title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"What would happen if I built a transformer where the primary coil was copper and the secondary was antimatter copper?"
] | [
false
] | null | [
"Yes, the free charge carriers in the secondary would be positrons. The direction of the current is always the direction of motion of positive charge carrier, so it would behave as expected in both coils."
] | [
"Ok that's cool. So it would be relatively easy to power antimatter electronics."
] | [
"The problem is making a device out of antimatter that doesn’t immediately get destroyed by the surrounding matter."
] |
[
"What, How, and Why do I get a heavy, pressing feeling on my chest when I see people get hurt?"
] | [
false
] | I can't watch those YouTube "Fail" videos that have people hurting them selves without feeling an uncomfortable heavy feeling on my chest during the moment of impact. What is it? Why does it happen? And is there any explanation as to How I feel seemingly simultaneous pain as someone in a video? | [
"OK but what is the mechanism behind it?"
] | [
"I'm gonna take a shot in the dark and say mirror neurons.\n",
"www.en.wikipedia.org/wiki/mirror_neurons",
"\nThe same reason a smile, yawn or laughter is contagious."
] | [
"its called empathy. And its all in your head. Its a physical reaction to a stimulus. The stimulus being the visual input and the the reaction is your gut turning or heartbeat racing."
] |
[
"If gold, silver, and other heavy metals were created by supernovae, does that mean that Mars and Venus have a similar distribution of these ores that Earth does?"
] | [
false
] | null | [
"MY TIME HAS COME! I am a Geological Engineering Student and am currently studying for an exam on many common ore deposits! ",
"Interestingly enough, ore deposits are considered economic sources of minerals, what this means in the context of this discussion is that ore is not the only place you will find things l... | [
"Yo, this is your TA speaking (Guess who!!! :P). Basically correct, good for you. ",
" Remember to include biogenic processes as well, they're important, and as far as we know unique to earth. Oxygenation of the atmosphere was also an important trigger for a lot of deposition.",
"Hope you did well on your lab e... | [
"Hey, mining engineer here. A mineral is only considered an ore if it can be mined profitably. As reaching and mining other planets is prohibitively expensive, there is no ore on other planets. Yet."
] |
[
"If you pointed a powerful laser (like the ones the military are using to take down missiles) at a mirror would it burn through the mirror or bounce off it?"
] | [
false
] | null | [
"Well, even a really great mirror isn't 100% reflective, so it will always absorb some of the light. If you pump strong enough, yes, you'll start to heat up the mirror faster than it can dissipate the heat and eventually it will melt. ",
"Another thing to consider is that the reflectivity of a surface depends he... | [
"Another thing to consider is that the reflectivity of a surface depends heavily on the wavelength of light. A mirror that might be reflective to visible light, say 99% reflective, might only be 5% reflective to infrared light. So if you were trying to build an anti-missile laser or a laser-proof missile hull, for ... | [
"Both. If the laser is powerful enough, the energy absorbed by a metallic mirror will burn it, even as a huge amount of energy reflects.",
"In some laser experiments, prisms are used instead of metallic mirrors. They have an advantage of very little absorption (using total internal reflection), but lose about 4... |
[
"Can light be caught in orbit?"
] | [
false
] | So relativity (or something) states that masses distort spacetime, which in turn allows light to be affected be gravitational fields, despite not having mass. Can light actually orbit a massive enough object? If a beam of light has a gravitational field is it possible for particles of light to orbit each other? | [
"If there's a black hole with a certain event horizon radius, there is a circular orbit for light at 1.5 times this radius. It's called the Photon Sphere."
] | [
"Its mass."
] | [
"Newtonian physics doesn't cut it, it comes from general relativity.",
"http://en.wikipedia.org/wiki/Photon_sphere"
] |
[
"Do the structures of animal and plant cells evolve over time?"
] | [
false
] | I can appreciate how features of animals change over time due to evolutionary mechanisms. Do features of cells that make up organisms change over time, and do they also alter due to similar evolutionary mechanisms at a microscopic level? For example, why did a cell wall form? Do we have an idea of what cells looked like millions of years ago? What will they look like in the future? | [
"IIRC, this is also believed to be the same story for chloroplasts in plant cells (or at least similar)."
] | [
"IIRC, this is also believed to be the same story for chloroplasts in plant cells (or at least similar)."
] | [
"Yes. In early life on Earth, the genetic material inside of cells was RNA. RNA has a simple single stranded structure and can self replicate (",
"http://www.sciencedaily.com/releases/2009/01/090109173205.htm",
") which made it perfect for basic life forms. The only problem with RNA is that it is a fairly unsta... |
[
"Looking to fund scientific research, not sure where to start."
] | [
false
] | [deleted] | [
"A good start",
".",
"It's hard to just give money away, though. You need to be a foundation, if I'm not mistaken. You could donate to a foundation with some stipulations. With that small amount, my recommendation would be for small grants/fellowships/stipends for up-and-coming PhD (or PhD/MD) students working ... | [
"start a grant agency... that's how most of the science is financed by now.\nyou can specify general topic of research in your conditions and\napplicants will present their ideas about how they are going to spend your money. then you check their credentials, previous results and consider possible outcome (e.g. how ... | [
"Are you a researcher yourself or you'd life to fund someone elses venture into it?",
"If the latter, I'd check out your local university and asks around for professors who do neurology research and tell them you have funds which you'd like to apply to that subject. If they themselves aren't doing it, ask if they... |
[
"[URGENT] Can someone please tell me what could have possibly bitten me, as well as what I should do?"
] | [
false
] | null | [
"Ask a doctor. Reddit doesn't offer medical advice."
] | [
"No hard feelings, just playing hall monitor."
] | [
"It only hurts when I put pressure on it",
"Yeah that reminds me exactly of a mosquito bite. Not saying that it's from a mosquito necessarily (mosquito bites don't normally swell up THAT much), just saying it's probably not serious."
] |
[
"Why does the water in a lake or pond not absorb into the ground below? When I dig a hole and fill it with water, it is absorbed almost immediately."
] | [
false
] | null | [
"It does absorb (infiltrate) into the ground below, but at some point that soil is saturated. What stops the water from continuously going down is that there are different types of soil/rock and some are less permeable than others. It usually goes along the line of gravel -> sand -> clay -> rock. Below the permeabl... | [
"If you dig a little hole, there's not much groundwater beneath it so any water seeps away quickly. But if you dig a big hole, you'll get down deep enough so the soil is already saturated and is unable to accept any more water.",
"My grandfather bought a farm in the 1950s, and had a government surveyor come out a... | [
"Aside from the usual streams or rivers that feed into a lake or pond there is also ground water seepage into the water body. Also the composition of the benthos (ground) plays a significant factor into the absorption--think porous sandstone vs granite. Also, you're probably only digging a superficial hole that isn... |
[
"What exactly makes a person dead?"
] | [
false
] | Why wouldn't it possible to bring back someone simply by pumping blood through their bodies? Can't we "restart" the brain? | [
"The medical practice has, over time, changed with regards to determination of death. At one time, heart was considered to be the determinant of life or death; now, the brain is. The question of what makes a person dead frequently comes up in the context of organ and tissue donation; see ",
"this summary",
" fo... | [
"Thank you, I'm just getting into this sub and you not shouting or getting mad really helps. I'll take note for next time! :)"
] | [
"Your thoughts are factually incorrect. See my reply to the OP for details."
] |
[
"Why has there only been one Big Bang? Or, if there has been more than one, why can't we see any of the other universes?"
] | [
false
] | null | [
"The answer to both questions is that if another big bang occurred elsewhere, it's too far away from us to observe, and may be permanently so.",
"Specifically what I mean is that at the very early part of the universe, the universe underwent inflation. It rapidly expanded at a tremendous rate. When inflation ende... | [
"I don't think many believe in the Big Crunch theory anymore, not since Hubbles initial observations showing presumptive acceleration of galaxies away from one another. This has been basically accepted now.. The further away a galaxy is, the faster it is moving away from us. Why this happens is not fully unders... | [
"There are plenty of theories in this area, but some scientists believe that the gravity in the universe will stop it's expansion and everything will come back in what's called the big crunch. If you believe this is true then we could be the first or the millionth universe to have existed. ",
"There are multiple ... |
[
"When eyeballs are donated by an organ donor, does the left eyeball have to be put in the left eye socket of the new body, and vice versa?"
] | [
false
] | null | [
"As others have suggested, transplantation of complete, intact eyes is not done because it's not within our current capabilities to reattach all of the nerves.",
"Donor eyes are essentially \"parted out\" for structural elements like the cornea, which can be used to replace deficient parts in the patient's eye."
... | [
"Not just corneas; sclera is also transplanted, either 1/4, 1/2, or whole globes are used.",
"Source: I work in organ and tissue donation."
] | [
"Not just corneas; sclera is also transplanted, either 1/4, 1/2, or whole globes are used.",
"Source: I work in organ and tissue donation."
] |
[
"Today's Nobel prize in Physiology or Medicine is on the role of oxygen in cells. The description says the research is important in aiding injuries and understanding cancer. Can someone explain it in a little more detail? Is it also relevant to aerobic exercise?"
] | [
false
] | null | [
"William Kaelin, Peter Ratcliffe and Gregg Semenza also won the Lasker for this in 2016.",
"They've independently researched how cells detect and respond to hypoxic conditions. Hypoxia is a state where cells are deprived of oxygen and potentially die.",
"Semenza discovered a protein (HIF-1) which basically the ... | [
"The overexpression of HIF-1 alpha in cancers is important for a number of reasons.",
"HIF-1 alpha is a transcription factor that increases expression of metabolic enzymes that support aerobic glycolysis and the ",
"Warburg effect",
" .\nThis metabolic switch allows cells to survive in hypoxic conditions and ... | [
"And no, improper healing resulting in a cancerous cell is not profound enough. It is like messing up part of a software program that is still trying to run and duplicate itself anyway and it goes rampant. I can go in detail but please tell me that is not what happened. If that is the case give me like 3 days and I... |
[
"Restoration and Preservation of Very Old Books"
] | [
false
] | I just saw an episode of 60 Minutes where they visit the Vatican Library, and they got to see some incredibly old texts, some 600 years old or more. They also showed the restoration area where they work to preserve old texts. NO ONE was wearing gloves to protect these incredibly old books!! Not the librarians, not the reporter they let touch the books, not even the restorers. Are they out of their minds??? | [
"Old books are likely to have a vellum book block, so the contact is skin-to-skin. Gloves introduce the possibility of of their harboring undetected moisture or contaminants. "
] | [
"Thats an incredibly well thought out reply, thank you. ",
"In the report they didn't give a sense for how frequently they handled the books but they seemed eager to show them. I got the impression that they might like to show them off more than a few times per century.",
"I'm also still horrified that they let... | [
"Thats an incredibly well thought out reply, thank you. ",
"In the report they didn't give a sense for how frequently they handled the books but they seemed eager to show them. I got the impression that they might like to show them off more than a few times per century.",
"I'm also still horrified that they let... |
[
"Someone I know is convinced Dinosaurs and Humans existed at the same time, I would like some info on the subject if it's not too much to ask. =)"
] | [
false
] | null | [
"See your other thread. Please do not double post."
] | [
"Yeah well my first post got downvoted, I assume because someone thought I was the one believing it and they had some agenda to fill. "
] | [
"Google \"carbon 14 dating,\" the \"fossil record,\" and \"James Hutton,\" to start. There is no evidence that dinosaurs and humans existed at the same time, because they did not. Present the evidence in a way that is relatable to your friend."
] |
[
"What would the effects be of receding coastal waterlines on soil fertility?"
] | [
false
] | Full disclosure: This is for a D&D campaign and I just want to have some sense of verisimilitude in the setting. Imagine we have some sort of geological event which results in the water level plummeting, say, six feet over 50 years. My interest is specifically in soil fertility in ocean shorelines. It's not clear to me how the salt content of the water would contribute to soil fertility. In freshwater areas, I'd assume the exposed lakebed would be a very good growing medium, but would a seabed be too salty to grow anything? Thanks! | [
"Obviously the revealed dry land would be salty. This would decrease depending on the amount of rainfall. Some desert regions have virtually no rain. So the salt would never leach away. ",
"But in high rainfall regions the soil would become fertile. ",
"Sometimes the limiting factor for irrigating crops is the... | [
"Answer depends on local topography.",
"There are examples such as the Netherlands, where roughly 20% of the country is reclaimed from the ocean.",
"Under the sand at your beach can be anything. In some locations such as the LA Basin, what's under the sand is fine sediment from geographical erosion of the mou... | [
"Hey, this is very late, but thank you for the excellent breakdown! I appreciate all the information. It will be very useful for my purposes."
] |
[
"Why aren't watercraft designed to be flexible like fish?"
] | [
false
] | I originally posted this question in askreddit and got a whole bunch of nonsense replies but I am extremely curious about this and would love an educated response. From what I've read, Vikings would build linear flex into their Dragonships which enabled them to easily ride over waves. I've searched extensively and I can't find a single example of lateral flex being built into a boat but in my mind it would greatly enhance turning while providing extra stability and possibly could be used for propulsion. Am I wrong? All comments are appreciated, thanks! | [
"Because fish are incredibly complex and boats are not.",
"Fish have thousands of muscles which are all delicately and intricately connected in ways that would boggle an engineering team's mind were they to try and reproduce them.",
"That being said we live in an age where you can almost gaurentee sombody is wo... | [
"A lot has to do with the complexity involved in adding a flexible materials. Most ships are built primarily out of steel, if a flexible member was added that would also add a joint. Where two different materials met will have a set of complication that have to be thought out. E.G. The thermal rate of expansion is ... | [
"First of all, \"flexible like a fish\" is ",
" flexible, to the point of a vessel not being usable any more. Remember, a fish contains mostly muscle which is needed to maintain some shape. If you ever picked up a dead/unconscious fish or animal of any sort (so, one that does not actively maintain shape) you know... |
[
"Pangaea: How did all the continents end up all crammed together in the first place?"
] | [
false
] | It seems really weird to me that all the above‐water landmasses would start out all clustered together on the same side of the planet, instead of more‐or‐less randomly distributed across the earth's like they are now (except, you know, a different more‐or‐less random distribution, presumably). How did they get that way? | [
"Well, let’s start at the beginning (of Earth’s history) with probably the least obvious aspect to this whole story - when Earth had accreted and differentiated into a planet with a core, mantle and crust (by about 4.50 billion years ago, probably a smidge before), ",
". ",
"In fact, the original crust was just... | [
"Thanks. That was very detailed."
] | [
"I don't think they ",
" all clustered together, but I'm not sure how far back in time geologists can extrapolate. But given that tectonic plates are always moving and they have a a finite surface to move around on, it makes sense that sometimes the continental plates would all be together and other times they wo... |
[
"Do Gases experience viscosity?"
] | [
false
] | In my chemistry classes we discussed Intermolecular forces and how those effect states of matter. We were told that Intermolecular forces affect viscosity as well. I understand that gases are fast moving therefore have weak IMF. If I was to create a pressurized chamber of a gas so it was condensed and then open the valve would the gas experience viscosity? | [
"Yes, ",
"gases have viscosity",
"."
] | [
"Thank you. "
] | [
"and the colder they are, the more viscous the are...an aircraft has more lift on a cold day and aerodynamic drag is caused in part by friction induced viscosity. ",
"And if you look at shooting stars, it is due to heat generated friction relating to the viscosity of the gasses."
] |
[
"How can scientists Map our sun?"
] | [
false
] | I was reading an article this morning about the solar storm we may experience today as a result of Solar flares. It explained that one of the solar flares happened at "an active region on the Sun known as 1429". That got me thinking...if the sun is just a big molten mass of plasma, how can we map it? How would we know if one sun spot has moved to another place on the sun while the core perhaps rotated differently? Anyhow, just thought I'd ask. Here's a link to the article in case you want to read it yourself. Sorry I can't hyperlink, I'm on my phone. | [
"The sun is actually a plasma not a liquid. There is a strong magnetic topology to the sun, which does not vary freely and erratically. The fact that it's a plasma is important because plasmas are generally constrained to move along magnetic field lines. Charged particles feel a force perpendicular to the magne... | [
"It first might help to consider what a sunspot really is. The surface that we see in optical wavelengths of light shows intense and ",
"\"small scale\"",
" convection features called ",
"granulation",
". Sunspots are really regions that are cooler than the surrounding material because surface convection ... | [
"I guess what I'm asking is, If the entire surface of the sun is liquid, it must move around freely and irratically. Wouldn't that make it impossible to systematically map out the sun?"
] |
[
"Why it's 0^0 indeterminate?"
] | [
false
] | [deleted] | [
"Because the function ",
" has different limits as ",
", ",
" → 0, depending on how you take the limit. For example, if you let ",
" = 0 and ",
" → 0 you will get zero, because zero raised to a positive power is zero. But if you let ",
" = 0 and ",
" → 0 you get one, because anything nonzero raised to... | [
"Haha ...\"an easy exercise for the reader\". I can't be the only mathematician here that feels the knife to the gut every time it shows up in a textbook. "
] | [
"Haha ...\"an easy exercise for the reader\". I can't be the only mathematician here that feels the knife to the gut every time it shows up in a textbook. "
] |
[
"Does regular exercise really make you more happy?"
] | [
false
] | I have recently read an article that states that 30 minutes af exercise three times a week increase serotonin levels and therefore make a person happier. The article even stated that regular exercise had the same effect as antidepressants. Is this true? and why would 1) regular exercise increase serotonin levels and 2) why would that make a person happier? | [
"Additionally, exercise has been shown to raise levels of endogenous cannabinoid compounds in your body. Cannabinoids are the chemicals found in marijuana that contribute to the \"high\" feeling that the drug gives you, and while I'm not sure of their exact mechanism of action in the brain, I'd expect a regular exe... | [
"Exercise and forced physical labor are not quite the same."
] | [
"Exercise and forced physical labor are not quite the same."
] |
[
"Can someone explain the difference between triplet oxygen and singlet oxygen?"
] | [
false
] | [deleted] | [
"The one opportunity for my user name to be relevant.... ",
"I feel I should add something though. ",
"Generating singlet oxygen is more difficult than simply exciting the electron using a photon, as the transition from triplet to singlet state is forbidden (excitation of electronic states is generally achieved... | [
"The diagrams they use are Molecular Orbital diagrams. They display the bonding interactions between the respective orbitals on each species. In short: Molecular Orbital theory pairs the interacting s, p, d, and f orbitals, taking into account orbital symmetries for overlap. Since this is an easy example where both... | [
"Hey. My old adviser would be disappointed that I had to look this up but it's been a while. For a better explanation than wikipedia check: ",
"http://www.healthcare.uiowa.edu/corefacilities/esr/education/2001/1/zhaol-paper1.pdf",
" (no connection at all to me, just cleaner than wikipedia)\nFrom what I can see ... |
[
"What are some strange things that happen under EXTREME magnetic fields?"
] | [
false
] | I was reading about the magnetar SGR 1806-20, which has a magnetic field of 10 Gauss (10 Tesla in intensity) . The article said that if this magnetar were as close as the moon to Earth, it could re-arrange the molecules in your body. What are some other wacky quantum and macroscopic things that happen under these most powerful magnetic fields in the universe? What could happen under even greater strength fields? | [
"Many of the things you don't usually consider to be magnetic are actually diamagnetic, which means that any magnetic field will repel them. This effect is usually very weak, but water and graphite are diamagnetic among other things. A sufficiently strong magnetic field would have a repulsive effect on these things... | [
"Magnetic fields follow an inverse cube law, meaning if you get twice as far away they will be eight times weaker. Even if you have a very powerful magnet, you don't have to move very far away before the field is basically gone. These kinds of fields are usually produced with large machines in a configuration calle... | [
"Does a powerful electromagnetic field have any measurable biological effect on living organisms; the frogs for example?\nIf so, what kind of precautions shield operators from theoretical magnetic force fields? "
] |
[
"Why are human brains more able to reproduce visual and auditory experiences, but not taste, touch, or smell?"
] | [
false
] | The mind is capable of reproducing sensory experiences that it has encountered in the past, such as a music, movie scenes, symbols, or heat. So why is it that when a person thinks about a song or visualizes an object, the mind can reproduce it with great clarity, but when trying to reproduce say a smell, the sensation is more akin to a memory than an actual sensation. I was simply wondering if anyone had a possible neurological explanation for this phenomenon. Does it have to do with the fact that sight and sound are more often used than taste or smell? | [
"I'm not sure about everyone else, but I remember tastes, touches, and smells with approximately the same intensity that I remember visual or aural stimuli.",
"Maybe its just harder to put these sensations into words? Its pretty easy to state the lyrics of a song, but harder to describe the bubbly sensation of so... | [
"I'm not on my personnal computer but olfactory memory exists in humans. Tast and smell can be remembered and imagined. I don't have access to my databse of articles but here's a ",
"review on the subject",
". I also invite you to read the following ",
"abstract",
" which I think discribes well why we have ... | [
"I think that it’s easier to remember because it's easier to narrativize visual and auditory phenomena. It’s just easier to remember stuff when you can make a story out of it. If you were to look at events in isolation, I think most of the advantage would disappear. I, for one, don’t think that there is any signifi... |
[
"Questions about the first episode of \"Curiosity\" with Steven Hawking."
] | [
false
] | Hello everyone! I had a few questions about some of the subject matter in the show and they're pretty specific so a google search didn't really help much. At some point in the show the narrator brings up the point that, at least at the sub-atomic level, it's possible for particles to simply spring into existence for short periods of time. From there the point is made that the universe was, at one point, smaller than a Proton, which allows for the universe to "pop" into existence without violating any natural laws. The first question I have is what exactly is meant by particles "appearing" from nothing. Does that mean that the particles literally create themselves, or were they just not visible to us before and then suddenly spring into the spectrum of our vision? If they do literally create themselves then do we have any clue to how they are able to do so? Also, in the event they don't "create" themselves and they simply pop in and out of our visible spectrum does this mean that they have always existed? My second question involves how these spontaneous appearances lead to a "big bang"? I understand that particles can appear spontaneously, but why would the result of their appearance cause an expansion of such proportions? Technically, we have particles "appearing" all the time at the sub-atomic level, but they don't expand after they appear, they simply dissipate, correct? Was there unique properties in the "first" particle that appeared to cause an expansion? Also, just pure speculation here, but would this be where the idea of a multi-verse came from? The realization that at one time the universe appeared spontaneously on the sub-atomic level, which means that the same event could possibly still be occurring, spawning an infinite number of universes? My last question deals with time. I've always thought of time as a man made construct, but on the other hand I realize that even before man invented the idea of keeping track of time the days still passed with the sun rising and setting every day. This means time exists in a way that is independent from human interaction. However, in the black hole example used in the show they say that if a clock were to be pulled into a black hole it would actually slow down until it finally stops. This either seems really weird to me, or maybe it's simply a bad way to illustrate the point they were trying to make? Would the mechanical mechanisms inside the clock that record a change in time actually slow down upon entering the black hole? If so why would this happen, and if not then I'm obviously grasping the concept of "time" in the wrong way and would appreciate it if anyone could clear up my understanding. In closing I'd just like to thank anyone reading/responding to these questions. I appreciate any insight this community has on the questions, even if currently I'm only capable of understanding a laymans example of what's going on. My current field of study is computer science so I'm a little ways away from my comfort zone asking questions in the field of cosmology. However, after watching this program my "Curiosity" (pun intended :P) really has seemed to have got the best of me and I'm interested in understanding a bit more about the universe, how it works, and how it came to be. With that being said, again thank you for your responses, and also feel free to point out if any of the questions I'm asking don't make sense, aren't relevant, ect. I understand that my ignorance level for this particular field is astoundingly high. | [
"The first question I have is what exactly is meant by particles \"appearing\" from nothing. ",
"Particles are states of a field; there's one field for each type of particle. It's possible for a field to jump from its ground state (no particles present at that place) to an excited state (one particle present). Th... | [
"...what is this supposed to mean?"
] | [
"Thank you very much for taking the time to respond.",
"You were definitely able to clear some things up, even if at this point I'm not capable of understanding the \"nitty gritty\". You did an excellent job explaining things without without really needing to go there."
] |
[
"Can the human body endure the vacuum of space (given a continuous supply of oxygen)?"
] | [
false
] | null | [
"No, ",
" You need a pressurized suit around your body to protect it, not just a scuba tank. ",
"The area around your whole body has to be pressurized for you to breathe properly, so a pressurized tank of air wouldn't work very well. Even if that weren't a problem you would continuously lose moisture as the wat... | [
"I think you came off as a little harsh, our body can endure the vacuum depending on what his question originally was... Which is for how long.",
"I know you posted an example which reading it looks great. However it would be possible, and tests showed that a human can at least survive up to 90 seconds in that ty... | [
"Oh, I didn't mean to imply that death would be instant or anything. But a human certainly can't 'survive' in a vacuum. Surviving to me implies...I don't know...extended orgy session ",
". ",
"I would totally do a space jump if my craft was on fire or otherwise compromised. "
] |
[
"Why do people feel tired when they overeat?"
] | [
false
] | [deleted] | [
"Post-prandial somnolence. I know what it's called because I get it good. I dont know the why behind though I am sorry. "
] | [
"Here's the wiki on ",
"Post-prandial somnolence",
". Seems there are four possible mechanism with either a endocrine (insulin) or neurological source.",
"Good that someone knows the term for it, I always just assumed it had something to do with blood flow to the brain and it is saying that is just a myth. So... | [
"Insulin",
", baby! Insulin is released when our food is digested and glucose (which is found in pretty much anything carb-y) makes the rounds in our bloodstream. I'm not an expert on what insulin does, but suffice it to say that glucose levels in the bloodstream drop after insulin does its thing.",
"What does ... |
[
"Do different animals see different sized rainbows?"
] | [
false
] | We see a rainbow as a spectrum of colour formed by the relative angles of light reflection within drops of water. For those animals that can see different ranges of light (infrared or ultraviolet), am I correct in thinking that their rainbow would be skinnier/fatter and positioned slightly differently? Are there any animals that see both infrared AND ultraviolet, and therefore can see a considerably wider rainbow than we can? | [
"We see a rainbow as a spectrum of colour formed by the relative angles of light reflection within drops of water. For those animals that can see different ranges of light (infrared or ultraviolet), am I correct in thinking that their rainbow would be skinnier/fatter and positioned slightly differently? ",
"Ye... | [
"Let's just say every bumblebee to ever see a rainbow (they see infared) had this reaction ",
"https://www.youtube.com/watch?v=OQSNhk5ICTI"
] | [
"would the effect droplets of water have on EM be the same through all frequencies?1. "
] |
[
"Why does stirring a soft drink with a wooden chopstick cause it to fizz?"
] | [
false
] | [deleted] | [
"The key thing to remember with fizzy drinks is that the bubbles don't just naturally form. Bubbles require nucleation sites - imperfections - in order to form around before they rise. A standard glass is of course not a perfectly smooth surface, hence why you see bubbles. Some companies will even specially design ... | [
"In the simplest terms the wooden chopstick isn't as smooth of a surface as the metal and thus provides nucleation points for the CO2 to drop out of solution and bubble out as gas. ",
"Diet coke and Mentos is a great example of an extreme version of this phenomenon. ",
"http://en.m.wikipedia.org/wiki/Nucleation... | [
"Because science."
] |
[
"What role does electricity play in mental state/memories/maintaining cognitive consistency?"
] | [
false
] | So as far as I know, the brain is a network of neural synapses and different processing structures that work together to create the conscious experience. I'm not sure, though, how much of this information is stored physically, for example in the rearrangement of synapses or in the restructuring of the brain. Is any information, for example mental state or memories, simply an abstraction of different electrical states of the brain? What would happen if we were to "zap" the brain and completely reset its electrical state? Would it no longer function? Does an electrical state need to be maintained in the brain at all times, or could we shut off a brain and fire it back up later? If so, what would change? Any memory loss or change in personality? Some of these questions may be impossible to answer I suppose Thank you | [
"First, understand that there are no wires in the brain. The most conductive neural materials are still offering a resistance of several KΩ/cm and axons in neurons are over the MΩ/cm. ",
"Sencond, in biology, contrary to a a typical digital circuit, electrical charges will be transported by ions and chemical reac... | [
"It's true that synapses work on electricity, but it is a slow, chemical process of positively and negatively charged ions floating around in a liquid, rather than the fast transmitting-current-along-wires electricity that most people are familiar with. Intuitions from electronics and computers will not translate ... | [
"AFAIK, the \"cognitive consistency\" of the brain is a result of its physical structure (synaptic organization) and not its on-going electrical activity. During a seizure, for example, there is widespread, wholly abnormal, electrical activity in the brain, and while there may be disorientation or loss of conscious... |
[
"Why are we able to get the common cold multiple times in our lifetime? Should the virus not trigger a secondary immune response when it enters our bodies?"
] | [
false
] | null | [
"common cold symptoms are created after a viral infection of the upper respiratory system. a memory response will be created for each strain of the virus. if the virus mutates, there is a chance that the secondary response will be either less effective or completely ineffective, leading to the standard primary re... | [
"Adenovirus, the primary etiologic agent of the \"common cold,\" mutates heavily. When you're a kid, without prior inoculation with any form adenovirus, you get symptoms. If you were inoculated with THE SAME STRAIN, you would see little to no symptoms at all. Because the virus replicates repeatedly as a part of its... | [
"You don't get the same 'cold' virus each time. The older you are the less likely you are to get a cold. Once you do reach said old age the effects of a simple 'cold' become far more significant merely due to old age."
] |
[
"Are there any two foods that are safe when eaten separately but dangerous to eat at the same time?"
] | [
false
] | null | [
"Grapefruit and lots of things, especially medicine. Serious effects.",
"Antibiotics and birth control pills, not really food, but the combination could cause something that you are obviously trying to prevent.",
" the pamphlet you got with your medicine."
] | [
"There is a psycadelic mix of plants called ",
"Ayahuasca",
" which contains ",
" vine and a DMT (the psycadelic component) containing plant such as leaves from the ",
" plant. The DMT when consumed alone does not have an effect. It is only when the other plant is added, which contains monoamine oxidase A i... | [
"I guess it depends on how willing you are to define alcohol as food, but alcohol consumption temporarily induces the cytochrome enzyme CYP2E1 which is responsible for the metabolism of some of the components of charred or burned food into more toxic compounds(i.e. CYP2E1 is primarily responsible for the metabolism... |
[
"How do the negative terminals of batteries stay at 0 volts?"
] | [
false
] | How can we make batteries that always sit at 0 volts on the negative terminal without accumulating charge at that node? | [
"Voltage isn't an instantaneous measurement, you have to measure it relative to something else. The negative terminal doesn't have a voltage of 0, the voltage between the positive and negative terminal is (in new batteries) at 1.5 V. "
] | [
"The potential can certainly be different. If you use a conventional multimeter, they might equalize quickly though. You can try measuring ground against the + of a battery and then measuring ground against the - of a battery though, or if that's too scary, you can do the experiment with + and - terminals of ba... | [
"Say you put 4 batteries in series to get a net 6 V source. The negative terminals can't all be at 0 V."
] |
[
"Do GPS receivers use signals from all GPS systems that are currently operational?"
] | [
false
] | For example, if I have an American cell phone and I go to China, would the GPS receiver interpret data from the American global system, the Russian global system, and the Chinese regional system to give me a more accurate signal, or would it only look for American GPS satellites? | [
"Depending on the receiver it uses the strongest signal. A majority of Cell phones use public GPS system (now 30 sats) and it is run by the U.S. government. Some vendors GPS receivers like Qualcomm, Broadcom and Exynos support Both US and Russian satellites systems... GLONASS, Galileo, BeiDou and Indian systems are... | [
"If you are asking about navigation GPS, then there are 24 Earth orbiting satellites, plus an extra three for back up and the constellation can support up to 30 satellites. The constellation is arranged so that the satellites provide maximum coverage all over the globe. So wherever you are in the world, your phone ... | [
"Your cell phone most likely does not have the technology, or antenna specs to be able to pick up multiple constellations. The constellations below have different communication standards, and operate at different frequencies. There are receivers in development with this capability.",
"http://www.sage.unsw.edu.a... |
[
"How can gravity be geometry in GR if..?"
] | [
false
] | Hi, I'm trying to understand how can gravity be actually just geometry in General Relativity. For example, imagine that the geometry of space-time is like the surface of an apple. Locally, you see that parallel straight lines don't intersect immediately, but in the end they actually may because the apple's surface is curved. And also the straight line can intersect with itself. I do get that. What I don't get with that example is that if you follow a straight line in the apple, it doesn't matter how fast you travel through that straight line, the path will be the same... but that doesn't happen with gravity: an object will follow a different path if he changes its velocity. I guess the answer is in the metrics of the system, like what is called proper time in special relativity: ds = -dt + dx + dy + dz So instead of using just distance as a measure in spacetime I should use proper time/distance. Am I right? | [
"So instead of using just distance as a measure in spacetime I should use proper time/distance",
"That's it. It's a 4-dimensional geometry we're moving through. If I'm moving in a straight line, or falling straight down onto the Moon, I'm following the same path in space (just a straight line), but I have a diffe... | [
"Okay thanks, I think I get it :)"
] | [
"I want to add that, in relativity, your \"speed\" in the full spacetime sense is actually always ",
", the speed of light. Adding to your speed (in just the space sense) takes away from your movement through time. So, for a given path through spacetime in the general relativistic picture, there's actually only... |
[
"Why do we still use bike and car tires that can lose air?"
] | [
false
] | It seems like by now we would have come up with a solution that doesn't allow for car and bike tires to deflate and have to be refilled - is there a practical reason that something completely air tight and factor inflated isn't a good idea? Is it simply easier, or to make it possible to repair a flat? | [
"Rubber tires can never be perfectly air-tight, although a fully sealed rubber time could get quite close.",
"More importantly, what would you do about temperature changes then? Or punctured tires? How would you calibrate these necessarily pre-pressurized tires, if they will be mounted on a wide range of vehicles... | [
"Have you pushed a stroller with completely rubber tires vs ones that inflate? Once I pushed a stroller with inflated tires and saw how much easier it was, I was hooked. Solid tires would be miserable in terms of shock absorption."
] | [
"Thanks for the thorough answer!"
] |
[
"Why do we get hot under pressure / when embarrassed?"
] | [
false
] | null | [
"Fight or flight instinct. Whenever you're in a stressful situation (and being embarrassed does count) you start releasing a lot of adrenaline, causing your heart to pump faster, which means increased blood flow. More blood flow means you feel hotter. The increased blood flow is also why you blush when embarrass... | [
"...but why is that our physiological response? Is it because the rapid blood flow to the areas are necessary in some way?"
] | [
"The heat is actually just the increased blood flow to the skin's superficial plexi, which occurs when the arterioles expand and allow more blood to flow near the surface. There is no increase in cell activity near the surface leading to heat."
] |
[
"Do we currently have a good explanation as to why the layers of the retina are inverted from what we would expect?"
] | [
false
] | From my understanding in my neurobiology course, the layers of the retina are not arraigned to best "capture" the light. The cones and rod cells are farthest away from the vitreous body instead of being the closest, and the light has to penetrate the ganglion and bipolar cells to order to strike the photo-receptive cells. Do we have an hypothesis at the moment as to why the layers are inverted? Does it serve to protect the cones and rods from infection, or is the clarity "good enough" and the change in developmental process large enough that a natural reversal is unlikely? | [
"An even bigger issue is that the optic nerve and blood vessels attach to the front of the retina, blocking a significant portion of it. My understanding is that there's no good reason for any of this and you're correct with your \"good enough\" explanation, but I'll leave that to someone who knows more about it...... | [
"The explanation we learned was evolution: photoreceptors came first and then more complex circuitry was added later. It turns out, cephalopods ",
"have stuff in the \"sensible\" order",
" and vertebrates do not. It's less of a big deal than you might think: a thin layer of tissue is mostly transparent - that'... | [
"I don't think we know for sure, but ",
"here's",
" an interesting theory.",
"Essentially, they believe that for small-eyed animals, an inverted configuration would save space by maximizing the amount of cells between the lens and the photoreceptors (a space called the vitreous humor that would otherwise be f... |
[
"If I can’t touch anything how am I able to push things?"
] | [
false
] | null | [
"Electrons in your hand repel electrons in the object and transmit the force from your hand to the objet."
] | [
"But how do they transmit force if they’re not touching? "
] | [
"Force can be transmitted at a distance, when you jump you are not connected to the Earth but you still feel it's attraction. Similarly electromagnetic forces act at a distance. "
] |
[
"Is Helium-3 a viable fuel source?"
] | [
false
] | I had the TV show Ancient Aliens playing for background noise while studying for finals (so I feel less lonely after being secluded in room 8+ hours). But the show claimed that a single space shuttle filled with Helium-3 could power all the U.S.’s power needs for a year. Is this even remotely true? If so, how feasible would it be to utilize this fuel source/ how realistic is it’s possible use? ( did a brief google search and all I really got was Helium-3’s use in nuclear fusion) | [
"That would perhaps have a semblance of truth if we had working fusion power plants, but we don't. The ones that do exist, which don't produce more energy than they consume, use deuterium and tritium as their reactants and not helium-3.",
"One would need about 20 tons of helium 3 per year in order to power the Un... | [
"There’s a lot of 3He on the Moon, but there’s also a lot of ",
" on the Moon. That is, you need to process a ridiculous amount of regolith in order to extract industrially relevant amounts of 3He. You need a trillion-dollar infrastructure on the Moon ",
" helium mining can become a trillion-dollar industry."
] | [
"There’s a lot of 3He on the Moon, but there’s also a lot of ",
" on the Moon. That is, you need to process a ridiculous amount of regolith in order to extract industrially relevant amounts of 3He. You need a trillion-dollar infrastructure on the Moon ",
" helium mining can become a trillion-dollar industry."
] |
[
"Do we know when voyager 1 will fall into the gravity of another star?"
] | [
false
] | null | [
"Now that NASA's Voyager 1 probe has left the solar system, its next big spaceflight milestone comes with the flyby of another star — in 40,000 years.",
"Voyager 1 entered interstellar space in August 2012, nearly 35 years after blasting off, scientists announced Sept. 12. As it leaves our solar system behind, t... | [
"it should be noted that voyager has \"left\" the solar system many times. this is due to the loose definition of solar system and interstellar space.",
"In that case voyager hasn't even passed through the oort cloud yet and won't for thousands of years.",
"edit: ",
"relevant XKCD"
] | [
"Well Voyager left several times our solar system. It's way you you define our solar system. I read somewhere it will take significant more time to actually leave the gravity influence of the sun. That would be the point it leaves our solar system for the last time."
] |
[
"What determines the \"warm-bloodedness\" of a creature?"
] | [
false
] | I know that warm-blooded animals generate heat through internal metabolic processes while cold-blooded animals have to rely on external heat sources. But why do they have to do that? What mechanisms do they lack that would have allowed them to be warm-blooded? | [
"This question relies on the assumption that being warm blooded is better, and cold blooded animals are lacking something. Evolving to be warm or cold blooded is simply an adaptation to the environment. ",
"Being cold blooded is advantageous in some environments like deserts where animals get the heat they need f... | [
"Temperature is the most obvious regulatiom but think wider. All our body cells perform complex biochemical reaction at astounding speeds to keep us alive and healthy.",
"But reactions have many variables to them: temperature and pH being just a few of them. For example, many reactions are dependent on enzymes, e... | [
"Both endothermy (warm-bloodedness) and ectothermy (cold-bloodedness) are successful biological strategies. Like a lot of things in life, it's about trade-offs. ",
"Endotherms spend energy in order to maintain a stable internal environment (aka homeostasis). This means we warm blooded animals have specific and na... |
[
"Is there an exact point when we evolve into another species?"
] | [
false
] | [deleted] | [
"There is no exact point. Look up \"ring species\" to read about a case where this transition happens through space rather than time."
] | [
"To get at the reason why there doesn't have to be an exact point, you have to understand that species are somewhat fuzzy concepts. They aren't like, say, buckets, where you can be in bucket A or bucket B but never kind of in both. As hybrids like mules demonstrate, you can be 50% one species and 50% the other (... | [
"As has already been stated, no, there is no specific point at which it happens. This sort of question has been discussed a few times on this board before, so in case you're interested in more extensive discussion, I'm attaching two of my previous responses. I know there are more out there in the archive, but these... |
[
"Do tumors cut off their own blood supply with their uncontrolled growth?"
] | [
false
] | If so, how do they survive and continue growing? If not, how do the cancerous tissues manage to stay connected to the circulatory system despite their chaotic growth? | [
"Sometimes, yes. Rapidly growing tumors often display central necrosis, indicating the growth rate outpaced angiogenensis (formation of new blood vessels). Many tumors produce and secrete growth factors (VEGF, EGF, among others) to help counteract this. Some therapies are aimed at blocking these growth factors or t... | [
"No, the reverse happens actually... Inhibition of tumor angiogenesis is a current target for drug therapies... If you can inhibit signaling for more blood flow, then you can basically starve the tumor of blood and the nutrients it needs to grow/propagate "
] | [
"Its been a long time since I have had to think about this in medical school... If I remember correctly, the cells releases growth factors informing close by vessels that they need more nutrients... If I remember correctly VEGF is the big factor that is studied and serves as the signaling molecule... Though I could... |
[
"Does Large Hadron Collider need re-calibration after redefinition of SI units?"
] | [
false
] | How are measurements in different detectors over at LHC connected to the current values of speed of light, kilogram, etc? Would redefinition of SI units need updates in other kinds of measuring devices in science laboratories across the world? | [
"No. The new unit is defined to be mathematically identical to the old one, and all measurement devices on the planet are still as correct today as they were last week.",
"We've just gone from having a very accurate experiment whose results depend on the size of the kilogram to having the kilogram depend on the ... | [
"Not exactly. The kilogram used to be \"the mass of a lump of Platinum in a vault in Paris,\" but now it's \"a unversal constant multiplied by a certain number, which is equal to the mass of a lump of Platinum in Paris on <whatever day the decision was made official>.\" That doesn't make any real difference now, or... | [
"Good question! I don't know. My guess is that a cylinder is especially easy to shape using a lathe. Lathes are easy to build and very accurate, while shaping a perfect cube requires a mill which is more complicated and difficult to align. Also, when an object is handled, bumps and scrapes tend to cause the mos... |
[
"How would vibrating at the speed of light affect the flow of time?"
] | [
false
] | [deleted] | [
"No, things can't vibrate at the speed of light."
] | [
"I'm trying to understand what 'vibrate at the speed of light' even means. When I think of vibrations I think of some kind of frequency."
] | [
"It's not possible to vibrate at the speed of light. However... taking that and setting it aside, time would flow for the people aboard a ship in such a way that it's speed would resemble a sine wave. \nLike any ship traveling at light speed, there'd be \"no running\" signs all over. lol (for reasons I'm too high t... |
[
"Do bacteria develop resistances to the soaps we use?"
] | [
false
] | I hear a lot about super bugs and their greater resistance to antibiotics. I do wonder though if bacteria could resist the hand soaps we use daily and if there are any documented cases about it. If they don't develop a resistance, then why not? | [
"Hand soaps are surfactants, they work by making the surface they're applied to too \"slippery\" for germs and particles to stick to. This is why the proper way to wash your hands is to soap up to a lather, then rinse away the lather down your hands to your fingertips and off, rather than just washing it away.",
... | [
"/u/milkysniper",
" is correct, it's unlikely that bacteria will develop major \"resistance\" to soaps. Some bacteria have the ability to cling to surfaces using pili and other attachment methods, so I suppose that is a form of resistance. But these aren't formed via the evolutionary process with soaps as pressur... | [
"Just to add, your hands and the rest of your body is always coated with a layer of oil which you secrete. Soaps are lipophilic and hydrophilic, and wash away part of that layer. Generally speaking bacteria go with it, along with some of your epidermis (which is dead anyway). It's pretty hard to evolve a resistance... |
[
"Apart from obvious cost-reasons, why didnt we build the LIGO-observatory in space? Wouldn't the accuracy be greatly enhanced by avoiding all disturbances on the earth?"
] | [
false
] | null | [
"LISA"
] | [
"Aside from cost reasons, LIGO is 4,000 meters long on each arm. To do this in space, we would need to send up multiple satellites for each arm, and be able to control their distances from each other extremely precisely. Right now, there are plans to build a space-based observatory, but there are some technologies ... | [
"Adding to this, the current space-based detectors that are proposed (e.g. eLISA) would be complementary to LIGO rather than replacing LIGO. ",
"See this chart",
" and compare the curves for eLISA and LIGO (there is a button to add LISA to the chart too). They would be designed to detect different types of even... |
[
"Are time and gravity inversely proportional?"
] | [
false
] | [deleted] | [
"None of this has anything to do with quantum physics. Let's get that out of the way right up front.",
"Every particle in the universe is in motion all the time. That motion includes a spatial component ",
" As you sit there reading this, you are in motion toward the future.",
"Massive bodies curve spacetime.... | [
"None of this has anything to do with quantum physics. Let's get that out of the way right up front.",
"Every particle in the universe is in motion all the time. That motion includes a spatial component ",
" As you sit there reading this, you are in motion toward the future.",
"Massive bodies curve spacetime.... | [
"Could you try rephrasing the question? Gravity is a force and time is a unit of measurement. There isn't really an \"inversely proportional\" relationship here."
] |
[
"What would fire look like under a microscope?"
] | [
false
] | null | [
"Fire would still look like a fire.",
"In essence, a fire is the light that's being given off as molecules are reacting in some type of combustion. Molecules are (typically) smaller than the wavelength of light, so at best you'd just see a \"large flame\" under the microscope objective."
] | [
"I am no expert however I can google like a mofo. ",
"Fire is light, heat and a flame so you'd have to use a spectroscope to get any real information.",
"Until an actual answer from someone comes along check out this awesome site and its awesome explanation on how one would look at fire under a 'microscope'.",
... | [
"Depending on the objective and depth of field it will just look like a bright light... or a blurry bright light."
] |
[
"Why is it called \"mononucleosis\"? Do not most cells have a single nucleus?"
] | [
false
] | null | [
"Leukocytes come in all shapes and sizes. Lymphocytes and macrophage / monocytes (which are referred to as mononuclear cells) do have a single unsegmented nucleus but granulocytes (Neutrophils, basophils and eosinophils) AKA PMNLs have what looks like multiple smaller nuclei nuclei joined by thing \"strings\" under... | [
"According to a well-referenced wikipedia entry (",
"https://en.wikipedia.org/wiki/Infectious_mononucleosis#History):",
" \"The word mononucleosis has several senses. It can refer to any monocytosis (excessive numbers of circulating monocytes), but today it usually is used in its narrower sense of infectious mo... | [
"My question really is, though, what makes \"mononuclear\" significant? The vast majority of cells have one nucleus, right? Do leukocytes tend to have multiple nuclei?",
"Aha! The ",
"WP article on leukocytes",
" indicates that most of them have multi-lobed nuclei, and are not considered to be mononuclear.",
... |
[
"How did the trait in which dead bees emit a scent that warns other bees of danger survive and make its way into the population when this trait does not aide the individual bee before reproduction?"
] | [
false
] | More generally how do genetic traits that occur after the point of reproduction survive and enter the main population if there is no mechanism (i.e. natural selection) to ensure its survival? Also, since this is a trait that benefits others and not the individual, how do such traits that only contribute to the welfare of others not the individual survive? | [
"The bees that the dead bee saves are genetically very closely related to the dead bee. Helping your close relations helps your own genes. Hence people are prepared to do a lot for close family.",
"It's called ",
"Kin Selection",
".",
"The fun thing about that is that it's mathematical, we know the formula ... | [
"The worker bees don't mate in general - only the queen does with her male drones. As this would obv benefit the queen via hive defence, it still makes sense under natural selection."
] | [
"Evolution in some parts of the insect world works pretty differently than it does with the kinds of sexual reproduction we humans are more familiar with.",
"The bee reproductive model involves ",
"haploid sex determination",
" in which different 'genders' within the colony have different numbers of chromosom... |
[
"Why do green screens have to be green? Would they work with any other colour?"
] | [
false
] | null | [
"Green is often ideal, as it's far from human skin color, the sky, and most other things that might be on screen. In post production any similar color on screen might be erased by accident.",
"Green is normal but blue is also often used if it makes more sense for the situation. Also rarely red can be used, but it... | [
"The process is called \"chroma key compositing\" and the chroma key doesn't need to be green. Green and blue are the most common chroma keys but any color can work. However, there are drawbacks to certain colors depending on what is in your shot. For example a blue chroma key would work poorly outside where the co... | [
"The green of the greenscreen only would interfere with grass and trees shot in the physically same location as the screen. You can replace the greenscreen with anything you like and that \"background\" source would be independent of the color of the screen.",
"You'd only have to worry about green grass your sub... |
[
"Can someone please explain to me what this is on the weather map and how it formed like this?"
] | [
false
] | [deleted] | [
"I see the radar site!",
"Weather radar sometimes misbehaves with cloud formations too close to the system. I'd bet good money this station's radar data comes from a site in Aberdeen."
] | [
"Are cloud locations triangulated? If so it's possible one station dropped out, meaning that range was only plotted from the remaining station, leading to a circle."
] | [
"A radar glitch is much more likely than the large government conspiracy HAARP. I'm not sure if you got lost, or if you thought this was ",
"/r/conspiracy",
", but this is actually ",
"/r/askscience",
", where evidence actually matters. "
] |
[
"If the lungs in land vertebrates evolved from the gas bladder, what did the gills evolve into?"
] | [
false
] | null | [
"Ah, the interesting thing is the gas bladder evolved from lungs! Early bony fish lived in fresh waters that were often low in oxygen. They commonly gulped air into their digestive tracts to absorb some oxygen through their gut. Pouch a bit off the digestive tract and you get a primitive lung. It seems that get... | [
"fish and land vertebrates both have pharyngeal arches (which become gill arches in fish) and pharyngeal pouches (which become the gills themselves in fish) during development",
"the gill arches have more or less become ",
"neck cartilage and bits of head bones",
", and the pharyngeal pouches turn into... wel... | [
"Teleosts, which are a particular branch of them"
] |
[
"How does salt water oral rinses increase mouth pH?"
] | [
false
] | Several online resources describing the benefits of oral salt water rinses mention the increase of salivary pH (more alkaline) as the means to inhibiting/slowing bacterial growth. However these sources do not describe the chemistry of how salt water increases oral pH. NaCl doesn’t change the pH of water so is it reacting with something else in the mouth to neutralize acids? | [
"Adding table salt probably isn't making your mouth more alkaline, but what is happening is that rinsing your mouth with water will help to remove acid build up from bacteria. This is likely what is raising the pH of your saliva. Highly saline water does make a good mouth wash, but the salt itself is probably not r... | [
"I guess it’s a bit of a positive feedback loop then. Kills bacteria > less acid produced > less acidic environment less favorable for bacteria."
] | [
"Haha yeah googling didn’t really get me anywhere either. I think osmosis/hydration might play a role. Salt rinses are supposed to be isotonic to slightly hypertonic. So in the theory it would dilute or draw water out to hydrate tissue surfaces more than plain water? But yeah, it’s all conjecture here, haha. ",
"... |
[
"Why are so many tornadoes occurring in the United States?"
] | [
false
] | null | [
"There aren't. The current count is on pace for a relatively normal total. This is the first year in a while that there have been F5's however...and they've been unfortunately placed",
"http://en.wikipedia.org/wiki/Tornadoes_of_2008#United_States_yearly_total",
"http://en.wikipedia.org/wiki/Tornadoes_of_2009#... | [
"If you mean \"...compared to the rest of the world\", then the answer is that the US has ",
" had more tornadoes then anywhere else in the world, it's completely normal. We're the lucky nation with the ideal conditions.",
"http://en.wikipedia.org/wiki/Tornadoes_in_the_United_States",
" "
] | [
"As someone who has grown up in tornado alley, I would anecdotally occur. ",
"There seems to be a bit more media coverage than usual. Natural disasters are the big topic right now because the news has nothing more interesting to talk about. ",
"It sucks, but if it was a year from now (US election season), you'd... |
[
"Could this solar flare potentially destroy the earth?"
] | [
false
] | [deleted] | [
"I visited NOAA's space weather prediction center last month and wrote a ",
"brief article",
" about this if you're looking to find out more. ",
"The upshot - yes a huge storm could seriously harm the electrical grid and communications network if we are not prepared for it. It could not \"wipe out\" countries... | [
"Probably not, although some damage has been done in the past they were by MUCH larger flares (this isn't even an X-class flare).",
"Also you should note that the majority of damage will be in things like transformers on the grid rather than in electronics.",
"This is because the flare knocks the earths magneti... | [
"I stumbled upon this article, saying that ... \"reach earth, and ruin all our electrical devices and potentially wipe out whole countries\"",
"All I see is that \"The CME is expected to deliver a glancing blow to Earth's magnetic field on Dec. 28th at 1200 UT\"",
"Ignore it. Nothing to see here. Happens all th... |
[
"Is there such thing as Zero Point Energy?"
] | [
false
] | Is Zero Point energy the same as energy of the vacuum? Could zero-point energy be used to power humanity if the right technology was developed? Is there such a thing, even theoretically? | [
"Is Zero Point energy the same as energy of the vacuum?",
"Yes. It's the energy present in some quantum system when it's in its lowest-energy state.",
"Could zero-point energy be used to power humanity if the right technology was developed? Is there such a thing, even theoretically?",
"Not even theoretically,... | [
"That is entirely consistent with what I said."
] | [
"Yes, and if you calculate the energy of a ball on the ground compared to the centre of the earth, you get a pretty large number. Still doesn't help you get any energy out of it whatsoever if it's already on the ground and can't go any lower. "
] |
[
"What does it mean that \"the electromagnetic force is carried by photons\"?"
] | [
false
] | [deleted] | [
"Virtual photons don’t literally exist. They are just mathematical things that show up in certain calculation schemes in quantum field theory.",
"To say that the photon is the “force carrier” for the electromagnetic force means that charged particles interact with the electromagnetic field, and excitations of the... | [
"So these \"states\" are the evolving quantum states in the process of observation/measurement/interaction? ",
"The state at t = -∞ is the initial state. It's whatever state you prepare the system in. For example, an electron moving towards another electron with a momentum of 5 GeV/c.",
"The state at t = ∞ is w... | [
"They are the states of the system at times t = -∞ and t = ∞. In other words, they're states that are actually observable."
] |
[
"Why does a major fall (say, 20ft) hurt less when you land with forward momentum on wheels (skates, skateboard) than with no forward momentum (in shoes) if horizontal and vertical motion are independent?"
] | [
false
] | Confusing question, but I'll try to explain a little better. In a physics class I took years ago, I was taught that horizontal and vertical motion are independent vectors and therefore don't affect each other. However, I used to skate, and noticed that jumping from a height with forward motion on skates hurt much less than jumping straight down from the same height in shoes, despite supposedly hitting the ground with the same amount of force (and not rolling my body or anything to minimize that force). Do the turning wheels somehow mitigate the impact force, or is there something else going on? | [
"This doesn't work. Ski jumping ramps are sloped downwards, such that ski jumpers do not land on a horizontal plane but with a downward slope (as seen ",
"here",
"). This slope is basically the same as the velocity of the ski jumper such that there is almost no ",
". \nThe vertical movement is slowed down, du... | [
"It's not the fall, but the sharp stop at the end that hurts.",
"If you jump forward onto a downward ramp, then - from your perspective - the ground is dropping away from you. That means that the relative speed that you hit the ground with is smaller. Hitting a downward ramp 'on the run' can work in a similar... | [
"I don't see a reason why the horizontal velocity should have an impact on how much a fall hurts; especially when you have wheels on your feet.",
"The only reason I can think of is that you land differently. Maybe you bend your knees more and your body is not upright, thus is able to buffer the fall better. If yo... |
[
"Which journal should I submit my paper?"
] | [
false
] | null | [
"This is an interesting question, but not really appropriate for ",
"/r/askscience",
". I would recommend ",
"/r/physics",
" or ",
"/r/asksciencediscussion",
"."
] | [
"This isn't the right sub for this question. Talk to your mentor. You can try ",
"/r/askacademia",
" or a similar sub"
] | [
"Thanks a lot for the heads up. I'll try those subs."
] |
[
"Do larger blacks holes have a stronger gravitational pull? Could a larger black hole suck mass off of a smaller one, similar to what a black hole does to a star? Could an infinitely powerful bomb magically placed at the center of a black hole disperse it?"
] | [
false
] | Sorry for all of the questions! | [
"Time.",
"It will eventually lose mass due to Hawking radiation, but it'll take quite a bit of time."
] | [
"The bomb in the black hole would have no effect other than adding to it's total mass. Once the bomb passes the event horizon, the total mass + energy of the bomb is now a part of the black hole and indistinguishable from it. An infinitely powerful bomb would create an infinitely massive black hole."
] | [
"Not really. Adding mass/energy just increases the black hole's lifespan a lot, by reducing the intensity of Hawking radiation it emits.",
"If the black hole is rotating (and real black holes should rotate), it has something called an ergosphere, which extends beyond the event horizon, a region in which objects a... |
[
"The pill is 99% effective. What happens to that 1% fetus when the woman doesn't realize she's pregnant and continues taking them?"
] | [
false
] | Would she have a miscarriage? Would the baby have birth defects or anything? What about the mother? Any adverse effects for her (aside from pregnancy)? | [
"Nothing much. There're some small/weak studies showing (sometimes disputed) associations with various pregnancy complications:",
"This case-control study",
" reports:",
"Maternal OC use during the first 3 months of pregnancy was associated with an increased odds ratio for 2 of 32 birth defects: hypoplastic ... | [
"It also helps to understand the mechanism by which hormonal BC works.",
"I can understand the chain of thoughts. Hormonal BC prevents pregnancy. If pregnancy does occur, wouldn't that preventive thing kick in? And then >Would she have a miscarriage? Would the baby have birth defects or anything?",
"But hormona... | [
"Looking at wiki, for perfect use it says it is 99.7% effective and clarified this mean 99.",
"7 percent of women using it will not get pregnant during the first year of use."
] |
[
"[Physics] Why is for example Lithium more electropositive than Potassium?"
] | [
false
] | Seing as they both lack the same amount of electrons. | [
"Just to clarify, electropositivity is the opposite of electronegativity. So since lithium is more electronegative, it is less electropositive. "
] | [
"Lithium is not more electropositive than potassium. Lithium has an electronegativity of 0.98, and potassium has one of 0.82. The reason for this is because potassium has more electrons, and they shield the pull of the nucleus from the valence electron, meaning that it is held more loosely than lithium's valence el... | [
"I'd rather put it like Ihmes: the valence electron is on average further away from the nucleus in the larger atom, so the electrostatic energy is larger, which makes it easier to strip away the electron. In both cases, the valence electron \"sees\" one positive unshielded charge in the nucleus."
] |
[
"Where is the force from a jet engine realised?"
] | [
false
] | I can see how I can analyse a jet engine as a system and get gas going one way so thrust in another but where does the 'force' actually manifest itself? Basically what needs to be built rigid? The combustion chambers don't look it and the rear end is probably drag. Obviously on a turbofan (a turboprop in a pipe) it is on the impeller but is this true of non-bypass engines? | [
"I still can't quite get a good grip of the forces. Maybe you can sketch a free body diagram of the nozzle?"
] | [
"Depends on the type of jet engine. A turbine is basically a mechanical device that converts moving fluids to rotary motion, slowing the fluid in the process.",
"Turbofan thrust comes mostly from the large intake fan being driven by jet exhaust. The ratio depends on how much of the jet thrust energy is used by th... | [
"Depends on the type of jet engine. A turbine is basically a mechanical device that converts moving fluids to rotary motion, slowing the fluid in the process.",
"Turbofan thrust comes mostly from the large intake fan being driven by jet exhaust. The ratio depends on how much of the jet thrust energy is used by th... |
[
"[physics]Why is the base unit of Mass Kilogramm and not simply Gramm?"
] | [
false
] | [deleted] | [
"The meter ",
" the base SI unit for length, however it is now defined as a fraction of c.",
"http://physics.nist.gov/cuu/Units/units.html",
"\n",
"http://en.wikipedia.org/wiki/SI_base_unit"
] | [
"It's for practical reasons. A kilogram is defined as the mass of an object - the International Prototype Kilogram (IPK) - and the gram was deemed to small to make or use accurately. When they decided to create the IPK, they couldn't very well redefine the gram as it already was in use and had a definition: 1g = 1c... | [
"Not in any commonly-accepted scientific use, no. Although \"megagrams\" isn't common either. It's a \"tonne\". (which is an SI-sanctioned synonym) "
] |
[
"Question about supposed link of vaccination and autism."
] | [
false
] | What would be the effects (if any) of delaying all vaccinations by 12 months? I ask this because if there weren't any harmful effects, why not have doctors delay all infant vaccinations by 12 months and see if the average age of children developing autism changes at all? I think it would prove conclusively one way or another. What do you think? | [
"There ",
"is no",
" \"supposed link\". The study that showed otherwise was based on falsified data and its author was found guilty of scientific misconduct."
] | [
"http://phys.org/news/2011-01-autism-vaccine-fraud-journal.html",
"http://www.cnn.com/2011/HEALTH/01/05/autism.vaccines/index.html",
"http://www.msnbc.msn.com/id/40951375/ns/health-childrens_health/t/autism-vaccine-fraud-leaves-lot-mistrust-mop/",
"http://www.sciencefriday.com/blog/2011/01/the-great-autism-va... | [
"delaying vaccinations by 12 months puts infants at risk for serious, life-threatening infections for 10 months longer than they have to be (most vaccinations start at 2 months of age)",
"There is NO. LINK. between autism and vaccination. Wakefield falsified his data, the paper was retracted by the journal and h... |
[
"What causes the Casimir effect?"
] | [
false
] | null | [
"The vacuum fluctuations are a fundamental feature of the universe. They aren't really \"caused\" by anything. All of our quantum theories contain these fluctuations in various forms. Do you have a background in quantum mechanics? If so, I can give you some more detail. But the long and the short of it is that nobo... | [
"Ripples in the various fields that occasionally and temporarily line up to resemble a more permanent oscillation.",
"This is a nice explanation below.",
"http://profmattstrassler.com/articles-and-posts/particle-physics-basics/virtual-particles-what-are-they/"
] | [
"As someone already pointed out, no one exactly knows ",
" this happens, but perhaps I can help you understand it a bit better.",
"I'm sure you're familiar with the Heisenberg's uncertainty principle [;\\Delta x \\Delta p \\ge \\frac{\\hbar}{2};] ",
"Another variation of this principle also exists:",
"[;\\D... |
[
"Why does a fan lower air temperature when you are adding kinetic energy into a system?"
] | [
false
] | I was thinking about this today when I was in my room. A fan is designed to be a mechanical machine that takes electrical energy and transforms into kinetic energy by moving the air molecules that come into contact with fan blades. Why does this increase in kinetic energy not translate into higher temperatures? (Ex. Wind chill factor) Edit: words | [
"Short answer: it does.",
"A fan not only adds extra motion to the air causing it to increase in temperature, but it also takes external energy and converts it to waste heat while moving the fan blades.",
"As a result, running a fan in a sealed room will increase air temperature.",
"The OTHER things the fan d... | [
"A couple of points...",
"First, the average speed of a molecule in a gas is way higher than you think. If you do the calculation for nitrogen at room temperature, you'll find that the average molecular speed is ~500 m/s. However, the molecules will be moving in all different directions. All the fan does is cause... | [
"It doesn't lower air temperature and does, ultimately, make a closed system warmer.",
"However, in terms of personal comfort, it's not really relevant what the total effect is on temperature. A human body will warm up and humidify the air around it, so a fan that blows away that bubble of warm, wet air will make... |
[
"Which part of speech is the most numerous? (prepositions, nouns, verbs, adjectives, adverbs, etc.)"
] | [
false
] | null | [
"Nouns are easily the most numerous. Nouns include the proper names of everything and everyone. They are often created to describe newly discovered objects. There are hundreds-of-thousands of last names in English alone."
] | [
"It should be pointed out that OP's question only really makes sense on a language-specific basis (or maybe family-specific basis), since there is no crosslinguistically valid definition of what a \"noun\", a \"verb\" or an \"adjective\" entails. So comparing English parts of speech with Inuktitut parts of speech."... | [
"Most numerous could mean in the lexicon, or it could mean in terms of actual words uttered. I don't know if nouns are most numerous in the second sense, though it's plausible they are. If not nouns then adjectives or verbs."
] |
[
"How do humans determine the location of sounds?"
] | [
false
] | Is it based solely on differences in amplitude between the ears, or are we able to detect the minor delay as well? | [
"Like with depth perception in vision, we unconsciously fuse multiple direction cues. We can detect the amplitude difference and the delay, but my understanding is that a lot of it is (as ",
"/u/HorsefuckerJim",
" says in more detail) that the shape of our outer ear (the pinna) alters the sound differently depe... | [
"It's based on the difference in timing between each ear (interaural time difference or ITD) and a difference between the sound's frequency (pitch) and amplitude (loudness) between each ear (interaural level difference or ILD). Your ears can scrutinize ITD to microseconds. ILD is also super precise but I'm not sure... | [
"This is the main factor. Other people are talking about ear shape and other factors, but as someone who is now deaf in one ear and can very rarely tell where sounds are coming from, the differences between the left and right ears is by far the most important factor for determining the direction of sound."
] |
[
"Why do we laugh when being tickled when it actually pisses us off?"
] | [
false
] | from . | [
"Tickling behavior has been discussed by a lot of biologists. See, e.g. ",
"this article",
". The upshot seems to be that it is an evolved set of instincts to learn/teach what areas are vulnerable and should therefore be protected. Thus, you can't (normally) tickle yourself and all but the least inhibited indiv... | [
"all but the most inhibited individuals would not tickle strangers",
"Could you elaborate on this please? It seems counterintuitive, since I would expect the least inhibited people to do this."
] | [
"Yes, it is called I need to proofread more before hitting \"save\". That should be least inhibited individuals. Thanks for catching that. "
] |
[
"Is it possible to construct a radially magnetized sphere?"
] | [
false
] | Consider a product like which is an arc-segment magnet, with one pole on the inside, and the other on the outside. Is there a way to produce a solid sphere in this configuration? Would it behave like some sort of simulated monopole with one pole all over its surface and the other at its center? Would it be at risk from fracturing/exploding from the magnetic pressure of the pole constrained at the center? Or is this all just a fool's errand? | [
"The second of ",
"Maxwell's equations",
" which is known as ",
"Gauss's law for magnetism",
" states that the divergence of a magnetic field is zero.",
"This means that if you imagine a sphere that encloses your \"simulated monopole\" and you sum up the magnetic field lines exiting over the entire surfac... | [
"This is the right way to think about it. If you could perfectly make that sphere, you'd have a magnetic monopole.",
"So you can't make that sphere have a perfectly radial field. Even in the link posted, those magnets do not have truly radially outward fields. If you carefully measured the field around that circu... | [
"If you could perfectly make that sphere, you'd have a magnetic monopole.",
"I'm not sure I like the above sentence. It might imply that we're just talking about manufacturing issues, if you read it a certain way.",
"I can't make a radially magnetized sphere as a neodymium magnet, or even a section of a sphere,... |
[
"If we threw a clock into outer space, at what point would it stop showing us the \"right\" time when viewed through a telescope?"
] | [
false
] | Okay, don't even totally know what I'm asking so bear with me here: We put an atomic†, never-running-out-of-batteries clock into outer space, maybe not even going at a speed fast enough to noticeably dilate time††, and we let it go for a long long time. When we look through a telescope at things very far away, we're technically looking . So when/where would that clock stop showing the same time as earth clocks? Or, rather, what would it show? † does that make a difference? †† is that even possible? Hopefully that question makes sense. I'm excited for the answers. Thanks! Edit: spelling and notes. Edit 2: Awesome answers guys! and thank you. In the light of day, I feel silly about how simple the answer is. I think I meant to ask more about what would happen while i was viewing the clock, but I think I figured out (with the help of you guys and a few other physics friends) that if the clock is moving away from me at a constant speed, the length of time that lapses between Space Clock's seconds will increase. ...exponentially? I think originally I wanted to know what time looked like over time, but these answers and discussions have been enjoyable. | [
"It depends on what you're sensitive to measuring on Earth. Let's say you moved it slowly enough to avoid the effects of special relativity and let's ignore the effects of gravitational time dilation for the moment too. Now let's say I can measure time to a precision with an atomic clock, which from ",
"wikipedia... | [
"At the most basic, the clock will be behind based on its distance from you. If it's one light-year away, it will be a year behind. If it's a light-minute away, it will be a minute behind, simply because it takes that long for the light to reach you. This ignores any relativistic effects, but I think it's what you'... | [
"Actually, atomic clocks are typically quite good for keeping time standards, unless you need some ridiculous precision. They rely on keeping good measurements of a natural process, so aren't really Earth-centric in that sense. It's when you want to start comparing atomic clocks that things get tricky but since you... |
[
"How did we adopt standard rendering settings such as 1080p resolution, 30-60 fps, 60-144 hz refresh rate, etc.?"
] | [
false
] | I'm curious as to how we came up with these standard values that most screen manufacturers, game creators, video rendering programs have adopted, etc. have adopted. | [
"The standard TV refresh rates - 50Hz in former \"PAL\" countries, 60Hz in former \"NTSC\" countries - came about largely because they matched the frequency of the alternating current used in the countries that developed them, although NTSC later screwed this up and has annoyed a generation of broadcast engineers b... | [
"It's not technically NTSC, as that is purely an analogue system (as is PAL), but we (former broadcast engineer, sort of, current video enthusiast) still call any video which is 704/720x480 @ 23.976/29.97fps (interlaced or not) \"NTSC\". Sometimes it's used to refer only to the framerate, even if the video itself i... | [
"I don't pretend to know how over-the-air digital works, so I have to ask if we are still broadcasting NTSC encoded digitally and still have that grandfathered in, or if we are using more modern codecs now?"
] |
[
"Friend has been working in the schools chem lab for years & still has no idea what this thing is for. Anyone?"
] | [
false
] | null | [
"Looks like an adaptor for vacuum evaporation that has an adapter to prevent any solutes from getting sucked up as well. "
] | [
"I believe it is a cold finger. ",
"http://en.wikipedia.org/wiki/Cold_finger"
] | [
"It's kinda hard to tell what it is from the picture. Can you get a better picture of it without so much glare/blurriness? ",
"From what's there in the picture, the best I can guess is some strange kind of distillation head or, if that tube on the bottom is sealed, the top half of a sublimator."
] |
[
"How does the mRNA from the new vaccines enter our cells?"
] | [
false
] | From what I understand most vaccines use a “vector” to deliver the payload to our cells, in order to trigger the immune response. But with these new mRNA vaccines there appears to be no vector. They just inject mRNA into the body directly and our cells just “slurp it up” somehow? | [
"But the RNA vaccines don't work like that, the idea of inject the RNA is for your own body to produce the spike protein"
] | [
"But the RNA vaccines don't work like that, the idea of inject the RNA is for your own body to produce the spike protein"
] | [
"The mRNA is packaged inside ",
"liposomes",
" or ",
"micelles",
" (not sure which), which are little (~50x smaller than a cell) packets of cell wall without any receptors. Basically fancy soap bubbles. There are a bunch of them naturally in your blood stream doing various things, and they are capable of ... |
[
"Is freezing point elevation possible?"
] | [
false
] | null | [
"Substitution of heavier isotopes will result in a higher freezing point. For example, you'll get roughly +0.04 °C elevation in the freezing point of water for every mole % increase of Deuterium. Freezing point elevations in other isotopomers, however, are generally smaller."
] | [
"Surprisingly, yes. In nanopores, phase behaviour of compounds are changed. In most cases, the freezing point will be decreased, but if the correct pore diameter and size is used, the freezing point will instead increase, as reported in this article by Kaneko et al.",
"Kaneko, K.; Watanabe, A.; Iiyama, T.; Radhak... | [
"Awesome. Just awesome. Thank you. "
] |
[
"What are the magnetic properties of light?"
] | [
false
] | Light is part of the electromagnetic spectrum, it's more common to think of light's electric properties, what's magnetic about light? How strong and useful are the magnetic properties? | [
"Light, in terms of how you wish to discuss it, exists in its wave form as orthogonal waves of electric and magnetic fields--fields is the important aspect. It doesn't exhibit magnetism in the sense of a traditional bar magnet--in fact, it doesn't really exhibit magnetism as we think of it in terms of classical ph... | [
"Well after doing my own research, ",
"light does of some magnetic properties.",
" and I was looking more along the lines of the power of it's magnetic field."
] | [
"Light is a traveling oscillation in the electromagnetic field. This means it does have a magnetic component, so it can influence charges like a magnet would. Light waves look like ",
"this",
"—the magnetic field component is shown in blue.",
"It's not so much that light has magnetic properties. It's more tha... |
[
"Is cold water detergent really worth the expense?"
] | [
false
] | null | [
"Here's a NY Times article talking about the introduction of cold water detergents. Not exactly what you are asking about, but relevant. The first paragraph is a good summary of the article:\n",
"http://www.nytimes.com/2011/09/17/business/cold-water-detergents-get-a-chilly-reception.html?pagewanted=all&_r=0",
"... | [
"Sorry, but you completely messed up the terminology there.\n\"Soap\" is a general term for mixtures of fatty acid salts which can function as surfactants. Metal ions in hard water will form precipitates with soaps, but this is not an intended function. For this reason detergents, the stuff you use to wash your clo... | [
"The idea of \"soap\", is to soften the water - remove metallic ions; it also degreases. I always wash-up using cold water and still get good results; it's just unpleasant to my hands on a cold day. It would seem, cold water detergent, could be a marketing ploy."
] |
[
"Is eating a raw diet the healthiest method of sustinence?"
] | [
false
] | Aka a largely vegan diet? I've heard this argument a great deal from vegans. As well as the argument that "we aren't supposed to eat meat" I.e. "Meat eating is unnatural". | [
"A very apt example is the vitamin B12 (cobalamin), of critical importance to the survival of almost every kind of human cell, that is only found in sufficient amounts in non-vegetarian food (read: meat).",
"This is the death knell of the idea that eating meat is \"unnatural.\" Without the ability to artificiall... | [
"To elaborate on this, our metabolism on a cellular level reflects our omnivorous role in nature. There are many fats, vitamins and other micronutrients that are essential to our survival that we can't synthesize even if we have the necessary ingredients.",
"There hasn't been any evolutionary pressure for human c... | [
"To elaborate on this, our metabolism on a cellular level reflects our omnivorous role in nature. There are many fats, vitamins and other micronutrients that are essential to our survival that we can't synthesize even if we have the necessary ingredients.",
"There hasn't been any evolutionary pressure for human c... |
[
"I know that computers use base 2, we use base 10 and base 12 would be more useful. But are there other (non-primitive) ways to count things other than \"base x\"?"
] | [
false
] | [deleted] | [
"The most important way is ",
"Continued Fractions",
". These are much better than any base, in terms of accuracy, but are not convenient to do arithmetic with.",
"A sequence [a",
",a",
",...] is the continued fraction expansion of a number x if x=a",
"+1/(a",
"+1/(a",
"+... For instance, the conti... | [
"There's Roman numerals, although that's very similar to base ten. There's also ",
"mixed radix",
" numeral systems. For example, there's 24 hours in a day, 60 minutes in an hour, 60 seconds in a minute, and 1000 milliseconds in a second. So if you say something takes 3 hours, 12 minutes, 26 seconds and 412 mil... | [
"This doesnt really answer the question of OP. The continiued fraction of a natural number n is just the number itself. Thats not really another way for \"counting\"."
] |
[
"Do vitamin supplements provide health benefits or am I just paying for expensive urine?"
] | [
false
] | null | [
"Let me know if I'm just misunderstanding your post; but isn't the gist of it: \"Healthy adults don't need multivitamins because they don't cure cancer or prevent heart disease.\" If that is it, then I don't think its answering OP's question or addressing the reason most people take vitamins. I was under the impr... | [
"The current consensus is that healthy individuals do not need any regular micronutrient supplementation. For example, ",
"this large RCT published in JAMA",
" looked at cancer rates in male physicians over 50, and found a small (8%) reduction in overall cancer rates, without significant reductions in specific... | [
"Pharmacist here: \nTLDR Version: Vitamins A,D,E,K are fat soluable vitamins and can be harmful if taken is excess as they are not excreted in the urine. Vitamin D supplementation is the new craze at the moment, but levels need to be monitored with blood draws so see your doctor before starting supplimentation. "... |
[
"How can lasers cool something to near absolute zero?"
] | [
false
] | [deleted] | [
"The easiest method to explain and I believe one of the earliest is Doppler cooling. The Doppler effect as it relates to light basically means that if you're moving towards a light source the light will be blueshifted, meaning it has a shorter wavelength and a higher energy, and if you're moving away it will be red... | [
"So collisions can be considered perfectly elastic?"
] | [
"Ah, this is really interesting.",
"First of all, atoms absorb and emit electromagnetic waves, i.e. light of specific, quantized, frequency (or wave length). Second, light carries momentum. Meaning it pushes on stuff it hits.",
"Big contribution to the temperature of atoms is their movement in space. And you u... |
[
"Why do Iron fillings highlight the field lines of a magnet?"
] | [
false
] | I understand that there is a magnetic field surrounding a bar magnet and they make a torus shape. And that the iron filings are showing that when we sprinkle them over the top. But why do the iron filings display them as lines? I thought they would be a somewhat smooth distribution. Is it some sort of frictional mechanism with the filings and the paper maybe? | [
"The \"lines\" are a result of the filings, and not discrete magnetic lines.",
"The filings are not round but small strips, and when subject to a magnetic field become magnetically attracted to each other, end to end, forming the lines.",
"Each filing more strongly attracts to the end of other filings than to t... | [
"That makes sense, thank you"
] | [
"The iron filings become tiny little magnets in the presence of the field. One end is drawn towards each magnetic pole. The net result of the two attractions and two repulsions present results in the filings pointing in the direction of the magnetic field lines."
] |
[
"I am about to attend my first scientific conference. What should I expect, and what should I do to get the most of it?"
] | [
false
] | I'm an undergrad who is really interested in research, and I'll be going to this year's SFN. I'm not presenting a poster, but I just wanted to see and learn from all the other work being presented. I don't know quite what to expect at a conference. Any advice for me from those who have experienced it all? Also, I'd love to hear if any of you will be at SfN. | [
"First and foremost, chill out!! These things are very relaxing and a very good chance to network while at the local bar. ",
"My best advice; Talk to lots of people at the poster sessions, even if it isn't your field, people are very open, friendly and more than willing to discuss there work with you, even if yo... | [
"Go through all the listings beforehand and highlight all the talks you want to attend. They usually are clumped by symposium so that will make it easy. For smaller conferences, the best talks tend to clump towards the beginning of the week in my experience. Carry a notebook for notes and contact info of interestin... | [
"Others have great points.",
"I would add: get the agenda and plan to see talks that are interesting to you and relevant to your ambitions. Ask people for cards, or where to e-mail for a pre-print and then FOLLOW UP.",
"Try to attend any cocktail sessions or other social events. Professors are most honest and u... |
[
"How does gravity work?"
] | [
false
] | Why are objects with mass attracted to each other? And how can the universe expand infinitely if all objects with mass are attracted to each other? (After reading the wikipedia page on I think I understand the answer to the second question... At least a very basic level.) | [
"Objects with mass are attracted to each other because mass curves spacetime. The ",
"Einstein Field Equations",
" describe this. These equations are, basically:",
"Curvature = Matter",
"So, if you've got two masses, they both cause space time to curve. This causes the masses to move towards each other. You... | [
"The Einstein equations are the central results of general relativity, which is a ",
" field theory. The graviton is a hypothetical particle which would enable us to model gravity using ",
" field theory, which is the framework with with we model all other physical phenomena. But, for various reasons, this fram... | [
" isn't really within the scope of physics, as far as we know. ",
" is explained by ",
"general relativity"
] |
[
"How do we know what happened during Big Bang Nucleosynthesis?"
] | [
false
] | I know that we use the modern day elemental abundances (mostly of H, D, He-3, He-4, and Li-7), baryon-photon ratio, and cross section to determine the conditions during BBN, but how exactly does all of this tie in? Is there one singular formula like those posed in that ties all of these together? Also, can we use these data to extrapolate into the future? It would be great if you're as specific as possible. | [
"Hi again. There is no simple formula to extract the ratios of these elements, it depends on detailed knowledge of the level structure and interaction crossections of these nuclei, particularly with lithium, which has the most complicated structure, being the largest.",
"If you're referring to equation 1 from αβ... | [
"So regardless of accuracy, how could I use aby to extrapolate backwards? "
] | [
"I don't know if I can explain it better than they do. They use the crossections (sigmas) they cite and find what conditions during BBN give the closest fit to the abundances we see now."
] |
[
"Will releasing store-bought Preying Mantises into my garden unbalance its ecosystem?"
] | [
false
] | My girlfriend works at a garden center that just started selling these little pods full of Mantis eggs, about 300 eggs per pod. You're supposed to release the eggs into the garden, and when they hatch after a few weeks, the little guys are supposed to descend upon the bugs in the garden like the black wing of death, devouring everything they can find. I'm thinking this is great, Praying Mantises are awesome, and they're eat all the pests attacking the plants, but won't they kill all the beneficial insects too? Bees and butterflies and so on? Will this ultimately be creating a much more severe problem than it's meant to fix? | [
"One problem is outbreeding depression. You would be modifying the resident gene pool with potentially foreign genes. the other possibility is that you could be introducing non-native mantises, and they may be an invasive species at you location."
] | [
"Yeah. You should probably not do that. They'll kill pretty much everything, and moving species around in general is almost never a good idea unless you're a conservation biologist and you really know what you're doing (and even then, it's hard to do without screwing up ecosystems)."
] | [
"Could you explain what outbreeding depressing is?"
] |
[
"Are there organisms with multiple brains?"
] | [
false
] | I am excluding symbiotic units for this question. And I'm also specifying only brains grown through cell differentiation, not through the assimilation of a foreign organism. And, if they exist, what are they? Thanks. | [
"You don't have multiple brains, but you do have spinal cord ganglia - clusters of nerves - able to process simple information and take independent action such as moving limbs away from pain without the delay of sending the message up and down your spinal cord.",
"Biologists say humans have a high degree of cepha... | [
"An octopus has a decentralised nervous system meaning that most of its neurons are actually in its arms, rather than the brain. With eight arms and a central brain, some people say that an octopus has \"nine brains.\" This is a bit flashy for my taste but depends on your definition of a brain.",
"Also strangely ... | [
"Octopus. If learnt that from \"finding dory\"",
"https://apnews.com/article/ri-state-wire-octopuses-ma-state-wire-ba6e3fa5bb804565b9d6d666b6d40a73#:~:text=The%20giant%20Pacific%20octopus%20has,making%20reality%20stranger%20than%20fiction.&text=A%20central%20brain%20controls%20the,that%20biologists%20say%20contro... |
[
"Why are the furthest 4 planets gas giants, but the closest 4 are rocky? Do gas giants always form farther away from stars?"
] | [
false
] | null | [
"As I recall from my recent-ish astronomy course, the outer gas giant planets are beyond the ",
"frost line",
". This means that in early planetary formation, the planets that had begun to coalesce beyond the frost line were able to take in icy compounds and combine them with the planets, which was an enormous ... | [
"Due to the centripetal forces acting on he spinning disk, those particles with less mass feel greater acceleration, thus moving away from the star much faster. As you can guess, this separates the disk into a dense, rocky center and a light, gassy outer ring.",
"Incorrect. All objects will feel the same accelera... | [
"The reason why gas giants form farther away from their host star then rocky planets, is that they need to be far enough away from their host star so that the temperature is low enough for compounds such as ammonia, water and methane to condense into solid grains(about 150 kelvin/-123 degrees celcius). The distance... |
[
"How much could the largest gorillas bench press?"
] | [
false
] | null | [
"Good ole ",
"wikipedia",
" archived discussion says that this has never been really truly studied. there is a neat factoid near the bottom of the article that says the Guiness Book of world records recorded a chimp did a 600lb deadlift. they extrapolate that to a gorilla being able to lift maybe 1200 lbs. "
] | [
"The Straight Dope",
" has an old article on how a 165 pound chimp once yanked on a dynamometer to the tune of 847 pounds with one hand, and a 135-pound female pulled 1260 pounds. It notes chimps have deadlifted 600 pounds without problems.",
"It then suggests a mature male gorilla \"could probably heft an 1,80... | [
"For context, the current deadlift world record is 460,4 kg (1015 lbs).",
"http://en.wikipedia.org/wiki/Deadlift#World_records"
] |
[
"What happens to a candle's wax as it burns? Why does it slowly disappear until there's none left at the end?"
] | [
false
] | null | [
"It oxidizes, as burning is a combustion reaction. The carbon compounds in the material break apart whilst reacting with the oxygen to form carbon dioxide, energy and byproducts (depending on the specific compounds, greatly simplified). The energy is the heat and light from the fire (mostly), the carbon dioxide is ... | [
"For the same reason as gasoline in your engine slowly disappears until there's nothing left. Or, if you stop eating, the fat & muscles in your body disappear until there's less of you left.",
"Generally, as with all oxidizable fuels, the oxidation (aka burning) of the fuel produces gasses (exhaust) + energy. T... | [
"The wax melts to form a pool around the wick. The hot wax rises to the surface. Wax as a liquid flows up the wick from capillary actions just as paper towels sop up oil. In the wick the wax turns mostly to gas which is oxidized and burns initially with a blue almost invisible flame. The orange and red flames are h... |
[
"How are there fish in dune pools/lagoons (ephemeral pools?) like those in North East Brazil?"
] | [
false
] | In Super/natural on Disney +, episode 6 titled “impossible journeys” a slider turtle finds pools of water that form in the desert after rain. My question is, how are there fish in these pools if there was no water before it rained? | [
"There are studies that suggest that mallard ducks are the cause.",
"Mallards consume large amounts of eggs from fish that have entered spawning season, most of which are excreted within an hour. In an experiment where about 500 eggs were fed, it is said that 3 eggs finally hatched.",
"If a mallard duck defecat... | [
"I haven't see the episode in question, however the most likely option for fish in ephermial pools is annual killifish. These fish live in temporary pools of water, lay their eggs on the bottom of these pools, and the eggs survive drying out and hatch when the next rain falls. There are many groups of annual kill... | [
"Killifish in general are pretty incredible and I’m surprised more people aren’t aware of them, there are also some species that can tolerate high salinity and very low oxygen conditions, and one species (the mangrove killifish, Kryptolebius marmoratus) can even survive for weeks at a time as an adult inside tree h... |
[
"Do the Halal and Kosher methods of animal slaughter increase or reduce the suffering of the animals (in comparison with stunning/conventional slaughter)?"
] | [
false
] | Is there any difference between the theory of the technique and it's actual practice (i.e. in theory it's better for the animals but in practice, X has to happen which is worse for the animal)? | [
"I raise hogs and have slaughtered them myself and seen how the pros slaughter cattle, both kosher and otherwise.",
"My opinion is that the slaughter is the ",
" important part of what differentiates an ethical operation from an inhumane one. As long as we're not talking about a psychopath deliberately torturi... | [
"To be honest, they come to approximately the same thing, especially for the animal in question. Both involve some suffering, and theres no way for us to accurate distinguish which is more or less.",
"Howerver, the halal and kosher slaughter method has less to do with being humane and more to do with cleanliness... | [
"Since we are mostly talking about large mammals here, consider this: ",
"If you cut off blood supply to the brain, how long before unconsciouness comes about? If I recall its 10-15 seconds usually. This is what is happening under the Halal/Kosher slaughter methods. These methods also do not cut the brain stem... |
[
"How did the first replicating RNA or DNA begin to result in organelles with functions?"
] | [
false
] | null | [
"At least some organelles seem to be the result of endosymbiosis - i.e. they were formerly independent life forms which became symbiotic with other life forms (like our ancestors). ",
"Mitochondria, which are in every cell in your body keeping you alive, in particular are thought to have originated in this way. "... | [
"But how did the nucleus, chloroplasts, and all the other internal structures form? And how did mitosis code for itself? "
] | [
"RNA itself is really versatile. It can act as an enzyme, and is used in ribosomes (which are pretty much the 'factories' that assemble proteins from amino acids). So after RNA does its thing you end up with proteins, which can be both structural and functional, and used in the organelles that you mentioned.",
"A... |
[
"Does string theory describe any actions or phenomena that occur in the hidden extra dimensions?"
] | [
false
] | Descriptions of string theory indicate various versions of theory require 6, 7, 10 or 11 dimensions whereas we only perceive 3, or 4 dimensions if you count time as one. The fact that we can't see or sense these dimensions is explained by suggestions that they are "compact" or curled up in tiny closed loops. Do any of the string theories describe forces or particles that transmit or translate through these hidden dimensions to create effects we can see and measure in the 3/4 visible dimensions? For example, particle quantum entanglement is bit of mystery in our current physics, especially the apparent "instaneous" communication of the quantum state information between entangled particles when one particle is measured. Do any of the string theories suggest the channel of communication between distantly separated entangled particles could be communicated through these hidden dimensions? Are there any other examples of forces or fields in the standard model that string theory says is operating through these dimensions? | [
"Small correction: superstrings are all in 10D. M-theory is in 11D, but it's not a string theory (it has no strings, so...). When going from superstrings to us, we compactify 10 - 4 = 6 dimensions (typically on a Calabi-Yau). When going from M to us, we compactify 11 - 4 = 7 dimensions.",
"Yes, all sorts of wacky... | [
"Hey thanks for a very informative response. Wonder if you can give some sources or search terms for some of the cross-dimensional dynamics you reference in your 2nd paragraph. To paraphrase \"Starship Troopers\", I'd like to know more. ",
"Also, same question in reference to Susskind, et al with regards to sui... | [
"You can read about the attempted search for experimental evidence for extra dimensions ",
"here",
"."
] |
[
"Are electric water cookers made out of plastic a health risk?"
] | [
false
] | I was always told as a child to avoid putting boiling water or very hot food into any sort of plastic container, based on the idea that toxins from the plastic would enter the food/drink and be bad for you. This has led to me having a general aversion to things like plastic cups for hot drinks (I a country where they serve boiling-hot tea in plastic cups all the time) and things like electric kettles made of plastic. But since these kettles are specifically manufactured to be in contact with boiling water that is then consumed, I would think that a sort of plastic would be used that is safe, and doesn't release any dangerous substances into the water. Is this the case? Is there any evidence to suggest that an electric kettle made out of metal would be a "healthier" choice? | [
"That's why I'm asking ",
"r/askscience",
", and not ",
"r/askreddit",
" or ",
"r/answers",
". "
] | [
"I am far too much of a coffee snob to use a plastic drip coffee maker anyway ;)",
"Stainless stovetop espresso makers or glass/stainless french presses are easy to come by"
] | [
"I am far too much of a coffee snob to use a plastic drip coffee maker anyway ;)",
"Stainless stovetop espresso makers or glass/stainless french presses are easy to come by"
] |
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