title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"If life exists elsewhere in the universe, how similar should we expect its biochemistry to be to our own?"
] | [
false
] | null | [
"It's really hard to say, as we only have one data point to work off.",
"I'd wager most astrobiologists agree that the ",
" of life must be similar- that any kind of life must have some sort of genetic inheritance, some sort of metabolism, and some sort of compartmentalisation (to name a few). There are excepti... | [
"Answers like these always amaze me. I mean I didn't understand anything when you started to use these technical terms but I still understood more or less what you wanted to say and it amazes me that people know so much about stuff like this that they can write almost 4000 characters about it. ",
"OTOH I really l... | [
"There's a lot less life than people imagine. You might think people and zebras are different but you'd be a long way off the mark. ",
"There's only a few types of different of life.",
"Even these all use CHON as their base. Carbon, Hydrogen, Oxygen and Nitrogen are abundant throughout the universe and formed e... |
[
"Deep ocean pressure and shipwrecks"
] | [
false
] | got me thinking about this, because it says the pressure at 4-500m would push a champagne cork into the bottle. Usually Randall is spot on with these sort of things, but if it's true how can a press release like , apparently from a reputable company that deals in ultra rare wines, be real? | [
"The wine collector is referring to wines of the same ",
" that were on the Titanic, not actual Titanic wine bottles. The xkcd comic is in fact referring to a full champagne bottle."
] | [
"Hmm...didn't see that caveat in the press release. Do you know of another source?"
] | [
"FTA: ",
"The wines are considered way past their used by date, however it is not beyond the realms of possibilities that the buyer may sneak an opening of one of the 6 bottles to really see if the wine is beyond drinking."
] |
[
"What is heat, and what is happening during heat transfer?"
] | [
false
] | I've read wikipedia and other sources, but I'd like it explained by AskScience, as their explanations seem to be easier to understand and include more current understanding by the science community. My current understanding is that 'heat' is kinetic energy at an atomic level. A way to understand it is to think of an at... | [
"Conduction occurs in solids and liquids, and theoretically in gases, although the mean free path of gas molecules is so large as to make conduction in gases largely indistinguishable from convection. In conduction, the kinetic energy of molecules in direct contact with one another is transferred through collision... | [
"although the mean free path of gas molecules is so large as to make conduction in gases largely indistinguishable from convection. ",
"Eh? The mean free path of a gas molecule at STP is minuscule. Did you mean something else?",
"(Otherwise, a very nice explanation of heat transfer mechanisms.)"
] | [
"Yes, sorry. I meant that convection (bulk fluid movement) in a gas space dominates heat transfer, as compared to pure conduction through a gas, as one might measure in the absence of gravity."
] |
[
"AskScience Cosmos Q&A thread. Episode 11: The Immortals"
] | [
false
] | Welcome to AskScience! If you are outside of the US or Canada, you may only now be seeing the tenth episode aired on television. If so, This week is the eleventh episode, "The Immortals". The show is airing in the US and Canada on Fox at Sunday 9pm ET, and Monday at 10pm ET on National Geographic. Anyone can ask a qu... | [
"Okay, so we're messing up the planet. What can the average middle class person really do about it? Seriously, I would like to know. What could we do that would have the biggest impact?"
] | [
"Tyson is a natural in this episode. Can anybody provide some sources on the \"asteroid ark\" theory? I don't find it hard to believe that it is ",
", I just want some more in-depth science to back this theory."
] | [
"There are a whole host of ways that humans are impacting the planet, but for the moment let's just focus on carbon footprint and energy usage. ",
"According to the EPA",
", transportation and electricity generation are the two biggest causes of CO2 emissions. One thing you'll find is that there are a whole lot... |
[
"Frost Wedging in the Grand Canyon?"
] | [
false
] | I know I saw a couple of documentaries (one was on the BBC, and the other National Geographic) which mentioned that the Grand Canyon got it's shape due to a freeze and thaw form of frost wedging which causes sections of rock to break away. I can't, however, seem to find references online which back that up. Did I imag... | [
"Perhaps you're thinking of Bryce Canyon? ",
"This link",
" says that it's the most important form of erosion at Bryce: ",
"Snow in the winter melts a little every day and flows into joints. At night it freezes and expands, breaking the rock into smaller pieces. This is called frost wedging. Bryce Canyon e... | [
"The Grand Canyon got it shape due to the Colorado River flowing past the ",
"Kaibab Plateau",
" as it lifted up. While the rims of the Grand Canyon have a fairly high elevation (the north rim being a bit higher), overall the Grand Canyon does not experience a ton of freezing weather once you get down into the... | [
"overall the Grand Canyon does not experience a ton of freezing weather",
"Freezing weather is ",
"quite common at the rim of the canyon",
" (around 7000 ft, 2200 m elevation); the average low temperature is below freezing six months out of the year! Even assuming that the canyon floor (around 2500 ft, 750 m)... |
[
"Does the speed of light have any special meaning? Why is it the speed that it is? Is the scalar value of the velocity (disregarding units) unique somehow?"
] | [
false
] | [deleted] | [
"It's the scale at which one unit of distance equals one unit of time. Imagine we measured horizontal distances in leagues and vertical distances in fathoms. We would need a conversion scale to tell us how many fathoms were in a league (~3038 or so). Well c is the scale that tells us how many seconds a meter is and... | [
"yeah, the units aren't important. It doesn't matter if it's meters and seconds, or furlongs and fortnights. The value, the number itself will change depending on which units you use, but at the end of the day it's always the ratio between equal units of space and time."
] | [
"yeah, the units aren't important. It doesn't matter if it's meters and seconds, or furlongs and fortnights. The value, the number itself will change depending on which units you use, but at the end of the day it's always the ratio between equal units of space and time."
] |
[
"How much would the average human life expectancy increase if we developed cures for all cancers?"
] | [
false
] | Let's suppose that we find something that does for cancer what penicillin and vaccines did for infectious diseases. Edit: It just occured to me that the answer to my question might be the same as the answer to the question "how much higher is the average life expectancy of people who don't die of cancer than the life e... | [
"It would take pretty intensive statistical work to accurately guess the effect this might have. ",
"Cancers affect different populations of people, curing one cancer might add an average of 70 years to a lifespan, where another type might add at best 1 year (think cancers caused by immunodeficiency like HIV, cur... | [
"Interesting, I didn't know that about the lungs. "
] | [
"It would increase average lifespan, but probably not ",
" lifespan, which might be more what you're really wanting to know. There is an oddity in the graph of cancer incidence vs. age, where it peaks in the 70s or 80s, but then goes back down again. That suggests that people who live to 100 or whatever have so... |
[
"Why do volcanoes keep erupting after the initial 'burst'?"
] | [
false
] | I've always thought of them as a pimple on the surface of the earth...once the pressure is released, it just kind of oozes. But watching the video from Kilauea, it seems to still be erupting relatively violently | [
"Volcanoes are fed by magma plumbing systems, and there's various ways of forming that magma. HOwever, basically it's about generating melt in the very upper bit of the mantle, that can then pool against the base of the crust and eventually make its way up to the surface. The way it does that is by exerting tensile... | [
"It's not clear whether you meant that it is water or a mantle plume that exclusively keeps a volcano active long term, but neither is true. ",
"Magma plumes feed some volcanoes yes, though many more are related to seafloor spreading or subduction processes, which can also be active for many millions of years. In... | [
"To add a caveat to the thread, Kilauea is a hotspot volcano which behaves differently and has a different structure compared to a classic volcano that form along actual fault lines, like subduction faults for example. "
] |
[
"How does the presence of a cell wall impact endocytic activity in fungi and plant cells?"
] | [
false
] | [deleted] | [
"No the question is perfectly clear and they meant endocytosis. OP is wondering how a cell can effectively endocytose when there is a physical barrier on the outside of its plasma membrane. This would be in contrast to amoebae or animal cells like macrophages that aren't surrounded by a cell wall."
] | [
"Ok, plants don't generally endocytose, but you didn't actually explain ",
" pinocytosis works in the presence of a cell wall, you only stated that it ",
" work and ",
" that's important, so OP's question still is unanswered."
] | [
"Oh, correct... Brain didn't click on the word :(",
"In that case the response would be ",
". It is said to be more difficult, because of the pressure I talked about in the parent comment, but I don't really agree with this interpretation, to be honest. As said before, plasmodesma means that the cells have othe... |
[
"What are the source of electrons when generating energy via turbines (steam, wind, etc.)?"
] | [
false
] | I understand the concept of electricity generation by a metallic rotor surrounded by a magnet, but I don't understand how electrons are continuously transmitted because I don't understand where they are transmitted from. | [
"I find it's easiest to think of electricity in terms of fluid moving through a pipe. The electrons are \"water drops\" that flow around a circuit. The voltage is the pressure differential - think of it as how tilted the pipe is, or how strong the pump at the source is. Current is the mass flow rate of the electron... | [
"They are not so much transmitted from one place to another, they are rather moved around in a loop. The magnets, if you like, provide the force to move them, and the load, whatever that is, provides the resistance."
] | [
"They don't actually. They mostly move around their initial position. What goes around is the effect. Potential is what moves fast and what goes around. Current is more of a manifestation of this. Both are extremely esoteric concepts. To be frank, at a basic level, we do not understand what current is. People say t... |
[
"Can you see the international space station from earth?"
] | [
false
] | null | [
"You don't even need a telescope, it's rather bright (about as bright as Venus last time I saw it). You can use ",
"this applet",
" to find when it will next go across your area. It's usually visible for about 3-4 minutes at a time."
] | [
"Here",
" is another page you can use to find out when it's the best time for you to observe it."
] | [
"It can be seen as a point of light with the naked eye and a general shape with binoculars, even. ",
"Here's",
" a website that'll tell you when and where to look."
] |
[
"At what point will we be forced to concede that the Higgs doesn't exist? What direction should we expect future research to take if that ends up being the case?"
] | [
false
] | null | [
"Kids today, I swear. So impatient. The Z boson was predicted theoretically in 1967; it was detected unambiguously for the first time in 1983. The top quark was predicted in 1973 and not detected until 1995.",
"We've been looking for the Higgs for about fifteen minutes. You can start talking about being \"forced ... | [
"The collider hasn't even powered up yet!"
] | [
"The W and Z were first detected at the Super Proton Synchrotron. It started in 1976 but the W and Z weren't conclusively observed until 1983. This shit takes time. The LHC has been colliding since 2010, but won't go up to full power until 2014."
] |
[
"If a person has been depressed for a long time, is there some kind of 'damage' to their brain, and can anti-depressants reverse the damage?"
] | [
false
] | null | [
"I'm a doctor and have done lots of reading in this area so can shed some light. ",
"",
"There is a neuroplasticity hypothesis of depression whereby as a response to stress our brains change at the cellular level in a dysfunctional way. This has been demonstrated by studies in mice, brain imaging and postmor... | [
"Yes, here's an ",
"article",
" that shows how people that are depressed have increased DNA damage markers, inflammatory markers, and oxidative markers in the brain when compared to healthy individuals. Essentially making people that are depressed age faster than those that typically aren't. The study also show... | [
"Do you know if natural recovery from depression without the use of medication can cause this process to begin reversing as well? I had severe depression for 4 years, and I definitely have felt these effects. It's been 1 year since I have recovered from said depression. If the process does reverse, it's definitely ... |
[
"I just bought a re-usable toy hand warmer for my son that works by \"clicking\" a small metal clip inside the sachet of clear liquid. The liquid turns opaque in an instant and the sachet becomes warm. How does it work?"
] | [
false
] | .. or to be more precise - the sachet is "recharged" by placing it in hot water. Eventually the white crystals dissolve and the liquid returns to it's clear state so the process can be triggered again (up to around 10 times apparently). Is the energy from the hot water somehow being stored in the liquid and then releas... | [
"The sachet is filled with a supersaturated solution of ",
"sodium acetate",
". By clicking the metal clip, you're providing a nucleation site for crystals to form. Since the crystallization of sodium acetate is quite exothermic, heat is released.",
"When you place the sachet under hot water, you're heating t... | [
"Probably not a good idea. In addition to possibly being contaminated by whatever was used to create the hand warmer, a super-saturated solution would probably taste terrible and/or be lethal. For example, compare pouring vinegar on a salad with pouring pure acetic acid on a salad."
] | [
"A supersaturated solution means you're dissolving as much as the water can dissolve - and then some more. So it is very concentrated."
] |
[
"If I have High cholesterol but very low blood pressure, does that mean I don't really have a cholesterol \"problem?\""
] | [
false
] | null | [
"Ok, sorry, it didn't even occur to me that medical questions could be construed as advice in the litigious sense... I get it. I will rephrase it so that it is strictly a scientific question."
] | [
"This has been removed because seeking for ",
"medical advice",
" on ",
"/r/AskScience",
" is against our guideline.",
"Please see our ",
"FAQ."
] | [
"If I remove the question about lipitor, can it count as a science question? "
] |
[
"What causes that distinctive smell of a person who comes indoors after being outside in cold weather?"
] | [
false
] | null | [
"I really misread that for a second..."
] | [
"I'd like to know this, too. It's kind of a sharp ozone, but much more satisfying."
] | [
"your brain tumor?"
] |
[
"Does Oxygen therapy increase the risk for ARDS?"
] | [
false
] | I seem to remember someone saying in a thread once that giving hospital patients too much oxygen can increase the risk for ARDS, but I can find anything on it. | [
"Respiratory Therapist here! According to Egan's \"Fundamentals of Respiratory Care,\" oxygen toxicity is one of the risk factors for ALI (acute lung injury) and ARDS (acute respiratory distress syndrome). There are certainly many other risk factors, such as direct injury to the lung (pneumonia, aspiration, near dr... | [
"According to Egan's again, in 0-12 hours one might experience tracheobronchitis and substernal chest pain. In 12-24 there may be a decrease in vital capacity (the total amount the lungs can inhale exhale at maximum). At 25-30 hours there can be a decrease in compliance (softness/stretchiness of the lung) and an in... | [
"As far as I know, there have not been significant studies regarding long-term high levels of oxygen on people who are not on a ventilator.",
"There are people who are prescribed oxygen therapy at home due to lung disease. These are typically people with diseased like chronic obstructive pulmonary disease from sm... |
[
"If gravity is caused by massive objects warping spacetime, then when I hold my pen above the ground, is the force I'm applying with my hand un-warping the pen's spacetime, and that's why it doesn't move?"
] | [
false
] | I understand why a traveling object move through space would get pulled towards a massive object since the mass is warping spacetime and the straight pathway now brings the traveler close to it. But I'm having trouble understanding how this would make an object I'm holding start to accelerate towards the mass when I'm ... | [
"Ok I think I get what you're saying and I hope you indulge me saying it back in my words as a confirmation.",
"NO.1 So if the pen was far enough out in space such that it wasn't subject to any gravitational influence (and at rest in respect say to the inertial reference frame of us on Earth) you would say it was... | [
"An object with no forces on it follows a straight line through spacetime; this is the cause of gravitational attraction, as you point out.",
"But once another, non-gravitational force acts on the object, it follows a ",
" path through curved spacetime (just like in Newtonian mechanics, an external force causes... | [
"Just to summarize what you are saying and make it more clear: the pen is not motionless with respect to earth because the mass in your hand unbends spacetime by the same amount that earth bends it. Rather, the electromagnetic force exerted by the atoms in your hand on the pen (the electomagnetic force is far stron... |
[
"What causes the 'blue electricity' of lightning and tasers and such?"
] | [
false
] | null | [
"To more explicitly state what other answers are hinting at, the taser is pumping a lot energy into the air molecules that are around the terminals. This excites them and moves their electrons into high-energy states, and as they drop back to a low-energy state, they emit photons. While the air is mostly nitrogen a... | [
"I went looking on Google. It took roughly 4 seconds to find this answer: The high voltage causes the airs electrons to jump to very high energy levels, some high enough to ionise (and thus conduct). The ones that dont quite ionise fall back to their original level, releasing a high energy photon, generally in the ... | [
"A taser is basically an incomplete circuit with a large power source. There's two pins that have a gap between them and breaks the circuit. But there's enough electricity going through the circuit to let the electricity to \"jump\" from one pin to the other, completing the circuit. Anything that comes into contact... |
[
"Why do suspended particles settle out as a heap when their medium is rotating?"
] | [
false
] | If I swirl a cup of tea, Alka-seltzer, or other liquid with suspended particles in it, the particles will tend to settle out as a heap in the center of the container. Why does this happen? Is it a result of the differing linear velocities resulting from circular motion, or is there another effect that explains this phe... | [
"This is the \"",
"teacup effect",
"\", and, curiously, it was first explained rigorously by Einstein."
] | [
"Just so I have it straight:",
"http://upload.wikimedia.org/wikipedia/commons/thumb/7/77/Tea_leaf_Paradox_Illustration.svg/213px-Tea_leaf_Paradox_Illustration.svg.png",
"Thanks. I had guessed that the settling pattern was a result of circular motion in that particles tend to settle slower in faster moving liqui... | [
"Yeah, that's exactly it. The rotation of the liquid forms a toroidal vortex, which moves down the outer walls of the vessel and up the center; however, the particles are too heavy to be carried up by the flow, so they get stuck at the bottom of the center."
] |
[
"How did the solar system take its current form?"
] | [
false
] | So, my guess is that for our solar system it all started with a huge cloud of space dust having mainly hydrogen, helium and all other elements in trace amounts... The dust had some initial angular momentum and therefore our solar system is more or less planar, the plane being perpendicular to the original angular momen... | [
"And Space Answers as well!",
"http://www.spaceanswers.com/solar-system/why-are-planets-closer-to-the-sun-more-dense/"
] | [
"And Space Answers as well!",
"http://www.spaceanswers.com/solar-system/why-are-planets-closer-to-the-sun-more-dense/"
] | [
"For the lazy, from Space Answers:",
"The planets in our Solar System formed from the solar nebula – the disc of gas left over from the formation of our Sun. Over time, this material began to collide and stick together, forming larger clumps that could collide with other larger clumps and gradually gather more an... |
[
"How is the mortality rate for COVID-19 calculated?"
] | [
false
] | I've seen estimates of 1%-5%. Looking at the total deaths vs. total recoveries yields a much higher number. What other factors are considered in the calculation? | [
"There are a number of ways of calculating the death rates of a virus.",
"The key number is the Case Fatality Rate, which is simply the number of deaths divided by the number of total cases (currently about 4-5%).",
"But there are estimates of asymptomatic carriers, which increase the number of cases, and drops... | [
"Two components: # deaths from COVID and # identified cases. The first number is theoretically easy to measure. Mortality data can be routinely collected from hospitals, death records, etc. The source of error here is in how a \"death from COVID\" is defined. In the US, if a death occurs and the patient is found to... | [
"There are a few reasons, especially in play while an outbreak is ongoing. For one thing, not all recoveries actually get tested and confirmed as recovered, especially when testing is scarce. So the number recovered can be an undercount. For another, since it usually doesn't take the same amount of time for reco... |
[
"Do rams have higher rates of brain injuries than other mammals?"
] | [
false
] | American football players tend to be more likely to have brain injuries than non-players. Seems to me that rams would suffer from similar issues. If they don't, why? | [
"Rams are specifically evolved for ramming into things, hence the name, while humans - professional football players or not - have not evolved for this function. Rams have very thick skulls and additional layers of muscle supporting their necks."
] | [
"That's precisely why I'm curious if there is a higher rate of brain injuries in rams than in other mammals. Have rams evolved enough to not get brain injuries as a result of ramming?"
] | [
"They've clearly evolved to reduce brain injuries:",
"“The large horn cores and expansions of the corneal and frontal sinuses of males, together with their internal bony septa, form a system believed to protect the brain by absorbing the impact of clashes during fighting” ",
"(Shackleton 1985)",
".",
"Argua... |
[
"What determines the amperage limit for a given density or thickness of a material?"
] | [
false
] | For example, a 34 gauge wire is going to fail at a lower amperage compared to a 0 gauge wire. How is that determined? | [
"I think that the ratings you see in the AWG wire tables are based on a conservative estimate of the allowable temperature rise in the wire under some nominal environmental conditions, which will be different for chassis wiring versus power transmission cable, versus other configurations. Some ",
"engineering not... | [
"But how are the fundamentals of that determined? Does it depend on the crystalline structure of the material involved?"
] | [
"Yes and no. The no part first:\nIn practice, the most important factors are the geometry and the enviroment near the conductor. For any given material you can determine a conductivity, usually per length. Depening on your geometry you can then calculate the power that needs to be dissipated for a given current and... |
[
"Why does my laser appear to stop at a certain distance?"
] | [
false
] | I own several high power personal lasers green and blue (500mw & 1W). When I shine them up at the sky at night they appear very bright (light sabre-like) but seem to stop at a particular altitude... like a mile or two at the most. I would think that it would diffuse? | [
"It's likely not your laser dissipating, but the lack of things for the laser to hit at higher altitudes. You can't \"see\" a laser beam, you can only see when it hits something: in your case dust and other aerosols in the atmosphere. Aerosols tend to stick ",
"in the lowest few kilometers of the atmosphere",
"... | [
"You should be able to test this easily by firing at different angles; given this hypothesis, it should end at the same ",
" even if the angle is such that it appears several times longer. "
] | [
"I'm not sure, but doesn't the fact that one is effectively looking along the length of the beam guarantee the appearance of an 'end' to it, regardless of the conditions, just by the geometry of the situation? ",
"Eg. if you had an infinitely long, straight glowing rod in vacuum, and held it out like the beam fr... |
[
"Why is it that microorganisms can develop resistance to medicines, but I have not heard of any organisms becoming resistant to soap?"
] | [
false
] | null | [
"One must also understand that natural selection has requirements in order for it to succeed in altering allele frequency in the subsequent generations. In your example, the assumption is that certain bacteria have variabilities in their resistability to soap, these variabilities in resistability confer a differenc... | [
"Soap in itself doesn't kill bacteria.",
"Whoa whoa whoa, it sure as shit does. Detergents, like the stuff that makes soap, well, soapy, disrupt and solubilize cell membranes, which does kill bacteria. Pretty well, in fact. ",
"I'm going to ",
"cite",
" the last time this question was asked. ",
"Here's",
... | [
"Soap in itself doesn't kill bacteria.",
"Whoa whoa whoa, it sure as shit does. Detergents, like the stuff that makes soap, well, soapy, disrupt and solubilize cell membranes, which does kill bacteria. Pretty well, in fact. ",
"I'm going to ",
"cite",
" the last time this question was asked. ",
"Here's",
... |
[
"Can two elections touch?"
] | [
false
] | I was wondering if it was possible that two elections touch each other, and what would happen if they did. I know Coulombs Law is F=KQq/r so my best guess would be that the force required would just get higher and higher as the distance got smaller until it was infinity, but I'm not sure so I wanted to get your take on... | [
"Coulomb's law ceases to be valid once distance grow sufficiently small (once you start getting in the angstrom range perhaps?). You have to calculate the interaction with QED, which once again, stops being valid after a point where you reach the so-called Landau pole, after which you need to pull out the full stan... | [
"That's not entirely true. That only applies to fermions. Bosons do not follow the same quantum state rule and can occupy the same space."
] | [
"I'm assuming the OP was referring to \"touching\" quantum state. Based on that, you asserted \"nothing ever touches\" I'm just clarifying that bosons are contradicting \"nothing\"."
] |
[
"I have 20/20 vision. When I put on glasses, everything is blurry but when I cross my eyes, everything looks clear. Why?"
] | [
false
] | null | [
"When you cross your eyes you focus your eyes on 2 different things, but the focus remains the same. Glasses change the focal point which will make things blurry - unless they're ",
" glasses and your built-in focal point is off by the amount the glasses are correcting for."
] | [
"There are three factors contributing to this:",
"Most glasses have different prescriptions (refraction indices) at the edges than at the centers. ",
"Polarized glasses tend to skew things near the periphery. ",
"Most glasses are thicker toward the edges than in the center.",
"Wearing prescription or readin... | [
"offset the offset. makes sense. thank you!"
] |
[
"Do identical twins have identical DNA?"
] | [
false
] | null | [
"At the very moment that the zygote splits, sure, the DNA will be remarkably similar. However, as the individual embroys grow and the DNA is replicated, mutations accumulate in the individual genomes which ultimately change genetic similarity, even if the changes are super minute."
] | [
"This is very interesting. Thank you so much. A few more questions then, if I may. Are these epigenetic changes detectable? In a forensic context, would two identical twins be distinguishable by their DNA? What environmental circumstances give rise to most epigenetic modifications? Do unrepaired modifications cause... | [
"This is very interesting. Thank you so much. A few more questions then, if I may. Are these epigenetic changes detectable? In a forensic context, would two identical twins be distinguishable by their DNA? What environmental circumstances give rise to most epigenetic modifications? Do unrepaired modifications cause... |
[
"If skin cells are one of the fastest replicating cells, how come moles, and birth marks don’t disappear over time?"
] | [
false
] | Same goes for warts and scars. | [
"Moles are still skin cells. So imagine you have an area of skin, and some part of it is “mole” cells and some is regular cells. Both parts are sluffing (losing skin cells) at similar rates, and then replacing those cells at similar rates. So the shape and structure of moles might change overtime, but on average th... | [
"There's quite a bit of half truths and misinformation in this answer. Scars are extracellular and do not have anything to do with stem cells.",
"Scars are produced from a wound site where the fibroblasts in the dermis are laying down extracellular proteins such as collagen. Normally they do this slowly and very ... | [
"There's quite a bit of half truths and misinformation in this answer. Scars are extracellular and do not have anything to do with stem cells.",
"Scars are produced from a wound site where the fibroblasts in the dermis are laying down extracellular proteins such as collagen. Normally they do this slowly and very ... |
[
"What is it in grass that makes it so itchy?"
] | [
false
] | Why does grass itch so much? I would speculate that its perhaps something to do with how sharp it is ... I'm picturing like microscopic little paper cuts being the cause of the itchiness but its just a guess. Is there something else at work here? | [
"Wait, really? So this isn't normal? I just assumed everyone got itchy when they rolled in grass without a shirt on (for instance). It never even occurred to me that it might be an allergy."
] | [
"From my experiences as a child, every single one of my friends who rolled on grass without a shirt on got itchy. Since I find it very unlikely that all of my friends were allergic to grass, there must be some other explanation."
] | [
"My hypothesis: grass itches because you are allergic to grass."
] |
[
"Is it possible that there are other colors that we humans cant see/have not found yet?"
] | [
false
] | null | [
"Colors are a psychological not physical property. "
] | [
"Other animals may be sensitive to light outside of the typical visible range for humans. For example bees are sensitive to light in the UV range. Human photoreceptors are actually also sensitive to light in that range, but the lens filters it out. In early versions of cataract surgery, lenses were replaced with a ... | [
"Yeah I understand that, but is it possible that maybe a certain animal can see a color we can't? Or is it all based on the RGB Spectrum we have now?"
] |
[
"Cell Automaton/Computer Science Question"
] | [
false
] | I recently read about cell automatons and I find these intriguing. For biochemical/molecular biology purposes, in what instance would someone construct a cell automaton to model something? I am thinking maybe to extrapolate some aspect of cell behavior given certain conditions. Also, what programs do people usually use... | [
"Not my sub-field, but I'll try.",
"Cellular automaton can be used to model extremely complex systems which have simple interaction rules. Fluid dynamics is one thing that comes to mind. Particles have extremely simple rules for interacting: bounce around. ",
"However, I can't find much post-80s. Probably becau... | [
"Ah well I stand corrected. Biology is not my field."
] | [
"As far as I know, CA are not used to model anything. They are mostly used to demonstrate and study how seeming chaos arises out of simple rules. They might have some applications in cryptography, but this is basically taking advantage of the \"chaos\" property they exhibit while still having a definite rule to b... |
[
"Can an unvaried diet cause the human body to learn to digest a certain (type of) food faster?"
] | [
false
] | I know that the ranks carbohydrate-comprised foods according to their effect on glucose levels. But are these rankings always accurate throughout an individual's life? Would, given sufficient repetition, the body adapt to process a certain food (e.g. Pizza) faster? | [
"Kind of. I might replace the word ::faster:: for ::more efficient::. The bacteria that thrive in your gut are the ones that eat what you’ve been eating lately.\nThis is why sometimes we get gassy or weird stools when traveling to foreign countries of different cuisine- your microbiome aren’t optimized for that cui... | [
"The problem with rabbit starvation isn't because it's just meat. Since the meat is so lean, the caloric intake is only protein which the body can only process a certain amount. This leads you to have a caloric deficit because you can only get a portion of what you eat. If the meat is fat, you will be fine."
] | [
"There are examples of people living with for very limited, but abundant, nutritional sources, including the native people of Canada in the extreme North surviving off mostly fish and seal, and the Nomadic Bedouin’s living off their camel herds. They did have other plant foods but I believe a majority of their norm... |
[
"How variable is human flexibility?"
] | [
false
] | Do we all have a base flexibility, or is it just that "naturally more flexible" people do more workouts and perform more motions that require flexibility? If I gain flexibility, then stop stretching, will I lose it as quickly as I gained it. Is my upper limit drastically different from somebody else's? I can never reme... | [
"Range of motion is partly result of the stretch reflex. When you train flexibility, a lot of it is training your stretch reflex; when people are anesthetized, they have a larger range of motion. But people's skeletal joints vary by a ton anatomically, as do the locations and size of muscles which also impact ran... | [
"Thank you! You're completely right."
] | [
"There's certainly peer-reviewed literature on this, and IFLScience have done a ",
"great job of summarising",
" whether stretching improves both flexibility, and chance of injury. The main findings (with links to the journal articles):",
"\"",
"Stretching acutely increases flexibility",
"\" (acutely mean... |
[
"With modern technology and measuring devices, how much warning will there be of the next Yellowstone supervolcano eruption?"
] | [
false
] | null | [
"WE can't forecast ",
" volcanic system particularly well at the moment. The Yellowstone system is one that has very long repose times (long periods between activity), and a wide range of activities (can throw out thousands of cubic kilometers, or can erupt a few hundred cubic meters). It's not erupted in recorde... | [
"We use seismic tomography to try and image the subsurface (a bit like ultrasound), but it has very limited resolution at those depths. Drilling at those depths into hot materials is not really feasible, and the last thing you want to do is drill into a eruptable magma. Even then, a drill core only tells you about ... | [
"there's a huge magma storage system down there, but we have no real idea of how full it is, or how fluid and eruptable that magma is, or how well connected the different pockets of it are.",
"Im not familiar with Volcanology at all but is there a technical limit as to why we cant find this info? Is there no way ... |
[
"How much does glucose consumption vary from brain to brain and how much could it effect overall metabolism?"
] | [
false
] | Alternatively: could person A who is mentally 'slow' have a slow metabolism whereas person B that is mentally 'busy' have a fast metabolism? | [
"So, ",
"this",
" paper states that the brain uses around 60% of our overall glucose that we contain in our body during a resting state (glucose is the main energy source for the brain, except for periods of starvation where it can utilize other energy sources to maintain itself). The brain relies, obviously, o... | [
"This may be a silly question but could someone with a disability effecting the brain be treated with high glucose intake, provided they process glucose like you and I?"
] | [
"Hey, thanks for the reply! Appreciate it"
] |
[
"[Mathematics] What number refers to the number of possible orderings of natural numbers?"
] | [
false
] | The number of unique orderings of a set of length n is n! and as such it seems logical to me that the number of unique orderings of the natural numbers is Aleph null factorial, but what does it mean to take the factorial of an infinitely large number as infinity minus one is still infinity(i think). I was also thinking... | [
"A rather simple way to encode numbers between 0 and 1 to all possible orderings of natural numbers would be to create decimal number between 0 and 1, and type each integer in order, in base-2, then use 5 as separator. So if your ordering starts like 1, 5, 16, 4, 2, ... Then we'd have our encoding of",
"0.1510151... | [
"From your response it seems clear to me that the number of unique orderings must be smaller than the set of real numbers, and in fact I am under the impression that it is even smaller than the set of real numbers between zero and one",
"Watch out: It might sound counterintuitive, but the set of all reals and the... | [
"It's pretty easy to show that N! = 2",
" using Cantor's Bijection theorem.",
"Elements of 2",
" are functions f:N -> {0,1}. Elements of N! are bijections g:N->N.",
"To inject 2",
" into N! , you can have g be the bijection that exchanges 2n and 2n-1 iff f(n)=1.",
"To inject N! into 2",
" you can \"w... |
[
"Do dogs taste spicy foods like humans do?"
] | [
false
] | Do they have different taste buds? Less taste buds? More? The spicy food in particular I'm curious about is jalapeños (was going to feed my dog a piece of my slice of pizza with a jalapeño on it, but I thought I'd ask here before I made him sick) | [
"You wont make him sick. ",
"In most developing countries, dogs eat what humans eat. I think Americans and the others in developed countries got suckered into feeding dogs dog-food... it is sooooo good for the dogs. In India for example, dogs reared by vegetarian families thrive (not survive - thrive) on veggie f... | [
"And indians eat like 10 gms of protein.. are healthy.. survive.. have long lives on vegetarian food.",
"Sorry, that's just plain wrong. No healthy adult survives on 10g of protein per day.",
"You need a minimum of 12% of your daily calories from protein. If your daily diet is 2000 calories, you need 240 calori... | [
"Really? That's cool. I didn't know that.\nI was told because they're carnivores, it's best if they eat mainly meat. I have read that they eat greens in order to control upset stomachs (which explains why we see dogs eating grass from time to time)."
] |
[
"What would a firework look like if it was set off in space?"
] | [
false
] | null | [
"Except it wouldn't trail down like the common umbrella shape most long bursts have. It would be more of a spherical pincushion all the way through the burn. "
] | [
"If its made with substances that can chemically react without the presence of oxygen then it would look the same as it does here. It would be visible at night if it was large and detonated somewhere around low earth orbit (we can clearly see the flash off the space station solar panels)"
] | [
"If it was fired on orbit then yes its in freefall. If it was launched straight up from the earth in a non orbital trajectory it would still have the umbrella shape. Carful about thinking of space as equal to no gravity. "
] |
[
"What is stopping scientists from adding more and more neutrons to an atom to create an infinite amount of isotopes?"
] | [
false
] | null | [
"What you’re talking about is referred to as the neutron drip line, which is the upper bound on the number of neutrons a stable isotope can have before it starts “dripping” particles. ",
"In an atom, there are several forces at play. The balance of these forces on an individual nucleon is the amount of energy tha... | [
"Neutrons and protons are fermions, so every state can only have one of them. Protons and neutrons have different states as they are different particles. A (ground-state) nucleus will have all the lowest energy levels filled up to some point. With a \"good\" proton to neutron ratio the highest filled energy levels ... | [
"I am having trouble understanding how turning a neutron into a proton makes the nucleus more stable. It would seem like the added electromagnetic force would only increase the repulsion, so what is really going on? Why is a Hydrogen atom with just a proton more stable than with added neutrons? What is causing t... |
[
"How does paper get recycled?"
] | [
false
] | (Note that this is tagged as biology since I'm not sure what else to tag it as, but biology seemed the closest) I've always seen that paper, glass, plastic, etc., is supposed to be recycled, and I get how most things are: they get melted and reformed into something with a different shape and purpose. but paper? that st... | [
"I think ",
"this article",
" shows the process reasonably well."
] | [
"it's weird to think that it becomes almost like a paste, but thanks!"
] | [
"The same way it’s made in the first place. Paper is wood that has been pulped to smaller fibers and mixed with a binder.",
"The wet pulp is formed, molded and pressed, then dried, which gives you paper.",
"In most cases there are additional steps in the process to align and untangle the fibers, bleach the pulp... |
[
"Why don't teeth heal by themselves?"
] | [
false
] | So when we get cavities we have to get a filling because it would grow back naturally, whereas, if I cut a chunk on muscle out it will repair and grow back. Why is this? | [
"Teeth form from a multistep extracellular mineralization process. This process begins with a mix of \"soft\" proteins and minerals (mainly calcium) which auto-assemble into a very tough mineral deposit. This mineralization occurs in very thin layers, each taking several weeks to mature. You can think of building a... | [
"There are reports of humans developing multiple sets of deciduous teeth, so we do have the capacity to support multiple rounds of tooth formation. The short answer is that we don't fully understand why we develop our permanent teeth early in life and maintain them throughout adulthood. This is a trait that we shar... | [
"The tooth is made of enamel which is not alive and so cannot repair."
] |
[
"When a napkin is dipped in water, where does the energy come from that allows the water to travel up the napkin, against gravity?"
] | [
false
] | null | [
"Whoa nelly, there is a lot of crazy semi-science going on here, I'll try to get at the heart of the problem:",
"Capillary action in this case is due to the high porosity of cellulose based materials (like napkins). Water has very favorable interactions with cellulose due to hydrogen bonding and wants to adhere t... | [
"Hmm... that is actually not a trivial question. I think the answer is yes, but the difference would be ",
". Hot water has more energy to propel the water molecules more quickly through the porous substrate."
] | [
"So boiling water would spread faster than say near freezing water? "
] |
[
"If low testosterone males experience chronic fatigue, why aren't women tired all of the time?"
] | [
false
] | null | [
"A woman's ovaries and adrenal glands will produce testosterone but on a much lower level than a man's testes. If a woman's body fails to produce appropriate levels (there's a sweet spot-not too much, not too little) of testosterone for the female body, she will probably exhibit symptoms. She could experience fatig... | [
"http://www.nejm.org/doi/full/10.1056/NEJMoa0911101#t=articleResults",
"Some men, a small proportion, have fatigue, but it's a relatively rare symptom compared to others. Fatigue is reported in less than 20% of patients even at the lowest testosterone levels.",
"Edit. On women.",
"http://aje.oxfordjournals.or... | [
"part of it is because we have estrogen. a female steroid hormone which has an extremely similar chemical compound to testosterone. made from the same precursor and can even be made from testosterone. ",
"http://en.wikipedia.org/wiki/File:Steroidogenesis.svg"
] |
[
"How does freezing solutions of ethanol work?"
] | [
false
] | I was reading ethanol's on wikipedia, and was a little confused by the freezing temps given for aqueous solutions. For example, it states that a 13.78% by weight solution will freeze at -6.1˚C. Does this mean that no freezing will occur until the solution is lowered to -6.1˚C? Does it also mean that when solids begi... | [
"First question: Yes, the freezing point works the same way regardless of whether it's pure or a solution. ",
"Second question: No, much as where distillation results in a vapor with a higher ethanol content (initially), freezing results in ice with a lower alcohol content (initially). You could say this is becau... | [
"Here you go",
".",
"The solid curve is missing because it is in such vast favour of one component or the other that it basically lie on the vertical axis.",
"For understanding solid/liquid phase diagrams, check out ",
"this example",
"."
] | [
"Thanks.",
"Then is it possible to plot a liquid/solid composition graph similar to the vapor-liquid equilibrium?",
"I saw a post on ",
"/r/mead",
" of someone saying they were going to try freeze distillation, and I was trying to figure out how much alcohol would be lost as solids in the process."
] |
[
"Regarding the transfer of energy"
] | [
false
] | I was reading the article about the fan in the room and it got me to thinking... if I had a large sealed room filled with air of different temperatures (hot spots and cold spots) the air would start to circulate of it's own accord until the hot air was at the top and cold at the bottom. But during the process of the ai... | [
"Gravitational potential energy associated with the distribution of densities."
] | [
"Great answer. To elaborate for the OP, the pockets of denser cold air act like any object in a gravity field: if you let them fall to a lower position they will have a little more motion and a little less gravitational potential. This is where the small amount of heat comes from. If it's a rigid container the pres... | [
"thanks for the elab. I had originally ruled out Gravitational potential energy, as I figured that the room as a whole, would still hold the same amount of Gravitational potential energy regardless of what happens inside, but I was wrong."
] |
[
"What is the status of and the general consensus on the Energy Catalyzer?"
] | [
false
] | For anyone who doesn't know, is its Wikipedia page. It seems that one scientist has come up with a possible mechanism, that the Nickel could form a Bose-Einstein condensate and this would provide a mechanism for a copper-nickel conversion with low-energy gamma rays, provided the reaction takes place at ~22 bar and abo... | [
"They have neither been able to properly demonstrate their claims, nor provide a physical mechanism for how it happens. Sounds a lot like BS to me. If they won't patent their device and allow people to look inside of it, then it sounds like a scam to rob investors of their money. ",
"Fusion happens when nuclei, w... | [
"Do you know how cold we have to get things to form ",
"condensates",
"? Nano-Kelvin. ",
"And if they're not doing open-box demonstrations, they're not doing demonstrations. They're doing magic shows. Science is about independent reproduction of data. Anyone anywhere should be able to rebuild my experiment, a... | [
"If it's not open and reproducible it can't be included in our body of knowledge of objective truths. The ",
" of their device boils down to \"this black box, when fed these inputs, will output energy like ",
".\" We should ignore all the claims about nickel turning into copper or whatever unless we can make ",... |
[
"To what extent can parents' DNA be reverse-engineered from their child's DNA?"
] | [
false
] | A child obtains 50% of their genetic material from their mother and 50% from their father. If a child's genome is mapped, how much of their parents' genomes could be reliably inferred from this? Can we determine more about their mother's genome than their father's? I'm guessing that in terms of genes, we will know what... | [
"research engineer here:",
"A haplotype (haploid genotype) is a group of genes in an organism that are inherited together from a single parent.",
"As the human genome consists of two homologous sets of chromosomes, understanding the true genetic makeup of an individual requires delineation of the maternal and p... | [
"There is no known way to determine this. Most of the previous post was about creating phased haplotype maps, which are reconstructed sequences we believe come from a single haplotype. These can at theoretical best only cover one whole chromosome (and even that's a longshot with the current technology), there's no ... | [
"Thanks for your detailed answer. I'm not sure what it's telling me in terms of what we can deduce about paternal and maternal genomes solely from a child (i.e. if we don't have access to the parents). ",
"How do we determine where a particular haplotype comes from - the father or the mother? "
] |
[
"It's impossible to determine a particle's position and momentum at the same time. Do atoms exhibit the same behavior? What about mollecules?"
] | [
false
] | Asked in a more plain way, how big must a particle or group of particles be to "dodge" Heisenberg's uncertainty principle? Is there a limit, actually? EDIT: Thanks for reaching the frontpage guys! | [
"The larger the particle the less consistently the interference is displayed. Buckyballs still show nice wavelike behaviour though."
] | [
"If you could make a slit small enough, yes it would. But nobody can make a slit small enough.",
"Edit: the slit has to be comparable in size to the de broglie wavelength of the object of interest, which is teeny tiny itsy bitsy (technical term) for a tennis ball."
] | [
"A small expansion of your statement: it's not just that a particle's position and momentum can't be determined at the same time. A particle can not simultaneously have a precisely defined position and momentum."
] |
[
"What can color change tell you about the qualitative study of an equilibrium reaction?"
] | [
false
] | So we're doing a lab tomorrow and I just want to get a head start on understanding some of the questions. This is what we're doing. First off, here's the equilibrium reaction for the lab. Fe (aq) + SCN (aq) <-> FeSCN (aq) We're mixing 5.0 mL of 0.0020 mol/L KSCN solution with 5.0 mL of distilled water in a test tube. T... | [
"I have a question.",
"How come it goes to FeSCN",
" and not Fe(SCN)3 ?"
] | [
"Because it is an ion in solution. Same reason why the chlorine in salt becomes Cl",
" and not Cl2 when it is dissolved in water."
] | [
"Hmm, that's a good question. Probably has something to do with it being ionized I suppose.",
"Any idea on my question though?"
] |
[
"What is dandruff and how does it form?"
] | [
false
] | null | [
"Sebum is the oily stuff your skin releases, and more of it is released on your scalp than most other places on the body.",
"There is a fungus that every human has that feeds on sebum.",
"The dandruff comes from your body having an inflammation response to the fungus, which leads to a faster pace in skin cells ... | [
"And the solution?"
] | [
"So be bald?"
] |
[
"Why the hype about the gut microbiome?"
] | [
false
] | From what I've gathered, which is very little, there does not appear to be any intriguing findings coming out of the research. The research basically confirms what everyone already thought (which is important at some level), that being what a person eats changes the microbe population in the gut. What am I missing? Als... | [
"It has important implications for treatment. We were generally aware that the microbe population can change, but once we have a better understanding of those changes, we can start developing therapeutic recommendations to improve the microbiome. Stool transplants are one example of a therapy being developed as a r... | [
"More on treatment: C. diff is a common hospital infection that occurs after taking antibiotics. Antibiotics can wipe out some of your normal gut flora = C. diff takes over because nothing is there to compete. By understanding the gut micro biome, we can predict who is more at risk for C. diff (besides past C. d... | [
"Key points: good digestion is key to good metabolism and technology is getting affordable."
] |
[
"How does an RNA 'know' which DNA strand to copy during transcription?"
] | [
false
] | Since RNA is single stranded, and each base codon codes for an amino acid, what DNA strand is copied greatly influences the protein being formed. If both strands had the chance of being copied then you could have two proteins being coded by one gene. Proteins which could have vastly different functions. Is my understan... | [
"Just as an intro, DNA is made up of nucleotides, which in turn are made up of the nucleobases that you probably know about (A, T, G, and C in DNA). Each of these nucleosides contains a five-carbon sugar (deoxyribose, in DNA). All the sugars in DNA are put together in the same direction, so that the 5th carbon of o... | [
"Yup, it's the promotors and whatnot that trigger expression of a gene, without those (or with just the mirror image of them) the gene won't be expressed. Also remember that there are start/stop codons, and those aren't matched on the mirror image strand.",
"Interestingly, some retroviruses, like HIV, have overla... | [
"RNA doesn't know anything. ",
" ",
"RNA doesn't know anything. Genes occur on both strands of DNA in a chromosome. Transcription of DNA into RNA occurs when RNA polymerase, the enzyme that makes RNA, is recruited to the region just upstream of the beginning of a gene. Depending on the type of gene we're t... |
[
"Is there a terminal velocity to 'natural' objects in space?"
] | [
false
] | Following the on regarding the impact on Jupiter, I was wondering if there is a top speed that comets and other elements can achieve (and if there is any registered) or if there is just limited by the gravitational pull of the planets 'that goes by'. Sorry for the layman terms... | [
"Sort of, but only in the sense that nothing can go faster than the speed of light. This isn't really \"terminal velocity\" with the real definition given by the other posters."
] | [
"Just as an aside, this is known as the ",
"GZK limit",
" for single particles. Bulk matter has a considerably lower limit as you mentioned."
] | [
"There is a sort of analogue to terminal velocity here, which is that aside from the speed of light itself, which is an absolute theoretical limit, as an object gets closer to the speed of light it would start being bombarded by highly energetic blue-shifted cosmic background radiation, not to mention high-speed co... |
[
"Are there any GMOs that out compete their wild-type counterparts?"
] | [
false
] | [deleted] | [
"Mosquitos",
", which they are already talking about using in ",
"Florida",
" ",
"There are in fact tons of GMO animals, ",
"glowing fish",
", cows that produce human ",
"antibodies",
" or ",
"breast milk",
" in their milk, ",
"goats",
" that have silk in there milk. ",
"Here is a new spec... | [
"Basically: have we been able to one-up evolution?",
"I know what you are asking but make no mistake, when you express the algorithms which govern natural selection, it is a law, as immutable as the laws of thermodynamics (and really just a complicated extention of those latter laws).",
"So even in the case of ... | [
"The GM mosquitoes have been release in several countries. These buggers were designed to have non-viable offspring. Not exactly what you are asking, but it's reported that these mosquitoes were able to ",
"reduce the population of mosquitoes in the Caymans by 80%",
" so in my opinion they out performed their n... |
[
"How do the bacteria that work for human food digestion get in?"
] | [
false
] | As far as I know, its impossible for one species to spawn another, so humans, or any other animal that needs them, cant create the vital bacteria themselves. So are the bacteria injected by the mother to the fetus already pre birth? Or do the bacteria get in post birth? If so do they get in with the food we eat or cr... | [
"The bacteria are initially acquired from passage through the birth canal. After a few years, the initial microflora are replaced by microbes the child acquires from its environment through ingestion (food, dirt, contact with other humans, etc.)."
] | [
"What about children born via caesarean section? "
] | [
"There's an excellent, albeit slightly old, review here: ",
"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3110651/",
"In short, there are differences, and those may be associated with the increase of some kinds of diseases seen in non-vaginal births. (Or they may not be; it's early days yet for this research.) ... |
[
"How can a black hole be so much smaller than a neutron star? Aren't neutron stars already super dense and without orbitting electrons, so without any void between nucleons?"
] | [
false
] | null | [
"That's not... known for an astrophysical black hole. All we know is that the radius of the mass is less than the Schwarzschild radius.",
"You're assuming that there's a physical singularity at the centre of the black hole. But I think it's much more likely that GR simply breaks down and we need quantum gravity..... | [
"Neutron stars form when the energy available from gravitational collapse is greater than the energy needed to overcome electron degeneracy pressure by forming neutrons from protons and electrons.\nTheoretically a higher available gravitational energy would overcome the neutron degeneracy pressure and form an even ... | [
"From the outside, it doesn't really matter what's inside a black hole, it's cut off from the rest of the universe.",
"Note that even a neutron star is dense enough to be a black hole if it's large enough. A neutron star larger than 14 solar masses would become a black hole because it would have an event horizon ... |
[
"What natural evidence proves that living organisms can evolve from non-living matter?"
] | [
false
] | What natural evidence/occurrences proves that living organisms can evolve from non-living matter? Moreover, just because an act can be completed in a lab under perfect conditions doesn't constitute an act to be naturally able to occur. Is the latter statement also a fair argument? | [
"Not really.",
"We know that amino acids can ",
"form during electrical discharges",
". We know that amino acids can ",
"spontaneously form chains",
" - thus, we get basic proteins, no life necessary. We know that some kinds of protein encourage similar proteins to form. Thus, you get competing species of... | [
"This question has nothing to do with evolution. The transition between non-living matter and living-matter that you're referencing is abiogenesis."
] | [
"I know of a couple other papers that are worth mentioning.",
"This one",
" showed that specific RNA sequences were able to indefinitely catalyze the replication of their own sequences.",
"This one",
" (lay ",
"summary",
") showed that the replication of lipid vesicles (which spontaneously occur when de... |
[
"Why is it hard to create a cream that can change skin color?"
] | [
false
] | Between tanning and skin lightening/whitening, it's pretty obvious that a lot of people want to modify their natural skin color. Yet, despite the billions in potential revenue from the creation of a successful product, spray on tans make you look like an oompa-loompa, and skin whiteners simply don't do anything. I can ... | [
"Had vitiligo."
] | [
"Had vitiligo."
] | [
"There is some research being done in this area. I know someone who did a bit of work for a large cosmetics company, looking at tyrosinase inhibitors for use in skin whiteners. Tyrosinase is part of the pathway that produces melanin, so inhibiting it reduces melanin production, resulting in paler skin.",
"From ... |
[
"How do dogs recognize other dogs?"
] | [
false
] | It baffles me that dogs can recognize dogs they have never met before, often from a great distance (suggesting smell is not a factor), and when different dog breeds look so different from one another. I have found scientific evidence suggesting that there is some level of recognition, or at least differential interest,... | [
"This can't be right for all cases. I know dogs that look out the window and will react to every passing other dog. No way when someone opens a car and a dog gets out, that the dog locked inside the house will smell the other dog so fast. "
] | [
"I agree, and this article agrees with you: ",
"https://blogs.scientificamerican.com/dog-spies/do-dogs-know-other-dogs-are-dogs/"
] | [
"Thanks. Now as you say it. I've shown printed dog pictures to dogs and they looked more interested at it than just a random picture of a landscape. "
] |
[
"Why do our thumbs have 1 joint less than our finghers?"
] | [
false
] | null | [
"And why is it gone?"
] | [
"I'm not sure why exactly the intermediate phalanx is missing in the thumb, but I would bet it has a lot to do with the evolution of thumb opposition (the \"opposable thumb\"). There is a rare malformation called a Triphalangeal thumb where the thumb has all three phalanges, just like the other fingers, and the thu... | [
"The difference between your fingers and thumb is the lack of a fifth metacarpal bone in your thumb"
] |
[
"[Computer Science] Why does solid state memory (SSDs, Ram) come in intervals of 2^x?"
] | [
false
] | [deleted] | [
"As you probably know, modern digital computers mostly use binary. Processor instructions are provided in binary form, and numbers are represented in binary formats. And sending an address to a storage device is also done in binary. ",
"When you are going to store something in memory, you need to tell the storag... | [
"In solid state memory, there absolutely ",
" 16 storage locations which are addressed. They are physical, permanent places on the die that you can point to. If you have a very small finger and exceptionally good eyesight. It is different for disc memory, and since SSDs mimic disc to some extent, you can say tha... | [
"SSDs currently use 8 GB ",
"NAND",
" dies so their storage is limited to multiples of 8 GB. They're usually following the powers of 2 because they just double the dies per package to increase the size. Keep in mind this is arbitrary and there's a lot of drives that don't double their sizes. Using some Corsair ... |
[
"Can a single atom be magnetic?"
] | [
false
] | null | [
"Yes. A single atom can have a magnetic dipole moment."
] | [
"As long as the electron spins are aligned? "
] | [
"The magnetic moment of the entire atom is determined by the sum of the magnetic moments of the nucleus and the electron cloud."
] |
[
"is time dilation theoretically possible? if so, how? anddoes it occur anywhere we know of?"
] | [
false
] | null | [
"Time dilation is not only possible, it definitely happens.",
"https://en.wikipedia.org/wiki/Tests_of_special_relativity",
"https://en.wikipedia.org/wiki/Tests_of_general_relativity"
] | [
"could theoretically one child be 10 years old and another child be 50 years old?",
"Yes.",
"so not only are \"clocks\" moving slower, but actual physiological effects happen slower as well?",
"Yes."
] | [
"what an incredible concept"
] |
[
"Why is the HPV vaccine not recommended for people over 26 years of age?"
] | [
false
] | Also, how likely is it to be beneficial for someone who's already sexually active? I mean, how likely is it that a person who has had several partners has already come into contact with every strain that's present in the vaccine? | [
"Because you have to get the vaccine prior to exposure. Otherwise it doesn't work.",
"The hight rates of prevalence (up to 80%) means that, statically, by the time you're 26 or older it's pointless to get it. There's no actual health risk and if you've not had sex before than, yes, go out and get it.(1)",
"Sour... | [
"A lot of health policy is based on the allocation of limited health resources. ",
"Not true. Health policy is based on the allocation of limited resources, ",
"How are these different exactly?"
] | [
"Full disclosure: I am an immunologist, I work on vaccines and immunotherapies, including those for HPV.",
"The reason it is not recommended for people over 26 years of age is due to the fact that the pharma companies who make the vaccine - Merck and GSK - have not done a study that provides data to suggest effic... |
[
"How does being blind at birth affect someone's sexuality/sexual development?"
] | [
false
] | null | [
"This is a really hard question because I do not think we have adequately answered from a research perspective if sexuality is something that is coded at birth or something learned.",
"New studies show that gender forms in the mind which helps define the roles we will play in sexual relationships. However most of... | [
"I could be mistaken but a post is being \"shuffled\" around based on a few levels of activity. One of which is commenting. If a commentor adds somewhat anecdotal comments atleast that's action for the thread which gets it attention.",
"I have had a number of posts where I have done this, I have gotten negative ... | [
"I could be mistaken but a post is being \"shuffled\" around based on a few levels of activity. One of which is commenting. If a commentor adds somewhat anecdotal comments atleast that's action for the thread which gets it attention.",
"I have had a number of posts where I have done this, I have gotten negative ... |
[
"What food contains gold in it?"
] | [
false
] | [deleted] | [
"Pure gold is nonreactive and nontoxic, but has no nutritional value and is not used biologically by any known organism. It does not appear naturally in any food.",
"It is approved has a food additive, because it is decorative, and because people like to say, \"hey, I just ate some gold\"."
] | [
"anything decorated with gold leaf I guess.\nAlso not so much a food, but Schnapps Cinnamon contain Gold flakes"
] | [
"Are you asking having discovered ",
"E175",
"? I'm sure there are traces of it in many things but as an additive ",
" it's used mainly as decoration eg. in Goldschlager."
] |
[
"What is the body's physiological response to getting kicked really hard in the balls and why is it so different from being kicked anywhere else?"
] | [
false
] | [deleted] | [
"Testicles are internal visceral organs that have migrated out of the body cavity - as such, they have visceral innervation rather than somatic. Visceral innervation is known for producing intense pain when the capsules surrounding organs are stretched. Classically, issues like bowel obstructions or stones (gall-... | [
"Visceral pain is commonly associated with nausea",
", and thought to be related to autonomic activity."
] | [
"Why do I feel incredibly sick when it happens?"
] |
[
"What is the fastest moving celestial object we have found?"
] | [
false
] | null | [
"This is an extremely vague question. However, if you want to know what star in the Milky Way has the highest velocity relative to the Sun, it appears to be a star known as ",
"SDSS J090745.0+024507",
" moving away from us with a velocity of about 850 kilometers per second. Such hypervelocity stars are likely e... | [
"Faster neutron stars have been seen",
", at up to 1500 km/s. These are probably the result of asymmetric core-collapse supernovae."
] | [
"Nice, I forgot about those."
] |
[
"How come it seems that the majority of dna mutations result in cancer of some type?"
] | [
false
] | If I understand it correctly, cancer is the result of losing growth or meiosis inhibitors. This seems like a decently specific change. When you have a dna mutation, what gets messed up should be random. How come out of the trillions of potential changes that the mutation could have made, destruction of cell growth inhi... | [
"Mutations happen all the time, but they mostly will harm the cell enough for it to just die off (and you never see it). Mutations that predispose to cancer can be of various kinds. Some of them are: Mutations in genes that keep cells alive (so the cells are kept alive even if they should die), mutations in genes t... | [
"It's a kind of confirmation bias. Why are all toupees terrible? Because we only notice the terrible ones. The rest hide in plain sight.",
"We see mutations that cause cancer because the other mutations have no effect (which we don't see) or cause cell death (which we don't see, or we don't recognise as a mutatio... | [
"Only a tiny fraction of mutations lead to cancer. "
] |
[
"So how old is the water I'm drinking?"
] | [
false
] | [deleted] | [
"It really depends on your definition of old. ",
"If you take a sample of water as a sort of bulk material object, it has a history and special properties, such as dissolved minerals and pH. Those bulk properties will change a lot any time the sample environment changes, for example moving from the pipes in the g... | [
"Mods forgive me, but ",
"The Oatmeal",
" seemed extremely relevant."
] | [
"Water is a byproduct of metabolism, and hydrogen is often stripped from the oxygen to produce alcohol groups, acids, ketones, or even just adding a hydrogen to carbon and water is produced again in breaking down those molecules. I would really love if someone could calculate the turnover rate of water molecules in... |
[
"What is the temperature of a black hole and why?"
] | [
false
] | [deleted] | [
"The temperature of a black hole is inversely proportional to its mass. The numerical value for the temperature in Kelvin works out to be [(1.23 x 10",
" kg)/M] K, where M is the mass of the black hole.",
"In classical general relativity with a quantum mechanical description of other particles, black holes rad... | [
"Mini black holes have never been observed, in a particle accelerator or elsewhere.",
"But you are correct that the smaller a black hole, the higher its temperature. When a black hole reaches its final stages of evaporation, its temperature is very high and it is expected to release high energy gamma rays."
] | [
"Does this value also apply to the mini black holes created in particle accelerators? If so due to the small mass wouldn't this be an incredibly high temperature?"
] |
[
"What prevents a normal, healthy heart from going into cardiac arrest during very, very intense exercise?"
] | [
false
] | [deleted] | [
"The heart adapts to higher rates. For instance heart rate is normally controlled by the sino-atrial node by a balance of sympathetic (+) and vagal (-) inputs. But the heart also gets sympathetic inputs to other parts of the muscle which alter the action potentials and conduction (e.g. shortening it), so that the f... | [
"I'm going off of memory here, but you have to consider the fact that the heart does need time between contractions of atria and ventricles for the vessels to fill with blood. If the heart is contracting ",
" fast, there is insufficient filling time. Further, during exercise, the heart has the benefit of regular... | [
"Thanks for this. Interestingly, when I had AVNRT the doctor mentioned to me that the rates that I had were some of the fastest he had seen. 290 bpm. I can tell you, it was not fun at all."
] |
[
"A few questions about the Human Heart"
] | [
false
] | null | [
"These are fairly easy figures to research, and the project seems to be very entry level. Instead of spoon feeding some answers here are some ways to expand your search:",
"1) search for cardiac pressure-volume loop making sure to understand end diastolic and end systolic volumes for both atria and both ventricl... | [
"It seems entry level because I'm a high school student, and I didn't think to look for those kinds of things, thanks, that should help a lot."
] | [
"Of course, one of the hardest parts of any research is figuring out where to start.",
"Good luck and if anything is still confusing feel free to PM me and I will help out to the best of my capacity."
] |
[
"Are there any molecular similarities between something being 'freezer burnt' Vs. being burnt by a flame?"
] | [
false
] | null | [
"Not really.",
"\"Freezer burn\" comes about when the water in a substance freezes, but is allowed to migrate to the surface and sublimate away. It's essentially slow-motion freeze drying, and in the process wreaks a lot of physical havoc on cellular tissue. Molecularly, there's not much change - proteins remain ... | [
"As someone in the industry, is there anything you do to consider the action of freezing? For example, what is done for food that is intended to be frozen?"
] | [
"depends what you mean by molecular? On a physiological level they both cause damage by transfer of energy to/from the affected tissue. The resulting damage is due to cell and protein destruction and local/systemic inflammation. A hell of a lot of other specific stuff goes on but they're effectively two paths that ... |
[
"If you were on a train travelling at 50m/s, standing at the back, and fired a bullet travelling at 100m/s in the opposite direction, hiw fast would the bullet be travelling relative to an observer on the platform?"
] | [
false
] | null | [
"Approximately 50 m/s."
] | [
"But why? There is no force on the ball by the train..."
] | [
"Why would that matter?"
] |
[
"If I wire a capacitor in series with a battery powered motor, will the motor have a greater power output?"
] | [
false
] | I know capacitance is amount of charge per volt, and motors depend on charge. Will the force that drives the motor increase with higher capacitance? | [
"That last bit is important: batteries are DC (zero frequency) so a capacitor in series breaks the circuit: the motor would be turned off, so zero power out."
] | [
"A capacitor wired in parallel with the battery will act in the same manner as the battery, storing charge. The difference is that the energy density is lower, but the current capacity higher, so the capacitor can help to \"stiffen\" the supply voltage against transient current demands.",
"A capacitor wired in p... | [
"it helps to understand that a capacitor is simply 2 metal plates that are not touching each other. cutting a wire in half is making a capacitor. again this is for DC only, way different when were talking about AC or RF"
] |
[
"Salt vs. Health . Is there evidence or not?"
] | [
false
] | Last weeks I've been seen submissions that bash the common belief that salt consumption in excess is bad for your health. Is this true or not? | [
"Is this true or not?",
"It is complete baloney.",
"The link between salt, hypertension, and stroke is almost universally accepted in the medical community. The evidence is very strong and there is almost no controversy among experts. Note that this is on a community level; some individuals may not be sensiti... | [
"Not an expert, but I read up on this study a bit: it is controversial and contradicted by other studies. I think currently there is no good consensus, partially because these kinds of epidemiological studies are really hard to control, and no one has the ability to run a truly controlled experiment. ",
"From ",... | [
"I had read somewhere that these studies suggested that, among the people who do not suffer from hypertension and stroke, those who consumed more salt lived longer. ",
"I'm by no means an expert, so please consider this a question and not a challenge to your response."
] |
[
"Does the human body lose more fat/calories shivering from coldness or sweating from hotness?"
] | [
false
] | null | [
"It's being studied",
"http://onlinelibrary.wiley.com/doi/10.1111/j.1467-789X.2010.00851.x/abstract",
"Meanwhile, recent studies of the role of brown adipose tissue (BAT) in human thermogenesis suggest that increased time spent in conditions of thermal comfort can lead to a loss of BAT and reduced thermogenic c... | [
"Yes. Shivering is the body activating the skeletal muscles to generate heat from their inefficiencies. Sweating is the release of moisture from the pores, and while this is not a zero energy action, it would be much less than shivering."
] | [
"Yes. Shivering is the body activating the skeletal muscles to generate heat from their inefficiencies. Sweating is the release of moisture from the pores, and while this is not a zero energy action, it would be much less than shivering."
] |
[
"What if the Golbach conjecture get verified ?"
] | [
false
] | Any odd number superior than three can be written as a sum of two prime numbers What would be its implications -in mathematics ? EDIT attempt : I am in the app, it's Goldbach. | [
"Not really too many direct consequences, it's not like the Riemann Hypothesis or anything. However, the methods to prove it are likely to be novel and interesting and can perhaps provide us with a new way to look at other problems."
] | [
"OP stated it wrong, it's \"every even integer number greater than 2 is expressible as the sum of 2 primes\". The odd version states \"every odd integer greater than 3 is expressible as the sum of (at most) 3 primes\" which in the case of 23 has a few solutions ",
"(I forgot to say that the Odd Goldbach Conjectur... | [
"It should be every ",
" number larger than 2 can be written as a sum of two primes."
] |
[
"When sp hybridization what benefits does Raman spectroscopy provide over IR spec? (grad student in chem)"
] | [
false
] | null | [
"A good home for this question is ",
"/r/AskScienceDiscussion",
".",
"Please see our ",
"FAQ."
] | [
"I read the FAQ why is this question a bad fit for askscience?"
] | [
"The question is mostly an open discussion on research techniques/technologies. It is also bordering on homework help. If you can be a bit more specific in explaining your question, focusing on the theory and specific details of the techniques so others can benefit from this discussion, then I will let it through."... |
[
"What would it take to put a country like USA or Canada in as severe an economic collapse as Zimbabwe around 2008?"
] | [
false
] | null | [
"It happened to Rome in a pretty big way when they were still the top dog of the world. Of course this was like 1700 years ago and the idea of inflation hadn't really occurred to anyone yet. It got bad enough that the armies wouldn't accept the worthless currency and the empire started paying them with the goods th... | [
"So in other words, what you would need to turn the US into an African country is a total erosion of our existing laws, business morays, and sensibilities.",
"Just for future reference, morays are eels - mores are customs.",
"I very much like the idea of a business moray, but I'm not sure if they make suits to ... | [
"So in other words, what you would need to turn the US into an African country is a total erosion of our existing laws, business morays, and sensibilities.",
"Just for future reference, morays are eels - mores are customs.",
"I very much like the idea of a business moray, but I'm not sure if they make suits to ... |
[
"If space based telescopes cant see planets how will the earth based European Extremely Large Telescope do it?"
] | [
false
] | I thought hubble was orders of magnitude better because our atmosphere gets in the way when looking at those kinds of resolutions. Would the same technology work much better in space? | [
"By being much much bigger. The big advantage of space telescopes is no atmosphere, meaning no seeing (the twinkling of stars) and no atmospheric absorption of light. The big disadvantage is price and size - it is extremely expensive to launch a space telescope, they can only be a few meters across.",
"Land based... | [
"Normally the sharpness of a picture is limited by the diameter of the mirror. Get a bigger mirror and you can make sharper images. The 8.2 meter mirrors in the VLT are about the biggest we can make with current materials.",
"Another way to increase sharpness is to compensate for deformation of the mirrors. These... | [
"There are some wavelengths of light that our atmosphere completely blocks.",
" To see light in these regions of the spectrum, our only option is to go to space."
] |
[
"Why can't we make an influenza vaccine that covers all possibilities?"
] | [
false
] | So in a class I am currently taking, my group members and I are researching the influenza virus. I learned about how hemagglutanin and neurominadase have 16 and 9 subtypes, respectively. With this we can name strains such as H1N1 (hemagglutanin subtype 1 & neurominadase subtype 1). I also learned how two different stra... | [
"You answered your first question with your second. The problem with flu vaccines isn't the multiple strain possibilities, it's the fact that individual strains aren't even covered by the same vaccine.",
"(By the way, your strain count is outdated. There are now 18 HA and 11 NA subtypes, counting the new bat st... | [
"Wow thank you so much for the detailed response! And thanks for the update/correction. So basically HA and NA subtypes don't mean that they are the same. So a subtype has similar structure but it can also have variation. Before I was under the impression that a subtype was the smallest unit to be mutated."
] | [
"Yeah, the small point mutations in HA (and to some extent NA) are the most important for ongoing changes in the vaccine. Occasionally new subtypes can enter the human population (such as in 1968, when an avian H3 strain recombined with the human H2N2 to make H3N2) and that can sweep the population as a pandemic a... |
[
"What happens to a body builder's muscles if he suddenly stops exercising?"
] | [
false
] | null | [
"As others have said, the muscles will atrophy. The SAID principle states that your body will adapt to the demands placed on it. For a body builder, that is the heavy weight lifting. If the person stops this, then the body will also adapt the other way, recycling the muscles so to speak for other things the body fe... | [
"They would stop gaining muscle. If the imbalance were bad enough, then the body could, in theory, use protein from elsewhere. For example, Bro only lifts upper body, but tries to avoid eating protein. If this imbalance got bad enough, Bro would begin losing muscle mass in their legs to compensate. ",
"Side note:... | [
"What about the opposite: if they stopped eating as much but continued trying to gain muscle, would their muscles still atrophy to be used for energy?"
] |
[
"What kind of MPG would a human get?"
] | [
false
] | null | [
"A lot.",
"One gallon of gasoline has 114,000 BTUs of energy, or 29,000 kcalories. So 1/10th of a gallon of gasoline would provide 2900 kcals, which is about the daily needs of a young reasonably-active male.",
"Now, drinking gasoline for your caloric needs will probably kill you ",
" ",
" But as many gradu... | [
"I jumped the gun and drank quite a bit of ethanol before I read your last reccomendation. What do I do now?"
] | [
"Quick! Drink a bit more so you have more energy and then run a marathon. That will use up all the ethanol energy so it won't kill you, also if you don't have enough energy the marathon will kill you.",
"Good luck!"
] |
[
"When a neuron dies, do its neighbors form new connections?"
] | [
false
] | I apologize if my understanding of neurons is wrong and makes this question moot. What happens to the neurons that receive information from the now dead neuron - do they realize it's dead or do they just process the signal from the dead neuron as a 0, off, no, etc.? | [
"It depends on how the neuron died.",
"Neurons can die naturally in a process called apoptosis, critical in child brain development. In apoptosis a neuron will shrivel up, die, and glial cells will discard it. The neighboring neuron that it was connected too will simply no longer receive a (typically inhibitory... | [
"I don't know if there is anything like spreading necrosis? Death from necrosis often causes neighboring neurons to go through apoptosis which is typically harmless to surrounding neurons.",
"Toxins and viruses can spread down a chain of connected neurons causing death in each one. Seizures can also spread very... | [
"Could toxic necrosis almost start a chain effect of the death of neurons? The death of one impacts another severely and in doing so that one effects another, etc? I realize the number of neurons in the brain, but how would something like this be stopped or eradicated?"
] |
[
"TIL there were 30,000 eletric cars running in the beginning of the 20th century. How were their lead-acid batteries charged?"
] | [
false
] | null | [
"Before widespread electrical grids, generators were used. Once available, they were charged from the grid, just like today.",
"Not all were powered with lead acid. Some of them were using nickle iron batteries. Our local electric vehicle association has a ",
"Detroit Electric",
"\"The front and rear compartm... | [
"It wasn't all that expensive as compared to the car. In the early 1900s, electricity was ~20 cents per kilowatt-hour - somewhat pricey by today's standards, especially adjusted for inflation - but nowhere near the ~$2,000 that purchasing an average electric car seems to have cost, based on what numbers I can find.... | [
"While electricity in one's own home was a bit of a luxury circa 1900, individuals wealthy enough to purchase an electric car either had home power or were within driving distance of a place where the cars could be charged."
] |
[
"If the human body relies on electricity in order to function, is there a possiblity of there ever being a short circuit?"
] | [
false
] | Where is the power source for the electricity? Is is the brain? Is it the cells themselves, do they act like countless little batteries connected in parallel? | [
"Per Wikipedia: ",
"A short circuit...is an electrical circuit that allows a current to travel along an unintended path, often where essentially no (or a very low) electrical impedance is encountered.",
"As other users have pointed out, the body does not use the same mechanisms to create a current that electron... | [
"Lovely answer. I'll add two more things: The power source, specifically, is the sodium-potassium pumps that are responsible for generating the resting (default) membrane potential. And the pumps are powered by ATP molecules, which are produced by the mitochondria via cellular respiration, which is essentially a co... | [
"Actually, there is at least one medical condition that does meet the definition of a short circuit: Wolf-Parkinson-White. It's the result of the derangement of the normal electrophysiology of the heart.",
"Normally in the electrical depolarization of the heart, an electrical impulse is generated in the sinoatri... |
[
"What are the string-like structures on the iris?"
] | [
false
] | Seen here is an eye with a blue iris, but what are those string-like structures in the iris, that surround the pupil? | [
"They are the parts (named below) within the Iris Dilator Muscle which are what physically contract to change the size of the pupil. ",
"\"The pupillary dilator consists of a spokelike arrangement of modified contractile cells called myoepithelial cells.\"",
"FROM: ",
"http://en.wikipedia.org/wiki/Dilator_pup... | [
"This is known as the ciliary body. It is a ring-shaped structure with ridges called ciliary processes that surround the lens. The lens is suspended from the ciliary processes by zonular fibers that extend between these structures. The ciliary body is associated with the ciliary muscle. The ciliary muscle's functi... | [
"Though you are correct about function of the ciliary body, it is not visible from the front of the eye - it is positioned behind the iris, as is the lens. OP is asking about the fibers visible as a part of the iris itself, which I would agree are the fibers of the dilator pupillae muscle, which are arranged in a r... |
[
"Would car brakes work on a frictionless road?"
] | [
false
] | null | [
"Car tires would not work on a frictionless road."
] | [
"but you could still get a car moving with other means, could you not?"
] | [
"It would be more like a sled than a car, I think, and you would have to introduce friction to slow or stop it. "
] |
[
"Are the laws of the universe assumed to be constant? If so how, why?"
] | [
false
] | The question is posed at 7:00 in the following video: Would someone care to elaborate on this? I'd be interested to hear a rebuttal of the entire thing, but I'm primarily curious about this specific question. EDIT: I'd like to thank everyone for contributing to this discussion. | [
"Not ",
", no. All scientific theories are based on empirical observations. The basic function of science is to propose and test hypotheses that help us to understand and predict the behavior of the world around us. More parsimonious hypotheses are favored -- if you can explain something simply, then there is no ... | [
"I can't address the questions about physical constants, but I can address a few of the many unfounded claims made by Mr. Sheldrake. In particular, he makes a great argument to ignorance about developmental biology, saying that we simply don't understand how it functions, and therefore his idea notion of morphic re... | [
"\"In an evolutionary universe, why shouldn't the laws themselves evolve?\"",
"Wow, face-palmed on the first sentence. The laws of nature are what allow evolution to occur in physical structures. The idea that this somehow entails that the laws themselves are variable, let alone subject to a form of evolution, ... |
[
"Quantum Physics, Mechanics, Etc. Any Books?"
] | [
false
] | null | [
"We have a book list in the sidebar."
] | [
"I will start on the basics of the quantum physics so thank you for that but could you also direct me to something that specifically goes over virtual particles?"
] | [
"This sub doesn't do book suggestion posts. Maybe try ",
"/r/askphysics",
", ",
"/r/physicshelp",
", ",
"/r/physics",
", or ",
"/r/suggestmeabook"
] |
[
"How exactly are quantum tunneling and nuclear fusion related?"
] | [
false
] | I was taught that quantum tunneling is necessary for nuclear fusion to happen but I am unsure how that exactly happens. | [
"Tunneling is essential to fusion in the sun. If you were to ignore quantum effects and just consider the amount of energy it would take to bring two protons together against their electrostatic repulsion, you'd find that this energy (called the \"Coulomb barrier\") is ",
" than the average kinetic energy of prot... | [
"I found a good answer to that: ",
"http://astronomy.stackexchange.com/questions/14018/what-would-the-sun-be-like-if-nuclear-reactions-could-not-proceed-via-quantum-tu",
"...and the explanation continues from there. It's very interesting, and includes some good discussion as well. "
] | [
"If we \"turn off\" quantum tunneling again, wouldnt a star like our sun just compress itself further untill the coulomb barrier gets reached with the increasing temperature?",
"Or would it become a neutron star or something before that?"
] |
[
"Does a strong immune system lower one’s risk of cancer?"
] | [
false
] | Trust me I am aware that cancer comes from our cells and is not some infection, but the immune system is made up of cells as well. | [
"Our immune system does prevent cancer all the time. As cells become cancerous, they express certain molecules that are not normally present in healthy cells. Immune cells recognize that and get rid of those problematic cells before they grow into a tumor. Well, most of the time anyway. ",
"I've not encountered a... | [
"There are loads of cancer immunotherapies other than CAR T cells that utilize the immune system to fight cancer."
] | [
"Yes you're right. I thought of CAR-T cell therapy as a good example because that is the first time that we engineered T cells to directly recognize cancer cells. Other immunotherapies up to that point have been by way of preventing the inactivation of T cells (i.e. inhibiting CTLA4, PD-1, or PD-L1)."
] |
[
"If I'm alone in a remote battlefield (or whatever) with an open wound, do I stand a better chance at avoiding infection by introducing maggots?"
] | [
false
] | Here's what I'm talking about: . I mean, I understand that disinfection is an intelligent precaution in a medical environment, but the breakthrough came from WW2 battlefields. Those soldiers got the all-natural cure, and turned out pretty well. | [
"non-expert here.",
"For the effort you would need to keep maggots that are not contaminated, you could instead keep rubbing alcohol.",
"Maggots are typically used to clean off dead tissue, not disinfect open wounds."
] | [
"Maggots are typically used to clean off dead tissue, not disinfect open wounds.",
"Good clarification."
] | [
"Yes, as put before. Maggots only eat dead tissue, and are good for removing it from a wound, but shouldn't have an effect on the infection, and if anything, could make it worse, if they wern't sterile before entering the wound."
] |
[
"If one cat sees and hears another cat purring, does it understand or interpret the purring cat as being happy?"
] | [
false
] | null | [
"They also purr under heavy stress (such as severe pain), but it's a different, coarser kind of purr. Some theories say this is intended to be a self-calming mechanism."
] | [
"We're not sure why cats purr, but one of the theories is that it's used as a way for nursing females to communicate with their kittens - this could also be interpreted as a cat saying the he or she is not a threat to other cats. "
] | [
"Cats also purr when they are engaging in a fight with another cat. This may be relevant. I don't have any answers, though."
] |
[
"How does an equalizer work?"
] | [
false
] | Specifically, how does it affect the volume of only specific frequency range(s) and is this mechanism significantly different for the different types of EQ? Assume a fairly basic understanding of sound and electronics. | [
"An equalizer can be implemented in digital or in analog circuitry, but the basic concepts are similar. Divide the spectrum into different bands, and for each band have a band-pass filter. Send the sound through all of the filters in parallel, and each band-pass filter will output only the sound within its band, c... | [
"In an analog filter, you use different values for the inductors and capacitors (and resistors). Inductors and capacitors respond differently to changes in current/voltage, and that allows you to make circuits that will resonate only at certain frequencies. You can arrange things to either pass those frequencies th... | [
"OK that makes sense, but how are the frequency ranges isolated? What is the mechanism that achieves this?"
] |
[
"Could Earth capture new asteroids into its orbit? If so what would happen?"
] | [
false
] | The moon currently orbits the Earth and Mars is surrounded by Deimos and Phobos. Is it possible for any near flying asteroid to be captured as well? Is the earths gravitational pull strong enough to hold them? I know size plays a role as smaller asteroids would be pulled through the atmosphere and destroyed, larger sim... | [
"I highly recommend playing with ",
"this gravity simulator",
".",
"If you assume just two bodies (the earth and the incoming asteroid), then capturing is not possible. The incoming body may come close to earth, but it will be moving too fast to be captured. It may just sail by with a slight bend, or it may... | [
"It's just the way that things happened. For a planet our size, existing in a mature star system such as ours, ending up with 0, 1, or 2 moons is the most likely outcome. Venus, for example, has 0.",
"Since our first moon is so large, the chance of having another decently sized moon (even 1/1000th the size of t... | [
"If you have RES, you should be able to ",
"save comments for later",
". ",
"Even without RES, you should be able to save the whole article, and then find the comment later."
] |
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