title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"Airfoil physics: Why does the air flowing the top of a wing *have* to catch up with the air flowing underneath it?"
] | [
false
] | This seems to be the key point to how an airfoil works, but I mean, it's not like they're inseperable lovers or anything... My apologies if this has been asked before, but i was reading back through xkcd and the title-text in got me thinking... | [
"It doesn't. This is a common misconception that has its own name: equal transit time fallacy",
"http://en.wikipedia.org/wiki/Lift_(force)#.22Popular.22_explanation_based_on_equal_transit-time"
] | [
"Even when I was in grade school this never made any goddamn sense. I was so happy when I found out in college that it was bullshit."
] | [
"Shorter, eh?",
"But how do wings work then?",
"Fucking Wings, how do they work?",
"http://en.wikipedia.org/wiki/Angle_of_attack"
] |
[
"Can the human body survive without any viruses?"
] | [
false
] | It is a known fact that we cannot survive without bacteria that preform a multitude of tasks in our bodies such as digesting food. In light of the new virus cure that MIT has developed, if we removed all viruses from our bodies will we survive? Hence, do we harbor beneficial viruses like we do bacteria? Furthermore wou... | [
"The human virome (all viruses that can be found in the body) is pretty massive. For example, over 1200 viral genotypes can be found in human feces. These viruses, mostly bacteriophages, surely play an instrumental role in shaping the bacterial communities of our bodies. However, it is unclear how these viruses ben... | [
"Layman here(Biochem. undergrad), but given that the majority of eukaryote viruses replicate via the ",
"lytic cycle",
", the final step of which destroys the host cell, I highly doubt that there are any viruses out there which are beneficial to the host, I'm sure an expert can maybe shed more light on this if ... | [
"You're genome is littered with ancient viral DNA that have integrated into your genome. They make up a lot of intergenic/non-coding sequence. Knowing that viruses shaped our genomes back in the day, I'd say taking them away (thus preventing further impact on our genome) would really change our evolution in the f... |
[
"Why are the gas giants in our solar system so vividly colored?"
] | [
false
] | The gas giants in our solar system appear to be made mostly of the same stuff (90%+ hydrogen/helium). The other trace constituents such as water, methane, hydrogen sulfide, etc., are colorless. Why then are the gas giants so beautifully colored? Why does Jupiter have such a wide variety of colors whereas the other gas ... | [
"Gas giants are brightly colored because of the other 10%. Water, methane, hydrogen sulfide etc. are individually colorless, but when you mix them all up and bombard them with UV rays for a long time you can get chemical reactions going that make some funky sulfur-organic type compounds. I don't think they make a... | [
"All good, but just to expand on this: the generally accepted hypothesis for Jupiter is that the planet is almost entirely cloaked in bright white ammonia clouds. The zones keep this bright white color because the tops of the clouds are quite high in those locations; in the deep brown belts, though, the ammonia clo... | [
"Uranus and Neptune have a lot more water in them. It's thought that Jupiter and Saturn are basically hydrogen and helium around a small rocky core, with the H and He turning to liquid, then eventually maybe solid form as you get closer to the core and the pressure increases. Its thought that Uranus and Neptune h... |
[
"Does other viral respiratory illnesses like common cold or influenza also cause long lasting cardiopulmonary or neurological sequelae like COVID-19 is doing?"
] | [
false
] | null | [
"Short answer: Yes ... Maybe. It's complicated",
"The long term side effects of various virus infections have been a part of research for some time now. It is hard to correlate these diseases with certain virus because the symptoms are usually long term and show up later in life. There have been some viruses maaa... | [
"Yes. Influenza is well-known to ",
"increase heart attack risk",
". And in the aftermath of the 1918 flu there was an \"",
"encephalitis lethargica",
"\" wave, which may have been related. Also, as ",
"/u/Typhun",
" mentioned GBS is known to be associated with influenza."
] | [
"Yes. ",
"Guillan-Barre syndrome and viral myocarditis are some of the more well known illnesses associated with viral infections. GBS is even associated with flu vaccines. ",
"Though not a respiratory illness, untreated HIV can result in dementia."
] |
[
"If the Earth's core is molten because of all the heat when Earth was created, is the core slowly losing heat?"
] | [
false
] | [deleted] | [
"Yes, but not as quickly as you may imagine. According to my textbook, The Solid Earth, An Introduction to Geophysics 2nd Ed. Fowler pg 371 about 20% of the heat lost at the earth's surface originates from the core.",
"Lord Kelvin ",
"famously",
" tried to calculate the age of the earth based off of heat tran... | [
"The bulk of the heat inside the planet actually comes from ",
"radioactive decay",
", not from leftover formation heat.",
"The original heat from the formation of the Earth probably only accounts for ",
"5 to 10%",
" of the total heat present at this point.",
"There are other sources of heat within the... | [
"Thank you for expanding. Those links were very enlightening. It's incredible to think that supernovas from billions of years ago produced enough energetic atoms that they are still heating the Earth today. I suppose either way that is true, but somehow it is even cooler that it is radioactive elements inside the E... |
[
"Why does color fade when left in sunlight for extended periods of time?"
] | [
false
] | We have a rack of DVD cases next to the window, and recently I've noticed the covers have all faded in color. Strangely the red ones seem to have faded far more than any of the others. | [
"The short answer is that sunlight causes irreversible changes in the compounds and molecules that gave a material its color in the first place, in a process we call ",
"photodegradation",
". As a result of these changes, the material gradually loses the ability to specifically absorb (and reflect) different pa... | [
"Eventually, yes, but it would take more than just a few years.",
"First, sunlight is ",
" brighter than any ordinary light bulb. Humans have trouble appreciating just how much brighter, because your eye has a logarithmic response to light (doubling the physical brightness does not double the perceived brightne... | [
"Yes, but in this case it is a measure of the amount of energy delivered to a specific area per unit of time that is important. Watts are a good measure for this and lumens are not. The pigments in dvd covers do not care how us humans perceive brightness vs actual intensity of a light source."
] |
[
"Why don't animals have more than 2 eyes. Or eyes in cool places like on the back of their head?"
] | [
false
] | If animals had eyes on the back of their head wouldn't it increase their vision?and that would be good for herbivorous animals right. | [
"Some animal ",
" have multiple eyes. Spiders, for example, generally have eight (and as many as twelve) though only the two front-facing ones are developed enough to detect complex shapes; the remaining ones are rather primitive and only detect the presence or absence of light. Horseshoe crabs have ten, though a... | [
"It's axiomatic with regard to evolution that traits which are, on the balance, detrimental to reproduction tend to disappear. But evolution also gets stuck at local fitness maxima (one famous example being the recurrent laryngeal nerves) and the mere fact that a trait isn't observed in the wild doesn't mean it wou... | [
"to add onto this, as to the question of why the ones that have two don't have more, that's a matter of energy expenditure. it takes more energy and/or more complex neurology to make use of. and evolutionarily speaking, nature doesn't generally add extra body parts unless they're necessary; if anything, ones that p... |
[
"How do we know that radioactive decay is truly random?"
] | [
false
] | [deleted] | [
"How do we know that this decay is non-deterministic?",
"Certain theorems (whose names escape me) prove that either determinism is false, or the variables required to make the universe deterministic are the same everywhere (",
" but not ",
" a violation of general relativity/causality). That is, they're not l... | [
"Basically, radioactive decay is a quantum process, and by Bell's Theorem ",
"http://en.wikipedia.org/wiki/Bell's_theorem",
" there are limitations on whether such processes can be predicted. In general, quantum processes are either random (i.e., cannot be predicted) or violate locality (non-local variables de... | [
"Based on how we define randomness, ",
"it is not possible to prove whether or not it truly exists.",
" Some people are happy to treat unpredictability and randomness as equivalent, but they are not. Unpredicability certainly exists and ",
"the Halting problem",
" proves that fully deterministic processes c... |
[
"Recently watched Mermaids: A Body Found on the Animal Planet Channel. My question, on an evolutionary level, how viable is the Aquatic Ape Theory?"
] | [
false
] | The 2 hour episode on this seemed a bit far-fetched, however the idea that certain apes may have possibly thrived in or near a beach to then later adapt to watery surroundings doesn't seem so crazy. Any thoughts? | [
"It doesn't seem ",
" crazy at first pass, no, but there's very little evidence in support of it, and a fair bit against it.",
"I'm not personally qualified to talk in any detail about it, as I'm not really an anthropologist, but I'd recommend the following resources:",
"http://www.sciencedirect.com/science/a... | [
"While the points the theory as it's known are excellent, they are mostly explained by unrelated phenomena. (E.g., hairless is a result of it carrying fewer parasites (important in social situations) and not being necessary to keep us cool with our super-sweat powers)",
"However, there are some points it raises w... | [
"It's a nice hypothesis that is not supported by evidence.",
"The alt-hypothesis (Now a developing theory.) is that humans became hairless after becoming bipedial to enhance the cooling action of sweating.",
"This (In addition to many other musculoskeletal changes ",
" being able to carry water) allows a sing... |
[
"How do animals with extremely sharp teeth/claws/beaks keep them sharp? Wouldn't they become dull over time?"
] | [
false
] | null | [
"not necessarily. For the most part wear only happens under forces that are large enough, or against surfaces that are hard enough. ",
"Teeth solve this problem by being really hard, and the sharp ones arent generally used against harder things. I.e. dogs arent using their sharpest teeth to chew on bones, theyre ... | [
"Human finger nails grow continuously and we either wear them of cut them. Cat claws also grow continuously but the keratin has a more obvious onion like layered arrangement, the current outer layer is not having new material added to the base instead a new claw is growing in through the middle of the old claw. The... | [
"Worth noting that cats shed their claws now and again, giving then a fresh claw ready for further sharpening."
] |
[
"Humans are known to help out an animal if it's stuck, injured or in problems in the wild. Are there any animals that are known to help other animals or humans in distress?"
] | [
false
] | null | [
"There are ",
" of cases of animals saving humans and other animals. I am going to stick to purely wild animals (no pets, no livestock, no zoo animals) saving humans, because I find them the most interesting.",
"In 2005, a 12-year-old Ethiopian girl was saved from kidnappers by ",
"three lions",
", who the... | [
"In 2003 a group of elephants released a bunch of captive antelope.",
" Conservationists thought the elephants were coming to take some of the food but instead, they circled the compound and one opened the latch to the gate. The antelope left, followed by the elephants, who never touched the food."
] | [
"Elephants have been reported many times to help humans and animals, although the case is more often than not \"helping by simply avoiding to crush someone under their enormous weight\". The ",
"Wikipedia article",
" gives several examples of elephant helpfulness. In general, elephants have very strong feelings... |
[
"Billions of years ago when the universe was considerably smaller, was matter smaller too? Was there less space separating the electron from nuclei and was the width of a single proton less?"
] | [
false
] | If this was the case, then is it understood what this might have meant for atomic physics? | [
"No. The size of atoms depends on a few fundamental physical constants. You can look at the formula for the ",
"Bohr radius",
" to see this:",
"a",
" = hbar/(m",
"*c*alpha)",
"On the right hand side you have the Planck constant, the mass of the electron, the speed of light, and the fine structure consta... | [
"none of those constants have changed since the beginning of the universe ",
"This isn't quite true, the coupling constants (including the fine structure constant) experience something called running, which is where the value of the coupling constants changes with energy scale. When the universe was very very you... | [
"If you held the tweezers there for the rest of time, the atom would remain smaller for the rest of time, no?",
"That's correct, but the universe being smaller is just like taking the atom from a big box and putting it in a smaller box. It doesn't imply anything like tweezers pushing the electron into the proton.... |
[
"What is Quantum Field Theory?"
] | [
false
] | I am merely just a curious passerby with no background in physics. My interest was sparked by this podcast , talking about how the universe has no 'physical point' as you go smaller and smaller past the atom. May someone explain the ideas and concepts of Quantum Field Theory? More specifically, what really are the part... | [
"This had just popped up on the front page a few days ago, take a look at the explanation by ",
"Sean Carroll",
". He answers the question very basically there, though if you watch the entire lecture he goes into further detail. "
] | [
"But in an atom, the probability of finding an electron (or the 'electron density') is in fact highest at the nucleus, and drops off smoothly as you get farther away from it",
"Whoa hold on that depends. Some of the radial hydrogen wavefunctions blow up at the origin, others go to zero. "
] | [
"I stopped listening to that as they started to repeat the common misconception that 'atoms are mostly empty space'. It's just not true in any meaningful sense. The only true bit is that atoms are very large relative their nuclei. But there is no great distance between the nucleus and the electrons. As quantum-mech... |
[
"Is there a limit to what resolution the human eye (and brain) can process?"
] | [
false
] | Following on from this question is there a limit to what we can see. | [
"Take a look at these past posts:",
"http://www.reddit.com/r/askscience/comments/m9bro/what_resolution_does_a_human_eye_see_at/",
"http://www.reddit.com/r/askscience/comments/eu58a/the_resolution_of_our_eyes/",
"http://www.reddit.com/r/askscience/comments/okot2/what_resolution_do_human_eyes_see_in/",
"There... | [
"Could you clarify what you mean by \"resolution\" and \"process\"?",
"Obviously, we don't see at infinite resolution, because we can't see (distinguish) things even at the micrometer scale.",
"However, the brain doesn't exactly subdivide images into discrete, regular units of an image's \"area.\" It doesn't ha... | [
"I heard on an ABC science program, that the raw output from a human eye is not even something you'd accept as a good image on your TV. Can't find the program link unfortunately.",
"But the idea was that the brain compensates for the lack of image clarity from the eye by interpolating images and basically a lot o... |
[
"What causes the change in our perception of a spinning object, such as a hubcap on a car, to appear counter-clock wise and switch to clock-wise or vice versa?"
] | [
false
] | What causes the change in our perception of a spinning object, such as a hubcap on a car, to appear counter-clock wise and switch to clock-wise or vice versa? I had always noticed this while in car rides or in commercials on tv but never put much thought into the optical illusion. Is this phenomenon different for other... | [
"No idea."
] | [
"This isn't a hubcap thing. It's a framerate thing. If your rotational frequency is slightly more than your framerate, then spinning things will look like they're going backwards. Basically, it's the camera doing this."
] | [
"Known as \"aliasing\" if you're talking about video. I think the explanation for vision might be somewhat more complicated."
] |
[
"Can you generate energy from atomic vibration?"
] | [
false
] | As most of us learned is high school, atoms vibrate based on temperature, faster=hotter. What I want to know is, could you get room temperature material, use the vibrations to generate energy, and dispose of the cooled material? | [
"In principle, if you had a cooler material to transfer heat to, you could extract usable energy from that process. However, it is not possible to get usable energy by transferring heat between two objects at the same temperature, or from a cooler object to a warmer one. Doing so would reduce the total entropy of t... | [
"Under normal circumstances, you cannot get usable energy from the heat content of an object that is at room temperature. But suppose that you live in the outer solar system, on a moon that is covered with the snow formed from freezing methane, nitrogen, etc. Any object at room temperature would be capable of cau... | [
"Someone asked essentially the same question ",
"here",
", so I'll repost my answer to that question:",
"So the proof that what you're imagining is not possible is known in thermodynamics pedagogy as ",
"\"the equivalence of the Clausius and Kelvin statements of the second law\"",
".",
"You're imagining... |
[
"If I have a device powered with 2 AA batteries, and the device is at 50% battery life, but I only have 1 AA battery left; would switching only one battery increase the battery life of the device?"
] | [
false
] | i.e. I have an xbox controller that is powered by 2 AA batteries. My controller is almost dead, at 20% battery life. If I switch out only one battery for a new one, does that increase the battery life of my xbox controller? Or does it remain at 20%? | [
"It increases it, but not as much as you'd think because the new battery winds up charging the old battery, so energy is lost to heat that would otherwise be useable energy. You could actually damage the batteries doing this unless they are rechargeable batteries."
] | [
"If they are in parallel then this is dangerous even with rechargeable batteries as you could get large currents and the batteries might overheat.",
"If they are in series you get a very small increase in running time as you can discharge the weaker battery slightly more now."
] | [
"It is dangerous to do so.",
"The problem is that you do not want to reverse charge batteries. Things will look good when you put the new battery in, but the flat battery will keep discharging. It will fully discharge, and then the fresh battery will start pushing current backwards through the battery, trying to ... |
[
"Are most Hypergiant stars already dead?"
] | [
false
] | Got a question are most Hypergiant stars already dead? Due to the fact they only live for millions of years. Or are hypergiants still being created? Second question is it safe to say most of the visible/ observed Hypergaints we know such as UY Scuti, and Canis Majoris have died now? Apologies for the stupid question bu... | [
"I can’t speak to whether hypergiant star formation is greater/lesser/the same as early phases of the universe, but I can at least take a stab at your much simpler second question.",
"Hypergiant stars that are in constellations visible to the naked eye must be both bright ",
" relatively close. Apparent brightn... | [
"What kind of gibberish is this answer?"
] | [
"What kind of gibberish is this answer?"
] |
[
"Fossils - How do fossil hunters know which rocks have fossils in them, before they split them?"
] | [
false
] | I was watching pawn stars where one guy brought in some rocks that he split himself, that contained very good looking fossils. How on earth did he know that those would have a fossil on the inside of them? | [
"According to my paleontologist friends: They don't know. They go to sites where fossils have been documented and just keep splitting until they find something. "
] | [
"Thank you. That question has been bothering me for a long time. Wow...so they just keep cracking open rocks until they find a fossil huh? I don't doubt that is the way they do it...but it just sounds a lot less efficient than I had thought."
] | [
"Some fossil beds are quite rich so it isn't as painful as it sounds. Additionally nature does a lot of the work for you: naturally broken surfaces may reveal fossils."
] |
[
"Spatiotemporal perception of the Big Bang"
] | [
false
] | Ok so can someone please explain to me (or direct me to info on) information on how the spatiotemporal Big Bang relates to our perception of it? To explain my question further - why is it, if we are detecting photons from close to the origin of the universe (temporaly), should we not perceive a photonic origin? The uni... | [
"You seem to be using words in ways that are entirely new to me. In particular, I have no idea how you're defining \"spatiotemporal,\" \"photonic,\" \"borne\" or \"curve.\" Or, for that matter, \"origin.\"",
"Let me see if I can clear some of this up.",
"Once upon a time, the entire infinite universe was filled... | [
"I really don't understand your question. At some point in the past the universe was very dense and hot so it was a opaque plasma. If you look far enough you can still see that plasma, that is what the CMB is."
] | [
"Thanks for your reply, and I apologise for the ignorance from which I am trying to comprehend.",
"Does this mean that the CMB map depicts the perceived density of microwave radiation?"
] |
[
"Can we, or will we be able to in the future, see \"outside\" of the observable universe by measuring the effect of gravity objects from outside that limit on the objects at the edge of the observable universe?"
] | [
false
] | null | [
"If the light from the object hasn't had time to reach us, then the transit time of the gravity from the far object to the close one plus the time for the light from the close one to us also wouldn't have time."
] | [
"If we were able to infer planets we couldn't see by observing the effect their gravity was having on objects we could see would the same type of effect hold true for the outer extents of our vision in the universe?",
"If we cannot do this yet, but should in theory be able to at some point, what types of technolo... | [
"This is essentially what was done with the recent BICEP2 result. We can see back to about 400,000 years after the big bang in the cosmic microwave background, but before that the universe was opaque to light. However, they were able to see the gravitational imprint from beyond that. Other ways to do that would be ... |
[
"What can we expect the world in terms of population, famine, resources to be like in 40-50 years?"
] | [
false
] | null | [
"There's a thing called the \"Rule of 70\". Basically, you take the \"human growth average\" (which is 1.1% at the moment) and divide it into the number 70. So, if the human growth average (HGA) stays constant for the next 70 years (which it definitely won't), it would take roughly 70 years for the human population... | [
"Well, going by the 1-4 step model, I'm assuming that China will level out. It's industrializing extremely fast, so I'm not surprised by the population boom its been having for a bit now. The culture will probably \"catch up\" with the technology, but I have no idea of a time frame. Plus, I expect the chinese gover... | [
"Well, going by the 1-4 step model, I'm assuming that China will level out. It's industrializing extremely fast, so I'm not surprised by the population boom its been having for a bit now. The culture will probably \"catch up\" with the technology, but I have no idea of a time frame. Plus, I expect the chinese gover... |
[
"Why is immunity to a disease determined only by the amount of circulating antibodies in the blood and not by other things as well such as T cells or Memory B cells specific to the disease?"
] | [
false
] | null | [
"It isn't. Antibody titres ",
" with specific immunity to a particular pathogen, and they certainly are a crucial component of adaptive immunity (see ",
"agammaglobulinemia",
") but are not the ",
" determinants of immunity (as you alluded to). We ",
" also determine if a patient is immune by isolating CD... | [
"Thank you. How about if a patient has memory B cels and memory T cells specific to the pathogen but very low or no free serum antibodies towards the pathogen. Would they still be considered immune?"
] | [
"What we're talking about is the distinction between, and relative contributions of, ",
"cell-mediated immunity",
" (T cells, NK cells, antigen-presenting cells, etc. all working together to orchestrate and tune the immune response) and ",
"humoral immunity",
" (an antibody response). ",
"Most often, thes... |
[
"Why are there no apes, monkeys, etc. native to North America?"
] | [
false
] | null | [
"While South American monkeys did make it up into central America and Mexico, the climate and topography of the southern United States (think Arizona, New Mexico, Texas) does not foster a good habitat for those types of animals. Monkeys and apes are adapted to climbing trees, and any monkey that attempted to migrat... | [
"How the ancestors to new-world monkeys got to South America is unclear, it is theorized that a small number were stranded and rafted across the, then relatively small, Atlantic Ocean. ",
"Edit: I just decided to share the prevailing theories and I get downvoted; I love it."
] | [
"This happens regularly, animals are swept out to sea and float on logs or such and land on opposite shores. However they are normally quickly eaten - unless they are more fit than the animals in their niche and can find food easily and safely."
] |
[
"Does your beard grow faster if you shave it often?"
] | [
false
] | I saw this in a thread in an ask reddit about myths and I would like if somone could give me more information on why this is a myth and what can cause a beard to grow faster. | [
"No. There is absolutely not reason to think it does biologically, and there is no evidence that it does. ",
"Perception can fool you good, though. After you've shaved the next day, all growth is a lot more beard than you had before! The next day, it doubles! The third day, it grows by another 50%! Then 33%. 25%.... | [
"People are easily fooled.",
"More accurately, people's brain are adapted to think logarithmically and not linearly."
] | [
"Another example may be that you feel the time went a lot slower when you were younger."
] |
[
"Rogue planets ejected from solar systems:"
] | [
false
] | What is the probability that some have serially (obviously over a period of time) encountered other stars and increased velocity due to a "sling shot" effect? Relative to the currently assumed number of rogue planets in the Milky Way, how many might have acquired significant relativistic speeds (say near .2 or .3c)? ... | [
"First of all, I wouldn't really call .2 or .3c \"relativistic,\" there aren't really very large relativistic effects. The phrase relativistic speed is highly context-dependent, but a good benchmark would be around .866c.",
"Second, it would be extraordinary, dare I say impossible, for a planet to escape a solar... | [
"Great answer!",
"What about when galaxies collide? With the relative velocities of, say, the Milky Way and Andromeda, how much could a planet or star's momentum change?"
] | [
"We don't know.",
"Galaxies are pretty empty places, meaning that it is quite likely that our Solar System would not be impacted severely by the eventual merger of the Milky Way and Andromeda."
] |
[
"Why don't we just irradiate all our food products?"
] | [
false
] | Instead of pasteurizing things or preserving them chemically, why don't we just irradiate our food and then seal them up, keeping them safe forever? I've heard of this before, but it doesn't seem to be very widespread. Wouldn't that pretty much get rid of any chance of food poisoning or other similar conditions? | [
"Looks like you have your answer. We don't irradiate all our food because of all the consumers who can't be bothered to ",
"understand the process.",
"The food is irradiated, people. not you."
] | [
"Radiation causes mutations in DNA, which can lead to cancer. This seems like a terrible way to keep food fresh when you look at the effects it has on other things.",
"Are you worried about your food getting cancer? You know it isn't alive anymore, right?"
] | [
"Radiation causes mutations in DNA, which can lead to cancer. This seems like a terrible way to keep food fresh when you look at the effects it has on other things.",
"Are you worried about your food getting cancer? You know it isn't alive anymore, right?"
] |
[
"How does one actually test for horsemeat?"
] | [
false
] | Here in Europe they are testing all our meat for horse as it turns out that much of our cheap 'beef' is actually horse. What is actually required to prove horse or beef? Can you tell under a microscope? | [
"It's come through DNA testing. "
] | [
"It was minced. It was determined by DNA testing. ",
"Although now, apparently there are concerns it was donkey meat. "
] | [
"If it's minced and mixed with ground beef, then only DNA testing would help. However, if you have raw steaks, the horse meat is leaner, darker and has a different texture and taste, so if you are a food inspector you would be able to tell the difference. Similar to how buffalo meat is different from beef."
] |
[
"If a grenade can kill a group of people so easily, why can a single person jumping on it walk away from the ordeal?"
] | [
false
] | Was reading up on the recent Medal of Honor recipient... | [
" Out of several dozen historically documented.",
"So I would say the odds of survival are 100 to 1 or less.",
"The first is Pfc Jacklyn H. Lucas, druing the battle of Io Jima in WW2. Pfc Lucas had the sense to cover two japanese grenades with his M1 steel helmet and using his rifle to further shield his body. ... | [
"Generally they do not.",
"A person does not jump onto a grenade intending to save himself. He does it in order to shield everyone else around him-- saving their lives by the almost certain sacrifice of his own. That is why it's considered a rare act of bravery, enough to earn medals.",
"In the rare cases the p... | [
"The most dangerous part of a grenade is the shrapnel and not the actual explosion.",
"True",
"A person's body can redirect the force of the blast since energy takes the path of least resistance.",
"Not even close.",
"the pressure wave of an explosion follows the \"Inverse square Law, so the force of an exp... |
[
"Can radio waves outside the visible light spectrum be thought of as colors we cannot see/ comprehend?"
] | [
false
] | I have had friends for years try to blow my mind saying that every radio waves is a different "color" that we cannot see or observe and so there are colors we cannot comprehend. I have never really thought that they were correct in that thought so I am wondering if there is any basis or discussion as to whether or not ... | [
"Yes! The different frequencies of visible light are what we detect as colors. You can totally make the same argument for larger differences in frequency. ",
"No! The only reason color has meaning to us is that we have specific structures in our eyes that parse a very small part of the spectrum that way. Since al... | [
"it is more accurate to say that both radio waves and visible light consist of electromagnetic waves. mirriam-webster defines color as a visual perception of light, a definition which most would agree does not extend past the visible spectrum.",
"radio waves and visible light are of the same nature, but they are ... | [
"It'd be more accurate to say that the visible light spectrum can be thought of as electromagnetic waves we can detect with our eyes. Colors are just how we differentiate between those within the range that we can detect."
] |
[
"Can you describe in Layman's terms how science believes other dimensions exist? And the proof behind this belief?"
] | [
false
] | I was watching a science show and it was mentioned that physicists believe there can be multiple dimensions, they said something like 10 or 11, happening at the same time as ours. How do they have any proof for that? What are they basing this idea off of? Is it a widely accepted idea or are there only a few that believ... | [
"The requirement for extra dimensions emerges in ",
"string theory",
". 11 is the number of dimensions required in M-theory. All those theories are attempts to describe the universe with a single theory (i.e., encapsulate both general relativity and the standard model in the same mathematical framework), and ... | [
"String theory hasn't yet made any predictions (besides supersymmetry, which is a requirement for string theory) that are testable ",
". Just because we don't currently have the means to falsify the theory doesn't mean it isn't falsifiable.",
"NINJA EDIT: Also, string theory is done in ten dimensions (and M-the... | [
"As far as \"proof\"- all the theories thus far which describe both general relativity and the standard model require additional dimensions to work mathematically.",
"I don't believe this is true. I'm not an expert on Loop Quantum Gravity by any means, but I'm fairly certain it doesn't have any particular require... |
[
"For Maritime Archeologists: Name the top five shipwrecks that no one has heard about."
] | [
false
] | Also, bonus points for talking about what was historically cooked aboard these shipwrecks. | [
"Top five that ",
" has heard about? Tall order!",
"But here are a few you ",
" not have heard about, in no particular order. These aren't the five most significant or anything, but they're cool, and important for various reasons.",
"Sutton Hoo",
" was not a wreck, but an Anglo-Saxon burial from the 7th... | [
"It varies based on jurisdiction. What follows is not legal advice.",
"It depends on where the shipwreck is and who owns it. Navies don't give up title to their ships, for instance. That means the ship and everything on it belongs to them, forever.",
"Other than that, it depends ",
" on the jurisdiction.",... | [
"You're one of my favorite ",
"/r/askscience",
" panelists, and I found myself amazed that no one really asked you questions on your fascinating subject. Also, ",
"this",
". :)"
] |
[
"Are there any plants or animals that are bioluminescent in the infrared spectrum only?"
] | [
false
] | Would this be possible? | [
"Hot blood animals, like mammals and birds, emit in the IR all the time, so in a sense they're bioluminescent in the IR only unless they are also standard light bioluminescent."
] | [
"Can you legitimately call black-body radiation \"bioluminescence\"?",
" "
] | [
"Electromagnetic energy emitted in the IR region is just as ",
" as any other. The difference is that IR energy is broadly absorbed by many molecules, including those in the air surrounding the emitter, in such a way that a good portion is converted to heat energy."
] |
[
"When you squint really hard, why do you hear a rushing wind like sound?"
] | [
false
] | null | [
"I believe what you are describing is a contraction of the ",
"tensor tympani muscle",
". This is a muscle that actually functions to dampen sounds, particularly those produced by other functions of your head, such as chewing.",
"I am able to contract this muscle voluntarily and create the wind-rushing, or ro... | [
"Congrats! You are an ear rumbler. ",
"Short summary:\nYou have the ability to control your tensor tympani muscle, which is used to control your cochlea in response to loud sounds. This creates a rushing, rumbling sound in your ear. Some people can only do it with eyes closed, some for only a limited time. Some ... | [
"Oh wow I did not know that this wasn't something everybody can do.",
"I can literally do this continuously and make different noises. I get these different crackling sounds too and can move the muscle so that I hear only that or only the rushing sound or both.",
"I also contract that muscle to pop my ears or ... |
[
"What makes us wake up when we've had enough sleep?"
] | [
false
] | null | [
"This is a common question here. I'll copy my answer from ",
"the last thread on this topic 2 weeks ago",
".",
"Besides environmental stimuli, there are ",
"two main processes that regulate sleep",
". It is the combined effect of these two processes that causes us to fall asleep and awaken at particular t... | [
"I have a link to an article discussing that which I'd just end up copying verbatim, so I'm just going to post it here.",
"The gist of it is that the body prepares you for waking up by releasing a hormone called ACTH (adrenocorticotropic hormone) about an hour before you prepared to wake up.",
"http://m.psychol... | [
"Do neurologists have any idea where that critical point is when the threshold is exceeded? Or is research still being conducted on it? "
] |
[
"why does our minds make clocks sounds like 'tick, tock' when in fact it's just 'tick, tick'"
] | [
false
] | null | [
"In a pendulum clock, the pendulum engages an ",
" ",
". Since both sides of the escarpment are not the same, it will make a unique sound for each direction its travelling.",
"http://en.wikipedia.org/wiki/Escapement"
] | [
"*Escapement",
"TIL Escarpment is also a word, but with an entirely different meaning.",
"He's absolutely correct though. And it's not just in pendulum clocks either, all mechanical clocks (and wristwatches) have these escapements that make the ticking noises, and they're always asymmetrical."
] | [
"Oops. Edited."
] |
[
"If velocity is relative, can I say I am travelling at c from the view point of a photon?"
] | [
false
] | null | [
"Something moving at c does not have a valid rest frame, it would violate the postulates of SR. So you cannot make any statements about the \"viewpoint of a photon\"."
] | [
"I'm reading about special relativity now and I'm still trying to wrap my mind around the concepts. The rest frame that you mentioned is the inertial frame of reference, correct? So does the photon have a non-inertial frame of reference even though it is no accelerating?"
] | [
"The rest frame that you mentioned is the inertial frame of reference, correct?",
"The frame I talked about (the rest frame of a photon) ",
". That's why it's impossible to even talk about the \"point of view\" of a photon."
] |
[
"Why do cold drinks/foods trigger the cough reflex?"
] | [
false
] | For bonus points, why does it not happen to everyone? | [
"Irritation of the sensory branches of the ",
"internal laryngeal nerve",
" at the base of the tongue and epiglottis, and perhaps other branches of the ",
"vagus nerve",
" distributed along the esophagus, triggers the motor branches of the vagus nerve, and may induce the cough reflex."
] | [
"This happens to me to too, although i don't know why. "
] | [
"Who is upvoting this? Isn't that what the OP is trying to do?"
] |
[
"How come aeroplane windows are so small?"
] | [
false
] | I've looked back at photos of planes going way back, and the windows have been tiny for ever. Surely we can do better. I like to look out during take-off and landing, and I like to look at the clouds. Unless I have the window seat, I can't see jack. | [
"First of all, for reasons of aerodynamics, they must be round. Square windows resulted in cracks in the fuselage and thus crashes. Second, the windows must be equipped with extremely durable panes inside and out for resistance to both ground and high-altitude pressures and temperatures, which are at extreme oppo... | [
"I should also mention that having windows at all is a huge hit to the strength of the aircraft structure. Windows are basically a bunch of little holes in your cylindrical body, which must be designed around to maintain the integrity of the structure. "
] | [
"There haven't been many advancements in the fuselage structure of aircraft. Most fuselages are still made of aluminum and with similar structures of aircraft 40 years ago. However, now with carbon fiber beginning to make its way into the fuselage structure windows are allowed to increase in size since the minimum ... |
[
"Why is Cantonese categorized as a 'dialect' of Mandarin?"
] | [
false
] | Why is Cantonese categorized as a 'dialect' of Mandarin instead of a separate language? When one thinks of dialect, it tends to be the same langauge with slight variation due to local culture or isolation. British English is a dialect of New York English which is a dialect of Texas English which is a dialect of Austral... | [
"I don't think that is quite correct. Cantonese is actually considered a dialect of Yue Chinese while Standard Chinese (what many people refer to as 'Mandarin') is a dialect of Mandarin Chinese. The term Chinese refers to a whole family of related languages that are mutually unintelligible but share some key charac... | [
"I've never heard Cantonese referred to as a dialect of Mandarin. I have very commonly heard both of them referred to as dialects of Chinese. The line between what constitutes a dialect vs. a language is not scientific, it's political....as some one here already said, a language is a dialect with an army and a n... | [
"Classification is important, absolutely. However, there is no benchmark by which we can say that A and B are separate languages, as opposed to being two dialects of the same language. All we can do is mark degrees of similarities or differences. ",
"As a person who has resided there, all the \"dialects\" of C... |
[
"How does an ulcer in your mouth heal?"
] | [
false
] | I thought of this due to an ulcer in my mouth. It seems to me that it is under constant assault to extremely harmful bacteria. How does it heal under those conditions? Why doesn't my mouth just rot out? | [
"If you're talking about a canker sore, this is incorrect. The underlying cause of ",
"canker sores",
"/oral ulcers are not known, but is not usually caused by herpes simplex. If you're talking about cold sores, then you have the herpes simplex virus, or very rarely in the case of what's commonly referred to ... | [
"If you're talking about a canker sore, this is incorrect. The underlying cause of ",
"canker sores",
"/oral ulcers are not known, but is not usually caused by herpes simplex. If you're talking about cold sores, then you have the herpes simplex virus, or very rarely in the case of what's commonly referred to ... | [
"When your new cell growth rate is larger than the bacterial cell growth rate, your healing starts.",
"A lot of this is generalized, and more vague than it actually works, but immunology is pretty awesome to learn about."
] |
[
"Why does adding or removing just one element from a compound change the properties of the compound so much, making it sometimes even deadly?"
] | [
false
] | [deleted] | [
"There is a general answer to your question and a different answer to your specific question.",
"The general answer is that adding or removing one atom from a molecule changes the molecule's thermodynamic stability and less stable compounds are more reactive and thus tend to be better at messing things up by reac... | [
"Thanks for the reply, i understood the first half of your answer, about the stability and thermodynamics of compounds, but the second half mostly blew over me."
] | [
"The short of the second half of his answer (CO2 vs CO) is that hemoglobin transports oxygen and CO2 through the bloodstream. CO, on the other hand, does not allow this exchange, and instead binds tightly to the iron in hemoglobin, preventing that molecule from carrying oxygen. Enough CO exposure = no oxygen in y... |
[
"What is stopping us from developing an alternative to the old fashioned rocket fuel launch?"
] | [
false
] | I'd be willing to bet that most you of immediately thought of the proverbial Space Elevator after reading the title, but that's not mainly what I'm referring to. I already know the answer to THAT question: There is no material that we can mass produce efficiently and relatively cheaply enough that has enough tensile st... | [
"Ok, let's assume you want to bring a satellite into geostationary orbit, which is pretty typical, I'd say. According to ",
"Wolfram alpha",
", that's 42000km from the core of the earth and it needs to have a speed of 3km/s.",
"That gives us the amount of energy the satellite needs, and thus the velocity it n... | [
"I've always thought the ",
"Launch loop",
" looked interesting. Seems more feasible than a space elevator, at least. "
] | [
"I think the major draw back to a rail gun type approach is that you would have to launch the vehicle at approximately sea level and deal with the huge aerodynamic drag.",
"A much more feasible method is to use a reusable conventional aircraft to transport the rocket to high orbit and launch it from there. This i... |
[
"Can someone explain the phantom radio station I am picking up in my bathroom?"
] | [
false
] | I keep speakers in my bathroom to listen to music when showering. I never turn them off (lazy) and I leave the audio jack hanging over the TP holder so it doesn't lie on the floor. One day I'm in there and I hear classical music, very quietly. I turn the speakers up full blast and I can faintly hear some kind of radio ... | [
"What you're picking up is likely an AM radio signal; Amplitude Modulation is very “simple” in that it doesn't require a lot of technical effort to demodulate. In consequence, it often gets picked up by inadequately shielded audio circuitry of all kinds (or in your case, probably the dangling audio cable, which act... | [
"Diodes (also see rusty bolt effect) and tuned circuits help pick them up, but if it's strong enough you will hear it in your toaster. I live close enough to massive AM towers that it's a chore to NOT hear it on all my stuff (even my air conditioner motor). ",
"Surely you've heard the cell phone blips/chirps on s... | [
"The only things you need for a simple AM radio receiver are an antenna, a tuned circuit, and a rectifier. This is how a ",
"crystal radio works",
". So, probably your amplified speakers inadvertently have all three components.",
"Find a list of broadcasters near your house here, ",
"http://fmscan.org/mai... |
[
"When Humans die, do our bones eventually decompose?"
] | [
false
] | [deleted] | [
"In humid warm places bones can break down in a few years easy due to bacteria and fungi. In a cool dry place they can easily last hundreds of years. Preserved by mummification they can go thousands. Fossilization, we’re talking indefinite preservation (although its technically not bone at that point since it all g... | [
"Not that i know of. We have bog bodies that are like 10,000 years old. Its the anoxic environment that keeps the bodies preserved. But eventually on a geologic time scale the bog will be gone/dry up so other factors could come into play."
] | [
"In the case of \"bog people\", does the acidic environment eventually dissolve the bones?"
] |
[
"What would the cancelled Superconducting supercollider have achieved?"
] | [
false
] | In news articles at the time they kept on saying it would lead to more powerful rockets which got my space obsessed childhood self excited, but they never said how, was that nonsense? | [
"I wouldn’t say that it’s nonsense, since many new technologies come out of fundamental science research areas such as particle physics. ",
"To answer your main question, if the SSC was indeed built, the energies of the colliding particles would have far succeeded the LHC energies. The main purpose would have bee... | [
"It would have achieved energies (40TeV) three times higher than that of the LHC. Basically, that is a range in which new physics might lie. It would have discovered the Higgs Boson obviously. On top of all that, it would have made America dominate in high energy physics. ",
"However, I don't see how it could hav... | [
"It's impossible to say. The immediate benefit to the \"every-man\" would likely be through engineering spin-offs related to unexpected innovation that fell out of trying to tackle the extreme engineering challenges that come from such a project.",
"I am not a particle physicist and the field of physics I'm from ... |
[
"I sat in disbelief as my physics professor told the class that cell phones emit EM waved that will fry your brain because they are the same thing as microwaves and UV waves. Was he BS'ing or am I just terribly misinformed?"
] | [
false
] | Radio waves (and microwaves for that matter) are non ionizing right? And any microwaves being emitted by a cell phone are insignificant, right? EDIT: There are way more comments than I have time to reply to, so here’s some general info. This professor is actually incredibly smart, and one of the best teachers I’ve had.... | [
"You're correct; (Edit: The poster, ",
" the professor's assertion, since some people apparently don't read more than the title) Cell phones emit in the microwave region, which is non-ionizing.",
"UV is also non-ionizing, but have far more energy. Enough to excite electrons in many organic compounds, which caus... | [
"Relevant xkcd",
"Randall Munroe also once pointed out that the potassium in a banana will cause you to absorb more ionizing radiation than any amount of cell phone use."
] | [
"The coal that comes from the ground is slightly radioactive. This is then burned and released into the atmosphere as waste. Material in nuclear plants is contained. "
] |
[
"How does the SpaceX rocket not tip over when launching so slowly?"
] | [
false
] | The rocket looks to barely deviate from vertical and maintains alot of control at what looks to be a low velocity. It looks like it would be top heavy and start to tip as it launches. | [
"Thrust vectoring. The rocket nozzle's orientation and thrust is continuously varied based on feedback from on-board sensors. When the rocket tries to tip, the engine adjusts to rotate it back the other way. ",
"This landing vehicle prototype",
" has a camera on the engine which shows the thrust vectoring adjus... | [
"To add to o0DrWurm0o's comment, which is quite correct, ",
"this",
" is what happens when those sensors fail. In this case gyroscopes failed due to a software error and the self-destruct mechanism was activated to prevent the Ariane 5 rocket from falling on populated areas."
] | [
"I remember hearing that the transport pads for spaceships had a laser on the bottom that would cause the pad to move along with the ground so that the shuttle did not tip over. Does the s function the same way?"
] |
[
"How does electricity flow through a substance?"
] | [
false
] | [deleted] | [
"Metals are able to conduct electricity because the electrons aren't really bound to the individual atoms. Rather, the electrons float loosely and are able to move about freely.",
"Batteries have a negative end (with an existing surplus of electrons; it doesn't \"create\" them) and a positive end (with a lack of ... | [
"You can think of it this way. The electrons flow in one direction for a short period of time. If for instance, they flow through something like a light bulb, this will generate heat/light (regardless of direction). Then then switch directions for the same duration of time, which again, generates more electricity. ... | [
"something to keep in mind is that the electrons are doing more \"pushing\" than flowing, if you switch on a light the electrons that move through the switch will take hours to get to the filament in the bulb - but the wave of electromagnetic potential propagates at a significant fraction of the speed of light",
... |
[
"If you are on a train, that’s traveling very fast, and you jump. Would you land in the same spot you jumped off from, or would you smash into the back of the train car?"
] | [
false
] | null | [
"If it is at a constant speed, the same spot"
] | [
"Whys that?",
"Edit: never mind I thought it through. I understand it. I was thinking about if that person was constant or stationary, but since he is touching the train, the train is pushing him along, if he jumped he would continue his path of forward movement along with the train, because he wasn’t stationary ... | [
"Relativity",
". If you flew to the back you could find an absolute rest frame."
] |
[
"How does testosterone make people become sexually attracted to others?"
] | [
false
] | I remember the day I started liking the opposite sex, but I don't understand how testosterone goes from my gonads to my brain to doing something in my brain that makes me start noticing figures and long legs. What does testosterone do once it reaches my brain that makes me like the opposite sex? | [
"I cannot break this down exactly the way you want but...testosterone does not control physical attraction. It may have a small part in overall attraction, such that you are man therefore you like women. Bam. ",
"There is a ton of research directed towards physical attraction. The coolest influencer of physical a... | [
"Testosterone facilitates sex drive, it's undetermined what role it plays in orientation though."
] | [
"What about people who say they are attracted to their same sex?"
] |
[
"If a person were on a spacecraft with a stretched-out orbit would he or she feel the acceleration and deceleration as the craft approaches perigee/apogee?"
] | [
false
] | [deleted] | [
"No. When you \"feel acceleration\" in a car or roller coaster, what you feel is the contact force, your seat is pushing on you to keep you moving at the same velocity as the vehicle.",
"But while in a spacecraft in orbit -- any orbit -- your acceleration is always equal to that of the vehicle, so there's no con... | [
"unlike other everyday forces, gravity acts equally on all the atoms in your body, so you can't feel it in isolation. Most everyday forces have to act on you through whichever part of your body they are contacting. The force must be transferred to other parts of your body, which you can feel.",
"This is exactly r... | [
"No. At all times the acceleration felt by the astronaut and the spacecraft are equal, so the relative speed of the astronaut to the spacecraft is always zero. In simpler terms, the astronaut experiences microgravity in the reference frame of the spacecraft even if accelerating at a very high rate in a reference fr... |
[
"Why do I sweat when I eat spicy food?"
] | [
false
] | Not just spicy and temperature hot things. Things like hot sauce, hot cheetos, etc. | [
"Capsaicin",
" the chemical that makes hot sauce hot interacts with receptors that sense heat."
] | [
"Since Tactless_Atheist has already give the gist of the answer, I shall refer you to the link that can answer in full - ",
"http://www.scientificamerican.com/article.cfm?id=why-is-it-that-eating-spi"
] | [
"Some foods are thermogenic. They increase metabolism and make the body generate more heat. Green tea is another.",
"What I'd like to know is whether capsaicin is as thermogenic as it feels. It feels so much more powerful than green tea or stimulants. Is it?"
] |
[
"Why do people say that right after the big bang, the Universe was very small? Wasn't the universe just as infinite then as it is now? Isn't it more accurate to say it was very dense?"
] | [
false
] | How can the universe be described as small? If the Universe was infinite at the big bang, but everything was very close together, doesn't this just mean that it was very dense? I don't study physics but I have some understanding of a cosmology but this description has always bugged me and no one ever addresses it. | [
"Measurements of the curvature suggest that it was indeed infinite but denser than it is now, although the error bars on those measurements include a universe that's non-infinite but ",
" larger than our observable portion can ever be.",
"Effective science communication is hard work, I guess a few things got mu... | [
"There are two length scales I think you may interested in. ",
"One is the size of the \"observable universe\". If we think about two points at opposite sides of that, then in the past they were obviously closer together. This is what some people are probably referring to when they say \"the universe was smalle... | [
"That would only happen if the universe has positive curvature, ie it was some sort of hypersphere.",
"If it's infinite, you won't wrap back to your starting point."
] |
[
"Would it confuse your brain if you switched sides on your eyes?"
] | [
false
] | I was curious how wired the brain is to seeing what it sees. Brain games talks about all the assumptions the brain makes. I started wondering what would happen if you switched them with special binoculars. So the right eye saw what the left normally sees and vice versa. | [
"If the input stayed consistent, then the ",
"brain would probably adapt and correct",
"."
] | [
"I doubt it would correct - sensitivity to binocular disparity is laid down pretty early, and people with poor or no stereo sensitivity (stereo-blind) rarely recover it even with a lifetime of binocular experience (strange counterexamples like Sue Barry and Bruce Bridgeman notwithstanding). Reversing the encoding o... | [
"Initially it would look like if you looked at the pictures in ",
"/r/CrossView",
" in parallel view, or the pictures in ",
"/r/ParallelView",
" in cross view. Eventually your brain would probably adapt and see the world with correct depth."
] |
[
"How to determine the function of a human protein based on the function of a homolog from another species?"
] | [
false
] | What type of experiments can be done (short of actually experimenting on a human embryo) to determine the function of a human protein thats homologous to a well-characterized and understood protein from a model organism? | [
"You can express and purify the protein in some other system (bacteria or insect cell culture) and perform experiments ",
". If there are assays for the protein's presumed function that can be performed outside of a cell they can tell you a lot about the protein: what it binds to, how strongly it binds to its par... | [
"to add to this you can also do a variety of experiments if you've cloned the protein of interest. expressing the protein in a heterologous expression system can allow for a variety of characterization experiments to determine protein function. additionally, if the crystal structure of the homolog has been resolved... | [
"Thank you! This was quite helpful!"
] |
[
"What about running water makes it less dangerous than stagnant water?"
] | [
false
] | I understand that you get are less likely to get diseases from drinking running water than stagnant water, but what about running water makes it so much safer than stagnant water if it is the exact same water? | [
"In stagnant water you get an incubator effect. If you take sterilized water, free of bacteria and running sterilized water and you compare them they will be exactly the same after a few days. ",
"The problem with stagnant water is a) because nothing moves, bacteria have a easy time feeding and b) it becomes a fe... | [
"Thanks!, this is off topic of the original question but do you know if the mosquitoes get the diseases they carry from both the water and the human or just breed in the water and then carry diseases between humans through bites. Or are mosquito eggs somehow harmful?"
] | [
"Mosquitos bite a person with the disease and carry it to the next person.",
"They are the vector (carrier) of some diseases like malaria and dengue."
] |
[
"Why are atoms always arranged the way they are, with protons and neutrons at the center and electrons orbiting?"
] | [
false
] | Was just thinking that I've never seen a diagram with an orbital neutron inside the electron cloud, or an electron-neutron cloud being orbited by protons. They seem intuitively like they should at least be possible, if not common. I'm aware that antimatter is inverted, but my understanding is that it's made from invert... | [
"The length scales of bound states are set by the properties of the particles involved and the interactions between them.",
"In an atom, there’s two kinds of bindings to consider: nucleons to other nucleons, and electrons to nucleons.",
"The interactions between nucleons lead to bound states with length scales ... | [
"I wouldn't use the words \"bounce and float\". The electrons are still \"clumping\" around the nucleus, just at a distance ~10",
" times larger than the size of the nucleus itself.",
"And yes, neutrons generally don't significantly interact with electrons, only nuclei."
] | [
"I'm going to try and say this back to make sure I understand it:",
"The force(s) binding nucleons (protons and neutrons) together is stronger but has a short reach, so once they get anywhere near each other they form a clump.",
"The force(s) binding electrons to the nucleons is weaker but can act over a much l... |
[
"Is there any scientific basis for so called \"Hitting Weather\" in baseball? When it's warm out most commentators say home runs are likelier to hit."
] | [
false
] | Usually they mention it on hot clear days. Today it was clear skies in the high 80 degrees fahrenheit (27 C) and just so happened that more home runs were scored than normal. That got me wondering about what is behind this phenomena and if it had any facts to back it up. Does it have something to do with air pressur... | [
"Sure, when it's hot out, the air density is lower, so the drag on a baseball is lower and you can hit further. Occasionally airlines deal with the same issue -- they have to cut weight because the temperature at the runway is overly high, and this makes the air less dense which makes the airplane produce less lift... | [
"http://www.engineeringtoolbox.com/moist-air-properties-d_1256.html",
"\n"
] | [
"Blake street bombers! "
] |
[
"What experiments are currently being conducted to discover what dark matter/dark energy is?"
] | [
false
] | null | [
"There are 3 main experiment types ongoing in the search for a particle candidate of dark matter.",
"First is what is known as \"direct detection\", whereby you infer the existence of dark matter in our galaxy by it's interactions with a large body of material (your detector). Typically these are noble liquid and... | [
"You can't be sure. But you do it in the hope that it will. It would not be the first time that a new particle was discovered as missing energy/momentum. And if you don't see anything, you can at least set new upper limits on the strengths of possible interactions between hypothetical dark matter particles and hadr... | [
"To piggy back off this question, if dark matter has hardly interaction with baryonic matter, how can we be sure that slamming baryonic particles together will infer presence of dark matter? Maybe I'm largely misunderstanding this process, but I'm looking to get educated. "
] |
[
"Could you slow down radioactive decay by speeding a radioactive isotope to relativistic speeds (99.9999999% the speed of light)? Just a thought experiment. Kinda Like the twin paradox but with 2 decaying isotopes."
] | [
false
] | [deleted] | [
"Yes."
] | [
"In principle yes, but in practice this is not what we do.",
"In order to study highly unstable nuclei, we need to produce them on-site at the time of the experiment. We produce them using certain types of nuclear reactions which work best in certain energy ranges. The energies that we use in nuclear physics expe... | [
"In principle yes, but in practice this is not what we do.",
"In order to study highly unstable nuclei, we need to produce them on-site at the time of the experiment. We produce them using certain types of nuclear reactions which work best in certain energy ranges. The energies that we use in nuclear physics expe... |
[
"Does an eye \"absorb\" a proton?"
] | [
false
] | So I am looking at the sky, at all the ancient stars. And the photons from those stars may have travelled for thousands of light years to get to me. When the photon strikes my retina, and alters (I think) the molecules, is the photon converted to energy and is now more or less a part of "me"?. Every time I look at t... | [
"Yes, this is an accurate description of the absorption of photons by the retina. ",
"They've traveled a very long distance for a very long time (in your frame of reference) to reach you. Once they hit one of the rods or cones of your eye, they convert to a chemical form of energy which is transmitted to the br... | [
"Then this should blow your mind.",
"Since time slows relative to the speed of light, does this mean that photons are essentially not moving through time at all?",
"Neil Tyson deGrasse replies:",
"yes. Precisely. Which means ----- are you seated?\nPhotons have no ticking time at all, which means, as far as th... | [
"This is certainly possible, but many of these absorbed and re-emitted photons will be scattered from their original trajectory. The reality is that some fraction of the photons will have a \"direct connection\", while some will have \"pit-stops\" along the way. The ratio will depend upon atmospheric conditions, ... |
[
"The CDC claims smoking a hookah for an hour is equivalent to smoking 200 cigarettes. I would like some clarification."
] | [
false
] | [deleted] | [
"So, the CDC website cites ",
"this",
" WHO regulation recommendation (that provides a good reference on how water pipes actually work and where the smoke comes from) which cites ",
"this",
" 2004 paper which seems to be focusing more on calibration of a smoking machine used in toxicology studies rather tha... | [
"The actual research and CDC releases do not obviously imply, as you say \"that smoking a hookah = smoking 200 cigarettes, ",
"\"",
"It says:",
"A typical 1-hour-long hookah smoking session involves inhaling ",
" inhaled from a single cigarette",
"It then goes on to say that this is not healthy. A statem... | [
"Tar and ash, which are carcinogens, are formed whenever biomass is burned."
] |
[
"Is wood alive? At what point does the tree go from being alive to dead?"
] | [
false
] | null | [
"It depends on the wood, and what you’re definition of “alive” is. Your salad is technically “alive”.",
"A typical cross section of wood consists of an outer bark layer, which is composed of dead corky cells. Beneath that is a super thin layer of live bark cells. The phloem is an active layer of tissue and is ... | [
"You could cut a tree off at the root flare it would still be alive if the roots are still growing and can push out new growth. This happens a lot....",
"For all the devistation wrought by the blight fungus upon the American chestnut, this feature is the saving grace that has allowed the species to functionally s... | [
"So just to clarify on \"living\" vs \"dead\", the sapwood has active cells in it (DNA transcription, protein synthesis, metabolism) and the heartwood does not?"
] |
[
"What organism do we share the least DNA with?"
] | [
false
] | null | [
"For all existing life on earth it would be the earliest deepest branching member of the bacteria, Aquifex a hyperthermophile. For animals it would be the deepest branching member of the Eukarya presently thought to be the diplomonad parasite Giardia."
] | [
"I think he is saying that the living thing we are farthest from is the bacteria, and the animal we are farthest from is Giardia."
] | [
"I was looking at molecular evolutionary distance from humans. Within Class Mammalia farthest from humans would be the monotremes (echidna and platypus)."
] |
[
"How do phones know what the date and time is when they're turned on after being off?"
] | [
false
] | null | [
"Older phones have a small timing chip with a small, dedicated voltage source (battery, capacitor, w/e) that does not turn off with the phone. Newer phones ask the cell tower, and barring a response, either show noon or the time stored on such a chip."
] | [
"Does this mean that if a newer phone is disconnected from a cell service, it won't receive the information?"
] | [
"I'm not sure whether the time is broadcast openly or requires an actual 2-way connection, so I don't know."
] |
[
"How large of an impact did the 2010 eruption of Eyjafjallajökull have on the CO2 levels in our atmosphere?"
] | [
false
] | null | [
"Not a whole lot. The wikipedia page which describes the various ",
"effects of the eruption",
" estimates ~0.15 million tons of CO2 were put into the atmosphere. That seems like a lot, but it is nicely put into perspective by the immediately following line that the disruption in air travel caused by the volcan... | [
"According to the climate science referenced here: ",
"http://youtube.com/watch?v=gh9kDCuPuU8",
" by scientist Richard Milne, the yearly impact of humans on the climate is 100 times that of all the volcanoes that go off in a year. Based on that, I supposed the answer would be almost nothing globally. I am at wo... | [
"The magazine for the AGU had a ",
"great article about this",
" (human vs. volcanic CO2 input)"
] |
[
"What would happen if you lit a match on Saturn's moon Titan?"
] | [
false
] | [deleted] | [
"Your basic red safety match contains red phosphorus, potassium chlorate, a bit of carbon and various binding agents and fillers. You rub it against a surface and the friction increases the temperature until it ignites and the phosphorus reacts with the potassium chlorate.",
"Your first obstacle to this task will... | [
"There aren't any usable amounts of oxidizer (like oxygen) in Titan's atmosphere so any fire would be unable to \"breathe\". Also, the match wouldn't even completely light itself as the wood requires oxidizer too. The tip ",
" burn like \"normal\", but I'm not sure if the phosphorus mixture requires an oxidizer o... | [
"Let's say there was an oxidizer in Titan's atmosphere. What would happen?"
] |
[
"Do rainbows refract more than the visible spectrum of light?"
] | [
false
] | Being that we are only humans and can only see the visible spectrum of light on the EM spectrum, do rainbows show more than just light we can see? Towards the red side, is infrared light emitted? Towards the violet side, is ultra-violet light emitted? | [
"Yes they do, in Neil Degrasse Tyson's ",
" he mentions that the very discovery of ultra-violet light made by ",
"Hershcel",
" is due to observations made on rainbows essentially. Here is a ",
"diagram",
" that is a pretty good illustrator. "
] | [
"And on a related note, Herschel discovered infrared light by sending sunlight through a prism to create a \"rainbow\"* and then placing a thermometer in the space just before red and detecting a temperature increase, indicating the presence of light.",
"*A spectrum created by a prism is technically not a rainbow... | [
"Super short answer: Yes. As previously stated they do. ",
"Longer answer: ",
"Here's",
" the mathematical relationship needed to understand what's happening as the light enters and leaves the rain drop. Now go over to ",
"this page",
" to get the values of n (the refractive index) for each wavelength you... |
[
"Since we are constantly generating new skin cells, what causes a scar to form and stay?"
] | [
false
] | null | [
"There are several types of scars. As a wound heals, a few different proteins are present, including elastin, fibrin, and collagen. Collagen and elastic are found in your skin, and provide a scaffolding to which your cells can attach. Trauma disrupts this scaffolding, and part of the healing process involves rebuil... | [
"The collagen and elastin create a mesh that the cells exist within. The cells may be replaced but to my knowledge the collagen/elastin mesh remains."
] | [
"But what makes the scar keep its shape and color after multiple generations of cells? How do new cells in a fibrosis know how to arrange the collagen fibres if that information isn't in the DNA? Sorry if this is a stupid question, it's been a long time since my last biology class."
] |
[
"Are there any materials/elements that are liquids at cooler temperatures and solids at warmer temperatures?"
] | [
false
] | [deleted] | [
"Yes, helium-3 and helium-4 both exhibit this behavior near a certain combination of temperature and pressure. But at still warmer temperatures, the substances melt again. For helium-3:",
"Below 0.3 K, the liquid has a lower entropy than the solid, and both the enthalpy and entropy of fusion are negative. It is a... | [
"It's also used in porn for fake semen, and as a lubricant. And in labs to support the growth of cells. And to treat constipation. It's cool stuff really."
] | [
"Methylcellulose, a gelling agent used in foods, is somewhat like this.",
"Imagine a reverse gelatin, where gelatin gels are liquids when hot and set when cooled, methylcellulose gels set as they heat up and melt as they cool.",
"Of course they're not a true solid they're a suspension of liquids in a carbohydra... |
[
"Why does my house plant seemingly never die of old age or get sick like my dogs and I?"
] | [
false
] | [deleted] | [
"Aside from plant pathogens (which I'm not familiar with), common causes of plant death in nature include root rot, animals and bugs eating them, extreme heat and cold, lack of sunlight, lopsided growth that causes it to uproot itself. Your plant is kept away from most plant-specific dangers and/or agers, and since... | [
"Great! I liked your question actually. I hadn't thought about it before. To figure out from a specimen if it's old, you'd likely need to know both what an older plant of its species tends to look like, and also what environmental stresses that plant experienced. A tree might be very old but just look like a young ... | [
"Great! I liked your question actually. I hadn't thought about it before. To figure out from a specimen if it's old, you'd likely need to know both what an older plant of its species tends to look like, and also what environmental stresses that plant experienced. A tree might be very old but just look like a young ... |
[
"If a person is born without all senses would they have any experience?"
] | [
false
] | If the mind is related to the body because it is how it acquires any information about the world, is it possible for someone who is born without any sense lack the ability to gain experiences/memories. As if he/she is just a husk of a person, or incredibly comatose. But in this case, he hasn't seen the world therefore ... | [
"If they absolutely had no senses; no vision, no hearing, no proprioception, no autonomic sensations, no sense of emotion; then I would imagine yes they could never have an experience or memory. But the question is rather un-answerable. Perhaps the sensory starved systems of the brain just start firing from the lac... | [
"It might be interesting to answer the question from the assumption that the question is referring only to the \"five senses\" of touch, taste, sound, smell, and sight. This way we can assume that the person can in fact regulate things like CO2 levels, blood glucose, internal temperature, etc. so that they do not n... | [
"it is likely that the baby would die from lack of brain stimulation",
"Never heard of this before, could you link some source on that?"
] |
[
"How do museums preserve the soft tissue remains of mummies (like the Mawangdui lady) and mammoths?"
] | [
false
] | Their remains aren't even put in the extreme cold. And does decay still happen at a rate higher than their natural rate? | [
"You cannot let wet organic material dry out. If you do, it's ruined. Like, forever-ruined. The cells collapse, and it turns to dust. If you don't want to keep it hydrated, you have to replace the water with something else. Historically, that's been polyethylene glycol, though in recent years people have been ... | [
"Lady Dai from Mawangdui is kept in an oxygen-free case. Ötzi the glacier man is kept in a cold wet box, very similar in conditions to the glacier."
] | [
"hmmm, I'm pretty sure Otzi still experienced slow rates of decay in the wild. Might it be preferable to keep him in something that isn't wet?"
] |
[
"Can someone answer a question about the expansion of the universe for me?"
] | [
false
] | I've heard quite a few times that the universe is expanding, and that the expansion is accelerating. Anytime I've heard this, it's explained that the galaxies close to us are moving away in all directions, and the further out you go, the faster the galaxies are moving away from us. Some even to the point where they ma... | [
"Anytime I've heard this, it's explained that the galaxies close to us are moving away in all directions, and the further out you go, the faster the galaxies are moving away from us.",
"We need to revise this before we go further.",
"What you've described there is the ",
" effect of metric expansion. As we lo... | [
"That ",
", by itself, show that the expansion is accelerating. To understand why, I'm going to first have to explain what the expansion is.",
"So in geometry, there's a function called the metric, which describes how distances work in some given geometry. The easiest nontrivial example of this is the 2 dimensi... | [
"Electrical (or plasma) cosmology provides and much clearer and startlingly strong model than current gravitational cosmology would like to admit.",
"We ",
" need to leave the crank pseudoscience out of it, please. You're not talking about a legitimate alternate model accepted by a minority of cosmologists. You... |
[
"Is our sense of time affected by the rate of chemical reactions?"
] | [
false
] | So if our biological chemical reactions occurred as quickly as nitroglycerin breaks down into gases, would our perception of time be different? | [
"grad students can consent. mice cannot."
] | [
"It is much more complicated than that, and is a very active area of research.",
"A professor at my school, David Eagleman, studies this stuff. He's a complete badass, check him out: ",
"http://en.wikipedia.org/wiki/David_Eagleman",
"edit: ",
"one of his famous experiments involves using magnetic energy to ... | [
"he also dropped grad students from a tall structure with a quickly-blinking watch to see if the fear of death would help them see what the watch was displaying.",
"It amuses me to no end that there are rules upon rules about how you can treat lab animals, but pretty much zero regulations about what you can do to... |
[
"If 8 years in advance, we detected that an object 1/3 the size of the moon were on a collision course with earth could humanity pull it's resources and save some small percentage of the species? How?"
] | [
false
] | [deleted] | [
"Could people return to earth after the collision?",
"Post impact earth would be better than mars I think..."
] | [
"Probably not. Such a large impact would melt a significant percentage of the Earth's crust, vaporise a lot of rocks, fuck up the planet's rotation and day length, possibly alter the orbit depending upon the impact velocity, and make the planet return to a state very similar to one it was in around 4.5 billion year... | [
"Simulation of what it would look like:\n",
"http://www.youtube.com/watch?v=LlF8APEkh-E"
] |
[
"Do we know why gravity moves at the speed of light? Do the other elemental forces move at this speed too?"
] | [
false
] | question reminded me of something I've always wondered, the speed of gravity. Why is it that specifically, gravity moves at the speed of light? And seeing as the speed of light changes depending on the medium, does the speed of gravity change as well? Does that mean gravity is carried by particles? | [
"Yes, that's a group-velocity effect. Light that moves through an electric field can be modeled as a wave phenomenon, and wave phenomena have both phase and group velocities. The phase velocity refers to how the individual wave phase moves, while the group velocity refers to how the wave's envelope moves.",
"Indi... | [
"There's maths involved, but basically it falls fully formed out of the equations of general relativity. The study of the way gravitation propagates through space is a ",
" deep one, involving things like gravitoelectric and gravitomagnetic effects, complicated aberration cancellations and so on. (One should not ... | [
"It's other way around. Things that aren't hampered by mass move at that speed. Light is massless, so it moves at that speed. It's just that light is the easiest thing to observe. ",
"Here",
"'s a paper where relativity is derived without reference to light."
] |
[
"If our sun went \"out\", approximately how long until the last human dies?"
] | [
false
] | Assuming our sun just "quit" (immediately and non-explosively stops producing heat and light), how long until every human on earth is dead? Consider all variables like the blanket of our atmosphere and resourceful people digging underground "vaults" or similar and exploiting geothermal/nuclear power/heat as long as po... | [
"The earth's surface would become unlivable within a matter of weeks due to the extreme cold. The temperature on the surface of the outer are around –355 degrees Fahrenheit. The earth's surface temperature would rapidly dive to that inhabitable temperature.",
"Geothermal heat from the earth will continue indepen... | [
"http://www.physorg.com/news62952904.html",
"\"the vast majority of the heat in Earth's interior—up to 90 percent—is fueled by the decaying of radioactive isotopes like Potassium 40, Uranium 238, 235, and Thorium 232 contained within the mantle. These isotopes radiate heat as they shed excess energy and move towa... | [
"I'm a bit confused by your association with magma and friction. My understanding is that the only real source of heat from friction is tidal forces. Most \"new\" heat in the mantle is from radioactive decay. Magma is produced through decompression or fluid flux, which don't seem to apply here."
] |
[
"In what fields of science can the hobbyist contribute something?"
] | [
false
] | I have taken an interest in aquaponics because there is a lot of experimentation going on - best ways to grow things, control temperature/chemistry, alternative fish feed production, etc. I am aware of protein folding research and would like to know more about how to get started in that. What else is there that I can u... | [
"Astronomy, The 2009 and 2010 impact events on Jupiter were discovered by an amateur astronomer using a 14 inch telescope."
] | [
"No one's mentioned it yet, so I guess I should:",
"One possible way to contribute, without any costs, is taking part in ",
"Galaxy Zoo",
". Galaxy Zoo is a project that gets interested non-astronomers to look at images of astronomical objects and try to classify them using a set of simple guidelines and que... | [
"If money is the only limiting factor, I really doubt that there is any field that you ",
" help by writing software. Protein folding is the obvious example that you can attempt from home, but pretty much every project I've seen would benefit from someone coming in and automating data gathering and analysis, if n... |
[
"Does light have any inherent \"luminous\" quality to it, or do our brains just interpret it as light?"
] | [
false
] | Does light (photons?) have any inherent luminous quality, as in they glow or something similar, or do our brains + eyes just take in light particles, and interpret it as "ok, there are a lot of photons, so I'm going to interpret this as a 'bright' light" or something like that? Not sure if all light is just photon part... | [
"It is our brains interpret it as light.",
"Our eyes are detectors of electromagnetic waves, and the range it can detect covers what we call the visible light. ",
"All light is just photon particles. The more photons hits the detector (our eyes), the more the detector is excited, so our brain interpret it as be... | [
"The photons don't glow - they are the glow of something else. What enables us to see is the photons hitting the photoreceptors in our eyes, and if enough photons hit a single photoreceptor it fires a signal to the brain, which in turn translate it to the color of \"a pixel\" of an image.",
"Our eyes are only abl... | [
"So our brains just take in photons and says \"ok, this area is bright, this area isn't... let's create a picture for this human\"? Haha probably not very accurate, but is this basically what's going on? Super cool."
] |
[
"My Chemistry homework has this problem on it. I can't solve it, and no one I ask knows how. Help?"
] | [
false
] | null | [
"http://www.reddit.com/r/homework"
] | [
"This question doesn't belong here. Ask your professor. "
] | [
"The only chemical reaction here was the decomposition of calcium carbonate, CaCO3 -> CaO + CO2. The calcium oxide present in the original mixture didn't do anything. Thus we start by looking at how much mass of the solid mixture was lost in the liberation of the carbon dioxide gas.",
"mass of CO2 liberated from ... |
[
"Since something so massive killed all of the dinosaurs all at once, did it kill all of the foliage/nature/plants? Are all the plants we have today completely new?"
] | [
false
] | Probably a dumb question. But I've had a few. | [
"Wikipedia",
" claims that about 57% of terrestrial plant species became extinct during the Cretaceous-Paleogene extinction event. Note that that number is the percentage of species, not the percentage of individual organisms or the percentage of biomass."
] | [
"Geologically, it was a blink of an eye."
] | [
"It didn't kill ALL the dinosaurs. The birds survived. "
] |
[
"Why when you mix Ice with Alcohol and Salt the \"temperature\" goes lower?"
] | [
false
] | I just want to know the chemical processes or reactions going on, or what property the Alcohol molecule has that allows this "lower temperature" or better heat acceptance. Thanks! | [
"Alcohol and salt water have a lower freezing point. So they can stay liquid at lower temperatures than pure water. So when you add them to ice, it returns to liquid and is able to get much colder before it begins to freeze again."
] | [
"Actually, if I understand correctly what you are trying to say, it isn't quite right.",
"if you have a mixture of ice cubes and water at 0 C and you add ethanol at 0 C, the temperature will drop below 0 C, so you CAN change the temperature as well as the phase, even when all components added were at the same tem... | [
"I think the question being asked here is when you mix these items, the system feels like it feels like it gets colder. This is because when the salt is added, and is solvated by the water / alcohol mixture, there is more energy taken in to the system than is given out. When something (anything) is solvated, there ... |
[
"Why do our eyes tear up when we yawn?"
] | [
false
] | Is there a reason for this? | [
"Diagram.",
"Normally, tears go from the lacrimal gland, across the eye, into the lacrimal sac, and finally drain away through the lacrimal duct. Note that the lacrimal sac acts as a reservoir for the tears to drain from.",
"When we yawn, our face muscles apply pressure to the lacrimal sac, which causes an exce... | [
"Part of the reason is that when you yawn, you squeeze your eyes tightly shut. The way that tears flow is that they come out of your lacrimal gland, which is on the upper outer side of the top of your eye; they then flow - in a film - across your eye obliquely downwards and inwards.",
"The tiny black dot on your ... | [
"Does that mean one could make themselves cry at will by flexing face muscles sufficiently hard? Moreover, is that why Peter Parker looks like he's trying to have a baby when crying for Harry in the 3rd Spider-Man? "
] |
[
"Are photons the only thing that can move at the speed of light?"
] | [
false
] | And if so how fast can/do other particles like protons, neutrons, electrons, or neutrinos move? | [
"Massless particles move at the speed of light. Aside from photons, we know that there is also gravitons (the particles mediating gravity) and gluons (mediating the strong force) which both are massless and thus move at the speed of light. Massive particles can move arbitrarily close to the speed of light, but they... | [
"massive particles",
"The neutrons, protons, and electrons OP asked about all have mass and thus can never reach the speed of light and neither can anything made of them, unfortunately for humans.",
"Neutrinos are a curious case because they were ",
"predicted to not have mass",
" but experimentally they do... | [
"Gravitons actually exist? How'd they isolate one ?"
] |
[
"Does a shallow continental shelf reduce the power of a tsunami?"
] | [
false
] | I kind of know how tsunamis work, but I'm curious if a wide and shallow continental shelf would have a noticeable impact on the size/strength of a tsunami. From what I understand, a tsunami can travel so far because there's much less resistance in the deep sea, and that when it hits the shelf it starts to rise and slow... | [
"The short answer is that there are trade offs with respect to the steepness of the continental slope (i.e. the transition from the deep ocean to the shelf) and the depth of the continental shelf and it depends on whether you're thinking about wave height or run-up height. ",
"To dig deeper, this paper from ",
... | [
"As you said before, there are trade-offs. If the incoming tsunami encounters a steep slope, leading up to the shoreline, there will be a greater build up of wave height, with which coastal residents will have to contend. But impacting the slope will also slow the forward speed of the wave, potentially affecting h... | [
"This is a great answer, thank you so much. I think I found studies like this when I was reading about it, but I wasn't sure if what I was after was wave height or not, since that seemed different from run-up (which seems like a better word for what I was getting at).",
"Just to make sure I'm not misinterpreting,... |
[
"a question about quantum entanglement"
] | [
false
] | [deleted] | [
"An important feature of quantum entanglement is that it is inherently a quantum phenomenon and cannot be described using classical observation- so any analogy used which is classical in nature will come up short. You are right, there is something \"very magic\" going on, which I use in the sense that it does not c... | [
"You're right in a sense, but this is related to classical mechanics. When we describe a wavefunction of a particle, the 'wave' describes the probability of finding that particle in space... WHEN THE PARTICLE IS OBSERVED. This last bit is extremely important, because when the particle is NOT observed it's location ... | [
"It is true, that quantum entanglement does not allow the transfer of information. Saying that it does not violate relativity is therefore technically correct. The collapse of the wavefunction does however violate general relativity in the sense that it is a nonlocal physical phenomenon, which does simply not fit w... |
[
"Question about life on nearby moons:"
] | [
false
] | So I recently turned my telescope to Jupiter, and was pleased to see the Galilean moons. Fantastic! Although Io happened to be occluded by the big planet and I only got to see the remaining three, I'm still pleased as punch that they're out there. In any case, I started wondering about the possibility of life on those ... | [
"Enceladus was recently shown to have liquid salt water, so it's now a candidate. Of course, Mars is always in the running.",
"Not to the best of my knowledge.",
"Pretty confident but not 100% sure. If there's water underneath then the surface would be water ice.",
"I don't think so.",
"Same.",
"There was... | [
"That's a bold statement, considering we can't exactly measure the probability of life spawning anywhere else at this time. However, one can only hope there is life elsewhere in our galaxy, let alone our solar system."
] | [
"I would say that considering how many moons there are in our solar system, something like ~135, I am pretty sure there has to be life, at least single cellular, on at least 1 of them."
] |
[
"How does natural selection make organisms lose useless functions?"
] | [
false
] | [deleted] | [
"It doesn't always, we still have an appendix but we don't use it!",
"https://en.wikipedia.org/wiki/Vermiform_appendix#Use",
"This is not known, it's assumed, and it is probably not true."
] | [
"There are a number of important evolutionary forces that shape an organism:",
"1) Positive selection - this is probably what you think of when you say \"natural selection\". Organisms that have a genetic variant that confers a reproductive advantage compared to other organisms multiply and the variant increases ... | [
"Well less energy = less energy for mating rituals, therefore you get picked as a mate less. Less energy for thermoregulation so you might not survive colder winters etc. etc.",
"Above all there is no real concrete road map for evolution, things effectively happen by accident and its hard to nail down exact reaso... |
[
"Why is it that a transformer only starts using electrical energy when a load is placed on the second coil that is not connected to the outlet?"
] | [
false
] | The primary coil is connected to the outlet and doesn't consume very much energy but as soon as a load is placed on the secondary coil electrical energy is used. I am trying to understand the relationship between energy and magnetic fields. The more in depth you could be in the explanation the better. | [
"Take a transformer with an unconnected secondary. If it helps think of it as if a very small capacitor was connected across the secondary; there's no path for DC current but a very small amount of energy can be stored in the electric field. This isn't really a good approximation but it may help you visualize the... | [
"The magnetic core causes the input and output windings to be tightly coupled (that is what it's there for). The two windings act as one. ",
"So when you put a load on the output it is reflected to the input.",
"Without a load, the input is high impedance. When a load is connected the input impedance drops dram... | [
"Thank you!"
] |
[
"Nutrient Absorption and Diarrhea"
] | [
false
] | Hey AskScience, If I eat a major load of carbs (2000-2500 cal range) and follow it up with something that gives me diarrhea (let's say coffee), will the carbs bypass the nutrient absorption areas such as the stomach and small intestine? The ultimate aim here would be the prevention of a glycemic response, so that the i... | [
"The short answer here is no. Carbohydrate digestion and absorption is quite rapid. Assuming you had normal gut flora there would still be a a large increase in serum glucose and a corresponding increase in insulin. Even if enough polysaccharides were left in the gut to cause osmotic diarrhea. ",
"Would the mouth... | [
"Thanks for your response! Can you cite a source on the speed of glucose uptake in the mouth vs the duodenum/jejunum?",
"P.S. I have no intention of using this practically. My real interest was in the speed of glucose uptake under the conditions of diarrhea."
] | [
"In ",
"this study",
" they showed that glucose absorption was negligible in the mouth. The main site of carbohydrate absorption is the duodenum and jejunum. This is the fastest site in the body by far because of a number of factors.",
"The surface area of this region is tremendous. The mucosa is folded 4 tim... |
[
"Do atoms get denser as you go up in atomic number, or do the atoms simply get larger and thus retain the same overall density in spite of their increasing atomic weight?"
] | [
false
] | null | [
"Density is generally thought of as a bulk property, and isn't really dependent on each atom's properties, but rather the way they pack together. Check out the wikipedia article on ",
"crystal structure",
".",
"At the atomic level, it is difficult to talk about density because that requires knowing something... | [
"Atoms do, in general, get denser.",
"The mass comes almost entirely from the nucleus, but the size is due to the electron cloud around the nucleus.",
"The size of the electron cloud is related, in a somewhat complicated way, to the atomic number. More protons -> more electrons -> electrons in higher orbits ->... | [
"However, the atomic weight is not the only factor in the density. For example, an atom of gold is lighter than an atom of lead, but gold metal is much heavier than lead metal. This is because the atoms are more closely packed, because of the electronic structure."
] |
[
"If there's acid rain, is there such thing as acid snow?"
] | [
false
] | null | [
"Yes, there is, and it can be more of a problem than acid rain.",
"For one, when snow is falling it spends more time travelling through the atmosphere before hitting the ground than rain. As a result of this, it has more time to collect pollutants, and can become more acidic than typical acid rain for the same re... | [
"Thanks a lot. Considering I have next to no knowledge is this field, your response is more than enough!"
] | [
"Plus, there are these awesome things called polar straospheric clouds. During the polar winter, it gets so cold that clouds consisting of tiny ice cristals form much higher than they normally would. On these clouds Chlorine reservoir species react with water and HCL, realsing the chlorine in molecules that are bro... |
[
"does carbohydrates (glycogen) turn into fat when not used in a certain amount of time?"
] | [
false
] | [deleted] | [
"They way I always thought was everything is broken down into simple sugars, and it's the excess sugars that your body stores. Eating to much of anything will make you fat. Carbohydrates produce alot of sugar when broke down and that's why you get fatter faster on a high carb diet. Like I said my understanding I... | [
"Nope, there is no way to convert glycogen into adipose tissue. ",
"Think of glygocen as more of a short term, fast burst energy. It's mainly stored in the liver and muscle tissue to that it can be converted into useful energy and used fast when a person needs it. Mainly used during anaerobic exercise (sprints, w... | [
"There is definitely a way for cells to convert between sugars and fat, it's just a matter of rearranging carbons around. ",
"This diagram is simplified but informative.",
"The second half of the question, though, is under what conditions does your body convert from one to another. If you are starving for sugar... |
[
"What is the rate of acceleration of photons?"
] | [
false
] | So the velocity of photons in water is ~2.25x10 m/s and in vacuum it is ~ 3x10 m/s. How fast does light accelerate between the boundary of water and vacuum? Also what causes this acceleration? Not sure if this is the right way to ask this question - perhaps the more correct question is what causes light to slow down in... | [
"The lower speed in other materials is because photons are absorbed and re-emitted by the atoms in the material.",
"This is not true, and is a commonly held (incorrect) belief. Atomic absorption features are narrow (like an ",
"absorption or emission spectrum",
") and occur over (nearly) discrete wavelengths... | [
"The lower speed in other materials is because photons are absorbed and re-emitted by the atoms in the material.",
"This is not true, and is a commonly held (incorrect) belief. Atomic absorption features are narrow (like an ",
"absorption or emission spectrum",
") and occur over (nearly) discrete wavelengths... | [
"Okay, but what would the photon model look like?"
] |
[
"Why is the core body temperature of humans seemingly so consistent, when we vary so much in other characteristics?"
] | [
false
] | To expand on the title, I'm asking why ideal core body temperature is the seemingly the same for everyone, regardless of age, sex, size, etc etc. | [
"It seems to me that some core body temperature regularity is required to maintain the functionality of our cells and organs. I’m sure there are a lot of factors that influence one’s given body temperature. ",
"From ",
"Wikipedia",
": “[Body temperature] depends on sex, age, time of day, exertion level, healt... | [
"The answer is homeostasis, but specifically why an infant and a 60 year old have about the same temp is because of human enzymes. Human enzymes (the chemicals that make our cells, help our organs function, etc) have a certain optimal temperature range in which they function properly. Outside of that range, we’d ha... | [
"Why does bacteria grows better on your table top than in your fridge? It's all about environment~ and temperature has a huge deal to do with your metabolism which the process of energy exchange that goes on keeping you (and I) alive.",
"1) Ask yourself what is temperature...\n2) Ask yourself how we measure tempe... |
[
"What is the difference between the observable universe and the universe."
] | [
false
] | I have also heard that we can't see past the Cosmic Background Radiation does that have something to do with my question | [
"The observable universe is, as the name suggests, the part of the universe that we can actually see. The universe itself may be infinite, but we can onlysee a finite part of it. The CMBR is the oldest electromagnetic radiation, because it originates from the time that photons became free to move around, so any l... | [
"The Universe is extremely big (it might even be infinitely big, though that's not really important for our purposes), but it only has a finite age. And light - the fastest thing in the Universe - travels at a finite speed. So light has only been able to travel a finite distance since the Big Bang.",
"That's the ... | [
"There are parts of the Universe so distant that light hasn't had time to reach us. Equivalently, in order for light from these places to have reached us by now, it would have to have started travelling ",
" the beginning of the universe. ",
"We can't quite see light from the very beginning of the Universe beca... |
[
"What are the main impediments regarding a manned expedition to Mars?"
] | [
false
] | Why haven't we been there yet, seeing how long ago the moon landing was? Having read that it would take a mere 8 months, I can't help but wonder: is a trip to Mars that different from one to the Moon? | [
"The lack of geopolitical will to do so is the number one impediment, and the only serious one. From a technological standpoint we are much closer to being able to go to Mars in 10 years that we were to getting to the Moon at the time of Kennedy's speech. If President Obama makes a Mars expedition a priority and gi... | [
"Ah. My question answered and my fears confirmed. "
] | [
"There's a good chapter in Sagan's ",
" that's about this. He basically says it's admittedly hard to justify such an expensive effort when it offers very few short-term political benefits. He predicted that Mars will be reached not by a lone nation but by a coalition of nations in order to regulate costs and spee... |
[
"How much acetone exposure is harmful to you?"
] | [
false
] | [deleted] | [
"Always check the ",
"MSDS",
"."
] | [
"Acetone has a low vapour pressure and evaporates readily in a warm room. You really should avoid breathing it in for prolonged periods as it's readily absorbed across your alveolar membranes directly into your bloodstream. You're basically getting drunk and a little poisoned on it, from the sounds of things. It's ... | [
"Hey thanks! I go to art school and it is a common prey of the EPA. I see these all of the time. "
] |
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