title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"Why does stimulated emission release two photons rather than 1?"
] | [
false
] | In stimulated emission, an electron in an excited state is struck by an incident photon. This causes the electron to emit two photons in the same direction and phase as the incident photon. Why does this occur as opposed to emitting one photon in such a manner, and later spontaneously emitting the second photon? | [
"Sort of. ",
"Because energy is quantized, there are discrete energy levels at which the target electron can live.",
"If the electron is in an excited state, and it interacts with the correct frequency electromagnetic radiation (i.e. a photon) the disturbance will cause the excited electron to fall into a lower... | [
"The photon behaves both as a particle and a wave. It's not just a single defined point particle that \"happens\" to interact. It's also an electromagnetic field, that is defined at every point in the Universe. Even though, in some limits,a photon can be treated like it is exactly at one point in the Universe, in r... | [
"That's not how stimulated emission works, the original photon isn't absorbed. Photons aren't just like little particles zipping along and running into things, they are packets of electromagnetic waves, which means that they are composed of oscillating electric and magnetic fields. When these oscillating fields int... |
[
"In the chemical reaction of photosynthesis, all the Hydrogen comes from water. Why is it that additional Hydrogen ions are taken in during the process? Why do Hydrogen ions not build up in the thylakoid because of this?"
] | [
false
] | When I say chemical reaction I’m referring to 6H20 + 6CO2 -> 6O2 + C6H12O6 Edit: To clarify, I know that the chemical reaction has balanced Hydrogen on both sides. My questions is that since this is balanced, the only source of Hydrogen that should be necessary for photosynthesis should be water. Yet, in photosynthesis... | [
"I think the additional hydrogens you are talking about are a part of a proton gradient that is established over the thylakiod membrane as a way to store and utilize the light energy taken in by the chlorophyll. ",
"What is actually happening when chlorophyll absorbs light is that electrons within the chlorophyll... | [
"Thanks for the thorough response. This makes sense. On further inspection it seems the H+ ions travel back to the OH- concentration outside the thylakoid due to the e field or diffusion and they must go through the ATP synthase which makes ATP with that energy. ",
"Looking back at it I think my confusion arose f... | [
"Well the chemical reaction you are referring to is correct. if we are able to radioactively label each of the reactants, we would find the same atoms in the product. It's been a while since i've taken biology but I seem to remember that hydrogen ions are responsible for things other than the direct reaction themse... |
[
"Are arctic mammals cold all of the time?"
] | [
false
] | Why or why not? I was watching a program on polar bears and thought, "Wow! They must be freezing!" Then I realized if it were that big of a problem, they probably would have migrated? I hope this isn't the stupidest question you've ever heard... | [
"I think you're getting downvoted for your third paragraph, which is a shame because no-one else has commented on the excellent point you make in your second paragraph.",
"Discomfort is an adaptation too, to induce a behavioral remedy to a survival challenge. If there is no behavioral remedy, discomfort is pointl... | [
"yeah but do they feel cold all the time? do they perceive cold as we do?"
] | [
"Those animals which do not migrate in winter and those in areas where weather can get below freezing... so most of Canada, Russia, and parts of USA for example, have special adaptations to deal with freezing temperature, lack of food and lack of fresh water (snow is difficult to eat, and often access to running fr... |
[
"Could someone explain exactly how enzymes work?"
] | [
false
] | null | [
"Enzymes are protein or nucleic acid complexes that through their structure lower the potential energy required to leave one steady state and move to another. Furthermore an enzyme can use potential energy stored in one molecule to force a reaction in another molecule from a low energy state to a higher energy stat... | [
"Enzymes work in a sort of lock-and-key relationship with their substrate or substrates. When a particular substrate bumps into its matching enzyme, some weak bonds form causing changes in the enzyme's shape as well as the substrate's bond energies. By doing this the enzyme becomes an environment in which a parti... | [
"Enzymes lower activation energy for a given reaction by facilitating the transition state between substrate and product.",
"The transition state is the high-energy intermediate between substrate and product. If the substrate achieves this state it can without further energy input transition to the product (or ju... |
[
"Why do films look so strange and unnatural when displayed on monitors with extremely high refresh rates?"
] | [
false
] | A few years back, I remember seeing The Empire Strikes Back playing in the window at a high-brow electronics store called Bang and Olufsen. The monitors were flatscreens and apparently had a high refresh rate. The movie looked as though it was filmed in a BBC studio and was very offputting. I assume if one were born ... | [
"Motion smoothing. The Empire Strikes Back was not filmed at such a high frame rate, but modern TVs can use interpolation techniques to \"reconstruct\" intermediate frames. ",
"Here",
" you can read about the effect and how to disable it on most TVs."
] | [
"Films have been shot at 24 frames per second ",
"since the 1920s",
". You've formed a psychological link between the low frame rate and \"movie-ness.\" A monitor or TV with a high refresh rate might still only show the film at 24FPS, but some modern sets will construct new frames to give the film a smoother lo... | [
"Most films run at 24 fps. Camcorders and digital video recorders often have higher frame rates (say 60 fps). These are often used by sitcoms and cheap TV because they are unable to afford film. Unfortunately, this means that people find higher frame rates look unnatural, and associate them with home movies or chea... |
[
"Does the injection site affect which cells express the spike protein from the mRNA Covid vaccines?"
] | [
false
] | null | [
"Most important cells are in the draining lymph nodes and details of injection site won’t change that"
] | [
"Is there a paper/study that can expand on this further? This seems to be in the direction of what I was asking..."
] | [
"previous questions in ",
"r/askscience",
" list some of the relevant literature"
] |
[
"Hey fellow scientists of /r/askscience, I've started a subreddit to help increase access to articles for those doing research. Need an article fast for an article/grant but your institution doesn't have access? Maybe a redditor can help"
] | [
false
] | ILLiad can be slow and you might not get the article you need in time but for a while now I've been asking friends at other universities to get me an article their school has access to that mine doesn't and I figured this sort of exchange could benefit others. I've created the subreddit to facilitate this exchange. A... | [
"See also ",
"/r/scholar",
"; most of the requests I've seen have been fulfilled quite quickly."
] | [
"While I think this is a fantastic idea I'm pretty sure it violates the licenses of those websites so I don't think it would fly on reddit. I am not an expert in this though.",
"I sent him the paper. I will help out other people assuming I don't get swamped."
] | [
"This is a good idea! I would help out when I can, provided I don't get swamped with requests, I already do this for a number of colleagues at smaller institutions with more limited resources.",
"Unfortunately I do not have access to the article you need but I have some knowledge about brain microdialysis if you ... |
[
"How does symmetry give rise to forces in Quantum Mechanics?"
] | [
false
] | I have read somewhere that forces are caused by symmetry groups of Quantum mechanics. Can anyone explain intuitively why this happens? | [
"I'm pretty sure OP is referring to Gauge Groups like SU(3)xSU(2)xU(1), which describe the standard model forces."
] | [
"The simplest example is that local U(1) gauge symmetry of electrons implies the existence of photons. There's a global gauge symmetry in the Schrodinger equation that says you can multiply the wave function by any phasor (magnitude one complex number) and still get the same answer. If we want to make this a local ... | [
"If you frame your description of the physics in a particular way it can look a bit like the symmetries cause the forces, but you can argue how useful that perspective is.",
"For example, you could write down a theory of free non-interacting electrons and positrons (or any spin 1/2 particle/antiparticle) which ha... |
[
"It's accepted that quantum entanglement can't be used to transmit information, but is there any reason it can't be used to coordinate action?"
] | [
false
] | Alice and Bob both have an entangled photon. Before heading off in separate directions with their respective photons, they agree that positive spin means buy milk, negative spin means buy bread. Hasn't this allowed them to do something they couldn't have done before? That is, separate by an arbitrary distance and the... | [
"What specifically is Bob or Alice doing that even requires entangled particles here?",
"You might as well seal two envelopes with instructions for one for milk and one for bread and give each of them one envelope at random. The entanglement is needless complication."
] | [
"I mean you could do that too with the envelopes. Also, ",
"do the same thing at the same instant in time regardless of how far apart they are",
"I can arbitrarily rig a reference frame that this is true as well as reference frames where this is false. Simultaneity of independent events (correlated or not) is ... | [
"I think I see what he's getting at.",
"Create an entangled pair of photons in phi plus bell state and send one photon to Alice and one to Bob, who are widely separated. Alice and Bob both agree to measure in a diagonal basis before hand, so they know that their outcomes will be correlated. If Alice measures |+... |
[
"How did scientists contain something 4 million degrees F?"
] | [
false
] | [deleted] | [
"\"Temperature\" in this sense is somewhat misleading, it's really just derived from the mean kinetic energy of a set of particles with an energy distribution. If you multiply the temperature in [K] by Boltzmann's Constant (8.617e-5 [eV/K]), you'll get the average kinetic energy in electron volts. For a fusion reac... | [
"You use a magnetic field to trap the (electrically charged) particles."
] | [
"The surface of the sun is only 5000K, so that's not really very much compared to temperatures achieved on earth.\nThe fusion core under construction in france (ITER), for example, will reach temperatures of up to",
" 150 million K.",
"They achieve those temperatures using three different types of heat generato... |
[
"Is there a difference between taking short or long breaths?"
] | [
false
] | [deleted] | [
"There is a major difference. Total lung capacity is about 6 liters. 150 ml of that space is anatomical dead space (nasal passages, oral cavity, etc) and doesn’t participate in gas exchange. This means rapid shallow breaths are a waste of perfusion to the lung. ",
"Second, rapid shallow breathing removes more CO2... | [
"Actually yes! There is multiple steps that happen when you breath in. First you take in air which your body processes the oxygen out of. But the big thing is that is removes the carbon dioxide from your body back into the air. Taking short shallow breaths can lead to a build up of carbon dioxide in the blood. This... | [
"Taking short shallow breaths can lead to a build up of carbon dioxide in the blood. This is done by increasing the flow in of oxygen but not allowing your body to process and remove the carbon dioxide from the body. This will cause dizziness due to this build up.",
"What would be the mechanism behind that? I've ... |
[
"Why is the ozone layer thinnest around Antarctica, why is ozone depletion not evenly spread around the world?"
] | [
false
] | null | [
"From wikipedia:",
"http://en.wikipedia.org/wiki/Ozone_depletion",
"Reactions that take place on polar stratospheric clouds (PSCs) play an important role in enhancing ozone depletion. PSCs form more readily in the extreme cold of Antarctic stratosphere. This is why ozone holes first formed, and are deeper, over... | [
"Ozone Depletion also takes place particularly within the ",
"polar vortex",
" of the southern hemisphere.",
"The chemistry of the Antarctic polar vortex has created severe ozone depletion. The nitric acid in polar stratospheric clouds reacts with CFCs to form chlorine, which catalyzes the photochemical destr... | [
"Chlorine radicals cause ozone depletion. These are all over the world. Now, the question is not only why the ozone hole is over Antarctica, but also why it ",
"only becomes significant in Spring",
". This is because the chlorine radicals get 'tied up' in compounds which do not cause ozone depletion. They form ... |
[
"Is there a reason we do not put our Depleted uranium/fuel rods on the moon, or in space?"
] | [
false
] | Was watching aftermath and was talking about some of the bi-product of nuclear energy and it's storage lastings hundreds and thousands of years, so I was wondering why don't we put them in space where it is constantly cold or into the sun? | [
"It's extremely expensive to launch things into space, especially given the number of launches it would take to remove all the waste accumulated over the past 60 years. Also, if a rocket exploded during launch, radioactive waste would be strewn over a wide area. Aside from that, it would be an effective long-term s... | [
"At about $20,000/kg and 3,000 short tons per year, it would cost the US about $60 billion annually just to get our waste into orbit."
] | [
"Plus depleted uranium is useful in a number of applications, mostly due to its enormous density.",
"It's 1.67 times as dense as lead.\n",
"http://www.wolframalpha.com/input/?i=density+lead+vs.+uranium",
"Plus I think you are associating nuclear waste with depleted uranium, and while it certainly is a by-prod... |
[
"If I were to make a mechanical clock from scratch, how would I know how long a second or a minute actually was?"
] | [
false
] | [deleted] | [
"You wouldn't. A second is an arbitrary measure; while it has been defined in terms of fundamental physical constants, it's not possible to measure the resonance of cesium with a purely ",
" clock."
] | [
"I would try to get the number of seconds between two consecutive sunrises to match what the daily paper and/or an astronomy website says the interval should be. Are you contemplating a primitive scenario where you have no access to a paper? Hmmmm... You may need a longer calibration period than one day."
] | [
"bit of a late reply, and you probably won't see this, but a 1 meter pendulum is roughly 1 second per swing.",
" "
] |
[
"Why is my pee omni-directional somtimes"
] | [
false
] | null | [
"Most men only use their penises for two activities, which means that men generally ignore what their penises are doing the rest of the time. Despite your best efforts (or possibly because of them) you will see or think of something sexually stimulating during your daily activities (or accidentally rub up against s... | [
"Thank you very much"
] | [
"You're right, It's not the Testicles that regulate the temperature of the sperms, it's the scrotum. "
] |
[
"What is the purpose of facial hair and why don't women grow it?"
] | [
false
] | [deleted] | [
"Everybody is a mutant, otherwise we wouldn't be people."
] | [
"This paper ( ",
"http://www.frontiersin.org/behavioral_neuroscience/10.3389/neuro.08.045.2009/abstract",
" ) posits that human beards and lion manes evolved convergently- to protect the male from intra-species attacks. Women wouldn't grow beards because it is men who were competing against each other for mate... | [
"From the cited paper:",
"Like the lion’s mane, male beards are widely assumed to be somewhat adaptive in the context of providing a visual aid to identification of gender at a distance; in advertising social dominance; or as sexually attractive to women (Barber, 1995 )",
"As an Asian man who cant grow a beard,... |
[
"Women between 65-69 are 5 times more likely to die after a hip fracture. Is it the fracture itself or something else that leads to increased mortality?"
] | [
false
] | [deleted] | [
"Combination of things. ",
"One is that after a hip fracture, a person is less likely to be very active, and being active correlates to a longer life. So in a sense the fracture caused that decline in life expectancy. ",
"A much smaller number might have complications related to the fracture, or to the treatmen... | [
"From what I recall from my bachelor course where we talked about this, it isn’t the fracture itself but other factors. A hip fracture alone, you are likely if it is a particular bad one to do some serious damage to your femoral artery as well, if you sever this artery you’re going to bleed out in something like 10... | [
"The hip fracture population has mortality rate approaching 20-30% at 1 year post fracture. This high mortality rate can be attributed to a few factors.",
"Pre-existing illness: People who fracture their hips from a fall from standing height are usually already frail. The fall and fracture can be a result of poor... |
[
"If there was another planet with the same orbit time as Earth, would we know?"
] | [
false
] | Hey all, If there was another planet with the same amount of time to orbit the Sun as Earth, but was on the far-side of the Sun, would we know? Dan O. | [
"Yeah, because Earth's orbit is elliptical and not circular we would still see it at times. Also, the probes we've sent to Mars and Venus and other planets would not have reached their destination if there was another planet on the other side."
] | [
"The elliptical/circular thing doesn't necessarily mean that we'd see the planet - if it had the same eccentricity that the Earth's orbit does, and has the periapsis line up with the Earth's periapsis, then we wouldn't see it because it would still always be opposite the sun.",
"Also, the ",
"Hill sphere",
" ... | [
"Yes. For one thing, it wouldn't be able to stay exactly in the same orbit over time. Perturbations from other planets would delay it or speed it up, so eventually it would become visible, and really it would eventually wreck havoc with the Earth's orbit. For another, it would perturb the orbits of other planets so... |
[
"Why are we able to eradicate some diseases via vaccines but not others?"
] | [
false
] | Humanity was able to eradicate smallpox in the wild thanks to a worldwide vaccination campaign. Obviously, we are far less successful with influenza. Is this due to the mutations/strains of the influenza virus making eradication impossible? If so, does the smallpox virus not have similar mutations? | [
"Only two diseases have been eradicated: Smallpox and ",
"Rinderpest",
", which is a disease of cattle. ",
"Guinea worm, a parasite disease of humans, is ",
"close to eradication",
", although there were some setbacks this year. Polio is also on the track toward ",
"eradication",
".",
"Polio, rinder... | [
"When it comes to influenza specifically, the big number of strains comes from the fact that influenza virus has a fragmented genome. That enables it to exchange some parts of its genome with different ones in case a human or animal is infected with two or more different strains. That's why we have lots of differen... | [
"most virusses and bacteria have what we call a reservoir, an animal or the soil which allows them to replicate or survive. For example the clostridium tetani bacteria can survive years in the soil. We will probably never be able to eradicate those diseases completely.",
"Some pathogens however have no such thing... |
[
"Why is coconut oil supposedly healthy?"
] | [
false
] | So I've seen the new "fad" (for lack of a better word - if it is based on sound science, I suppose it isn't a fad...) in the health food stores of selling coconut oil as the healthiest oil for cooking. What is the reason it is supposed to be healthy? Coconut oil is a saturated fat, which in epidemiological studies have... | [
"Perhaps you already know all this, but the main thing with MCTs is that their intake promotes their oxidation. This is in complete contrast to LCTs, which are preferentially directed towards storage when other fuels are available. Consequently MCTs elicit a higher thermic effect than \"normal\" dietary fats, and t... | [
"Actually, if its a saturated fat, by definition it is not an omega-anything. So any omega-3s in there that skew the ratio towards the healthful ratio would be from the non-saturated portion, which is very small. It would make more sense to stick with flaxseed oil for that. ",
"Flaxseed oil does have a low smoke ... | [
"It's supposed to have more medium chain triglycerides. MCT help alzhimers. MCT are also an alternative, non-glucose way of energy via ketone bodies, i think the advocates also say that this makes you lose more fat because it puts your body into \"use ketone bodies not sugar\" mode.",
"http://www.ncbi.nlm.nih.gov... |
[
"Why is a boat propeller so small compared to the size of the boat it's propelling?"
] | [
false
] | I've grown up around boats all my life and have been wondering this for quite some time. My family's 23ft power boat's propeller isn't even a foot in diameter (from edge to edge of the blades if it were spinning and making a full circle). A 93ft boat that runs charters in my town has 2 props that aren't even 3 feet acr... | [
"While a larger diameter propeller is generally more efficient than a smaller one, the boat propeller size will be typically a function of the boat's draft. The bottom of the propeller should be above the boat bottom, to avoid damaging the propeller against the sea bottom. The top of the propeller should (there are... | [
"I've wondered the same thing, and I don't know the answer. Maybe a better question is \"why is the vehicle size to propeller size ratio so different between boats and planes?\" In that light, I wonder if there is some material property of the fluid that affects the ratio - viscosity or density or compressibility?"... | [
"Suppose you don't care about draft: you want to make a ship that can only sail in deep waters. How large would the optimal propeller be?"
] |
[
"A question about Human cell regeneration."
] | [
false
] | Ok, while watching QI, a question was posed about 'How old are you' and in typical QI fashion it was a trick question, where the true answer was based on the fact that every (roughly) 5 years or so, you regenerate every cell in the body. If this is true/remotely true, do brain cells do the same? And if yes, how do the ... | [
", which is the generation of new neurons, only occurs in certain parts of the adult brain. Many of the neurons you are born with are, in fact, the ones you're stuck with until they or you die. However, even \"permanent\", non-replicating cells need to be replenished; over the course of 5 or so years, every neuron ... | [
"Cells have very varied rates of replacement...so dismiss anything about trying to generalize that.",
"In terms of brain cells, you should understand that there are two main types: neurons and glia. Glial cells do readily divide, migrate, get replaced, etc. whereas neurons are not generally undergoing such a dyn... | [
"every (roughly) 5 years or so, you regenerate every cell in the body.",
"This isn't true, as far as I know. Different types of cells in the human body have different lifespans.",
"Some cells are very short-lived; for instance, ",
"intestinal epithelial cells last about 5 days before they are shed",
".",
... |
[
"Energy equals mass times the speed of light squared. How can light be squared when the answer would be greater than the speed of light? which can't be exceeded?"
] | [
false
] | null | [
"I'm not sure how else to say it... you're saying, essentially, how can E be greater than c? They aren't the same units. So it doesn't make sense to compare them that way. That's like saying how can 10 feet be bigger than 5 kg? Look, you're also multiplying c by m so c*m > c. Again, this comparison doesn't actually... | [
"I'm not sure how else to say it... you're saying, essentially, how can E be greater than c? They aren't the same units. So it doesn't make sense to compare them that way. That's like saying how can 10 feet be bigger than 5 kg? Look, you're also multiplying c by m so c*m > c. Again, this comparison doesn't actually... | [
"186,000 miles/s * 186,000 miles/s is not equal to 355,000,000 miles/s. It equals 355,000,000 miles",
" / second ",
" That is ",
" the same thing as 355,000,000 miles / s. It does not say anything about any mass being accelerated to or moving at c and applies perfectly well to objects that are at rest. (Also ... |
[
"If I gain 10 lbs of fat, lose it, and then gain 10 lbs again, am I \"refilling\" those same fat cells before creating new ones?"
] | [
false
] | null | [
"When you gain weight, your adipose tissue cells swell with fat causing them to greatly expand , then divide if they get big enough. When you lose weight, the cells shrink down to their minimum size as their fat reservoirs are depleted, but the cells themselves remain put. So someone who was once obese and is now a... | [
"http://www.nytimes.com/2008/05/05/health/research/05fat.html?_r=0",
"Every year, whether you are fat or thin, whether you lose weight or gain, 10 percent of your fat cells die. And every year, those cells that die are replaced with new fat cells, researchers in Sweden reported Sunday.",
"The result is that the... | [
"Nice response.",
"Is there any way for your body to breakdown these empty cells?"
] |
[
"While reading the Wiki on \"Project Longshot\", which was a proposed craft to fly to Alpha Centuauri I was stunned to see that the proposal included transmitting data via laser to Earth for the duration of the flight. My question is RE: the accuracy required for such a transmission."
] | [
false
] | . Relevant excerpt: The reactor would also be used to power a laser for communications back to Earth, with a maximum power of 250 kilowatts. For most of the journey this would be used at a much lower power for sending data about the interstellar medium, but during the flyby the main engine section would be discarded an... | [
"The relevant math here is the diffraction limited ",
"\"Airy disk\"",
", which represents an angle of 1.22 times the ratio of the wavelength of light (lambda) to the diameter of the aperture (d). For tiny angles this gives a value for \"feature size\" to be 2.44 * lambda/diameter * distance. If you plug in som... | [
"I'll follow up on this a bit. Let's say you wanted a small fleet of detector satellites around the inner solar system. The technology to pack and unfold large structures in space is pretty well established:",
"http://www.boeing.com/defense-space/space/bss/factsheets/702/702fleet.html",
"The Boeing 702HP tele... | [
"I thought that the definition of a laser is that it does not spread out. Is that true only at short distances?"
] |
[
"How do you easily find updated information on an organisms taxonomy?"
] | [
false
] | While researching Northern White Rhinos I found they might be an entirely new species and not just a White Rhino subspecies. If this is the case, is there any reliable scientific source that can announce this fact if it were to come true. I know of some sources, however they are slow at updating, when an organism is an... | [
"As far as I know there's no comprehensive database for this sort of thing. Tree of Life web aims to do it but is nowhere ",
" to being complete, even for common animals. ",
"http://tolweb.org/",
" Wikipedia has nearly everything but quality is variable.",
"Also bear in mind that you often have constant... | [
"Possibly the NCBI's Taxonomy DB is more compete than ",
"/u/atomfullerene",
"'s suggested TOL link, check ",
"http://www.ncbi.nlm.nih.gov/taxonomy",
"Edit: I double checked, NCBI's Taxonomy DB only covers 10% of organisms I the genbank. So not a very comprehensive list. ",
"Although in both cases these... | [
"So in some sense there's no point waiting for an official declaration. You either won't get one or you will get too many.",
"This really, really depends on the extent to which a clade's taxonomy has been formalised. Solanaceous plants have an active and somewhat formal body of taxonomists who do produce \"offici... |
[
"How does LSD cause hallucinations?"
] | [
false
] | What is the mechanism of action that causes humans to see visual hallucinations after ingesting LSD? Please go as in depth as possible! | [
"I can get you started, but I won't be able to answer all of it. LSD is a serotonergic psychedelic, along with drugs like DMT and psilocybin, which means that it binds to serotonin receptors. It acts as a partial agonist for these receptors, particularly 5-HT2a. Its action at the 5-HT2a receptor site is ",
" resp... | [
"Considering how complicated it is to make in a lab, how the hell did they come up with the formula to make it then? How did they know it would do what it was going to do?"
] | [
"Albert Hoffman's ",
" random experimentation. ",
"Let me explain: Albert Hoffman was a chemist working for Sandoz Laboratories. He was isolating the active components of something called \"ergot\", a fungus that causes hallucinations when consumed in large quantities, along with lots of unpleasant side effects... |
[
"Does any other animal need a \"balanced\" diet, as in can a bird survive by eating only a single insect?"
] | [
false
] | Like is there any fish or mammal that wouldn't be able to survive if they just had a single source of food? | [
"The idea of a \"balanced\" diet is a decidedly human one. See, as we became better and growing a processing our food we didn't have to worry about food scarcity so much. We began to have true options in our diet. Having a choice led many to neglect certain foods that they find distasteful. Meaning they neglected v... | [
"I know I’m abit late to this but yes animals do need a balanced diet, in some sense. Look into Nutritional Geometry and the concept of nutritional rails and how they effect an animals fitness landscape; some animals may actively regulate by eating more of one food than another- if they have choice and eat more tha... | [
"Animals all have different biologies to humans. For example most other mammals produce vitamin C in their livers so they don't need to eat it in their diets. So in this way many animals can be perfectly fine just eating bugs or grass or whatever. They are specifically made to do so.",
"However if we were to figu... |
[
"About when did humans (or our ancestors) begin boiling water?"
] | [
false
] | and before that did everyone just have constant diarrhea? | [
"We really don't know when humans started cooking. Well-educated estimates vary wildly."
] | [
"It's ridiculously huge, like 50,000-2,000,000 years ago.",
"Super early prehistory like this is out of my expertise though, so I'm not really qualified to make judgments about who's right."
] | [
"this article suggests that it could be as old 500,000 years ago: ",
"http://daha.best.vwh.net/boiled/history.html",
"\n(TL;DR see the 4th paragraph)"
] |
[
"I do not understand time dilation. How can a clock on a spaceship move slower than an exact same clock on earth?"
] | [
false
] | null | [
"You always travel through spacetime (a fourdimensional fabric) with the speed of light. ",
". Even now, when you're probbably sitting comfortbly in your chair. But since you are not moving through space, you are moving with the speed of light through ",
". If you now start to move around through space, you hav... | [
"IMO its a bit confusing to say that we are always traveling though spacetime at the speed of light. The technically precise thing to say is \"the magnitude squared of the velocity 4 vector is always c",
" I'm making this pedantic distinction because 4 vectors are not normal vectors. For nomal vectors, the distan... | [
"If the traveling clock has stopped accelerating and is now moving at a constant velocity relative to the earth, both observers would see the other clock as going slow."
] |
[
"What is anti-matter?"
] | [
false
] | Please answer questions like: Where is it found? Do regular-matter elements share properties with its anti-matter counterpart? (e.g. is anti-chlorine poisonous like regular chlorine?) Is it dangerous like it is portrayed in movies in video-games? Is dark-matter the same thing as anti-matter? If not, please explain what... | [
"I like to err on the side of caution and not have to explain that \"it doesn't interact at all\" means \"we don't see any photons and have no reason to expect that we will therefore\". For all intents and purposes, yes, dark matter doesn't interact electromagnetically."
] | [
"Side note: It is REALLY nice to see in the matter of minutes (there are currently six replies to this question and it was posed only thirty five minutes ago) that four of the top level replies have all been lengthy, accurate and well written. Makes me feel all warm and fuzzy :)"
] | [
"The difference between regular and antimatter is that various quantum numbers are flipped. An antielectron(positron) has electric charge +1 instead of -1, antiquarks are antired/antigreen/antiblue instead of red/green/blue, and various other things.",
"It's not really \"found\" anywhere. Cosmic rays have some an... |
[
"When released, does a helium balloon accelerate or travel upwards at a constant velocity?"
] | [
false
] | Also, what would cause the balloon to act in said manner? | [
"The terminal velocity of a helium balloon is about 2 meters per second, according to my calculations and assumptions. It would accelerate until it reaches around this speed. There would probably be some second order effects as the atmosphere gets thinner."
] | [
"Over a short time scale it accelerates until it hits its terminal velocity and rises at that rate.",
"Over a long time scale it will rise into air that is at a lower pressure and less dense. The lower pressure may cause the balloon to expand and the lower air density reduces the balloon's buoyancy. The combinati... | [
"See iorgfeflkd's response above."
] |
[
"Why does Moore's Law, the law that states that computing power approximately doubles every 2 years, advance at such a linear pace if the continuing advancement of computers requires innovative approaches?"
] | [
false
] | How do we keep finding space on flash drives for instance so that their storage capacity continues to increase at such a predictable pace? | [
"I'd say it's a trend. Its fits on a graph over the last 30 or so years and and is projected to continue on the same trajectory "
] | [
"One thing I'd like to point out is Moore's law originally that the same amount of transistors would double in density every 18 months. Due to innovation we changed the law... So it's not really like a law... Maybe a hypothesis?"
] | [
"It's worth noting that Moore's law is no longer active (in processors) and will come to a crashing halt at some point over the next 5 - 10 years - at least with it's original parameters (doubling the density of transistors). This is because Silicon transistors \"go quantum\" if the manufacturing process is 7 nanom... |
[
"Why did Homo sapiens evolve with less hair?"
] | [
false
] | Wouldn't it have been beneficial for the species to have kept its hair as we migrated to colder climates? | [
"The general theory is that we evolved in warm african climates, and then recently migrated to colder climates. When we began to spread out, we had already started wearing clothes. When we where in africa we evolved less hair because it is easier to stay cool with less hair. Humans sweat. Sweat evaporates faste... | [
"There is a common theory that relative lack of hair was a beneficial adaptation, because it allowed for much more efficient cooling. This allows humans to run long distances without fatigue, a trait that is somewhat unique. While there are plenty of animals that can outrun us in a sprint, there are relatively fe... | [
"You would get less sunlight, but I would say hair has more to do with temperature regulation. Skin color has more to do with sunlight absorption and vitamin D synthesis. "
] |
[
"What does a \"two-mile-wide tornado\" mean? Is the funnel cloud literally two miles in diameter?"
] | [
false
] | null | [
"Meteorology graduate student here. We generally measure the size based on damage assessment surveys. Generally the condensation funnel will cover most of the rotation. That being said, extremely strong winds still exist just outside the funnel. The tornado is \"fed\" by what are known as inflow jets. These are ban... | [
"There really isn't a definitive answer to that question. The size of funnels vary greatly depending on conditions. You can have violent EF5 tornadoes with a needle like funnel and weak EF1 tornadoes with a mile wide funnel. The only way we can come close to measuring funnel width at the ground is by post storm dam... | [
"Those violent winds ",
" the funnel cloud are still part of the tornado. They do damage assessments, they look for touch down, follow it's path, and look at the swath the tornado cut to get width. ",
"For instance, the tornado that destroyed Greensburg Kansas was estimated at 1.7 miles wide, which is wider tha... |
[
"How does a video game or software randomly decide something?"
] | [
false
] | I've been wondering this for a long time and has never really found an answer to this. When a game has a certain percentage chance of getting a critical hit for instance, how does it decide wether or not give you one? I don't quite understand how a computer can just randomly decide something without having a real consc... | [
"Well that depends - are you asking what algorithm they use to determine a critical hit? Or how the random component of that works?",
"Because the former is basically \"whatever teh programmer wants\". But how an RNG (Random Number Generator) works is much more interesting.",
"As you've apparently surmised, c... | [
"One company, I forget which, uses a wall of fecking lava lamps to seed their random number gen.",
"A wall. Of Lava lamps."
] | [
"CloudFlare. They use it for ",
" random number generation as opposed to pseudo random number generation like the parent explained. For things like games a PRNG is usually sufficient but for things like generating secure keys real world entropy like the LavaRand system are the way to go.",
"https://blog.cloudfl... |
[
"Consider the feeling you get when you're zooming down a roller coaster. Would this feeling be the same if you were really, really tiny?"
] | [
false
] | I don't know much about the physics behind roller coasters, but I believe it's a relationship between g-forces, the weightlessness feeling of free-fall, and gravity's forces all interacting with your body. If you were to somehow create, say, a roller coaster for ants, you'd be traveling much shorter distances up and do... | [
"I'm going to Palin this and talk about something else: really tiny things generally have a much bumpier ride because of Brownian motion. You don't notice the effect of atoms bumping into you randomly, but when you're smaller than a millimeter you start to. So for microorganisms moving through water, it's akin to a... | [
"I would assume they would feel about the same. The acceleration is what causes the funny feeling, and that acceleration doesn't change when you scale the ride, even if you scale the speed. "
] | [
"This is what I was thinking but then, one has to consider things like air resistance. I'd imagine there'd be a much more profound effect upon the roller coaster itself at that level. ",
"But if you ignore that, then yes you'd get the same feeling I should think, as long as you have your semi-circular canals wer... |
[
"Why don't seeds sprout while inside the fruit?"
] | [
false
] | [deleted] | [
"Healthy fruit contains Plant growth regulators (PGRs) which prevents seeds from germinating, when the fruit dies or the seeds are removed, the seeds are no longer exposed to these chemicals and can germinate freely."
] | [
"Some do, and this is known as ",
"vivipary.",
" It is occasionally seen in tomatoes- people bring home the tomato, and they find they have small seedlings growing inside when they cut it open.",
"For the most part, vivipary is undesirable; seedlings need to be established under the right conditions. Seeds ma... | [
"Seed dormancy is an interesting phenomena, and is based on the presence/absence of certain plant-specific hormones. ",
"Here",
" is the wiki of it, but in short, there are two hormones involved, Gibberellin (GA) and Abscissic Acid (ABA). ",
"Increased levels of GA will trigger the germination of seeds, where... |
[
"Does salt water help heal wounds?"
] | [
false
] | [deleted] | [
" post absurd speculations regarding individual's health; unless you have good citations/references or you are a qualified health professional."
] | [
" post absurd speculations regarding individual's health; unless you have good citations/references or you are a qualified health professional."
] | [
"osmotic shock",
"In your case, open wounds are always an invitation to infection. Seawater contains far more variety of microbes to just deal with its salt content. "
] |
[
"Is the steam emitted from a nuclear power plant radioactive?"
] | [
false
] | null | [
"Nope. It's just regular steam as the water does not come into contact with anything that is radioactive.\nNuclear is one of the cleanest forms of energy we produce with very little waste and a lot more reliable than other clean energy sources and produces much more energy for its footprint size."
] | [
"This is so frustrating to me because it's not impossible to process high-level waste into fuel that can be reused and low-level waste that can be disposed of safely, but there are no facilities that do it in the US. If we really invested in it we could have a system that doesn't leave behind any high-level waste b... | [
"I don't think that's correct, coal and nuclear have very similar efficiencies of around 35%. Natural gas is much higher, but once again nuclear has the edge in energy density and GHG emissions."
] |
[
"How quickly can food \"run through you\"?"
] | [
false
] | I hear people say, "oh man that food is running right through me" as they scamper off to the bathroom 20 mins after they ate. Is there any truth to this? I guess the question is how quickly can the body consume, digest, and expell a meal? | [
"Food generally takes about eight hours to pass through you. More rarely, it can take only two or three hours. But if someone is running to the bathroom within just a few minutes, then that is because the food they just ate caused the intestinal tract to start convulsing to move food through it, which caused an i... | [
"Does water (and other liquids) pass through significantly faster?"
] | [
"More likely the new food is causing intestinal irritation (or they're just full/gassy) and the peristalsis & pressure are pushing out previous meals. But I've seen upper GI exams where barium was in the colon after only 30 minutes (2-4 hours is more normal)."
] |
[
"Has the orbit of the earth around the sun changed in any significant way since the earth was first formed?"
] | [
false
] | The moon is slowly receding from the earth, so its orbit around the earth has changed as it used to orbit closer in. Has there been any similar change in earth's orbit around the sun? | [
"There is orbital decay due to gravitational radiation, but that is really really slow. According to my calculations, the Earth is getting closer to the sun at about 350 femtometers per year, which is approximately zero. In five billion years, that's about a millimeter. I imagine brownian motion from the interplane... | [
"Why would the earth get closer if the sun is constantly losing mass?"
] | [
"Gravitational radiation. But that has essentially zero effect."
] |
[
"Can I have an explanation on what the strong and weak forces are?"
] | [
false
] | null | [
"The strong force is very similar to the electromagnetic force, but instead of the \"charge\" being a real number, it's a 3-component vector. Additionally, the strong force is very strong, and interacts with itself. So that makes calculations involving the strong force difficult. The strong force is responsible for... | [
"The coupling constant is small, and the mediator particles have huge masses, so the force has effectively zero range."
] | [
"What level of explanation are you looking for?"
] |
[
"Einstein's Theory of Relativity, explain? Are there different tiers of time progression?"
] | [
false
] | [deleted] | [
"Your question is kind of vague, but here's my best guess at answering it:",
"Time's rate of passage will change, relative to a stationary observer, if you travel at a different speed to them. The rate at which your experience of time, compared to the observer, varies is determined by your relative speed. \n",
... | [
"I think, to take the last sentence... don't think of the \"present\" as being universally true. It's only ",
" present. Someone at a different altitude, or travelling really fast with respect to you will disagree on which events constitute \"the present moment.\" And therefore, you may disagree about what consti... | [
"Do you have a specific question?"
] |
[
"What controls/limits the amount of current a battery can supply?"
] | [
false
] | Example: a 1600mAh battery may have a maximum output current of 100mA. Obviously the capacity is 1600mAh, but what's limiting the current? Why? What limits how much current a charger can "accept" and store? Why? | [
"Very good explanation. The only thing I might add is the question appears to be what is actually limiting the current, which is going to either be 1) In the case of very simple/cheap/low power devices ensuring that your design will never have a current drain greater than the battery can handle or 2) Adding active... | [
"Very good explanation. The only thing I might add is the question appears to be what is actually limiting the current, which is going to either be 1) In the case of very simple/cheap/low power devices ensuring that your design will never have a current drain greater than the battery can handle or 2) Adding active... | [
"batteries aren't just electricity in a box, they are tiny chemical power plants. the chemical reaction has a set voltage it can produce, and the ",
" at which that chemical reaction occurs is controlled by the current. ",
"the chemical reaction that happens to give you electricity also produces heat. the most ... |
[
"Could \"polarized\" matter ever exist in a similar manner to polarized light?"
] | [
false
] | With polarized light, you can do things like project two images onto the same screen, and separate them back out with special glasses (as with 3D movies). Is there any analogue to matter? I.e. can matter exist as "transverse" waves that don't interfere with one another? | [
"This is wrong. MRIs work because hydrogen nuclei have a magnetic moment, so in the presence of an external magnetic field they will align parallel to it. Radio waves are then used to knock them into a different alignment, and the change in magnetisation as they return to their previous alignment is measured. The t... | [
"This is wrong. MRIs work because hydrogen nuclei have a magnetic moment, so in the presence of an external magnetic field they will align parallel to it. Radio waves are then used to knock them into a different alignment, and the change in magnetisation as they return to their previous alignment is measured. The t... | [
"Yes! Matter can exhibit a similar behavior. This is called ",
"spin polarization",
" and depends on how the spin of the object relates to some direction. A common application is electron polarization. If this direction is the direction of motion, then it's referred to as helicity."
] |
[
"How do 'anti-fogging' products work when applied to your (car) windows ?"
] | [
false
] | I would like to know how to decrease condensation forming on the surface of a window, inside a car. There are online videos which show that shaving cream does this well compared to application-specific products, why is that so? A quote from the safety-sheet of a popular anti-fog product shows the following ingredients... | [
"Yes, but what prevents condensation from forming into drops on the window? How does starch affect this ? I have seen people test applying starch from a potato on video, but it doesn't work as well, compared to different mixtures of methyl alcohol, glycerol and others."
] | [
"If the condensation beads up you can see it, but if it is absorbed and spreads out you can’t. \nThe juice of a fresh cut potato has starch in it so that is a cheap alternative I used in my youth. ",
"The layer of starch will last until it washes or is washed away. Forever on the inside of my car windows. "
] | [
"The water soaks in to the starch. Or wets the layer of glycerol. Not sure if a zero residue such as alcohol can work after drying. "
] |
[
"Would it be possible for life to emerge within the goldilocks zone of a star WITHOUT a planet?"
] | [
false
] | Is it possible for the ingredients necessary to sustain carbon-based life to exist in a sort of atmospheric cloud within a solar system? What might a society of sentient beings evolving from this hypothetical form of life be like? | [
"One problem comes to mind is that without a large celestial body to create the gravity (and thereby atmospheric pressure) required for a liquid medium, ice would sublime into vapor in the vacuum and heat of the nonplanetary \"goldilocks\" zone. (This is why we observe in vapor trails from icebound comets that fly ... | [
"You might enjoy \"The Smoke Ring,\" a sci fi book on this concept."
] | [
"Start with ",
". That's the first book, and ",
" is the sequel."
] |
[
"If artificial trees are powered by a coal power plant, can they still produce a net reduction of CO2, while the coal plant still produces a net gain in power?"
] | [
false
] | null | [
"Never heard of an artificial tree until now. What do you do with the CO2?"
] | [
"from wikipedia: \"The CO2 would be captured in a filter and then removed from the filter and stored.\""
] | [
"I know but where and how?"
] |
[
"What is money, exactly? If I discover a ton of gold buried in my backyard, does the value of all other gold drop a proportionate amount? How does one create \"new\" wealth, exactly? Are economic gains necessarily offset by economic losses somewhere else?"
] | [
false
] | edit: thanks for the helpful answers, everyone | [
"To massively oversimplify:",
"There are two sides to the equation: Money, which includes dollar bills, credit cards, gold, and anything with no intrinsic (or mostly no intrinsic when it comes to gold) value that we arbitrarily assign value as a way to more easily barter and trade. The other side of the equation... | [
"its not the knowledge that causes the value to go down (inflation) its the addition of the money in circulation. Even if no one ",
" more money was added, if enough is added it will start having effects. ",
"example: say every sunday you have a potluck dinner with some friends. Everyone brings some food they m... | [
"/u/arrogantsob",
" addressed the money supply issue pretty well in his top-level comment, so I thought I'd address the last question:",
"Are economics gains necessarily offset by economic losses somewhere else?",
"No. The idea that economics is necessarily zero-sum is depressingly pervasive. The fact that ... |
[
"Can someone please disprove the idea that vinegar is a cure to acid reflux?"
] | [
false
] | So I was reading around about vinegar. I saw somewhere that it's good for acid reflux. It's one of those email forewords that I highly dislike. I was discussing this with someone recently and they won't believe me. That didn't make sense at all to me. Acid reflux is due to too much acid. Adding a lower PH acid(its asce... | [
"You should always hold the source of such claims accountable for explaining themselves. There is no logic from a chemistry perspective in the claim. There may well be biological processes at work, as I have seen several people claim that it is effective. However, these claims, without scientific research, amount t... | [
"Vinegar is acetic acid (CH3COOH), stomach acid is mostly hydrochloric acid (HCl). Adding one acid to another does not reduce the acidity of a substance; this is essentially the same as 'fighting fire with fire'.",
"Traditional antacid tablets (e.g., Tums/Rolaids) are made of calcium carbonate (a base) which acts... | [
"It's like putting me, a 25-year-old nerd, in a middle school soccer team. My mediocre physical prowess is amplified only because I have a larger frame than my fellow competitors.",
"Now imagine putting me in a professional soccer team. What little skill and physicality I can bring is nothing compared to the wors... |
[
"Questions about natural selection/mutation. What is the evolutionary advantage of dominant/recessive genes?"
] | [
false
] | Random imaginary example. 5000 years ago, tribal times. My child has a mutated gene, X, which causes him to have much bigger lung capacity. In terms of natural selection, assume he's at a big advantage. However this mutated gene is recessive. When my mutant child has children (and he will have many, for his bigger lung... | [
"Firstly it needs to be said the whether a gene is dominant or recessive is a matter of biochemistry, not evolution. A dominant gene might be for example an enzyme that produces a pigment, where as its recessive counterpart does not. This would mean that if you have just one copy of the gene, you are going to expre... | [
"The gene has no reason to be selected out - having it is never negative, so it will just potter around in the population until two copies come together and then it will be selected for, so will increase as a portion of the population (all be it slowly).",
"It is probably worth mentioning that there is rarely suc... | [
"the mutant's children may have slightly better lungs than the other humans, but not as pronounced as the original mutant?",
"Precisely. As an example in the opposite direction, a female with both X chromosomes missing the functional gene form for clotting agents will have hemophilia. A female missing only one of... |
[
"What does mantle material look like?"
] | [
false
] | If we were able to dive down and photograph mantle material what shapes/colours would we see? what are some every day objects that we could compare it to as far as its viscosity? | [
"And here's a typical mantle xenolith, surrounded by the (dark) crystallised magma which brought it up.",
"http://newswatch.nationalgeographic.com/files/2012/11/3_xeno_close-933x700.jpg"
] | [
"There is no shortage of mantle rocks exposed at the surface in Ophiolitic complexes.",
"The rocks are mainly ultramafic (meaning low silica and high Fe and Mg content), with the main types beeing peridotite, dunite, and hartzburgite. Because of their high Fe and Mg content and mineralogy (olivine, clino- and ort... | [
"Dat olivine!!!",
"Lovely!"
] |
[
"If Kepler is orbiting the Sun (ie. moving really fast), how can it remain focused on a single patch of sky with such precision?"
] | [
false
] | null | [
"It's focusing on things ",
" far away, on the scale of many light years. So even though it's moving fast, the most that the stars will shift in its field of view is the parallax of the star - the very closest star has a parallax of less than .8 arcsec.",
"TL;DR: The fluctuations are ",
" small, especially on... | [
"No, it can maintain its orientation (to an approximate, but nearly precise degree) no matter where it's pointing.",
"Keep in mind that the satellite won't be rotating constantly as it circles the sun (i.e. it won't always be pointing directly away from the Sun no matter where it is in its orbit - replace \"direc... | [
"So...that means it must be pointing either upwards or downwards, otherwise it would have to rotate somehow to keep the same spot in view. ie. it can't be looking anywhere on it's orbital plane"
] |
[
"How do satellites like Voyager 2 know where to aim their lense?"
] | [
false
] | Does NASA program it to just flail about and hope it captures something? | [
"So I work on the Navigations team for OSIRIS-REx. There's a few things that need to be done in order to properly point a camera (or an antenna) at something.",
"The first (and most important) is you need to know what is known as your \"attitude\". Attitude is simply the mathematical concept of \"how you are or... | [
"There is very very little for Voyager 2 to take pictures of. The cameras are long since disabled to conserve energy and keep the probe running for as long as possible. ",
"But, in general, probes need to stay oriented to communicate (they have a really narrow antenna and low output effect of the radio). The orie... | [
"In theory, it is essentially the same. In practice it can be quite difficult. I've never had to deal directly with anything like that, as most of the \"observation\" type things I've had to work with are with distant and relatively slow moving targets. ",
"However the idea is the same. The Entry, Descent and... |
[
"How is it that hydrogen and oxygen (gases) make water, a liquid?"
] | [
false
] | [deleted] | [
"Unlike O2 and H2, the water molecule forms a ",
"dipole",
" that attracts other water molecules, so it is liquid instead of gas at normal temperature and pressure."
] | [
"What we're talking about here is the forces between the molecules. If the forces are very strong, all the molecules stick together into a solid. If they are weak, they can stay disconnected and float around as a gas. If it's in between, you get a liquid.",
"The bonds between hydrogen molecules aren't strong. Thi... | [
"This reaction needs a high activation energy and is exothermic, so the temperature is usually high enough to make water vapor, a gas. But to answer your question, water has a lower boiling point (exists as a liquid at the same temperature that hydrogen and oxygen exist as gases) because water molecules have higher... |
[
"Why does time seem to speed up as we get older?"
] | [
false
] | null | [
"I read an article arguing that the perception of time is based on new, unique experiences. At a very young age, almost every experience is new, and will thus stand out in your memory. As you age and have experienced more, the likelihood of an event being completely new dramatically decreases.",
"As less event st... | [
"Well then I'll keep it here until something sourced is presented, because thus far, that's the only answer that's been given, and whether it's helpful or not, layman speculation is still an answer in a subreddit designed to answer questions.",
"Once a panelist posts, or someone cites a relevant paper, I'll gladl... | [
"I think the rule is correct, and I understand it.",
"Speculation should be allowed to be posted, but should be downvoted. They are not mutually exclusive. ",
"You can take three words of my post out of context and project anything you want, at least read the rest of the sentence."
] |
[
"If it wasn’t for pants or belts, would belly fat be distributed down your pelvis too?"
] | [
false
] | I’ve noticed that belly fat stops right around my belt line and I see it in many other people too. The traditional “beer belly”. Is that caused by where you wear your pants? Like if I wore my pants lower, would fat start to deposit there more. Hopefully I’m wording this so it makes sense. | [
"Try reversing the cause and effect in your head and see if it makes more sense. Is our body shaped because the clothes we wear, or did we end up designing clothes that best fit our body shape?",
"Hope this answers your question."
] | [
"Your body is pre-disposed to accumulate fat in certain areas. Your arms and legs are frequently moved, and if they were chubby that would make them more difficult to move. That might slow you down enough that a predictor could catch you. Your chest can't be restricted by padding because you need to breath, and ... | [
"I suspect it may have to do with accumulation of visceral fat. When we get fatter, it's not just the fat layer under the skin, but also we're gaining fat surrounding internal organs, which is called visceral fat. Upper abdomen contains a lot of organs -- liver, stomach, intestines, pancreas, spleen, and so on. So,... |
[
"Why does our brain have receptors for rare drugs that we wouldn't normally ever encounter, such as LSD?"
] | [
false
] | null | [
"The receptors aren't specifically for LSD. They're serving their own regular function related to normal brain behavior. Then, every once in a while a scientist will discover/invent a new chemical that happens to fit one or more of the existing receptor sites."
] | [
"Drugs like classical psychedelics (LSD, mescaline, psilocybin) mimic the effects of serotonin, a neurotransmitter. They have a similar enough \"shape\" to fit the same receptors site as serotonin. The presence of these substances in plants served as an evolutionary advantage for said plant. It works as sort of mil... | [
"That's a rather loose use of \"purified\", given that ergot-infested rye doesn't contain LSD."
] |
[
"Is the current snowpocalypse caused by global warming?"
] | [
false
] | I got in an argument with some co-workers who scoffed at me when I said the current snowpocalypse (as well as the previous ones) is all part of global warming (or technically Climate Change, but I never could make that point after first saying it was global warming). From my understanding, weather (cold fronts, warm fr... | [
"As far as I know, it's impossible to say whether any one storm is caused by global warming, but it is said that the frequency of such storms can be expected to go up as the earth warms."
] | [
"This. exactly. Anyone who says climate change caused one event or another is lying. Climate change is about long-term trends in weather patterns globally. So if we have more of these events in the next 10 years than we've had in the past ",
" is climate change. "
] | [
"You're on the right track. If the planet is generally warmer, the oceans will be generally warmer. If the water is warmer, more of it will evaporate. If there is more water vapor in the air, then there is more available to condense and fall as snow or rain when the conditions are right.",
"One snow storm in i... |
[
"How is queen bee becoming a queen bee ? Is it natural or is it acquired ?"
] | [
false
] | null | [
"Any female bee can become a queen bee based on diet, so it is an acquired trait.",
"Extra information (aka me info-dumping on bees because I love them):",
"The way bee sexes work is that the queen can lay fertilized (two sets of chromosomes, one from her and one from a mate) and unfertilized (one set of chromo... | [
"From Wikipedia :",
"\"All bee larvae are fed some royal jelly for the first few days after hatching but only queen larvae are fed on it exclusively. As a result of the difference in diet, the queen will develop into a sexually mature female, unlike the worker bees. Queens are raised in specially constructed quee... | [
"Actually fascinating, thank you for your bee knowledge!!",
"I am especially amazed by the emergency queen scenario, and the last ditch attempt to send drones out to fertilize another hives queen... It is incredible how strong and crafty the instinct to survive is in nature..."
] |
[
"Siema to ja xd"
] | [
false
] | null | [
"Xdddddd"
] | [
"Xdddddd"
] | [
"Xdddddddd"
] |
[
"Why are birth defects of the ear (like preauricular pits) sometimes indicators of kidney defects?"
] | [
false
] | [deleted] | [
"http://www.oregon.gov/dhs/odhhs/pages/tadoc/hloss13.aspx",
"http://www.annualreviews.org/doi/abs/10.1146/annurev.med.60.052307.120752?journalCode=med",
"I don't have access to the second one unfortunately, but unless you wanted a really technical step-by-step breakdown, I think that the categories outlined in ... | [
"Here",
" is the second article in its entirety. It's a good overview of the main ear/kidney syndromes."
] | [
"My sister was born with a messed up ear. Deformed and deaf in one side. Her twin died of potter's syndrome and was born without kidneys. I don't know much about it but I would also be interested in knowing the reason for this."
] |
[
"Is it actually possible for fetuses to grab things/stick their hands out during surgery like they so often do in TV shows?"
] | [
false
] | null | [
"http://www.snopes.com/photos/medical/thehand.asp",
"tl;dr: if mom is under anesthesia, baby is as well. Baby would be just as unconscious as mom."
] | [
"Don't they quite frequently give just an epidural? If so would that knock the baby out? From what I know of how epidural work it wouldn't."
] | [
"np, this bothered me when i got that email chain letter back in the day. Seemed inhumane to be operating on a fetus that was conscious enough to grasp your hand."
] |
[
"Do virtual particles create a residual energy at the quantum level?"
] | [
false
] | To my knowledge residual particles are able to pop in and out of existence taking the form of a subatomic particle before passing on. With newtonian physics I know that energy can not be created or destroyed. But at the quantum level is it possible that these virtual particles come into existence, posses energy and giv... | [
"An inexact way to think about this is that the Heisenberg uncertainty principle allows you to \"borrow\" energy from nowhere but requires you pay it back in full in a very short time. So you can have particle pairs appearing but they must then completely disappear very rapidly. So they cannot pass energy to their ... | [
"Thank you for the response. My inquiry arose when I pondered if their could be an \"energy leak\" at the quantum level. This energy leak would then force expansion beyond the planck length. Once the planck length was reached macroscopic objects could then come to being.\nThis came to me when I was thinking about e... | [
"Unfortunately there are many flaws in this logic. Firstly in a big-bang scenario the entire fledgling universe is quantum, there are no observers or macro-systems to \"bring it to reality\". In fact its reasonable to assume an explanation of the big bang should only involve quantum objects (there is no macroscopic... |
[
"Will things stop sinking at a certain depth?"
] | [
false
] | Just as balloons will reach an even stand point when floating, will a rock eventually reach a point of so much pressure it cannot float any lower, if dropped into the ocean? I want to go fishing in the marinara trench | [
"The density of water some changes very little, around a couple of percents at most by the time you get to the Mariana Trench ) however, the density of a rock is usually several times that of water.",
"What determines buoyancy is the relative density of an object compared to the one of the fluid around it. Anothe... | [
"The rock also experiences the buoyant force."
] | [
"The pressure on a rock is on every direction around it. Which means that there's not resultant force acting of the rock. The only force action on the rock is gravity. But that logic the rock should fall until reach the bottom or it breaks from the pressure."
] |
[
"Is it true that \"non-mineral water\", for example filtered rain water, does not dehydrate the body as well as the aforementioned?"
] | [
false
] | Some people said that because rain water doesn't have electrolytes, it's not as hydrating. I think that's rubbish but am curious to know. | [
"Do you have a reference for this? (I'm aware that it's parroted all over the web; I mean a real reference, with numbers and citations.) It seems ridiculous on the face of it, because it implies that the food you eat has no electrolytes. You say, for example, that drinking distilled water would cause you to lose s... | [
"Rain water is water. And only water is hydrating. Hence the \"hydro\" root of the word \"hydration\". Electrolytes (sodium and potassium salts) are not hydrating. ",
"The point of electrolytes is to help retain water and to replace the loss of minerals through sweating. But they are pretty much pointless for mos... | [
"Drinking demineralized water actual has serious side effects as it does not contain minerals/salts your body needs. It's consumption will cause your body to lose stored mineral (calcium, sodium, potassium etc). Over time this will have adverse health affects due to low electrolytes which are required for proper ce... |
[
"Does science \"prove\" things??"
] | [
false
] | I often hear people say things like "Science does not prove things" I usually hear Popper mentioned along with this claim. Please use examples. For example, is it proven by science that, lets say, leaves break down and become part of the soil?? | [
"The purpose of science is to build a logically consistent framework useful in modeling the universe. Describing something logically consistent within its framework doesn't necessarily mean it is a physical phenomena or even happens. It simply means it is not contradicted by our body of knowledge.",
"You could sa... | [
"For people not engaged in the practice of science, this is mostly a linguistic confusion. When people ask \"does science prove this\" they tend to mean \"does science show that this is true\". In that sense, yes, science can prove a lot of statements true, for most intends and purposes.",
"Here is how you say th... | [
"It's easy to go wrong either way on this one. If you assume every scientific hypothesis is God's truth, you're making an error. On the other hand, if you assume that it's impossible for anyone to know anything, then you're also making an error.",
"The scientific method is a tool for learning things about the wor... |
[
"If the Hubble Telescope cannot take pictures of pluto, how is Hubble currently hunting for smaller objects further away than pluto for the New Horizons spacecraft to visit?"
] | [
false
] | Link to what I'm referring to: | [
"As ",
"/r/adamsolomon",
" said, Hubble can take pictures of Pluto. The problem is that Pluto is so small and so far away that it's hard for Hubble to take a good, high-resolution image of Pluto. ",
"What this article is talking about is that Hubble will be looking for new objects for New Horizons to visit. H... | [
"Hubble can certainly ",
"snap photos of Pluto",
"."
] | [
"Hubble wont be able to see anything in detail, but will be able to see if there's ",
" there. Basically it will stare at the patch of space New Horizons is flying towards and see if anything moves. More details ",
"here"
] |
[
"If we have been using HeLa cells for so many years, how can company still have low passage number HeLa cells in stock?"
] | [
false
] | Wouldn't all the HeLa cells been already passaging many times in order to generate huge amount of stock for sale? | [
"Most types of cells used in a cell culture systems (e.g. HeLa cells) can easily be grown to really large numbers without having to passage them too often. Passaging just means that you take the cells from one surface (or one suspension) onto a new one, ususally with a smaller number of cells.",
"These cells are ... | [
"A \"passage\" in cell culture isn't defined in terms of time in culture/cell divisions. In theory, you could produce any number of cells within a single passage, you just woudl have to choose a large enough growing surface."
] | [
"Depends on the cell type. Fibroblasts especially need cell-cell contact or they just won't grow, so you can't split them out too thinly."
] |
[
"Why doesn't my brain know when it's dreaming?"
] | [
false
] | null | [
"I would actually argue that your brain does not know.",
"We know that your brain is active during sleep, especially during certain phases. These electrical firings are no different than real firings you would receive during actual daytime activity. For example, your motor cortex will be active and firing if you ... | [
"Sounds like you need to visit ",
"r/luciddreaming",
" "
] | [
"in your dreams, your brain processes everything that needs to be worked on technically, your brain knows, it's just that you yourself do not realize it. But you can train yourself to realize if or if not you're dreaming, that is by \"controlling if everything is normal\".\nif checking your wristwatch or your hands... |
[
"How is a orb weaver spider able to make a large web that pans over 10 feet across? They obvious can't fly, so how do they do it?"
] | [
false
] | null | [
"I have seen them do this. They first climb to the highest point of attachment and using a continuous web tread \"bungee jump\" to the lower point. They can repeat this for other web connections and then start filling in the space between the vertical strands. If there is a gentle wind blowing, they can attach to o... | [
"Some spider can hop pretty far with their web in tow, a la \"spiderman\". Honestly there are hundreds of ways spiders spin webs, entirely evolution-driven."
] | [
"Oh yeah, they like to find drafty areas in the hope a wandering fly will pass through"
] |
[
"Is there anywhere that models predict will get nicer to live because of climate change?"
] | [
false
] | Every time I read about the impacts of climate change, it's stories of ecological collapse, droughts, hurricanes, and so on. Is there anywhere that models predict the climate will get more moderate, the land more arable, and with more abundant fresh water? To put another way, what's the best place to move to minimize t... | [
"First off, \"nicer to live\" requires individual value judgements because not everyone is the same in what they like. By conventional metrics, most places are going to be losers in climate change but if the mean temperature was a bit warmer there will be some places which will generally be considered more pleasant... | [
"My understanding is the regional impacts of climate change have not been determined. It isn't completely clear when, or even if, the thermohaline circulation will stop. If it stops in your lifetime, you are likely to experience an ice age in short order. If it doesn't stop, Ohio is more likely to feel like Georgia... | [
"Focussing simply on climate (and ignoring any political instability, climate refugees, economic impacts etc), the UK and Ireland are predicted to have increased risk of severe flooding in winters, but warmer and drier summers. So depending on how close you live to a river, it might or might not be nicer."
] |
[
"Why do photons always go 299 792 458 m / s in a vacuum? A marble can go various speeds."
] | [
false
] | null | [
"See the instructions in the autogenerated comment"
] | [
"Hi extreme_douchebag thank you for submitting to ",
"/r/Askscience",
".",
" Please add flair to your post. ",
"Your post will be removed permanently if flair is not added within one hour. You can flair this post by replying to this message with your flair choice. It must be an exact match to one of t... | [
"Physics"
] |
[
"Bright, slow moving light in night sky, eventually dims and disappears."
] | [
false
] | My friend and I were out front of my apartment at around 9:30pm, in Ohio. In the sky, directly above our heads, we notice a rather bright object moving slowly across the sky in a straight line, from west to east. After a couple minutes, the light seemed to slow down considerably, almost to a stop. Shortly after it bega... | [
"I'm willing to bet it was the ISS. ",
"Here",
"'s the best times for sightings for Columbus, Ohio.",
"From that site: At 9:19 PM on Aug. 31, the ISS was visible for approximately two minutes flying roughly from the northwest to the east-southeast. This sounds just like what you described.",
"Also, upvote f... | [
"Iridium flares",
" and the ",
"ISS",
" can get quite bright. Iridium flares in particular can be much brighter than Jupiter or Venus, almost as bright as a half moon."
] | [
"If you have a smartphone (at least Android and most probably IOS also) You can get an app that will tell you when and where to look for Iridium flares and the ISS."
] |
[
"Why are Lagrangian points only limited to the orbital plane?"
] | [
false
] | Shouldn't there be additional points above and below the plane of orbit where the two gravitational fields provide the correct force vector? | [
"No, there are no such points. So the whole Lagrangian points are only relevant in a rotating reference frame so that's what we're going to use. There are three forces present. Gravitational force towards each of the two bodies and the centrifugal force (centrifugal force is very real in our reference frame, don't ... | [
"At any given point in the orbit, yes- but they won't stay in that configuration. For orbits outside of the orbital plane, as they move through their orbit they will change their location with respect to the other two bodies, thus no longer will the forces add correctly. "
] | [
"wouldnt there always be a component of the vector pointing back towards the orbital plane and none pointing away from the orbital plane, thus no place where all the forces cancel? "
] |
[
"If radians are dimensionless units can I drop them as needed in calculations?"
] | [
false
] | null | [
"The formula you are using is \"arc of a circle\", which is ",
"s = r * theta ",
"but it is only valid if theta is in radians, which is the case here (if it was in degrees, the formula would have been s = pi",
"theta / 180) The formula comes from the definition of radian itself, the ratio of the length of the... | [
"Yeah, that's totally fine. I think the reason it seems \"wrong\" is that the rad unit here simply represents 1. Usually dimensionless units exist to make conversions between quantities simpler, for example the mole allows us to work using convenient quantities of mass instead of molecular masses, and the percent (... | [
"Short answer: in your problem, there are 21 cm per rad, or 21 cm/rad. Thus the \"rad\" cancel out.",
"Look at ",
"this picture",
". The red line has length r cm. When the line is folded, you can see that it gives 1 rad, so there are r cm/rad.",
"I am uncomfortable with the whole \"radians are dimensionless... |
[
"Phase of a single molecule."
] | [
false
] | If you have a single molecule of a substance, say water, can it have a phase such as solid, liquid or gas? does the physical state depend on other molecules around it? | [
"No, not really. When we think of phases of matter, it only makes sense when we refer to a very, very large collection of particles. Phases of matter strongly depend on the attractive and repulsive interactions between one particle and the others."
] | [
"Well, a single molecule in vacuum would/does have essentially the same properties as a molecule in the gas phase. Since by definition, the gas phase is the essentially the phase where the molecules are separated to such a degree that the intermolecular forces are insignificant. ",
"So when we calculate the prope... | [
"Cool, my friend and I were discussing this and we thought it would either not be a phase at all, or maybe be considered a gas, thanks for clearing it up."
] |
[
"Would heavy metal elements be found in a gas giant?"
] | [
false
] | I was playing ME2, and on a gas giant planet was a large deposit of platinum. I'm curious to know how realistic this is (because this game is so rooted in hard science, right?), and what other sorts of elements might conceivably be found in a large gas giant planet. | [
"It's not possible to recreate conditions deep inside Jupiter here on Earth. The core should be around 43,000 F and under more pressure than any Earthly diamond anvil can reach.",
"This means questions like \"Is platinum soluble in oceans of white-hot liquid metallic hydrogen?\" aren't fully answerable. You're pr... | [
"While you're correct that the pressures are beyond what static compression can reach, dynamic compression is approaching Jovian core conditions. ",
"Here",
", for instance, diamond at pressures up to 5 TPa is observed; this is around half that predicted at the centre of Jupiter, but well within the core. ",
... | [
"Technically you could get them. But I don't think they'd be in any significant concentration. The inner Rocky planets of our system got most of their solid mass when the system was forming. An outer gas giant won't get as much.",
"They'd most likely come from capturing comets and asteroids and such. I don't thin... |
[
"Is it possible to focus or concentrate anything besides light?"
] | [
false
] | [deleted] | [
"Don't tempt me."
] | [
"Well, yes, but AM radio has a standardized frequency range, right?"
] | [
"Sure. Fresnel lenses for microwaves have been built as DIY projects, and also sold commercially, for quite some time.",
"http://www.tomshardware.com/forum/26365-4-alternatives-dish",
"You could also do mirrors for X-rays. This has been done since quite some time ago for X-ray satellites. But it's more like a t... |
[
"Say that atoms found in the island of stability were found to be really stable. What could we potentially use them for?"
] | [
false
] | There is something called the island of stability which dictates that it may exist heavy elements that are stable. If we create such elements and their half-time is on the order of years. What could we use this new material for? | [
"Some things that we need heavy materials for could be improved if we had ",
" materials. For instance, shielding against gamma radiation. You want something with a high Z so that it's got a lot of electrons which can leech energy from a gamma ray via the photoelectric effect and Compton scattering.",
"Superhea... | [
"You might find relatively stable nuclides at any of the magic numbers. 126 is a ",
"magic number",
" for neutrons, so it's reasonable to think it might be for protons as well. That's the next one in the sequence, but there are even higher ones as well.",
"And I have some ideas as to why, but why must the ele... | [
"Elements heavier than Iron exist naturally as products of neutron bombardment. Either in stars, slowly through the s-process (atom absorbs a neutron or two, then after a while decays into a higher atomic number element, then absorbs more neutrons, etc.) or in supernova rapidly through the r-process (atoms absorb l... |
[
"At what point in miniaturization does engineering transcend the border between it and chemistry?"
] | [
false
] | [deleted] | [
"This!",
"Having said that, the transition region between microsystem engineering and chemistry happens around the 10 to 100nm feature size, with nano-particles and such. The difference between the fields would more likely be about how the structures are created, with chemists working with their traditional react... | [
"This!",
"Having said that, the transition region between microsystem engineering and chemistry happens around the 10 to 100nm feature size, with nano-particles and such. The difference between the fields would more likely be about how the structures are created, with chemists working with their traditional react... | [
"chemistry governs the world around us and is an important part of engineering no matter the scale"
] |
[
"Do any species besides humans cry?"
] | [
false
] | I've seen thread, but there are only a few sources there. Is there a good explanation for why we are the only species that cries? | [
"Elephants cry."
] | [
"I don't see how there is a such a huge difference. Of course since our brains have evolved over thousands of years to respond acutely to different forms of crying we would perceive greater complexity in human cries versus animals. However, given that there is research that proves numerous infant (and occasionally ... | [
"I am fairly sure most mammals cry to some degree; though the social cues are most likely different. "
] |
[
"If a person is frozen, is there any way to unfreeze them?"
] | [
false
] | Or would there be no chance of them surviving? | [
"When a person freezes, the liquids in their bodies crystallize. This breaks the cell membranes, leading to death. ",
"There's research looking into ways to prevent this (there is a frog that does it) in humans, but so far it's all research. "
] | [
"Thanks for the answer, i was just watching a bit to much Futurama, and what happened to Fry seemed a bit fictional, but i wanted to see if it was possible."
] | [
"Yes, this. There are fairly ways of preserving very small tissue samples so that they can be revived (eg, sperm & eggs at fertility clinics), but the whole \"ice crystals rupturing your cells\" is a huge problem once you try to scale up to an organ."
] |
[
"Can photon sieves reduce noise/background in epifluorescent microscope imaging?"
] | [
false
] | I read that scientists are using photon sieves to block unwanted 'light' and increase the resolution of telescopes in space. Can photon sieves, or something similar, be used in fluorescent microscopy to reduce light diffraction recorded by the camera sensor and increase resolution? Similar idea to space, but a differen... | [
"Ok, I was the topical editor of a well-known journal of optics where the topic included stuff like this, so naturally I have an opinion on such things, but of course it is just an opinion.",
"So the photon sieve pattern you are using is a type of pupil-plane coding. What is pupil-plane coding? It's placing a p... | [
"Thanks for your feedback! I'm currently doing in vivo imaging with miniaturized wide-field fluorescent microscopes... Hoping to improve the resolving power, but very limited what elements I add because of the size/weight of the system. We are experimenting with a few things, but this was my out of the box idea to... | [
"Seems like there's a little research into its applications in the visible light spectrum: ",
"Huang et al. Ultrahigh-capacity non-periodic photon sieves operating in visible light. (2015). Nature Communications."
] |
[
"This is a debate betwixt Bill Nye and Joe Bastardi from Accuweather on Climate Change. I understand Nye's argument. Can someone help me understand where Bastardi is coming from, and if what he says is accurate?"
] | [
false
] | [deleted] | [
"Would you care to provide a link to the debate?"
] | [
"I am sorry, I screwed that one up.",
"LINK",
" to new thread :/"
] | [
"That's fine, try again with link and we'll take a look."
] |
[
"What would it require to move the ISS to the moon? Could it be done? And how?"
] | [
false
] | Is this even possible? I know it’s in low orbit, but I figure it’s got to be easier now that everything is up there. I mean, it's a , people live there. Why not take it to the moon for a week or two? They’ve got big solar panels, right? Could it make it there under it’s own power?? Would it require rocket power to brea... | [
"Its possible, but not logistically feasible. The space station is fragile, any thrust applied would have to be very small and/or very uniform. This men's multiple rockets. ",
"You can't just use solar panels like an electric car, you need rockets. You need to expel mass in order to move in space (simplified), t... | [
"A solar sail would be an uneconomical way to move the space station. The logistic problems, coupled with the cost, make it unfeasible. ",
"If you want to go to the moon, you design a system specifically for that. Space travel isn't like car travel where just about anything with wheels and an engine will get you... | [
"The ISS has a ",
"mass of about 4.5x10",
" kg and an orbital velocity of about 7.7 km/s",
". To get it to the Moon, the orbital velocity would have to be roughly doubled, thus we would need to give it about 40 TJ of energy. To put this in more familiar terms, that's about 11 ",
"watt hours or the equival... |
[
"If artificial sweeteners can replace simple sugars such as glucose in fizzy drinks, could they replace more complex sugars like starch in foods like bread and pasta for zero-carb alternatives?"
] | [
false
] | [deleted] | [
"Artificial sweeteners only work as a substitute for the flavor of sugar, not its other properties. You couldn't make caramel or hard candy out of it.",
"There are sugar-free candies, but they use other things to replicate the texture, like isomalt, which has the physical properties of sugar, without the sweetnes... | [
"Sweeteners like ",
"stevia",
" have very little in common with sugars chemically. It just happens to fit into the receptors on our tastebuds for sugar.",
"Cooking is basically chemistry. If it doesn't match then it will behave very differently in the oven. There's all kinds of polymerization and oxidation ne... | [
"Thanks for explaining!",
"Do you know if the 'natural' low-cal sweeteners like Stevia have any potential for this? Could you use whatever molecule that is and make chains like with starch?"
] |
[
"How much is embryonic development affected by gravity?"
] | [
false
] | Were it possible to conceive a child and carry the pregnancy full term in a zero gravity environment (e.g. aboard the ISS), how would the embryo develop? How much of our terrestrial embryonic development is influenced by gravity? I am NOT aboard the ISS and I have NOT gotten anyone pregnant aboard the ISS! This is pure... | [
"It seems that it might not be possible to concieve child aboard ISS and i it was there is high probability of miscariage and severe deformities.\nTry to look ",
"here",
". It is not about humans and it is seven years old, but you will get the idea. "
] | [
"This is EXACTLY what I was looking for. Thank you."
] | [
"I think this is one of the larger unsolved questions for human spaceflight. No one knows, and there are somewhat obvious ethical challenges in experimenting."
] |
[
"Is there a significant difference in the structure or behavior of the corpus collosum, between animals with opposing eyes, such as squirrels and deer, versus animals with them at the front, such as cats, dogs, or wolves?"
] | [
false
] | null | [
"Why would there be? "
] | [
"Have you ever noticed in squirrels, the way in which they evade a threat?",
"They turn and run diagonally away in one direction, appear to get frightened all over again, and cross the other way, to run away diagonally, and this repeats. It isn't necessarily ineffective, but it appears as though they don't get mu... | [
"Well information from the two eyes goes to both hemispheres via the optic tract not the corpus callosum so I'm not sure what you're getting at..."
] |
[
"Can our brains recognize cause and effect in the context of food poisoning? Allergies?"
] | [
false
] | When I say brains I don't mean the conscious, higher-thinking portion of our brain, but the more instinctual part that does stuff like vomiting or fear. This is a kind of specific question, but anecdotally, I see a lot of stories about people getting food poisoning, and if they know where they got it from (say, potato ... | [
"These are called conditioned taste aversions, and frequently form to food that did not cause the illness, but was eaten right before it occurred. ",
"https://www.webmd.com/oral-health/what-is-conditioned-taste-aversion",
"I have a chronic illness that causes gastric issues, and I have issues with aversions to ... | [
"I think there's pretty good evidence that our brains are strongly wired to associate flavors with nausea and exhibit aversion to those flavors in the future. There's a series of classic experiments done by John Garcia that showed this with rats...rats would avoid a flavor paired with nausea after a single experie... | [
"The source you posted says you can get symptoms 30 min after eating in the earliest case. Depends on the pathogen. So immediate food poisoning is possible.",
"Also, if the food has been spoiled for a relatively long time, the bacteria produces lots of toxins, which can make you sick almost immediately when eaten... |
[
"How hard would it be to detect a Jupiter-sized planet with an orbit perpendicular to the ecliptic (i.e., a polar orbit around the Sun)?"
] | [
false
] | And has such a thing ever been theorized? | [
"In our solar system? It would be pretty bright and strongly affect the orbits of other objects. Given that Jupiter was known about before anyone knew what the ecliptic is, I don't think you could say we'd missed it just by not looking in the right place."
] | [
"Have you seen how bright Jupiter is in the night sky? It would be pretty much impossible to miss, no matter what the orbit was.",
"Unless you are talking about an incredibly removed planet beyond the orbit of Pluto, however in that case the probability of its formation is really low."
] | [
"Not very difficult. Besides visual detection--Jupiter would be an easy target for a small telescope or large binoculars even if it were ten times more distant--its effects on known Kuiper Belt object orbits would be unmistakable. Indeed, it is this very kind of orbital evidence that is leading the current hunt f... |
[
"What's the highest possible IQ?"
] | [
false
] | Now I know IQ measurements are extremely subjective, and no one test can really accurately measure intelligence (if such a thing can truly be quantified), but I was just wondering why some people make ridiculous claims about IQ. From what I have been able to tell, IQ tests for adults these days generally tend to use a ... | [
"Theoretically you are correct. But even if IQ scores are theoretically perfectly normally distributed over the entire human population, no test can capture this. People are born and die every second, and there is no way to test every single human.",
"So, an IQ test's scores has to be modeled on a small populatio... | [
"Marylin vos Savant",
" is reputed to have scored and IQ of 228, despite this the worlds most intelligent (according to IQ score) individual is officially recorded as ",
"Kim ung Yonga",
" with a score of 210.",
"For frame of reference, I once took an IQ test that appeared in a popup, and after 10 questions... | [
"Tests will often fall apart outside its statistical range",
"This is a common problem with IQ tests. You can't easily make a test that's sensitive enough to cover the normal range, and discriminating enough to tell the difference between 150 and 170 on the high end. SO, you'll see different tests for different e... |
[
"If the Milky Way Galaxy was the size of a grain of sand [~1mm] how far away would the Andromeda Galaxy be?"
] | [
false
] | I'm trying to explain to a friend just how absurdly vast our universe is and using light years just isn't registering with him. I need something that he can relate to a little easier. For example, would it be comparable to the distance from the earth to the sun, earth to moon, USA to Fiji, etc..? Thanks Reddit, you guy... | [
"Galaxies are actually pretty close to each other compared to their size. That's why they're always colliding and interacting - unlike stars which are quite far apart compared to their size, and almost never get anywhere near each other unless they formed together.",
"So let's say for simplicity that on your scal... | [
"Great answer!",
"Also, for reference, the size of the observable universe at this scale would be about the size of ",
"these crop circles",
", or about .5 km."
] | [
"Well... suppose the Earth is 1mm in size. Then the sun is 12m away, so basically the other side of your apartment. Alpha Centauri is more than half way across North America or Australia. And the Andromeda Galaxy is about the distance to Jupiter."
] |
[
"The average temperature outside airplanes at 30,000ft is -40° F to -70° F (-40° C to -57° C). The average causing speed is 575mph. If speed=energy and energy equals=heat, is the skin of the airplane hot because of the speed or cold because of the temperature around?"
] | [
false
] | null | [
"You have to be careful when saying things like \"speed = energy\" and \"energy = heat\"; those aren't really true in general.",
"But anyway, if you assume a steady, adiabatic flow of ideal gas around the wings of the plane, we can say that c",
"T + v",
"/2 is constant along any streamline.",
"c",
" is ju... | [
"adiabetic adj. Of, relating to, or being a reversible thermodynamic process that occurs without gain or loss of heat and without a change in entropy. -- ",
"wordnik/adiabatic",
"That's a new word for me. My reading stuttered, having read \"a diabetic\"."
] | [
"You still wrote it as \"adiabetic\".... it's \"adiab",
"tic\"."
] |
[
"Do subliminal messages really work?"
] | [
false
] | I just downloaded a program called "Subliminal Messages." It claims that by flashin text too fast for me to read it can help me do things like quit smoking, have more confidence, etc. Is this true? | [
"Almost certainly not. Subliminal messages are just messages that fall below the human threshold for perception.",
"People often connect them with their sub-concious, which is wrong. They have no more effect on your subconscious that any regular message you come across. If it did work, it would almost certainly b... | [
"That study was shown to be a complete hoax. The researcher made up the data"
] | [
"That study was shown to be a complete hoax. The researcher made up the data"
] |
[
"If we can build Nuclear-powered submarines, why don't we have Nuclear-powered space ships?"
] | [
false
] | I've always heard that fuel is such a huge cost to space flight and especially leaving the Earths atmosphere, but why can't we use nuclear power for this? Is Nuclear power just not viable for space travel? | [
"We do. ",
"However, they are not used for propulsion. In space, propulsion is achieved via changes in momentum. You propel something out of the rocket rearward to make you go forward. Nuclear is not particularly useful for that. ",
"On earth, with gravity, you can apply a torque to the ground for propulsio... | [
"As others have said, you need a reaction mass to expel backwards in order to get momentum in space. Nuclear power can provide the energy to throw it back, and it'd be useful to throw it faster (increase the specific impulse) so that you need less propellant.",
"Possible ways are:",
"Nuclear-thermal propulsion:... | [
"https://en.wikipedia.org/wiki/Nuclear_thermal_rocket",
"there where proof of concept engines that worked great without radioactive exhaust, the main obstacle is political, not technological..."
] |
[
"Is it possible to see, with the naked eye, matter-antimatter electron-positron annihilation?"
] | [
false
] | According to , it is. According to my Astronomy Professor, is it not, and this video is either not telling the whole story of the experiment, or is completely fabricated "for TV" as the annihilation causes energy to be released in gamma ray form of 511 keV, whereas visible light is only 1 to 3 eV. So, reddit, how is t... | [
"No it isn't.",
"From that video, it looks like a cloud chamber or a bubble chamber, where an energetic particle causes liquid in the chamber to turn into a gas, forming tiny bubbles that you can see. However, these are usually used to detect charged particles, whereas other methods are used to detect photons, so... | [
"Morgan Freeman would never lie to you. ",
"First of all, the two-gamma case is the lowest possible number of photons. You can have many photons. Additionally, these photons then interact with other matter, which release multiple lower-energy photons. "
] | [
"The fact that the video states that positrons are the smallest particles imaginable discredits the video right off the bat. Actually viewing matter-antimatter annihilation is impossible just too small, maybe just maybe they are using something to react with the gammas given off, that would be my guess. I find it h... |
[
"What makes a day hotter (or cooler) than another?"
] | [
false
] | Specifically, day-to-day increments. Let's get the obvious out of the way: How dynamic is the greenhouse effect? Does it trap enough heat during the night to make a noticeable difference the next day? (For example, after a hot, clear day it will trap some of that energy keeping the night warm and giving the sun a 'head... | [
"In Utah, we have a weather pattern called an \"Inversion\" where cold weather makes all the pollution drop lower to the ground in a thick blanket. It blocks out the sun (like a nuclear winter scenario) and causes the ground to get exceptionally cold in the winter sometimes.",
"Would be great to see a meteorolog... | [
"So you're right, from day-to-day the Sun's energy input for a given parcel of land will be consistent. However, a parcel of land in the tropics will have a much greater thermal input than a parcel of land near the poles.",
"This difference sets up a strong thermal gradient. Winds in the atmosphere (and currents ... | [
"Here in San Francisco, we have to deal with what happens in inland California. If it's hot in, say, Sacramento, the pressure decreases and sucks in all of the air from the west. That pulls fog and clouds over San Francisco. However, when it's not so hot in Sacramento, we usually have a nice day because we're no... |
[
"Why is there such a debate about the inclusive taxonomy of \"Life\" in regards to viruses?"
] | [
false
] | So, I understand why there are always people/scientists debating about wheather to consider viruses "alive" or not. I'm a biology student and I have a focus on evolutionary aspects- I get it. What I don't get is why this deabte has been lasting for so long. When it comes to viruses, of course its never going to be as s... | [
"This is the sort of problem taxonomists encounter all the time: once you decide how to quantify something as belonging to a particular set of animal/plant/life something else shows up (is discovered) that defies classification under the old system. Some of the common definitions of 'life' include being able to re... | [
"Just an IMO, but debates over \"life\" from politics -- creationism, right-to-life, environmentalists -- may be part of it."
] | [
"Well, that was another thing that I was thinking about. If Protobiotic lipid spheres were still existing today (as they are believed to existed and became the first primitive cells), then where would we classify those? ",
"Just like how viruses have genetic material but cannot reproduce, proto-cells were most li... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.