title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"Is DNA actually an acid?"
] | [
false
] | I understand you the A in DNA stands for acid but is it an acid in the same way hydrochloric acid is? Are the 4 base pairs acids? Is it a totally different thing? | [
"DNA behaves as if it is a polymeric partial ester of phosphoric acid, and as far as I know, that is why it was referred to as an acid when it was first isolated.",
"In practice, at physiological pH, it is in the ionic (salt) form (that is, it has been 'neutralized')."
] | [
"It is an acid but it is not a strong acid like hydrochloric acid is. It's more on the order of how ethanol is acidic - that is to say only slightly"
] | [
"You're right that it's not as strong as HCl, but it's a phosphoric acid derivative, so it's many, many orders of magnitude more acidic than ethanol."
] |
[
"What is the likelihood of the Yellowstone volcano to blow in the next 100-200 years"
] | [
false
] | I do understand that wile it is a geologically active area, but another discussion got me thinking about the topic, and I don't want to hijack that. | [
"I figured I should come by with my shiny tag and say something.",
"To confirm, it is extremely unlikely that Yellowstone will have a super eruption in the next 100-200 years. The volcano does not show the precursors of future eruption, i.e. seismic unrest, smaller eruptions, diking events etc. that are indicativ... | [
"I highly recommended that book as well! The answer to the question is \"very soon\". Soon in relation to the age of the earth, maybe not so soon for you and me."
] | [
"I highly recommended that book as well! The answer to the question is \"very soon\". Soon in relation to the age of the earth, maybe not so soon for you and me."
] |
[
"is it safe to drink PURE water?"
] | [
false
] | i saw on and it reminded me of a question i've had for a while. is it safe to drink pure H2O? i know a lot of water has flourides, or salts, or chlorine in them. is it alright to drink pure dihydrogen monoxide? or is that basically what that article is talking about? | [
"That article was written by someone who has some interesting misconceptions of how the body works. Yes, we call water the \"universal solvent\". Yes, \"solvent\" is a scary word in some contexts. No, this does not mean that pure water is dangerous. Drinking too much of any kind of water can lead to ",
"\"wat... | [
"written by someone who has some interesting misconceptions of how the body work",
"That's a remarkably charitable way to put it. ",
"I'd say that this article is a good illustration of how people without knowledge of human biology can write ill-informed words designed to scare those with even less knowledge o... | [
"It's safe as long as you are getting the salts, minerals, etc, from other sources.",
"But as a general rule to those who don't consider dietary requirements.. no, distilled water is not safer than tap water."
] |
[
"Are there any foods that I can eat now that dinosaurs would have eaten?"
] | [
false
] | I was looking at a bunch of also known as 'dinosaur kale' due to its distinctive leaves, and momentarily wondered if dinosaurs had eaten it. Since it's a cultivar of kale, an offshoot of the family, probably not. But I got to thinking - are there any food crops that humans now eat, which were eaten by dinosaurs? | [
"Alligator is "
] | [
"Fiddlehead ferns. Gingko nuts are edible. ",
"When gingko first evolved, fruit was a new concept, so instead of \"fruit flavor\", the fruits have the \"rotten meat\" flavor that was popular with seed dispersers at the time. But the seeds are edible, if you can handle processing the fruit."
] | [
"So are sturgeons and snapping turtles. And both of those were around for the last couple hundred million years too!"
] |
[
"Are there any instances of Solar Systems with hundreds or even thousands of planets?"
] | [
false
] | As I was looking at Jupiter this morning I wondered what a sky might look like with hundreds or even thousands of planets. Got me thinking, are there any stars known to have over a hundred planets. If not is there a reason why we wouldn't expect to see such a thing occur? | [
"Using the current definition of a planet, we currently hold the record for the largest known planetary system - with 8. ",
"HD 10180",
" comes in close with 7, but there are possibly two more planets unconfirmed that would bring it to a total of 9."
] | [
"I'm not sure if this is a material enough distinction to warrant mentioning, but I will anyway just to be safe:",
"The correct expression is \"star system\" or \"planetary system.\" The expression \"Solar system\" only refers to ",
" star system. Sol is the name of our sun, and \"Solar\" is a reference to that... | [
"Plus current thought has many more planets in our solar system to begin. Some were sling-shot out. Some collided (such a collision with the earth lead to the moon's formation)."
] |
[
"What weapon could have been used in the US Cuban diplomat attacks?"
] | [
false
] | null | [
"This question can't be answered based on knowledge? How is it any different than this question?",
"What does 72 pounds of plutonium look like crashing into Saturn?"
] | [
"This question can't be answered based on knowledge? How is it any different than this question?",
"What does 72 pounds of plutonium look like crashing into Saturn?"
] | [
"This question can't be answered based on knowledge? How is it any different than this question?",
"What does 72 pounds of plutonium look like crashing into Saturn?"
] |
[
"If I'm listening to music while I yawn or stretch, the pitch of the music will audibly change while I'm yawning/stretching. Why is this?"
] | [
false
] | Just noticed this. It always happens but I've never really thought about why. If I'm listening to music and I yawn/stretch, I can hear the pitch of the music bend slightly. Is there an explanation for this? | [
"I'll answer quickly but I'm on my iPhone so I won't be linking a source. Shame on me. ",
"When you yawn, breath in deeply, or breath out forcefully, you create a pressure gradient between your chest cavity and atmospheric pressure. ",
"Try an upper airway Valsava maneuver, you should feel your ears \"pop.\" Y... | [
"That's basically it. Just a few comments: The anatomical connection is called the eustachian tube, and it balances middle ear pressure with external air pressure when you yawn or swallow or do a valsalva. This momentarily stiffens the ossicles and tympanic membrane, leading to a momentary conductive \"hearing loss... | [
"For people with perfect pitch, do they notice this? and if so, does it move their point of reference?"
] |
[
"if concrete has a limited lifespan (~75-100 years?), what's going to happen to all the bridges, damns and sky scrapers we've built that are starting to reach that age?"
] | [
false
] | [deleted] | [
"From the ",
"Bureau of Reclamation",
"As the dam began to rise to fill the canyon, it grew in fits and starts. Rather than being a single block of concrete, the dam was built as a series of individual columns. Trapezoidal in shape, the columns rose in five foot lifts. The reason that the dam was built in this ... | [
"you aren't quite familiar with how concrete structures work. If all you needed was a concrete cube that did nothing, Taktl would be awesome. But we require concrete to span things, to support eccentric loads, and other situations where concrete experiences tension. concrete is not good at tension, so we place m... | [
"Civil Engineering Student from GA Tech here: ",
"It really depends on the type of concrete used, what kind of loads the structure will be subjected to, and the environment that the structure is in. There is still concrete from the Romans that is still structurally sound, such as the Pantheon in Rome, which is th... |
[
"Can the right hand rule (in electromagnetism) be derived?"
] | [
false
] | Is the fact that things follow right (or left) hand rules instead of left (or right) hand rules possible to be derived from laws of physics or is it just something we know empirically? | [
"Sorry, I should clarify. Conventions aside, the force on an moving electron in a magnetic field (for example) has a direction. I'm wondering whether we can derive that direction, or if we just have to fire an electron in a field and find out which way it goes."
] | [
"The right hand rule is just a mnemonic to remember definitions."
] | [
"It's the result of the definition of right-handedness, which in turn follows from the shape of human hands and which side of us we choose to call 'right'.",
"The handedness (orientation) you give to space is conventional. This affects the definition of the cross product among with a lot of other things, but a gl... |
[
"Is time truly infinite in a black hole?"
] | [
false
] | From Wikipedia: The appearance of singularities in general relativity is commonly perceived as signaling the breakdown of the theory. This breakdown, however, is expected; it occurs in a situation where quantum effects should describe these actions, due to the extremely high density and therefore particle interactions.... | [
"We can observe black holes indirectly, via their affect on light in various solar systems, notably binary star systems. We cant \"truly\" know how they behave until we are able to closely observe one. Even if we could launch probes into one, by our current theory it would take nearly infinite time to reach the eve... | [
"it would take nearly infinite time to reach the event horizon",
"Isn't it the case that the probe would follow a normal path into the black hole, but would appear to take a long time only to an outside observer? That is, it wouldn't take such a long time from the probe's perspective right?"
] | [
"From the probes perspective, everything else in the universe would slow down. From the outside perspective, the probe would slow down. Either way, it would be difficult to get useful data from the probe. Even if it emitted gamma ray signals from near the even horizon, they would be red shifted into low power radio... |
[
"I am a computer science student and want to work on brain-computer-interfaces after I got my degree, any helpful information?"
] | [
false
] | null | [
"learn to love dissecting rat."
] | [
"check."
] | [
"Step 1: go to the future."
] |
[
"Are blackholes only formed by the gravitational collapse of a star? What about supermassive black holes?"
] | [
false
] | Could they have been formed from mind boggling large stars? Or can blackholes merge together? I've also have another question, slightly related, about stars. If stars are formed by large clouds of hydrogen being compressed by gravity, does that mean there is a finite amount of hydrogen in the universe, as stars use/con... | [
"This kind of supernova is called a 'core collapse supernova'. Basically the big ball of iron and whatnot at the center is under incredible pressure from the gravity of the star. The electrons in this matter are what provide the repelling force to keep the core from collapsing, which is more or less the same reas... | [
"Could they have been formed from mind boggling large stars? Or can blackholes merge together?",
"Once formed, black holes can certainly continue to accumulate mass as more stuff falls into them. We only observe them via the energetic emissions of stuff spiraling into them, for instance.",
"According to ",
"w... | [
"We have no reason to think so, and it isn't any standard scientific theory."
] |
[
"Could you give me some great books?"
] | [
false
] | null | [
"This isn't really the place. Try ",
"/r/books",
"."
] | [
"This isn't really the place. Try ",
"/r/books",
"."
] | [
"thanks a lot."
] |
[
"Why do the electron and proton have the same electric charge?"
] | [
false
] | It seems kind of weird, since one is a fundamental particle, and the other is a composite particle. Is it an approximation, like when we say the proton and neutron have the "same" mass? Does it have something to do with the fact that the proton cannot be separated into its quark components? On a side note, is the funda... | [
"That's a good question that doesn't really have a good answer yet. According to some pretty high precision experiments, they really are exactly equal. ",
"There is a proof by Paul Dirac (IMO one of the most brilliant physicists in history) that if even one ",
"magnetic monopole",
" exists anywhere in the u... | [
"We'll probably both get our comments deleted, but I highly recommend ",
"The Strangest Man",
". It's written by a physicist and actually goes into his theories and others of the time. "
] | [
"Paul Dirac is not just one of the most brilliant physicists ever, but his life is also a great source of amusing anecdotes."
] |
[
"What is the actual cost of nuclear waste storage?"
] | [
false
] | I cannot seem to find any clear information on actual costs of nuclear waste storage. Are there any accurate calculations of nuclear waste available, that don't just take the first 100 years or so in account? Are these costs actually considered when calculating the price of nuclear power? Do the energy companies pay fo... | [
"That pdf is only about the decommissioning cost of a specific type of power plant."
] | [
"Wikipedia",
" refers to a ",
"pdf from the IAEA for specific costs"
] | [
"At present, all nuclear power plant are storing spent fuel on site in dry casks and expect to do so indefinitely pending the availability of a permanent repository. Not sure if there is a cost associated with that can be separately evaluated. Also not sure what you mean by \"costs actually considered when calcul... |
[
"Are microtubles in plant and animal cells same?"
] | [
false
] | null | [
"It honestly depends at which level of difference you're looking for. Microtubules aren't even identical between different humans, in fact they can be different between your own cells even by the amino-acid code for the proteins that make microtubules. Cell morpholology, differentiation and stage of the cell cycle ... | [
"For the purposes of your question, microtubules in plants, animals and fungi are the same. \nVariation exists in the amino acid sequence from species to species, and more so eukaryotic kingdom to kingdom, but the basic structure of alpha and beta subunits in a tube is conserved throughout the eukaryotes. \nThis is... | [
"Hey thanks for wonderful reply. I am concerned with microtubules because i am working on plant cell and i have no background on it. My question was also more on the functionality. As far as i know microtubules align the cellous fiber in plant cell thar makes the cell wall. Also microtubules themselves align accord... |
[
"Is there a liquid adhesive that remains tacky/sticky after \"drying\"?"
] | [
false
] | I thought this would be an easy item to find, but I can't seem to come up with anything. I need a liquid adhesive that acts like double-sided tape, not a permanent bond. | [
"What you are looking for is a ",
". One of the most famous of these types of products is the liquid adhesive that is applied to the back of ",
"3M Post-It Notes",
". This adhesive was ",
" by accident when the inventor was trying to identify a super-strong adhesive, but the result was a low tack, reusabl... | [
"Awesome, thanks for the education!",
"Would you know of a particular product that would work well with plastics, including ABS? I found ",
"Perma-Tack",
" however I'm not sure if there are more suitable products. I'll keep looking, but if you know any please let me "
] | [
"Unfortunately, I'm not sure on specific products that could help you. Know that there are quite a lot of them, so look for one that claims it works well with the materials you are working with."
] |
[
"How does air look in a solid state?"
] | [
false
] | null | [
"Here's a video where they make solid nitrogen.",
" It looks pretty much the same as water ice. And carbon dioxide ice. And most likely oxygen ice. It's just a clear solid, although unless you take great care to prevent bubbles it looks like a white solid."
] | [
"In addition, oxygen is magnetic at low temperatures. This makes it a major pain if any air enters the sample chamber of a cryogenic magnetometry system."
] | [
"Liquid oxygen is actually light blue! Frozen oxygen is ",
"apparently",
" blue as well (at least at 1 atmosphere of pressure)."
] |
[
"Does being exposed to tetanus while vaccinated \"renew\" your vaccination?"
] | [
false
] | null | [
"the Tetanus vaccine is does not give you antibodies to the bacterium. the tetanus vaccine stimulates your immune system to produce the antibody to the tetanus toxin. In order for your immune system to get a \"booster\", you'd have to be exposed, infected, and have that infection persist long enough for the bacteri... | [
"Thank you."
] | [
"No. Vaccines work by exposing your body to either killed or weakened versions of the infecting agent. They do so in numbers so that your body freaks out and begins eradicating them, thinking it's a massive infections (though it's really harmless). This strengthens your immune system to recognize the threat early a... |
[
"Why doesn't the active site in hemoglobin bind to nitrogen gas? After all, N2 has the same electronic geometry as carbon monoxide."
] | [
false
] | I understand how the Fe in the heme group binds to the lone pair of O2, and I understand how CO binds to the same site to competitively inhibit hemoglobin function. I even understand how the shape of the active site adjusts the affinity for CO over O2 to a manageable level. I don't understand why CO bonds with such a ... | [
"It's because N2 is a very poor ",
"pi-acceptor",
" and sigma-donor especially compared to CO. This makes N2 a very ",
"weak field ligand",
". Stronger ligands further split the HOMO and LUMO in the resultant molecular orbital. This increased splitting makes the anti-bonding orbitals harder to fill.",
"Ad... | [
"I would guess this is also part of why it's so difficult to fix nitrogen from N2 into other chemical forms, requiring special, mega-turbo-enzymes to do so. Is that a reasonable assumption? "
] | [
"That's part of the reason the catalysts are so difficult to design. The actual break down of N2 is additionally difficult due to the very stable N-N triple bond."
] |
[
"[Biology] If a disease is eradicated, how does it come back just from someone not getting vaccinated?"
] | [
false
] | Someone posted a screenshot indicating that the first case of polio has been discovered in the US recently. I am unsure if this is true, but nonetheless it piqued my interest as a whole. | [
"If a disease is eradicated, it can't come back. ",
"But polio hasn't been eradicated yet. There are still cases of polio in the wild in ",
"Afghanistan and Pakistan",
". ",
"That said, I haven't heard about wild polio cases in the US and I don't think there have been any cases in the US since 1993. ",
"P... | [
"By eradicated it means no people diagnosed while showing symptoms in an area. Animals might contain a strain that is transmittable to humans, or people might be carriers, and when you don't get vaccinated there are more opportunities for those disease vectors to propagate."
] | [
"People travel. Only global eradication is truly safe.",
"I didn't find a report about polio in the US, just something ",
"\"polio-like\"",
" - but that is a different disease. There was one potential case in Venezuela earlier this year but that turned out to be a false alarm. ",
"Article",
"."
] |
[
"Does altitude make a difference during earthquakes?"
] | [
false
] | Let's assume the source of the earthquake is perpendicular to your position and at a fixed depth based on sea level. Would you or buildings be less effected from the quake in Nepal (lets say 4000-5000 km above sea level) than beeing on german plains (at maybe 200m)? If so, how much/would it be significant? I guess my q... | [
"Let's assume the source of the earthquake is perpendicular to your position and at a fixed depth based on sea level.",
"Would you or buildings be less effected from the quake in Nepal (lets say 4000-5000 km above sea level) than beeing on german plains (at maybe 200m)? If so, how much/would it be significant?",
... | [
"Are you an AI? You are too good at this. Consistently so, and not just in-depth answers, but with links to multiple and relevant published papers.",
"Thank you."
] | [
"Wow, thank you! Very interesting read."
] |
[
"What makes a voice unique?"
] | [
false
] | Pitch is just the vibration of vocal chords at a certain speed to generate a certain wavelength right? So why do two people singing at the same pitch sound different? P.S. not sure if I used the right flair because I’m not sure what impacts it, sorry 😅 | [
"What we refer to as pitch is just the fundamental, or lowest, frequency. A pure frequency just sounds like a beep, so what makes instruments sound unique are their timbre, or overtones. Overtones are generally not distinguishable in the sense that they’re more of a continuous ”buzz”, but you can sometimes hear the... | [
"I clearly am missing large amounts of information. Is there a name for this kind of study or course?"
] | [
"You can learn about it in various contexts, i.e. music theory, acoustics, singing, speech therapy/medicine, etc. I dont know if there is a single study or course for it."
] |
[
"Can you build a laser powerful enough to mess with satellites in orbit?"
] | [
false
] | A conversation about Starlink got me started down a rabbit hole of imaging satellites currently in orbit and potential "vandalism" from the ground. I'm wondering if imaging satellites could be tracked and blinded by ground-based laser for significant portions of their orbit, and if so why this isn't a common occurrence... | [
"Yeah, this is one method proposed for deorbiting space junk. If you focus a laser to a point on the surface of the thing you want to deorbit you can heat one side of it to enormous temperatures if your laser is powerful enough. This effectively burns material off the surface (though it's not true combustion, there... | [
"The main issues would be atmosphere attenuation, distance losses due to beam widening, and tracking the satellite"
] | [
"Man I asked if we could do this on another post. No answer. But I’m glad I finally have the answer. Lol.",
"Would it have to be a very large laser? Also would the laser dissipate if we missed and hit the earth?"
] |
[
"Is the universe a closed system?"
] | [
false
] | [deleted] | [
"There are a number of theory's about black holes, but all of them (that I've read about) stay within our universe.",
"As for your actual questions, that is not something that can really be answered right now. Even an educated guess would just be wild speculation. We really know very little about the universe as ... | [
"Energy can be neither created nor destroyed -- IN A CLOSED SYSTEM. ",
"There are many theories that contend that our universe is a closed system, and others that state it is open. If the universe truly is infinite, then it is an open system in which matter, energy, and information can be created or destroyed all... | [
"Figures he would say something like that. Black holes are not literal holes. They're objects large enough that their gravity can trap light. Obviously there's more to them than that, in many ways and nuances, but the point is that they're big and have huge gravitational pulls. Anything that \"goes in\" is just stu... |
[
"spacecraft (tps) thermal protection systems"
] | [
false
] | what does it mean to be actively cooled and how does it work exactly? seems to be rather light on the subject. would you start said system before or during reentry? edit: would this be the same as firing say water in to the shock layer? | [
"It might be easier to think of this as an automotive engine. A 60s Volkswagen air-cooled engine will be passively cooled. The heat will dissipate off through the atmosphere without a system forcing air there. A modern engine is actively cooled, through coolant circulating the engine and off to the radiator where t... | [
"I'll take any and all corrections, but if the only thing I'm getting wrong is my memory of older VW engines I think I did OK ;-). ",
"I was just going off the engine that we had in the Type 3 when my dad picked it up to \"try to restore it\" (he got bored of it in the end since he couldn't get the carbs to wor... | [
"Hmm, so is it at the rearmost part of the car or is it up before the transmission (so its directly connected to the tranny)? ",
"Here's a picture of the fastback engine",
" The left side plastic cover is covering the belt, but it could be the second to last thing (so right before the pulleys, that makes sense)... |
[
"Methods for long term dna storage?"
] | [
false
] | So, just hypothetically, what would be the best method to store dna for long periods of time, (and what kind of range is currently technically feasible? 100 years? 1000 years?) storage with minimum degradation, as the dna would be intended for cloning purposes? | [
"Well, in my lab we store DNA in buffer in a regular freezer. It lasts as long as the freezer does. Basically if you keep it cold enough and mechanically stable, not much can happen to it. Perhaps a dewar of liquid nitrogen would be a good solution. The thing about long long term storage is you have to make sure pe... | [
"TE buffer",
" at -80 ºC is the preferred laboratory long term storage method, I believe.",
"And considering that DNA has been recovered from Neanderthal remains (which are at least 25,000 years old at minimum, although I don't actually know the age of the specimens that DNA ",
" been isolated from), I'd say ... | [
"Carve the base sequence into a slab of iridium."
] |
[
"Why isn’t Earth’s escape velocity 9.81m/s?"
] | [
false
] | null | [
"Why do you think it would be?"
] | [
"Because escape velocity is 9.8m/s",
" so having that extra hundredth of a meter per second would ",
" overcome gravity.",
"I know it’s not exactly 9.8, but that’s the approximation value."
] | [
"You're confusing acceleration due to gravity with escape velocity."
] |
[
"If we can lose hundreds of skin cells by scratching at them, why is it hard to rub off pen or marker on our skin?"
] | [
false
] | [deleted] | [
"Depends on the solvent as well. But if you get sharpie on you, draw on top of it with dry erase marker. Then they both wash right off. "
] | [
"Thank you for the best, and ",
" answer. "
] | [
"The solvents used to keep Dry Erase Markers liquid until the marker ink gets onto the whiteboard and dries are also great at disolving other inks."
] |
[
"Why do humans kiss?"
] | [
false
] | How did this start? Is there an evolutionary or psychological reason? Why is it so enjoyable? it seems like a random way to express affection. | [
"(",
"http://health.usnews.com/health-news/family-health/sexual-and-reproductive-health/articles/2009/02/13/pucker-up-what-science-is-discovering-about-why-we-kiss",
")",
"(",
"http://earthsky.org/human-world/sheril-kirshenbaum-on-the-science-of-the-first-kiss",
")",
"(",
"http://people.howstuffworks.... | [
"\"Today, the most widely accepted theory of kissing is that humans do it because it helps us sniff out a quality mate. When our faces are close together, our pheromones “talk” – exchanging biological information about whether or not two people will make strong offspring. Women, for example, subconsciously prefer t... | [
"Kissing involves swapping bacteria, but saliva carries anitbacterial agents that can protect us against infection. So it acts a bit like an immunization, especially between mother and child. It has evolutionary benefits obviously, so it makes sense that it has become connected to pleasure and is enjoyable. ",
"S... |
[
"Is there a scientific system for describing various patterns of bird flight (e.g. the equivalent of terrestrial 'sprinting', 'walking', 'running', etc)?"
] | [
false
] | With horses you have galloping, trotting, etc., but I can't seem to find anything about bird flight. | [
"Some common types of bird flight are hovering, gliding, thermal soaring, dynamic soaring, diving, undulating, and bounding. Not all birds are capable of all types of flight though and it is more common to classify birds by wing type than flight type. The four common wing types are elliptical wings, high speed win... | [
"Yes, there are a lot of them, as ",
"/u/dude142",
" has pointed out. However, for those interested, I can outline a few of the more commonly encountered types: ",
" - ",
" hovering occurs when a bird generates lift just by flapping, with no assistance from headwinds. ",
"Hummingbirds",
" are famous fo... | [
"Here you go",
"! Elliptical wings are short and rounded, used for maneuverability and rapid flapping. High speed wings are short and pointed, used for ",
" rapid flapping (e.g., Peregrine Falcons). High aspect ratio wings are long and slender, used for slow-speed flight and/or long periods of gliding and dynam... |
[
"Breaking a bar magnet in half creates two new bar magnets with a north and south pole. How many times can a bar magnet be broken in half until the poles of the new parts are no longer discernible?"
] | [
false
] | [deleted] | [
"The poles aren't physical things. The magnets are made of atoms, and each atom can be thought of as producing a tiny magnetic dipole field. When they're all pointing randomly, they cancel out, but when they are aligned, there is a net magnetic field. So if you cut a magnet again and again and again, you'll eventua... | [
"No. A single atom would also be a dipole. Monopole magnetic fields are only theoretical and have not been observed."
] | [
"No. A single atom would also be a dipole. Monopole magnetic fields are only theoretical and have not been observed."
] |
[
"If one fills a room with sprayable fly poison and leaves it be for maybe a hour or so, what happens to the rooms bacteria?"
] | [
false
] | [deleted] | [
"That's like saying that because ethylene is a plant hormone, if you (a human) take ethylene you'll grow boobs (or leaves). ",
"Fly poisons probably have no or little effect on bacteria."
] | [
"Nothing? It's fly poison, not bacteria-poison. In other words, it's probably not anti-bacterial."
] | [
"Well the first question is, why is it a poison to flies? It looks like some fly sprays inhibit acetylcholinesterase, as explained ",
"here",
". This doesn't matter to bacteria, but that doesn't mean the spray won't affect them at all."
] |
[
"[Engineering/Physics] How do thermonuclear warheads get decommissioned, without anything blowing up?"
] | [
false
] | If it were opened by cutting action, wouldn't that trigger the conventional explosives inside (and the nuclear explosion too)? | [
"They were put together somehow, so you'd just take them apart the same way. It's not like they're sealed in a solid metal container or anything, you just remove the bolts and open the thing.",
"Even if you did open it with a cutting torch, it wouldn't set off a nuclear explosion. Depending on the conventional ex... | [
"Actually, thermonuclear devices derive a significant amount of their explosive power from fission. They are generally three-stage devices: a fission primary, a fissile \"spark plug\" surrounded by fusion fuel, and a fissionable (but not fissile) casing (usually depleted uranium). The primary generates the neces... | [
"I probably should have just said \"implosion-type weapon.\" I was trying to make the distinction that there are designs that would be significantly easier to set off accidentally, like the gun-type design used in Little Boy, and I don't think any modern warheads are pure fission devices. I just had the typical Tel... |
[
"I've read that running water under a spaceship hull is a good way to protect from radiation while minimizing weight, as astronauts need water to drink anyway. But would that not just result in an irradiated water supply?"
] | [
false
] | [deleted] | [
"Radiation in space is charged particles, mostly protons and helium nuclei. As they traverse matter they give off their energy by causing ionization in the surrounding material, and this way they slow down. Cosmic rays have extremely high energies, so most of them won't be stopped by the water, just slowed down a b... | [
"It's more complicated.",
"Cosmic radiation is too hard to shield against, so with any realistic protection astronauts are still at risk of developing a cancer or cardiovascular disease in the long term. But it can't kill them in the short term because it's a small daily dose over a long period of time.",
"Sola... | [
"It's more complicated.",
"Cosmic radiation is too hard to shield against, so with any realistic protection astronauts are still at risk of developing a cancer or cardiovascular disease in the long term. But it can't kill them in the short term because it's a small daily dose over a long period of time.",
"Sola... |
[
"What in the brain gives certain memories for a rememberer a sense of 'sureness'?"
] | [
false
] | How are some memories rated by witnesses to an event from unsure to sure? | [
"You can think of it as listening to the chorus of a room full of people. If everyone is saying the exact same thing in synchrony, it will be loud and clear and you will be sure of what you are hearing. The less synchronized everyone is, the more there will be other voices saying something else, or just plain noise... | [
"You hear one voice wich is the one you give to yourself when you want to think about something.",
"However, your subconscious mind, what you don't hear, is a bit like a congress. Tons of little people deciding what you should do and how should you feel about something. When a big majority agrees, you think (or r... | [
"That blew my multiple mini minds that were decided that they were a majority of blown mind, which my conscious mind heard and was blown away as a whole. "
] |
[
"Why is it that people can be born with half a brain, but getting stabbed/shot/hit in the head can kill you?"
] | [
false
] | null | [
"So the child's brain has a great deal of what's called ",
". Meaning the interconnections between brain regions, and even between brain and body, are readily changeable. This plasticity is part of what makes learning so easy for children. I have seen patients, under ten years old, who have had one-half of their ... | [
"Thanks!"
] | [
"Blood kills brain cells so any trauma up there is serious.... But I don't think that is what you are asking. I'd you have enough functioning brain tissue in the right areas your brain can just wore itself around what is missing. When a chunk is damaged, it's like someone just cut the wires. There is no path for th... |
[
"What do scientists propose as an answer to the problem of global warming?"
] | [
false
] | [deleted] | [
"So cutting emissions is the first thing. Besides that, there aren't a whole lot of good, clear cut solutions to deal with climate change, in large part because it will have drastically different effects in different parts of the world. The best thing to do is really prepare to mitigate the damages and adapt to a w... | [
"The future refugee crisis is, I think, one of the areas that doesn't get enough air time. Europe is currently tearing itself apart dealing with, at most, a few million refuges from Syria. When the seas really start rising we are going to see tens even hundreds of millions of people wanting to relocate (it's estima... | [
"The one point that I would add to this is that -- IF fusion plants become a reality -- then there is a possible solution. There are already numerous carbon capture and sequestration (CCS) technologies available -- the problem is that most of them are either prohibitively expensive and/or require a ton of power to ... |
[
"Question from my 12 yo: Why are the water levels of the Pacific Ocean and Atlantic Ocean different on each side of the Panama Canal?"
] | [
false
] | [deleted] | [
"Not correct.. ",
"the ocean is in fact at a different level on the pacific side of panama, about 20cm (due to differences in salinity)",
"Almost all the rest of the variation due to tides.. the tidal variation on the pacific side is almost 20 feet and the Atlantic side only a few feet.. ",
"http://geography.... | [
"They aren't different. The Panama canal, unlike the Suez canal, is not all at sea level. There is a mountain range through the middle that proved too difficult to cut through. They dammed a river and made a lake. The locks are needed to lift the ships into Gatun lake, 85 feet above sea level. Lock are used again o... | [
"That's not the reason they use locks. The explanation is still valid."
] |
[
"Can a tsunami be stopped by an equal and opposite amount of force?"
] | [
false
] | Looking into the future there's a lot of human settlements that are densely populated and by the water. Evacuating so many people on such a short notice will probably prove to be somewhat difficult. Is there any conceivable technology that could cancel out the massive wave that a tsunami would produce? | [
"Creating an equal and opposite tsunami, if it isn't positioned at the origin if the first one, might create a 2-source diffraction pattern: regions where the tsunami is canceled, interleaved with regions where the tsunami is twice as high.",
"Mega-engineering technology? Sure, how about a ",
"Bragg mirror",
... | [
"Wow that's crazy! Would the source of such energy have to be something nuclear?"
] | [
"Tsunamis are waves, and waves undergo superposition. However, there is such a massive amount of energy in a tsunami that it isn't likely feasible or plausible.",
"There may be some non-linearities in the interactions between the tsunami wave and the sea floor, and tsunamis aren't exactly standing waves.",
"In ... |
[
"Do birds sing in certain \"keys\" consisting of standardized \"notes\"?"
] | [
false
] | For instance, do they use certain standards between frequencies like we have whole steps, fifths, octaves, etc? Do they use different tunings? If so is there a standard for certain species, with all the birds using the same? Are there dialects, with different regions of the same species using different tunings and inte... | [
"Oh man, you hit on a favorite topic of mine, partially due to helping with previous research into this! So let's start with the two \"types\" of bird song: learned and unknown.",
"A very classic study species for bird communication is the Song Sparrow. Beecher in particular has done ",
"extensive",
" researc... | [
"This subject has long been of interest to ornithologists, musicians, and musicologists. It's tricky to study, because musical training can help you parse sounds in a detailed analytical way, but it can also lead to hearing it in a framework that could impose human musical structure beyond what is inherent in the ... | [
"“Scientists at the Max Planck Institute for Ornithology in Germany, working with U.S. colleagues, report the songs of the aptly named Musician Wren use the same intervals -- octaves, perfect fifths and perfect fourths -- heard as consonants in many human cultures. Consonant intervals, which sound calm and stable, ... |
[
"Do solid objects have a surface tension?"
] | [
false
] | Does surface tension have anything to do with the shape of planets? | [
"Here's a video from sixtysymbols about a recent paper on surface tension in granular systems. ",
"http://youtu.be/2uWps9LczH8",
"It shows that some non liquid systems can have a surface tension. I'm not savvy enough to know if it has any applications to your second question."
] | [
"Planets are spherical because a sphere minimizes the gravitational potential energy of an object.",
"Edit: Well they're roughly spherical....."
] | [
"Surface tensions only applies to liquids,",
"You get an F in materials science. All condensed matter, solids and liquids, exhibit surface tension (i.e., a energy penalty when surface area is increased, due to the interruption in internal bonding). Surface tension, also known as surface energy, can be measured in... |
[
"How exactly does a smart meter know the difference between TV usage, AC usage and other?"
] | [
false
] | My utility bill shows me a chart of energy usage based on device (AC, refrigerator, Always on and other). I'm curious how it can know what devices are using electricity and how accurate the information on my bill is. | [
"The utility is collecting the data every 15 seconds or 1 minute or so and is searching for patterns.",
"\nIf there is a regular pattern of 100W usage during 15 minutes every hour day/night then it is likely a fridge, 1500W during 2 minutes at 06:30 probably means you put on the kettle for a cup of tea, a lot of ... | [
"Appliances draw different amounts of energy and usually have fairly consistent on/off cycles. Both of these things can be used to infer what appliance is doing what.",
"For example, your fridge is likely going to draw around 500 watts and will consistently cycle on and off 24 hours a day. Your clothes dryer is g... | [
"What if two or more appliances are running at the same time?"
] |
[
"What would it look like on the pole of a planet with no axial tilt?"
] | [
false
] | If the months-long polar days and nights are due to the Earth's axial tilt, what would it be like on the North or South Pole of a planet without any? | [
"If there was no axial tilt, everywhere on Earth would in theory have 12-hour days and nights year-round. On the Poles, however, there's no Earth to block the Sun during the \"night\", so the Sun would never set. It will circle around the sky at the horizon."
] | [
"You can basically see this during the spring and fall equinoxes on the poles of our planet, too.",
"Actually, not just on those exact days... but then it's when it's closest."
] | [
"Thank you! That sounds like it'd be a sight to see."
] |
[
"Neil DeGrasse Tyaon wrote in one of his books that the universe was a few light-years across 1 second after the big bang. Shouldn't it have only been one light-second across?"
] | [
false
] | "By now, one second of time has passed. The universe has grown to a few light-years across, about the distance from the Sun to its closest neighboring stars." , pg. 343, "In the Beginning". If nothing can travel faster than light, all those particles should have only travelled one light-second, right? Were conditions d... | [
"He means that since they're outside of our observable universe (and we're outside of their's) there is no way for us to affect each other; information doesn't travel fast enough. "
] | [
"Entanglement does not transmit information. In principle, you could have correlation due to entanglement, but almost any interaction with the environment would destroy this, so it is not only highly unlikely, but impossible to verify."
] | [
"Entanglement does not transmit information. In principle, you could have correlation due to entanglement, but almost any interaction with the environment would destroy this, so it is not only highly unlikely, but impossible to verify."
] |
[
"What's going on when I'm getting a \"kink in my neck\" after sleeping in an odd position?"
] | [
false
] | I must have slept weird but I woke up with a kink in my neck. What happens that causes this? | [
"Tissue viscoelasticity. The extensible elements in your musculoskeletal system have taken on a certain 'set' after prolonged immobilization. That's why normal sleep is best in a large bed to permit frequent involuntary re-posturing during sleep. Like the flat spot that forms in a tire while the auto is parked. A b... | [
"Also called \"acute torticollis, or wry neck;\" basically what's happening as you sleep, your muscles adapt to a new position, whether shortened or lengthened, or even exposed to the cold for long periods over night. When you wake up, as the muscles and joints try to move into there normal resting position, they a... | [
"So it happens basically because you don't move around as much when you sleep on a couch?"
] |
[
"What happens to farts when you hold them in? Is being polite bad for your health?"
] | [
false
] | null | [
"medicated anal gas purging",
"Taco Bell."
] | [
"It just moves back up your colon, and comes out later, it's not absorbed, and it can't be burped out, the fart is about 25 feet from your mouth.",
"As per my job, people burp inches from my face multiple times every day, I would quit right there if someone burped a fart into my face. "
] | [
"Good to see someone with credentials revealing their methods."
] |
[
"What are some specific, practical contributions from the field of theoretical physics?"
] | [
false
] | null | [
"/r/AskScience",
" does not offer help with schoolwork. "
] | [
"I'm a 31 year old guy working at a family business, actually. I'm genuinely curious."
] | [
"Ah, okay. It sounded like a writing prompt for a class, and we've had about a million of those today, up to and including pleas for thesis topics and sources. We really don't want to be writing people's essays. ",
"This is more of a discussion-based question rather than one that's strictly scientific. It's bette... |
[
"Could technology advance to a point where we could film a room filling with light in slow motion?"
] | [
false
] | You know when you shine a laser into a smoke filled room you can see the beam of light? Well could we get to a point in technology where we could film this in slow motion and watch the light move though the smoke? | [
"It's been done, more or less. ",
"Here you go!"
] | [
"This is not exactly what it appears to be, although it is still extremely cool. They managed to get the timing of the camera so precise that they could take individual frames from a continuous beam of light and put them in order consecutively so that it appears to be a continuous movie of a beam of light. In reali... | [
"Yes, they say as much in the TED talk I linked, from 5:09 to 5:36.",
"The effect is essentially the same, and it is not possible to record in the way you suggest, where the frames are actually separated by femtoseconds. Insufficient light would strike the camera lens in such a short time to create any useful fo... |
[
"What happens if a GPS satellite gets KO'd?"
] | [
false
] | I know it's a bit redundant in case of this kind of thing, but does NASA go replace it? Pretend it gets mashed in the next meteor shower or something. | [
"Apparently, the minimum amount for the GPS system to be operational is 24 satellites. However, as at the moment 31 are operational, there is small chance of harm to the GPS system. If one satellite were to fail, there are enough others to keep the system working. Satellites do age and get decommissioned all the ti... | [
"How can you have 3? Trilateration requires 3 satellites but you need a fourth to use for a time signal. ",
"https://en.wikipedia.org/wiki/Global_Positioning_System#Problem_description",
"\"Since the equations have four unknowns [x, y, z, b]—the three components of GPS receiver position and the clock bias—signa... | [
"GPS receiver still give you a position if you only have 3 satelllites visible. They do that by moving the equation around and assuming that you are on the ellipsoid or last known altitude. That reduce the number of unknown variable to three, 2 positions and time and the system can now be solved. The precision and ... |
[
"Could ocean water freeze under the high pressures/low temperatures at the ocean floor?"
] | [
false
] | null | [
"If you examine ",
"water's phase diagram",
" you'll note that at the pressure in the deepest part of the ocean, roughly 100 MPa (versus 100 kPa at sea level), water freezes at something like -10°C. The water at the bottom of the Mariana Trench is something like 1 to 4°C, so pure water here would not freeze.",... | [
"Methane hydrates/clathrates",
" are fascinating structures, in which methane is bound within a crystal structure of water ice. They are found in sediments at ocean depths of ~250-550 m at low to high latitudes, respectively ",
"(ref)",
". \nA line that stands out from that reference:",
"The solubility of m... | [
"Yes, there are phases of ice more dense than seawater, but the conditions for its formation are far more extreme than those found in the Mariana Trench.",
"To give an idea of how much more extreme, the pressure at the bottom of the Challenger Deep is about 110 MPa at 11 km deep. You don't start getting into the ... |
[
"How would you feel standing on the surface of Kepler 22b, as opposed to the feeling of earth's gravity?"
] | [
false
] | Would I feel 2.4 times as heavy in relation to earth's mass? | [
"I'm not so sure you've got that right. Because of the Archimedes Principle, in a denser atmosphere, you'd be more buoyant. This makes intuitive sense if you imagine the atmosphere being so dense that it was like water. Well, what happens when you are under water? You float because you are buoyant. In water you do ... | [
"It's mass is unknown but constrained to be less than 0.11 Jupiter masses (from the Exoplanet Encyclopedia, ",
"link",
"); It's radius is 2.4 Earth radii. If you plug that in to the formula for gravitational acceleration: g = GM/r",
" , with M= 0.11 Jupiter masses and r= 2.4 Earth radii, you get g = 60m/s",
... | [
"According to the ",
"Wikipedia page",
" Kepler 22b may have a surface gravity 2.4 times that of earth, so yes you would weigh 2.4 times as much as you do on Earth if Kepler 22b has the same average density as that of Earth.",
"To calculate surface gravity you need the mass of the planet and its radius (by co... |
[
"I know that there is no sound in a vacuum...but what happens when sound HITS a vacuum?"
] | [
false
] | For a plausible scenario, say the sound of a jet engine in the upper atmosphere reaches to the vacuum; does it echo back or just release energy into space? | [
"It depends on how the boundary is separated. If sound is travelling from a dense medium to a low density medium, it can eject a liner of material at the interface into the low density zone, under the right conditions. An example would be explosives on the surface of a tank causing the inside surface to eject into ... | [
"Interesting question... I don't do acoustics or kinetic theory specifically so I had to think a good bit about it. One of our acoustics people can correct me if I'm approaching this way wrong.",
"First, if you're talking about a gas with a sharp interface to a vacuum, that can't really happen. A dense cloud of g... | [
"This can be simulated by flicking a wave through a stretched slinky with your hand, after attaching one end to a string that is in turn hanging from something. The wave is reflected off of the end with the string because \n going from a denser to a less dense medium, much like your sound wave hitting the vacuum. "... |
[
"So my wife has a nero spinal cord stimulator, she has the hardest time trying charge it, I would love some suggestions (explain more inside and with link to what she has)"
] | [
false
] | null | [
"So by all your silence of over 500,000 subscribers, not one person can suggest or even comment to help.",
"Thanks... "
] | [
"You have not received any responses because all posts are held for moderator approval. It can take us a bit of time to get through the posts. Due to the large number of submissions we receive, we don't provide removal reasons for every post. We encourage people to contact us using the \"Message the Moderators\" bu... | [
"Thank you very much for responding, my apologies on not realizing it was a violation of this sub. ",
"Just been a ruff year and we've tried to talk to the doctors who are in charge of her operation, but they talk to her like a child a blow off what ever she has to ask, so I'm just kind of at wits end.",
"So m... |
[
"Can Three of the Four Types of Volcanic Eruptions Happen Underwater?"
] | [
false
] | A volcanic eruption is measured in two constants--gas and viscosity. For clearance, low viscosity is like squirting water off a nozzle, whereas high viscosity is like squirting caramel off a nozzle, which takes more effort to do, which ultimately makes it more dangerous. In geology, there are four different kinds of... | [
"All four of those cases you listed depend only on the magma, not whether there's surface water, so yes, all four can occur underwater. ",
"This page",
" gives a nice summary of hydrovolcanic eruptions.",
"As you can see it's a bit complicated and depends on the circumstances, how much water there is, the dep... | [
"Depth is not a condition for the formation of pillow lava, it's enough that the lava has sufficiently low viscosity. It will however look different depending on the depth it formed since lava formed above 3km depth will have formations in the rock showing where steam/gas escaped from the lava as it solidified."
] | [
"To put it simply, all 4 can happen underwater. Gas or viscosity are irrelevant as to whenever or not water is above the magma source.",
"Generally you also only have 2 types of reaction between magma and water:",
"Well, that is atleast as far as I remember that stuff? If anyone has any corrections please tell ... |
[
"Can someone explain this (or refute it) a little further? \"There's an object so dense and massive in the universe that it is pulling all galaxies towards it!\""
] | [
false
] | Link to the picture where I found the quote: | [
"Not sure about all the galaxies but you can read up on ",
"the great attractor",
"."
] | [
"Yes.",
"Edwin Hubble observed that ",
"galaxies are moving away from us",
" and the further the galaxies are the faster they are moving away from us.",
"If we were all going towards the same place this would not be the case."
] | [
"I'm a little confused by what you're saying... You are disagreeing with the idea that there is a single object that we're headed toward, but you said yes?"
] |
[
"What`s the thinnest layer of material which isn`t transperant?"
] | [
false
] | How, do I calculate the critical thickness, when 100% of a specific elctromagnetic wave frequenz gets absord. So nothing of that frequenz gets to the other side. (I am studying mechanical engineering, but I am not a native speaker) | [
"The amount of light that transmits through a material decays exponentially based on the thickness of a material so only an infinitely thick layer would absorb all light that strikes it. The exponential decay depends on the magnetic and electrical properties of the material."
] | [
"thank your for this nice answer. So how do I get than these properties?"
] | [
"The Beer-Lambert law describes the absorption of light in a medium. It is simply Intensity(L) = I*e",
" where I is the initial intensity and Σ is the attenuation coefficient. Σ=4πκ/λ, where λ is the wavelength in a vacuum and κ is the extinction coefficient. In this case, Σ has units of Length",
" .",
"You m... |
[
"Is it possible to have game of thrones like seasons (of unpredictable length) on an actual planet?"
] | [
false
] | null | [
"There are 2 pathways leading to models which might, perhaps' produce a GOT-like outcome.",
"One involves a planet orbiting multiple stars (see ",
"/u/asachemicalengineer",
" 's post).",
"The other might involve irregular changes in the composition of the atmosphere and the ratios of greenhouse gases. Say, ... | [
"Here's a rather rumorous paper describing the surface temperature of a planet orbiting two stars producing variable seasonal length:",
"\n",
"http://arxiv.org/abs/1304.0445",
"\n\"Submitted for publication in the Oldtown Journal of Evil Omens\""
] | [
"It is fairly easy to imagine irregular orbits, especially if large bodies occasionally passed perpendicular to the system's orbital disk. Should such a body pass through the system during formation and be captured, it is very probable that it would be at an angle. Ove r very very long periods of time, it would cre... |
[
"Why does cold air hold less water than warmer air?"
] | [
false
] | I understand that in general more water vapor can be present in warmer air than in colder - I'm trying to understand how temperature factors into this. Is it because water is more likely to exist in a gas state when it's warmer or is it more a property of the air that allows it to hold more water vapor? | [
"It helps to understand what temperature is on a microscopic scale. Temperature describes the average energy of molecules. At hotter temperatures, they have more energy- they bounce around faster, they vibrate and rotate more.",
"This higher energy means it's easier for molecules that are stuck together to bounce... | [
"More clarification and context of this correct answer. The way people often talk about air holding the moisture incorrectly implies that the water vapor is somehow attached to the other air molecules, or otherwise hosted by them. It's not. The amount of water vapor that can be present in some volume at some tem... | [
"To expand on this, higher kinetic energy allows for more water to be in a gaseous state via expansion of gases, increasing the saturation vapor pressure. When the actual vapor (partial) pressure of water vapor matches saturation vapor pressure, you get condensation if any more vapor is added or overall volume lost... |
[
"What would happen to a planet with many moons if the total mass of all moons combined exceeded that of the planet?"
] | [
false
] | null | [
"This system would not occur naturally. Gravity pulls all objects towards each other, all the time. The moon orbits the earth because the Earth is way, way bigger; same with the earth and the planets, etc. If the moons were of a comparable mass to the planet, they would all be pulling on each other, all the time. T... | [
"Stability in physics generally refers to how a system reacts to outside influence. A system is said to be stable if it will return to it's beginning condition after being acted on, whereas a system is said to be unstable if it will not return to it's beginning condition when acted upon. The classic example is a ... | [
"Couldnt you have two large bodies orbit each other while having a smaller one centered in the center of gravity of the other two? ",
"O o O",
"something like that, wouldnt it be stable?"
] |
[
"Given that a black hole can be completely described by mass, spin, and charge, would it even be possible to discern a black hole with equal mass spin and charge as an electron from an actual electron?"
] | [
false
] | Excluding Hawking radiation. | [
"There are two answers to this question:",
"(1) A charged black hole (no spin) has 2 characteristic length scales: r",
" (the Schwarzschild radius) and r",
" (no special name AFAIK). The black hole itself has two horizons: an outer event horizon and an inner so-called Cauchy horizon. If you cross the outer ev... | [
"Just keep in mind that the description of the charged black hole as essentially a naked singularity surrounded by a \"black hole shell\", which itself serves as multiple wormholes to multiple universes is, well... probably mostly science fiction and not true science. Of course, the description I gave is mathematic... | [
"Any black hole with less mass than about a grain of sand will instantly evaporate with a bang and release all its energy.",
"It's a bit weird to state this with such a level of assuredness.",
"The behaviour you describe is hypothesised by plugging numbers into the equations for Hawking radiation. But we ",
"... |
[
"Is it better to chew food thoroughly before swallowing? Why is that? Furthermore, how does your body break down huge pieces of food that you swallow without chewing very much?"
] | [
false
] | I swallowed a huge bite from an apple without really chewing it. How is my body going to "take care" of that??? | [
"This is a bit outside of my field, but technically yes. The bolus of apple that you chewed has only undergone one part of digestion, which is a process of ",
" alteration. All chewing does is provide additional surface area for chemical digestion to take over.",
"Once it is in your stomach, further chemical ... | [
"Thanks"
] | [
"No problem!"
] |
[
"Has a new animal species evolved since mankind’s existence?"
] | [
false
] | null | [
"Yes, hundreds of them. Mankind dates back maybe 200,000 years, if you limit it to Homo sapiens, and there are many species far younger than that:",
"Haplochromine cichlid fishes of Africa’s Lake Victoria region encompass >700 diverse species that all evolved in the last 150,000 years. ",
"--",
"Ancient hybr... | [
"I seem to remember watching a programme where some light winged moth have a new strain of dark winged moths after the industrial revolution when soot was making the tree bark black. The two strains had got to the point where they had trouble interbreeding so, new sources.So that’s in the last couple of hundred yea... | [
"It’s debated whether domestic dogs are species or subspecies. The arguments are arcane and extremely tedious. Since it’s pretty much irrelevant to the question here (are there five thousand species since humans appeared, or five thousand and one?) I’m not interested in this semantic argument."
] |
[
"In a piezoelectric element, does mechanical force have to be pulsed or can it be constantly applied?"
] | [
false
] | I just saw a video of a guy heating up a resistor by pressing a piezoelectric element in a clamp. It remained hot for awhile. | [
"It would violate the law of conservation of energy if the piezoelectric element continued to generate current while the mechanical force remained unchanged (e.g. a clamp tightened to a fixed point) because there would be no work being done yet energy would be 'created', so you can safely assume that it would be im... | [
"The current flow would have lasted only as long as the strain increased. However, it's very typical for one heat transfer mode (here, Joule heat generation, or volumetric heating from a current passing through a resistor) to be much faster than another (here, convective, conductive, and radiative cooling to the en... | [
"a piezoelectric element shows a différence of potential (a current flow ) when a force is applied on.\ninterestingly, the process is reversible, so applying a force onto a piezo will create a difference of potential. \nedit : sorry. deformation occurs when difference of potential is applied on.",
"if you need to... |
[
"What is the best Scientific Calculator to buy"
] | [
false
] | Hi Reddit I am starting a course with the OU in the new year with the aim of achieving a degree in Physical Sciences leaning towards courses in Astronomy. My question is for this course what is the best Scientific calculator to get, as I have never really had a use for one in the past I do not know what I am looking fo... | [
"Id suggest a HP calculator the ",
"HP 50g",
" specifically, you can get it for just under £100. ",
"Several things that are awesome about 50g: ",
"But most of all it has to be all about the ",
"RPN",
"(postfix notation). Once you get the hang of it RPN will save you alot of time and you will never hav... | [
"Mathematica",
"for tests you don't really need a calculator, but for homework, mathematica is invaluable.",
"I just turned in an assignment that was 13 pages of mathematica. The assignment took me 8-10 hours, but would have taken me twice as long without mathematica to do all the really annoying algebra."
] | [
"Imo if you just need to make some quick simple calculations get a calculator that just does those. If you want to plot and such, it is better to figure out how to make your regular computer do that, not sure what i recommend. The computer has advantages, calculators get outdated and then the software on it probabl... |
[
"Is there a fundamental limit to how much computation can be done per unit of energy?"
] | [
false
] | null | [
"Yes, see: ",
"https://en.wikipedia.org/wiki/Limits_of_computation",
"and in particular: ",
"https://en.wikipedia.org/wiki/Landauer%27s_principle"
] | [
"Indeed. But for a given amount of energy, the upper bound on the number of operations is that amount divided by the lower bound on the energy per operation."
] | [
"Which is why some of our encryption algorithms are immune to brute forcing regardless of future computing technology. No matter what, it would cause the heat death of the universe before reaching a solution."
] |
[
"Before the discovery of nuclear fusion, what theories were there for the Sun's energy?"
] | [
false
] | Nuclear fusion is a relatively new topic in science. , fusion was theorized in 1920, and the first paper linking it to stars was published in 1929. Surely the question as to what powers the stars has been around for much longer. What were the wrong answers? | [
"I'm on mobile at the moment, so I'll get the links later.",
"Initially it was thought that the sun might exist as a large ball of combustible fuel, like coal. This is obviously impossible when considering things like lifespan, mass and energy production.",
"A more popular (and accurate) theory emerged in the 1... | [
"to add to this, charles darwin was deeply concerned by this, as his prediction for the timescale of evolution was well beyond estimates at the time of the sun's lifetime"
] | [
"Kelvin also estimated the age of the Earth via a thermodynamical explanation and used this short time (~100 Myr) as an argument against evolution. He thought the random natural selection was too slow to have occurred in the lifetime of the solar system and was instead guided by a creator.",
"Whether Darwin or Ke... |
[
"Where did matter come from before the Big Bang?"
] | [
false
] | This came to mind when reading another post about the Big Bang... What is the theory behind where the big clump of matter came from before the Big Bang? Was there a collapse of the universe before the Big Bang to combine all matter to one central point? Was it due to some sort of gigantic black hole? If there was a ... | [
"We don't know, and there does not currently seem to be any way of knowing, as the earliest we can directly observe is the CMBR."
] | [
"that is one of the great unknowns in science."
] | [
"By CMWB he actually means CMBR, or the cosmic microwave background radiation."
] |
[
"Are we learning about other viruses besides COVID while learning about COVID? If so, what"
] | [
false
] | null | [
"So far, probably not so much. ",
"Early research on SARS-CoV-2 has focused on stuff that is clinically critical, but that doesn’t have a lot of general research implications. Transmission style and rate. Transmission chains. Receptor usage, receptor distribution. Susceptibility by age, comorbidity, distance, aer... | [
"I'd like to add that the clinical and public-health related work done ",
" doesn't add much to the body of technical knowledge, but in the future studying what was tried and what wasn't, as well as the efficacy of those efforts will dramatically improve our knowledge of how to respond to a pandemic caused by a p... | [
"That’s true and we could probably point to things like masks as examples - there has probably been more mask research in the past 6 months than in the previous 60 years."
] |
[
"What classification of photodetector is the human eye?"
] | [
false
] | Although more of a biology question than physics, I've been studying photo-multiplier tubes (PMT's) and SiPM's (Silicon photo-multipliers) since the summer in an undergraduate research position. From my understanding, the eye receives photons and focuses them on the rods & cones that convert the light signal to an elec... | [
"http://en.wikipedia.org/wiki/Phototransduction"
] | [
"I'll try to answer the first question you pose i.e how the conversion process takes place. \nSo as you say there are rods and cones. Rods are for B/W and they are about a hundred times more sensitive than cones, and therefor provided vision in dim light. Cones provide color sight via 3 different types of cones (re... | [
"Please! The more details the better"
] |
[
"Why do some plastics get stronger when stretched?"
] | [
false
] | I was trying to tear a plastic bag from the grocery store apart when I thought about this. I was trying to rip the "handles" off, but it just stretches to the limit of my strength, extends but doesn't tear. Why is that? I know I could tear it apart easily by applying force from another angle and whatnot, but I'm curiou... | [
"Good question! The mechanics of plastics (which are various types of polymers) can be very different from I've to another, so don't assume it's always true, but here goes.",
"Plastic bags are almost always polyethylene. Depending on the processing and the size of polyethylene (PE) chains used, the properties can... | [
"Absolutely! To explain this briefly, if you pull fast enough, the chains don't have time to slide past each other as much, and you can break them before they realign. The slower you pull, the more they have a chance to reconfigure.",
"It's funny to think of it this way as most people think of plastic as a solid ... | [
"Additionally, a lot of plastics behave differently depending on how fast you pull. If you pull really fast, the plastic rips without stretching."
] |
[
"How do sections of Canada experience less gravity than the rest of the world?"
] | [
false
] | but I still feel like its baffling considering the explanation says its because the mantle is "slowly oozing sideways". I'm certainly no expert, but isn't all the earths crust moving? Is it just moving faster in Canada and why would this effect gravity? | [
"(For the sake of explaining lets pretend you are now eating pancakes in Canada)",
"Gravity is determined by the amount of mass between you and the core of the earth. More mass= more gravity.",
"The study explains that the ice that formed in de last ice age pushed the mantle of the earth down and away from the ... | [
"I've read this 5 times now and I'm still trying to figure out what pancakes have to do with anything... D:"
] | [
"Yes, but here, mass is not distribured equally and you're kind of near the core, too. So the mass which has been displaced to the side might still attract you, but not in the same direction... What I mean by this is that Earth's total mass to be considered in (G",
"m2)/r",
" is relative to how far ",
" the E... |
[
"If an aluminum rod and a copper rod were heated up to 100 degrees celcius and both were dropped in different cups of cool water that were the same temperature, which one would warm the water more?"
] | [
false
] | null | [
"Aluminium has a higher heat capacity (0.9 J/gk) than copper (0.4 J/gk). So from a glance and given that the masses of metal and water are constant between the systems the final temperature for the aluminium + water system will be higher. More energy has to be given to the aluminium metal to raise it's temperature ... | [
"Yes as I said \"given that the masses of the metal and water are consistent across the systems\"."
] | [
"It depends if the rods are the same mass or volume.",
"Copper is over 3 times as dense so if they're the same size then the copper will warm the water more."
] |
[
"What causes this [see attached image] slight \"bump\" in temperatures in the Southern Californian climate every winter?"
] | [
false
] | Every winter, the climate in the Inland Empire of Southern California experiences a slight "bump" in temperatures from about mid-December to mid-February. What causes that to happen? Is it related to the reasons why it usually only rains in the winter? | [
"Well, I certainly stand corrected: it does appear to affect a large number of clustered sites with long histories.",
"Honestly I have no clue what could be causing this. I'll ask around at work and see if anyone has any clues."
] | [
"It appears to be a real phenomenon. And I really don't know what it could be except a statistical anomaly; there are no known meteorological processes that are that regular on a yearly timescale."
] | [
"It is from WeatherSpark, so directly linking to that page isn't really possible. Also, most of the NOAA stations around the IE report the same trend.",
"To see it in more detail, try going to weatherspark [",
"http://weatherspark.com/#!dashboard;q=Riverside%2C%20CA%2C%2092507%2C%20USA",
"] and zooming out o... |
[
"How do sugar substitutes like sucralose affect blood insulin levels?"
] | [
false
] | Do artificial sugar substitutes affect blood insulin levels? How does this compare to real table sugar? | [
"More like blood sugar is so variable that for this to be at all useful you need to have a huge sample and a lot more controls. In other words, you can't take anything from one person doing this experiment, once. "
] | [
"They don't really/No it doesn't.",
"\"Blood glucose increased only in response to sucrose (P < 0.05). GLP-1, GIP, and insulin also increased after sucrose (P = 0.0001) but not after either load of sucralose or saline\"\n",
"http://www.physiology.org/doi/abs/10.1152/ajpgi.90708.2008",
"\"Oral stimulation with... | [
"They don't really/No it doesn't.",
"\"Blood glucose increased only in response to sucrose (P < 0.05). GLP-1, GIP, and insulin also increased after sucrose (P = 0.0001) but not after either load of sucralose or saline\"\n",
"http://www.physiology.org/doi/abs/10.1152/ajpgi.90708.2008",
"\"Oral stimulation with... |
[
"When talking about photons, what does \"wavelength\" actually mean?"
] | [
false
] | When I think of waves, I'm accustomed to thinking of s-waves and p-waves, but it occurs to me that neither of these make any sense in regards to photons that are supposed to travel in a perfectly straight line with a constant speed. Individual photons don't have fluctuations of energy that I know of, either. So where d... | [
"\"how can two beams of light travel at the same speed but have different frequencies?\"",
"By having different wavelengths. ",
"How can people walk with the same speed, while taking a different amount of steps per second? By taking differently large steps. Frequency is steps per second, wavelength is the lengt... | [
"s- and p-waves in quantum mechanics refer to the orbital angular momentum (s means ℓ = 0 and p means ℓ = 1).",
"Photons can certainly carry orbital angular momentum, but that's not what wavelength is.",
"For ",
" particle, the relationship between its wavelength and its ",
" momentum is:",
"λ = h/p, wher... | [
"The amplitude of the electric and magnetic fields associated with that photon is oscillating in it's frequency. "
] |
[
"How does the clotting cascade work, and why is it so complicated."
] | [
false
] | Here is what I think I know: There are two big starting points in clotting "intrinsic" and "extrinsic" (though I believe this is outdated language). "Intrinsic" clotting is essentially a cascade of factors being activated which in turn activate other factors, down the line until Tissue Factor (from the "extrinsic" path... | [
"Try not to use \"intrinsic\" and \"extrinsic\" if possible. They are ",
" classifications. It doesn't work like that ",
".",
"The best model right now would be the ",
" which basically talks about ",
"Addit: Why do we know this? Because a drug company made recombinant activated FVII and when you have pla... | [
"Regarding stasis can clot: why? I'm trying to understand the clotting process in terms of the chemistry, so why does stasis lead to clotting?"
] | [
"Regarding stasis can clot: why? I'm trying to understand the clotting process in terms of the chemistry, so why does stasis lead to clotting?"
] |
[
"How fast can we safely accelerate a human being? What velocity can a human being travel at safely?"
] | [
false
] | null | [
"Short Answer: 3 g's of acceleration. Velocity doesn't really matter.",
"Usually we talk about acceleration on human bodies in terms of ",
"G-Forces",
". In the article John Stapp survived multiple acceleration and deceleration experiments up to 35 g's but also suffered a number of side effects, such as broke... | [
"1 G is equal to the force of gravity that pulls you down to earth. 2 G's would feel like you weighed twice as much as you do. 3 G's is 3 times and so on. If you were to experience 35 G's and you weighed 220 pounds you would feel 7700 pounds of force just from your body.",
"To accelerate to the speed of light? Re... | [
"Thank you for your reply! I googled a little bit, and it seems that 1 g is roughly a change in velocity of 9.8 meters per second. What would the formula be to determine how long it would take to go from standing still, to safely accelerating a human up to the speed of light?"
] |
[
"C in all reference frames?"
] | [
false
] | I'm aware that the speed of light is the same in all reference frames, but, what would a passing photon look like to another photon travelling in the opposite direction? | [
"Sadly, special relativity does not define reference frames for photons or anything else propagating at ",
" c. So we cannot answer what a photon sees. This manifests in the mathematics of a spacetime interval, ",
"ds",
" = (cdt)",
" - dr",
"which for light, the null interval has ds=0, ",
"0 = (cdt)",... | [
"I'm skittish to say \"no time,\" as popular science writers like to say. I'm more comfortable saying that time is not defined for light as we lack the machinery to even define geometry in that context. We can't define space sitting on light either, but few going around saying light travels no space."
] | [
"You can say that, but it's not neccessarily true. Just like you can say that 1/0 = infinity; it's a nice thought, and it seems intuitive, but it's wrong.",
"In truth, the reference frame of a photon is not a valid frame as ",
"/u/AsAChemicalEngineer",
" showed, so it makes no sense to talk about observations... |
[
"Does caffeine consumption affect serotonin?"
] | [
false
] | null | [
"Yes (for a time)? ",
"http://www.ncbi.nlm.nih.gov/pubmed/8039038",
"This study indicated that the effect of caffeine to decrease body fat deposition in the obese mice might be associated with the recovered increases of sympathetic activity.",
"FTFY: caffeine... might be associated with a 'better' fight or fl... | [
"I did some searches, but I honestly couldn't find much. That makes me question this relationship, but I don't have any specific evidence either way.",
"But here is what I found:",
"From ",
"this",
" study:",
"Evidences also indicate an important role of caffeine as an adenosine receptor blocker in depres... | [
"Isn't it more of a biochemistry or neuro related question?",
"\nHe isn't asking for medical advice, just how some stuff interacts with out body."
] |
[
"Can a plant pollinate its self?"
] | [
false
] | I guess you can literally say go f*** yourself | [
"I'm not sure whether you meant to imply this, but hermaphroditism is not the same thing as self-fertilization. About 95% of plants species are hermaphrodites, but only 20% of them can self-fertilize."
] | [
"I'm not sure whether you meant to imply this, but hermaphroditism is not the same thing as self-fertilization. About 95% of plants species are hermaphrodites, but only 20% of them can self-fertilize."
] | [
"Yes, provided the plant has both male and female elements in it's flowers/ reproductive organs. Not all plants are considered \"flowering plants.\" Some plants may depend on self-fertilization to one extent or another. Especially if no other plants are nearby.",
"However most plants have evolved strategies for a... |
[
"What is the cause of the pain in one's eye when you do glance at the Sun?"
] | [
false
] | null | [
"Ah, that's a really interesting response. It does feel somewhat like the feeling when I've pulled a muscle in my eye (eye strain).",
"Anyone else corroborate?"
] | [
"neurons don't \"send pain\"",
"i believe the pain OP felt was because the muscles that close the iris are contracting too much to compensate for the influx of light that you exposed yourself. basicly, it's like you trying really hard to lift a car"
] | [
"neurons don't \"send pain\"",
"i believe the pain OP felt was because the muscles that close the iris are contracting too much to compensate for the influx of light that you exposed yourself. basicly, it's like you trying really hard to lift a car"
] |
[
"Is it possible to actually damage your brain by thinking certain ways?"
] | [
false
] | Can the things you think actually damage the structure of your brain? It's an odd question, I know. | [
"DISCLAIMER: I'm by no means a scientist. ",
"This",
" lecture by ",
"Stanford Professor, Robert Sapolski",
" is the source of my information.",
"Actually, according to Professor Sapolski, yes. Supposedly stress actually causes physical damage to the brain, and makes brain injuries more damaging. He says... | [
"Sapolski is a very prolific scientist - if yall have time some of his work on estradiol is pretty impressive."
] | [
"What about addiction? Can you do things within your conscious control (like thinking) in ways that change the brain in ways to be more like an addicted brain? Perhaps day dreaming all the time?"
] |
[
"What happens if you are given the wrong blood type?"
] | [
false
] | null | [
"In an acute reaction, the patients antibodies attack and kill large numbers of the donated red blood cells. The hemoglobin released into your blood stream from the destroyed red blood cells can then cause kidney damage. Occasionally, you might also face disseminated intravascular coagulation (spontaneous clottin... | [
"No. The antibodies have to be specific to HIV, which they would not be in this case."
] | [
"Your blood cells are (with the exception of O- blood types) covered in proteins specific to your blood type. A has a certain protein, B is another, AB has both and O has none, and the Rhesus factor (which decides if your are a + or -) is another\nIf you are inject with a blood type that has a protein that your bod... |
[
"If we isolate an atom of a radioactive element of half life 24 hours, what would there be in 24 hours?"
] | [
false
] | null | [
"We don't do purely calculation questions on ",
"/r/AskScience",
", but this is fairly simple to figure out if you ",
"look at the definition of a half life",
". You always have the same amount if material left over after one half life. For more explanation you may want to check out ",
"/r/HomeworkHelp",... | [
"The half life definition assumes a large mass of the element. But what about a single atom? How does it decay? "
] | [
"Oh I see what you're saying! Sorry, I was reading quickly and skipped over that it said ",
" atom. The timeframe is irrelevant for the question. Actually, this ",
"also came up recently",
", although it's phrased differently. ",
"If you have questions after looking at that, you can resubmit. I'd rephrase i... |
[
"If sound is a pressure wave in the air, how can I hear the sound of wind before the wind reaches me?"
] | [
false
] | null | [
"The two are different.",
"Sound is a compression wave. This means that it travels but the air itself only compresses locally and does not follow the wave itself. The speed of the compression wave is about 340 m/s.",
"Wind is bulk motion of the air. This means that the air particles travel long distances. The s... | [
"The sound of the wind is most likely moving air vibrating objects which you are then hearing. When hit by a gust of wind in an open area, you often do not hear anything before except the air moving through things, trees, grass, or that weird sounding hole in the neighbors shed. If the moving air mass is not hitt... | [
"It's essentially a ",
"bow wave",
" of the wind which hits before the actual gust."
] |
[
"Are \"mass-produced\" animals (cows, chickens, etc) evolving faster than other species?"
] | [
false
] | Might be a dumb question, but I was thinking the other day about the notion that evolution takes place over hundreds of thousands (millions?) of years and is in response to the environment (natural selection?). Because we are killing entire generations of animals which humans eat on a daily basis, such as chicken and ... | [
"Because we are killing entire generations of animals which humans eat on a daily basis, such as chicken and beef, are these animals going through a more rapid process of evolution, seeing as their theoretical \"great-grandparents\" were probably only alive less than a month ago.",
"I think you underestimate the ... | [
"Well i only have a basic grasp of evolution and natural selection, but i believe that for natural selection to occur there has to be a situation in which the gene mutation can prove to better the organisms chance at survival as opposed to the original specimen. And since they're just being bread and killed there i... | [
"Yes, there are tons of strains of E. Coli, and for that reason you're more likely to use one that is already heat resistant or antibiotic resistant (these are selection methods, so for instance if you want to make sure you got a gene to actually transfer into a specific E. Coli genome you could tag it with antibio... |
[
"Why does light get polarized when it reflects from an insulating surface?"
] | [
false
] | I'm currently studying about light and electromagnetic waves. In all the books I've read it says that light is polarized it reflects from an dielectric (insulating) material. Nowhere have I found an explanation for this, even Google didn't help. Could someone please explain this to me. | [
"Check out the ",
"article",
" on Wikipedia"
] | [
"While true the brewster angle reperesents a very specific scenario. Even more general the reflectivity of a dielectric surface can be calculated using ",
"Fresnel's equations",
".\nIf an unpolarized beam hits the surface it can become at least partially polarized as the reflectivity may be different for the di... | [
"It's because the TE and TM mode reflections have different coefficients of reflection, so more of one of the polarization gets reflected than the other. TE is where the electric field is perpendicular to the plane formed by the k vectors of the incoming and reflected waves, TM is where it is the magnetic field pe... |
[
"2 years later, do we have any data or suggestion on why people react so wildly differently to COVID?"
] | [
false
] | How come most people get mild or no symptoms at all, and other people die? That's quite a range of afflictions. Do we know anymore than 2 years ago? | [
"Blood type is only one of the variables that show association with symptoms, for COVID and other infections. ",
"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8286549/",
"Many studies report that blood type A might predispose one to increased susceptibility of infection with SARS-CoV-2, and type O and Rh-negati... | [
"Viral subtype. Mutations in the virus have changed how it interacts with the host. Newer strains seem to be more adapted to humans causing a less severe disease.",
"Viral load of exposure. A patient exposed to a small dose of infection will have less tissue damage than a patient exposed to a large dose.",
"Pat... | [
"It must not be a factor. In the ABO system, we describe A-ness and a separate B-ness. Having A is more reactive to Covid maybe. This above says having no-A (and also no-B?) is better? I suspect it really means A (+A,-B) and AB (+A,+B) are worse off, and B (-A,+B) and O (-A,-B) are better off.",
"The ABO system i... |
[
"Why is my computer speaker currently picking up a radio station?"
] | [
false
] | I thought I was going crazy, but my wife confirms that 93.3 is coming out of my small crappy computer speakers. This happens whether or not the jack is plugged into my computer. If I turn up the volume the static increases but the volume of the radio transmission does not. Obviously if the speakers are turned off, no s... | [
"Wires (like headphone wires or speaker wires) are often long enough to fairly efficiently pick up stray signals like radio, acting like an antenna. This signal can then be fed into something that rectifies the signal (like a diode or an integrated circuit) and be fed into an amplifier (like powered speakers) and b... | [
"i hate that problem... there's fucking gospel music playing softly 24/7 out of my headphones when my speakers are on and it's so obnoxious"
] | [
"To solve the problem, you can buy Ferrite Beads at a place like radio shack generally. I'd put one on each end of the wire and tape them there snugly with electrical tape. I learned that trick in high school when I did equipment setup for a local band for a while. "
] |
[
"What would happen if a nuclear weapon went off at the bottom of the ocean?"
] | [
false
] | [deleted] | [
"This",
" \"what-if\" from xkcd covers the subject in detail. Essentially, at the pressures present at the bottom of the ocean, a nuclear explosion won't be very large. Think of the difference between detonating a firecracker in a cup of water and in a barrel of water. It won't cause a tsunami because those happe... | [
"Awesome article. Thanks. "
] | [
"There's a really cool documentary on Netflix called \"Trinity: the atomic bomb movie\" which features lots of footage of test explosions, including some underwater shots. Nothing as deep as the marianna trench, but still interesting. There is also some footage of the devastation caused when used in a mock village ... |
[
"What's at the center of Jupiter?"
] | [
false
] | What elements are there? What state of matter are they in? | [
"Generally we use the term ice for solid water that is cooled down under 0°C. However temperature is only one way to change the state of matter, the other one is pressure. Increasing pressure can cause substances to change their phase. That's how propane can be liquified and is also the reason why we have solid ir... | [
"That's hard to answer because current models are bas on estimations and computer calculations. The best model suggests, that jupiter has a inner solid core made of iron and therefore siderophile metals aswell and sillicate rock. It is surrounded by by an also solid layer of hot ice. ",
"These are the main ingred... | [
"solid layer of hot ice.",
"Would you mind elaborating on this?"
] |
[
"How do you generate the electron density map or structure factor from an X-ray diffraction pattern for a protein?"
] | [
false
] | Hello, I'm currently taking a course on proteins and one aspect that we cover is protein crystallography and structure determination through X-ray diffraction. *how do the intensity and position of spots on a diffraction pattern make the electron density map that a crystallographer can fit the amino acid sequence into?... | [
"These days x-ray structures of proteins are solved fairly regularly with varying degrees of difficulty depending on the type of protein. Some simple answers without going into anything excruciating:",
"here",
"Each spot tells us about the size and pattern of the crystal/protein. The spot intensity is proportio... | [
"As I'm sure you're aware, performing XRD on crystalline materials yields a very orderly graph that can be used to determine the periodic structure and length scales of these structures.",
"When dealing with a protein, unless the protein is orderly, you would not be able to determine these things with such precis... | [
"Thanks for the thorough answer. I suppose everything is done primarily using software these days then and the actual calculations for intensity and determining the phase aren't really performed by the person running the experiment. "
] |
[
"What kind of doors open if scientists create a programmable quantum computer. [Xpost from ELI5]"
] | [
false
] | Other than the obvious speed increase what does this mean for the modern world? What barriers does this break down? I've heard some buzz around the internet about unbreakable encryption. That's really cool, but what does it change? | [
"Quantum Computers can efficiently solve a class of problems known as ",
"BQP",
". Some nontrivial problems are in this space, like integer factorization/discrete log and a few other more esoteric ones. ",
"Last I heard, we haven't yet found a quantum algorithm to solve some of the more challenging problems s... | [
"What do you mean by \"not speeding up anything\"? That's exactly what quantum computers do: speed up certain computational tasks tremendously, such that they go from completely intractable to solvable within at least polynomial time.",
"And the results of a quantum computation are certainly not \"random\" either... | [
"Backlyte's comment is a pretty decent summary. To expand slightly there are a few things to note: First although we think that quantum computers can do some things faster than classical computers, this has only been proven in some very narrow cases.",
"So what can we do with quantum computers that we can't (to o... |
[
"If you are trying to fill up a bucket with water from a hose, will it fill up faster if you \"spray\" it into the bucket, instead of just letting the water run from the hose?"
] | [
false
] | [deleted] | [
"Ultimately, no. The hose has some specified amount of water pressure it can supply, which will give some flow rate, say 1 gallon per minute. If you had a five gallon bucket, it would then take you five minutes to fill it. If you put your finger over the opening of the hose, you will decrease the area that 1 gallon... | [
"This is true because water has some viscosity, so you can't force it through an arbitrarily small hole at high speed."
] | [
"This is true because water has some viscosity, so you can't force it through an arbitrarily small hole at high speed."
] |
[
"If cones in the eye peak at 560 nm (yellow), 530 nm (green), and 420 nm (violet), why are the primary colors red, green, and blue?"
] | [
false
] | Humans have three types of cones in their eyes that respond to different wavelengths of light. the three types of cones' response peak at at 560 nm a yellow color, 530 nm a green color, and 420 nm a violet color. Why then are the three primary colors red, green, and blue, and not yellow, green, and violet? | [
"There is not a single set of primary colors. For example RYB is commonly taught in elementary art classes, and any set of colors can be used to define a color space.",
"That being said, RGB is used commonly used in graphics not because it corresponds to peak responses of the various photoreceptors in the eyes, b... | [
"To expound on the other comment, another example is CYMK which is (or at least was when I worked in a coatings lab) used for print color.",
"When we'd measure colors of finished costings we'd use a 3 dimensional color space with the following axes:",
"blue vs yellow",
"red vs green",
"White vs black",
"Y... | [
"Partially because the peaks happen at a wave length that still triggers the other cones. Look at red for example. A bit right from the peak, the ratio of red cone activation to green/blue is actually higher. That means that using a wavelength further to the right, more colors can actually be mixed by using RGB lig... |
[
"Can you use a loop of superconducting material to hold a current indefinitely, like a battery with no losses?"
] | [
false
] | null | [
"Yep. In fact, that's how they measure the resistance of a superconductor is experimentally determined to be zero (although you can never actually say anything is zero with absolute certainty experimentally.) The idea is that if you start a current flowing in a closed superconducting loop it behaves somewhat like a... | [
"Superconducting magnetic energy storage",
" is also used industrially. It is a very nearly 100% efficient battery with fast response time, with the downside that big strong superconducting things are expensive and need liquid helium."
] | [
"Oh, for sure. If we had a room temp superconductor it'd be amazing for energy storage. But whether that's a physical possibility is a big big question. My money's on graphene based supercapacitors as the next step forward in energy storage."
] |
[
"How do Ants Actually Eat?"
] | [
false
] | I know that ants can suck up liquid food like sugar water and bug guts and then return to the nest to share the food through trophallaxis. What I want to know is what ants do with the breadcrumbs and meat fragments that they drag down their anthills. How do they get the bits of bread and meat into their bodies? | [
"You can more or less assume that insect digestive systems are the same as ours for most generalised purposes. They have mandibulae and maxillae just like we do, which break solid food up to make it fit into our digestive tract. They gave a long tube that goes from mouth to anus, they have gut bacteria, and they po... | [
"Asking the important questions!",
"Fortunately, you're not the first and you won't be the last! Ants are fairly meticulous about hygiene. They have to be; their colony structure means that the threat of disease is a constant danger. An infectious disease in the colony could literally kill all of them. Almost eve... | [
"To be fair, while this is true for ants, which have \"chewing mouthparts\", this is not in general true for all insects.",
"Check out the jaws on this cutie"
] |
[
"Found these little guys growing in my garden. What are they?"
] | [
false
] | Here's a . The tallest ones are about an inch tall. | [
"these guys might be able to give you a quicker answer:",
"http://www.reddit.com/r/mycology/"
] | [
"Common Ink Caps i think "
] | [
"Thanks!"
] |
[
"What is the beef with expensive hi-fi?"
] | [
false
] | I have been a long time fan of hifi but I didn't have the space to use my system for many years and recently I bought some components to upgrade the system and it was somewhat of an epiphany. My question is: in a blind test is it possible to hear the difference between two different speaker cables? I did some blind tes... | [
"I'm not aware of any blinded study which has found any noticeable difference in signal quality between expensive and cheap cables. If you Google for something like \"audiophile coat hanger\", you'll find lots of people talking about blind comparisons between expensive cables and coat hangers and finding no differe... | [
"As a both a skeptic and an audiophile, my take is this: speaker cables (high current signals from amp to speaker) really don't matter. If you can't measure a difference, you can't hear one. That said, it is important to use large enough wire that losses are minimized on long runs, and I use oxygen-free copper beca... | [
"It also depends on the length of the cable. A ",
" coat hanger will have significantly worse quality than an insulated cable with a ferrite core."
] |
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