title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"How we know that how kreb cycle actually happens in the cell?"
] | [
false
] | How do scientists study microscopic biochemical mechanism at cellular level like Na/K Pump, glycolysis, kreb cycle etc. In cycles products keep changing/converting so how do they keep a track of all of them? Considering they are so so minute and so so less in amount in comparison to average lab samples and experimentation. | [
"One powerful technique is isotopic labeling - a compound that is known to be part of a process is labeled with either a stable isotope or a radioactive one, then the label is tracked through the various transformations. For instance 13C or 14C labeled pyruvate could be fed into the citric acid cycle, producing lab... | [
"Yes, and after that we can look at genetics - if we delete a gene does respiration cease?",
"And then knowing which genes are involved in respiration we can do microarray (or other expression assays) that can show us when in time different genes begin to be expressed after, say, giving a starved cell sugar."
] | [
"To amplify the point about gene deletion, that has the added benefit of enriching the intermediate preceding that enzyme in the cycle. The system may still crank through, but everything backs up at that point, making it easier to find the compound."
] |
[
"Is there/was there a selective animal breeding program focused purely on intelligence?"
] | [
false
] | I ask because I have never heard of such a program, and the little bit of research I have done has only provided me with abstract information about the feasibility of the idea, not its implementation. | [
"We've been doing that for a while with dogs that need to be intelligent in some way to do their jobs.",
"http://en.wikipedia.org/wiki/Border_Collie",
"http://pets.webmd.com/dogs/features/how-smart-is-your-dog"
] | [
"Interesting question but what kind of intelligence exactly? "
] | [
"I was thinking in terms of problem solving ability."
] |
[
"Do insects experience pain in the same way we do?"
] | [
false
] | For instance, would a bee have a similar experience to a human if their leg was torn off? | [
"One problem with the question is that pain research often tosses \"perception of potentially harmful stimuli\" in the same pot as \"suffering\". ",
"Many very simple organisms have ways to perceive and react to things that might hurt them. A bee doesn't like to be squeezed and will sting in defense if it gets to... | [
"Those animals seem to not fall under the category of \"simple animals\" and definitely ",
" perceive both pain and suffering, because we can clearly observe suffering in those more complex animals. Dogs, cats, etc. can learn to wince away from a human's hand if they've been hit before. They yelp and cry if they ... | [
"Interesting topic. ",
"The current theory is that there is a correlation between complex and non complex organisms and the interpretations of pain. More complex organisms feel pain similar to humans. ",
"For example vertebrates, like a dog or human, are more complex then a spider or bumble bee. ",
"An experi... |
[
"Is it possible to diffract bacterium?"
] | [
false
] | In a similar fashion to electron diffraction, is it possible to diffract bacterium? | [
"Actually, yes. I'm not sure about bacteria specifically yet, but a couple of techniques let us get that kind of data from other small things. ",
"Some of the earliest work done at the Stanford Free-electron laser was ",
"obtaining the diffraction pattern from a single virus.",
"This is an image of diffractio... | [
"Very informative, loving those diffraction patterns. Just out of curiosity, is diffraction a useful tool for studying cells or microscopic processes?"
] | [
"Depends on how you frame it. If you're looking at entire cells, that's brand new science and we haven't got far with it yet. It could be very promising, but there are huge technical challenges to get by before it becomes easily applicable. ",
"However, the field of ",
"x-ray crystallography",
" (that I happe... |
[
"Why are there so few species of mammals?"
] | [
false
] | It seems like mammals can have a lot of variance before we call them seperate species. There are more species of frogs and toads than all species of mammals. Is Mammelia just a younger Class? Are they better at breeding with more distant relatives? (And why are there so many species of bats? They take up like 20% of mammalian species) | [
"So species arise through divergent evolution. Evolution essentially occurs as genetics are altered from parent to offspring whether by genetic \"mistakes\" or by more purposeful routes such as combining DNA from multiple parents as with sexual reproduction.",
"More species would arise from a single progenitor sp... | [
"The bats thing isn't surprising to me. There are like 9-10k species of birds. There's a lot of niche space for \"flying things\". I wouldn't be surprised if a similar fraction of dinosaur species were birds 70 million years ago. Bats are also pretty small. You can pack more small species into a given area t... | [
"The physical size of mammals is larger, on average, than anurans. That might have something to do with it. On the flip side, mammals occupy a much wider range of ecological niches. I bet you are correct about geographical isolation as well. Freshwater fish are incredibly diverse for just that reason."
] |
[
"Which agency has more accurate typhoon wind estimates: JMA or JTWC?"
] | [
false
] | [deleted] | [
"Converting the JMA's estimate from 10- to 1-minute winds gives an intensity of about 165mph, which closes less than half of the gap. ",
"Can you explain what you mean by \"converting\" a 10-minute wind estimate to a 1-minute wind estimate? How are you doing this conversion?"
] | [
"I don't think that conversion is a useful estimate. 1-minute average wind-speeds, especially when searching for the maximum winds in a hurricane, are wildly chaotic. The ",
" departure of the 1 min wind from the 10 min wind may be a 1.14 multiplier, but I don't know how useful that is case-by-case. What's the... | [
"I don't think that conversion is a useful estimate. 1-minute average wind-speeds, especially when searching for the maximum winds in a hurricane, are wildly chaotic. The ",
" departure of the 1 min wind from the 10 min wind may be a 1.14 multiplier, but I don't know how useful that is case-by-case. What's the... |
[
"How would I give myself the best chance at becoming a fossil once I die?"
] | [
false
] | What sort of preparation, if any, would increase the chances of fossilization? Would calcium or other mineral supplements help? Where should I have my bodied buried? Near a river? In the arctic? Would a casket hinder this goal? To be clear, I am not talking about mummification. I want my bones preserved in stone to be dug up millions of years from now. | [
"What you're interested in looking at is ",
"taphonomy",
", which is the study of what happens from the time an organism dies until it is discovered as a fossil. ",
"Here",
" is a journal article about it. You'll find this stuff if you go through some taphonomy papers or sites like the ones I linked to abo... | [
"Someone over at ",
"/r/geology",
" might be able to help you more with this. A paleontologist would know more details on the matter.",
"From my understanding, the best naturally occurring conditions for fossilization is deep underwater in mud or silt where there is little oxygen. ",
"The best example of th... | [
"Have your body tossed into a peat bog. Or be buried in the desert. No casket. To last the longest you'd probably wanna go with peat bog "
] |
[
"How high would the lunar return module of the Apollo lander be able to go if it left from the surface of the earth?"
] | [
false
] | null | [
"The ascent engine could only lift the ascent stage in lunar gravity, where is had 1/6 of it's earth weight. On earth, the stage and fuel weighed around 10,000 pounds. The engine had a thrust of 3,500 pounds. So, the answer to your question is it would not even lift off."
] | [
"0 m. With only a ",
"2.1 thrust-to-weight ratio",
" on the moon, and lunar gravity being only 1/6 of the earth's, it would not be able to overcome earth's gravity.",
"If we ignore TWR, the ascent stage has a delta-V (kinda like a measure of how 'far' it could go) of 2.2 km/s. Space Ship One's sub-orbital fli... | [
"Do you mean the ",
"Lunar module",
" or the ",
"Command Module",
"?",
"The LM would get nowhere. It has a TWR (from Earth) of about 0.2 initially, and 0.5 when empty. It wouldn't be able to lift off the surface. The Ascent stage of the LM would get up as high as 0.3. Remember that the moon's gravity is a... |
[
"If used often, could a cup go without needing to be washed?"
] | [
false
] | [deleted] | [
"From",
" the Department of Physics - University of Illinois at Urbana-Champaign:",
"Here's a short and probably incomplete listing of ways to kill germs: ",
"1) Heat them up. Many germs fall apart when they are too hot, and perhaps more so when they are too hot and wet. Boiling water kills most germs in it a... | [
"I suspected as much. Thank you kindly, nobleman of the askscience page!"
] | [
"I suspected as much. Thank you kindly, nobleman of the askscience page!"
] |
[
"What causes water rings on cups?"
] | [
false
] | When you leave a glass, why do your contents, end up in a ring around the glass, when there was no liquid outside the cup? | [
"Are you talking about ",
"water rings on the surface the glass was resting",
"? That's due to condensation, most prominent when you pour a cool drink onto the glass. Water vapour from the air condenses onto the surface of your glass because it is cooler, and when enough water has condensed it rolls down the si... | [
"Thats odd. My almond milk was all over the table. But what really confused me, was how there was water under the main spot, like you know how there is ridge all around the rim, on the underside of the cup, and then it hollows out a little bit? Anyways, thanks for the answer"
] | [
"If you're convinced it's your almond milk, you're either spilling it when drinking (some liquid is left on the outside after you take a sip, and rolls down), or it is leaking."
] |
[
"Can a stray balloon make it to space?"
] | [
false
] | null | [
"No, for most definitions of space. ",
"Balloons don't really push themselves up, it's more that the air around them is pushing down harder than they do, and the air pushes them out of the way, thus up. As you get higher, there's less air to push the balloon higher. Eventually one of two things happen:",
"/u/mo... | [
"Months ago this same questions was asked and I was bored that day so I ran some numbers and I think I found that, under some extremely unrealistic expectations for material strength and weight, it is technically possible. I'll see if I can find the post but it was a while ago.",
"If I don't, basically what peop... | [
"Not to mention the balloon would pop once it reached a point in the atmosphere where the pressure in the balloon was so much greater than on the inside that it would explode."
] |
[
"Why does my microwave mess up the (wi-fi) internet when it's on and is there any way to stop this?"
] | [
false
] | other than buying a new microwave | [
"Some quick googling landed me with the following information:",
"Approximate frequency of Microwave Oven: 2450 MHz (2.4 GHz)",
"Frequency of type b,g,ad protocol for Wifi: 2.4 GHz with channels taking the range from 2.4 to 2.5 GHz.",
"So you have either a b,g or ad type router (probably g) and your microwav... | [
"The fact that his microwave causes WiFi disruption doesn't mean his oven is defective. Virtually all electronic devices emit radio waves. It should not emit so much as to violate the FCC class C power requirements, which are designed to avoid interference that disrupts radio communications. But the FCC isn't th... | [
"Thanks for that. I was unsure of the power of the emitted radio waves from a microwave oven, I just assumed that it wouldn't violate FCC requirements. "
] |
[
"Why do we base attractiveness on such seemingly trivial factors? Why do fetishes exist?"
] | [
false
] | Couldn't a fat woman birth a child as efficiently as a skinny woman? Do the size of breasts serve any evolutionarily beneficial purpose? In short, WHY does the factor of attraction vary so much on seemingly trivial factors, ones that seem to serve minimal survival purposes? | [
"I'm going to be contrary to what other people in this thread are saying, and point out that things like attractiveness and beauty vary hugely over time and space. That is to say, different cultures have different concepts of beauty, whether its different because its somewhere else in the world, or different becaus... | [
"For one thing, a narrow waist indicates the woman is not already with child, which is clearly desirable since a pregnant woman is not available for procreation. Also wide hips indicate an easier and more successful birthing. I've seen it suggested that large breasts imply more milk for the child although I've neve... | [
"What easily visible factors would you consider to be non-trivial?"
] |
[
"How is having such dependent offspring selectively advantageous for humans?"
] | [
false
] | null | [
"Well, first of all, humans are extremely K-selected in comparison to most mammals. We put a lot of effort and care into each individual which is born. You can have a supremely dependent offspring when you put a lot of care into it. Additionally, our babies are born in what we call a secondarily altricial state. ... | [
"It's a tradeoff. We can walk in two legs and have big heads at the cost of having needful childrens who take a lot of time and effort to raise.",
"The start is more difficult, but the potential to develop is higher. That's why it works."
] | [
"Thanks a lot. This is really helpful."
] |
[
"What's happening when you break in an engine, and how do different break in methods effect the engine's performance and longevity?"
] | [
false
] | Also, what effect do cylinder coatings such as nikasil or SCEM have on break in? | [
"Breaking in an engine is about making sure that all of the bearings and moving parts settle in together and wear evenly. If you don't do it, the engine will fail sooner, but there are so many variables you can't really say for sure how much damage you'll do. ",
"You could end up with piston rings that don't sea... | [
"Motoman needs more then entirely anecdotal evidence. ",
"Did yo notice the part where he said you could port your intake and exhaust to restrict airflow and improve power? ",
"He only talks about piston rings. There are plenty of other parts in an engine effected by the break-in period.",
"He's also trying t... | [
"Breaking in an engine effects only two major components. The camshaft and the piston rings. It polishes the camshaft against the lifters and the piston rings against the cylinder walls. ",
"There are only 3 types of break-ins, too soft, just right, and too hard. When replacing parts, the manufacturer will tell y... |
[
"If Gravity Is Not a Force, but the Curvature of 4D Spacetime, Why Do We Want to Unify It with the Other Fundamental Forces?"
] | [
false
] | Gravity always seemed to be the hardest force to tie into the bunch of the 4 fundamental ones, but gravity is also the only force for which we go out of the way to claim that it's just a result of curvature in 4D spacetime and that it isn't really a force. So, if it actually isn't a force, why are we so keen on unifying it with the three leftover forces in the pursuit of a "Theory of Everything"? | [
"Because this curvature is still describing a classical phenomenon. ",
"Think of this. Maxwell's equations describe electromagnetic interactions as interactions with fields and charges. That's the classical view. But quantum electrodynamics (QED) describes it as charged particles exchanging photons (quanta of... | [
"If we had a Saturn-sized detector in close orbit around a neutron star, we would detect a graviton per century. However, it would be drowned in a neutrino background; the required neutrino shield would be massive enough to make everything collapse into a black hole.",
"But hey, maybe you'd see a graviton."
] | [
"Physics is not in the business of determining an objective, underlying reality; it's in the business of providing models that describe observed behavior.",
" of our models, including relativity and the standard model of particle physics, are essentially just \"a nice way of looking at things\" that may be \"actu... |
[
"Why can particles such as muons pass seamlessly through matter, such as humans?"
] | [
false
] | [deleted] | [
"Wow, this is exactly the answer I was looking for! Thank you very much! :) I'm surprised I've never heard of the Bethe-Bloch formula, but I'm very glad I was introduced to it. "
] | [
"Wow, this is exactly the answer I was looking for! Thank you very much! :) I'm surprised I've never heard of the Bethe-Bloch formula, but I'm very glad I was introduced to it. "
] | [
"No, I am specifically talking about muons. Areas of research such as muon tomography lead me to this question. "
] |
[
"[Biology] Is the inside of a resting neuron negative, or just MORE negative (a.k.a. less positive, but still positive) than the extracellular fluid surrounding it?"
] | [
false
] | I've been looking at YT videos and various websites for a while now and they seem to use vague language in describing this | [
"You may find the wording vague because as with any other discussion of potential difference, it is the ",
" in electric potential that matters; the absolute value can be anything you want.",
"We know that real cells are aqueous systems, and by the law of electroneutrality we know that the system is overall neu... | [
"You're discussing membrane potentials while I think OP meant to ask something akin to \"if we count all the positive and negative ions according to their charge ",
", will it be a net positive or negative?\"."
] | [
"You're discussing membrane potentials while I think OP meant to ask something akin to \"if we count all the positive and negative ions according to their charge ",
", will it be a net positive or negative?\"."
] |
[
"so, i have some questions about solar power"
] | [
false
] | [deleted] | [
"I'm no expert on solar power, but I have done a bit of research into the matter. ",
"First, a solar panel is made up of photovoltaic cells, which simply put convert energy from the sun into useful DC voltage. (Google how they do that if you wish.)",
"The energy will then either be stored or sold back to the gr... | [
"This is a very good answer.",
"To add to this I was listening to a podcast on alternative energy with a journalist and a scientist and they were talking about how one of the main problems with the main types of renewable power sources (wind, solar tidal etc...) is that they cannot be controlled as easily.",
"P... | [
"I know that where I live, the majority of generation is not renewable, and may account for only 10% of the total generated electricity, so this would not work. Even if this number increased dramatically, it still wouldn't be feasible. Your typical coal generator doesn't simply turn on with a switch, it can require... |
[
"silly math regarding supermassive black holes and average density."
] | [
false
] | So, regarding the new largest ever black hole that's been discovered... I was doing some math. Badly, likely. Can someone proof this? This is not homework, and was done for fun on another thread. The diameter of the event horizon for the new black hole was estimated to be about the size of the orbit of Neptune, or 4 light-days, which would give us a radius of... r= 51,804,136,742,400 m (299,792,458 m/s x 60sec x 60min x 24 x 2) and pi is 3.14159265359 so the volume of the event horizon would be 26,486,747,264,016,772,492,836,761,361 cubic meters. If that's correct, we can move on. The current heavyweight comes in at 17 Billion solar masses. 1.9891 × 10 kg (suns mass) x 17,000,000,000 = 33,814,700,000,000,000,000,000,000,000,000,000,000,000 kg. So, the average density of that event horizon volume would be 1,276,664,879,342 kg/m3 if my shitty math is correct. It probably isn't. Now, this conflicts with things I've heard, that the average densities of supermassive black holes are in fact very light, some even lower than water. That doesn't jive with my ad-hoc calculations. Any input? | [
"Now, this conflicts with things I've heard, that the average densities of supermassive black holes are in fact very light, some even lower than water.",
"I thought this was totally wrong at first, but then I ",
"ran the numbers myself in wolfram alpha",
" and got a density drastically lower than water. Thing... | [
"As for your math, I think you may have made an error in calculating the volume. Since the radius is about 5 x 1013 m, and the volume V = (4 pi r3 )/ 3, the volume should be something like 6 x 1041 cubic meters, which is way higher than what you have in your post.",
"Ahhhh. I see. I used the area of a circle inst... | [
"Das_Mime already answered your question, but I wanted to direct you to my comment ",
"here",
" regarding the notion of black hole density and, in particular, my response ",
"here",
" regarding the fact that the volume of a black hole isn't particularly well defined. As such, any discussion of the density o... |
[
"Sucking hot air out or sucking cool air in - what's a more effective way to cool down a room?"
] | [
false
] | I have a fan I put on my window sill, and I have the type of windows that open horizontally (so there's a large patch of open window that the fan does not cover. I'm guessing heat pump, but all the physics I know was from my chemistry courses so I can't say for certain. My reasoning is that the air in my room is hot and the air outside is cool, so having a fan that moves air along the gradient in a thermodynamically-favorable direction would take less work (from the fan) then the reverse. I don't know if there is a significant difference in air pressure between my room and the outside environment when a window is opened. I think that in the overall system, the total air pressure of the room VS the outside world moves to equilibrium quicker then the temperatures, possibly mitigating the effect of pressure (if my assumptions aren't too flawed). Also, the fact that the opening to the outside is not completely sealed by the fan may have an effect that I'm unaware of. Just something I've wondered about. Curious to know if someone has a more conclusive answer. | [
"Time to do some science!",
"Given what I can tell about your current setup, I'd recommend putting the fan at the bottom of the window, and move your bed/desk so it's pointing at you. Sure, it may seem obvious, but here's why:",
"If you want to get really fancy, go get a smoke machine, smoke bomb, or something... | [
"anytime you can justify lighting off a smoke bomb indoors gets my upvote"
] | [
"I think it's less about thermodynamics than about the circulation of the air within the room. ",
"When you point the fan outward in a window that's only half covered by the fan, you create a low pressure area behind the fan. Assuming that the room is pretty well sealed, there will be an equal volume of air comi... |
[
"Why must the electrode of a pH meter never be removed from a solution while the device is on?"
] | [
false
] | Hello scientists! Every lab manual I've ever run across insists quite vigorously, often in italics, that one must remove the pH meter's electrode from solution while still on. I've dutifully followed these instructions, but answers as to why this an imperative aren't easily available online. I'm sure there is a simple explanation, and the strong warning language makes me curious as to what it is. Presumably it ruins the device and/or data, but as a man of the world, I simply need more answers (which you lot are overqualified to provide.) What's the deal? | [
"I'm not too sure about this, but i think it might have something to do with drying out the electrode's glass coating which would results in unreliable results being detected. So it should always remain in the solution or in a specific container with electrolytes which keeps it moist and prevents drying out.",
"I... | [
"I would say that the electrode can be taken out of solution while the instrument is on. I do all the time. I do not however encourage leaving the electrode out in open air for more than about 30 seconds. This is where you start running into the problems that Tanukki has described."
] | [
"If you let it dry, salt crystals or contaminants could accrue inside the instrument and cause blockage or errors later on. Well, it's probably only a concern if you measure more viscous things, but the maintenance routine exists as a preventative measure.",
"Fischer Scientific also says this: ",
"Allowing the ... |
[
"Why do larger elements (e.g Moscovium) have such short lifespans - Can they not remain stable? Why do they last incredibly short periods of time?"
] | [
false
] | Most of my question is explained in the title, but why do superheavy elements last for so short - do they not have a stable form in which we can observe them? Edit: Thanks to everyone who comments; your input is much appreciated! | [
"A contributing factor is that we probably haven't synthesised the most stable isotopes of many superheavy elements. The higher the atomic number, the greater the neutron/proton ratio required for stability, and since superheavy elements are synthesised by fusing two lighter ones together it's hard to get enough ne... | [
"Interesting.",
"I am wondering if we'll ever see a stable isotope of Roentgenium, the fourth precious metal. And I wonder what color it would be."
] | [
"Just because it is in the same group/column as copper, silver, and gold on the periodic table."
] |
[
"longest eartly shadow possible?"
] | [
false
] | the empire state building blocked the sun from me from 20 miles away where I grew up...whats the longest possible shadow that you could possibly observe (and distinguish) | [
"Strictly speaking, I think an object can cast an infinite shadow, albeit not for very long.",
"Consider a single ray, moving from the sun to the earth, and assume that this ray misses the earth by a tiny margin, say 3 feet or so. If we ignore the effects of gravity, then this ray will move past the earth and out... | [
"Well, if we imagine a structure built to cover the whole earth, it would be casting a shadow from the sun on 50% of the earth at any given time. ",
"A single vertical structure? Depends how thick? Still. Imagine a pole extending out to the sun. Move it a few degrees either way, it will cast a shadow on almost 45... | [
"But that shadow would be caused by an earthly object. I think the OP wants to know how long could a shadow be on earth. So, what is the longest shadow that could be cast by a vertical object on a sphere?"
] |
[
"At what point if at all, do an exotic species become a native species?"
] | [
false
] | Can an exotic species become so well intregrated into the local ecosystem that it can be consider a native to that system? | [
"Once a non native species establishes a sustainable population it’s pretty much a part of the ecosystem. This happens a with a lot of organisms. If it’s overtaking ecological established niches it’s an invasive."
] | [
"There is no strict and universal definition of what counts as native vs exotic (or invasive), it is controversial and debated in science. ",
"Here",
" is a paper discussing the lack of consensus in science and government and possible solutions."
] | [
"Native is less a biological definition and more of a human one. Terms like \"predator\" refer to how species relate to other species in their environment. On the other hand, terms like \"weed\" refer to how species relate to humanity (or how humanity relates to the species). Native is more like the second type ... |
[
"If an electron has a non-zero chance to be a very long distance from the atom, then doesn't the amount of atoms in the universe makes a certainity that there is at least one electron out there orbiting meters away from it's atoms?"
] | [
false
] | Also, does this even matter, or the whole concept of the electron as a point particle that "is" somewhere is stupid? | [
"the whole concept of the electron as a point particle that \"is\" somewhere is stupid?",
"I think that a better way of imagining the electron is as a localized wave. It does, after all, behave according to a modification of the wave equation.",
"Although people tend to talk in terms of the probability of findi... | [
"Your question is a good one but not stated well. It doesn't make sense to say that an electron \"is orbiting meters away from its atoms,\" because an electron can't be considered to be following a definite path. Ever. This is Heisenberg at it's finest. (If you want more details, go ahead and ask, I don't think it'... | [
"he's right. I'm not a english born speaker but this is no excuse – I wasn;t paying attention to the title."
] |
[
"Is there a common explanation why people who took LSD describe similar visual experiences e.g. colorful, fractal, vibrating strings/stripes ?"
] | [
false
] | null | [
"LSD affects a specific neurotransmitter receptor in the brain called ",
"5HT2a",
". Activation of this receptor leads to many changes in activity across the brain. A recent ",
"study",
" looked at how taking LSD affects the part of the brain that processes ",
"visual information",
" using a technique c... | [
"Well, what other stimuli? Presumably the answer is because the two groups they are comparing are people on LSD looking straight ahead at a blank screen in an MRI scanner, and people in the same condition except not on LSD. We have overwhelming evidence for the specific role of neural activity in early visual areas... | [
"Those fractals are actually called Form Constants! They're a result of (often) psychedelic stimulation to your visual cortex. They've also been heard of in patients with severe migraines.",
"Wikipedia's explanation is a follows: It is believed that the reason why these form constants appear has to do with the wa... |
[
"How do you invent a programming language?"
] | [
false
] | I'm just curious how someone is able to write a programming language like, say, Java. How does the language know what any of your code actually means? | [
"Designing a computer language is a pretty tricky business, really. There are a lot of tradeoffs to be made, which explains why there are ",
"so dang many",
" of them. When starting a new one from scratch, you ask yourself a lot of questions. Ultimately, the question that matters most is, \"What do I want to be... | [
"At the bottom, as ",
"/u/somethingpretentious",
" said, it all has to be translated to 1s and 0s, or machine code, as that's the only thing the computer can understand.",
"So to see how a programming language tells the computer what to do, we should first look at how machine code tells the computer what to d... | [
"This is one of the greatest posts on reddit! A beautiful summation of programming languages and compilers (I studied comp sci)"
] |
[
"If i put a candle in a box, then put a candle and a mirror in another box, will the one with the mirror be brighter inside?"
] | [
false
] | thought about this as i put a mirror up in my room. i flicked on a flashlight in the dark and it shone through the mirror to reflect back into the room. then i wondered if the room was actually any brighter now than it was without the mirror. | [
"Yeah, as JushiBlue pointed out, it depends where you're looking. Some of the first \"flashlights\" (or torches you crazy Brits you) were basically this principle. Stick a candle in some type of enclosure and a bunch of reflective mirrors to focus the light outward very brightly. That outward light is much brighter... | [
"It depends on where you measure the intensity of the light. Assuming you have a setup like Mirror----Candle-----Wall, then the wall will be brighter than just a candle----wall setup. This is because the wall will receive the intensity of the candle as well as the intensity of the reflected light. It will be approx... | [
"I'll further add that if the box had no lid and you looked into the box, it would definitely look brighter. This is because more light is being reflected from the mirror surface out of the top of the box and into your eye. Presumably the box has a fairly matte surface which scatters and absorbs light more than a... |
[
"How exactly do geologists know the number of supercontinents that have formed in the past?"
] | [
false
] | [deleted] | [
"To understand the reconstruction of paleocontinents (and supercontinents), one must delve into the basics of paleogeography. There are 2 main Toolsets in this discipline:",
"1 - ",
" When continents break up, they carry with them rocks with similar géologies, sedimentary environments and fossil faunas. These ... | [
"I would like to add to ",
"u/Gargatua13013",
"'s excellent answer, and also add that the closing of oceanic basins creates what are called paired metamorphic belts.",
"Paired metamorphic belts are parallel stripes of what are called greenstones (high temperature, low pressure facies) and bluestones (low temp... | [
"Some proof of this. I'm an engineer/machinist. A company I do work for makes kettles (furnaces for extracting precious metals). These things normally go to Siberia, Africa and North America. We was doing one for Ireland which was unusual. The reason he told me was, whilst mining a very rich seam in Canada a very c... |
[
"Is there a drug that induces sorrow as its primary effect?"
] | [
false
] | null | [
"Alcohol often induces this effect in people, it is a depressant of the central nervous system."
] | [
"There is a class of hallucinogens called deliriants that, in contrast to more popularly used recreational drugs, most often cause feelings of dread, anxiety, and dysphoria.",
"Anti-psychotic drugs very frequently induce dysphoria as well. You could maybe say it is one of their 'primary' effects even though it's ... | [
"yes, source - ",
"http://en.wikipedia.org/wiki/Depressogenic"
] |
[
"Why are American aircraft carriers flat, while British aircraft carriers sloped upward?"
] | [
false
] | Surely there must be an internationally agreed upon method for launching an aircraft into the air from a very short distance, especially with the aircraft being so similar? What explains the disparity? | [
"British carriers are designed for Harrier jets which can take off under their own power off a sloped deck. Their engines can be turned downward to assist takeoff.",
"US aircraft are launched off the carrier with a catapult that accelerates the plane from zero to flying in 2 seconds. US carriers can fly a range o... | [
"These guys are obviously having fun, but for the rest of us:",
"LHA = ",
"Landing Helicopter Assault",
", \" general purpose helicopter-carrying amphibious assault ships\"",
"LHD = ",
"Landing Helicopter Deck",
", \"multipurpose amphibious assault ships which are capable of operating helicopters and ha... | [
"That's just one portion of the carrier design to consider. The larger size, angled deck, catapults, and arresting gear of the US carriers allow them to accommodate a variety of aircraft and allow for simultaneous launching and recovery operations. Ski-jump carriers have been smaller, and do not support simultane... |
[
"Is Delta T (Temperature) subject to momentum?"
] | [
false
] | [deleted] | [
"The greater the difference in temperature between two things, the faster heat will conduct between them. So hot water in cold air will initially lose heat faster than lukewarm water ... but by the time it cools down to lukewarm temperature, all other things being equal, it will cool at the same rate as the lukewar... | [
"Hot water freezes faster than cold water given equal size droplets and temperature of air; this is quirky but 100% true fact."
] | [
"That sounds bizarre but interesting! What's the reason behind it? What mechanism is going on?"
] |
[
"Is the latent heat of fusion of water altered with different crystalline structures of ice? (Ice formed under very high pressure vs STP) If so, is there a formula?"
] | [
false
] | The thought is, because ice formed under high pressure cannot optimize for hydrogen bonds (why it normally expands when frozen), that it would require less energy to undergo the phase transition | [
"Yes. Latent heat is the difference between states A & B at the conditions of phase transition, in terms of energy stored in the configuration of molecules (internal energy including sum of all intermolecular interactions).",
"There are 18 known phases of crystalline solid water, so I don't think there's a simpl... | [
"The other answers have done a good job here but I wanted to mention that you can harness the latent heats associated with different crystallization states to make self-thermoregulating materials (much like ",
"coffee joulies",
" use a phase-change material to achieve the same style of thermoregulation). If thi... | [
"This is all correct, I would only add that it's not necessary that states A and B be directly adjacent on a phase diagram to speak about a heat of fusion. To modify your statement the heat of fusion is defined where A & B have the same free energy, if you get rid of all the other phases of ice other than the one y... |
[
"Why is there mist that covers the skyscrapers in Dubai, when it is a desert city?"
] | [
false
] | I was watching The Arrivals and they mentioned that since the building of the Burj Dubai Tower, there has been a mist that surrounds it and other skyscapers. EDIT: I understand it's on a sea-shore, but the mist never used to be there, it showed up after the Burj Dubai became the tallest in the city. Why did the mist suddenly show up? | [
"It's on a sea-shore. "
] | [
"Well... that didn't take much science to solve."
] | [
"That's where she sells sea shells"
] |
[
"Do stars have lagrange points?"
] | [
false
] | Since our star is orbiting the centre of our galaxy, does it have it's set of L-points? is there some far off L4/L5 position of just some colossal clump of debris never to have a star of it's own to orbit? If so, could a sufficiently large enough star hold entire other star systems in it's L4/L5? and should you be some astronomer to evolve in such a star system, would you be able to tell that you were in the L4/L5 of a larger body and not infact independently orbiting the central mass of the galaxy? would that have any implications? Thanks! | [
"For most of the galaxy the gravity of the center is very small relative to the gravity of all the other stars in the galaxy. So any stellar Lagrange point would be swamped by the effect of gravity from other stars."
] | [
"Just a note, our star isn't really orbiting the center of the galaxy, at least not in the same way the earth orbits the sun. Our star's path around the center of the galaxy is determined by gravitational pull of all the mass that has a smaller galactic radius than us.",
"Basically, galaxies are not point masses... | [
"I've never seen Lagrange points used in the literature to discuss anything other than ",
". Basically, to have Lagrange points you need a massive object and a satellite- so the Sun-Jupiter points are good for asteroids, the Sun-Earth points are good space telescopes, etc. ",
"For extended distributions of mass... |
[
"Are there any materials in this world that are impenetrable by gamma rays?"
] | [
false
] | [deleted] | [
"It all depends on thickness of the material. Air can effectively stop gamma rays from outer space. The 100 km of atmosphere make a very good shield. The Earth itself stops them. But if you are looking for a thin material, I would have to say no. Gamma rays are just high energy light and subject to the same Beer'... | [
"Like he said, it depends on the thickness. ",
"But 'dimming' the intensity doesn't make the individual photons less energetic, it just means less photons are getting through. So the radiation getting through the shielding is still dangerous to anybody there."
] | [
"It depends on the gamma ray energy. In general gamma rays don't get deterministically stopped, some of them always pass. There's an exponential law describing the percentage of photons stopped depending on the thickness of material traveled. \nWith low energy photons (10 keV or less) some half of the photons get a... |
[
"Why do green house gases not stop as much light from entering the atmosphere as they keep from exiting the atmosphere?"
] | [
false
] | I understand how greenhouse gases prevent light from exiting our atmosphere, but why do they not prevent an equal amount of light from entering? | [
"The big greenhouse gases on the Earth (water, carbon dioxide, methane, oxygen, etc) work because those molecules have specific bands of wavelengths where they absorb light. These are greenhouse gases because those bands are most effective at absorbing infrared light.",
"The light coming into the Earth from the s... | [
"The big greenhouse gases on the Earth (water, carbon dioxide, methane, ",
", etc)",
"Just to be clear, the oxygen we breathe (O2) is not a greenhouse gas, although ozone (O3) does have a slight greenhouse effect."
] | [
"The energy coming in and the energy going out are not in the same form. The energy coming in is mostly around the Sun's peak blackbody emission frequency, which is to say, the visible light range. The blackbody radiation coming back off the Earth's surface is mostly at much lower frequencies, the deep infrared ran... |
[
"The Mars Perseverance Rover's Parachute has an asymmetrical pattern to it. Why is that? Why was this pattern chosen?"
] | [
false
] | Image of Parachute: | [
"The asymmetry in the coloring makes it easier to study the video and assess the parachute's performance. In multi-chute systems, you'll see that each parachute has a different pattern so they can tell them apart.",
"Edit: more explanation: the parachute is able to twist with respect to the vehicle (and therefore... | [
"Any patch of about 10% of the parachute is enough to identity the orientation.",
"This would be especially useful in a failure situation where there might be a just a few frames of vision to work with. If it all works, it's just a pattern."
] | [
"High contrast color patterns are far easier to see from a far distance at low resolution than some shapes.",
"Here, I drew A B C on it, then shrunk it down to 50x50.",
"https://imgur.com/a/uFe0qNH",
"You can still clearly see the red/white pattern, but the letters are basically invisible. Good luck trying to... |
[
"Now that a piece of wreckage from flight MH370 has been confirmed on Réunion Island, is it possible to use our understanding of direction and speed of currents in the Indian Ocean to narrow down where it likely crashed?"
] | [
false
] | Confirmation the wreckage is from MH370 can be found here: The crash occurred 515 days ago. If this points an area out, where would it be? Is the area outlined by this method an improvement of the previous search perimeter on the one where search parties were operating? Are they even close? | [
"There's a pretty good summary ",
"here",
". What I took away from that was that it'd be insanely hard to pinpoint an exact starting location since planes aren't really Lagrangian drifters and ocean flow is more turbulent than it is laminar. What say you, ",
"/u/sverdrupian",
"?"
] | [
"I agree. The ocean is full of eddies. Over the course of a year those eddies stir and mix the ocean so much that back-tracing the path of any single piece of flotsam is impossible. We know for sure now that the plane crashed in the southern Indian Ocean but this finding isn't going to narrow the search area any ... | [
"There are likely several oceanography modeling groups gearing up to do this right now. Some probablistic information may be better than no information. My gut (based on years of working with ocean data) is that the resulting estimate is unlikely to eliminate any of the areas where they have been searching: ",
"m... |
[
"What ever happened to the hole in the ozone layer?"
] | [
false
] | Are my poor little phytoplankton going to be okay? | [
"Since 1981 the United Nations Environment Programme has sponsored a series of reports on scientific assessment of ozone depletion, based on satellite measurements. The 2007 report showed that the hole in the ozone layer was recovering and the smallest it had been for about a decade.[62] The 2010 report found that ... | [
"The problem was actually handled. Much like the acid rain problem.",
"This is what regulation solving problems looks like."
] | [
"The fact that we got our shit together on this gives me hope for the future."
] |
[
"If energy cant be created or destroyed. How can it be here?"
] | [
false
] | Existence and creation are different things but how it can be here if in coudnt be created? | [
"There are basically two options:",
"The total energy is constant, has always",
" existed and will continue to exist forever",
"Energy is created in some process that we aren't sure about yet. One candidate for such a process that may violate energy conservation is cosmic expansion of a space with a positive ... | [
"Yes, but be aware that this is a bit of a point-of-view matter. If space-time changes, energy of systems inside the space-time need not be conserved. The other view is to interpret the maths in such a way as saying that energy is actually conserved, it goes into (or out of) the gravitational field.",
"See this b... | [
"I think it answers it pretty well. The question was asking how energy exists if it can't be created. The answer given was \"Nobody knows, but it must have either always been here, or it can be created through some process we haven't figured out yet.\"",
"Remember, scientific discovery is an ongoing process, so... |
[
"I thought electrons didn't actually orbit the nucleus, but this SciAm article talks about possible relativistic effects in large atoms from their \"orbits\". Please help me understand."
] | [
false
] | My previous impression was that electrons sat in a "probability cloud" around the nucleus of the atom, and they didn't actually orbit the atom a la planets, as the old simplified models talked about. In the latest Scientific American article titled "Cracks in the Period Table" (Edit: the article is about the properties of synthesized super-heavy atoms), there is a paragraph in the intro that says, "But as the atomic numbers -- the number of protons in a nucleus -- reached higher, some of the added elements no longer behaved the way the period law requires; that is, their chemical interactions, such as the types of bonds they form with other atoms, did not resemble those of other elements in the same column of the table. The reason is that some of the electrons orbiting the heaviest nuclei reach speeds that are a substantial fraction of the speed of light. They become, in physics parlance, "relativistic," causing the atoms' behavior to differ from what is expected from their position in the table." So, can someone help me understand exactly what orbiting means when it comes to electrons, and why there is a speed involved if it's a probability cloud? And if there is some sort of orbit involved, what path do the electrons follow, and how does the path twist into an orbital shape? | [
"Ah yes! That's the problem with describing them as a 'probability cloud'. See, if it was ",
" a cloud of electron density, one might wonder what quantum mechanics is for, since classical EM has no problems modeling a 'charge cloud', so to speak. ",
"But that's not the whole story. The probability of where the ... | [
"Electrons might not have a classical velocity associated with their orbitals, but they do have well-understood values of momentum, which (combined with the known rest mass of the electron) gives them effective velocity values. When these are high enough, as in heavy elements, you begin to see relativistic effects ... | [
"Thinking of momentum and mass is probably more correct - in particle physics, you often describe particles by their total energy, their momentum, and their rest mass. All three are related by E",
" = m",
" c",
" + p",
" c",
" You could work back from those to get the speed of the electrons, but it probab... |
[
"What defines measurement which affects quantum outcomes? Or what is wrong with my understanding?"
] | [
false
] | It's my understanding that when one "measures" results in a quantum experiment, it will affect the results. That is, if I fire buckyballs though some slots, they will take every possible path and these paths will interfere and create an interference pattern. I may be mistaken, but I understand that measuring the buckyball impacts will affect the experiment's outcome. This must be my misunderstanding, as eyeballs and testing equipment (amplifiers) should not affect the interference pattern. But the original experiment consisting of a single buckyball resulted on a well defined path, or so I thought? My base question, besides how is my understanding flawed, mis what defines the measurement that will affect this outcome? Perception? Sensation? I'm very confused. Help! | [
"You are misunderstanding what it means to observe/measure in quantum physics. ",
"This has been addressed before",
" (",
"try this search too",
"). It's worth checking out previous threads."
] | [
"Thanks for the links. They better defined my question and I realize now that I understand the uncertainty quite well. I also realize it is quite uncomfortable for me to understand. "
] | [
"I also realize it is quite uncomfortable for me to understand.",
"It's uncomfortable to everyone. Don't fret. :)"
] |
[
"What happens to the light that strikes a solar cell but is not converted into electricity?"
] | [
false
] | null | [
"If it's absorbed it's turned into heat [just like any other light that is absorbed], if not it's sent packing back into space or wherever.",
"Ironically heating up a solar cell makes it less efficient so the ideal solar cell is highly reflective."
] | [
"When light hits the IC and it cannot be converted to free electrons it's converted to heat. That heat \"slows down\" (makes more resistive) the circuit which then drops the efficiency of the circuit.",
"The ideal ratio is to have 100% of the capture photons converted to electrons and the rest reflected but that... | [
"That is the most simple way to explain it, that our primary losses are due to heat losses and reflections. ",
"Absorption is what happens when an electron absorbs the photon and is liberated from the atom to which it is bonded. As we have a bandgap in the semiconductor, the absorbed energy must be enough to prom... |
[
"What causes a random long white strand of hair to grow?"
] | [
false
] | [deleted] | [
"This question was asked recently (not complaining, but the search function might give you some additional responses to your query). "
] | [
"Please reserve top level comments for answers to the OP's question, or futher, related questions"
] | [
"Please reserve top level comments for answers to the OP's question, or futher, related questions"
] |
[
"What exactly are the new states of matter?"
] | [
false
] | We all know the big three but now there's bose-einstein condensates and dropletons? I have read a few articles on them and their discovery but I still don't quite get what they are. | [
"Since this is a physics question, I have to say first: no one REAALLY knows what they are. But in terms of my knowledge I believe I might be able to help on the BEC side. Bose certain materials when cooled to extremely low temperatures the energy in their atoms/molecules and it is no longer made up of fermionic ma... | [
"So BEC are what is present in superconductors during quantum locking?",
"EDIT: What differentiates BEC's and Dropletons from the other states of matter?"
] | [
"I think the big difference is mostly that liquids, solids, and gases exist in everyday life. You breathe air, drink water, and eat food. Additionally many of the lesser known states of matter are either hard to create in a lab, or hard to observe even when they're there. Plasma is not as rare as some states of mat... |
[
"What is mild hyperexpansion of the lungs?"
] | [
false
] | I had chest X-ray done a while ago, and while flipping through my records, I noticed that the doctor had left a note "Lungs are mildly hyperexpanded..." What is it? | [
"You need to ask your doctor. We can't interpret exactly what he meant, and anyway the internet is a bad place to be looking for medical advice."
] | [
"Take all of that with a grain of salt.",
"Don't take it at all. ",
"If there was reason to suspect disease, your doctor would have informed you and pursued it clinically. If you have more questions, talk to the doctor that ordered the x-ray.",
"EDIT: OP shouldn't be asking medical advice, Fmeson shouldn't ... | [
"Take all of that with a grain of salt.",
"Don't take it at all. ",
"If there was reason to suspect disease, your doctor would have informed you and pursued it clinically. If you have more questions, talk to the doctor that ordered the x-ray.",
"EDIT: OP shouldn't be asking medical advice, Fmeson shouldn't ... |
[
"Does the heat index actually correlate to a specific dry air temperature well?"
] | [
false
] | With the heat rising in the northeast U.S., the topic of heat index keeps popping up on my radar. What I'm trying to figure out is whether a heat index of 110 deg F is actually comparable to a dry air temperature of 110 deg F. I'm basing this off of experiencing I've personally had while living in NJ where the heat index is 105 deg F vs. an air temperature I've experienced of 110 deg in Las Vegas. To me, I felt significantly warmer in NJ than I did in Vegas, despite the heat index being lower in NJ. From what I've read, the correlation is based off of relative humidity and the body's ability to reject heat to the atmosphere. Obviously perspiration is the primary method of heat removal, which is inhibited when the ambient humidity is increased. The amount of heat removal is apparently directly related to how hot we personally feel. I still don't understand how this determination is made, since I feel much warmer in a humid environment than in a warmer, dryer one. OR, am I confusing discomfort of sweat with heat, making this question useless? | [
"The calculation is a curve-fit to a specific set of data from the 1970s but each individual experiences heat differently. The data for the classic heat index assumed a 5'7\" man weighing 147 pounds, wearing long pants and short-sleeved shirt while walking 3 mph in the shade with a slight breeze. Your results ma... | [
"That is ridiculously specific.",
"Isn't science meant to be ridiculously specific?"
] | [
"That is ridiculously specific.",
"Isn't science meant to be ridiculously specific?"
] |
[
"For something as medically useful and clinically important as Lithium, how do we not yet know its mechanism of action?"
] | [
false
] | null | [
"Most drugs, especially those as old as Lithium, were discovered serendipitously. ",
"In 1849, a researcher named John Cade, wanted to see if any chemicals in urine from manic patients were toxic, so he dosed guinea pigs with urine samples from patients with mania. To solubilize uric acid crystals as control, h... | [
"To put things in perspective, deorphanizing a drug (finding the target) is one of the hardest problems in the biological sciences. The workings of a cell are like a setup of dominos, you knock one over and everything changes. How do you tell the difference between what happened directly and what happened as a cons... | [
"OP should know that the same can be said about a lot of drugs, especially those used to treat psychiatric or neurological disorders. As an earlier poster mentioned, serendipity is often how many were discovered. Amytryptiline was first tested as an antihistamine/decongestant. Viagra as a treatment for hypertensi... |
[
"Are there any animals that don't sleep?"
] | [
false
] | null | [
"Some animals with simpler brains like worms and insects don't sleep, at least not the same way we do."
] | [
"Worms",
" and ",
"insects",
" do sleep."
] | [
"I don't know if this is what you are looking for, but ",
"this",
" article talks about dolphins, and their ability to rest half of their brain at a time. So, while they are still technically sleeping, never fully unconscious. "
] |
[
"Why aren't siblings of the same gender genetic twins?"
] | [
false
] | Ignoring random mutation of gametes, why don't brothers with the same parents have the same genome? The way I understand it, each parent contributes half of the genetic code, in the form of half of the 46 chromosomes. If a specific set of chromosomes (eg the odd numbered from dad, the even numbered from mom) are in each gamete, copied from the parent's genome, the resulting offspring are identical. If each ovum had a different set of chromosomes, that's a huge number of possible combinations (2 to be exact, for humans), and the fertilizing sperm would have to match up identically, otherwise bad things would probably happen. Not saying that they don't, but those bad things would be far more common. So, obviously I'm missing something, because my brother is not my twin genetically, but he managed to be granted a relatively normal set of chromosomes, just like me. | [
"I think the main thing you are missing is the fact that humans are ",
". This means that we have two copies of our DNA that are very similar that make up our entire genome. Each of the 46 chromosomes has a twin making 23 pairs of closely matching chromosomes. When a gamete is formed one of each of these pairs is... | [
"Nope. So your mom has 2 copies of each chromosome and your dad has two copies of each, and you already seem to know you get one of each from your mom and your dad. ",
"Now lets just look at chromosome 4. You get one chromosome 4 from mom (who has two to give, A and B) and you get one chromosome 4 from your dad (... | [
"If each ovum had a different set of chromosomes, that's a huge number of possible combinations (222 to be exact, for humans), and the fertilizing sperm would have to match up identically, otherwise bad things would probably happen",
"Wait, what do you mean bad things would probably happen? There they do not matc... |
[
"If a spaceship is in the dead of space, unaffected by gravity, will firing the rockets increase the ships speed indefinitely?"
] | [
false
] | null | [
"An object moving with constant proper acceleration will technically continue accelerating forever, however its speed will asymptotically approach c.",
"There's a derivation ",
"here",
"."
] | [
"Just to make an addition to ",
"/u/RobusEtCeleritas",
"' answer, if one imagines a trip from, say, Earth to the nearest star system Alpha Centauri - a distance of ~4 lightyears - it is a result of relativity that from the perspective of the Earth and the perspective of Alpha Centauri, as you constantly accele... | [
"The lack of particles to push against in space will mean that acceleration will be slower because the rocket exhaust will need to push the ship forward from other particles emitted from the exhaust.",
"Say what now? The accelerating force provided by a rocket's exhaust does not require the presence of a medium ... |
[
"How does a ground/earth pin work on a plane?"
] | [
false
] | I was on an American Airlines flight and noticed that there were power plug holes on the backs of the seats, 110v 60hz, they had earthing ports, how did they work? | [
"The ground pin doesn't have to connect to the actual ground: what matters is that it connects the case of the electronic device to something else the user is touching, so the device and the user are at the same voltage. No voltage difference, no shock.",
"In a car, for instance, the ground is the metal frame of... | [
"One question. The user is almost definitely not directly in contact with the plane's frame, how is it guaranteed to work? The seat is cloth, the user's shoe is rubber, etc."
] | [
"The user gets shocked. It's no different that when you touch something in your house or car and you have a static built up that hasn't been grounded through other means. This however usually doesn't happen, as it doesn't take much to discharge. Humidity can do it. Also, it merely a static change difference from g... |
[
"In basaltic magma, how much is recycled crustal material and how much is mantle material?"
] | [
false
] | I'm curious about both mid-ocean ridge and mantle plume/hot spot magmas, and potential differences between the two. From what I can gather, granitic magmas usually result from recycling of crustal material at subduction zones; but I'm not so clear on the composition of basaltic magmas. How much of the material at mid-ocean ridges/hot spots originates deeper in the mantle and is brought up by convection, and how does this interact with the astenosphere and moho? Thanks! | [
"I believe that the magma that has the greatest amount of crust recycling is in a subduction zone such as the one around Oregon and Washington states. The oceanic crust slips underneath the continental plate, melts in the mantle, and then feeds into the volcanoes in the area."
] | [
"In both the scenarios you outlined the crust is oceanic in origin anyway. You will get some remelting on the way up but its essentially the same composition as the melt you already have. My geology degree was 20 years ago and I sucked at it so I am sure someone will come along soon with a more wordy explanation."
... | [
"Magma usually forms in the Asthenosphere. There is almost no convection in the asthenosphere, just some vertical movements of themperature.\nThe difference in magma formation are: ",
"These three processes form a basaltic melt in the Asthenosphere which is less dense than the Asthenosphere and therefore rises. T... |
[
"What is it called when the products of a chemical reaction inhibit further production of the same chemical? Same with when the products of a chemical reaction facilitate more production of the same chemical?"
] | [
false
] | The phrase sympathetic and parasympathetic keep coming up, but I an't find them in the right context. | [
"In biology and especially when talking about metabolic pathways, you would use the terms negative feedback and positive feedback, where a metabolite allosterically regulates the activity (positively or negatively) of an enzyme earlier in the pathway. For example, the first step of glycolysis is the conversion of g... | [
"There are two ways to interpret this question - from a kinetics standpoint, or from a thermodynamic standpoint.",
"A product can ",
" the reaction that produced it, so in that way it is \"facilitating more production\". This is known as ",
"autocatalysis",
". Likewise, there is ",
"autoinhibition",
" a... | [
"You described the chemistry--I might chime in with some biology as well.",
"While not directly thermodynamically inhibited, certain proteins synthesized in organisms follow whats called a ",
" substrate-level inhibition system. I can't remember if all organisms have this, but certain organisms produce enzymes ... |
[
"Why does Venus rotate in the opposite direction to the other planets in our solar system?"
] | [
false
] | null | [
"This is due to the impacts by asteroids in the early years of their formation.",
"No, this is generally ",
" the consensus answer any longer in planetary science.",
"Some 30 years ago, this was the standard explanation why Uranus' and Venus' odd axial tilts were the result of giant impacts. Bear in mind, tho... | [
"This is due to the impacts by asteroids in the early years of their formation.",
"No, this is generally ",
" the consensus answer any longer in planetary science.",
"Some 30 years ago, this was the standard explanation why Uranus' and Venus' odd axial tilts were the result of giant impacts. Bear in mind, tho... | [
"Another theory is they may have completely flipped 180 degrees. Moons stabilize planet tilts and Venus has no moon to help with that. "
] |
[
"Does exercising in the morning really increase your metabolism all day vs exercising any other time?"
] | [
false
] | I've asked this question before and got no responses (~1 month ago), so I figured I'd try again. I hear this claim often spouted here on reddit and is "common" knowledge among gym goer's, but it never made sense to me. I don't see how the metabolic response induced by exercising would be any different depending on the time of day. | [
"Nope. It's a myth, like locational fat burning (eg. doing crunches to burn tummy fat) or burning more calories at a lower heart rate. ",
"Metabolic rate spikes after exercise but then tails off after a few hours back down to slightly above the BMR for up to a couple of days regardless of time of day you start th... | [
"Myth Confirmed : ",
"http://www.ncbi.nlm.nih.gov/pubmed/20837645",
"\nTLDR:while the morning isnt a factor, working out in a fasted state is and that is most likely to be true in the morning. Only the group that exercised before breakfast gained almost no weight and showed no signs of insulin resistance. They... | [
"I think the emphasis should be on ",
" and not stretching, in my personal experience. Muscles don't really ",
" all that much, only your ligaments. You don't want \"loose\" ligaments."
] |
[
"How are temperatures as high as 4 trillion Celsius contained?"
] | [
false
] | Doesn't a temperature that hot melt everything around it? | [
"Searched",
"Relevant ",
"discussion",
"Original question by ",
"speed_is_all_I_need",
"Take the ",
"Z-Machine",
" for example. How do you contain 6.6 billion degree temperatures? I feel like it would melt nearly anything in an instant. What materials would be needed to create a heatsink that could de... | [
"Since Temperature is an average quantity over many molecules, how can they have a temperature over the volume of one molecule? I understand a huge kinetic energy but not a Temperature."
] | [
"It says the volume of an atom, not referring to a single molecule. The proton beams at CERN send many protons around at once, not just one. The average kinetic energies of these protons define the temperature. ",
"All this is saying is that these protons only take up the volume of about 1 atom, which is a little... |
[
"Is it possible to know things in your dreams that you don't know in real life?"
] | [
false
] | null | [
"The second one. It's possible to access memories/knowledge that you might not be able to access (or at least not find yourself in the correct context to access) while awake."
] | [
"That is essentially what our friend darwin2500 said."
] | [
"That is essentially what our friend darwin2500 said."
] |
[
"The Mormon Church Released pictures of the \"Seer Stone\" reportedly used by Joseph Smith. Can you make a geological analysis of it?"
] | [
false
] | null | [
"I'll give this a whirl, it's not everyday that one gets first pick at looking at a sacred relic.",
"First, the shape. That is a prolate ellipsoïd with very well devellopped rounding. There is definitely no faceting such as you'd find on a glacially derived cobble. The shape, roundness and exteranal smooth textur... | [
"\"I will now give you a description of the manner in which the Book of Mormon was translated. Joseph Smith would put the seer stone into a hat, and put his face in the hat, drawing it closely around his face to exclude the light; and in the darkness the spiritual light would shine. A piece of something resembling ... | [
"RE patina: not a geologist, but I have worked on a lot of antique wooden objects, and the thing really does look like it's been varnished, and that varnish has , typically, yellowed with age. Whether it's shellac/ spirit varnish, a long-oil varnish, or simply years of being shined with a bit of linseed oil, I don... |
[
"What stops an electron from falling into the protons within an atom?"
] | [
false
] | what stops the negatively charged atom from being attracted and falling towards the positively charged protons? | [
"Because of quantum uncertainty, the electrons are already as close as possible to the nucleus.",
"People sometimes explain this as an ",
" consequence of quantum mechanics. This is far from obvious; for example it would be false if our Universe had 4 spatial dimensions, and electrons ",
" fall into nuclei ev... | [
"Wow!!"
] | [
"Am I being annoying if I ask how?"
] |
[
"Why can I tell when a tv has been turned on from really far away, even when nothing is playing on it?"
] | [
false
] | In sixth grade we would often watch a short educational film after returning from "specials" (gym and the like) and the tv would alread by setup when we got back. I began to notice that I could sort of 'hear' that the tv was on in the classroom, long before we got there. The best way I can describe it is that there's just sort of a buzz that I'm aware of, and that means a tv is on somewhere. remember nothing is playing on the tv. This happens even if the tv is just on a black input/line/tv-video screen. Anyone know what's going on here? Can everyone do this? | [
"A TV's electronics generate around 500 lines at 30 frames per second, or ~15000 Hz, which is at the upper threshold of human hearing. Lots of adults can't hear the noise due to high frequency hearing loss.",
"Edit: I'll add that this is similar to the noise of power transformers - i.e. the so-called \"60 Hertz... | [
"This effect pisses me off so much. People who can't hear it often end up leaving their TVs on and it drives me mad. But then I look like a nutter turning off an off television!"
] | [
"Sorry if this is too far off topic. I attended a manufacturing/automation expo as a field trip during my engineering undergrad. There was a guy showing off sonic welding equipment for joining plastic parts. As soon as he turned it on it sounded like a TV, but loud enough that I instantly recoiled and covered my... |
[
"Do LCD monitors emit outside the visible spectrum?"
] | [
false
] | Chemist here, had someone ask me to tell them what wavelengths are emitted by a computer monitor. (They are doing research on eye disease) I don't have a set-up that will allow me to do emission spectroscopy on anything as bright as a computer monitor, or even an iPhone. | [
"LCD spectra would be limited to the type of backlight used. CCFLs are the most common, so you can look up the spectra for those. LEDs should generate even less non-visible light due to their higher efficiency."
] | [
"Basically what Cookie has already said. The only light generating element of an LCD is the backlight. What's in front is a couple of polarizers, some liquid crystals that allow light through or not depending on applied voltages, and a small window over each 1/3 pixel of RG or B. ",
"http://www.youtube.com/wat... | [
"Truthfully? Because I don't know how I'd explain what I was up to! ;) ",
"The main problem is the instrument I have access to does UV-vis absorption, not emission. I don't want the source light to reflect off the iphone and register on the detector. I also don't want to overload the detector. ",
"The other iss... |
[
"Physics and Psychology of Music Question: Why do the lengths between the frets on a guitar get smaller and smaller?"
] | [
false
] | So, I know that the sensation that humans hear as pitch corresponds to the frequency of the sound wave - a note that may considered to be high/low has a sound wave with a higher/lower frequency than the sound wave of the origin note. In western music theory the difference between pitches (or the interval between pitches) is quantized in units of whole steps and half steps (with two half steps making a whole step). To my ear, the half step (or semitone) between both A4 (440 Hz) and A4 (466.16 Hz) and, say, D5 (587.33) to D5 (622.25) is the same "distance," musically. But obviously, by either doing the math or looking at one's guitar fretboard* (example ), the actual frequency difference between those sets of notes are not equal. Why? What is the difference between musical pitch and physical frequency? Has spending my entire life listening to only music built on western music theory conditioned my brain to recognize those frequency differences as "half notes?" General comments on the connection between the physical phenomena of music, its theories thereof, and its perception by humans are also appreciated. *The frets on a guitar are equivalent to the keys on a piano. A specific fret or key corresponds to a specific note (frequency). | [
"Frequency is related to pitch on a logarithmic scale...each time you raise a pitch an octave, the frequency is doubled. That is why the difference between your A and A# is different than that of the D and D#. To compensate on a guitar, the fretboard must also be built \"logarithmically\". ",
"Guitar#frets"
] | [
"Adding on to this, when we perceive pitch differences, we are actually looking at the ratio between the two pitches, rather than the difference between them. For example, the two notes of a P5 interval are in a ratio of 2:3. So A4:E4 would be 440:660, while A3:E3 would be 220:330. The difference between the fre... | [
"This doesn't answer the question, but is pretty relevant: ",
"https://www.youtube.com/watch?v=i_0DXxNeaQ0&feature=youtube_gdata_player"
] |
[
"Question about calories"
] | [
false
] | [deleted] | [
"You ask a good question, one I wondered and researched. First, let me say that this is a hard question to find answers on. But, I will share with you what I found. ",
"Today, the way it is found out is by referencing look up tables. Different \"ingredients\" are known to have certain calories (by ingredients, I ... | [
"No no, a scientific endeavor like this takes the cooperation of ",
" researchers."
] | [
"They burned some food, measured the calories. Then, they fed the exact same food to a person, collected his feces, then burnt his poop. The difference in the heat (calories) is how many calories your body absorbed.",
"What you're saying is: somebody probably spent 10 years getting their PhD in biochemistry and t... |
[
"Where does the gas go when a person takes a bean-o?"
] | [
false
] | [deleted] | [
"Beano contains an enzyme (",
"Alpha-galactosidase",
"), which breaks down complex sugars into simpler sugars which can be more thoroughly digested, producing less gas."
] | [
"Does this mean Bean-o helps you digest and absorb food more efficiently?"
] | [
"Right. The gas comes from complex sugars making their way into your large intestine, where bacteria that naturally live in your gut consume them, producing carbon dioxide as a by-product. If the sugars are broken down, then they'll be absorbed by your digestive system, and there will be less food for the bacteria ... |
[
"How do we know that the universe is expanding everywhere, as opposed to just around us?"
] | [
false
] | One of the ways that inflation is traditionally taught in schools is to half-inflate a balloon, draw "galaxies" on it, and then further inflate it. I realized suddenly recently that this "view" of the universe assumes that we, the observers, are at the center of the balloon. I mean this in the sense that all of our instruments with which we've gathered our entire understanding have only existed (roughly) within the confines of our solar system, and so instrumentally we've only established that the universe around us is expanding. I'm curious to know on what grounds we reason that the universe everywhere is expanding. It seems like a reasonable assumption to make, and presumably it matches with our observations and models. I guess I'm wondering whether the hypothesis of local inflation (or inflation only around large masses) is something that's been specifically tested/reasoned about. I.e. is inflation uniform at cosmic scales, or "spotty" (up to the extreme hypothetical limit of "only one spot, and you're in it"). | [
"You've missed the point of the balloon analogy. In that example, we aren't at the center of the balloon, we're on the surface as well, in a curved 2D universe. Ignore the volume of the balloon. If you pay attention to the surface, you'll notice that every point on the surface is moving away from every other point,... | [
"Just, to start off, two quick points. \"Inflation\" and \"expansion\", despite being synonyms in English, are not actually the same thing in the lingo of cosmology. Expansion is the expansion of space that underpins Big Bang cosmology. Inflation refers to a specific epoch of expansion that is hypothesized to have ... | [
"For starters, because our measure of cosmic expansion couldn't really tell the difference between the center of the universe being here on earth or it being some other planet in this galaxy, or indeed even in our galactic cluster.",
"Secondly, because there is really nothing special about 'here' that would lead ... |
[
"At what scale would the \"hold my finger over the tip of a straw and pick up water\" effect no longer work?"
] | [
false
] | All kids play around with the straw in their drink and hold their finger over the tip of it and pick up some of the fluid in the straw and then release their finger dropping it back into the cup. This is due to a combination of the vacuum created in the straw and the surface tension of the liquid at the end of the straw I presume. At what scale would this no longer work? Could a giant space alien with a giant straw dip into the pacific ocean and grab a bunch of water with its finger over the tip of the straw? For the liquid in question lets try using fresh water to keep it simple. Im not sure how much difference salt water makes in the question. | [
"At about thirty-four feet, which would correspond to about fifteen pounds per square inch of pressure at the bottom of the straw. Atmospheric pressure at sea level is about 15psi, and that is what is keeping the water up the straw; pull the straw higher than 34', and an empty space will begin to form above the wat... | [
"OP, maybe you should clarify the question. I read it as though you're asking about the situation where you lift the end of the straw entirely out of the water, and the water in the straw stays in because of the narrowness of the straw. If you use a wider container, like if you cut the ends off a bottle, stick the ... | [
"Thats exactly what I meant. I thought the phenomenon of kids playing with the liquid in their straw was clear. I'll add an edit to the post to clarify."
] |
[
"Biological question concerning the relationship between mitochondria and it's prokaryotic homologies."
] | [
false
] | If a prokaryote, let's say a bacteria, truly is closely related to the mitochondria, then would that mean antibiotics targeting the ribosomes of bacteria would also target mitochondria? Or is the genetic differences too great? | [
"Yes! See ",
"Zyvox",
" for one example. Mitochondrial ribosomes are actually quite similar to their prokaryotic brethren. It's true that there are some exceptions to the universal genetic code that we've only found in mitochondria, but this has nothing to do with the ribosome; rather, these differences are due... | [
"If I remember correctly: Some potential antibiotics have been rejected because they hurt mitochondira too."
] | [
"The differences are too great. The differences are so large that mitochondrial ribosomes have a different genetic code from the one that is found in prokaryotes and eukaryotes. However, the similarities in broad strokes between mitochondria and prokaryotes are still very large."
] |
[
"How do we determine and measure the average temperature of Earth?"
] | [
false
] | I assume that the average temperature of Earth changes based on multiple variables: Distance from the sea/ocean, altitude, hours of daylight, time of day etc. What are the criteria for measuring the average temperature of Earth? I also assume that each nation gives their own averages, but how do we determine the weights for each country? For example Russia is a lot bigger than Luxembourg, so Russia should have more variation in temperatures and their landmass should represent a larger proportion of the average temperatures. | [
"I would bet each principal investigator of global temperature changes would calculate that in a unique well-reasoned way. Your question may be best revised to be \"What well-regarded agencies and scientists are there that measure global temperature?\" And then looking into/asking them their methods.",
"Here's a ... | [
"I think OP is interested in the averaging method more than the measurement method. In which case, you could interpolate to model a matrix of values across the whole earth surface at some resolution, then do arithmetic or geometric average. There are some other built in assumptions about time resolution, vertical... | [
"Exactly. ",
"Science is often really precise, but when you have multiple different organizations measuring temperature with different standards, how do we determine the average? ",
"For example, I imagine that we have more datapoints from land than oceans (because it is easier to stick a measuring tool on gro... |
[
"What would the day/night cycle be like living on the moon?"
] | [
false
] | null | [
"There is no \"dark side\" of the Moon. There are permanently shadowed craters near the south pole (maybe the north as well, I'm not sure), but that doesn't really constitute a side. What's often called the \"dark side\" of the Moon is better called the far side of the Moon - the side not visible from Earth (it's a... | [
"Re: #2: The Earth is between the Moon and the Sun every 28 days. This is during a full Moon, and that's when a lunar eclipse can happen. The reason there isn't a lunar (or solar) eclipse on every orbit of the Moon is because the Moon's orbit doesn't put the Moon directly in the line of sight between the Earth and ... | [
"Thank you, very informative!",
"Re: #2 - I'm having trouble wrapping my mind around this (probably because I don't have a visual)... the moon orbits the earth every ~28 days, right? So how is it that the Earth isn't between the moon and the sun every 28 days?",
"Re: #4 - How much of the sky would the earth tak... |
[
"Why do banana peels turn brown so much faster once it has been peeled?"
] | [
false
] | null | [
"So I looked it up and apparently the contact with oxygen causes an enzyme called polyphenol oxidase (there are other enzymes too) to increase/start chemical reactions that produce melanin. Melanin is a strong pigment. Interestingly melanin is the same molecule that give people skin pigment, which protects us from ... | [
"Polyphenol oxidases (PPOs)! The same class of enzyme causes browning in a lot of soft plant tissue in response to damage, like the browning in apples, potatoes, etc. after bruising or cutting. The putative function is to protect the plant from pathogens that might enter during tissue damage. ",
"Somewhat related... | [
"That is a very nice observation, I wonder if the same would happen in a vacuum. "
] |
[
"Can you create a machine learning algorithm to create a computer virus?"
] | [
false
] | So I have seen a lot of machine learning videos, including , , , . Then, I also saw . It made me think about since there are so many ways to produce machine learning algorithms in so many disparate fields and to do so many things, could you have an xkcd style virus-farm and try to use machine learning to look for security holes? The MarI/O simulator found a glitch in Mario, on so it might not be too far a jump to consider that a really advanced neural network might be able to evolve a way to hack computer systems? If so how would it work? Note: . I just thought it would be an interesting idea. | [
"Sure. Check out the DARPA cyber grand challenge for an example of fully automated exploit creation. They didn't use ml but in principle it would work.",
"But remember that ml isn't magic. It is sophisticated curve fitting. So I wouldn't worry about this having any worrisome implications about dystopias or whatev... | [
"The successful teams in CGC used a combination of random fuzzing (trying random inputs to programs to see what happens) and a technique called dynamic symbolic execution, which tries inputs and then carefully considers how to change those inputs to force the code to do something different next time.",
"The detai... | [
"Huh. I looked it up, but only found some simplified articles, that don't explain how the hacking boys work. So how do they?"
] |
[
"Did scientists know when the Trinity Atomic test occurred?"
] | [
false
] | Obviously the scientists involved knew what was going on, but what about other scientists monitoring other experiments? What did they think it was? | [
"If you don't get an answer here, you could try ",
"/r/askhistorians"
] | [
"That is an excellent point about other explosions going on at the time. "
] | [
"I thought of that, but I figured there might be more insight from the science community on how someone may have noticed this huge seismic event at the time. ",
"I'll give it a day here then head over that way."
] |
[
"What would the W and Z mass be without Higgs ?"
] | [
false
] | Just like technicolor, already in QCD the exchange of gluons in the spin zero, isospin zero channel is attractive, causing the formation of a quark condensate, which dynamically breaks chiral symmetry : SU(2)_L x SU(2)_R -> SU(2)_V The corresponding would-be Goldstone bosons contribute to the longitudinal components of the W and Z. In my understanding, the reason for introducing the Higgs is that the QCD condensate contribution is much too small for the W,Z phenomenological mass. Would anyone know of a reference were the QCD condensate contribution is evaluated ? My searches failed and I would be very grateful. | [
"Take a look at the following:",
"http://arxiv.org/pdf/hep-ph/0203079.pdf",
" (see p.14)",
"and this comment from Matt Strassler:\n",
"http://profmattstrassler.com/articles-and-posts/particle-physics-basics/the-known-apparently-elementary-particles/the-known-particles-if-the-higgs-field-were-zero/#comment-1... | [
"Note that 93 MeV/175 GeV is about .05%, not .5%",
"But in addition, the contribution is actually smaller than this (see Matt Strassler's comment). The contributions add in quadrature; instead of just X, it is sqrt(X",
"+Y",
"); when Y<<X, this becomes X(1+Y",
"/2X",
"), and so the effect of the condensa... | [
"Thank you. The article seems excellent. It suggests a contribution of the order",
"\n93 MeV / 175 GeV ~ 0.5 %",
"\nIf this estimate were accurate, that would mean that the QCD condensate is ",
" than the present experimental accuracy. Because of that, I would imagine a more precise evaluation must have been... |
[
"Can somebody slightly \"dumb-down\" the four levels of protein structure for me?"
] | [
false
] | [deleted] | [
"ELI5 version (Using Power Rangers):",
"Primary: The smaller parts that make up the zord (i.e. ball bearings, connecting rods, etc.)",
"Secondary: The specific structures of the Zord (i.e. arm + leg = alpha helices, torso = beta sheet)",
"Tertiary: Zord",
"Quaternary: Megazord",
"p.s. in case you didn't k... | [
"Ponies don't assemble into anything :( how about legos? or maybe Barbie Dolls?",
"EDIT: I'll just roll with Barbie dolls, with additional metaphor explaining the importance of structure on enzyme activity: ",
"Primary: Barbie's parts (i.e. legs, arms, torso head) The order they are in is meaningful. If they we... | [
"Yes, Tertiary refers to the overall structure of a single protein. Secondary refers to specific structural elements of that protein."
] |
[
"If teleportation will be available for human transportation, will the individual that \"arrives\" at a certain location be the same but not the original that \"departed\" from another location?"
] | [
false
] | null | [
"That's one way to do it. Probably the only theoretically possible way we have right now. But I'm hoping for another way that actually transports your matter intact."
] | [
"My argument is more philosophical than technical. In my oppinion there are two ways to \"teleport\". The first is to read all the atoms in a body, send that information to the other end and recreate that body. Even with perfect quantum replication it is still just a copy, and destroying the original is still murde... | [
"Whether you consider the first kind of teleportation murder is dependent on how you understand personal identity. Keep in mind that all of the cells in our body die and are replaced over time and all the parts of each cell are constantly decaying and being rebuilt with new material. Thus if you held that continuit... |
[
"Microbiologists and biologists of Askscience: Is it true that not washing hands will \"train\" one's immune system?"
] | [
false
] | I regularly get mocked for refusing to eat without hand washing. My friends assert that touching food with dirty hands is healthy because it will keep their immune systems in shape. I guess they mean that inoculating a fairly small amount of bacteria or viruses isn't harmful for the body because this will help it to recognize the pathogens. My idea is that they are incorrectly applying the idea behind a vaccine to live microbes; it is also proved that spending some time regularly in a wood or forest is a huge immune booster. Just not washing hands is plain stupid and dangerous. Am I wrong? Just to clarify, I am not a paranoid about hygiene. I just have the habit of washing hands before eating, because my parents told me so when I was young and I picked the habit up. again: thanks for all the responses! | [
"You're not wrong. Bacteria is good, but that's the non-pathogenic form. Most pathogens that cause disease in us have mechanisms that can specifically override our immune system. Just because you expose yourself to that bacteria doesn't mean you won't get infected. That's why they at least kill the pathogen before ... | [
"This is what I came here to post. ",
"*edit: I didn't have anything to add right when I made the comment. I only commented in order to lend the credence of the tag, otherwise I would have just upvoted.",
"Now for some additional quick info: Wash your hands before you go to the bathroom to protect yourself, was... | [
"I think in this case, it's completely warranted. A backing from another voice in the field."
] |
[
"Can an average consumer find/afford solar panels that easily \"plug in\" to regular appliances (i.e. window air conditioner) AND provide adequate power?"
] | [
false
] | Is this possible? Its hotter than Satan's va-jayjay here but I feel so wasteful having the AC on 24/7. What equipment (size of solar panel, converter, etc.) would be needed to power the unit, which plugs into a standard U.S. three-prong outlet, for even just a couple hours per day? Along with environmentally friendly, I'd prefer to be wallet friendly too, if you know what I mean. | [
"Usually you'd hook your solar panel into your home energy grid - that way, if you make more energy than you burn on just an AC, you can use it for everything else in your house (things like the fridge and washing machine are big ones, for example, but even lightbulbs add up). It doesn't matter that a solar panel i... | [
"I met ",
"this guy",
" at a conference I attended for work. He told me he leases people solar installations for $0 down for home use and generally people start saving more money than it costs, starting in the first month. I am not backing this statement up, as this sounds like a typical elevator pitch. He a... | [
"There are two problems with what you want to do.",
"To solve that second problem there are two approaches:",
"An offline system, which means you have a large bank of batteries that are charged by the panels. Much like a bank account, this lets you accumulate energy while you aren't running any electronic devi... |
[
"Relativity says that there is no \"right\" perspective. That seems to imply that the universe isn't in one particular state at a given point in time. What does that mean and how is this possible?"
] | [
false
] | null | [
"incorrect to say that the baseball exists at a finite location at a specific point in time?",
"No it's perfectly correct, the problem is that the numbers you get are unique to your reference frame and not values you should expect others to share.",
"it's actual location in the universe",
"There is no such th... | [
"Thank you for your submission! Unfortunately, your submission has been removed for the following reason(s):",
"/r/AskScience",
"/r/askscience",
"For more information regarding this and similar issues, please see our ",
"guidelines.",
"This is a common question covered in the ",
"AskScience FAQ",
"If ... | [
"Relativity removes absolute geometrical relationships between reference frames. Using your baseball example, two different observers will both see a baseball, but disagree on how far away the other observer is from the baseball, the speed of the ball, how clocks move on the base ball and the other observer even th... |
[
"What's actually happening to your rods and cones when your eyes are adjusting to the light/dark?"
] | [
false
] | I understand that when your eyes adjust to the light or dark that it takes time for your rods and cones to adapt to the change in condition, but what's actually going on with the cells for this to happen? | [
"When your rods and cones adapt to bright light, what is happening is they are \"photobleaching\". When rods & cones are bleached, they cannot process incoming light. Here's a short mechanistic description of photobleaching from ",
"this paper",
":",
"As a result of the work of G. Wald and his group\n[ 1 ] it... | [
"Thanks! Perfect answer!"
] | [
"The main effect is not in the cones and rods but you pupil which will close in reaction to bright light to let less light into you eye.",
"The rods and cones will react to constant stimulation by lowering their output. That is why when you take off colored sunglasses the colors seem off. This happens due to the ... |
[
"How did the Big Bang not form a super massive black hole?"
] | [
false
] | So, when a star's mass exceeds a certain threshold, it collapses into a black hole. In the beginning, all the mass in the universe was in close proximity. How could all that mass not trigger a black hole collapse? Surely there was more mass in the local area of the blast than exists in a black hole, and light (a massless particle) is a lot harder to suppress than actual mass. Therefore, it should have been impossible for any matter to have escaped the Big Bang (?!). What am I missing... EDIT: Front page! Thanks reddit! | [
"The Big Bang singularity isn't the same as a black hole. A black hole is a point in space time with infinite curvature. The Big Bang singularity was the entirety of space time. And the entirety of space time expanded. ",
"That being said. We have no working theory of black holes or the Big Bang. We just see that... | [
"In the beginning, all the mass in the universe was in close proximity. ",
"No, in the beginning, all the mass in the universe was closer together, but still evenly distributed throughout all of space. ",
"How could all that mass not trigger a black hole collapse?",
"Since the density of the universe was, and... | [
"A black hole is a point in space time with infinite curvature. The Big Bang singularity was the entirety of space time.",
"This is the first time an answer to this question has made sense to me."
] |
[
"what needs to happen for us to be able to colonize Venus?"
] | [
false
] | This question was brought up , but I'd like to investigate it further. What technological challenges do we face? What atmospheric conditions does Venus present now, and how bad would those conditions be for human life? Any estimates on when, if ever, we can start living there? | [
"I think that was \"The Jetsons.\""
] | [
"Obscene surface temperatures and a toxic atmosphere both present challenges. No chance of agriculture unless the planet was terraformed. We could potentially do something like a \"city in a bubble\" but then the only advantage we gain is extra land, and almost nothing in the way of new resources."
] | [
"Don't forget that a Venusian day lasts 116 Earth days since the planet is tidally synced with it's orbital period."
] |
[
"How long does it take a virus (such as Covid-19) to reproduce from the moment it enters a cell?"
] | [
false
] | How fast is viral reproduction on the level a single virus? Once it enters a cell, how long does it take for it to take over the cell, create more viruses and burst forth from the host cell? Does time vary significantly from virus to virus? Are ones with shorter time generally more dangerous/infectious? | [
"A complete viral replication cycle includes:",
"-Cell entry",
"-Unpackaging of genome and proteins",
"-Genome replication and protein synthesis",
"-Assembly of virions",
"-Release of virions from the host cell",
"The time required will vary quite a bit from virus to virus. Generally positive-sense RNA ... | [
"To answer your question: yes, it varies from virus to virus. It depends on the host cell too. We probably ain't too sure of the exact time needed for the virus life cycle in our body, simply because the cell type and conditions in our body are different from those in labs.",
"Lethality is hardly correlated with ... | [
"Reproduction time can be seen as a factor of spread, and possibly even incubation period before signs and symptoms appear, due to levels required before active disease such as the amount of the bacteria E-coli is needed before it passes a threshold to become illness causing, it is not a good indicator of much more... |
[
"What would happen if two stars merged together?"
] | [
false
] | null | [
"In some cases a nova or supernova would result. Some recent papers proposed for example the element gold could only be synthesized from the collision and merger of two neutron stars. Assuming some stars with considerable nuclear fuel remaining/time on the main sequence, there would be fairly massive explosion/outb... | [
"White dwarf collisions create something called Type 1A supernovae, which have a very unique emission signature. These events are more luminous than entire galaxies for a few days/weeks.",
"Neutron star collisions are thought to create certain types of gamma ray burst, which are the highest energy electromagnetic... | [
"Seems doubtful that either would happen, but it is hard to really know. There are forces at work in the core of a star that we have an incomplete understanding of that would greatly matter for problem like this.. Lots probably depends on how exactly they are rammed together.",
"It is just educated speculation, ... |
[
"Do rooms with hard reflective walls (such as a bathroom) leak less sound?"
] | [
false
] | I've recently been practicing my ukulele late at night in my apartment, and have wondered lately whether practicing in my bathroom (with its hard reflective walls) will leak less noise than playing in my living room. If I can hear myself more loudly inside, does that mean that outside the room there is less noise leaked? | [
"Depends on what you are comparing it to, but all else being equal: yes. If I have two closed rooms, one with hard tile walls and the other with sound-permeable drywall, less sound is going to leak from the tile wall room.",
"However, this assumes that all the sound is going through the walls. In truth, you have ... | [
"It depends. In addition to the transmission and reflection you are already considering there is the possibility that the sound is absorbed in the wall. It's possible for a wall with high reflection and low absorption to transmit more sound than a wall with low reflection but high absorption."
] | [
"One thing to keep in mind: When you move to a new apartment and experience the empty rooms, you experience much more echo/hall than now, where its fully furnished. The sound situation in your bathroom might still be something else, but I just want to call the attention to a possible misinterpretation regarding the... |
[
"While sleeping, if nothing from the outside world triggers our wake-up, what most commonly triggers it?"
] | [
false
] | For instance, does something just sort of trigger in our brain and tell us it's time to wake up? Thanks | [
"First, it should be noted that sleep is not a continuous block. Even without any environmental stimuli, spontaneous awakenings are common during the night. For a healthy adult, it is typical to wake briefly about 20 times per night, with increasing frequency towards the end of the night. You don't remember most of... | [
"For a healthy adult, it is typical to wake briefly about 20 times per night, with increasing frequency towards the end of the night. You don't remember most of these awakenings because short term memory does not function normally during sleep or shortly after awakening.",
"Do you have a citation for this?"
] | [
"Sure! This study reports an average of 20.1 awakenings per night in healthy young adults, 22.9 in middle-aged, and 27.9 in older adults.",
"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2817908/pdf/aasm.33.2.211.pdf",
"I can tell you from data from my own lab that a range of around 10-30 nighttime awakenings is ... |
[
"Do learned behaviors have an effect on evolution?"
] | [
false
] | For example, there are pods (?) of dolphins that have learned special methods of hunting fish, like stirring up mud to trap the fish against the surface. The dolphins teach their offspring this method, increasing the chances of their offspring surviving because of this superior hunting method. It seems to me that even if a dolphin weren't particularly fast or healthy, it could still survive because of this "smart" hunting. Some species of monkey have also learned to use tools to open nuts/fruit, which is another behavior that is passed on through nurturing. Another (extreme) example would be humans and modern medicine. Have we "beaten" evolution because we can cure the people who otherwise would have died from Chicken Pox, etc.? | [
"While learned behaviors certainly influence evolution, it is important to remember that the specific learned behaviors themselves are not being passed on via evolution, and that there is a cost to learning. Nobody 'beats' evolution, but what exactly is under selection can change.",
"What you're talking about in... | [
"Yes, as anything that increases an individual's fitness is going to increase the likely hood of passing on its genes to future generations. ",
"As for humans \"beating\" evolution, no you don't beat evolution, not with our understanding of genetics anyways. Certain factors, like inherent disease resistance, may... | [
"What you are asking about is actually a fascinating topic called the ",
"Baldwin effect",
", which describes how learning can affect evolution, and even, intriguingly, accelerate evolution - certain kinds of evolution are only possible in \"smart\" creatures. A related component, is a shift of behaviors that s... |
[
"Why is northern Alaska and Canada pockmarked with \"lakes\"?"
] | [
false
] | I was looking over google maps when I noticed that northern Alaska and Canada had these dense "lake" formations. What are these from and why do they form that way? For example: | [
"I have been waiting for a geology themed question for AGES!",
"The answer to this is glaciers! During the last ice age massive multi-km thick sheets of ice covered canada, alaska and some northern parts of the lower 48. Think Antarctica, but in Canada! These super thick sheets of ice move very slowly, but over t... | [
"The other neat thing about glaciation also, is the rebound of the lithosphere due to the lifting of weight when the glacier melts. This is why Finland gains altitude of about 11 mm/year. So as you rebound the crust, if you don't do it at the same time, you can have migrating lakes. "
] | [
"http://www.nationalparkstraveler.com/2009/10/melting-permafrost-may-help-explain-why-many-denali-national-park-wetlands-are-drying4724",
" \"The lakes and wetlands in this part of the world were formed about 8,000 years ago when the most recent glaciation ended, and many (but not all) owe... |
[
"Is there any material that has a different melting and freezing point?"
] | [
false
] | i.e. is there any material that will tend to "stick" to whatever state it was in, whether that was solid or liquid, for some period? I know that there are other reasons that all snow doesn't melt as soon as it gets above 0 degrees (it takes time for heat to transfer, different specific heats of air vs. water, "above 0 degrees" on the weather doesn't account for shade vs. sun, etc.). But is there any substance where you can take a solid sample and a liquid sample, bring them into an environment with precisely the same conditions, and have them remain, respectively, solid and liquid? What about gas and liquid? I know that water vapor, liquid, and ice can continue to exist in the same room for a while, but again because of varying conditions... but I'm wondering if there's a further stickiness. Basically, a material that turns solid when it gets to temperature/pressure/etc. conditions X, but won't turn back into liquid again until it gets to X + 5 degrees, leaving a window where both states are stable. I hope I've explained my wondering sufficiently... | [
"What you're describing sounds like ",
"hysteresis",
", in which the state of a substance depends not only on current environment but also on prior environment. The example wikipedia lists is ",
"agar",
", which melts at 85C but freezes at 40C. Other '",
"antifreeze proteins",
"' and ",
"nonprotein ... | [
"Even though the material \"knows\" it wants to be in a different state, it is sometimes easier said than done to get there. An ELI5 analogy: imagine you have 30 screaming kindergarteners in a classroom, all running around doing various things, and it is time for recess. Even though the kindergarteners would rath... | [
"No.",
"The situation being described by the OP is indeed hysteresis as stated by ",
"arumbar",
", and can ONLY occur for non-equilibrium situations. Agar is neither freezing nor melting because freezing and melting are explicitly ",
"first order phase transitions",
" which are equilibrium phenomenon. Aga... |
[
"Why do rotating black holes look so weird?"
] | [
false
] | So I found website from ESA where you can play around with a black hole and the rotating black hole (Kerr black hole) looks so weird. Why does it have that shape? | [
"It's because of an effect called 'frame dragging': The spin of the black whole ",
"twists the spacetime",
" with it. This means that trajectories of light look very different when orbiting the black hole clockwise in contrast to orbiting it counterclockwise. They are 'dragged' by the rotation.",
"For an outs... | [
"Black holes have mass, charge and spin. If charge and spin vanish, it's called a Schwarzschild black hole. If it has spin, but no charge, it's called a Kerr black hole. The spacetime for a Kerr black hole is very different, for example it has an ergosphere, a region around it where it is impossible for objects to ... | [
"I didn't see the Kerr black hole with scalar hair but thanks for explaning it too."
] |
[
"is there a name for ability to control the shape of the crystalline lens in humans, and is it common?"
] | [
false
] | I am able to blur my own vision by moving a part of my eye, that I assume is my crystalline lens. I'm able to control this consciously, as I would tense a muscle. I've never been able to find any evidence of this in another human. | [
"Your cornea is the external \"bump\" of the eye that lies above the iris and the lens. It is fixed and does not change in focus, though it can become occluded or scratched by things getting in your eye. ",
"The lens of the eye is comprised of layers of transparent, interlocking cells that are individually rigid ... | [
"I apologise if my only evidence is of my own experience, but I have never been able to find any evidence of the phenomenon anywhere. I also did read the guidelines, and have done my best to abide by them."
] | [
"It's a very common ability. When you tell people to 'focus far away' to do a magic eye picture or something they change the focus of their lens and the confocal point of their eyes at the same time."
] |
[
"How do we calculate rates of change mathematically knowing what we do about quantum mechanics?"
] | [
false
] | The obvious example is current. We know charge is a discrete value, so we can't use basic calculus to find the rate of change of charge as the derivative which, as I know it, can only be done on a continuous function. | [
"In many applications, we may simply assume that the charge can take arbitrary values, and this is usually a good approximation. For instance, in a wire, the elementary charge is negligibly small compared to the total charge in some cross-section of the wire. Precisely, in any cross-section, the charge is ",
", w... | [
"Yes, as I mentioned, for plasmas or fluids, you need a full kinetic theory. Classical kinetic theory, for instance, is based on probability theory and the Hamiltonian and Lagrangian formulations of classical mechanics. (There are quantum and relativistic kinetic theories also.) A good analogy is \"statistical mech... | [
"I don't know what your professor said exactly or what he meant. But Euclidean geometry encompasses a lot more than circles and lines in a two-dimensional plane. The non-Euclidean nature of the universe is not important in the classical limit, but only in the relativistic limit. There is plenty of interesting physi... |
[
"Does the universe have total angular momentum different from zero?"
] | [
false
] | Is the total angular momentum if the universe zero? If not, wouldn't this determine a privileged direction in space? | [
"You can set up polar cosmological coordinates (FLRW basically) and in fact do compute said angular momentum with respect to some origin (say, Earth). It turns out to average to zero above the supercluster scale. If it wasn't so, you wouldn't have an isotropic Universe in those same coordinates, but you actually do... | [
"Thank you. I assume above the supercluster scale means huge huge scale, which is what I meant. Also, what you mean about energy is due to the constant accelerated expansion of the Universe thus increasing kinetic energy? If this is the case, does this increase vastly outscale the decrease in potential gravitationa... | [
"There is no kinetic energy: in cosmological coordinates, we're all stationary (i.e., the derivative of the position coordinates wrt the time coordinate is zero). We are just getting further apart.",
"However, energy is being created because of other reasons. For example, dark energy is a constant energy density,... |
[
"I was recently told that loss of antarctic ice was causing changes in the gravity of earth, how is this possible? if gravity is based on mass how can melting ice reduce the reduce the mass of earth?"
] | [
false
] | null | [
"It's not changing the mass of the Earth, it's changing the mass distribution. If you look at ",
"gravity maps of the Earth",
", it's not perfectly uniform everywhere because the mass of the Earth is not spread out perfectly equally.",
"Melting large amounts of ice basically redistributes mass from that area ... | [
"The earth's mass would remain the same. It could affect the distribution of mass. ",
"So if there is 1 million tons of ice at the poles... If it melted, the mass of the water would be distributed more evenly in the ocean. No longer just at the poles. ",
"It seems like the mass distribution change would be min... | [
"This",
" is what the earth looks like where gravity is equal.",
"\nRocks (Africa/Europe) is heavier with more gravity pull than the (Indian) Ocean, and that km's thick ice-sheet on top of Greenland (above sea level) is pulling the water upwards. ",
"(Google 'pictures' of \"gravity potato\" for more if yo... |
[
"Why +90% of people live in the northern hemisphere?"
] | [
false
] | [deleted] | [
"I don't know if the answer needs to be sciency enough, but this looks like it can be explained without it. ",
"First of all, most of the landmass is in Northern Hemisphere. Secondly, we also have the entirely to Asia in it, which contains two of the most populous countries - China and India.",
"Now, it doesn't... | [
"I like the landmass point, but the rest of your argument is kind of like saying \"90% of people live in the northern hemisphere because the northern hemisphere is where 90% of people live.\" \nI think the fundamental question OP wanted answered was why people are so concentrated in the northern half relative to th... | [
"And even though Australia is a large landmass in the southern hemisphere a lot of it isn't very habitable. "
] |
[
"Why do we panic?"
] | [
false
] | I understand the fight or flight response, but panic seems to be somewhere in the middle and tends to cripple most people like a deer in headlights. All rational thought seems to go out the door.. Why? | [
"Not wanting to excite a predator has got to be at the top of the list of reasons, but there are other instances it can be useful.",
"\nYou freezing up in a dangerous situation might keep you from making a situation worse, or injuring yourself further.",
"\nIn a group scenario, having everyone running in all di... | [
"There are interesting but speculative evolutionary theories on panic, depression, etc. Check out ",
"Randolph Nesse's",
" work in evolutionary psychiatry. Like you said, the fight or flight aspects are easy to understand but the debilitating aspects are harder. Why wouldn't selection weed out genes for crippli... | [
"Cite sources please.",
"edit: Downvoted for asking for supporting research? This place really has taken a nosedive."
] |
[
"Are proton-proton and neutron-neutron nuclear force interactions provide significant attraction? Can one hadron only 'bind' with another hadron via the nuclear force?"
] | [
false
] | [deleted] | [
"Are proton-proton and neutron-neutron nuclear force interactions provide significant attraction? ",
"Yes, their interactions are generally attractive, except at very short distances.",
"Can one hadron only 'bind' with another hadron via the nuclear force?",
"In principle you could have two hadrons of opposit... | [
"Okay thank you so much for your reply. Since this isn’t my field of expertise there’s a couple concepts I just wanna reiterate to make sure I understand you.",
"Same-same hadron bonding is possible but the isospin pair (triplet state) to cause this is rare?",
"And only one hardon is bounded to another hadron. ... | [
"The isospin triplet is unbound on its own.",
"In a nucleus with A > 2, every nucleon still interacts with eve ey other nucleon.",
"What do you mean by “nonexclusive nucleonic force”?"
] |
[
"How do our immune systems know not to attack healthy bacteria?"
] | [
false
] | I'm assuming it's some sort of chemical signal secreted by the bacteria, but what's the exact mechanism? | [
"According to ",
"Wikipedia",
" there are 1 quadrillion bacteria in the gut. That's ",
"10 times",
" the number of cells in the body. So even if the immune system was going to, I don't believe it would be successful. But there is ",
"information on how the immune system interacts with these bacteria",
"... | [
" - ",
"I'll start this off by saying that my Immunology is a little bit rusty.",
"Inside the layers of our skin and mucous membranes there exists dendritic cells that detect bacteria and bacterial components known as Antigen Presenting Cells (APC's). These APCs present the components to other cells in the imm... | [
"Actually lamina propria DCs (specificaly CX3CR+CD103+ if you are interested) project pseudopodia into the lumen of the intestines. They can sample antigen there an actually bring it back to the Peyer's Patches and mesenteric lymph nodes. I believe this process is important for the immune reaction against salmonell... |
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