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l1zi4e
|
about calories, Kcal, and energy
|
So I was reading this page [this page]( URL_1 ) and it says > For example, a 55-year-old woman weighing 130 lb (59 kg) and 5 feet 6 inches (168 cm) tall would have a BMR of 1272 kcal per day. As I understand this, this is the amount of energy the woman would need just to stay alive for an entire day. Now the thing that is confusing to me is, a calorie is defined as (going by [this page]( URL_0 )) > the amount of heat energy needed to raise the temperature of one *gram* of water by one degree Celsius That would mean for example, a 500KCal chocolate bar contains enough energy to increase the temperature of 1KG (aka 1L) of water by 500C. How can that be!? That sound insane honestly. Does that mean I, as a human need 2200kcal, (that is enough energy to increase the temperature of 1Kg of water by 2200C) every single day, just to survive!? Does that mean that I need 9204800J of energy every day (since a calorie is 4.184J)? That would mean I consume 9204800J / (3600s \* 24) = 106.53W of energy EVERY SECOND. I'm sorry but this is just difficult to understand. My CPU is 5W Edit: wow this is just amazing, I never realised our bodies needed this much power.
|
Physics
|
explainlikeimfive
|
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"Yes, that is what it means. Your body uses a lot of energy, not much more to understand. Think about it in terms of heat, maybe, since all that energy eventually becomes heat that you put out. A small space heater uses ~1500 Watts. So a room with 15 people in it warms up as much as a room with a little space heater. Sounds right, no?",
"The thing is, a body using 100w per second to function isn’t that much when you compare it to your cpu using 5w. The cpu is only switching transistors on and off at the nanometer level. Where as a human body is using energy for a lot of things, cell repair/replacement, heart pumping blood, stomach digesting, brain working and so on. I suppose it is hard to understand sometimes how food can have that much energy. The answer very basically is, our bodies are very good at extracting and converting our food into energy.",
"I think you are just shocked about how much energy the body needs and uses. It takes A LOT to be alive. Edit: forgot to add that yes your body is that much energy. You have the right idea and everything",
"There are so many activities going on in your body that 106.53 J s^-1 would be very efficient. The clue to your story is that staying alive requires a lot of energy. So you’re right, you’re just underestimating how many cels there are in your body that need to produce energy."
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l1zo93
|
Why is a warm weather front called a "pressure high", although warm air is less dense and therefore lighter?
|
I'm trying to understand ground weather maps and this is a bit baffling to me.
|
Earth Science
|
explainlikeimfive
|
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"Don't confuse density and pressure. Warm air at equal density to colder air will be at higher pressure. That said, the warm air mass behind a warm front will tend to rise over the colder air. This is why you see descending clouds as the front approaches. Fronts generally circle low pressure systems, not high pressure."
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l1zp54
|
Why are voices so unique and distinguishable? Even a single word can let you recognize someone.
|
Biology
|
explainlikeimfive
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"When you hear someone speak vowel sounds in particular, the timbre (resonant characteristics) is determined by the physical dimensions of a person's body, especially their throat, mouth and nose. Your brain learns to decode this to learn about the speaker, just as reverberations provide clues about the room you're in.",
"Same with faces, and lots of other things. Your brain is amazingly capable of distinguishing the smallest differences in nearly everything, but obviously only does so in what it thinks is important to. Recognising voices is clearly quite important, so we do. Recognising the intonation and tone in a word is very important if you’re a primary mandarin speaker, and so they can, a natural English speaker would find it difficult to do the same, as they don’t need to, and can you tell the difference between the moo’s of two different cows? Well you better believe that Barry the cow can tell the difference between Maisy and Suzy’s moo’s!",
"Our ears are very fancy, they are not like single microphone, but rather set of thousands of microphones called [[\"hair cells\"]]( URL_0 ), that allow us to distinguish not only a single sound, but also \"whole bouquet\" of all sound frequencies that fall into our ear. Someone talking to us might have a major sound that is dominating in their voice, but it will always be a combination of many different sounds and reflections, that's also how even with our eyes closed we can recognize if a person is standing in front of us or behind.",
"There's a lot of characteristics to a voice. * The tone/timbre of the voice * The rhythm/cadence at which someone speaks * Their prosody, ie. how their inflexion changes throughout a sentence (or even a word) * Their accent; particularly how they pronounce certain vowel sounds * and additionally their dialect. What kind of words they use That's a lot of different features for identifying a voice, it's not just a sound. Example: Look how well Tom Hiddleston impersonates Graham Norton: [ URL_0 ]( URL_0 ) He's paying attention to each one of the points I mentioned above (except dialect, he used fairly standard language).",
"Humans evolved as social animals, so we are typically very good at distinguishing human features, including faces and voices. Physically, our faces and voices are as similar to each other as the faces and voices of sheep, but we can't distinguish sheep as easily as we can distinguish humans. It is the power of our brains.",
"You can tell the difference between different instruments. Just by playing one note, you can tell whether that instrument is a piano or a guitar. This is because the sounds aren't just made of the fundamental pitches of those notes, but also other pitches and tones in different ratios that are unique to each instrument. Human voice boxes work the same way; every voice box is different, and so if you're familiar with the sound of a voice you can identify it when you hear it.",
"Has anyone seen any \"guess which voice goes with which face\" research? With factors such as gender, age, country of origin, race/ethnicity, fitness/obesity, maybe height. I've always felt like I could identify obesity by someone's voice.",
"For me, they are not. I get voices mixed up all the time. I don't know who's singing a song, many voice actors sound the same to me, and I can't always tell what family member I'm talking to on the phone. So explain that to me...why can't I tell the difference?",
"**TL;DR**: we all have different bodies and backgrounds and that affects the timbre of our voice and it has been evolutionarily beneficial for us to be able to distinguish between voices and voice characteristics. **Full Response** All of the responses so far discuss how the ears receive sounds and how the brain decodes the sound, but no one has given a deeper explanation as to why voices are so unique to begin with. This is an extensive topic so I won’t be able to cover everything, but I’ll provide enough of an explanation to get you going. All sounds that we hear are really just acoustic waves. When you breathe out and make any “sound” from your mouth, you are pushing a certain amount of the air in front of you with a certain amount of energy which causes the air to move at a certain speed. Your body causes this energy to change rapidly over time, going up and down as you speak, and that causes the acoustic wave moving through the air to change rapidly as well. If I put a little spring in front of your mouth and an electromagnet behind the spring to record signals into a computer about how the spring moves when it is struck by the acoustic wave, I can plot this movement on a graph that shows the position of the spring at any given time. This generally looks like some sort of wave that goes up and down. A “pure” wave can look like a smooth sine wave, flowing evenly up and down over time at a particular frequency (i.e., the number of ups and downs over a period of time). But in reality, most acoustic waves aren’t so smooth. Some get tall very fast — this is often called a fast “attack”. Some stay loud for a long time and slowly get soft — this is called a slow “decay”. Some might have a fast or slow decay, but continue making a sound for a long period of time — this is called “sustain”. And when the sound suddenly falls off, it can happen abruptly or slowly — this is called “release”. In addition to these aspects, there are other subtle nuances that can change the acoustic wave called “overtones”. These are very important to your question. If I sing a note an A note, which is 440 Hertz (a measure of frequency), the fundamental frequency of my sound is 440Hz. But, if I make the sound more nasal sounding, certain overtones will be produced. These overtones occur at a higher frequency than the fundamental frequency. On a graph of this signal, the overtones can look like little bumps along the fundamental frequency, but what is really happening is that the overtones are being added to the fundamental frequency tone to produce a complex signal. With that in mind, it’s a bit easier to understand this excerpt from the Wikipedia article on overtone: > Most oscillators, from a plucked guitar string to a flute that is blown, will naturally vibrate at a series of distinct frequencies known as normal modes. The lowest normal mode frequency is known as the fundamental frequency, while the higher frequencies are called overtones. Often, when an oscillator is excited — for example, by plucking a guitar string — it will oscillate at several of its modal frequencies at the same time. So when a note is played, this gives the sensation of hearing other frequencies (overtones) above the lowest frequency (the fundamental). > Timbre is the quality that gives the listener the ability to distinguish between the sound of different instruments. The timbre of an instrument is determined by which overtones it emphasizes. That is to say, the relative volumes of these overtones to each other determines the specific \"flavor\", \"color\" or \"tone\" of sound of that family of instruments. The intensity of each of these overtones is rarely constant for the duration of a note. Over time, different overtones may decay at different rates, causing the relative intensity of each overtone to rise or fall independent of the overall volume of the sound. A carefully trained ear can hear these changes even in a single note. This is why the timbre of a note may be perceived differently when played staccato or legato. In addition to the above, complex waves have something called an “envelope”. If I were to draw a smoothed out line from peak to peak over a complex sound wave, the envelope is essentially that smoothed out line. Our brain often picks up that envelope as well. The crazy thing is, our brains can actually hear and decode the envelope of an ultrasonic sound. In other words, we can hear the envelope of a signal that has a fundamental frequency that is too high for the human ear to hear. One fascinating corollary and consequence of this is that ultrasonic sounds have a smaller cone of dispersal — they can be aimed more precisely at, say, a single person in a crowd. But if I modulate the ultrasonic sound to have an envelope in a frequency that your ear can hear, then if I aim that ultrasonic signal at you while you’re standing in a crowd, only you will hear that sound. Creepy stuff, right? I actually wrote a patent on this technology and casinos are working to implement it into their games (which can be used both positively and with devious effect). But to finally answer your question, voices are so unique and distinguishable because each person’s body is very unique. Some people might have a larger soft palette than others, some may have a uniquely shaped nasal cavity, some may have a stronger diaphragm, some may have lungs with a larger air capacity. And those are just physical aspects. Social aspects can result in tons of unique pronunciations and and habits in how a person uses their unique physical system. Similarly, various other things can come into play. For example, cortisol levels, particular diseases such as the common cold and covid-19, and tons of other biological aspects that can result from external sources can affect the voice. If you’re interested in that last bit, look at the research of Rita Singh. In conclusion, there are tons of different aspects that can change from person to person, and these aspects all affect the timbre, overtones, and many other factors that can be picked up in an acoustic wave. That is at least a good starting point for why voices are so unique and distinguishable. As for why our brains are able to perceive and decode those different sounds so precisely, that’s an equally long discussion that deals with evolutionary psychology, auditory processing pathways in the brain, social psychology, neuroscience, and much, much more. The high-level answer is because being able to distinguish between voices and voice characteristics has been beneficial to the survival of our species. But the detailed answer as to why and how we do that is far more than any one response can cover.",
"This is partly confirmation bias. You know a select set of voices you associate with people. It's very possible you would mix them up with others, but are not exposed to a voice \"match\" . You are also an 'expert' on those voices so unless the match is similar you are very unlikely to make a mistake. Sort of like never confusing a twin, but you only ever saw one of them and didn't know the other one existed.",
"It's similar to why we can read facial expressions so well, and it's hard to make it look perfect, even in modern video games, our brains are really really good at distinguishing vocal sounds and facial expressions.",
"They aren't always, my brother and I sound so similar on the phone that our parents sometimes need a moment to figure out which of us they're talking to and we aren't twins or anything. Voices are a combination of the sounds your body makes just because of its physical properties, and also how you learn to use that physical instrument. Your accent, cadence, slurring and other features of your voice are all properties that you learned growing up. This is why even identical twins can have pretty different sounding voices. Voices tend to seem unique and distinguishable because we tend to hear voices from only a small number of people over the course of our lives. For example, for most of us Arnold Schwarzenegger has a super identifiable accent and voice, yet his voice is a result of his learning English as a second language and in fact a lot of people from Austria where he came from have similar accents in English. If you were around these people all the time, you might not think Arnold has such a unique voice.",
"They just aren’t. Sound is one of those things we think as human are good at but we’re not. Impressionists can fool us and we’re regularly confused by parents and children on the phone. It’s purely in our heads that we are great at hearing voices. It’s our eyes that do much of the heavy lifting. We can be easily fooled by audio illusions and are tricked by binaural audio. Far and bar are interchangeable based on mouth movements. Go look at audio illusions."
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"https://www.youtube.com/watch?v=zzqWPDnYEik"
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l1zsmv
|
How can our brain store so many different memories without forgetting them, with such precision?
|
Biology
|
explainlikeimfive
|
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"Well, \"with precision\" isn't a very good description. Memories are reconstructed as you remember them, and that seems realistic in spite of the fact eyewitnesses are often proven wrong by camera recordings."
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l1zws1
|
How does Imre Lakatos mean we should separate between science and pseudoscience?
|
I'm really struggling with finding/understanding the essence of what Lakatos is saying about how to identify what science is, and what pseudoscience is.
|
Other
|
explainlikeimfive
|
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"Lakatos considered many different means of distinguishing science from pseudoscience and found them lacking. In particular, he found the popular idea that scientific theories are falsifiable while pseudoscientific theories aren't to be not quite right. Many established scientific theories resist falsification in much the same way as pseudoscientific theories. Faced with evidence that appears to falsify the theory, people invested in it being correct come up with explanations for how that evidence is actually consistent with the theory or can be driven by some heretofore overlooked consideration. In science, this can be a productive avenue towards additional discoveries. In pseudoscience, it simply piles misconceptions on top of each other. Instead, Lakatos proposes that science should be distinguished from pseudoscience because it produces novel facts. He uses the example of Halley's comet. Halley used Newtonian principles to predict when and where a comet would reappear. 72 years later, it did exactly that. Without Halley's prediction, nobody would have thought to look at that particular patch of sky at that particular time. But science predicted it would be interesting, and it was. Rather than trying to explain the evidence after the fact, Halley told us where we could find additional evidence. These moments, where a scientific program tells us a new place to look and correctly anticipates what we find when we look there, help us to distinguish between lines of thinking that illuminate the world and those that obscure it. Thus, according to Lakatos, we should treat something like Flat Earth as pseudoscience not because there's copious evidence against its hypotheses, but because Flat Earth theorists have never used their system to produce a novel prediction that turned out to be true.",
"The *very* abridged relevant history is: Verificationists in the early part of the 1900s say that science proves things. If something can't be proven with evidence, it's not science. Only statements that can be tested are even *meaningful* according to them. Popper (Lakatos' teacher), said that verification is impossible. Scientists can't prove things are true, they instead try to *disprove* things by imagining an experiment which could produce results that disprove your theory. What makes something scientific is that it's *possible* to falsify it (astrology, for example, can't be falsified, because no piece of evidence would disprove it) If you try really hard to prove something is false, and you can't, then that's a good sign, right? Kuhn comes along and says that what gets counted as science is a sociopolitical question, not a technical one. He describes a historical process through which science has changed over time, and says that its not just steady progress; there are big revolutionary leaps, like from Newton to Einstein. These revolutions change what science *is*, because they change its basic assumptions about reality. Lakatos wanted to combine the good bits of Kuhn and Popper. He agrees with popper that we can't ignore the rest of human activity if we want to understand science, but he also thinks Popper is right that trying to disprove your own theories is part of what makes an approach (good) science. Lakatos doesn't give a nice tidy criterion for answering 'is this science?' in the same way that Popper does. He's much more interested in describing what good science looks like. He says it happens in research programs which have a 'hard core' of assumptions (and are a lot like Kuhn's 'paradigms') with less fixed theories wrapped around them. The aim is to come up with a research program that can explain the most stuff without giving up on the core assumptions of the program. Gotta be honest this was not an ELI5 friendly answer but you did ask a question about *Imre lakatos' answer to the demarcation problem* so uh... Hope that helps! Edit: unfinished sentence."
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l20ss6
|
Why do we have a dominant hand and why is right-hand dominance more common than left-hand dominance
|
Biology
|
explainlikeimfive
|
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"The real answer is no one knows for sure. The most prevalent theory is that it’s a sort of balancing act of advantage. the use of a particular hand in society is useful, as it means that tools can be made and designed knowing which hand it is going to be used in, there doesn’t need to be a reason why it was the right hand that won, maybe so maybe just random, but if you are right handed in a society which makes tools and weapons for right handers, then you have a good evolutionary advantage, and eventually all humans are right handed. The mystery then is why we still have left handers, and the answer is seen if you look at certain sports. Around 10% of people are left handed, but around 50% of elite baseball players are left handed. I myself am left handed, and am a fencer, and can tell you the huge advantage that gives me in the sport. My opponents practise for years, perfecting moves, defending against attacks, attacking themselves etc, almost always practising against another right hander, as they are most common. And then what happens when they face me? Every attack from me comes from the right, rather than the left that they are used to, most defensive moves have to be reversed, my defence (practising also mainly against right handers) is most effective in a right handers weak areas, and weakest in a right handers strong areas and they now have to attack areas (my right hand side, so their left) that they are not used to aiming for. If instead of fencing, we were sword fighting for real, you can clearly imagine the evolutionary advantage this would give a left hander. So left handedness is favoured, until such a time that there are so many left handers that people start practising how to defend against them, and it becomes a disadvantage again, and basically it’s this equilibrium which we see today. We see evidence for this (fighting hypothesis) in research which suggests that the more competitive a society is/was, the more left handers it had/has, the less competitive, the fewer left handers. If fighting and competition was important to survival then being left handed is more of an advantage, if cooperation is more important then being right handed is.",
"Handedness stems from one hemisphere of the brain being more dominant than the other, which will inevitably happen. Left brain dominant means right handedness, opposite for left handed. As far as why? We really don't know. The vast majority ( > 90%) of the human population is left brain/right hand dominant, and roughly only one in ten humans is left handed. Even if both parents are left handed, a child will only inherit that trait about 25% of the time. So handedness is a very disproportionately inherited trait. Our best guess is that handedness develops due to a mix of genetics and the environment we grow up in. There are undoubtedly benefits to left handedness- natural advantages in sports (we get the term southpaw from baseball) and hand-to-hand combat to name a couple- but for some reason, nature hasn't balanced out the ratio yet. It's a difficult question we're still trying to answer. A prominent theory is that our brain evolved for the left brain to do most of the heavy lifting- speech and verbal processing are two of its jobs that we as social creatures rely heavily on- and the right brain is used for visual and spatial processing, among other important tasks. This is known as lateralization. Under this theory the brain of a left handed/RB dominant individual is actually much less lateralized than right handed/LB individual in terms of division of labor for these tasks. While this may or may not confer natural advantages in certain areas, the enormous degree of natural variability in our brain structures prevents us from saying for sure.",
"Hand dominance makes evolutionary success. Things tend to be \"good enough\", but not so good as to take resources at the cost of other critical functions. You absolutely need a great hand, but while two great hands would be awsome, it might cost neural resources that the body also needs (vision, advanced thinking, etc). Evolution will tend to result in the best “overall” balance to meet the current environment. “Cost” is a huge part of that balance, bigger brains are not cheap to grow and maintain in terms of calories and opportunity costs. The fact one hand is more commonly dominate is also evolutionary. Creatures that have a common dominant hand, find it easier to teach each other, “copy what I do” without mental mirroring. They can more easily share work (one left hander in the middle of packed right-handers often gets in the way, I speak as a left-hander saying that)",
"Left-handed vs Right-handed is genetic, there are DNA differences which lead to differences in brain structures. That said, many people learn to do many things, like eat and write, with both hands. That's simply a matter of practice."
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l20w1r
|
How do the magnetic field lines in a closed current carrying loop not intersect?
|
Doesn't each point have its own magnetic field? How is each point able to have its own magnetic field without the lines intersecting?
|
Physics
|
explainlikeimfive
|
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"The lines are imaginary, meant to give a visualization. A field is a quantity that exists at every point in space. The magnetic field is a vector field - so every point in space has a magnetic potential with a certain magnitude and direction. This is somewhat hard to visualize so to illustrate it lines are drawn to represent this field. This doesn't mean that the field ONLY exists where the lines are drawn. An analogy would be kind of how you would draw lines to represent the flow of water in a stream. Intersecting them would generally not make sense because it wouldn't represent how a water particle would \"flow\" if it started at that point."
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l20z47
|
What determines the value of a sports franchise? How come some really unsuccessful franchises are worth so much more money than some other really successful franchises?
|
Economics
|
explainlikeimfive
|
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"They sell tickets, get sponsors, money from TV broadcasting, sell stuff with their name and logo on it. Usually how good a team is is somewhat correlated to how popular they are which is then correlated to how many people are going to spend money on them, both as sponsors and consumers. But if it's a traditional club with really dedicated fans or if the design of their logo is just nice so that people who are not into sport still wear that, their value could be high despite their success being meh."
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l216f4
|
why when you've added something of color to water(like mio) does the water adopt the color however when shaken, the bubbles do not appear to contain any color?
|
I'd expect the bubbles, which I believe to be formed from surface tension of water around trapped air, to at least share a hue of the color when thick and foamed.
|
Physics
|
explainlikeimfive
|
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"Bubbles are to thin to do that. Water reflects every color when it’s that thin, hence bubbles tend to shine every color that is on a rainbow"
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l21nuo
|
Why is it relatively easy to hold it in before you pee, but hard to stop during it?
|
Biology
|
explainlikeimfive
|
{
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"The smooth muscle that makes up your bladder isn't under direct conscious control. It works mostly automatically - once it starts draining it will keep going till it's empty unless something stops it. You can stop it using other muscles that are under direct conscious control but it takes a bit of practice and you have to develop those other muscles enough that they are strong enough to effect the bladder."
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l21t56
|
How does sunscreen work?
|
I (kind of) understand the ones that form a physical barrier. But how does the other lkind work? It baffles me
|
Other
|
explainlikeimfive
|
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"They contain chemicals that reflect UV light. They actually are physical barriers too, but they're a \"colour\" we can't see. They're transparent to visible light but they reflect the harmful rays that cause sunburn. If you could see in ultraviolet, like some insects, the \"clear\" stuff would look just like the \"physical barrier\" stuff.",
"A window is solid, yet you can see through it. This is because the light is a form of radiation in what we call the electromagnetic spectrum, specifically called 'visual light'. If you had heat vision (thermal imagery), you could also see through some walls because that type of radiation is inferred on the electromagnetic spectrum. UV is also on the electromagnetic spectrum; however, just like heat; we can't see it. Just like a wall blocks ' visible light' the chemicals in sunscreen form a wall that blocks UV. Different types of materials can block radiation on the electromagnetic scale; UV is no different.",
"There's chemical sunscreens and Mineral sunscreens. Chemical sunscreen products typically include a combination of two to six of the following active ingredients: oxybenzone, avobenzone, octisalate, octocrylene, homosalate and octinoxate. [Source]( URL_0 ). These chemicals create a layer on your skin that absorbs the UVA and UVB rays so your skin doesn't. The problem is that these chemicals are sometimes bad for you and absorb into your body. They can also cause rashes and redness. Also, chemical sunscreens are damaging to coral reefs when you get in the ocean. So much so they're banned in Hawaii. Mineral sunscreens are ones containing titanium dioxide and zinc oxide. These sunscreens basically create a force field on your skin that reflects harmful rays back into the atmosphere. Mineral sunscreen contain ingredients that are are safe to put on your body. They protect better than chemical sunscreens in my opinion and they typically last longer per application. Mineral sunscreens are safe for coral reefs. They are good for sensitive skin including babies. SPF 50 is the strongest mineral sunscreen and it's all you will need. [Australian Gold]( URL_1 ) botanical sunscreen is a really good one or anything that says \"Mineral Sunscreen\"."
],
"score": [
6,
4,
4
],
"text_urls": [
[],
[],
[
"https://www.ewg.org/sunscreen/report/the-trouble-with-sunscreen-chemicals/",
"https://www.meijer.com/shop/en/fsa-hsa/sun-care/australian-gold-botanical-sunscreen-spf-50-lotion-5-fl-oz/p/5440251053"
]
]
}
|
[
"url"
] |
[
"url"
] |
l21vke
|
what about cancer makes it hard/impossible to find a cure and how does chemo work?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gk3dqe6",
"gk3dr1g",
"gk3e2cf"
],
"text": [
"Cancer is your own cells misbehaving. Stuff that kills cancerous cells has almost a complete overlap with stuff that kills *all* of your cells. We know a truckload of ways to kill cancer cells, the hard part is finding a way not to kill the patient too. Cancer cells suck up more resources than most normal cells due to dividing very often, so we basically pump weak poison into the patient hoping that the cancer cells will suck it up and reach lethal dose before the other cells do. This also fucks up other resource hungry cells such as hair follicles and nailbeds and the creation of blood cells, hence the baldness and sickly looking thing going on.",
"Because \"cancer\" isn't one thing. There are hundreds of different kinds of cancers that all vary wildly in deadliness, ability to metastasize, how quickly they mutate, and a bunch of other factors. Finding a cure for all of them at once is nearly impossible because \"all of them\" is a huge group. Chemo works by targeting dividing cells and killing them or otherwise preventing them from dividing. This works well for cancer, because one common feature of cancers is that they divide much faster than regular cells. This does cause problems for other cells that divide rapidly though, like your stomach lining, hair and skin, and other naturally fast dividing cells.",
"Cancer cells are your cells. They’ve gone rogue and are now dividing out of control, but they’re still *you*. They baffle your immune system by looking exactly like healthy cells upon inspection. They baffle doctors and surgeons by spreading out or wrapping themselves around organs and systems that you can’t just start hacking away at. So the trillion-dollar question has always been: how do you kill these specific rebellious human cells without killing all of them? One way we’ve done this is by killing all the cells that are dividing. Cancer cells are *always* dividing, but cells in your heart and brain are almost never dividing. Radiation or chemical treatments that wipe out vulnerable dividing cells will case a mass die-off of the cancer cells, and hopefully not too much collateral damage among hair, blood, and digestive system cells that are also trying to divide."
],
"score": [
12,
4,
4
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"text_urls": [
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[],
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|
[
"url"
] |
[
"url"
] |
|
l2205q
|
What is so amazing about the F35 to warrant its $1T budget? Do the benefits really justify the R & D costs?
|
I've read a number of different estimates for the F35 project but everything seems to fall in the ballpark of $500B to $1T. I've seen some pictures (renderings?) and it just looks like another F16. What in the world is so great about this jet to justify this amount of R & D expense?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gk2ro0r",
"gk2rvbi",
"gk2s4hp",
"gk2wb1o"
],
"text": [
"A major thing that continually gets glossed over by people citing the $1 trillion figure; that's the **lifetime** cost of the project. By comparison, the airframes that are being replaced by the F-35 would have had a combined cost somewhere on the order of $1.8 to $3 trillion over the same time frame that the F-35 is expected to run in, but those costs don't get talked about nearly as often because they're in smaller, more manageable chunks. Making one airframe that is (largely) the same across all three of it's variants makes it considerably cheaper from an upkeep and manufacturing perspective, because you can take advantage of economies of scale to crank out loads of parts for the aircraft. By comparison, we currently need completely separate lines for the F-16, the F-15E, the F/A-18E/F, the A-10, and the AV-8B; a manufacturing line for one of those aircraft can't easily (or quickly) be retooled to make parts for the others, but the majority of the F-35 parts are shared across all three variants. The F-35, counterintuitively, is rather cheap on a per-unit basis (hence why it costs less than the competitor Rafales and Eurofighters that it's actually superior to), but it's a *huge* program, hence why it has such a large overall price tag.",
"The main reason that the F-35 program's total cost is so high is that it's a huge project intended to make a whole ton of planes; F-35s of various versions are going are supposed to replace huge sections of the Air Force, Navy and Marine fighter fleets. The has undoubtedly been bloat and cost overruns, but the current cost per aircraft isn't that much higher for a F-35 than for a new production legacy fighter like the F-16.",
"The F-35 is not a single airframe but rather three different airframes which have different capabilities. This is so that they not only replace F-16 but also F-18, F-15E, Harrier, A-10, among other different airplanes used today. The US Air Force is putting all their money into making the ultimate fighting aircraft that can be configured to do anything. Just like the US Army did with the development of the Bradley Fighting Vehicle. Edit: list of aircraft it replaced were corrected.",
"In addition to the other comments about why it's a huge program that isn't really directly capable, to directly answer your question of why it's not just another F-16... It's far stealthier. It's not quite F-22 stealthy but, compared to any legacy fighter, it's still stealthy. That's a huge deal for modern operations in \"contested airspace\" (where you don't have air dominance, like the US is used to). It can operate from carriers, the F-16 can't. The VTOL variant can takeoff and land vertically, the F-16 can't. It has a \\*vastly\\* superior sensor suite. Not just radar, but optical and electronic. And a far more capable network/datalink system so it can share all that information with other aircraft and units in real-time. An F-35 is like a tiny AWACS. An F-16 has nothing like that capability to coordinate or inform on what's happening. F-35 carries more than 2x the fuel with a larger payload, for double the combat range with more weapons."
],
"score": [
11,
4,
3,
3
],
"text_urls": [
[],
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|
[
"url"
] |
[
"url"
] |
l222q4
|
How come it is a recent discovery that water can get cooled down to -48 celcius (- 54 F) before freezing?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gk2thbp",
"gk2ty86",
"gk2ukk6"
],
"text": [
"Thermodynamics phenomenon known as supercooling was discovered in 1724 by Daniel Gabriel Fahrenheit. It is important to mention that melting and freezing aren't the same, when you are warming up a substance (such as ice), it will always melt at 0 °C, 32 °F, 273.15 K (known as melting point of ice). But when cooling water down there need to be some \"crystalization starters\" known as *crystalline solids*. In the absence of them, the spontaneous formation of a large and regular structure from the disordered liquid is unlikely. By using very pure water and cooling it down, we can have it in liquid state without freezing, even below water melting point.",
"Not sure which discovery referring to but - Phase change is highly dependent on the surrounding conditions, for example water boils at a lower temperature at higher elevations which is why baking instructions have a \"high altitude\" section. The opposite is also true - at higher than normal pressures water freeze at a lower temperature. There are charts that show this - for example [ URL_2 ]( URL_1 ) Another possible source of your question is that water ice usually requires something called a 'nucleation point' to freeze around. Essentially some sort of irregularity that water can 'grab onto' and start freezing, in special circumstances you can remove those irregularities and keep water liquid at low temperatures. for example this video - [ URL_3 ]( URL_0 )",
"Your asking about things just published 2 years ago involving a SUPER advanced subject that requires a Ph.D. to understand fully on a subreddit about explaining things like you are 5? I will do my best, as I happen to be one of those people. & #x200B; You see matter has different states it can exist in. A solid, liquid, and gas. Each of these states involves molecules existing in different arrangements. In a liquid molecules can flow past each other and are not locked rigidly into one position, if they were it would be a solid. Now as we study materials we actually find that the divisions between different states are not so clear cut. For the purposes of this topic they are defining solid water (or ice) as having a particular crystal arrangement and liquid water as having a different arrangement. Then using advanced measuring techniques that can detect this different arrangements. One is called x-ray diffraction that gives more exact information on the arrangement of repeating units of molecules and the other is laser interferometry, which can reflect off different things depending on the wavelength of light used. They used InfraRed (IR) light to measure the distance of the Oxygen-Hydrogen (OH) bonds and estimate temperature from these lengths. They could not use traditional thermometer setups because the bulk temperature in the vessel did not represent the individual temperature of the microdroplets they were using. & #x200B; The temperature at which something freezes depends on many factors, including pressure, surface area, and volume. By making very small droplets (called microdroplets) they have reduced the volume as much as possible and increased the surface area as much as possible, while still being able to consider the cluster of molecules a liquid and not a gas. They then inject these microdroplets into a vacuum chamber that has almost nothing in it. As such most of the droplets immediately vaporize (become gas) and this lowers the temperature in the chamber. Many others start to freeze and become effectively snow (solid ice falling to the bottom of the chamber), but some very small percentage were able to stay liquid and not freeze until their cluster reached around -42.5 °C according to the aforementioned laser measurements of individual clusters. This was repeated using x-rays to measure the structure and found some interesting physics happening, but as of yet we don't have a great explanation. & #x200B; All of this is to say: The reason we didn't know about it sooner is because it does not happen on some large scale that is observable by human eyes. It takes very fancy equipment with very fast and precise measurement abilities. None of this was available until recently. For most people water freezes at 0 °C unless you add salt to it or lower the pressure a lot."
],
"score": [
16,
4,
4
],
"text_urls": [
[],
[
"https://www.youtube.com/watch?v=_9N-Y2CyYhM",
"https://en.wikipedia.org/wiki/Phase_diagram#/media/File:Phase_diagram_of_water_simplified.svg",
"https://en.wikipedia.org/wiki/Phase\\_diagram#/media/File:Phase\\_diagram\\_of\\_water\\_simplified.svg",
"https://www.youtube.com/watch?v=\\_9N-Y2CyYhM"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l225e3
|
Is it easier for the human body to gain or lose heat?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gk2umap"
],
"text": [
"People mostly spend time in environments that are colder than they are. Therefore the body is almost always losing heat at some rate. This is balanced by a constant generation of heat from e.g. muscle movement. The body has various mechanisms for reducing loss if the rate is too high (vasoconstriction, shivering) or increasing it if the rate is too low (vasodilation, sweating). My point is that the body is always losing heat, you don't really gain heat through the skin in any normal circumstances. It is possible to use warming packs, but these are not terribly efficient."
],
"score": [
10
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l225gy
|
This paragraph taken from the Principles of Macroeconomics
|
This paragraph is was taken from Page 7 of the Principles of Macroeconomics by N. Gregory Mankiw, and discusses principle # 7 : Rational people think at the margin. *"Consider an airline deciding how much to charge passengers who fly standby. Suppose that flying a 200-seat plane across the country costs the airline $100,000. In this case, the average cost of each seat is $100,000/200, which is $500. One might be tempted to conclude that the airline should never sell a ticket for less than $500. In fact, however, the airline can raise its profits by thinking at the margin. Imagine that a plane is about to take off with ten empty seats, and a standby passenger is waiting at the gate willing to pay $300 for a seat. Should the airline sell it to him? Of course it should. If the plane has empty seats, the cost of adding one more passenger is minuscule. Although the average cost of flying a passenger is $500, the marginal cost is merely the cost of the bag of peanuts and can of soda that the extra passenger will consume. As long as the standby passenger pays more than the marginal cost, selling him a ticket is profitable."* How is the marginal cost equal to the cost of the bag of peanuts and soda? Am I reading too much into it, I'm not sure
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gk2se35"
],
"text": [
"The marginal cost is simply the cost difference when something goes up by 1. If it costs the airline $100,000 to fly that plane, then that's...just how much it costs. If there's an empty seat, then it...still costs them $100,000. If they fill that seat, then the cost increases, because now it's $100,000 + another bag of peanuts that the person will eat + another soda that the person will drink. So the marginal cost is \"bag of peanuts + can of soda\". If that person spent $300 for the ticket, then the ticket price was far more than the marginal cost, so the airline made a profit, even though the person paid \"less than they should have\" for the ticket."
],
"score": [
46
],
"text_urls": [
[]
]
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|
[
"url"
] |
[
"url"
] |
l228oa
|
Why is the moon supposed to be so cold if it’s right next to the earth, and I’m assuming, getting about the same amount of sun as the earth?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gk2sbik",
"gk2sf5a"
],
"text": [
"It has no atmosphere to retain heat, so it's unbearably hot in sunlight and dead cold on the dark side.",
"The moon does not have an atmosphere. This makes a huge difference. Venus is hotter than Mercury even though Mercury is much closer to the sun. Venus just has a much denser atmosphere that causes pressure which causes heat."
],
"score": [
15,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l22suo
|
How do we know what the other planets in our solar system are made of if we don't have the technology to take samples?
|
Mathematics
|
explainlikeimfive
|
{
"a_id": [
"gk2vzlw"
],
"text": [
"Using the science of [spectroscopy]( URL_0 ), astronomers are able to analyze the patterns of emission and adsorption of specific wavelengths of light coming from celestial bodies, which tells them what elements are there in that celestial body. Basically, every single element on the periodic table of elements has its own a particular fingerprint in terms of the way it interacts with light. Light interacting with Hydrogen has a different fingerprint from light interacting with Helium, or Oxygen, or Iron, or whatever. These fingerprints can be seen by taking the light coming from a star or planet, spreading it out into a rainbow, and then looking for lines of missing light in that rainbow that correspond to particular elements."
],
"score": [
7
],
"text_urls": [
[
"https://en.wikipedia.org/wiki/Spectroscopy"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
l22ven
|
Why does it hurt so much when your arm/leg recovers after you have slept on it/sat on it for too long?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gk32669"
],
"text": [
"When you arm/leg/hand/foot “falls asleep” or starts to do that pins and needles tingling feeling, it’s because the way you were sleeping had pinched a nerve, preventing nerve signals from going up to your brain from your arm. You brain typically filters out all the extra signals you get sent that aren’t that important, like your finger touching a pillow, or the air brushing against you, all the really small stuff that isn’t super important. But when you arm stops sending signals to the brain because the nerve in pinched/blocked/squished, you brain kind of loses that filter, because it can’t filter nothing out of nothing, there’s nothing to filter, so it loses the filter. Then, when you unpinch the nerve and your arm starts to “wake back up”, you get that pins and needles feeling because you is suddenly receiving thousands of new signals from the arm that was previously blocked, and it isn’t sure what sensations are important and which ones aren’t yet, so everything feels like tiny little points of pain until you brain gets back to understanding what signals are important again and which it can just kind of filter to the side and not focus on."
],
"score": [
7
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2347o
|
What does the -punk in genre labels such as cyberpunk mean?
|
I'm told that -punk originally meant a cultural undertone with relation to the setting, rather than what it means today (aesthetic of). Example: What is "punk" about cyberpunk? What makes it cyberpunk rather than a blend of contemporary and sci-fi? Same with steam. Where's the punk in steampunk?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gk2yev6",
"gk2z1xy"
],
"text": [
"Punk was/is an antiestablishmentary movement that loosely self identified with an ascetic style that was very clearly against societal norms. Stuff like crazy multi colored hair, wild hair do's like a spiked mohawk, facial and body piercings ect. Mostly when something is referred to as punk it usually means that it borrows those style cues from punk culture and usually has anti establishment themes.",
"-punk means nothing. They guy who came up with the term \"cyberpunk\" just came up with it, and later, unrelated other people started using the suffix -punk to apply to other related genres, like steampunk. In modern context, of course, the association is there but there isn't a definitive meaning behind the word -- we just associate having the -punk prefix in fiction with these variety of genres > What makes it cyberpunk rather than a blend of contemporary and sci-fi? Cyber punk is a blend of that! In fact a lot of cyberpunk tends to have a sorta concept of high technology with the lower dredges of society, crime, murder, detectives, flith and scum in the ghetto. Essentially, a society full of high technology and promise, but overridden with greed, megacorporations (Zaibatsu's) corruption and class divides-- and we generally explore the nasty side of the world. Often there is a strong japanese influence too, especially Japanese megacorporations. here are many \"classic\" cyberpunk stereotypes, which to be fair, are mostly heavily driven and derived by stories by William Gibson, especially his most famous work, Neuromancer, which is basically the core of building out cyberpunk worlds"
],
"score": [
6,
3
],
"text_urls": [
[],
[]
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}
|
[
"url"
] |
[
"url"
] |
l237m5
|
Why can't we imagine colors we have never seen before?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gk2yv04",
"gk34fau"
],
"text": [
"Because you can't describe a color without using that color or an object of that color. If I asked you to describe \"red\" to a person born without sight, you can't describe it in any way that makes sense to them. You can describe objects that are red, but that doesn't tell them what \"red\" *looks* like.",
"Interesting fact, most humans have 3 photoreceptors that let us see the colors we see. A handful of humans have one extra one which will enable them to see a bunch of colors we can't comprehend. There exist a shrimp called the Mantis Shrimp that have 12 to 16 photoreceptors!! Imagine that?"
],
"score": [
14,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l23qok
|
Why do we hear music lower than it really is, after listening to it at maximum volume?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gk32lrq"
],
"text": [
"You mean if you listen to it at a normal volume, then you crank it up to max, then turn it back to normal and it sounds kinds quiet? It's pretty similar to waking up during the night to pee. You can see the room okay in the dark. Then you put the light on for a minute. Then when you put it off again, you can't see anything. Our ears adjust to volume. Our brain adapts too and tries to normalise sounds. So there's some of that going on. But also, if you listen to something that's too loud, it can damage your hearing. So, your ears try to protect themselves. There are 3 bones in your ear (the hammer, anvil, and stirrup) that are the smallest bones in the body and make up what is called the ossicular chain. They help carry sound from your eardrum to your inner ear. When you hear a very loud sound, the muscles around these bones tighten up, called the stapedial reflex. This makes it harder for the sound to carry, therefore lessening the damage it can do. But it takes a bit of time for the muscles to relax back to normal. So, things sound quieter. As a footnote, this often means the sound is too loud. If that's the case, turn it down. If you're at a gig, wear earplugs!"
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l24pxt
|
If commercial plane engines are not strong enough for a vertical takeoff, how can they keep the airplane afloat during the normal operation?
|
Commercial planes cannot fly vertically (like this [ URL_0 ]( URL_0 )), so their engines are not powerful enough to lift the aircraft vertically. Then how are they able to slowly gain altitude while flying normally (horizontally). I understand that the shape of the plane and the wings provides lift, but the energy to lift must come from the engines in the end (they cannot cheat physics). So, my question is, how is it that the commercial plane engines are not strong enough to lift the plane vertically, but are able to do so when flying horizontally. Is my assumption that the commercial plane engines not strong enough wrong? If so, why do the airplanes stall when the nose goes up too much (i.e. when no wind goes over the wings)?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gk38l71"
],
"text": [
"The engines on a commercial aircraft are not intended to make it go up, but forward. By going forward, air is forced over and under the wing. As air flows around the wing, the shape of the wing creates more pressure on the bottom than the top, which lifts the airplane."
],
"score": [
7
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
l24q13
|
How do satellites and the ISS correct their orbit in space?
|
I know that the International Space Station (ISS) and man made satellites often have to move to make small orbit corrections, but since they have no fuel, no aerodynamic and no oxygen, how exactly do they do this?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gk380el"
],
"text": [
"They have fuel and thrusters to make small corrections to their orbit. You might think satellites are just out there flying through space doing nothing, but in reality, they are making small corrections on a daily basis and are actually being 'flown' by a team on the ground. They only have a limited amount of fuel though, so once they run out... thats probably gonna be the end of the satellite. The often will save just enough fuel to de-orbit it either into a \"graveyard\" orbit, or back into the earth to burn up in the atmosphere. Many satellites are only expect to have a lifespan of 10-25 years, for many reasons, with fuel obviously being a concern"
],
"score": [
15
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
l24uqx
|
Why is it that a watered down drink tastes worst than just straight water?
|
Shouldn’t some sugar / flavor taste better than having none?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gk3jzrx"
],
"text": [
"Some chemicals can be tasted even if you add a lot of water to them, whereas other chemicals can only be tasted when you put a lot of them in a small amount of water. Flavors are usually made of multiple chemicals together, so when you dilute a flavor by putting in more water than it's supposed to have, you upset the \"taste balance\" of the flavor. You're only able to taste some of the chemicals in the flavor and not others. This can make the diluted drink taste bad. Edit: more specifically, bitter chemicals are often easier to taste when diluted. Probably because those chemicals are more likely to be dangerous, since strong bases taste bitter and are often caustic or poisonous."
],
"score": [
8
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
l24x2d
|
How does a pill medicine help, for example, a headache? Doesn't the pill just get disintegrated by the acid in our stomach?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gk393jj"
],
"text": [
"It does. And then the drug is absorbed into your bloodstream through the sides of your stomach (just like water your drink or sugar you eat)"
],
"score": [
5
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l250ez
|
Does inflation go on forever even if an object's value remains the same? For example: An egg costs 1 coin 100 years ago, 10 coins today, 100 coins next century, and so on, even if its value as food remains roughly the same throughout the centuries.
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"gk3a2o5"
],
"text": [
"Inflation isn't some universal law, it's something that's decided upon indirectly by your government. Not many financial systems have survived long enough to even know for sure if it can be a stable system forever. We seem to think it can with the proper care."
],
"score": [
5
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l258b8
|
does radiation from an outside source effect radio waves? And if so how was nasa able to talk to their astronaught on the moon from earth with all the radiation In space between earth and the moon?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gk3da5s"
],
"text": [
"Because photons do not interact with each other. If you send radiation from two sources and the streams colide the direction of the radiation won't change. So they can send radio waves back and forth without any disturbance."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l25hki
|
what causes people to pass out from “gross” things?
|
What causes people to pass out during things like getting their blood drawn, watching a procedure, etc?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gk3f02j"
],
"text": [
"Cerebral hypoxia - low oxygen in the brain. Passing out is your brain's sure-fire way of restoring blood/oxygen flow to the body's most important organ (the brain). By passing out, you're now lying flat, making the heart's job of pumping blood to the brain a whole lot easier. Gross things have a cardiac impact as well as neurological, resulting in passing out which is usually resolved pretty quickly."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
l25jiy
|
when you see geological maps (the layered ones that show different periods of earth) why does earth stack layers? In theory because of erosion and whatnot shouldn’t it actually get lower?
|
Earth Science
|
explainlikeimfive
|
{
"a_id": [
"gk3d7zk",
"gk3dnoc"
],
"text": [
"Exactly, some places get eroded, those partials get transported to other areas where they stack back up again. Great example is the grand canyon, you can see the layers all the way down. Aka, it was a spot were stuff used to stack up. Now it's being eroded away by the river. Those partials are being transported down stream to be deposited elsewhere to begin making new layers.",
"Basically, earth is constantly changing. Some area's are being \"stacked\" while others are worn away. Most \"layered\" areas are places that used to be oceans, where you would have a lot of stuff accumulating on the bottom over time. In addition, think about erosion. For every little bit of soil, rock and debris that gets worn away in one place, it has to end up somewhere. The Entire grand Canyon was worn away, but all that rock and sand is still somewhere. So anywhere you have erosion you also have places that are being \"filled\" up. When somewhere formed layers, it is just a result of receiving more material than what has eroded away, usually over thousands if not millions of year."
],
"score": [
8,
5
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l25vnf
|
The first humans made crude stone tools 2.5 million years ago, but our recorded history is only 5000 years old. Wtf did we do for 24,995,000 years?
|
Was it only recently that we started to build cities? Did something snap inside us 5k years ago, and we were like, "Alright, time to start civilization." Why did it take our ancestors, people with very similar brains to ours, so long to start making real strides in community building? Are their Forrest cities that just vanished in time? I know this question sounds incredibly stupid. I'm just really curious about pre-history.
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gk3fdhh",
"gk3fp0y",
"gk3frbs",
"gk3fqa3"
],
"text": [
"It was a long, slow buildup. We're used to history moving *FAST* because we have a globalized civilization with excellent record keeping, near instant access to huge amounts of data, and perfect communication. For the vast majority of human existence \"civilization\" was the 100 or so people you would ever meet in your life, records were whatever the oldest person could remember, data was whatever you personally could remember, and communication happened at walking pace. With those conditions it takes a long time for the right resources to come together to increase the complexity of your society and technology.",
"Well, 2,495,000 years. It’s a long technological jump from a stone picked up off the ground to break open bone marrow and a Clovis point arrow head. You have to also have the right kind of stone. Each advance requires someone unhappy with the current situation and willing to improve it. We’d still be using house phones if it weren’t just so very much more useful to carry a phone in your pocket. Also, taming fire is more like 100,000 to 200,000 years ago. And that is probably the invention that triggered some modernization. Then there’s farming. Once we decided to farm instead of forage, things really took off about 12,000 years ago.",
"The general answer is \"roaming around in small bands of no more than a couple hundred and hunting and foraging for food.\" However, the reason it took so long to develop complex social structures and agriculture (the real sufficiency conditions for civilization as we know it) is a whole field of study for historians, anthropologists, and biologists. I would note a couple of big things, though, the domestication of animals and plants was a looooooong term process and it was only after they had happened that agriculture became a viable option. Secondly, in the early days there were only a select few locations that were really amenable to early civilization. It's not a coincidence that every place that independently developed agriculture happened to be a regularly flooding river valley with grains that grew in the area. Again, though, this is a big question with lots of answers.",
"For most of prehistory, a hunter-gatherer lifestyle was just more practical. Trying to settle down in one place usually just plain meant death. Civilization was largely able to start because of the invention of farming, which is really not an intuitive thing to do. But once it was finally figured out, people suddenly had surplus food and didn't have to keep moving around. And even after that, writing wasn't invented until much later."
],
"score": [
30,
11,
6,
4
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
l2646z
|
what happens to your money if your bank goes out of business?
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"gk3gd67"
],
"text": [
"It depends where you live, in Europe a certain percentage of your savings are protected by the government, but there's a limit for each different bank you're with ( €100,000 )."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l266ql
|
How did people originally discover the earth’s axis and its degree of tilt?
|
Mathematics
|
explainlikeimfive
|
{
"a_id": [
"gk3hu0p",
"gk3i8er",
"gk3jhz3"
],
"text": [
"If you are able to travel around the world and use sextants and things to measure the compass bearings and angles of stuff in the sky, then the difference of Earth's spin axis to its orbital axis can be worked out. One way you could measure this is go stand somewhere on the equator, and keep records of where the sun rises and sets every day. If the Earth's axis were perfectly flat, then the sun would always rise and set perfectly due east and west. But in reality, that only happens on the equinoxes. On the solstices, the sunset and sunrise are at their furthest from true east and west. (You can also make this measurement from somewhere other than the equator, but deriving the axial tilt from that measurement requires a bit more math.)",
"This is something that has been known for centuries or more because humans like to stare at the night sky. Many ancient megalithic structures have been found that track the solstice and equinox, which are astrological events directly tied to the axis of the earth. One example is Chaco Canyon in New Mexico: URL_0 \"Between AD 900 and 1150, Chaco Canyon was a major center of culture for the Ancestral Puebloans.[a] Chacoans quarried sandstone blocks and hauled timber from great distances, assembling fifteen major complexes that remained the largest buildings ever built in North America until the 19th century.[2][4] Evidence of archaeoastronomy at Chaco has been proposed, with the \"Sun Dagger\" petroglyph at Fajada Butte a popular example. Many Chacoan buildings may have been aligned to capture the solar and lunar cycles,[5] requiring generations of astronomical observations and centuries of skillfully coordinated construction.[6] Climate change is thought to have led to the emigration of Chacoans and the eventual abandonment of the canyon, beginning with a fifty-year drought commencing in 1130.[7]\"",
"Shadows. Track the shadow at high noon each day for a year, a shadow cast by a fixed object that is not moved. By measuring the limits that the shadow reaches with the top of the structure that casts the shadow you can calculate the \"altitude\" (in degrees) of the Sun. For finding the Earth's axis, it will be parallel with the base of the shadow-casting structure and the shadow at high noon."
],
"score": [
5,
4,
3
],
"text_urls": [
[],
[
"https://en.m.wikipedia.org/wiki/Chaco_Culture_National_Historical_Park"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l267v2
|
Why aren't clocks/calendars 3/4 of a day behind (ahead?) the year before a leap year? Where does that 1/4 day each year go to wait?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gk3h9tl",
"gk3he02"
],
"text": [
"Well, they're ahead of the \"real\" solar year. It takes the Earth ~365.25 days to revolve around the sun. This means our calendar's year really does run ahead until we add the extra day every four years. > Where does that 1/4 day each year go to wait? It just means that Jan 1st 2021 started when the Earth was just a bit further back in its orbit around the sun relative to where it was in Jan 1st 2020. The \"time\" didn't go anywhere. Our days just don't evenly fill up a year.",
"It doesn't go anywhere, it just sits there. You simply won't notice the seasons being 3/4 day out of sync with the date, which is all the calendar being out of sync with the actual year length does."
],
"score": [
14,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l26ii7
|
Why do the fashion industry display "freakshows" on the catwalk? They know no one is actually going to walk with those outfits on the street?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gk3jcu5",
"gk3j1vr",
"gk3joxz"
],
"text": [
"The clearly “unwearable” is intended to be walking art, more or less. Similar to a traditional painting or sculpture, the textiles are the medium and the end product often serves as a social commentary, thought provoking piece, or simply creative outlet for the designer. These pieces are not created as Ready to Wear (RTW) or haute couture, which edges closer to, but not entirely unfathomable, as an item someone would purchase with the intent to wear.",
"Explanation Part A) Those runway looks are like commercials, the intention behind them is to market a brand identity and aesthetic more than it is to market actual clothes that actual people will actually wear. It's like those absurd car insurance commercials (looking at you GEICO) that are very surreal and silly but have nothing to do with car insurance; the point is that you remember them. Explanation Part B) You only see images of/remember the most radical and bizarre runway looks, because those are the ones that the media pick up and show to you, precisely because they are so absurd. And furthermore, it is their absurdity that makes them memorable to you, and being memorable is precisely what the designers wanted, so mission accomplished. Obviously the clothes that you end up buying are the ones you see in the stores. But you will tend to search for the clothes, and you will be more likely the buy the brands, that you have some memory of and some association in your mind of what their aesthetic is.",
"Same reason car companies spend millions designing and engineering concept cars that will never come to market, for the attention, the marketing, brand recognition..."
],
"score": [
22,
7,
5
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l26jw2
|
why pyramid schemes don't just stop recruiting people.
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"gk3j222",
"gk3j9x3"
],
"text": [
"If I'm in a pyramid scheme, I mostly gain money from people below me. If I'm at the bottom, how will I make money?",
"Because that's not how pyramid schemes work. Each level *doesn't* bring in consistent money - each level has a bunch of product they don't need and that they can't sell. They're down a bunch of money so their only choice is to recruit new people to sell that batch product to - people who don't want it but expect to be able to sell it themselves and make a profit. Each level can only break even by recruiting new members and shifting all their deficit onto their victims, which means once they run out of people to recruit the whole thing collapses and the people recruited on the lowest levels lose a lot of money."
],
"score": [
9,
5
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l26ocd
|
Why do humans have such complex vocal chords, with the ability to make extremely diverse noises, but other mammals can’t?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gk3ol2z"
],
"text": [
"Someone will be along with a better answer, but IIRC it has more to do with control over the vocal cords rather than our throats being particularly special. One article talks about a region of the brain's frontal lobe that is responsible for vocal pitch ( URL_0 ). There is also Broca's area in the left of the frontal lobe which is specifically tied to speech production ( URL_2 ). Some primates have been shown to have good enough vocal cords to reproduce human speech, but they're missing the brainware. This might include things like detailed motor control over the vocal tract ( URL_1 )."
],
"score": [
13
],
"text_urls": [
[
"https://www.sciencedaily.com/releases/2018/06/180628151903.htm",
"https://www.sciencemag.org/news/2016/12/why-monkeys-can-t-talk-and-what-they-would-sound-if-they-could",
"https://en.wikipedia.org/wiki/Broca%27s_area"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
l26vcx
|
Why and how does soap change into foam once it is mixed with water?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gk3y52w"
],
"text": [
"Soap molecules are composed of two parts: one is hydrophobic (avoids water) and the other one is hydrophile (is attracted to water). When they can, they orientate so that the hydrophobic part doesn't touch water but the hydrophile part does. When there's not a lot of soap, it goes on the surface, with the hydrophobic part sticking out. But when there's too much soap, they need to create more surface: they make bubbles with a layer of water surrounded by two layers of soap molecules (one on the outside of the bubble and one on the inside). And all the bubbles form foam. (It's easier to understand with a drawing, you can probably find some on google)"
],
"score": [
5
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l27f99
|
Would the medication of a “shake well” medication that separates be stronger or weaker as you reach the bottom of the bottle and why?
|
I want to think if anything it would be either the same or maybe even stronger, but I’m asking because when I start the bottle there is a thick layer of powder separated, but when I get towards the end there might not even really be any powder. I’d expect there’d be less obviously but just not that much less, making me think it might be weaker.
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gk3oyqn"
],
"text": [
"It depends on if the medication itself was more dense than the diluent. Take water and oil and put them together. The oil will float to the surface because it's less dense than the water. If the oil is the medicine, then as you get lower it will be weaker. If the water is the medicine, then it will get stronger. Assuming you don't mix properly, of course."
],
"score": [
5
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
l27l76
|
why do small objects like scraps of paper, or sand stick to the body?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gk3pp88"
],
"text": [
"static electricity. if an item is too large, the weight of the item is too great for base electrical charge. also, it has a little to do with moisture."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l27ltx
|
why aren’t bigger brains smarter?
|
Whales brains are much bigger than ours, why aren’t they smarter than us? I know density is important, such as our brains are wrinkled for more surface area, but shouldn’t sheer size of other species’ brain cancel out those benefits? Ps something something Neanderthals also had a bigger brain but still died out for some reason
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gk3r4qa",
"gk3qk4d",
"gk3rkc3"
],
"text": [
"In addition, some seemingly less intelligent brains tend to be incredibly tuned for certain functions like instinct, reflexes, and sensory specialization. So even though they don't often exhibit things like self reflection, emotion, or other human like traits, it doesn't necessarily mean they aren't smart in their own way.",
"The number of folds increase the surface area which is fractal in nature and isn't easy to replicate with pure increase in size. Also, a key difference is the prefrontal cortex which is particularly well developed in humans which is said to have a large effect on our intelligence.",
"Computer processors are getting both smaller and faster with each successive generation. This happens because each time they make the processor smaller the electrons have to travel a shorter distance between transistors. Since they always move at the same speed making the distance shorter means they get there faster. Even though each move is only a tiny bit faster when you multiply that by the millions of electrons flying between transistors in a computer core the end result is a much faster processor. The other thing that they gain by going smaller is that they can pack more actual transistors into the core but still occupy the same space and use the same amount of energy as a larger processor. So each time they make the processor smaller it gets faster and more complex. Brains work in the same way. A large brain with large cells isn't going to be as powerful as a brain with more smaller cells. That was the biggest difference between Neanderthal and human brains, our brains were smaller and had more cells packed into a smaller space."
],
"score": [
7,
3,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
l289ea
|
Why in video games do bodies of water look so real but liquid in a drinking glass looks so fake?
|
These days in video games, rivers, streams, oceans etc look so ridiculously realistic that you could swear you were looking at the real thing. But if a character pours a glass of scotch, they might as well be pouring a glass of light syrup. What’s the reason for this disconnect?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gk3y080",
"gk3uwtq"
],
"text": [
"Large bodies of water are usually not interactive, developers can make a flat plane texture that looks really good with minimal work. Liquid in a glass has to move in real time with a moving container, and is just a much smaller asset. This is especially hard if you can hold and manipulate the container in any way you want. Both can look better with things like real-time physics simulations, but large bodies of water are usually worth more attention and work than drinks in cups. Related, Polygon just did a video about Half Life Alyx's bottles - the liquids inside are simulated WAY better than most games. If you're interested enough to pose this question you'll probably enjoy the video",
"The mundane task of drinking is not an artistic focal point. Sailing on the sea as a pirate on the other hand, makes the sea very important."
],
"score": [
5,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
l28lcu
|
Why are human babies so incompetent at life compared to other species.
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gk3w5b3",
"gk3w7nz"
],
"text": [
"Evolutionary trade off. An adult human-sized brain would not fit through the birth canal of a woman, so as our brains continued to develop there were two options - have development happen after birth, or develop larger birth canals. Evolutionary pressures selected the former.",
"Basically: big heads. The size of our brains means that babies have to be born before they're really ready so they're starting from an earlier development point than most mammals."
],
"score": [
7,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l28ny6
|
How do you call phone numbers that have text in them?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gk3x99j",
"gk3wdnu"
],
"text": [
"Have you never seen letters on a phone keypad?",
"Number keys map to letters. Most phone pads show the letters as well, in a small font. 2 = ABC 3 = DEF 4 = GHI and so on."
],
"score": [
9,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l28ofk
|
Why does food taste better when you're hungry?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gk3y28e"
],
"text": [
"It hits the reward centre in your brain. Your brain is telling your body that it's starved of nutrients, so when it gets them the reward functions are switched on to encourage the behaviour. They are switched off when you are full and that's when eating food or drinking a drink feels like a mission. It's also why obese people and those with food or drink issues cannot sometimes control themselves. Their brain is messing with their perception of how satisfied they are. Their body is also used to a certain amount of calories, good or bad. Getting fit and healthy isn't just about food and exercise, it's a cognitive behavioural change of the brain. And the brain is a lazy bastard that hates change the older you get, which is why it's hard to change habits after it becomes a habit. The brain is amazing. Read some neuroscience books and stories and it's crazy what the brain can do and help you achieve. ALSO your gut/intestine is surrounded by its own brain tissue. Which affects people with irritable bowel syndrome (inflammation of gut due to certain foods, but less likely to cause cancer or colostomy), and irritable bowl disease/crohnes disease (similar name to ibs but different disease of the gut which can cause cancer and colostomy in the end with the wrong foods alongside liver/kidney/other organ damage). And these brain cells in your gut have their own ideas and don't always talk to the brain in your head. How amazing and weird is that!!!"
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l29ih5
|
How does Monosodium Glutamate (MSG) act as a flavor enhancer as opposed to something like table salt?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gk42f4j"
],
"text": [
"Monosodium glutamate, as you can work out from the name, dissociates into sodium ions and glutamate ions. The sodium acts as sodium always does; the glutamate stimulates its own set of taste buds, separate from the ones sodium does. This is what gives rise to the distinctive flavor of MSG."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2ajqm
|
what happens if you wear single use masks more than once?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gk48ykg"
],
"text": [
"Single use masks actually can be worn more than once. The issue is that you’re supposed to wash between uses or let it “air out” in a sanitary space before using it again. If you rewear single use masks without these precautions, you’re more likely to get the virus because you’re not killing it between uses. [source]( URL_1 ) [source]( URL_0 )"
],
"score": [
21
],
"text_urls": [
[
"https://www.google.com/amp/s/news.yahoo.com/amphtml/reuse-disposable-mask-yes-steps-192223361.html",
"https://www.connexionfrance.com/French-news/Disposable-masks-can-be-reused-and-washed-up-to-10-times-says-French-group-UFC-Que-Choisir"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2atnl
|
How is earth’s population made up of almost precisely 50/50 men and women? How do the numbers stay so close together?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gk4a22l",
"gk4rmin",
"gk4a3zb",
"gk4gujq",
"gk4aadl",
"gk4a4k4"
],
"text": [
"The law of large numbers. If something is random, the greater the number, the more it converges to the natural average. So like flipping a coin, if you do it ten times, you may get 8 heads and two tails, far off from the 50/50 chance expected. The more you do it, the closer to 50:50 it gets. And yeh 7 billion is a large number.",
"The sex ratio (percent of males/females born) in humans is slightly biased to males at 51%. It's generally close to 50/50 among the various species of animals. It turns out it's an advantage evolutionarily to have about half-and-half because it leads to the best chances of those people having more babies when they grow up. There are exceptions to the rule, but there's usually a weird reason. Woods Lemmings have about 75% female babies but they've got kooky genetics.",
"There is a 50/50 chance your child is a female / male. If you flip a coin 10 times you might get all heads. Flip a coin 10 billion times your most likely going to see results close to 50/50.",
"All the other answers explain how it's 50/50, but they don't explain why. The answer is evolution. Basically, if there were more of one sex than the other, then it would be advantageous to have offspring of the scarce sex, so genetic mutations that benefit the production of that offspring would have an advantage. But, after a few generations, the problem flips, because that scarcity becomes abundancy. It turns out that 50/50 is the stable equilibrium. [I leave a video about this same question, made by It's Okay To Be Smart.]( URL_0 )",
"It has to do with chromosomes, a man has x and y while a woman has x and x. That means that a child will get an x from its mother and an x or y from its father and since x and y have an equal chance of being given the polulation is roughly 50/50.",
"If you repeat any 50/50 situation like a coin flip a few billion times it’s very likely to end up being a dead tie. Yes there are more than just two outcomes (a coin can come to rest standing up on its edge) but law of probability says if you repeat this enough the result will be half and half."
],
"score": [
27,
10,
9,
8,
5,
3
],
"text_urls": [
[],
[],
[],
[
"https://www.youtube.com/watch?v=C3dCWxxVhVc"
],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2aufo
|
How do scalpers buy up goods online in seconds?
|
So I've been trying since the release date of the xbox series x to get a console for my nephew but everytime new shipments arrive they are gone in seconds wouldn't buys of this magnitude flag the credit or debit cards associated as fraudulent and not allow the transaction to process?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gk4a7y5",
"gk4fpt0"
],
"text": [
"They're not fraudulent transactions, they're real. The retailer doesn't care who they're selling to, they care about selling the product. If they have 1000 and they sell 1000, they're happy and the buyer is happy. Something in really high demand might have millions of people trying to buy at once, it's easy to sell out in a few seconds. Popular concerts see the same thing with ticket sales (in the beforetimes). If they have terms of service specifically to prevent scalping then they might be able to do something, but why would they care? The ire is usually directed at the console maker, not the retailer.",
"Simple answer is monitors. I do some reselling for side money and there are plenty of paid discord groups called \"cook groups\". The entire purpose of these discords is to provide people with information on all things reselling. They also have what are called monitors. They are web scraper bots that detect when items restock on specific websites and relay the link to the discord. Some people try to buy them manually by just clicking the link and others use software specifically for buying in mass quantities very fast that are just called bots. As for the fraudulent charges aspect. Credit and debit cards detect fraud mostly based on purchase history patterns so if someone is spending tons of money consistently then the charges will not be flagged. Also if you're wondering why websites can't just ip ban the people purchasing tons of the same item it is because bots use what are called proxies. Proxies are able to change the apparent location of all the virtual \"people\" trying to check out for that person's bot. It's all very complicated and bot devs are constantly updating their software to combat websites antibot strategies."
],
"score": [
7,
5
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
l2ax8x
|
How is it that the same food can have a different taste based on your mental state (i.e. hungry vs not hungry, stoned vs sober)
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gk4d5k5",
"gk4exjj"
],
"text": [
"Taste isn't a single thing (like flavor is), but an amalgamation of your senses. Texture, smell, mental state can all have a big effect on how food tastes.",
"Your body chemistry changes it. Gatoraid actually designs their flavors to taste best when exercising. Probably has to do with what you need in a situation like craving sweets when your blood sugar is low etc."
],
"score": [
4,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2b8d2
|
Why can't Flight Traffic Controllers remote control Airplanes in Emergency Situations?
|
So I just learned that all the new, big airplanes can basically do everything on auto pilot, even land and stop the plane. So why can't they just program the auto pilot remotely if e.g. the pilots passed out?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gk4cgp5",
"gk4dids"
],
"text": [
"> So why can't they just program the auto pilot remotely if e.g. the pilots passed out? Because both pilots becoming incapacitated pretty much **never** happens, so it's not worth the effort to establish the necessary infrastructure",
"The risk of that system being compromised and used for evil grossly outweighs the incredibly tiny fraction of times you’d need it. This isn’t new to new airplanes, large jets have been routinely capable of auto land for about 50 years."
],
"score": [
8,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
l2bgi2
|
why do we do a double-breath-thing when we are crying and/or had a bad day
|
I really don't know how to describe it, necessarily. Its like hyperventilating, but calmer? For instance, it usually occurs when I've finished sobbing or holding my breath in unconsciously.
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gk4dtmn"
],
"text": [
"When you are stressed your breath shallower or “into you chest”. The correct way of breathing (yes there’s a correct way) is breathing deep with your diaphragm. Feels like you’re breathing into your stomach. Your double breath, or gasp, or yawn is because you are literally out of breath from breathing shallow. Side note - deep breathing is wonderful practice to maintain. Very beneficial."
],
"score": [
7
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
l2cftw
|
Why are pepper packets so empty compared to salt packets?
|
I'm talking about the single serving packets that are used in some restaurants, especially fast food ones. I sweat the salt packets are 3-4x more full.
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gk4kvgu",
"gk4v9uc"
],
"text": [
"Pepper is more expensive than salt. In the olden days (15th-16th centuries), Indian pepper was highly sought after by Europeans. The status of Indian pepper was akin to gold in value, such was its demand. It's not so valuable now, but it is definitely more valuable than salt. This seems to be why the quantity of pepper is controlled more than salt, especially in the freely available single serve packets.",
"Salt is a mineral that exists in vast vast quantities, can be mined, collected from sea water, etc. It's daaaamn plentiful. Pepper is made from the dried ground seeds of the peppercorn plant, originally only found in India. According to the UN, in 2018 the world produced 732,524 tonnes of pepper. That same year, the world produced ~300,000,000 tonnes of salt. Even though only about 7% is food grade, that still leaves a ratio of 28 tonnes of food grade salt produced per every one tonne of pepper."
],
"score": [
9,
5
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
l2cjpa
|
how do pens with open pen caps not dry out?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gk4mgj4",
"gk53fag",
"gk4vx7j",
"gk4ktsq",
"gk5ea96"
],
"text": [
"[This is the writing end of a ballpoint pen.]( URL_0 ) The ink is in a tube and the ball rolls over it and only part of the ball is exposed at any time.",
"The modern ballpoint has a cap mostly as a vestigial feature. They work basically like a stick of roll-on deodorant. The ink is a rather viscous mix of pigment and lubricant that won't really dry out when exposed to air. Even if it does, only the exterior side of the ball will be exposed, and it'll pick up more wet ink when its spun around when you write. This is why scribbling will usually get it to write again. The cap also keeps it from writing on surfaces (like your shirt or your skin, if you use it to scratch your back) that you don't mean to. You can achieve this by retracting the pen too, like in fancy pens, so you don't really even need a cap for a ballpoint. Before the ballpoint, there were fountain pens. Fountain pens function in quite a different way. Ink is stored in a reservoir, runs down a series of channels (via capillary action) to the page. Its basically like writing with a finely controlled leak instead of roll-on deodorant. For capillary action to work, the ink in a fountain pen had to be quite runny, so its water-based. The water would evaporate over time (quite quickly, actually) if exposed to air, so caps were air tight.",
"Pen caps aren't intended to keep them from drying out, they are intended to keep the pen from marking up your shirt when you put it in your shirt pocket.",
"I might be wrong but I believe most if not all pens have a ballpoint mechanism, so as soon as you start rolling it (moving the pen tip against the paper) ink starts falling onto the ballpoint and to the paper, that's why old pens take a few scribbles to get them working.",
"It depends on the type of ink. Gel pens dry out. Ballpoint pens dry out, but over a much longer period of time. Space pens never dry out. Here is why a pressurized fisher space pen does not dry out - the ink is thixotropic. That means that it is a solid when still, and is liquified by being sheared by the ball. So when the pen is not being used, the ink does not dry out."
],
"score": [
39,
14,
11,
11,
5
],
"text_urls": [
[
"https://imgur.com/6RjoMFy"
],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2csu6
|
Why do our ears make a low, deafening ringing noise for a short period of time at random times in a day?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gk4ujoj",
"gk4uzd5"
],
"text": [
"This is not a universal experience. Speak to a doctor. Do not take medical advice from the internet. Do not take medical advice from Reddit. See your doctor for medical advice.",
"Sounds (heh) like tinnitus, s'what I've got. Random ringing, occassional muscle tremors in the inner ear from not giving af about my hearing. Get in touch with your doctor to be sure, though."
],
"score": [
24,
11
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2cucv
|
Why do we (and other animals) scream, moan etc. when feeling pain, pleasure, shocked and scared?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gk4mbu1",
"gk4maj5",
"gk4mnuz"
],
"text": [
"In social animals, all of those states are things you want to communicate to others, especially feelings associated with danger. A lizard doesn't really make noise when it's hurt, but a cow wants to alert others for aid and their safety.",
"Because it brings up emotions of distress to other animals/humans arround us. They sense that we’re in state of pain when we cry and they see that we’re scared when we yell",
"These are all vital things for social animals to communicate. When startled, we want to get the attention of others and frighten them; we scream. When we feel good, we want others to know so that we may continue to do what we are doing."
],
"score": [
9,
3,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2d3ja
|
Why do we have multiple pee “streams” sometimes?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gk4wjrh"
],
"text": [
"The walls of the opening of the urethra can sometimes stick together and form a temporary obstruction (especially post-orgasm). Once that happens, it's the same effect as if you were to hold your thumb over the end of a running water hose. The water sprays in random directions at higher pressure due to the obstruction."
],
"score": [
28
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2d7o9
|
What makes a force "fundamental"?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gk4oqfk"
],
"text": [
"To put it simply a fundamental force is an interaction that can't be *reduced* to just a combination of simpler interactions. For example, the force of a chair pushing up on you is really just the electrons in the chair repelling the electrons in your body through the electromagnetic force. However, the electromagnetic force itself can't be turned into a combination of other interactions. It just *is* for lack of a better word."
],
"score": [
9
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2eafz
|
Charliehorses are caused by acid build up in the muscle tissue, but what causes your leg tendons to seize, so much so, it causes your anlkes to turn almost into clubbed feet?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gk50w9o",
"gk51b7e"
],
"text": [
"Tendons can't contract; muscles contract. Muscle spasms can be caused by overwork, dehydration, strain, or electrolyte imbalances. You can alleviate severe spasms with proper nutrition, hydration, stretching, and massage. I've had horrible cramps and spasms my whole life and have found that taking Calcium, Magnesium, and Zinc help considerably.",
"I don't think the premise of this question is even correct. Charlie horses aren't caused by acid buildup..."
],
"score": [
4,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2edg7
|
Refinance Student Loans?
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"gk4zkvd",
"gk4x8er"
],
"text": [
"You have a loan with lender A at 7% interests. Lender B offers to pay off those loans and give you a new loan for the same amount at 4%. Now you save a ton in interest and bank B gets your interest money instead of the original one.",
"Basically just business. A competitor giving you a better deal. Let's say I lend you $100 but you can only pay $10 a month. I agree to lend you the $100 but you got to pay me $10 for 12 months so I make a profit of $20 on a capital of $100. 6 months pass you paid me $60. Someone else offers to refinance your loan. He's gonna pay the $60 you owe me, so you won't owe me anything anymore. But you have to pay him $8 for 10 months. Easier for you but he's gonna make $20 on a capital of $60. This is an over simplification there are plenty of other factors to consider of course"
],
"score": [
3,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2g0e7
|
Why do we feel hungry when we don't eat for a while? Why can't our body use stored fat and prevent us from getting hungry?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gk5628c"
],
"text": [
"Your brain telling you that you're hungry is a survival mechanism designed so that you can maintain a comfortable weight and level of energy to function. So you don't forget to eat. So there are consequences and signals for not eating. So you can't focus on any other goal than to find food and satisfy that gnawing discomfort. Your body using stored fat is a survival mechanism preventing you from dying if you choose to ignore those signals telling you to eat. But stored fat runs out eventually. And then you die. So both of these mechanisms are needed to survive."
],
"score": [
11
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2g5qh
|
California nutritional label warning
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gk57nfd",
"gk57dpo",
"gk582jv"
],
"text": [
"California passed a law as a ballot prop (a law proposed by people rather than politicians) that requires this warning. Unfortunately the wording of the law is a bit poor I'm that it includes anything in any quantity that could possibly cause cancer. Specifically anything that has a 1 in 100,000 chance of increasing risk by any percentage. It's not bad in principle, but it means that a ton of different products that aren't really cancer risks unless you say, vaporize the thing in a fire and inhale the fumes for a fee weeks. The law itself was only ever even meant to protect drinking water. So you can't flush things like Xylene, or a chopped up laptop into river water. All these false alarms mask the real cancer risks and make the labeling not really useful at all as a warning. Like there's no difference between the labeling on say a gallon of MEK (which isn't even sold anymore) and a bottle of glue or a teacup.",
"The state of california passed a law, proposition 65, which requires any product which may contain even trace amounts of any chemical known to cause cancer in sufficient quantities to have that label. This means that basically anything with a wood product, any heating process, or any plastic, to have the label. Translated: WOOD. COOKED FOOD. The law fails to distinguish danger levels. Something which has no danger whatsoever unless you burn it and huff the fumes gets exactly the same label as gasoline.",
"California has a much higher (stricter) bar with regards to what degree of cancer risk needs a label. So for most things if you have a below a 10/1,000,000 (made up number) chance of getting cancer from it they typically don't put a warning label on it because its like warning you about meteorites. California has it set to 5/1,000,000, so all the things that have 7/1,000,000 need a special label for california but not for everywhere else. The truth is nearly everything causes cancer (literally), but most things aren't carcinogenic enough to worry about, california is just (legally) more sensitive to that stuff, thats all."
],
"score": [
9,
5,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2gkyl
|
What happens in the brain, when you're really tired but you force your brain to concentrate on a complex matter.
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gk8mryw"
],
"text": [
"Oh boy. The neuroscience of concentration, which is under the umbrella of what neuroscience calls \"attention\" is extremely complicated. It's very difficult to define, and because it's hard to define it's hard to test. You're asking about what we call top-down attention. And the one you're talking about is near-impossible to test. When you think about something without moving, there's no way we can examine it short of neural imaging. In neural imaging we can only see what's parts of the brain are most energetic but we can't know why or how it's happening. Different kinds of top down attention will require different parts of the brain. Is it math? Music? COD? Meditation? Each one requires a vastly different network of brain activity. And if brain activity is the only thing we can look at to check attention, we don't have much going for us at all. There are a couple super broad commonalities of how top down attention works. One commonality of top down attention is that they all involve the front outer part of your brain called the frontal cortex, some way some how. Other aspect of top down attention is that the brain will selectively begin to filter out irrelevant info to make the thing you want easier to \"focus on.\" Depending on what you're trying to focus on, the mechanisms will be very different. Unfortunately it only gets murkier from there. You're asking about \"complex matters.\" Some neuroscientists will say that tracking a triangle as it moves through a bunch of wiggly lines is complex. Others will say lifting an arm is complex. Other people will say math is more complex. Then there's the philosophical issue. Whoever in the brain making the decision is sometimes nicknamed the \"mover unmoved.\" In other words, it's the theoretical thing in the brain that isn't being controlled by something else. In a world where every action is the product of another action, does that truly exist? If not, maybe there's no such thing as deciding to pay attention at all. If youre interested in ADD, however, I can try to explain in the comments how its not a simply concentration problem either. TLDR: No one knows"
],
"score": [
18
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2gqyn
|
I have 8GB RAM on my phone, why is it that usually only 4GB of that is available? What is it using the other 4GB for if i don't have any apps in the background?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gk5a0ht",
"gk5ls3w",
"gk5pl1n"
],
"text": [
"Your phone itself, cellular signal, WiFi signal, Bluetooth signal, etc.. all these things and more take up RAM while your phone is running.",
"If it always shows as having exactly 4GB the manufacturer probably locked 4GB of ram for OS and hardware uses and then lets apps use the remaining 4GB. If it usually shows as having close to 4GB available but can vary between 4 and higher numbers like 5 or 5.5 then your phone probably just has a really inefficient version of android installed or some other custom OS that has not been well optimized.",
"Another factor is graphics memory. Phones don't have dedicated memory for its GPU so a certain amount of RAM is reserved. Otherwise, keeping things in memory allows things to be opened faster. It doesn't consume any more power, RAM is always powered regardless of capacity used. I imagine all phone OEMs are keeping camera apps in memory to get those booted up faster."
],
"score": [
9,
4,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2h18q
|
How do neurotransmitters get to your nerves? Like, where are they the rest of the time and what sends them to a nerve and how and where do they go?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gk5dmkf",
"gk6yk6s"
],
"text": [
"The neurotransmitters are formed at the nerve end and stored inside the nerve end called as vesicles. When a stimulus/depolarise they are released into the synaptic cleft where they are uptaken by the receiving end which can be a muscle or another nerve. URL_0",
"Each neuron (brain cell) manufactures its own supply of neurotransmitters, and, when activated, releases them from the ends of its axon (essentially an output cable). [Illustration here]( URL_0 ). Some neurotransmitters are made in the cell body (soma) and \"shipped\" down the axon to the terminals. Others are made in the terminals themselves, using cellular machinery that was shipped down the axon from the soma. Each neuron 'decides' when to release neurotransmitters based on its inputs (the signals it gets from other neurons via its dendrites). This is a startlingly complicated process. How the inputs are physically arranged on the dendrites can make it so that inhibitory input X can cancel out excitatory input A, but not B, and the combination of excitatory input A and C might be enough to make the neuron fire, or B and D, but not A and B (or any combination of A/B with C/D). Lastly, it's important to understand that neurotransmitters are a direct, targeted neuron-to-neuron signal. They do not just float around the brain, affecting everything that's going on. Part of the definition of a neurotransmitter is that when neuron A releases a neurotransmitter, it only affects neurons that neuron A is directly connected to. My best analogy for explaining neurotransmitters is based on farts. A hormone is like farting in a closed room. Everyone smells it. Neurotransmitter release is more like firmly pressing your butt onto your best friend Steve's face, so that your cheeks form a seal (this is essentially what a synapse is), and farting directly up his nose. Only Steve gets to smell it, and you only need a tiny fart to make sure Steve gets the message. Of course, neurons can connect to many other neurons, so you'd have to have multiple butts (and multiple friends as close as Steve) to pull this off properly. And everyone would need more noses as well. About 7,000 butts / noses, on average."
],
"score": [
4,
3
],
"text_urls": [
[
"https://images.app.goo.gl/tjtFKWtgT13ZvTqw9"
],
[
"http://droualb.faculty.mjc.edu/Course%20Materials/Physiology%20101/Chapter%20Notes/Fall%202007/figure_07_02_labeled.jpg"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2h77z
|
What is the difference between cow milk and other animals' milk which makes us drink cow milk more, in other words, why do we mostly drink cow milk and not let's say pig milk?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gk5d9ey"
],
"text": [
"Cows make a lot of milk, especially modern breeds. And they're fairly easy to milk, unlike, say, pigs. Sows get bitey when they're nursing. But it's not just cows. European cultures use sheep milk and goat milk, and, in some places, [water] buffalo milk. It mostly goes to cheese, but you can find whole milk if you look around. Other cultures milk horses and camels— and now we're about out of domestic animals that are big enough to be worth milking."
],
"score": [
25
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2hga9
|
Why, on maps, does Greenland never have any data?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gk5fzbm",
"gk5ebh9",
"gk5jr7e"
],
"text": [
"Many of these statistics you see on these types of maps come from reports within the country. Greenland is a part of Denmark, so technically, they could fall under the statistics of Denmark. However, Denmark might not separate Greenland's results from the mainland's. This could create odd numbers. Denmark is in the 10 of the GDP per capita. However, Greenland is not a rich place. Denmark is rich, and Greenland is a part of Denmark, but it would misleading to say that there is richness in Greenland proper. Since these map makers don't really know how to extract Greenland's specific data from Denmark, they might say that they have no data.",
"What do you mean? Greenland has plenty of data on Google Maps. At least the populated areas do. The unpopulated ones dont have any data because well, theyre unpopulated. What is a map of a region that is unpopulated supposed to show?",
"There's a few places that have almost no data ever published, but Greenland just happens to be a very large chunk of land so it's hard to ignore. Also it's really really sparsely populsted. Like 60,000 people vs Denmark's near 6 million. So like 1%. Because it's mostly independent, but still part of Denmark it generally gets counted as its own region on maps, but it's statistics are buried in Denmark's, and often not split out if it was collected at all. French guiana is in a fairly similar situation with France and likewise often shows up blank on data maps a lot. But French Guiana is smaller and easier to miss. I found this really neat chart that shows how often places aren't included in statistics maps which is pretty neat and worth a look. Though other areas that don't have data have reasons different from greenland. Like North Korea who just doesn't publish statistics, or Western Sahara because it's ownership is in dispute. URL_0"
],
"score": [
7,
3,
3
],
"text_urls": [
[],
[],
[
"https://assets-rbl-ms.cdn.ampproject.org/i/s/assets.rbl.ms/18339603/origin.jpg"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2hhjd
|
How do pregnancy tests work? How are we able to take a chemical change in our body that is very complex and turn it into something simple, and easy to identify?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gk5en4w",
"gk5f4ck",
"gk5epyj",
"gk5ewlo"
],
"text": [
"The human body is run by chemical and electrical signals. The chemical signals are called hormones. When a woman is pregnant, the special hormone called *human chorionic gonadotropin*. This is released when a fertilized egg attaches to the uterine lining. All the pregnancy test does is look for this specific hormone. If it detects it, then it gives the positive result.",
"Pretty easy. When pregnant, the woman's body makes HCG all by itself. And it excretes it in urine. So we test for HCG. If you have HCG, you are pregnant. It can also be found in the blood so you can do a blood test to see if you are pregnant. Lucky for us the human body just designed this all by itself. Not very complex at all. Its as easy as just detecting it.",
"This [image]( URL_0 ) sums it up pretty well. The tests look for hCG in the urine. Antibodies bind to it, then they bind to antibodies on the strip.",
"It's because pregnant women produce a very unique hormone called HCG during pregnancy. Pregnancy tests detect elevated levels of this particular hormone and uses it to determine if you're pregnant. In very rare cases, you can have a false-positive result. This means you're not pregnant but the test says you are. You could have a false-positive result if you have blood or protein in your pee. Certain drugs, such as tranquilizers, anticonvulsants, hypnotics, and fertility drugs, could cause false-positive results. Men can also test positive because certain testicular cancers results to elevated levels of HCG."
],
"score": [
9,
4,
3,
3
],
"text_urls": [
[],
[],
[
"https://i1.wp.com/www.compoundchem.com/wp-content/uploads/2018/11/How-do-pregnancy-tests-work_.png?ssl=1"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2humb
|
The cost of gasoline a month
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gk5gghy"
],
"text": [
"Not enough data. We don't need to know how many minutes, we need to know: 1 - The cost of gasoline 2 - How many km per gallon the SUV gets Then it's simple math. 280 km divided by km per gallon, multiply that by the cost per gallon."
],
"score": [
4
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2iavb
|
Why is it so hard to find where im going if my music is too loud?
|
Like when youre in a car trying to find somewhere you arent familiar with it becoms much harder if the music is too loud, so we turn it down to be able to see better.
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gk5iwhb"
],
"text": [
"It's not seeing that is the problem. It's looking for specific landmarks or street signs while music attempts to distract the brain. Essentially the problem is that you can't hear yourself think"
],
"score": [
11
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
l2icz1
|
Why do we tend to prefer the cold side of the pillow?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gk5r60q"
],
"text": [
"I am here, my children. A Neuroscientist by the name of Matthew Walker was on Joe Rogan a couple years ago and he basically did the entire episode on sleep. I'll link it below. To answer your question; the reason we like the colder side of the pillow is because the brain (or the body in general) has to dip a few degrees in order to be comfortable enough for sleep. So what's happening is that you warm one side of the pillow, get uncomfortable (because it's too warm to cool off/let off heat) then you turn the pillow which hasn't been in contact with your body heat and is cooler than your body heat. Taking a warm bath before bed also helps your body to expel a lot of internal heat. As does sleeping in your boxer or whatnot. Source; URL_0 Tldr; Brain and body needs to be cold to go to sleep."
],
"score": [
3
],
"text_urls": [
[
"https://youtu.be/pwaWilO_Pig"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2igc0
|
How are fireworks designed? How do theyake the fireworks into shapes when it explodes?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gk6gyq6"
],
"text": [
"There are a few different types of ways to make fireworks. But for the starshells that you often see in fireworks display creating the pretty patterns they are basically a big ball of gunpowder with smaller \"stars\" in them which glow in different colors when ignited. When the fuse runs down and ignites the gunpowder it explodes creating a loud bang and throwing the stars out in all directions igniting them at the same time. The stars that are towards the edges of the shell will be thrown the furthest and the stars in the center of the shell will be thrown the shortest. So the stars end up in about the same relative position to each other as they were in the shell. Fireworks manufacturers use this to make sure the stars are placed neatly in certain patterns within the shell and stay in place embedded in the gunpowder until it explodes. By being careful when you launch the shells into the sky you can also keep its orientation as well."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2irmr
|
Why does steller fusion end at Iron? Why does Iron have no more energy to give for fusion?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gk5lpbt",
"gk5lwci",
"gk5lisl"
],
"text": [
"[Because of this chart up here.]( URL_0 ) Going from elements lower on the chart to higher on the chart by fission/fusion/other means releases energy, going down requires energy. As you can see, iron is the peak.",
"As the size of the nucleus increases, the energy you get out of fusion decreases. Iron just so happens to be the place where there isn't enough energy being released to keep the fusion process going.",
"Iron is the most stable element. Fusion and fission basically harvest energy by binding nucleons more strongly. Iron is the most strongly bound one. So pretty much the same reason why you can't light up water or CO² to release even more energy. It's already in the most stable state and can't give more energy by stabilizing further."
],
"score": [
6,
5,
3
],
"text_urls": [
[
"https://upload.wikimedia.org/wikipedia/commons/thumb/5/53/Binding_energy_curve_-_common_isotopes.svg/500px-Binding_energy_curve_-_common_isotopes.svg.png"
],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2j1h3
|
Why do senior citizens often fall for simple/transparent scams ?
|
Psychology
|
explainlikeimfive
|
{
"a_id": [
"gk5mq5n",
"gk5mpmc",
"gk5mt29",
"gk68iyd"
],
"text": [
"I learned about this in my marketing persuasion class. Sometimes they can feel lonely so a phone call can make them feel like they have someone to talk to. They also trust others easily, so they’re easier to persuade and are more vulnerable.",
"Dementia, general slower cognitive functioning, along with quickly advancing technology that they don’t understand fully.",
"A majority of senior citizens are living off of a fixed income. They’re desperate to find another income stream that suits their lifestyle. This is before taking account any sort of naivety they may have of modern scams and technology. God forbid they be simultaneously suffering any sort of cognitive decline.",
"They have learned to accept that many things in the world do not make sense. Their generation learned to trust people who sound official, or people who run websites. I knew a woman who struggled to realize that *anybody* could host a 'news' website without any credentials. So, if somebody calls you and tells you your computer is broken and needs their help, you say \"okay\". Of course, this can be largely prevented with some critical thinking, but it's easier not to do that."
],
"score": [
7,
6,
4,
3
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2jvge
|
Why does direct sunlight make people sometimes sneeze?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gk5rq5g"
],
"text": [
"It's called the [Photic Sneeze Reflex]( URL_0 ) or Autosomal Dominant Compelling Helio-Ophthalmic Outburst (**ACHOO**) syndrome. The nerve for your eyes in bright light triggers the sneeze reflex as they are right next to each other. It affects 18-35% of people. I'm one of them!"
],
"score": [
31
],
"text_urls": [
[
"https://en.wikipedia.org/wiki/Photic_sneeze_reflex"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2k8jr
|
Why do sausages fried in a pan curl up but sausages fried on a BBQ remain straight?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gk5su7u"
],
"text": [
"The difference isn’t likely the cooking method. Different sausages will curl differently depending on the collagen levels in the skin. When the collagen is heated it shrinks! When heated unevenly it shrinks unevenly, creating a curling effect. Good appliances that heat evenly will create a straight sausage!"
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2kegz
|
How did we vividly learn about the lives & history of people or events that happened way way back (Like BC era/Socrates' life/stuff like that)?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gk5teh6",
"gk5txwv"
],
"text": [
"Mostly from writers of that time whose works were preserved. We basically reconstuct the past from many different sources that are partially incomplete or not necessarily historically accurate. But when several independant writers agree on something we can be pretty sure it really happened. Aside from that we have the archaelogical record. Buildings, objects and even graves from that time that confirm or disprove certain parts of writing to make the picture more clear",
"Broadly speaking, there were historians contemporary to ancient peeps that jotted some things down. Or even a shopkeeper that wrote \"Socrates owes me five bucks for wine\". Tax records, church records, and census are another common contemporary source. Then, there were later generations who wrote down stories of oral histories. They may have talked to descendants or explored places famous people lives while the structure still stood, so it's super helpful for us modern peeps. Even later, professional history people collected this information and found more, like rubbish heaps which give them an idea of what the ordinary crap no one would bother to describe in a history or diary. Also, they might find a body (depends on the circumstances) and go full Forensic Files, checking bones or whatever else for health to get an idea of diet. The collate all this info and get a picture of what a figure's life would have been like in the context of their environment. However, the caveat is they don't know-know. It's circumstantial evidence. They have good guesses, and good ideas, but people do make mistakes or tell lies in stories, historians might make incorrect assumptions. Still, it's a pretty decent picture."
],
"score": [
4,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2ktr0
|
Why does money always take a few days to arrive when you send it to a bank account. And why can you sometimes send it instantly and sometimes not?
|
Thanks :)
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gk5wuuo"
],
"text": [
"If the accounts are held in the same bank, transfers are usually immediate. If not, the transaction is usually sent for clearing which might be batched at the end of the day. What happens depends on the systems in the particular country. International transfers will take even more time. Of course, the cynical response is that there is no direct incentive (other than customer satisfaction and marketing) for a bank to want to speed this up for standard account holders. When you are sending money, the money is deducted immediately from your account (or put on hold) and the recipient doesn't necessarily get access to those funds until a few days later. Note: the US is a bit primitive in some respects, many countries have systems that allow for nearly immediate fund transfers between accounts at different banks at very low cost. EDIT: assuming you are in the US."
],
"score": [
6
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
l2l5nd
|
Due to solar flares that affect the Earth's magnetic field, many sea creatures lose their sense of direction and get washed up. While I understand the direction issue, how can big mammals like whales end up on the shore? Don't they see or feel the water getting shallower and therefore unsafe?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gk62mhd",
"gk61ve2",
"gk61ysu",
"gk6qcqx",
"gk61led",
"gk6jdzk",
"gk64wsg",
"gk6eaku",
"gk6okbf",
"gk64ckt",
"gk6v5hm",
"gk65utk",
"gk6g00r",
"gk61jq3",
"gk75znz"
],
"text": [
"Maybe a slightly better answer: the flare is affecting their senses, but noticing the shore getting closer would also be some sense data. Instead of overly-trusting your GPS, think of it like the brain falling for optical illusions due to trying to understand what the sensory organs are perceiving. Or more ELI5; if your sight says the car is far away but your hearing says it honked right next to you, which sense do you choose to believe? Some animals lose the coin flip.",
"So similar to how people trust their navigation systems and drive off the road or into a lake, animals will trust their navigation systems implicitly too. Adding to this, whales and a lot of aquatic life cant swim backwards so if they start to get stuck all they can do is turn to try and head back out. Meanwhile the waves are pushing them closer to shore little by little and their struggling to turn will move them closer to shore little by little while giving the waves a bigger surface area to push on. And depending on the time if day, the water maybe going out for low tide.",
"I think the reasoning for whale beaching is not 100% known? Some theories being disorientation, sickness/disease, damaged senses (such as hearing from shipping), and even suicide such as due to pain. And others might be accidental after hunting, as orcas at least have been repeatedly been seen jumping on top land to hunt seals. This is the first time I've seen it suggests solar flares could cause any disorientation to whales. Edit: Based on comments there seems to be a lot of consensus on (military) sonar damaging or disorientating whales.",
"This may not be the answer you wanted to hear, but recently studies are showing that ship SONAR, and in particular military grade SONAR is very highly correlated with beaching events. The whales have mind-boggling \"hearing\" abilities for water, and we're going around blasting superpowered pops to map things. We're probably either making them go \"deaf\" or torturing them. They are also MORE social than humans, or perhaps any other creature, so when something goes wrong in a pod, it could easily be mass psychosis. (Something humans are testing out more and more, if you catch my drift..)",
"Probably the same way we humans sometimes drive off a cliff. By being distracted or having a panic attack",
"I remember reading something about some whales beaching themself, because they are old, weak or sick and they either beach or drown. And since they are mammals, their anti drowning reflex is still super strong, so they rather beach themselves than drown.",
"i know this sucks as an eli5 answer but when it comes to whales especially, environmentalists blame humans to the largest degree. sonar and all kinds of military grade equipment and even explosions are apparently to blame. i cant comment on it any further, but if someone had a source on any of that, i'd add it to the op link from comments: URL_0 thanks to ToYoungForTragedy",
"The cause of cetacean stranding (beached whales) isn't clearly known. Although it's happened since before recorded history, some of the more recent beachings have been related to mid frequency active sonar. I imagine hearing some screaming, piercing sound might either mess with your focus, or be so painful or scary that you do anything to escape it, and consequently head to shallower water where the sound is more likely to attenuate in the waves and reefs. I'm not saying this is what happens, I'm saying it's what I imagine happens. No one really knows why whales beach themselves",
"Ever follow your gps into a traffic jam or if you were an early adopter, into a lake? It’s like that.",
"Maybe they're trying to evolve to live on land again - like mudskippers? :)",
"Sonar created by humans and used by submarines/ boats cause whales to beach themselves. It isn't solar flares.",
"Whales may be stranded due to navigating by the Earth's magnetism or be confused by sonar and other noise in the water.",
"I have followed my GPS straight into a ditch. Like literally a ditch. GPS was taking me along some back roads and I was on a dirt road with a gate that was open, and ahead of me was nothing but dirt that was, like, carved out? There was clearly a center of the dirt road and along the center were deep ditches (as if someone had driven a car A LOT along the road and then rain washed/eroded it further down). I thought \"This looks dangerous but I guess if the GPS is taking me this way, it must be right?\" And I drove forward and the wheels promptly dropped and high centered my car.",
"Why would they feel the water getting shallower?",
"When I'm dizzy, my eyes tell me the ground is getting closer but my equilibrium says go that way. I don't know if it is the same thing, but I can certainly understand how it feels to get conflicting information from my senses and not be able to do anything about it."
],
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[],
[],
[],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2ll75
|
Even battery packs consist of many cylindrical cells making a bigger battery, why are they not in a cuboidal shape so there is no space between cells and can store more of the chemicals for a battery which lasts longer? Why is cylindrical the standard?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gk5yzqc",
"gk5yuyk"
],
"text": [
"Batteries are actually made up of thin layers of foil. The more you can compress these together the higher energy density you will get. There are currently two common ways of doing this. First is to roll the foils up into a very tight roll and then encapsulate it in a cylinder. The other is to fold the battery in multiple layers so that you end up with a flat rectangle that is then pushed into a box. This is for example how cell phone batteries are made and you would expect that this would be more efficient for large batteries as it can fill the entire volume while cylinders needs space between them. But the problem is that in order to get the best density you need to compress the foil very tight together. However if only one part of the foil gets compressed too much it will catch fire. This was the reason for the public recall of certain cell phones a few years back. To avoid this you need the plates used to push the foils together to be very strong so they do not flex. And this takes up both space and volume. However the cylinder shape is much stronger then a plate and will apply an even pressure over the entire content. So the walls of a cylindrical battery can be made much thinner then the walls of a flat battery. And this makes up for more then the lost volume by using the cylindrical batteries.",
"Some electric vehicles do use prismatic cells. Cylindrical cells are very efficient in their manufacture and energy density, so there is no guarantee that a prismatic cell has higher volumetric energy density than a set of cylindrical cells. Further, there are considerable challenges of removing heat from large battery packs, and having air or fluid flowing between the small cells is a useful way of achieving this."
],
"score": [
13,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2m2m9
|
Why do we have to purchase website names why can't we just have a system like usernames on sites? Like whom are we even buying from? What stops us from just straight up using it for all I know internet is free right?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gk60qz4",
"gk61kbu"
],
"text": [
"Let's say the post office was an entirely private operation, and would only send and deliver mail to people who were customers. So you sign up to have your address added to their list of customers so you can do this \"mail\" thing- otherwise, you just flat don't exist for mail purposes. You're buying recognition from the companies that route and sort electronic traffic (the equivalent of mail in the postal service example) when you buy a website name.",
"In addition to what u/ShalmaneserIII correctly pointed out you may consult [this]( URL_0 ) if you're interested in the more technical background. Also keep in mind that you're generally not **buying** domain names from accredited registrars. You're **renting** them."
],
"score": [
8,
3
],
"text_urls": [
[],
[
"https://en.wikipedia.org/wiki/Domain_Name_System"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2m3qb
|
Why does the Bohr model only work for hydrogen and why are models like the Schrödinger model more accurate than the Bohr?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gk61dby"
],
"text": [
"The reason is the complex interaction between protons and electrons. Each individual proton has a unique effect to each electron and visa versa. When you get multiple of each the model becomes exponentially more complex as you have ever more force vectors from each particle and each is de localized through an area especially when incorporated into benzene rings or something like that. I know the explanation isn’t perfect but I hope it helps"
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2m9yx
|
2020 rover system specs.
|
Why does the 2020 rover have such weak system specs? For example my pc has 16 GB ram and 4.0 ghz cpu. Meanwhile this multi million dollar machine that is meant to travel to another planet only has 2565 megabytes of ram and a 0.2 ghz cpu. & #x200B; [reference]( URL_0 )
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gk61r0j",
"gk62oyh",
"gk669am"
],
"text": [
"Why does it have to have strong system specs? Is someone going to be playing games on it? These are optimized to be as resistant to radiation as possible and to make sure their computations are accurate. 200 MHz is plenty for what it needs to do.",
"They don't build these from off the shelf hardware. They build them from very well known, very well tested, radiation hardened hardware. If your CPU is bad you send it back and get a new one. If your rover's CPU is bad there isn't a service center on Mars. And with radiation it turns out the more gates you stuff into your CPU, the more it suffers from radiation. So you don't want the latest Threadripper, that would die there in 5 minutes. You want the simplest CPU with the least amount of delicate bits that will get the job done. Then there's that it doesn't really need to do all that much. It has to drive around, control instruments and send stuff back to Earth. There's no reason to do any heavy processing on Mars when we can do it here, where we can have huge datacenters dedicated to it if we need.",
"You can not launch any consumer electronics into outer space. It will just get damaged by the radiation and stop working after a short time. You need to have electronics that use different transistors and with a lot more checks in place. So what they do is that they take a processor architecture that is already out and modify the design to be able to withstand the harsh radiation and temperatures of outer space. This might take a couple of years and is a quite expensive process as you need to test it in various different conditions to make sure it works as expected. Then new space project can start designing their computers around this new processor. But they will not be lanuched for another few years. Especially for a high profile mission like a Mars rover it takes a lot of time between selecting a design and actually launching the mission. In addition due to the costs of the processor development they do not come out with new editions every year, it is more like every decade. In the case of the Perseverance rover it is actually more of an upgraded Curiosity rover and is therefore using much of the same computer systems which includes the processor. Curiosity used the latest and gratest hardened processor on the market at the time, the IBM RAD 750 which was based on the PowerPC 750 from the late 90s. But even though the technology is over two decades old it is perfectly fine for the task it is designed to. But do not fear though because newer spacecraft is designed with more modern technology. The latest and gratest in the RAD series includes fancy features like up to 1.4GHz clock frequency, 64 bit instruction set, DDR3 memory and up to 4 cores. And yes, it is based on a decades old technology but we do now finally have a tested hardened design that have been incorporated into new spacecrafts so you will soon see it launch for the first time."
],
"score": [
8,
7,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
l2mcmq
|
How do they shoot those scenes in movies where the camera is moving around a scene frozen in time? And how do they sometimes put the same characters in that same scene more than once and show it all in one camera panning?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gk624z7",
"gk62dx8"
],
"text": [
"The way they did it in The Matrix was by surrounding the scene with cameras which all took a picture at the same time (or in quick succession if they want slow motion). See [this video]( URL_0 ) for example.",
"The Matrix I believe was the first movie to popularize shots like this. So if you want to see some detailed information on it, check out the making of that movie. But I'll summarize here: There are a couple of tricks they can do to do a shot like that. Like multiple cameras set up around the subject and then smoothed out in post to give the appearance the camera is moving. They could even have a camera on a rig that moves super fast around the subject. But usually both of these require the use green screen and cgi."
],
"score": [
13,
8
],
"text_urls": [
[
"https://www.youtube.com/watch?v=uPNBdDNZbYk&ab_channel=FrankieGochicoa"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2o1py
|
Why do our stomachs make noises? (ex: grumbling)
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gk8cp5r"
],
"text": [
"Our stomachs, when not digesting food, eat away at the mucus membrane lining our stomachs. It’s replaced fast enough for your stomach not to eat itself, but eating the mucus membrane lets off gas. That’s why you sometimes get gassy after you wake up or have not been eating for a while."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2ovyt
|
Why do people and animals stretch and why does it feel so damn GOOD when we do it???
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gk75p2n",
"gk8blvl"
],
"text": [
"Stretching releases endorphins--endorphins make our body feel good. Additionally, muscles that need to be stretched are, therefore, tight. Loosening up of the muscles reduces this tightness.",
"you're releasing pressure on joints and muscles that were previously being used, your body thanks you for this with the use of endorphins. any act one does that is beneficial to long term health, you are wired to find that pleasurable i.e exercise feels good, sex feels good (continuation of species) fatty food tastes good (less likely to starve). & #x200B; That is my theory, anyways."
],
"score": [
9,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2po0e
|
How do smartphone and other devices know what time is it even without internet connection? And even when they were turned off and then turned on.
|
Sorry for my bad English.
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gk6qb2a",
"gk79gnd"
],
"text": [
"Your English is fine. Most wireless electronic devices have a little quartz crystal and battery (much like a watch) to keep time. The battery charges the crystal, the crystal vibrates at a certain frequency, and the frequency is used to measure time. This isn't always 100% accurate, so over time, the longer you keep your phone disconnected from the network, the less accurate the clock might become.",
"> And even when they were turned off and then turned on. The power button doesn't turn everything off. The clock keeps running as long as there is a battery. > How do smartphone and other devices know what time is it even without internet connection? Smartphones (and many other digital devices) can also get the time from the cell network and/or GPS."
],
"score": [
5,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
l2qb2b
|
back in the day before television and internet, people knew about major international news through newspapers. But how did these reporters that wrote for newspapers get their international news from?
|
how did newspapers reporters before technology gather their info about international affairs/news/events and where did they get it from?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gk6y36f",
"gk71a5i"
],
"text": [
"Before the internet, newspapers used to have so many subscribers that they could afford to have offices all over the world with their reporters in them. They would investigate first hand and send the story back home.",
"The reporters would communicate with eachother, and then travel to cover events. The NYT, for example, was tipped of by an early member of the Nazi party that Hitler was going to attempt to overthrow the German government, so that reporter traveled to Munich to watch Hitlers beer hall speech before the failed coup began. The reporter was likely already living in Germany or France at the time, so it would have been a pretty short trip. On top of that, we tend to forget how well we communicate with eachother. We strung the first communications cable across the Atlantic ocean in the 1850's. By the time the US civil war wrapped up, you could instantly send telegram messages from the US to the UK."
],
"score": [
7,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
l2qhpk
|
; if we never ever left solar system, how in the world do we know what shape is our galaxy ?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gk6yy4k",
"gk6yfma",
"gk74giw",
"gk6z5oo"
],
"text": [
"You can ascertain the shape of the room you're in while you're still inside it, can't you? With enough time, and careful observation of the stars and their movements, astronomers have been able to form a picture of the Milky Way. It also helps that we can see other similar galaxies and how they move.",
"Because you can track how things move. You can see it’s relation to other stars and planets. It’s just plotting points.",
"We can get pictures of tons of other galaxies and we know the vast majority fall into only a few common shapes. We can’t observe our entire galaxy but we can see enough of it around us via telescopes to have pretty confident knowledge of which type it must be for those observations to make sense.",
"Lots of observations. Red shifting and blue shifting lets us know what direction an object is moving in relation to us, and we can tell the difference now between a star and a galaxy. Some of the \"stars\" you can see are galaxies, with many more that you can't see because they're too faint. And we can observe enough galaxies to learn how they behave and extrapolate that to our own."
],
"score": [
6,
4,
3,
3
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2qnc1
|
why are we more prone to be more angry and emotional when we are hungry?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gk719z7"
],
"text": [
"Our brain generally lumps all stressors together as a single emotion - the feeling of stress. And if you think of stress as a sliding scale between \"total chill\" and \"freaking out,\" then hunger slowly pushes us up the scale, meaning that any other stress needs to only have a minimal impact before we're set off. The same thing applies to sleep and pain too. Of course, everyone is different and context is important too. Hunger just serves as an amplifier for how people would normally respond to stressful events."
],
"score": [
12
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2r7h0
|
. What happens to compostable packaging and other compostable materials when they are thrown in the garbage?
|
Does packaging designed to be compostable, such as that made from corn or other materials, still breakdown in a landfill or are they just as polluting ad throwing out the plastic version?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gk79gi8"
],
"text": [
"Generally, they will break down faster than plastic, but much slower and more harmfully than if they were composted. The key here is aerobic vs anaerobic decomposition: Whether the bacteria breaking down the material are using oxygen or not. The reason why you turn compost heaps is to get air in for aerobic decomposition, because it’s faster and more odourless than anaerobic decomposition. Since we bury trash in landfills, oxygen can’t get in for aerobic decomposition, and so it breaks down much more slowly. It also results in the decomposition giving off methane instead of carbon dioxide, which is a much more powerful greenhouse gas"
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
l2rfog
|
Why do aircraft measure their speed in knots and not KM/Hr?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gk785fh",
"gk79gin"
],
"text": [
"Air navigation is like an evolution of the kind of navigation we used to do a lot - maritime (on the sea). A lot of the charts (maps) that were put together for long-distance travel, especially over the sea, are measured in *nautical miles*. And many of those charts were used early on for air travel. It just became the norm to use knots because it's kind of what was used since the beginning. Modern charts still tend to use nautical miles and knots are the recommend unit of speed measurement by the International Civil Aviation Organization.",
"1 knot is equal to 1 nautical mile travelled per hour. 1 nautical mile is 1/60 of 1° (latitude) So... if an aircraft or vessel is travelling at 60kt, it's covering 1° of the distance between the equator and the pole per hour. It's always said that metric is based on the earth's dimensions, but this system is more representative of our planet. IDK why it it isn't used more widely"
],
"score": [
13,
6
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2rkg2
|
Why do cold drinks taste different to the same drink but, warm/hot?
|
For example, take a beer. When warm, it tastes awful. Throw it in the fridge for a few hours and now you've got something that tastes pretty good.
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gk79yz9"
],
"text": [
"Two factors are at play here. 1. You've learned to like the taste of a food at a specific temperature, and you've also learned to expect it to be that temperature. Eating it at another temperature is an unpleasant surprise. 2. Volatile compounds (i.e. the chemicals that floats off of food to give it its smell) become more or less concentrated depending on the temperature, and their ratio can change as well. This alters the scent of a food, which alters its flavor. Likewise, your taste buds also change their sensitivity based on the temperature of the food, so certain flavors are more pronounced if the food is hotter. Again, this changes the food from your expectation, which is unpleasant."
],
"score": [
8
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
l2s5f9
|
when you drink alcohol on an empty stomach, you get drunk pretty quickly. As soon as you eat something, you feel like sobering up extremely fast again, although your BAC doesn't change. What's the mechanism behind this?
|
Also, do you **really** become more sober by eating (not BAC-wise, but considering concentration, coordination, slurred speech etc), or does it just feel like you do? Would you fail as hard at, for example, driving a car after eating something as you would without? Is it something like the nutrients helping the brain to improve electrical connections between synapses or similar? Just to prevent any misconception, I do not intend to get drunk, eat a pizza and drive home, it's just an example. I do occasionally drink a maximum of one beer if I've gotta drive a car afterwards, completely zero alcohol before riding my motorbike.
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gk7gj9a"
],
"text": [
"No. When you're drunk it's in your blood. What you put in your stomach is irrelevant at that point"
],
"score": [
4
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
l2sbxh
|
Why does video production take so long? I have a friend who was in a commercial last year and did two 12-hour days for it, but was only on screen for like 3 seconds. And it wasn’t even an ad with special effects- just him in a car making a face.
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gk7kkjf",
"gk7n2qi"
],
"text": [
"Because they require a lot of people, dozens, possibly a hundred or more in larger productions, all being where they’re supposed to be at the right time. The lighting crews, the sound crews, the camera crews, the actors, the make up artists, the crews who provide catering to all these people, everyone, needs to make sure they get their job done at the right time when’s it’s needed. And now you’re in charge of it all, what is easier? A. Coming up with a complicated hour-by-hour schedule of when people need to show up and then when they can leave, and hoping that it runs perfectly smoothly and nothing goes wrong or gets messed up or no one is late. Or B. Just have everybody just show up and be there the whole time so you don’t have to worry as much about a scheduling nightmare. And if something does go wrong the people who can fix it are still their, and none of the actors will ever be late because you made them show up 4 hours before they’ll probably get infront of the camera. Tl:dr it’s way simpler and causes less headaches to just have everyone involved in a shoot be there the whole time, instead of making a complicated ass schedule.",
"Adverts take especially long. TV drama might be ~3 minutes a day on average, but adverts need to be \"perfect\" and additionally the advertising agency has to justify the outrageous fees they charge the advertisers, also. I had a director friend once who got the packshot in 90 minutes, but the agency had a word \"look, the client is here, and we're charging them for a 12 hour day, so this need to take an extra 8+ hours\". I spoke on the phone with him for 90 minutes that day whilst he was \"waiting for a runner to come back with the extra light he needed\" just so the agency could bill the client the markup."
],
"score": [
10,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2sh7n
|
what is the mechanism for prescription drugs that cause weight gain? Do they slow your metabolism or make you overeat?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gk7issd"
],
"text": [
"Could be either and more. Some drugs slow your system down. Some cause you to retain water. Some make you overeat. For example, it's very common if you are on a steroid, that you will eat a lot more, and retain water. Also, you get cravings for sugars. All this leads to weight gain. Some drugs just slow down your metabolism and make you burn less calories than you normally would. So if you don't eat less, you gain weight. Some also just make you very tired, and if you sleep more, you won't be using as many calories. It's all about chemicals, and I don't know all the details, but I do know that when we put drugs in our systems and it messes with our chemical makeup our bodies do wild and crazy things."
],
"score": [
5
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2swtk
|
What do people who rely on medical equipment, both at home and in hospital, do when the power goes out?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gk7lonl"
],
"text": [
"Hospitals have generators private citizens may have generators as well. Also if you rely on power for certain medical devices many utility companies will know this and prioritize you for repairs."
],
"score": [
4
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2tknu
|
Why is it that the drawstring in hoodies always gets uneven after wearing it for a while?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gk7t7ya",
"gk82ld4"
],
"text": [
"Because it moves around freely. If you pull on it, it's gonna move. You simply have to pull on one side a bit to move it. Some sweaters smartly sew it into the back so it can't move. But most dont.",
"There's only one configuration where the lengths are equal, and many many many situations where the lengths are different. As you move around, even a little bit, you're moving the hoodie, which moves the cord, which may or may not move evenly depending on how the fabrics happen to push and pull against each other. It doesn't take long before the configuration of the string positions has shifted a little. Since there's only a single configuration where they're equal, but endless options where they're different, any change is massively more likely to make them different and will almost never make them more similar."
],
"score": [
3,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l2tolh
|
why the size of online games is so big?
|
when someone installs an online game (WoW, FF XIV, etc), the game usually downloads \~30 GB, if I can't play offline and can't see the models, what are these files, do I really need \~30 GB to make the connection?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gk7uczc",
"gk7varw",
"gk7ugtm"
],
"text": [
"The files are the game, all of the art assets, the code that says how it's run, etc. When you play online games basically what happens is that you send a very small message to the server, and the server then sends you back a very small message of what files to load on your computer. If you see a monster, it's because the server told your computer to load those files and display the monster, it didn't actually send you the file for that monster. & #x200B; That's why if you have ever played one of those games and disconnected while playing, it looks like you can keep playing for a few seconds but nothing \"new\" happens monsters will keep doing their animations, you can move your character, etc. All of that stuff is on your computer and until your computer hears from the server it will just use those local assets. & #x200B; tl;dr, you arent streaming all the visuals.",
"> if I can't play offline and can't see the models, what are these files, do I really need ~30 GB to make the connection The files *are* the models and textures and everything else that you have no business downloading every single time you connect. If you *didn't* have those files locally, you would need to stream them to your computer on-the-fly. Not only do you likely not have the internet speed to do this as quickly as would be necessary, but you may not even have the available bandwidth on your internet. Imagine if every time you connected to WoW, you had to sit at a loading screen for 15 minutes while your game loaded all the models of the city you were in, except you logged on to go to another city to do something, so now you travel there and hit another load screen and wait another 10 minutes to load (less time because some of the content was reused). You do what you wanted to do so you close the game for the day, oh but wait you forgot to turn in a daily quest that will expire if you don't do so before tomorrow....time to load the game up again *and wait another 15 minutes for it to load*. EDIT: You also totally *can* see the models and such offline. That is, if you have a program that can extract them from the data files. If you do enough research you an even write this kind of program yourself - but there's little need to do so because the game client does this for you when you connect online.",
"When you install an online game, it is optimized for performance so you can play. In order to do so, they download all assets to your local PC. All visuals, all graphics, all program code, etc. So that when you play the game, the only thing going over the Internet is your computer telling their servers what you are doing, and their servers telling your computer what else is going on. If you didn't optimize like this, you would not be able to play online games with any speed or decent graphics. There just isn't enough bandwidth to support downloading all the assets in real time or before each match. Think of it this way. You ride a bike to work and back. Would you rather have your bike all assembled every day safe in the garage, and just be able to hop on and go? Or would you rather have it that every time you want to use your bike, you have to assemble it from scratch? Assembling it from scratch would obviously take way more time than just hopping on and going."
],
"score": [
11,
4,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
l2uhnr
|
What causes structures in orbit to fatigue and develop structural problems?
|
I saw that the ISS [has developed small crack]( URL_0 )s in the hull. While structures in our atmosphere experience fatigue from gravity and wind among other things, what causes stress to structures in space?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gk83ge9"
],
"text": [
"Mostly temperature changes. Anything that's orbiting close to earth basically spends half it's time in shadow and half in the sun unless it's in specially selected weird orbits. Background temperature when you're in shadow is \\~3K, in the sun it's more like 300K. So every orbit the structure swings between two temperature extremes. For the ISS that's about every 90 minutes. Way too fast to get all the way to stable temperature so it's constantly going through thermal cycles. Thermal cycling, by itself, doesn't cause stress if it's even. But it's generally uneven because the structure doesn't heat/cool at the same rate everywhere, and the structure is made of many different materials with different coefficients of thermal expansion. The combination means you constantly have thermally induced cycling stress through the structure. There are materials that don't do this, but they tend to be heavy and make lousy space structure."
],
"score": [
6
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
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