title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"How do scientists map superclusters?"
] | [
false
] | Ive been hearing a lot about the newly discovered Laniakea supercluster. The biggest question I have is how do we know where we are, and what it looks like. But a bigger question is how do we know there are other superclusters near us, and that ours is right next to perseus-peces. Im 14 so links are helpful when you sa... | [
"The light from these galaxies has reached us. In fact, because the universe is ~13 billion years old, we can see objects as far as ~13 billion light-years away. Of course, when we look at something that's, say, 7 billion light-years away, we are seeing light that left that object 7 billion years ago, so we don't... | [
"Maps of things like galaxy clusters (and superclusters) are created by measuring the distances to objects all over the sky.",
"If you think about it, when you look at stars on the sky, you are really seeing a 2-dimensional projection of a 3-dimensional universe - all the stars appear scattered across the surface... | [
"In fact, because the universe is ~13 billion years old, we can see objects as far as ~13 billion light-years away. ",
"Actually because the universe is expanding we can see objects much further, about 46 billion lightyears. This is because the light set off when the universe hadn't expanded so much, so distances... |
[
"What chemically causes a liquid to viscous or non-viscous?"
] | [
false
] | What exactly determines the viscosity of a liquid? The only chemistry knowledge I have is a basic High School Chem course, and all the stuff I've read on AskScience (I really like chemistry) | [
"The answer is intermolecular forces (not inTRAmolecular). I could go on a long spiel about this, but there are different kinds, including hydrogen bonds, dipoles, ion-dipole, ion-ion, and LDF's (London Dispersion Forces). Basically, extremely viscous forces have stronger intermolecular forces, and this causes them... | [
"There is a little bit more to it than just the strength of the intermolecular forces. If that were true, then water (hydrogen bonding) would have a much higher viscosity than oils, honey, or melted polymers (all LDF's). Even more important than the strength of the interactions between the molecules in the liquid... | [
"Interesting, thank you for the answer."
] |
[
"Before feeding tubes were invented how did people survive being unconscious for extended periods of times?"
] | [
false
] | I don't know if it's just a fiction thing, but I've seen it in books and movies and sometimes a character would have been "out for days." Sometimes even weeks. Just wondering how was possible to give water/feed unconscious people back in the day. | [
"Do you mean in a coma? ",
"They didn't. "
] | [
"If you're unconscious, your water and food needs are dramatically reduced. One could easily survive for a few weeks without food. For water, it's a little harder, but typically unconscious people still retain some swallowing reflexes. I've heard of putting a rag dipped in water in their mouth, or even honey sw... | [
"Thanks for the source!"
] |
[
"Since the moon has enough gravitational pull to create such large waves in the ocean, does it effect anything else, e.g. the way we walk or does it influence the way we design buildings?"
] | [
false
] | This began as a highdea, but now I'm just curious as fuck. If the moon can pull massive amounts of water to crash onto shores, in what other ways does it effect us... or does it? I realize that the gravitational pull is not that strong and waves start miles into the ocean, but can we run faster when we run in a certain... | [
"Gravity is an exceptionally weak force - we tend to think of it as powerful because we only observe it on very large-scale systems - like planets. It is only easily observable on a large scale because it is so weak - it takes that much mass to notice."
] | [
"The tidal forces show themselves over the extended objects, because gravitational pull is strongest on the point nearest to the Moon, and is weakest at the farthest point. ",
"A simple way to imagine that is this - Moon attracts surface of Earth under it stronger than it attracts Earth's centre. This force diffe... | [
"This makes sense. You're right, I have always thought gravity was a strong force. Thanks for giving a different perspective."
] |
[
"We can turn matter into energy pretty easily, can we turn energy into matter? What would that take?"
] | [
false
] | [deleted] | [
"can we turn energy into matter?",
"Yes, this is routinely down in particle colliders. You accelerate particles to high speed so that they have high kinetic energy and then you smash them together, and a large part of their kinetic energy is converted to matter in the form of hundreds of new particles that come f... | [
"Sure, you can get an arbitrary number of photons as long as there are at least two. ",
"However, three or more photon production is unlikely. A rough approximation is that the probability of producing each additional photon goes down by a factor of 1/137. So the vast majority of annihilations produce just two ph... | [
"Yes, the probability of two, three, four etc photons can be calculated to high precision in Quantum Electrodynamics (QED) using a technique called the Feynman Calculus. ",
"What is really cool about this technique is that you have a series of algebraic terms that you add up to determine the probability of a type... |
[
"What does it mean for mercury to be in retrograde?"
] | [
false
] | null | [
"That visualization is of a retrograde orbit. However, Mercury is not in a retrograde orbit. The orbits of all the planets in the solar system are prograde - they orbit the Sun in the same direction as the Sun's rotation.",
"The OP's question is about ",
" retrograde motion",
", where Mercury appears to cha... | [
"thanks for correcting that! "
] | [
"Mercury does have retrograde motion as seen from Earth. ",
"This article",
" discusses Mercury's motion in particular.",
"A simple way to think about it is that seen from Earth, Mercury is always close to the Sun, because its orbital radius is much smaller than ours. Its orbital period is also, as you ment... |
[
"Is the growth of algae on turtles' shells harmful to them?"
] | [
false
] | I recently saw a post on another sub about a woman who was scrubbing clean these turtles' shells and that got me thinking if that was actually helpful or if there is a whole ecosystem dependent on that. Cheers! | [
"Long term, algae reduces the turtle's ability to raise its internal temperature thus causing it to move slower and be at more risk. Aquatic turtles are especially prone to this since so much time is spent in the water. Turtles shed their scutes naturally as a way to remove the algae, aquatic turtles more than othe... | [
"Basically the algae acts as a buffer between the turtle and light/heat source. Making it harder for the turtle to absorb the heat it needs. This is really important for aquatic turtles since they are more prone to shell rot since so much time is spent in the water. They bask in the sun to raise their internal temp... | [
"That's interesting. How does it affect the turtle's temperature and how common is it to grow so much that it becomes a problem?"
] |
[
"Since objects are constantly abrading against one another, will everything eventually be smooth?"
] | [
false
] | I used to own a rock tumbler when I was younger that would turn rocks and sand over repeatedly until they were very smooth. This lead me to think that, if within this closed system, after enough time and movement, everything in the system eventually became still then the same might be true of the universe, or at least... | [
"No, because sediments such as sand and clay can form sedimentary rock, which can then break into sharp pieces once again. Sediments can also be subducted into the mantle and eventually spat back up as lava, forming igneous rocks."
] | [
"There's never a state of absolutely no friction between two objects. There can be very, very little friction certainly, but friction is a constant force in our world and friction is abrasion basically, so regardless of how smooth the rock became it would still be ground down, albeit more slowly than if it was roug... | [
"Eventually everything will fall into black holes, and then even after that the black holes will radiate until they are gone, leaving only light. "
] |
[
"How does Google Fiber significantly increase download speed?"
] | [
false
] | With only parts of Kansas city currently using google fiber, how can their speeds be as they are when so much of the world still uses slower mediums? Wouldn't the information still be passing through an entire "network of slow" before it hits the google-fiber neighborhood and can speed up? | [
"Google owns the backbone infrastructure for their fibre network. Generally broadband connections slow down at a much more local network, and in improving the connectivity at this level they improve end user speed.",
"Imagine a water pipe that has to supply a whole neighbourhood, and everyone trying to use that. ... | [
"Ars Technica may not be a scientific publication, but they did an excellent article on how ",
"The rest of the Internet is too slow for Google Fiber",
". It seems the major bottlenecks for users of Google Fiber is typically the remote servers' connection speed, since the rest of the network is sufficient to h... | [
"Hello, Network tech here.",
"/u/tj111",
" posted a decent article from ars. But I think it needs to be expanded on in a more technical fashion. ",
"for starters google fibres 1Gb/s speeds are shared speeds. You are offered up to 1Gb/s and not a dedicated line of speed. (EG: you and your 10 neighbours have go... |
[
"How long would I have to put a dish sponge in the microwave to sterilize it (or come close)?"
] | [
false
] | null | [
"Two minutes at full power kills or inactivates 99% of all the living germs and the bacterial spores."
] | [
"throw it in a pot of boiling water for a few minutes. this would be a much easier way to get the kind of heat you're looking for throughout the sponge while not melting or burning any part of it."
] | [
"30-60s according to this paper"
] |
[
"Nominal fees and commitment. What is the name of the phenomenon that when somebody pays a small fee for something, they are way more likely to engage in the activity or use the thing?"
] | [
false
] | As a bit of background, I work with youth with mental illness. Given the well established physical health risks associated with these illnesses, I'm applying for funding to start up a running group. I'm going to be asking for money for shoes, gear and a race entry fees. However, I know there is evidence to suggest t... | [
"Sunk Cost Fallacy (",
"http://en.wikipedia.org/wiki/Sunk_cost_fallacy",
") in Economics research.",
"Commitment Escalation/Bias (",
"http://en.wikipedia.org/wiki/Escalation_of_commitment",
") in more behavioral fields. ",
"I am by no means an expert on the practical applications/exploitation of these ... | [
"Social Psychology research refers to this phenomenon as the \"Foot in the Door\" technique. ",
"http://en.wikipedia.org/wiki/Foot-in-the-door_technique"
] | [
"Came here to say this. People tend to assume that, because they've already invested time, money, etc. into a project, that they should continue in this pursuit, even when it becomes no longer beneficial, because otherwise they would \"waste\" this previous investment. However, this investment is a sunk-cost that w... |
[
"What geographic features allow hurricanes to happen in certain ways?"
] | [
false
] | null | [
"Can you be more specific about this question? It's difficult to understand what you're asking."
] | [
"Sure! Why do hurricanes happen in the Caribbean and Atlantic, but not in the Mediterranean or the Baltic?"
] | [
"The Mediterranean and Baltic are too far north from the deep tropics. Hurricane formation requires (among other things) warm sea surface temperatures and high humidity - my guess is that these basins don't have these necessary ingredients."
] |
[
"Does my cellphone really have more computing power than the whole NASA circa 1969?"
] | [
false
] | I keep hearing my cellphone/car has more computing power than the whole NASA system when they sent people to the moon in 1969. Does it really true? How much do you estimate the power of the whole NASA back then? And if it's true, how could they even possibly send people to the moon with limited calculation? Is sending ... | [
"Definitely yes, in terms of pure computing power.",
"In 1969, the world's fastest computers (CDC 6600) had about 1MFLOP of computing power. NASA would use IBM 360s, which had less than that. The most powerful desktop CPUs now have in excess of 100 gigaflops - a hundred thousand times more power than the CFC 6600... | [
"When you think about computing power, it's not really the complexity or simplicity of the math that it can do, but instead just the speed that it can do it. The math equations required to calculate how to launch a rocket and get it the moon are probably more complicated than anything required to run your smartphon... | [
"That's kind of a tricky question to answer. On the surface, yes, because NASA was using ",
"IBM 360s",
" as their mainframe, usually running one actively with the other two as backup. With the 360 having a processing power that can be approximated as 1-50MHz, and topping out at 8MB RAM, that is indeed far less... |
[
"Weight loss/Physics question?"
] | [
false
] | [deleted] | [
"Yes, that is the majority of the weight that is being lost. The other waste streams you mentioned would also include some components like water, urea, electrolytes and metals but most of the organic waste will leave your body as carbon dioxide through your breath."
] | [
"Then is it possible (although very minute) that, that CO2 is changed back into Carbohydrates through photosynthesis and reintroduced into the body to start the cycle over?"
] | [
"Absolutely, and if you start going in the crazy probabilities that happen with these scales then it is almost certain that you have re-eaten the same carbon atom at least once."
] |
[
"Will the avg person gain more weight if they eat a cake spread out over the course of a week, or if they eat it all in one sitting?"
] | [
false
] | Replace cake with "half-cake" if a full cake seems like too much to eat in one sitting. | [
"I disagree. If you eat a whole cake at once your much more likely to expel nutrients than if you had spaced it out. Your body can only do so much and without being accustomed to eating that much every day, a lot will go through you."
] | [
"Of all the comments I've read this week on reddit, nothing reeks more of bullshit speculation and \"I actually don't have a fucking clue what I'm talking about\" than this one. Either provide some sources (you won't because you can't) or just don't comment when you clearly don't know what you're talking about."
] | [
"Weight Gain is 100% purely down to calories in minus calories out. last two sentences are entirely bullshit, coming from someone whose mum helps run Weight Watchers and has done so for many years. ",
"On to what the OP was asking. If you typically eat an 800kcal meal for dinner and all of a sudden you eat an 800... |
[
"Assuming the observable universe is the largest \"object\" we know of, and a quark is the smallest, what would be an example of an object at the midpoint between the two, in terms of size?"
] | [
false
] | null | [
"A quark is 10",
" meters* and the observable universe is 10",
" meters (in diameter). So something midway between would be 10",
" meters, or about half the length of Manhattan island.",
"*Not the size per se, but the so-called \"contact interaction scale\"."
] | [
"So something midway between would be 10",
" meters, or about the distance from Los Angeles to Shanghai.",
"You're probably thinking of kilometers, not meters.",
"10",
" meters = 10 kilometers. That's about 6 miles, a lot shorter than the distance between Shanghai and Los Angeles."
] | [
"According to ",
"this paper",
", the upper bound on the contact interaction scale of the quark is 7.5-14.5 TeV, which corresponds to a wavelength of about 10",
" meters.",
"I know the electron has an experimental upper bound of about 10",
" meters (Hans Dehmelt), although I'm not sure how we can really p... |
[
"Using bond energy from atomic to diatomic state of atoms as fuel?"
] | [
false
] | Excuse my ignorance on this, I haven't been able to find any answers to this question, and chemistry was not my best subject. I was wondering, outside of cost, is there any reason why we can't just react atomic oxygen with itself to produce O_2 and use it as a completely non harmful fuel for rockets or jets? From what ... | [
"Sounds great, but how are you going to store this atomic oxygen without it reacting with itself.",
"This is why elemental oxygen is always written O2 not O. Or elemental hydrogen is H2 not H, or elemental fluorine etc..."
] | [
"I'm assuming that it would be possible use high energy UV to break the bonds.",
"Yes, but then you'd have to put in more energy to split the molecules than you can get back from the reaction."
] | [
"Thank you so much, this is a good point I'm not sure why I didn't recognize it before. The rest kind of goes past the scope of the original question, but these may be solutions.",
"I assume that maybe storing the oxygen as a plasma could fix this, it would be low density decreasing chance of two oxygen atoms int... |
[
"Is there any data to support the assertion that the current generation of students are spoiled, self-entitled, etc.? I hear this all the time from my older coworkers."
] | [
false
] | Some of the examples they cite are parents buying them cell phones, not making them do chores, lenient parenting styles that are now popular, overprotectiveness, etc. Anecdotally it seems to be true, but as we all know anecdotes are unreliable. | [
"Two articles I read recently suggest that the younger generation isn't any more entitled than young people of previous generations. ",
"Do Today's Young People Really Think They Are So Extraordinary? ",
" ",
" The present research investigated secular trends in narcissism and self-enhancement over the past... | [
"Just a reminder:",
" "
] | [
"'College Students Are Less Empathetic Than Generations Past'",
"\\2. This is from the Atlantic, but they provide significant supporting data: ",
"'Millennials: The Greatest Generation or the Most Narcissistic?'",
"Edit",
"\nSorry for the sloppy numbering. If anyone knows how to fix that, I'd love to hear i... |
[
"Would animals with non-round pupils (such as cats and goats) see a different shaped image to us, additional to that which is granted by the different eye position?"
] | [
false
] | null | [
"When light passes through an aperture, each point of out-of-focus light (what photographers call bokeh) takes on the shape and size of that aperture. If you took a near-sighted member of each species and put them far away from a point-source light, each of them would see it as a different shape. A cat would see a ... | [
"Let's take the cat for example. ",
"Interesting that pursuit predators like a cheetah have round pupils and ambush predators like domestic cats and lizards have vertical pupils."
] | [
"Could be to do with size ratio of predator to prey. Domestic cars go after very small prey in relation to their body. So a mouse darting side to side that horizontal sharpness is really important. Big cats I think go after larger prey even when you take into account their larger size."
] |
[
"What makes Light move?"
] | [
false
] | I understand that light moves at a velocity but what powers this movement. This seems like an unanswerable question to me but maybe you guys could shed some light on the matter. (terrible pun intended) | [
"light can't ",
" move. That's just its nature, and the nature of all massless things. They're always in motion. When it's created, it's created in motion and can't be stopped unless it's absorbed by/interacting with charged particles in a material."
] | [
"E = hf can be derived from E",
" = m",
" c",
" + p",
" c",
"\nSince photons have no mass (m = 0), the equation becomes:\nE",
" = P",
" c",
"P = h K / 2pi (K is the wave vector, and K = 2pi / wavelength)",
"P = h / wavelength (wavelength = c /f)",
"P = h f / c",
"E",
" = P",
... | [
"Photons get absorbed and reemitted while traveling through the material, which makes it look like they're moving slower. The photons are always traveling at c, though."
] |
[
"How is Ophiocordyceps unilateralis (\"zombie fungus\") able to affect an ant's behavior?"
] | [
false
] | null | [
"At my laptop now, so I think I'll try again. This isn't my field, so it's a little speculative.",
"The fungus releases a cocktail of chemicals, ",
"though we currently haven't characterized all of them",
", so we can't know the specific effects of each one. ",
"The effects that the fungus elicits include s... | [
"Thanks for the reply. I'll check out that link!"
] | [
"You might as well say it works by affecting the ants' biochemistry. That's how little your reply actually answers the question. Is the mechanism in any way similar to LSD? Do ants even have the same type of receptors on their neurons that LSD binds to? Why even mention ",
" particular substance if it has nothing... |
[
"Can someone explain, on a mechanical level, how acetic acid kills bacteria?"
] | [
false
] | null | [
"The acid is acidic because it has a hydrogen atom that is barely hanging on. If it comes into contact with anything less acidic, the hydrogen can be transferred from acid and onto the bacteria or whatever is more electronegative. When this hydrogen from the acid attaches to the bacteria, it’s possible that the wat... | [
"To add to the other great reply, bacteria also have a field of protons around themselves at all times. You can imagine this as a sort of forcefield that must be kept up for the bacterium to be able to generate energy (via the proton-motive force) and move around (by powering a sort of water wheel that runs on prot... | [
"I'm pretty sure it just sucks all of the water out of the bacteria. Water will diffuse out of the cell in order to equalize the acetic acid concentration inside and outside of the cell. Since there is essentially no acetic acid in the cell, it will completely dehydrate it. From there it may also be able to dissolv... |
[
"How does the immune system not identify organ transplants as \"foreign?\""
] | [
false
] | [deleted] | [
"Short answer is that it ",
" identify them as foreign objects. Organ transplant recipients are given a variety of drugs that they have to take for the rest of their lives that force their bodies to accept the organs.",
"I think."
] | [
"The immune system does recognize foreign tissue. That's why ",
"immunosuppressants",
" are used."
] | [
"You are mostly correct. ",
"Medline Plus: Transplant Rejection",
"Tissue typing ensures that the organ or tissue is as similar as possible to the tissues of the recipient, but the match is usually not perfect. No two people (except identical twins) have identical tissue antigens.",
"Doctors use a variety of ... |
[
"Why is the immune system reduced during pregnancy? Wouldn't an increased immune system be more adaptive?"
] | [
false
] | If the immune system response is reduced during pregnancy, how is this an adaptive trait, or has it just not had enough of an impact to be selected out? It would seem that an increased immune system would be more adaptive, since both the mother and the child would have a higher chance of survival. Also, and some othe... | [
"\"Increased\" or \"decreased\" immune responses are not inherently good or bad. Someone with the flu probably wishes that their immune response was increased, but someone with rheumatoid arthritis (where antibodies are attacking their joints) or MS (where T-cells are infiltrating the brain) probably wish they had ... | [
"you don't want your body to treat the foreign object growing in your belly as an invader do you?"
] | [
"Right. The fetus is a source of new things that your body hasn't seen before. This comes from the mixing of genetic material that has produced the baby in the first place. Specifically, the proteins on the surface of the cells can be recognized as a foreign body and attacked with the adaptive immune system (antibo... |
[
"Is there a physiological explanation for the worsening of hangovers with age?"
] | [
false
] | null | [
"Hangovers are caused by tons of things. \n1. Presence of formaldehyde in cheaply produced alcohol. Formaldehyde is toxic and will make you feel like garbage. - Drink higher quality liquor to alleviate this effect.\n2. Alcohol inhibits the release of antidiuretic hormone, causing you to lose more fluid (the reason ... | [
"Alcohol is broken down by 2 enzymes. First ADH breaks alcohol down to acetaldehyde (toxic). Then ALDH breaks acetaldehyde down to acetate (safe). As you age, you lose ALDH, causing an increase in the amount of acetaldehyde in your system. This causes worse hangovers.",
"Chronic drinking can lead to fatty liver a... | [
"Academic textbooks are usually really pricey. 98USD is even considered really cheap in that category. Also usually ebooks arent available, because theres a lot of diagrams and other visual information, which is better suited for a pdf. ",
"But im pretty sure u can find the book on libgen"
] |
[
"How much does body hair actually help in the retention of body heat?"
] | [
false
] | As a hairy man, I am curious. | [
"Hair helps to create a layer of standing air between the surface of the skin and the outside environment. It works in the same way as a styrofoam cup (air in the material) or a wetsuit (same idea, but with water). In addition, body hair helps protect from solar UV radiation.",
"In humans, as ",
"/u/hansax",
... | [
"Not scientific, but when I shave my head clean I get much colder easier. I am normally a hot (temperature wise) individual but shave my head and man I'm cold, quick. "
] | [
"This, 100%. Also, I have cross dressed (for charity, honest!) and it was noticeable how much colder my legs were with tights on than they had been the day before in shorts. I am assuming it's because the hairs were flattened against my skin instead of slowing down a layer of air.",
"At any rate, this will be m... |
[
"What is the correct serotonin structure?"
] | [
false
] | Yesterday I got a tattoo of the serotonin structure. I looked around on the internet and finally decided on the image on wikipedia: After I got it tattooed, the boyfriend of my sister that studied biology send me that the three lines inside the convex should be rotated one position. I looked around on the internet and ... | [
"Your tattoo is fine: these are just the two equivalent resonance structures that can be drawn to represent the same thing.",
"Instead of alternating single and double bonds in the 6-membered ring, the electrons in an aromatic system (in this case the benzene ring) actually recombine to form one delocalized pi-b... | [
"Another representation (one which I favor, if only for the artistic element) is a circle within the ring. The circle shows that it's not directly connected to any one particle, yet the bond exists nonetheless."
] | [
"Your tattoo is totally fine, (although I'm guessing/hoping he didn't study much biology, because he really should have known this). The double bonds (two parallel line) represent 4 electrons, two forming a sigma bond and 2 a pi bond. In that six membered ring, there are 12 electrons in sigma bonding orbitals (repr... |
[
"How accurate is day 10 likely to be on a 10 day weather forecast?"
] | [
false
] | null | [
"Not very. ",
"Simulating and predicting the weather in the Earth's atmosphere is difficult primarily because the forecast can be very sensitive to small changes in the initial conditions you feed into the models. This means that small errors due to things such as incomplete observations compound overtime and gro... | [
"I used to be a sysadmin at NOAA in the Forecast Systems Laboratory (which is now part of the Earth System Research Laboratory). Basically what they do in places like this (NWS does this sort of work too) is to develop and test forecast models and validate their results. There are tons of models...I don't know th... | [
"It really depends on the location and what's going on, weather wise. Weather models have some geographic areas that are fairly easy to determine -- there isn't a lot of variability or unknowns. Other areas encounter frequent variability, which leads to less than accurate forecasts.",
"Also consider that when air... |
[
"Why do number theorists generate formulas with so many log functions?"
] | [
false
] | I was reading an article in Wired that mentioned that number theory formulas are notorious for having many log functions, referencing Robert Alexander Rankin's formula for prime gaps, which contains ten logs. I can't wrap my head around why this might be. What is it about log functions that makes them well suited to t... | [
"This doesn't answer the question of why the number of primes up to N is asymptotic to N/log(N), or why (from the ",
"article",
" mentioned in the OP and the related ",
"preprint",
") we now know the largest gap between consecutive primes up to N is at least log(N) log log(N) log log log log(N) / log log lo... | [
"Note: Typically what is meant by log in these formulas is natural log, so ln.",
"I can't specifically comment on higher level stuff, but if I had to guess it has to do with the ",
"Prime Number Theorem",
". This might be a good place to start. I only have taken an intro number theory course, and this was rea... | [
"at least log(N) log log(N) log log log log(N) / log log log(N), when N is sufficiently large",
"The paper says it's at least positive constant * that. Do you know if this constant has been shown to be at least 1?"
] |
[
"Why is the error term in the Störmer-Verlet method O(Δt²) and not O(Δt³)?"
] | [
false
] | If positions at t + Δt are: r(t+Δt) = r(t) + v(t) + ½a(t)Δt² + ⅙b(t)Δt³ + O(Δt⁴) and for t - Δt the positions are given by: r(t-Δt) = r(t) - v(t) + ½a(t)Δt² - ⅙b(t)Δt³ + O(Δt⁴) And the subtraction of both equations results in r(t+Δt) - r(t-Δt) = 2v(t) + ⅓b(t)Δt³ + O(Δt⁴) Which is the same as r(t+Δt) - r(t-Δt) = 2v(t) +... | [
"You might have forgotten to multiply v(t) with Δt",
"\n(since you cannot simply add a position and a velocity because they have different units):",
"\nr(t+Δt) = r(t) + v(t)Δt + ½a(t)Δt² + ⅙b(t)Δt³ + O(Δt⁴)",
"\nr(t-Δt) = r(t) - v(t)Δt + ½a(t)Δt² - ⅙b(t)Δt³ + O(Δt⁴)",
"\n=> r(t+Δt) - r(t-Δt) = 2v(t)Δt + O(... | [
"Ah, so I was messing up my maths! That makes sense, thanks."
] | [
"The velocity is a central difference, centered stencil, so it is order del(t)",
"The expression you created is close to a finite difference stencil but lacks del(t) needed in the divisor.",
"The reason to choose a specific stencil may have more to do with numerical stability and the error term of the modified ... |
[
"In the graphic of Earth's energy budget, the outgoing thermal radiation is greater than the incoming, why is that?"
] | [
false
] | I'm referring to this , the incoming radiation absorbed by the surface, how can the energy emitted by the surface be greater than this? How is the energy amplified, isn't it a violation of the 1st law of thermodynamics? I'm sorry, this is a stupid question, I just couldn't find anything online why it is higher. | [
"I think you're misinterpreting the graphic. The energy leaving is less than incident. 77+22.9+239.9 = 339.8, which is less than the incident, 340.4. The other sources, thermals and latent heat, don't leave the atmosphere. That's accounted for the emitted by atmosphere number, rolled into total outgoing infrared ra... | [
"Blackbody radiation. All things with temperature radiate energy in the form of electromagnetic radiation with a “color” based on temperature. It’s why you can be seen like a bright red sore thumb on an Infrared camera and why molten iron glows red/orange/white hot. Things have to be really hot to be seen in the vi... | [
"Where does the energy coming up from the surface come from? In no way contesting your answer, just trying to understand the graphic better."
] |
[
"Why can a human heart beat 24/7 for decades upon decades but not suffer from \"soreness\"?"
] | [
false
] | The human heart beats about 60-100 beats per minute, starting during pregnancy and ending only when you die. During this time, there isn't a burning sensation or a feel of a "muscle pull" when it does this unending motion for your entire life. No buildup of lactic acid, no strains (minus heart problems, obviously). So,... | [
"The muscle soreness you typically feel in your skeletal muscles (often called DOMS for Delayed Onset Muscle Soreness) is the result of an inflammation and swelling response from muscle damage. Although it can occur from any form of muscle damage from unaccustomed loading, it most often occurs from eccentric loadi... | [
"Yep, any skeletal muscle soreness you have has nothing to do with lactic acid (lifting weights, running, etc.). ",
"Unless you're running extremely hard, you probably aren't even seeing a buildup of lactate in your blood. Most people don't last very long working at intensities above the lactate threshold (the ... | [
"It's not entirely clear if lactic acid is the actual reason for muscle soreness, but the heart doesn't produce lactic acid as it runs primarily (possibly entirely) off of oxidative respiration. That means it has a LOT of mitchondria and it requires a continuous supply of oxygen to function. So, to some extent it... |
[
"Why do scrapes hurt longer than cuts?"
] | [
false
] | Why is it if you cut yourself the pain lasts only a few moments, but if you scrape off a layer of skin or two it will wind up being irritating all day? | [
"When a tissue is injured, it releases what I call pain producing substances, such as bradykinins, K+, serotonin, and prostaglandins. These molecules bind to free nerve endings and produce action potentials in afferent nerves. These action potentials are interpreted as pain in the sensory cortex in the brain. When ... | [
"Wild guess? When you cut your skin, you expose some number of pain receptors, but when you abrade your skin you expose a larger number, so you end up getting a larger and more enduring pain response from what is really a less serious injury.",
"I also wouldn't be surprised if it's got to do with pain receptors b... | [
"Outstanding. I was hoping someone with actual knowledge would jump in. Thanks so much!"
] |
[
"How does a person develop a sense of humor?"
] | [
false
] | We’re all born with the ability to laugh amongst other ingrained reactions such as crying and smiling . Whether laughing is a predetermined tool to be utilized in social settings is a different question, but I’m here to ask why do we find certain things funny and others not so much? Some have dark humor, some laugh at ... | [
"Humor is a good indicator of IQ. If you laugh at someone's jokes, chances are they are of even or even slightly greater IQ. Of course, this varies from social setting to personal backgrounds.",
"For example, a low IQ person, perhaps a baby, would find fart noises and googly eyes funny. But if you did that to an ... | [
"That makes sense and explains why the people around me have the sense of humor that they do. Do you happen to have any sources? I would love to read more on it. Thanks for your input! "
] | [
"Higher IQ humor is often witty remarks or ironic / snarky comments",
"So sarcasm is not the lowest form of wit after all. And that's because the actual quote is \"Sarcasm is the lowest form of wit... but the highest form of intelligence.\" Oscar Wilde knew what he was talking about."
] |
[
"Explain this hoverboard design and why I shouldn't get excited."
] | [
false
] | null | [
"Supermagnets spinning over expensive copper slabs. Yes real. Here's my ",
"1995 demo version",
"Here's a man-lifting version from [Korea] ",
"http://www.youtube.com/watch?v=uHEQgjNcFBo",
"Only trouble is, this is Maglev Train technology: it requires a track, and it needs about a kilowatt to lift an av... | [
"Roads don't need to produce a magnetic field, but rather they simply need to be made out of a material which would conduct electricity (such as metal).",
"The hoverboard shown works by spinning a circular disk with embedded permanent magnets above a conducting sheet (sheet metal in this case, probably aluminium)... | [
"More fun would be a two-dimensional zero-gravity room, where you become a \"flatland\" creature.",
"Lay on your back upon some sort of frictionless surface, looking up at a giant mirror on the ceiling facing you. It feels like you're stuck to a wall. You're seeing yourself floating in 2D. Kick off from the si... |
[
"What is the reason for dial up internet to make the weird screechs and dings when it first connects to the internet?"
] | [
false
] | null | [
"Traditional telephony systems",
" have a frequency response range between 200Hz and 4KHz",
" Analogue modems work by taking digital data and encoding it as a rapid series of audible tones that can be sent over a telephone line. So at its most basic, those \"weird screeches and dings\" are just the sounds the... | [
"Actually, the sounds at startup are the negotiation sounds, as the modems at either end probe the phone connection to see what it will support in terms of data rates and codings. Different phone connections have different qualities.",
"If you were to pick up a phone line perfectly (without introducing any sound)... | [
"Excellent information, thank you!"
] |
[
"What makes a parrot able to speak english?"
] | [
false
] | [deleted] | [
"A parrot who can mimic other parrots has proven it has good eyesight, hearing, voice-box, memory and social intelligence, which are good traits to look for in a mate. Like with human brains the sender is mostly the receiver; a parrot who can recognise mimicry in other parrots must have social intelligence, good he... | [
"Agree with the above, and ",
"here is a Lyre Bird showing off",
"."
] | [
"That is truly exceptional, the chainsaw noises made me a bit sad though :-("
] |
[
"If I cover my entire body in sunscreen, does my body still produce vitamin D when I'm outside?"
] | [
false
] | null | [
"Solar UV-B radiation (λ ≈ 290-315 nm) stimulates the production of vitamin D₃ from 7-dehydrocholesterol (7-DHC) in the epidermis of the skin.",
"A properly applied layer of SPF-30 sunscreen absorbs about 97% of the UV-B in sunlight. So you could still produce D₃, but at a greatly reduced rate."
] | [
"And how long do you need to be exposed in the sun to reach a normal level of vit D pls ? Tks"
] | [
"That depends on many factors, e.g. your age, your skin type, the area of exposed skin, the time of year (less UV-B penetrates to the Earth's surface due to low Sun angles in Winter), your location on Earth (less UV at high latitudes due to low Sun angle, more UV at higher altitudes due to less atmospheric absorbti... |
[
"Which element produces the most neutrons after nuclear fission?"
] | [
false
] | null | [
"As others have said, the number of outgoing neutrons after fission is dependent on the incoming neutron's energy. You can find nice plots of the energy dependence down at the ",
"National Nuclear Data Center",
". Just click an element, click an isotope, and then click the plot link next to the \" (n,total nuba... | [
"You use a particle accelerators to get an ion going super fast and then hit something that releases neutrons, like a ",
"spallation target ",
" [pdf], with it."
] | [
"How do you create such high energy neutrons? In these lists i find energies up to 30 MeV , but the highest energy i could think of with my limited knowledge is 14,7 MeV from fusion neutrons. "
] |
[
"Is one Mole of atoms visible by the naked eye?"
] | [
false
] | null | [
"Yes, one mole of atoms will be equivalent to the atomic mass of the element in grams. So, for even the smallest element, hydrogen, there will be 1.008g of hydrogen in a mole, which is a noticeable amount. ",
"Of course, this assumes that the element is visible in general, so perhaps a clear gas is a poor example... | [
"Assuming that the material itself is visible, yes. ",
"For example, one mole of carbon."
] | [
"Yes. Take one mole of uranium. That is 238 g. You can easily see 238 g of uranium. "
] |
[
"Why is thiamine the predominant nutritional deficiency in alcoholics?"
] | [
false
] | In other malnutrition cases, it's often protein, electrolytes, or B12 that is the concern. What makes thiamine deficiency specific ot alcoholism? Does alcohol metabolism deplete thiamine? Does alcohol use reduce absorption or increase urinary excretion of thiamine? Do alcoholics favor foods that are disproportionately ... | [
"Oh! I can give you some answers here! I wrote a paper on this a couple of semesters back for a human physiology class. ",
"1) Alcohol interferes with absorption of thiamine in the gut.",
"2) Alcohol interferes with the conversion of thiamine to thiamine pyrophosphate, which is the form that participates in the... | [
"The pathophysiology hasn’t been elucidated on great detail, but we do know that chronic alcohol intake reduces the expression of the thiamine transporter genes, preventing efficient absorption of thiamine from the gut into the body. I don’t believe it’s known how the transcriptional change occurs, but alcohol and ... | [
"I give this to ppl constantly thanks for telling me why."
] |
[
"Why do Caucasian people have coloured hair?"
] | [
false
] | First off, I want to be clear and say that this has nothing to do with racism. I was sitting on the bus last night and was thinking about Caucasian girls with black hair, it then hit me that it's a rare sight. I then got into thinking about how Asians, Native Americans or, many other races only have black hair. What is... | [
"The current prevailing ",
"theory",
" as to why white people exist at all is that it was an adaptation to deal with an extreme lack of vitamin D in their environment. Humans adapt very quickly to vitamin D levels in the environment as both too little and too much can impact fertility. So when a group of peop... | [
"Caucasians",
" aren't",
" the only",
" ones with",
" light hair",
".",
"As those pictures show and explained better by others blonde hair is found amongst the Melanesians of New Guinea for instance. It is interesting though the variations that humans have."
] | [
"Here's a ",
"map of the historic incidence of blond hair",
". ",
"Technically, everyone has colored hair, and non-black hair is less colored. If you look at apes, most of them have black hair, with Orangutans having red hair.",
"Light colored hair is a genetic mutation that sticks around in places where it... |
[
"What is happening when hydrogen peroxide bubbles when it come in contact with an infected area?"
] | [
false
] | I recently got my ears pierced and due to me not keeping up with cleaning them as much as I'm supposed to they have gotten infected. To help clear up the infection I dipped them in some hydrogen peroxide. After that they began to bubble. I assume that that just means its killing the bacteria but just to be safe I thoug... | [
"Great question!",
"Blood and cells contain an enzyme called catalase. Since a cut or scrape contains both blood and damaged cells, there is lots of catalase floating around.",
"When the catalase comes in contact with hydrogen peroxide, it turns the hydrogen peroxide (H2O2) into water (H2O) and oxygen gas (O2).... | [
"Note: store bought hydrogen peroxide is stable at room temperature (usually a 3% solution in water) but concentrated hydrogen peroxide is extremely unstable and is highly reactive/explosive."
] | [
"In that case, what is it about hydrogen peroxide that disinfects?",
"Does the free oxygen work as a free radical?"
] |
[
"Do carbonated liquids go flatter quickly in a narrower or wider glass?"
] | [
false
] | What properties of a drinking glass make a carbonated liquid go flatter quicker or slower? Is it the height of the glass? The neck size? The base area? Or some combination of all these and/or other properties? | [
"I would hypothesize that the wider glass would lose carbonation faster. It has a wider air-to-liquid interface area, and more internal area (more nucleation points) "
] | [
"I'm not sure this is correct.",
"First of all a wider glass doesn't necessarily have a larger surface area. For a constant volume a cylinder has a minimum area when the diameter equals the height but goes to infinity both when it gets taller and thinner and as it gets shorter and wider.",
"Even that assumes th... | [
"I believe this to be the correct answer as well. The CO2 will want to diffuse out of the liquid into the air because of the concentration difference. Rate of mass transfer is largely due to surface area where exchange can occur."
] |
[
"Could antimatter be arranged to form objects like anti-water, anti-cheese, or anti-humans?"
] | [
false
] | [deleted] | [
"This is an open question in physics I believe. So far colliders have only been able to create very basic anti-atoms like anti-hydrogen, but they can now store it long enough to begin ",
"experiments",
" on its behavior. The standard model is very well tested but does not incorporate gravity or explain the imba... | [
"mastering fusion has little to do with it. we've been able to do fusion reactions for decades. \"mastering fusion\" generally means doing fusion in a way that produces net electric energy, which isn't necessary for this. "
] | [
"so it's not a question of whether an anti-matter particle in a magnetic trap will hit and annihilate with a particle of matter it's just a question of when.",
"BASE trapped antiprotons for a year without observing any loss. ",
"Source",
".",
"I could imagine that it is possible to produce a few nuclei of a... |
[
"At a molecular level what's happening when I join the (-) and (+) leads of a battery without a load. Why are there sparks?"
] | [
false
] | null | [
"I freaking love that we can know and utilize nature like this, with our 1.3kg of wet mash sitting in a dark cavity. Easy to get cynical in a modern world and forget how amazing the members of our species are who first figured it out."
] | [
"Lots of things are invented or discovered by accident. However, I can't imagine anything has been perfected without thinking in to what is really going on."
] | [
"When connecting together two wires or clamps or a ring terminal- the initial point of contact is FANTASTICALLY small cross-section. Almost zero. It may be copper, but we could be talking about 1/10,000th of a sq mm.",
"Resistance is higher there, and the total volume of metal at the point of contact is so smal... |
[
"Is the human jaw powerful enough to tear through flesh as easily as depicted in zombie shows/movies?"
] | [
false
] | null | [
"The human bite is pretty pathetic.",
". At 120lbs of bite force, it's strong enough to bite through flesh easily, but not enough to break any of the long bones. The problem with the human mouth is that it can't open very wide, so our bites are rather small.",
"Ripping and tearing of the flesh is very possible ... | [
"120 lbs of force isnt the important stat. its the psi (lbs/sq in) that count. any info on that?"
] | [
"Lets say only the front 4 teeth are used. After a quick look in the mirror that seems about 1/2 cm",
" of surface area (probably even less than that). Quick conversion to real units gives us a pressure of 1.068E7 Pascals. (This assumes the 120 lbf was measured at the front teeth.)",
"Basically a shit-ton of pr... |
[
"How do villi/enterocytes promote absorption of fluid?"
] | [
false
] | I'm quite hazy as to how intestinal absorption and our villi actually work. My initial understanding was that sodium was secreted basolaterally, resulting in lumenal diffusion of water. Apically, water and solutes are transported back into the cell. Also the crypts are (perma?) secreting solute. After trying to researc... | [
"Thank you for taking the time to answer; I appreciate it! I'm sorry for being unclear, but yes I meant principally absorption in the duodenum/jejunum.",
"When you say Na is pumped out into the blood, do you mean pumped into the blood supply within the villous? Or another blood supply? I think this is a significa... | [
"Thank you so much! I feel like I've had that \"light-bulb moment.\" The diagrams definitely confirmed my suspicions after reading your first answer a few times. My first understanding was just so wrong; I'm very happy to have it rectified."
] | [
"There are many different mechanisms for absorption and arrangements of epithelium throughout the digestive tract. ",
"I'm assuming you're talking about fluid and electrolyte handling in the upper small intestine, so I'll focus on that. ",
"sodium was secreted basolaterally",
"I think your first misunderstand... |
[
"Is there any evidence for using the size of lunula as a health indicator?"
] | [
false
] | Do the "moons" in your nails really have anything to do with your health? | [
"In short, yes. An abnormal form or color of the lunula can indicate the presence of skin or systemic disease, which Cohen describes in J Am Acad Dermat 1996; 34: 943-53.",
"A few examples:",
"Small or absent lunula may be indicative of atherosclerosis, renal failure, congenital disorders and a vast range of ot... | [
"The article by Cohen only deals with observed and reported (in the medical literature) co-occurence and not causation. I am not a docter and know little about the mechanisms behind this. Surprisingly, there has been little research into the lunula. PubMed yielded approximatley 100 hits. "
] | [
"Is there a reason why the lunula is linked to these diseases?"
] |
[
"Hybridization in Sulfuric Acid"
] | [
false
] | Do you have to invoke molecular orbital theory to explain the tetragonal shape that H2SO4 takes on? | [
"you could always invoke MO theory if you really want to, and it's kinda fun actually. but you don't need to do so.",
"the tetrahedral shape around the sulfur is due to (1) 4 things being bonded to sulfur and (2) the sulfur has no lone pairs. orbital hybridization must be invoked to explain the how the tetrahedra... | [
"it had been thought that sp3d and sp3d2 hybridizations might be possible in this context, but invoking d-orbital participation has been ruled out for hypervalent 2nd row main group elements (",
"source",
"). it's late and i'm not thinking well right now, but i'll try to give it some extra thought and come up w... | [
"i'll take a look at that when i get a chance, but keep in mind that hybridization is just a tool to explain what is actually going on. the shape and character of these orbitals is often thought of in a linear combination of atomic orbitals (LCAO) approach. from a quantum mechanics standpoint, molecular orbitals ar... |
[
"How is the 60hz electric power frequency and 60hz NTSC TV standards (refresh rate) related?"
] | [
false
] | Should they be matched for the electric devices to work? | [
"Long story short, NTSC uses a 60Hz refresh rate because the power supply runs at 60Hz. Similarly, the European PAL standard runs at 50Hz because of their power grid frequency.",
"This is especially relevant for old analog tube TVs. The TV's circuitry would use the AC frequency as a timing signal to control dir... | [
"Not necessarily. A beat is not going to sound like its frequency. It is going to be nulls and peaks that alternate at the rate of the beat. Its really easy to hear a 1Hz beat between two similar frequencies, since it goes quiet and loud once a second. Obviously a 1Hz noise is inaudible.",
"As far as 10Hz goe... | [
"Of course, lately there have been a lot of TVs equipped with electronics that can take all standards.",
"The 20 year old Goldstar CRT TV we had in our home (Europe) already could handle PAL/SECAM/NTSC inputs."
] |
[
"How does the structure of a muscle respond to the development of fine motor skills?"
] | [
false
] | [deleted] | [
"Surgeon here. There is nothing specific about the muscles as far as I know. I know surgeons who are body builders with thick muscular firearms and some are people averse to exercise in general like me with skinny firearms.",
"It is not about the muscles as much as it is about using postures and support to do the... | [
"As an artist and formerly newbie martial arts practitioner, I find it more to do with neural path. Not that I am expert on neurological pathways or can test it, but I had to think of how I move my arm before it became near instinct. It isn't really specific to the muscle structure as it is more influenced by techn... | [
"Yes I think the majority is of the mind, of course. What I hoped to achieve with this post was an isolated perspective of muscles to see how much of fine motor skills is attributed to them.",
"If I could draw up another example, imagine you're an extremely fast learner, but your muscles grow poorly. You have goo... |
[
"How does one locate a planet outside of our solar system?"
] | [
false
] | First and foremost, I have very little knowledge of anything astronomical, so please excuse my ignorance! Also, apologies if this question has been asked, but I was unable to find anything in the FAQ or after a search. Assuming faster-than-light travel, if one were to travel to a planet beyond our solar system - how wo... | [
"There are two primary methods for detecting extra solar planets or just exoplanets. The first is to search for them by looking for the tell-tale \"winking\" of stars whose planets orbit along a plane that is perpendicular to our line of sight. When a planet passes between us and its star we see the light from the... | [
"What are the limits of these detection methods? What if you want to get from 'our' neighborhood to one in a different galaxy or at the other end of the universe? "
] | [
"See also ",
"Wikipedia: Methods of detecting exoplanets",
"."
] |
[
"How exactly does a stimulant, like adderall or concerta, calm down a person with ADHD?"
] | [
false
] | null | [
"But then why do some normal people take Adderal to study better? "
] | [
"But then why do some normal people take Adderal to study better? "
] | [
"Would developing a dependency on stimulants cause the neurotransmitters to regress or deteriorate in function below where they were before use (i.e. start at 40%, after time, base level without stimulant use at 30%)? ",
"Additionally, does a stimulant impact only the 'desired' area of the brain, such as attentio... |
[
"Is visual focus psychological or physiological or both?"
] | [
false
] | When focusing on sign, the text is easy to read but if you focus on somewhere to the side, it becomes harder. I've heard there are less rods and cones near the perimeter of the retina and more toward the centre. So is this the cause for focused/unfocused vision or is it psychological, or a mix of the two. | [
"It's a little bit hard to answer your question because it's unclear how you are using the word \"focus\". ",
"There are actually three separate ideas that play a role: foveating, focusing, and attending. ",
"Hold a finger up in front of you and look at the tip of your finger. You are ",
" on the tip of your ... | [
"Thank you very much, that was very interesting to read and answered the question well. Thanks!!!"
] | [
"two things:",
"The physical resolution of the visual field is greatest in the center, and declines sharply out in the periphery. This is because of how the cones are packed in the retina - in the center, the ",
", the cones are very small and very closely packed together - in the periphery, the cones get large... |
[
"Why do hot substances have a higher dissolving capacity than cool substances?"
] | [
false
] | null | [
"Whilst this kinetic explanation may seem intuitive, as you have mentioned it is fundamentally flawed and doesn't explain why dissolved gases show inverse behaviour. A more correct intuition can be found when considering entropy.",
"Dissolving materials in liquids is mostly driven by entropy. For dissolving solid... | [
"Yes, but what effects the gibbs energy with changes in temperature? T*ds.",
"So the sign of the entropy change effects how the favourability (gibbs free energy) changes with temperature. The small changes in enthalpy due to temperature are typically ignored."
] | [
"When a solid dissolves in water, it forms weak bonds with the water molecules. In order for those bonds to form, the molecules need to be close to each other. Molecules are always moving, so they are rapidly colliding with other molecules around them. Every time they collide is an opportunity for a bond to form.",... |
[
"How is anesthesia managed when an unconscious/comatose patient needs emergency surgery?"
] | [
false
] | How do anesthesiologists work when an unconscious patient is brought to the ER and needs emergency surgery? Do they give the same dose of the same molecules as if the patient were conscious, or is it too dangerous if the patient is already unresponsive? | [
"That is very much depending on the reason why the patient is unconscious. \nE.g. a patient receiving cpr can be intubated without further sedation. If consciousness is returning you usually dose the drugs based on the vitals and the person's response. ",
"Someone who is unresponsive because of a drug overdose bu... | [
"a patient receiving cpr can be intubated without further sedation",
"Being dead is an excellent sedative",
"But yes, I would tailor the anesthetic based on the mental status of the patient. Brain dead? No hypnotic needed. Unconscious but responsive to pain? Narcotic induction. Intubated and unconscious? Inhala... | [
"Anesthesia has a buttload of different drugs that do different things, for example:",
"- Amnesia (prevents you from forming memories of what is happening)",
"- Sedation (knocks you out)",
"- Pain (importantly, this is not the same as sedation; just because you are unconscious doesn't mean your body doesn't p... |
[
"Do parasites serve an ecological function? I know a lot of insects that we consider pests are actually important in the food chain (like ants and spiders) but do things like fleas and ticks actually contribute anything to their environment or do they only sap energy from their hosts?"
] | [
false
] | null | [
"They serve the ecological function of exploiting a niche within the ecosystem. ",
"Remember that nature is not 'working together'. Nature is the result of countless different species attemating to survive and clashing with one another. This then leads on to species adapting to exploit or avoid other species. Mos... | [
"Exactly. The starting point of viewing a species as serving a \"purpose\" is flawed. "
] | [
"Parasites have an ecological function of regulating populations mostly through negatively impacting the host's intrinsic lifespan or fecundity."
] |
[
"Does donating blood have an impact on blood pressure?"
] | [
false
] | Would donating blood regularly contribute to relieving high blood pressure by removing blood from the system? | [
"Research published in 2012 demonstrated that repeated blood donation is effective in reducing blood pressure.\n",
"Source",
"There is a ",
"Clinical Trial",
" underway to confirm this"
] | [
"Speaking strictly from a volume standpoint, it wouldn't have much effect.\nWe do use diuretic medications which cause fluid loss in the urine to treat blood pressure. However, you'd need to donate blood far too often for this to work from a volume standpoint."
] | [
"funny thing a large portion of americans have metabolic syndrome so the study can be somewhat generalizable. "
] |
[
"Are there any animal species where the male to female ratio is not very evenly split?"
] | [
false
] | null | [
"But as a general principle in the animal kingdom that reproduces sexually the 50/50 split is long term stable.",
"Except in the insects, where bees, ands and even mosquitoes have either very few males, or the males only exist for a short period to reproduce."
] | [
"Have a look at the tuatara in New Zealand. They’re sex is determined by the temperature during their incubation period with females being produced at lower temps and males being produced at higher temps. With climate change there is a higher % of males than females"
] | [
"Joe Hanson did a video in 'It's ok to be smart' and tackled this question: ",
"https://youtu.be/C3dCWxxVhVc",
"He mentioned that there are some exceptions such as the Australian Bushbabies where the females can favor having more boys or more girls depending on circumstances. But as a general principle in the a... |
[
"The weak-force is different for anti-matter. How would that affect the formation of anti-matter versions of macroscopic structures?"
] | [
false
] | null | [
"Sorry I never really know what the difference is. What makes something a 'discussion' question vs a 'regular' question?"
] | [
"Open-ended, hypothetical, speculative, or discussion-based questions fit better there.",
"In this case, your question is about a hypothetical situation where we could create macroscopic objects out of antimatter, and what kinds of effects the weak force would have on such objects."
] | [
"Hello,",
"This question would be more appropriate for ",
"/r/AskScienceDiscussion",
".",
"Best."
] |
[
"When we smell something constantly, our brain begins to ignore it. Does this happen to any of our other senses?"
] | [
false
] | null | [
"Since nobody has yet answered anything, I'll take a stab at it.\nEdit: Reddit says this thread has three comments, but it shows me only my own. If this has already been answered thoroughly, sorry.",
"The short answer is yes, it does. You can observe this in several ways, but the easiest is with hearing. Do you h... | [
"Another example which is easy to reproduce is looking at a bright color on your screen for some time and then looking at a white wall, which will appear in the complementary color of the one you looked at before."
] | [
"Sorry if this is the wrong area, but it has to do with senses. Is it possible to manipulate or learn to ignore senses? For example, as a child I was terribly ticklish, after being determined to win tickling wars, I trained myself to ignore the feeling. I can now easily turn the sensation off. What is the science ... |
[
"Why do the edges of a shadow get blurrier the further they land from the object?"
] | [
false
] | null | [
"https://en.m.wikipedia.org/wiki/Umbra,_penumbra_and_antumbra",
"Short version - because in the real world, light sources (light bulbs, the sun) are not single points, but have a surface area from which light is emitted.",
"If a light bulb was a single, mathematical point with no volume all of its shadows would... | [
"Nicely said!",
"Not sure I agree that shadows will \"always be sharp\" with a point source.",
"The reason I say this has to due with the wave nature of light. When a wave encounters an obstacle, the wave is not blocked in a straight line. It diffuses behind the obstacle more and more as the wave travels furthe... | [
"I agree. And if it wasn't clear, in real life the scattering isn't just off of your object. The light has to passing through air and floating particulates/ dust, which are also diffuse scatterers. So the farthest edge of the shadow is defined by light that has had to travel the longest path (encountering the most ... |
[
"How does the deep sea maintain life?"
] | [
false
] | Sun light is the main source of power for life but deep in the ocean is pitch black so, how does it sustain life without a high energy source like the sun flowing into the system | [
"There are microbes in the deep sea that can perform chemosynthesis, by eating chemicals flowing from thermal vents on the ocean floor. There’s also whale falls, when a dead whale (or other large animal) dies and sinks to the bottom, along with other random flotsam sinking down. "
] | [
"Most of the nutrients that keep life in the deep going are brought in from elsewhere (surface) through vertical migration of animals or marine snow (bits of organic debris falling from the surface). However, as this \"food\" falls from the surface it looses both quality and quantity so the deep sea can only suppor... | [
"There's sources that can provide heat energy other than photons. In regions such as the Mariana trench, there exist ",
"mini volcanoes",
" (of hydrothermal vents, to be more scientific) that provides heat energy to the given area. But, now you might wonder, how do they replenish their biological resources? Wel... |
[
"What IS a gravitational singularity at the center of a black hole?"
] | [
false
] | I'm trying to understand the concepts behind a black hole but the vocabulary is beyond my grasp. Conceptually, I get the gist of an event horizon, , and , but what at the center of the black hole (singularity)? Is it impossibly crushed matter of everything the black hole has eaten? Or is it just a single point, becau... | [
"General relativity predicts that for large enough objects with the right initial conditions the collapse of that object into a black hole, which has an event horizon. The collapse continues, according to general relativity, till there is a point of infinite mass density at the center of the black hole.",
"Howev... | [
"I once heard Unruh say something like \"people think quantum mechanics will get rid of the singularity inside a black hole. But quantum mechanics is weird, and it might be that quantum gravity replaces the singularity with something that is so weird we ",
" we had the singularity back!\"",
"I thought it was an... | [
"The singularity is a limit that you run into when modelling black holes with general relativity.",
"General relativity is incompatible with quantum field theory. Once we are in the realm of a singularity, we're in the area where we don't have a model of physics that is consistent.",
"Which is a long way of say... |
[
"I was fucking around with some fire, wax, glass, and ice. Something happened that I can't explain. I'm hoping /r/askscience can. There's a video of what happened."
] | [
false
] | null | [
"Released! Hope it finds some good answers!"
] | [
"Well. I uh... yay for home science. Repost this without the fucking in the title and I'll let it out of the spam bin for you."
] | [
"Haha :)",
"That's more than fair - ",
"http://www.reddit.com/r/askscience/comments/qax6w/i_was_tooling_around_with_some_fire_wax_glass_and/",
" "
] |
[
"What is the retrograde transport system of the Golgi Appartus?"
] | [
false
] | My book has just a quick blip about this, and I don't understand it but I really want to. That kind of thing is fascinating to me. "Recent data suggest that the Golgi apparatus has yet another function: it can receive proteins and other substances from the cell surface by a retrograde transport mechanism. This retrogra... | [
"I don't remember too many details about the system itself, but I do remember what it's called. ",
"http://en.m.wikipedia.org/wiki/COPI",
"Maybe that can answer some of your questions until someone with more knowledge than I comes around."
] | [
"Edit:\nFor a good review on the exploitation of retrograde transport of toxins, check out ",
"3",
".",
"I'm going to fill this comment in with more information as I read more and remind myself of everything I've forgotten, but essentially the mechanism involves recognition of a protein by transmembrane and v... | [
"Note: I'm assuming based on your other comment that you're a student studying this, so I'm going to assume some background knowledge. Feel free to ask me to clarify anything.",
"In mammalian cells, depending on what cell types you're talking about, but nutrients are often pumped across the cell membrane (for thi... |
[
"Another dimension"
] | [
false
] | null | [
"I'm sorry if i forgot this \"?\" "
] | [
"Additionally, the answer is no, we don't know how to make places that you can travel to that are not part of the universe as you or I experience it. We do however have ",
"escapism",
" in various forms! You might enjoy to learn about the concepts of ",
"virtual reality",
", ",
"lucid dreaming",
", and ... | [
"Thanks for the help but i can't go to another dimension? "
] |
[
"Why does the radio that is used for wireless communication have that distinct chatter-y sound?"
] | [
false
] | Is it because of some special reason? Because we have crystal clear sound from our smartphones which are also wireless but those radio sounds are kinda hard to understand. Edit: Grammar | [
"The phenomenon you are describing might be \"picket fencing\". This describes the behavior of radio waves to be distorted in a chatter-y way. Here is the Wikipedia on it: ",
"https://www.wikipedia.org/wiki/Picket-fencing",
"The reason certain calls on cellphone can be so clear is that the voice is transmitted... | [
"A-ha. That was much clearer for me. I wonder why airports or military still use it though. I mean, it should be very important to have clear and concise informaton relay, isn't it?"
] | [
"A-ha. That was much clearer for me. I wonder why airports or military still use it though. I mean, it should be very important to have clear and concise informaton relay, isn't it?"
] |
[
"Canada decided to delay second doses by up to four months due to lack of supply. Will this time frame leave us less protected?"
] | [
false
] | [deleted] | [
"The UK has been doing this, to get more people first-dosed quicker. Including me, so I've kept an eye on it.",
"The last figures I saw indicated a first dose effectiveness at stopping covid infection of around 75%, but effectiveness at stopping serious effects such as hospitalisation as almost 100%.",
"https:/... | [
"It is also a question of triage and it seems clear that getting a broader population one dose would have better outcomes for the population as a whole than half that population two doses."
] | [
"It is also a question of triage and it seems clear that getting a broader population one dose would have better outcomes for the population as a whole than half that population two doses."
] |
[
"Why didn't the universe collapse into a black hole immediately after the big bang?"
] | [
false
] | All the stuff, matter, energy that would ever be was in a space that would seemingly have to be dense enough to be a black hole. Why are we not crushed inside of a black hole? | [
"One important condition for the formation of a black hole is that the spacetime away from your distribution of mass you'd like to be a black hole is asymptotically Minkowski, meaning it gets quickly flatter and flatter as you move out. This is not the case for the early Universe since it was homogeneous (all point... | [
"Because that matter was everywhere... the universe was infinite at the time of the big bang, so even though things were dense, they were dense ",
".",
"If you tried to arbitrarily pick a point saying \"this area should collapse\", you'd see that area was being pulled OUTWARD as it was surrounded by equally den... | [
"asymptotically Minkowski",
"Sounds like a physics punk band. Would you be able to say when the first black hole would theoretically have been possible to have formed?"
] |
[
"Are we anywhere near being able to control the weather ?"
] | [
false
] | I realise that changing the climate of an area is impossible. However if there was a specific event occurring that we needed to prevent it raining for have we ever come close to doing that ? | [
"Well, there's ",
"cloud seeding",
"."
] | [
"Well, China did it successfully to have a rain-free opening of the Olympics: ",
"http://hubpages.com/hub/China-Stopped-the-Rain-for-the-Beijing-Olympics"
] | [
"June has been incredibly shit though. April was far nicer. Where is our fucking summmer?"
] |
[
"Good book to learn about circuits?"
] | [
false
] | null | [
"Art of Electronics, just started reading it actually, and I gotta say it's really well written. ",
"http://en.wikipedia.org/wiki/The_Art_of_Electronics"
] | [
"I got that book for a class, but it reads more like an encyclopedia, and it's really hard to figure out how circuits work because of the way everything is ordered."
] | [
"If you're looking for basics, any E&M (electricity and magnetism) textbook would work.",
"Once you read through the basics, I really learned a lot by looking at demos on the internet. There are a lot of neat circuit apps around that you can learn a lot from. I don't mean iphone apps (those may exist as well), ... |
[
"In space, is there a limiting factor for the speed of craft traveling in space other than the speed of light?"
] | [
false
] | [deleted] | [
"A few limiting factors. The two major ones are fuel and collisions. ",
"The more fuel you carry, the more fuel you need to carry. Since fuel has weight and thus inertia, the fuel itself starts to slow you down. Each additional unit of fuel has diminishing returns in terms of how far it can propel you.",
"Bu... | [
"IIRC Voyager's power is running off the heat from radioactive decay from a radioisotope thermoelectric generator (RTG). This is basically using atomic energy that is emitted slowly and for a long time to generate electric power.",
"If you are moving through space and heating up from hitting stuff along the way ... | [
"This is a very good answer. Which leads me to ask you this. If photons hitting you would heat up the ship. Would a heat driven ship not be the way to go? If such propellant ever was invented (emdrive). Or atleast to keep the acceleration.? ",
"Background info:\nVoyagers power is running on heat. "
] |
[
"Where does the water go in drought?"
] | [
false
] | Im from Germany, and like many places in Europe, we lose a lot of water this summer. In school I learned there is and was always a fix amount of water on this planet. So my question is, when the soil is dry, the rivers are draining and there is no rain, where is all the water? | [
"The ocean.",
"It's a more complicated cycle than what we're taught in school. Everything is connected.",
"Ordinarily water evaporates from the ocean. As the air moves it cools and condenses over land (th, and releases the water as snow or rain. During the colder months it freezes (snowpack, glaciers, etc), lar... | [
"Also, rivers, especially low land rivers are also indirectly filled from rainfall. July tends to be high rainfall month around European lowlands. Sometimes it's even catastrophically rainy. But this year it's the opposite."
] | [
"Drought actually increases the likelihood of floods when lots of rain does occur. The tightly packed soil doesn’t absorb the water as readily as hydrated soil. Sounds backwards, I know."
] |
[
"How do people with Down syndrome differ intellectually?"
] | [
false
] | How well do people with Down syndrome score on IQ tests? Or other tests? Also, please throw any other research that shows differences in cognitive abilities at me. Maybe something to do with self-awareness? I don't mean to offend, I'm just curious. | [
"Please don't come back."
] | [
"The normal IQ range falls between 90 and 110. Down's syndrome children have an average IQ of about 50.",
"This website is run by the NIH and is a good source for general information on Down's Syndrome. ",
"http://www.nichd.nih.gov/health/topics/down_syndrome.cfm"
] | [
"Does their brain structure differ? (not sure if I can ask another related question)"
] |
[
"What are the effects of inhaling alcohol?"
] | [
false
] | In another , somebody mentioned a . In the wiki article, it is said that the effects of this machine are not known. Does anybody know if there are negative or positive consequences from inhaling alcoholic vapor? Also, would dropping dry ice into an alcoholic drink have the same effect? | [
"I'm not an expert in this area, but that machine seems kind of silly to me. ",
"Inhalation is a more direct and faster way of introducing alcohol (or other substances) into your bloodstream, but it might be dangerous to introduce so much alcohol so quickly. Even the people selling the machines don't recommend ... | [
"What about people with ulcers, IBS, or Crohn's disease, many of whom can't drink alcohol because it irritates the gut?",
"I agree with your overall point, just giving an example of a potential target audience for these things."
] | [
"Very well. I had assumed that the OP could rely on the normal means of alcohol ingestion."
] |
[
"If the gravitational force is transmited at the speed of light, does the earth orbit a 8-minutes-before sun?"
] | [
false
] | 'Seen' from the center of the galaxy or any other outter reference frame. | [
"There's a subtlety: the gravitational field of the sun is retarded by 8 minutes, but it also encodes information about the sun's velocity, so the Earth is actually orbiting where the sun is \"now.\"",
"http://arxiv.org/pdf/gr-qc/9909087.pdf?origin=publication_detail"
] | [
"Questions like this are why it doesn't make sense to speak of simultaneity over relativistic distances. For all intents and purposes, where we see the sun right now is where it is, right now. Information about anything it might be doing differently (location, velocity, brightness, etc) won't reach us for 8 minut... | [
"Ignoring any effect of that third body on the Earth, then the Earth would continue orbiting where the Sun would have been had it not moved for eight minutes. The Earth always feels the gravitational field of the Sun due to its properties (mass, velocity, etc.) eight minutes ago. If the Sun is moving slowly in roug... |
[
"Is The Mass of The Universe Constant?"
] | [
false
] | If not, how can it be gained/lost? | [
"Other comments suggest mass itself is not conserved while mass+energy is. It's true mass and energy are interchangeable but in general relativity they are not conserved on a large scale. Conservation of energy is consequence of time invariance in physics, but under GR different reference frames variate in time sig... | [
"The red shift of light is primarily caused by stars traveling away from us.",
"This is true, but that motion is due to their recessional velocity and not their peculiar velocity. So the redshift can be said to be caused by the expansion itself. Remember that velocities of distant objects are not actually well-de... | [
"Does every conservation law come from a symmetry? What about something like conservation of lepton number? "
] |
[
"Did the unpleasant side effects of menstruation affect the reproduction rates of ancient humans? Clarification inside."
] | [
false
] | [deleted] | [
"Its not a stupid question to ask, women with particularly bad cramps can be in a large amount of pain and unable to preform physically at their best, which would reduce their chances against a predator.",
"Ancient women (if you want to call them that) would have had a few things working in their benefit to avoid... | [
"Just because women in modern times spend the vast majority of their time ",
" pregnant doesn't mean it was so in the past. Not that I'm asserting the opposite, but it's something to consider."
] | [
"Most don't experience that bad cramps, just a little ache that can be helped with a warm bath. "
] |
[
"Why can we consume raw seafood and undercooked beef but not raw chicken?"
] | [
false
] | [deleted] | [
"The short version: you ",
" eat raw chicken without getting sick.",
"However, you ",
" eat raw chicken, because you have a much higher ",
" of getting sick.",
"It's not a property of the meat itself, but the frequency and commonality of microbial presence on the meat. Chicken, by the nature of their diet... | [
"Not all raw seafood. ",
"Generally saltwater fish is good to eat raw (there are exceptions of course)",
"Freshwater fish tend to harbor lots of bacteria and worms, so its better to cook those.",
"White meat animals harbor harmful bacteria and because of the way we mass produce these animals, its not very cle... | [
"It has mostly to do with the processing. With beef, when it is slaughtered, bacteria will grow on the surface of the meat. This can happen for a variety of reasons, but the bacteria is not forced into the meat.",
"With chicken, they are processed in a way that has a lot of cross contamination between birds. E... |
[
"How does an animal with a sensitive nose use it to navigate?"
] | [
false
] | Most animals have a much stronger sense of smell than humans do. While there are obvious difficulties in asking phenomenological questions about non-humans, I'm wondering how this ability is used to navigate (like a bloodhound tracking someone, or flies finding your fruit). | [
"Many animals can sense the direction of a smell (so can humans, but not very well). If you've ever seen a dog sniffing around you will notice that they take many short, shallow breaths quickly."
] | [
"More than just sniffing. They will regularly exhale forcefully through their nose to stir the scent up - just watch them sniffing in the snow. Also, they will move back and forth as theey follow a scent, either their entire body or just their head, to track. As the scent weakens, they will scan back to find the pa... | [
"Is the mechanism behind \"stereo smelling\" understood? Does it work the same way as stereo hearing (i.e., your brain can tell which nostril receives input first)? "
] |
[
"What is actually happening when a stimulant makes you feel more awake and full of energy?"
] | [
false
] | For example caffeine makes you feel more alert when you might other wise want to sleep. How does it keep the need for sleep at bay and what physical effect does this have? | [
"http://en.wikipedia.org/wiki/Caffeine"
] | [
"Yes, I read that but it doesn't really answer my question. I was wanting to know the actual mechanism."
] | [
"What are you looking for? This is the known mechanism: ",
"http://en.wikipedia.org/wiki/Caffeine#Mechanism_of_action"
] |
[
"What would happen if you were to release a volume of gas in space?"
] | [
false
] | null | [
"Space is a \"near-perfect\" vacuum. There are particles even in space. The amount of gas in an oxygen tank would flow quickly out of the tank, expanding outward. For a short time, there would be more oxygen in the nearby area than usual, but it would disperse."
] | [
"A gas will expand until its fills a container. Since we are still unsure as to what the bounds are for the universe it safe to assume the gas will expand to the point that it either irrelevant if it was sa small volume or if you released enough gas it may create it own gravity."
] | [
"This is fascinating. So, theoretically, if we were to release an immense amount of the stuff, could we create a livable environment for a short period of time?"
] |
[
"What is the current status on a cure for Eczema?"
] | [
false
] | Additionally, what is the impact of Eczema on the immune system's ability to deal with another sickness such as the flu or a grazed knee? | [
"This is talking about atopic dermatitis, and not the other types of eczema.",
"To answer the second part of your question, I'm going to summarize the information from the ",
"clinical immunology text book",
" I use, but also point you to a more detailed paper in ",
"The Lancet",
".",
"The basic thing w... | [
"There is a more recent article dated July 2010 at the Lancet website that describes Emerging Treatment Options for the Treatment of Eczema [1] ",
"here",
". The Introduction to the article states the Th1/Th2 T-cell imbalance theory has largely been replaced by the theory that Atopic Eczema is caused by a \"Pri... | [
"You can try going to a local university's library (they are almost always open to the public if it's a public university, especially if it's a public university med school). You can access the articles there if they have subscribed to them, and it opens up the wide world of pubmed to you.",
"I wouldn't say it ha... |
[
"How many possible genetically-distinct people are there?"
] | [
false
] | from Richard Dawkins has me wondering. I imagine it's a much more difficult question than just computing the number of permutations of base pairs on our genome, as many - or surely - permutations would not be viable as human beings. And I'm guessing that the line between human-and-non-human would be another gray area... | [
"If so, you have three billion base pairs with four possibilities at each position. That's 4",
" people.",
"No. If you look at all possible combinations of 3 billion base pairs, you are talking about 4",
" possible varieties of DNA goo, not humans. Only a very very very infinitesimally tiny fraction of those ... | [
"If so, you have three billion base pairs with four possibilities at each position. That's 4",
" people.",
"No. If you look at all possible combinations of 3 billion base pairs, you are talking about 4",
" possible varieties of DNA goo, not humans. Only a very very very infinitesimally tiny fraction of those ... | [
"There is no way to make an even reasonably close estimate. Too much information is lacking.",
"The only answer is \"some huge number\".",
"I see in that quote that Dawkins compares it to the number of grains of sand in the Sahara. I guess that is one way of saying \"some very large number\" without being preci... |
[
"Does anyone know what contraction rates for rabies are?"
] | [
false
] | I've been trying to research this in my off time and it's turning to be somewhat trying. I'm looking for individual rates (per vector ideally, but we'll see if that's possible) and most of what I'm finding are population models. I see things like that list a couple rates as examples, or articles like that are paywalled... | [
"If you are asking what the chances are of someone bitten by a rabid animal actually developing the disease are, then the answer is basically 100%. If you are asking what the chances of a rabid animal transmitting the disease are, there are probably too many variables to make an accurate prediction. Thus, populatio... | [
"Is the near 100% chance due primarily to the infectivity of the disease, or to the general violence of the attack? (Several deep puncture wounds instead of just one, for example.)"
] | [
"I think it's just highly infectious and present in many bodily fluids. Bats transmit it readily through bites that are too small to see. "
] |
[
"Besides your stomach feeling empty, what other ways does your body tell you or show that you're hungry? Are there even other ways?"
] | [
false
] | null | [
"Someone correct me if I'm wrong...",
"There are a few ways that your body will tell you that you are hungry. Obviously, your stomach will feel empty, but there are also a range of ways to tell if you are hungry, but not every person experiences them all.",
"Firstly, as you become hungry, your stomach may growl... | [
"I see, so I guess most of the other signs aren't really noticeable by you yourself since you become more cranky and tired and don't naturally attribute that to being hungry. I just thought there were other noticeable ways to tell beyond feeling hungry, such as fidgeting or rapid eye movements, etc. Guess not, than... | [
"There's a part of your brain called the hypothalamus, that is involved in regulating a lot of these kinds of homeostatic things like hunger, thirst, cold etc. ",
"When you get hungry there are hormones being released and signals being sent that eventually tell your hypothalamus you need food, and it responds by ... |
[
"Why is Graphene such an amazing electrical conductor but Graphite isnt?"
] | [
false
] | [deleted] | [
"The bonds between layers absolutely do affect conductivity. Using the tight binding approximation to calculate energy dispersion you find that it is linear in graphene (at the Dirac points). That means the effective mass of electrons is zero, so the conductivity approaches infinity. In graphite, however, the effec... | [
"I just want to add, this doesn't mean that graphite isn't electrically conductive. \nWhile its conductivity is less than that of graphene, its still pretty conductive and it (and its derivatives) are frequently used in battery electrodes or in polymer blends to increase electrical conductivity. "
] | [
"I just want to add, this doesn't mean that graphite isn't electrically conductive. \nWhile its conductivity is less than that of graphene, its still pretty conductive and it (and its derivatives) are frequently used in battery electrodes or in polymer blends to increase electrical conductivity. "
] |
[
"Would dust in a PC slow down performance in any way?"
] | [
false
] | Almost feels like something for , but would cleaning dust out of a PC make it run faster? | [
"It could - computers need to cool off to operate. When computers are \"working harder\", they are using more energy. That energy is dissipated as heat. If a CPU gets too hot, it can damage itself. Most modern CPUs have temperature monitoring circuits to protect themselves against excessive temperature. ",
"Moder... | [
"To a point, no. Until the fins on the heat sink for the CPU or GPU are blocked, there will be minimal impact. But as the heatsink becomes blocked, airflow is reduced and the components begin to run hot. If left to become bad enough, the computer begin to throttle, limiting performance to protect the components. If... | [
"Here",
" is a very rough illustration of the effect."
] |
[
"What Is Different In The Processes Of Superheating Sand To Get Silicon Vs Glass?"
] | [
false
] | Sorry If the Flair was wrong, took me a minute to think what could possibly fit best, Watched a poor video by Intel in my recommendations on YouTube and saw they used sand. How do you get silicon from sand and not glass/ vice versa. Thanks! | [
"Watched a poor video by Intel ",
"I'm assuming this was in relation to semiconductor manufacturing? Making silicon into wafers suitable for IC chips require carefully controlling the cooling/solidification of molten silicon in such a way that a single highly pure crystal is formed rather than an amorphous solid... | [
"Thanks!"
] | [
"Thanks!"
] |
[
"Can you create matter out of pure light?"
] | [
false
] | [deleted] | [
"more commonly occurs when a photon impacts a massive particle",
"Well... kind of. What you may be thinking of is when a high energy photon hits something like an atom. Since there are electromagnetic fields between the electrons and the nucleus of the atom, the high energy photon can often donate some of its ene... | [
"http://en.wikipedia.org/wiki/Pair_production",
"\nPhotons can in principle collide with each other to produce particle-antiparticle pairs, although I think that this more commonly occurs when a photon impacts a massive particle. But yes, you are correct that on the quantum scale, mass and energy can readily tran... | [
"While it's possible in principle to start with light and end up with matter, it's a fundamentally quantum process, and as such is naturally probabilistic. So if you put two extremely high-energy, high-intensity light sources together, you'd get various charged some particles out (mostly electrons and positrons by ... |
[
"How does the water supply network still remain liquid in cities even at very cold temperatures? Why don't the pipes freeze?"
] | [
false
] | null | [
"They are buried below the frost line which is a depth where the temperature of the earth doesn't go below freezing. Here in Chicago it's about 48\", so.ewhere like Minnesota is more like 55\" so it varies by climate. Occasionally in really bad will they will get below freezing but it's really hard to freeze moving... | [
"In the past when pipes may not have been deep enough it was not uncommon to see a guy with a big welder in a truck. Stop, run welding cable to two fire hydrants and put a few hundred amps thru the water pipe for an hour or so.\nDoes not work so well with plastic pipe."
] | [
"And in some more extreme locations with permafrost the water is run as a continuous recirculation. So the pipeline is a “spoke and wheel” approach, instead of a “tree and branch”. The main pipeline is a loop, continuously circulating back to the reservoirs to make sure it is always moving and doesn’t freeze. Also ... |
[
"What causes guns to be so deadly?"
] | [
false
] | Sorry for the extremely silly question (technically I suppose this falls under the medical category), but I just don't get it. Most bullets seem to be rather tiny, and yes it goes at the speed of sound, but shouldn't that cause the bullet to go right on through, making a small hole in the person? Unless it hits a vital... | [
"This isn't a silly question at all. This won't be heavy on the science and physics, but this is more of an education on firearms in general.",
"Your first question brings up quite a few points. Bullets can be quite tiny indeed, but I'm not sure if you're talking about just handgun cartridges, rifle cartridges, o... | [
"Full metal jacket bullets, that is, bullets which are one piece of solid metal, will go right through you pretty much all the time.",
"However, lots of bullets aren't full metal jacket, and are in fact hollow points filled with lead, or have a urethane tip, or are just left hollow point (just to name a few). ",
... | [
"Secretly I'm just a high schooler with Wikipedia. Don't tell anyone."
] |
[
"I read that insulin is a hormone, but also that it is a protein. How can something be both?"
] | [
false
] | [deleted] | [
"A hormone is a signaling chemical in the body, whereas a protein is a type of chemical compound. So, insulin can be a protein (in that it's made of amino acids and has a protein structure) and a hormone in its job (regulating different metabolic functions). "
] | [
"I really don't think any more elaboration than this is necessary. Good answer."
] | [
"Something being a protein and hormon is not mutually exclusive, since hormones can be proteins (eg. insulin, prolactin, growth hormone). ",
"Other hormone classes include lipid/phospholipid-derived hormones and monoamines (derived from amino acids). "
] |
[
"In modern steam power plants, can the amount of power output be managed?"
] | [
false
] | In modern power plants that heat water, make steam, and turn turbines through steam power, is the output set, or can the operators feed it less fuel, produce less heat, create less steam, and output less power? I'm curious due to the nature of the power grid, where excess power just goes to ground. It is such a big wa... | [
"Different power plants have different responses, and different time scales. A combined gas cycle plant, running off Natural gas can respond to the grid very quickly increasing its power output. They are often used as load balancers as they are rather expensive to use all the time. ",
"Other plants such as a n... | [
"Additional info on the nuclear power plants... ",
"Civilian nuclear power plants are designed in such a way (fuel and neutron poison loading) that they do not change power rapidly, because it is most cost effective to run the reactor at 100% power 24/7 once you've spent the money on the fuel. Nuclear reactors on... | [
"As a former submarine nuclear reactor operator, I can vouch for this. Big transients were what kept life interesting.",
"Edit: Didn't know that regarding fuel/poison loading in civvy plants, as I do I&C at a specialty chemical refining plant now. Interesting, thanks."
] |
[
"If the sun's core only generates 276.5 watts per cubic meter, how does it turn itself into plasma?"
] | [
false
] | is not enough energy to do that, is it? | [
"It is all a matter of volume versus surface area.",
"Consider a ",
"spherical cow",
" with a radius of one meter, that produces 276.5 watts per cubic meter in body heat. The cow has a volume of 4.2 cubic meters, and a total power output of 1158 watts.",
"This means that the cow is producing 1158 Joules of ... | [
"The sun was heating before fusion occurred, as the gasses that would eventually comprise the star collapse gravitationally, the gas molecules move randomly with higher velocity - which means more heat energy. The protostar has to radiate off energy in order to continue collapsing. By the time proton-proton fusion ... | [
"Sorry, I should have elaborated. Even though the sun is producing a relatively small amount of energy per unit volume, it has enough volume compared to its surface area that it accumulates an enormous amount of energy in the core before it reaches equilibrium. It's like saying \"how did you move that far when yo... |
[
"Why do we feel most comfortable sleeping laying down?"
] | [
false
] | More specifically, why did we evolve to sleep in a prone position? And why is 8 hours the ideal amount of sleep? How did that come about? | [
"Sleep functions essentially as a \"recharging\" state for the body. Your muscles and body systems are repairing damage and preparing for the next day. ",
"Sleeping laying down allows the least use of skeletal muscles, which comprise a large portion of the muscle in your body (most muscle which you have active co... | [
"This is a really interesting answer. But then why are some other animals able to sleep standing up?"
] | [
"Some animals are capable of unihemispheric slow-wave sleep. Essentially they keep half of themselves awake while the other half sleeps. Birds are capable of this, as well as a few marine species, including dolphins. ",
"Animals like horses who can \"sleep\" standing up are unique in having what is called a \"sta... |
[
"Antimatter Black Hole Collision"
] | [
false
] | If an antimatter supermassive black hole were to collide with an similar sized matter black hole, what would happen? The aspect I am most concerned with is the intense gravity versus energy release aspect... Would the energy of such a astronomical collision overcome the gravity and cause an explosion? Or would the equi... | [
"There's no such thing as an \"antimatter black hole.\" Black holes aren't matter or antimatter. They're black holes. ",
"Nothing overcomes the gravity of a black hole once inside the event horizon. Even in principle, there is no way to make a black hole explode. Throwing energy into a black hole in an effort to ... | [
"Particles in Hawking radiation do not come from within the event horizon."
] | [
"As far as we can tell, there's no difference between a matter and anti-matter black hole for someone outside the black hole event horizon. This is known as the ",
"no hair theorem",
". They will just merge like regular black holes."
] |
[
"Why can the Golden Ratio be found all over nature?"
] | [
false
] | I've been looking into the golden ratio( fibonacci sequence) and I'm curious why it shows up in nature in many different places. Why does a geometric ratio play such importance that it withstood evolution? Edit: Thanks reddit for collectively taking my Front Page V-card. What are some applications of the golden ratio n... | [
"It cannot, most of the supposed appearances in natural phenomena are fabrications. ",
"https://www.lhup.edu/~dsimanek/pseudo/fibonacc.htm"
] | [
"As other commenters have mentioned, the exact golden ratio might not be as common but the pattern of something growing in a fractal (or more simplistically self-repeating/self-affine) pattern is very common in biology since it's the simplest way to encode a full structure using the lowest amount of information (se... | [
"Vi Hart did a 3-part series on why the appearance of phi in plants is unsurprising. ",
"https://youtu.be/ahXIMUkSXX0",
"Basically, in order to not have any leaf shade the one below it, it makes sense to use an irrational ratio. Phi works out so that the next leaf always ends up in the biggest gap. It's obvious... |
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