title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"Why don't the chemicals in pills get totally dissolved by our stomach acid? How do they make it to the blood stream?"
] | [
false
] | When I take a vitamin, or a melatonin gummy, or aspirin, why doesn't our stomach acid just totally destroy those chemicals, rendering them useless. Are some molecular bonds immune to acid? I probably don't understand how acid actually works, so maybe you can start there. | [
"So a lot of drugs are actually designed to be activated in your stomache. I.e. they are in a \"pro\" form, or prior to use form, where upon entering your stomache and interacting with the fluids there, they get turned into the final form of the drug as they enter into your blood stream. ",
"Also, yes. There are ... | [
"Well I'm glad it helped you understand. There is another definition of acids and bases, which is electron donors and acceptors, which is a bit more comprehensive, but the proton thing works in most cases"
] | [
"This is part of he reason that certain drugs (such as insulin for diabetes) cannot be administered orally. Insulin (as an example) is a peptide. While peptides are relatively able in stomach acid, they are rapidly digested by enzymes, so they must be injected. By the way, stomach acid is dilute enough that it does... |
[
"How do we define the solar system boundaries?"
] | [
false
] | I keep reading voyager 1 is about to leave the solar system. How exactly does science define the boundaries of the solar system? First thought would probably be "any object under the gravitational influence of the sun is in the solar system" but that does not seem right as the gravity formula applies whatever the distance and is never zero for two objects of any mass > 0. It's my understanding that even stars are under each other's gravitational influences anyway. So what is exactly that "limit of the solar system" everyone seems to talk about? How can an objet such as voyager 1 be said to be "inside" or "outside" the solar system? Thank you ! | [
"Yes -- when people are talking about voyagers reaching the edge of the solar system, they are talking about the heliopause. The sun whips out energetic particles in a highly magnetized solar wind. The sun is also moving through through a low-density interstellar medium (ISM), a partially ionized gas. At some point... | [
"In the case of Voyager 1 (which is about 120 AU from the Sun, i.e., 120 times as far from the Sun as the Earth is), what you are hearing about is that Voyager 1 is approaching the ",
".",
"From the Sun comes a stream of charged particles; this is the solar wind. There is a bubble in space, essentially, in whi... | [
"Thank you all for your answers ! It's definitely clearer for me now and it bugs me traditional media don't explain this clearly and just use general throwaway sentences \"woah it leaves the solar system\" style. AskScience is an amazing community."
] |
[
"Would it be possible to propel a man in an open aired vehicle fast enough to travel along side a bullet?"
] | [
false
] | null | [
"Yes, this is possible, however very hard to do. Vacuum would make things even harder. You just need a very fast care like ",
"this",
". The hardest part would be to fire a gun close enough to the driver to reach it.",
"From the driver's point of view, he would see a bullet simply falling on the ground. The a... | [
"I would think a vacuum would make things easier(assuming it's easy to get a large vacuum to work with). The vehicle and the bullet is going to slow down at different rate in the atmosphere, you won't have that problem in a vacuum."
] | [
"You would need a different kind of propulsion, as ordinary methods need air to work, driver would have to wear a space suit, because people can not be exposed to vacuum for more than a couple tens of seconds and building a vacuum chamber big enough is far beyond current technology. "
] |
[
"If the sun emits heat into our solar system like a giant space heater then why is the universe so cold if it has trillions of stars like the sun?"
] | [
false
] | My dad brought this up to me when we were talking about space and I didn't really have the answer for it. I'm not sure how dumb of a question it is but I couldn't think of a reason. | [
"The nearest star to the Sun is a few light years away. We're about 100 million miles away from the Sun, about a millionth of the distance to the nearest star, and even here the Sun barely warms space. The Earth is warm because it has an atmosphere to trap the Sun's heat, but leave the atmosphere and you'll freeze ... | [
"The universe is bigger than stars are hot."
] | [
"Doesn't it dissipate proportional the surface area of that sphere, r",
", instead of its volume r",
"?"
] |
[
"How does this \"Mitochondrial Eve\" thing work? Did humanity really population-bottleneck to a single female at one point in time?"
] | [
false
] | So, every single living human being today, can have their lineage traced back to a Mitochondrial Eve. How does that even work? Did we really come that close to extinction that at some point, there was only one female human on the entire planet whose descendants didn't die out before making contact with others? That's some cosmic horror level stuff right there. Every other pocket of human population dying, only the children of one woman living on... Holy crap... Shouldn't this show some lower than normal genetic diversity tho? I heard cheetahs have debilitatingly low genetic dieversity due to a bottleneck in their population thousands of years ago... yet I never heard of humans having such. | [
"It's a little more complicated than that - it's not that nobody else alive had any descendants, it's that there are no other unbroken maternal lines. The other women alive at the same time as MtEve may have descendants, it just so happens that they hit a generation that was all sons. ",
"You only inherit your mi... | [
"Here is a nice essay on the subject. It says basically the same thing as ",
"u/mikelywhiplash",
"http://pages.ucsd.edu/~dkjordan/resources/clarifications/MitochondrialEve.html"
] | [
"Oh, that's really a good way to put it. Thanks!"
] |
[
"Ask Anything Wednesday - Biology, Chemistry, Neuroscience, Medicine, Psychology"
] | [
false
] | Welcome to our weekly feature, Ask Anything Wednesday - this week we are focusing on Do you have a question within these topics you weren't sure was worth submitting? Is something a bit too speculative for a typical post? No question is too big or small for AAW. In this thread you can ask any science-related question! Things like: "What would happen if...", "How will the future...", "If all the rules for 'X' were different...", "Why does my...". Please post your question as a top-level response to this, and our team of panellists will be here to answer and discuss your questions. The other topic areas will appear in future Ask Anything Wednesdays, so if you have other questions not covered by this weeks theme please either hold on to it until those topics come around, or go and post over in our sister subreddit , where every day is Ask Anything Wednesday! Off-theme questions in this post will be removed to try and keep the thread a manageable size for both our readers and panellists. Please only answer a posted question if you are an expert in the field. . In short, this is a moderated subreddit, and responses which do not meet our quality guidelines will be removed. Remember, peer reviewed sources are always appreciated, and anecdotes are absolutely not appropriate. In general if your answer begins with 'I think', or 'I've heard', then it's not suitable for . If you would like to become a member of the AskScience panel, . Past AskAnythingWednesday posts . Ask away! | [
"are there any breakthroughs in diagnostic testing and treatment for fibromyalgia (or it’s more recent title) in 2022-23?"
] | [
"Why does fusion stop releasing energy after iron?"
] | [
"At the point a star makes Iron it's dying. Fusion costs energy when you hit iron, or so I have been told."
] |
[
"Does evolution move toward reproduction at earlier stages in life?"
] | [
false
] | So, evolution as we know it, in simplest terms is survival of the fittest. But really all that matters is that the animal is fit only until it reproduces. After reproduction, the success of various traits in the animal don't get passed on and therefore, evolutionarily don't matter. Wouldn't it make sense if more animals evolved to reproduce sooner in life? Do animals that reproduce at earlier stages in life evolve more quickly? Is this happening already and I just don't know about it? | [
"Older animals would be better suited to caring for offspring, increasing the chance of their children's survival."
] | [
"There are two main types of reproductive strategies, r and k.",
"r-strategists live short lives, are smaller, have many children, and replicate early.",
"k-strategists live long lives, are bigger, have few children, and devote lots of time to caring for them.",
"Having lots of offspring early is good if your... | [
"It depends on the life-strategies of the organism. You are refereing to ",
"r/k selection theory",
"R species - grow fast, reproduce fast and reproduce many young. They are well suited for fast changing unpredictable environments. And yes, they do accumulate mutations faster - and the changing environment sele... |
[
"Do blind people require less sleep because their eyes don't stress the brain as much?"
] | [
false
] | null | [
"No. We really don't know why we sleep. We think it may have to do with clearing out unneeded information, consolidating memories and recovering energy, but it's really not known for sure. We can rest without sleeping to recover energy as well. You can also get sleepy from eating a heavy meal; that has nothing to d... | [
"No. We're not sure why we need to sleep, but it's not because we have eyes."
] | [
"Well, sleep is the body's way of recovering from a day of spent energy, primarily because of stress on the brain from visual, physical, and mental activity, right? I don't think you understand my question. A large portion of my cue to fall asleep is the heavy sensation under my eyelids. I feel like if that sensati... |
[
"Why do lights flicker as you turn them on?"
] | [
false
] | null | [
"Are you talking about normal light bulbs? Like when you flip the switch slowly and it flickers a bit? That's due to a poor connection within the switch. The circuit is closing/opening over and over.",
"Or, are you are you talking about fluorescent bulbs? The kind that take a few seconds to warm up sometimes? It'... | [
"Hi, thanks for the response!",
"The thing that got me wondering was a regular bulb flickering, so the first case. It's not the case that I flick the switch slowly, I would guess that it's a normal flick. When I do, however, there is a slight delay, and then the bulb flickers into shining. ",
"Do you know why t... | [
"Switches have springs in them, and that makes the contacts bounce off few times when it changes position. Normally this isn't visible to the naked eye, though electronics have to deal with it anyway. If you have a device where a key press registers as several presses sometimes, bad denouncing is probably at fault.... |
[
"Do we burn more calories when we work our brain harder?"
] | [
false
] | [deleted] | [
"From what i have read the answer is yes, but it is not neccesarily the brain itself that burns the extra calories, it could be the rest of the body. It could be result of increased heart rate and general awareness/stress levels in the body as a result of the difficult task putting us into some kind of \"performanc... | [
"Is there a source for this fact about grandmasters?"
] | [
"Is there a source for this fact about grandmasters?"
] |
[
"What is the evidence for the existence of other universes or that ours is but one universe in a greater \"multiverse\"?"
] | [
false
] | is there any real evidence for this idea? i know many very highly reputable physicists have proposed it as a possibility I just have never seen any evidence for it. | [
"None yet. But the theory has made testable predictions for what it should look like if another eternally-inflating bubble universe should look like if it collides with ours. Most of these predictions have to do with looking at the structure of the cosmic microwave background, so these people are anxiously awaiti... | [
"It is the product of a certain model of quantum mechanics.",
"No direct evidence has yet been observed for the concept."
] | [
"I'd clarify that there is no evidence that distinguishes Many Worlds from other modern interpretations, since all tests of QM so far have been evidence for all of them, since they all make similar predictions for a single observer. Though some (myself included) argue that Many Worlds contains fewer assumptions and... |
[
"How do rockets keep themselves stable during liftoff when the main source of thrust if coming from the bottom?"
] | [
false
] | [deleted] | [
"First, whether the source of thrust comes from the bottom or from the top doesn't make any difference for stiff objects like a rocket. That's a bit counter-intuitive perhaps: generally we're used to the notion that pushing something tends to make it rotate, while pulling something tends to straighten it. But that'... | [
"In addition to adjusting thrust, many (maybe most?) rockets use gimbaled engines that can swivel side to side to correct drifting."
] | [
"Don't forget that most rockets have their direction of thrust aimed at center of mass, in case an engine fails, it doesn't cause the whole assembly to go off-axis."
] |
[
"When will quantum processor's be in every PC and how will they differ from todays technology."
] | [
false
] | Just curious as to how long until they are made commercially available? Best guess is all I'm looking for... Are you talking about 10-20 or 100 years? How will they differ from the tech we have today? How much faster will they be? How will quantum processors change the computing world? What is the latest news/progress on QP's? Thanks guys! | [
"More than likely, if made practical, quantum processing will be for solving niche problems and may not be the most efficient way to work with general computation. I imagine that the transister CPU will live alongside the quantum processor, the latter being used at universities and governments while your CPU + GPU... | [
"Thank you."
] | [
"A quantum computer allows a different range of algorithms (Called quantum algorithms) to be used. Currently these algorithms can only be simulated with classical computation in a very limited way.",
"The most significant real word applications are probably in breaking large prime number encryption and searching ... |
[
"The strength of the mentally handicapped."
] | [
false
] | [deleted] | [
"My sister is special needs, so I have always had a theory. She is shorter than everyone in my family, but is very strong (We have to restrain her at the dentist, which takes about 3 grown people).",
"I think, with her, and probably others, is that their motor skills are so messed up. Leading them to learn to f... | [
"I'm not an expert, but I'd agree with your thoughts on them just not being able to control their own strength. ",
"I think it's just relative, and in the end, we seem to remember the mentally handicapped who grow up to be rather large grown men with lots of muscle on them (possibly because a person with so much ... | [
"We all have the capacity to use enough strength to injure ourselves. An average person starts to hurt herself with over exertion and eases off. Someone with a mental handicap might not receive or interpret those signals telling her that the force she's using is hurting herself too. ",
"That's one possible source... |
[
"How does invisibility of a material to a wavelength of light work?"
] | [
false
] | null | [
"Following your answer, why would light just pass through if it doesn't have the energy to promote the electron? As I understand it colours are given off by an atom because the when the electron is promoted it may be in an unstable state and then drop back, releasing a photon of energy in the process. If a photon h... | [
"Lets talk about solids. In solids, you have nearly an infinite number of atoms, which all have atomic orbitals. To form the solid we take in phase and out of phase combinations or each individual orbital. If we start will 1,000,000 atoms each with 1 atomic orbital, we will end up with 1,000,000 'molecular orbitals... | [
"Energy levels in atoms are quantized. If you don't have the right energy, the atom won't absorb. In solids, there are no electronics states between the bands, so if the light is of insufficient energy to promote an electron, then it is transmitted. Now, very low energy light interacts with lattice vibrations in th... |
[
"What would weigh the most: all whales, all humans, or all ants?"
] | [
false
] | What would weigh the most if you added up all the whales, all the humans, and all the ants alive on the planet? | [
"It depends on how you measure biomass. Do you mean dry biomass, wet biomass, or number of carbon atoms? Wikipedia has the answer, and you can sort the table in different ways. ",
"http://en.wikipedia.org/wiki/Biomass_(ecology)",
"Ants have the most wet biomass (of animals on your list), but humans have the mos... | [
"Use backslashes before parenthesis.",
"http://en.wikipedia.org/wiki/Biomass_\\(ecology\\)"
] | [
"It's not the underscore but the parenthesis."
] |
[
"Why are there both on-center and off-center receptive fields in the retina & LGN?"
] | [
false
] | Center-surround receptive fields are useful for detecting changes in luminance across the visual field, but I would think just one organization (i.e. excitatory-center inhibitory-surround inhibitory-center excitatory-surround) would do the trick. What is the point of having both organizations? Is it redundant coding? I have read some places that the two organizations are because you want to be able to detect a dark object on a lighter background or a light object on a darker background, but again, I can see this done by the same organization. In an ON-centre cell, a dark spot would decrease firing, and a light spot would increase firing. Done, and done. I need another example to help me figure this out. Thanks in advance... :) | [
"The reason is basically that baseline firing rate for post-retinal neurons is close to zero. In cortex, baseline ",
" zero. So, a zero-contrast stimulus gives you zero firing rate. That means there's no room in the response range to represent both positive and negative polarity stimuli.",
"Even if it were poss... | [
"What I'm going on is having seen many plots of response as a function of contrast; even for RGCs, the response begins near zero for zero contrast, then increases monotonically. e.g. Kroner, Purpura and Kaplan PNAS 1993, or Kaplan & Shapley, PNAS 1986 (that one is good, one of the first figures is an average over a... | [
"Sure, let's see what I come up with:",
"Say we have a simple pattern of light, consisting of three vertical bars, like this: |||",
"The outer bars are black (very little light), the inner bar is white (lots of light), and they're surrounded by a mean gray field (an intermediate amount of light).",
"There are... |
[
"Is light a wave, or is it packages of energy?"
] | [
false
] | I'm a little confused. | [
"Hi, unfortunately the answer is that it is in fact both! Light is made up of little packets called photons, each with one quantum of energy.",
"The reason for this is that light demonstrates a lot of properties- in some cases the photon (packet) explanation is the only one that works. In some cases the wave expl... | [
"wow thanks for the answer :D Now I am a little more cleared up :)"
] | [
"It's neither, really. Light is what it is and we choose to ",
" it as either behaving as a particle or behaving as a wave. It's important to emphasize that light doesn't exist as a particle in some cases and as a wave in other cases. It's us humans who choose one model or the other to describe an interaction ... |
[
"If you eat a fish with cancer, is it unharmful?"
] | [
false
] | null | [
"The tumors were right behind the gills so I guess it would be lung cancer.",
"Haha, epic. Eating a cancer-ridden animal is fine, cancer isn't contagious across our own species, let alone across species lines. The reason cancer is so strong is that it evades our immune system by looking almost exactly like our ow... | [
"You have to remember that all diseases aren't the same. Rabies is a virus, a very powerful one that can gain virulence (infectious power) though crossing species lines. This is what happened with H1N1 flu.",
"Cancer is simply rogue cells that have lost contact inhibition, apoptosis ability, and divide very rapid... | [
"You have to remember that all diseases aren't the same. Rabies is a virus, a very powerful one that can gain virulence (infectious power) though crossing species lines. This is what happened with H1N1 flu.",
"Cancer is simply rogue cells that have lost contact inhibition, apoptosis ability, and divide very rapid... |
[
"What makes human altruism different than, say, other hominids or even avian?"
] | [
false
] | If the same underlying principles of evolutionary biology hold, shouldn't we expect the same "feel-good" nature of altruism in other hominids? Furthermore, why do Homo sapiens perform self-sacrificial acts of altruism at a higher rate than other species (again, assuming similar selective pressures)? If it's due to our complex brain, then why have such a brain in the first place? It consumes an inordinate amount of our body's resources, leaves our infant state unbelievably vulnerable, and thanks to our huge noggins, makes child-birth deadly to this day. | [
"There is some extent of scientific agreement that altruism arises in organisms only if there is some amount of relatedness between the organism helping and the one being helped. Why does it happen more in humans than their immediate relatives? (Well, we're definitely not the MOST altruistic organisms though: look ... | [
"Taken my vastly different approaches to education (bs in biology and minor in leadership studies which is heavily philosophy based), I have somewhat conflicting notions of the idea's of altruism. While Biology does in fact characterize humans as an altruistic creature (we will lower our fitness to temporally impr... | [
"But what then sparked our social revolution? Is it some luck of genetics that ancient ancestors developed sufficient cognitive ability to \"create\" culture? Did other hominids not also have the same opportunity?",
"I guess my question also ties into the classic question of why we tip, even if we don't plan on v... |
[
"What exactly are the differences between Active ingredients and Inactive ingredients in medicine?"
] | [
false
] | Obviously (or so I think), the active ingredient is the one that is the most important for chemical reaction to help out the taker's problem. But what exactly is the purpose of the inactive ingredients? Is the name "inactive" a misnomer because the name seems to imply it does nothing? For example I have some flavored Tums (an antacid) in front of me: Active Ingredient: Calcium carbonate USB Inactive ingredients: Sucrose (for flavor?), Calcium carbonate, corn starch, talc, mineral oil, natural and artificial flavor, adipic acid, sodium polyphosphate, red 40 lake, yellow 6 lake, yellow 5 (tartrazine) lake, blue 1 lake. I'm guessing the lakes are food coloring. | [
"Yup, those are things for coating/dissolving/stabilising/making taste good the active ingredient so it can do it's work."
] | [
"Ah I see. That makes sense. I guess the wording \"inactive\" just was confusing because that implied (to me) that they were useless. I guess it was more meant to be \"inactive in helping the main cause of the medication\"."
] | [
"They don't eat foods that are artificially colored."
] |
[
"Why does birth control fail?"
] | [
false
] | If a woman takes it exactly as prescribed, or has an IUD, then how can they get pregnant? Why is it only 99% effective? | [
"A full answer to this would be extremely long and involve a lot of \"we don't know.\"",
"There are a lot of mechanisms geared towards reproduction, and biological mechanisms aren't precisely engineered. They have some tolerances built-in, and these vary from person to person (and from cycle to cycle!).",
"The... | [
"This has been studied for the copper IUD and it is the most effective form of emergency contraception, yes.",
"However, it is still less effective as emergency contraception than as non-emergency contraception."
] | [
"OP said that the effectiveness of the contraceptive was over 99.9% effective. Surgery always carries risks of being performed improperly, and our bodies are always trying to heal ourselves, so for tubal ligation to be less effective than this birth control you're looking at a surgical failure rate of 1 in 2000 (tw... |
[
"When we break the sound barrier, we get a sonic boom. Theoretically, what would happen if we broke the light barrier?"
] | [
false
] | null | [
"Since nothing can go faster than ",
" your question can not be answered. (No physics exists for it.)",
"Edit: In the situation of light in a medium where it is less than ",
" and can be overcome - the result is ",
"Cherenkov Radiation",
"."
] | [
"It's kind of like asking where the lungs are on a coffee table. "
] | [
"Theoretically, you can't. It isn't a \"barrier\", it's simply impossible to reach no matter how more force you give something.",
"There is a whole lot of interesting stuff that happens when you are going ",
" to the speed of light though."
] |
[
"Can there be gas moons?"
] | [
false
] | There are both terrestrial and gas planets, so can a planet's moon be gas as well? How would this form? | [
"This couldn't happen, because a gas body is quite large. You could end up with a gas binary planet system, with bodies of similar size, but not anything of the size disparity to be considered a moon/planet system. Either the moon would dissipate or it would be consumed by the planet.",
"If you had something the ... | [
"That is true, the definitions are ambiguous. I do not know the math behind the stability of certain mass gas giants orbiting much larger mass gas giants. I suppose at this point we would call them both \"gas giants\", the defining factor perhaps would be which one orbits which. If they each orbit each other, they ... | [
"That is true, the definitions are ambiguous. I do not know the math behind the stability of certain mass gas giants orbiting much larger mass gas giants. I suppose at this point we would call them both \"gas giants\", the defining factor perhaps would be which one orbits which. If they each orbit each other, they ... |
[
"How subjective is the human sense of smell?"
] | [
false
] | Describing odors is probably one of the most difficult things to do (outside of organic chemistry where everything smells "camphor-like"). But is it really more subjective than the other senses? | [
"I think it's mostly an issue of vocabulary. Anyone with significant experience with organic solvents can easily identify the smell of a new solvent in relation to other solvents, in my experience.",
"I can tell you when something smells \"like Xylene\", which generally means it's an aromatic hydrocarbon, or \"li... | [
"sound can be high pitched or low",
"Though, if you combine multiple sounds - creating a harmony for example, you will often get something",
"complex or hard to describe",
"Also harmonies are very subjective as they trigger different emotions (or memories, or whatever) in people. So is there really such a big... | [
"Probably because a sound can be high pitched or low, light can only be so many distinguishable colors, but smell can be anything of 10,000 recognizable unrelated things!",
"Or to put it in language people like me understand, the state space of scent has thousands of basis vectors."
] |
[
"Is there an \"average\" temperature in space?"
] | [
false
] | The other thread about black holes got me thinking. There was another thread 3 years ago that mentioned that space is about 2.7 Kelvin, very close to absolute zero. But that temperature is measured in a vacuum, meaning that the radiation received would be similar to that of matter at 2.7 K. So, we know about stars and how big and warm they are (there is warm matter) and black holes (the bigger the colder) which also has matter. Then there are rocks floating around, the side towards the sun is warm and the side facing away is cold and so on. I don't even know about super novas, I mean there is matter there we can see it, but at that point it's all separated particles which surely can't keep warm for long, until they fall back into each other and form new stars or such. So, if we only take matter into account, what is the estimate here? Is there more warm than cold, on the account that space itself is full of energy, or is there more "dead" matter than alive, lowering our average? | [
"Yes, you could compute something and call it the 'average' temperature in space. But it depends on how you want to frame the problem.",
"My default interpretation would be this: ",
" So, for example, if you were dropped somewhere near the Earth's orbit, you would settle at a temperature around 250K because you... | [
"the vast majority of matter in the Universe is in stars.",
"That's definitely not true.",
"The vast majority of matter in the Universe is in dark matter. Here's a breakdown of just our Milky Way Galaxy:",
"Mass of Interstellar Medium (Gas & Dust): 7 x 10",
" Solar-masses",
"Mass of Stars: 5 x 10",
" So... | [
"the vast majority of matter in the Universe is in stars.",
"That's definitely not true.",
"The vast majority of matter in the Universe is in dark matter. Here's a breakdown of just our Milky Way Galaxy:",
"Mass of Interstellar Medium (Gas & Dust): 7 x 10",
" Solar-masses",
"Mass of Stars: 5 x 10",
" So... |
[
"Are there any patents on the covid vaccine or are all companies sharing \"open source\" tech at this point?"
] | [
false
] | null | [
"Currently no, however there is a ",
"vaccine",
" in phase 2 trials that is open source. Once approved it will still need to be manufactured by proper facilities so not as open source as something like software. At this point any facility capable of producing a covid vaccine is already making them under contrac... | [
"There are many patents covering the vaccines and their manufacture. The notion that they should make their core IP public domain was ridiculously naive. The mechanism for providing access, or more manufacturing capacity is to license the relevant patents. ",
"My analogy is that you can let someone stay at your h... | [
"Here",
" is one that is published but not granted in Russia.",
"There is probably more but I don't really want to look through it all: ",
"https://patents.google.com/?q=Covid-2019&oq=Covid-2019+"
] |
[
"How often do cats lose their whiskers?"
] | [
false
] | My cat lost a whisker last night. From what I've found online, this is normal (as long as it doesn't happen too often), but I can't find anything from a reliable source on how often this happens. Any veterinarians out there who can give me an answer? | [
"The worst that might happen if they lost several whiskers would be that they might have some balance/coordination issues.",
"This is a myth. Feline whiskers' purpose has nothing to do with balance. Like all mammals, a cat's sense of balance are from the inner ear. Whiskers are used as \"feelers\", mainly to judg... | [
"I am not a veterinarian, but two things: First, giving/requesting medical advice in this subreddit (if not all of reddit) is frowned upon. With that being said, your question ",
" scientific.",
"Second, yes, this is normal. Your cat will be fine, at least as far as losing one (or a couple) whiskers. Their whis... | [
"This is what I know the whiskers are for as well. It appeared in a primary school textbook, and it mentioned that if you cut a cat's whiskers off it could potentially trap itself in a tight space because they lose the ability to judge the 'width' of their bodies properly."
] |
[
"Rain Question"
] | [
false
] | I have a really random question. Has there been any studies done to see how far a single drop of rain moves on its descent from the cloud it originated in? So basically if I drop something depending on weight and whether it flies or glides it will land directly below the point where I released it, how close to directly below the cloud it came from does a raindrop land? | [
"This is almost impossible to answer.",
"It's impossible to give an exact answer, but we can give some rough limits. Raindrops form at an altitude of about 100 to 5,000 meters. On average, they fall at a constant terminal velocity of 10 meters per second, meaning that they take about 10 to 500 seconds to reach th... | [
"I think rain is most heavily affected by the wind - starting from the initial motion of the cloud it forms in (also caused by wind), then any individual raindrop is going to be moved around by whatever the wind is doing on its way down, potentially even moving in different directions if the wind or gusts are diffe... | [
"This is almost impossible to answer. Keep in mind there are an infinite amount of variables in this equation.",
"\nFirstly, a particle of dust is the beginning of the \"drop\" of rain, cold air rising into a warm front (or vice versa) creates condensation, so other small molecules of water begin to collect on t... |
[
"Why is it that if two cars run into each other while both going 60mph the collision isn't equivalent to a 120mph crash?"
] | [
false
] | null | [
"That 60 mph crash is into a solid, unmovable wall, and all the energy is absorbed by 1 car. In the two cars colliding head on at 60mph each, each car delivers as much energy as the other, but also absorbs as much, so while the total energy in the collision might be double, it's also absorbed by double the number o... | [
"Because kinetic energy is given as 1/2 mv",
"In the collision between 2 60 mph cars, assuming both cars are the same mass you end up with kinetic energy proportional to 2(1/2 60",
" ), or 3600",
"In the case of 1 car going 120 mph, you end up with kinetic energy proportional to 1/2 120",
" or 7200.",
"In... | [
"At least in the US, road maintenance is paid for primarily by gas taxes. ",
"The fuel efficiency of a smart car is 36 mpg combined. The fuel efficiency of an F-150 is 17 mpg. Assuming an equal number of miles driven, the F-150 driver is paying about double the road taxes of the smart car driver. "
] |
[
"Does Gravity move slower in different mediums? (e.g. water, air)."
] | [
false
] | If the speed of light = the speed of gravity, but the speed of light moves slower in different mediums, then is the same true for the speed of gravity? | [
"light moves slower in water, etc. because light interacts with the water, not because \"the speed of light\" changes in water. \"the speed of light\" is the speed that an object would have to travel in order for the vector describing the velocity to be null (g_{ab} v",
" v",
" = 0). the water doesn't actually ... | [
"wait, that's kind of an absurd question, of course gravity interacts with water. gravity interacts with anything that has mass.",
"The reason it SEEMS like light slows down is because the atmospheric particles absorb, reflect and discharge light. So the light you see is not a straight beam from its source. It's ... | [
"You are basically asking whether gravity is a quantized force (or whether there is a graviton) or not. That is still not certain. Moreover, quantum gravity does not necessarily mean that matter slows its propagation.",
"What empathetica1's explanation means is that there is some ultimate limit of all information... |
[
"Is it possible to land safely in a wingsuit without a parachute?"
] | [
false
] | From what I've heard (and this could be off), a person generally travels forward twice as much as they drop in a Wingsuit. The speeds look pretty fast. Would it be possible however to arc yourself upwards to a point where your velocity and momentum would be offset by gravity to come to a soft (and safe) landing? | [
"The performance varies, but a measured reference was 300km/hr horizontal speed with a 30km/hr descent.",
"A person with enough speed built up can temporarily slow their descent, but it's temporary, soon the loss of velocity makes them drop, more than they were dropping initially. ",
"Gary Connery's record-bre... | [
"Well the easiest solution would be to just build a setup similar to ski-jump hills. The landing zone is sharply graded. Obviously though some people might take exception to that as a \"landing\"."
] | [
"Well the easiest solution would be to just build a setup similar to ski-jump hills. The landing zone is sharply graded. Obviously though some people might take exception to that as a \"landing\"."
] |
[
"Will the Sun's gravitational pull on Earth change as it expands?"
] | [
false
] | I was thinking about the Sun's expansion at the end of it's life- as it expands a portion of it's matter will become ever closer to us, but on the opposite side of the sun from us matter will be getting farther away. Will the change in distance of matter on both sides cancel itself out? Will the Earth experience a greater pull, sucking it in before the expansion would have consumed it? Is this a completely misguided question? Thanks in advance. Edit: I did Google the question before asking, but none of the answers addressed the matter / mass getting closer to Earth, which to me would change the gravitational force. The answers simply stated that gravity wouldn't change. The volume is increasing, but not mass. | [
"It will, but for a different reason - the Sun loses mass in the same process. If the mass would stay the same it would stay the same. This is the result of the ",
"Shell theorem",
". Any mass distribution with a spherical symmetry (a good approximation for the Sun) leads to the same gravitational force as a po... | [
"because the center of mass grew",
"The center of mass is, by definition, a point. It does not grow."
] | [
"because the center of mass grew",
"The center of mass is, by definition, a point. It does not grow."
] |
[
"Has science (engineering) come up with a better microphone than a human ear?"
] | [
false
] | If so, can it compete with natures best? | [
"If by better, you mean more sensitive, then yes. "
] | [
"\"Better\" is qualitative. There are sound capturing devices that are able to capture sounds (both directional and not) that an ear couldn't. Whether it is \"better\" or not is a function of the use of the ear and the purpose it serves which is impossible to answer. For examples \"is it better to have 1 child o... | [
"Based on ",
"Fletcher–Munson curves",
", the human hearing range is from 20 Hz to 20 kHz (or < 20 kHz less if you're older). The dynamic range of our hearing is, at best, around 130 dB. For starters, let's ask if there's a microphone that beats that..."
] |
[
"How does water get to the top of huge trees through adhesion, cohesion, and capillary action, when atmospheric pressure should limit the uptake to 10 metres?"
] | [
false
] | null | [
"Imagine a long vessel starting at the roots and ending in te stomata of leaves. The roots take up water by osmosis after which it moves into the xylem vessel. It would not go far indeed but for evaporation at the leaves (trough stomata) which creates a lower pressure at the top of the water “column” thereby drawin... | [
"It would make it less effective but there is still an enormous surface area across all the leaves for evaporation to occur. And even at 100% humidity water will still evaporate since it is a state of equilibrium and is not static, but it will be very slow."
] | [
"I have heard this explanation too, but I have to wonder what would happen in conditions where the air is saturated with water vapor. That would mean the evaporation wouldn't work. Should that not make this mechanism muss less effective?"
] |
[
"If a chemical is turned into plasma, does it keep it's uses/properties?"
] | [
false
] | [deleted] | [
"From ",
"https://en.wikipedia.org/wiki/Plasma_(physics)",
"\"A plasma can be created by heating a gas or subjecting it to a strong electromagnetic field applied with a laser or microwave generator. This decreases or increases the number of electrons, creating positive or negative charged particles called ions,... | [
"In the case of NaCl, if you pefectly exclude all water and oxygen for the entire process you may recover NaCl after cooling to room temperature. You wouldn't be able to cook the eggs with it. The Na and Cl nuclei would react with whatever they touch upon quenching and you'd lose at least a portion of the saltine... | [
"So do the Na and Cl seperate as well?"
] |
[
"Could non-carbon based lifeforms be living among us without us being able to recognize them as life-forms?"
] | [
false
] | null | [
"Not having proof of something's existence does not mean that it doesn't exist or that has to be false. I'm not saying this about ghosts but it's the way you put it...Back in the days there was no proof that the earth was round. Proofs come when you look for them when trying to validate/invalidate a theory"
] | [
"It's important to get a good definition of \"life\" for this question. Assuming the scientifically used definition of \"being manifested by growth through metabolism, reproduction, and the power of adaptation to environment through changes originating internally\", all of these phenomenon would be observable in th... | [
"You're right, except this post asks for \"the scientific angle\" regarding \"if 'ghosts' could be life-forms\". Science says we have no proof that they exist."
] |
[
"Why are people more likely to be right handed than left handed?"
] | [
false
] | I hear people say it's a "right handed world" where a majority of items are designed for right handed people as default. How did it even get to be like that in the first place? Why are we not inclined to be more left handed, or even ambidextrous? | [
"So a lot of people are touching on the idea of where language is localized. Most of the time we have language localized in our left-hemispheres. The left side of our brain controls the right side of our body, and vice versa. It is commonly believed that this is why most people are right-handed. ",
"This article"... | [
"I thought the reason for left-handers living shorter lives than right-handers was because in the past left-handed people were forced to use their right hand, so left-handers that have died recently have tended to be on average much younger than right-handers that have died recently.",
"This was covered in my int... | [
"A couple of theories floated in the literature:",
"It might be a secondary/derivative trait, a result of the lateralization of language in the brain: ",
"http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=176485",
"It might be a primary trait, with an allele all of its own: ",
"http:/... |
[
"Is there one \"color\" on the light spectrum that is more prevalent in our universe than the others, or is each represented equally?"
] | [
false
] | null | [
"My first thought is that the cosmic microwave background would dominate on a cosmic scale. These photons were generated everywhere in the early universe during the recombination epoch: the time when the universe cooled enough to allow electrons and protons to form stable hydrogen atoms.",
"One interesting thing ... | [
"This isn't a direct answer to your question, but is along the same lines of thought, and also kinda neat.",
"A survey of the colour of all light in the universe added up to a slightly beigeish white, called \"Cosmic Latte.\""
] | [
"Damn that's awesome thanks man! "
] |
[
"If I drop a boat into a hollow air-filled shaft in the ocean, then move it into the water and let it rise back up, can it generate net energy this way? If so, how?"
] | [
false
] | null | [
"No you can't make energy this way. Pushing the object in/out of the airlock and pumping it would take as much (actually more if you account for losses) energy as what you would gain from dropping the object and letting it float up."
] | [
"That seems correct only if the volume of the float is completely replaced with water inside the lock, then you would have to pump all that water out, but this seems avoidable.",
"Consider that the lock is a cylinder and the float a very close shape. Say there's a quarter inch space difference all the way around ... | [
"The pressure on your push piston is proportional to the water column heigh so all you energy would be spent pushing the object out. It doesn't matter the voIume of water you let into your lock. Your idea is a pretty classic \"free energy\" machine concept that people have. You should be able to find plenty of expl... |
[
"What was the radiation exposure per year for a \"Radium Girl\", who painted clock dials with luminous radium-based paint in the 1920's?"
] | [
false
] | Most of the dial-painters died either of anemia or cancer. My daughter is designing a program for a play, "Radium Girls", about the struggle of these women for recognition and recompense, and wants to use either as the cover or as the center page. She'd like to note the estimated yearly dosage in sieverts a dial-painter would have collected on the chart. I didn't realize it would be so hard to figure out - our heads are spinning with all the units - rads, rems, curies? sieverts? becquerel? gray(?)??? After asking a couple of physics students, I realized I needed to ask YOU, reddit. Here are some resources I've collected. Using an estimated exposure per year of 500 microcuries of radium, how to figure the "dose" in sieverts? Thank you for your help. I used to be intelligent, but I'm feeling pretty confused now. | [
"This is actually an extremely complicated calculation. External exposure calculations are easy - you look at how much radiation hits which parts of the body, and calculate the effective dose. For ingestion, you need to know the following things:",
"How much was ingested?",
"What fraction of the ingested acti... | [
"Here is a very rough calculation which excludes the decay products of Radium: ",
"Assuming 500 microCuries( .005 Ci) of nothing but alpha decays from radium through out the year and an alpha particle energy of around 5 MeV according to Wikipedia then we get a total absorbed energy of 9.2*10",
" MeV/sec or 1.4... | [
"The problem with radiation units is that they are not that complicated but they are confusing. I started a very lengthy response that just got out of hand. One issue as you point out is that there are different unit systems. In the US we used to deal with curies (activity), roentegens (energy delivered to nearby m... |
[
"Why aren't solar panels mounted on wind turbine towers?"
] | [
false
] | My thoughts so far: A 3 MW wind turbine tower (ca. 5.000.000 kWh / year) is 100 m tall and about 5 m wide. It should be possible to mount about 500 m facing east to west with a 45° mounting angle to produce roughly 50.000 kWh / year in northern Germany (where I am) up to 100.000 kWh / year in Texas (I used an online calculator and tried to maximize output by changing locations). So only 1% - 2% solar in comparison to wind. very little shadows on the panels electrical installations are mostly (?) already in place low installation cost, as the towers are produced en masse and in factorys slightly higher grid stability (when the wind blows and it's overcast / when the sky is clear and it's calm) (also solar should be able to produce at least more than the 1 - 2% of wind stated above, since thats per annum and in reality solar produces power only half of the day -> 2 - 4% ?) vertically mounting solar panels reduces efficancy by roughly 35% (but panels could be mounted at an angle) maintenance difficulty due to hight wind puts high stresses on panels | [
"Because adding fixings for solar panels adds a stupendous amount of complexity to tower manufacturing, transport and erection.",
"First of all, these towers are not mass produced in factories, at least not like cars or electric appliances. There are many different kinds of towers (steel, concrete and hybrid) to ... | [
"So imagine that wind turbines did not exist in the world and you are sitting in your office and you think...",
"\"Would it be a better idea to build solar panels on the ground or 300 feet in the air? ",
"Also, solar panels (those that do not rotate with the sun, are still in a fixed direction to take advantag... | [
"The problem with solar power has never been \"where do we put it?\" The problem is that solar panels are really expensive and the electricity they produce often doesn't offset that cost."
] |
[
"If the atmosphere of Mars is less than 1% the density of Earth, why are there large dust devils and sand dunes?"
] | [
false
] | null | [
"Two factors are involved there. First, windblown sand is not like beach sand, it's much finer, almost like talcum powder. Desert sand dunes are not much like beach sand dunes, which is a very common mistake people make, as most people are more familiar with the latter rather than the former.",
"Second, since t... | [
"This was a big thing when they made the islands in Dubai (",
"http://en.wikipedia.org/wiki/Palm_Islands",
"). The prince of Dubai, who came up with the idea, at first thought it would be easy. Just take some sand from our huge desert and dump it in the ocean in this pattern. It then had to be explained to h... | [
"Since others have already covered the dunes, I'll talk about why Mars has so many dust devils.",
"Dust devils can only occur where there's strong convection. Warm plumes of air rise from the surface, pulling in lots of the surrounding air in the process, which then proceeds to \"spin-up\" due to conservation of ... |
[
"What causes the glow in nuclear reactor cores?"
] | [
false
] | null | [
"It's Cherenkov radiation, coming from charges particles moving faster than c/n in some material of index of refraction n."
] | [
"Next question. Would we see anything if it was outside the liquid? Besides all the usual health hazards. "
] | [
"There would be a lot less Cherenkov radiation. Whether it would still appear to glow blue, I'm not sure."
] |
[
"Do our eyes stop sending signals to our brain when we sleep?"
] | [
false
] | It seems like it would be a waste of energy to be continually sending a signal to the brain while we sleep. Do the eyes cease this signaling while we sleep? | [
"As you can imagine, this question requires a pretty complicated answer since the physiology of the brain is not yet completely known. For example, of the four types of wave forms drawn from an EEG, the alpha wave grows in amplitude when the eyes are shut.",
"There are several theories in how we perceive light, a... | [
"We can easily find out how the light interacts with our cells, but how these intracellular signals create the perception of a color is unknown. We know quite a bit about the mechanisms for turning the external stimulus into an internal signal. There are ",
"three cones",
" responsible for seeing color. The pro... | [
"Most of the body becomes paralyzed during sleep. Other wise we would flail wildly during our dreams.",
"But our sensory pathways are still active. Otherwise you wouldn't be able to wake someone up."
] |
[
"Carbon Dating?"
] | [
false
] | Sophomore in high school now and science has really grabbed my attention. I'm currently reading Life Ascending by Nick Lane. At the start of the book he says, "... a few grains of rock from that bygone age have survived the restless aeons to this very day. Inside them are trapped the tiniest specks of carbon, which bear in their atomic composition the nearly unmistakable imprint of life itself." What about carbon makes it so special? What properties does it have that makes it preserve stuff well? I heard that carbon dating after a few thousand years becomes inaccurate so how does he know how such a long time has passed? | [
"The passage you are quoting is not referring to carbon as a geochronometer using the decay of the radioactive isotope C",
" but to the properties of two of its stable isotopes, C",
" & C",
" . And you are correct, C",
" geochronometers are useless outside a rather narrow range of values, down to about 12 0... | [
"Thanks for the awesome reply! Had to look up a few words, but I'm glad I full understand what you wrote."
] | [
"A pleasure! ",
"Enjoy your reading!"
] |
[
"Is there any material that is accessible to humans (either natural or artificial) that can withstand the temperature of our sun?"
] | [
false
] | And if so, how have/can we used/use it to our benefit? | [
"Short answer: No.",
"Long answer: We currently don't know any materials able to withstand the temperatures of our sun, but the prospects of finding such a material depend on where on or in the sun. ",
"The surface of the sun has a temperature of roughly 5800K. The material with the currently known highest melt... | [
"If you think about heating a material from 0 up to the temperature of the sun, something must remain, though it could be a gas! Rhenium is a liquid at 5778 K, and I wouldn't be surprised if there were some metal oxides still solid at that temperature. Most of the oxides have useless mechanical properties though."
... | [
"As far as I understand:\nThe sun fuels itself through nuclear fusion. This is where matter changes state to plasma, so from cold to hot you have three phases of a material, Solid, Fluid, and Plasma. Within fluid, it changes state from liquid to gas, but both are fluids, just with different properties.\n(for nit-pi... |
[
"How exactly do we know that nuclear fusion occurs on the Sun?"
] | [
false
] | I know that nuclear fusion occurs on the sun thanks to the vast amounts of hydrogen atoms fusing together to form helium and other elements, releasing a great amount of energy in the process. What I want to know is, in whatever detail necessary, how did scientists come to figure this out (through what observations and experiments)? | [
"When in doubt, go to the source, especially when that source is Hans Bethe. Bethe won the Nobel Prize for his determination in 1939 of the mechanism of energy production in stars. His 1967 Nobel lecture gives a clear account of how these ideas developed. The first couple of pages are quite non-technical, and you... | [
"I think it was first that they calculated the energy the sun could produce via gravitational potential energy and found it wasn't high enough for the sun to have lasted much more than a few hundred million years(I can't remember actual numbers). They already knew the earth had been around for billions of years fro... | [
"Beyond the already-mentioned work by Bethe, the most direct evidence is the observation of ",
"neutrinos coming from the sun.",
" They are emitted in the various beta decays as protons turn into neutrons after certain fusions.",
"Ray Davis",
" got a Nobel Prize for ",
"the first observation of them,",
... |
[
"Why does human perception seem to follow a logarithmic scale?"
] | [
false
] | null | [
"Perception of what? Not all things do. Perception of length is on a linear scale. Perception of electric shock is exponential."
] | [
"I was wondering about loudness and musical notes, which seem to be logarithmic along with brightness. I kinda assumed all things were like that.",
"I didn't know electric shock was exponential, that's really interesting"
] | [
"See ",
"Weber-Fechner law",
" and ",
"Steven's power function",
". ",
"As to why it is logarithmic for brightness -- we can come up with stories: detecting some amount of light vs. no light is very useful and seeing in low light is also very helpful, so we want big jumps in perceived brightness as a func... |
[
"How did Einstein work out that the speed of light is the fastest speed there is? How do we know this?"
] | [
false
] | null | [
"The origin is in Maxwell's equations. These are the equations that describe how electric and magnetic fields evolve and interact. They were compiled together by James Clark Maxwell, who basically took everything that was known about electric and magnetic fields and put them together into a single set of equations.... | [
"For those who are interested, Einstein's original paper is available ",
"here",
" (translated from German to English), and he quite explicitly states that relativity comes from Maxwell's equations:",
"It is known that Maxwell’s electrodynamics—as usually understood at the\npresent time—when applied to moving... | [
"Just cleared up ten years of confusion, thanks!"
] |
[
"Are planets with more moons less likely to be struck by asteroids?"
] | [
false
] | This leads me to think it may deter impacts. | [
"Depends on the spatial orientation of the moon, planet and the asteroid at that time.A moon might slingshot an asteroid not colliding with the planet into the planet or it might actually push it out of the way of a planet like in the case of the animation. Both are possible."
] | [
"The gravitational pull of the moons may or may not help. It may move an asteroid out of the path of a planet, or move it into the path. All we know for sure is that it will (slightly, depending on distance and size) move it somewhere.",
"However, the moons themselves can be hit. Any asteroid that lands on a moon... | [
"Well of course it depends on the exact trajectory of each particular asteroid, but I think OP is asking if planets with more moons, on average, are hit more or less often than planets without satellites."
] |
[
"What prevents bighorn sheep from constantly getting (fatal) concussions? And could we adapt this anatomy for improvement of football helmets?"
] | [
false
] | I was watching NatGeo last night and they mentioned bighorn sheep slam head-to-head at about 20mph, which would instantly kill a human. And then I immediately thought of the the concussion controversy going on in the NFL (and other sports) and I wondered if why bighorn sheep were less susceptible to concussions (or are they?) and if we could use this knowledge to improve football helmets. | [
"Bighorn sheep slam their horns together during mating season and they do not drop to the ground. They have unique adaptations that allow them to slam or bang their horns together and not drop dead. Concussions in humans are caused by events that make the brain hit the inside of the skull. This is why a human get c... | [
"just asking because you sound like you may be able to help. ",
"looking at all of those adaptations, would it be reasonable to think that this species might be fertile ground to research against prion disease?"
] | [
"I think you may have misread something. Prion diseases are caused by misfolding of proteins in the brain, which leads to cell death and the formation of tiny cavities in the brain. Hence the other name for them - Transmissible Spongiform Encephalopathies. Blunt trauma doesn't really play into it, so the physical a... |
[
"How can light be always at a constant speed but still be influenced by gravity?"
] | [
false
] | Lets take a black hole for example. The gravitational pull is so large that not even the speed of light is a sufficient escape velocity. But wouldn’t that mean that light escaping from gravitational pulls is slowed down? That in theory a gravitational body with the same escape velocity as the speed of light would make light "stand still"? | [
"This is a pretty subtle question. Light travels at a constant speed in the sense that if you perform measurements ",
", in a box small enough that you can ignore the effects of gravity, then you'll measure the same speed of light no matter where you are or how you're moving.",
"When you look ",
" at a larger... | [
"This makes sense, thank you!"
] | [
"The time it takes to the center is indeed finite, as long as you use a sensible time coordinate. For massive objects, which travel below the speed of light, there's a very natural time coordinate to use, namely the time measured by a clock carried by that object.",
"With light (and other massless particles), the... |
[
"Is sound/soundwaves affected by gravity?"
] | [
false
] | As far as I know light is affected by gravity, according to what I've been taught anyways, and so as I was watching the music video of Chris Hadfield in space playing a song I was wondering if gravity or lack of gravity affected sound. | [
"A sound wave is different from light. Photons have momentum and are affected by gravity. A sound wave is a true wave in that it's a traveling disturbance in a medium. There are no \"sound particles.\"",
"So sound is affected by gravity only in the sense that whatever medium sound is traveling through is affec... | [
"Ah ok I see thanks."
] | [
"Technically it should.",
"Gravity effects mass, and sound is disturbance waves propagating through mass.",
"As far as Gas and liquid go, higher gravity means higher density -- the force which pulls particles towards the ground becomes larger, while the force which pushes them apart remains the same (almost, it... |
[
"Does the quantity of water on the Earth fluctuate?"
] | [
false
] | [deleted] | [
"When people are talking about wasting water, what they mean is wasting clean/drinkable water and or polluting water systems.",
"There is a lot of water on earth, but most of it is unusable, usually because it is either vapor, frozen, or salty. Overusing fresh water means there will be less water that we can use.... | [
"Does this mean there is finite amount of drinking water? Or could we potentially turn undrinkable water back into drinkable water thus eliminate worries about wasting water?",
"Would this be like what Dean Kamen's 'Slingshot' is doing, or would that have its limitations too?"
] | [
"You can filter/distill undrinkable water to make it drinkable. Water can be reused indefinitely. The only question is if there is enough for everyone to use at once. "
] |
[
"Why does the universe care if it is observed?"
] | [
false
] | In quantum mechanics, apparently it is the case that everything is described as a probability function, or in other words: the universe itself does not know the state of itself... it only knows the chances of itself being in certain states (like Schrodinger's cat). The universe only lands on a particular conclusion when it is observed... does anyone have insight into why the universe should only land on a definite outcome when a clump of chemicals, such as the human brain, tries to make sense of it, and not when in the presence of other - lifeless - chemicals... does this mean that logical beings are truly distinct from everything else since they somehow make the universe jump to conclusions... Seriously blows my mind, is there any explanations or even acceptable theories? | [
"This is a common misunderstanding. Observation = interaction.",
"It has nothing to do with life / non-life (which has nothing to do with physics). ",
"In the case of the photon, it just means whether the photon has interacted with anything. Before it interacts = superposition, after it interacts, that superpos... | [
"In the case of the photon, it just means whether the photon has interacted with anything. Before it interacts = superposition, after it interacts, that superposition collapses.",
"A subtle, but important, clarification here. When a photon interacts with a particle, the superposition doesn't collapse, the photon ... | [
"It is just a confusing language of quantum mechanics. QM is primary designed to describe outcomes of experiments. It uses terms of the system and the observer. Observer isn't a person. It's a piece science equipment which interacts with the system in order to measure something. It can also be natural phenomenon w... |
[
"If you forced different gases through a whistle, would it change the sound?"
] | [
false
] | null | [
"It can do.",
"An organ pipe produces a sound with a certain wavelength, depending on the length of the pipe. But your ears perceive the pitch of a sound based on its frequency. If the speed of sound in the gas in the pipe changes, then the pitch will change.",
"A real-world example of this is the calliope or s... | [
"Yes. Helium changes the sound of your voice because the speed of sound is different in helium and air at the same pressure. I don't see any reason why that effect wouldn't apply to whistles or any other wind instrument."
] | [
"Here's a technical paper describing an instrument that uses the frequency of a small whistle to precisely measure the composition of an unknown mixture of gases.",
"https://www.ncbi.nlm.nih.gov/pubmed/24420261"
] |
[
"Are Blue Whales actually the biggest ever?"
] | [
false
] | We are taught that blue whales are the largest mammals/vertebrates to ever exist. Isn’t this unlikely considering our lack of seabed fossil evidence? | [
"Any time scientists say anything you can assume there is a \"*to my knowledge\" attached to it. They have never found a mamal bigger than the blue whale so that is currently the one they say is the largest to ever exist. No serious scientist waould say there's no chance of finding another one. As far as how in dep... | [
"We actually have a lot of seabed fossils. We find them all the time on land, including whales in the Sahara and seashells on Mt Everest. The oldest current oceanic plates are only about 200 million years old. Older crust gets uplifted to become dry land, or subducted and destroyed in the mantle. Considering the pa... | [
"This. Biology always deals in 'as far as we know this is what happened', specially with such a difficult field as paleontology that, like the OP said, depends on the fossils found and the stimations done."
] |
[
"A coin of unknown fairness is tossed N times. It results in H heads. What can you tell me about the coin?"
] | [
false
] | Imagine it's tossed 10 times. Even if it's all heads, you can't be sure if it's unfair, or to what extent. All you know for certain is that it is not an "all-tails" coin. I'm not entirely sure how the answer would be framed, but I assume there is some probability distribution for the "heads-ness" of the coin that changes with each result. Eg: After N flips, given some results, there is a Q% chance the coin is P likely to give you heads... I'd love to see the answer derived. And, also, how would one go about this if it were a S-sided coin -- that is, we're not even sure how many possible outcomes there can be? For a coin, even with all heads results, I assume we'll think there is chance of tails coming up -- does that means there is chance of some other side turning up? If so, aren't there infinitely many possible sides, how is this resolved? | [
"You are asking about statistical estimation: given some observed data and an underlying statistical model, what is the best estimate for parameters that define that model? (There are other ways to phrase the problem if you don't know exactly what the underlying statistical model should be.) One particular method o... | [
"/u/midtek",
" talks about MLE's. An alternative formulation of your problem is the Bayesian point of view.",
"TLDR version: If you say \"I got a fair coin and got 10 heads,\" I would say \"you got lucky, it happens sometimes.\" If you say \"1 in every trillion coins is magic and always comes up heads! I go... | [
"This type of approach is used in the real world in engineering in quality control fields, in which you have to check a certain percentage of products and make a determination as to whether or not a process is flawed or not. (In practice, you dont go through the theory everytime. You just determine a z value and us... |
[
"If wave nodes are static, how do they transfer energy?"
] | [
false
] | I had this question way back in high school and I was never able to get a good explanation. So, a couple of basic assumptions: The "node" of wave is where motion/amplitude is zero. Energy travels through motion or heat, right? So how can the energy on one side of a wave travel through each node if each node doesn't move, and there's an assumption that there's no heat buildup? | [
"Well, it's a standing wave, so the energy for each non-stationary region (between the nodes) just stays where it is. If you want energy transfer, you have to talk about propagating waves instead, where there aren't any nodes."
] | [
"Actually, no net energy is transferred through a node in a standing wave. The equation for the power transfer is proportional to the rate of change of the displacement, which for a node is zero."
] | [
"So I guess my question is if no net energy is tranferred, how does the actual transfer happen. Energy MUST transfer, because the movement continues through a node."
] |
[
"A Few Questions About Schizophrenia"
] | [
false
] | I've recently been studying mental disorders, and Schizophrenia really interests me. A few questions in no particular order: 1) Normal people (as far as I know) DO (sub)vocalize their thoughts, but they realize it's their own "voice in their head". From discussing with people, they also don't always think in the same voice or sound the same, depending on mood, situation, subject, etc. What's the difference between this and "voices in your head"? Just that you don't see them as originating from your own thoughts? Or do they actually sound like someone was standing right next to you speaking aloud? 2) How do the schizophrenic mind and a normal mind under the influence of a hallucinogen such as LSD/psilocybin compare? I've heard there are similarities. 3) I guess with as much specific detail as possible, how does the schizophrenic mind process things differently than a "normal" mind? I guess I've always thought if it as a lack of structure to your thoughts, almost. Like things just randomly fly at you out of context? Thanks! Sorry, not the most awesomely-phrased questions, but I'd love to know more about any of the above. | [
"I've worked with numerous schizophrenics in the last few years in an inpatient setting:",
"1) It depends on the person. Some may have a whole bunch of voices in their head both male and female that aren't necessarily theirs. It may seem to them that they are actually hearing them with their ears or that the vo... | [
"Med student here. I got off an inpatient psych rotation a few weeks ago. I'm not expert obviously but...",
"Patients who had been previously diagnosed with schizophrenia tended to show up in the ERs after quitting their meds when the voices became too much to ignore. They recognized they were in trouble and were... | [
"Pretty much. One guy I worked with had a psychosis where the voices made him laugh hysterically all day long, while this other woman was stuck hearing her children being continuously tortured. ",
"This",
" is kind of an interesting video by Janssen, the makers of antipsychotics Risperdal and Invega. Mental ... |
[
"How does Truvada (PREP) prevent people from getting infected with HIV?"
] | [
false
] | For example, say two guys have unprotected sex and the "top" is HIV+ and does not have an undetectable viral load. How exactly does PREP work to prevent the "bottom" from contracting HIV? Wouldn't it be impossible for Truvada to be inside/protecting every single one of his T Cells? If just one immune cell is infected, would a viral reservoir be established? Why can this HIV drug stop a person from becoming infected even if that person has been directly to exposed to HIV, yet these drugs can't cure people who have already been infected? And finally, lets assume the same scenario except the "bottom" isn't taking Truvada. Why is the infection rate (I think) around 1%? Why wouldn't it be 100%? Thanks. | [
"PrEP is a combination of two Reverse Transcriptase inhibitors (if you don't know what reverse transcriptase is, please ask and I'll be happy to explain what the enzyme is and the actual mechanism by which the inhibitors work).",
"The reason the drug works is because the drugs were designed to specifically target... | [
"So reverse transcriptase is a viral enzyme which converts RNA to DNA. Both of the drugs are analogs of nucleotides (one is an adenine analog, another a cytosine analog, but that isn't really important) and these nucleotide analogs get taken into the reverse transcriptase, they are added to the DNA strand, but beca... | [
"I see, that's in fact simultaneously brillant and very simple (at least theoretically, i'm not talking about the process, which I know nothing about). Thanks a lot for your time."
] |
[
"How does vocabulary influence cognition?"
] | [
false
] | ...................... | [
"So an early version of this theory is the [Sapir-Whorf hypothesis] -- the strong version of which is that the language that you speak determines the kinds of concepts / thoughts that you have. The strongest form of this is linguistic determinism which is that language ",
" determines cognitive processes; no one ... | [
"I'm not a linguist, but if you don't get a response consider posting your questions to ",
"/r/linguistics",
".",
"They might be more responsive than ",
"/r/askscience",
" (since it's a subreddit devoted to a specific field of science), and you might get more in-depth answers."
] | [
"I'm not a linguist, but if you don't get a response consider posting your questions to ",
"/r/linguistics",
".",
"They might be more responsive than ",
"/r/askscience",
" (since it's a subreddit devoted to a specific field of science), and you might get more in-depth answers."
] |
[
"Why does glucose require insulin to be metabolized but not fructose since they are so similar in structure?"
] | [
false
] | null | [
"glucose doesn't require insulin to be metabolised; rather insulin causes cells to absorb glucose. It's a significant distinction since fructose and glucose metabolism are similar in that the same kind of chemistry occurs, albeit with different enzymes.",
"The short answer is that the small differences between fr... | [
"Just because chemicals are similar in structure doesn't mean they are necessarily processed the same way. Indeed, even differences in enantiomers (ie same exact chemical structure but just mirror-images of each other) can lead to very different effects. The classic case is thalidomide, where one enantiomer was ter... | [
"Just wanted to confirm that glucose is an aldohexose while fructose is a ketohexose. "
] |
[
"Why is sapphire an electrical insulator as well as a thermal conductor?"
] | [
false
] | [deleted] | [
"thermal and electrical conductivity typically go hand in hand in ",
" (see ",
"Wiedemann-Franz law",
" ), for insulators there is no such correlation. If you look at this chart of measurements from wikipedia: ",
"thermal conductivity.svg",
" you'll see that diamond (while also being an insulator) has a v... | [
"Yes. In disordered materials, phonons can't be described in the simple way we can model them for crystals, and long-range phonons don't really exist there. Basically, phonons are a collective motion of many particles. If the material is disordered, this will disrupt the collectivity, so large-wavelength phonons ca... | [
"Yes. In disordered materials, phonons can't be described in the simple way we can model them for crystals, and long-range phonons don't really exist there. Basically, phonons are a collective motion of many particles. If the material is disordered, this will disrupt the collectivity, so large-wavelength phonons ca... |
[
"Are thoughts physical objects?"
] | [
false
] | I know it's a strange question, but I have a hard time thinking about it. How do we see and hear thoughts, are thoughts three-dimensional? Thank you very much for the enlightening responses, they help tremendously. For anyone else interested, this might set you on the correct path- . If somebody has a more legitimate source, please post a link. I'm very skeptical of that website. | [
"Thoughts are to your brain like Walking is to your legs.",
"Thoughts are an emergent property of brain activity, just like walking is what happens when you legs work.",
"Your brain is a physical thing, your legs are a physical thing. Thoughts aren't, walking isn't. Can you pick up \"walking\" and put it in a j... | [
"Thoughts are webs of electricity traveling through different sections of your brain. Most are reactionary responses to outside stimuli, and then chained together based on memories that surface during the process... ",
"I try not to think about it really; that our entire lives are just a chain of reactionary elec... | [
"They're physical, but not objects exactly, more like patterns of energy and matter moving around inside the brain.",
"Think about a flashlight. It's a physical object. Turn it on and electricity flows through it and light comes out one end. The electricity and light are physical, but they're not objects (unless ... |
[
"Can patients diagnosed with serious psychopathologies (i.e. schyzophrenia) lose their pathological traits after a brain trauma, coma or amnesia?"
] | [
false
] | null | [
"This is a really complex question and has multiple layers, and no single answer. ",
"First of all: we'd have to consider the pathology. A lot of the ones that are in the forefront of science right now (like Schizophrenia, Alzheimer's, Parkinson's, etc.) are either problems with particular proteins which are foun... | [
"except perhaps in the case of epilepsy/chronic seizures. Epilepsy is one of those diseases where there is synchronous hyperactivity of neurons, and a last-ditch effort among neurologists and neurosurgeons for some years now has been to cut the corpus callosum ",
"But then the cutting of the corpus callosum can c... | [
"Thank you for your answer.\nI'm sorry as my knowledge in the matter is that of an absolute outsider, and I discover with your answer nuances I ignored in my question: I'm talking exclusively about psychological disorders for which we're not sure they are \"protein-related\" or at all caused by autonomous physical ... |
[
"Why are the Earth's magnetic and geographic poles so close together?"
] | [
false
] | I searched for previous answers on the sub but none had what I was looking for. | [
"In very simple terms (and simple is all I can do as the details of geodynamo theory are beyond me), the geographic pole is the rotational axis of the planet. The magnetic field is generated via a ",
"dynamo",
", which basically means that the geomagnetic field is induced by currents within the liquid Fe/Ni out... | [
"The rotation is only one part of the equation, so the Earth does not have a magnetic field solely because of the angular momentum of the accretionary disc, but the rotation of the earth is a part of why we have a magnetic field. Dynamos are incredibly complicated and can get weird. We see similar patterns in sever... | [
"I mostly stick to atmospheres, so while I don't work directly on planetary dynamos/magnetospheres, quite a few of my friends do.",
"While Uranus and Neptune's magnetic fields are very tilted, we think we understand the basic idea why. Their magnetic fields are generated in a shallow superionic water sea (rather ... |
[
"Are there non continuous macroscopic physical quantities?"
] | [
false
] | Temperature, speed, pressure, energy... are all continuous in any situation, to the best of my knowledge. Even square waves are in practice continuous. Do non continuous macroscopic physical quantities exist? Why or why not? | [
"Yes. Look at ",
"this",
" diagram of typical superconductor during phase transition.",
"Superconductivity is quantum effect but it can be seen on macroscopic scale because piece of superconductor can be of arbitrary size given that you can cool it down below critical temperature. "
] | [
"Yes. Ie. all material properties are discontinuous at the edge between two materials. (Ie. diffraction and reflection at the border between air and water is due to a discontinuity of the speed of light in those materials). Also, every phase transition has discontinuous properties related to it, ie. if you melt ice... | [
"This is probably the best example of a completely discontinuous phenomena in physics. Many discontinuous phenomena end up looking reasonably smooth anyway but this one is just so striking"
] |
[
"Does CERN use proton-proton collisions in the accelerator? If so, why not proton-antiproton collisions?"
] | [
false
] | The only things I have been able to find seem to suggest that they use proton-proton and proton-heavy ion collisions. Wouldn't a matter-antimatter collision make more sense as their entire mass would also be converted into energy which would go into making particles? Also, are there any other experiments today that do use matter-antimatter collisions? | [
"For some particles the production cross sections differ significantly between proton-proton and proton-antiproton collisions. See for example this standard plot: ",
"http://www.hep.ph.ic.ac.uk/~wstirlin/plots/crosssections2013.jpg",
" .\nThe thick red line labeled sigma_top has this weird jump at 4TeV, which i... | [
"It does proton-proton, lead-lead and proton-lead. The Tevatron at Fermilab near Chicago used proton-antiproton. The predecessor at CERN, the LEP, did electron-positron. The protons have about 7000 times as much kinetic energy as mass energy, so that extra part doesn't really make a difference."
] | [
"Thank you, makes sense.\nThat is so crazy that they'll only need that much, it looks so insignificant compared to what they do there. Really a wow moment!"
] |
[
"Is nuclear waste management a big problem with nuclear energy?"
] | [
false
] | A few days ago, me and my colleagues were discussing nuclear energy v/s conventional energy and I was debating for the nuclear side. Of all their arguments (including nuclear disasters, escaping radiation etc.), I was able to provide counter arguments and references, but when one of my co-workers mentioned nuclear waste management and said that as of now we don't know how to handle nuclear waste effectively, I did not have an answer. Simply, I had never thought of it or read extensively about it. So, what I wanted to know is, are our current methods of nuclear waste management essentially ineffective or largely inefficient? | [
"It depends on the type of nuclear reactor used. Breeder reactors do not produce much waste at all, but for whatever reason these are not the preferred reactor in most countries. In the uk waste is a big problem, Sellafield reprocesses waste into new fuel which reduces some of the problem. ",
"Storage of waste in... | [
"I will try and expand this comment later, but...",
"There are technologies to handle waste management (e.g., reprocessing), but the US in particular does not use them, due to an executive order by Jimmy Carter. Geological storage (namely Yucca Mountain) was also a viable solution (though not very good compared t... | [
"Yes, that's what I meant by volume reduction, though I guess I should have spelled that out (I had to head out the door, so my original answer was a placeholder). Reprocessing doesn't burn everything, though you can get very high burnups with a full implementation of a closed cycle using fast reactors, breeders et... |
[
"Why do ice cubes crack when liquid is poured over them?"
] | [
false
] | null | [
"Rapid temperature change, which also leads to a change in density.",
" The density change pushes and pulls the molecules around it, applying mechanical force within and around the ice cube that breaks its crystal structure. Water is actually most dense at 4 deg C. It's very similar to you snapping a pretzel."... | [
"LTP",
"Life Tip Pro?"
] | [
"Fun tidbit, the forces at play can, on rare occasion, cause the ice to crack with enough force to make a piece jump out of your drink. I’ve witnessed a grand total of one time in my life. It was spectacular.",
"The forces at play are similar in some ways to the “prince rupert’s Drop”. Variable stress within t... |
[
"Would a body encased in cement decompose?"
] | [
false
] | I was watching The X-Files on Netflix and they discovered that someone had buried a body in concrete. When they went to dig the body up, it had completely decomposed and all that was left was the bones. Would this happen in real life? Or would the concrete sort of preserve the body from anything that would decompose it? | [
"concrete is quite porous and will allow moisture to escape slowly over the years (which means given enough time the flesh would become desiccated), in the mean time anaerobic bacteria would go to work on any energy source it can digest"
] | [
"Thanks so much for your response! Do the bacteria need oxygen to decompose the flesh? If so, would the porous nature of the concrete allow for oxygen to reach the bacteria?"
] | [
"not enough to sustain very many bacteria and these would be out-competed for resources by the anaerobes "
] |
[
"Why is it reptiles and certain animals are able to survive such long periods on a single meal, compared to humans?"
] | [
false
] | I was watching a documentary and saw that a Nile Crocodile could last an en entire year after a meal. How is this possible? Even if the animal it ate was large, surely the eaten animal couldn't sustain a big crocodile for such a long time? | [
"Cold blooded. Humans use up massive amounts of energy keeping ourselves at optimum temperature, humans also have higher than average energy requirements than most other mammals due to our larger brains. Humans can survive months without eating btw."
] | [
"Yeah, I didn't deny that? They can't last as long from a single meal though and instead rely on large fat stores."
] | [
"There are plenty of warm-blooded animals that can last months without food "
] |
[
"When I flick a lighter/flint next to an already-burning fire, the sparks cause extra sparks to go off in and around the flame. How/why does this happen?"
] | [
false
] | I could not find any videos, but it is really easy to see the phenomenon with a candle and a lighter. Light the candle, and then flick the lighter a couple of times near the flame. "Extra" sparks will go off around the flame up to a second after you stop flicking. This completely baffles me--why does it do this? | [
"The flint dust that was leftover gets kicked up and ignited.",
"It's made of ",
"Ferrocerium",
".",
"Basically you're burning metal shavings."
] | [
"well sure, it's little splinters of metal that fly up and get ignited and combust. You can call them mini-fires if you like.",
"Thought what shavera said may be true, I don't believe this is what happens most often. It would look different i'd think - much more of a mini-fireball-woosh effect."
] | [
"You can achieve the same effect by holding the lighter upside down and grinding the flint slowly onto your fingernail, then flicking the accumulated shavings into the flame. I loved doing this when I was a kid."
] |
[
"How does the 'security pattern' in the Canadian polymer bills work?"
] | [
false
] | Short description of what I'm talking about: In 2011, the Bank of Canada started issuing the Frontier Series of Canadian banknotes, which were the first to be produced on polymer. If you look through the circle in the middle of the frosted maple leaf, there is kind of a 'display' of the denomination of the bill. How does this work? Specifically, why can't I see it on the actual bill (i.e. in the reflection of the circle), and why does it stay centred on the point of light? For that matter, why does it only work with a small light source anyways? Examples: , | [
"It uses a ",
"diffraction grating",
" to produce the images. The diffraction pattern in this case produces the denomination amount. The second video produces a much clearer image of the denomination amount because they used a laser, which is a source of coherent light."
] | [
"I guess a bank could have the note pass over a laser on one side with a detector on the other side to measure the shape of the diffraction pattern. A focused laser would allow the pattern to be more easily deciphered at smaller distances."
] | [
"My guess is this works similarly to how the glasses which make bright small light sources appear differently work. For example, making the lights on a Christmas tree look like snowflakes. ",
"What such glasses show while driving, for example.",
" Or for a more natural explanation, how when you look at a traff... |
[
"How can the universe be both infinite and expanding?"
] | [
false
] | If the universe is expanding then that implies that there is something to expand into which would imply an end to the universe. I just cant wrap my head around this. | [
"Think of the number line. Multiply every number by two. The distance between any two points has just increased (by a factor of 2) yet the number line is still the same length."
] | [
"Metric expansion",
" is entirely analogous to this. I was trying to give the simplest example where",
"If the universe is expanding then that implies that there is something to expand into",
"(i.e. the first premise) is incorrect"
] | [
"Yeah? And that's how you try to make sense of abstract concepts."
] |
[
"How large can stars get?"
] | [
false
] | null | [
"There is not a single answer to this question. Previously stars were expected to top out at around 150 solar masses, in part due to the Eddington luminosity which describes the point where the radiation pressure would exceed the pressure due to the gravitational force.",
"https://en.wikipedia.org/wiki/Stellar_ma... | [
"Stars can get very large indeed. The largest star yet discovered is UY Scuti in the constellation Scutum (Latin for shield) near the constellation Sagittarius. ",
"Our Sun is enormous. It accounts of 99.8% of all the mass of our solar system. If you wanted to fill the volume of the Sun with planet Earths you wou... | [
"The limit outlined in that paper is the practical limit because the black hole won't grow appreciably if it cannot form an accretion disk. But there are known black holes close to this limit (the same order of magnitude) at 40b solar masses",
"https://en.m.wikipedia.org/wiki/List_of_most_massive_black_holes",
... |
[
"When someone has an operation to remove an organ, what fill the space left behind?"
] | [
false
] | Say I get a lung or kidney removed, they obviously took up space and had blood vessels and muscles attached to them, what fills that empty space, and what happens to all of the now unnecessary blood vessels? | [
"Here's a book that describes what happens with lung resections. It's a special case because the lung cavity is subjected to a big variance in pressure when you inhale and exhale.\n",
"http://www.intechopen.com/books/topics-in-thoracic-surgery/pathophysiology-of-extravascular-water-in-the-pleural-cavity-and-in-th... | [
"Usually when a kidney fails it because it's not filtering blood properly anymore. One of the complications is that the kidneys are attached to major arteries/veins so it's usually better to leave them in place. If the tissue itself is undamaged (just not functioning) then it's better for the patient to leave the k... | [
"A lung is a pretty dramatic example nowadays - if you have an organ removed, you normally replace it. But let's say it's your spleen which is relatively dispensible. ",
"You have a total splenectomy. The blood vessels are ligated and cauterised to prevent them leaking blood into the peritoneal cavity. The muscle... |
[
"What are the epidemiological reasons for immunizing healthcare workers before at-risk populations?"
] | [
false
] | "Frontline healthcare workers and elderly residents of long-term care facilities will receive the very first COVID-19 vaccinations, a Centers for Disease Control and Prevention (CDC) advisory board recommended Tuesday. These groups will make up Phase 1A of U.S. vaccine recipients who will receive the first 40 million or so doses that could be available by the end of the year. The Food and Drug Administration (FDA) is currently reviewing two vaccines, from Pfizer-BioNTech and Moderna, for emergency use authorization." - Time I am wondering why we're not immunizing older folks or people with pre-existing conditions first, from an epidemiological standpoint (not asking if it's moral to do so). Does the overall amount of deaths actually decrease if you immunize healthcare workers first? What are the epidemiological implications and justifications of this decision and how will it alter the trajectory of the pandemic, as compared to if we immunize the at-risk population first? | [
"Health care workers are the most likely people to spread the disease because they have to work with people who actually have it. Other demographics, especially at risk people, aren't likely to visit lots of people and aren't likely to deliberately visit people who do have it. Vaccinating the people most likely to ... | [
"Also to protect capacity within the healthcare system. You don't want outbreaks removing nurses and doctors when they're needed most."
] | [
"If the health care system crumbles, who will care for the sick? (Including the non-covid sick). People still get into car accidents, have heart attacks, need emergency surgery, need prescriptions.",
"Also, because we see so many people in such a short period of time, we are very likely to be asymptotic carriers.... |
[
"What you see traveling near the speed of light"
] | [
false
] | null | [
"The joke is you would suffocate because you were traveling through the vacuum of space (with no mention of a spacesuit/oxygen -- the comic character specifically not having one drawn) and has nothing to do with relativity.",
"Sort of similar to ",
"xkcd 669",
".",
"Note for the other panels, you don't have... | [
"Image",
" Experiment",
" The other two are still lost on the infinite plane of uniform density.",
"Comic Explanation"
] | [
"I am officially very stupid, hahaha. I don't know why I thought that one was real fact, knowing the other ones were spoofs on fun facts. ",
"Thanks for pointing out my sillyness"
] |
[
"Some of the most massive craters on the surface of the moon and elsewhere throughout the solar system seem relatively \"shallow\" considering how wide the craters are. What gives craters this wide and flat shape?"
] | [
false
] | null | [
"This is not entirely consistent with discussions in the literature on impact craters, e.g., ",
"Robbins et al, 2017",
" discuss relationships between crater depth and impact velocity (and angle) with references to more detailed studies."
] | [
"The ",
"impact depth",
" is approximately (Length of Object)*(Density of Object)/(Density of Target). One thing you will note is that the velocity or energy of the impactor does not effect how deep it will penetrate. As more energy is added the crater gets wider but doesn't penetrate any better, this is the re... | [
"The Modification stage of crater formation. See figure ",
"here",
" of simple crater formation.",
"So long as there aren't huge density differences, the initial excavation from the impact is pretty close to a hemisphere centered on the impact point. However, the resulting crater walls are usually a fair bit ... |
[
"How does the body maintain the same amount of blood that it contains?"
] | [
false
] | I'm not sure if this is a silly question or not. I have just given blood and, as a male, I have about 11 pints of blood left in my body which will (hopefully!) increase back to 12 pints. It got me thinking about how the body maintains this consistent level of blood and doesn't produce too much/too little? | [
"There is a lot that goes into the formation of blood. In your blood you have: water, rbc's/wbc's/platelets, plasma proteins, and electrolytes (there are some other things, but they are not as fundamental). ",
"When you lost that pint of blood, the first thing that happens is constriction of the blood vessels and... | [
"In case of excess fluid in your blood vessels, the same system works in reverse: the renin-angiotensin-aldosterone system becomes less active, the kidneys will excrete more Na+ ions, and because of that will also excrete more water. At the same time, lack of hypoxic stress (because of the sufficient availability o... | [
"Blood is a mixture of water, cells and some molecules and ions, each of one has its amount rigorously controlled. When you donate blood, you lose about 400 mL. The first thing your body does to compensate this loss is to drive water from the tissues to inside the vessels. This will keep your blood pressure. After ... |
[
"How does climate effect human behaviour? eg how would living in tropics change society will it change sexual behaviour?"
] | [
false
] | null | [
"Hello,",
"This question would be more appropriate for ",
"/r/AskScienceDiscussion",
".",
"Best."
] | [
"Have I been shadow banned?"
] | [
"No, this thread is just removed."
] |
[
"What has caused the characteristic shape of eye among alot of native asian people?"
] | [
false
] | We all know that native africans have darker skin than other people because exposure to strong sunlight during millions of years, but what has caused the characteristic shape of eye that is common among native asian people? | [
"It has been described as a defense against the cold and winds of northern Asia, or the harsh sun's rays in tropical parts of Asia.",
"But, it is also seen in a number of medical disorders (such as Down Syndrome, Turner Syndrome, Fetal Alcohol Syndrome, and more) and in fact all people have these folds in the wom... | [
"Ha yes I will admit that it's partly Google, but I'm also studying developmental biology, so I come across things about this from time to time. "
] | [
"I think it is safe to say that it is always okay to google a lot. :)"
] |
[
"Could humans circumvent breathing by directly oxygenating their blood?"
] | [
false
] | I've always wondered if it would be possible to do this. I can see it being incredibly useful for a navy seal team (for example) if, instead of holding their breath or using an 02 tank, they could directly oxygenate their blood. In my head it would involve connecting a device to a major artery or vein (idk which would be more efficient/useful) and blood would make a short trip out of the body and into this machine which would draw the oxygen out of the water and infuse it to the blood, eliminating the need to breath. I'm not sure what the process would have to be for pulling the 02 out of the water or what it takes to oxygenate the blood (though, since your blood is always red when you cut yourself, i would hazard a guess that simple exposure to oxygen would do it) What do you guys have to say? | [
"Promising future research aside, the only clinical way to accomplish this currently is via extra-corporeal membrane oxygenation (ECMO); also known as a heart-lung bypass machine. It is similar to what you're imagining in that it inserts into major blood vessels - in the surgeries I've taken part in, usually the I... | [
"Graphene seems to be very popular right now. A machine that makes oxygen + graphene out of airborne co2 would probably net you a couple of bucks.",
"Also, I think the machine you describe is called \"a tree\"."
] | [
"You have to get rid of the CO2 produced though cell respiration. Even if you oxygenate the blood, CO2 will build up and throw you into ",
"acidosis",
", eventually resulting in death. A 140 lb person exhales about 42 grams of CO2 per hour through basal metabolism, so you can see it would build up quickly if no... |
[
"What'd happen to the charge of the plates if you insert a dielectric between the capacitor, then remove the battery 1st then the dielectric after?"
] | [
false
] | I know that the charge would increase in the capacitor in the presence of dielectric and battery. But what if I remove the battery with dielectric still in place, then remove the dielectric after the battery is removed. So after I remove the dielectric, the capacitance would drop so it wouldn't be able to hold that much charge, but the extra charges can't flow back to the battery because it's removed so what would happen to those extra charges it's holding? Thanks. | [
"Just remember the capacitor equation. Q = C*V",
"Q is charge",
"C is capacitance",
"V is voltage",
"If the plates aren't connected to anything, and I assume there is no arcing, that means that Q, the charge, is locked and cannot change. If Q is constant, and we know C goes down, the V (the voltage) must i... | [
"Thanks a lot :)"
] | [
"This is correct, except that a dielectric ",
" the capacitance. So:",
"1: Constant Q --> V decreases",
"2: Constant V --> Q increases."
] |
[
"Why is the mole the SI unit of measurement for amounts of chemicals?"
] | [
false
] | We are currently covering stoichiometry in my chemistry class, and this question doesn't seem to be answered in the course content, so I was wondering if anyone would be able to answer this question for me. | [
"Well consider the following: You know the elements, and you know their weights relative each other. Hydrogen is 1 U or 'Dalton' and oxygen is 16 U, so H2O weighs 18 U and the increase in mass on burning oygen to water is 18/16 = 112.5%. So you know 1 pound of oxygen will burnt with hydrogen to produce 1.125 pounds... | [
"Isn't your example a bit off? 12x10",
" is two moles of carbon. so 24 g."
] | [
"To put it simply, the inverse of Avogadro's number is the atomic mass unit in grams. Avogadros number is the conversion factor between atomic mass units and SI mass units."
] |
[
"Why can't we do massive blood replacement to help fight diseases in the blood such as HIV/AIDS?"
] | [
false
] | This might be a super stupid question, but I was just thinking, with diseases like HIV/AIDS which slowly 'infect' your blood. Could you not do a massive blood transfusion? Essentially removing most of your current blood and replacing it with a donor's blood which doesn't have your white blood cells massively infected? I realize this couldn't cure you because the infected and fresh blood would have to touch since you can't be drained of all your blood and survive (or can you?), but it seems like if you did do this you could at least remove a wide majority of the infected WBCs and supply it with a fresh supply, slowing the total assimilation of your blood and reducing the risk you would die from an opportunistic infection? Could this also work with other diseases of the blood? I am assuming it can't, but why not? Edit: Thanks all for the great answers, it seems like you can do this technique, but only for diseases existing only in the blood and I had mistakenly though HIV was one such disease. I LOVE ASK SCIENCE /moar | [
"The blood replacement would not work because blood transfusions only occur in the peripheral bloodstream. The WBCs that HIV infects (CD4 lymphocytes, macrophage, dendritic cells) are located in the bloodstream and other areas. ",
"If you transfused all of someones blood you would be left with HIV infected cells ... | [
"HIV uses the bodies immune cells to replicate itself, so removing all blood would not remove all of the HIV virus."
] | [
"There is a technique like this called ",
"exchange transfusion",
" which is sometimes used for severe malaria (which infects red blood cells). ",
"It wouldn't work to cure HIV because it hides away as others have mentioned. Anti-retroviral drugs can get HIV in the blood down to almost undetectable levels. "
... |
[
"What would the lifespan of someone born in the past two decades be?"
] | [
false
] | [deleted] | [
"Here are the ",
"actuarial tables",
" the US Social Secuirty administration uses.",
"A 21 year old male can expect to live to be 76, a female 81."
] | [
"our increasing lifespans are largely due to medical advances, new drugs and treatments..",
"So unless somebody wants to go out on such a limb as to predict the next 50 years of medical advances, the question can't be answered reliably.."
] | [
"I don't know, but I heard that the majority of children born today here (Sweden) can expect to reach 100.\nEDIT: Actually, this is not a Swedish source. It comes from the Lancet. See for example, ",
"http://abcnews.go.com/Health/WellnessNews/half-todays-babies-expected-live-past-100/story?id=8724273"
] |
[
"If antihistamines can reduce swelling and vasodilation without negative side effects, why do our bodies do this in the first place?"
] | [
false
] | [deleted] | [
"Just because we have allergic reactions to things like pollen, it doesn't mean it evolved because it was advantages. It could be a negative offshoot of an overall beneficial biological process. The \"swelling and vasodilation\" are very important in the bodies response to harmful stimuli. This is how the body re... | [
"Here is the reason life has not figured out a workaround yet. It hasn't had the need to, nor has it had the time to if there was enough selective pressure to eliminate them. Allergies are a relatively new phenomenon. Children in third world countries do not develop allergies nearly as frequently as children in fir... | [
"Here is the reason life has not figured out a workaround yet. It hasn't had the need to, nor has it had the time to if there was enough selective pressure to eliminate them. Allergies are a relatively new phenomenon. Children in third world countries do not develop allergies nearly as frequently as children in fir... |
[
"What mammals are more plentiful than humans?"
] | [
false
] | I'm wondering about the number of individuals of various mammalian species. There are currently just below 7 billion humans on Earth. Are there any mammalian species that come close to or exceed this number of individuals of the species? Mice, rats and possibly certain species of livestock come to mind as possible candidates, but I can't find any estimates of the number of individuals of these species. | [
"Birds are not mammals. "
] | [
"Would you consider, for example, all species of mice just \"mice\" or all species of bat just to be \"bat?\" It's an important distinction, and I think that if you were to consider all species of mice or bat, both groups would out-populate humans. "
] | [
"It was an interesting piece of information anyway. I had no idea there was such a vast number of chickens."
] |
[
"When you dissolve NaCl in H2O, and then boil the solution so that the H2O molecules begin to evaporate, what keeps the evaporating molecules from carrying Na and Cl atoms away with them?"
] | [
false
] | When the water boils away, there is always NaCl left over. Why are the ions not carried away with the water? Don’t the ions bind to the polar ends of the water molecules? | [
"The energy you put into the water when you boil it breaks the bonds between the ions and the water molecules. Gaseous molecules, to a decent approximation, are not bound to anything but themselves. ",
"Bonus fact: because the bonds between the ions and water are stronger than the bonds between water molecules,... | [
"Na+ and Cl- have a higher boiling point than water. If the salt water was heated to 1621 degree Fahrenheit then the salt would evaporate too.\n The water boiling away is a type of distillation. For more information on distillation using differing boiling points, look up fractional distillation or go to ",
"http:... | [
"Got a source for that?"
] |
[
"What underlying force caused the expansion of the universe after Cosmic Inflation ended but before Dark Energy became the dominant factor in the universe?"
] | [
false
] | null | [
"Was it some kind of ‘inertia’ ",
"Basically, yes. "
] | [
"That seems about right."
] | [
"Thanks, I appreciate the answer! This definitely pointed me in a good direction.",
"I’ve kept reading with inflation and inertia as my search terms, and my real rough understanding is that space expands because vacuum energy has negative pressure which provides an effect that acts like the opposite of gravity. (... |
[
"How does oral plaque originally form inside humans?"
] | [
false
] | null | [
"You're right, plaque is definitely (predominantly) bacteria. In fact, it's composed of not one but hundreds of different bacterial species as well as protein, polysaccharides, and even some of your own cells. ",
"This is a really complete review on the subject of plaque",
". It's a little long but even just re... | [
"Thank you for the interesting reply! ",
"One of the reasons I asked this question is because I was wondering if there was a particular bacteria that we could force into extinction. I see now that's not the case. ",
"Thanks again."
] | [
" and ",
" are reportedly the most common bacterial species responsible for early dental plaque.",
" It is unclear exactly how children are colonized. One study found a significant number of those born via c-section acquired ",
" earlier than those born vaginally.",
" There is evidence for transmission from... |
[
"I don't know if this is specifically a science question, but why does NASA seem to assign such short missions to probes that can apparently operate for much (even decades) longer than that mission?"
] | [
false
] | null | [
"The answer will depend on what probe you're talking about. For space telescopes which operate in the infrared, they need coolant, often liquid helium, which will eventually leak out and boil away, making it impossible to keep the telescope cooled to temperatures where it can continue functioning.",
"There are ot... | [
"Underpromise, overdeliver."
] | [
"Two reasons, one financial, one cynical. First, the financial, the initial mission funding is for a specific time, NASA may want to run longer, but it would have to be approved in next years budget, so, they design it to last as long as possible, in the hope of continued funding. The second, is that they deliberat... |
[
"How come different allotropes of an element have such drastically different characteristics? For example, the major differences between Diamond and Graphite."
] | [
false
] | I have never studied chemistry, but I know that allotropes differ from one another based on the way the atoms are structured, but how come some of them are so different? For example, diamond vs graphite - both are made of Carbon, but Diamond is very hard and clear while graphite is soft and black. | [
"The carbon atoms in diamond and graphite bond to each other differently, which leads to different crystal structures. Graphite is a layered 2-dimensional structure, and graphite is a more 3-dimensional structure (you can easily find pictures on the internet of how the atoms are arranged).",
"Graphite is soft in... | [
"The molecular arrangement of the atoms is very important as well. Graphite is composed of sheets of carbon atoms ",
"layered",
" on top of each other. Diamond, on the other hand, is arranged in a 3D structure called a ",
"diamond lattice",
", which makes it both hard and transparent."
] | [
"Elemental silicon has the same crystal structure as diamond, but is definitely not transparent. It sounds like the effect you're likening it to (the cloudy lens) is a scattering process due to disorder on a much larger scale (10's of nm's to um's). ",
"The \"transparency\" is due to the lack of energy level diff... |
[
"Are we born with the cells of the adaptive immune system?"
] | [
false
] | [deleted] | [
"Yes, more or less. They're actively produced (and dying) throughout our lifespan. Adaptive immune cells are primarily B and T lymphocytes. These cells, in their development (again, constantly happening throughout your life) edit their individual genomes to generate the receptors which detect specific pathogens, in... | [
"Cool thanks, I don’t remember the source I read on it, but it must have been 10+ years ago, and I only got the gist of it"
] | [
"If I understood your question right the answer would be no, you dont have an uncountable number of naive cells waiting to be activated by their antigen. The adaptive (and inate) immune cells are constantly produced from hematopoietic stem cells in the bone marrow, with consequent maturation in spleen (B cells) and... |
[
"How does computer memory work?"
] | [
false
] | [deleted] | [
"I see some wavy hand explanations....but as someone who has an ECE degree, and engineers enterprise storage servers, I may be able to provide some insight. Here is the list of memory types we will go through...i'll skip over optical and tape media...as they're largely obsolete:",
"SRAM (static random access memo... | [
"There are many many layers to this. I can't really cover the details, but I can give you some information. But an important distinction is that it depends on the type of memory. There are four basic types that I know of:",
"RAM",
"magnetic disk",
"solid state drive",
"optical drive",
"I assume you're les... | [
"The RAM you are describing is called static RAM and is generally only used in caches these days. Dynamic RAM is almost always used for main memory. This works by storing each bit on a capacitor and periodically refreshing the value by reading it back and rewriting it. Dynamic RAM is significantly smaller and mo... |
[
"Would the way Dexter (from the TV series) covers up his murder scenes (from the actual site of murder to the disposal of bodies in the ocean) be constantly elusive to actual police forensics or are there some flaws in how he does it? (In terms of DNA, blood spatter etc.)"
] | [
false
] | null | [
"In case anyone wants to answer, but isn't sure of the specifics. ",
"off the top of my head Dexter does this:",
"Surprises victim in a secluded area (sometimes more secluded than other times) and injects them with something that immediately knocks them out. He loads them into the trunk of his SUV",
"Brings h... | [
"Good point. I never really thought about it that way. What do you think about from when he actually has the victim in the murder scene though?\nEDIT: From a scientific perspective."
] | [
"Good point. I never really thought about it that way. What do you think about from when he actually has the victim in the murder scene though?\nEDIT: From a scientific perspective."
] |
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