title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"How big can a black hole get?"
] | [
false
] | In terms of mass or the volume of the region inside it's event horizon. | [
"There is no physical upper limit, however, there are limits on how big one could realistically get given galactic evolution. That is likely in the billions of solar masses."
] | [
"There's no theoretical limit. ",
"This",
" is the largest ever discovered, at 40 billion solar masses. That's really large. If put in the place of our sun, the event horizon would be 47 times further from the sun than Pluto.",
"The fact that this quasar is so far away (and therefore being observed at a the y... | [
"Theoretically, no. But in the real world (or universe I guess), yes. A black hole will continuously get larger as more mass gets pulled into it, but this will eventually stop. One reason for this would be that there simply just isn't any matter around it anymore, thus the black hole couldn't get any bigger. But le... |
[
"Why is the three-body problem considered “unsolvable”?"
] | [
false
] | I just watched a that explains the and it states that the problem is unsolvable. But I don’t understand why. As I understand it we can run computer simulations that can show what happens with 3 bodies rotating around each other. But if we can simulate it why can’t it be solved for with a function? | [
"What is meant when we say that the 3-body problem is \"unsolvable\" really just means that there is no ",
" solution in terms of finite combinations of standard functions, like polynomials, exponents, trig functions, etc. This just means that there isn't a relatively simple expression where you could plug in any... | [
"I think the issue is deeper than just that we want to write the solution in the specific form of using only elementary functions. The real problem is that the solution is chaotic, which is an inherent mathematical fact that has nothing to do with what functions we want to use. The reason why we want to solve with ... | [
"Chaotic is different from stochastic. Stochastic means there are randomness involved in the evolution of the state. 2-body and 3-body problems are deterministic, not stochastic. The state always evolve the same given the exact same initial condition.",
"But for 3-body problem, it's chaotic. If you don't have exa... |
[
"Why do pictures of bright lights/stars come out in the shape of a plus?"
] | [
false
] | For example, see how this picture of the stars doesn't show stars as a circle, but instead a plus? Same kinda thing for these Christmas lights image: Are those lines a byproduct of cameras? Or something strange about light? | [
"Those spikes are called ",
"diffraction spikes",
". They are caused by the light diffracting around the support arms that hold up the secondary mirror in the telescope. "
] | [
"Yes, cameras can have this effect as well, although usually less pronounced because they lack the support struts that many large telescopes use on their secondary lens. We even see this effect through our eyes. If you look at stars or other bright spots, they often don't appear round. This is due to suture lines t... | [
"The shape of the pattern doesn't really depend on the brightness. Although it can be easier to see the pattern if the point is brighter than the area around it. What determines the pattern is the shape of the aperture the light went through.",
"Your eyes also do this, there are structures in the eye that cause d... |
[
"If I put my hand on a table, am I actually touching it?"
] | [
false
] | [deleted] | [
"I suppose it depends how you define touching."
] | [
"Ultimately it's that push."
] | [
"Ultimately it's that push."
] |
[
"Is sound affected by gravity?"
] | [
false
] | I'd assume since sound travels through air and other things which are affected by gravity, gravity must have some effect on the propagation of sound waves? Is there a measurable or even easily noticeable difference between a sound heard on Earth and one in a zero-gravity environment, or one played in an environment wit... | [
"There is indirect influence. Atmosphere pressure gradient is caused by gravity. Speed of sound is faster in the higher altitudes. Wave which is entering a thiner medium can be relected. So you can hear distant sound as if they come from the sky. However there is also difraction which is not affected by pressure wh... | [
"Aparently dependence of speed of sound on hight in the Earth atmosphere is much more complicated than I thought. I take that back."
] | [
"Aparently dependence of speed of sound on hight in the Earth atmosphere is much more complicated than I thought. I take that back."
] |
[
"Is there a unit to describe the speed that time passes?"
] | [
false
] | Such as the speed of time when at rest vs. moving near the speed of light or moving close to a large gravitational body? | [
"The unit of time is the second. A \"speed\" is defined as how a variable changes per unit time. Therefore, within a single reference frame, the \"speed of time\" would have units of seconds per second, which units cancel out to end up not being units. Furthermore, within a single reference frame, the speed of time... | [
"Well technically radians ",
" a \"false\" unit. There are a couple of different ways to approach measuring an angle measure in radians, however.",
"Degrees (obviously) are not bad but you have to include some measurement of size of the circle to know arc length, at least.",
"Meters are somewhat less useful s... | [
"For some reason, I've spent a decent amount of time thinking about this curiosity, to.. well, to mostly no avail, but I guess I have a vaguely useful opinion on it. Since we're sharing...",
"Clearly something is going on when you have to hold on to 'radians' in all your calculations, even though they don't have ... |
[
"Regarding the energy released during atomic fusion vs. atomic fission."
] | [
false
] | Since we know that: 1)Atomic fission releases less energy per mass than fusion (at least for the common fissile and fusion elements: Plutonium isotopes and Hydrogen isotopes.) 2)Fusion of heavier elements releases less and less energy per mass until iron, at which point it would begin requiring energy and is the beginn... | [
"Fusion releases more energy per nucleon than does fission because of the relative steepness of the two sides of ",
"this curve",
". Jumping from hydrogen to helium releases a colossal 7 MeV per nucleon, whereas the maximum you can gain from splitting e.g. ",
"U is about 1.5 MeV (if you were to split it right... | [
"Free hydrogen nuclei (i.e. protons) have no binding energy and so occupy the zero position on that curve. Nucleons in a helium nucleus are in a bound state, which means they have less energy than the equivalent free nucleons. This makes intuitive sense, because the strong force is attractive - in order to separate... | [
"Great reply, thanks. ",
"Somewhat related: I'm often confused by the right signs in binding energy. Since it's been over a decade since I looked into it, maybe you can help me out where the following reasoning goes wrong:",
"The binding energy of Helium is 7 MeV per nucleon. So, in order to create a Helium ato... |
[
"Can stomach acid burn organs?"
] | [
false
] | null | [
"Normally, the cells in the lining of the stomach secrete a mucus that protects the stomach from damage from gastric acid. When your body moves your stomach contents (which contains substantial amounts of stomach acid) into your small intestine, your body pretty much immediately neutralizes it with alkaline secreti... | [
"GERD can cause precancerous changes to the esophagus. It's called Barrett's esophagus or Barrett's syndrome, when normal esophageal cells are replaced with abnormal cells. I've had this and have been prescribed omeprazole for over 24 years, because my esophageal sphincter eroded."
] | [
"Other reasons like getting stabbed?"
] |
[
"Why do sunsets contain every color except green?"
] | [
false
] | null | [
"This article",
" has a good explanation."
] | [
"This says that the green and blue wavelengths get scattered by the atmosphere, but why does it only appear blue and not green?"
] | [
"They do contain green sometimes, if the atmospheric conditions are correct."
] |
[
"Is it possible to eat just enough, to not have any waste?"
] | [
false
] | Urine and feces are our bodies' way of expelling parts of food that either cannot be digested or are just aren't digested. Given that, would it be possible to ingest exactly enough nutrients in exactly the right form, that our bodies would digest 100% of the material and we wouldn't have any waste whatsoever? Assuming... | [
"No, because feces is not just \"unused\" food, and for that matter is not at all \"unused\" food. Feces is roughly 30% bacteria. And the characteristic brown color is partially from \"dead\" red blood cells (not sure what percentage though). Urine on the other hand is bodily waste cleared out via the kidneys, a... | [
"to answer question number two, the color begins as biliveridin, which is green, and is broken down by biliveridin reductase into bilirubin. which is yellow, this is the state in which it is passed through the urine. it is also passed through the liver to the small intestine as a component of bile and is converted ... | [
"The best I remember is that it's by weight. Whether that is dry weight or wet weight, I no longer remember.",
"The broken down heme in urine is what makes urine yellow, and the heme comes from broken down red blood cells (it has another name at that point that starts with a u, but which I don't remember). What... |
[
"Theoretical question: Two identical planets that orbit each other ...."
] | [
false
] | null | [
"Well there is a lot of different answers here because much of what controls a solar system's orbit is defined by the mass of the planets and how fast they orbit the host star. Also, the moon's orbit is not perfectly stable, as it drifts slowly away from us over eons. So a number of scenarios could exist that satis... | [
"The distance at which a stable orbit occurs depends on speed. The two planets could orbit each other closely if they were traveling very fast, and if they were moving relatively slowly they could orbit at a farther distance. The same idea applies to your two-planet system and the sun."
] | [
"The distance at which a stable orbit occurs depends on speed. The two planets could orbit each other closely if they were traveling very fast, and if they were moving relatively slowly they could orbit at a farther distance. The same idea applies to your two-planet system and the sun."
] |
[
"Why do proteins evolve at different rates?"
] | [
false
] | null | [
"Imagine you have a short story - it's composed of letters written on a page. If you change a letter like \"e\" or \"a\", letters that are deeply involved in almost every word, you can end up with a garbled mess that's very difficult to read. If you change a letter like \"q\" or \"z\", then the story may still be q... | [
"This is a fundamental question in molecular evolution, and we do not have a complete answer yet. Nevertheless, it seems that there is a universal rule of thumb in protein evolution: \"Important\" proteins tend to evolve slowly. To explain what is meant by \"importance\", we should first define how the rate of a pr... | [
"Cheers, i knew it was something along these lines I just couldn't word it right in my mind, thank you!"
] |
[
"Would the light of a populated planet be more apparent to us?"
] | [
false
] | null | [
"Hi EmoSensitivo thank you for submitting to ",
"/r/Askscience",
".",
" Please add flair to your post. ",
"Your post will be removed permanently if flair is not added within one hour. You can flair this post by replying to this message with your flair choice. It must be an exact match to one of the fo... | [
"Planetary"
] | [
"Planetary"
] |
[
"Do thoughts have mass?"
] | [
false
] | null | [
"are you retarded?"
] | [
"Please keep discussion civil. Name calling, insults, racism, sexism, etc. will not be tolerated."
] | [
"http://www.reddit.com/r/breakingbad/comments/maaib/what_does_this_mean/c2zex57"
] |
[
"If a male/male set of identical twins had a pair of children with a female/female set of identical twins, would the children be identical? [xpost from askreddit, I wasn't familiar with categories, my apologies!]"
] | [
false
] | null | [
"The short answer is no, they'd probably look as similar as siblings, because while the genetic material of the parents is indeed the same, how it gets passed on is not. It is exactly the same as one couple having two children.",
"Remember that for each chromosome you have two copies, one from your mother and on... | [
"In text form, if we call dad's two copies of a chromosome D and d, and mom's M and m, a child could have DM, Dm, dM, and dm in equal possibilities of 1/4. So the odds of any two children have the same combination of the same chromosomes is the product: 1/16. This would apply to each and every chromosome, because t... | [
"two coins",
"Sorry sorry, I stand corrected."
] |
[
"How do new species propagate?"
] | [
false
] | [deleted] | [
"Accessible explanation from PZ Myers' blog ",
"Pharyngula",
"."
] | [
"jahutch2 hit it; 'species' is an artificial thing; we made it up to categorize something that's not really discrete. ",
"First, you have to keep in mind that there are several equally useful and accurate ",
"definitions",
" of \"species.\" To clear it up, let's take a hypothetical case study on fast forward.... | [
"I've posted ",
"this article about human/chimpanzee divergence",
" several times, but never gotten an expert critique of it, so I'm not sure if it's true.",
"Basically the guy is saying that it's still possible for new species to mate successfully with their root species until one final mutation causes a bre... |
[
"What are the effects of masturbation on motivation, productivity and non sexual relationships?"
] | [
false
] | [deleted] | [
"I've found ",
"one paper",
" that links masturbation frequency with a reduction in almost all satisfaction measures. Nonetheless, this is the only study that I've been able to find doing a quick search so the results should be interpreted with caution because there could be some confounding factors. ",
"On t... | [
"So they are linked, but which came first, the chicken or the egg? "
] | [
"Good question. Unfortunately, determining causality is quite complicated. In my opinion, masturbation is not a causal factor in improving or decreasing motivation or non-sexual relationships. ",
"Nonetheless, having a good and active sexual life, with one or multiple partners, is very healthy and benefits multip... |
[
"How many bits of data can a neuron or synapse hold?"
] | [
false
] | What's the per-neuron or per-synapse data / memory storage capacity of the human brain (on average)? I was reading the Wikipedia article on . It lists humans as having 86 billion neurons and 150 trillion synapses. If you can store 1 bit per synapse, that's only 150 terabits, or . That's not a lot. I also was reading ab... | [
"The brain is a computer analogy is nice sometimes, but it doesn't work in many cases. Information isn't stored in a neuron or at synapses per se, and we're not certain exactly how information is stored in the brain at this point.",
"Best we can tell information recall happens as a product of simultaneous firing ... | [
"Exactly. In addition, there are many more cellular processes that affect neuronal signalling than just synapse location and strength.",
"The entire milieu of the metabolome of a given neuron at any given instant will be constantly changing, and will impact the response that neuron generates.",
"This means that... | [
"Neurons don't work like individual bits of a data in a hard drive. They basically work all of their memory from association. It's based on the concept of \"",
"\" and vice versa. It's best explained with an example. I'll use \"horse\" since another comment mentioned it. When you hear the word \"horse\" you proba... |
[
"Why does my accent shift from American to British/Irish/Australian?"
] | [
false
] | null | [
"Psychology"
] | [
"Psychology"
] | [
"We can't really comment on anecdotes / isolated incidents without resorting to speculation which we try to avoid."
] |
[
"What kind of meteor impact would it take to stop the Earth's rotation?"
] | [
false
] | I was inspired by a post of a related topic on this subreddit. I was curious how large the impact of a meteor opposing the rotation of the Earth would have to be to stop or dramatically slow Earth's rotation. | [
"First let's calculate the angular momentum of the Earth. ",
"L = I * (2*pi/T), where I is the moment of inertia and T is the Earth's rotational period.",
"I = (2/5)* (mass of Earth)*(Radius of Earth)",
"Then L = [(2/5)* (mass of Earth)",
"(2*pi/T) = 7.063 * 10",
" kg m",
" / s\nGreat.",
"Now, L= r x ... | [
"Buzzkiller: in collisions, planets act more like droplets of water than solid masses. ",
"Anything with enough energy to completely stop the Earth's rotation would turn the planet (and itself) into a very fine spray of hot magma."
] | [
"An online figure puts the earths rotational kinetic energy at 2.138×1029 J, so a similar quantity of energy would have to be dumped into the system to counteract the spin. So a 100 billion tonne asteroid moving at 22% of the speed of light would about do it.",
"This is by no means an accurate calculation. But it... |
[
"[medicine] How does the body create an immune system that functions when one is born without a thymus but has parathyroid glands?"
] | [
false
] | I'm trying to learn about how the immune system functions, creates, and teaches immune system cells when one is born with no thymus. I've read all about how the immune system works when there is a thymus in play, but what about no thymus? I can't find anything online to explain this to me. Ps. I've read about no thymus... | [
"Haven't got any sources as I'm on my phone but I'll clear up some things.",
"Firstly, the parathyroid has no role in the immune response - it is a gland attached laterally to each lobe of the thyroid and produces parathyroid hormone which stimulates bone breakdown and inhibits proximal tubule reabsorption of pho... | [
"I agree with you on the anti-rejection/immunosupressant medication side of things, the point I was trying to make is that previously (and in the case of the 'Bubble Boy') the bone marrow donation was unmatched - i.e. there was no screening process - and assumed to be best fit as it was from a close relative. This ... | [
"Wow. Thank you so much for this incredible and detailed reply. It's extremely appreciated. I am also grateful you took the time to type all of that out on your cell phone. ",
"Because I know very little about this I assumed that the parathyroid had something to do with the immune function because someone classif... |
[
"Why don't all phones, computers, etc, have a coating on the important electronic circuitry and other components for waterproofing?"
] | [
false
] | I know coatings are out there. I have even seen some posts on reddit. Is it a cost or heat problem? It seems a thin spray would not be expensive and I can't imagine a microthin layer being that much of an insulator. This would have saved my last two phones (RIP). | [
"Those phone cases aren't air tight, the electronics inside can still shed heat to the air within the case.",
"Also, your sim card and battery need electrical contacts. ",
"Another possibly issue is the heat damaging the coating."
] | [
"Heat exchange is the primary reason I originally thought this would not work, but would a super thin coating really be that great of an insulator?",
"My big concern there is surface area. Even a very thin coating could fill in spaces between components where air circulation would occur.",
"I could see gaskets... | [
"Cooling issues mostly. There's also the problem of servicing or reconfiguring such electronics."
] |
[
"Is it possible for nuclear fuel to accidentally reach criticality?"
] | [
false
] | [deleted] | [
"Ah, well that's far simpler. For that, any explosion or fire, following physical damage to the fuel bundle, will spread radioactive dust over a wide area. The higher the cloud (vertically), the more widespread the damage. Note: Only spent/used fuel bundles are dangerous. Virgin fuel is more or less safe, even if p... | [
"Ah, well that's far simpler. For that, any explosion or fire, following physical damage to the fuel bundle, will spread radioactive dust over a wide area. The higher the cloud (vertically), the more widespread the damage. Note: Only spent/used fuel bundles are dangerous. Virgin fuel is more or less safe, even if p... | [
"PWR / BWR fuel bundles (they are basically the same) can go critical if physically damaged ",
" in the presence of water (ie: submerged). The catch is, normally when they are physically damaged, they do so by melting, which boils all the water off, so...what breaks them that isn't heat?"
] |
[
"So I just finished book that deals with epigenetics..."
] | [
false
] | How real is it? Is there anyone who can point me to some articles and papers either supporting it or denying it? The book I finished is called . Just trying to get some context, thanks! EDIT: Here's a link to the wikipedia page for epigenetics EDIT2: Sorry was in a hurry before. The author does site all of his sources,... | [
"Not familiar with the book. Does it not have references to scientific papers? (if it doesn't, yikes.)",
"Epigenetics is real. The most famous example of epigenetic influence on phenotype is probably ",
"Angelman syndrome",
" verses ",
"Prader-Willi",
": The same genetic problem, depending on whether it c... | [
"Nature affects nurture, nurture affects nature. Sorry for being touchy but I have a peeve with \"vs.\" Genetic effects influence things like maternal care, home environment, and internal biochemistry (through influences on food and drug choice, for example). Environments can completely determine the direction of a... | [
"Well, I don't know that book, but it sounds very pop-sciencey. Epigenetics is a real field of good and valid scientific research. What ",
" about epigenetics were you interested in?"
] |
[
"What distance do your eyes move in a given day?"
] | [
false
] | If your pupil moves from one corner of your eye to the other, although it is rotating, the pupil probably covers around 1cm? I was wondering what the average distance your eye moves over the course of a day? | [
"I'm sorry to hear that. I'm also sorry to hear that it has made you so sour."
] | [
"I wouldn't be surprised if it were miles. I have a program that tracks how far in miles I move my cursor everyday, it's usually well over a mile."
] | [
"What program is this? I would live to try it."
] |
[
"What's the role of imaginary numbers in electronics and circuits?"
] | [
false
] | I just don't get how the square root of -1 can be so relevant in these areas. | [
"I'm going to disagree with ",
"/u/fishify",
" for a bit because I think it's more fundamental than simplifying computation. That's sort of a trick of phasor analysis, but the reason that works has to do with more complex (heh) things. ",
"Circuits behave according to a set of linear differential equations. I... | [
"It's for calculational simplicity. If you are dealing with sinusoidal signals, you can represent these more easily using complex numbers. Since e",
" =cos(a)+i sin(a), anything you can do with sines and cosines you can do instead with complex exponentials. But exponentials are simpler: the derivative is an ex... | [
"You do not have to have complex numbers to do sines and cosines. What complex numbers allow us to do is to collapse multiple equations into 1 due to the orthogonality of the sine and cosine functions. Note that in your examples the sines and cosines go with either the real or the imaginary part and not both."
] |
[
"Why is the dibromonation reaction of 2,3-dimethyl-1-pentene stereospecific?"
] | [
false
] | null | [
"It's a matter of ",
"assymetric induction",
". Essentially the existing chiral feature (the methyl group labelled) will affect which face of the c=c bond will be attacked. "
] | [
"You are correct about the mechanism. I want you to draw out each of the possibilities that you could get in forming the bromonium ion intermediate. In one instance, the bromine will have no steric interference with the isobutyl group and in the other, there is severe steric strain. The latter will be formed slower... | [
"so would I be correct in concluding that the stereoisomer on the left would be more readily formed?"
] |
[
"Are we hampered in understanding by the languages we use?"
] | [
false
] | This is prompted by the post about deaf people thinking in sign language. I remembered reading that some cultures have very limited systems of counting, so I wondered if it was possible that our languages could be ruling out the possibility of us grasping some concepts. | [
"To add on to this: in addition to English, I speak a language where there is a separate word for large spoons and small spoons (that is more present in the vernacular than the words teaspoons and tablespoons are in English), but no such distinction for different sized forks. I noticed that the kitchen drawers of ... | [
"Linguistic determinism is dead in the water, but research on linguistic relativity is alive and well, mainly at the Language and Cognition research group at the Max Planck Institute for Psycholinguistics in Nijmegen, and in the cogsci department at UC San Diego, but there are also plenty of others."
] | [
"I'm no linguist, but you might find interest in the ",
"Sapir–Whorf hypothesis",
".",
"As a piggyback to your question, I'm interested if there are any hypotheses or evidence that ",
" has any impact on conceptualization, not just limits imposed by a spectrum of verbs and nouns."
] |
[
"Where does there energy in the Earths core come from?"
] | [
false
] | Was just thinking about how almost all life on earth has is energy provided by the Sun, but the sun never reaches the core of the planet, so where does all this energy in the center come from? There's so much energy there (seen by volcanoes, earthquakes, tectonic shifts etc). Where is this energy actually from? Is it a... | [
"In my astronomy class last semester we talked about this. The Earth's core is heated(at least partially) from the differentiation of materials in the mantle and core. Differentiation is when the heavier and denser materials, like iron and nickel, move towards the center of mass(the core) and heat the surrounding m... | [
"The core's rotation, and the rotation of the planet itself, is an artifact of the angular momentum of the protoplanetary material carried as it formed our planet. Imagine a big, swirling cloud of elements, falling in slowly as gravity takes over. Because all that dust and debris is moving, it conserves it's angu... | [
"Well it's mainly do to gravity. See since earths hot firery formation the heat has been kept in its core. Tidal friction is a big factor in keeping the earth warm but it's not enough. Plus the moon is inching away from earth so our days will also be longer. I digress, it's really just the compression of the mass o... |
[
"What happens when the universe expands too far?"
] | [
false
] | If the universe is continuously expanding and taking into the conservation of mass, would the universe eventually freeze because the distribution of all energy and mass is spread too far? | [
"Yes. The alternative is that the universe won't continue expanding forever, which a few physicists believe."
] | [
"It doesn't have to expand into anything. \"Expanding\" in this context just means \"the distance between two points increases with time\"; there's no need for something outside the universe to hold it."
] | [
"What does \"around our universe\" mean? \"Around\" is a weird word in this context, because there's no direction you can go that's into or out of the universe."
] |
[
"What would \"The Suns\" on a binary system look like from the surface of a planet?"
] | [
false
] | If such a planet exists, is there any mechanical understanding of how a planet might orbit the stars? would there be two days or one drawn out one? Seasons? Is there a size limitation or minimum on orbiting bodies? | [
"Depends on how luminous the stars are and the distance between them. It's also important to know the orbital configuration. The stars can orbit each other very closely with the planet orbiting both stars further out. Or a planet could orbit a star, while a companion star orbits further out. ",
"In the first case... | [
"Just a quick correction:",
"...even the smallest stars are extremely massive compared to planets (75 solar masses at the very minimum)...",
"Don't you mean 75 ",
" masses or something smaller? Since, by definition, stars would have to be able to be just one solar mass (and smaller)...",
"Otherwise, very i... | [
"Aye, it's 75 jovian masses, not solar masses. Thanks for the correction!"
] |
[
"I have a question about planetary gravity."
] | [
false
] | I was wondering: If there were a planet physically smaller than Earth, but with a core sufficiently dense enough to compensate, could you end up with the same gravitational pull as Earth? Or a larger planet with a very light core? Is that how that works? Thanks. | [
"The acceleration of gravity is related directly to mass and inversely to the square of the radius, so as long as m/r",
" is the same, the gravity will be the same."
] | [
"To expand on that, if you write mass in terms of density ϱ, then as long as ϱr is the same, the gravity will be the same. If you double the radius, you need to halve the density.",
"EDIT: This is assuming constant density throughout the planet. It gets a bit complicated otherwise. Also, we are referring to the g... | [
"Right, just to expand a little more...If the surface gravity is the same on a much smaller planet..the volume of space around the planet that could house orbiting satellites would be much smaller. ",
"For example, the earth's radius is 6,000km, and the gravity is about 10m/s",
" . This means at 12,000km, the g... |
[
"What are possible solutions to the issues that GMOs (in agriculture) present? [more ?s inside]"
] | [
false
] | Can GMOs feed the world? Does it matter if it can or can't? Potential Environmental Risk: -Gene flow -The emergence of resistant pest and weeds What can be done in regards to GMOs and consumer confusion? If a GMO product isn't labeled how can one know whether or not there are consequences to the consumption of GMOs? Is... | [
"What about Golden Rice II a 70gram serving provides a daily requirement of vitamine A. It is licensed for humanitarian use.\nWhat about animals engineered to produce certain drugs in their milk, between a few animals can be produced the worlds supply of a drug needed to treat emphysema which used to cost per patie... | [
"At the risk of getting downvoted into oblivion, i'd like to offer what should be perceveid as an ",
"Today's commercial GMO's are a load of rubbish i cannot even begin to describe the amorality and bullshit-laden top of. That is: Leaving all the science behind for a moment, and honestly there isn't much \"real\"... | [
"Oh i don't doubt it. Who developed these, how are they licensed, and who is selling them at what profit margin to whom?",
"Never said \"GM is evil\", but i did say \"the people that deal in GMO's are evil\"*",
"*: for an implied realistic definition of \"evil\""
] |
[
"Questions about how they're keeping the Fukushima nuclear cores cool."
] | [
false
] | I've been keeping up on Fukushima and know the basics, but I was reading and am confused as to why they need 400 additional tons of water a day to cool the core. I get that they need a lot of water to keep the core(s) cool. My question is why they aren't using some kind of closed loop system, incorporating some kind of... | [
"The other response here is a poor response that not only doesn't answer the question, but also places judgment on a particular reactor design based on opinion. ",
"The cooling system involves injection through the core spray, feedwater, or coolan injection lines. The water trickles down through the remains of th... | [
"Around 5-6 months after the event they reached cold shutdown. This means that the average water temperature is below 200 degrees, so there should be no boiling and consequentially no steam. Unless there's something we don't know (but that's just speculation)"
] | [
"As for why they are adding water, we do not know.",
"Hmmm. If they're adding water as a result of loss to the system (in the form of steam, maybe?)...that is an awful lot of loss, but it wouldn't explain why they are still needing to store so much water.",
"Thank you for your answer."
] |
[
"How would inserting a floating balloon into the atmosphere of a planet from space be technically different from landing a craft on the rocky surface of a planet from space?"
] | [
false
] | So I know there are a some important technical differences between landing a craft on Earth (which has a moderate atmosphere) versus landing a craft on Mars (which has a thin atmosphere). If my understanding is correct, the thinner atmosphere of Mars poses particular challenges because it's not thick enough to make use... | [
"Edit: I realized I wrote something that looks more like an ",
"/r/AskHistorians",
" answer than a ",
"/r/askscience",
" one. But at this point I have put too much work on it. I hope it answers some of your questions anyway.",
"\"We\" have already done it! And by we I mean the Soviet Union. Technical data... | [
"Very nice. Thanks for the post. "
] | [
"Astounding... can't believe I didn't know about these missions and pictures. Thank you so muchfor sharing!"
] |
[
"How much warning would we have before a solar flare?"
] | [
false
] | Would the lapse between solar flare going off and its effects hitting earth but more or less than the ~8 minutes it would take to get here? Just curious considering how catastrophic for electronics it would be. Follow up question, in that interval between us knowing there would be a flare and the flare's effects hittin... | [
"Solar flares doesn't travel towards earth at the speed of light. Solar flares consists of particles with mass, and according to the wikipedia article, they reach earth within one or two days. The SOHO satellite can spot flares and warn earth, so we'll know within a day or two that a flare is about to hit earth.",
... | [
"Well, we certainly couldn't know about it in less than 8 minutes. If the light from the flare was the dangerous part, we would see the flare at the same time it hit us. But the X- and UV radiation produced just causes temporary radio interference and possibly increased atmospheric drag on low-earth orbit satellite... | [
"We're pretty well protected here on the surface, by the atmosphere and magnetosphere. My understanding is that a very large flare which might happen less than once per century may take down part of our power grid, and maybe expose people on high-altitude aircraft to enough radiation to cause minor, temporary healt... |
[
"What happens to a tumor once the person dies? Assuming nothing is done to the body."
] | [
false
] | null | [
"Just like any other cell in the body, it stops receiving oxygen/nutrients and dies. This process is ",
"necrosis",
".",
"One interesting side note is that, due to the malformed vasculature of most tumors, there are generally regions of a large tumor that do not receive any blood. So often times a tumor wil... | [
"More accurate than or as accurate as?"
] | [
"Well for very internal tumors, it doesn't. Generally you might experience this in a tumor that has broken through the skin, like a very advanced breast cancer. Another possibility is for the odor to be present in the breath of a lung cancer patient. ",
"Second interesting side note: Studies have been done to ... |
[
"Statistics Question!"
] | [
false
] | In recent front-page article it talks about the . My question is what difference is there between their method and just taking the average of the samples and doubling it to find the maximum? You know that the average is going to be half the maximum since the numbers are sequential. And just as the accuracy of their met... | [
"Think about it this way. Suppose you sampled serial numbers 1,2,3,4, 100. The average is 22, double that is 44, but you know that there must be at least 100 tanks. This is an extreme case that almost never happens, but there are lots of inextreme cases that are off a little bit. You can also get off the other ... | [
"Both methods would \"work\". The sampling distribution of means will approach the population mean with sufficiently large samples (n>20). The MVUE is a better estimator over all samples, as other have said. So you'll get a closer estimate with MVUE than with the mean doubling method nearly every time. ",
"T... | [
"is there a way to plot the accuracy as it increases with the number of samples for the two different methods in order to visualize it?",
"Further searching finds ",
"http://en.wikipedia.org/wiki/Uniform_distribution_%28discrete%29",
" which gives the variance of the estimate-from-maximum method as being (N-k... |
[
"Neurologically speaking, what makes a child's brain better at learning new skills and languages than that of an adult?"
] | [
false
] | null | [
"Lack of myeline around axons makes new synapsis easier to form, and our cerebral axons get myeline coats from age 25 or so onwards.",
"A very young child also has quite a bit more neurons than will have as an adult, and those will make a massive ammount of synapsis. Most of those will end up being pruned.",
"O... | [
"A child doesn’t really lose his neurons. It’s rather that the connections between the neurons (synapses) change. For example the number of synapses can decrease if the child doesn’t use a particular part of his brain."
] | [
"Becoming adult, how does a child \"lose\" his/her neurons?"
] |
[
"If the universe is expanding, does that mean that space between particles in my cells is expanding too?"
] | [
false
] | The way universe expansion has been explained to me is that every point in the universe is moving away from each other. Does that mean that we expand as well (although staying the same size relative to the universe). | [
"The metric expansion of the universe only occurs on the inter-galaxy-group scale. Within a galaxy, space is not expanding. It's not just that it is expanding such a small amount that we don't notice. Space inside a galaxy is not expanding at all. "
] | [
"Not exactly. This is a popular explanation but it is misleading. Rather, spacetime is only expansive away from matter. Metric expansion is simply the cost of having empty spacetime. At the sub-galactic-group level, spacetime is curved such that objects are attracted to each other, and beyond this level, spacetime ... | [
"Space itself is expanding, but particles can hold onto each other with chemical/electric bonds, gravity, magnetism, etc. These forces are strong enough to make sure you don't drift apart. Gravity is strong enough to keep entire galaxies together, the expansion of space is only really noticable between them."
] |
[
"Why is Ebola so successful this time around?"
] | [
false
] | Ebola has appeared many times, killing less than 100 people each time, and then it is gone. Why is it killing so many more people today? Is this a new strain with better propagation characteristics? What has changed? | [
"Africa has changed, not Ebola. There are now more than a billion people in Africa, in the 80's, less than half that. With more people packed into bigger cities and more people pushing out into the rural areas, and with faster transportation between the bush and the cities, it was only a matter of time before Ebo... | [
"\"The virus amassed 50 mutations during its first month, the researchers found. They say there is no sign that any of these mutations have contributed to the unprecedented size of the outbreak by changing the characteristics of the Ebola virus — for instance, its ability to spread from person to person or to kill ... | [
"Well, obviously it's mutating some, but all viruses constantly mutate. That's not really relevant. Fundamentally, it's behaving in exactly the same way it always has. It's just in large cities rather than small isolated villages. If you were to take a sample of ebola from an earlier outbreak and release it int... |
[
"Is a measurement of Planck time arbitrary in time?"
] | [
false
] | Does a measurement of Planck time have to occur during a discrete period/cycle (i.e. clock cycle), or can it be measured during any arbitrary period along an infinite timeline? And if time is not infinite, does this then impose a universe "clock cycle"? | [
"The Planck time is far too short to be measured with any existing technology. However, there is often a misconception about the importance of Planck units. They are not universal pixel sizes, they are just units constructed from physical constants.",
"https://www.physicsforums.com/insights/hand-wavy-discussion-p... | [
"Could universal pixel sizes exist?"
] | [
"Aw c'mon. Speculate here. What if you're right?"
] |
[
"How are drug classes grouped or chosen?"
] | [
false
] | [deleted] | [
"You can group them by any of those categories to be honest. SSRI's are all selective serotonin reuptake inhibitors, meaning they all have relatively similar affects on the brain/neurotransmitters. PPI's and NSAIDs are also grouped by effect. You can also classify by structure like TCA's. TCA's are all tricyclic am... | [
"It help a little but it seems like it's not as clear cut as I had thought. What brought this up is I'm a pharm tech and we had a dr order flurbiprofen (I'd never seen it before). I assumed it was an nsaid (and was right) just based on the -profen suffix. I was just wondering if all the -azoles, -azolams, etc. all ... | [
"I worked as a pharm tech for 3 years so yeah I get ya. A lot of them are named similarly so you can guess like that (ketoprofen too etc). And yes there are many other classes that have similar names but not all of them are, so be careful. Fluconazole and itraconazole are \"azoles\" but metronidazole isn't. So yes,... |
[
"Doctors, If a HIV positive person lived out the rest of their life in a sterile bubble without medication, what would they experience?"
] | [
false
] | From the understanding that HIV only weakens the immune system and AIDS is all the diseases you get as a result of not being able to kill easy to kill viruses, what would happen if a still healthy HIV person lived in a sterile bubble for the rest of their life and was never again exposed to viruses. What other problems... | [
"They could still end up succumbing to the infectious agents already in their body waiting to reemerge. Most people end up getting exposed to a variety of viruses that remain latent and don't cause much of a problem: ",
"CMV",
", ",
"EBV",
", herpes, ",
"HPV",
", HHV-8, etc. With AIDS, you can get react... | [
"Thanks! I couldn't sleep last night and this was one of those middle of the night \"what ifs\" that came into my mind."
] | [
"Bacterial cells outnumber your cells 10-1 in the body, so there would definitely be an infection from a bacteria getting somewhere it should and would normally just be phagocytize. "
] |
[
"If we were to theoretically point the James Webb Space Telescope straight towards Earth, how magnified of an image will we be able to see?"
] | [
false
] | null | [
"So, this wouldn't actually be doable - Earth is too bright and too hot etc - but JWST has a resolution of about 0.1 arcseconds, where an arcsecond is 1/3600th of a degree, and at its distance (1.5 million km), that comes out to a resolution of a bit under a kilometre. So JWST's resolution would be enough to make a... | [
"That might be lower resolution than you'd think, but JWST really is very far away, many times further than any astronaut has ever travelled from Earth.",
"This is a really important point. If you look at reconnaissance satellites (and wave, because they're looking at you!) then they're in much closer orbits. The... | [
"Also, pointing at the Earth would also point it nearly directly at the Sun - which would destroy it almost immediately."
] |
[
"What would need to happen in order for it to be called the LAW of evolution?"
] | [
false
] | There's laws of motion, gravity, and thermodynamics (and I'm sure others), what other laws are there, and what does it take to become a ? | [
"There's nothing weak about the word theory. For instance, quantum field theory is the most accurate description of nature that we have.",
"As for laws and theorems in physics:",
"*Bell's theorem",
"*Newton's law of gravity, laws of motion, law of heating and cooling",
"*Kirkchoff's laws",
"*Kepler's laws... | [
"'Laws of Science' on Wikipedia",
"Theories are models. 'The world is like this'. Laws are fundamental rules that always apply (in the specified circumstances) and are distilled into statements of fact. Natural selection could perhaps be formulated into a law, or set of laws, but evolution is not a simple proposi... | [
"I don't think laws and theories are really the same thing. ",
"Theories are conceptual frameworks that suggests at a mechanistic explanation at how something happens, while laws seem to tend to be concise statement of a specific, accurate observation. ",
"For instance, Newton's law of gravitation is just a spe... |
[
"Why doesn't the brain filter out Tinnitus?"
] | [
false
] | I know that the brain filters out inputs after being present for too long (thus if you don't move your eyes AT ALL the room starts to fade to black). So why doesn't the brain filter out Tinnitus? It's there all the time. | [
"This is not my field of expertise (otolaryngology), though, in 2014 a ",
"comprehensive review and clinical guidelines",
" were published in ",
".",
"It includes, amongst many other notable portions on the pathology, the current understanding of the disease, the treatment options, and further avenues of ex... | [
"The acoustic reflex, which decreases sound transmission to the inner ear, is dysfunctional. This makes loud sounds which previously weren't too loud become significantly louder and reach a persons uncomfortable level. ",
"https://en.m.wikipedia.org/wiki/Acoustic_reflex"
] | [
"The acoustic reflex, which decreases sound transmission to the inner ear, is dysfunctional. This makes loud sounds which previously weren't too loud become significantly louder and reach a persons uncomfortable level. ",
"https://en.m.wikipedia.org/wiki/Acoustic_reflex"
] |
[
"What happens to the earth/soil beneath large cities over time?"
] | [
false
] | [deleted] | [
"It really really depends on the type of geologic environment you're building on. In NYC, it's mostly alluvial, so the foundations of the buildings go very very deep, whereas in Finland, you can build a highrise just on almost the open ground because the bedrock is on the surface. ",
"Buildings are no where near ... | [
"This is probably an exception, but the city of Venice is sinking partially due to the weight of the buildings on the soft water-logged ground.",
"You can watch about it on Nova's ",
"The Sinking City of Venice",
". I linked to the time where I think they explain it but I can't verify it as I have no sound on... | [
"This is very hard for me to answer since it pulls on a couple years worth of soil science classes and requires such sweeping generalities. I will try to be very brief.",
"Chances are that what's underneath buildings is not soil; it's either fill or dirt. Soil is a highly complex and alive combination of physical... |
[
"Can someone give a detailed explanation on how the touchscreen cellphone works in laymen's term?"
] | [
false
] | [deleted] | [
"This explanation is not correct because it implies you have to touch a capacitive touch screen, this is not the case.",
"The two main types of touch screens used in phones are capacitive and resistive. In both cases there are a grid of sensors.",
"In the capacitive case as you bring your body closer to the obj... | [
"http://computer.howstuffworks.com/question716.htm"
] | [
"There are also IR-based touchscreens, which use a grid of infrared transmitters aimed across the screen at infrared receivers. When something (finger, stylus, link sausage) blocks a horizontally and a vertically aimed set of beams, the intersection is easily calculated.",
"I believe that one of the new Kindles ... |
[
"Antarctic Research - I was looking at a map of US research stations and had questions about placement."
] | [
false
] | [deleted] | [
"I spent some time at McMurdo. Part of the reason that we use that area today is heritage. It was first chosen not for science purpose, but pure exploration. It is the furthest south you can go on the water, and hence provides the closest access to get to the south pole. Even now if something is going overland ... | [
"I don't do antarctic research, but I work with people who do. The geographical significance of McMurdo is due to how you get to the continent. Flights leave Christchurch, NZ provided the weather is favorable, and weather conditions can keep travelers laid-up for weeks at a stretch waiting for a window. It's not... | [
"oh, and the belt of sites is temporary science sites. All the permanent stations are on the second map you linked. I'm not sure what they all studied, I think the big 'X' is just core sample sites, but if you zoom in on the first map with all the red dots and go just to the left and down from mcmurdo that was my... |
[
"Why biofuel? isn't it just burning what amounts to man made fossil fuel? how much better is it for the environment if at all?"
] | [
false
] | I saw on but they used the term biocrude, making me think this is something similar to crude oil. What is the difference? What are the byproducts? how are those byproducts different from petroleum | [
"If a biofuel requires no fossil fuels to produce, it's better because it doesn't introduce new carbon into the system. This is the problem with fossil fuels: when burned, the carbon they introduce into the system is new carbon, in the sense that it has been sequestered and kept out of the system, and now it is bei... | [
"FYI the term is \"carbon neutral.\""
] | [
"And by saving fossil hydrocarbons, we can later use them for useful stuff like plastics and medicines instead of just burning them."
] |
[
"Why are anti-particles shown as going backwards in time in Feynman diagrams?"
] | [
false
] | Are they really going back in time, and if so would this explain the lack of antimatter, due to the anti particles essentially creating an identical universe, just going back in time, relative to us? | [
"Really, it's just a way of determining which quantities in your perturbation series are negative. It's mathematical notation only - it doesn't mean particles are actually traveling backwards through time.",
"That being said, it is a necessary mathematical convention to preserve causality. Particles traveling a c... | [
"It doesn't ",
" mean particles are actually traveling backwards through time. That they really are is a perfectly valid interpretation."
] | [
"It really should be stressed that feynman diagrams are not a description of what is physically happening at all. It is a way of representing a single term of an infinite expansion. It happens that in many cases the first term in overwhelmingly dominant, but NEVER a physical system does \"single virtual particle ex... |
[
"I don't quite understand Gamma decay. How does an atom emitting a gamma ray cause it to gain a proton?"
] | [
false
] | null | [
"This is not the case. The emission of a gamma ray (photon) does not occur until after a process of beta decay (or alpha decay, or electron capture) leaves a new nucleus (with more or less protons or neutrons) in an excited state. The new nucleus in an excited state will then decay into a lower energy state by em... | [
"A photon is a packet of energy. The nucleus had extra energy, spat out that extra energy as a photon, and now the nucleus has less energy."
] | [
"This is a common misconception. Except in a handful of contrived cases, there is no such thing as pure \"gamma decay.\" What you have is ",
" decay, which leaves the nucleus in an excited state. This excited state decays via gamma emission, and so you can call this \"beta decay with associated gamma decay.\" ... |
[
"Why wasn't the grand canyon uniformly eroded?"
] | [
false
] | [deleted] | [
"The grand canyon was carved out over a long time and spans a large area. Many things could have fallen in the stream, altering the speed and rate of erosion. There might be some answers from the geological side too but I'm unsure of it."
] | [
"Fractals! In general, it's a consequence of the scale-invariance phenomenon in Complex Systems found throughout nature: patterns created by nonlinear effects, rather than hidden patterns in the ground being eroded. \"Grand canyons\" of very similar structure can form in drainage ditches on the scale of meters "... | [
"It's all about the rocks. Simply put, not all rocks are the same. Some are harder than others. The classic canyon shape that we see today comes from these different types of rocks eroding at different rates. Hard rocks typically form cliffs, soft rocks form slopes. At GC there hard and soft layers mixed together (... |
[
"How does bee hair or trichome work?"
] | [
false
] | [deleted] | [
"I'm not familiar with the term trichome, where did you see it? I do not recall seeing it regularly in bee literature.",
"The hair on bees is typically branched unlike the hairs on other hymenoptera (ants, wasps). This is one of the distinguishing features of bees. The hair attracts pollen, and other dust like su... | [
"I am sure someone has but I don't have a direct source for it. It is commonly known that flying bees generate a positive charge, collisions with minute particles in the air strip electrons. ",
"There has recent been work showing that [bees sense](http:/dx.doi.org/10.1126/science.1230883) a negative charge and g... | [
"Thank you I thought I was never going to figure this out. I thought or rather assumed bees had trichomes which help collect pollen as they land on the flower. So thanks for clearing that up. I am mostly interested in the collection of the pollen, when you say \"slight charge\" what do you mean by that? Has anyone ... |
[
"Q: Why do clouds lump together, rather that spread out evenly across the sky?"
] | [
false
] | Sometimes when the sky is clear you might see one solitary cloud moving across the sky. Why don't they spread out until the vapor is more evenly distributed? Is it because the water molecules are "attracted" to each other? | [
"Clouds do not stick together at all. Clouds are formed by micron sized droplets of water. They appear to stick together because the temperature-humidity characteristics of the atmosphere in the locality of the cloud is right for the droplets (cloud) to form. ####This is totally copy/pasted."
] | [
"There's no attraction involved, per se. However, once formed, a cloud tends to maintain a local environment of high humidity, which reduces evaporation. ",
"Also, water vapor does not evenly spread out rapidly, it is concentrated and moved around by atmospheric motions. ",
"So once a cloud forms, as long ... | [
"Don't think of clouds as physical objects in the sky. A cloud is simply a patch of air where conditions are right to condense water. A cloud does not necessarily have more water in it than the air around it, it's just that the water in a cloud is visible."
] |
[
"What makes the velocity of a charged particle, the direction of the magnetic field, and the direction of the force felt by the particle all perpendicular to each other?"
] | [
false
] | Why is it a cross product? | [
"I can think of at least two ways to answer this question. On the one hand, almost all fundamental \"why\" questions are meaningless: eventually the answer is \"because that's how it is\". In this case, we can say in a rather anti-climactic and probably unsatisfactory way that the magnetic force is proportional to ... | [
"This is probably the same thing ",
"/u/Midtek",
" said, but I'm going to try to say it with fewer words.",
"We can observe charged particles. We can observe the forces they exert each other when they move. But the magnetic field is entirely our own invention. It's a mathematical model we use to predict how a... | [
"Like u/ midtec said, the key is lorentz invariance. A magnetic field can be viewed as an electric field the appears in a moving reference frame.",
"Tak the example of two stationary charges q1 and q2 at positions (0,0,0) and (x1, y1, 0) respectively in a reference frame (R2). The electric force on q2 is F2=(q1*q... |
[
"The planet Mercury is actually just a core?"
] | [
false
] | Is it true the planet Mercury is simply a core of a former planet? Is there any research going into what happened to the rest of the planet? Like did the rest of the planet.. the surface exists before it got close to the sun or was it melted away by it? Edit: sorry I have been having notification issues on reddit. Than... | [
"you should edit the wikipedia page if you think the text is misleading"
] | [
"Mercury's core has a higher iron content than that of any other major planet in the Solar System, and several theories have been proposed to explain this. The most widely accepted theory is that Mercury originally had a metal-silicate ratio similar to common chondrite meteorites, thought to be typical of the Solar... | [
"Actually not a higher Fe content... a larger core relative to the size of the planet. The Wikipedia wording is misleading. I don't know of any theories which postulate that the inner planets started as gas giants. In order to make a gas giant you probably need to be far enough from the Sun that ices can form to he... |
[
"Do overweight people have extra amount of nerves and pain receptors distributed around their body?"
] | [
false
] | [deleted] | [
"Yes - ",
"https://www.quora.com/Do-obese-people-have-more-touch-receptors-than-non-overweight-people-Or-are-people-who-are-obese-less-sensitive-due-to-their-touch-receptors-being-spread-out-over-their-bodies-increased-skin-surface-area",
"Basically the skin is an organ and is continuously remodeling itself. Th... | [
"If your skin would shrink accordingly, yes. Since it doesn't and your cells won't get more dense: No. "
] | [
"So theoretically, if you were to become obese and then rapidly lose weight, would you have a significantly higher density of nerves? "
] |
[
"Mandelbrot sets, Julia sets and fractals in general."
] | [
false
] | Periodically, I come back to the world of fractals and remind myself that I still do not fully grasp their implications. I've watched documentaries, played with Java applets and read articles on the subject; however, I still only see it as an infinitely complex shape and not so much a fascinating, mathematical constru... | [
"Consider asking this in ",
"/r/math",
", a little better fit.",
"There are many different kinds of fractals, with different math behind them, but as a rule, fractals are more interesting than they are important. ",
"If there is one important thing they show, it is how very chaotic behavior can arise from ... | [
"One significant aspect of fractals sets is that it's difficult to tell whether a particular point ",
" or ",
" part of it, along the frilly edges. If it takes 7 billion iterations to determine that a point falls out of the set, that really tells you nothing about any given nearby points. Move over 0.0000000007... | [
"The key feature of a fractal is a self repeating pattern. You look at it as a whole, then zoom in on one part, and it looks as it did when you were zoomed out. "
] |
[
"Is there any research on the percentage of depressive outpatients that complain of loss of cognitive function(and of which type) even after their illness remission?"
] | [
false
] | [deleted] | [
"I don't have a reference off hand for you, but it is important to note that loss of grey matter is not the only cause of cognitive complaints.",
"Residual rumination, worry, and sleep disturbance (",
"which is common after remission of depression",
") can all contribute to cognitive inefficiency. A continued... | [
"Predominantly insomnia symptoms - difficulty initiating and maintaining sleep. This is in contrast to older views that insomnia could be secondary to (caused by) depression. A considerable amount of research has now shown that insomnia can have an independent clinical course, and so merits focused treatment, parti... | [
"Predominantly insomnia symptoms - difficulty initiating and maintaining sleep. This is in contrast to older views that insomnia could be secondary to (caused by) depression. A considerable amount of research has now shown that insomnia can have an independent clinical course, and so merits focused treatment, parti... |
[
"Does the act of boiling actually help cook foods (e.g. potatoes), or do you get the same results with really hot (99C) water?"
] | [
false
] | null | [
"Boiling is simply the hottest water temperature you can achieve under given atmospheric conditions. Typically, when cooking food by submerging it in a non-oil liquid, there is no danger of burning the food, so the highest available temperature is preferred because it will yield the shortest cooking time.",
"Thi... | [
"I agree with all of this, but I thought I'd just throw in my 2c as a biologist. Let's think for a second about what \"cooking\" actually is: It's the denaturation of proteins and lysis of cells in your food. We cook food for various reasons, but high on that list is to kill the bacteria, and also to make the food ... | [
"And this is exactly why it is more nutritionally beneficial to steam your vegetables than to boil them: when the cells do lyse, all of the contents get distributed among the boiling water solution, and thus not in the cooked vegetable food you finally eat. Steamed veggies, on the other hand, may also have lysed c... |
[
"Froze a bottle of gatorade, turned to ice, left gatorade out at room temperature, melted back to liquid form but with a significantly higher amount of water (i.e. it was watery). Why?"
] | [
false
] | null | [
"What would happen is that the water would freeze out; if you freeze salt water, you get ice- not salty ice, but ice. As the Gatorade froze, the solutes (the sugars, etc.) would be the last to freeze. As it re-melted, the ice would float on top, and the sugar and other components would sink to the bottom. As more o... | [
"Did you do this with the bottle cap on or off?"
] | [
"On sir."
] |
[
"Do black holes obey conservation of mass-energy when it grows/evaporates?"
] | [
false
] | [deleted] | [
"Energy is still conserved when considering black holes. The energy taken away by hawking radiating equals the energy the black hole looses. Incidentally this radiation equals what you would expect if you treat a black hole as a black body and were to calculate its black body radiation. A black hole is then a very ... | [
"So, as this layman understands it, inside a black hole is a veritable \"no man's land\" of physics, where laws break down.",
"Not really. It's just that unless you happen to be falling into a black hole yourself, the event horizon is a solid, impenetrable boundary which nothing ever crosses. And if you ",
" fa... | [
"No-hair is false."
] |
[
"Why is there \"more\" land above the equator?"
] | [
false
] | As the question asks, why is there "more" land above the equator? I put more into quotes because I don't know if Antarctica equals out off of the North's land mass. | [
"You're not the first person to ask this question... ",
"The notion of Terra Australis (The Great Southern Continent) was introduced by Aristotle. His ideas were later expanded by Ptolemy (1st century AD), who believed .. that the lands of the Northern Hemisphere should be balanced by land in the south."
] | [
"To put dinosaurs into perspective, more time passed between Stegosaurus and Tyrannosaurs than between Tyrannosaurus and human. In fact there was 10 million more years between Stegosaurus and Tyrannosaurus than Tyrannosaurus and human."
] | [
"The reason it's arbitrary is because the of continental drift. We're considering a very particular time in the billions of years of Earth's existence, during which land mass has evolved enormously. It just doesn't make sense to ask why at some seemly unimportant time more land mass exists in a particular hemisphe... |
[
"How could natural selection bring about the evolution of wings?"
] | [
false
] | All aspects that require flight, such as wings, feathers, and low body mass seem like evolutionary disadvantages up until flight is possible. Why would creatures such as chickens, or the predecessors to flying birds, evolve these features if they didn't immediately present an advantage? | [
"Excellent link on the evolution of flight in birds by justanotherusername_",
"However, winged flight evolved independently at least 4 times (I wont argue the case of instances of gliding such as flying snakes and sugar gliders...) in the following lineages:",
"Birds (duh...)",
"Pterosaurs",
"Mammals (bats)... | [
"Indeed - a key concept in the evolution of new and powerfull capacities is \"pre-adaptation\" (which is often mistakenly taken to imply the directed evolution of features in view of future benefit, which it isn't). Evolution doesn't work on a vacuum, it need to work on structures and variation. Thus a little nubbi... | [
"excellent point that insects first may have evolved wings for purposes other than flight. it is theorized that birds early ancestors, (think ovoraptor, bipedal, with feathered forelimbs) the feathers wouldn't be useful for flight just yet, but they were awesome at keeping a nest of eggs warm. the further developme... |
[
"Is it true that the effects of caffeine in (black) tea are inversely proportional to the brewing time?"
] | [
false
] | I've heard several times already that if you brew black tea longer, it's not going to have as much effect on you (or that if you want to get a biggest "kick" out of your tea you should brew it quicker not longer). Google couldn't seem to find anything "serious" on the subject. page for tea says that tannins released by... | [
"I had always assumed that the caffeine was destroyed by the heat of roasting, not that it sublimed out. ",
"Also, it seems strange: Coffee-roasters stand in front of open-top coffee roasters - you'd think that they'd inhale the caffeine, and adsorb it through the lungs and airways?",
"Oh, and about the tea - b... | [
"http://jat.oxfordjournals.org/content/32/8/702.full.pdf"
] | [
"There's obviously going to be more raw caffeine in a tea brewed longer than one brewed shorter, but I think your idea of tannins interfering with bioavailability is spot on. Sorry for the shitty reference, you're right about the lack of serious articles on the subject, but ",
"this",
" experiment uses tannic a... |
[
"If we could rearrange all the atoms(protons, electrons-all that jazz) on earth into denser elements, would gravity stay the same?"
] | [
false
] | null | [
"Nope. If the earth becomes denser, the gravity at the surface GM/R",
" is now using a smaller R, so becomes higher. Measuring mass and radius of exoplanets lets you not only determine surface gravity, but also tells you a lot about what materials make up the exoplanet based on the density. Is it mostly ice? Roc... | [
"However, gravity at the same distance from the center (where the old surface was) would stay the same."
] | [
"Yes, just like for black holes, there's no extra pull, it's just that you can now get closer to the same mass."
] |
[
"Sexual reproduction - Why?"
] | [
false
] | Why do we have various species including plants perform sexual reproduction? Isn't asexual reproduction more efficient? What advantage would sexual reproduction have over say splitting or budding? | [
"Well, in asexual reproduction, if one plant has a gene that gives it sharper thorns and another has a gene that gives it stronger roots, that's all there will ever be. If their descendants survive, there will be plants with sharp thorns and plants with strong roots, but no plants with both. And whichever one gives... | [
"Sexual reproduction allows variations in genetics, which can provide important advantages to the species. ",
"For instance, in a Reef Aquarium, most corals multiply by budding or splitting. If a disease is introduced that effects a species multiplying in such a manner, there is no diversity from one of said cora... | [
"Sexual reproduction has a distinct advantage due to the opportunity to acquire new (and potentially better) genes. New genetic material can also replace damaged genetic material and restore a healthy genome."
] |
[
"Why can I hear the bass from music playing far away but not the high frequencies?"
] | [
false
] | null | [
"Bass is low frequency, so it has longer wavelength, so the sound wave is more likely to propagate around obstructions instead of being reflected or absorbed by them. "
] | [
"This is also the reason that foghorns have a low frequency (or pitch)."
] | [
"not entirely. That's a lot more to do with the ionosphere being reflective of that band of frequencies. "
] |
[
"AskScience AMA Series: We're Chris Joyce, a science correspondent for NPR, and Rebecca Davis, a senior producer with NPR's science desk. Ask us anything about plastic pollution!"
] | [
false
] | We've been taking a . Global plastic production has grown to 420 million tons in 2015, and some plastics will last for centuries or even longer. NPR most recently published a story looking at for the plastic waste from their products and who've been campaigning to ban plastic bags. ready to go at 1 PM (ET, 17 UT)! Foll... | [
"We will never replace the concept of plastic (lets use a better term, consumer polymers. Plastics are a fuzzy lay term for thermoplastic elastomers, a technical term for certain polymers). However we are trying, with some success, to make consumer polymers that mimic the properties of the nondegradable polymers th... | [
"What alternatives to plastics can be mass produced on the scale plastics are produced? Can plastics be reverted into a previous compound more suitable to ethical standards? And what strides are being made to clean up plastic pollution? "
] | [
"Hi. One shouldn't burn plastics at all. That can release toxins into the environment. If you have recycling at all just follow your local recycling guidelines. Don't put anything you aren't sure can be recycled into recycling because it creates contamination and reduces the possibility that other recyclable plast... |
[
"What are some areas of science that can still be added to by a hobby scientist a la Sir Isaac Newton?"
] | [
false
] | If someone had a strong scientific/ technical background but wanted to pursue research as a hobby rather than strictly a profession as the "gentleman scientists" of yore did. I know of the DIYBIO movement, etc. If you were going to attempt to contribute some meaningful scientific knowledge to the world, what area of sc... | [
"The area a single hobbyist is most likely to contribute to (IMO) is anything computational.",
"It seems limiting, but you can work in almost any field via computing. You can work on computational physics problems, simulate chemical reactions, model infectious disease, analyze the human genome, mine behavioral d... | [
"Keeping a natural history journal is something a layman can do easily. It can contribute to baseline data of an area. Ecologists look back at these journals to figure out what has changed in an ecosystem among other things. Once you know a place well enough you can determine whether a certain species is invasive, ... | [
"Anything that can be done with computers!",
"Let me tell you what all you can do with just a desktop PC that I could think of in 5 minutes (any of which I'd love to do if I can squeeze more time off my unorganized life):",
"You can run simulations to fold proteins (few Tesla GPUs and small simulations are easy... |
[
"Dopamine surges in the brain cause down regulation of dopamine receptors. Is this always true, regardless of what caused the surge? (Drugs vs. natural rewards like orgasm, food, ect)"
] | [
false
] | Can overstimulation caused by abusing natural rewards be equally as "damaging" as the same amount of over stimulation caused a drug/drugs? | [
"Well, there are couple things to consider.",
"1) Amphetamines can lead to increased synaptic dopamine (DA). Theoretically, this increase in DA levels should produce more DA receptor activation, and a function of that would be increased DA receptor desensitization. A common compensatory mechanism to said desensit... | [
"As an educated guess I would say yes. Similarly to the way that viewing pornography frequently for an extended period of time can decrease the brain's \"value\" for actual sexual intercourse. I wouldn't expect it to be anywhere near as drastic as drug use can be. In example, MDMA. The substance itself acts on the ... | [
"a condition known as \"serotonin syndrome\".",
"No. That's not what serotonin syndrome is. SS in an acute excess of serotonin, which causes symptoms ranging from anxiety to seizures. ",
"https://en.m.wikipedia.org/wiki/Serotonin_syndrome"
] |
[
"Why is cuisine from hot places, spicy?"
] | [
false
] | I have observed that the food in all Hot places around the world tends to be much spicer than the cooler areas. Be it Mexico & central Americas, Sub-saharan Africa, or India, the food eaten is usually spicy and lot of chilies are usually used. If you name any spicy food, it is a good bet that it comes from the equatori... | [
"There are a couple of reasons\n1. cover taste\n2. antibacteria\n3. natural availability",
"Many spices have Antibacterial qualities. As you can read from the link\n",
"http://www.news.cornell.edu/chronicle/98/3.5.98/spices.html",
"Also, just FYI, many spices (cummin, curry, black pepper) have been shown to h... | [
"They don't just cover up the spoilage, some spices have antimicrobial properties and actually prevent it."
] | [
"lay person - hot temperatures mean more food spoilage, more spices are used to cover that up. "
] |
[
"How long after eating a peanut butter sandwich must I wait before I kiss someone with a peanut allergy?"
] | [
false
] | Let's say I eat a peanut butter sandwich at noon and go out later that night and meet a girl who tells me she's got a peanut allergy. I say: "oh that sucks" and then we start making out at midnight. 12 hours enough time? What if I brush my teeth and rinse with mouthwash beforehand? If I was dating a person with a peanu... | [
"Is letting go of peanuts so hard? ",
"Seriously though it depends. Try to be as clean as possible and go ahead once, (with precautions like meds on the side of course) and see what happens. Then decide yourself..",
"But letting go is simpler right?"
] | [
"There is an unknown variable in this, so it's difficult to answer.\nHow severe is this peanut allergy? Are they going to die or just get a rash?",
"If I was dating a person with a peanut allergy does that mean I would have to avoid peanuts too?",
"You should obviously be more selective of when you consume pea... | [
"My gf in high school was allergic to peanuts. One of the more severe allergies. One time someone in 1st period ate some peanut butter crackers and got some crumbs on a desk. When fifth period came around, she entered the room and her throat started itching and closing up.",
"Needless to say, I once kissed her... |
[
"What are the distinctions between antisocial personality disorder and psychopathy and sociopathy?"
] | [
false
] | null | [
"Psychopathy is an outdated term. It was replaced by antisocial personality disorder in the DSM III. Sociopathy is the layman's term for antisocial personality disorder.",
"They are all the same."
] | [
"Work Cited ",
"Bergman, M (Producer), & De Palma, B. (Director). (1983) ",
" [Motion picture]. United States: Universal Pictures. ",
"Drake, J., et al. (Producers), & Harron, M. (Director). (2000) ",
" [Motion picture]. United States: Lions Gate Films"
] | [
"What do you base that classification on?"
] |
[
"How long does it take to measure the physical effects of age? Conversely, how soon could it be conclusively determined that someone is not aging?"
] | [
false
] | null | [
"The question becomes \"at what scale\"?",
"Physically, it's my understanding that the length of telomeres during mitosis can be seen to reduce during subsequent replications, which would allow one to measure the physical effect of age, in a cell, as soon as that cell divides a second time. Conversely, you could... | [
"I would say theoretically you are correct. But our methods of detecting subtle changes in Telomere length have limits and the difference between the two measurements would likely be within error. ",
"Now, I have no idea on a time scale, what those limits are to detect \"aging,\" but I would have to say greater t... | [
"Hi feo_sucio thank you for submitting to ",
"/r/Askscience",
".",
" Please add flair to your post. ",
"Your post will be removed permanently if flair is not added within one hour. You can flair this post by replying to this message with your flair choice. It must be an exact match to one of the follo... |
[
"There's a lot of pseudoscience in the fitness community, so anyone know of studies which show what kinds of exercises lead to the most strength gain?"
] | [
false
] | [deleted] | [
"Isn't that a fitness community that apparently has a lot of pseudoscience?"
] | [
"Eh I'm inclined to agree with OP and PillsInButt that anything fitness related is plagued with pseudoscience. It is really truly difficult to know what's out there with scientific evidence. ",
"r/fitness",
" is a nice community and they may have a lot of anecdotal experience, but what does the data really say.... | [
"You've been here for 1.5 years?!",
"You should check out ",
"/r/conspiracy",
", ",
"/r/health",
", etc. for more accurate information that's free from pseudoscience and anecdotal evidence."
] |
[
"If, as suspected, the earth was hit by Theia early in its creation, why don’t we have a ring of debris around us like Saturn?"
] | [
false
] | null | [
"Because Saturn has multiple moons that actually keep its rings in a (roughly) stable orbit. The inner moons actually speed falling particles up and keeps them from falling into the planets atmosphere while the outer moons slow objects down and keep them from escaping the planets gravity.",
"That’s really simplif... | [
"Agreed, nothing atomic is happening. Then again, nothing atomic is happening during the actual impact either. The same amount of potential energy is converted to kinetic energy whether it's a dust cloud or meteor, as long as it's the same amount of mass. So sure, spectacular meteor shower, but still boiling oceans... | [
"Agreed, nothing atomic is happening. Then again, nothing atomic is happening during the actual impact either. The same amount of potential energy is converted to kinetic energy whether it's a dust cloud or meteor, as long as it's the same amount of mass. So sure, spectacular meteor shower, but still boiling oceans... |
[
"Why do skydivers have a greater terminal velocity when wearing lead weight belts?"
] | [
false
] | My brother and I have to wear lead to keep up with heavier people. Does this agree with Galileo's findings? | [
"For a quadratic drag force, your terminal velocity is proportional to the square root of your weight. If everything else is the same, an object with a higher mass will have a higher terminal velocity."
] | [
"The acceleration due to gravity is independent of mass and is not affected by the lead weights.",
"What is affected is drag. Loosely speaking, the drag when falling depends on the shape of the object that is falling. Your shape does not change significantly with the lead belt, but your mass does, and the result ... | [
"A quadratic drag force takes the form of ",
" = - cv",
".",
"It has magnitude cv",
", and direction opposite to the velocity of the object.",
"c is a constant that depends on the medium and the object. You can roughly expect c to be linear in the cross-sectional area of the object.",
"To find the termi... |
[
"Why are snowflakes flat? Why not something with more depth?"
] | [
false
] | null | [
"Under the conditions where snow crystals grow, the growth is fastest in regions where the crystals are sharp",
". So basically, the rate at which the crystal gets thicker is much lower than the rate at which it spreads out in it's major plane."
] | [
"If you look into the work of Wilson A. Bentley, you'll see that he discovered, through photography, that they do in fact form much more complicated shapes such as columns and pyramids. Kind of hard to find the pictures, but if you look enough they're there."
] | [
"This is ultimately the answer I was looking for, thanks. "
] |
[
"Can anyone explain the anthropological basis of grinding grain to produce a flour?"
] | [
false
] | [deleted] | [
"I think the question is ",
" they discovered this. Waking up one day and saying \"Eureka! We will get more nutrition this way!\" seems unlikely, but something allowed cultures that were not in contact with each other to come up with the same concept. ",
"I'm curious on this one as well myself."
] | [
"I think that people will commonly try grinding any foodstuff that's tough or difficult to chew, and they often decide that continuing to do so is a good idea. "
] | [
"Well remember that ancient grains like teosinte the original corn was very hard almost rock hard So prehistoric people had to grind them down to get inside. "
] |
[
"In which direction is the universe expanding? Is the universe expanded the same in all directions?"
] | [
false
] | If the Big Bang theory is right, wouldn't the universe have some kind of 'center' it 'errupted' from? Shouldn't we see celestial objects move in a certain direction? It would seem really contra intuitive for everything to move away from earth in the same manner, like it would be the center of the universe. | [
"If the Big Bang theory is right, wouldn't the universe have some kind of 'center' it 'errupted' from?",
"No, although this is a very common misconception. The Big Bang wasn't an explosion, and the subsequent expansion isn't like debris spreading out from a central point.",
"A better picture to have in your hea... | [
"The expansion appears to be homogeneous (the same at all locations) and isotropic (the same in all directions), as described by the ",
"FLRW metric",
"."
] | [
"When you are thinking about The Big Bang, you shouldn’t think about objects moving through space because of some “explosion”. Instead, it is space itself that is expanding.",
"Imagine a deflated balloon. If you draw a bunch of dots on the surface and then start to blow air into the balloon, what happens? Each do... |
[
"When an object is burnt completely what happens to all the atoms, electrons and protons that are there in it?"
] | [
false
] | null | [
"I'll define burning as oxidation. If something is completely burned, it is completely oxidized. All of the molecules break apart and form oxides. The carbon becomes carbon dioxide, hydrogen becomes water, etc. Under incomplete oxidation (insufficient oxygen, low temperatires), you will see carbon monoxide and soot... | [
"Nothing really happens to them other than being combined in different compounds.",
"If something burns completely away, it's not gone. It's all been converted to gasses or smoke which is blown away. ",
"Which is why I think it's kind of funny, for example on a sci fi movie, if someone is vaporized they just ... | [
"Yep, what DarkMatter wrote is correct; burning is simply a chemical reaction, not a nuclear reaction as the OP seems to be asking, so all the atoms, electrons, neutrons, and protons are there in the combustion products. Much of the burnt fuel is converted to gases and vapors, so it might appear that some matter i... |
[
"Why do some beer bellies feel firm if they're caused by extra fat? Why aren't they soft and squishy like fatty tissue in other areas of the body?"
] | [
false
] | Okay, so odd question, I know. But sometimes when a man gets a beer belly, it can feel kind of firm, like the belly of a pregnant woman. I searched a little online for why, but all I could find were "causes of beer bellies" which, is obviously extra calories leading to extra fat. What I want to know is why the beer bel... | [
"This is not specifically down to excess fat as a result of calories in alcohol, but down to the difference between subcutaneous ('soft') fat and visceral fat, which is fat stored deeper in the body, which also feels firmer.",
"For reasons mostly down to genetics, some people divert excess calories to visceral fa... | [
"So when I hug a guy with a big, firm beer belly, am I feeling his abs? If so, is the fat behind the abs? Or, I guess a better question- How much deeper is \"deep?\"",
"Is the visceral fat stored between the organs? Would it eventually run out of room in there and go more toward the surface? I can't imagine muscl... | [
"You're very welcome! Check out ",
"this colorized MRI",
" that shows visceral adiposity and subcutaneous fat storage in two women who are the same height (one normal weight/thin, one morbidly obese). The black represents air so the weird black things you see on the left image are her intestines that have been ... |
[
"Why do small birds hop and not walk to move around?"
] | [
false
] | I walked past 4-5 small birds today and they just hopped away, then started taking steps as they ate things off the ground. | [
"I believe it's actually a very efficient way to move around, using less energy to cover the same distance.",
"Another example of this type of movement would be the astronauts hoping around on the moon. I seem to recall one of them commenting how efficient it was to move around that way."
] | [
"I am pretty sure someone with bird knowledge will expand but I read in a book that's their fear instinct kicking in. By hopping they are ready to fly away at moment notice since they spring themselves before taking off."
] | [
"I assume this is the reasoning behind small mammals hopping also? Rabbits, kangaroo mice, etc."
] |
[
"Are there non-primates that live to see their grand-young? If so, do they recognize them as such?"
] | [
false
] | null | [
"Elephants and orcas both live in matrilineal societies often headed by a grandmother, orangutans are another species that even though they do not live in tight groups you often see multiple generations in over lapping territories. We think that there are multiple ways of identification include scent and other bio ... | [
"Elephants live that long, as do some turtle species. Elephants probably would as their society is dominated by very close nit family bonds. Herds are mostly either matriarchal or bachelor groups, and the matriarchal ones are usually run by the eldest female, so she would more than likely live to see her grand-offs... | [
"Turtles wouldn't recognize their offspring regardless of whether or not they can recognize individuals because they're not around to watch them hatch."
] |
[
"Can people who have a cochlear implant tell which direction sound is coming from?"
] | [
false
] | null | [
"Hi dangerevans007 thank you for submitting to ",
"/r/Askscience",
".",
" Please add flair to your post. ",
"Your post will be removed permanently if flair is not added within one hour. You can flair this post by replying to this message with your flair choice. It must be an exact match to one of the ... | [
"Medicine"
] | [
"Medicine"
] |
[
"Physics mistake with the rotating body of Rama - does nearing the outside of the cylinder increase centripetal acceleration, even while not in contact?"
] | [
false
] | null | [
"My impression reading the book was that the atmosphere inside the cylinder would push him around and give him the lateral acceleration needed to create the centripetal acceleration."
] | [
"But would the air really be swirling? I'd figure it would be turbulent around structures, but otherwise wouldn't be rotating uniformly."
] | [
"I realize now that my answer is laymen speculation which is forbidden in askscience, but over time any gas inside the rotating cylinder would begin to rotate at the rate of the cylinder due to friction."
] |
[
"How did fish wind up in lakes that are far inland or in high altitude areas?"
] | [
false
] | If I had to guess, then I imagine they are remnants of when the oceans were in that particular location but I would like clarification on this. | [
"If the fish were from when the area was covered by oceans then they would be unique species, having evolved from old salt water species. That's almost never the case with lakes.",
"Rather, the answer is much simpler. Lakes often have streams or rivers connecting them elsewhere, and so fish migrate along those ro... | [
"I read on here that fish eggs can be carried inadvertently by birds."
] | [
"I won't speak for all alpine lakes but in Yosemite NP in th US, the park authorities used big bombers left over from WW2. To increase the \"value\" of the lakes, they basically bombed them with fish. I was a ranger there but ill update this with a more legitimate source once I'm off my phone.",
"edit: info ",
... |
[
"What is the deal with solar energy?"
] | [
false
] | I hear every week about a breakthrough in solar be it using some kind of bacteria or nano-material or what not. I've also read that solar efficiency is doubling every year and is only a few doublings away from out-competing fossils. Basically it just sounds a bit too good to be true and my sensationalist-senses are tin... | [
"Not every development that works in the lab works in the field. Not every concept is capable of working on a commercial scale.",
"Most of these 'breakthroughs' are news releases to publicize academic research, which in turn 1) promotes the academic research facility (in order to secure more funding, improve the ... | [
"Most of these 'breakthroughs' are news releases to publicize academic research, which in turn 1) promotes the academic research facility (in order to secure more funding, improve the name of the institution in rankings which are largely a beauty pageant anyway, and get better students)",
"I believe the term is \... | [
"What do all these new \"breakthroughs\" mean for solar? Has any of them produced commercially viable improvements yet?",
"Industry tends to lag behind academic research by something like 10 years. Everything in use now was first discovered in a research lab. That said, the biggest push towards cheaper and higher... |
[
"How did the Ice Age support huge animals such as Mammoths and other giant versions of today's animals?"
] | [
false
] | The cold would likely hinder plant growth and thus limit food resources available to herbivore species, which carnivores also need to survive. How were such animals anle to live in that time? | [
"Remember that evolution and the occurrence of a natural ice age work over very long periods of time. The plants and the animals had a chance to evolve with the changing climate.",
"The land was also differently distributed because of plate tectonics.",
"Next there's the fact that we experience cold currently b... | [
"This is a great answer and I agree with pretty much all of your points apart from one:",
"The land was also differently distributed because of plate tectonics.",
"This factor is actually completely negligible on the timescale of the Quaternary ice age, which is only the last 2.5 million years or so. Plate tect... | [
"A large animal a a smaller surface area to mass ratio than a smaller animal. It helps to retain heat."
] |
[
"The faster you go the slower time goes relative to Earth; what happens when you go much slower than how fast Earth is traveling and is there an actual zero velocity relative to the Universe?"
] | [
false
] | I apologize if this is a stupid question but I've been wondering it for quite some time. Everyone always compares speeds to Earth and considers it as the point of zero. However we're actually traveling through our solar system which is traveling through the galaxy, galaxy clusters, etc., so the rate at which we perceiv... | [
"There is no absolute frame of reference, therefore there is no \"zero speed\".",
"The time dilation you're referring to applies to two frames of reference. If you are moving very fast relative to me, I would observe you as travelling through time slowly, while you would observe the same for me."
] | [
"So if I'm moving fast I still would see the person moving slow as moving slow through time, not fast? That's odd... ",
"I guess I worded my question wrong. Let me are if this makes any sense: there's a point at which time can reverse itself, or faster than light speed. Is there a relativistic speed that makes ti... | [
"if you were traveling at .999c then time for you would travel \"normally\" but if you stepped out of your spaceship, time would have traveled \"insanely fast\". i don't want to do the math, so here is a very rough estimate: if you traveled that fast for what seemed like 1 second, then the world outside would have ... |
[
"If all galaxies in the universe are flying away from each other (red-shift, right?), how is also true that the galaxy Andromeda is on a collision course with us?"
] | [
false
] | As I understand it, everything in the universe is moving away from each other. We know this because of the red-shift in galaxies far away, and galaxies that are furthest away have the most red-shift - meaning the universe is expanding at an expanding rate. But I also understand that we are on a collision course with An... | [
"The expansion is most evident on extremely large scales. At smaller scales, it's practically undetectable. Everyday objects have EM interactions that utterly overwhelm the expansion. The planets aren't moving away from each other or the sun because they are ",
", so aren't affected by the expansion. Similarl... | [
"The space between galaxies is expending, therefore some galaxies move apart, while other galaxies, that are close together, are attracted though gravity and will merge."
] | [
"While the universe overall is expanding, that doesn't account for every single part of the universe. Think about it like a big, expanding, crowded asteroid field; if you look at the asteroid field as a whole it's expanding, but it's so densely packed with asteroids that the odds are pretty significant a few of tho... |
[
"Is there any way to make oneself dream less often?"
] | [
false
] | null | [
"Ever since I started smoking weed, I rarely have dreams. It seems to take a few days of sobriety for dreams to return."
] | [
"You can learn to control them - that way you won't be able to get enough. The first evidence of lucid dreaming was produced in the late 1970s by British parapsychologist Keith Hearne. A volunteer named Alan Worsley used eye movements to signal the onset of lucidity, which were recorded by a polysomnograph machine.... | [
"If you feel like you're dreaming too much, there is a good chance you aren't going into the deeper sleep cycles and there are factors preventing you from reaching deeper sleeping states. Generally either too much light in the bedroom or your health and hormones are out-of-wack."
] |
[
"Where do photons go? [elaboration in the text]"
] | [
false
] | null | [
"They are absorbed by the walls and objects in the room."
] | [
"Absorbed how? Where do they go once they're in the wall?"
] | [
"https://en.m.wikipedia.org/wiki/Absorption_(electromagnetic_radiation)"
] |
[
"How long would it take to get to Mars if you accelerated at 1G til half way there, swivelled around and then decellerated at 1G the rest of the way?"
] | [
false
] | The idea being you experience earth-like gravity for the journey. Also - what would your top speed be? | [
"Are you sure this doesn't belong in ",
"/r/homeworkhelp",
"??",
"The Earth and Mars are 2.629×10",
" kilometers apart at their closest. 1g=9.8m/s/s. So half the distance is 1.315×10",
" kilometers. d = 0.5",
"t",
"Answer is ",
"11 days",
"I forgot to divide by acceleration as others pointed out... | [
"Cheers",
"I haven't been in high school for over 15 years and wasn't smart enough to do the math back then either!"
] | [
"Fun fact: the top speed would be about 0.5% the speed of light."
] |
[
"How do candles work?"
] | [
false
] | I know the wax is burning, but why is a wick necessary and why doesn't all the wax catch on fire? | [
"Liquid wax doesn't burn in a candle, vaporized wax does."
] | [
"The burning of the wax is a chemical combustion reaction, in which the wax hydrocarbon reacts with oxygen in the air to form water and carbon dioxide. There is an optimum ratio of oxygen to wax which can be determined from the balanced chemical equations. \"Wax\" typically is not a single pure compound, but a mi... | [
"Good point! As the liquid wax is drawn up through the wick nearer to the ongoing combustion reaction, some of that released heat energy is again absorbed to drive one more phase change, from liquid wax to vapor. This helps to explain why the wick, itself, does not burn (or burns very slowly) as the candle burns:... |
[
"Are we able to harness the power of waterfalls and is the output enough to make it a viable source of renewable energy?"
] | [
false
] | [deleted] | [
"That's essentially what hydroelectric power is, except in most cases the \"waterfalls\" are artificial."
] | [
"Have you looking to the power station at Niagara Falls? Have a look at the (overview on Wikipedia)[",
"http://en.wikipedia.org/wiki/Niagara_Falls#Power",
"]. ",
"Hopefully more people will chime in on this one. I know there are other hydroelectric plants positioned on waterfalls."
] | [
"Snoqualmie Falls, in Snoqualmie, WA generates power by having a cavity ~ 100m below the top of the falls and behind the falls themselves where water falls through the turbines. ",
"Here's a few images of the cavity during renovation work"
] |
[
"If lightning struck a pool of pure water with someone submerged in it would they survive?"
] | [
false
] | I know that pure water does not conduct electricity because it does not dissociate into ions, but would that insulate someone from the lightning? | [
"Water actually autoiionizes. Water dissociates into H+ and OH- spontaneously, albeit to a small extent: ",
"http://en.wikipedia.org/wiki/Self-ionization_of_water",
"This is enough to carry a current through the water. "
] | [
"Pure water has a resistivity of 182 Kohms per meter which while high is not much compared to the power of a lighting strike. ",
"Assuming you are half a meter under the water you would experience at least 32 amps. About 0.3 amps are fatal btw."
] | [
"It's worth noting that 0.3 amps ",
" can kill you. The body has a high resistance already that will lower the effective current, and the path the current will take might not pass directly through the heart. This is why most people struck by lightning survive the event. The electricity will enter through their a... |
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