title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"How do strong nuclear forces create mass?"
] | [
false
] | I came across the sentence, "Most of the mass of a common proton or neutron is the result of the ; the individual quarks provide only about 1% of the mass of a proton." in the But it also says that they're caused by Gluons which have no mass. I thought conservation laws meant that mass couldn't be created or destroyed... | [
"Gluons are a very special case, because they carry color charge, and QCD is non-perturbative/confined at low energies. QCD is a lot like QED, except for those two important points. But you have no problem thinking of situations with real photons. You can distinguish in your mind a real photon from a virtual photon... | [
"I mean, what's inside, then?",
"You might be interested in this enlightening article from Matt Strassler",
"https://profmattstrassler.com/articles-and-posts/particle-physics-basics/the-structure-of-matter/protons-and-neutrons/"
] | [
"The gluons being referred to here are virtual particles. There are no literal gluons inside of a proton/neutron.",
"But anyway, kinetic and potential energies contribute to the masses of physical systems. The kinetic and potential energies of the interactions between the quarks in the proton/neutron contribute t... |
[
"Why do dogs lick our faces, but not each others?"
] | [
false
] | I know they have a second olfactory gland in their mouth. Do they get the best scent out of us by licking our face as opposed to smelling another dogs bum? | [
"http://en.wikipedia.org/wiki/Dog_communication#Tongue_.28Licking.29",
"\nTongue (Licking)",
"A very common form of communication is for a dog to lick another dog, or a person. Dogs lick other dogs' faces and mouths when they greet each other to indicate friendliness. Dogs like to lick human skin not only for t... | [
"Just a heads up, but this subreddit is pretty unique and has some special rules about posting. Look over to your right to learn more. Posting anecdotes or unsourced claims are not typically allowed, and the rules are more stringently applied for top level replies such as yours. "
] | [
"Just a heads up, but this subreddit is pretty unique and has some special rules about posting. Look over to your right to learn more. Posting anecdotes or unsourced claims are not typically allowed, and the rules are more stringently applied for top level replies such as yours. "
] |
[
"When we look at a picture of the surface of the sun, how much of that represents actual fusion, and how much is merely \"hot gas\"?"
] | [
false
] | null | [
"On the surface it's all hot gas and plasma."
] | [
"Most of the fusion is deep in the core. To sustain thermonuclear reactions like fusion, you have to have a combination of high density and high temperature. The center of the Sun has a density similar to that of solid rock, and a temperature of millions of degrees K (the surface is pretty cool at only 6,000K -- ... | [
"Fusion reactions occur in the central regions, where pressure and density are highest. Heat produced in the core, where temperature reaches in the millions of degrees, is transported to the surface by radiation and convection currents. What you see is plasma glowing from heat produced hundreds of thousands of kilo... |
[
"What happens when a hypothetical black hole would exist that's so big that metric expansion becomes noticeable across it's diameter? Would this affect its Schwarzschild radius? It's temperature? Anything else?"
] | [
false
] | null | [
"i can't tell you anything specific about it, maybe someone else can expand or correct me, but it seems to me what you are looking for is something like the ",
"https://en.wikipedia.org/wiki/De_Sitter%E2%80%93Schwarzschild_metric",
"which describes a black hole in expanding space (cosmological constant). maybe ... | [
"you're right about the pure schwarzschild metric. this is about the ",
" schwarzschild metric though",
"de Sitter space is the simplest solution of Einstein's equation with a positive cosmological constant. It is spherically symmetric and it has a cosmological horizon surrounding any observer, and describes an... | [
"which describes a black hole in expanding space (cosmological constant)",
"It does not. The Schwarzschild metric is a ",
" solution of the Einstein equations."
] |
[
"Why do birds have white feces?"
] | [
false
] | Title | [
"Basically this comes down to the fact that birds (and reptiles) don't urinate (there are some rare ones which do but it is not common at all). All animals have to deal with the nitrogenous (containing nitrogen atoms) waste products of protein metabolism. You eat food, you make proteins and then you breakdown those... | [
"Your kidneys can very efficiently get rid of all other water soluble waste from your blood simultaneously as they filter out urine, which is a huge benefit. ",
"And urea is biochemically simple to generate (the urea cycle) greatly streamlining protein breakdown. And urea, as it is water soluble, can be directl... | [
"Also uric acid is much less toxic than ammonia or urea, which comes into play as birds spend time in an impermeable shell"
] |
[
"Are smoke and ash composed of the same chemicals?"
] | [
false
] | Are the chemicals in ash and smoke the same, and are they present in the same ratio? By "smoke" I'm referring to the particulates, not any gases. If the answer depends on the material being burned, answer for cigarettes. | [
"Typically ash contains the unburnt elements, with ",
"wood ash",
" this is mostly potassium, calcium, sulphur and iron sometimes.",
"Smoke on the other hand when it is visible is mainly water vapor, and partially burnt hydrocarbons. In a well controlled fire, it should be nearly clear until the water vapor c... | [
"Interesting. What happens to nitrogen when proteins burn? Is it released as N2? In my ignorance I always thought ashes were nitrogen compounds.",
"edit: reworded to avoid ambiguity"
] | [
"Depending on the flame temperature you can get various NOx released, even when burning pure methane. I'd assume that at a high enough flame temperature to breakdown the proteins would leave the nitrogen free to form nitric oxides in the same way.",
"NOx on Wikipedia",
"Although the complete mechanism is not fu... |
[
"Can we transfer information through UV, Xray, and Gamma waves?"
] | [
false
] | In class, we are currently learning about the physics of energy - Our definition for a wave is 'an oscillation/vibration that transfers energy/information through the medium in which it travels.' so is it possible to transfer information through UV, Xray, and Gamma waves? | [
"You could, but those frequencies are not as good as radio for data transmission as they are readily absorbed by solids or air. Also, they all give you cancer.",
"They're good for imaging though. Near-UV photography is a thing, in fact a very interesting thing. X-rays are obvious. Also, there's UV astronomy, X-r... | [
"Higher frequencies give you faster maximum bitrates. The faster you can vary the signal the more bits you can send. ",
"So why aren't we using gamma ray routers? For one, we don't need to. You can send ",
"stupid amounts of data",
" through fiber optic cable without bottlenecking on bitrate. Visible light ha... | [
"Oh yeah! I forgot about optic fiber! I was concentrated on wireless."
] |
[
"Is space infinite because it's round/a sphere?"
] | [
false
] | null | [
"Well, yes, you've definitely got some misconceptions there. Our ",
"Milky Way galaxy",
" is most definitely NOT infinite. It is a bit over 100,000 light years across and has hundreds of billions of stars. These are large numbers, maybe incomprehensibly huge... But if you can put a number to it, then it might a... | [
"Because of expansion and the finite speed of light, the parts of the universe that we can see are limited",
"Could you elaborate on this? How exactly is lights speed finite? I don't understand how it relates to how far we can see in the universe. "
] | [
"It is a fundamental truth about the universe that anything which lacks mass will travel at 299,792,458 meters per second. This has been confirmed by both experiment and through ",
"derivations",
" starting from Maxwell's equations.",
"If you have a light that you can turn on with a remote control, it may see... |
[
"Is Recycling spent nuclear fuel the ultimate solution for the US?"
] | [
false
] | This link explores some of the issues. What are the risks? | [
"This comment is not entirely accurate. All isotopes of both uranium and plutonium are fissionable, that is, they are capable of undergoing fission following a neutron absorption. Not all fissionable isotopes are fissile however.",
"A fissile isotope is capable of supporting a chain reaction. Not all isotopes ... | [
"Liquid Fluoride Thorium Reactors can \"burn-up\" both Uranium and Plutonium into \"safe\" nuclear remnants. They are the best answer to fix our nuclear crap-pile and also the energy needs of the future."
] | [
"This makes me so happy to hear that at least someone in the US is considering Molten Salts again.",
"Please tell me they are intending to use Thorium as a potential fuel source?"
] |
[
"Why does air feel cooler when it blows past you, like from a fan? The air is the same temperature."
] | [
false
] | Thought of this last night, as I sat near a fan. Thanks in advance. | [
"Because it increases the rate of heat transfer. If the air is cooler than your body temperature, increasing the air flow will cool you down faster. If the air is hotter than your body temperature, increasing the air flow will heat you up faster. To gain an intuition, think of the extreme case of absolutely still a... | [
"Exactly. Body temp is around 36°C, room temp is like 22°C. So the layer of air around you will gradually connect these two temperatures. If you blow it away, you get contact with 22°C air and you feel colder. Also hair helps keeping warmer air close to your body."
] | [
"Your skin does not really feel temperature. It feels heat gain or heat loss. When the air is cold you lose more heat, and you think \"it is cold\". When the air is really hot, or sunlight is strong, or you touch something very high temperature, you gain heat and think \"it is hot\".",
"Your skin is usually about... |
[
"How does the flu actually kill people?"
] | [
false
] | null | [
"They are often at risk populations like the elderly, children, or immune-compromised. What typically kills them isn't \"flu\" exactly but that it causes potentially fatal situations such as pneumonia, sepsis, electrolyte imbalances triggering arrythmias or seizures, worsening existing health problems such as COPD,... | [
"Influenza infections can kill directly, or through various stages of indirect effects.",
"Influenza infection can cause pneumonia (damage to the lungs) directly. Most normal human influenza virus infections mainly infect cells of the upper respiratory system (the trachea and upward), but sometimes the virus will... | [
"One of the common causes of death is not the flu itself, but a secondary bacterial infection causing pneumonia. The influenza virus will cause damage in the respiratory tract, setting up a good environment for bacteria to grow. ",
"However, the flu can kill people all on its own. You can get rapid and severe pul... |
[
"How and why are complex numbers used when calculating things like impedance and power in an AC circuit?"
] | [
false
] | To expand slightly: Why is a complex number needed to represent impedance, admittance, etc.? What kind of influence does the imaginary part of Z=R+jX or Y=G+jB have in practice? How do complex numbers describe the real, actual values, can they be measured? Why does the impedance of inductors and capacitors have only th... | [
"Short(ish) answer, you can generalise the Ohm law (V = R * I) by replacing the resistance R with the complex impedance Z, writing V = Z * I.",
"In the case of AC signals, both the voltage V and the current I can be represented by sinusoidal functions that have the same frequencies but different amplitudes and ph... | [
"The apparent power S is the combination of the true power P and the reactive power Q. When powering a load whose impedance is Z = R + jX, only the resistive part will participate in power dissipation, the reactive part will reflect a fraction of the power back to the source.",
"Take the example of a device (load... | [
"Thank you for answering a bit more in-depth to my questions!",
"To follow up with a short question in regards to power; if the real power P is the amount of electric energy dissipated as heat and the reactive power Q is the amount that returns to the source, what does apparent power S represent?"
] |
[
"What are some interesting topics for infectious diseases?"
] | [
false
] | null | [
"My best friend is doing his Masters of Infectious Diseases currently. I can ask him when I get to the computer. ",
"I do know that he has done his thesis on a few strains of a local disease. I dont know what it was called, as I only proofread his thesis and don't fully understand all of the terminology. It's not... | [
"Histoplasmosis",
"The life cycle is the cool part.",
"Just a taste: Just about any mammal that has lived in the US Mississippi River Valley area for an extended period of time (months to years) has inhaled the spores of this fungus, and have a deposit currently sitting somewhere in their lungs. If that spore e... | [
"Four words: ",
"mathematical modeling of zombies",
". ",
"Warning: link is a PDF (some folks seem to get bugged about that)."
] |
[
"Does geology play a part in showing the average temperature of the Earth in a certain time period, like the chemical makeup of the rocks? Or is there more to it in determining geologically what the climate was like in the past?"
] | [
false
] | Had someone mention in another thread that we have historical data on temperatures obtained by geology studies that shows the climate currently doesn't match with the general trend we'd expect to be naturally occurring, so I'm curious as to if there's something geologically that shows the Earth's average climate in com... | [
"The rocks generally just offer insights to the climate of the time. Showing us if it was deep sea, continental shelf, delta, beach, grassland, moorland, mountainous, jungle, forest etc",
"Fossil evidence can show the cycles of population booms and falls over millions of years, pointing to ecological instability ... | [
"There's a few ways of determining temperature in the geologic past. ",
"The most common is something called δ18O, which involved looking at the ratio of light to heavy isotopes of oxygen in carbonate. The broad description of how it works is that in warmer climates the ocean contains less light isotopes of oxyge... | [
"Just wanna say: you can also say a lot about the temperature from oxygen isotope ratios, but a reply to a comment isn't the place to explain differential sequestration of heavy isotopes which correlates strongly with temperature and other useful climate data.",
"Basically, the oxygen bound by some processes does... |
[
"At what point do we call a data set Qualitative?"
] | [
false
] | null | [
"Your example of color is spot on, but it fails to demonstrate why qualitative data might be preferable to quantitative for certain research questions. ",
"What most of what people call \"qualitative\" differences are really differences that come about because of vast complexity. Groups of people form based on di... | [
"A good example of a truly qualitative data set is one that uses focus groups or semi-structured interviews with participants. These are sometimes used in the social sciences. They are typically used to explore an issue beginning from a participants point of view. So instead of the researcher making assumptions ab... | [
"Color is actually less quantitative than you may think due to the way your eye works. Consider: you can achieve \"yellow\" either by using something like 440 nm sodium light, or by mixing green and red in appropriate quantities. ",
"Which one is \"true\" yellow? Your eye cannot necessarily distinguish it because... |
[
"What exactly does \"relative to C-12\" mean? A question regarding atomic weight."
] | [
false
] | So I'm trying to understand the definition of atomic weight (? a bit confused with the names as well). Here's what I understand so far: - masses of atoms are cumbersome to express in kilograms, so scientists came up with a more simplified way of expressing them: - by using the stable and abundant C-12 isotope, containi... | [
"So what's the mass of a CO2 molecule?",
"12 u + 2*16 u = 44 u, easy.",
"12*1.66 yg + 2*16*1.66 yg = let me get my calculator. Sure, 1.66 =~ 5/3, and 44/3 is about 15, so the result will be somewhere around 74, but what's the point of this extra effort for nothing?"
] | [
"You can just express everything in kilogram, but it's awkward. Atom masses have ratios that are close to integers. If you don't need a high precision it's perfectly fine to treat a nucleus with x nucleons as having a mass of x u.",
"It's not exact because there is the binding energy, and based on the mass/energy... | [
"That's still awkward because you have this factor of 1.66 everywhere."
] |
[
"If we think in our own voices, how do we sometimes read things in other people's voices?"
] | [
false
] | null | [
"Our neocortices are believed by many neuroscientists to extract statistical regularities of our environment. Speech patterns are a part of this regularity. Our ability to reconstruct patterns, such as those of speech, internally is likely due to a mechanism that allows us to predict what is going to occur around u... | [
"wow, very informational. it all makes sense now. thank you!(:"
] | [
"Wow I watched a video of people with heavy indian accents and at the start I barely understood but then I started easily understanding them, this is why! Thanks"
] |
[
"What is a practical way to form a moderate acidic solution using strong acids?"
] | [
false
] | null | [
"Just do successive dilutions. Take 1ml of your concentrated acid into 999ml DI water to make solution X (you should have instruments precise to 0.1ml at least). Repeat the same procedure on solution X to make solution Y. Y is already a million times less concentrated than your stock acid. Titrate your Y against a ... | [
"take 1ml of your very strong acid and put into 999ml (that's manageable I hope) water. now you have 1L of acid 1/1000 original concentration.",
"Then take 1ml from this 1L and put into FRESH 999ml of water. Now you have 1L of acid 1/1000000 original concentration. Hope that helps.",
"You only need 2L of water ... | [
"I'm not sure how strong your acid is, but you should probably consider diluting the acid with distilled water to a more appropriate molarity. I had a similar problem while acidifying samples for my research dissertation - the lab only had ~37M H2SO4 in stock which would have been impractical to use, i subsequently... |
[
"Why does the sound of water filling change while the bottle is filling up?"
] | [
false
] | null | [
"What you hear is air resonating in the cavity between the top of the water and the top of the bottle. The frequency of this resonance depends inversely on the height of the cavity (you can imagine one wavelength fitting between the water and the top, and that wavelength getting smaller as more water is added). So ... | [
"This is a similar question why does a small hand drum sound different from a massive 6ft bass drum: the resonating cavities are different sizes and shapes. ",
"Sound is a pressure wave, and that pressure wave is created by air particles bouncing off the bottle and each other. As those change, so does the resulti... | [
"The best analogy I can think of is a slide trombone. ",
"When the trombonist buzzes his lips in the mouthpiece,it generates sound waves inside the tube of the instrument. This causes the column of air inside the t-bone to resonate at certain wavelengths in the same way a guitar string will vibrate. This is able... |
[
"Doesn't the burning of fossil fuels actually return elements to the atmosphere that were there originally?"
] | [
false
] | I was wondering about this today. Fossil fuels are made of carbon and hydrogen which is locked inside the Earth. This carbon and hydrogen was pulled out of the atmosphere by plants during photosynthesis. I understand that we're doing it at an extremely fast pace, but aren't we really returning these elements to t... | [
"Coal and oil were generally laid down well before the dinosaurs. The Carboniferous period was like 360-300 Million years ago. The earliest dinosaurs show up in the Triassic, around 250-200 Million years ago.",
"Anyways, yes it is true that the carbon in coal and oil was once absorbed from the atmosphere and trap... | [
"As I reread this is seems poorly written and with a low quality analogy. Instead try this unprofessional ",
"mspaint",
" drawing."
] | [
"Valid points, but some caveats we must think of:\n1. Its possible that fossil fuels have attained some sort of equillibrium levels over the eons. This would not be the case if becoming a fossil fuel was a one-way trip. Some geologists here?",
"We do not know (or I do not know) if during the time of Dinosaurs the... |
[
"Why are papercuts so painful?"
] | [
false
] | [deleted] | [
"Paper cuts are superficial injuries (they don't go very deep into the skin) and thus don't cause much nerve damage. A sharp knife, on the other hand, can cut deep enough to sever or damage the underlying nerves."
] | [
"TIL being cut with paper hurts more than being cut with a knife."
] | [
"I always figured paper cuts hurt worse than deeper or more serious injuries because there is less nerve damage with such a shallow cut. Also, there are a whole fucking lot of nerve endings on one's fingertips, which is where most of them happen. A paper cut on the arm, say, would also likely sting, but not as badl... |
[
"What is it about catnip?"
] | [
false
] | [deleted] | [
"wiki",
"The nepetalactone in catnip acts as a feline attractant. This chemical enters the feline's nose.[15] Cats detect it through their olfactory epithelium, not through their vomeronasal organ.[16] At the olfactory epithelium, the nepetalactone binds to one or more olfactory receptors. "
] | [
"Not all cats are affected by catnip.[12] Roughly half to two thirds of cats are affected by the plant.[17][18] The phenomenon is hereditary.[12]",
"That is also from the wiki. From that, I would infer that it is a genetic factor, and some cats carry the genetic information necessary to produce such a receptor, ... | [
"Interesting! ",
"Would you happen to be able to find why nepetalactone attracts only cats and not humans or even dogs or other animals who have a strong sense of smell?"
] |
[
"When/How did Earth get water?"
] | [
false
] | From my understanding of the history of the Earth, it started out as just a big rock covered in lava (magma?) some-billion years ago. And then, a few billion years later, it had some water, which then held life. Now, where the life came from is a question for another time. But, where did the water come from? | [
"There are two main possibilities for the origin of water on Earth: an extraplanetary source - comets, meteorites etc, and an internal source - water contained in the structure of minerals in the mantle. The main problem that has to be dealth with by both is of volume, and of reconciling the geochemical signatures ... | [
"Earths hydrosphere, along with it's atmosphere, came from gasses being released by the lava left over after volcanic eruptions. When earth was forming into the massive sphere that it is, it trapped many different elements inside itself. Star dust coalesced into an object with enough mass to develop a strong attrac... | [
"Actually, the Earth is 4.5 billion years old, and scientists suspect that there was a solid crust (because we have evidence of liquid water) when the Earth was only 120-200 million years old."
] |
[
"Why is there dangerous radioactive waste left over from nuclear reactors?"
] | [
false
] | If the waste that comes out of a nuclear plant is still dangerously radioactive, why can't we keep using it to provide energy until it's no longer significantly radioactive? | [
"It no longer becomes energy profitable to keep \"burning\" those very radioactive nuclei in a power plant.",
"Lets go to basics of nuclear fission: Neutrons are the currency of a nuclear reactor. They cause fission reactions, which in turn make more nuclear reactions. There are certain nuclei that are have la... | [
"I don't think any of your points answer his/her question.",
"Also:",
"Radioactive decay heat accounts for 5% of a nuclear reactors power at steady state....so it makes a huge impact!"
] | [
"\"The mass of a nucleus is mostly made up of the binding energy of the neutrons and protons in the nuclei.\"",
"No its not, the rest of the explanation is great but this statement is false. The mass of the nucleus is mostly made of gluon-quark interactions in the protons and neutrons.",
"The binding energy is ... |
[
"Is blood doping with white blood cells possible to create a super Immune system?"
] | [
false
] | As I understand Lance Armstrong style blood doping extracts red blood cells then puts them back in to increase the amount of oxygen available during an event. So could we take out white blood cell at intervals while healthy and store in a bank and then when we get sick put them back in? | [
"It would be quite pointless if we were using our own white cells. If you ever encountered am given pathogen before your immune system \"remembers\" it and relevant white cells multiply when it's encountered again. When a new antigen is found your immune system just needs to learn it. But a \"doping\" like that is ... | [
"So it wouldn't help speed recovery or possibly your immune system adapting to a new pathogen to have an rapid increase in white blood cells that your body didn't have to produce?"
] | [
"Using antibodies is cheaper and carries less risk of strong immune response than using white cells. Remember, our immune system reacts to most things that are not marked as part of our body and is not used to, including cells from other people/animals. Whole white cells would probably trigger an inflammation or so... |
[
"What happens to a metal baseball bat when \"it dies\"."
] | [
false
] | In most non-pro leagues expensive, metal baseball bats are used that typically last for 1-2 years (less if used by a whole team) before they are considered "dead." This means the bat no longer seems to have the pop as the ball comes off the barrel and typically results in the baseball flying slower and shorter and beco... | [
"High-cycle metal fatigue. Collisions between a new bat and the ball are mostly elastic and lose little energy, transferring most of the kinetic energy of the bat into the ball. Over repeated collisions, the metal fatigues and the collisions become increasingly plastic, losing more and more of the kinetic energy in... | [
"While this makes sense its a little disappointing as answer as I still feel like I don't know any more than I could reason going into the question, so I looked a little harder at what I could find out about this.",
"What does High-cycle metal fatigue mean is happening beyond just wearing down after many at bats?... | [
"Okay, so High Cycle fatigue works as such: metals are made up of a bunch of tiny crystals. There are so called \"dislocations\" in these crystals, basically places where the metal doesn't line up properly. Once you hit them with a stress such as a baseball bat hitting a ball, you move these dislocations to the e... |
[
"Bond strength between amphipathic molecules and air in saltwater?"
] | [
false
] | This question is related to protein skimmers. How strong is the bond between the amphipathic molecules and the air in a protein skimmer chamber? I understand that some molecules will be more hydrophobic than hydrophilic, but what is the window that they operate in? From instance, how strong is the strongest bond with a... | [
"It's just surface tension, which is ",
" the molecules don't bind to air. A molecule at the surface will have higher energy compared to one in solution, because it's only forming intermolecular bonds on the sides facing the solution. Now, if you put some amphiphilic molecules in the solution, they have a hydroph... | [
"What bonds? There's no bonding of air molecules to anything there, to any significant extent."
] | [
"I guess I misunderstood what I researched. If that's the case, then how is the organic compound attached to the air bubble? I was under the impression it was a chemical bond."
] |
[
"How would time dilation affect the decay of elements?"
] | [
false
] | [deleted] | [
"Then it'll appear to decay at its normal rate to anyone on the ship, and slower to someone on the planet."
] | [
"People on Earth would see it decaying at a reduced rate. People on the ship would see it decaying at the normal rate.",
"Let's say the ship leaves Earth at 0.8c and flies for 1.25 years before arriving at a deep space station, all as measured by people on Earth. Then the ship is now 1 light-year away, and it's c... | [
"Is the element on the ship or on the planet? The decay rate of an element is given in the frame-of-motion of that atom. So if it's moving very fast relative you, it will have a longer lifetime. (Which is indeed seen all the time with fast-moving cosmic muons and such things)"
] |
[
"Can a bright light outside the visible spectrum hurt your eyes?"
] | [
false
] | For that matter, what exactly's happening when a bright light "hurts"? | [
"Yes. Absolutely light outside the visible spectrum can be harmful. Both visible and other than visible light can be harmful, but in both cases, it depends on the intensity. The reason outside-visible light (such as UV/IR) can be much more harmful is because you can't see it so you don't blink to shield yourself... | [
"Latching on to the top comment - UV and IR light ARE quite dangerous due to the fact that they don't have the aversion effect (blinking) that visible light does. However, the reason ambient UV and IR have less of an effect (damage wise) on the retina is very much due to the cornea's absorption spectrum. ",
"Th... | [
"Absolutely! Ultraviolet and (near) infrared can both cause pain and eye damage similar to a bright visible light because they will still be focused onto your retinas with enough intensity to cook them.",
"Infrared lasers can be dangerous to work around because the beam is invisible and often quite strong. Wear y... |
[
"Where does the electricity go when it's \"grounded\"?"
] | [
false
] | [deleted] | [
"This is a pretty poor answer. The earth is at a potential of 0V only with respect to itself, as is ",
" any other point you want to choose as \"ground\". ",
"The correct answer to OPs question is that \"the electricity\" returns to the source from which it came. This is always true when current flows. See ... | [
"This is a pretty poor answer. The earth is at a potential of 0V only with respect to itself, as is ",
" any other point you want to choose as \"ground\". ",
"The correct answer to OPs question is that \"the electricity\" returns to the source from which it came. This is always true when current flows. See ... | [
"You just described closing a circuit when you said bring one sphere into contact with another. Static discharges when it finds a path (circuit) to take.",
"Even a capacitor must have a path to ground in order to charge it. If you don't believe me, try charging a capacitor with one lead disconnected."
] |
[
"If the Hubble Space Telescope can view images of galaxies 13 billion ly away, why can't it take photos of extrasolar planets?"
] | [
true
] | [deleted] | [
"To elaborate on some of the half truths here so far:",
"Luminosity is only somewhat of an issue. Though its true a planet would appear extremely dim as long as it still reflects some light it would be possible to integrate on a signal long enough to produce an image. Now its also entirely possible that the int... | [
"Correct. And then distinguishing it from other sources becomes the trick using motion."
] | [
"Let's estimate it! The limiting factor will be angular resolution. Hubble has an angular resolution of about 0.05 arcseconds. So if something is smaller than 0.05 arcseconds, it can't be resolved, if it is bigger than that, it can be resolved. The angular size of something is (Physical size) / (Distance away).",
... |
[
"Why does biology/evolution favor a 50-50 gender split in humans and other mammals even though from a reproductive perspective the male is not necessary after successful insemination?"
] | [
false
] | null | [
"The 50:50 split is favored in most species due to the benefits of producing offspring of different sexes.",
"We'll use an example population of 100 individuals and we need to start at some unbalanced sex ratio. Let's use 70 males and 30 females (you'll see by the end that it doesn't matter what our starting poin... | [
"if those societies have a 50-50 split, a significant portion of males have to fail to reproduce, whereas if they were female they could have",
"Assuming 'ideal' polygamy, where you have 1 man with a group of N women and reproduction only happens within the group (with no 'cheating'), you'd find that the smaller ... | [
"Since I've thought about similar to OP, I can understand why a male sex-skew would be discouraged, but not a female one. If a population was 30 males, 70 females, there would be some reward to parents who produced more males, but wouldn't there be the same reward for parents who simply produced more promiscuous ma... |
[
"A few physics around the house questions..."
] | [
false
] | A few things have always perplexed me. How come when I put down a gallon of milk, it sometimes seems to "slide" a half an inch or so after it was at rest? How come when put ice in a cup and fill up the cup with a liquid, sometimes the ice stays near bottom, but rises to surface when I pick up and put down the cup? Als... | [
"Gallon of milk: it's likely that the you have jostled the liquid in the container when you set it down. When this mass of liquid then rushes to the other side of the container, it has some momentum. When it hits the side, the milk jug will move slightly, since it was essentially struck by a moving mass.",
"Ice: ... | [
"Wow that's interesting about the angled mirrors. Mucho Gracias!"
] | [
"(muchas gracias)"
] |
[
"Why don't loud sounds travel faster than quiet sounds?"
] | [
false
] | It seems to me that if loud sounds 'have'(i can't really think of a better term to use) more energy than quieter sounds, then they should travel faster. Why is it that they don't? | [
"Sound propagates in the form of pressure variations in fluid mediums and molecular vibrations in solid mediums. So the speed of sound depends on the properties of the material and the surrounding conditions that it travels on. Louder sounds have got a greater amplitude of vibration ie. the pressure variations are ... | [
"You are probably thinking of sound like a ball, where a higher kinetic energy corresponds to a higher speed. Sound is actually a wave. It is a waving oscillation in the pressure of a material. For all waves, the propagation speed of the wave is determined by the properties of the material or field it is passing th... | [
"Just to add a bit more to this... The reason why the speed of sound is constant regardless of its amplitude is very closely connected with the reason why a mass and spring system will oscillate always at the same frequency, regardless of the amplitude of the movement. ",
"If this latter statement doesn't chock y... |
[
"Is carbonated water still acidic after it has gone flat?"
] | [
false
] | Additionally I guess I would like to know if there's any difference between still water and water that was once fizzy but is now flat. | [
"\"Still\" water is just a term meaning \"non-carbonated\"; it doesn't necessarily refer to distilled water."
] | [
"'Flat' carbonated water is just water that is no longer supersaturated with carbon dioxide. It would still contain some residual CO2, depending on temperature, and would therefore still be very slightly acidic (ph 6 or so).\nI'm not sure what you mean by still water. If you are talking about distilled water, it wo... | [
"Yes, though not strongly so. When carbon dioxide dissolves in water, some of it becomes carbonic acid. However carbonic acid is not a strong acid so it's not going to be as acidic as say, a soda (to which citric acid has been added for flavor)."
] |
[
"Why is a Neutron star considered a star when it has a very similar make up to a planet?"
] | [
false
] | null | [
"How does it possibly have a similar makeup to a planet? ",
"Neutrons stars are remnants (primarily the cores) of particularly massive stars that undergo supernovae. During the star's collapse, the gravitational pressure in the core is sufficiently high to overcome electron degeneracy pressure and cause the cor... | [
"Neutron stars form because higher mass stars have undergone such decay that they consist only of neutrons. This is unlike a planet ",
" a star.",
"The nomenclature is most likely due to the fact that the Neutron star is the result of a star collapsing. "
] | [
"Neutron stars are nothing like planets, they are very ",
" stars. I don't know any planets that have the mass of a giant star compressed into something the size of Brooklyn. "
] |
[
"When engineers work with devices emitting electromagnetic radiation, how do they control the frequency of the EM Radiaiton?"
] | [
false
] | Specifically microwave radiation... I don't understand how frequencies can be controled and manipulated the way they are. | [
"Inductors and capacitors are the two rudimentary \"reactive\" circuit elements in basic circuits. They are essentially resistors whose resistance depends upon frequency. With these elements, you can create a sort of logic in analog circuits.",
"With inductors and capacitors, one can create filters that accept o... | [
"I will try.",
"To control the frequency of E/M radiation, you simply have to control the frequency of the ",
" in a circuit. The circuit will radiate away the same frequency that it has inside it. ",
"There are two pieces you can put in a circuit that respond to frequency. They respond to frequency simply... | [
"You also need an oscillator--something to produce the frequency in the first place. If you simply connect up some LC circuits to form a filter, generally nothing happens. AltoidNerd already mentioned Voltage-Controlled Oscillators (whose output frequency is tuneable with a voltage, generally across a fixed range s... |
[
"Benefits of sleep after the snooze button?"
] | [
false
] | null | [
"It can actually make it worse. The best option is to actually wake up without an alarm and then stay up. ",
"Your body goes through a natural sleep cycle going in and out of deep (rem- rapid eye movement) sleep. You will feel the most refreshed if you wake up while not in REM sleep. ",
"By hitting the snooze a... | [
"*depends on if you peed"
] | [
"well now nobody knows what I'm talking about "
] |
[
"Why does 65 mph in a car feel nothing like going 25 mph on a roller coaster?"
] | [
false
] | What I mean is, why can you feel the speed on a roller coaster, but not get that same feeling in a car going twice as fast? | [
"Acceleration, my friend. Roller coaster accelerate both by changing direction and by changing speed. This creates a strong feeling of acceleration in directions which are atypical for driving on a flat surface. Essentially, you merely aren't used to that kind of motion, so it feels different, and thus exciting."
] | [
"Yeah, adding to mloewen's answer, you actually never \"feel\" speed, you only ever feel ",
". Airplanes, going at hundreds and hundreds of miles per hour, are just as comfortable as cars. ",
"In a roller coaster, you are subject not just to abnormal accelerations from sharp turns and loops and such, you are ... | [
"Cars are designed for comfort, roller coasters are designed for that \"feel\". Also because cars are closed(mostly) and run on flat surface and can't make turns at high seed. Coaster turn at high seed and you fell the centripetal(centrifugal?) force. Also many of them go up side down. "
] |
[
"How much energy does an electron/beam of electrons have to have before it becomes dangerous to human health?"
] | [
false
] | I was wondering in the context of a particle accelerator. For example, some of the largest particle accelerators can produce beams on the scale of GeV or TeV, which is obviously very dangerous. What's the lower bound of that scale? How energetic can a beam be before it gets dangerous? | [
"It's not just the energy that matters, it's the intensity as well. A single electron with a TeV of kinetic energy is not going to be as physically harmful as an intense beam of 100 keV electrons.",
"In terms of harm to your body, if you believe the ",
"linear no-threshol model",
", then ",
" amount of ioni... | [
"Suppose a crazed physicist offered me the choice of standing in a beam of photons of with energies of 10 eV, or an equally intense beam of electrons each with 10 eV of kinetic energy. By equal intensity I mean each beam delivers to its target (me) the same number of photons or electrons per unit area per unit ti... | [
"If I was faced with this situation, I would look into the dose equivalent deposited into human tissue by these two types of radiation and choose the one which is smaller.",
"I would probably also look into the range of both kinds of radiation in human tissue (or water as a decent substitute). Neither will penetr... |
[
"Why do eukaryotes have introns?"
] | [
false
] | Why do prokaryotes not? Introns early? Late? Somewhere in between? | [
"An intron is cut out during splicing. This allows the exons that are between them to arange in many different ways, bacause they don't have to reconnect in the same order as they were before. This allows the cell to create multiple different proteins (or RNA in that matter) from a single sequence. If you meant to ... | [
"Though their function is not 100% clear yet, many scientists believe that non-coding areas in our DNA have something to do with the high adaptation rate in eucarya during the evolution.",
"A gene is an Intron until it get's a specific starting and end codon which will make it work. The resulting Proteine can be ... | [
"There is no clear-cut biological answer to this question, and there probably never will be. Lots of people will propose various explanations, such as introns allow greater complexity, they play a regulatory role by affecting the expression of neighboring exons, etc. (see the other answers in this thread, for examp... |
[
"Dear r/askscience, how plausible would it be for the universe to be a sphere?"
] | [
false
] | I was thinking about the universe, and how plausible would it be if the universe was in the form of a hollow sphere, where the sphere is constantly "inflating" like a balloon. I have theorized other things but this will go first. I'm 16 so sorry if this is a dumb question. | [
"this was the way we thought of it for a long time. But look on a globe, notice how you can make a triangle from (0,0) latitude longitude, walk north to the north pole, turn 90° walk down to the equator, turn 90° and walk back to where you start to find yourself 90° with respect to your original path. You've made a... | [
"I wouldn't think that the shape of the universe as a whole would affect us, just as we don't notice the Earth is round when we walk on it."
] | [
"but if we do very precise tests of the Earth, we do find that it's curved. The same of our universe. We do very precise tests and don't see it to be curved. Unless it's greater than 251 times the size of our observable universe. Which then leads physicists to wonder why the curvature should be so small, but not ex... |
[
"Does sound travel farther/more quickly in cold air then it does in warm or humid air?"
] | [
false
] | I’ve noticed that it sounds different outside when it gets cold, like I can hear more ambient noise, so I was wondering if this is just in my head or if this is actually something that occurs. | [
"Speed of sound is directly influenced by the tenperature of the air.",
"Acoustic speed is equal to the square root of gamma (ratio of specific heats, usually 1.4) times R (gas constant of air, 1716 using Rankine or 287 using Kelvin) times the temperature of air (Rankine or Kelvin). ",
"The higher you go in the... | [
"I would say depending on the area the cold would help someone hear better outside due to less critters making noise."
] | [
"I would say depending on the area the cold would help someone hear better outside due to less critters making noise."
] |
[
"My kitchen sponge is smelly. I pop it in the microwave for a minute, rinse it off, and the smell is gone. Is this really because the bacteria are killed?"
] | [
false
] | Surely the "smell molecules" are inanimate and will just hang around until washed regardless of whether the bacteria that created them are alive or dead Also, are there any reasons (toxicity etc) why you shouldn't microwave a sponge? Sponges need to be wet before being microwaved or they are apparently a fire hazard. | [
"When answering this I am making two assumptions:\n1. it is a moist or wet sponge when you are heating it.\n2. it is steaming and really hot when you are done heating it. ",
"What you are doing is increasing the temperature of the sponge to boiling (100 C). This is a relatively high temperature for aroma chem... | [
"Yes. Microwaving is also more effective in ",
"killing yeasts and molds",
" than cleaning products like bleach. "
] | [
"Because microwave radiation is extremely effective at boiling the water in any mixture away; no moisture, no mold."
] |
[
"Is it possible to train your brain to recognize the other eye as the dominant eye?"
] | [
false
] | [deleted] | [
"This reminded me of how lazy eyes are treated in children; an eye patch is put on the STRONG eye. This means that the weaker or 'lazy' eye now has to compensate and provide vision for the whole of the brain. Over time, the lazy eye becomes stronger, until it functions as a normal eye. This theory uses neuroplastic... | [
"You're completely right, depth perception is best achieved with two eyes; this makes it a good task for strengthening one eye. The harder the activities the better. \nIf you've already had problems with depth perception maybe just stick to finding tasks with your weaker eye, and then build up to using both eyes fo... | [
"I have a pretty significant astigmatism in my left eye and was forced to use an eye patch over my right eye for several hours every night as a young child. According to the doctor, my astigmatism was so severe I could have gone blind in my left eye without the eye patch treatment.",
"Question, how could you perf... |
[
"What exactly causes the pain from a static spark?"
] | [
false
] | Is it due to direct electrical stimulation of the nerve endings? Is it due to a change in temperature? Or is it something else? | [
"Source?",
"The timescale of a shock-induced pain response is much shorter than one corresponding to temperature-induced pain and qualitatively distinct as well.",
"EDIT: due to the lack of any better answer, I'll weigh in with a bit of evidence-based speculation. The pain experienced is most likely the effect ... | [
"The pain is actually a heat response. Static sparks are hot, that little zap you hear is from the air being super heated (like a lightning bolt). That heat will affect the tiny point of contact, giving a pain sensation."
] | [
"The typical energies in a static shock range from 100-500 mJ ",
"source",
".\nIf you take the highest energy (500 mJ) and assume local heating effects only (lets say 1g of finger tissue is heated) then you get a temperature rise of 0.12 C."
] |
[
"Why do photovoltaic cell graphs level out?"
] | [
false
] | I recently did an experiment similar to this one: When discussing my graph and data I wasn't sure why the graph of a photovoltaic cell's voltage output in relation to LUX levels out. Is this because pv cells have a maximum capacity or some other reason? And if so, what is it? | [
"If this is for a class, you need to warn your teacher that the experiment in the link is fundamentally incorrect.",
"The author has you measure the open-circuit voltage, i.e. the voltage under zero-current conditions, with no load resistor connected across the solar panel. This is wrong, since the voltage isn't... | [
"I have stuff to add to that.",
"People build solar panels to get power, which is measured in watts and is volts multiplied by amps. People also always want as much power as possible from their cells.",
"So you plot a graph of voltage vs amperage (called an IV curve) and find the point where power multiplied by... | [
"See above, \"In answer to your original question.\"",
"Ideally the graph should be 9V at ",
" light intensities. I don't know the type of solar panel you have (probably amorphous thin-film on glass?), but probably contains eighteen cells in series, each of which produce 0.5V. That 0.5V comes from the PN ju... |
[
"Do we have any idea why there's a correlation between a nation's cancer rate and economic development?"
] | [
false
] | null | [
"This is one of those \"there is way more than one significant reason\" questions. ",
"One of the most significant reasons is almost certainly longer lifespans. ",
"Cancer incidence increases incredibly dramatically with age.",
" So even a small in average lifespan may sharply increase your cancer incidence. ... | [
"To put it bluntly: We all die of cancer, unless something else gets us first.",
"So by reducing other causes of death (accidents, preventable and treatable diseases) you inflate the number of cancer cases. Richer countries generally have higher safety levels and better healthcare, so they see higher rates of can... | [
"First World countries, particularly those with public health care systems, are far more likely to notice cancer because of the wider availability of superior technology to pick up and diagnose tumours. This is either in life using various imaging methods or in death via autopsy. Unfortunately much of the world doe... |
[
"Why is the International Space Station is kept at 14.7psi?"
] | [
false
] | I read today that the International Space Station is kept at 14.7psi. This seems odd, commercial aircraft don't even pressurize to this level. if I recall they generally choose something higher to avoid airframe stress. Why would NASA choose this pressure when obviously trying to minimize the weight of bulky payloads. ... | [
"I think it is for compatibility with the long standing practice on the soyuz, and more recent practice on the shuttle. Now that you mention it it does seem strange that they don't event go for 10 psi, with the same partial pressure of oxygen. You would need more gear to handle the transition, but your structures w... | [
"The obvious answer is 14.7 psi with 21% oxygen is the same total atmospheric pressure and partial pressure of oxygen as is the atmosphere on Earth. However, after the pure oxygen debacle of Apollo 1, NASA still used a lower pressure, higher oxygen content atmosphere on the Apollo space missions. The numbers I've s... | [
"14.7 psi is 1.00027 atm, (almost) the same as sea level pressure on Earth. ",
"Reportedly",
" this results in benefits for crew comfort, and is much safer than the alternative, a pure oxygen atmosphere, which has cause problems in the past."
] |
[
"When I look up into the night sky how far away into space am I actually seeing before my eyes cannot detect light anymore?"
] | [
false
] | null | [
"GRB 080319B",
" was a gamma-ray burst whose emissions arrived at Earth at 0612 UTC on March 19th, 2008. Its peak visual magnitude was 5.8, roughly comparable to the average brightness of the planet Uranus. While not visible from sites such as inner cities, this brightness is easily achievable from a rural locati... | [
"How far away you can see is dependent on the absolute magnitude of whatever you are looking at. The most distant object that you can see is the Andromeda Galaxy, which is about 2.5 million light years away.",
"However, the only reason that you're able to see that far is because it's the combined output of billio... | [
"When and why are gamma-rays dangerous? If we could see that gamma-ray it must have hit us surely?"
] |
[
"How much of a role does aerodynamics play in a car's performance? Why is every modern car shaped like an egg?"
] | [
false
] | null | [
"So my follow up question would be, how much of a difference would the performance of a car from say 50's/60's, if only it's body were to be redesigned with modern aerodynamic? Would it be a drastic difference or just slight?"
] | [
"Short answer: It makes a massive difference.",
"Long answer: Aerodynamic forces are extremely complex and difficult to deal with simply, but the classic drag equation (an approximation) tells us that the drag force experienced by an object moving through a fluid is proportional to the square of the object's spee... | [
"Thanks for answering by the way. What I'm trying to find out is, if modern body designs of sedans actually improve car performance alone as compared to older car body designs, and by how much. Is there somewhere to look up the aerodynamics of the bodies of cars alone? Would there be comparative data? Can we compar... |
[
"Does light decay?"
] | [
false
] | Edit: Jesus. You all made my brain hurt. | [
"As far as we know, it doesn't.",
"If it does, it must have a lifetime of over three years in its own rest frame (which it would have if it had mass, which it would need to decay), but because light moves so fast it is dilated to much longer than the age of the universe in our rest frame.",
"http://arxiv.org/pd... | [
"Can someone re-word this sentence so that it makes sense?"
] | [
"At relativistic speeds particles with certain lifetimes (i.e. times before they decay into other particles) appear lengthened to us because the lifetime would be measured in their frame.",
"Imagine a particle that decays after 10s, and now imagine this particle going maybe 0.8c. I don't have anything near me to ... |
[
"WHY do antimatter and normal matter annihilate?"
] | [
false
] | null | [
"That is a great question, but it is really difficult to explain to someone without basic knowledge of quantum field theory, so I hope my explanation makes at least a little bit of sense, even though it's really long.",
"Quantum Field Theory models the behaviour of fundamental particles, and it incorporates quant... | [
"The simplest way to think about it is that the particle presents +1 of something and the antiparticle -1, and when you put them together you have zero of that particle.",
"For example"
] | [
"Electrons are not the anti-particle of protons, even though they have opposite charge. In simple terms, an anti-particle is not just a particle with the opposite charge to another, it a particle that is exactly the same as another except for the sign of some of its properties (in the case of electrons and positron... |
[
"Why do humans have a full head of hair?"
] | [
false
] | Apologies in advance to the follically challenged among us for the incendiary title. I have read the on hair evolution, but it's not completely satisfying, so I was wondering if anyone here had thoughts on the matter. I can see the UV protection being important, but would the UV light really penetrate through the skull... | [
"In evolutionary biology, a Spandrel is a phenotypic characteristic that is a byproduct of the evolution of some other character, rather than a direct product of adaptive selection."
] | [
"UV light doesn't need to penetrate to the brain to do damage. It would make sense that the skin on the top of your head is the most exposed to UV damage and that it would be advantageous to have skin on your head."
] | [
"If I recall my anthropology classes correctly, we're not quite sure but we can give some guesses. The most prominent factor is probably sexual selection. Basically, chicks don't want to bang hairy dudes and dudes don't want to bang hairy chicks. This of course brings up the question of why such a trait has rema... |
[
"Does the length of sleep affect the perceived length of dreams?"
] | [
false
] | Time in dreams is a bit scooty, but I'm sure it's a pretty common experience that we sometimes have dreams which seem to go on for much longer than others. Is this at all related to the amount of time we're asleep? Can we have dreams which feel like they're longer than the time we actually slept for? | [
"Your sleep cycles vary. You will have shorter, shallower sleep cycles later on in your sleep, so you will have more dreams per hour the more hours you sleep that night.",
"As to each dream itself, no. You might remember 20 seconds of a dream and feel like it was a 3 minute experience, or vice versa."
] | [
"As to each dream itself, no. You might remember 20 seconds of a dream and feel like it was a 3 minute experience, or vice versa.",
"This concept of how we perceive time while dreaming is so fascinating. Sometimes I’ll take short naps and have dreams that feel like feature length movies lol."
] | [
"I doubt there's a satisfying answer to this.",
"Personally, my state of mind has a lot to do with the perceived length of a dream. In times of distress or melancholy, I'll have anywhere from feature-length dreams to the kind where you feel like you've woken up from living some other life. Whether it's a nap, 8 h... |
[
"Is there a link between high IQ scores and disorders like ADHD and Asperger's?"
] | [
false
] | null | [
"Short answer? No. People with a high IQ score do not, as a population, have a higher incidence of ADHD or Asperger Syndrome. You will find no major study specifically tasked with finding such a link (but many debunking the notion) for the reasons listed below.",
"Long answer? Still no, but for a pretty wide ra... | [
"That's not what that article says. It only says that most mentally ill people aren't creative geniuses, and vice versa, but that's not what I was asking. If (randomly making up numbers here) 15% of everyone with an IQ within the 99th percentile have ADHD, compared to 5% of the population in general, that would mea... | [
"That's not what that article says. It only says that most mentally ill people aren't creative geniuses, and vice versa, but that's not what I was asking. If (randomly making up numbers here) 15% of everyone with an IQ within the 99th percentile have ADHD, compared to 5% of the population in general, that would mea... |
[
"Where does water come from?"
] | [
false
] | I feel like this is a really really dumb question but recently i was thinking about aquifers and for some reason it made me wonder how the sea level rises every year if that’s where our water supply comes from. Pls don’t roast me ❤️ :) | [
"Water from the oceans evaporates creating clouds that drop water on the land filling rivers etc that eventually make their way back to sea. It’s called hydrologic cycle, they often get you to do diagrams of this cycle a few times through school. \nGenerally our water supply comes from creating dams at points in th... | [
"Hydrogen was created after the big bang as subatomic particles collided with eachother. Stars fuse Hydrogen atoms together for fuel and make more complex atoms as a result- one being Oxygen. After the star lives out its life and goes super nova, it leaves behind the elements within the nebula. The elements are un... | [
"Speaking generally at a global scale, sea level rise is caused by two main things: Temperature increase of the liquid water, causing it to expand in volume, and melting glaciers resting on land, adding to to total water in the ocean. Aquifers are made up of water that long ago fell as rain and soaked into the roc... |
[
"What tasks are faster to do with a computer that uses quantum processing (aka qubits) ? How faster it is compared to normal bits?"
] | [
false
] | There are only a limited scenarios where quantum bits provide a improvement over conventional processing. When that applies how faster that computing is? It's like a quadratic or exponential function of number of bits? qubits are useful in brute-force attack in cryptography? (I have no knowledge over this, so the nomen... | [
"RSA relies on integer factorization. On a classical computer, it's not actually exponential, but the time increases about exponentially with the cube root of the number of bits. It's still really fast. On a quantum computer, it's about the square of the number of bits. I think that's also around how much longer it... | [
"We don't always know how fast a task can be done. (The most famous example of this is the P=NP question.) A lot of the things that people are excited about for quantum computing are problems like that. There are specific examples where people are excited about possible performance improvements.",
"If you look... | [
"It's still really fast.",
"Think you meant 'slow'."
] |
[
"Helium balloons only deflate and drop because the helium leaks through the latex. Is there any material that is light enough to float without leaking the helium?"
] | [
false
] | [deleted] | [
"The helium still escapes through the seals and is still capable of escaping through microscopic defects in the mylar.",
"Sure, very slow leaks, but even mylar won't contain helium forever."
] | [
"Yes, there is - a plastic called mylar. It is often aluminized - coated inside with a thin coating of aluminium. It is the stuff that potato crisps packets are made out of, and it is used for those shiny, metallic balloons. And, unless pierced by rough handling, mylar balloons last practically forever."
] | [
"I'd use hydrogen rather than helium:",
"The best combination would seem to be mylar, as it is less permeable, and hydrogen, as it is less prone to permeate balloons than hydrogen, and more plentiful. But hydrogen is flammable."
] |
[
"In beta decay, how does a neutron turn into a proton, accompanied by an electron and a positron? In addition, why does having extra neutrons make the atom unstable?"
] | [
false
] | I have 2 main problems/questions I'm struggling to understand. + Additional Question: What makes the C14 atom go, "Let's change one of our neutron instead of getting rid of 2 neutrons and turning into C12"? To sum it all up, what's a beta decay? Thanks in advance! | [
"Why is the positron necessary? Why would you need a positron when charges of proton + electron = neutron ? Is it because of the spin, or something that I need to balance out?",
"To go from a proton to a neutron, electric charge has to be conserved. This can either be done by having an electron in the initial sta... | [
"Beta- decay is a neutron turning to a proton, an electron and an antineutrino. No positron involved.",
"Beta+ decay is a proton turning to a neutron, a positron and a neutrino. This rarely happens naturally as there are not many mechanisms producing proton-rich nuclei.",
"There is also electron capture: electr... | [
"Same thing. Charge has to be conserved, so there has to be an electron in the final state or a positron in the initial state. But unlike electrons, there aren't positrons around in normal matter, so there's no \"positron capture\" decay mode, just beta",
" decay."
] |
[
"How much electricity does a cargo ship use on an average day while making a journey?"
] | [
false
] | null | [
"The term you are looking for is \"Hotel Load\".",
"The term hotel load is used with respect to ships to describe their non-propulsion energy requirements. It can be thought of as the energy load required to operate all 'non propulsion' systems aboard ship - lights, air conditioning, computers, water purifiers, r... | [
"Got some additional information from the boat owner. We have 2 navigation radars. One is 2 KW, and the other is 20 KW. The 50 KW load is with only the smaller one in operation."
] | [
"I'm actually asking about electrical use. Navigation systems, lighting for the crew, stuff like that."
] |
[
"Is the human race becoming weaker biologically."
] | [
false
] | null | [
"The answer to your question lies in the definition of weak. If being plucked from an urban area an thrown into the wilderness then your theory would hold some water (note that this is hardly original). However, if successfully surviving in the human construct that we call society constitutes being strong then natu... | [
"mutations that are beneficial to them and give them a better chance of surviving ",
"Careful, they don't have to give any particular ",
" a better chance of survival. You could for instance have a hypothetical gene that made 10% of the people with it infertile, while it made the other 90% much more fertile. It... | [
"Always thought about the same thing, with evolution and survival of the fittest the weakest of the species die out. So with society even the weakest can propagate forward, does this mean evolution has come to a stand still? "
] |
[
"Are we producing more atmosphere than we lose at this point in time?"
] | [
false
] | I guess my question is pretty simple. At this point in time is the planet producing more atmosphere than we are losing to solar wind or are we slowly losing atmosphere? What are some of the factors affecting our atmospheric production or decline? Is our atmosphere undergoing any kind of changing state? As in, more oxyg... | [
"So, what we know of climatology and the how the Carbon cycle works is inferred knowledge from a bunch of proxies.",
"Starting way back, we knew there was very little oxygen in the atmosphere, due to the presence of Pyrite in very early rocks. When iron is exposed to oxygen, you'll know that it forms rust. No oxy... | [
"We are always slowly losing atmosphere. As you mention, we do have solar wind stripping us, but there is also the spontaneous generation of free hydrogen and helium by radioactive processes to consider. These are usually trapped within rock or liquid, but once freed, the atoms experience buoyant force, and barring... | [
"And what about massive amounts of gasses from burning fuel?"
] |
[
"What happens to a weak electromagnet if you apply a strong magnetic field opposing it?"
] | [
false
] | If you have a massively large neodymium magnet and place it opposite a small electromagnet, would they repel? I've read Which implies that the electrons slow down but reading about drift velocity and propagation of wave speed, none of it implies lowering the overall number of charges/second So here's what I imagine hap... | [
"So i have a bachelors in electrical engineering so I will try to help out.",
"Things I know. The electric field around an electromagnet is proportional to the current at that time. ",
"If you alter that field you induce a voltage that changes the current and if you change the current you change the field st... | [
"Magnetic fields are additive. An electromagnet like a solenoid is just a bunch of wires adding their fields. OP was correct in his assessment. It gets significantly more complicated when magnetically permeable materials are involved, but its still generally true that the magnetic fields simply overlap. The str... | [
"I cant draw magnetic field lines in ascii but I was thinking more along the lines of first year physics if you placed two north poles next to each other the field lines dont comnect they repell. So the polarity of the poles remains. The path of the field lines through space are distorted. "
] |
[
"How much extra energy (if any) does it take to do hard mental tasks?"
] | [
false
] | Like studying all day, or taking an exam or anything that requires a lot of extra brain power | [
"It is very hard to quantify this. During baseline activity the brain uses around 20% of our body's energy supply making it the most energy dependent organ in our body. However, the beauty of it is that it is extremely adaptable. To use an example relevant to your question: if you didnt study a particular topic and... | [
"are we talking a spike of a few percent or like an extra 10% total energy consumption?"
] | [
"We are talking about a spike because higher energy demands are not sustainable. The amount of energy that can be redirected is limited because the body cannot afford to restrict energy usage of vital organs such as the heart, lungs etc. So thats why initally you feel tired. Your brain fulfils the extra energy dema... |
[
"If two radioactive atoms were entangled, would they decay at the exact same time?"
] | [
false
] | null | [
"Two particles may be 'entangled' - with respect to ",
". That means that that particular property (e.g. which spin state the particle is in) is correlated between the two particles. You cannot say that 'particles' themselves are entangled, it's really their states. In quantum mechanics, you can completely descri... | [
"Sorry if I'm misunderstanding, but did you mean to say",
"Entanglement does ",
" mean two 'entangled' particles suddenly act like each other's clones.\n?"
] | [
"Yes and sorta, respectively. Entanglement is well understood with math, but it's kind of tricky to translate that math into something a non-specialist will understand.",
"Consider this analogy: suppose you shuffle a deck of playing cards, you take 26 of them and your friend takes the other 26 to the Andromeda ga... |
[
"If humans had wings, what wingspan would be needed for gliding and self-powered flight? Could the human metabolism keep up with the energy demands?"
] | [
false
] | I had this discussion with a friend once, but never reached a conclusion. Let's assume a 80kg human without aerodynamic clothing or hairstyle. Let's disregard the fact that the human body has no point where the needed bone structure and muscles could be be attached, although that, too, is an interesting subject (we'd w... | [
"I actually have a book that discusses such a thing. It's the Science of Supervillains, specifically the chapter about the Vulture.",
"I'll go get the book and scan you the part.",
"Edit: ",
"Here you go",
". It's actually a very cool book. Fun meshing of science with comic books.",
"TL;DR: ",
"he will ... | [
"TL;DR: Now the numbers get interesting. If the Vulture weighs 90\nkilograms (fully equipped with wings and costume) and is sprinting at\n6 m/s (a record-setting pace, running a kilometer in less than\n2 minutes 30 seconds), ",
". Of course, that assumes he can keep\nmoving at 6 meters per second all the time he ... | [
"His numbers are out by a factor of 10 compared to what we see in very small hang gliders. You can get a higher lift coefficient, run about 25% faster, and weighing less than 200 pounds helps.",
"I thought his math was wrong but was mistaken."
] |
[
"whats the shortest flash a human can register?"
] | [
false
] | null | [
"That post largely addressed a different question, though. A bright enough flash, no matter how short, will still be registered by the human eye because it will temporarily overload the sensors in our eyes, but we won't have a good impression of how long the flash ",
".",
"For example, I have an underwater came... | [
"[deleted]",
"\n ",
"This comment has been overwritten by ",
"this open source script",
" to protect this user's privacy. The purpose of this script is to help protect users from doxing, stalking, and harassment. It also helps prevent mods from profiling and censoring. ",
"If you would like to protect ... | [
"This post already has some nice info!",
"https://www.reddit.com/r/askscience/comments/1vy3qe/how_many_frames_per_second_can_the_eye_see/"
] |
[
"Why Titan has atmosphere and other, larger moons don't?"
] | [
false
] | Larger celestial bodies have more gravity with which they can obtain and keep an atmosphere. Titan is not the biggest moon in our Solar System, why Ganymede, which is larger, does not have atmosphere? | [
"Larger moons? The only one larger is Ganymede and there is evidence of a thin atmosphere on Ganymede. Not to mention Titan is a million km from Saturn, while Ganymede is a million km from Jupiter. Being near Jupiter is probably a really bad place to be when collecting material from the gas cloud that the solar sys... | [
"According to ",
"this",
" article, other factors besides size allow a body to retain an atmosphere. Titan has volcanic activity from Saturn's tidal forces. This is a continuous source of CO2, water vapor, nitrogen gas, and methane into the atmosphere. Titan's extreme cold ensures that much of these gas partic... | [
"As an atmospheres guy, jumping on board this comment to say the first explanation is far, far more likely. Daytime temperatures on Ganymede get up to around 160K, while Titan maintains an even 90K. That means it's much easier for gas molecules on Ganymede to gain escape velocity."
] |
[
"If blue eyes are recessive, how come the mutation can be traced back to one ancestor?"
] | [
false
] | Does this mean it was only possible through incest? -sorry if this question has been asked before, i looked. and follow up question: if that mutation randomly occured, then isn't it possible that a person could also randomly have a mutation develop w/o being a carrier? | [
"We're all rather inbred. Humanity has a relatively low amount of genetic diversity compared to other species, from what I recall.",
"And yes, it's possible that the same mutation could arise indepently multiple times. But I believe it's incredibly unlikely given the sheer number of locations in the genetic code ... | [
"One published study claims that ",
"one mutation is responsible for blue eyes in all humans",
".",
"A carrier is someone whose genome contains one copy of a recessive allele, and thus does not show the outward signs of the trait that would be displayed by someone with two copies of that recessive allele, bec... | [
"It depends on what you take to be incest. If you mean something like reproducing with your parents, siblings, or even first cousins, no, it's not a necessity. As you know, the gene is recessive. All humanity is inbred to some extent, especially if you trace your ethnicity to outside of Africa. If we had the knowle... |
[
"What's up with this study on fluoride?"
] | [
false
] | Some new review study about fluoride was published recently. It must be getting promoted on alternative health websites, because I've got some friends and family asking me for my opinion on it. (The abstract on Pubmed is here: ) Apparently, this study concludes that fluoride causes "significant damage to health and par... | [
"Don't know about the current research on the subject but: \n- Journal with impact factor of 0.6 \n- Articles are not even in English\n- English abstract badly written",
"These are just hints -nothing would prevent an article with these features to be excellent- but I wouldn't give it too much credit at face valu... | [
"The full text is available but it's in Spanish and I can't get Google to translate it well. ",
"I'm just going to put this out there. The citations on this article are almost all from Chinese journals. I am ",
" saying that China doesn't do good research, however the way their publishing works makes a large am... | [
"I am not saying that China doesn't do good research, however the way their publishing works makes a large amount of publications unreliable. ",
"I am saying that ",
", China doesn't do good research. That means: They surely have excellent people and institutes, and Chinese students in the West tend to be excep... |
[
"Could an astronaut be rescued if they ever became detached from his/her spacecraft?"
] | [
false
] | After viewing this image it made me think what would happen if there was a mishap and for whatever reason an astronaut was lost in space. Could a rescue mission be launched and would the astronaut just sink back towards earth and die during re entry or would they just float endlessly? | [
"Check out this thread:\n",
"http://www.reddit.com/r/askscience/comments/m3ld5/what_are_if_any_the_established_methods_to/"
] | [
"No, instead they have a smaller version called ",
"SAFER"
] | [
"Same force, not speed. Since the magnet is many magnitudes less massive than the astronaut + equipment, the speed would be very different."
] |
[
"Would two extremely smooth pieces of metal stick together?"
] | [
false
] | I learned about metallic bonds in school a few years ago, and when I asked my teacher why two pieces of metal don't stick to each other when you hold them together, he didn't really have an answer. My hypothesis was that the surfaces might be too rough for the metallic bonds to be strong enough. | [
"So... Two flat, smooth pieces of gold (say, Avogadro-project-grade smooth) would indeed stick together?"
] | [
"So... Two flat, smooth pieces of gold (say, Avogadro-project-grade smooth) would indeed stick together?"
] | [
"That's awesome. Thanks for answering and sharing. I don't know if I'm allowed to thank people in ",
"/r/askscience",
" though, so I apologize if I'm not."
] |
[
"Why do hoarders hoard?"
] | [
false
] | null | [
"Asking people to take a survey is not absolutely appropriate on AskScience. We don't even allow posts that solicit opinions from people. We require answers to be supported by peer-reviewed research. "
] | [
"Does this mean I can't post this? Even though it is based on empirical and theoretical research, and I am conducting empirical research that is aimed to be eventually published in a peer-reviewed journal? Could you please help me to understand how to adapt my post so that it is suitable for AskScience? Thank you :... | [
"No. We are not here to do original research for you, and you cannot post links to surveys.",
"Also, if all you do is ",
"spam this site with the same link",
", this admins of reddit will ban your account. The purpose of this site is to have users who contribute content to the community, not just mine it for ... |
[
"Why do animals have mating seasons, and why don’t humans?"
] | [
false
] | [deleted] | [
"Because you don't want to have a child in October and raise it through the winter when there's less food.",
"Since humans spend 18 years as a dependant it doesn't matter what time of year u have them as they are going to see a winter as an infant"
] | [
"A proximal, mechanistic answer: because many wild animals are seasonally polyestrus, meaning they are only fertile several times in a particular season. This is controlled by hormones from the central nervous system acting within the central nervous system and on the gonads and uterus. These hormones are primarily... | [
"It's also worth nothing that chimps and bonobos also don't have a breeding season, so it's not unique to humans."
] |
[
"I was microwaving some water, and it exploded all over the inside of the microwave with a loud \"pop\". What happened?"
] | [
false
] | The mug was about half full, and I had heated it up about half an hour earlier but left it in the microwave for too long, so I ran it for another minute and walked into the other room. At about 45 seconds I heard a loud pop, and when I went back to check it out I found water all over the inside of the microwave and har... | [
"Superheating happened.",
"Water normally boils at 100",
" C or 212",
" F, but that is only if there is a nucleation site for the first bubbles to form. A nucleation site can be a defect in the vessel (your mug in this case) or contaminates in the water. If you had relatively clean water, and a nice smooth mu... | [
"way too many"
] | [
"Like others said, it's superheating. I got burned that way once, not fun. ",
"For the cooler (heh) and less dangerous flipside to it, try supercooling.",
"Take a sealed bottle of distilled water (not spring water; distilled water) and put it in the freezer. Place a roughly equal volume of tap water next to it ... |
[
"How did the underwater internet cables get there?"
] | [
false
] | [deleted] | [
"These underwater cables are deployed by boat. It essentially involves outfitting a ship with a large cable reel and sailing from one coast to the other while deploying the cable. The cable is dense enough to sink to the bottom.",
"More interesting is the process to repair such cables. Because defects happen from... | [
"No one's swimming to the bottom, Specialty ",
"Cable Laying Ships",
" are used to roll out cables across expanses of water, including all the major oceans."
] | [
"Repairing a cable is actually far more complex than that (and more interesting). I know you were trying to keep things simple, but I actually find it quite interesting.",
"Because of the way that the cables are laid, there's not enough slack to haul the cable to the surface. Instead, the cable repair ship drags ... |
[
"Can multiple optical telescopes be used in the same way as radio telescopes like the Very Large Array?"
] | [
false
] | Someone mentioned in a different thread that no (presumably optical) telescope can resolve either Voyager spacecraft any more, which got me wondering how large a lens would have to be to do so, and whether multiple, widely separated optical telescopes can be used to increase the effective resolution of the array, which... | [
"Yes, it can be done.",
"Read ",
"this",
" from 2002 about a 6 optical telescope array and a little of what was involved in getting it working.",
"You can also find a list of ",
"optical and infrared interferometers",
" on Wikipedia, with a guide to the wavelengths ",
"here",
"."
] | [
"The twin 10 meter ",
"Keck telescopes",
" in Hawaii can be operated as a single astronomical interferometer. They are about 40 meters apart.",
"Unlike with radio telescopes, optical technology is not yet able to do this over large distances. The wavelength of light is much shorter than radio wavelengths."
... | [
"So for an optical interferometer to resolve voyager 1 at it's current position you would need it to be 1000 km across. A telescope would have to roughly double that size because interferometers do a bit better.",
"A second issue will be just how dim it is. Because all it's visible light is reflected from the Sun... |
[
"Since newer cars have the general shape of an airplane wing (the profile of it), do they get lift when traveling freeway speeds (65-70) and does it affect gas mileage?"
] | [
false
] | null | [
"Traction doesn't impact gas milage, it impacts your control in corners but as long as the wheels don't slip nothing has changed, you have ",
" friction to continue on your way and you will never know.",
"Spoilers, like the wings on an F1 car, increase the weight of the car, but not the mass, so it gives you be... | [
"Traction doesn't impact gas milage, it impacts your control in corners but as long as the wheels don't slip nothing has changed, you have ",
" friction to continue on your way and you will never know.",
"Spoilers, like the wings on an F1 car, increase the weight of the car, but not the mass, so it gives you be... | [
"Road friction will slightly impact fuel consumption but its mainly because of the deformation of the tire. Softer road surfaces will also tend to create more resistance.",
"Also, spoilers do increase fuel consumption because they create drag, which is the main factor at higher speeds, more than mass."
] |
[
"Is there an understanding of how likely cooked foods that have \"gone bad\" are to contain harmful bacteria or toxins?"
] | [
false
] | I understand the answer may depend on many things such as the type of food (for example I am aware that heat resistant spores can be present in rice that multiply only after the rice is cooked), or whether it is in an oxygen-free environment, and so on. But generally speaking, or for specific food types, how likely is ... | [
"Unfortunately the USDA's guide is too vague to satisfy my curiosity. It is possible that my question is too broad, but I would be curious if there is any quantitative information for even just one kind of food, such as milk or bread. For example: fungi {X1,X2,X3} is present above harmful threshold {Y1,Y2,Y3} in {Z... | [
"The USDA has a reasonable ",
"guide",
" that lists what do trust/not trust when it shows spoilage. The general consense appears to be that anything with higher moisture content and no hard surface should be discarded as toxins will have penetrated the food. ",
"They don't list sources, but I'm fairly sure ... | [
"Yes, I am aware that you didn't say it, I just wanted to point it out. However, penicillin is not a bacterium. It's a mould."
] |
[
"[Biology] Do trees and other plants, like animals, slowly lose the ability to heal quickly as they age?"
] | [
false
] | null | [
"Animals mostly lose their regenerative capabilities once their reproductive success rate is significantly dropped. This is because, there is very little selective pressure on genes required for longevity and tissue regeneration after an animal can no longer reproduce and pass on genes. In other words, you might ha... | [
"Not necessarily, the pressure is for successful reproduction. So more effective cycles, cycles when there is less (or no) competition, longer cycles and more are all selected for. Whatever is actually most successful in the environment in which the individual finds itself in is what's most selected for."
] | [
"Thank you!"
] |
[
"Is there any evidence that listening to something while you sleep will help you memorize/learn it?"
] | [
false
] | null | [
"In general, ",
"recall of material presented during sleep is very poor",
". People can retain some information if they are in a very light stage of sleep -- see ",
"this study",
" that linked EEG alpha activity to recall, for instance -- but not if they are deeply asleep.",
"However... there are two rece... | [
"Went off what I learned in cog sci/psychology classes however I'll oblige:",
"The sleep boundary is fluid, my assumption that information gleaned in \"phase 1\" sleep (which people often assume is being \"awake\" but falling asleep) could be retained is based off studies that information learned just before slee... | [
"In regards to the question posed I think the lack of evidence that you can put on a tape and \"learn/memorize it\" while you sleep is proof enough.",
"There aren't a lot of studies published that say \"you can't learn something while you're in deep sleep for obvious reasons- the same reason why you don't see stu... |
[
"This question about gravity has been bugging me for a long time."
] | [
false
] | [deleted] | [
"We orbit around where the sun is ",
". More precisely, we orbit around where the sun's momentum 8 minutes ago predicted it would be now.",
"Change in gravity does take time to spread, but it doesn't change due to velocity.",
"See: ",
"http://www.reddit.com/r/askscience/comments/knlzm/do_we_orbit_the_sun_wh... | [
"In general relativity, the speed of gravitational waves is the same as the speed of light. See ",
"the Wikipedia article",
" for more info. ",
"Note that gravitons have never been observed nor is there a complete theory describing them."
] | [
"Gravitational radiation consistent with general relativity has been inferred from the change in the orbital period of binary pulsars. The 1993 Nobel Prize in Physics was awarded for this discovery. Gravitons, on the other hand, don't even have a consistent theoretical framework to describe them, much less experime... |
[
"Can it be possible for a nearby star to be billions of years older or younger than our sun?"
] | [
false
] | Or does their relatively close proximity insinuate that their ages are also similar? Thanks askscience! | [
"Yeah, it's possible - the population of stars \"mixes\" fairly quickly (100s of millions of years), so a star that was born billions of years before or after our sun could totally be in the neighbourhood. We could also at some distant time in the future just happen to pass by a globular cluster or something, which... | [
"Right. It should be added that it's not possible for a star much more massive than the sun to be much older than the sun. It would have already become a white dwarf or gone supernova."
] | [
"In addition to what Astrokiwi says, it's totally possible that stars formed from the same cloud could be quite different in age and so, as well as an unrelated, differently aged, star just happening to be close by, it's feasible that a sibling star to the Sun could be very different in age. Their ages could certai... |
[
"During the halogenation of propane with Chlorine, we can get two possibilities, Chloropropane and 2 - Chloropropane. How do we know which one will occur ?"
] | [
false
] | [deleted] | [
"Your reasoning is incorrect. You have forgotten to take into account the reactivities towards primary hydrogen abstraction versus secondary hydrogen abstraction. For chlorine, the rate for secondary abstraction is 3.8 times faster. For this reason you get ~55% 2-chloropropane versus ~45% chloropropane.",
"If you... | [
"Radical stability describes thermodynamics, not kinetics. ",
"Kinetically, the primary hydrogens are more accessible (albeit only slightly), but the secondary radical is preferred thermodynamically, so hydrogen abstraction occurs preferentially at this position. Refer to ",
"/u/grapeNerds",
" post for specif... | [
"As far as I'm aware, this proceeds via a radical mechanism, so you need to have an unpaired electron on one carbon at some point. This intermediate species would be more stable on the central carbon, so kinetically substitution on the middle carbon is preferred. "
] |
[
"Do animals resort to incest?"
] | [
false
] | null | [
"As someone who has kept dogs over a number of generations, I can say that if the bitch is in heat, every male dog around will try and get at her, regardless of whether its his mother, sister, or daughter.",
"Disclaimer: I do not have a PHD, nor have I ever done experiments involving hundreds of animals on the su... | [
"Incest avoidance is commonplace in animals that live in families, such as wolves, lions, elephants, rodents, insects, etc."
] | [
"Paraphrased from an old Nature article...",
"If we define incest as parent-child or brother-sister this accounts for less than 2% of observed sexual activity amongst birds and mammals.",
"I have no idea what you mean by \"resort to\" as it seems you are asking about some undefined situation."
] |
[
"How hard do your testicles need to be punched to render you infertile? I look at Steve-O from Jackass and have to imagine he cannot produce valid sperm."
] | [
false
] | null | [
"I hope you didn't rotate on Urology, because you clearly need to read further about the vasculature of the testes. ",
"This is my new all-purpose put-down."
] | [
"I hope you didn't rotate on Urology, because you clearly need to read further about the vasculature of the testes. The testes have redundancy of blood supply. You can easily take out the gonadal artery and the testis survives on blood flow from the cremasteric and vasal arteries."
] | [
"In order to answer you properly, you would really need to clarify your question. Infertility is a clinical disorder resulting from a broad spectrum of etiologies. It's such a wide ranging area that there is an American Urologic Association certified subspecialty with fellowship training.",
"Your question suggest... |
[
"If photons travel at the speed of light, does that mean that time stands still from their POV?"
] | [
false
] | I know it's slightly meaningless to talk about the point of view of a photon, but if we were to make the ridiculous assumption that a proton is a conscious being... from their point of view, would they not experience all of time as a single "moment"? EDIT: I clearly meant photon. :P | [
"From a photon's perspective they travel 0.0 distance in 0.0 time. Length forward and behind is perfectly contracted to nothing and takes no time to traverse.",
"edit: Why are people downvoting her replies? They're not egregious errors of ",
" decorum, just amazement at some of the facts of Special Relativity. ... | [
"I input that exact number into the formula and time goes 15 orders of magnitude faster, and distances are 15 orders of magnitude shorter. To put this into perspective, approximately ",
" would pass to the rest of the universe while 1 ",
" passes for you. And a light year would be approximately 10 meters in fro... | [
"So a photon is essentially static in time/space (from its own point of view)?",
"W.... T.... F."
] |
[
"How many counts per second is too many?"
] | [
false
] | null | [
"There's a lot of additional information necessary to answer this. If you were working around dangerous amounts of radioactivity, you would probably be trained on it."
] | [
"Didn't get the training but only a warning not to spend to long around the marked boxes as they can be unsafe normally these boxes are kept in a hot shack but the area I am currently at is no longer occupied. what other info would i need ?"
] | [
"You want to convert the count rate into a dose equivalent rate for it to really tell you how dangerous it is."
] |
[
"Why does temperature affect the appeal of food?"
] | [
false
] | [deleted] | [
"Temperature increases volatility, and taste is roughly 75% olfactory. On top of that it affects texture and color, which also play a role in flavor. Taste in foods with a temperature higher than 86 degrees F or lower than 68 degrees also becomes more difficult to distinguish- Hot coffees taste less bitter whereas ... | [
"Among many other factors, temperature affects the mouthfeel of fatty foods--lipids start to become waxy-feeling and hardened as a hot meat dish cools down, which is why things like stews and barbeque generally are served hot. Connective tissue/gelatin/etc. also starts to solidify as they cool, making even slow-coo... | [
"Hunger really affects it? I always said it as a joke \"hunger is the best seasoning\" had no idea it had science behind"
] |
[
"How come estrogen and progesterone protect women from heart attacks? What’s the connection?"
] | [
false
] | null | [
"A heart attack occurs when there is a blood clot inside the heart arteries. Usually, the blood clot is caused by a plaque that ruptured.",
"Estrogen increases the risk of blood clots. For example, ",
"birth control pills",
" (which contain estrogen) doubles the risk of heart attacks.",
"There is actually a... | [
"its weird how i never read about these and birth control pills. unquestionably it is very common in men but its deadlier for women maybe because of this? i really don’t know and understand why i have always seen the opposite and positive affect. btw are you saying the more you get pregnant more the chances of havi... | [
"Yes, that seems to be the case.",
"Although acute myocardial infarction is a rare event in women of reproductive age, pregnancy increases the risk 3- to 4-fold.",
"https://pubmed.ncbi.nlm.nih.gov/16534011/"
] |
[
"why does chicken pox and shingles cause different symptoms when they’re the same virus?"
] | [
false
] | null | [
"It's more the route of activation for the virus. During the first exposure of the Vzv(varicella-zoster virus) which is contracted through breathing or contact with the rash. The infection begins at the upper respiratory tract where it incubates for about 2 weeks before it enters the lung, travels to the blood stre... | [
"chicken pox is the acute phase of initial vzv infection. shingles is reactivating a prior vzv infection that has laid dormant in the nerve root. the symptoms are different because it’s attacking the body in different ways at different phases in the “life cycle” of the virus. (airquotes cuz virus arent really alive... | [
"You shouldn't get shingles if your immunity is through a vaccine. This is why chicken pox parties are idiotic. Just give your kid the shot, otherwise they'll need the shingles shot later anyway."
] |
[
"If the Earth were in its nearest sustainable orbit around Jupiter, how big would the red giant look in the night sky?"
] | [
false
] | I've seen many posts regarding how big Jupiter would appear if it were the same distance away as the moon, but the consensus was that the Earth would be destroyed at such a distance, which then implanted this question into my head. Also, I would appreciate other details about the orbit, like average distance around Jup... | [
"Let's say the earth is orbiting Jupiter at a distance of 750,000 km, any closer and the earth would be destroyed by tidal forces.",
"At this distance, Jupiter would have a size of 5.3° or about 11 times the Moon. The Earth's orbital period would be 4 days, 3 hours and 52 minutes."
] | [
"Any idea what kinds of radiation we'd be subject to on the surface of the Earth?"
] | [
"I think that the earth's magnetic field and atmosphere would shield us from almost all of it."
] |
[
"Does sanitizing less often, eating \"dirty\" things, playing in trash, etc. really boost the immune system?"
] | [
false
] | null | [
"Yes... and No.",
"...",
"The literature is very mixed. I will briefly describe the two sides in the field, as I know it to be. ",
"...",
"There are some sources that say yes: Eat Dirt! and in fine print \"only when you are young.\" There are others that say it has a completely different cause. ",
"...",
... | [
"Doing said activities allows your body to come into contact with a greater number of pathogens. Your body recognizes those foreign bodies and combats them building up an immunity. If you've never been in contact with them and are suddenly exposed your body would freak the duck out. That is why if you live in a dev... | [
"Doing said activities allows your body to come into contact with a greater number of pathogens. Your body recognizes those foreign bodies and combats them building up an immunity. If you've never been in contact with them and are suddenly exposed your body would freak the duck out. That is why if you live in a dev... |
[
"Sleeping with music playing"
] | [
false
] | Hi guys, i'm wondering. Almost 5 years I have been sleeping with my music on, not headphones, just playing it from my laptop, pretty silently, but still easy to listen to (chillstep mixes, trance and so on). I just hate that buzzing sound I hear when i'm trying to sleep and there is not a single sound around. It starts... | [
"In general, noise throughout the night is disruptive to sleep, especially if the noise level is highly variable, e.g., occasional loud noises. However, a steady background noise (e.g., white noise) can be beneficial to sleep quality if the environment is inherently noisy, e.g., ",
"the ICU of a hospital",
". O... | [
"Of course, if the white noise itself is very loud, sleep quality is adversely affected[2] .",
"In that study, the white noise was 93 ± 2 dB. Do you know what levels white noise should be at to not be disruptive to sleep? Is 60dB loud enough to disturb sleep quality?"
] | [
"Are you asking if listening to an audiobook while asleep ",
" allows you to more easily recall the information?"
] |
[
"What, if any, are the differences between systemic nervous system synapses and those found in the brain or central nervous system?"
] | [
false
] | Different neurotransmitters? Structurally different? | [
"Hi there,",
"I am only a biomedical student so I may not be able to help you completely with this.\nI am going to presume with systemic nervous system you mean either the sympathetic nervous system and/or just the peripheral system.",
"First of it is important to understand that the central nervous system/brai... | [
"To start, I am gonna make the assumption that the systemic nervous system you're referring to is the PNS - please correct me if this is wrong!",
"They are different in both ways.",
"Neurotransmitters: In the CNS, the main NTs are glutamate and GABA. In the PNS, the main NTs are acetylcholine and noradrenaline ... | [
"Just what I was wondering thanks. "
] |
[
"If a fly flying north hits a train moving south will there be a point in time in which the fly's velocity is equal to zero?"
] | [
false
] | null | [
"Yes."
] | [
"Can you elaborate? Why would the fly be at zero velocity? What would happen if the fly and the train would both be a single atoms? one heavier and faster than the other?"
] | [
"The velocity of the fly is a continuous function of time, and it changes sign. So it must pass through zero.",
"Single atoms don't have well-defined positions or velocities, they should be treated with quantum mechanics."
] |
[
"Looking for material that forms needle-shaped crystals?"
] | [
false
] | [deleted] | [
"I recall MSG being rod-like crystals. It's certainly easy to get. I've never crystalized it from solution though. "
] | [
"Salicylic acid aka Aspirin. ",
"Here's a procedure to make it in a lab",
"Edit: Solubility in water is a bit low 2 g/L at 20 °C"
] | [
"In medicine, gout is partly diagnosed by finding microscopic needle-shaped crystals in joint fluid. This finding indicates increased calcium pyrophosphate or sodium monophosphate levels. Not sure if this is helpful at all, or whether these would form macro crystals on evaporation, but it could be a lead if all els... |
[
"Why do solar flares seem to 'rewind' themselves along the path they traveled?"
] | [
false
] | This is a video of the sun in 4k resolution from October 14-30, 2014: Watch the far right side of the sun. Around 0:53 there's an explosion and that goes up (north), then it seems to suck the entire explosion right back into the path it traveled (south, toward the equator). This happens a few times in a row. Really, it... | [
"They're traveling back down magnetic flux lines. The flares you see consist of charged particles, plasma and the like, therefore they're affected by the suns intense coronal magnetism. Think bar magnet diagrams, these shots are an excellent visual demonstration of magnetic flux, similar to iron filings and a regu... | [
"You're right in that the flares are a basic visualisation of the flux lines. The material is being ejected due to perturbations in the coronal magnetic field, said material is ejected at high speeds, but once it slows down due to inductive forces it travels back to the surface along the magnetic field. You'll some... | [
"I'm just learning about about flux lines in one of my classes right now. So, from what I gather, the flares are kinda a physical representation of the flux lines? I know that's not really a proper way of explaining it, but the flares seemingly \"rewind\" because they are on a certain flux line?"
] |
[
"Could polar bears and penguins be introduced to their respective opposite poles (south, north) and survive?"
] | [
false
] | Would the conditions be similar enough weather wise to make it sustainable? | [
"Its unlikely that they would survive. ",
"Polar bears",
" are adapted to eating seals, but its very hard to hunt them in the open water so they hunt on land. Two common ways of catching seals include: crashing through the ice using their paws and kill the seals in their dens or stalking air holes and kill seal... | [
"Wow that was more thorough than I had ever thought was possible, this is why i love ",
"r/askscience",
". Thank you for such an awesome response! "
] | [
"Yes, I would assume that they would eat a penguin given half the chance - their diet isn't limited to just seals but they will also scavenge whale/seal/walrus carcasses as well as... \"Polar bears have also been observed to eat a wide variety of other wild foods, including muskox, reindeer, birds, eggs, rodents, s... |
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