and it folded nicely on top of itself. The space elevator principle is based on a string of 36 thousand kilometers. Currently there is no material which can carry that weight without breaking. | 2 |
jnv2cb | Technology | why older cars need long extendable antennas for radio reception, while modern cars often only have little stumps on the top but still good reception title | Sorry for my English. I ll try to be as short as possibile since it's in this subreddit. I think you are referring to fm am frequency, The answer is, it's a compromise for aethetic and more import cause GPS satellite antenna need to be protected. So ideally the antenna must be the same of the wavelenght but since you can't have 3 meter antenna even the 1/10 fraction can work. And now you also need antenna for GPS plus sometimes more satellite type. So we can do 2 things. We can use the back window of the car and hide a longer antenna around the borders that actually work better and stick the GPS in the little fin on top, or we can stick even the fm antenna inside the fin, bend it a lot and stick a rear inductant coil to try to gain more power, and be almost as good. In most case both solution are good enough. But again ideally even today, if you want to receive fm and am, best solution would be an antenna around 3 meters or ten foot on top of your car. Hope I was clear enough. Bye | 3 |
5lfw4b | Repost | What is the emotional 'awwww' feeling we get when we see cute things? Why does it happen? | It's a vestigial hunting instinct. Notice that it's almost always accompanied by a desire to squeeze the thing as hard as you can. | 10 |
9iqxn1 | Biology | Why do humans respond to rhythm/music? | As my username suggests, I'm not the best at what I do. But I'll try! The reality is we aren't entirely sure why music provokes such responses from humans (we more or less know the biological reason, but not the deeper reason behind that). When you look at every single culture in the world, one thing that eventually develops is a form of music within that culture. They may not label it or think of it as music themselves, but pretty much every culture eventually creates its own music. So clearly music appears to be a significant part of human culture, no matter where. On top of that. rhythm and music also trigger certain processes in the brain ranging from improving memory and attention to lifting emotional moods. We know this happens, but aren't sure yet if this is the result of social/cultural associations or if it is "hard-wired" into our brain as humans. So there isn't really a definitive answer to your question - but it's a good one, and extremely interesting as well! No doubt there are studies being done towards figuring this out as we speak. | 3 |
k29ha3 | Technology | What the hell is ping in gaming? I keep looking up the definition and I still don’t get it. So what is it? | Ping is a pretty old concept: you send a package to another computer, and wait for an answer. And then you time it, so that you know how long you have to wait for an answer. The number tells you about the network and server response times: If you press a button, and actually do something in a game, the ping time is the time you will have to wait, at least, to get a response back from the server that properly reflects what you just did. Perhaps not particular important when you play by yourself, but when you play with others, it will give you a number on if the information you see on the screen is actually accurate. How old that information is. How efficiently you can react to that information. If it's even worth the trouble to react, or if the information is already so inaccurate that a reaction is fruitless. | 1 |
6y95ug | Technology | Why did TVs skip 2560x1440 and went straight for 4k? | Most of the content shown on TVs is delivered by cable companies. Cable companies only broadcast a handful of video standards so most content created for TV networks uses one of those standards. It takes a *long time* to retool those systems for a new standard. Switching from SD to HD720 and then HD1080 took many many years. So for that reason TV makers are only going to consider upgrades that make a noticeable impact. And evens till when sitting at the typical distance one views a TV from, the difference between 1080p and 4K isn't very noticeable. | 3 |
i0iife | Physics | how exactly do tides work, why are there two a day, what determines the size of the tide? I understand the absolute basics but that’s about it. | The answer is a little complicated. In short, the Earth and moon and sun rotate on the same plane. The earth rotates the same direction as the moon. However there is a 50 min difference, so the gravitational pull causes multiple low and high tides. Or what you would say is twice daily. | 4 |
6hcimx | Biology | How do different meats get their distinct taste and texture? You can usually tell chicken from pork, beef, etc. What causes different meats to be so different from one another? | Why they have different tastes: Different animals are straight made of different stuff. Carrots and parsnips look pretty similar (at least to the same degree as different meats), cook very similarly, but don't quite taste the same. They have extremely similar structure, but a different chemical composition, which causes a different taste/smell. In the same way that the olfactory nerves in your nose react chemicals and send signals to your brain representative of different smells, the gustatory nerves in your tastebuds react to chemicals and send signals representative of different flavors. Because different animals eat different things, produce different hormones, and process food differently, they are made up of different chemicals, which can even result in different tastes in the same species (grain-fed vs. free-range). Why they have different textures: Cows, pigs, chickens, elk, rabbits, etc. are all different sizes and shapes, and they all move differently. This causes them all to have differently shaped and toned muscles, and different fat density. These differences are evident in the cooked meats texture. In addition, different cuts of mess can have different tastes and textures. For example, pork belly and pig heart are very different, even though they come from the same animal. Furthermore, cooking processes can throw everything out the window, especially in the taste department. Even just burning a different type of wood can result in a vastly different flavor, and cooking a steak five minutes longer can give it a much tougher texture. | 1 |
776a9u | Economics | How were banks able to transfer large sums of money before the internet? | This is one of the things that the Federal Reserve system was made for. To make a large transfer, one bank will deposit money into the other bank's account at the closest Federal Reserve bank. The other bank then has access to that money by withdrawing it from their Fed account. (It doesn't have to be the Fed, smaller banks used bigger banks much the same way people use small banks. This was especially the case leading up to the Great Depression since banks were limited to having just one branch. So small banks would have accounts in large New York banks and would transfer funds to each other through those accounts. They could sent a telegraph to the bank telling it to transfer X dollars from their account to another bank's account.) This is similar to how checks work: When you deposit the check into your bank, that bank processes the check and sends the transaction to the Federal Reserve, who sends the transaction to the bank that the check was written from. That bank then transfers the money out of the writer's account, sends it to your bank's account in the Fed, and your bank then puts the money into your account. Cool fact: The system works the same way as it did a century ago. It's much more automated and much faster, but it's still the same flow of transactions. | 2 |
dkk8iv | Other | Why do all vitamin supplements say that their claimed benefits aren't verified. Do we really not have any confirmation of what vitamins do? | URL_0 I love this guy! He actually does shows if he was proven wrong. | 14 |
ieptva | Biology | how we don't usually roll off our beds in our sleep, and if this were a deliberate feature, whether it would stop us rolling off cliffs in our sleep? | [When in deep sleep our brains tell our bodies not to move.]( URL_0 ) | 2 |
fi8yqz | Biology | Why did historical diseases like the black death stop? Like, we didn't come up with a cure or anything, why didn't it just keep killing | According to my wife (PhD in molecular biology, wrote her dissertation on tuberculosis) the primary cause is toilets. When started installing technology that saved us from having to throw buckets of human waste into the streets regularly our levels of disease dropped faster than at any time in history. | 25 |
neqrra | Biology | If we store more fat after fasting, then is that why we eat vegetables? I heard that if you don't eat for a week, and then if you start to eat, your body will store more fat because it thinks that food is getting scarce, therefore fasting is not a reliable way of losing weight. But if we eat Dietary Fiber vegetables (food that we cannot fully process) instead of literally starving ourselves, then does the body say "oh look, the stomach is full, therefore no need for storing fat" ? Does this mean that if i make my diet 70% vegetables and 30% soup, will i start to lose weight? | The human diet is still poorly understood and even nutrition is a very complex topic. We store calories in excess of those we need to function as fat. We can then convert the day back into sugar when our calorie intake is less than needed for our daily activities. When we run a significant calorie deficit for an extended period of time out body will consume our fat, and muscle to keep calories for our brain. The variety of foods you eat is important to avoid malnutrition but it doesn't matter if it was meat or vegetables, if you are at starvation level intake your body response will be the same. The mixture of vegetables and meat is not what is critical is the calorie content. There high calorie vegtables avocado is high in fat and thus high in calories. | 4 |
o1itns | Technology | Why does speeding up recordings make them higher pitched? | Sound is a frequency of waves in the air. The closer together those waves are, the higher the pitch. When you speed up a recording of someone/something then those waves are moved closer together. If you slow down a recording those waves spread out and lower the pitch | 1 |
keu7nm | Biology | why do beer guts on guys (I’ve never seen them on women or haven’t been able to tell) look like a pregnant belly (raised with a definite shape) whereas you can tell the larger stomachs caused from bad diets flatten out and have rolls? | I have seen beer guts on women many times including some family members. I think it's more noticeable on men because men typically do not deposit fat on their buttocks and thighs. so you have fat on the stomach, but none below. this gives a more obvious contrast. Also visceral fat tends to push the belly out but the stomach muscles are still there like rubber bands holding it in. In other words it's less likely to droop over the belt line, but this gives the impression that it's a bigger belly than it really is. For example i have an uncle who looks pretty skinny actually but his belly sticks out so far you would think he's in liver failure. | 10 |
iy4gid | Other | What happened after WWII that changed the widespread racism and bigotry in Germany? Like I can't imagine all the racist, supremacist German citizenry that enthusiastically supported Hitler just decided to stop hating Jews and gypsies and etc after the war. How did Germans go from literal Nazis to probably the most anti-Nazi people on the planet? | Reeducation programs basically. First it was a slow process, it took decades. The allies tried to get rid of Nazis in schools and administration, but it was impossible because everyone of status and education either joined the party or was ruined, so in the 50s and 60s a lot of teachers were still old nazis (my parents still met them) Nazi propaganda was banned, and the old nazis had to hide their beliefs, so they couldn't object when the truth was made public. A lot of germans didn't know about concentration camps, and when they first found out the reaction was "if Hitler would have known he would've prevented this". Around the 70s we finally started dealing with the whole truth of the past, and the "we don't talk about anything before 45" slowly lifted. And yeah then the new generations got taught what went wrong, what crimes the nazis did, and how they used hate and racism to justify these crimes. Now history lessons focuses around 50% on the third reich, how it came to be and why we can't ever let it happen again. (As an example my middle school history class included talking to eye witnesses who told us about the horrors of war and hunger first hand) Some habits die hard though. My grandparent generation was indoctrinated in the Hitler Youth, so they still believe some of the things they got hammered into their head back then. Just as an example one of them is a really nice guy who respects everyone, but still believes jews control the world secretly. | 4 |
5w2g85 | Technology | How does Planet Earth get all these insane angles and right next to animals without disturbing their natural choices? | If you got DVD at the end of each episode they show how they filmed some parts. It includes, helicopter(drones later) shots, hidden cameras, motion activated cameras(for snow leopards), people hiding for few days in small spaces filming through hole. | 8 |
mpczk7 | Biology | What causes that lump in your throat feeling before you're about to cry? | Stimulation of the [vagus nerve]( URL_0 ) causes that feeling. The vagus nerve is a fascinating link between the brain and body. | 5 |
jvaf3y | Biology | where does eyelashes trapped in your eyes go? | They get covered in eye discharge, called rheum and get shifted to the corner of your eye. From there they come out in the form of crust also called the eye mud. This rheum is pretty much like the mucus of your nose, which you may call snot. All day, dust particles go into your nose, where do you think they go? They get trapped in the nasal discharge and then become a part of phlegm. | 1 |
a4wr1w | Other | At Gas Stations, how does the lever on the gas dispenser know when to cut off the gas flow when the tank gets close to being full? | The nozzle has a hole to suck up the vapors. These vapors are sucked up and blown into the underground tank (and the truck that delivers fuel actually sucks the vapors out, and they eventually get burned at the distribution place, they suck the vapors out of the empty truck when refilling it). Anyways, since the pump is always sucking in vapors, it's fairly easy and it doesn't require much of a vacuum. When the tank is full bubbles and liquid gasoline goes into the vapor line the pressure drops (it's more difficult to pull liquid up). This low pressure causes the switch inside the handle to activate (vacuum actuated switch), and that turns off the gas. | 1 |
npx1fr | Physics | Hawking radiation So I need to do a presentation about Stephen Hawking tomorrow. I have his life pretty much down but since its for physics I also will need to explain a bit of Hawking radiation. If anyone could help that would be great. | According to Quantum-Field-Theory the vacuum is filled with random creations of particle and antiparticle pairs that immediately destroy each other again so we don't notice them. But near a black hole the gravity gradient is so steep that one particle can get absorbed while the other gets away. Simply by conservation of energy the black hole has to lose some mass for the particle that was just created and doesn't have a partner to annihilate with. So these particles fly away from the black hole taking some of it's mass with it. That is the hawking radiation. | 2 |
kzpp2r | Other | Why does our voice sound so different when hearing it from a recording? | When you're listening to your own voice the sound is coming primarily through your skull rather than the air, which tends to make it sound deeper than it actually is. Obviously when you're listening to a recording you're hearing it transmitted through the air, as other people would. | 2 |
8mhf44 | Biology | - why do people pick at scabs, fits, pimples, etc? We know it's bad and it hurts, but we still do it. | Because sometimes it works out. Some pimples really do just go away or at least look less horrid when they pop, and some scabs are ready to come off, and humans like to believe the best possible outcome will happen when they try to do something. Even though this isn't skill-based, we don't want to believe we'll "screw it up" by picking at it. | 3 |
d9a6i3 | Other | Why do gas stations knowingly have a higher price than the gas station across the street when they won't bring any customers in since everyone would rather go across the street for cheaper gas? | Because price isn't the only factor that decides where people buy. There is brand loyalty, (perceived or actual) higher quality in some brands vs others, rewards benefits (fuel cards or fuel points systems), wait time, and likely other factors as well. For myself, I drive Uber and Lyft full time and so fuel price is the only factor I care about and I will drive around 10 minutes away if I stand to save 10 cents a gallon, but when I wasn't driving as much, I would just go wherever was most convenient and would be quickest to get through regardless of the price. If you drive the "average" for an American each year, about 12,000 miles, and you have a vehicle that gets 30 mpg average, then that's 400 gallons of fuel per year. If you go out of your way to save an extra 3 cents per gallon, then you are only saving 12 dollars for the whole year. Even if you were to save 10 cents per gallon, then it's still only 40 dollars per year, it just doesn't add up to enough to justify making your choice based on price for most Americans. | 3 |
m1yn2x | Biology | When you get a shot in the arm, how can you be sure the contents are being released into a blood vessel? When you donate blood the needle goes into a large, visible vein in your arm or hand but when getting a shot the needle just goes somewhere in your arm. | OH YOU'RE TALKING ABOUT **INJECTIONS.** ~~Well when you get shot in the arm, the bullet can fragment into little tiny pieces but since your blood vessels will be damaged, it's highly unlikely the fragments can travel through them.~~ | 19 |