title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"Why do the strong and weak fundamental forces have a limited range?"
] | [
false
] | This is something which has bothered me for a while now. I mean, both gravity and electromagnetism (the forces that are more familiar in everyday life) have an unlimited range (e.g. you can feel the gravitational pull of something no matter how far away from it you are), but the strong and weak interactions apparently drop off entirely beyond a range of 10 or 10 meters or so, respectively. Like, if you were to graph the strength of these forces versus distance, would they suddenly drop to zero after you reached a certain point? Or do they just drop off so quickly that we say they're effectively zero after the distance becomes large enough? In other words, how do these forces behave with respect to distance? | [
"The strong force range is based on the amount of energy needed to isolate a particle with a bare strong/colour charge.",
"Specifically, the strong force - unlike the other forces - gets stronger with distance. The potential energy stored in a bare colour charge therefore also increases with distance. Eventually,... | [
"Two addenda:",
"(1) Massive particles lead to short range forces whether or not they are unstable. (That exponential ignatiusloyola refers to drops off over a distance inversely proportional to that mass.)",
"(2) The explanation by ignatiusloyola addresses why the fundamental strong force is short range. But... | [
"Anyone who wants a more substantial answer should refer to Zee's Quantum Field Theory in a Nutshell. The calculation that shows massive particles correspond to exponentially decaying forces is one of the first done in that book and can be done with an understanding of undergraduate quantum mechanics and a strong b... |
[
"What is the difference between Δ, δ, d and ∂ when used in math and physics?"
] | [
false
] | I have never quite understood the difference between Δ, δ, d and ∂ when it comes different equations and formulas. I've understood that has to do with derivatives and infitesimal changes and whatnot, but I would like to get a better understanding of the differences. | [
"'",
"' -- means a change in some variable. This makes it a difference operation: ",
".",
"'",
"' -- means an 'infinitesimal' change, or a \"",
"differential form",
".\" It's kind of like a limit as ",
" -> 0, but it is compatible with relative rates or different kinds of limits, so that the notion of... | [
"It's also common to see δ used to refer to a variational derivative."
] | [
"'∂' can also mean a boundary of an area in topology and this leads to some annoyances in multidimensional calculus if you aren't paying attention to the context. "
] |
[
"Why, and how, does a combination of isopropyl alcohol and salt, plus a lot of shaking, remove the resin tar from the inside of a water pipe?"
] | [
false
] | null | [
"Isopropyl alcohol is a good solvent for resin/tar. Salt is not very soluble in the alcohol and acts as a scrubby abrasive that can get into every curve and crevice, while not being hard enough to scratch up the glass. You could use isopropyl alcohol and sand and it would clean great but scratch the glass over time... | [
"This is the correct answer. ",
"Just for fun, you can shine up dull coins and metal with vinegar and salt. For the same reasons."
] | [
"You could use sugar, but if you don't fully rinse it out then the inside of the glass pipe will get sticky and dirty faster. Since salt is not very expensive, there's no reason to use sugar.",
"Some people use rice, which seems like it absorbs some of the tar and is also abrasive. However rice can get stuck in... |
[
"How far underground do you need to go for the earth's crust to not be affected by seasonal changes in temperature?"
] | [
false
] | To put it another way: how deep down should we dig to not be able to tell if it's summer or winter? | [
"About 50feet (15meters) down in our latitude.\nIt should be deeper in the north, but might get shallower again when we reach permafrost regions. (i have to think about that!)",
"You wont have to dig at all at the equator for obvious reasons. ",
"source: im a geothermal engineer + ",
"http://www.renewables-m... | [
"visit a salt-mine and be amazed about the relative insignificance of surface-temperatures..."
] | [
"Yup. You've probably heard of a root cellar. They work on this very idea. They're not often that deep, but as you go further into the ground, the temperatures get more consistent. I'm guessing you didn't grow up in a house with a basement. "
] |
[
"Is there something tangible in the brains of serial killers and the like that separate them from people that can comfortably function within the confines of societal rules?"
] | [
false
] | Obviously there are people that murder out of desperation -- I'm excluding them. What makes a mass murderer different neurologically, say, from me who cannot imagine taking another person's life because it just seems ? Doesn't the "triad of sociopathy" (bedwetting, pyromania, cruelty to animals) point to a problem that could maybe be recognized on a cat scan? | [
"Doesn't the \"triad of sociopathy\" (bedwetting, pyromania, cruelty to animals) point to a problem that could maybe be recognized on a cat scan?",
"Well, psychopathy couldn't really be seen on a CT scan as that type of neuroimaging has relatively poor ability to visualize the structures of the brain. ",
"Howe... | [
"do you personally think that it has more to do with nature or nurture?",
"It doesn't matter what I personally think, it matters what the research says. At this point my (somewhat limited) understanding of that literature suggests that both are likely involved, but I don't think enough research has been done to ... | [
"He's also written a book called, The Anatomy of Evil. I daresay the read is better than the watch."
] |
[
"Do colors exists in the real world, or is it something our mind does in response to lights of different wavelengths?"
] | [
false
] | [deleted] | [
"You can get into semantic arguments about this, but I would say that wavelengths of light are physical phenomena, while colour relates to human perception of that light.",
"A human typically has three colour receptors in their eyes, which cover overlapping bands of wavelengths. We perceive colour by how much eac... | [
"You can get into semantic arguments about this, but I would say that wavelengths of light are physical phenomena, while colour relates to human perception of that light.",
"This is basically it. To answer the OP's question, wavelengths exist in the real world, and colours are what our brain \"perceives\" in resp... | [
"It's true that each single wavelength of light will be read by your eye/brain as a specific color. But some colors that you perceive don't line up with a single wavelength, only a combination of wavelengths (e.g. magenta). And there are multiple combinations of wavelengths that you will perceive as the same color.... |
[
"If the Earth's gravity has caused most of the iron on earth to \"sink\" to the core of the Earth because of its mass, would that also mean most of our supply of precious metals like gold, platinum, and uranium are also in the core?"
] | [
false
] | null | [
"Density is NOT the only sorting parameter. Chemical affinity/behaviour is also really important.",
"The elements that get concentrated in the core are what we know as siderophile elements; basically they concentrate in iron, and therefore are associated with iron in the differentiation process which separated ... | [
"So somewhat the same mechanism, except reversed, as how hydrogen should be nonexistent on earth due to its density(like helium is), but because it forms a dense compounds with carbon/oxygen/etc, we have plenty sitting around?"
] | [
"Yeah, not a terrible analogy."
] |
[
"Is it possible to create an evolving program?"
] | [
false
] | Would it be possible to create a program that evolves by adding a random set of code from a library to its own coding as it duplicates? Essentially creating a simple program with no commands beside mutate, survive, duplicate. (cell.exe) Then create a separate program (darwin.exe) that checks the offspring programs for desired traits, and deletes the undesired traits before the next generation is duplicated. Essentially you'll have created the digital equivalent to a protein and an environment for it to evolve in and eventually you will have lots of completely unpredictable and complex programs. Even AI. | [
"Yes indeed, the ",
"Lisp",
" language contains a command to run a list as a program and lisp programs and data are just so lists. Other programming languages contain equivalent evaluation functions.",
"Your idea for a self-evaluating ",
"evolutionary algorithm",
" might run into difficulty because such ... | [
"eventually you will have lots of completely unpredictable and complex programs.",
"You were right until you got here.",
"Evolutionary algorithms are not used to create arbitrary programs. You'd quickly end up with far far far far too many programs to simulate and manage. Instead you use it to find a ",
" pro... | [
"Almost certainly not. You need selective pressure. In the real world, things that don't reproduce don't pass on their genes. But in this evolutionary system, an algorithm decides what programs should get to \"pass on their genes\". This means you use test cases to see which programs get you closer to your goal and... |
[
"What is the most recent common ancestor of human and any other currently living animal for which we have physical remains?"
] | [
false
] | I am asking because i got asked in a debate about evolution for an example of a fossil of human and chimpanzee common ancestor. I understand that fossilizing is a rather rare event, combined with a chance that it would happen to one of our direct ancestors makes it very unlikely. But can somebody explain better why, if there is none? | [
"We don't have fossils of the MRCA, but it's estimated to have occured 5-7 million years ago based on genetic studies.",
"We have three possibilites for MRCA that has fossil remains- ",
"Ardipthecus",
", ",
"Sahelanthropus",
", and ",
"Orronin",
"."
] | [
"I am assuming that you are talking about MRCA of human and chimpanzee. What about other animals. Is there a fossil about which can be said that it was our ancestor (not necessarily MRCA) and we share it with other animals? "
] | [
"Tiktalik I think thats how its spelled was one of the first amphibians, but whether we are directly related to any fossilized individual is highly unlikely, however i believe it is reasonable to assume that our direct ancestor would be geneticlly very similar to tiktalik. "
] |
[
"How do we know electrons are negatively charged?"
] | [
false
] | And likewise, how do we know that protons are positively charged? And if it was proven that they are charged that particular way, what experiment was used to find this out? I was thinking about this in my chemistry class today and I realised that we were never explained why they were given that charge. | [
"It's known they have opposite charge. Which one is called which is an arbitrary convention."
] | [
"Generally, it doesn't matter at all: it is what physicists call a symmetry (in particular, C-symmetry). You can swap charges between electrons and positrons and noone would bat an eye - every process in the known universe would stay the same, except for a single case: weak interaction, which ",
"violates that sy... | [
"The experiment used to identify the charge of the electron and proton were done by J.J. Thompson and Wilhelm Wien in the late 1800s.",
"In short Thompson's ",
"experiment",
" observed the deflection of a cathode ray that s passed through an electric field. The ray's deflection was always towards the cathode ... |
[
"What factors determine the lifting force of a hot air balloon?"
] | [
false
] | Edit: What I should have specified is: how do factors such as lateral surface area of the balloon and volume of the balloon relate mathematically to how fast the balloon rises, or how much buoyant force the balloon has and mathematically how might one calculate the "minimum" volume/lateral surface area or other features to minimize actual surface area (aka: "production costs") of the balloon? Or how much a hot air balloon can lift. In our engineering class, we were challenged in groups to build a balloon out of basically tissue paper and glue that would be able to carry a GoPro to the top of our gym (~170g). As of now, our balloon actually works (yay!) But being high school students we pretty much have no clue how (we aren't aerospace engineers... Yet). Would someone explain how this works? On paper, our balloon has the shape of an upside down square pyramid, if anyone's interested (base ~5m*5m, height ~5m, bottom vertex cut out to fill balloon with). If you'd like more details I can provide them! | [
"The reason balloons float in general is the ",
"bouyant force",
". When the balloon as a whole is less dense than the air around it, the air pushes it up with a force equal to the weight of the air the balloon displaces. Helium balloons are lighter than air because helium is a lighter gas than nitrogen and oxy... | [
"Buoyancy force scales with density difference and volume.",
"The lifting force is the difference between the buoyancy force and the weight of the balloon, which depends on how it's made.",
"The terminal velocity of the balloon (rising) is a balance between the lifting force and drag with the air, which scales ... | [
"Thanks to your reply! What I should have specified is: how do factors such as lateral surface area of the balloon and volume of the balloon relate mathematically to how fast the balloon rises, or how buoyant the balloon is and mathematically how might one calculate the \"minimum\" volume/lateral surface area or ot... |
[
"What is the largest stable molecule known? What molecule has the largest number of unique elements contained within it?"
] | [
false
] | null | [
"To answer part of your question, things like proteins, fats, and DNA strands are just very large molecules known as macromolecules. The largest known protein is Titin. It has the chemical formula C169723 H270464 N45688 O52243 S912.",
"Some notably large macromolecules are found in the human genome. The genome co... | [
"technically speaking, following vulcanization, the rubber in a car tire could be considered a single molecule",
"http://en.wikipedia.org/wiki/Vulcanization"
] | [
"Considering that the tire rubber has a number of low MW additives (antioxidants, antioxonants...) which are not part of the vulcanization scheme, yes, the rubber of a car-tire is not a single molecule.",
"But at the same time, the concept is correct. There are endless number of very large objects that are cross... |
[
"Why can't we continue to bombard fission products with neutrons to end up with products that have shorter half-lives and/ or are less dangerous?"
] | [
false
] | null | [
"We can do that."
] | [
"So why don't we do it all the time?"
] | [
"It's still in the R&D phase. We can't do it for many kilograms of material yet."
] |
[
"Are humans the only species that (sometimes) feels remorse/empathy when members of other species die/suffer?"
] | [
false
] | null | [
"Lots of other animals appear to mourn their dead, especially primates. ",
"Here's a video",
" of a chimpanzee mother that is clearly upset that her child is dead. And ",
"a mother elephant",
" tries to save her baby calf and appears to be showing what we would call empathy. ",
"I think people seriously u... | [
"Koko & All Ball",
" is one instance that spring to mind. Then in relation to Ryguythescienceguy's point about dogs and man there is, for example, the case of ",
"Greyfriars Bobby",
". Both pretty anecdotal though."
] | [
"The key point here is appear. Female chimpanzees and some monkeys (such as geladas) are known to carry around dead infants - in some cases for days, well after the body has begun to decay. At the same time, anecdotes (which do not count as evidence) of primates helping injured or sick group members besides their... |
[
"Is biological evolution driven by isolation?"
] | [
false
] | null | [
"[biological] evolution is driven by isolation",
"If by isolation they mean gene flow, then yes it has an effect; though, it's certainly not the only factor. You also have to take into account a number of other variables, including selection, population size, genetic drift, mutation rates, etc."
] | [
"To me, that sounds like an attempt to use population genetics to justify a personal political/cultural view. ",
"That being said, it ignores the fact that migration is an important source of variation. It can introduce novel alleles that could be beneficial for the recipient population (and vice versa), ones tha... | [
"I hesitate to give a definitive answer because - as I mentioned earlier - there are many variables that must be considered. If we make assumptions regarding these factors (e.g., no stochastic events, which can have a huge effect on small populations, etc), then it would boil down to time frame. In the short term,... |
[
"I've heard multiple times recently that our classic model of the atom isn't actually what atoms look like, what exactly do people mean by this? What do atoms (really) look like?"
] | [
false
] | [deleted] | [
"Typically this stems from a model of the atom depicting electrons as inhabiting a distinct path around the nucleus. This is not the case. Electrons do not follow a path, or even move in a way you and I would be familiar with. Rather the electrons can be modeled in terms of probability. A model which captures some ... | [
"In addition to probability of where it is, depending on the energy level of the electron, it will follow a different probability cloud pattern than those with different energy levels. So say, you have an atom of lead, those electrons which are housed in the lowest energy level (or on average closest to the nucleu... | [
"A proton is made of three quarks, with charges 2/3, 2/3, and -1/3. These quarks are pretty tiny, much closer to electron mass than proton mass. The proton gets the bulk of its mass from the gluon binding energy that keeps the quarks together. So the electron does have more 'oomph', but not by too much. "
] |
[
"How did monkeys get to the New World?"
] | [
false
] | null | [
"Primatologist/biologist here. Rafting is the most currently plausible theory, as /avec_aspartame stated. Here is something to think about if this sounds implausible: All Platyrrhines (new word monkeys) are monophyletic. This means that they all share a common genetic ancestor, and the extant evidence points to ~35... | [
"It's worth noting that the Atlantic was somewhat narrower 35 million years ago. Still wide, but not ",
" wide."
] | [
"Probably through a rafting event. During strong storms and floods, large sections of wetlands can be ripped free and set adrift. Under favourable conditions, such rafts can cross more than a thousand miles of ocean. ",
"South America and Africa were ~1,000 kilometres (600 miles) closer than they are today. Sea l... |
[
"How do network lines carry more than one signal?"
] | [
false
] | My basic understanding of the internet is as follows: information is broken down by the client into bytes and put in packets with an address, then sent onto the wires transferring them. The server reads the wire and finds the packet, looks where it's supposed to go, then puts it on the proper wire and the end client reads the wire and finds the packet there, unpacks it, and the message has been transmitted. But surely there can't be a direct line from every single network connected to the internet straight to an ISP's servers. They must be combined somehow, but then how can all of the packets be sent to where they need to go? If they go one after another, the network gets backed up with traffic, each client waiting to see a packet for them on the wire. If they all go at once, they surely just blend into noise, as there's no good way to tell which bit belongs to which packet. Is this not how information is transmitted over the internet? If it is, how big of a problem was this to early designers of the internet, and how was/is it solved? | [
"My basic understanding of the internet is as follows: information is broken down by the client into bytes and put in packets with an address, then sent onto the wires transferring them.\nThe server reads the wire and finds the packet, looks where it's supposed to go, then puts it on the proper wire and the end cli... | [
"What you're missing is that there's usually not a direct connection to a physical server, packets on the Internet often go through over a dozen ",
".",
"Each router is basically a special purpose computer system which has several physical jacks for connecting network cables. The router matches the address in ... | [
"Ignoramus checking in. Is 'mulitiplexing' still used? Idle curiosity."
] |
[
"Can animals really predict disaster ahead?"
] | [
false
] | [deleted] | [
"The seizure sniffing dogs are a legit thing. They're a form of service animal that are ",
" highly trained. I saw one assisting his \"owner\" (for lack of a better word in this context). About a minute before the guy started to seize, the dog did something (I didn't notice the signal, but apparently the guy d... | [
"It's a numbers game. Let's say you have 1000 pet owners in a town. Every day, 10 random pets are going to behave oddly for some reason - not important which. The owners most likely will shrug or maybe tell their friends about it over dinner. ",
"Now let's say we have an earthquake. Of those 10 pet owners maybe 2... | [
"This paper studied a case where a number of toads left their breeding pond for higher ground a day before an earthquake. ",
"It suggest that they were able to sense the release of certain ions from the rock below and move away from the pond before the water became potentially toxic due to a change in PH as a res... |
[
"What is the rate of formation for Uranium 235 in relation to Uranium 238 and how do we know?"
] | [
false
] | In supernovae, where Uranium 235 and Uranium 238 are formed, how much Uranium 238 is formed in relation to Uranium 235? And More importantly, how do we know why this is the case? As far as I know: When working out the age of the earth you have to know what the rate of formation are for the different nuclear isotopes so that you can use their different rate of decay to calculate the age of the earth. | [
"The ratio of production of U-235 to U-238 in supernovae is roughly 1.65:1, however, this isn't relevant to radiometric dating.",
"Radiometric dating works through processes that cause elemental separation which then makes it possible to measure the amount of time since that separation occurred. In the case of Ur... | [
"Thanks. "
] | [
"If you happen to know I'd still like to know how we came up with the 1.65/1 ratio."
] |
[
"Schrödinger's Wave Equation"
] | [
false
] | null | [
"Well, we must be a bit careful with the word \"derivation\" in this case. Obviously, one can't truly derive the Schrodinger equation from classical physics. Some extra axioms and ansatzes have to be put in, but there are many equivalent sets of axioms that will define quantum mechanics - even proposing the Schro... | [
"There's a nice little derivation on page 94 in Townsend's QM book (I hope ",
"this link works",
"), which just uses the ideas that the Hamiltonian should generate time translations, and time evolution should be unitary."
] | [
"I was mainly referring to the derivation from the de Broglie wave equation which Schrödinger originally did. But I heard there are flaws with Schrödinger's original paper, and apparently no translations, so I was wondering what the best derivation of it is from established theory prior to it. I guess proof migh... |
[
"Is there a cause for the orientation of an accretion disc around a black hole?"
] | [
false
] | [deleted] | [
"There are two common situations. First, a stellar mass black hole in a binary star system. Second, a supermassive black hole in a galaxy's center.",
"You never really have a free-floating stellar mass black hole with an accretion disk -- the density of gas in the interstellar medium is just too low for that to h... | [
"Wow! That was really helpful. Thank you!"
] | [
"You're welcome! :) Glad to have shared something I learned."
] |
[
"Is there any truth to the practice of Acupuncture?"
] | [
false
] | null | [
"This is a blog run by Dr's, medical scientists, etc.. check out some of their articles on acupuncture. ",
"Science Based Medicine"
] | [
"May be asking to get downvoted, but also why religion made it this far."
] | [
"So doesn't work whatsoever, how has it lasted this long in a modern setting?"
] |
[
"Older theories of planetary formation?"
] | [
false
] | I just finished reading the 1979 SciFi book (Piers Anthony). It's a good read, if a bit convoluted. Anyway, covered within the book was a theory of planetary formation wherein the gas giants were formed from what sounded more or less like "black dwarfs" -- burned out stellar remains, which were captured by our protosun. While this is certainly not the current model (Wikipedia seems to indicate the as the most accepted model right now), was it ever seriously considered? My core question is, was this guy just making up stuff for his novel, or was this a serious model of solar system formation prior to our current understanding of stellar evolution (with the three endpoints being a white dwarf, neutron star, or black hole, if I've read correctly)? | [
"I know that prior to the discovery of fusion, it was thought that the mechanism of the sun's heat was Kelvin-Helmholtz contraction, which gave it about an 8 million year lifespan. (while this is the established mechanism of formation, it ends when fusion starts and there is a new hydrostatic equilibrium)"
] | [
"I don't think this idea was ever seriously considered. The closest thing to it is the theory that the gas giants formed by ",
"disk instability leading to localized gas collapse",
", as opposed to starting with massive cores and capturing gases (as described in this ",
"pdf",
")."
] | [
"I remember an old theory of planetary formation I was taught in undergrad. Basically it went that planets form when two stars pass close enough to one another that a significant amount of mass is pulled between them and meets in the middle where it condenses into a planet which begins to orbit one of them."
] |
[
"Is the total amount of water on (and in) earth (within the atmosphere) a constant amount or does it vary?"
] | [
false
] | I always wondered this because I would like to think that there is some kind of balance where all the watermolecules on the earth added up will end up in one big total number. That number would include all the molecules captured in ice, rain, air, earth itself and so on. Given the climate changes we see happening all around us could this total number (‘balance’ if you like) be influenced by human intervention to gain beneficial improvements for a sustainable future? | [
"As recently as a few years ago (2014), announcements were being made about ",
"huge quantities of water",
" on Earth that were previously unknown. ",
"To answer your question in the strict context of climate change, however, we need to consider how of the water we know about actually participates meaningful... | [
"I don't know the relative magnitude of these effects, but they won't balance exactly. So yes, the amount of water close to the surface (and also on Earth in total) changes."
] | [
"It varies.",
"2·H2O -->->-<-<-- H3O(+) + OH(-)",
"The arrows are for dynamic equilibrium.",
"K=1 meaning that it's forward and reverse reactions are equally likely to occur.. This means that your water is going to dissociate into hydronium (or simply a single proton but I like hydronium much better in th... |
[
"How do you measure the weight of matter that weighs less than air. For example, how much does a tonne of helium weigh?"
] | [
false
] | null | [
"1 tonne....\nBut to actually be helpful, usually for fluids (gases and liquids) we simply multiply their density by their volume to obtain their mass\nBut now you're just asking how we find the density",
"The first way that comes to my mind would be to turn a graduated cylinder upsides down and blow some helium ... | [
"It does not weigh one tonne because weight is a measure of force not mass. It's weight would be about -70,000 N within air. ",
"-p_h=0.18\n-p_a=1.28\n-\\DeltaM=M_h-M_a=1000(1-1.28/0.18)\\approx 7,000\n-g\\DeltaM \\approx 70,000"
] | [
"First things first, a tonne of Helium would weigh a tonne, because a tonne is a unit of weight.",
"I think you're getting confused between mass and weight, they are not the same thing.",
"The mass of something doesn't depend on the medium it's in. Mass is a measure of how much matter something is made up of, s... |
[
"If heat kills bacteria, why can't you simply reheat all food, no matter how old?"
] | [
false
] | If heat kills bacteria, then why are there so many guidelines for food safety? Couldn't you just reheat any food and kill that bacteria? (obv this might impact taste, but it seems simpler than the complex food safety laws) | [
"Sufficient heat will kill live bacteria, sterilizing the food as far as infection risk, however many food-borne pathogens create toxins as part of their metabolism and those toxins will remain even after killing the bacteria. ",
"For example, the bacteria ",
" produces botulinum toxin which is capable of block... | [
"Also important, even if the toxin isn't particularly dangerous, it can still make your food taste pretty awful. "
] | [
"Both botulinum toxin and shiga toxins are easily destroyed by heat. ",
"However certain strains of E.coli produce a group of \"Heat-stable Enterotoxins.\"",
"Certain strains of Staphylococcus, for example MRSA, produce a heat stable toxin. Staphylococcus spcs. don't grow easily under refrigeration or under ac... |
[
"Is the distribution of isotopes the same on other planets as it is on Earth?"
] | [
false
] | For example, on earth about 75% of Cl has atomic mass of 35, with the other 25% having atomic mass 37, is this distribution the same is space? | [
"Stars and Supernovae are the sites of nuclear reactions that consume/create isotopes, so other solar systems almost certainly have different ratios of the things.",
"As for planets in the same solar system, I don't know but I guess it should be sort of the same. (Although an important caveat is that one should k... | [
"Not exactly the same, no, but there very interesting similarities and trends. A full answer to this question would be quite involved, so I'll just point out a few aspects of it.",
"The various isotopes are made in \"nucleosynthesis\" processes. There are a few major ones which produce most of the material in t... | [
"The ratio of the various isotopes is slightly, but measurably, different between Earth/Moon, Mars, and asteroids, etc. Page down a couple times and the following link should prove to be interesting. ",
"http://solarsystem.nasa.gov/scitech/display.cfm?ST_ID=2398",
"When the Apollo astronauts brought back sample... |
[
"When we say that a rotating gyroscope's axis is 'fixed', it is fixed relatively to what?"
] | [
false
] | [deleted] | [
"gyroscopes seem to violate the laws of relativity of frames of reference",
"This applies to linear motion, not to rotational motion. There is no \"absolute zero velocity\", you can always pick another inertial reference frame to change the observed velocity of all objects.",
"But there is an \"absolute zero\" ... | [
"Apply newtons laws and see that they dont line up with reality unless you introduce fictitious forces arising from your rotating frame. If they do work okay without them, your frame isnt rotating"
] | [
"A zero rotational frame is a rotational frame in which a light beam never makes a spiral, no matter how you orient the beam."
] |
[
"As we age, do our organs lose transplant value? If they do, are there any with more longevity? Like, a 70 year old heart might not be desirable, but maybe kidneys or something else retain some value despite age?"
] | [
false
] | null | [
"Short answer yes, they basically retain their age. ",
"That is why there is a large shortage of donated organs even though old people die all the time. You can not transplant a 80 year old kidney in a 20 year old. If we could do that, organs would be a dime a dozen. ",
"You can of course transplant a young org... | [
"Lung/heart units are the worst organs as far as degeneration, then small bowel, then livers then kidneys are more resilient IIRC from my transplant rotation ",
"Skin is not transplanted directly as skin. Instead the cells are stripped out and the underlying tissue matrix is used for tissue re-enforcement. So thi... | [
"That's interesting. It makes sense, but I had no idea. Does it apply to all organs? I mean, I've heard things about the amazing resilience of livers, does a liver hold up better than a lung?",
"Also, I'm kind of surprised by the idea that skin and corneas would hold up, since they seem to visibly degenerate t... |
[
"Hey /r/askscience, I'm having a hard time understanding how force carrier particles (gluons, etc.) work, can you help me clarify?"
] | [
false
] | First of all, I am having a very hard time understanding how a particle travelling between two points (such as a gluon or a graviton) can transmit a force that has the effect of "pulling" the objects together or closer, as is apparently done by the Strong force and Gravity? Secondly, I am wondering if the force carriers of the EM field are the photons? And if Gravitons are the force carriers of gravity and the curving of space time? And last I have what might seem as a bit odd question. How can gravity pull on photons if photons are massless particles that are moving in the speed of light, just as gravitons are. In another perspective my question is like this; If I am driving my bike trying to push my friend who is also biking. We are driving at the same speed. How can I (Graviton) catch up with my friend (the Photon) and push him? I know Gravitons are a theoratical particle, put my question on how gravity can influence light still stands. | [
"There is a general miscommunication between experts and lay people that leads to your confusion. That miscommunication is the couching of forces in terms of \"virtual particles.\" This is misleading on a number of fronts, but I'll just say that \"virtual particles\" are the result of a mathematical tool, and not a... | [
"Yes you are confused due to poor pedagogy (this is a frequent confusion). The Casimir effect is evidence for the existence of quantum fields that fill the vacuum of space. It is evidence for this vacuum having physical properties. The Casimir effect can be calculated without ever talking about \"virtual particles... | [
"Lowly undergrad here. You say that virtual particle exchange is 'unphysical' and should not be taken literally. It had been my understanding that the Casimir effect proved that these virtual particles do exist and are a physical effect, not just a mathematical description or am I confused?"
] |
[
"How far back can we successfully recover DNA?"
] | [
false
] | With the new , I often wonder if scientist have ever found a way to really mine DNA from amber or some other source. I remember reading in the past there's a finite limit no matter how ideal the conditions. DNA has a half-life of several hundred to 500 years? As of today, are there any new innovations which could push the envelope? I'm only getting older and I need to clone my reclassified Brontosaurus today! | [
"Depends what you mean by recover. ",
"This",
" happened last year - it was still fully functioning. As for recovery of DNA from organisms no longer living - much much older - ",
"See here",
". "
] | [
"Really cool, scary, but cool. Yea, so here's the ",
"half life excerpt",
", but a few years prior, ",
"they did find soft tissue in a T-Rex bone",
". Scientist were able to ",
"sequence the soft tissue samples",
". Apparently, if there's enough ",
"Iron content",
" in the dino's body, it can help... | [
"Well according to the article they sequenced the protein rather than the DNA, though even that is really really impressive. "
] |
[
"Does temperature affect how sound travels?"
] | [
false
] | I feel like I hear things more clearly on a cold winter night. | [
"Sound travels faster in warm air, because soundspeed (c) is given by:",
"c=√(ΥRT/m)",
"Where Υ, R, and m are the ratio of specific heat for air, universal gas constant, and molar mass of air, respectively. And T is the absolute temperature. Because R is a constant and both Υ and m are determined by the gas, so... | [
"That's actually a misconception about sound. the sound speed I gave was specifically for gases, but a more general form is given by c=sqrt(B/rho) where B is the bulk modulus (stiffness) and rho is density.",
"In other words, density actually causes sound speed to ",
", not increase.",
"The real reason why li... | [
"Yeah, it travels faster in warmer air. An empirical formula is v=331+0.6T with v in m/s and T in degrees Celsius."
] |
[
"How is Gravitational Potential Energy Stored?"
] | [
false
] | [deleted] | [
"The potential energy is not stored in the object, it's stored in the gravitational field. ",
"On a separate note, I may be being stupid here but does applying a force not require energy.",
"Applying a force doesn't require energy, energy is required only when that force is applied through some distance. That m... | [
"because if force carrying particles are needed, then it requires energy",
"You need to elaborate on this, because it seems like you have a misconception of what force carrying particles are."
] | [
"because if force carrying particles are needed, then it requires energy",
"You need to elaborate on this, because it seems like you have a misconception of what force carrying particles are."
] |
[
"Circular weather pattern around large cities only at night."
] | [
false
] | Hey AskScience. I recently started the night shift in a NOC and in monitoring the weather I've noticed that as night falls across the US, strange circular formations crop up over many large cities, especially in the midwest. Here's a national radar image from a few minutes ago, from radar.weather.gov: None of my colleagues know what causes this either. A search of the reddits reveal a few similar questions over the last year but no answers, just speculation. My colleagues and I have speculated that it's caused by an increase in humidity at night, but that doesn't really explain why it's primary located around high-population areas. Is this an actual meteorological phenomenon or is it the result of some fundamental issue with current radar technology (considering weather radars tend to be located in high-pop areas)? If anyone knows about weather radar tech or meteorology, if you could help us satisfy our curiosity we'd really appreciate it! | [
"UPDATE!",
"A colleague with superior google skills figured it out.",
"It's caused by many nocturnal species of birds that tend to migrate southward behind cold fronts. Their nocturnal migration appears around radar locations as a circular formation with radars that are behind a cold front showing larger, darke... | [
"This is not the only reason. If you look at a specific radar image from NOAA, youll see from the debug info that the radars go into \"clear air\" mode overnight, making them more sensitive to reflections. Sorry that I can't get you a link, because I'm on my phone. But this combined with your info (as well as insec... | [
"I've heard of this sort of thing referred to as a \"bird-burst\". It's surprising to see them happening over so many regions simultaneously."
] |
[
"If I drive my car at a constant velocity, then take a turn around a corner, I feel the force of acceleration. Assuming that the earth is traveling a constant velocity (universe expanding etc.) and yet it \"turns\" around the sun, why don't we feel this acceleration?"
] | [
false
] | null | [
"EDIT: Whoops, my bad. Thanks for all the comments below me. Earth is in free-fall around the Sun, so there is no centrifugal force because you are ",
" in free-fall around the Sun and glued to Earth by its gravity. ",
" if you're on the side of Earth that faces towards or away from the Sun, you will get very s... | [
"What? There is certainly acceleration in orbit; it's just that the ",
" acceleration is that due to gravity."
] | [
"See ",
"proper acceleration",
". An object in freefall does not undergo any proper acceleration - which is a sufficient answer to why one doesn't feel any acceleration."
] |
[
"If there is an Earth-like moon orbiting a gas giant in the habitable zone, would we be able to find it?"
] | [
false
] | null | [
"There are several projects currently trying to find large moons orbiting planets discovered by the Kepler mission. They're trying to discover the moons similar to the one used to discover the planets – the transit method. When the planet appears to pass in front of its star, we see a decrease in the amount of ligh... | [
"Right now, it could mean either. I would say that their sample size is a bit too small to say that there aren't any, but it would suggest that either: (1) not all planets that could host habitable exomoons actually host exomoons or (2) if they do, they're typically smaller than Earth."
] | [
"Does that mean they might be too small to detect? Or that there isn't any? "
] |
[
"How/Why did it snow in the Sahara Desert just very recently?"
] | [
false
] | I've seen the same pictures on a lot of different media that it has snowed on the Sahara Desert ( ) and that it hasn't snowed in about 40 years. So, how did this happen and why? | [
"Hi, I am a german meteorologist with not much experience in forecasting weather in desserts or in Africa (mainly not that exciting anyways), but the main reason is explainable. Obviously it's true, that weather is weather as the others wrote, but of course there is also a scientific reason. This explanation is bas... | [
"A desert is a large continuously-dry place, and therefore hostile to - and generally barren of - most life. \nBut \"dry\" desert terrain can include never-melting ice / snow. For example: Antarctica, with its massive blizzards and snowfalls is also a desert - its bitter-cold, dry interior is loaded with snow - m... | [
"So what happened is that one of these waves (they can reach pretty far south on the northern hemisphere in winter) ",
"This is the really important bit. We tend to think of the idealized planetary-scale circulation in terms of Hadley cells: warm air rising at the equator, moving towards the poles aloft, falling ... |
[
"why are most consumer drugs dosages in two pill form?"
] | [
false
] | every painkiller type dose is 2 every anti-gas pill, anti-diarrheal, anti-histamine etc. why wouldn't they just put the same amount of medication in one pill? is because then the pills would be too large to swallow, or the body will absorb it better if the medication came from more than one source? or is it a marketing thing, so that when you buy a pack of 30 caplets, you think that you're getting twice the amount than you really are, 15 doses? | [
"This is not the correct answer, the OP is wondering why dosage is often \"2 pills\" that are taken simultaneously."
] | [
"IAMA uh person. ",
"why wouldn't they just put the same amount of medication in one pill?",
"Diphenhydramine is a common anti-histamine. It comes in 25mg doses in most OTC preparations. When it's combined with acetaminophen it's generic name is ",
". A tylenol PM pill contains 25mg of diphenhydramine and 500... | [
"Metabolic half-life. In order to maintain levels of a drug in the body at a certain (medicinally effective) level, dosing must be repeated at specific intervals in order to achieve the desired benefit of a drugs. Taking too much would accrue side effects. "
] |
[
"Can bugs get fat?"
] | [
false
] | null | [
"Recent studies in fruit flies (",
") have found that individuals with mutant forms of an intracellular calcium signaling channel (Inositol 1,4,5-trisphosphate receptor) have significantly altered lipid homeostasis, leading to the storage of excess triglycerides and, ultimately, obesity given a normal diet",
"S... | [
"Fruit flies are commonly used as model organisms for complex eukaryotic processes (even for human systems). In that regard, it would not be surprising if similar biochemical pathways are present in other insects, though it would be unwise to assume so based on a handful of studies on one type of organism, especial... | [
"So would these findings be applicable to all insects?"
] |
[
"Is it theoretically possible for a planet to have a figure eight orbit around twin stars?"
] | [
false
] | null | [
"It would be thoroughly unlikely, because the orbiting planet would act on both the stars, a little bit, and the stars would act on each other. That instability in multiple degrees would probably cause the orbits to decay into each other, and then your figure-8 wouldn’t be.",
"Under ",
" conditions... maybe."
... | [
"Well let’s get real, statistically, every configuration is possible with near infinite opportunities"
] | [
"Most configurations of the 3 problem body are non-periodic. However, some periodic configurations exist, and one of them follows an 8 figure (although it is not exactly the one you are thinking about). You can find more ",
"here",
", along with a nice animated gif."
] |
[
"The half-life of Beryllium-6 is ~5 zeptoseconds. How were we able to determine such a miniscule time?"
] | [
false
] | . To put this into perspective, in that time, . To put into perspective, the empirical atomic radius of a hydrogen atom is . How were we able to determine a half-life that is so short, it could be considered small even at an atomic scale? | [
"This is more of a particle physics question. You have to remember Heisenberg's Uncertainty principle. Not the position and momentum one, but the uncertainty in energy and time",
"(delta E)(delta t) >= hbar/2",
"The reaction they did was probably this",
" Li + ",
" He -> ",
" H + ",
" Be",
"and the ... | [
"/u/FoolishChemist",
" answered it correctly. It has too short of a half-life to measure using conventional methods."
] | [
"I wonder if this is how they do it.",
"I wouldn't imagine so. I can certainly see it for long half-lives where you can take a large sample, observe it for a length of time and extrapolate from there.",
"Going the other way seems like a trick though. It's not like you'll have a large sample at any given time an... |
[
"Are we humans really that much more intelligent than other species? How much of our perceived intelligence can be attributed to inherited knowledge and experience?"
] | [
false
] | I'm not sure how one would go about measuring something like this or if it's really comparing apples to oranges, but it is something that intrigues me. Certain animals certainly can, at the very least, appear to be highly intelligent but the best cases always seem to involve human training. It's obviously taken us a long time to get where we are today as a species but I get the feeling that our perceived dominance over all other life in terms of intelligence can be largely attributed to a very small number of traits - sort of like the total being more than the sum of the parts. This makes me think that certain animals, such as Dolphins or Elephants given a few hundred thousand years or so (just as we have had) could possibly rival us if only they had an effective means of writing (hands/opposable thumbs) because I think the recording of information for future generations is the biggest contributing factor to our intelligence. Here's some more anecdotal evidence - from time to time (actually pretty damn regularly) we all do stupid things. When I really think about what it is that I know and consider myself intelligent for I cannot attribute to myself and are all things that I have learned from other peoples trials and tribulations. TLDR; Are we really that intelligent? or just standing on the shoulders of giants? | [
"Humans had fully-developed language long, long before the first writing system was invented. Writing arose around 3000-6500 BCE, depending on what you count as a writing system, whereas the estimates for the emergence of spoken language range anywhere from 50,000 to 2-3 million years ago. ",
"Presumably, we ha... | [
"Great post. How long is it thought to have taken between the emergence of \"identifying grunts\" and simply naming things to the emergence of spoken logic? Example, not merely having a name for herd of caribou, but being able to tell your children that the caribou will return once it gets warmer."
] | [
"My understanding is that we really aren't that much smarter. We have just enough of an edge in being able to teach, learn, read, and things like that. This lets us build up knowledge beyond what can be learned and memorized by a person in their lifetime. And the amount of new knowledge that can be generated is ba... |
[
"What sorts of things exist between the Galaxies in intergalactic space?"
] | [
false
] | Do planets exist there? Is there dark matter there? Are there black holes there? I am really interested in what things we have observed and what things are predicted to exist there. | [
"Nothing much. A hydrogen atom every cubic meter or so. It's really quite boring for the most part.",
"Here and there you'll find some rogue stars. There are three main ways that a star can get ejected out into intergalactic space. ",
"Hypervelocity stars",
" are stars which are thought to be ejected by 3-bod... | [
"Approximately one hydrogen atom per cubic meter.",
"There are ",
"occasional stars",
" that have been ejected from their home galaxies. How stars do this is ",
"not fully understood",
". ",
"Any planets hypervelocity stars once had are probably moving at a significant percentage of the speed of light, ... | [
"Nothing much. A hydrogen atom every cubic meter or so. It's really quite boring for the most part.",
"Well... the ",
" is very low, but it looks like almost half of the baryonic mass of the universe is in this hot intergalactic medium."
] |
[
"Do new social insects learn from their peers or is their complex behavior mostly or entirely genetic?"
] | [
false
] | [deleted] | [
"Queen Mary University of London has done such studies, showing that worker bees learn from observing other worker bees:",
"Real paper: ",
"http://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.1002564",
"Associative Mechanisms Allow for Social Learning and Cultural Transmission of String Pulli... | [
"I don't know about any purposeful experiments like that, but most ants, wasps and termites have their colonies started by a single queen (that is, the swarming behavior of bees is unusual) and newly hatched workers probably can't learn any complex behaviors (especially related to the outside activities) from the q... | [
"I don't know about any purposeful experiments like that, but most ants, wasps and termites have their colonies started by a single queen (that is, the swarming behavior of bees is unusual) and newly hatched workers probably can't learn any complex behaviors (especially related to the outside activities) from the q... |
[
"Why are there only small dinosaurs such as Chickens,Ducks and Geese the only one left?"
] | [
false
] | Why didn't the dangerous live? or did the these Birds evolve from dangerous to harmless? | [
"Worth noting that the oxygen hypothesis for mage fauna is not at all supported by what little evidence we have."
] | [
"Worth noting that the oxygen hypothesis for mage fauna is not at all supported by what little evidence we have."
] | [
"Just pulling this out of my bum, but I would presume after a disaster like this there is far less food to go around. Smaller creatures need to eat less to survive so they manage to hang in there while the big creatures and predators no longer have the resources (food/prey) available to sustain themselves."
] |
[
"Can you miss something by a molecule?"
] | [
false
] | As in, if I was bowling could I miss hitting a pin by a molecule? | [
"I don't know about bowling, but there's a technique called non-contact atomic force microscope where you move a probe very near to, but not touching, a surface and the wigglings of the probe tell you about the surface, without touching it."
] | [
"First off, a molecule isn't a unit of distance. However, if we talk about the size of a specific molecule, then yes. You can miss something by the length of one molecule.",
"If the molecule was a piece of stretched out DNA (a few feet) it's easy to miss a bowling ball by a few feet.",
"If the molecule was a ... | [
"What if the bowling pin was composed of a single cross-linked polymer? Then it might be argued as a 'huge molecule'..."
] |
[
"How long would it take for the water in a toilet bowl to fully evaporate?"
] | [
false
] | null | [
"That depends on a boatload of factors. Atmospheric pressure, temperature, humidity...",
"It could take anywhere from a few days to a few months, and possibly never happen if the humidity was high enough."
] | [
"So assuming houston's current weather (85.6°F, 29.85 in Hg, 72% humidity), how long would it take?"
] | [
"I hate these responses in askscience. Instead of addressing anything about the poster's question just ask for detail upon detail upon detail. Make some reasonable assumptions and give an order of magnitude answer. "
] |
[
"Would it be possible to create a virus that transmits like Ebola, yet has the same pathology as AIDS?"
] | [
false
] | I've always wondered why is that the deadliest viruses have the most optimal routes of transmission, while the slow developing viruses like AIDS mostly spread through sexual contact and blood transfusion. Would it be possible to create a deadly combination of Ebola and AIDS using current technology? If not, is it even theoretically possible? | [
"That's exactly what you want us to think..."
] | [
"I don't think you need to make Ebola any more dangerous. From what I know about Ebola, the major reason that it hasn't killed everyone yet is it is just too virulent. You can't infect that many other people if you die in 2 weeks."
] | [
"Explain your belief that ebola has the most optimal route of transmission. Isn't the goal of the virus to spread its genetic information? Symptoms are just the result of a host trying to eliminate the invader or enhance transmission but they are secondary to the goal of replication. ",
"Hiv infects more people t... |
[
"Why does extreme velocity and extreme mass create relativistic effects?"
] | [
false
] | Is there a connection between higher velocities and high mass objects? | [
"It doesn't. The universe is relativistic (at least to an insane degree of accuracy). The real question is why do slow speeds and low velocities give the approximation to relativity they do. This is due to Taylor expansion basically.",
"As for relation between mass and velocity. This depends on your perspective.... | [
"To expand on this: our intuition is shaped by our environment and we, in terms of the totality of our species history, have lived exclusively in the realm of unnoticeable relativity. This means that classical Newtonian physics is \"normal\" to us. This does not make relativistic deviations unusual, rather it just ... | [
"Special relativistic effects can occur totally independent of the effects of general relativity (essentially we can always choose a small region of space to governed only be special relativity). Special relativistic effects occur because of large speeds, obviously large speeds are easier to achieve with small mass... |
[
"How do: planetary, interstellar, and intergalactic space relate and differ?"
] | [
false
] | [deleted] | [
"Hi there,",
"There are actually differences between these because you're right, space is a vacuum, but it's not a ",
" vacuum. The vacuum part starts around 100km up from Earth, but there's still quite a bit of atmospheric particles as well as particles from the sun in our Solar System, and this is enough to ... | [
"Pretty much- how much a radio signal scatters over a certain distance is determined by the number of electrons in its path. "
] | [
"The reason we see expansion between galaxies, but not planets and stars, is that galaxies are not usually gravitationally bound to one another (exception, galactic clusters). Everything within a galaxy is gravitationally bound together, so as space expands, the galaxy stays the same. If you separated all the compo... |
[
"What causes hair loss from eating disorders?"
] | [
false
] | Is it a high stress level? Or lack of nutrients or something | [
"Malnourishment.",
"When a person’s body is malnourished, such as during an eating disorder, the protein stores in their body become depleted. When this occurs, the body has to make sure that it takes care of essential functions (such as organ function and retaining muscle tissue) above all else. Our hair, which ... | [
"This is true, though there's more to it than just not having protein—a protein-sparing severely hypocaloric period can still involve the same abundant hair shedding, as can non-nutritional events.",
"The term for the whole thing has a name that sounds like it came out of Harry Potter: ",
"Telogen Effluvium",
... | [
"Why does the body target hair on the head and not the bodily hair on the rest of the body. Agreed that there are more hair on the head compared to other parts, but does it also mean that bodily hair is lesser/weaker source of protein compared to hair on the head?"
] |
[
"Suppose I have a balloon filled with Deuterium. How often should I expect quantum tunneling or lucky collisions to merge two of the nuclei into a helium nucleus?"
] | [
false
] | null | [
"So you're asking for the rate of DD fusion reactions at room temperature and atmospheric pressure? Very, very low."
] | [
"Any idea how low? Are we talking weeks or Gigayears per?"
] | [
"If you take the S-factor at zero energy to be around 50 keV b, and the Gamow factor to be around 1 MeV, I get a cross section in barns which is so small that my phone calculator calls it zero.",
"Not to mention that under these conditions, you wouldn't have free deuterons but rather D",
" molecules."
] |
[
"Why did they put speakers on the Mars Curiosity? Surely not just for will.i.am?"
] | [
false
] | [deleted] | [
"I don't think Curiosity has any speakers - it's just going to stream the audio back to Earth.",
"http://www.space.com/17320-mars-rover-will-i-am-song-broadcast.html",
"A lot of news sources are saying it will be played through speakers but it might have just been a misunderstanding that was propagated."
] | [
"\"Though Curiosity has no speakers, it will transmit the song via radio waves back to Earth to be received at 1 p.m. PDT (4 p.m. EDT)\" good call sir"
] | [
"Basically because they decided there probably wasn't anything worth hearing.",
"http://www.reddit.com/r/IAmA/comments/ybmmh/we_are_engineers_and_scientists_on_the_mars/c5u3d45"
] |
[
"Can medicine really be injected into the body as shown in the movies, just stab the syringe into a fleshy area and inject the medicine, instead of searching for a vein like how the regular doctors do it ?"
] | [
false
] | [deleted] | [
"Many medications are given intramuscularly, meaning they are injected directly into muscle tissue. Most vaccines are given this way. More care is taken than just stabbing the patient because the proper location and depth reduces pain at the injection site, but in principle it could just be a fast stick. This is wh... | [
"You usually inject something into a vein when you want a very fast delivery of the substance all over the body or at least to a part of the body that is reached by blood. For example in a hospital setting for rapid relief of severe pain, morphine may be injected into a vein as it can then reach certain areas of th... | [
"There's also subcutaneous injections, which are put into the layer directly below the dermis. It all depends on how quickly you want the drug absorbed and how it interacts with the body."
] |
[
"Digestion/Absorption of Pills: Does Size Matter?"
] | [
false
] | null | [
"The ",
"placebo effect",
" is a powerful one. In many cases, the more involved / invasive placebo elicits a bigger effect than smaller ones. So the bigger pill is more effective, based on placebo effects alone, than the small pill.",
"Unless the two pills have different designs (one for continuous release, f... | [
"Amount of food matters - especially for large, polar drugs. If you have lots of food in your stomach, the stomach will spend some time churning its contents before food is passed onto the intestine - this is called gastric emptying. Many drugs don't cross cell membranes well, so they're not absorbed very much in t... | [
"Amount of food matters - especially for large, polar drugs. If you have lots of food in your stomach, the stomach will spend some time churning its contents before food is passed onto the intestine - this is called gastric emptying. Many drugs don't cross cell membranes well, so they're not absorbed very much in t... |
[
"When a song gets \"stuck in your head,\" what part of your brain is doing the singing?"
] | [
false
] | Sometimes I realize that a song has been "playing" in my head for a while, without me actually consciously thinking about it or even noticing it. Then my normal thoughts are interrupted when I realize I'm "hearing" this song in my head. I feel like this must be similar to when you actively start thinking about something else while reading, but you actually keep reading. Then you reread the paragraph a few times before you actually get your conscious mind back on the words in front of you. Is this another "type" of conscious thought that also happens in the same area of the brain as my thoughts that sit on the surface? Or is it some kind of unconscious thought that happens elsewhere? | [
"Thoughts related to interpreting and producing language are in ",
"Wernicke's area",
" and ",
"Broca's area",
" respectively. They are tightly linked but reside in two different lobes of the brain (frontal and auditory cortex-fissure between temporal and parietal). Language interpretation (what is being ... | [
"meditation"
] | [
"i think that's probably more of a cerebellar or motor area phenomenon. As in, you are doing the motor movements required to move your eyes pretty much automatically but your left hemisphere isn't really processing the information.",
"Audition is produced in the temporal lobes (specifically heschl's gyrus) and me... |
[
"Why are species with dark fur or skin located in warm climate and species with light fur or skin in cold climate? Shouldn't It be the opposite ?"
] | [
false
] | Think a bear or a wolf (or a human but I don’t want to trigger any knee jerk reaction). According to physic a light surface reflects energy and a dark surface absorbs it. Seems to me that a species with dark fur or skin would be better equip to absorb solar energy and remain warm in a cold climate. On the other hand a species with a light skin would be able to better equip to regulate its temperature. It the reason why we tend to dress in white in warm climate. Evolution seems to have taken the opposite direction. Why is that? | [
"Because the fur colors didn't evolve to increase the animal's temperature, but instead to reduce their visability. If they need to be warmer the coat can get thicker, but nothing's gonna help a black fox hide on an Arctic tundra. So the animals who had some mutated fur color could hide better and had a better chan... | [
"It's not reflected, it goes right through. If you look at your skin color, for example, it's not the sort of brilliant white that's actually reflecting a huge proportion of light."
] | [
"I'm totally ripping this off of the cosmos but... typically in colder climates there is snow. And simply put a brown bear is easier to See by prey in a snowy environment. So over time A mutation happens in a brown bears DNA that causes it to have white fur instead. This gives the bear an advantage in a snowy envir... |
[
"Does anyone know if a handy online database of online tutorials to brush up on science ?"
] | [
false
] | null | [
"For maths and to a certain degree science, ",
"Khan Academy",
" is the ultimate source. It has a plethora of videos covering almost all imaginable subjects and a really good regimen of online training exercises for maths.",
"Absolutely worth for as well beginners as the more experienced!"
] | [
"khanacademy.org",
" Go there now, seriously.",
"Perfect for this. You are going to really like it. Lots of subjects.",
"EDIT: Also, there was a list created by reddit for online learning ",
"HERE"
] | [
"Oh man, this is precisely what I was looking for. I knew it existed just didn't know the name !"
] |
[
"Why does corn pop and can you pop anything else?"
] | [
false
] | What makes corn kernels pop into popcorn when cooked on the stove? Can you pop other seeds or is there something special about the physiology of corn kernels? | [
"It's a sudden evaporation of the moisture inside the kernel.",
"I'm certain that it works with wheat and rice as well, as the result is sold as cereal, probably other grains too."
] | [
"You can pop ",
"amaranth",
" "
] | [
"Green coffee beans have two stages of \"pop\" when they are roasted, referred to as first and second \"crack\"."
] |
[
"Is voyeurism a purely human phenomenon?"
] | [
false
] | Or do animals like watching other animals bang? Does it have the same physiological effect on them? On a related note, are there Instances of paraphilia in the animal kingdom, like necrophilia or pedophilia? Or are those also purely human? | [
"This is practically a FAQ here.",
"Animal porn was discussed in quite a bit of detail in ",
"this question from 2 weeks ago",
"Monkeys ... value pornographic material ... showing young male pandas \"panda pornography\" is widely credited with a recent population boom among pandas in zoos",
"And around th... | [
"Well, the need/desire for privacy during sexual activity is considered a fairly unique human trait. I'm pretty sure it was mentioned in [this video])",
"http://www.youtube.com/watch?v=LOY3QH_jOtE&feature=player_detailpage#t=5033s",
"). That would seem to rule out any ",
" thrill associated with watching sexu... | [
"Is that a universal human trait; or a result of some religious / cultural training?"
] |
[
"If you place water and an ice cube in a cup so that the cup is entirely full to the brim, what happens to the level of water as the ice melts?"
] | [
false
] | null | [
"assuming the ice is floating, and not pushed down under the surface, the volume of the ice that is under the surface is the same as the volume of liquid water that has the same mass as the entire ice cube (This is Archimedes' Principle). as the ice melts, its volume will decrease both above and below the surface o... | [
"assuming the ice is floating, and not pushed down under the surface, the volume of the ice that is under the surface is the same as the volume of liquid water that has the same mass as the entire ice cube (This is Archimedes' Principle). as the ice melts, its volume will decrease both above and below the surface o... | [
"He's talking about the volume of water that makes up that ice when frozen is exactly the same as the volume of water that the ice displaces. A bouyant object displaces the volume of water that matches its own weight. An ice cube therefore displaces the same weight in water - and therefore, the same ",
" when it ... |
[
"What happens to the areas of the brain involved in language production and recognition in the non-dominant hemisphere when language becomes lateralised to a specific hemisphere?"
] | [
false
] | I'm currently studying lateralisation that occurs in the brain during human development for a university subject. I understand that approximately 70% of all people, regardless of handedness, have speech lateralised to the left hemisphere of the brain, specifically in Broca's and Wernicke's areas. From what I understand, during development we have the capacity to develop speech in the left or right hemisphere as these areas are symmetrical and non-lateralised. What happens to these areas in the non-dominant hemisphere when language becomes localised to one hemisphere? Do other functions arise in the other hemisphere where Broca's and Wernicke's areas would have arisen? Are these areas still loosely involved in speech or do they control something completely different? | [
"Might be slightly askew to your question but... Right Hemisphere is involved with the discrimination, repetition, and production of linguistic and emotional prosody (essentially the \"rhythm\" of language i.e. how it is said) as well as comprehension of emotional processing. Linguistic prosody is stress on words e... | [
"We think singing can be produced from right-lateralized regions, ",
"as demonstrated here",
".",
"Some of it stays as related to speech - there's some arguments in the rehab literature for the involvement of the right for speech recovery (and also for inhibition of the right). The right region tend to be ge... | [
"There is no distinct Brocca or Wernicke \"area\" on the opposite hemisphere perse - that I can see in the literature (please correct me if this is not the case). By rhythm of language I am referring to how it is said e.g. think about how you ask the same question when you are angry in comparison to when you are ha... |
[
"Does the way that parents treat their child really determine how the child turns out?"
] | [
false
] | When kids grow up, the way they turn out (e.g. slacker or hard-working, disciplined or not) is usually attributed to the way their parents bring them up (i.e. nature vs nurture and all that). But now that we know so much more about the inner workings of the brain and genetics, can we really still calim that? Wouldn't the personality type and character traits be mainly determined by the genotype and neurochemistry, and not the parental upbringing? Is there any data on that? | [
"This work highlights a much more powerful influence from genetics:\n",
"http://www.sciencedaily.com/releases/2012/05/120516115903.htm?utm_source=rss&utm_medium=rss&utm_campaign=character-traits-determined-genetically-genes-may-hold-the-key-to-a-life-of-success-study-suggests"
] | [
"Nice find! Thanks!"
] | [
"The answer is yes. I remember reading a wonderful article about this a few years ago and here it is.\n",
"http://ehp.niehs.nih.gov/1307892/",
"\nThe topic you are dipping into is called 'Behavioral Epigenetics', and is concerned with how DNA is modified through methylation, etc. by things such as early life s... |
[
"Has the invention of shoes changed the anatomy of human feet?"
] | [
false
] | null | [
"Short answer, no.",
"\nFull foot covering shoes are a relatively new thing, only being around for the last 1000 years or so, and before that any type of footwear was usually sandals or similar or just went barefoot. Once you go barefoot awhile your skin thickens to the point you can walk over stones without an i... | [
"What about things like flat feet or bunions? Do shoes increase their incidence?"
] | [
"What about things like flat feet or bunions? Do shoes increase their incidence?"
] |
[
"Why don't we circulate ATP in our blood?"
] | [
false
] | It seems to me that all the conversions between ATP and carbohydrates (the light independent reactions of photosynthesis) and then back again (respiration) must result in a huge loss of energy overall. Why do organisms bother? | [
"http://employees.csbsju.edu/hjakubowski/classes/ch331/oxphos/olcouplingoxphos.html",
"It's actually fairly stable. It is kinetically unfavorable for it to convert to ADP and it only does so normally with the aid of enzymes."
] | [
"ATP is very ",
"ionized",
" because of it's phosphate groups, and therefore doesn't travel through cell walls readily. You'd need a transport mechanism which would probably have to be active because of the rate ATP is utilized (facilitated diffusion would be slow without a lot of proteins, and increasing the n... | [
"ATP has a half-life of about ",
"1 second in blood",
", mostly because of hydrolyzing enzymes. It is a potent signaling molecule in the vasculature and nervous system as well. ",
"You might envision an arrangement where this isn't the case, and ATP is supplied from a central organ to other parts of the body.... |
[
"Why are some grapes sweet and some sour/bitter on the same cluster?"
] | [
false
] | null | [
"Veraison",
" happens in cultivated fruits as well as wild plants. Each grape on a cluster could be at a different level of ",
"ripeness",
"--with the sweeter ones being more ripe."
] | [
"Veraison",
" happens in cultivated fruits as well as wild plants. Each grape on a cluster could be at a different level of ",
"ripeness",
"--with the sweeter ones being more ripe."
] | [
"Thanks for the response!"
] |
[
"Why is a tesseract depicted the way it is?"
] | [
false
] | A few guys at work were talking about Interstellar, and we started talking about all those 'funny physics' - relativity, time dilation, black holes, and, of course, the tesseract. One of them didn't really understand the whole tesseract thing. I understand the challenges and concept behind depicting four dimensional space in a 3D universe, so I tried to explain it to him. This is how I explained it (which may or may not be accurate, it'd be nice to be corrected): I took a piece of paper and drew some grid lines on it. I told him to imagine that this was space. I put a point in the middle and said that we have a light source there, and we flash it. Then, at the first set of grid lines, I drew a circle originating from the point and said that this was one light-second. Then I did it for two light-seconds and three light-seconds. Three concentric rings outwards. "Now," I said, "we have space as two dimensions - left / right, and up / down. If we add time as a third dimension - upwards - and we draw our light rings, what do we get?" Then I drew the . We've now depicted space and time as a 3D object... sort of. I then explained where our comprehension ends: light doesn't travel in two dimensions, it travels in three. In order to understand time from the third dimension, you have to add a fourth, but we're locked in the fourth dimension, unable to move forwards and backwards, only able to experience it at the present. I then more or less paraphrased Carl Sagan's piece on the tesseract, explaining with the flatlanders and how they can only comprehend their own two dimensions, and that while we can project a three dimensional object into their dimension, it will appear 'off'. A 3D cube has perfect right angles and equal sides, but a 2D representation of a 3D cube has all sorts of funny angles and sides of different lengths. Then I drew a tesseract and said that the tesseract, if we made it a 3D model, is a box within a box with the verticies connected. That box is what a fourth dimensional object looks like projected into three dimensional space. Then he asked something along the lines of 'how do we know that's what that represents', and honestly I found myself unable to answer that. I went around looking for Youtube videos where it gets explained better, but honestly, I really don't see anything. The tesseract just "is" depicted as it is, because that's how it's going to be. So, a little help? I'm not sure how to categorize this. I could be astronomy, but not really. It could be physics, but hell, even our understanding of physics doesn't completely work at this level. So let's call it math, because math is what all science boils down to anyway. | [
"I don't know anything about Interstellar so I don't know if I'm missing some important sci-fi context, but as far as why a tesseract is often drawn as a cube-with-a-cube it's fairly straightforward.",
"Start with a point. This is your 0-cube.",
"To go up a dimension, add another 0-cube parallel to the first on... | [
"I think what you're asking is, \"how do we know that a tesseract projected into 3-D space looks like a cube within a cube.\" ",
"tl;dr: projection into spaces of lower dimensionality is a coordinate transformation that maps the 4D coordinates of a tesseract's vertices to some 3D coordinates in 3D space. Those 3D... | [
"Right. When we draw a 3D cube on paper, we're typically drawing it with perspective scaling, where the parts father away are shrunk closer to the center of view, because objects father away reflect/emit less light that hits your retina than closer objects.",
"If we drew an orthogonally aligned 3D cube on paper i... |
[
"Scientists of r/askscience, what are some glaring scientific inaccuracies that everyone understands to be the truth?"
] | [
false
] | null | [
"That glass flows at room temperature. "
] | [
"The big bang was not a bang, nor was it an explosion."
] | [
"This question is probably more suited to ",
"/r/AskScienceDiscussion"
] |
[
"Hi Askscience! Got some questions on black holes!"
] | [
false
] | Hi guys! I'm 15 years old and I'm stupid compared to alot of you, lets start of by saying sorry for my not-so-good english. Ok, 1st question is: As of what I've understood, a black holes is practically the closest thing to nothing as it gets, yet it has an incredibly large mass. How is this possible? If a black isn't "nothing" as i claimed, what is it then? I've maybe misunderstood the word "singularity" (told you, I'm stupid). How large is a black hole actually? Like a football field or? (I'm talking about the actual black hole, so the event horizon is not included). I've read somewhere, that if you got into the event horizon, there is no way back, not even with a magical engine, which can go to whatever speed, because when you get into the event horizon, you won't be able to see anything, and you won't be able to come, because there is something called "spacetime" (i will go to Wiki about spacetime, so don't bother about me not knowing what it is). So my question is, how can this be true, because if you look from outside, you could imagine the core of the Earth being the singularity, and the rest the event horizon the outer parts of the Earth, or am i wrong? Thanks for reading, now, enlighten me! :p | [
"1 A black hole is an object so dense that the escape velocity exceeds the speed of light. Since nothing can travel faster than the speed of light, things can only fall into it; they'll never be escape. This concept applies to light, too. Light is affected by gravity, see. This is part of the theory of special rela... | [
"Basically it's a region in which any path something can take leads towards the center. From the outside, this has the appearance of the thing being black, because light can't escape.",
"Usually a few kilometers across, except for the supermassive ones at the centers of galaxies, which are billions of times that ... | [
"We can do quantum field theory in curved spacetime, but I don't know that anyone has every worked out the dynamics of even a free field for the interior of a black hole."
] |
[
"In regards to superposition, why does observing an object cause it to leave the state of superposition?"
] | [
false
] | I just finished reading THE CODE BOOK which dives into quantum encryption, superposition, Schrodinger's cat ETC as well as what I could find with a brief google expedition. If anyone out there could take the time to explain it to me I would be ever grateful :) | [
"When a quantum object interacts with another object (the \"observer\"), its quantum state becomes entangled with that other object. This is a more complicated situation than the simple superposition it was in before, so phenomena such as interference are modified, and may disappear."
] | [
"Why does the act of just looking at something cause an interaction though? Does our field of vision shoot particles or something? "
] | [
"It has nothing to do with us looking. It has to do with the light that bounces off the object, that might or might not enter our eyes. If we close our eyes, the entanglement (of object with photon) still happens."
] |
[
"How will/Can wide-spread use of wind energy negatively effect the environment/world?"
] | [
false
] | null | [
"First off, I just want to make it clear that ",
" was a miserable failure from a scientific standpoint. I know you said you were aware it's just a movie, but I just want to be clear. Nothing in that turd of a film should be taken seriously. ",
"That aside, the actual question you are posing has been a topic... | [
"Another issue that we're seeing in Nevada is that it disturbs Sage Grouse (if you don't know about the shitstorm surrounding sage grouse, look it up) and can interfere with migration of many animals. Turbines frighten them quite a bit. ",
"Source: I work for NDOW. "
] | [
"Ok. I have time now. ",
"Sage grouse may kinda maybe be endangered, but not listed. So anything that may hurt them (or hurt them more, depending on your views) causes a great clusterfluck. All sorts of projects are going on to preserve their habitats, and turbines interfere with that. "
] |
[
"Why isn't nuclear physics considered to be chemistry?"
] | [
false
] | null | [
"Chemistry is primarily concerned with things at the atomic or molecular level. Nuclear physics is concerned with the nucleus itself. There is a whole branch of chemistry called \"nuclear chemistry\", and what they do is essentially identical to what nuclear physicists do."
] | [
"why is the subject matter of physics so broad, and why isn't chemistry physics?",
"Well, you could say that chemistry ",
" physics. The goal of physics is to understand the natural world. Nature doesn't care how humans decide to divide up the sciences.",
"why was there a need to distinguish between the to wh... | [
"Chemistry is mainly concerned with the electron interactions between various atoms. Anything more fundamental is more physics than chemistry."
] |
[
"How fast would a dyson ring/sphere have to rotate to maintain constant 1g?"
] | [
false
] | null | [
". Also equivalent to ",
".",
"\n∴",
" = ",
" = 14 * 10",
" m",
"\n",
" = 9.81 m/s",
"\n",
" = 117,192 m/s ",
" ",
"This last bit is quite important, since the constant acceleration towards the Sun will negate part of this effect - which is the reason anything in orbit feels as if there is n... | [
"The acceleration is due to the centripetal force on the objects attached to the inner surface. Therefore, it's given by ",
"*",
" , where ",
" is the radius of the ring and ",
" is its angular speed. Since ",
" = 1.39x10",
" m, and ",
" = 9.81 m s",
" , it results ",
" = 8.39x10",
" rad s",
"... | [
"thank you for a great answer. i was thinking about an inner and an outer disk, where one is in a \"classical\" orbit at 308,709 m/s and another spinning faster so it's inhabitants would have \"gravity\". Adding all the accuracy i could conjure, the outer ring would have to be spinning at 425,575 m/s for a g."
] |
[
"Does it seem like there is a gap between published research findings and actual implementation of findings (if applicable)?"
] | [
false
] | null | [
"I work in a field where this issue is turned on its head, but extremely relevant. Scientists often use a \"bad\" numerical technique for their given problem because they haven't read the literature or aren't sufficiently knowledgeable about computers or mathematics to make an informed decision. Oftentimes, a mat... | [
"I'm sure there are other reasons beyond my purview, but sometimes it just comes down to funding (especially in medicine). The cost of bringing a technology or product to market is much more than that of discovering a new gene/reaction/effect in the lab. ",
"Even if an experimental research team seems like it h... | [
"I know that in certain fields, alternative energy being a good example, announced 'breakthroughs' tend to be one dimensional. So, for example, nearly every day there is a breakthrough in battery chemistry, solar panel development, etc., etc.. The problem is these breakthroughs relate to a specific thing: how fast ... |
[
"do quantum mechanics disprove the consapte of CAUSALITY?"
] | [
false
] | null | [
"I like the book ",
" by Shankar."
] | [
"No, QM does not say anything against causality."
] | [
"can you recomand any book/article"
] |
[
"Why do earthquakes take place at a focus/epicenter instead of a plane or line?"
] | [
false
] | Paleo major in college, I just never got this. Why is the eq starting at a point instead of a plane? Wouldn’t the earthquake move the whole block along the fault plane? | [
"This question gets asked fairly often, e.g. the ",
"FAQ on it",
", or ",
"this answer",
" or ",
"this one",
".",
"In short, earthquakes do represent rupture (i.e. slip) of a portion of a fault plane. The hypocenter represents the point on the fault plane where the rupture starts, and the epicenter is... | [
"Just to add. The hypocenter is relatively easy to locate by triangulating based on the arrival times of the first seismic waves at different seismometers. It takes more work to establish how the rupture propagated in the fault plane after that.",
"For small earthquakes, the length of the rupture is comparable to... | [
"Yes, and while automation of routines has really sped up the calculations of the details of the rupture, it's still the difference between having a location for an epicenter literally seconds after the first seismic waves arrive at a few seismometers to several hours (or longer) for enough data to be collected, sh... |
[
"Why does it feel like the body is more prone to pain and why does the body also magnify pain in colder environments?"
] | [
false
] | null | [
"not a medical specialist makes you a laymen, no laymen speculation"
] | [
"not a medical specialist makes you a laymen, no laymen speculation"
] | [
"Yes. A lack of understanding of common knowledge 'facts' can lead to wildly inaccurate extrapolations which, although occasionally correct, mostly serve to confuse and to spread misinformation."
] |
[
"can I see the past if i travel any amount of light years instantaneously?"
] | [
false
] | null | [
"Yup. The only hiccup is, of course, the ability to transverse such a distance. "
] | [
"And of course, the ability to see things in detail from such great distances, which we also cannot do well.",
"According to the Rayleigh Criterion, you'd need a telescope that has a lens with about a 20-light-year diameter to be able to view a 2 m dinosaur from 65 million light years distance."
] | [
"This and the fact that when you arrive, you'd be viewing the past at a great distance. Look at the stars at night. They are tens, hundreds, and millions of years old when the light hits your eye."
] |
[
"Can two ions with the same number of electrons have different electron configurations?"
] | [
false
] | I thought you could have two different electron configurations even if the number of electrons are the same... | [
"Yes they can. Electron configurations can change if the electrons are excited. ",
"Another instance is when a transition metal forms a ligand, the d orbital can spit. Sort of like this:",
"http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch12/graphics/12_17.gif",
"Depending on the gap between the two spl... | [
"It's possible if electrons are excited by light. In an Li+ ion, for example, the usual electronic configuration would be 1S2, but it is possible (but highly unlikely) that light would promote one of those elections to the 2S orbital, giving a configuration of 1S1 2S1.",
"It is also possible if the 'ion' is part... | [
"The ground state is the configuration with the lowest energy. You may have degenerate ground states in which different \"micro\"-configurations all possess the same energy, but you couldn't tell these apart from the outside because, well, they're degenerate.",
"Actually, for different electronic configurations y... |
[
"What is the Delta variants mortality?"
] | [
false
] | I’m seeing 10,000 new cases a day in the UK and no increase in the death rate. Is there good data on the mortality of the delta variant? | [
"A number of factors to consider here:\n1. There will be a delay from new case reporting to hospital admissions to ICU admissions to mortality. Death is a trailing indicator!\n2. A large proportion of the UKs population that is most vulnerable have already been vaccinated, meaning that even if they are infected, ... | [
"I have no data on the mortality rate, but the \"no increase in death rate\" is likely because the cases only started climbing a few weeks ago. The death rate increase (if it happens) typically lags 2-4 weeks behind."
] | [
"In the Public Health Scotland/EAVE II study, Cox proportional hazard regression was used to estimate risk factors for the time from test to hospitalisation among individuals who tested positive. Hospitalisation with COVID-19 was defined as any admission within 14 days of a positive test or where there was a positi... |
[
"How come sewage is so filthy?"
] | [
false
] | [deleted] | [
"Soap doesn't magically \"clean\" something. It solubilizes whatever you don't want - grease, stains, etc. - and ",
" wash it out.",
"If your plate is dirty, does it magically get clean when you dump detergent on it and let it sit? No! You need to ",
" to get rid of it. All the stuff you don't want leaves the... | [
"I know, but what about the water that goes down the drain? Or is it just basically a poo water solution?"
] | [
"What about it? It's a solution consisting of everything you dump down the drain."
] |
[
"How is the suffix of an element determined?"
] | [
false
] | I woke up with this weird question on my mind for some reason. You have some elements ending in "gen" IE: Oxygen, Hydrogren, and some ending in "ium" IE: Cadmium, Helium, Francium. How are these suffixes determined? | [
"Well \"gen\" is ",
" greek for maker, or generator, the word \"Hydrogen\" literally means \"Water Maker\", whereas Oxygen (somewhat misnamed) means \"Sharp (Acid) Maker\"",
"Not too sure what \"Ium\" means, but ^ is where the gen comes from!",
"Hope that helps :)"
] | [
"Wiktionary says it's from Greek:\n",
"http://en.wiktionary.org/wiki/hydrogen",
"\nBut there's also the word \"genus\" in Latin which can mean birth.",
"The -ium/-um is from Latin (Ferrum is Iron for example). The latin names for hydrogen and oxygen are hydrogenium and oxygenium"
] | [
"There really isn't much of a rhyme or reason behind it. Since the majority of the elements were discovered a long time ago their names have been assigned by their discoverers without too much consideration. Check the wiki on ",
"chemical elements name etymology",
" for more info. I can't remember where I read ... |
[
"Could the number of dimensions be infinite?"
] | [
false
] | I'm only of a casual understanding of all of this, so, you know, laugh away. I'm working off of the . We operate spatially in dimensions 1, 2, and 3, moving along 4. If you combine all of space (1,2,3) into a given point, then you can treat dimensions 4, 5, and 6 as if they are spatial, right? If matter is built from something which signifies information, then perhaps a point in dimensions 4,5,6 behaves like a point in dimensions 1,2,3. Perhaps the fundamental building-block of our universe is a point representing dimensions -2, -1, and 0, just as all of our spatial reality forms a building-block in dimensions 4,5,6. Perhaps this proceeds infinitely in both directions, or perhaps it loops in on itself. Any meat on that bone? EDIT: After watching , I see now that I am retarded. | [
"The ten dimensions video is ",
" but pseudo-science. It has ",
" to do with reality.",
"Edit: we just had ",
"this discussion",
" a few days ago about it."
] | [
"Sorry, Maybe I was too harsh. I really, truly didn't intend to embarrass. I'm just more frustrated with the people making these videos and presenting them as fact. Before I learned physics, I would have easily bought into something like this myself. If you take a bunch of fancy words that sound technical, you can ... | [
"You weren't nearly harsh enough. I agree that Jan shouldn't be embarrassed, but that video and the accompanying book are a con job of the worst kind."
] |
[
"Why do the „warm“ and „cold“ seasons happen a bit later than the „bright“ and „dark“ seasons?"
] | [
false
] | 21st of June is the day with the most sun hours, 21st of December the one with the least. So why do the really hot days occur in July and August, and the coldest ones usually in January and February? (I live in Germany, if that matters) | [
"Sunlight heats a place up ",
", it doesn't make it instantly become warm. June 21 or thereabouts is when we in the northern hemisphere get the most sun, so it's also the time when our regions heat up the fastest, but that's not the same as saying that's when they have the max temperature. That only happens after... | [
"For a perfectly sinusoidal heat flow / temperature relationship you would expect the point of maximal and minimal temperature to be exactly halfway between the point maximal and minimal heating",
"I'm not sure this is true. If the earth's temperature on the timespan of a year behaves something like an LTI system... | [
"Right. I had a straight up differential equation in mind: dTemp/dt = Light."
] |
[
"Why do most Mandarins have 11 segments?"
] | [
false
] | I've been counting them for a while, and some have twelve, some have 10, but the majority have 11. Why such a strange number? | [
"The segments of the fruit are derived from carpels which are a part of the flower, so they will usually come in multiples of 3, 4, or 5. The carpel is part of the female reproductive organs and contains the ovules. So each segment will have seeds and the number of different segments will help with seed dispersal, ... | [
"I'm afraid that question exceeds my botanical knowledge. I'm more of an insect kind of biologist. I just happen to know a bit about the citrus because I used to live next to the ",
"National Clonal Germplasm Repository for Citrus & Dates.",
" ",
"Which is probably the world's premier citrus repository. In... | [
"Is the stamen on a flower segmented by number of carpels? Is it possible to fertilize only some of the carpels and get oranges of reduced numbers of segments?"
] |
[
"Why do your lungs get sharp pains when you go running in colder (possibly drier) weather?"
] | [
false
] | I've lived in Florida most of my life and I noticed that when I run in cold weather (it is also drier) I experience sharp pains in my lungs which I do not experience when running in warmer, more humid weather. I have heard others with this complaint and have been told that it does not affect everyone. I have also been told it may have something to do with the cold air interacting with phlegm lining your throat. Can askscience help? | [
"Your upper airway exists to moisten, warm, and filter air. When you are breathing harder, the air spends less time becoming moist and warm in your upper airway before it proceeds down into your more sensitive lower airways. This causes discomfort. However, if this pain is accompanied by shortness of breath or ... | [
"It depends where the pains are, and how long you've been running. Cold weather can induce asthma, and also causes the mucociliary function of the respiratory tract to decrease. Pain can be a sign of vaso occlusion (if the pain is unilateral), maybe it would help if you described it more. It could also just be that... | [
"My best differential would be that the air makes your alveoli less compliant then. When you breathe in too much, you are expanding them past where they want to go, and feeling pain as a result of the increased intrapleural pressure caused by the cold air. Still, I'd see a PCP about it if it's bothering you"
] |
[
"*Nuclear Engineers* Why did Fukushima melt down if the loss of cooling water should actually kill the reaction?"
] | [
false
] | null | [
"Thank you for your submission! Unfortunately, your submission has been removed for the following reason(s):"
] | [
"The flawed premise is that the Fukushima reactors melted down due to an uncontrolled chain reaction, when in reality they were SCRAMmed immediately after the earthquake (which was long before the tsunami arrived).",
"The issue is that the cores continue to produce decay heat even after the chain reaction is stop... | [
"Ok thanks for that. My question was still valid however, in the last part I asked “Or is even a dead reactor still hot enough to warrant continued cooling and can still lead to a meltdown?”. Which you just confirmed to be true, which makes it inappropriate to remove my post, as my premise wasn’t completely flawed.... |
[
"Are breathing exercises generally useful or harmful ? In what context ?"
] | [
false
] | Hello ! I would like the post to stay focused on respiration exercises, rather than practice that include, among other things, monitoring of your respiration. I tried to search for the benefits of respiration exercise, and didn't find much that was scientifically backed, actually I even found some website saying it was a bad idea. So, are breathing exercises useful ? harmful ? In what context ? Edit : Would like more focus on the "are breathing exercise " part. | [
"Could someone who knows more also comment on the notion that deep abdominal breathing stimulates the vagus nerve, which causes relaxation? I've heard this from multiple sources, but nothing I'd consider truly trustworthy, but I haven't been able to find anything debunking it either."
] | [
"Because they're still under the placebo effect of the doctor telling them it can still work, even though they're not under the placebo effect that the sugar pill is an actual drug."
] | [
"Any support for this ?"
] |
[
"What causes light to be emitted as one of the results of friction?"
] | [
false
] | [deleted] | [
"It has to do with ",
"Black-body radiation",
".",
"All matter emits electromagnetic radiation when it has a temperature above absolute zero. The radiation represents a conversion of a body's thermal energy into electromagnetic energy, and is therefore called thermal radiation.",
"Black-body radiation becom... | [
"That is not equal to black body radiation.",
"Black body radiation originates from vibrations of the charges."
] | [
"Agreed. Light can be emitted through changes in electron states, but this is not thermal black body radiation. An accelerating charge produces light, thus vibrating atoms will do that."
] |
[
"Does high cortisol in the body, or a stronger than average cortisol response to external stressors, equate to a person being generally more stressed out? In other words, stress 'causes' cortisol, but does cortisol cause stress?"
] | [
false
] | We know that external stressors and/or stress generally result in a statistically significant cortisol response. Has the opposite connection been shown to hold statistical significance? In other words, stress 'causes' cortisol, but does cortisol cause stress? I'm asking this because I've come across studies in the past about this and general comparisons of stress in urban and rural populations. For example, I quickly found comparing rural and urban upbringings. I'm not well-versed enough to know whether this or other studies on cortisol and cortisol responses directly claim or show that more cortisol equals more stress. | [
"Both. Cortisol is a sign of how aroused the hypothalamus-pituitary-adrenal axis is, which is a central part of the body’s response to chronic stress. But at the same time, neurons in the cortical and limbic structures express corticotropin releasing hormone receptors that act in a kind of feed-forward dynamic, to ... | [
"Cortisol is a hormone that does a lot of things in the body. It is a glucocorticoid and is involved in the regulation of blood glucose. This hormone has been linked to behavioral and cortical arousal (increased levels of hormone lead to increased arousal). One of the main factors in waking from sleep is the secre... | [
"What’s your source on stress inhibiting adult neurogenesis? I swear I read a paper on that exact topic but I don’t remember where. "
] |
[
"As a method for speciation how does \"Oceanic Dispersal\" really work (considering how much ingenuity it takes for humans to survive long periods on rafts)?"
] | [
false
] | [deleted] | [
"You're right, it's a tough question. But the first thing to remember is that millions of years ago, Africa and South America were actually in contact, then split from tectonic movements and have been diverging ever since. So it may not have been several months. It could have been weeks or even days, depending when... | [
"Look at ",
"this frame",
" from ",
"this graphic",
" and tell me that Africa and South America were one land mass 40 million years ago, when New World Monkeys diverged from Old World primates. "
] | [
"Nah, I got the time frame wrong."
] |
[
"Why is epinephrine used to treat severe allergic reactions?"
] | [
false
] | null | [
"Epinephrine is a catacholamine that stimulates the sympathetic receivers (beta 2) in the upper and lower airways, bronchials and bronchi to dilate. During an allergic reaction there is swelling, narrowing and possible obstruction of the airways. In a severe allergic reaction there also is a possibility of arteria... | [
"Great explanation, but it's *catecholamine and *bronchioles. "
] | [
"It also stimulates beta 1 which increases chronotropy (rate) and inotropy (force) of heart contractions which increases cardiac output. That, combined with the vasoconstriction from alpha 1, helps to maintain blood pressure."
] |
[
"Japan has smoking population that is about 1/3 of its total population. How do the they have the second longest life expectancy in the world, when so many people smoke?"
] | [
false
] | null | [
"Epidemiologist here. Just wanted to raise a key point I haven't seen the responses thus far. ",
"It takes a long time for smoking to induce lung cancer. ",
"Peak rates of smoking in a population result in peak lung cancer rates decades (~30 years) later. ",
"For example, lung cancer incidence in Canadian men... | [
"Do you have a source for that claim that 1/3 are smokers? Seems a little high to me. Or possibly out of date. When I moved to Japan (1996) it seemed like the whole country was one large smoking section but there has been a sharp decline in smokers in the past decade or so. In 1996 I didn't think it was odd to find... | [
"Your question is related to what is called the \"Japanese lung cancer paradox\". This is based on the observation that Japanese men smoke more than American men, but have much lower rates of lung cancer. ",
"The exact cause is not known. Speculation includes: \" more toxic cigarette formulation of American m... |
[
"I remember in school we had a PTC test (taste test for Phenylthiocarbamide)... Is this why certain foods, such as coriander, are so distasteful to certain people"
] | [
false
] | (I remember hearing people talk about how they would rather eat dirt than have coriander on there food and there are multiple sites on the internet dedicated to the dislike of coriander) | [
"The ability to taste PTC and a dislike of coriander/cilantro are not controlled by the same genes, as far as we know. This is a qualified answer, because there doesn't seem to be a lot of work on why coriander is disliked. The ability to taste PTC is caused by the TAS2R38 receptor (see ",
"Wikipedia",
"). T... | [
"thank you for this, in follow up, is it theorized that taste preferences in general are due to individuals mutations of specific receptors?"
] | [
"I'm by no means an expert in the genetics of taste perception or taste preference. I just happen to have read about the genetics that affect how people perceive the flavor of coriander.",
"Taste perception (which we were talking about with PTC and coriander) is different from taste preference (what flavors you ... |
[
"If global warming ramps up C02 in the atmosphere, wouldn't that potentially cause plants to grow bigger and faster as it got worse?"
] | [
false
] | I could be completely wrong in my understanding, but from what I assume we are really just worried about our liveable conditions in the environment. When plant life will, like they always have, thrive on warmer temperatures and increased C02 in the atmosphere. It could eventually pan out that we will find it difficult to live in new evolutions in climate change. But from what I gather this only means other organisms will have a better chance to thrive. Kind of like mother natures way of forcing us to stay in-doors, because we couldn't play with the rest of the kids nicely. | [
"While this is partly correct, I would like to point out that this does not really paint the whole picture and leaves out important caveats. This is because CO2 is not a limiting resource for most plants. Nutrients in the soil (like phosphorous or nitrogen) or even water availability limit how much plants grow in ... | [
"One might ",
" plants to do better in higher CO2 concentrations, but realistically only plants where CO2 is the limiting nutrient will have any significant short-term improvement due to increasing CO2 levels. And while this question is ongoing and still very much being studied, it looks like CO2 is only rarely t... | [
"While carbon dioxide isn't usually a problem, there's a reason C4 and CAM plants exist - carbon dioxide is collected by opening the stomata, resulting in water loss. So a higher concentration of CO2 would result in faster acquisition of required carbon, with corresponding lower water loss.",
"Of course, this wou... |
[
"Can someone identify this old circuit diagram I found in a book from 1931?"
] | [
false
] | I found this paper folded up in a book called "Frieder Im Thuringer Wald" with a copyright date of 1931. I'm not sure if the book and the paper with the circuit diagram are related, but they both seem pretty old and fragile. I'm curious as to what the circuit diagram might be. Thanks for your help. | [
"Well first, you're holding it upside down.",
"Using the orientation you took it at, bottom appears to be a radio receiver, three stage tube amplifier. The others looks like alternative amplifier designs and seem half drawn out. It's not a crystal radio, I don't see a crystal.",
"Looks a whole lot like this 3 t... | [
"Yea, someone else said it was upside down as well. I took the pic with that orientation because when the paper is flipped over, the stationary is right side up.But, thanks for the info."
] | [
"That makes a lot more sense. I didn't recognize the vacuum tubes!"
] |
[
"How would donut shaped planets work?"
] | [
false
] | Hello, I'm in fifth grade and like to learn about planets. I have questions about the possibility of donut shaped planets. If Earth were a donut shape, would the atmosphere be the same shape, with a hole in the middle? Or would it be like a jelly donut without a hole? How would the gravity of donut Earth be different than our Earth? How would it affect the moon's orbit? Thank you. :) | [
"I've saved a few sources on donut-shaped planets. (The mathematical word for a donut shape is ",
", by the way. The adjective form of that is ",
" ",
". And if you're interested, the branch of mathematics that deals with neat shapes like this is called topology.)",
"Here's a video",
" that discusses rota... | [
"This reply is a pretty good start. Going to be a while before you can deal with the math. Maybe get a teacher to help you with the higher end portions.",
"Good question by the way. Not many think about things like that."
] | [
"If you look at the formula F = GMm/d",
" it's not actually the center of mass. That's only an approximation. For a donut, you'll still be pulled toward the 'ground' because the gravitational force on your side of the donut is far stronger than the gravitational force from the other side of the donut."
] |
[
"How do the same cacti appear in widely separated deserts all over the world?"
] | [
false
] | [deleted] | [
"There is only one species of cactus that is native to the Old World (and also the New World), ",
" (aka Mistletoe Cactus). It is thought that the seeds were probably distributed to the Old World within the past couple thousand years by migratory birds. The other species of cactus you see outside of the Americas ... | [
"There's also the \"all deserts are the American southwest\" issue which crops up in movies and so forth. The planet has a wee bit more biodiversity than you'd assume from what shows up on the television."
] | [
"There seems to be a common misconception that you can go to the Sahara and see saguaros everywhere."
] |
[
"Does the concept of DL³ exist. Why does it or why doesn't it, and if it doesn't exist, what would make it possible to exist?"
] | [
false
] | null | [
"What is DL",
" ?"
] | [
"Cubic Decilitre"
] | [
"A decilitre is already cubic."
] |
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