title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"Could a black hole that's big enough, cause a \"Big Bang\" large enough to create a new universe?"
] | [
false
] | I don't know much about black holes, but I'm wondering if they can get so big and heavy, that they explode in some way to create what we would perceive as a big bang. I like the idea of there being multiple universes, and that the universe can be born again and again infinitely, so I thought about what it might look like if a person zoomed out far enough to see what the universe looked like, with other universes around it. I tried to think about patterns we see on small scales and large scales, and came up with this sketch I made Since the big bang comes from one point, I thought it might look like a bubble of some sort, and if it came from an exploding black hole (White hole?), maybe there could be others too. The image I made would try to show a cross section of entire universes created by big bangs. Other universes would collide with eachother, forming big concentrations of galaxies and matter of all kinds, making huge black holes that we have not even seen yet. At these super concentrations of galaxies and stars, there would be a lot of black holes, all converging and eating eachother until there was one big enough to get too big to exist, and explode. That is, if black holes ever explode. I'm using the word 'universe' in a way that makes it sort of just an area in space created by it's own big bang. Like how we call a swirling group of stars orbiting a super-massive black hole a galaxy. I'm not very educated on the matter, just been to high school, so forgive me if this idea and question sounds silly! | [
"Black holes do explode, or die violently, but sadly only small ones do. In fact very massive black holes are incredibly stable and emit very, very little energy. I'm talking less then the power of a small LED. Also it's best not to think of space as nothingness, even empty space is something and the Big Bang was t... | [
"Thank you for your info, it's very interesting. :) I have seen that map before, it's what inspired me to make these images I make. My image would be on a much larger scale than that map shown, the jpeg you linked would make up a tiny rectangle in one universe on my image.",
"Thanks again!"
] | [
"Very interesting! Thank you for your insightful reply. :)"
] |
[
"Physics Question: Fourier's Law, heat dissipation from one material to another?"
] | [
false
] | Fourier's law states that the heat flux of a material is equal to the the product of the temperature gradient in the material and the thermal conductivity of the material. But, when calculating heat dissipation using Fourier's law, shouldn't there be a variable describing an additional material, to which the original material is transferring the heat? There is no variable to take into account the thermal conductivity of the surrounding material. A red-hot steel cannonball's rate of heat dissipation would be much higher in 10°C water than in 10°C air. Conversely, a steaming hot cup of coffee would cool down much slower in a ceramic mug than in a metal cup. In such a case, shouldn't there be two different thermal conductivity coefficients in Fourier's law? Or is it that I'm approaching the calculation of heat dissipation erroneously? | [
"Depends on the approximations you can make. Is the solid highly conductive compared to its heat loss to the gas? Then you can use the lumped capacitance model and just use Newton's law of cooling to find the heat transfer, since the entire body is at approximately the same temperature. If not, you have to direct... | [
"You're approaching the problem erroneously. ",
"Fourier's Law describes the flow of heat in a ",
" material. For example, you can use Fourier's Law to calculate the heat flow through a solid material suspended between two heat sinks (",
"example",
"). It assumes that the material does not interact with any... | [
"Thank you. If that is the case, how would I go about calculating the rate of dissipation of an object's heat into its surroundings? What formula exists for this?"
] |
[
"What's the difference between a cancerous and a non-cancerous tumour?"
] | [
false
] | [deleted] | [
"I haven't had an oncology course in a while, so this may or may not be entirely correct, but I hope I remember enough so that the general concept is true even if all the details are not.",
"Im guessing your question refers to the difference between a benign and a malignant (cancerous) tumour. This isn't really a... | [
"Benign tumors form when cell cultures exhibit hyperplasia, an excess of cells. Basically something in the cell cycle has gone wrong and they're dividing excessively. Malignant tumors on the other hand are what we call tumors composed of cells with altered morpholigies. Basically these cells are so far mutated that... | [
"Thanks, that clarifies things :)"
] |
[
"How can space be cold?"
] | [
false
] | It is my understanding that if you go to space without a space-suit, you will freeze. But how can that be? If heat is 'stored' in the vibrations of the atoms involved, and there's no atoms around you to transfer those vibrations to, how can the heat leave your body, so to speak? And on top of that, why doesn't the sun keep you warm? I mean, there's nothing like atmosphere to remove energy from the sun's rays before they hit you, so shouldn't it be really hot? Sure, the rays only hit you, and doesn't warm up your surrounding air and the ground beneath you, but still. Can somebody explain this? | [
" Thermal energy can take a lot of forms. In matter, it's the kinetic energy of the particles. In space, the temperature is determined by the energy density of photons. If photons didn't carry energy, how else would the sun warm the earth?",
" If you were dropped in space without a space suit, the first thing tha... | [
"If find the placement of that one smiley very disturbing.",
"Otherwise, great explanation."
] | [
"We are actually. Everything gives off photon radiation. This is known as ",
"Blackbody Radiation",
"."
] |
[
"Can you measure pain?"
] | [
false
] | [deleted] | [
"Yes! Tell me, ",
"how much does it hurt on a scale of 1-10?",
"As crude as self-report of pain seems to be, that has been the gold standard of measuring pain for as long as medicine, and is still what is most commonly used clinically today because it is easy to collect and useful.",
"Of course, this isn't wh... | [
"This is a fantastic overview! I feel like this is why a lot of people steer clear of pain research, because it's just as much psychology and philosophy as neuroscience.",
"I also want to add that for quantifying pain in patients, the gold standard at least here in Canada is the ",
"McGill Pain Questionnaire",
... | [
"As a researcher in a neurobiology lab studying pain, we use many models to study acute and chronic pain conditions. The comments below address the obvious complications associated with the self-assessment of pain, although we avoid this discrepancy from our molecular approach, being that we limit our research to n... |
[
"How does mixing magmas of different types cause large explosive volcanic eruptions?"
] | [
false
] | I've read from several different sources that when a fresh injection of basaltic magma intrudes into a more silica-rich magma chamber under a volcano, some sort of reaction happens that ultimately leads to a large explosive eruption. I've specifically heard this implicated for the 19th century Krakatoa eruption, where people point to volcanic rock of varying color bands indicating partially mixed magmas that cooled preserving the different rock types. However, these sources don't mention a mechanism for this. Is there some sort of chemical reaction between the different magmas? Is it a physical reaction relating to different temperature/density/viscosity/gas content/something else? What leads two bodies of relatively stable magma to generate immense pressure and explode when mixed together? | [
"Temperature difference. The lighter felsic magma in the primary chamber had been cooling down for some time. This theory around the magma mixing, involved a darker body of much hotter and more mafic magma intruding into the chamber. This caused a pressure spike, followed by the very large kaboom.",
"The other th... | [
"The added heat from the mafic magma induces convection and vesiculation (i.e., bubbles) which has long been argued to be the trigger (e.g., ",
"Sparks et al., 1977",
"). There are definitely chemical changes as a result of the mixing (e.g., the chapter on magma mixing as an eruption trigger by ",
"Morgavi et... | [
"It is not so much about the mixing of two different magma leading to explosive eruptions although that can happen. There are other factors that help explain the reasons...",
" The ",
" of the magma is an important factor. ",
"i) Magmas that contain more Silica tend to be more viscous and sticky. ... |
[
"Are plants as efficient as solar panels?"
] | [
false
] | If I plant grass on 1km and burn it in 100% efficient engine after month, would it give me more energy than 1 km of solar panels in the same time? | [
"Not really, from what I have read solar panels have around a 15% efficiency (average). Plants have a ",
"theoretical maximum efficiency",
" of around 13%. Plants have an ",
" efficiency",
" of around ",
"1% to 7%",
" "
] | [
"Not really if you look at their biochemistry. They take water, carbon dioxide, and oxygen to work along with nutrients in the soil. Then we should remember some of that energy is used to keep the plant alive.",
"Think about humans. We eat a couple of pounds of food per day, yet we dont gain a couple pounds every... | [
"Not really if you look at their biochemistry. They take water, carbon dioxide, and oxygen to work along with nutrients in the soil. Then we should remember some of that energy is used to keep the plant alive.",
"Think about humans. We eat a couple of pounds of food per day, yet we dont gain a couple pounds every... |
[
"Will vacuum decay happen? Is there strong evidence supporting its existence?"
] | [
false
] | [deleted] | [
"Will vacuum decay happen?",
"No, it's incredibly unlikely—and that assumes our vacuum is actually metastable (lives for a long time) which is also an \"if\".",
"Is there strong evidence supporting its existence?",
"The decay of the false vacuum isn't nonsense, but a real thing depending on the physical laws.... | [
"Just want to say an undercooled liquid will still eventually nucleate a solid phase even without agitation or an outside force. Classically, the nucleation rate is severely hindered by the very small successful attempt rate. The exception to this is if you can cool it through a glass transition since then it's act... | [
"I don't have the prerequisites to understand math above, but I like the way you presented your answer. "
] |
[
"Why do my eyelids/general eye area hurt if I haven't slept enough?"
] | [
false
] | null | [
"Wow, and this is why we can't have nice things. Class it up in askscience please. Not the OP, but the responders."
] | [
"Agreed. If you're not qualified to answer by virtue of having studied this particular topic for many years, there better be a link showing us where you got your information. ",
"For example, to the person that posted \"well we spend the majority of our time in REM sleep\" below, he should read this article, whic... | [
"Optometrist here. In general tired/fatigue causes eye discomfort for two reasons. (1)Most common is dry eye, as any others have pointed out. In general the longer we're awake and the more fatigue/tired we are the surface dries out. In addition, we blink less, causing more drying/desiccation by evaporative acti... |
[
"What goes on in our brain when we become confused?"
] | [
false
] | I was trying to understand something that my friend told me the other day and it made me wonder what exactly was going on in my brain when I was so confused. Is there a change in how the neurotransmitters/neurons travel? (To be honest I'm actually not sure what happens when we're thinking normally) Or is there no change in our brain activity? | [
"{ Joke: Please Ignore }",
"Complex ",
" and ",
" is still too ",
" to ",
"?"
] | [
"What do you mean confused? You mean a loss of orientation, ie not understanding date/time/place/event/identity/etc?",
"Confusion, delirium, and even dementia are the results of your brain attempting to do very normal things and being unable to adequately accomplish the task. Thought seems to be the process of ... | [
"Okay well we have basically no idea how \"understanding\" works. At all. We get how learning works in principle, but what separates basic learning from complex abstraction and understanding is WAYYY beyond us.",
"The theories I am familiar with of how it works is that when you are unable to create strong enoug... |
[
"If everyone was required to stay at home for 2 months with zero contact with other people could we wipe out the cold/flu forever?"
] | [
false
] | [deleted] | [
"Not a chance, the biological world consists of a lot more than just humans, influenza in this case infects a wide variety of animals, hence the \"swine\" or \"bird\" flu you hear about. Also a lot of diseases can have incubation times or even be dormant for decades like in the case of TB."
] | [
"The ",
"xkcd-book",
" has a section about this, and the answer comes down to: Almost, but not really.",
"The common cold is usually caused by some variant of the rhinovirus, which is eradicated from the human body by a healthy immune system after about a week. And since this virus doesn't cross species, and ... | [
"To further this and clarify, the flus don't infect the animals, so to speak, there is typically no disease or illness. They treat the host species as a vector, mutate for one or several generations, and then we catch this new, evolved version.",
"\"Zoonotic vectors\" are what we're talking about."
] |
[
"Is it possible for two truly simultaneous events to occur?"
] | [
false
] | [deleted] | [
"In principle nothing prohibits two events from taking place at the same time--and essentially you're bringing up a notion from Zeno's paradoxes, the notion of divisibility. Ultimately, there is nothing special that two events occupy the same parcel of time versus being offset slightly and practically, our measurem... | [
"Define \"truly simultaneous.\" In classical physics or in the same reference frame yes. One event could happen at exactly the same time to way more than any measurable amount of time, even absolute. HOWEVER, if you then move that reference frame, you now have two events that occur at different times.",
"An \"eve... | [
"Did I not also read somewhere that there is no such thing as \"At this very moment in a far away galaxy...."
] |
[
"Why does it appear most craters on the moon are fairly true circles?"
] | [
false
] | I was looking at a video of the moon and noticed that all the craters I could make out appeared to be nearly perfect circles. I would think that an object striking the moon at an angle would form a less perfectly circular crater than a direct hit. If the moon's gravitational pull isn't very large, and it has no atmosphere to slow objects down, why does it appear that most impacts come at a very high angle? | [
"It doesn't have to be at a high angle to create a circular crater. If the object is moving fast enough (and it will be, since it's falling at interplanetary speeds), it will create a massive explosion when it hits. The shock wave is circular, and will be much much larger than the object itself. That's what creates... | [
"The impactor is completely vaporized due to the energy involved, and the shock wave is through the solid mass of the surface."
] | [
"Yeah, when things start moving kilometers per second, not much is left after impact. "
] |
[
"Can someone harmonize these seemingly conflicting lung cancer studies?"
] | [
false
] | Can you harmonize these seemingly conflicting results? Our study (Moghaddam et al) and Dance-Barnes’s are similar in that carcinogenesis was initiated in both by an activated allele of K-ras (G12D in ours and G12C in Dance-Barnes’s), expressed in airway secretory cells under control of the CCSP promoter, and the concentrations of dietary curcumin were similar (1% in our study and 0.4% in Dance-Barnes’s). However, the studies differ markedly in their mechanisms of transgene expression. We used a hit-and-run strategy in which the Cre recombinase is expressed in airway secretory cells by the CCSP promoter prior to the 6th week of postnatal life to induce rearrangement and activation of a conditional K-ras allele, with permanent subsequent expression under control of the endogenous K-ras promoter in an inflammatory model (20). This strategy was adopted because we had found that the CCSP promoter is downregulated by inflammation, resulting in reduced carcinogenesis when the oncogene remains under control of the CCSP promoter (20). Dance-Barnes et al. (39) used a bitransgenic strategy with the reverse tetracycline transactivator under control of the CCSP promoter and an activated K-ras allele under control of a tetracycline-inducible promoter. Either or both of these promoters could be influenced by curcumin, resulting in upregulation of the expression of the K-ras transgene. Since tumor progression was mild in this model, occurring late in life and at a low grade, carcinogenesis should be sensitive to small changes in oncogene expression. While these differences in the genetic models could explain the discrepant findings between our studies, further experiments will be required to provide evidential support. Abstract: In the current study, we demonstrate that curcumin unexpectedly promoted the progression of lung lesions from benign hyperplasias to ADs and carcinomas, similar to the known lung tumor promoter butylated hydroxytoluene (BHT) (34–36). Furthermore, we provide evidence that after 1 week of curcumin administration in the diet, lung tissue demonstrated enhanced levels of oxidative damage. This early pro-oxidant effect may account for the tumor-promoting effects of curcumin in lung tissue. Abstract: We conclude that curcumin suppresses the progression of K-ras-induced lung cancer in mice by inhibiting intrinsic and extrinsic inflammation and by direct anti-tumoral effects. These findings suggest that curcumin could be used to protract the premalignant phase and inhibit lung cancer progression in high-risk COPD patients. "In summary, the results presented here support further the effectiveness of curcumin as a therapeutic agent, alone or in combination with current therapy against lung cancer. It could also be considered for use by current smokers or ex-smokers with or without COPD as a chemopreventive agent. Further understanding of the molecular mechanisms affected by curcumin treatment will provide a basis for rationally directed clinical testing of the efficacy of this agent and other selective anti-inflammatory/anti-tumoral agents in preventing COPD progression and lung carcinogenesis." Here is some background on Curcumin. | [
"One of the really cool things about scientific literature is that it's all a huge, ongoing conversation. Most of the time, when you have two papers with conflicting (or seemingly conflicting) results, the authors of the later paper will talk about the conflict, and try to give some explanations for it. In this ca... | [
"thanks for the reply. in the legal services industry we have a similar organizational framework where judicial opinions are essentially having a similar conversation with each other. Published materials (cases, journals, briefs, statutes, etc.) are often citing to previous materials for reference. having said that... | [
"The short answer is given by the paper as Jetamors pointed out. One group used a mouse that had the K-ras mutation from 6 weeks post birth whereas the other used an inducible mutation that they turned on right before the experiment. Their explanation is that while their model uses a slow and steady tumor induction... |
[
"If human bodies reject organ transplants because of foreign DNA, why can we receive blood transfusions from other people with no problem?"
] | [
false
] | null | [
"Blood and organs are rejected for slightly different reasons. Organ rejection is largely dependent on ",
"MHC I/HLA",
" proteins which are expressed on all nucleated cells. These are encoded by your DNA but DNA plays no direct role in organ rejection. ",
"Red blood cells are not nucleated cells and they do n... | [
"It’s not the foreign DNA, it is the markers on the outside of the cells. Those are typically glycoproteins or lipids with carbohydrate chains. In a simple way of explaining, If your organ of transplant has similar markers as the recipient , rejection will be minimal. The purpose of compatibility testing and biomar... | [
"So it’s rather fortunate for us, that red blood cells aren’t nucleated, and don’t produce MHC I/HLA? Otherwise we’d need immunosuppressants for any blood transfusion?"
] |
[
"What is the most toxic chemical element?"
] | [
false
] | I know that elements like plutonium or polonium are lethal at very low doses but they owe their toxicity primarily to their radioactivity so I'm wondering which is the most toxic element when only chemical interactions are taken into account. | [
"Actually it is so unstable that you can't have a sizable, pure amount of it -all of its physical properties have been calculated by theoretical calculations rather than actually measured. "
] | [
"Surely a banana doesn't contain potassium in elemental form? The question was what is the most toxic ",
".",
"Also, \"Toxicity is the degree to which a substance can damage a living or non-living organisms\" (Wikipedia), so an explosion in your gut would qualify. :)"
] | [
"He said toxic elements. A nuclear weapon is not an element."
] |
[
"How does the SARS-CoV-2 replicative machinery differentiate viral RNA from host RNA?"
] | [
false
] | How do the nonstructural proteins of SARS-CoV-2 avoid replicating human RNA while they are replicating the SARS-CoV-2 genome? | [
"Coronaviruses use a protein, NSP1 (non structural protein 1) to shut down host protein synthesis. Then coronaviruses utilize double membrane vesicles to separate the viral processes from the cellular ones (which are being shut down to divert all resources towards viral reproduction). The double membrane vesicles c... | [
"This is really interesting. Is it more correct to say that the virus is moderating the host's replicative machinery rather than providing it's own though?"
] | [
"This is correct. Viruses hijack the host machinery to perform many of its functions. Instead of encoding the machinery it may encode a protein to hijack it. Viruses do also encode a number of other protein to aid in immune invasion. This includes proteins which bind to host proteins which seek out the virus."
] |
[
"Is it more efficient to set my home's thermostat to vary between 65F when I'm not home, and 70F when I am home... or just leave it at a constant 69F all winter long?"
] | [
false
] | I live in a 2 story condo/apartment in New England and I have a fancy thermostat that I can program in all kinds of various ways. I used to set it to be 70F in the morning, 65F while at work, 70F when I get home, and back to 65F about the time I went to bed. Then I got to thinking, is this actually more efficient? Is my boiler actually doing more work by having to heat up the house those extra 5 degrees 2x per day? Would it not be easier and more efficient to just set it to a constant 69F throughout the entire winter? (For reasons I dont wanna get into here, lets just assume 65F is the lowest setting). Thanks for any information you may provide. | [
"Most home thermostats work by turning on the heater when the temperature falls below a certain level, then turning it off when the temperature goes above a certain level. It will be cheaper to leave your house at a colder temperature."
] | [
"\"You can easily save energy in the winter by setting the thermostat to 68°F while you're awake and setting it lower while you're asleep or away from home. By turning your thermostat back 10°–15° for 8 hours, you can save about 5%–15% a year on your heating bill—a savings of as much as 1% for each degree if the se... | [
"It's always more efficient to have the heater or A/C off rather than working, even if you want to have it at a different temperature in the future. Keeping your house at a constant temperature uses more energy than letting it cool down when you're not there or asleep and heating it back up when you're around. "... |
[
"If a cup of water saturated with NaCl and a cup of Ice were both brought to 0 degrees F, and then left in a room at 70F would they reach room temperature at the same time?"
] | [
false
] | I am trying to learn which is more efficient at keeping things cool; frozen water, or non-frozen water-salt mix. Basically, if I loaded a cooler with drinks, would ice keep it colder for longer, or would cold salt water? Thank you! | [
"A cup of ice will require more energy to heat up to room temperature than a cup of saturated NaCl solution at zero degrees. This is because ice requires extra energy, equal to the energy of fusion, to turn into liquid water, before any energy goes into raising temperature.",
"The reason many recommend you to use... | [
"A cup of salt water and a cup of ice would not reach steady-state at the same time, because they have different heat transfer coefficients with air, and because some of the heat transferred to the ice cup would go towards the heat of fusion (to melt the ice).",
"Ice is better because of this fact - it absorbs he... | [
"Yes. Also, the colder you can get your ice, the more heat it will absorb before melting. Basically, you want as much thermal mass, at as low a temperature as possible. Phase changes (melting ice) helps, too."
] |
[
"If we were standing on Mars, what color would Earth be?"
] | [
false
] | When we're looking at Mars, it's a faint red. So what color would Earth be if we were standing on Mars? | [
"Here's a picture",
". It's a kind of pale gray, but that's likely due to the Martian atmosphere. ",
"Here's a picture",
" from (I presume) a satellite orbiting Mars, and it's blue."
] | [
"No, it was taken by HiRISE: ",
"http://www.nasa.gov/mission_pages/MRO/multimedia/mro20080303earth.html",
"EDIT: To clarify, the removed comment stated that the second photo was taken from the Juno probe. The parent comment is correct. "
] | [
"No, it was taken by HiRISE: ",
"http://www.nasa.gov/mission_pages/MRO/multimedia/mro20080303earth.html",
"EDIT: To clarify, the removed comment stated that the second photo was taken from the Juno probe. The parent comment is correct. "
] |
[
"How do meteorologist forecast the path of a cyclone so accurately?"
] | [
false
] | null | [
"One thing they do is throw ",
" of computing power at the problem, re-running many simulations from the same initial conditions with small perturbations. This builds up a probabilistic picture of how the path of the system is likely to evolve, given the currently available information.",
"If you watch e.g. pre... | [
"And they collect tons of real world data (wind speeds, rain fall, water temperatures, etc) to feed into those models. Here is a link to the ",
"Hurricane Forecast Improvement Project",
" which talks about this kind of thing in way more detail."
] | [
"Via Data Assimilation that blends data and model output to produce the best estimates. Some of the data is collected using adaptive sampling, they fly a plane to collect local information in and near the cyclone guided by thee forecasts"
] |
[
"What's the difference between your skin being burned by fire, UV-rays, and ionizing radiation?"
] | [
false
] | At a certain level of severity are they all the same or are they each radically different at every scale? | [
"Chemist here. On a physicochemical level they damage tissues in different ways. Heat increases the rate of otherwise negligibly slow reactions, UV excites electrons causing bonds to break, and ionising radiation kicks electrons out of molecules. But I would presume that with a high enough exposure to and intensity... | [
"A lot of the practical damage caused by UV radiation results from ",
"thymine dimers",
", and their repair mechanisms recent won a ",
"nobel prize",
"."
] | [
"Is UV radiation considered non-ionizing? Why/why not?"
] |
[
"Quick very simple electrical circuit question"
] | [
false
] | When you discharge a charged capacitor, does the current go in the opposite direction that it did to charge the capacitor? And if so, how is the battery factored in? Do we then kind of consider the capacitor as the emf and the battery as a wire? (This is all in terms of basic circuits, not trying to get technical here) Thanks a bunch | [
"When you discharge a charged capacitor, does the current go in the opposite direction that it did to charge the capacitor?",
"Yes.",
"And if so, how is the battery factored in?",
"The capacitor discharges when the battery is no longer maintaining the voltage across the capacitor. Generally this happens when ... | [
"There are three states a battery can be in in this circuit.",
"Where Vbat>Vcap, the cap charges.",
"Where Vbat=Vcap, there is equilibrium, and no (or negligible) current flow in wither direction.",
"Where Vbat<Vcap, the current flows back to charge the battery, and the energy is stored. From the point of vie... | [
"When you connect the plates of a charged capacitor, excess electrons go from the negative plate to the positive plate.(Thus, charge flows from +ve to negative)"
] |
[
"Why can we develop a vaccine for COVID in 8 months, but still don't have a vaccine for other viruses that are decades old?"
] | [
false
] | Not anti vaccine or anything and I plan on getting the covid one, but just wondering how a vaccine for COVID was made so quickly, and we still don't have a vaccine for HIV, respiratory syncytial virus, Epstein-Barr, etc. | [
"HIV is a highly mutagenic virus - there are a handful of different COVID strains circulating around the world, but in HIV the virus continues to mutate readily after infection, leading to the presence of multiple strains per individual ",
"(source)",
". This makes it a much more difficult task to come up with ... | [
"\nShort answer: Many many reasons",
"\nSlightly longer answer: "
] | [
"I also want to throw out that the COVID vaccine is not simply the product of 8 months of work... tons of work on other similar virii, like SARS, had already been done, and we'd been working on the mechanics/production of mRNA based vaccines for a long while too. To a degree, we got lucky with COVID in that it beha... |
[
"How much of our bodies do we (humans) need to live?"
] | [
false
] | I searched this question up and couldn't really find a definitive answer. For example, if we lose a leg or arm, we can still very well live. How far does that go? Is it possible, like in some sci-fi movies, that we can "live" with just a brain and machine-fed nutrients? I know "live" is somewhat subjective, but let's say enough to think and perhaps communicate? | [
"You can lose:",
"and be more or less OK. Now, there are other things that can be compensated for. They are:",
"And there are some things which really can't be replaced in an effective way:",
"There are ways to compensate for some of these (ECMO for heart/lung, total parenteral nutrition for GI tract), but ... | [
"Why would you say that, it makes sense, there is nothing strange about it."
] | [
"Why would you say that, it makes sense, there is nothing strange about it."
] |
[
"Is mathematics universal? By this, I mean if an alien species were to develop their own system of mathematics, would it resemble our own? Would it share the same concepts?"
] | [
false
] | null | [
"Quite possibly not a base 10 system, but certainly any technically evolved civilization would have mathematical concepts of counting, arithmetic operations, etc."
] | [
"Whenever I see a question like this I like to remind people that for a very long time mathematical developments were primarily geometric. Algebraic interpretations of what's going on in physical systems is, necessarily, an abstraction. Geometrically though you're not that far removed from the actual thing you are ... | [
"A math friend once joked that all number systems are base 10, because what we call base 8 would still be written as 10. They would call our system base 12. Hm, maybe i suck at math jokes, but it was funny and thought provoking to me when I heard that."
] |
[
"Can scientist compare corona virus in the wild to what was being studied in the wuhan lab genetically to see if it matches?"
] | [
false
] | null | [
"Unclear what you’re asking. The wuhan lab was studying wild viruses. There are many wild matches for them. Easily googled, many recent papers."
] | [
"I thought dna sequences were very precise. Your saying the wuhan lab had virus the genetically matched with what has been found in the wild?"
] | [
"The wuhan viruses ",
" wild viruses. You seem to have some conspiracy theory misunderstanding here."
] |
[
"Does a Patina affect the Thermal Conductivity of Copper?"
] | [
false
] | I have seen a few different answers to this, from Water cooling blogs saying, "The Patina is nothing to worry about, it won't affect performance" to people using the Patina to justify why Aluminium Radiators are now preferred. So lets ask Reddit. If a Patina forms on a Copper Radiator, will that Radiator preform worse then a brand new, perfectly clean Radiator? Does it depend on the type of Patina (brown vs black vs Green) as they are different chemicals? For that matter if this is true of a Copper Patina, would it hold true for all Patinas (say for example, Silver Tarnish)? And even if it does make a difference, is this difference as significant as the decrease performance that would be caused by Paints or Powder Coats that are often used to protect the Radiator? Or for that matter is the drop in thermal performance enough to justify, say, an Aluminium Radiator? Or a Nickel coated radiator? (Something I have never seen) ((We are assuming Galvanic Corrosion does not exist for this question. Obviously that will play a bigger role in whether you will be able to use Aluminium in most cases.)) | [
"copper oxide is what forms copper carbonate, thats true. more specifically it is i believe hydrous carbonate of malachite or hydroxide and that turns the copper green during the oxidizing reaction process."
] | [
"the word patina is not a specific enough term, its like saying \"is food good or bad\"? a 'green' *patina (*which is a generic term for any surface coloration resulting from a chemical reaction on a surface) , is specifically called 'vertigris'. the general name for copper oxide. copper oxide will conduct heat , o... | [
"A fair point.",
"A Brown Patina, in this context, is typically the intermittent stage between raw copper and the Green Patina. The Brown Patina is Copper Oxide where as when it becomes Green it has become either Basic Copper Carbonate, or Basic Copper Chloride.",
"A Black Copper Patina usually forms in the pre... |
[
"Can dark matter collapse and form black holes?"
] | [
false
] | So, the only way we can detect dark matter is through gravitational effects. Could dark matter theoretically clump so dense that it forms black holes just like baryonic matter? If so, would these black hole be any different to the ones that formed from "normal" matter? | [
"If you had a bunch of dark matter at low enough energy and high enough density, it could collapse into a black hole. Black holes have no identity beyond mass, spin, and charge, so it would be like any other black hole of similar charge. However, this is extremely unlikely to happen because dark matter particles ha... | [
"Well after it becomes a black hole it's not dark matter anymore."
] | [
"The point is that dark matter only can have very weak interactions, which makes it impossible to lose enough angular momentum to clump together. ",
"It is very unlikely that enough dark matter moves head on to the same point to form a black hole."
] |
[
"Why does color see so different from pitch?"
] | [
false
] | edit: that should read "seem," not "see" in the title. Color and pitch are the way our brains interpret the frequency of light and sound waves, respectively, but they seem like very different kinds of interpretation to me. While pitch has a pretty straight-forward low-to-high thing going on, color doesn't have a clear high/low interpretation. Red seems just as similar to purple as it does to orange. Color also has odd groupings of colors (we generally recognize six kinds on the red-violet spectrum) which pitch doesn't seem to mimic, while pitch has this repeating pattern every time frequency doubles which color doesn't seem to mimic. Brightness and loudness do seem pretty similar to me, and much simpler in both cases, so I'm wondering why color and brightness don't also. | [
"We have 3 types of color receptors in our eye, for red green and blue, so every color we see is a permutation of those three. Meanwhile, our ear has 20,000-30,000 fibers with different resonant frequencies, to tell us which pitch we're listening to. ",
"So they're quite a bit different. A large continuum of s... | [
"Actually, they are very similar, and the color of visible light changes with wavelength in a very linear gradient from red to violet - the key is that there is no such thing as the color \"magenta.\"",
"Our minds interpret certain combinations of red and violet light into a \"color\" we call \"magenta\" but the... | [
"Also pink. There exist no pink photons."
] |
[
"When you put a spray nozzle on a hose, why doesn't pressure build up until it bursts?"
] | [
false
] | You attach a spray nozzle to a garden hose and turn the water on. Nothing comes out of the nozzle until you squeeze the trigger. All the while, water is still flowing into the hose. It seems like lots of pressure is being built up here. If that's true, why doesn't it burst? | [
"The water company is only supplying so much pressure to the water feed. Hoses are designed to be able to contain that pressure. Consider that when the spicket for your hose is turned off, the pipes within your house are holding the water without bursting, and they are only thin copper; under your sink they are a f... | [
"Water pressure varies wildly, but 75psi is slightly above normal. Ultimately water pressure comes from the height of the water tower that serves your house. Each foot of height makes 0.43 psi, so a 165 ft water tower has a water pressure of about 71 psi at the base. But if your house is a quarter of a mile awa... | [
"If you want a more detailed explanation why water doesn't keep pushing into the hose from the water company:",
"The water company supplies water ",
", which is like how hard the water pushes against something like the sides of the pipes or your hand if you block the flow. In the narrow pipes in your house, or ... |
[
"If a chromosome is made from two chromatids, and a chromatid is made from one DNA molecule, why do we have different chromosomes? Are all DNA molecules in our body the same?"
] | [
false
] | [deleted] | [
"Each chromosome has different genes (ie different DNA). The overall genome (composite DNA content) of each cell is identical however. "
] | [
"Have included a TL;DR. It's not that DNA is packaged differently in chromosomes. All DNA is super coiled in the same way. It is in fact the sequence of the DNA that is different. For clarity I shall give a brief over view of the DNA structure.",
"Each DNA molecule is made up of two strands of complimentary seque... | [
"A chromatid is ",
" copy of a single chromosome. A chromatid occurs when cell division happens. Before the cell can split, all chromosomes get replicated and neatly organised into chromatid(s). For a brief amount of time the original (a chromatid) and its copy (a chromatid) are held together (as sister chromati... |
[
"Why does excessive/tumultuous motion people to become nauseous, and why does this happen to only some?"
] | [
false
] | null | [
"In short, the brain uses feedback from your inner ear, eyes, and the position of your body to figure out how to balance and remain upright. This nausea occurs when two or more of those senses contradict each other (I.e. when you're in a car, starting at something inside the car and your inner ear is saying that yo... | [
"But why does this cause nausea?"
] | [
"There are several theories as to why this happens, as discussed on ",
"this Wikipedia page",
" but nobody knows for certain."
] |
[
"Because the JWST will be orbiting way out at the L2 point and out of suborbit what are the backup plans if by chance JWST turns into a Hubble fiasco?"
] | [
false
] | null | [
"My instinct is no but it is a difficult question to answer. The L2 position is about 5 times higher than the moon, it is more complicated than that though as we do not orbit the earth at it so we not only have to gain altitude but shed our velocity of our earth orbit. ",
"We can reach L2 with significantly small... | [
"You are right that the location of the JWST makes a service mission incredibly difficult. It is impossible for any current (or past) manned spacecraft to reach the L2 point and thus carry out any repairs to a broken design.",
"Nevertheless, the design for the JWST does include the ability to dock with other spac... | [
"Not even a Saturn V could go there?"
] |
[
"Why is it that some people get eaten up by bugs while others seem to remain untouched?"
] | [
false
] | null | [
"Specifically in regards to mosquitoes, they have a preference for certain blood types and other blood characteristics which they can actually smell. First off, mosquitoes find their way to humans by following CO2 gradients in the air, simply the way you breathe and how much CO2 you exhale might make it easier for ... | [
"I have a blood disorder that causes too much iron in my blood - apparently most bugs (especially moquitoes) really really hate high iron content for some reason. So most bloodsucking bugs tend to avoid me - to the point that if someone is sitting/sleeping next to me, the side of their body that is closest to mine... | [
"they enjoy sweet things, so they're more attracted to people with a high carb diet.",
"But... how do they know? As far as I'm aware of glucose isn't a volatile we might leak into the air through our skin.",
"Does a high carb diet cause us to release a chemical that is somehow related to \"sweet blood\"?"
] |
[
"Why don't our bodies become immune to certain diseases and illnesses once we recover from them?"
] | [
false
] | null | [
"It has to do with the way our immune system responds: it starts making antibodies that binds to the microbes that caused the illness; antibodies bind to specific features on the surface of these Antigens. If the virus/bacteria later evolves and that evolution changes its surface features, the existing antibodies b... | [
"Is there a limit to the number of different antibodies that the immune system \"remembers\" it needs to fight illnesses?"
] | [
"Yes, there is. But don't think about of it, it's a pretty high number of different antibodies. ",
"If you ask why, it's due to the ageing process. As you get older your body would have \"spend\" more and more of your B cells (Lymphocytes B) which are the responsable of making those Antibodies. But, as I said, do... |
[
"Bacon - Fridge required? Questions on bacterial growth..."
] | [
false
] | Hey Reddit, So, I was thinking about shipping some meat, however the logical refrigeration part is a bit of a bitch. Now, I mentioned this to my SO, who stated that bacon doesn't require a fridge. He stated that it is vacuum sealed and that it really shouldn't matter. His key points: no air = no decomposition. it's refrigerated because of perception and nobody would buy bacon off a shelf. Mine: Why would stores pay tonnes of money to keep it refrigerated? Why would the packaging say to keep it in the fridge? If vacuum sealed meat was all it took, why don't they seal ALL meat? I understand the concepts of bacteria requiring material (said bacon), air, and moisture, and that if one of the three doesn't exist, then it shouldn't spread, but then why do we require a fridge? | [
"There are plenty of ",
"anaerobic bacteria."
] | [
"The bacteria may die, but the toxins they produce are easily left behind."
] | [
"Staph and E. Coli are both facultative aerobes, meaning that they can survive in the presence of oxygen as well as without it, there are many bacteria that fall into this category.",
"Most bacteria cannot reproduce at a rate sufficient to create a problem below the temperatures at which we typically store food. ... |
[
"This may be a stupid question, but what is the universe?"
] | [
false
] | null | [
"Depends which physicist you ask, really. \nThere is ",
"string theory",
", some other scientists believe everything is a wave, maybe there are some other theories. "
] | [
"There are no stupid questions.",
"\nYou need to focus your question a bit more if you want to get an understandable answer. I'd say Universe is the whole observable space we see and theoretically know about (i.e. the edge of universe) and all matter/anti-matter enclosed in it, whether we know about it or not."
] | [
"What I meant that what is is fundamentally? Is is just a spontaneous energy in various forms interacting through fields?"
] |
[
"Ice and salt."
] | [
false
] | I was wondering, why does it burn if you put salt on your skin then put ice on it? These kids at work have been doing it, and have ridiculous burn looking injuries from it. | [
"\n- Richard"
] | [
"That makes sense, thank you for the answer."
] | [
"Also those burn looking injuries are frostbite. Very bad for you.",
"Edit: Just realize the other person mentioned frostbite in the answer. Doh!"
] |
[
"Was most of the matter in the early universe created by massive hadronization during the initial inflationary epoch?"
] | [
false
] | I've always wondered whether the process of hadronization was the mechanism by which most of the matter in the early universe was created. Were the earliest quark pairs/triplets/groups or the quark gluon plasma stretched incredibly quickly by inflation causing hadronization to occur on a massive scale once the initial phase of inflation ceased? I'm imagining (as a simplified thought experiment), for example, a lone quark-antiquark pair suddenly being separated by a huge distance in an incredibly short amount of time and then the new space between becoming rapidly populated by a massive amount of new mesons and hadrons (formed from the energy of the inflation due to confinement). Is this picture totally wrong or is it a decently accurate description of what happened in the early universe? Was confinement even "in place" or rather, operating, at that time, or did the initial inflation occur before confinement started to govern the earliest quarks and gluons? Thanks for reading, and I apologize if any of this doesn't make sense, I'm just an interested layman. | [
"It's a smart idea you've had and a reasonable question to ask, but no, we don't think it happened via that mechanism.",
"The ",
"leading theory",
" or collection of related theories has a universe that's cold and empty or mostly empty of matter but that has a great deal of vacuum energy in the form of an inf... | [
"Inflaton field energy loses energy until it hits a stable level and couples with (presumably less energetic) matter fields and then it's energy is transformed into matter via some decay process.",
"More or less, and I'll elaborate a bit on that below. ",
"If this is the case, and considering that, as you say,... | [
"What happened to the quark fields during inflation, though? Was the expansion too slow to drive hadronization by tearing apart any baryons present at the time?"
] |
[
"If we are able to use to use fairly simple catalysts in labs and in industries, why do organisms utilise mindbogglingly complex catalysts- enzymes?"
] | [
false
] | I've read about metals and their oxides, which are simple molecules, being used as catalysts, and some simple organic molecules too. Why do all living beings have such complicated catalysts, huge molecules with intricate structures? | [
"There are numerous ways to go about answering this, so I'll just highlight a few that I subjectively think are the most important.",
"edit: typo"
] | [
"M.S. in Biotechnologies here :)",
"\nSimply because inorganic catalysis can be very hard to control for a living being (think especially at bacterias, very similar to the first living forms known to have existed). A metallic catalyst will \"blindly\" catalyse any possible reaction, with no specificity. This woul... | [
"There are different containers and steps and there are machines/humans to move stuff from one reactor to another, so we can afford to use \"stupid\", straight-forward catalysers.",
"I tangentially addressed this in my comment (i.e. the process of boiling off a volatile product to drive the desired reaction), but... |
[
"Can we spin molecules using electromagnetic waves?"
] | [
false
] | Hello, I have been learning about radio, and now my understanding of a microwave oven is that water is polar, so changing electromagnetic fields can cause a torque(?)... Which reminds me of how an electric motor works. Surely if that's the case, we can spin molecules with electromagnetic waves. If we can, is there applications? Does anything interesting happen if molecules spin quickly? | [
"One of the most interesting things we can do by spinning molecules in my opinion, is identifying what that molecule is based off the way it spins. ",
"https://chem.libretexts.org/Bookshelves/Organic\\_Chemistry/Supplemental\\_Modules\\_(Organic\\_Chemistry)/Spectroscopy/Nuclear\\_Magnetic\\_Resonance\\_Spectro... | [
"One of the most interesting things we can do by spinning molecules in my opinion, is identifying what that molecule is based off the way it spins. ",
"https://chem.libretexts.org/Bookshelves/Organic\\_Chemistry/Supplemental\\_Modules\\_(Organic\\_Chemistry)/Spectroscopy/Nuclear\\_Magnetic\\_Resonance\\_Spectro... | [
"For molecules in the gas phase, unequivocally yes. For liquids, it gets complicated. For solids, (usually) not.",
"In the gas phase, molecules are mostly isolated from one another. As with all things on these scales, rotation is quantized. This means that you have only discrete allowed rotational energy and angu... |
[
"What magnitude would the earthquake in “The Land Before Time” be?"
] | [
false
] | null | [
"Ok, so this is definitely on the edge (and maybe beyond the edge) of what's sort of an appropriate question for AskScience, but it's fun and it provides a useful context to understand how we discuss earthquakes and the damage associated with them, so let's go with it. For those unfamiliar, I assume this ",
"YouT... | [
"r/AskScienceDiscussion",
" is like the lite version of this sub, much more casual."
] | [
"Just for curiosity's sake, does anyone know of a better place for questions like this?"
] |
[
"Does being born blind have any effect on learning to speak?"
] | [
false
] | After 3 years this is my first submission anywhere, go easy on me. Watching a new Netflix movie "I am mother" ... girl being raised by a robot who has learned to speak from listening to a robot. This got me thinking if that would actually work. Obviously blind people learn to speak but I am wondering if not being able to see other's lip/tongue/mouth makes it more difficult to learn to speak. | [
"Possibly, although it may be related more to social interaction rather than just seeing the person form the words.",
"http://faculty.washington.edu/losterho/kuhl_nature_neuroscience_reviews_2004.pdf",
"A study that compared live social interaction with televised foreign-language material showed the impact of s... | [
"I would say that blind people get clues from other senses than vision. In that case probably the air blowing out of the mother's mouth (while talking close to the baby's face) would be detected by the baby's sense of \"touch\". Also the sounds you make while talking (lip contact, tongue noises, \"moisture noise\" ... | [
"Thank you!"
] |
[
"Why do foxes have slitted pupils when other members of canidae have round?"
] | [
false
] | I'm not sure if all others do, and I've been having a hard time finding information on it. Resorted to just looking up google images and squinting, trying to see. I got a close-up look at a fox for the first time recently at the zoo where I work, and was surprised to see its eyes were slitted. I'd just assumed they would be round, based on dogs, wolves, etc. Foxes seem to have similar hunting habits to other canidae species, as far as moving around in the day as well as the night, so why do they get the slitted pupils and others don't? | [
"Animal eyes that are primarily used under low-light conditions usually have optical systems of short depth of focus, such that chromatic defocus may lead to considerable blurring of the images. In some vertebrates, the problem is solved by multifocal lenses having concentric zones of different focal lengths, each ... | [
"A question about pupil shape",
"In the paper linked there they mention that smaller felines tend to have slit eyes, and that this trend is present to some extent in canids too."
] | [
"Foxes are crepuscular (feeding at dawn and dusk) and a bit more nocturnal that wolves and wild dogs. So in order to deal with poor light conditions their pupils are more slit than a dog or a wolf. Dogs and wolfs have average night vision, where a fox would have above average but not amazing night vision."
] |
[
"How do spacecraft measure their velocity?"
] | [
false
] | As an accomplished Kerbal Space Program spaceship pilot, I've come to understand how critical accurate understanding of velocity is with respect to orbital bodies. When spacecraft change their orbit by adding or subtracting from their velocity vector, how is this measured? I know of many physical sensors that measure acceleration (since force and acceleration are directly linked) but to get back to velocity, you need to integrate over a time period and eventually end up with an unmanageable error term for most applications. Direct measurements of velocity usually use the distance/time relationship - sending out a pulse and measuring the return time. But without a "reference" object to ping something like sonar, radar, etc off of, how does an object in the vacuum of space know how fast it's going? | [
"Unless we're going intergalactic (which I'm unfamiliar with how they do that), speed is always calculated based on the objects orbit, or by radar sites on the ground (when trying to determine the objects orbit). Orbits are really what determines an objects speed, so when changing orbit you burn a set amount of fue... | [
"You can't measure a spacecraft's orbital elements. You can only get them from knowing the spacecraft's position and velocity vectors at a certain time. If you know the spacecraft's position very accurately (from GPS), then you can calculate its gravitational acceleration, and the accelerometer on board will tell y... | [
"Imagine the possible position you calculate like a sphere for every pulsar.\nWith 2 pulsars they intersect into a circle.\n3 gives you two possible positions on this circle.\nAnd 4 signals finally give you a accurate 3D-position.",
"graphic"
] |
[
"Can mRNA technology be used to create the antibody itself, for example to replace rabies immunoglobulin?"
] | [
false
] | null | [
"Yes, this has been done, though not for rabies immunoglobulin (kind of pointless since that works well already). For example, from 2018, ",
"Engineered mRNA-expressed antibodies prevent respiratory syncytial virus infection",
". ",
"As with most mRNA deliveries, it’s essentially identical in concept to DNA-m... | [
"Sure, antibodies are just proteins and any cell knows how to make proteins. ",
"In practice, these are mainly targeting fibroblasts and epithelial cells, which are abundant, structural, and generally turn over rapidly."
] | [
"It's not uncommon to see single monoclonal antibody therapy leading to immune escape variants, if that's what you mean. It's common to use a cocktail of multiple monoclonal antibodies as antiviral therapy for that reason.",
"Expressing mAb through mRNA or DNA could lead to the same issues, but the goal there is ... |
[
"Why can most people cross their eyes, but not move their eyes independently in any other way?"
] | [
false
] | Most people can cross their eyes but other than that cannot move their eyes independently of each other. What is so special about crossing your eyes that your eyes can move that way, but not independently in any other way? | [
"Our eyes are supposed to converge, which is what we all do naturally when we read. So crossing eyes is over converging, also called esophoria (or esotropia) when our eyes do it without us trying.",
"\nBut we don't have a normal situation for exophoria/tropia, which is the condition when the eyes point outwards. ... | [
"We are able to converge our eyes (point them both towards our noses) because that is how the each retina focuses when something is moving closer to you to maintain single binocular vision",
"The body has no other need for your eyes to go in different directions. There is a fibre on each side of the brainstem ca... | [
"A slight correction: esotropia is not crossing our eyes. Its a condition when one eye is turned in. Crossing our eyes is called excessive convergence."
] |
[
"How large would an asteroid need to be to incinerate the entire surface of Earth after impact?"
] | [
false
] | null | [
"To incinerate the surface of Earth, you need a lot of energy - around 10",
" Joules.",
"The XKCD comic is fun, but in reality, most asteroids hit Earth around 12 - 20 km/s. If we assume the asteroid is traveling at 16 km/s, then it's diameter must be around 8 km to produce 10",
" Joules energy (because kine... | [
"Well it depends on velocity too.",
"Here's ",
"a fun XKCD what-if",
" on the subject with fixed size and varying velocity."
] | [
"45 Degree impact. Average speed for an asteroid impact."
] |
[
"Is it possible to discover a new element that is stable?"
] | [
false
] | I've been watching a lot of science fiction movies lately and in a lot of them they "discover" a new metal with super cool properties. So is it possible, or have we reached the point where there are just too many electrons around the nucleus to be stable? | [
"As the nucleus gets larger, the electrostatic repulsion of protons starts to outweigh the attractive strong force. So for elements heavier than bismuth, the result is that everything tends to decay by shedding protons in some way - either alpha decay or spontaneous fission.",
"All our data suggests that there i... | [
"The reason that the island of stability is predicted is because the nucleus follows a similar \"shell model\" as electrons.",
"Well, the \"shell model\" analogy does give the general idea (some nuclei are more stable than others), and serves as a starting point, it doesn't work nearly as well for nuclear structu... | [
"Island of Stability",
"The island of stability in nuclear physics describes a set of as-yet undiscovered isotopes of transuranium elements which are theorized to be much more stable than others. Specifically, they are expected to have radioactive decay half-lives of at least minutes or days as compared to second... |
[
"Do mitochondria get cancer?"
] | [
false
] | [deleted] | [
"Not exactly, since we don't consider mitochondria to be separate organisms, however ",
"they do have their own DNA, and mutations in mtDNA have been linked to cancer in humans"
] | [
"As in uncontrolled mitochondrial division inside the cell? I'm not sure if there are cancer forms where the cells start to generate excess amounts of mitochondria, but the cancer never lies in the mitochondrion per se.",
"The mitochondrial DNA only encodes 14 proteins, 13 of which are proteins of the electron tr... | [
"Disclaimer: The 'as far as I know' here is implied.",
"There is still some aerobic oxidation going on in there, and, obviously, every cancer will be different due to their very nature. But glucose also needs to be delivered to the cells in some manner, which is why angiogenesis is so important for the survival o... |
[
"If anything having mass has an equivalent amount of energy and vice versa, does heating up an object change its mass? How?"
] | [
false
] | The mass-energy equivalence states that anything having mass has an equivalent amount of energy and vice versa. If we have a mass of metal and we heat it by some x decrees Celsius then it's potential (correct definition?) energy increases. This is what I recall from my Physics classes. But how does heating up an object increase that object's mass? How does it lose mass as it cools? | [
"Not all energy has a mass equivalence. E = mc",
" only applies in a frame of reference where the total momentum of your system is zero. But if you consider some object in its rest frame, and increase its internal energy by an amount U, you’ve increased its mass by U/c",
"."
] | [
"The mass increases if you heat something and take care no atoms escape, although the increase is too small to measure with current scales (getting close - might be possible in 10-20 years). The volume can change if you heat something but that is an independent topic."
] | [
"Its mass will increase, yes, since the mass of a system at rest is equivalent to its energy."
] |
[
"How much would the sea level drop by if all the fish etc were removed?"
] | [
false
] | [deleted] | [
"I answered this ",
"on askscience",
" about a year ago and I've since expanded on it ",
"on my blog.",
" - I'll just copy paste what I wrote last time: ",
" A few microns. ",
" Let's talk about ",
"biomass.",
"\nDifferent people give different estimates, but we can probably get this to an order of ... | [
"Was that your plan to save the Maldives ?"
] | [
"So not enough to save the Maldives then, thanks"
] |
[
"Do all mammals experience nausea, and how can scientists determine this?"
] | [
false
] | For example, dogs experience nausea and it is often indicated by drooling and excessive swallowing, and anti-emetic medications work for dogs. But outside of observed behaviors, do scientists have other ways of knowing whether nausea is something that all mammals experience? Could it be determined by studying mammalian brains? | [
"Nausea is a subjective experience of a physiological phenomenon. It's qualia rather than an objective, measurable state. We can definitely say that animals experience the physiological indicators of nausea but whether they experience nausea as a subjective, conscious thing is an extremely difficult and perhaps imp... | [
"Goats are not capable of vomiting (they usually reach a life threatened state by the time they’d need to vomit), so they are one of the mammals I had in mind.",
"I also just read that squirrels, mice, beavers, and gophers cannot vomit.",
"I still wonder whether such animals might experience nausea even if they... | [
"Goats are not capable of vomiting (they usually reach a life threatened state by the time they’d need to vomit), so they are one of the mammals I had in mind.",
"I also just read that squirrels, mice, beavers, and gophers cannot vomit.",
"I still wonder whether such animals might experience nausea even if they... |
[
"[physics] Why does the texture of icecream change when melted and refrozen?"
] | [
false
] | I was eating some sorbet (not icecream I know but the same thing happens to icecream), and I made the mistake of taking a post-sorbet nap without putting it back. It melted, I refroze it, and now i'm eating it again to find that the texture is no longer soft, it's like a frozen slushie now, full of hard icy flakes. Why is that? | [
"its probably not a very safe idea to eat refrozen ice cream.",
"Why is this?"
] | [
"When you refroze the sorbet, it cooled quite slowly. This allowed the growth of large (up to a few centimeters) crystals. This is the main reason your sorbet is not as good, and why chefs try to get the sorbet to freeze as fast as possible, by stirring, or by using liquid N2 (for fancy chefs). \nA second reason, i... | [
"From what I found, the lower temperatures along with the sugar and fat in the ice cream makes it a perfect host for bacteria like listeria. "
] |
[
"How do magnetic fields work/interact?"
] | [
false
] | I just read most of the wiki article and another short Q&A about this and am still a little confused. I understand the electromagnetic carrier is the photon and that "virtual photons" exist in a magnetic field but I'm not sure what that all means. If I hold a compass level in my hand, the needle will align along the earth's magnetic poles. What causes the needle to move? Where are these photons coming from and what frequency (ies) are they at? This was prompted by someone suggesting animals could "see" a magnetic field. Is the earth's magnetic field just a stream of moving photons from magnetic N to S? | [
"When you want to talk about macroscopic magnetic ",
" it's much better to just think of it in terms of the classical field, imo. Otherwise you're talking about ",
" photon interactions with each charge, which I think is difficult to do. And each of those is an excitation of the electromagnetic interaction that... | [
"It's best not to get bogged down in quantum electrodynamics. Just remember that a field is anything that's defined over all of space.",
"In this case, we're talking about every point in space having a direction and a magnitude associated with it — a \"which way\" and a \"how much,\" basically. This value represe... | [
"Also? Ghosts. Totally.",
"So either you were reading the same thread or somehow happened upon a coincidence that the discussion was about additional sensing ability of animals versus humans and in some respects, ghosts. Creepy."
] |
[
"How does catnip get cats high?"
] | [
false
] | It's not smoked, injected or ingested yet they get all fucky. Why? | [
"Catnip (Nepeta cataria) releases a chemical nepetalactone, which binds to olfactory (smell) receptors at the epithelium tissue in a cat's nose. Here, the nepetalactone triggers a faux pheromone response. Pheromones are used for cat communication (e.g. marking places and objects) and are typically produced in a cat... | [
"I once saw a documentary (i think it's just called \"Life\" and is narrated by David Attenborough) in which a tiger in a jungle actively seeks out a plant or fungus and starts eating it. It's a plant/fungus with a psycho active substance that triggers hallucinations in a tiger and it's assumed that the tiger know... | [
"So even cats have psycho-active plants in their evolution too. This world is awesome."
] |
[
"If all mosquitoes vanished form the face of the earth, how badly would the world food chains collapse?"
] | [
false
] | null | [
"Actually, mosquitos have been targeted for forced extinction by a number of groups. The ",
" thinking of some entomologists is that their threat to human life is fairly great due to malaria, and they wouldn't be that missed if they were wiped out. The ecological niche they fill would quickly be filled by other... | [
"This sums it up pretty well",
", we can do without mosquitoes to be honest.",
"There is nothing mosquitoes do better than any other insect that might take their place except one thing, the transfer blood diseases, fewer mosquitoes means fewer people getting sick and dying.",
"The food chain would be quite al... | [
"There are mosquitoes in quite cold places such as Lapland as well. "
] |
[
"If the cyanobacteria that became chloroplasts were unable to sexually reproduce after endosymbiosis, how did they lose so many traits over time? Shouldn't mitosis have kept them more or less identical to their free-living ancestors?"
] | [
false
] | null | [
"NoDiceChicago, if you're interested, what polistes described is known as Muller's Ratchet, and it's a fascinating part of the explanation for why sexual reproduction is widespread."
] | [
"Producing asexually and through mitosis does not mean that the genetic code can never change. When duplication of the genome takes place, sometimes mistakes are made in copying the genetic code, possibly leading to malfunctioning of the gene. If these mistakes are in nonessential genes, this has no consequences fo... | [
"Mutations occur frequently in bacterial genomes -- perhaps one base change in every 10**9 replicated bases. This mutation rate is very important, and is carefully controlled. Too high a rate produces poor survival. But too low a rate is also bad. Recall that Darwin postulated the importance of descent WITH VARIATI... |
[
"Can an individual's blood carry a cure for a virus outbreak like the movies?"
] | [
false
] | I've read there are some experiments suggesting plasma from covid survivor's could help fight the spread. Though it got me wondering how much truth is in the possibility of one persons blood being the key to a widespread virus like many movies. | [
"Isn't there a dude that has donated blood 1000's of times due to some unique property of his blood that is able to help others that are deficient in it? So going from that, I wouldn't be surprised if that is the case.",
"Edit: not thousands but over a 1000. His name is ",
"James Harrison",
")"
] | [
"Yes, you can carry antibodies to the virus. A good example of this was plasma from healthcare workers who recovered from the Ebola virus being used as an emergency treatment. There's a great Crash Course video that explains this particular this case, as well as the broader discussion of the immune system defense... | [
"Not necessarily. If you’re a frequent enough donor they might phenotype you or if you’re found to have a rare blood type. Rare blood types are usually discovered when you have a reaction and they do a work up. Basically, there’s ABO/Rh then it gets broken down into like forty other blood groups of varying seriousn... |
[
"solar panels + bicycle + flywheel + electric generator"
] | [
false
] | I have a 3 member household. We use about 12 KWH per day but we could definitely reduce this number by conserving better. Let's say I am a strong bicyclist that can ride at moderate intensity for 2 hours per day. The other two members ride bicycles but not as intensely. For the purposes of this question, let's say that combined we can expect 1 hour of moderate intensity per day for a grand total of I live in sunny southern California a little north of Los Angeles. Installing solar panels on the roof should be feasible. Question 1: Assuming I could charge it up, how much battery capacity would I need to deliver steady electricity to my home? 5 KWH? 10? 20? More?! Question 2: How massive of a flywheel would that be? Would a flywheel leak too much energy to ever be practical? Question 3: How many square feet of solar panels would I need on the roof? Bonus Question: What I need to reduce my energy usage to in order to make the idea work? EDIT: other storage options like chemical batteries would be fine too. I just think flywheels are so awesome. Maybe a flywheel connected to the bicycle and a chemical battery connected to the solar panels? | [
"i best advice is to try to keep a 100W lightbulp on for an hour by riding a bicycle. trust me, it is already difficult enough. it gives a very concrete idea of what 1000Wh are. here is more:\n",
"http://www.manicore.com/anglais/documentation_a/slaves.html",
"site's not mine, i invite you to look around.",
"a... | [
"You would be lucky to be able to sustain 200 W of cycling output for an hour, so for your three riders each doing an hour you're looking at 0.6 KWH of power, minus the conversion inefficiency of an inverter (~75-90% efficiency). In other words, your cycling wouldn't even make a dent in your power requirements. A... | [
"10 kWh per day for 3 people sounds really low to me. Is your heat and hot water part of this? I have an electric hot water heater and I observe that a 15 minute hot shower costs me about 6 kWh, which I think sounds reasonable if you do the math.",
"My wife and I are only two people and aside from my long showe... |
[
"Why does the jaw bone shrink when teeth are removed but no other bones in the body act the same way?"
] | [
false
] | [deleted] | [
"Bones respond to mechanical loads. If the load on a bone increases, it strengthens. If it decreases, the bone is weakened and absorbed. The jaw bone is just reacting to a decrease in mechanical load by absorbing bone that was previously there. The same thing occurs in other bones in the body. For example, there is... | [
"Stress at the attachments of muscle also causes changes in bone density and structure, as stated in Wolff's Law. ",
"There are several places on the skull that bear a large amount of stress from muscles, such as the jaw and cheekbones, which are the attachment sites for the muscles involved in mastication. "
] | [
"Stress at the attachments of muscle also causes changes in bone density and structure, as stated in Wolff's Law. ",
"There are several places on the skull that bear a large amount of stress from muscles, such as the jaw and cheekbones, which are the attachment sites for the muscles involved in mastication. "
] |
[
"Do 3D glasses work for everyone?"
] | [
false
] | I've seen several 3D movies in my life, and I've never understood the attraction. At best, the glasses make everything focus better (but no 3D effect that I can see), at worst I end up with a headache. I am not color blind, but I do have presbyopia. So is there something that I'm missing? Or it it nothing more than a case of the Emperor's New Clothes? | [
"No. 3d does not work for everyone. Up to 5% of people cannot \"see\" the 3d effect provided by current 3d technology (which uses physics tricks with light polarity that I really can't explain well). A smaller percentage of people actually experience adverse effects from the 3d images, such as headaches, nausea, ... | [
"Thanks for the feedback. Looks like being in the 5% isn't a good thing in this case."
] | [
"It's polarization, and there's a pretty reasonable explanation ",
"here",
". Essentially, two different images (similar to what you'd see using your two eyes to look at an object with depth) are transmitted using \"opposite\" (orthogonal is more correct, but paints less of an intuitive picture) polarizations.... |
[
"Why do things \"glow\" under a black light?"
] | [
false
] | And is there a difference between different things glowing ie; stains, white shirts, teeth, bugs. | [
"When you point a UV source at a material, it starts absorbing photons. The material loses most of that energy by re-emitting longer-wavelength (and therefore lower-energy) photons. Under intense UV, often you'll see pairs of photons absorbed, allowing emission of higher-energy photons than the original source.",... | [
"Exactly. Although the blacklights at Spencer Gifts use glass to shield the dangerious tanning rays and only let through the tail end of violet. Tanning beds use the same bulbs, but instead of glass they're made of quartz which doesn't block the carcinogenic UV.",
"Also, visible violet light will make things gl... | [
"so you're saying black lights are just really intense UV lights? as in, I could get a tan from one? Do they use essentially uber-blacklights in tanning beds?"
] |
[
"Is analytic continuation of the Riemann-Zeta function more than just a reflection over a vertical line?"
] | [
false
] | Watching video of an animation showing how to think about the Riemann-Zeta function geometrically, I am left with the impression that the Analytic Continuation of the function is just a reflection. Please tell me how I am wrong. | [
"It's almost a reflection about the line Re(s)=1/2 (the critical line), but not exactly. If it were a reflection, then if s were a point to the left of this line, its value there would be equal to the value of the point exactly opposite on the right side of the line, and this point is 1-s. That is, we would have Z(... | [
"You can use power series to talk about it and really formalize it, but it really boils down to the rigidity of differentiable functions on the complex plane. If f(z) and g(z) are any two functions on some domain of the complex numbers, and there is an open set, of any size, so that f(z)=g(z) for all z in this open... | [
"I don't typically pay attention to the usernames of people who write comments; I just skip over them and read the text. So whenever I see an explanation which answers the question so well and then proceeds to blow my mind with some weird math concept, I think to myself \"that's gotta be ",
"/u/functor7",
"\". ... |
[
"How does the immune system fight off viruses?"
] | [
false
] | null | [
"Firstly, the virus will invade a cell, a virus is essentially just packaged genetic material, when in the cell the virus will uncoat and release its genetic material (DNA or RNA) into the cell cytoplasm/nucleus, where transcription and/or translation will occur. The cell is now producing viral proteins which are p... | [
"I believe phagocytes can pick up viruses, but remember viruses are intracellular parasites, so want to be inside a cell. Some can evade the phagocytes killing mechanism and live in the cytoplasm for a long time. Take HIV as an example. "
] | [
"Yes toll-like receptors are transmembrane receptors for PAMPs (Pathogen associated molecular patterns) and is one of the mechanisms a cell has for detecting viral antigen, such as viral envelope proteins, before it enters the cell. ",
"As for your first question, the activation of a receptor (such as a toll-like... |
[
"Why do we need to sleep?"
] | [
false
] | I know the question sounds a bit silly, but for real: Is it a biochemical necessity? Wouldn't there also be an evolutionary advantage with being able to hunt 24/7? And, consequently, are there any species that do not sleep? Thank you all for your input so far! Very intriguing, indeed, and certainly a hard nut for science to crack. I've Google-Scholar'ed around a bit and found publications from 1901 to 2005, all saying "while we don't know we need to sleep..." - unfortunately all paywalled so I can't check them out more closely before I get back to work tomorrow... | [
"Animal species with atypical sleep: whales and dophins can rest their brains one hemisphere at a time. Fishes can swim in their sleep. Common swifts can sleep in four-second intervals while in flight (studied by Emile Weitnauer).",
"Muscles must rest to restore ATP, brains need energy and oxygen, food needs to b... | [
"Not an expert on this, but I recommend checking out an ",
"episode",
" on the topic of the excellent Radiolab for a layman-friendly discussion.",
"tl;dlisten: we don't know; maybe, but there are advantages to sleep (the dreams part goes into this); not that we know of."
] | [
"As far as I know, brain moves information from short term memory to long term memory during sleep. I am guessing it helps that during this process, there is almost no external input to the brain.",
"Also, dreams prepare us to certain situations. It's not uncommon that people dream of being naked in front of peop... |
[
"Is vitamin C the same the world around?"
] | [
false
] | My parents are convinced that the vitamins in an orange (or anything natural) can not be provided in the same way by those in a multivitamin. Is there any merit to this? Aren't they just the same compounds no matter how you get them? | [
"Well, technically they are wrong, but in some regards they are right.",
"Vitamin C, any B Vitamin, mineral, etc., is the EXACT same where ever it comes from. At a base level these are just chemicals--your body doesn't have a clue where they come from, just that without them carrying out thousands of different r... | [
"The molecular structure of synthetic vitamin C is identical to that of the vitamin C found naturally in foods. The only difference between multivitamins and food is that the other chemicals in food can and do modify how well your body absorbs it. However, this doesn't prove your parents correct; some foods increas... | [
"A lot of vitamins can have stereoisomers if produced synthetically. Usually only one isomer in a racemic mixture is biologically active. This is why vitamins are either extracted from biological sources or produced using fermentation."
] |
[
"Is it possible for an object to be travelling so fast it would bounce off the atmosphere?"
] | [
false
] | Basically the title, but is there theoretically a speed/shape that if it were to collide with Earth's atmosphere at a certain angle it would bounce off the atmosphere like a rock skipping on water? | [
"\"Bounce\" is a bad word for it. Bouncing implies that the kinetic energy of the incoming object gets converted into some sort of spring potential and subsequently converted back into kinetic energy in a different direction. That doesn't happen.",
"However, there are two things that could happen. One option i... | [
"Absolutely. The ballistic entry angle ",
"has to be just right",
" to keep that from happening. In fact, skipping off the atmosphere was a big fear during Apollo 13. ",
"There is also the more deliberate atmospheric braking, which is still kinda skipping off the atmosphere. "
] | [
"Oh wow. So its never \"skipping\" like skipping a pebble across a pond, but its always just aerobraking right?"
] |
[
"If the circumference of the Earth is 25,000 miles at the equator, but 0 miles at the pole, why don't we feel the difference in speed at different parts of the Earth?"
] | [
false
] | null | [
"Because what you feel is relative to the Earth and its atmosphere, and by your exact logic, they are also moving faster at the equator and slower at the poles."
] | [
"Hmm, that makes a certain amount of sense. But why isn't there a difference in atmosphere etc?"
] | [
"Because from the atmosphere's point of view, it also cares most about things relative to the Earth. There isn't anything in space to keep if from spinning at the same speed as the Earth. The whole planet spins together (excluding weather effects, tides, etc.) because there isn't anything slowing any of if down."
] |
[
"What is happening during a panic attack?"
] | [
false
] | What is happening in the brain/body physiologically? Is it usually triggered by something or do they just happen out of the blue? | [
"Yes, relaying what you heard from an expert is hearsay and definitely doesn't qualify yourself as an expert, and describing your personal case is most definitely anecdotal.",
"Please ",
"consult the /r/askscience guidelines on answering questions",
"."
] | [
"Yes, relaying what you heard from an expert is hearsay and definitely doesn't qualify yourself as an expert, and describing your personal case is most definitely anecdotal.",
"Please ",
"consult the /r/askscience guidelines on answering questions",
"."
] | [
"Please ",
"consult the /r/askscience guidelines on answering questions",
"."
] |
[
"Why do humans \"need\" sleep?"
] | [
false
] | Could there ever be an animal that could just stay awake and conscious all the time? | [
"I can answer this question. The answer was found very recently by neuroscientists. You see, neurons in the brain use a lot of energy, and they don't have enough space to store excess chemical energy (in the form of glucose or lactate). So neurons get excess energy from ",
"astrocytes",
". Astrocytes store chem... | [
"From the worlds absolute leading expert, the (co)discoverer of REM sleep, who has devoted over 50 years to research on the subject:",
"\"As far as I know, the only reason we need to sleep that is really, really solid is because we get sleepy.\""
] | [
"Just a note, but caffeine works by bonding to adenosine receptors without activating them, which makes you less tired."
] |
[
"What percentage of people are carriers for limb girdle muscular dystrophy in the UK ?"
] | [
true
] | [deleted] | [
"from the merck manual : \"On average, 1 of 3,000 boys born has Duchenne muscular dystrophy, whereas on average 1 of 30,000 boys born has Becker muscular dystrophy.\"",
"You can infer the rest from that. You can get tested if you are really paranoid but be aware that only the mother being a carrier matters becaus... | [
"Also be aware that because it is a recessive disorder even if the parent is a carrier still only 50% chance of it being passed along."
] | [
"Er -- limb girdle muscular dystrophy is a group of similar problems with different dominant/recessive inheritance patterns. And the 50% inheritance pattern of some faulty genes is more complicated than simply dominant/recessive. "
] |
[
"What holds a cloud together?"
] | [
false
] | When i smoke and breath out a cloud it gets dispersed fairly quickly, even inside where there is no wind. Now I know that they are always changing but sometimes you can watch a cloud move all the way across the sky looking like the same cloud. Why dont they constantly disperse and form into new clouds due to winds/other forces? | [
"The key to understanding this is realizing that clouds are not a single object; they are simply a \"blob\" of air which has cooled to the point where water vapor can condense into cloud droplets. ",
"When the \"blob\" is small, like the cloud coming out of your mouth on a cold day (yes, it is technically a cloud... | [
"Wait, does this mean their is some dynamic of the cloud which is governed by the square-cube law? So, more massive clouds are less likely to \"disperse\"? I'm not sure what this implies, but it's still cool. "
] | [
"Yes, there's definitely a \"square-cube\"-type effect going on here. Diffusion (both true diffusion and ",
"turbulent diffusion",
") is proportional to the surface area of the cloud on a large scale, so the larger the cloud the slower diffusion will act to disperse it significantly."
] |
[
"Why is desalination/purification/etc. of water so difficult? Why can't we just purify ocean water?"
] | [
false
] | Clean water has always seemed to be a pretty pervasive issue around the world. The necessity is there, so why is water purification not a bigger industry? I know there are real hurdles with it, I just don't know what they are and am wondering if the need for water will one day force us to overcome them. | [
"Energy. It takes an enormous amount to desalinate water."
] | [
"If you had a dam to work with, you would have fresh water from a river or lake, and won't need desalination. Most desalination plants are needed around coastal areas where water is at sea level."
] | [
"If you had a dam to work with, you would have fresh water from a river or lake, and won't need desalination. Most desalination plants are needed around coastal areas where water is at sea level."
] |
[
"When net gravitational force exerted on the object is zero, would gravity still affect time?"
] | [
false
] | Let's say there is an object which is middle of the two identical blackholes where net gravitational force exerted on the object is zero. In such a case, would gravity still affect time? | [
"Good question--and to answer this, let's move away from necessarily describing the net force, or acceleration, acting on that object. Instead, consider where that objects sits in terms of a gravitational well. If we think about the depression in a rubber sheet analogy of spacetime caused by a massive object, we ca... | [
"What I think this means in practice is that two black holes could be circling close in the center of a galaxy with a planet at their mutual orbit point and,.. well it wouldn't be stable because Lagranian points are a semi-static solution, but the planet's time would be dilated even though it might sit in the comov... | [
"IIRC there is ",
" no solution to GR with two black holes, yes?"
] |
[
"Even and Odd Functions"
] | [
false
] | I'm directing this question to all walks of scientists and engineers, which is why I posted to this subreddit. Today in pre-calc, we learned about even and odd functions. I understand the definition of even and odd functions. ( f(-x)=f(x) and f(-x)=-f(x), respectively.) So, understanding this concept, my question is why do we care whether a function is odd or even? Will there be something further down the mathematics pipeline that will utilize this concept? | [
"You'll learn later that the integral of an odd function over a periodic interval is zero, and the integral of an even function over a periodic interval is equal to twice the integral over half the interval.",
"You can visualize this by looking at something like the sine and cosine functions. The integral can be... | [
"Because every time you instantly cross out some gnarly looking integral as equal to zero because it's odd you'll feel like a badass."
] | [
"It's not a super-important concept in and of itself. Symmetries, of which this is a simple example, ",
" super-important in mathematics, though, and this gets you thinking about such things--the answer to your question about its utilization down the mathematics pipeline is an emphatic ",
". It is a huge and ... |
[
"Will the recent freeze in the United States somehow result in less bugs this Spring / Summer?"
] | [
false
] | I'm hoping for yes. | [
"That depends on the species and where you are. The expansion of some species is limited due to their ability to overwinter in cold temperatures. Those that are on the northernmost temperature limit will most likely suffer from reduced populations, some becoming locally extinct. They'll recolonise, but it'll take a... | [
"There's some speculation that the cold temperatures will have a negative impact on some invasive insect (namely emerald ash borer, wooly adeldig, pine beetle) populations, but we won't know the true extent until the spring. "
] | [
"It might destroy some insect eggs. However, last time we had a bug free summer was when there was an intensely warm period (think 60s) in March, when all eggs hatched, followed by a snowstorm in early April, killing all larvae. I hope the freeze this time was sufficient to kill most of the bugs, but if not, let's ... |
[
"Why do Quasar's burn out?"
] | [
false
] | null | [
"The supermassive black holes (SMBHs) that power quasars are 'fed' via the accretion of gas. The accreting gas forms a disk around the black hole due to the conservation of angular momentum, and the disk heats up due to friction because different radii of the accretion disk orbit at different speeds. Because of t... | [
"From a video on the brightest things in the universe i saw on ",
"r/videos",
" yesterday, a quasar is a ring of matter spinning around a black hole very fast fueled by stars being torn apart. They \"turn off\" when the black hole becomes so massive stars are no longer torn apart but instead \"swallowed whole\"... | [
"As an aside, an accreting black hole is the most energy efficient engine in the Universe, converting matter to energy at a rate of ~ 10%-50%",
"For comparison, fusing Hydrogen to Helium-4 is about 0.7% efficient."
] |
[
"What happens if you were to heat water in a sealed container for a really long time with a very high temperature source."
] | [
false
] | I always wondered about this when I was younger: Suppose you had a 1 kg of water completely filling an indestructible container. You heat the water inside the container using something that can exceed 10,000C (container can also withstand this temperature). What happends to the water inside the container as it passes beyond being superheated and supercritical? Can the water absorb energy indefinetley and actually reach 10,000C? What would the pressure be? What would the properties of water be at this point, or whatever point the water can reach before it stops absorbing energy? What would happen if the container were to rupture after the maximum amount of energy has been absorbed from the heat source? | [
"Liquid water in a sealed container would, as you've described, become superheated and eventually become a supercritical fluid. At this point, you can think of it as a very, very dense gas. It would lack properties like viscosity that we normally associate with liquid water.",
"Eventually, if you pumped the energ... | [
"The plasma collapses into radiation. ",
"here's a story of tungsten and steel being heated up to emit 2 billion kelvin x-rays",
"edit: after further reading and understanding, i guess the plasma only collapses until energy is radiated away. but with a constant heat source, and no energy escaping? it doesn't se... | [
"What would happen if the container were to rupture after the maximum amount of energy has been absorbed from the heat source?). ",
"Something like ",
"this",
". You do not want to be near it."
] |
[
"What is this?? http://i.imgur.com/y6fm3.jpg"
] | [
false
] | null | [
"You will have to re-submit to change the title, it can not be edited. But beyond that, this question can be answered by doing a google search or searching previous topics in AskScience."
] | [
"Your link is broken. Also, please conduct a google search, you should be able to find it that way."
] | [
"Does the link in my post work? I don't know how to edit my post title cuz that one doesn't work :-/"
] |
[
"Does roadkill select for wildlife that is more wary of humans?"
] | [
false
] | [deleted] | [
"There are not a whole lot of studies which looked into the selective effects of roadkill. The best one I know of is Brown, C. R., & Brown, M. B. (2013). Where has all the road kill gone?. Current Biology, 23(6), R233-R234. see: ",
"http://www.cell.com/current-biology/pdf/S0960-9822(13)00194-2.pdf",
"What they ... | [
"There is data on inventories of roadkill for assorted mammals (and other groups) in various locations, and on sites more likely to generate roadkill. It'd just that those data sets look at which critters are hit more than others, or the effect on species preservation. As I said, there is very little data which mea... | [
"There is data on inventories of roadkill for assorted mammals (and other groups) in various locations, and on sites more likely to generate roadkill. It'd just that those data sets look at which critters are hit more than others, or the effect on species preservation. As I said, there is very little data which mea... |
[
"Why do trees have rings? And how accurate are they to the calendar years?"
] | [
false
] | null | [
"This is the result of alternating rapid and slow growth phases that correspond to summer and winter respectively. They are highly accurate if you are good at reading them and it's the right kind of tree growing in temperate climates."
] | [
"This is askscience. We don't assume!"
] | [
"So would it be reasonable to assume trees near the equator don't have rings?"
] |
[
"What is the minimum % of oxygen we could have in the atmosphere and still breathe fine?"
] | [
false
] | I saw a BBC documentary (The modern alchemist) where they were in a chamber with 15 % oxygen, and they couldnt light a lighter there, and a match wouldnt burn. Yet they could breathe fine there. Made me wonder how low we can go! | [
"this is an interesting question, and the answer will probably surprise you.",
"at this very second, we're living in an environment that's about 21% oxygen. the bulk of the atmosphere is actually nitrogen, clocking in at 78%. the 1% of air that's left over is mainly composed of argon and carbon dioxide.",
"i'm ... | [
"I can't speak to the actual medical parts of it, but according to OSHA anything under 19.5% is considered oxygen deficient and anything under 16% is considered Immediately Dangerous to Life and Health (IDLH).",
"edit: ",
"Here's some info:"
] | [
"Also, when mouth to mouth is preformed, about 14% of the gas pushed into the lungs of the person is oxygen. ",
"Just a cool fact..."
] |
[
"Problem with a gravity simulation: Every planet needs the same orbital velocity in order to achieve a circular orbit. How is this even possible?"
] | [
false
] | [deleted] | [
"It looks like you (or someone else!) rearranged ",
"Kepler's Third Law",
" incorrectly and are missing the dependence on distance (a) - it should be sqrt(GM/a)."
] | [
"Lol. Well, yea. Of course I rearranged it, that's the whole point. It still worked, which it shouldn't have. Hence my problem. ",
"The good news is, I slept on it. And it took me 2 minutes of clear headed thinking to figure out the problem in the morning. Which is a lot better than spending 8 hours thinking abou... | [
"Solid science."
] |
[
"Could there be more unknown elements that exist in the universe?"
] | [
false
] | [deleted] | [
"Not really. Every element has a whole number of protons, so there can't be sneaky elements hiding inbetween the elements we know. The only unknown elements are ones with very large numbers of protons, and these are known to be unstable. There may be \"islands of stability\", where specific combinations of large nu... | [
"Even if they have short lifetimes, are superheavy elements expected to be formed in events like supernovae or neutron star collisions? They're such massive events with loads of energy and neutrons about that to me it would seem strange if they ",
" create at least a trace of superheavy elements but we can create... | [
"\"Quickly\" ... as in seconds or minutes, long before the on-going supernova cools down enough for the superheavy elements to acquire a few electrons, and give off a detectable spectrum. I don't know how we could see anything from a few totally ionized atoms deep inside a supernova."
] |
[
"Can someone explain in layman's terms why cancer is so hard to cure?"
] | [
false
] | From what I've heard, there are a lot of different types of cancer and each type is different. But isn't the fundamental problem being that the cells divide uncontrollably? The and is different for each type, and that's mainly what I'm curious about. For example, how is the (pathology?) of lung cancer different than say, colon cancer? How do cancers differ at the cellular level which makes it so we have to find a cure for each one individually? Hopefully it's possible to answer this in layman's terms. | [
"Cancer isn't quite as simple as a cell dividing uncontrollably. There is an episode of the excellent Radiolab about tumors that gives a good layman explanation of how tumors evolve and why it is so difficult to cure.",
"http://www.radiolab.org/2010/may/17/",
" the segment in question starts at about 12:40 but ... | [
"Cancer is disease of the cell cycle.",
"Like how there are 1000 different diseases of skin, there are 1000 ways to break the cell cycle and develop cancer. Cancer is simply a catch all for breaking the cycle. \n",
"http://en.wikipedia.org/wiki/Cell_cycle",
"There are \"checkpoints\" in the cycle that allow t... | [
"Cancer is hard to treat because \"cancer\" is thousands of different diseases, each with its own cause.",
"As we unlock the genetic basis for individual cancers, we'll get a better understanding of what makes cancers tick. We can talk in generalities about tumor suppressor genes (loss of these can give you a can... |
[
"What do the data storage properties of nucleic acids mean for trans-binary computing?"
] | [
false
] | [deleted] | [
"There are lots of non binary computing investigations. This sort of quaternary system was a curiosity decades ago. The nucleotides can store data with high density but they are fragile (susceptible to ionization damage from chemicals and radiation) and storage and retrieval are very slow. And they are not computer... | [
"Before computer architecture eventually settled on binary, Russians did have base-3 computer which according to wikipedia was way faster than binary alternatives of the time, and this was somehow tied to base 3 and advantages of it.",
"They eventually switched to binary computer butI've always wondered, why was ... | [
"You get more information out of it per computational cycle, and likely a higher density of information into a given number of memory components (3",
" vs 2",
"), but possibly at the cost of smaller noise margins (I don't know what the Russians were using for memory) meaning you'd need to have error-correcting ... |
[
"Other than the Croatian Lizards, which evolved within 30 generations, what other documented cases of natural evolution are there that have occurred within recorded history?"
] | [
false
] | [deleted] | [
"No, it is still evolution. Antibiotics are a natural pressure for bacteria, they can \"evolve\" and \"reverse evolve\" antibiotic resistance. "
] | [
"No, it is still evolution. Antibiotics are a natural pressure for bacteria, they can \"evolve\" and \"reverse evolve\" antibiotic resistance. "
] | [
"TalkOrigins has some good stuff on this. ",
"From memory:",
"London subway mosquitoes (really)",
"Cichlid fish in African lakes",
"Speciation of ",
" introduced to the island of Mauritius"
] |
[
"If one intentionally ignores the urge to urinate, why do the bladder muscle weaken, but other muscles (eg heart) get stronger when actively engaged?"
] | [
false
] | I hope that makes sense. I hear that it’s bad to hold in your urine, it weakens your bladder muscles. If resisting the urge to pee is done by voluntary muscle engagement, isn’t this the opposite to other muscles that strengthen with use? | [
"The short-term answer: Muscles work best at their ideal length; if they are too short or too long, they won’t have maximum strength. So, if you ignore the urge to urinate, the muscles get overly stretched and do not work effectively. \nLong-term answer: actually, we see this in older men who develop prostatic hype... | [
"People with any kind of blockage for urination have thicker bladder walls. ",
"Also, if you hold it too much, the bladder muscles distend too much, and that makes it weak. And you can’t empty it after. ",
"Usually combined with a blockage, the weakened muscles can’t overcome that blockage and result in retenti... | [
"So basically the same reason that you “weightlift” a pregnancy belly 24/7 for months and still end up with abs that are weaker than when you started."
] |
[
"If matter cannot be created or destroyed, does it follow that there is a finite amount of matter in the universe?"
] | [
false
] | If so, doesn't that mean the universe can only be infinite in the sense that it is infinitely expanding, and the space between matter infinitely growing larger, while the number of stars and other celestial bodies remain the same and finite? What would happen, then, if I were to pass the last star (the most farthest one, after which there is no more matter)? Could that star mark the "edge" of the universe? Edit: Also, I realize I'm thinking of the universe as being flat, which I know may or may not be true, but my uneducated mind doesn't know of any other way to imagine it. | [
"Not if the Universe is infinite. What should be conserved is the amount of matter in an expanding volume. Since the Universe is bigger than we can see, due to the finite speed of light, asking how much matter there is in the ",
" Universe is not a particularly scientific question!",
"It bears saying, by the wa... | [
"Matter is not conserved; mass-energy is conserved.",
"The total amount of mass and energy is constant within the universe."
] | [
"Actually, the total energy content of the universe is not conserved. It only would be if the universe were not expanding. ",
"http://blogs.discovermagazine.com/cosmicvariance/2010/02/22/energy-is-not-conserved/"
] |
[
"Why does an electron have the same amount of charge as a proton, even though a proton is much bigger?"
] | [
false
] | An example of this size could be a negatively charged cat trying to discharge a positively charged building. | [
"They both have a the minimum amount of charge that can exist freely in this universe. This is independent of the size of the particle. The W boson is 80 times as massive as the proton and has the same charge."
] | [
"Quarks probably don't exist freely."
] | [
"Binding energy",
"Not really. Binding energy is actually negative: a carbon atom has ",
" mass than the three helium atoms that made it. Binding energy is the energy you have to add to something to unbind it.",
"It turns out a proton isn't just 3 quarks. The 3 quarks usually referred to are called the \"v... |
[
"Why are white and silver different colours?"
] | [
false
] | If a white object is reflecting all frequencies and a silver object is reflecting all frequencies then why do they look different? Most of the explanations I have found so far talk about specular and diffuse reflection but that doesn't seem to tell the whole story. Specifically, what about shiny white objects (like a whiteboard) or matt silver objects (like the dull side of kitchen foil)? The most satisfying explanation so far is that it's "something to do with electrons". | [
"Most of the explanations I have found so far talk about specular and diffuse reflection but that doesn't seem to tell the whole story.",
"Are you sure that explanation is insufficient? The range of possible roughness explains the range of possible appearances.",
" Imagine shooting a grid of photons at a perfec... | [
"And to add, shiny white is typically due to a flat but reasonably transparent film on top of a bumpy white substrate - there is partial specular reflection from the shiny film, but most of the light will come back from the bumpy surface, so you have a combination of the two. ",
"Beyond that you can have layered ... | [
"I would note that a shiny white surface like a whiteboard has a rough white surface underneath a smooth transparent plastic or glass. There is partial reflectivity from the plastic/glass, which isn't the quite same as a polished metal surface.",
"Polished aluminum is \"white.\" It has very good reflectivity acro... |
[
"Why are the wavelength intervals in some radio tuning interfaces not spaced in a consistent fashion?"
] | [
false
] | I see AM-FM radios with tuning interfaces like this all the time: Usually at least one of the broadcasting bands (FM or AM) have their numbers in irregular intervals, not linear, or not even apparently logarithmic in progression. Sometimes the FM band may have the intervals evenly spaced but the AM spacing is more "erratic" (especially the spacing between 540hz and 600khz, then a 100khz change across the same distance). What establishes the reason for the irregular spacing and granularity? Are some wavelengths naturally more difficult in certain regions to broadcast signals without interference? Are the less granular areas mostly allotted for other, non-public and non-commercial purposes? | [
"Radios like that use a variable capacitor to tune the stations. When you turn the dial, you are turning a set of plates which intermesh with, but don't touch, another set of plates. The capacitor forms part of an oscillator and the frequency is dependent on the square root of the capacitance. Since the square root... | [
"I'm building a radio. Is there a formula I could use to accurately space out tick marks on the AM and FM radio dial? Is it x"
] | [
"It depends on the tuning capacitor and the circuit. An accurate simulation should be able to do it, but I would just build it and graph the tuning knob angle vs received frequency. Then find the points you want to mark on the graph and read the angle off the other axis. No estimation or guesswork involved. "
] |
[
"How is LIGO different (besides scale) from the Michelson-Morely experiment, and how are they similar?"
] | [
false
] | null | [
"Thank you for your submission! Unfortunately, your submission has been removed for the following reason(s):",
"You question is either commonly occurring or has been recently posted on ",
"/r/AskScience",
". It may also be answerable using a Google or Wikipedia search.",
"To check for previous similar posts... | [
"It's not a recent post here and I can't find a satisfactory answer online, you must have a good answer to block the question right?"
] | [
"If you google \"ligo michelson morley\", you can find lots of information on the similarities and differences. If you have a more specific question, feel free to post that!"
] |
[
"What is actually happening when a jet breaks the sound barrier?"
] | [
false
] | Why is there a physical cloud you see, how does one actually do this and what is the effect? | [
"This ",
"link",
" explains it well, but I will attempt it as well.",
"\nImagine a jet as a point; as the jet moves it gives off soundwaves that are faster than it. As it passes the speed of sound it catches up to the soundwaves it already gave off while still producing soundwaves. These waves now pile up cre... | [
"Sound travels at some speed. The plane is not a sound wave, so it can travel faster than that. The way the sound waves it generates pile up because it is moving so quickly creates the shock wave, which has the characteristic conical form (this is where the condensation cloud gets its shape)."
] | [
"The shock wave, and the boom, travel along behind the aircraft, ",
"as depicted in the animation on this page",
"."
] |
[
"If a bottle is completely filled with water and I shake it. Does the water still move inside?"
] | [
false
] | null | [
"submerge the whole bottle then close it"
] | [
"submerge the whole bottle then close it"
] | [
"Could we test this by putting drops of dye in the bottle and shaking it? "
] |
[
"Can a popped out eyeball still see?"
] | [
false
] | null | [
"Sure, if you don't damage the optic nerve.",
"It's a pretty tough cord with slack built in so the eyes can turn in their socket. ",
"There's an article in JAMA about it from 1932.. sorry for the paywall..",
"https://jamanetwork.com/journals/jama/article-abstract/1153806"
] | [
"This is called globe luxation (i.e. dislocation) and usually results in vision loss because of avulsion (tearing/pulling out) of the optic nerve. Generally, the orbital socket and muscles around the eyeball also help hold it in place. Usually, this will present as a bulging eyeball. The optic nerve isn't long enou... | [
"https://12ft.io/proxy?q=https%3A%2F%2Fjamanetwork.com%2Fjournals%2Fjama%2Farticle-abstract%2F1153806",
" no paywall"
] |
[
"When something gets \"sun bleached\", where does the color go?"
] | [
false
] | I had an old grill cover that was red, and after a few years it turned white/pink. Where did the original color pigment go and how does the sun cause that? | [
"Bleaching is an umbrella term that refers to (in this case) the degradation of the organic dyes that give rise to the apparent color of the material by sunlight. Such changes occur because the energy of the photons making up the light can oftentimes activate a large host of chemical reactions, particularly in the ... | [
"It's because we perceive sunlight as white. If there is no absorption, then the object will reflect all incoming light with effectively no wavelength selection and so the color of the object will just be the color of the incident light, in this case- white."
] | [
"Yep, it's destroying the melanin in the strands, and since your hair is dead there's nothing that can \"heal\" it. When sun hits your skin, it's also destroying melanin, but your skin is alive so it can heal that damage and responds by making more (hence tanning). ",
"Of course all that being said, put on suns... |
[
"What do \"degrees of freedom\" really mean in research?"
] | [
false
] | [deleted] | [
"It entirely depends on context, but it generally it means \"how many variables are we in control of?\"",
"The term obviously comes from the notion of movement in 3D space: six degrees of freedom means that you can move in any of the six cardinal directions along an orthonormal basis in three-dimensional space--u... | [
"Right, the other three degrees of freedom are orientation."
] | [
"Up, down, left, right, forward, back are only three degrees of freedom, since we \"control\" only three coordinates. A point in 3D always has three DOF, that's why it's 3D: Either x,y,z in cartesian coordinates, or r, phi, theta in spherical, or something else entirely."
] |
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