title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"Are there any animals whose blood is not red?"
] | [
false
] | When I googled this all I could find was sci-fi stuff | [
"Yes, but it's not particularly common. A common example is the ",
"horseshoe crab",
", which has hemocyanin in place of hemoglobin. Vertebrate blood's red color comes largely from hemoglobin, which is bright red when oxygenated and a darker red when deoxygenated. Hemocyanin is blue when oxygenated and color... | [
"I did some reading about the difference between hemoglobin and hemocyanin, mainly highlighting why hemoglobin is more common and the reason that oceanic mollusks and arthopods such as squid and octopus have hemocyanin. That left me with one unanswered question that I'd like to ask. Why do land dwelling slugs/snail... | [
"Hemocyanin is an ancestral trait for those groups. The transition to land likely happened after it evolved."
] |
[
"Isn't Einsteins gravitational field the same thing as the aether that was disproved by the Michelson–Morley experiment?"
] | [
false
] | Because when two black holes orbit each other, they create waves in the gravitational field that ripples outward and this slows their spin down enough that they begin to get closer and closer till they merge. So it seems like all of "matter" is on top of this "pool" that does affect our inertia.. just have to be large ... | [
"The \"gravitational field\" you're referring to is spacetime. Orbiting black holes create gravity waves which move through spacetime. And you're right, all matter is embedded in spacetime. ",
"The postulated luminiferous aether was a medium through which light traveled which permeated all of spacetime. ",
... | [
"Isn't Einsteins gravitational field the same thing as the aether that was disproved by the Michelson–Morley experiment?",
"No -- the luminiferous aether from the Michelson-Morley experiment would have been the hypothetical medium in which light exists, outside of which it might not, or may take a different form.... | [
"This is exactly what the Michelson-Morley experiment disproved. If there were a medium, then moving with respect to it would change the properties of light. Michelson-Morley showed this did not occur."
] |
[
"Are there any computer animations of what a supernova would actually look like in real life? What would it look like?"
] | [
false
] | Most animations, movies, etc depict supernova as just really big explosions that happen quickly. If you were close to the supernova, but have it still be in your field of view (and let's pretend you can't die, and that your eyes can handle it), wouldn't it appear to expand very slowly (due to speed of light limitations... | [
"Yes, many of them look at the fluid dynamics during the collapse so might not look like the massive explosion you want, but here are a few:",
"https://www.youtube.com/watch?v=2RxIwtxdEnQ&t=22s",
"https://www.youtube.com/watch?v=x0jh26fr8Xg",
"There is also the long term telescope images of the 1987 supernov... | [
"It depends on how close you are. If you are very close, you see nothing and then suddenly you are in the supernova (because the light doesn't travel much faster than the matter behind it).",
"If you are more distant and don't get directly hit by fast matter, you see the expelled matter expanding very quickly. If... | [
"This is amazing,thanks for sharing this."
] |
[
"Does a magnet ever lose its power?"
] | [
false
] | null | [
"Magnets do get weaker over time, very slowly. It's a chemical process rather than anything fundamental to magnetics- magnets lose strength at a similar (like, rough within two orders of magnitude) rate as their structure changes.",
"Neodymium magnets are one of the most stable magnets, for the same reason they'... | [
"No, as long as it's above absolute zero than random thermal motion will eventually mess up the structure."
] | [
"So if that neodymium magnet was kept in a vacuum or in a chamber with some noble gas (basically, in a place where nothing could react with it), would it theoretically last indefinitely? "
] |
[
"Can single-atom black holes exist?"
] | [
false
] | null | [
"A black hole that small would have a radius much smaller than a Planck length. As such, this is the domain of quantum physics. But it also has a black hole, so it's general relativity. Basically, we need a theory of quantum gravity to figure out what would happen.",
"The minimum size to keep the radius above a P... | [
"The minimum size to keep the radius above a Planck length is a Planck mass, which is about 2.18*10-8 kg, or about the mass of a flea egg, though a black hole that small would still evaporate extremely quickly.",
"This isn't quite right; there's a factor of two when you calculate the Schwarzchild radius of a Plan... | [
"Uh... let me wave my hands and whisper ",
" ",
"At that scale, it's hard to say. We're mixing incongruous theories. "
] |
[
"WHY do waves propagate?"
] | [
false
] | I'm ashamed to say that after studying physics as an undergrad, I never once thought to ask "why?" I understand that as far as, let's say, sound waves go, basically the energy is vibrating through the atoms. The energy travels through air until it hits an atom, then the atom absorbs and then releases energy, and the pr... | [
"This is a fairly subtle question, actually. The idea of a wave is very challenging to define as it incorporates a huge variety of phenomena. One characteristics of a wave is a transfer of energy from one point to the next without transporting any mass or substance. How can this be achieved? Well, the medium that h... | [
"In transverse stress waves, the particles do move up and down."
] | [
"the particles moving up and down while the energy is travelling perpendicular",
"So, its not the particles themselves that move up/down. The up/down represents pressure variation. Think of a compression wave travelling along a slinky, if you periodically squeeze one end of the slinky and let go, you'll have a wa... |
[
"What would the 50 Mt Tsar Bomba blast look like if seen from ISS or the moon?"
] | [
false
] | Wikipedia says that it was visible up to 620 miles away. It had a fireball 5 miles in diameter. The blast was still measurable on its third pass around the earth. Surely something of this magnitude could be seen from ISS, but what about the moon? Say ISS was passing over at the time of the blast. What effects could hav... | [
"As ",
"This picture here",
" shows pretty well, details even 5 miles in diameter would be nearly impossible to see from the moon (at least with the naked eye). I can't say for sure whether or not the flash itself would be visible, but it certainly doesn't seem impossible, if the bomb detonated facing the Moon,... | [
"The light wouldn't travel in a column, it would radiate (nearly) isotropically. The diameter of the fireball doesn't matter, what matters is the energy released as light, and if its intensity at the moon is such that it is detectable by the human eye.",
"The eye can detect on the order of 10 photons. 50 megaton... | [
"Wow, very cool. Thanks for taking the time to do (and share) the calculations. This leads me to wonder the smallest a blast could be and still be seen. Could, perhaps, all of our nuclear detonations be visible from the moon?"
] |
[
"Why does newly laid pavement have less water on the surface than older roads?"
] | [
false
] | Whenever I drive and it's raining, I noticed that roads that have recently been paved seem to have a lot less or close to no water on the surface than older roads. Mostly because there's a lot less aquaplaning on these roads. Does asphalt lose it's tendency to absorb water over time? Is this true, or is it just an illu... | [
"Modern asphalts are actually designed to be porous to allow drainage. Over time, dust clogs the pores and their ability to drain is affected."
] | [
"Also, ruts can form and puddle water in old roads that see heavy truck traffic"
] | [
"How is this done? Does it drain all the way through, or does it just have more surface area to evaporate? "
] |
[
"At what altitude above Earth do the effects of Special and General relativity cancel each other out?"
] | [
false
] | First, if this question doesn't make sense, please tell me, because I am going under some very rocky understandings of special and general relativity. So as I understand it, in special relativity, the faster someone moves, the slower time is for them, relative to someone who is stationary. In general relativity, the fu... | [
"Wow, this is an interesting problem!",
"The time dilation factor for an ",
"object at rest near a spherical planet is",
":",
"t_e = t_f sqrt(1-r_s / r_e) ",
"where t_e is the proper time elapsed at radius r_e, t_f is the coordinate time elapsed very far from the object, and r_s is the \"Schwa... | [
"Fantastic response! Thank you very much for this answer! Funny how some seemingly complex questions can have surprisingly simple solutions."
] | [
"That was an excellent question! Thanks for sharing!"
] |
[
"Magnet pushed into an open circuit solenoid"
] | [
false
] | By Faraday's law of electrostatic, there will be an induced emf. But since there isn't a complete circuit, so no current will flow through it (ignoring that little current). Since there is no current then there won't be a induced pole forming, so no repulsive force when I try to push a magnet into the solenoid? | [
"That's right. An open circuit has practically infinite resistance, so the finite emf (which comes from -d(BA)/dt) will result in zero current and therefore zero induced magnetic field."
] | [
"This is correct, however there will still be eddy currents in the metal which create a drag on the magnet. There is a neat demonstration showing this where you take a copper tube and drop a magnet through it. The magnet will fall very slowly because of the currents induced in the copper tube. This effect will be m... | [
"Oh thanks, I read about that Eddy current which is sort of an induced movement of charges in the solenoid. But I'm in GCE O levels so I don't really bother so much about it. Thanks for the help."
] |
[
"Do wasps have an important place in our ecosystem or could they be removed without any really noticeable effects?"
] | [
false
] | null | [
"Wasps eat flies and other insects. Think of it this way; one female house fly with fertilized eggs, if all her offspring survive and their offspring also survive, etc... in less than a year there would be enough flies to cover the entire earth with flies. So predators on insects are important, although flies are ... | [
"I know that wasps and fig trees coexist. The figs give the wasps a home to reproduce & what-not, meanwhile the wasp helps spread the fig trees sperm (or whatever it is fig trees have).",
"Source: ",
"Common knowledge"
] | [
"This is a blanket response. True, no species on Earth could be removed without consequence, but my question is whether or not there would be a large noticeable consequence. Species have gone extinct, even some recently, and yet not all of them have a truly noticeable impact on our ecosystem as a whole. Bees, while... |
[
"Can someone explain how this picture of an Atom might be a bad representation of what it's like to be an atom?"
] | [
false
] | [deleted] | [
"Scale misrepresentations aside, the orbiting electrons are one of the biggest flaws of the Bohr Model, and the point-particle diagrams are inaccurate as well.",
"Firstly, As ",
"Maxwell's Equations",
" state: \"all changing electric field (i.e. moving electric charges) must produce a magnetic field (and the ... | [
"Electrons exist in orbitals. Think of a \"shell\" around the nucleus, and the probability for finding the electron exists throughout that shell. As they occupy different states of orbital angular momentum, these shells can take different shapes. ",
"This image is more realistic",
", again keeping in mind that ... | [
"i have been taught energy levels as S P D F how does l and m relate to this?"
] |
[
"Wheel movement problem!"
] | [
false
] | So my physics teacher poses this question that I thought was very interesting, and while I have my own answer for it, I feel like it's not correct. Assume you have a wheel on a ground where friction is too high for ANY skidding to occur. The pedal on the wheel is pointed down wards. The wheel turns right if the peda... | [
"Ooh, this is very clever. Assuming the pedal is shorter than the radius of the wheel, the contraption doesn't move.",
"Let the radius of the wheel be 1 meter. Let P the length of the pedal shaft, anything less than 1. Let θ be some angle in radians that the wheel rotates around its axle, less than π/4 radians-- ... | [
"The wheel will rotate on its vertical axis towards the direction the rope is being pulled."
] | [
"I like this answer! I plan on actually testing this out today, and I'll come back and post if you were right! "
] |
[
"Why are some languages (Kanji and Traditional Chinese, for example) written as \"pictures\", so to speak, and western languages are based more on syllable structures? Is there a historical reason for it?"
] | [
false
] | Why have some languages evolved to be picture languages, whereas western languages are usually based on syllables? It can't be random. There's got to be a certain historical reason for it. I'm sorry if the term "picture" language is incorrect, I tried to think of a better way to describe Kanji/Trad. Chinese and this is... | [
"Writing was independently invented in only a handful of places on earth, and all modern writing systems are descended from the ones invented in Mesopotamia and China. They actually seem to have begun similarly, using pictographs to represent first whole words, then evolving these into more abstract forms (logogram... | [
"One advantage is that a single written language can more easily be used by people with different spoken languages and dialects. (Monolingual) Cantonese speakers won't understand Mandarin, indeed speakers of one dialect of Mandarin might not understand another, but all will understand written Chinese (if they can r... | [
"What are the advantages of logogram systems? At first I thought it would be a lack of words that mean multiple thing but in Chinese there are many words that mean multiple things."
] |
[
"When and where would I have to stand on the earth to be traveling the fastest through the universe?"
] | [
false
] | So, I'm assuming that it would have to be somewhere on the equator to be moving the fastest on earth. Then there would be a point durring the day that I would be most inline with earths orbit around the sun. And then I would assume that there is one time a year that the earth is moving forward the fastest. But I have n... | [
"Right now, at this very moment, you are moving at very, very close to the speed of light. You are also at rest.",
"\"Speed through the universe\" isn't a well defined concept. There is only \"speed relative to [thing]\". You can ask where on Earth you should stand to be traveling the fastest relative to the sun... | [
"I remember talking to some professor about a science fiction book about the wealthy building their houses in the sky to live longer. You might also find this interesting: ",
"http://www.independent.co.uk/news/science/einsteins-theory-is-proved--and-it-is-bad-news-if-you-own-a-penthouse-2088195.html"
] | [
"The earth is at perihelion (closest to the sun) on January 4 (note this changes slowly over time). When the earth is closest to the sun is when it will be moving the fastest in its orbit.",
"So, on the equator at night (not sure of exact time) on January 4.",
"NOTE: I am not sure where we are in our orbit ar... |
[
"Is there any evidence that Dark Matter is comprised of individual Dark Elements? Is there a Dark Periodic Table of Elements? [x-post from /r/AskReddit]"
] | [
false
] | Credit to for original question | [
"There has been a proposal along these lines by Kaplan et al. You can read a journalistic account of their ideas ",
"here",
" or see their paper ",
"here",
". While this proposal is certainly speculative (we do not have the evidence to rule it in or rule it out), the authors do identify features that woul... | [
"There's very little indication about what dark matter is, other than that it ",
" interact (very much) through the electromagnetic force. That's why it's dark!",
"So that means there could indeed be more than one dark particle, even dark forces that dark matter feels but other matter doesn't. That could mean t... | [
"I have what is probably a silly question, but from what I read there is way more dark matter (85%) than ordinary matter (15%) in the universe. Why isn't there any here? Or is it here right around us and we just can't detect it?"
] |
[
"How does our brain determine which musical tones sound correct or incorrect?"
] | [
false
] | The more I learn about music, the more it seems like a sixth sense. What makes a musical tone sound "in key" or "out of key?" How do we detect notes that are sharp or flat? | [
"It is worth adding that the notions of \"in key\" and \"out of key\" are learned concepts. As Skull_flower says, the ear works by registering the different frequencies in a sound. But whether that pitch sounds right or not has to do with our cultural conventions of what tones we think are acceptable."
] | [
"It has to do with how our brain processes sounds from the ",
"cochlea.",
" A certain region of the cochlea is excited for every musical pitch (frequency) and your brain can remember which region that is with practice."
] | [
"So someone that has never been exposed to music could have a really different idea of what sound musical?"
] |
[
"Can a sun have a ring?"
] | [
false
] | null | [
"Yes, and our own sun has two! The ",
"asteroid belt",
" and the ",
"Kuiper belt",
". They happen to be pretty far our from the sun, and may not look like \"classical\" ring systems like Saturn, but consider:",
"Asteroid Belt:",
"a torus-shaped region in the Solar System, located roughly between the orb... | [
"There are other homologies between Saturn's rings and the Main Asteroid / Kuiper Belts, too.",
"Saturn's ring system is particularly detailed in its ",
"gaps",
", which in turn are caused by ",
"resonances with nearby moons",
". If I'm a particle orbiting in the rings and keep getting a nearby pass of a ... | [
"Protoplanetary disks",
" are basically rings. Just like the rings of the planets have gaps from moons these disks develop gaps from planets."
] |
[
"What causes people to act different when drinking than when sober?"
] | [
false
] | null | [
"From a medical perspective, alcohol affects different parts of the brain in different concentrations. The most sensitive area of the brain to alcohol is the prefrontal cortex. This is the area of the brain responsible for urge inhibition, planning, and executive thought. With alcohols intoxication, these processes... | [
"From a legal perspective, it's a matter of proximate cause. You may not have been acting intentionally once drunk, but you intentionally ",
" drunk. "
] | [
"While the medically relevant effects show up after drinking a lot, most of the behavior we associate with people who have had a couple of drinks is due to social conditioning. ",
"There is a study that took four groups:\nthe first was given a couple drinks and were told they contained alcohol",
"the second re... |
[
"Why do cans of soda sitting at room temperature always feel slightly cooler than the air itself?"
] | [
false
] | null | [
"Metal conducts heat very well. Both the air and metal can are at \"room temperature\" and your body is much warmer. Metal pulls heat from your body more quickly than the surrounding air does, which makes it feel colder."
] | [
"What kind of biochemical mechanism would there be for detecting heat transfer? Not meant to be a rhetorical question, as I really would like to know. I was under the impression that we do feel temperature, but it is the temperature of our own skin and not of the thing we're touching."
] | [
"Just adding onto this - you don't feel temperature, you feel heat transfer. This is why 80 degree water feels cooler than 80 degree air (the water transfers heat away from you better). ",
"If you could build an object that was 300 degrees but somehow took heat away from you, it would feel cold to the touch. "... |
[
"What exactly happens in the breakdown of ingested materials?"
] | [
false
] | When we ingest anything, it ends up in our stomach, where there's a very low pH of ~1. This breaks down food, right? My question is, I keep hearing how our bodies take in Amino Acids, Proteins, Drugs, everything through the digestion system. Does the HCl present in the stomach not break down this compounds further? Fro... | [
"There is a special enzyme released in the stomach at the same time that the HCl is. It is called pepsinogen and at very low pHs it is cleaved into pepsin. The pepsin enzyme then breaks down the proteins. Once they are broken down into their basic units, they can be absorbed by the blood stream. ",
"The most amaz... | [
"Your teeth are your first step in breaking down the food to a level that's digestable. Your stomach continues this. The pH in the stomach is debatable, because foods will buffer it, so food may only be exposed to pH of 3-5. Regardless, the stomach does not break down glucose or proteins into atoms, so most of the ... | [
"MD/PhD student here, hoping I can help:",
"The stomach actually relies on more than just acid to break down food. It secretes additional factors that help, including two worth a brief mention: pepsin and intrinsic factor. Pepsin plays a role in breaking down proteins into short chains of amino acids, while intri... |
[
"Is there enough genetic material left in a loaf of bread to trace it back to the wheat plants used to make it?"
] | [
false
] | null | [
"Hmm. Interesting question. The first thing to ask is did we destroy the genetic material during the milling process? It turns out that DNA is pretty sturdy, and in labs we’ll often subject cells to some pretty tough conditions (blasting glass beads against them at a high speed, or sonication, for instance) just to... | [
"The next step is finding the plant of origin. Is there enough diversity in domesticated wheat to do so?"
] | [
"So, I’ll say up front, I deal entirely with prokaryotes, which wheat is not. However, when we want to identify a bacteria, we will examine the 16s rRNA gene, the gene that encodes for the RNA that makes up the ribosome. It’s particularly useful in that it’s conserved enough (or similar enough) in all bacterial spe... |
[
"(Psychology/neurology) Can anyone help me explain some childhood mental/somewhat hallucinatory experience?"
] | [
false
] | null | [
"Hi bigbluesanta thank you for submitting to ",
"/r/Askscience",
".",
" Please add flair to your post. ",
"Your post will be removed permanently if flair is not added within one hour. You can flair this post by replying to this message with your flair choice. It must be an exact match to one of the fo... | [
"'Neuroscience'"
] | [
"Neuroscience"
] |
[
"How does NASA figure out how to rendezvous with a meteor?"
] | [
false
] | null | [
"Hi novalavaly thank you for submitting to ",
"/r/Askscience",
".",
" Please add flair to your post. ",
"Your post will be removed permanently if flair is not added within one hour. You can flair this post by replying to this message with your flair choice. It must be an exact match to one of the foll... | [
"Your posting guidelines doesn't mention anything about flair"
] | [
"'Astronomy'"
] |
[
"Do we know if there is some evolutionary benefit to 'cringing' at things?"
] | [
false
] | null | [
"I always thought of it as something useful surviving as part of evolution, not developing due to it."
] | [
"I understand that, but people think that many social actions are an evolved response. For many things I.e. laughter, disgust you can see the benefit to them. However I cannot see what is a benefit of cringing."
] | [
"I agree with this. It could be that we've developed empathy through evolution, and a side-effect is cringing at others' pain."
] |
[
"Why don't we just shoot nuclear waste of our atmosphere and into the Sun?"
] | [
false
] | A lot of the criticism regarding Nuclear energy that I hear is regarding the decaying materials afterwards and how to dispose of it. We have the technology to contain it, so why don't we just earmark a few launches a year into shooting the stuff out of our atmosphere and into the Sun (or somewhere else)? | [
" Because it's stupid expensive and it's stupid dangerous if a rocket blows up on the launchpad. Please don't do this. ",
" ",
"This question gets asked surprisingly frequently.",
" So frequently, in fact, that I'm surprised there is no FAQ answer for it. Anyway.",
"At the moment, the current cost of launch... | [
"People thought about putting the waste into subduction zones. However, the fear was that those regions are typically active with volcanoes too and then you have the possibility of it coming out. Radioactive volcanoes would not be fun to deal with."
] | [
"Russia proposed a plan for a ",
"\"Hot Drop\"",
" where hot, dense radioactive waste would be concentrated inside a tungsten ball, dropped in a borehole, and simply allowed to melt and sink into the Earth indefinitely.",
"The melting process would be very slow, but the heat generated simply would have nowhe... |
[
"What would be the result if we disproved the Equivalence Principle?"
] | [
false
] | I just read and while it has a stupid/flashy title, the real message is pretty amazing: it claims that results show that the electromagnetic coupling constant varies across the observable universe. What does it mean for us if the universal constants weren't, well, constant? (In other words, what does it mean if we fals... | [
"From the article:",
"which negates Einstein's equivalence principle, which states that the laws of physics are the same everywhere.",
"This is actually the ",
" principle",
", not the equivalence principle."
] | [
"Ah, you're right. But the question still stands, just swap the words."
] | [
"Actually, I think the cosmological principle states that there is no preferred position or direction in space; this leads to the isotropic+homogenous symmetry reductions that give us an FRW form of the metric on large scales.",
"There are several different 'equivalence principles': weak, Einstein, and strong. Sa... |
[
"Would a multivitamin be more effective at preventing illness taken before or after being exposed to a virus? Or would it be negligible?"
] | [
false
] | [deleted] | [
"There is actually no evidence to suggest taking supplementary multivitamins help with immune function (assuming you eat a balanced diet and don't have any metabolic disorders). ",
"",
"Interesting note: The whole vitamin C immune thing was started by Linus Pauling, a Nobel Prize winning chemist. Later in his... | [
"Generally the answer is going to be negligible because, for the most part, whether you take it before or after, a multivitamin won't do much to help prevent illness caused by a virus infection.",
"One vitamin that is critical to immune function and which many people are deficient in is vitamin D so it's certainl... | [
"Didn’t he get cancer and die?"
] |
[
"What do magnetic field lines actually represent?"
] | [
false
] | I used to think they just graphically represented the direction of the field at a given point, but Wikipedia's article on ferrofluids states that they are regions of higher field strength (hence the spikes on ferrofluid near a magnet). | [
"They do represent the direction of the magnetic field at a point. The strength of the field is typically indicated by the density of field lines, i.e., a high density of field lines represents a high intensity field."
] | [
"But then what causes the ",
"spikes",
" in ferrofluid? Surely there must be a larger magnetic field at those points?"
] | [
"Hmm, so it's like dunes in the sand — minor asymmetries build up to make big ones?"
] |
[
"Could an induced coma cure someone of an addiction?"
] | [
false
] | This was mentioned in a thread on when someone claimed that they went into a coma due to a motorcycle accident and through it lost their addiction to cigarettes. If this is possible, then would it be possible, in very drastic cases, to induce a coma in a person to cure them of an addiction? | [
"If a person is unconscious through the duration of their withdrawal symptoms, they could possibly be over the physical addiction when they wake up."
] | [
"When using Naltrexone to \"fast-detox\", a person is put under general anaesthetic so that they do not get the physical withdrawal "
] | [
"It exists ",
"UROD",
" but I dont know much about it , and I cant get access to any of the pubmed papers ( all of which are about 20 years old anyway ) so i cant comment on how effective it is"
] |
[
"AskScience AMA Series: We are Tabitha Lipkin and Liv Williamson a Naui Dive Master and NBCLX host and a marine biologist respectively. Ask us anything!"
] | [
false
] | We partnered to teach you all about how to restore coral reefs and save our oceans. Liv is a Ph.D. candidate and scientific SCUBA diver at the University of Miami with a passion for coral reef conservation. She loves baby corals, and runs a sort of "fertility clinic" to help corals reproduce and raise their offspring t... | [
"What are some suggestions for how to stop the reduction of coral reefs around the world?",
"Also do you have any internships for a junior in environmental science with a focus on marine conservation?"
] | [
"Thanks so much for your question! There are many ways that citizens can contribute to coral reef conservation. ",
"Vote! Coral reefs are under threat from many environmental stressors, so voting for politicians that advocate for protecting the environment and oceans is a great way to contribute to positive chang... | [
"I think artificial objects can be a wonderful way to start. Many life-forms in the ocean actually cling to and build off metals and concrete. Tires are made of rubber and not all artificial reefs are the same. marine life doesn't seem to cling-to the rubber the same way, plus they can be corrosive and toxic. Check... |
[
"Do metals/alloys resonate electrically like quartz and other crystals do?"
] | [
false
] | I know that quartz crystals can be made to oscillate electrically, and for this reason are used as high-Q filters for the feedback paths of electrical oscillators. Is there a similar resonant property for metals (obviously not piezoelectric)? I know that the quartz resonant frequency is influenced by its dimensions, so... | [
"The reason quartz works is because it's a piezoelectric. This is determined by the crystal structure, which has to have some sort of charge ordering that's distorted when pressure is applied. It also (as far as I know) has to be insulating or else you don't get the localized charges you need. This makes metals inh... | [
"The reason quartz works is because it's a piezoelectric. This is determined by the crystal structure, which has to have some sort of charge ordering that's distorted when pressure is applied. It also (as far as I know) has to be insulating or else you don't get the localized charges you need. This makes metals inh... | [
"Well, from my perspective the issue is that you won't get any sort of resonant frequency aside from the phonon spectrum, which probably would be a really complicated way to figure out purity."
] |
[
"Why does antimatter have opposite electric charge instead of opposite strong force color (or something)?"
] | [
false
] | [deleted] | [
"It has opposite charges for ",
" - this includes the color charge."
] | [
"Mass is different from charges in many aspects."
] | [
"The answer is that they do, but particles we can actually \"see\" are always white, and the actual color of each quark is always changing anyways.",
"Anyways, the color charges are red, green, blue, anti-red, anti-green, and anti-blue. Particles group up to form white total color charge. So that can be combinati... |
[
"Is it remotely possible for us, in 2029, to send a satellite probe to check out Apophis as it passes so close to the earth?"
] | [
false
] | null | [
"It is very possible. We've already launched ",
"a bunch of missions to asteroids",
" and ",
"comets",
"."
] | [
"Well, I suppose this shuts me up. It's amazing what these guys can do."
] | [
"Wouldn't it make for an awfully small target?"
] |
[
"Can the gravitational pull of a black hole be measured in terms of speed? If even light can't escape it's pull, does it mean its faster than light?"
] | [
false
] | null | [
"Gravitational pull doesn't have a speed. At most, you can measure it as an acceleration. "
] | [
"If you want to compare it to speed, then think of a black hole's ",
". The escape velocity of a large body is that speed required by any spacecraft (or other small body) to completely escape from the large body's gravitational influence.",
"Note this is higher than orbital velocity, which is what is achieved b... | [
"Great explanation thanks."
] |
[
"Ask Anything Wednesday - Economics, Political Science, Linguistics, Anthropology"
] | [
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! ... | [
"Are we actively excavating sites like Gobekli Tepe or is it all shut down due to COVID and other geopolitical reasons?"
] | [
"I have observed as a citizen in the United States that of my fellow citizens usually vote for the person they dislike the least. Has this been measured and if so is my observation accurate?",
"The term for this is \"Negative partisanship\". Here's a 538 article on the topic.",
"https://fivethirtyeight.com/fea... | [
"This isn't exactly a scientific question...it's not like we have lots of examples of big collapses in modern societies that we can study and do statistics on to discover the answer.",
"But in a broader sense, I'd say that working at jobs and paying bills are the means by which our society's structures and networ... |
[
"What's making these ice pieces slowly move onto land like this? So bizarre I can't explain it...VIDEO inside."
] | [
false
] | I found this video being shared on Facebook and it blows my mind. It shows pieces of ice moving onto the land, encroaching on someone's home. What's causing this? Will it stop? How much force is here? Can this cause serious damage to the house? | [
"This is a lake shore property. The ice is coming off the lake, moved by the wind. Imagine a ",
" sheet of ice, several square kilometers, and blow a strong, steady wind across it. The force from all the wind adds up and can be enough to push the entire ice sheet slowly, but steadily onto land. This results in wh... | [
"Thanks for the answer! If the wind is so strong it's blowing ice like that, how are those people standing up, let alone holding a camera steady?"
] | [
"The wind speed is not necessarily very high, it is just enough in the same direction over the surface of the ice that the vectors can add up to push the ice. There may even be no wind at all where the people are standing, the wind could just be out on the lake over the ice; then, the ice you see coming onto shore ... |
[
"The cosmological constant is sometimes regarded as the worst prediction is physics... what could possibly account for the difference of 120 orders of magnitude between the predicted value and the actually observed value?"
] | [
false
] | null | [
"Unfortunately, you won't get a nice single \"correct\" answer with this question; this is one of the bigger unsolved problems in physics, and there isn't a consensus yet, although a ",
"number of solutions have been proposed",
"."
] | [
"The cosmological constant can be calculated two ways: from cosmology and from particle physics, and it's the difference between these two calculations that is this gigantic 120 orders of magnitude.",
"The value from cosmology is fairly robust, since it can be calculated from the extensively studied statistical p... | [
"At what point does the vacuum of space rip a gas environment from a planet?",
"It doesn't. If you have a small planet in an empty vacuum in isolation and you add an atmosphere, the atmosphere will stay surrounding the planet indefinitely, although the density will depend on the mass of the planet. (If you add a ... |
[
"What would happen if you made the hull of a ship superhydrophobic?"
] | [
false
] | I've been thinking about this question for a few days now. I saw this video a while back: And I was wondering if you made the hull of a ship superhydrophobic if it would sink, or move faster, or whatever. If anything at all would change. Also curious what would happen to a submarine. | [
"There would be less friction between the ship and the water. Much less. This would result in less drag while the ship is moving."
] | [
"only if the cost of making it superhydrophobic was less than the savings"
] | [
"Could this save money on fuel?"
] |
[
"If everyone with HIV/AIDS on earth were quarantined or suddenly died, would HIV/AIDS cease to exist?"
] | [
false
] | null | [
"Actually, we do know exactly where the virus came from. It is not a mystery and there is a good deal of scientific consensus on this. In this way there IS a animal reservoir of HIV known as SIV. SIV is still found in non-human primates so as long as we keep consuming non-human primates or coming into contact with ... | [
"We got HIV and AIDS from consuming contaminated non-human primates which had SIV for bushmeat, for sport and under unhygienic conditions - where body fluid transfer risk (e.g. blood to blood) is very high.",
"Just to elaborate on this a bit.",
"HIV made the \"jump\" from non-human primate to humans this way. ... | [
"If you could somehow quarantine or killed every single thing on the planet that carried the HIV virus, including any reservoir animals, then yes. "
] |
[
"Is it hypothetically possible to 'capture' light?"
] | [
false
] | Let's say you were able to produce a "perfect" mirror (lets no light pass through it and reflects every photon that comes into contact with it without any loss of energy) and you made it into a hollow sphere, with the reflective side on the inside. Inside that mirrored sphere, you created a total vacuum. If you were ... | [
"Yes. If you had a hollow, evacuated sphere with perfect reflection on all the surfaces inside it, there would be nothing there to absorb the light and it would bounce around in there forever.",
"In a more realistic situation, of course, your sphere would not be perfectly evacuated and your mirror would not be p... | [
"Sort of related to your question, is ",
"the experiment where",
" ",
"physicists 'froze' light",
" by storing the information of a light pulse in an ultra-cold cloud of sodium atoms."
] | [
"To the excellent replies I can only add that, if you could construct a box of perfect mirrors and trap some light inside it, the box would have additional mass equal to E/c",
"That way, even though you couldn't see the trapped light, you could detect it indirectly -- on a super-sensitive scale."
] |
[
"Since we can heat metal to the point where it turns into liquid.. can we theoretically heat it to a temperature thats high enough to boil / evaporate it off?"
] | [
false
] | I'm just wondering. I know metal doesn't have the same properties as water, but since we can get water to boil and evaporate off.. can we do the same to metal? | [
"The name \"freeze drying\" comes from the fact that we first freeze the food so the water turns to a solid (ice), then put it under a vacuum (very low pressure) so that the ice sublimates off, hence removing the water (drying)."
] | [
"Yes and it is ",
"used",
" all the time to deposit thin films of metal in many fields of science such as microelectronics and nanotechnology. The most common methods are resistive heating evaporators and electron beam evaporators. "
] | [
"This is called Sublimation. Which, funny enough is also how we Freeze dry foods."
] |
[
"How do blood vessels get nourished?"
] | [
false
] | Other parts of body gets nourished because blood is supplied to it through blood vessels. What supplies blood to blood vessels (their different layers) ? | [
"Interestingly, there are actually tiny vessels that innervate the external walls of larger vessels called “vasa vasorum” (vessels within the vessels). These help regulate construction and dilation of large vessels. The inner walls of large vessels obtain nutrients directly from the blood that travels inside them. ... | [
"Thank you but what i meant to ask was how does blood vessel get nourished?"
] | [
"THANK YOU! That helps a lot"
] |
[
"Do any of the Gallilean moons of Jupiter or the large moons of any other gas giant have stable geostationary orbits?"
] | [
false
] | Writing a novella and I had the idea for space elevators at these moons, but I wanted to check the hard science first, and I can find very little to no research on this online. | [
"Assuming you mean geostationary orbit around the moons themselves, not the gas giants:",
"All the large moons in the solar system are tidally locked to the planet they orbit. That means their rotational period is the same as their orbital period. In this case, it is only possible for a satellite to stay statio... | [
"In fact, there are semi-serious proposals to build a space elevator from the Earth's Moon to the Earth-Moon L1 point.",
"I'll be damned. I thought that space elevator on the Moon was impossible. I forgot about Lagrange points."
] | [
"It's surprisingly easy. The cable for such an elevator could be built with current technology, and launched to space in a single launch. Just needs some dedicated R&D for all the details and some funding."
] |
[
"Why was the jet engine on the plane I took yesterday not round?"
] | [
false
] | It was a 737-800, and the engine looked like . Why this shape and not a circle? Thank you! EDIT - I realise my title suggests the wasn't round, of course I meant the intake. | [
"The answer is \"minimum ground clearance\". The flat bottom of that cowling will be parallel with the ground when the wing tanks are fully loaded. There are FAA regulations requiring a particular minimum ground clearance between the engine and the ground, and that cowling shape is necessary to comply with them."... | [
"Its worth noting that inlets don't have to be round. As long as the engine is getting enough air at the right pressure, it doesn't care what shape the air entered in. Ex. F-4s and F35s have rectangular inlets, F-16s have ovals, A10s have circles. Pretty much any shape works."
] | [
"Because it gives the room for the needed components, while keeping the engine above the minimum clearance requirement. If you're asking why it is specifically oval in shape, it's the best shape to reduce drag, given the situation.",
"Basically, the customer (in this case Boeing) asked ",
" CFM (GE) for an eng... |
[
"At what point is the body officially hungry or full?"
] | [
false
] | Let's say I have a bag of chips, and I am hungry. After I finish them, I am full. At a certain chip does my body tell me that I am full through use of hormones, or is it after a period of time that my body responds with the message of "you are full"? | [
"Actually, it's much more complex than that. You are assuming that the physical feeling of fullness is the only signal processed by the brain to maintain a feeling of hunger or \"fullness\". ",
"The first part is a ",
"biological response",
"#Biological_mechanisms). As you eat, your blood glucose slowly incre... | [
"The neurology of the digestive system is INCREDIBLY RIDICULOUSLY complex. SkepticalRaptor's answer is good, but it's my understanding there are entire generations of PHD dissertations about this.",
"I hope some of the medical heavy-hitters find this thread."
] | [
"There is a complex cocktail of hormones involved in the feelings of fullness in response to a meal, both in the short term and the long term. The physical distention of the stomach and duodenum from food stimulates the release of cholecystokinin which acts to stimulate contractions of the gall bladder as well as ... |
[
"Why doesn't this work?"
] | [
false
] | null | [
"Because the ball entering the water on the left must displace a quantity of water equal to its volume upward under the pressure that exists at that depth, the energy required to do so being exactly equal to the energy required to push the ball down on the right side from the surface to the same depth, neglecting f... | [
"http://www.hp-gramatke.net/pmm_physics/english/page0550.htm"
] | [
"You can't ever beat the laws of thermodynamics. You will lose every-time."
] |
[
"How does regenerative braking recharge the battery in an electric car or motorcycle?"
] | [
false
] | null | [
"A generator and an electric motor are identical. A motor takes electricity and turns it into motion. A generator takes motion and turns it into electricity. When it comes time to stop your vehicle you can switch the function of the motors to harvest the kinetic energy of your vehicle and rapidly slow you down at t... | [
"In regards to discharge, the colder the battery the higher the internal resistance becomes. At very cold temperatures (10°C and less) this leads to a lower capacity.",
"In regards to charging the battery, the same resistance issue applies (less held charge and longer charging time), but additionally if temperatu... | [
"The important thing to remember about batteries is that they're ",
" storage systems. Resistance is, in a way, the reluctance of something to let its electrons move. Batteries undergo chemical reactions to free up or absorb electrons. ",
"When it's cold, the chemical reactions slow down, since there's less th... |
[
"Is there a limit to how much hair a human can grow?"
] | [
false
] | Not just on your head, but everywhere | [
"Theoretically, no. Hair follicles can be implanted everywhere, and theoretically grow to infinite length.",
"Hair is fairly easy for your body to generate. It's made of protein, specifically keratin. By the time you reached a severe enough protein deficiency to affect hair growth, you'd have bigger health proble... | [
"You're right: eyelashes and eyebrows are an interesting one. Unlike regular head/body hair, it has a very specific biological function; to protect your eyes. Eyebrows help divert fluid from entering your eye area, and eyelashes trap dust and debris from getting into your eyes.",
"Your body will attempt to restri... | [
"Isn’t another factor that certain hairs will just fall out before reaching a certain length? Which is why eyebrows and eyelashes don’t grow to insanely long lengths? "
] |
[
"If we don't burn fossil fuels is the accumulated carbon lost forever?"
] | [
false
] | Without humans extracting oil, would Earth run out of carbon as more and more fossil fuels are naturally made from dead organisms over millions of years? | [
"No, it would reenter the long term carbon cycle (e.g., ",
"Berner, 2003",
"). Buried carbon in the form of fossil fuels has a few potential fates. If it was subducted, it would end up back in the mantle (a long-term, and large reservoir for carbon) and can return to the surface through volcanic outgassing. If ... | [
"I think you're ignoring or at least minimizing other long term fates.",
"I'm confused generally, as you essentially describe transfer between the same reservoirs in my answer and as discussed in detail in the Berner paper.",
"Carbon captured as carbonates and buried into sediments becomes limestone and can be ... | [
"Not \"enhanced\" for any of the life on Earth from the past few million years. Ordovician life might like it though."
] |
[
"Why do plants absorb visible light wavelengths and others not?"
] | [
false
] | I mean, why do plants absorb the same spectrum of colors that the humans see (the visible spectrum) and not UV nor IR rays (and others)? Is this something related with an evolutionary process? Thank you all! | [
"That's a very good question. I will try to explain to the best of my abilities, but keep in mind that English is my second language.\n Firstly, you are correct in saying that the sun emits all kinds of wavelengths, but it doesn't emit them in equal quantities. Most of the energy is emitted in the visible sector. ... | [
"That's an awesome explanation! Thank you so much! :D"
] | [
"The other answer is a great start but I have a few corrections. ",
"1) a minor point for the purpose of this answer but photoreceptors are not proteins but pigment molecules (chlorophyll, carotenoids, xanthonoids). ",
"2) The graph at the link below overlays the emission spectrum of sunlight with the absorptio... |
[
"What do you think about 23andme genetics test?"
] | [
false
] | I just received my kit today as they are on sale for a limited time. I always wanted to do this, but only now I can afford it. From a scientific perspective what do you guys think about the reliability and usefulness of such a genetic test? | [
"Most people will misinterpret the results, but it's still a lot of fun. Just don't go thinking that if you're \"less susceptible\" to a particular disease, that you can go ahead and eat whatever you want because you won't get it. Absolute risk is not calculated. Even if you're 100 more likely to get a disease, 100... | [
"For diseases they just give you probabilities of elevated, typical, or lowered risk. It does not say anything about future risk, so I'm assuming it's simply genetic risk based on current research. There is a section where they tell you whether or not you're a carrier of variants of certain genetic disorders. There... | [
"They're not currently worth the money if you're looking for medical advice (unless you have a known risk of a rare genetic disorder). We don't have enough information on which risk factors are important to make the tests useful yet. We also don't know how to translate that knowledge about risk factors into treatme... |
[
"Can there be oxygen and nitrogen chains?"
] | [
false
] | Basic carbon chains (alkanes) have carbon atoms bonded to each other in a chain, with three hydrogens bonded to each end of the chain and two bonded to the other ones. Could you do the same thing with nitrogen (two hydrogens at each end and one for the rest) or oxygen (one hydrogen at each end and then just oxygen), an... | [
"A peroxide is a pair of oxygens bound to one another with groups hanging off either end",
".",
"An ozonide is similar",
".",
"An azo compound would be closest to a peroxide with nitrogen instead of oxygen",
".",
"As for extended polymers, I can't think of any stable ones. All of the compounds here are... | [
"However, you can sometimes string a ",
"shockingly large number of nitrogens together",
"."
] | [
"Hell yeah. That's one bitchin' molecule.",
"From the experimental, via the comments:",
"The use of suitable protective clothing,in particular a face shield, ear protectors, a ",
", arm protectors,and kevlar gloves,as well as appropriate shoes for protection from electrostatic charge,is mandatory. Ignoring t... |
[
"Are electric cars actually better for the environment? Wouldn't the increased electricity generation be just as bad or even worse than gasoline?"
] | [
false
] | Probably not the most scientific question, feel free to interpret it however. | [
"Electric cars are a net win no matter what the fuel the power plant consumes. On the broadest level, the larger the heat engine, the more efficient it can run. GE manufactures a combined-cycle gas turbine that generates electricity at 60% efficiency. ",
"For comparison, a modern, typical gasoline engine in a ... | [
"not only this, but electric cars also separate the source of energy from the vehicle itself. This allows future grid improvements such as solar or nuclear to take place without having to replace the vehicle",
"also, when an electric vehicle is stationary it is hardly using any energy at all (save for what it ta... | [
"What thegreatgazoo said:",
"http://cleantechnica.com/2012/05/18/txu-is-first-to-offer-free-night-time-electricity-rate-plan/",
"Wind power tends to be greatest in the wee hours. Texas wind power sometimes has to be curtailed or wasted because there’s no one to use it at night.",
"If you charge your electric ... |
[
"How do the beam splitters in a Michelson interferometer split the light initially and then only allow 1 returning beam to reflect and the other returning beam to travel through?"
] | [
false
] | Im not sure how the beam splitter can act as something transparent and reflective(im not talking about the initial splitting but when the light splits and it returns somehow the 2 split beams paths are altered or not altered through the beam splitter into the detector). On another note: no light is reflected back towar... | [
"I think it is reflected back to the laser as well. The description says that \"50% of the intensity of each reflected beam is transmitted/reflected towards the screen for observation\", so the other half would be transmitted back towards the laser. It's just not shown in the figure, since it's not the thing that y... | [
"If the beams travel exactly the same distance, their light waves will be perfectly aligned so that they result in total destructive interference (LIGO is deliberately designed to make this happen if no gravitational waves are passing). But if for some reason the lasers don't travel the same distances, their light ... | [
"You will see a change in intensity as the path length is varied between the two beams. The detector is an intensity counting machine. ",
"If you think of the double slit experiment, you have a spatial pattern in intensity (bright and dark areas). This is because the path length difference between the two slits i... |
[
"Just how effective is the 12 step program as a treatment for Alcoholism on a purely scientific basis?"
] | [
false
] | null | [
"Generally it has a high drop out rate after the initial program has been completed, the system has many critics, some look at it as just another way for religions to recruit new vulnerable members with the treatment program taking a backseat. ",
"http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.476.5193&... | [
"Tricky to quantify. Ethically, you can’t run an RCT on a group of alcoholics because death is a real possibility. Also, the fellowships are founded on anonymity, making longitudinal studies notoriously difficult. See: Orford, J. (2008), Asking the right questions in the right way: the need for a shift in research ... | [
"https://www.theatlantic.com/magazine/archive/2015/04/the-irrationality-of-alcoholics-anonymous/386255/?fbclid=IwAR257gOG5X_gS4aGcg0BP-JCzsWPScDYseDvVBzxww3-j_WG3MZE--bFgBs",
"An interesting article on this issue."
] |
[
"Do we know how large dinosaur populations were?"
] | [
false
] | When we’re shown concept imagery of dinosaurs, we often see that dino’s were plentiful. Is this accurate to the actual population sizes? | [
"There are 2 easy ways to infer significant population sizes:",
"Fossilization is a very rare event. Therefore the rich fossil record requires a large potential number of dinosaurs to be fossilized ",
"Species do not persist and evolve with small numbers. Disease, bad weather, natural disasters can and frequent... | [
"Oh, so the populations must have been large enough for natural selection to occur at all. \nAre we able to estimate population sizes by the density of fossils in a certain area?"
] | [
"You might find this interesting, it discussed some of the ways",
"http://tetzoo.com/blog/2020/5/1/stop-saying-that-there-are-too-many-sauropod-dinosaurs-part-5",
"Basically, one thing you can do is try to calculate how much the environment could support based on some assumptions about plant productivity and gr... |
[
"Why is it that some celestial objects (such as planets) spin clockwise and others spin counter-clockwise?"
] | [
false
] | [deleted] | [
"The solar system didn't come into existence until about 9 billion years after the Big Bang. There is no way that the planetary spins observed can be related to it in any way. Most planets in the solar system spin in the same direction as the result of accretional processes in the original protosolar nebular disk. ... | [
"No, the big bang caused the expansion (or the expansion is what tells us there was a big bang, depending on how you look at it).",
"The point is that the spin of our solar system has nothing to do with the spin of the spin of the universe at the time of the big bang. It's more like the big bang produced a lot of... | [
"So, then, the expansion of the universe is not related to the big bang?"
] |
[
"If two observers are traveling in opposite directions at half the speed of light, are they traveling light speed relative to each other? If they use a laser to communicate, what would happen?"
] | [
false
] | null | [
"Their relative speed is found by the formula for relativistic velocity addition. Whenever classically you'd have u+v, relativity tells you that the relative velocity is actually",
"(u+v)/[1+uv/c",
"]",
"Here, where u=v=.5c, we get a relative velocity of .8c, or 80% the speed of light.",
"If they use a las... | [
"Is it possible for objects to exceed light speed, relative to each other? What happens to the laser signal in such a case?"
] | [
"Is it possible for objects to exceed light speed, relative to each other? ",
"No, the relative speed is always capped by the speed of light.",
"The laser signal itself travels at the speed of light according to all observers; this is one of the fundamental principles of Special Relativity."
] |
[
"What's stopping us from creating smaller than ~5nm transistors and also makes it difficcult to even reach there?"
] | [
false
] | [deleted] | [
"TL;DR: uv lithography uses wavelengths way larger than the transistors it draws and extreme uv is not viable yet.\nNot an expert but I just watched a video on this I think it was from gamers nexus but Idk.\nFirst understand how insanely small and precise 10nm is: a human hair is 181μm according to Wikipedia so a c... | [
"I've also heard that at a certain point quantum tunneling can begin to be an issue. With such small gates (~5nm) it is possible that the electrons that you are trying to observe and run through the gates will just \"blink\" around the gate. The likelihood of this happening increases as your gates get smaller. This... | [
"Extreme uv lithography is supposed to be the next step up (13.5nm wavelength) and would allow for much more precision, however it can only be generated by a Tin plasma laser currently as the plasma absorbs 13.5nm light. So its way harder to make a high intensity source, tin constantly accumulates on the mirrors so... |
[
"Magnetism and the conservation of energy."
] | [
false
] | Suppose I had a giant cloud of hydrogen that I then separated into two stars. A little fusion later and I've got two giant lumps of ferrous metal that are magnetic. Suppose I then put the two lumps close to one another, perhaps on the surface of a planet in between the two stars. Magnetic attraction draws them toward e... | [
"To simplify the thought experiment, imagine two containers of iron in plasma form, separated by some distance. The plasma cools, leaving us with two magnets some distance apart. Suddenly we have potential energy in the system, equal to energy it would take to pull the magnets apart. Did we just get free energy?",
... | [
"Thanks for the response. Wouldn't the potential energy fluctuate based on the distance between the two magnets? If so, would the energy required to align the iron atoms also be proportional to the distance between the two masses?"
] | [
"Certainly the potential energy increases as you pull the magnets apart.",
"There is also the energy involved in aligning an atom even in the presence of a single magnetic field. When the containers are far apart, the influence the fields exert on each other is negligible, of course.",
"Potential energy can be ... |
[
"How exactly does nuclear radiation interact with water?"
] | [
false
] | null | [
"Being exposed to radiation doesn’t necessarily mean it will become radioactive. Only in particular cases does that occur. The water itself may become slightly activated, but it’s nothing compared to the radiation coming directly from the core or the spent fuel.",
"“Contain a fatal dose of radiation” isn’t really... | [
"1) If you stirred the water to create a current, would the radiation spread outside of the safe zone because of the movement of the water, or would the nature of water (being dense) still block the radiation from going too far?",
"If there is radioactiv",
" in the water, it will diffuse and advect around withi... | [
"1) If you stirred the water to create a current, would the radiation spread outside of the safe zone because of the movement of the water, or would the nature of water (being dense) still block the radiation from going too far?",
"If there is radioactiv",
" in the water, it will diffuse and advect around withi... |
[
"Is there any validity to the idea that light slows down in medium due to being absorbed and reemited by atoms in the medium?"
] | [
false
] | So I've been told several times that this common explanation of why light slows down in a medium is wrong because it implies that light should exit the medium in random directions which doesn't match observation. That's always made sense to me, but a few months ago I came across that uses a similar explanation but spe... | [
"If you want to get a group of physicists to fight, get them in a room and ask them why light travels slower and refracts when passing through matter. The fact that there isn't an agreement on the matter might make you say \"oh, so they don't know.\" But I would answer \"we do know, there's just multiple ways of th... | [
"If you want to get a group of physicists to fight, get them in a room and ask them why light travels slower and refracts when passing through matter.",
"This is accurate and I have literally seen this happen. Not a physical fight, but a pretty heated discussion at lunch."
] | [
"Yes."
] |
[
"Are there any known moons that have moons orbiting them?"
] | [
false
] | If not then is there any theory to this? | [
"No, there are not any known moons with natural satellites.",
"It is certainly possible however. I mean, we have been to the moon, and we have had many orbiters around the moon. The theory behind this is simply gravity.",
"Naturally however, depending on the mass of the planet, a moon's moon would probably be... | [
"Typically no, although I suppose it depends on a bunch of factors. For one, multiple star systems tend to orbit a common center of mass, instead of one orbiting another, which then orbits another, etc., since they are typically of similar masses.",
"The mass distribution of the stars matters. In a planet-moon-... | [
"Sorry but I don't quite understand what you're asking here. Are you asking why there aren't any planets whose moons have moons?"
] |
[
"How do forest fires start 'naturally'?"
] | [
false
] | I know that forest fires are a natural part of the lifecycle of an arboreal environment, but how do they start? Most lightening occurs during a rainstorm which would reduce the chance of starting a large fire. Are there other causes? | [
"Lava flows/volcanic sources, spontaneous combustion from organic material overheating (think compost piles or certain types of coal), and rockfalls producing sparks are all potential other sources but lighting is by far the most common.",
"Rainstorms are often isolated sporadic events. For example it can rain on... | [
"Lightning can occur with little rain, or the lightning can occur on the edges of the rainstorm. ",
"See this cartoon.",
"Forest fires can travel in root systems underground, over large areas. Organic matter in the soil and wood underneath the forest canopy (partly shielded from rain) can smoulder for long peri... | [
"lightning or lava"
] |
[
"Why aren't animals living in the Mariana Trench translucent like those discovered in that lightless cave in Romania?"
] | [
false
] | null | [
"Some are, and some are colorless, like that amphipod.",
"From my answer to a similar question",
".",
"There are some in both habitats that are translucent, or pale reddish, or dark red.",
"The basic reason behind it is that pigmentation is an energy sink in those habitats. The other is that other pigments ... | [
"At 6 to 10 km down, aside from bioluminescence, is there any \"light\", therefore colour, at all? Maybe infrared from lava vents?",
"I don't understand what an animal could \"see\" down there."
] | [
"At even less than 6km it's the aphotic zone, which is devoid of sunlight. There may be bioluminescence, or light from thermal vents, but animals living at that depth don't rely on vision, since you're right there's not much to see at all. If their eyes aren't reduced, the can certainly see bioluminescence. They mu... |
[
"Why is in the Alveolar gas equation the pressure of water subtracted from the atmospheric pressure?"
] | [
false
] | I would have guessed that it would be added on top of the atm-pressure. Any help is much appreciated! | [
"What is subtracted from atmospheric pressure is the saturation vapor pressure of water. This is the total vapor pressure of water at a given temperature and pressure. By subtracting this off from atmospheric pressure you get the pressure that is available to be filled with oxygen. If the total pressure is 100 kPa ... | [
"But why exactly is the vapor pressure not further increasing the total pressure. And why is it space that could potentially be filled by oxygen when it is a volume in and of itself? It just doesn't click"
] | [
"Ah, so your confusion is with what a ",
" is. The partial pressure is the fraction of the total pressure taken up by a component gas in a gas mixture. Basically, if you sum up all the partial pressures in a gas you will get the total pressure of the gas. ",
"One of the assumptions of the equation is that the a... |
[
"When does a comet stop moving?"
] | [
false
] | Where does it derive its velocity from and how long will it travel through space? Would gravity from stars and planets it passes through somehow slow it down? EDIT: I need to re-phrase. 'Would gravity from stars and planets it passes somehow slow it down?' | [
"You can think of a comet entering our solar system as a ball rolling down a hill. As it gets closer and closer to the sun, it'll speed up more and more. When it heads away from the sun, it'll be slowing down, like a ball going uphill. This is because of the effect of the sun's gravity. It won't otherwise come to a... | [
"There definitely is a force present, namely the force of gravitation. And it changes the momentum of the comet all the time. What doesn't change is the mechanical energy, that is the sum of potential energy and kinetic energy.",
"Or if you look at the whole system which includes the comet and all other relevant ... | [
"I can't answer all of this without doing more research, but the velocity is derived from its momentum - there is no new force or thrust being applied, the zero-resistance conditions in space simply allow it to go for a very, very long time on momentum. Where that momentum comes from isn't clear; science isn't sure... |
[
"Do atoms have colours?"
] | [
false
] | I know they're more likely to reflect certain colours (blue and hydrogen, for instance), but as I understand it, this is a result of electrons moving rather than any property of the particles themselves. Do atomic particles have colours in and of themselves? Is it possible for them to have it? | [
"No. ",
"Color is a property our brain assigns to electromagnetic rays within the visible spectrum. An atom, however, can never be \"seen\" in visible light.\nThe reason for this is, that the wavelength of visible light is ~400-700 nm = 4 x 10",
" - 7 x 10",
" m.\nAtoms have roughly the size of ~1Å = 1 x 10"... | [
"What? Try and read this sentence one more time. Maybe read it out loudly. Sometimes this helps people who have a hard time understanding written content. "
] | [
"These are color charges of quantum chromodynamics. They have nothing to do with visible colors. It's just a convenient way of keeping track of an abstract system which has three possible charge types."
] |
[
"Why are the Galapagos Islands specifically so important to study?"
] | [
false
] | I always see the Galapagos Islands as the big place that people are studying. I realize there are major historical discoveries that have happened there, but aren't there likely to be many archipelagos that are near a mainland that display the same amounts of natural selection and adaptive radiation? Are they just the... | [
"It's for a number of reasons. Largely because of the fact that the Galápagos is a volcanic landmass that was never connected to any continent. This means that all the species there had to migrate there, and there are no natural large predatory mammals, so they're able to survive there. Because of this, and because... | [
"Hawaii has almost 1.5 million people on it is heavily tainted by long and significant occupation and the introduction of feral species."
] | [
"It's a combination of being far from the mainland, and the actual islands being relatively far from eachother. This is important for two main reasons:",
"",
"1: Because they're far from the mainland, and were never attached to a land mass, all animals on it migrated to the islands from one place or another. ... |
[
"When you roll a snowball across a snowy surface, why does it grow rather than shrink? Why is the transfer of snow always from the surface to the snowball?"
] | [
false
] | null | [
"I most agree with your answer.\nThe wikipedia page for sintering cites the compaction of a snowball as an example. I believe that is the technical term that encapsulates what you have described. ",
"https://en.wikipedia.org/wiki/Sintering"
] | [
"I most agree with your answer.\nThe wikipedia page for sintering cites the compaction of a snowball as an example. I believe that is the technical term that encapsulates what you have described. ",
"https://en.wikipedia.org/wiki/Sintering"
] | [
"The density of a snowball is higher then the density of freshly fallen snow. This results in a greater force from the ssnowball to the freshly fallen snow, than within in the freshly fallen snow. So this force causes a compression in the contact zone between snowball and freshly fallen snow, similar the process of... |
[
"How do the power tester strips on the side of batteries work?"
] | [
false
] | I don't know if they're common or not so these are what I'm talking about . When you press down on the white bits it shows a yellow bar to show it has power left. | [
"When you press, a strip of conductive material makes contact with the battery terminals. It has a well-characterized resistance so it heats up to a temperature that varies with the battery state of charge. It's covered with a strip containing ",
"thermochromic crystals",
" which change color. Then there's a... | [
"Ok I like that explanation. Please add to it by explaining why the strip fills up like a thermometer going up. Shouldn't the whole strip heat up linearly? Why does a low voltage cause a small fraction of the strip to change? Why does a high voltage cause the whole strip to change? "
] | [
"It sounds like it would work the same as the ",
"thermometer pictured in the Wikipedia article",
" except instead of 6 discrete cells there's a continuous gradient of temperatures. As you go further up the strip it requires a higher temperature to change the color, so the 100% section only changes color at the... |
[
"Have any animals ever re-evolved the ability to breath water after evolving to live in water again?"
] | [
false
] | I have noticed land animals that have evolved to live in the water, like sea snakes, sea turtles and whales, have just developed the ability to hold there breath for a very long time (or an anaerobic process for help). Has anything re-evolved gills or water breathing ability? If not, is it not really practical/possible... | [
"Whales can't breathe underwater, they just hold their breath for a long time.",
"like sea snakes, sea turtles and whales, have just developed the ability to hold there breath for a very long time (or an anaerobic process for help)"
] | [
"Just to clarify (you're not wrong) animals which \"breathe water\" are breathing the air which is in the water. "
] | [
"huh! what a great question. i can't think of any, but i would love to know if there were/are. i don't think it would have been \"practical\" (although evolution has no direction so you can't really talk about it as a thought process)... so, if an animal with developed lungs started exploiting aquatic sources for... |
[
"Sometimes night time is not so dark because the sunlight reflecting off of the moon acts as a \"night light\", is this the same for the moon when it is dark? Does the sunlight reflect off of the earth and light up the moon?"
] | [
false
] | null | [
"I think some of the Apollo astronauts talked about the illumination from earthlight when they were there.",
"You can also see, when the moon is nearly new, some illumination of the moon's dark side— as I understand it, this is sunlight reflected off the earth (which would be nearly full at that point from the mo... | [
"about the size of a quarter in the sky",
"This isn't a good way to describe size in the sky because you don't know how far away to hold the quarter. If you said a quarter one foot from your eye, you'd have a better description. You can also use the angle of view that it covers which doesn't vary with distance fr... | [
"The Earth/Moon radius ratio is nearly 3.66, so it would appear about 3.66 times as large in diameter or about ten times as large by area. "
] |
[
"What about water puts out a fire?"
] | [
false
] | Is it blocking off the fuel from making contact with air? Stealing away the activation energy? Something else? All of the above? | [
"Mostly, it steals away the energy from the area. The evaporation of the water requires a lot of energy, and thereby results in reducing the temperature. Hopefully below the ignition point of the fuel, so the fire is contained or even put out. Most everyday things will only burn if the heat is concentrated. Like a ... | [
"It absorbs some heat and vaporizes, which reduces oxygen available to burn (pushed away by water vapor)).",
"It also absorbs/marries with MOST fuels making the fuel more difficult to oxidize and burn for the same reasons.",
"If you wet a porous charcoal, it can't begin the burning process until the water is go... | [
"For a short answer, the water leeches away the activation energy. Water has a very high \"specific heat\" meaning it takes a lot of energy to heat up a cup of water by 1 degree.",
"There are other substances that would do this too but water is readily available and convenient.",
"With enough water, like subm... |
[
"Probability help: 10,000,000 coins, each flipped one time - select 100 at random: What are the odds all 100 will be heads?"
] | [
false
] | I'm having trouble remembering how to calculate this. I posted this as an example in comment. Now someone is asking for an explanation, and I don't remember how to do the math. Help? | [
"Yeah, ",
" is correct. The probability is (1/2)",
" and it doesn't matter how many coins you originally flip since each coin has a 1/2 chance of being heads. Anyway, what I REALLY came to say is I read your original post, and ouch that hurts. I think what you meant to say is that if you flip 10,000,000 coins, ... | [
"The coin flips are independent events, it doesn't matter how many coins you flip, just the number of flips you are counting. Thus, flipping 10000000 or just 1 coin doesn't matter, so long as you get 100 total flips to count. The ",
"Binomial distribution",
" is the correct one for modeling coin flips, and the ... | [
"It doesn't matter how many coins you flip before choosing your 100. Look at it another way. You have 10,000,000 unflipped coins, select 100, and then flip all 10,000,000. You've reversed the order, and its obvious the other coins don't matter in this situation, but this is equivalent (since you aren't choosing the... |
[
"Simple question about the uncertainty principle of quantum mechanics."
] | [
false
] | I understand that this principle explains you can not know where the object is and what it is doing at the same time, (If this is wrong please correct me.) Does this hold true for dual/multiple observers? In other words, does the number of observers change the accuracy of the detection? Where I was leading with this is... | [
"I understand that this principle explains you can not know where the object is and what it is doing at the same time, (If this is wrong please correct me.)",
"It's close enough for nontechnical purposes.",
"Does this hold true for dual/multiple observers? In other words, does the number of observers change the... | [
"Alrighty, Thank you for the timely response!"
] | [
"It's actually even more interesting. If you have multiple copies of the same system, you can't ever measure both the position and momentum in such a way that violates the uncertainty principle, even if you do the measurements on different copies."
] |
[
"I sit for 5 minutes in the hot sun during my hour break every day without sunblock. I don't burn at all but it keeps me from looking pasty. Could this be dramatically increasing my chance of getting cancer?"
] | [
false
] | null | [
"I am not a doctor, but I've taken a fair amount of bio classes, and I can tell you two things. First, all sun exposure, no matter how brief, increases your risk for skin cancer. Second, the amount it increases your risk grows with continuous exposure. So, 12 five minute sessions are less risky than a solid and con... | [
"So pretend it isn't personal and just think about the question relating to sunblock and sun exposure.",
"Aren't all questions asked for personal reasons?"
] | [
"It continually bemuses me that people like you post things in ask science. Go to the wikipedia page on vitamin D and read ",
"."
] |
[
"How does graphene integrate into spider silk?"
] | [
false
] | null | [
"Hi dawillus thank you for submitting to ",
"/r/Askscience",
".",
" Please add flair to your post. ",
"Your post will be removed permanently if flair is not added within one hour. You can flair this post by replying to this message with your flair choice. It must be an exact match to one of the follow... | [
"'Biology', 'Chemistry', 'Engineering'"
] | [
"Chemistry "
] |
[
"Electromagnetic radiation and its alleged negative health effects. A hoax, or legitimate."
] | [
false
] | Electric heat blankets to transmission lines. As far as my understanding goes emf is produced from alternating current. That said, dc power sources should have no such effect. Also there are advertisements for anti-radiation pads, yet I was taught nothing could interrupt emf waves. | [
"There's no evidence that the fields or radio emissions from alternating current have any negative health effects, attempts to detect things like claimed ",
"electromagnetic sensitivity syndrome",
" (not a recognized medical condition) have all turned up the result that there is no detectable effect on people."... | [
"Electromagnetic radiation can harm you, it can be harmless. For example: \n-UV radiation in sunlight causes sunburn\n-gamma radiation from space can cause cancer\n-X-rays can cause problems if the dose is too high",
"But visible light, radio waves, and lower energy waves are harmless.",
"Also, electromagnetic... | [
"To clarify: EM radiation of all frequencies can be harmful, because too much of it can still impart a harmful amount of energy."
] |
[
"Would altering the physical characteristics (e.g. pureeing) food affect it’s available calories or nutritional content?"
] | [
false
] | Basically I’m think in terms of either eating a carrot or steak as-is, versus throwing them in a blender. You would still be ingesting the same content, it would have just been broken down physically. (Excluding heat or cooking as a factor.) Would this impact our effective calories or nutritional benefit during digest... | [
"In some cases yes. For example, when a chef tenderizes a slab of meat by pounding it with a mallet, what happens is some of the muscle cells are broken apart, and certain enzymes in the cell leak out and begin to digest the tissue. This makes for more tender meat, but also increased content of smaller molecules (m... | [
"I may be oversimplifying.. But are you saying if I eat cut up raw broccoli, it increases my risk for cancer?\nTried to find the full article, but could only read the abstract "
] | [
"Gram for gram - No the chemical bonds remain the same and thus the same amount of energy (calories) can be extracted from it. (This is NOT true for heating)",
"However, pureeing food may make it easier to consume a larger (? My own hypothesis) amount and change the practical intake and therefore increase the cal... |
[
"Is there an equivalent of evaporation for melting?"
] | [
false
] | [deleted] | [
"This is a question that really bugged me when I was first studying materials science as a PhD student, my undergrad training being in a different field. To put it more generally, if we know that all solids at equilibrium must be surrounded by their own gas, why don't all solids also exhibit a thin layer of liquid ... | [
"Yes, even below the freezing point, part of the frozen water would dissolve in the ethanol."
] | [
"Yes, even below the freezing point, part of the frozen water would dissolve in the ethanol."
] |
[
"Why do some drinks drip down the side when poured and others don't?"
] | [
false
] | null | [
"Mercury will run out of a glass (without \"dribbling\" down the side) MUCH easier than water. This proves that \"dribbling\" is not caused solely by surface tension. From your post, one would expect that the higher the surface tension, the more \"dribbling.\" This is not the case.",
"Surface tension is causing i... | [
"Sorry if I was unclear. ",
"The OP asked about water sticking to the side of a pitcher when it is slowly poured. The explanation given was that water has some amount of surface tension, and that surface tension causes the water to stick. To overcome that, the water must be poured faster to break the surface tens... | [
"The simple answer is surface tension. Say you're pouring water out of a pitcher. Surface tension is causing it to stick to the pitcher. Liquids like to stick to hard surfaces because it's a lower-energy arrangement, so when you have a really full pitcher and tip it slightly so you don't flood the glass immediately... |
[
"Dear Astronomers / Physicists, could you help me understand tidally locked planets?"
] | [
false
] | I'm curious about tidally locked planets orbiting red dwarves, such as GJ 581g, and their potential for sustaining atmospheres or even life. As one side of the planet is faced away at all times from its star, do the freezing temperatures that occur prohibit an atmosphere from forming? Also, in regards to the red dwarve... | [
"While we have no tidally locked planets in our solar system, consider that:",
"Venus rotates so slowly that night lasts about 60 Earth days, but its dense atmosphere transports heat so effectively there is virtually ",
" difference between daytime and nighttime temperature of the surface.",
"Earth's poles ex... | [
"As far as I know we do not have clear observational evidence for atmospheres around Earth-like exoplanets that are tidally locked. If the atmosphere is dense enough before tidal locking occurs, it could transport some heat to the night side, perhaps enough to keep it from fully collapsing. One thing you might look... | [
"Thank you so much for the detailed explanation and the paper! Luckily I was betting on the survival on such a planet to be neigh impossible without some fictional intervention, and you gave some excellent boundaries to write a story within."
] |
[
"A shot glass that was sitting on a table for days, untouched, just violently shattered into pieces for seemingly no reason. What the heck just happened?"
] | [
false
] | It was directly i front of me about 10 ft away, and there was nothing near it at all. The shot glass was very thick glass, and there was a little residue of liquor in it. I was in direct view of it while watching tv when it happened and it scared the crap out of me. | [
"Your shot glass must have been made from ",
"toughened glass",
". It allows internal faults to build up without notice until the glass fails \"spontaneously\". When the outside layer is scratched it fails catastrophically.",
"News story"
] | [
"Prince Rupert's drops",
" are a pretty specular demonstration of how this can work. (better view of the ",
"shattering here",
")"
] | [
"Glass dust, don't breathe this"
] |
[
"How does mercury polish silver?"
] | [
false
] | ive seen it , but i want to know! | [
"Two processes: Mercury dissolves the outer layer of silver in amalgamation, as another poster stated. Also, mercury directly reacts with silver sulfide (the main component of tarnish) to form cinnabar (HgS) and metallic silver, so it directly attacks the tarnish as well."
] | [
"This is probably a better answer than mine. I didn't bother explaining the reaction and simplified it."
] | [
"Anyone who doesn't know what he's talking about, ",
"here's a video",
".",
"It's a process called ",
"amalgamation",
". Basically, the mercury combines readily with the surface silver, which is tarnished. Gently polishing the outside will remove the amalgamated layer, the tarnish, from the pristine insid... |
[
"Why did the Space Shuttle have main engines? Wouldn't it just be easier to have more powerful boosters and just equip the shuttle with orbital maneuvering thrusters?"
] | [
false
] | null | [
"The solid-fuel boosters alone couldn't have carried the shuttle to orbit without being ridiculously large. The shuttle needed the more efficient liquid-fuel engines.",
"Development of the space shuttle was...long and complicated, but I think the general intention is that by keeping the main engines on the orbite... | [
"The boosters were solid fuel rockets. Solid fuel rockets are simple, powerful, and relatively cheap. But that simplicity comes at a cost: you can't really control them. You don't have much in the way of a throttle, and stopping and restarting them is all but impossible. They're great for getting you off the ground... | [
"There were plans to give the Shuttle liquid fuelled boosters that would land themselves, like Falcon 9, but the funding was cut."
] |
[
"What will happen when all the coral reefs die?"
] | [
false
] | What will happen if all coral reefs die? Recently there more and more news coming in about the death of coral reefs.. eg. | [
"Extinction. An ecosystem which has existed for millions of years will be gone forever. Some specimens will continue to be kept in aquaria and laboratories. But if we continue to burn all the oil and natural gas we can find, the oceans won't be a safe habitat for reintroducing them for 10,000s of years.",
"Edi... | [
"In terms of ocean biochemistry, I don't think it will be a big impact. There is indeed incredible species ",
" on reefs but in terms of total ",
" in the ocean, corals are a small blip compared to all the krill, copepods, diatoms, dinoflagellates, etc. Locally, the absence of reefs will have effect on the oce... | [
"There's potential for there to be an effect on the earth's radiative budget. The extent of this is still pretty unclear though. The idea stems from the ",
"CLAW hypothesis",
". It essentially is an idea that biological sources (in particular, phytoplankton, but coral is also considered) are part of a feedback ... |
[
"Why do movies look more blurred when paused?"
] | [
false
] | I noticed that when I pause a movie to get a print screen, the still image is blurrier than the moving image would lead me to believe. Is this an optical illusion: i do not notice blur when it is moving. Or is it the result of a halted interpolation by the media player. Or something else? extra: if it is the second cas... | [
"Most movies are shot at 24 frames per second (fps). While it is possible to create 24 sharp images of a moving object in one second, the result would look very choppy, since the fps is way too low. You would clearly see each frame and jumps between different positions of the object. By letting each frame get a bit... | [
"Also a lot of films are shot at a 180 degree shutter angle. That means each frame is exposed for half the amount of time as there are frames per second (one 48th of a second for film shot at 24fps). Doesn't sound like much but if you shot all your still photos at 1/50 sec you'd see more blur than you would think. ... | [
"Is this an optical illusion: i do not notice blur when it is moving",
"Essentially yes. Your brain is exceptional good at reading these images as real moving things. It builds a model that appears detailed and smooth rather than slightly blurry and going 24 steps ",
"Or is it the result of a halted interpolati... |
[
"Why does the Swift-Tuttle debris stay put?"
] | [
false
] | I know that the Perseid meteor shower is the Earth passing through the debris left by the tail of the comet Swift-Tuttle. But Swift-Tuttle has a 133 year orbit. Why does the debris stay in place, thus allowing us to pass through it every year? Why doesn't it dissipate or move? | [
"It doesn't stay in place. It travels on the same orbit as comet Swift-Tuttle. "
] | [
"Just like the Earth's orbit itself doesn't change much over the course if a human lifetime, neither does the comet's. The two orbits intersect in one particular place, which is the position the earth happens to be in around August 13. Swift-Tuttle's orbit is filled with debris, all in about that same orbit around ... | [
"so how is it that we travel through it at pretty much the same time every year? Or is the reason it may move a day or two every several years because of this?"
] |
[
"Quantum Entanglement and Black Holes"
] | [
false
] | So Quantum Entanglement allows us to know what is happening to one particle when it is entangled with another, so if it were to be entered into a black hole, would we be able to understand the inside of a blackhole? | [
"Entanglement doesn't really let you know what is happening to the other particle in general. If you have two entangled particles, A and B, then you can measure B and it will tell you something about A, but what you just learned about A could have come about just because you measured B, not because of something tha... | [
"That's an interesting question. I think we do not really know the answer yet. What's clear is that entangled particles do not transmit any information between them, so the particle in the hole wouldn't be able to tell it's former sibling what's going on in there.",
"What's ",
" clear however, is where the info... | [
"On that note, people seem to think that if you change particle A, particle B changes as well. Their idea is that this could let you transmit information instantaneously across the universe. In reality, if you change particle A... you disentangle the particles. They don't let you violate causality."
] |
[
"Would a house with a self contained electric system run more efficiently on DC power? Could higher voltage be used to achieve better efficiency?"
] | [
false
] | I feel like in the future, houses may run on self contained solar/ battery systems. Would it be more efficient to run everything at, say, 400 VDC instead of 120/240 VAC? Could most appliances be easily converted/ designed to run on DC power. Would higher voltage be a problem due to insulation? | [
"So this, for the most part, is true. However, HVDC (high voltage direct current) is quickly starting to become a good choice for high power long distance lines (Such as the one from the Columbia River ",
" on the Oregon side, down to California). ",
"It's good for long distance bulk power transmission with no... | [
"Never.",
"Well sort of.",
"You have to remember when it comes to products their are three types, consumer, intermediate, and industrial/commercial and have there different grade.",
"Companies are much more adapt to spend more on more efficiency and longer life even if it hurts them short term, they will make... | [
"Wikipedia page \"War of Currents\" might be relevant for you to look at:",
"http://en.wikipedia.org/wiki/War_of_Currents",
"Basically, DC is good if you have a small power source close to where the current is being used (e.g. a battery in a flashlight). AC is good if you want to transport current over long dis... |
[
"Do greenhouses gases also keep sunlight from entering the atmosphere in the first place?"
] | [
false
] | [deleted] | [
"And ",
"here's a chart",
" which compares the spectrum of incoming radiation from the sun vs. outgoing thermal radiation from the Earth. As you can see, there's very little overlap."
] | [
"Most of the sun's energy arrives in the form of visible light. ",
"Chart",
" Relatively little energy is coming in as infrared.",
"Almost all of the energy trying to leave Earth is in the form of infrared. As it happens, CO2 has an absorption band close to the wavelength that corresponds to Earth's black bod... | [
"The gas does block some incoming sunlight, but it blocks the outgoing infrared better. A lot of the sunlight that hits earth warms it, and then the earth \"glows\" in infrared light. In effect, the visible light gets changed into infrared, and the greenhouse gas (or glass in a greenhouse) blocks outgoing infrared ... |
[
"What are the Primary, Secondary, Tertiary, and Quanternary structures of a protein?"
] | [
false
] | I do not understand how Tertiary and Secondary differ, and how Tertiary and Quanternary differ. | [
"Primary is the sequence of the amino acids. Secondary is local substructure, typically alpha helices and beta sheets. Tertiary is the overall folded structure of the protein and how all the secondary structures interact. Quaternary structure is how the protein interacts with others into an active holoenzyme, fo... | [
"One way to think of it is that each structure level represents interactions of the preceding one.",
"Primary structure is the single, unbroken chain of amino acids. Secondary structure is the amino acids interacting with one another to form regular structures such as helices, turns, and sheets. Tertiary structur... | [
"Not exactly a biochemist, but some synonyms I've heard commonly used are primary sequence, secondary and tertiary folding, and quaternary interactions. You could also use shape, or conformation."
] |
[
"Why do I get the conservation of energy when I solve the Euler-Lagrange equation?"
] | [
false
] | null | [
"There's a theorem called Noether's Theorem that says that when a Lagrangian (or the action) is invariant under a particular transformation, the system exhibits a symmetry pertaining to that transformation. ",
"In the case of conservation of energy, when we shift the system from q(t) to q(t+dt), you can easily se... | [
"If a Lagrangian has no explicit time dependence, then the system exhibits conservation of energy. The energy turns out to be the Hamiltonian H associated to the Lagrangian L (i.e., H is the Legendre transform of L with respect to the velocity variables)."
] | [
"Strictly speaking, no explicit time dependence in the Lagrangian means that the Hamiltonian, H, is a constant of the motion, which will not necessarily be the total energy of the system. While in many cases of course it is, there are fairly simple systems you can construct where H is conserved, but it does not cor... |
[
"Passing on your genetic material without having children?"
] | [
false
] | [deleted] | [
"There's not much to add to this except that this is basically the topic of much of Richard Dawkins's book ",
". A classic which everyone should read!"
] | [
"It's not exactly \"passing on your genetic material,\" it's more that genes that are identical to yours can be passed on to the next generation because other people also have that gene. Your siblings are about 50% genetically identical to you. That is, you share about 50% of your alleles with your sibling. So when... | [
"Seriously?"
] |
[
"What happens to the blood vessels in fat when you lose a lot of weight?"
] | [
false
] | So I've heard the "rule" that for What happens to those vessels when you lose that fat? | [
"Yep, and sometimes it gets grotesque; patients who've had extensive lipo will get neck fat, etc."
] | [
"Oh dear. Mother Nature wins again."
] | [
"Unless you have surgery - you don't loose fat cells they just shrink. SO the blood vessels would still be in place but having to cover a smaller area. Often leading to varicose veins."
] |
[
"What are the criteria for being a primate?"
] | [
false
] | [deleted] | [
"Oh, humans are primates, there's no dispute there. I prefer genetic demonstration over morphological when it comes to proving it though; retroviral insertions & psudogenes are quite convincing."
] | [
"That seems like a pretty comprehensive list, what kind of features are you looking for?"
] | [
"not certain kinds of features. i've seen in museums and online and heard biologists reference a set of defining characteristics that make something a primate so to speak, but i don't remember seeing anywhere what they are. i remember reading something recently that said \"there are 8 [or so, i don't remember the... |
[
"Can gravitational waves be affected by gravity?"
] | [
false
] | [deleted] | [
"Yes."
] | [
"With suitable definitions, they carry energy-momentum, just like light. Also as small fluctuations from a background shape, they can be proven to be affected by the background shape itself."
] | [
"How can gravity manipulate it? Aren't they fluctuations in spacetime rather than anything with mass/energy, and thus unable to interact with gravity?"
] |
[
"How many calories does the human brain consume in a day?"
] | [
false
] | null | [
"Your brain runs around ",
". 10 Watts = 10 Joules per sec. There are 4.184 Joules in a calorie (little c, not Calorie, which is 1000 calories). That's 2.39 calories per second. There are 86400 seconds in a day. 86400 x 2.39 = 206496 calories, or ",
"EDIT: I was going off of some research that I had done about ... | [
"In other words, if you were a brain living in a jar, you would only need to eat one bowl of Ramen every day to support yourself. With a six pack of Ramen at $1 each, that's an annual food cost of $65.21 including tax if you live in California."
] | [
"the question is, can your brain handle that much sodium?"
] |
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