title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"How to Catalysts Actually Work?"
] | [
false
] | I'm a high-school student and the common definitions say that that they aren't used up in a reaction, as seen when writing the reactions. But there are simulations online often depicting the catalyst combining, even have if not permanently, to the reactant molecules. And surely, the enthalpy 'hill' on a graph can't jus... | [
"They make reactions go faster ",
" providing a different way to get from A to B.",
"In many cases the catalyst gets \"consumed\" in one step and then \"produced\" again in another, so the net effect is that the catalyst is not used up, but they are very much a part of the reaction.",
"The enthalpy hill doesn... | [
"They serve as an intermediate step in the reaction, then restore themselves to their original form afterwards. ",
"Exact mechanisms are probably around second year university chemistry level (typically with understanding chirality as a prerequisite), but you might find ",
"https://en.wikipedia.org/wiki/Hydroge... | [
"Does the catalyst consist of the same atoms after being consumed and reproduced?\nIf not, could this be used to replace isotopes or radioactive particles in molecules?"
] |
[
"Does Proxima Centauri have it's own solar system? If so what might it look like?"
] | [
false
] | null | [
"Though Proxima Centauri ",
"has been searched for planets",
", none have been found (yet). However, Proxima Centauri may be in a triple star system, with two stars orbiting each other from a small distance - Alpha Centauri A and B - and Proxima Centauri orbiting that pair from a great distance. We have found a... | [
"A point that bears repeating as we continue to discover more planets is that ours is the only \"",
"solar system",
"\" since our star is Sol. Other systems are called \"",
"star systems",
"\" or \"",
"planetary systems",
"\"."
] | [
"This.",
"Also, in that case, OP could have just used \"system\". "
] |
[
"Is there any data to show/explain trends in food allergies? Wheat, Nut, and so on - has there been an increase in afflicted people?"
] | [
false
] | Just something my friends are chatting about - that it's strange how there's a lot of people afflicted with allergies to some of the most common food products - is there a reason for this? | [
"This",
"00523-X/abstract) is the study Got-Engineers is referring to. The researchers took a historical look at stored blood from military people, tested it for Celiac disease, and compared it to a cohort of current military people. They did see an unexplained significant increase over 50 years in the number o... | [
"This article: ",
"Recent advances in coeliac disease\n",
" mentions an important point that celiac disease is now diagnosed using more sensitive factors like a positive serology, whereas before it relied on symptom occurence.",
"Edit: I believe there are studies that support a positive trend upwards that acc... | [
"While your 2006 paper is correct, the 2009 paper (whose link doesn't seem to want to work), used seriology equally across both the historical blood samples, and from the modern cohort. So it really is a possible case of more people having celiac disease."
] |
[
"How fast are the molecules moving?"
] | [
false
] | How fast are the molecules moving around in say a glass of room temperature water? Could this be measured or visualized by adding food coloring? It seems like its not that fast. | [
"A general average temperature for a gas of molecules with mass M and temperature T is the square root of 3kT/M, where k is Boltzmann's constant. This works out to a few hundred m/s for air.",
"Liquids are a bit more complicated because the molecules interact, but a water molecule might, on average, go about 50 m... | [
"Well, it's a bit more complicated than that. It's actually diffusion. So even though the molecules would be moving faster than that, they keep bumping into each other, so the average velocity is actually zero. That number is basically how the average ",
" distance a molecule travels in a second."
] | [
"edit: I ignored boiling which was kinda dumb. The post holds for any gas, though.",
"Good question. I went way over length as usual, but if you want any clarification feel free to ask. To answer the question, we need three ideas:",
"The equipartition theorem",
"The Boltzmann Distribution",
". ",
"Diff... |
[
"Is there any scientific evidence to support being born gay?"
] | [
false
] | before i start im pro same-sex marriage. but the question i have is if there is any evidence that you are born gay Vs being nurtured into it by your environment. i ask this because from an evolutionary perspective it doesn't make any sense. so have there been any cases of identical twins being born, however one being g... | [
"I feel the need to chip in here, partially because the hand-waving, \"anything is possible\" nature of many evo-devo arguments drives me nuts, but mostly because I feel as though we need to define terms better.",
"\"Gay\" is not a scientific term, any more than \"rich\" is. Homosexuality is certainly a phenomeno... | [
"wikipedia's article provides a good primer on the topic",
" ",
"So far, the current belief is that it isn't ",
" genetic, but genes enter into it at least partially. The other factors seem to be stuff like conditions in the womb.",
"As for evolutionary stuff...scientists think it is actually beneficial i... | [
"It's too good of a post not to read in full for anyone who deliberately clicked the link."
] |
[
"What happens to sound energy in space?"
] | [
false
] | Since sound doesn't travel in space, what happens to all of the energy that would be sound waves? Do they just not produce sound initially? For example, if I could just shout in space, what would happen to my shout? | [
"The energy would just bounce around in the medium for a while, diffusing into a very low thermal energy. Back to the visor, initially the sound would make it vibrate like a speaker. But the sound waves would go back and forth, weakening due to damping effects and getting scrambled by continual reflections from the... | [
"The energy of sound only exists in a medium. If you could shout in space, that would assume you had air in your lungs. If you were in your space suit and shouted, the sound would be audible inside your suit, and the vibrations would be readable from the outside. But if your visor was vibrating from the sound of yo... | [
"so in short, sound vibrates the last medium it can reach and then just vibrates until it dissipates? "
] |
[
"During short term periods of carbohydrate overfeeding, what happens to the extra glucose that the body can't convert to fat with de novo lipogenesis? Does it get urinated out?"
] | [
false
] | I'll set up the situation specifically: Person A eats at a caloric deficit, and keeps carbohydrates low (<30g/day) for 6 days. On the 7th day they eat 200% of their body's energy requirements in carbohydrate (starch/glucose) over a 24 hour period, while keeping protein at 1g/lb, and dietary fat to 10-12% of the calorie... | [
"How short a timeframe are we talking about here? After feeding blood glucose levels peak for about an hour before it goes down as it is being metabolized.",
"Most likely the excess gets passed out through the urinary tract. The blood has to keep its solute content constant, after all, so it will dump the remaini... | [
"You don't have to be diabetic to pass glucose in the urine. if you dump enough glucose, your blood sugar spikes beyond what the kidneys can reabsorb. you only have so many glucose pumps in the nephrons; when they cannot pump all the glucose back to the blood, you lose it in the urine. My A&P instructor related a s... | [
"You don't have to be diabetic to pass glucose in the urine. if you dump enough glucose, your blood sugar spikes beyond what the kidneys can reabsorb. you only have so many glucose pumps in the nephrons; when they cannot pump all the glucose back to the blood, you lose it in the urine. My A&P instructor related a s... |
[
"Are there any gross evolutionary pressures still acting on the human species?"
] | [
false
] | According to video, there aren't. I'm a little sceptical on this one.. | [
"Yes I agree and would say that the video is misleading. These should thoroughly answer your question:",
"http://www2.yale.edu/eeb/stearns/pdf/PNAS-2009-ByarsEtAl.pdf",
"http://www.anthro.utah.edu/PDFs/accel.pnas.smallpdf.pdf",
"http://www.facstaff.bucknell.edu/jvt002/BrainMind/Readings/Laland2010.pdf",
"Al... | [
"Evolution is the change in allele frequency over time. This will happen with or without natural selection through drift. So yes, we're still evolving.",
"Are we still influenced by natural selection? Yes, in many ways. Our blood types (",
"Duffy group",
"), disease risk (",
"Parkinsons?",
") and lots... | [
"What I don't understand when it comes to natural selection is that for a genetic trait to be transmitted, or not, only counts if the organism has been successful in reproducing. So how could we become immune to disease that hit us in late ages, when we are not reproducing anyway, like Parkinson, Alzheimer, some fo... |
[
"Why is space expanding?"
] | [
false
] | What causes spaces to expand, how does it expand and why is it doing it? | [
"Broadly speaking, there are three relationships at work. They all boil down to something that ",
" and ",
" very much like pressure.",
"Seal up a box full of air and apply heat to it. What happens? The pressure inside the box goes up. If the pressure goes up ",
" the walls of the box will literally expand;... | [
"That's not the reason. It would expand without vacuum energy as well, just not accelerated. It would even expand if it was empty and negatively curved."
] | [
"I'm afraid this is one of those questions where we can't give a better answer than \"That's just how it is.\"",
"It's a consequence of general relativity. You can derive the Einstein Field Equations from a set of assumptions, and if you do all the math, it turns out that the universe must expand. Einstein could... |
[
"It took a couple of billion years for cyanobacteria to convert the atmosphere into current state. How long will it theoretically take animal life to convert it back considering deforestation etc. Is it even possible? Very interested in gas exchange rates."
] | [
false
] | null | [
"The oxygen cycle is a self regulating feedback loop.",
"Too little oxygen, animal life declines and uses less, and eats fewer plants, causing levels to rise.",
"Too much, you get more animals, and things start to catch on fire, bringing levels back down."
] | [
"Thanks."
] | [
"Does anyone know the approximate size of early cyanobacteria?"
] |
[
"Would a preserved brain have a consciousness?"
] | [
false
] | Is it possible to preserve a brain so that brain activity continues? If so, would there be any type of consciousness even without a body or senses? I've had nightmares where, in them, I'm trapped alone in my own thoughts for an eternity without any senses. | [
"I am a programmer who has done a lot of thinking about the brain and artificial intelligence.",
"I don't really buy the idea that the human brain is as unfathomably complex as everyone makes it out to be. I think that the commonly made comparisons to ultra-powerful computers refer to the difficulty of simulatin... | [
"Well, I'm no biologist, that's for sure. I don't want to minimize the difficulty of figuring out the brain or minimize the efforts of the researchers. The task of completely discovering and specifying the brain's processes is certainly the hardest part of the job.",
"I am aware of the massively parallel nature... | [
"10 000 bits is roughly 1.2 kilobytes, 1200 bytes, that's not much. But your brain doesn't do math with 1200 byte long numbers (universe doesn't contain that many particles!). Every neuron has hundreds of inputs, but those don't add to the \"bitness\" of a neuron. It's just a flawed comparison made to impress peopl... |
[
"Why does inbreeding cause genetic abnormalities?"
] | [
false
] | I've always heard with inbreeding, there are higher risks of abnormalities. Why is that? | [
"Normally get two slightly different copies of your genome from your parents. If one has a minor fault in a gene often the other copy works fine and compensates. With inbreeding you get identical copies (you loose heterozygozity), so any fault will be present in both copies and will cause problems. "
] | [
"This. One more relevant thing to note is that we all carry a bunch of these minor (or even major) faults, they just don't do (usually) any damage as long as the other copy is fine (they are recessive). So for two people who are unrelated, the likelihood of them having a fault in the same gene is pretty low, and th... | [
"For example there is a family that has some kind of genetically caused sickness which transferred to family members in no regular way (like every 2nd person has it). So the chances that the baby of brother and sister of this family will get these mutated genes from its parents is much higher that if there is just ... |
[
"Given enough time, is it theoretically possible to travel to the centre of the universe? Would it be different from any other point? Noticeable older perhaps?"
] | [
false
] | null | [
"There is no center. The universe is likely infinite in extent, or else finite but unbounded. Either way, no center. See the FAQ for more."
] | [
"So would there be a bit of universe that is older than any other bit of the universe? I'd settle for going there. "
] | [
"No, the whole universe is the same age."
] |
[
"Does our subconscious constantly run certain \"subroutines\" (for lack of a better word)?"
] | [
false
] | My office is two doors down from my supervisor's. I've noticed that, while at work, my brain subconsciously listens for him to say my name in conversations with others and I start actively listening to what's being said after my name is mentioned. I think this is probably the case with our names outside of this situati... | [
"Yes, it is constantly carrying out check-ups of your surrounding, and associative memory is always on the go, deducing what is happening. Type 1 process are automatic and involve no cognitive strain. You should read Daniel Kahneman's 'Thinking, fast and slow' for superb insight into all of this. You will really en... | [
"Thank you all for your answers. They were very helpful. And thanks to acetylserine for the suggested reading. I'll definitely give it a look."
] | [
"No, not in the way you're describing. What are you describing, though, is called the ",
"Cocktail party effect",
" (note, that this term is used in multiple fields with different properties). ",
"There is no real \"subconscious\" or \"subroutines\" as the terms are used. But those terms describe what the fie... |
[
"When measuring nutritional information and suggested serving size, is that including the empty space inbetween that food in a half cup measurement?"
] | [
false
] | What I'm trying to figure out: Example - When I look at the side of my box of Cinnamon Toast Crunch, the suggested serving size is 3/4 cup at 130 calories. Is that 3/4 of a cup as if I had just scooped up 3/4 out of the box? Or is it 3/4 of a cup of cinnamon toast crunch that has been ground up and is filling all space... | [
"Seems like this is a perfect opportunity for you to do your own measurements. The label includes a mass as well (usually says \"per 3/4 cup (100 g)\" or something.) If you have a kitchen scale, you can scoop your own 3/4 cup and weigh it."
] | [
"It is 3/4 of a cup as if you had just scooped up 3/4 cup straight out of the box."
] | [
"There are soooo many instances on askscience where I just want to tell the person...\"JUST GO DO IT!!!\" I'm always worried about down votes because its askscience, not doscience...or some such nonsense. I applaud and upvote you rupert1920."
] |
[
"Why do particles (photons, electrons) interact only with themselves in double-slit experiment?"
] | [
false
] | If a particle is an excitation of a field, what is the nature of this excitation that it knows which whole it's a part of? As in "oh, look here, seems this part of field excitation is a part of my probability density distribution function, let's subtract/add to it". Normally, when I throw two stones into a pond, create... | [
"I can make the experiment in non-ideal environment at home, using a laser and 0.05mm graphite from mechanical pencils. Still, as I understand, for some reason the photons are \"forbidden\" from interacting with other photons, happily interacting with themselves."
] | [
"There you go:",
"http://www.youtube.com/watch?v=ZXyxnxnWAAQ"
] | [
"In that case I think the coherence of the light would ensure they mostly interacted with themselves; as far as I am aware other frequencies ",
" occasionally interact but at a level you would be unable to detect with such a setup."
] |
[
"Are more calories burned in hot or cold weather?"
] | [
false
] | [deleted] | [
"Sports Science in-training here. You burn more calories in cold weather because your body needs to work a little harder to keep your core temperature up. Ever heard of turning down the heat to lose weight? When you shiver you are using ATP (muscle energy currency in plain simple English) and when ATP is used a by-... | [
"Just to make it clear so someone won't kill him/herself.",
"If you are fat and you try losing weight by staying cold, you are a fat idiot."
] | [
"You're always \"burning calories\". About 2000 per day."
] |
[
"Why are diseases such as Alzheimers and Creutzfeldt-Jakob non-treatable? What is the best method of prevention?"
] | [
false
] | My understanding is that rouge, denatured proteins aggregate and deposit within specific tissue. As with AD, amylod-B deposit into brain material and the byproduct is linked to dementia is not well understood. What would be the best Chem/biochem solution to prevent aggregates from occurring in-vivo? | [
"First, I'll answer the question you didn't ask but everyone is going to answer. Alzheimer's and CJD are probably not closely related diseases. CJD is a prion related disease, caused by a build up of a more stable foldings of naturally occurring proteins that auto-catalyze (i.e., make more of themselves). ",
"... | [
"Nobody knows really. Genetics appears to have an effect so start by not being related to anyone who developed dementia. Insulin-like Growth Factor (IGF) appears that it may play a role but the literature is somewhat evenly divided showing it is both neuro-protective but also induces amyloid deposition. So there is... | [
"With respect to treating CJD, as I understand it, the main problem is developing a method that targets the PrP",
" (abnormal) proteins while ignoring the PrP",
" (normal) proteins. Given their only difference lies in their structural conformation this is a difficult problem.",
"On a more banal note, as with ... |
[
"To what extent do massive asteroid impacts effect the tectonic plates?"
] | [
false
] | null | [
"Hey, we check all posts before releasing them onto the sub and yours got stuck for too long. Would you mind resubmitting? It may take a couple hours to get released. If it doesn't show up again, please reply here or send us a modmail. Sorry about that!",
"Also, \"effect\" in your title should be \"affect\". No b... | [
"Haha, I agonized over effect/affect because I knew I would get a ton of corrections. Somehow those 2 words are the only ones in the English language I can never remember the difference between."
] | [
"A good rule of thumb is that \"effect\" can't be a verb."
] |
[
"With a lot of misinformation being spread, how are we certain this is delta that is causing the rapid uptick?"
] | [
false
] | null | [
"https://covid.cdc.gov/covid-data-tracker/#variant-proportions"
] | [
"So In essence my assumption is correct. Due to sequencing we confirmed there was a mutation. We have confirmed that the mutated strain of the virus is present in the US. The change of behavior in the statistics then confirm that it is spreading. ",
"It’s unfortunate that people prefer to argue against this when ... | [
"It's like standing in a blizzard and saying it isn't snowing."
] |
[
"Why do scientists think spaghettification is real if there is no friction in space?"
] | [
false
] | null | [
"Spaghettification has nothing to do with friction, it’s about tidal forces. You are not a point mass. If you’re in a situation where gravity is much stronger at your feet than at your head, you’re not going to be accelerated uniformly."
] | [
"I understand that gravity is stronger at my feet than my head. But it still doesn't make sense to me that I would spaghettify. If I attach a rubber band to the wall and pull it, the rubber band will stretch. But if the rubber band is not attached to anything and I pull it it will just move instantly however I... | [
"There's a nice animation ",
"here",
".",
"If you consider the pieces of mass that make up your body as separate, it's easier to visualize. The fact that they're actually attached to each other to form a larger body doesn't change the way that gravity acts on each individual piece of you."
] |
[
"In 2005 the UN said that by 2010 there would be 50 million climate refugees. Why were they wrong?"
] | [
false
] | null | [
"The figure seems to come from ",
"this",
" publication.",
"That publication (which was published in 2008, as the cached page clearly shows) claims \"There is a serious potential for future conflict, and\npossible violent clashes over habitable land and natural resources,\nsuch as freshwater, as a result of c... | [
"I would not describe the Katrina outflow as \"climate refugees,\"",
"I wouldn't either, and in fact, I wasn't (I thought I'd made this clear when I wrote the post, but re-reading it, I can see how perhaps I wasn't clear enough on this point). I cited them as an example of people in a major first world country, f... | [
"I was more interested in what facts led them to come to this conclusion and what has changed since then? I'm asking out of genuine curiosity, not because I want to promote some sort of agenda. I remember that report in 2005 and I was worried, but by 2010 I had forgotten about it entirely."
] |
[
"How would the night sky look if we could see the whole electromagnetic spectrum"
] | [
false
] | This is sort of a question relating to how the night sky is dark and not full of light. If humans could see the full electromagnetic spectrum (or at least more than what we are able to see normally) what would the night sky look like? Or even how would the world appear to us? Although I am not sure this has been tested... | [
"Unfortunately our atmosphere is opaque to most frequencies that we can't see. There are notable exceptions (radio):\n",
"http://en.wikipedia.org/wiki/File:Atmospheric_electromagnetic_opacity.svg",
"Here's a hint at what things would look like from space:\n",
"http://www.armaghplanet.com/blog/image-of-the-mon... | [
"Something like ",
"this",
"."
] | [
"Please keep wild conjecture at a minimum"
] |
[
"Why does the polynomial x^5 - x + 1 = 0 have no exact solution?"
] | [
false
] | I just saw that mentioned the fact that this polynomial only has an approximate solution, not an exact one. However, when I rearrange the equation into x - 1 = -1/x and graph the two individual functions (you can use ), the "approximate" solution of -1.167... is where these two functions cross. Since they are both cont... | [
"This is actually a fascinating question, with an even more fascinating answer. First off, it is important to note that there is a real solution to that equation. There are also four other complex solutions that you would expect by the fundamental theorem of algebra. ",
"The real question here is, why can you onl... | [
"I think this stems from a misconception of what an \"exact solution\" is in this context. ",
"Does the equation x",
" - 2=0 have an exact solution, in your opinion ? ",
"You will probably answer : Well of course it does ! It's the square root of 2 !",
"But think about it, the square root of 2 is ",
" as ... | [
"The solution is definitely an algebraic number but it is not an \"algebraic solution\" in the sense of having a closed form algebraic expression. The alternative terminology that I see in other discussions of the Abel-Ruffini theorem is \"expressible in radicals\" etc. which to me is a little more clear in its dis... |
[
"If we know what kind of bacteria causes the majority of cavities, why don't we just make an antibiotic that targets them and distribute it like a vaccine at a doctor's office?"
] | [
false
] | [deleted] | [
"Antibiotics that target a specific bacterium are tricky. There are a small handful that have been demonstrated, but very few, and only for research purposes. Even then, it's more of a \"kills bacteria x very efficiently, while y and z will mostly survive\" deal.",
"The reason is, simply, how targeting can be don... | [
"/u/rlgl",
" answered the question \"why don't we just make an antibiotic that targets them?\"",
"The kind of bacteria believed to cause ",
" of cavities is ",
"mutans Streptococci",
", but they don't cause ",
" cavities. There are also some respected researchers that think the role of mutans streptococ... | [
"That might work. Maybe. But that branch is still new, and bacteria can become resistant to phages just as much as to antibiotics. Again, sort off."
] |
[
"Why do astronauts breathe 100% oxygen?"
] | [
false
] | In the Apollo 11 documentary it is mentioned at some point that astronauts wore space suits which had 100% oxygen pumped in them, but the space shuttle was pressurized with a mixture of 60% oxygen and 40% nitrogen. Since our atmosphere is also a mixture of these two gases, why are astronauts required to have 100-percen... | [
"It's actually not a biology reason but an engineering one. Humans can breath pretty much ok as long as the oxygen pressure is around what we are used to. For example at 1 atmosphere of pressure we have about 20% oxygen in air. The trick you can do it lower the pressure and increase the oxygen content and people wi... | [
"Very interesting, thank you for the great answer!"
] | [
"Great answer by ",
"u/electric_ionland",
", I'd also like to point out that by using one gas, you only need one gas tank, not two. You don't need complicated mixing/regulating hardware to mix in nitrogen for breathing either. Saves weight and complexity. Apollo continued using pure oxygen, even after Apollo 1.... |
[
"How far from the coast must one go inland for ground water to be drinkable (not saltwater)?"
] | [
false
] | So I'm watching HBO's "Rome" and there's an episode where the protagonists are stranded on an atoll/small island without water. It made me curious if there's a minimum distance from the coastline/radius of an island that would make water from the ground drinkable and not too much like salt water to be harmful. Is there... | [
"Groundwater can actually be fairly unintuitive, but one possibly illustration of the situation is ",
"here",
". In this case, you could dig for water basically anywhere on the island, and find some fresh water. For any given island, the shape of that freshwater bulb under the island will be controlled by a n... | [
"Excessive pumping of limited freshwater supplies will cause saltwater intrusion. The salt flows in to replace the vanishing fresh.",
"This means places that have been lived in for a while near the ocean get progressively worse. "
] | [
"I'm definitely not an expert on the topic, but your question reminded me of the existence of submarine springs. These are freshwater springs that emerge off the coastline in saltwater. I seem to recall hearing that ships would sometimes use these springs to replenish their supplies, the difference in density mak... |
[
"Years are ~365.2564 days long. We have leap year, but are we accounting for that .0064 at all?"
] | [
false
] | null | [
"The rule for leap years is actually quite complicated. A year is a leap year if 1) it's divisible by 4 (e.g. 2012 is a leap year), 2) it's not divisible by 100 (2100 won't be a leap year) or 3) it's divisible by 400 (2000 was a leap year).",
"In the end, it's more precise than 365.25 and we have several thousand... | [
"Fun fact: We had a leap second earlier this year which practically broke the internet. "
] | [
"There is also the ",
"http://en.wikipedia.org/wiki/Leap_second",
" of which there have been 25 since 1972 which are used to keep time-of-day in sync with the earth's (surprisingly very slightly irregular) rotation."
] |
[
"What is the average density of the universe, or in the case of an expanding universe, an equation for the average density?"
] | [
false
] | Finite amount of matter / Size of universe. Lets break out the scientific notation! Feel free to stray from kg/L if it makes things easily :) | [
"First, there is no reason to suppose that either the amount of matter or the universe is finite.",
"That said, the density of the universe appears to be around ",
"10",
" g/cm",
"."
] | [
"Thanks for the response! Do you care to elaborate on any assumptions or estimates this number caries with it? The reason I ask is because of the preface you gave before answering. Thanks!"
] | [
"As a mathematician, I would like to point out that there are perfectly reasonable ways to deal with this using measure and coarse geometry. In the limit, large balls in ",
" are half even. Similarly, in the limit, large balls in the universe have average density 10",
" g/cm",
" as stated."
] |
[
"Why is it that when walking down a busy street with earphones in..."
] | [
false
] | Whenever I walk down a city street with headphones in, and a very loud sustained external noise is happening (say a bus or truck starting to move at a green light, or whatever), you can turn the music all the way up and it doesn't hurt your ears (even though you still can't hear it) but as soon as the truck or bus pull... | [
"In music production, we have something called ",
"Dynamic Range Compression",
". What it does is essentially taper off the loudness of a sound after a certain point. In other words, it applies a rule like \"any loudness above 6db will be cut in half, such that each decibel you add to the input only adds half a... | [
"Wow, this is awesome. Thank you."
] | [
"It could also have to do with the two tiny intrinsic middle ear muscles: tensor tympani and stapedius dampening the truck noise and then relaxing making the music blare. This is just a guess. "
] |
[
"Why are solar panels glossy? Isn't the goal to absorb light and not reflect it?"
] | [
false
] | null | [
"A surface being glossy instead of matte doesn't change the total amount of reflected light very much. Solar panels actually only reflect a tiny fraction of the incoming light, about 1-4% depending on the coating. The sun is so bright that it's enough to notice, but a vast majority of the energy is actually being a... | [
"The cells themselves are usually matte in appearance, but they're also fairly fragile. That means that usually, manufacturers try to find something protective to put over the cells-- but it needs to be simultaneously sturdy, cheap, and very transparent. So there's typically a layer of glass over the top. ",
"S... | [
"A matte surface scatters light, meaning it would be less than great with all incident angles of light. With a smooth surface, most light is allowed to pass through. ",
"Compare it to a pane of clear glass versus a frosted glass for a shower door. Most of the light can pass straight through clear glass, but the ... |
[
"How are memories formed and stored in the human brain? How does information go from \"pattern of electrochemical activity\" to \"hard\" storage?"
] | [
false
] | I've heard that memories are solidified during sleep: does this mean that information is sitting in "RAM", so to speak, until then? And is this why we get tired? Are there specific structures that contain memories, or are they distributed throughout our neural net? A combination? Can we detect changes as memories are f... | [
"There are multiple views on the answer to this question.",
"First off, memory Is also consolidated while awake, but sleep does have a significant effect, especially on episodic and semantic memory.",
"As for your specific structure question, there is an ongoing debate between the sparseness hypothesis and the ... | [
"There's a phenomenon in the brain called ",
"Long Term Potentiation",
" which essentially causes synapses in the brain to fire more easily when they are used frequently. There's some speculation that part of how memory works is from LTP. This is due to the fact that the hippocampus (a structure associated with... | [
"We really aren't very close to knowing how memories are formed or represented in the brain. We can't really observe the scale at which memories are formed, possibly in large part due to the gaps in resolution of the techniques we have for detecting brain activity. ",
"We can measure activity of 10s or 100s of ne... |
[
"With a big enough optical telescope could the human eye perceive an \"astronomy picture of the day\" deep space object in full technicolor glory?"
] | [
false
] | With a big enough optical telescope (on earth or in space) what would a human see when looking at an object like I understand at a superficial level how astrophotography works (collecting photons over time, lucky imaging etc.) but I'm curious what the upper limit would be for someone looking through a telescope could s... | [
"Those are not \"real\" colors. Several images are taken with different filters with only allow specific wavelengths, which are then combined and colorized with a computer. ",
"Here you can see the data for the picture",
" and the Hubble website has a ",
"very nice interactive tool",
" which does a better j... | [
"You can definitely see some colors. The ",
"Orion Nebula",
" can be seen as clearly blue through even a small telescope in the 8-inch range. One can discriminate between redder and bluer objects in many cases. If you put an eyepiece on a 2.4-meter telescope, your eye would probably be able to tell that the mid... | [
"The problem is not merely a lack of light-gathering power (although that does contribute, since our color-sensitive cones are not as sensitive to faint light as the monochromatic rods are), it's the way that the human retina sees color. ",
"Cone cells have three different wavebands which they can detect in",
"... |
[
"What is and isn't possible with a DDoS attack and counter-attack?"
] | [
false
] | got me curious. I understand the basics of a DDoS attack, and what it is, but I have no knowledge of details and what is/isn't possible. Could Anon have actually done anything, or are they full of baloney? | [
"For curious people in this thread, here's a quick intro to denial-of-service attacks.",
"Denial-of-service (DoS) attacks are attacks intending to exhaust targets of some resource. For example, on many Unix machines, running the infamous shell one-liner ",
":(){:|:&};:",
" will cause the system to lock up; th... | [
"Thanks, this is much more helpful."
] | [
"Yes it is possible.\nBy flooding a certain ISP's backbone with another DDoS attack, you can cause the current DDoS attack to be rerouted. ",
"An example...\nSay Person A is DDoSing a server in the US. Person A is renting a Russian Bot-Net. The Bot-Net is primarily European. There are only a few interconnects bet... |
[
"Interesting little experimental probability vs theoretical question that occurred to me."
] | [
false
] | While I was flipping a coin to decide between Beef-Broccoli and Beef-Fried Rice, when a question occurred to me.(I know it's technically more of a mathematical question) I know that the more trials you do in probability experiments, the closer your experimental probability gets to equaling your theoretical probability.... | [
"Your question setup is a not very clear. You're basically talking about building a binomial or an approximation of a normal distribution. But I don't see why things are 0% or 100%. There is no such thing as \"most\" trials. You can keep going and flip that coin forever.",
"Can you clarify what you mean?"
] | [
"I've gotta run (literally, it's time for my run), but I threw this together with a quick Matlab script to show you how the probability converges to its expected result for a fair coin (p = 0.5) and an unfair coin (p = 0.9).",
"Link",
"The top plot is the running average of each coin. The bottom plot is the di... | [
"yeah that was pretty unclear....I'll just explain with an example. Say you're flipping a coin, obviously there's a theoretical 50 percent chance of it landing on heads. However, in an actualy experiment, if you only flip the coin 5 times, it may turn out that heads only came up 30% of the time instead of fifty. I ... |
[
"How can yeast produce THC?"
] | [
false
] | I recently came across article and was curious. How is this possible. Can yeast be made to produce any chemical compound? | [
"Disclosure: I know one of the members of the company profiled, though we've never talked about this work.",
"This is done by introducing biosynthetic enzymes into a yeast. If the pathway that a plant uses to make the compound is known, you can clone the genes, insert them into the yeast, and then make sure they ... | [
"yeast and E. coli are by far the most heavily utilized organisms for engineering - theoretically, with the right enzymes, any compound can be produced metabolically by the organism. The difficulty lies in finding the correct combination and sequencing of said enzymes to achieve the desired product. Many companies ... | [
"I too love the gene gun because of its simplicity but check out crisper."
] |
[
"Could you use liquid nitrogen to clean up an oil spill?"
] | [
false
] | null | [
"Chemistry major. Nope, the ocean's temperature is generally warm and really hard to change, so the cost would be enormous! Also, you can't just drop it from a chopper, because it would evaporate into the air. "
] | [
"It might freeze some parts of the oil, though I don't really see how it fixes the problem. It still has to be removed. "
] | [
"It might freeze some parts of the oil, though I don't really see how it fixes the problem. It still has to be removed. "
] |
[
"why do some people sweat more than others? does sweating a lot or a little have any pros/cons to one's health?"
] | [
false
] | null | [
"Sweating is a means to lower your core body temperature. Sweat is mostly water, but contains some minerals and urea. You sweat when you work out because the exertion causes heat, and your body attempts to normalize it's core temperature by shedding warm water. As sweat appears at the surface of your skin, it be... | [
"Speaking from a biological standpoint the more diverse a species is the more likely is it able to adapt and survive in a changing environment. ",
"Imagine a case where people who are able to sweat more may have an easier time surviving in very hot conditions because they can lower body temperature faster than th... | [
"As a heavy sweater please answer this."
] |
[
"Is it possible to make an alpha particle gun?"
] | [
false
] | [deleted] | [
"so would it be possible to create an alpha particle-emitting device that could disrupt things like computers?",
"Easily. Just buy 10,000 smoke detectors, extract the Americium-241 from each, and put the result in a shielded container with a controllable port. I emphasize that I'm not actually recommending this."... | [
"to follow on here, alpha particles are practically trivially stopped by any material. They can only travel a few cm in air, and get stopped by paper, tissue paper even."
] | [
"I was only wondering if it was possible or previously attempted.",
"It has been -- ",
"David Hahn",
", the so-called \"Nuclear Boy Scout\", did it pretty much as I described above."
] |
[
"Is there a means to recover astronauts during spacewalk accidents?"
] | [
false
] | During extra-vehicler-activity is there a real risk of an astronaut becoming stranded/seperated from the space station? | [
"NASA astronauts on ISS always maintain some sort of tether to the station",
"Though note that in the past there have been some ",
"untethered spacewalks"
] | [
"The risk is extremely low. NASA astronauts on ISS always maintain some sort of tether to the station to prevent that from happening. Additionally, they always wear the SAFER equipment on their EVA suits. This is a small set of thrusters which would allow them to return to the station even if for some reason their ... | [
"Well there is a risk, but the astronauts' space suits include an emergency jetpack called ",
"SAFER",
" that they could use to rescue themselves. It's based on the older ",
"Manned Maneuvering Unit",
", used during the Shuttle era, which was more of a general-purpose device for flying out away from the Shu... |
[
"If the earth was placed at the border of our universe (some planet must have ended up there?). Will half of the sky be completely black?"
] | [
false
] | Or what will we see or be able to measure from the other side? | [
"The observable universe — which is often what people mean when they say \"the universe,\" and that ambiguity of terminology causes a lot of confusion — is simply a sphere centered wherever the observer in question happens to be. The radius of the sphere is a function of the age of the universe. Every point that li... | [
"There's no answer in that case. There is no border of the universe."
] | [
"Yes, there's copious data. Let me see if I can put it in terms that don't make you want to set yourself on fire. Apologies in advance if this ends up being too elementary for you.",
"There's this phenomenon called cosmic microwave background radiation. As the name implies, it's microwave radiation, and as the na... |
[
"If you were tumbling in space and closed your eyes, would you still experience the sensation of tumbling/dizziness?"
] | [
false
] | If you are experiencing microgravity, and are lacking a visual frame of reference, would your body have enough (for lack of a better word) context to realize that it's tumbling? Would you feel dizzy? Would the small amount of gravity present be enough to trigger some sort of up/down frame of reference? What would be ha... | [
"I suspect the answer is yes because there is still an angular momentum imparted on your body. For instance, if you swung a ball around attached by a cord and then let go of the cord don't you expect the ball to move away from you?",
"So as you tumble the fluids in your ears would still want to keep at rest whic... | [
"Yes. The previous poster is correct. It has nothing to do with gravity and everything to do with the conservation of angular momentum. Inside of the petrous portion of your temporal bone (a very bony portion of your skull) are three circular canals, unoriginally named \"the semicircular canals\" (known from now... | [
"One should be very careful about guessing how the balance system behaves, because much of it is highly non-intuitive. For example, I have visited the Royal Air Force medical something-or-other department, where they have a little machine they put their pilots in for training and tests. It is basically a chair in... |
[
"What is the differerence between phonetics and phonology?"
] | [
false
] | [deleted] | [
"Try ",
"r/linguistics",
" for this question."
] | [
"Phonetics is the performative aspect of language (the sounds you actually produce) while phonology is the study of the sounds that you recognize mentally.",
"For instance, in English we make no distinction between aspirated and unaspirated consonants (you can tell if a consonant is aspirated by putting your hand... | [
"does askscience have linguists to answer questions about language? I know there are one or two people who field answers to neuro-ling and computational ling, but I noticed language questions here tend to get inundated with speculation/lay-man answers, rather than the viewpoints of actual language scientists."
] |
[
"Is there an empirical method to calculate the surface area of an irregular solid?"
] | [
false
] | Archimedes (apocryphally, at least) provided us with an empirical method of calculating the volume of an irregular solid using water displacement. Is there any analogue for surface area? It would be nice if there were a method that doesn't rely too much on technology (I kinda want something that could've been produced ... | [
"You could take a can of paint would form layer of certain thickness, submerge the object in thispaint, take it out, and see how much paint is missing. Divide by thickness and there you have surface area.",
"This would rely on the paint consistently forming layer of specific thickness, and while it's roughly true... | [
"Apply a layer of spray adhesive to an object of known surface area, such as a cube of 1 cm on all sides. Put a known mass of fine sand in a tray. Roll that sticky cube in the sand until no more will stick. Measure the new mass of the tray of sand. That gives you a rate of that sand sticking per square centimeter."... | [
"Chemical reactions that happen on the surface of the object (e.g.: corrosion), would release energy as a function of the surface area.",
"Heat transfer by conduction is also a function of surface area, although creating an ideal scenario is difficult considering complex convection in the surrounding fluid. It ma... |
[
"If all galaxies are moving away from each other how is it that the Andromeda galaxy will collide with our own galaxy?"
] | [
false
] | null | [
"The average trend is that galaxies are moving away from each other. On small scales (e.g. nearby galaxies), your normal motion through space (from gravity etc) is in some sense \"stronger\" than the expansion of the universe, and so on a small scale you can get galaxies moving in all sorts of directions relative t... | [
"Whoops, I misread your question! So the Local Group is part of the Virgo Supercluster (but ",
" the Virgo Cluster, although that's the main component of it - i.e. we're in New York State, but we're not in New York City), but I'm not sure if we're bound to it or not. I'm looking up some papers to check.",
"Edit... | [
"The entire Local Group is gravitationally bound as far as I know. Is that the largest bound (i.e. it will not eventually become unbound due to the expansion of space on any reasonable time scale) structure we're part of?"
] |
[
"How big is a bit(or storage unit) on a hard drive ?"
] | [
false
] | null | [
"I'm pretty sure you mean the ",
" size of a bit. i.e. the amount of magnetic material required to represent a bit. For example, a floppy disc, which stores data on a linear track, has 686 bits per mm. Hard drives can store somewhere from 300 - 600 Gb / in",
" and flash memory can reach ten times that density.... | [
"awesome thanks! "
] | [
"The bit is the smallest unit of memory storage for computers. Compared to the memory a computer has, it is tiny. For example, let say you have a hard drive with a space of 8 Gigabytes. 1 gigabyte is equal to 2",
" bits or 8,589,934,592 bits. So compared to the rest of the hard drive, one bit is about 100 billion... |
[
"Has there ever been an observed impact of a meteor hitting the moon?"
] | [
false
] | Would a significant (but not catastrophic) impact be observable from earth with the naked eye? | [
"Yep, they've even been caught on video. ",
"This one",
" was apparently as bright as the North Star, so it'd be easy to miss if you weren't already watching closely.",
" Way back in 1178 a bunch of monks watched in awe as the moon writhed and spat out sparks and flame, which may have been a meteor impact res... | [
"That's awesome. Thanks."
] | [
"There does seem to be a distinct lack of other expected evidence for that theory, though (as per the linked page) - no other witness records of the event, nor any records of any subsequent meteor storm as debris should have entered Earth's atmosphere.",
"A coincidental Earthly meteor does seem more likely. I won... |
[
"When a black hole 'dies' what happens to its mass?"
] | [
false
] | null | [
"That's not quite right (sorry to T.S. Eliot). The black hole radiation does start out to be fairly minimal, and stays small for quite a while. The temperature of a black hole is inversely proportional to its mass, and the power emitted in Hawking radiation is inversely proportional to the (mass)",
". So most ... | [
"I think you misunderstand Hawking radiation.",
"A black hole does not suddenly explode into Hawking radiation. It gives off very little radiation and this radiation causes the black hole to lose mass. After enough time, all the mass has been carried away and the black hole ceases to exist. Evaporation is a bette... | [
"The Hawking radiation evaporation of a black hole is a slow process. Black holes go out not with a bang, but a whimper."
] |
[
"Why is the oort cloud spherical while the rest of the solar system flattened itself out into a disk?"
] | [
false
] | null | [
"So the Oort cloud is big, and its formation history and evolution is not fully understood. ",
"Check ",
"this picture.",
" The Kuiper belt is barely visible in that picture - the inset shows Pluto's orbit. My point is that the Oort cloud covers a vast expanse of space, extending almost halfway to the Centaur... | [
"So why isn't the outer Oort cloud spherical? I think it's fair to say that its formation history is not fully understood. ",
"Well, it's not like we don't understand anything about it.",
"The working hypothesis is that it was created when small icy planetesimals were flung out on very long orbits by gravitatio... | [
"can it be that Oort cloud is our solar system in forming stage? that eventually in few million years it will be disk like inner Oort cloud? "
] |
[
"Why do tropical cyclones migrate polewards?"
] | [
false
] | I know it is a way of heat transfer, but what makes it move polewards? | [
"This is actually due to an effect called the Corolis effect. Its all to do with the fact that the hurricane wants to travel in a straight line but its instead sitting on the surface of a rotating body (in this case the earth). ",
"Its a bit like you sitting on a rotating childs roundabout and throwing a ball out... | [
"I understand Coriolis effect, but I don't know what makes it move in a straight line towards the poles in the first place."
] | [
"This is not correct.",
"The poleward migration of a tropical cyclone is due to ",
"Beta drift",
". If a hurricane were traveling purely zonally, it wouldn't experience any poleward Coriolis deflection."
] |
[
"If a person is unconscious on a spinning object, will they wake up dizzy or not?"
] | [
false
] | null | [
"There is a lot of ambiguity in your question in regards to how the object is spinning, but I will phrase my answer to address that.",
"If the object is spinning in such a way that the person in the same setup would be dizzy if they were awake and had their eyes closed for a long time, then they will also be dizz... | [
"When you wake up, you'll have gotten used to the spinning platform (I assume constant angular speed) so you might get dizzy if/when you see beyond the platform, which then isn't spinning. The equilibrium organs think you're not spinning while your eyes tell you you clearly are, so you might get dizzy from that. ",... | [
"The thing to add here is that the balance organs don't detect absolute rotation or translation to that fact, but rather rotational or translational acceleration, so it's not so much consistent long spinning motions in films that result in conflicting signals, but rather the quick twists and turns. Here you expect ... |
[
"Is the genotype a phenotype?"
] | [
false
] | I can select for specific individuals with a desired genotype by establishing their genotype in the lab and then removing all of those individuals who don't have the correct genotype. This even though selection is traditionally supposed to act on a phenotype. Does this mean that an organism's genotype is in fact a phe... | [
"Those terms were coined about a century ago, back before we had any idea how genetic information was transmitted. Back then, the only reliable way to get the genotype of an animal was after the organism had given rise to a few generations of controlled breeding. ",
"There are exceptions to this, though. Imagine ... | [
"When you remove subpopulations of a certain genotype from a larger population in the lab, you are acting as an exogenous agent of selection within your system. You should ",
" interpret this experiment through the lens of Natural Selection; you have replaced Natural Selection with artificial selection (i.e. sel... | [
"Phenotype is best defined as being any trait that is not genetic material per se. The distinction matters because the genotype is what is transmitted to the next generation, not the phenotype.",
"When selection acts on a particular phenotype, there may or may not be a genetic basis to that phenotype. We often th... |
[
"Why does peanut butter glow in the dark? (and other nuts)"
] | [
false
] | When shining a blue/violet/UV laser on peanut butter it exhibits brief but noticeable phosphorescence, usually a yellow or green color. Evidence: I previously posed this question to " " BBC podcast, but I disproved their answer (they said the peanut oil was simply fluorescing which is false) tested items are as follow... | [
"Peanuts absorb at 365nm and emit \"delayed luminescence\" at peak wavelengths of 440-460 nm, as ",
"this paper",
" puts it. They state that delayed luminescence is a general phenomenon in living biological systems, and may last between 10",
" and 10s (they cite some studies in the alga ",
"). However, they... | [
"I think we'll need some ",
"NIST standard reference peanut butter",
" to make sure any experiments are controlled appropriately..."
] | [
"the plastic does not change the effect, i would have shined the laser on a spoon of PB but this was just cleaner "
] |
[
"Why can OLED tvs be so thin compared to a LED tv?"
] | [
false
] | Ive looked up some stuff on OLED and what amazes me is how thin they can be. Is this because of the organic layer and why does the organic layer work this way? | [
"LCDs can be made very, very thin as well. It just hasn't been a real selling point outside of the phone and laptop universe. But in the phone world, there's essentially no difference in thickness between OLED or LCD phones, and televisions made to chase maximal thinness would be very close as well.",
"But stri... | [
"LED TVs aren't LED TVs, they are LCD TVs with LED backlights. LCD TVs require two layers, an LCD layer which allows or blocks light through individual pixels, each of which also have a color filter. The LCD layer passes through the light from the LED layer behind it.",
"An OLED display is a true LED display, eac... | [
"The light source gets moved to the side in that layout, but the light still essentially comes from the back. In addition to the diffuser you mentioned, there's a light guide and a reflective layer. The light has to be behind the LCD whether the source is there or not, so there will always have to be some sort of... |
[
"Where in the atom is the Higgs boson located?"
] | [
false
] | null | [
"The Higgs boson is a ripple in the Higgs field. Making such a ripple requires a lot of energy, but the flat \"pond\" that is the field is always there."
] | [
"Not at all, pretty much. The Higgs field on the other hand is everywhere"
] | [
"Doesn’t the Higgs field need a Higgs boson to exist? Or am I misreading that?"
] |
[
"Reflected light from a colored object?"
] | [
false
] | From my understanding, when I shine a white light on a green object the atoms electrons 'absorb' the energy as the light has the same resonant frequency as the electrons which allows for the max amount of energy transfer. This means that the colors(wavelengths) other than green are absorbed the most while the green lig... | [
"It depends on the object. Absorption and re-emission in a random direction (scattering) is the most likely case.",
"The electric field of an atom doesn't do anything - electromagnetic waves don't interact with electromagnetic fields directly in a way relevant in everyday life situations."
] | [
"No. In a classical model the incoming light moves electrons around which then leads to emission of electromagnetic waves again. There are electric fields in the material, but it is misleading to say that these fields would reflect the radiation."
] | [
"Isn't the electric field created inside the material responsible for reflection from a dielectric surface, as well as from a metallic surface?"
] |
[
"Let's say I get punched in the head and suffer brain damage. What, exactly, is happening inside my head?"
] | [
false
] | null | [
"Well, to be honest, that depends on what actually happened inside your head. Every brain injury is not the same and the differences can be quite significant. "
] | [
"I think it's important to note that is but one possible mechanism of brain injury and may not be the case in all instances of head trauma."
] | [
"The acceleration of the skull causes it to impact the brain, damaging the brain at the site of impact (or general direction of where the punch came from). A secondary injury could occur at the opposite side of the brain, which is where the \"rebound\" occurs. That's known as ",
"coup contrecoup injury",
"."
] |
[
"Why is it that water expands when it freezes rather than contracting like most other substances?"
] | [
false
] | [deleted] | [
"Nice to see this question again, I've struggled with it for a few weeks in highschool. So nice to help someone out with it.",
"Ok so, (almost) everything has three phases depending on the temperature and pressure it is in. Namely; Gas, liquid and solid. ",
"This is illustrated very well in something called a p... | [
"The hydrogen bonding network is the reason it forms this structure."
] | [
"The molecule H2O has a bent shape due to the number of leftover electrons on the oxygen. Picture a V with a 105 degree bend, the middle being oxygen and the two ends of the legs being hydrogen. This bend cause one end of the molecule to by negatively charged (the oxygen) and the other end to be positively charged ... |
[
"Where does wind start?"
] | [
false
] | I'm fairly sure most energy on earth comes from the sun or our superheated core, but where does the energy for wind come from? | [
"All wind is due to to pressure and density differences in the air between different places. These pressure and density differences happen due to temperature differences: the sun heats different parts of the earth by different amounts (so-called ",
"differential heating",
") on both large and small scales, both... | [
"Sudden wind gusts are caused by a few different phenomenon, but the most common is just plain old turbulence. For almost every layer of the atmosphere, except for just above the ground, wind speeds are relatively constant over short periods of time (in other words, they aren't \"gusty\"). Friction in the ",
"pla... | [
"What accounts for small gusts of wind we feel as opposed to large steady movements of air? "
] |
[
"How high off the ground do you have to be in order for there to be no bugs?"
] | [
false
] | [deleted] | [
"Very interesting article, thanks for that. Whelp, so much for my brilliant plan for high-altitude insect-free camping."
] | [
"This one",
" claims a single termite found at 19000 feet, the highest we've found an insect."
] | [
"The height actually changes with the temperature and seasons. There was actually this village on a mountain that was just above this line. Global warming later caused the line to rise, thus allowing the mosquitoes and other insects to survive.",
"As for the approxamate height, I'm not quite sure. I am pretty s... |
[
"Krebs Cycle: Where does the extra oxygen come from in the oxaloacetase+Acetyl CoA-->Citrate step?"
] | [
false
] | I am in a high school biology class, and I was studying the krebs cycle specifically tracing the oxygen through the cycle; in my textbook the diagram shows acetyl coA donating one oxygen to Oxaloacetate, which already has five, and then becoming Citrate, which has 7. Where is this mystery extra oxygen coming from? What... | [
"Good catch - this step in the process is catalyzed by the ",
"Citrate synthase enzyme",
". While enzymatic reactions are more complex and beyond the scope of your question, it is essentially an ",
"Aldol Condensation",
". Which is one of the more painful common reactions that most first year O-chem stude... | [
"Like you said, one of the oxygens comes from the acetate group. The other comes from a water molecule. ",
"The reaction, catalysed by citrate synthase, is a multi-step reaction, ",
"as seen here.",
" As you can see, in that last step a water molecule is added and the CoA is released. The actual mechanism her... | [
"Thank you, I especially appreciate the diagrams!"
] |
[
"If something/someone could be inside the very center of the planet, would gravity pull the object/person outward from all directions? How would it be different from being in Space without any gravity?"
] | [
false
] | null | [
"This entry in the FAQ",
" is what you're looking for."
] | [
"If you ignore the immense pressure, it would be identical to being in orbit. You would be weightless."
] | [
"I've been subscribed to this sub from the get go and I never saw that FAQ... Well, my day is booked."
] |
[
"What are rocks made of?"
] | [
false
] | Like, i know it sounds dumb, but I dont really know what they would be made of. Like, if I look at a diamond, I know it's carbon. If we talk about air, ik its oxygen, nitrogen, etc, etc. But what are rocks made of? | [
"At the shallowest level, rocks are made of ",
"minerals",
", i.e., a naturally occurring chemical compound with a well defined crystal structure. As that definition implies, minerals are made up of elements, so this means that rocks are also made up of elements, but we tend to define them in terms of the miner... | [
"The ten most common elements in the rocks of Earth's crust are oxygen, silicon, aluminum, iron, calcium, sodium, magnesium, potassium, titanium, and hydrogen. Sulfur is also a notable element.",
"The atoms of any individual rock are organized into mineral crystals, in which the atoms are arranged in a regular, ... | [
"Thank you for writing this"
] |
[
"Why do people only have 10 seconds of useful consciousness at high altitudes when most can hold their breath for at least 30 seconds?"
] | [
false
] | On average people are able to hold their breath for 30 seconds, but in the event of rapid decompression at high altitudes (40,000ft) they will become useless after just a few seconds. Why is this? | [
"That's only at like 45000-50000 ft where the air pressure is close to 2-3 psi. You can't hold your breath because your lungs and throat and such can't deal with the 12-13 psi difference. Time of useful conciousness decreases the higher you go. Around 15000 ft it's like 30 minutes.",
"Add on that since the concen... | [
"The higher up you go the thinner the air, therefore the lower availability of oxygen. ",
"If you're on Mt. Everest and take a deep breath, oxygen still comprises the same 23% of air that it does at sea level, but there is only 1/3 the air pressure over all - that means there is only one third the number of all ... | [
"Sure. The time of useful conciousness is an estimate after all. You can probably function perfectly fine at 15000 ft if you take time to adapt to altitude or are reasonably fit. ",
"But you take an average person who lives around sea level helicopter them up to the peak and drop them off in a T-shirt and shorts ... |
[
"Can we breed giant insects?"
] | [
false
] | null | [
"There is the factor of ",
"structural integrity.",
" where ants would not be able to support themselves as well the size of elephants. ",
"Then what do your giant insects breath in our relatively low oxygen world?"
] | [
"Insects are limited in size by the amount of oxygen in the air. \n",
"http://www.aps.anl.gov/Science/Highlights/2007/20070808.htm",
"I am not sure why Frank was down voted. "
] | [
"Maybe they thought I was being dismissive of OP,",
"\nI will admit that the second part of \"what would they breathe?\" was based on the attached article of being attacked by giant insects, and was thus questioning, to continue the conversation, how would they fare when released out of their high concentration b... |
[
"Is the \"teen\" stage that humans experience (heightened hormones, erratic) present in other species? Does it play any role in nature?"
] | [
false
] | I'm just wondering if this stage of development that we've labeled the teen years is unique to humans, or a process in multiple species. If the "teen years" are present in other species, do they play any significant role in nature? | [
"In my physiology and neurobiology classes class we briefly discussed the endocrine system. The take home from combining both courses is this: we experience very strong hormonal stimuli almost every second of everyday. Our brains sort through and prioritize these signals.",
"When we become teenagers we see change... | [
"Yes, in my opinion.",
"In my own research of birds, namely American crows, we've noticed juveniles will do all kinds of crazy things. They'll often play with one another, have relationships that get them \"in trouble\" with parents, and much more.",
"When first-time \"teen\" parents are nesting, it can also b... | [
"Dogs certainly do go through the \"question authority\" phase (which is pretty important to guide them through correctly, especially for more wolf-like breeds, both because this psychological change is more pronounced in them and because they are more dangerous), when they switch away from child-parent relationshi... |
[
"What exact does a blood thiner do?"
] | [
false
] | Is it the same thinning as say, paint thinner? That is to say, in a medical sense, what does a thinner even do? Can other bodily fluids be thinned? Lastly, what measurables in the blood can be affected the most by blood that is overly thinned? Thanks. | [
"Hey, I study one of these! There are two main types of blood thinner, and I will summarize the activities of both.",
" block the clotting cascade - a sequence of events leading to blood clotting and recruitment of platelets, which are essentially cells which are meant to clot over wounds. These include:",
" - ... | [
"So what would determine whether to use an anticoagulant or antiplatelet medication? I notice Aspirin is OTC while heparin and coumarin are prescription, so would I be correct in assuming that anticoagulants have a much higher capacity to prevent clotting? "
] | [
"Many clinical trials have been done to determine which medications we would use in which circumstance. With these drugs you have to balance the risk of a blood clot and the risk of bleeding, as these \"blood thinners\" increase your chances of having internal bleeding such as from an ulcer. Many clinical trials ha... |
[
"What things are humans surprisingly good at compared to other animals (besides the obvious)?"
] | [
false
] | The Obvious: Tool-building (opposable thumbs) Logic Language | [
"I have heard long distance running. Can anyone confirm or deny? (phone surfing - unable to provide links/sources). "
] | [
"There's ",
"good evidence",
" that our sense of hearing is more sharply tuned than that of other animals - i.e., if you play a tone at frequency ",
" and another at ",
", the smallest ",
" at which we can distinguish the tone as a different note is smaller than it is for other animals. There's some spec... | [
"Why would I want to take the saddle off my woman just to see her glow? Do you have any idea how hard those are to get on? Not worth the effort.",
"(it's not a top-level comment, be gentle!)"
] |
[
"I have a few problems when waking up, but only in certain conditions."
] | [
false
] | [deleted] | [
"Sounds like you are pinching your nerves.",
"Regardless personal medical advice is not allowed on reddit."
] | [
"Don't sweat it. Laws and good medical practice make it unwise to try and diagnosis over the internet, but I can guarantee you would benefit from seeing a doc to go over sleep hygiene with you and check your blood pressure and such to ensure nothing more serious is going on."
] | [
"Please keep discussion:"
] |
[
"Found a gif on front page - Why does tape make fogged glass clear? (gif inside)"
] | [
false
] | null | [
"Frosted glass scatters light because the surface is rough, so you get diffuse scattering, where light coming through the glass is redirected to random directions. The result is a blurry image.",
"Tape can fill in these surface imperfections and provide a smooth interface for light to pass through."
] | [
"To elaborate a bit, there is still a rough surface between the glass and tape just like there is between the glass and air. The difference in index of refraction glass to tape is much less than glass to air so the light does not get redirected as much."
] | [
"The fogging is caused by a very fine roughness on the glass - picture many tiny hills and valleys. When you apply tape, it \"fills in\" the valleys, making the surface smooth and reducing the blur. ",
"Kinda like how if there's rocks at the bottom of a fish tank, you can pour in water to eventually get a flat,... |
[
"Does speaking a different language affect non verbal comunication?"
] | [
false
] | null | [
"Different cultures have different sets of non-verbal communication techniques and are connected to the language. Simple example: I can say thank you in English without moving by body but I can’t say it in Japanese without my body reflexively adding at least some bowing motion (slight downward nod of the head for ... | [
"To avoid redundancy, I'd add that in addition to the cultural influence on non-verbal communicative gestures, there is a bevy of research suggesting that the language one speaks influences how one thinks (Sapir-Whorf Hypothesis). This could, transitively at least, affect non-verbal communication."
] | [
"I'm half American and half Danish. I've lived in both countries and speak both languages. When I speak English I'm more animated (I talk more with my hands). My impression is that Americans are more animated in their expressions than Danes are.",
"Until I read your comment I never thought about my gestures being... |
[
"White flakes from melted ice in Texas. What is it? (xpost from answers)"
] | [
false
] | This has fascinated and terrified me for years. What is it? I never finish a glass of ice water (on the rare occasion that I use ice) because of the flakes creepily waiting for a passport to my mouth at the bottom of the glass. I have seen this in no less than 3 different households in 3 different cities from 3 differe... | [
"http://en.wikipedia.org/wiki/Calcium_carbonate"
] | [
"Uh... any way to get a picture that's in focus?"
] | [
"\"More than 85% of American homes have hard water...Hardest waters (greater than 1,000 ppm) are in streams in Texas, New Mexico, Kansas, Arizona, and southern California.\""
] |
[
"Are there any previously thought finite resources we've been able to synthesize? Any that we might be able to in the future?"
] | [
false
] | null | [
"Taxol comes to mind. The original production required extraction from the plant at such low yields that demand would have pushed the tree to extinction. They then figured out how to make it from the needles instead of bark, then a total synthesis, and now it is grown in fermenters. ",
"Insulin would be another e... | [
"It isn't quite the same as regular gasoline, but \"fossil\" fuels can be produced from biological products now: ",
"http://en.wikipedia.org/wiki/Biofuel"
] | [
"They can also be synthesized from water and CO2 from the atmosphere, if you're willing to spend to energy to do it."
] |
[
"Why doesn't gas build up in our bladder?"
] | [
false
] | Since it can build up in our intestines and produce farts, why is there no build-up in our bladder? | [
"Well...the bladder is also topologically on the outside of the body."
] | [
"Well...the bladder is also topologically on the outside of the body."
] | [
"That would imply that there's bacteria in your bladder that are digesting your urine and producing gas. It's bad enough that bacteria cause UTIs when they infect the bladder/urethra."
] |
[
"Do you really piss away multivitamins?"
] | [
false
] | I've read too many conflicting articles on the subject. Are multivitamins worth taking, or do you piss them away? | [
"Even if you eat crappy foods, as long as you're getting things like vegetables and what not (IE not surviving off twinkies and coke), you still aren't going to need a vitamin supplement. ",
"And to answer the OP: Yes, you are literally just pissing away money when you take one. If you just ",
" to take one, ... | [
"Multivitamins are worth taking if your normal diet is lacking in the vitamins that your body needs.",
"Basically, they are (like the label says) a supplement. I found that when going on one of my \"once in a while\" healthy binges eating fresh salads, fruit and the like, that my urine also came to a very saturat... | [
"It becomes more dangerous in vitamins you don't piss out easily, namely the fat-soluble ones. A, D, E, K all are not excreted from the body as easily and can build up to dangerous amounts. Fortunately, (or unfortunately, as this is one of the major factors causing vitamin deficiencies around the world) they also d... |
[
"Why are metals found in veins/lodes rather than all mixed together?"
] | [
false
] | Liquid magma erupts from the mantle to become crust. Why isn't the crust well-mixed? Why are veins of precious metals, rare earths, actinides, etc, found in specific locations? If these veins are actually remnants of meteorites, which are remnants of supernovae, same question. Why would they clump together by element (... | [
"Only a few metals are found in their metallic state (gold, silver) - the rest are found as minerals. As to why they are in veins, super hot water from deep under dissolves the metals or minerals, the water percolates up and cools and releasing the metals. As the water squeezes though narrow defects and holes to ge... | [
"This topic is actually rather complicated and depends on multiple factors and I will simplify this a lot.",
"\nFirst of all; not all elements behave the same. For each mineral that is forming from a magma, every element has a specific partition coefficient. That means that the longer a magma evolves (meaning for... | [
"Thank you friendly Kentucky miner."
] |
[
"The NPR population visualization video is great. Please teach me about a more detailed version of the model used in that video."
] | [
false
] | The video represents global population as flow into (births) and out of (deaths) containers representing major world population regions. As an engineer this was immediately recognizable as a "salt-tank" problem that we all learn about in our differential equations class. I began to think about other factors that could... | [
"It was a very neat demonstration, and yes - it did remind be of the \"draining tank\" problems we all see in DiffEq.",
"The problem with using 'salt concentration' as an analogy to wealth is that the salt concentration would be homogeneous throughout (whereas wealth is certainly not equally distributed throughou... | [
"Ah yeah. I remember those assumptions now.",
"Hmm, so the height. ......scribbling......scribbling....",
"So..the volume is the population, and the height increases as the volume increases, but at a slowing rate based on the angle of the cone.",
"So perhaps it could represent something that a population con... | [
"Like the quantity of dirt required to add the incremental height to a hill versus a mountain. The height is productivity and the dirt is the population."
] |
[
"How much energy is being wasted on useless flash banners and ads?"
] | [
false
] | I recently read an article that described chrome to be the first browser that stops rendering flash animations that are in other tabs/not in screen. Since flash is quite an intense program for the CPU, how much energy is being wasted on flash animations? i dont mean youtube videos, but ads, banners and other spam. And,... | [
"As a software engineer, I don't think you're going to get an accurate answer. There are simply too many factors to take into account. Here are a few:",
"I could go on for a while. I'm sure someone more informed can give you a number, but I would be ",
" surprised if it's remotely accurate. Heck, I would be imp... | [
"That requires the initial assumptions to be of reasonable quantities. I'd love to be proven wrong, but the scope just seems a bit too crazy for an accurate answer. I wouldn't even know where to begin. "
] | [
"There is also the extra energy used in all of the extra network requests that take place. Those transit a half dozen routers at a minimum. Add the energy used by the ad servers. Then there is the cost of the CDNs for lower latency. Then the ad brokers, who run high speed auctions for your eyeballs when you load th... |
[
"How can water be heavier than the respective elements that make it up?"
] | [
false
] | So I understand basically that electrolysis of water splits water into its base elements of Hydrogen and Oxygen, but how can combining them create something that is heavier than the sum of it's parts? How can both Hydrogen and Oxygen be lighter than water if they make up water? Edit; Wow, this has been really eye openi... | [
"Water actually weighs very slightly less than its constituent parts. Bound states are lower energy than unbounded states and this is manifested as a slight defect in mass. This is why you must put energy into the system to break it apart."
] | [
"Oxygen has a molecular weight of 16. Hydrogen has a molecular weight of 1. Water is H2O, so 2 H, and 1 O. 16 + 2x1 = 18. The molecular weight of water is the sum of the weights of its constituent parts. What's the problem here? "
] | [
"Maybe the confusion is that water is a liquid at room temp while H and O arent?"
] |
[
"What does the vy stand for in the name of the largest known star: vy Canis Majoris?"
] | [
false
] | null | [
"Variable stars inside a constellation boundary, like Canis Major, are given a prefix to distinguish them from regular, constant stars, like Alpha Canis Major (Sirius). The Roman alphabet is used, and if not enough letters available, two letters are used."
] | [
"Just to expand on this, the system is much sillier and backwards than what was described above, all because the system doesn't start with the letter A.",
"The ",
" variable star discovered in a constellation boundary is given the letter ",
", and single letters continue to be used for ",
" through ",
". ... | [
"As if astronomy wasn't interesting enough on its own you all had to go in and create bizarre taxonomies. I realize in science you're often describing before you're explaining as knowledge progresses but can't we just hit a reset button and all agreed to start over on these at some point? Think of the students, fo... |
[
"question about osmotic pressure in a U-shaped tube."
] | [
false
] | I would have a hard time explaining the demonstration, so i have included a picture. for the water to diffuse through to tube to achieve equilibrium, it seems to me that it must fight gravity to ascend the originally hypertonic side of the tube. my question is, where does the energy for this come from? surely it takes... | [
"Things in nature like to be equal. Osmotic pressure is a manifestation of this tendency. The difference in concentrations creates a pressure, I am unsure about the nature of this pressure. I'm sure you are familiar with the equation for calculating osmotic pressure. I'm not too keen on formatting, and will probabl... | [
"i think i understand all of this, but it just seems to me that some force must act on the solution to create this hydraulic pressure. creating a difference in water level must take some energy. where does this energy come from?",
"edit: to clarify, this is sort of a \"conservation of energy\" question rather t... | [
"i did not know that a concentration gradient has potential energy. the way you put it makes sense. "
] |
[
"How can sexual dimorphism exist even though offspring of both sexes inherit genes from both parents?"
] | [
false
] | null | [
"In humans, for example, males have an X and Y chromosome with different genetic information. Only one of those gets passed on (Y to male children, X to female). See here: ",
"https://en.m.wikipedia.org/wiki/XY_sex-determination_system"
] | [
"But doesn’t the Y chromosome have almost no genes on it at all besides the one that makes you male? So how can these complex traits be inherited through the Y chromosome?"
] | [
"Focusing on humans: the Y chromosome does have relatively few genes compared to the X, but even a single mutation in a single gene (and not just on the Y chromosome) can have profound effects. In this case, a ",
"single gene on the Y chromosome",
" controls the development of testes which in turn produce testo... |
[
"How does a pop-fliter for a microphone work?"
] | [
false
] | null | [
"A pop filter blocks the flow of air from your mouth to the microphone, thus reducing \"wind noise\" caused by exhaling. ",
"Since its not a significant barrier to pressure waves it achieves this with little or no attenuation of the sounds you intended to make. "
] | [
"Popping and clipping at two completely different things. You can have a pop without clipping and you can clip without a pop. ",
"There is no breaking up of sound energy with a pop filter, whatever that means.",
"A pop filter is not a compressor. It does not change how sound is presented to a mic, whatever that... | [
"Popping and clipping at two completely different things. You can have a pop without clipping and you can clip without a pop. ",
"There is no breaking up of sound energy with a pop filter, whatever that means.",
"A pop filter is not a compressor. It does not change how sound is presented to a mic, whatever that... |
[
"What is the maximum resolution for optical fiber bundles (like the ones in endoscopes)? Could one, say, make a 20 MP \"noodle lens\" for a smartphone camera? What would be the caveats (e.g. thickness, color fidelity)?"
] | [
false
] | EDIT: pointed out that I misused the word "lens", since fiber bundles only transmit the light. It would require an additional lens in order to focus light. My question is more about the "noodle" part rather than the "lens". | [
"I don't know any specifics here, but when using a fiber bundle as a simple optical path (rather than transferring digital data), you get one pixel per fiber. I highly doubt 20 MP is possible at a practical diameter.",
"More importantly, though, a fiber bundle is not a lens; it doesn't focus light, it just transm... | [
"A stop is a unit of measurement of exposure in photography. Each stop gives half as much, or twice as much light as the next, the name is derived from the stops on a lens aperture control ring, which control an iris inside the lens, used to give depth of field. Without an iris, camera lenses have very shallow dept... | [
"A company called NPC used to make a Polaroid back for 35mm cameras, and they solved the problem of getting the plane of focus out of the body of the camera and back onto a sheet of Polaroid by using a block of optical fibres about 6-7mm thick. Worked okay, was a bit softer than your usual Polaroid, and lost about ... |
[
"What exactly are quantum computers and what are their functions?"
] | [
false
] | null | [
"A quantum computer is a device that exploits one or more quantum mechanical phenomena in order to perform information processing.",
"The fundamental unit of classical information is called a bit, and a bit can be in one of two states, 0 or 1. It's possible for the computer to measure which of these two states an... | [
"You need to jump through a few hoops because quantum gates have to be reversible, but yes, you can do any classical computation on a quantum computer. If quantum computing ever becomes possible and economical, I would expect it to always be coupled to a classical processor and employed whenever a task would benefi... | [
"The idea is that the measurement problem only affects the readout and that when the qbits interact with each other, they're not restricted in the same way.",
"A larger system - like one with more qbits - will also have a larger number of orthogonal states - n qbits can have 2",
" orthogonal spin states."
] |
[
"Is the energy the Earth receives from the sun constant?"
] | [
false
] | null | [
"Are there any noteiceable differences in weather or temperature, for example, on earth due to this?"
] | [
"What you are asking is primarily driven by the angle at which the sun shines on the earth (i.e. different seasons). The differences in solar intensity due to distance from the earth are negligible for weather systems (long-term changes can have impact on past/future climate systems though)."
] | [
"No. The sun goes through a 22-year cycle in which its magnetic field gradually flips. Sunspot activity is highest during the middle of this process, and during that time the sun puts out slightly less energy.",
"The Earth also has an elliptical orbit, meaning that it is not always the same distance from the su... |
[
"Would it be possible to make a magnet in the form of a hollow sphere where the north is the outside and the south is the inside?"
] | [
false
] | I Assume it would require a tiny hole somewhere to be able to put something inside it to create the polarization of the magnet? | [
"No. Or more precisely, you can, but the magnetic field wouldn't leave the magnet. One way to prove the problem is the ",
"shell theorem",
". You have a spherically symmetric magnet, so the total pull from it if you're outside the magnet is the same as if it were concentrated in a point, in which case north and... | [
"It wouldn't leave the outer sphere, but that may not be the point. We have all kinds of uses for capacitors, which act very much the same."
] | [
"Yeah, the magnetic field is within the shell of the sphere but could also be set up on concentric spherical shells."
] |
[
"How do wasps communicate with each other?"
] | [
false
] | I live in Berlin, Germany, which every year in August becomes the wasp Mecca of the universe... I've noticed when sitting outside enjoying my sweet Rosinenschnecke that a lot of time can pass without any wasps attempting to feed on my delicious pastry. But once one stumbles upon it - beware - 5 or 10 of her friends wil... | [
"You probably already know that honeybees communicate the location of food sources to their nest mates via a dance-like sequence of movements, known as waggle dance. Other bees use variations of that. Wasps inform their peers of the existence of nearby food by drumming their abdomen. Wasp considers your food delici... | [
"Thanks,now i'l imagine a wasp rubbing her belly and drumming mettalica boom boom boom food heere time to paaaaarty."
] | [
"imagine when you had to give directions, you had to do it in a rhyme.",
"\ngoogle maps would be interesting"
] |
[
"Why do many substances appear as white powders?"
] | [
false
] | null | [
"Most compounds are insulators, which means they have a band gap greater than 3-5 eV. (Visible light is around 1 to 3 eV) insulators cannot absorb visible light, because their band gap is greater than the energy of visible light, so they transmit that light. Large crystals of insulator see clear, like glass. When t... | [
"i dont think spirit of the question was \"why do these powders appear white?\", but \"what is it about these chemicals that make white the most common color for certain powders?\"",
"one refers to the light spectrum, the other to chemical composition",
"i only post this because im a little curious myself"
] | [
"Colour of a substance depends on the chemical structure, or crystal structure of the substance.",
"If the structure absorbs certain wavelengths of light, and reflects others, you will see the reflected wavelengths (only if they are in the visible spectrum, ~400-700 nm)",
"You see a lot of white solids because ... |
[
"What percent of mental illnesses cannot be treated/managed?"
] | [
false
] | Basically the title, what percent of mental illnesses cannot be reasonably treated or managed and are just too extreme for any kind of normal living or recovery? | [
"This is a bit of a hard question to answer from available data. The basic concept of treatment resistance has seen a lot of research, and we can talk about that, but it takes a much higher symptom burden to cause the kind of impairment you're talking about. Some examples of what we do know:",
"*A manufacturer's ... | [
"There are a ton of factors at play but those unhoused neighbors constitute the large majority revolving door of psychiatry. Sadly, I'd imagine a good proportion of them could become medically stable if there was a good public safety net and public (mental) health was dealt with appropriately. If you think about al... | [
"This is a very informative response; thank you.",
"I've always wondered: I live in San Francisco and (not to get too graphic or sensationalistic) there are a number of (apparently unhoused) people dissociated who basically walk around all day yelling. What are the ranges of outcomes for someone in a situation l... |
[
"Do we create light?"
] | [
false
] | [deleted] | [
"[...] present since forever via energy transfer [...]",
"You're on to the right idea here. Everything that we experiences follows the laws of conservation of energy. That is, energy is never lost, it only changes forms or is given from one system to another.",
"With regard to light, the energy is being taken... | [
"not only your laptop.... but you emit light believe it or not... you emit a form of light in the infrared spectrum (we cont observe it with the naked eye).. you constantly emit light, and that light will escape into the universe and will probably interact with something else... maybe the telescope of an alien astr... | [
"It is assumed that the big bang was incredibly bright on all wavelengths and extraordinarily hot as well. Now that atoms are stable these days, and microwave background radiation is rather cold.. It would be much much less."
] |
[
"If there is no change in the environment of a species, is there an impetus for an organism to undergo evolution? (For example, tardigrades, who can survive in extreme conditions?)P"
] | [
false
] | [deleted] | [
"You're asking if there's evolution in the absence of natural selection. Yes, there is. ",
"Natural selection is the best-known driver of evolution (to the point that it's often confused with evolution), but even Darwin figured out ",
"sexual selection",
", and since the 1960s we've known about ",
"neutra... | [
"Indeed, over very long time scales organisms will in principle reach an \"equilibrium\" between drift and selection: drift increases the frequency of deleterious mutations, and selection decreases them. This is also one of the reasons the distribution of mutational effects itself changes over time. If an organism ... | [
"Evolution occurs due to selection pressure, which means that the species is in some way resource-constrained. Under selection pressure, the species may adapt to use the resources more effectively.",
"So in order for evolution to not occur, the species would have to be under no selection pressure. That means not ... |
[
"Scientists, tell us your science related mysteries?"
] | [
false
] | null | [
"Hi 12thman-Stone thank you for submitting to ",
"/r/Askscience",
".",
" Please add flair to your post. ",
"Your post will be removed permanently if flair is not added within one hour. You can flair this post by replying to this message with your flair choice. It must be an exact match to one of the f... | [
"‘Chemistry’,’astronomy’,’physics’"
] | [
"Thank you for your submission! Unfortunately, your submission has been removed for the following reason(s):",
"guidelines",
"/r/AskScience",
"If you disagree with this decision, please send a ",
"message to the moderators."
] |
[
"Does your metabolism slow down as you age and if so, how?"
] | [
false
] | The recent "How did you get fast?" ask reminded me of something I've wondered about: It's commonly accepted that your metabolism slows as you age, and it is often treated as a phenomenon apart from changes to lifestyle and behavior. However, if someone maintained the same level of activity, ate the same diet, and exerc... | [
"The age-related decrease in BMR is almost entirely explained by the loss of lean body mass. Once LBM is controlled for, the effect of age seems to be minuscule. In ",
"this study",
", age explained only 2% of the observed variation vs. 63% for LBM."
] | [
"Well yeah, slightly lower. \"Significant\" in this context refers to statistical significance, not the magnitude of the effect. The 6.3% figure is relative to the ",
" variation after the effect of LBM had been removed. So overall it's still just ~2% of the total.",
"The factors underlying individual differenc... | [
"Growth requires additional energy, so, relative to their size, kids have a higher metabolic rate than adults. But adults burn more calories overall because they are bigger."
] |
[
"if an airplane wing can take X amount of load, would a 2:1 scaled down version of said wing be able to take X/2 load, or is this not a linear relation?"
] | [
false
] | my intuition tells me this should be X/2 but my intuition (as a product design engineer) also tells me that there might possibly be some kind of relations that would alter these specifications a bit. I have no idea how to google this question because I don't really know what kind of typical set up or problem I am looki... | [
"The simple answer is, planes that are smaller will take higher loads, relative to their size, than larger planes. According the the square-cube law:",
"\"",
"\"",
"This is part of the reason why ants can lift many times their own weight."
] | [
"So if we scale the plane with a factor 2, we have to divide the volume (and therefore approx. the weight) by 8 and the wing area by 4. So the formula is: (original weight / original wing area) * (4/8). The factor 1/2 seems right if all other factors stay the same. (please correct me if I'm wrong)",
"However, if... | [
"This sort of dimensional analysis is extremely useful in prototyping and testing concepts using scale models. To get a decent understanding of the aerodynamics of a plane using a scale model, for example, you can (as you mentioned) scale the power to get an 'equivalent' speed, but you can also change the density o... |
[
"what's inside a black hole?"
] | [
false
] | null | [
"There's two sides to this question: What the math says, and how we interpret the math.",
"The math says that inside the event horizon, there is a dimensionless point of infinite density that we call a singularity. The problem is though: How do we interpret this when thinking about physical reality?",
"Well... ... | [
"My view: It literally doesn't exist.",
"Would your view change if you were an observer falling into a black hole? Would you cease to exist the second you crossed the horizon, or would your interpretation of the mathematics suddenly change?"
] | [
"Ahh! and now we get into the subtleties of it all.",
"This is where the apparent paradox of causality violation arises with black holes. How can someone fall into a black hole in their own reference frame, but someone far away observe that it takes forever to cross the event horizon? Well, the answer is that wha... |
[
"It seems like a lot of species' natural poisons are actually just blood coagulants. Are there many examples of poisons that target other functions?"
] | [
false
] | null | [
"Blood targeting poisons are known as hemotoxins, there are also neruotoxins, cytotoxins, and myotoxins. Neurotoxins target the ability of nerves to function. One common target of neurotoxins is acetylcholine function, interruption of which results in loss of muscle function. Neurotoxins can lead to loss of motor f... | [
"Are you talking about Komodo Dragons?",
"Bacteria transferred from an animal's mouth to a wound are not a toxin themselves, but can produce their own toxins."
] | [
"do those categories include a bacterial toxin, like those lizards (that I cant remember the name of?)"
] |
[
"If there was a bag of 10 balls, 9 white and 1 red and 10 people including you has to pick one randomly and who gets the red ball wins, does it matter what order you all pick, or is it better to go first or last with probability?"
] | [
false
] | null | [
"It doesn't matter.",
"The first person to pick has a 1/10 (10%) chance to win. So he has a 9/10 (90%) chance to not win. That means that the second person to pick has a 9/10 (90%) chance to get his turn (which only happens if person 1 doesn't win), but if he gets his turn he has 1/9 (~11.11%) chance to win. That... | [
"It should be noted that it ",
" matter if people put the marbles back into to pot after they draw and the game is stopped once someone wins (sampling with replacement)."
] | [
"Yes, because there's a chance that the game could end after the first pick, but because of the replacement every person has the same chance to win if they do get a pick. "
] |
[
"Will it ever be possible to create a direct image of an extrasolar planet in the same way we can view, say, Mars or Jupiter?"
] | [
false
] | I know that there has been some amazing images of extrasolar planets, such as those around HR 8799 by the Keck Observatory using motion interpolation. But, is there any possibility of acquiring an image in visual light - so that you could say "It's green" or "It's blue". Thank you! | [
"Will it ever be possible to create a direct image of an extrasolar planet in the same way we can view, say, Mars or Jupiter?",
"That's a tough question. I would say, yes. But the real question is the timescale. ",
"Most of the really incredible images of ",
"Mars",
" and ",
"Jupiter",
" were taken b... | [
"Pluto is roughly 1/2000 of a light year from us. So to view an exoplanet 50 LY away with the very blurry resolution of the image you link to would need an aperture 100,000 times the Hubble. Roughly 200 km. That's quite some constellation. I see formidable obstacles to doing optical interferometry over distances of... | [
"The hard part about interferometry is you need to be able to align things to within a fraction of a wavelength. Comparatively easy at radio frequencies, virtually impossible at optical wavelengths unless the telescopes are immediately adjacent to each other (large binocular telescope as an example)."
] |
[
"On the nature of 'time'."
] | [
false
] | null | [
"...perception of time ",
"You have to choose your words carefully here. An observer's perception of their own time never changes. What happens is that if you look at another observer moving at a large speed relative to you, all processes in that observer's frame (like the ticking of clocks and all biological fun... | [
"You original question was a \"why\" question. The answer to a \"why\" question depends on what kinds of reasons you're looking for. If you're looking for a mathematical explanation the answer is that the universe (ignoring gravity for simplicity) appears to look like a 4-dimensional world which has a Lorentz symme... | [
"Thank you for that. I realise that 'perception' may carry certain baggage with it. Just to clarify, at the moment it is my intention to only be referring to particles during this series of questions."
] |
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