title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"Is there any promise in the idea of sonofusion or bubble fusion or is it absolute bull? And is this still an active area of research?"
] | [
false
] | null | [
"Thread from yesterday: ",
"http://www.reddit.com/r/askscience/comments/290k88/is_bubble_fusion_feasible/"
] | [
"Not really..it's weird that it came up twice in a row."
] | [
"Not really..it's weird that it came up twice in a row."
] |
[
"How was the first virus found?"
] | [
false
] | What methods were used to distinguish viruses from other pathogens so that we knew it was something different than all the known stuff? | [
"It was found because of its size. Viruses are much smaller than bacteria.",
"The experiment that discovered viruses involved taking plants infected with ",
"tobacco mosaic virus",
" and passing a puree of the plants though very fine filters which should remove any bacteria. The filtered liquid was still capa... | [
"Adding to this, because it couldn't be cultured and couldn't be filtered, they assumed it was a self-replicating poison of some kind, hence they called it virus from Latin meaning ‘slimy liquid, poison’."
] | [
"By the late 1880’s, Scientists already knew that bacteria could cause disease, and scientists had filters fine enough to filter out bacteria in a liquid. When he was doing research to isolate the pathogen for tobacco leaf mosaic disease, Dimitry Ivanovsky noted that the liquid from homogenized infected tobacco lea... |
[
"If spent nuclear fuel requires constant cooling before it's stored, why don't they use it to keep powering turbines while the waste is still hot?"
] | [
false
] | null | [
"The heat produced is very small. By the time the fuel is removed from the reactor it is only a few megawatts. ",
"Using the spent fuel to produce electricity means you need to keep the spent fuel in a boiler or pressure vessel, in order to allow it to get hot enough to efficiently produce steam. If you put nucle... | [
"I just added a little to my first reply on that.",
"So here are some issues. First is to get 470watts of output, voyager's RTG operated with a hot temperature of 1832 degF. At this temperature, the zirconium cladding around spent fuel embrittles and is highly susceptible to damage. If you try to operate the spen... | [
"What about electricity generation without turbines? Similar to how RTG's get power."
] |
[
"Why Oxygen?"
] | [
false
] | I have always wondered why did we evolve to use oxygen instead of Nitrogen? If the atmosphere is roughly 78% nitrogen, 20.95% oxygen, 0.93% argon, 0.038% carbon dioxide | [
"Not much useful chemistry can take place with nitrogen. Nitrogen fixation in legumes, for example, needs to happen in an oxygen depleted root nodule by Rhizobia bacteria. It is extremely difficult, as nitrogen (N2) is an extremely stable, inert gas, and requires a lot of energy to split. ",
"The ultimate purpose... | [
"I'll add that the \"toxic\" intermediary and \"harsh\" conditions are only described as such because we don't use them. Oxygen-rich air was toxic to most life back when it first appeared. ",
"But the point that oxygen is more electronegative than nitrogen is correct. Also, the activation energy required to break... | [
"Another reason, which I learned from david attenborough's doc about the origins of life last night, is that the origin of multicellular life is thought to be due to an increase in the concentration of oxygen in early earth's atmosphere, because it enabled these rogue single cells to produce the molecule collagen. ... |
[
"Is there a name for words are are universal or required for language, and are there any notable linguistic exceptions?"
] | [
false
] | null | [
"What do mean by a word being universal or required for language? Do you just mean a word that appears in all languages? "
] | [
"Words that, from an English speaking perspective, seem like basic requirements, words like: the, a, or. Or words that seemingly every langue should have, like sky, or eat."
] | [
"Not all languages have articles (the, a); for example, Russian does not. ",
"I think the term you are looking for is ",
"linguistic universal",
". "
] |
[
"There is a debate on the \"Squirrel biting\" video as to whether or not squirrels can transmit rabies. Maybe someone here can shed some light?"
] | [
false
] | null | [
"Small rodents (like squirrels, hamsters, guinea pigs, gerbils, chipmunks, rats, and mice) and lagomorphs including rabbits and hares are almost never found to be infected with rabies and have not been known to transmit rabies to humans. ",
"http://www.cdc.gov/rabies/exposure/animals/other.html"
] | [
"Care to share a source on that second part?"
] | [
"The issue with bats is that you can be bit by a bat and not know it, especially when you are sleeping. If you are bit by a larger animal and are in a developed country, you are likely to seek treatment."
] |
[
"Can planets in the habitable zone have moons that also supports life?"
] | [
false
] | I was just thinking about our moon and how cool it would be if it was green and lush when we looked up at it. But it has no atmosphere since its too small, also, its too near the sun for its size, i guess? Also no magnetic shielding. Would this also be true for other moons around planets in the habitable zone? | [
"I think that the magnetic shielding would be a big issue. Even larger planets like Mars have their atmosphere stripped away by the solar winds, and Mars is much larger than our moon."
] | [
"What if the planet had a very large magnetic field, or the moon was still geologically active?",
"That can happen right? moons be active I mean"
] | [
"Jupiter has a very strong magnetic field. Unfortunately for its moons this magnetic field accelerates charged particles and bathes them in radiation.\n",
"http://en.wikipedia.org/wiki/Magnetosphere_of_Jupiter"
] |
[
"I woke up at 3 a.m and noticed it was raining heavily and the sky was green. Why is this?"
] | [
false
] | [deleted] | [
"The tornado doesn't need to be particularly close. I grew up about 70 miles from Detroit, MI, and I distinctly recall one hitting Detroit and the sky was Bright Goddamn Green.",
"The other possibility is that the clouds feeding the rainstorm were bloody enormous. ",
"Source"
] | [
"Huh. Didn't know that. Thanks."
] | [
"It's because of tornados, which you obviously seem to know already... I don't actually know, but there's this: ",
"http://www.news.wisc.edu/15301"
] |
[
"The Problem with the Specious Present"
] | [
false
] | [deleted] | [
"I don't think this technically has anything to do with science, much more of a philosophy question, but I will take a crack at it. ",
"It defines all time as a series of instances which take up no time themselves, so since no given instance takes up time, time doesn't exist. I would just view that as word play m... | [
"So all in all, you are saying that this is cleverly disguised faulty logic?"
] | [
"In my opinion, pretty much. I feel like the same thing happens when people try to make sense of things with analogies (ironic given the fact I used one earlier). It is easy to misinterpret thing A when it is compared to thing B in a situation when thing B does not actually represent thing A, even if you can phrase... |
[
"Why do you need eye protection when welding and why can you watch a video of someone welding without this protection ?"
] | [
false
] | null | [
"Sparks can fly into your eye when you weld and blind you."
] | [
"Then why can't you see anything with a welding mask ? You could use a clear visor if it was only the sparks ?"
] | [
"Oh, I see what you mean. Welding arcs emit a ton of UV and IR light. Intense, prolonged exposure can damage your eye. That's why welding helmets use a tinted shade (like sunglasses). "
] |
[
"Why don't we create synthetic gasoline?"
] | [
false
] | Why hasn't anyone created synthetic gasoline? Can it not be created by a similar process that synthetic motor oil is created? Or is that a completely different process. It seems like a no brainer to try and create as it would reduce dependency on foreign oil. Oil companies then could create this instead and still keep their profits. Obviously there is something preventing us from doing this, so I thought I would ask. | [
"The difficulty with creating a fuel is that you have to put the energy into it that you are going to extract later when you burn it. For something we only make a little of like motor oil, that's not a big deal. Replacing all transportation fuel, however, is a very big deal."
] | [
"Why hasn't anyone created synthetic gasoline?",
"They have. Various commercial level processes exists for creating synthetic liquid fuels, notably ",
"Gas to liquids",
" processes which convert a gas (typically 'syngas', a mixture of H_2 and CO) into liquid fuel, and ",
"Coal liquefication",
" which conv... | [
"Doesn't the fact that motor oil is used for lubrication rather than as an energy source make a huge difference here?"
] |
[
"You are standing on the moon. Your friend is standing on the Earth. He shines a special laser pointer at you. Is it true is true that you will see the dot from his laser pointer appear next to you before he does because you're already at the destination and he is not?"
] | [
false
] | null | [
"No -- perception is the result of photons entering your eye. They physically have to get there (at the speed of light)."
] | [
"Yes because the light has to travel from his flashlight to the moon and then a very short distance to your eye and this is a much shorter distance than to the moon and to the eye of the observer on earth."
] | [
"Light from the laser and light from the person's hand as they push the button will essentially arrive at the same time since both travel at the same rate and are right next to each other in space."
] |
[
"If matter cannot be created nor destroyed , then what happens to the matter that falls into a black hole?"
] | [
false
] | [deleted] | [
"It becomes part of the black hole.",
"Also, matter can be created and destroyed; for example, a free neutron can decay and turn into a proton, an electron, an antineutrino, or an electron and positron can annihilate and turn into two photons. Various properties have to be conserved (unchanged), such as the tota... | [
"The conservation of mass is only applicable in classical mechanics ie most of the things we do on Earth in kinematics, engineering, etc. ",
"However, when we start to delve into the quantum or relativistic realms, mass becomes a little for volative. Einstein's famous mass-energy equivalence formula (simplified a... | [
"Huh, interesting. Thanks mate."
] |
[
"Do animals actually understand each other's calls like humans understand speech?"
] | [
false
] | I know they can understand each other, but do animals interpret each other's calls as intricately as humans can with our speech using words and such? | [
"Like humans? Yes, maybe. We think dolphins actually have a complex language with syntax. There is evidence that they even each have individual names that they get from their mother's name. But we haven't made much headway in learning their language if it's there. ",
"Other animals certainly recognize conspe... | [
"There is evidence that they even each have individual names ",
"I hadn't heard about that bit. Link to where I could read more?"
] | [
"I absolutely love the idea of some breakthrough team cracking dolphin speach and using advanced communicators to talk in real-time with a dolphin. The thought alone is a poshy of mental masturbation"
] |
[
"How do exchange particles know which way to go?"
] | [
false
] | Whenever you see diagrams of something like neutron decay, the exchange particles always know where to go or what type to be. How is this possible? | [
"That is because Feynman diagrams are just graphical representations of algebraic terms in a computation of how likely a specific collision or decay process is to occur.",
"The positions of all vertices and internal lines are completely irrelevant. The only thing that matters is which lines connect to which verti... | [
"It was the other way around actually! Ellis lost the bet and therefore had to use the word 'penguin' in his next paper."
] | [
"Feynman diagrams aren't an attempt to illustrate an actual interaction, they're instead a neat hand-writing short hand for the mathematical integrals one has to solve. In the actual math one sums or integrates over all possible positions and/or all possible momentum (I.e. directions). So it's in the math, but no... |
[
"Do microwaves kill bacteria?"
] | [
false
] | I've always wondered if a microwave oven could be used as a disinfectant. Does it kill bacteria outright? Or is it the created heat in food/other elements that does the trick? | [
"To some extend a microwave can kill bacteria, but not all bacteria can be considered equal in terms of conditions required to inactivate or kill them. As you might understand there are many factors in play to consider such as the material, thickness of the material and the type of bacteria so it's not possible to ... | [
"It should be mentioned that even though most bacteria die the toxins produced by them may remain, so you can still become sick by ingesting spoiled food that is microwaved."
] | [
"The real kind as opposed to the imaginary kinds your spa treatment is supposed to purge. ",
"Lots",
" and ",
"lots",
" of different classes of toxins."
] |
[
"Does it take an infinite amount of time to fall towards an event horizon of a black hole?"
] | [
false
] | Closer you get to the event horizon, greater is the time dilation. So for an outside observer an object will take more time to cover the same distance as it approaches the event horizon. Technically at the event horizon dilation if infinite, well, we do not yet know clearly what happens at that point, but we can see that time dilation is very high at a point which is really really close to the event horizon. So, for an outside observer it would appear that it takes infinite time for an object to fall into the event horizon. Is this right? | [
"Say we have two observers, Alice and Bob. Say Alice is stupid enough to cross the event horizon of a black hole described by the Schwarschild metric (symmetric, non-rotating, zero net charge). Bob is hovering outside the event horizon observing Alice falling into it. What do Alice and Bob see from their own refere... | [
"The redshift beyond detectability would actually happen very rapidly. It would be measured in milliseconds, with the last photon reaching Bob in less than a second."
] | [
"That's my understanding. You would see Alice appear to slow down slightly, but she would become undetectable to any distant observer in a very short period of time. ",
"In proper time (i.e. from Alice's perspective), she would cross the event horizon as if she were crossing any other imaginary barrier. From the... |
[
"What threat does glacial melting pose to the gulf stream?"
] | [
false
] | As in, if global warming were to go out of control, and the glaciers in antarctica melt, would the flow of water disturb the gulf stream to any large extent, and if so, what would the consequences be? I heard that it would plunge northern Europe into an ice age, but what credibility does this theory actually have? Thanks in advance. | [
"The Gulf Stream primarily exists because of the action of winds blowing across the subtropical Atlantic. A good (but small) map of the surface currents is ",
"here",
". Unfortunately, many people are taught this ",
"image",
" of ocean circulation which both dramatically simplifies the Thermohaline Circu... | [
"It turns out I meant the arctic, not antarctica. My apologies."
] | [
"The biggest consequence for the Gulf Stream would come from arctic melting in Greenland and northern Canada. All that cold and less saline water would barge into the north atlantic where it might both slow thermohaline circulation and shift the path of the Gulf Stream further south; say towards North Africa. It wo... |
[
"Implying this is true - Why did the menarche occur earlier and earlier?"
] | [
false
] | I heard that women used to get their period after 16 or so, now the average menarche occurs between 12-13, and girls as young as 9 are getting them. Why is this? | [
"The answer is we don't know. There is no solid evidence showing why this is occurring just that it is. Some believe it's environmental insults; some believe it's BMI related; some believe it's genetic; and some believe it's psychological or a combination of these.",
"BMI: ",
"http://www.ncbi.nlm.nih.gov/pubmed... | [
"BMI is the theory I subscribe to mostly (with a host of other contributing factors but it's my primary factor). There is solid evidence that a reaching a weight triggers menarche (and indeed is necessary to trigger menarche)"
] | [
"How could it be psychological? Is the hypothesis that girls were hiding their \"early\" onset back in the day thus skewing the data? I cannot come up with any other possible \"psychological\" reason."
] |
[
"Why do particles that are not noble gas atoms want to become ions? If the reasoning is to maintain a ground state or low entropy then why aren't more electrons transferred to minimise the space between sub-atomic particles and minimise the entropy of the atomic system?"
] | [
false
] | Looking at sodium metal and a sodium ion in NaCl, when sodium metal reacts with water it violently gives off its valence electron and causes a massive exothermic reaction after which the remainder sodium is now stable with its new valence electron shell filled. But what is the benefit in this? I understand that they want to have a ground state but what's the benefit of that? I've heard one view on Quora suggesting that it's to do with the universe favouring less entropy in a system. So by becoming an ion there's less entropy within the sodium atom because the sub-atomic particles are closer together but.... by that logic why doesn't the atom give off MORE electrons so the remainder sub-atomic particles are closer together to minimise the system entropy? If only I could personally ask the sodium atoms :'). | [
"It is not favoured for the sodium atom to give up its electrons. It takes energy. Copared to other atoms the energy reqired to remove an electron from the shell is lower, however, still existent. The reason to form the salt is that chlorine \"wants\" the electron and that afterwards, the lattice energy from solid ... | [
"I'll give a go at some quick answers for you since you seem to have a decent understanding of the underlying concepts. ",
"First, the energy required to remove the valence electron in a neutral sodium atom is very low compared to other atoms. This is largely due to electron shielding. Basically the electron shel... | [
"Thank you for the brilliant reply! Could you expand a bit more into your edited part? As in why the electron change is enthalpy driven and not entropy driven?"
] |
[
"How does hypothermia kill?"
] | [
false
] | So how exactly does hypothermia kill? Is it something like enzyme reactions getting out of their 'operating temperatures', or the body's temperature-regulating mechanisms spiraling out of control once they get too far out of wack, with fatal effects? | [
"Below 34C the heart tends to stop beating properly. We cannot accept any rhythm an ECG provides when the body is below this temperature, they're simply not appropriate rhythms and require treatment, we wouldn't declare someone dead on the basis of an ECG finding while they're cold (not that an ECG alone is ever e... | [
"They follow a progression. Initially they become tachycardic (high heart rate) then quickly become extremely bradycardic (under 40 bpm if I recall hard numbers appropriately, but it varies as always in medicine.) They present a specific J wave on ECG below 28C, again if I'm recalling hard numbers right, and then... | [
"Are the arrhythmias a primary result of low temperature, or are they results of other systems getting wacky from the cold?",
"If a primary result, do we know what causes the problem? Is is an electrical issue, or a cardiac muscle issue?"
] |
[
"I am currently learning about resonant circuits, and there is discussion of current leading voltage and voltage leading current. How can current and voltage not be happening at the same time? Aren't there always electrons? How can this be possible?"
] | [
false
] | null | [
"Think of current as flow of water and voltage as pressure of water.",
"First of all, it's obvious you can increase pressure without increasing flow (if water has nowhere to flow to — for example, increasing pressure in a closed container). ",
"Second, it's obvious you can increase flow without increasing press... | [
"Fair enough. I meant obvious not in the sense \"you should have seen this\" but in the sense of \"now that I am telling you, I am sure you see it\"."
] | [
"Good explanation, but I think what you're saying is obvious actually isn't obvious. That's actually where the question was solved (at least for me)."
] |
[
"If the world's most powerful telescope was pointed towards the moon how closely could we examine the moon's surface?"
] | [
false
] | null | [
"It would be on the order of 10's of meters. If you're asking if you could see the American flag planted by the apollo astronauts, then no, there is no telescope capable of doing that. (For reference, it would take a reflecting telescope 1/4 mile wide to resolve the flag on the moon to a few pixels on a monitor whe... | [
"Small note, ",
" cannot resolve the moon landing site. Some of Nasa's crafts have taken pictures of the site.",
"http://www.space.com/12796-photos-apollo-moon-landing-sites-lro.html",
"I got chewed out on this a while back."
] | [
"Correct, I should have noted that. I have seen the photos, you can see the landers as very small objects, and moreso the shadow that they cast. I will see if i can find them. ",
"Here's one from nasa.gov ",
"http://www.nasa.gov/sites/default/files/images/369234main_lroc_apollo11labeled_256x256.jpg"
] |
[
"My science teacher doesn't believe in global warming because of volcanoes and their CO2 levels after they erupt. Is this credible, and is it possible that he is right?"
] | [
false
] | My science teacher is a very smart man, but there are several things that I question with him. For example, he does not believe in global warming. He says it is a normal cycle in the history of the world. He backs this up by talking about volcanoes and their carbon dioxide. Apparently, when a volcano set off a couple years ago, they measured the CO2 in the atmosphere and saw that it was almost 400% higher than it was used to. (I'm not sure if it was 400%, I'm just repeating what he told us.) Now, he says that if people are worrying about global warming - then why did the CO2 in the atmosphere have no ill effects? He then says that the CO2 went back down to 'normal levels' in a short amount of time. So, that means that if the earth was really bogged down with all this carbon dioxide that we humans are making, it could easily stop it and reverse it. Now, my teacher is persuasive and well spoken. He did convince a lot of people in my class, and even made me doubt my beliefs. Can someone explain to me if he is right/wrong? And why? | [
"Skeptical Science",
" has a ton of facts and figures (with citations) that are aimed at addressing most of the common misconceptions about climate change. I highly recommend it in addition to the answers that were given here."
] | [
"The ",
"Keeling Curve",
" has shown an incredibly consistent rise in atmospheric CO2 over the past 50 odd years. A 400% sudden increase in atmospheric CO2 from any single event would just be ridiculous."
] | [
"Here's the ",
"link",
" to OP's question on that site, for the lazy. Good find. :)"
] |
[
"Mechanism for Type 2 Superconductors?"
] | [
false
] | Is there a generally accepted mechanism for the function of Type 2 superconductors? I've been reading about BCS theory for Type 1 superconductors and have a decent understanding of the formation of Cooper Pairs and the overall mechanism. I have however, been able to find nothing on how Type 2 superconductors work other than "it's different from Type 1". | [
"(It's been a while since I did this particular theory, but I think my explanation is correct).",
"Type 2 superconductors superconduct by essentially the same mechanism as the type 1s, so far as we understand, though the factors affecting cooper pair formation may be different and more complicated. The difference... | [
"The Ginzburg-Landau theory",
" is a phenomenological theory (does not propose a mechanism) that boils a superconductor down to a couple numbers. The coherence length is about how far the superconducting state extends in a solid. The penetration depth is how far into the solid a magnetic field can penetrate. I... | [
"I'm afraid I don't know the details, but it probably comes down to the particular structure of the material. In some, it will be energetically be favourable to have a vortex state, but in others it's simply a lower energy state to cease superconducting."
] |
[
"Could wormhole travel make us go beyond the observable Universe?"
] | [
false
] | null | [
"Show me a wormhole - and then we can experiment and see.",
"Since nobody has yet to discover a wormhole, we can but at best speculate."
] | [
"I love healthy debate on the internet. Now there's a sentence I thought I'd never use.",
"To be sure, the question of wormholes does lend itself to some speculation and depends on certain assumptions and definitions. The following is my understanding of the situation. ",
"The wormholes they speak of arise fro... | [
"Some very highly respected scientists like Carl Sagan and Neil deGrasse Tyson have voiced support for the idea that wormholes might exist. I'm not trying to make an appeal to authority, but rather curious as to why these seemingly smart and rational people accept the possibility wormholes might exist, while seem t... |
[
"How does light give objects their colors?"
] | [
false
] | [deleted] | [
"Materials can absorb or reflect the radiation from light, or they can do both. If you hit a green object with white light, the object absorbs most of the spectrum, but reflects the light of the frequency range that corresponds to the color green. That reflected light hits your eye and you see the color green."
] | [
"Check out the ",
"guidelines for r/askscience",
"."
] | [
"Oops.. Well I apologize on that one. Better?"
] |
[
"How did vacuum metallurgy develop? Is it possible to actually locate part of the metal-making process in deep space, like the bay of the space shuttle for instance?"
] | [
false
] | I've heard that you can basically make crystalline metals that have amazing properties using this technique. Is this true? If so, what are some of the neat properties these metals/alloys display? | [
"When you say nearly all metals are naturally crystalline, do you mean polycrystalline or single crystal? The former, right?"
] | [
"When you say nearly all metals are naturally crystalline, do you mean polycrystalline or single crystal? The former, right?"
] | [
"When you arc melt, what pressure do you work with? To strike an arc there has to be at least ",
" gas to ionize, right? I always wondered what near-vacuum pressures were considered normal when arc melting. I've seen the process before, but have never done it."
] |
[
"What's the most complex parasite life cycle that we know of?"
] | [
false
] | null | [
"I am almost sure someone will one-up me, but the ",
"Lancet river fluke",
" deserves at least an honorable mention. Their cycle is mammal -> poop -> snail -> snail-eating ant -> herbivore mammal accidentally eating ants while eating grass. It passes through three totally unrelated creatures. Mammals are also t... | [
"Toxoplasma gondii",
" has a very interesting mechanism behind its life cycle. The full life cycle can be seen ",
"Here",
". It can reproduce in most warm blooded animals but it can only sexually reproduce in cats. There is evidence of induced behavioral changes in infected mice that make them less afraid of ... | [
"I doubt it's the ",
" complicated, but the ",
"life cycle of ",
" (the cause of malaria) is pretty convoluted.",
"So I count 5 distinct parasite stages that live in two different human body sites (liver, blood) and two different mosquito body sites (gut, salivary glands). I only gave the names of the extra... |
[
"At what speed does glass break?"
] | [
false
] | If I were the throw a rock through a window, how fast would the glass break from the point of contact (with the rock) to the outer edge of the windowpane? Also, what defines what path the fracture will take from the contactpoint to the outer edge of the window? | [
"The speed at which waves travel through a material is the same as the speed of sound in that material. The speed of sound in a material can be estimated by knowing that material's density and bulk modulus. The formula is ",
"c=(K/p)",
"where c is speed of propagation, K is the modulus of elasticity, and p is... | [
"Could you explain why you think a crack should move as fast as a pressure wave? Microscopically, a crack must be caused by breaking of bonds, and while there are certainly the same interatomic forces involved that also play a role in wave propagation, I would be surprised if there wasn't some difference in velocit... | [
"/u/nepharan",
" touched on this, but I think it's important to highlight the difficulty of the mathematics here: You're dealing with bulk material (the glass pane) with defects (which make it hard to apply quantum mechanical modelling to everything). So you think, oh, I'll use some kind of mechanics model. But a... |
[
"How/where does immunity to disease live in my body? Before starting a new job, I had blood tests to confirm immunity to many diseases. Does that mean my blood is forever changed every time I get a flu shot, or is it stored elsewhere?"
] | [
false
] | null | [
"White blood cells, also called leucocytes, are the cells which fight diseases. They are produced in the bone marrow from the same stem cells as red blood cells.",
"Leucocytes live everywhere in the body, especially blood, lymphatic nodes, spleen and thymus. In a time of need, they migrate to tissues where they f... | [
"Although not an expert on immunology, I'll hopefully try and clarify. Basically there are two components of the immune system, they are variably classified as either innate and adaptive immunity or humoral and cell-mediated immunity. ",
"As mentioned, the immune system is made up of many type of cells that der... | [
"The immunity of our body is taken care of by the cells called WBCs( white blood cells) .Some of which float around in the blood looking for signals that indicate the invasion of body by any microorganisms.",
"When there is a Microorganism where its not supposed to be, the tissues around it ( infected or dead) re... |
[
"Does any species have a symbiosis with viruses?"
] | [
false
] | Many species including humans have formed symbiosis with some other lifeform. One example being humans and gut bacteria. Does any species have a symbiosis with viruses? And if so, how does it work? And if not, why are viruses so special in this regard? Thanks in advance! | [
"The coolest example of viral symbiosis in my opinion is seen in some parasitoid wasps. Lots of wasps have venomous compounds that they use to paralyze or otherwise incapacitate prey, but a few actually use viruses instead. Certain ichneumonid and braconid wasps have entire, intact viral DNA within their genomes,... | [
"Yes! ",
" (baker's yeast) has a virus (technically, it's a satellite but w/e) that encodes a toxin that kills other yeast cells that don't have the virus. So in this example the virus increases the host's ability to compete with its neighbours."
] | [
"Retroviruses, like HIV, synthesize DNA fragments from their RNA once inside the cell. These DNA fragments can become incorporated into the hosts genome and, if it’s a germ line cell, passed on to offspring. The human genome contains about 5-8% retroviral like genes, some of which have been shown to be involved in ... |
[
"Sodium halides"
] | [
false
] | [deleted] | [
"There's no health reason",
"Except that bromide salts can cause ",
"bromism",
"."
] | [
"We do need the Cl ions. There are specific Cl conducting ion channels in our neurons, which regulate in part the resting potential. Check ",
"http://en.wikipedia.org/wiki/Serum_chloride",
" for other physiological functions.",
"Cystic fibrosis is also cause by misregulation of Cl absorbance in the lungs.\nTh... | [
"Evolutionarily we are adapted to dealing with chloride ions, mostly because they are such a dominate anion. Fluoride, bromide, iodide and other anions all have health issues if taken in anything more than trace amounts. Polyvalent anions are more difficult for active transport mechanisms to handle. The ion size... |
[
"How do headphones change volume, whether plugged in or with Bluetooth? If the electrical energy is changed into sound, does the amplitude and strength of the electricity determine the volume?"
] | [
false
] | null | [
"A Bluetooth signal is digital - the amplitude of it doesn't matter as long as it is large enough to be detected clearly. The volume is transmitted digitally as well. The speakers then produce sound with the right volume.",
"Headphones you plug into the headphone jack: That is analog, louder just means more volta... | [
"There's a bunch of different profiles/versions for bluetooth audio-- if memory serves, I think if the headphones/speaker/whatever doesn't support AVRCP v1.4 or later, that the volume control happens by making the signal smaller (and less precise as you point out) at the source side. If it does, then the device is... | [
"Yes, that's it exactly. ",
"The speakers don't change anything, you just send them a weaker signal. ",
"With bluetooth, there is essentially a whole radio included with the headphones. I don't know if the volume is done by scaling the data in the radio signal, or by adjusting the gain in the receiver. "
] |
[
"Besides being cut or menstruating, how does the body dispose of old, used blood cells?"
] | [
false
] | [deleted] | [
"They ",
"get eaten",
"."
] | [
"The lysosomes break apart and release digesting enzymes which break down the cells and allows the different base compounds to be reused "
] | [
"Enzymes break down your red blood cells and tries to keep as much useful parts as it can like iron and the protein parts. Others is just excreted via urine like bilirubin (this stuff is what makes your pee yellow and your poop is brown/yellow)!"
] |
[
"In a house with no air conditioning, would it be better to keep the windows closed or open during the day?"
] | [
false
] | null | [
"I actually designed systems for passive cooling. Option 1 is correct, but there's another big angle to this... if you want the house to keep cool, don't let sunlight in. Radiant energy from the sun still passes through those windows, but if you shutter them, a lot less gets in. A house that's more reflective of... | [
"Yes. Heat flows from higher temperature to lower temperature. So the basic idea is if it's cooler outside, open the windows. If it's cooler inside, keep the windows closed."
] | [
"Yes. Heat flows from higher temperature to lower temperature. So the basic idea is if it's cooler outside, open the windows. If it's cooler inside, keep the windows closed."
] |
[
"If the theory of Thia colliding with Earth created the moon was true. Would it have been possible for the Moon to developed an atmosphere and harbor life?"
] | [
false
] | What conditions would it have taken for this to happen? And how likely/unlikely would it be to happen after 2 planets collide | [
"The Moon ",
"does have an extremely thin atmosphere",
", which its extremely low gravity allows to escape (be blasted away by the solar wind). It is continuously replenished, but continuously blown away. If the Moon were ",
" heavier, its gravity would enable it to hold a more substantial atmosphere.",
"Ap... | [
"Continuously replenished by what?"
] | [
"Answer is in the linked Apollo 17 article."
] |
[
"Is sea salt chemically different from table salt?"
] | [
false
] | If table salt is NaCl, is sea salt that you buy at the grocery store any different? | [
"If you mean the salt (as in all the different salts in the package you buy) then I can note a single major difference.",
"No Iodine is added to Seasalt... This can be problematic for many people who do not eat enough foods rich in iodine and depend on the added source in table salt. Also seasalt can generally co... | [
"Close, it's MgSO",
" that's used as an anti-caking agent, not MgCl",
"."
] | [
"Im sorry but you are mistaken.",
"According to the Mayo Clinic:\n\"Sea salt and table salt have the same basic nutritional value, despite the fact that sea salt is often promoted as being healthier. Sea salt and table salt contain comparable amounts of sodium by weight.\"",
"No salt has Iodine naturally in it.... |
[
"Why isn't there two-photon imaging using x-ray probes for imaging of the entire mouse brain?"
] | [
false
] | In optical imaging of mouse brains (with a cranial window) two photon imaging has penetration depth of hundreds of microns. This limits imaging to cortical regions only. Why haven't fluorophores been developed which are excited by higher energy photons (x-ray for example) which would allow penetration to deeper regions of the brain? I understand higher energy photon are potentially damaging to tissue. Is this the main reason? | [
"Two reasons.",
"One is contrast. Two-photon fluorescence imaging is typically done with near-IR photons, which your body is mostly transparent to (losses mainly due to scattering, not absorption)- this means you only get two photon emission ",
" where the beam is focused. ",
"Que the famous picture.",
"Typ... | [
"Another reason, we have no good way of building an x-ray lens and no material from which to build one with (though new metamaterials may get around this). This is why x-ray experiments are relient on scattering or diffraction - the sample image is only later reconstructed. Though scattering experiments are being ... | [
"You're right. Big schools are good if you just want to throw yourself in the mix and be sure to find a little of everything and lots of talent in one place. If there's something in specific you're interested in, then go for it."
] |
[
"Why is the dirt around anthills so different from the dirt around it? As if the anthill dirt is uniformly size and dried"
] | [
false
] | null | [
"As they dig out new tunnels and chambers the ants carry the dirt out of the nest. They drop the removed soil at the mouth of the entrance, and it builds up into the mound. So the anthill is made of soil from below the surface, which may have a different makeup than the topsoil, packed into discrete balls of an o... | [
"I believe it is because when the ants excavate their home, they use their jaws and cut out little bite size pieces of dirt and carry them one by one to the outside. And because the ants are all roughly the same size, they all cut out roughly the same size chunk of dirt."
] | [
"don't they also spit on the chunks to make them stay together when being carried?"
] |
[
"How does hair know when to stop growing?"
] | [
false
] | null | [
"Please do a search beforehand to find other threads like ",
"this"
] | [
"Sorry about that! Taking my question down now. "
] | [
"no worries, just leave it up or else all your other submissions will go to the spam filter\nI've removed it :) Happy learning!"
] |
[
"What gives Blood that distinct smell?"
] | [
false
] | null | [
"See ",
"this thread",
" and ",
"this thread",
"."
] | [
"It's the iron in your blood, actually. That's what gives it the metallic, tangy smell and taste.",
"Your blood has proteins called hemoglobin, in which iron is used to transport oxygen throughout your body. That was to just explain why it's there."
] | [
"It would be a pretty imperceptible change. The iron levels in someone's blood don't fluctuate that much, even when they're considered to be deficient."
] |
[
"Is there anything in our universe that is truly random?"
] | [
false
] | In learning more in depth about mutations in genetics, it sort of came to me that not even a mutation is sort of random. It happens as a result of physical interactions and not an arbitrary event. Could an omniscient being (with unlimited powers of observation and processing ability) be able to predict everything, or is there truly randomness at a subatomic level? | [
"As far as we know, quantum mechanical processes are truly random- certainly they are random to the extent that we have no mechanism for predicting the outcome of a quantum process with certainty (we can only predict probabilistically), and there is strong evidence (Bell's theorem) that any theory which is able to ... | [
"Nuclear decay is a good example. "
] | [
"It's reasonable to treat some things as random for practical purposes, but proving true randomness is impossible. A process would have to be observed forever in order to decide it has no pattern. Randomness is not required for fundamental unpredictability. Something which is part of the universe, cannot precisely ... |
[
"Why is it that HIV/AIDS and cancer are so difficult to cure?"
] | [
false
] | Is it because they are relatively new? | [
"Variability.",
"HIV mutates in the body with a very high rate, making it difficult to eradicate it with a single agent. ",
"more info",
"\"Cancer\" is actually an umbrella term for hundreds of different diseases. Every cell in the body which replicates has a chance to become cancerous, so there are hundred... | [
"Vaccines also prevent disease, not infection",
"No, vaccines boost the immune response, thus practically avoiding ",
"."
] | [
"Slash, burn or poison."
] |
[
"How can a parrot imitate human language and why can't other species do so?"
] | [
false
] | [deleted] | [
"Birds have a structure called a syrinx located at the base of the trachea that they use to make noise. All birds have it, however in some birds (like song birds parrots and mynahs) it is extraordinarily complex and can be used to make more than one noise at a time. In other birds (herons geese and raptors, for exa... | [
"But we can! We have the most complex vocalization of any mammal. We can imitate dogs, cats, cows, horses, chickens, etc. Some people are better than others though.",
"The thing with birds is, the males who are best at a specific task tend to get all the females. If all women wanted to have babies from that b... | [
"The chainsaw and camera shutter sound too good to be true. Is there some way to confirm the video's claims other than David attenbourough is in it?"
] |
[
"How does inflation solve the flatness problem in the big bang theory?"
] | [
false
] | I realize that the amount of e-foldings inflation caused would really flatten out a universe sort of like a pancake. However in a cosmology book I have it says we can use the Friedmann equation to extrapolate backward to before inflation even happened, and see that the universe was already extremely flat at that point, so inflation doesn't really seem to resolve that issue to me. Am I interpreting something wrong here? Since I've never actually seen or heard anything about this. Been struggling with this question for a while now, don't really know exactly where to ask this so I hope this is a good place. | [
"Since you asked a technical question, I hope you don't mind if I give you a slightly technical answer. Inflation's resolution to the flatness problem - as well as its other miracles, solving the horizon, relic, and structure formation problems - lies in the simple fact that during inflation the ",
" shrinks with... | [
"I'm sure I could look this up somewhere, but for the interest of brevity, do you know how much time the inflationary period lasted, with respect to, say, the Quark-Gluon Plasma era? There's been a lot of talk in our field about the hadronization freeze-out of the QGP leading to the overdensities in the early unive... | [
"Off the top of my head, probably about 10 to 20 orders of magnitude. Inflation would likely not have lasted much longer than the Planck era."
] |
[
"I read that nicotine stimulates ADH release. Does this mean that during times of temporary water shortage, it may be beneficial to smoke? Or are the effects to small?"
] | [
false
] | So ADH makes your urine more concentrated, and makes you pee less, helping you retain water in your body more easily, right? If nicotine stimulates its release, then if I was hypothetically in the desert, would smoking or chewing nicotine gum help me preserve water any significant amount? I know the chances are pretty low of me being stranded somewhere with nothing but 20 cigarettes, a nicotine patch and a packet of pretzels, but I'm still curious. EDIT: Sorry about the grammar derp in the title. | [
"Here's an article in the British Medical Journal from all the way back in 1945 called \"",
"The Antidiuretic Action of Nicotine And of Smoking",
"\". The entire thing seems really interesting and worth the read, but just to keep it short...",
"I found this sentence right on the first page: ",
"Now, who kno... | [
"Doesn't help that nicotine itself is a carcinogen, and you should probably limit exposure."
] | [
"There are other articles, more recent, that discuss ",
"cigarette effects on vasopressin",
". Interestingly, nicotine alone has no effect.",
"However, if I were in the desert, I'm not sure an antidiuretic would be that helpful, since it might cause hyponatremia, or low blood sodium. It also raises the blood ... |
[
"Why does having both an inductor and a capacitor make a circuit AC?"
] | [
false
] | I had it described to me like a slinky bouncing above and below it's resting level, and this represents the back-and-forth of inductors and capacitors, but I'm still having a hard time understanding. | [
"AC is typically used to describe the type of power supply (or voltage source) for the circuit. Inductors and capacitors will behave differently if driven by an AC power supply. You can find more info here:\n",
"http://web.mit.edu/viz/EM/visualizations/coursenotes/modules/guide12.pdf"
] | [
"The other comments are correct in that you can drive an alternating current with a power source, but I think the point being made is that ",
" a power source and assuming no loss of energy (e.g. through resistance of the wires), a circuit with just a capacitor and inductor has the ability to oscillate at a natur... | [
"A follow up question then would be is it this characteristic which led to AC being an initial choice for domestic circuits?",
"\nI can kind of intuit a mythical notion of stability and distance as a result of ossiclation at a specific frequency (60khz for instance).",
"[ to clarify -- by initial choice I mea... |
[
"With the advent of an asteroid flying by, what would be our plans for an asteroid heading directly towards us?"
] | [
false
] | null | [
"A little off topic here, but with them hitting the earth all the time and not doing much damage...",
"Isn't the theory on how earth had such large oceans due to constant bombardment by thousands upon thousands of asteroids containing ice?",
"If this is so... what happened to them all? I'm not knowledgeable at ... | [
"citation neeeded :)"
] | [
"Realistically, though, the plan is to hope it's not large enough to cause an extinction event and a lot of us will probably die. We simply don't have the technology or resources to detect and divert asteroids soon enough.",
"However, asteroids hit the earth all the time, most of them are quite small and don't c... |
[
"What is the \"Pseudo-gap\" and how does it relate to every day life?"
] | [
false
] | Not long ago, there was a news brief about the discovery of evidence that the Pseudo-gap was real. The pseudo-gap sounded not like a fake clothing retailer, but was instead something responsible for blocking the conduction of electromagnetism. Can someone explain a bit more about what the pseudo-gap really is and if it can be overcome, how will it change our technology? | [
"The recent news said something rather different, actually - the pseudogap has been well-known to exist for quite some time.",
"Before we get to the pseudogap, I need to explain what a(n energy) gap is. In materials, electrons can occupy lots of different states with lots of different energies. However, in some c... | [
"Do you think generating a material that superconducts at higher temperatures is feasible or still out of range? Apart from the applications, the principle is remarkable on its own too. Is there a general class of materials that people are thinking could exploit this?",
"This is extremely well-written and easy ... | [
"High-Tc (critical temperature) superconductors are something that people have been searching for for decades. We've made some incredible strides. Initially, we only knew of materials with critical temperatures in the liquid helium range (4 Kelvin, ~-270C), but now we have materials (BSCCO, YBCO) that are in the ... |
[
"Could there be life in oceans deep under the crust?"
] | [
false
] | [deleted] | [
"These \"oceans\" are a misnomer. There are not oceans deep under the surface. There is a vast amount of \"water\" in the mantle of the Earth, but it is in the form of hydrous minerals. These are just minerals with Hydrogen and Oxygen in them - not literally water. And only as a very small % of the elements in mant... | [
"For now the known thermal limit of life is ~120°C. But it is not expected to be much higher, there are some claims that it could be possible for slightly higher temperatures, but the current limit already only exist under laboratory conditions.",
"\nYou have the problem that DNA degrades faster with increasing t... | [
"they are not literal oceans, due to subduction zones a lot of water gets pulled into the mantle so the mantle naturally contains a lot of water - therefore, you also encounter very water rich minerals and rocks in the vicinity of subduction zones",
"\nand to counter evaporation you just need enough pressure, tha... |
[
"If we stopped an object's orbit in space, would it \"fall\" towards the sun?"
] | [
false
] | null | [
"Yes, that is correct, unless the object is under stronger influence of another body. For instance, if you stopped the Moon from rotating around the Earth, it would collide with Earth. Likewise, if we stopped Earth, it would fall into the Sun.",
"So the \"reach\" of gravity is basically defined by an object's H... | [
"An orbit is essentially falling towards an object with enough lateral motion to continually miss. If we remove the lateral motion, then you are simply falling toward it."
] | [
"By my math, it will take closer to 1/6 of its orbital period, as the acceleration increases as distance decreases."
] |
[
"Does a caterpillar retain it's \"Identity\" when it become a butterfly ?"
] | [
false
] | In other words, is it the same individual or does the caterpillar "dies" when it undergoes metamorphosis for a new butterfly with no prior memories or experience to be born ? If yes it means that the nervous system of the caterpillar is preserved during metamorphosis ? Thanks for your answers ! | [
"There is probably no clear answer to this, since there is a lack of a clear definition for \"identity\" as you use it in this context.",
"The nervous system is changed in the metamorphosis, but it is not completely destroyed and rebuild, see here for example ",
"https://www.frontiersin.org/articles/10.3389/f... | [
"Yes, the nervous system persists during metamorphosis, although it is also greatly extended and remodeled - the adult insect has very different senses than its juvenile self, and responds to them with very different behaviors. But an adult insect can still respond to cues it was taught to respond to as a larva.",
... | [
"I listened to a segment about this on NPR several months ago, and it was absolutely fascinating to learn this."
] |
[
"Geologists of reddit: what is this rock I found?"
] | [
false
] | Neither a fingernail nor a penny seems to scratch the rock. The penny leaves a streak of metallic shine on it, but since the side of the penny is also damaged, I am concluding that the penny, not the rock, was scratched, and the penny just left some residue on the rock. | [
"That could be a few things. Realgar, or Cinnabar. Looking from the fracture and what I can see though, the likely hood it is Chert is very low. In my opinion, it is Realgar. ",
"@ Freezer: BIFs are dominantly from 3.7 -> 2.6Ga. Although, BIFs can form anytime the ocean/sea is \"choked\" off from surface air. Th... | [
"Cool, you're right. I should have checked the range, I was working from memory. If it's chert, I still doubt this originated in Iceland, but I'm not familiar with Realgar. How is it formed?"
] | [
"You don't need BIFs for chert. Chert is simple a chemical sedimentary rock that can be found in many environments (from river deposits to limestone to BIFs etc). My guess is some hydrothermal fluid dissolved some iron and silica and deposited as chert. ",
"Edit- I am on my phone so I can't see the pictures very ... |
[
"Would it be possible to selectively breed dogs back into a wolf, or is the process completely irreversible?"
] | [
false
] | [deleted] | [
"Depends on what you mean by that question.",
"Could we selectively bread dogs to physically appear like wolves? Yes, it would take a while but simply selecting for more wolf like characteristics and breeding them will eventually lead to an animal that looks like a wolf. Something similar was tried in Germany w... | [
"Technically yes they wouldn't be wolves, but it would be possible to breed dogs that look and behave much like wolves. It might not even be too difficult."
] | [
"Genetic recombination means genes will be lost from a population in favour of the genes you selected for artificially. So the basic answer is yes it would be theoretically possible to return a dog breed to what is essentially a wild wolf without involving wolves again to reintroduce lost genetic diversity. Genes d... |
[
"Sand that’s beneath the sand at the deepest part of the ocean - is it wet too or is it dry due to some kind of intense pressure barrier?"
] | [
false
] | null | [
"It's still wet. ",
" It is possible to completely dry an ocean sediment, but (1) not through pressure alone and (2) not under conditions that exist in most sea-floor sediments.",
"Sea-floor sediments are (obviously) water-saturated at the point of deposition so to obtain dry sediment, some process has to remov... | [
"Fantastic answer! Explained the simple terminology so well I was actually able to follow and understand."
] | [
"I always thought it was the heat that did this. Does heat still playa factor there though?",
"Yes, but the pressure is more important. ",
"This is the most famous form",
" of the metamorphic phase diagram which essentially tells you key mineral assemblages that start forming at different temperature-pressur... |
[
"How do we know the \"stable\" isotopes don't just have absurdly long half-lives (as in several magnitutes times the age of the universe)?"
] | [
false
] | I know bismuth was formely considered stable until it was discovered it just had an extremely long half-life. | [
"We don't really, it is theorized that protons even in stable atoms may decay over long enough timescales, in this case no atom would truly be stable. There are also the tiny probabilities that collections of stable atoms may slowly undergo spontaneous fusion events which isn't radioactive decay but would mean that... | [
"As has been pointed out, the best we can do is to set lower limits on the half-times of various nuclei and even protons which we believe to be stable. To put some numbers on it, the age of the universe is about ",
"10",
" s",
" and limits on the lifetime of the proton are ",
"tau_p > 10",
" s",
". So w... | [
"The standard model predicts infinite stability - this is because it conserves baryon number, and there are no lighter baryons for a lone proton to decay into. ",
"In contrast, grand unified theories often do not have that conservation law, and predict that protons can and do decay."
] |
[
"Are the cells of donor organs replaced by the recipients cells over a long period of time or do they remain..?"
] | [
false
] | To elaborate. Let's say I donate my heart to somebody after my death. Through mitosis my cells should be replaced and supply the hearth tissue with healthy new cells. Does this continue to go on or will the recipients body start to send out totipotent or pluripotent cells / or earlier heart cells of some kind to start to replace my cells. The real question to me is, will re recipient still have genetic material of me inside him when he passes away? Thanks in advance, sorry if this question sounds weird. | [
"To my understanding of developmental biology, the organ will always be composed of cells from the donor. The cells that would divide in your heart to replace old/dead/damaged cells would come through the mitosis of other cells also within the heart as opposed to the liver or the immune system.",
"The real quest... | [
"Your understanding is correct, which is why solid organ transplant recipients require lifelong immunosuppression, to prevent rejection of the foreign cells."
] | [
"Histidine's response is largely correct, but being a heart researcher I figure I'd provide some specific info regarding the heart -",
"The heart is a very special organ in that most of the heart cells are not replaced throughout your lifetime. There's extremely limited regenerative potential in the heart, which... |
[
"Do all male mammals have useless nipples like humans do?"
] | [
false
] | null | [
"Platypi and echidnas do not have nipples, true. They have broader glands under the skin, and suckling occurs through the skin proper and not a mammary.",
"However, all eutherian, placental mammals (non monotreme, non marsupial) have nipples regardless of gender, and these are functionally identical save that mal... | [
"Platypi and echidnas do not have nipples, true. They have broader glands under the skin, and suckling occurs through the skin proper and not a mammary.",
"However, all eutherian, placental mammals (non monotreme, non marsupial) have nipples regardless of gender, and these are functionally identical save that mal... | [
"females (XX) and males (XY) initially develop the same.",
"in the womb all babies develop as female. then the Y kicks in by producing a protein that changes the genital tubercle from a clit to a penis. hence leaving nipples because the baby initially developed as female."
] |
[
"How much, if any, Vitamin D can I get from indirect sunlight?"
] | [
false
] | null | [
"This article is very informative ",
"http://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/",
"\"The factors that affect UV radiation exposure and research to date on the amount of sun exposure needed to maintain adequate vitamin D levels make it difficult to provide general guidelines. It has been sugg... | [
"I would like to point out that you don't get vitamin D from light, you make its precursor which is converted to active vitamin D by light."
] | [
"Would it dramatically change depending on latitude and season?"
] |
[
"Why don't dipole-dipole interactions induce a spontaneous chain reaction and align all molecules in a polar liquid/gas?"
] | [
false
] | My best guess is that the random motion of the molecules due to their kinetic energy prevents them from organizing like that. Is this true/ the whole story? Do MRIs work by overcoming this kinetic energy with a strong magnetic field? Is this what is going on when a polar substance like water freezes? | [
"I'll talk about something similar: small particles that are longer than they are wide (anisotropic colloids). These are sometimes known as liquid crystals.",
"There are various benefits to having them aligned. Perhaps due to a dipole interaction, or because they're being squeezed together. However, the entropy o... | [
"My best guess is that the random motion of the molecules due to their kinetic energy prevents them from organizing like that. [..] Is this what is going on when a polar substance like water freezes? ",
"Yes, that's essentially correct, with a slight caveat. For a simple dipole (say, NaCl), there's only really on... | [
"I've spent time hanging out with the members of the ",
"Whaley group at UC Berkeley",
", who study interactions in arrays of cold, dipolar molecules. For more than I give here, check out some of their recent publications.",
"At zero temperature, there are definitely a variety of systems in which fluctuations... |
[
"Can a material be both electrically conductive and an isolator?"
] | [
false
] | I mean, for example, you flip a switch and make a material an isolator, and than flip it back so current can flow through it. Is that physically possible? Could you make that? | [
"Superconducting electromagnets often make use of a powdered superconducting material, embedded in a thin tube of metal like silver or copper. (The SC itself is often quite brittle, hard, and otherwise very difficult to shape into wires, strips, or coils. )",
"These magnets have the advantage that, once a current... | [
"I think you're kinda missing a big one here, which is the entirety of semiconductor and computer technology, which involves flipping something from an insulator to a conductor and back by applying a voltage at the transistor gate."
] | [
"Yes, this is how computer chips work, they're just trillions of MOSFET transistors that flip the conductivity of the transistor channel electrostatically. You also control conductivity through applying strain and by inserting impurities. There are also things like phase-change memory where you can literally re-ord... |
[
"Is there a Universal base number system?"
] | [
false
] | null | [
"Whether a number is whole or not has nothing to do with the base of the number system used. Pi will never be a whole number, because it is not an integer. ",
"There's no reason, I suppose, that you couldn't use a base-pi number system... Except that then all the integers would be infinite non-repeating decimals,... | [
"Not really. The (interesting) properties of numbers should generally be independent of how we write them."
] | [
"I found this cool ",
"Radix Converter",
", along the lines of what I'm pondering."
] |
[
"Is it correct (Scientifically) to refer to Humans as Omnivores?"
] | [
false
] | Not all of us eat meat, not all of us eat plants and some of us enjoy both. We've got a couple of sharp teeth for tearing meat (I assume) and some flat ones for chewing greens (I assume). Whats the verdict askscience?? | [
"We are omnivores by design, even if we arent all by habit. Same way that someone with backwards sleep habits would not put our status as diurnal as any different."
] | [
"Evolutionarily speaking, we are omnivores. Biochemically, we have the means of obtaining nutrients from both plant and animal matter. Culturally, or by habit as IamPolaris_247 says, it doesn't means we HAVE to eat both, but we certainly are capable of it. "
] | [
"So you are saying that a human can live with either plant or animal matter without really ",
" the other?\nThen why is it a nutritionist recommends that we have both in a balanced diet?"
] |
[
"If I have a quad core CPU, what consumes more power - running one core at higher frequency, or a multiple cores at lower frequencies?"
] | [
false
] | To be specific, what consumes more power - Running one core at, say, 1.4 GHz Running two cores at 700 MHz, or Running four cores at 350 MHz? | [
"Really depends on the internal details, but there are simple arguments that says running multiple cores at lower frequency is better for power usage. I recall nvidia specifically using this argument behind their claim of improved battery life in one of their Tegra chips.",
"The basic idea is that in order to run... | [
"CS MS here. Note that your options are not necessarily computationally equivalent. Depending on the actual parallelism of the algorithms being executed on these cores, which depends (among other things) on the intrinsic parallelism of the problems the algorithms are trying to solve, you may have four cores at 350 ... | [
"So there's no way if knowing for sure? Considering the same load? "
] |
[
"Question in Cosmology: Wouldn't the big bang have produced a completely homogenous universe? Wouldn't objects exist at ~equal distance from one another and all look relatively the same?"
] | [
false
] | I am not discrediting the theory by any means, but I obviously am misunderstanding something about the theory and would like some clarification. According to Newton's first law of motion When viewed in an inertial reference frame, an object either is at rest or moves at a constant velocity, unless acted upon by an external force That would mean all matter leaving the initial blast would have evenly distributed as there wasn't anything else to act upon it. Nothing would have caused one section to go further than another. So then, why when we look at the universe do we see so many different shapes of galaxies and why aren't galaxies (and the objects inside of them) pretty evenly distributed? The only answer I was able to come up with for this is that the "space" that matter occupied had to expand as well, and as we don't exactly understand how the edge of our universe works, maybe it doesn't expand evenly, leading to the differences we see in the universe? Thanks in advance. Also, I did read the rules and I realize that hypothetical questions are discouraged. I am not looking for personal theories or hypothetical answers, but to understand if this is a question that has already been explored and answered to some degree by scientists. Edit: Thanks for the answers and . This has really cleared up some confusion I had | [
"Surprisingly enough, the universe is quite homogeneous and isotropic.",
" The deviations in the CMB are very, very small amounts. While the picture you see of the CMB shows drastic colour differences (colour representing temperature), keep in mind that these differences are just tiny percentages over the norm. I... | [
"bertrussell is totally correct that this is still an unanswered question, but I thought I'd give one possible answer:",
"A high temperature gas means that the individual components of that gas have random motion. ",
"Furthermore, heavier objects (such as helium, lithium, etc) existing in that gas will exhibit:... | [
"A high temperature gas means that the individual components of that gas have random motion.",
"Sorry, but this is a non-explanation. The question is: Where does the randomness come from in the first place? Heat isn't just magically \"random motion\". Every bit of this motion for every single particle/molecule wa... |
[
"How are steel construction building beams allowed to get rusty and remain exposed to wet weather? Wouldn't that compromise their integrity?"
] | [
false
] | [deleted] | [
"Sea cans are made of a grade of steel that skins over a protective layer of rust that goes no further than the surface.COR-TEN, or Corten steel, is commonly referred to as weathering steel. The name Corten is the trademarked name. It may seem counterintuitive, but when exposed to the elements its chemical makeup... | [
"What is a sea can?"
] | [
"The large 10x10x40 shipping containers you see on cargo ships and transport trucks. "
] |
[
"Where does the earths core get its heat energy from?"
] | [
false
] | from what I understand, the core of the earth is extremely hot. It's temperature is similar to the temperature of the sun's surface. The earth's core has been burning hot for billions of years. What are the sources of its perpetual energy? Also, how far would we have to dig to feel the temperature rise? | [
"The main contributors of the earth's internal heat are gravitational heating (dense stuff moves toward the core, trading gravitational potential energy for thermal), and radioactive heating (heat production by decay of unstable radioisotopes, particularly U, Th and K).",
"The top few tens of meters of the crust ... | [
"Every time an earthquake goes off on earth those seismic waves propagate through the planet. We have hundreds of seismic sensos lcoated around the planet, and that means that when they detect that earthquake we get hundreds of different signals from that one event. The difference in those signals is a function of ... | [
"Something I've always wondered: how exactly do scientists measure the temperature and composition of the earth's core?"
] |
[
"Does Foucault's pendulum demonstrate that the earth is spherical or merely that it rotates?"
] | [
false
] | null | [
"The Foucault pendulum demonstrates that you are in a rotating frame of reference, so it shows that the Earth is rotating.",
"A collection of Foucault pendula at different locations could be used to infer that the Earth is spherical, as the pendula at different locations will have different periods."
] | [
"Not a stupid question -- don't have a time for a long answer now, but take a look at ",
"Newton's bucket argument",
" and, more generally, ",
"Mach's principle",
". One way of framing your question is whether or not rotational motion only has a relative meaning.",
"The general view today is that you wou... | [
"Possibly a stupid and/or meaningless question:",
"If the Earth were the only body in the universe, could it still rotate? In other words, is a second object required to define a frame of reference in which the first is rotating. If so, do Foucault pendula act like simple pundula in that universe?"
] |
[
"So broadly speaking, white reflects radiation and black absorbs radiation. Then why do paler people experience sun damage so much faster than darker people?"
] | [
false
] | I mean I know it's because of melanin but I guess I'm just approaching biology like the amateur physicist I am here and I'd like to reconcile the two! I mean why does melanin end up making skin darker to reflect more light? EDIT: Thank you all so much for your great answers! Really enjoyed reading the discussions that were started too :) I think the reality of biology tends to be so much more complex than the (relatively) simple scenarios examined in physics, and that's part of what makes it so interesting! | [
"The purpose of melanin is not to reflect light. Melanin actually absorbs the UV radiation from the sun. Without sufficient melanin the UV radiation penetrates our skin cells and damages the DNA. If you're out in the sun without protection long enough the DNA damage gets severe enough to kill the cells resulting in... | [
"Actually, the cells damaged by the sun \"kill themselves\" so that they don't become carcinogenic cells."
] | [
"Hopefully. When that programmed cell suicide goes awry, and they also happen be multiplying uncontrollably, you get a malignant tumor."
] |
[
"Is there any probably reason (other than pregnancy) for a woman with an irregular period, not on birth control, to be late by over a month?"
] | [
false
] | null | [
"The short answer is yes, there are a variety of reasons for irregular periods. Most of them are good reasons to visit the doctor."
] | [
"My wife was on the depo for several years and once she stopped getting the shot, she had irratic periods for about a year and half with them sometimes coming within 2 weeks of each other and sometimes skipping a month or so. Other factors can come into play as well such as stress and diet. She might want to go see... | [
"Stress, underweight... a lot of things :/"
] |
[
"I have IBS: constant diarrhoea. How much nutrition am I likely to miss?"
] | [
false
] | Not here for health advice - have been seen by specialists etc, and the consensus is that I should just put up with it, which I do. My question is, how much of the goodness of the food I eat will go through without being absorbed? Oftentimes, the food I eat barely touches the sides - I'm on the throne within minutes. I eat good healthy food, and I get the sense I might as well throw it straight in the sewer without involving the middle-man. Follow-up question: If I do miss some nutrients, might that cause lethargy and malaise, in general? | [
"I have IBS and am extremely healthy. You have nothing to worry about aside from the inconvenience, pain, and embarrassment of constant shitting.",
"FWIW I got myself a medical marijuana card and it's a miracle cure, provided you can use it when necessary. "
] | [
"Hey, thanks for the reply. I've heard other people say that the MJ helps, but there's no medical MJ here in New Zealand. \nIt's kind of easy enough to get anyway, but I'm getting too old to be dealing with drug dealers.",
"So I should be alright nutritionally though huh. That's good."
] | [
"Sorry, another follow up question: Exactly how does the marijuana work, do you know? What does it do, physically?",
"I'm not talking about getting stoned, I was wasted through two years of my degree; I mean, what does the MJ do that makes it a miracle cure?"
] |
[
"If you had mugshots of a billion people, would current computer technology be able to sort them by appearance?"
] | [
false
] | The system would create a huge map of everyone, and the closer you were to someone the more they would look like you. Or maybe this has already been done by Facebook/NSA/etc.? | [
"https://en.wikipedia.org/wiki/Eigenface",
" is the reference you want."
] | [
"Facial recognition software doesn't work the same as how humans recognize faces. If you don't tell the system what gender and ethnicity the face is, it might find a similarity between an African man and a Chinese woman - just because the distances between the facial features are similar"
] | [
"Just wanna point out the simplest eigenface implementations have a bunch of issues.",
"Lighting, clothes, and facial expression can all be significant (so the algorithm might not recognize you at night, in a different shirt, or if you are smiling instead of frowning)."
] |
[
"Why don't we know the size of the entire universe?"
] | [
false
] | We know when it started and how fast it expands, so why are we unsure about how much 'space' there is beyond our observable universe? | [
"The Big Bang isn't an explosion of matter within space - it's the expansion of space itself. If the Big Bang was a classical explosion within some large or infinite space, you would indeed expect all the matter in the universe to be contained in a sphere, about 13.7 billion light-years in radius.",
"However, the... | [
"It's not mathematically necessary for a flat universe to be infinite, but for it not to be, you either have to defy the Cosmological Principle or allow especially \"weird\" topologies, like the universe is a higher-dimensional torus.",
"Defying the Cosmological Principle is effectively a non-starter for any theo... | [
"Thanks for this response. Does a flat geometry necessarily mean the universe is infinite? In other words, if we knew that the universe was flat, would that also mean it was infinite? Is it possible to have a flat geometry that is not infinite?"
] |
[
"Does the immune system remember it's last attempt at shuffling genes when searching for a better \"recipe\"?"
] | [
false
] | Hey guys, I know that the immune system is able to shuffle some genes around in the hope of finding a protein that binds on some part of the pathogen it's trying to get rid of. It's very simplified I know. I have no background. Here's my question. It will be a mess because I don't really know how to formulate it. Please bare with me! I was wondering about this : It finds a recipe that kind of work but it not a perfect fit. The system needs to shuffle the deck again. Does it remember that the last recipe only worked at 60% for example and it only needs to refine the last 40%, or does it starts from scratch hoping to find an event better solution since it can't really remember or feel how well it worked? Is it able need reiterate from prior attempt and knowledge gained? | [
"No, it doesn't \"remember\" anything. We like to imagine that biological systems are intelligent in some way and that the things that happen on a molecular basis have some kind of consciousness. For example: \"a cell grows and when it's big enough divides into two new cells\" or your example \"immune system fights... | [
"You are actually describing two different processes that happen in the evolution of antigen binding proteins (antibodies or T-cell receptors). I will describe antibodies as I think people are a little more familiar with them, but T-cell receptors work in very analogous ways.",
"First, before any antigen is prese... | [
"Exactly true. We far too often anthropomorphized processes that are purely chemical, purely probabilistic."
] |
[
"How much force does it take to stop a bullet?"
] | [
false
] | I use a Powdered Actuated Tool at work. It uses .22 caliber rounds to drive a nail into concrete. How much force is acting against me when I use it? | [
"Any finite force will stop a bullet eventually."
] | [
"What kind of universe did I step into where joules are a unit of force?"
] | [
"What kind of universe did I step into where joules are a unit of force?"
] |
[
"Why do nuclear reactions emit electromagnetic waves?"
] | [
false
] | Mass converted to energy through e=mc is in the form of kinetic energy and electromagnetic waves, now my question is why they form electromagnetic waves? | [
"Disturbances in electromagnetic fields manifest as electromagnetic waves. It's usually the movements of electrons that we associate with these disturbances. Protons, being charged particles, can also disturbe electric fields when they move/change in nuclear reactions."
] | [
"E=mc",
" in fact refers only to the rest energy of a particle. In early physics, a box at rest would be considered as having zero energy if it was taken to be \"on the ground\". Einstein's famous equation simply says that mass itself is highly compacted energy, and as such, even a stationary particle with no oth... | [
"Thanks for your comment! I have a question to add on to what you said, does the energy of the nuclear reaction influence how fast the proton accelerates, and therefore make the electromagnetic wave more energetic?"
] |
[
"Do we know what the core temperature of the earth was when it was formed, and do we know how much it has cooled since then?"
] | [
false
] | null | [
"I haven't been able to find a lot on the temperature of the core at the time of formation, but scientists estimate it will take 91 billion years to completely cool. In practical terms it may not get time to cool completely because the Sun will enter its Red Giant phase in approximately 5 billion years.",
"Based ... | [
"Our sun is NOT going to 'go nova,' it's going to enter its red giant phase and maybe expand enough to include Earth's current orbit, maybe not. There's plenty of room in the uncertainty on the specifics of our star's future evolution for some or all of the inner bits of the Earth to survive the whole red giant pha... | [
"No, thank you for the correction."
] |
[
"What makes copper (Paragard) IUDs safe?"
] | [
false
] | I read that copper IUDs work by releasing copper into the uterus and causing an inflammatory reaction. How could it be safe to have a constantly inflamed uterus for up to 10 years? | [
"To clarify, all IUDs (regardless of whether they are copper releasing, levonorgestrel releasing, or inert), ",
"cause localized inflammation",
". It's also important to acknowledge that the exact mechanism of IUD activity is not perfectly understood, though there are a number of likely pathways worked out. "... | [
"Your citation does not support your statement that copper IUDs cause PID due to a low grade inflammation.",
"The concern that IUDs cause pelvic inflammatory disease is based on the hypothesis that insertion or maintenance of the IUD device \"may facilitate the ascendance of sexually transmitted organisms from th... | [
"Does science have an understanding as to how the paragard causes increased cramping for many/most women who have it? Why does the cramping tend to go away with time?"
] |
[
"What are the benefits from bringing back resources from asteroids?"
] | [
false
] | I see what Planetary Resources is attempting but why would such great quantities of resources helps us? Are we currently limited by our resources, excluding oil I mean? | [
"the earth does not have an equal distribution of all elements so this causes some of them to be extremely rare and therefore expensive."
] | [
"Such elements as?\nWould any of these be usable as an alternative power source?"
] | [
"In particular the platinum group metals: ruthenium rhodium iridium osmium palladium and platinum. These are extremely useful in advanced electronics (things like electric cars, etc.) and are quite rare in the Earth's crust. ",
"In terms of power sources, some asteroids contain abundant water ice that can be extr... |
[
"Is the reaction of Silicon and Chlorine dangerous?"
] | [
false
] | [deleted] | [
"This reaction is producing silicon tetrachloride (SiCl4), a volatile liquid used in industrial silicon refining. It is a dangerous molecule because it produces hydrochloric acid when it touches water. The reaction producing it is also quite hazardous because you're heating chlorine gas up to a few hundred degree... | [
"Chlorine gas definitely isn't something I would recommend using in \"my first ever Chemistry project for school\". When it comes in contact with water (including that in your cells) it creates hydrochloric acid. Having strong acid form in your lungs if something goes wrong isn't really a risk worth taking in my op... | [
"Whenever you want to know the hazards of a chemical, google \"chemical name MSDS\"",
"Like ",
"silicon tetrachloride",
"and ",
"chlorine"
] |
[
"How can fruit ripen even after having being picked?"
] | [
false
] | null | [
"When the fruit is on its tree or bush, the roots are bringing up water and other minerals from the ground, while sunlight is being shined upon leaves. Very simplified, photosynthesis converts CO2 from our atmosphere with water to create glucose, which is the plant's energy source in order to grow. Inside each frui... | [
"Ethelyne reacts or catalyzes?"
] | [
"Ethylene is actually a plant hormone, much like testosterone and estrogen are for humans. When plants begin their reproduction cycle, ethylene production is increased, via the Yang (methionine) Cycle. Plants also produce ethylene during times of stress and physical damage. So, it would not be considered an enzyme ... |
[
"Since plants have immune systems just like animals, is it possible for them to have allergies?"
] | [
false
] | null | [
"Yes! The plant immune system recognizes and responds to certain pathogenic proteins. These pathogenic proteins (called \"effectors\") are sometimes referred to as \"avirulence genes\" in the pathogen, because the plant immune system will efficiently recognize a potential infection by a pathogen with an \"avirulenc... | [
"It's as analogous as you will find when comparing such diverse organisms as plants and animals. An allergy is an immune response above and beyond the \"helpful\" scope. Similarly we can create visible HR \"lesions\" by exposing plants to ETI-inducing proteins at a higher concentration than normal. ",
"Plant immu... | [
"Does that still count as an allergic reaction, though? Those are a result of the body overreacting to a perceived threat and releasing chemicals into the bloodstream that cause a slue of problems. If it’s intentional, I don’t think it counts"
] |
[
"How do they know what colour dinosaurs were?"
] | [
false
] | They always seen to be brown or green. Are these just guesses, because fossils don't offer any clues to skin colour? Surely there were some variations to the brown/green dinosaurs, as there are variations in animals these days. Were there any brightly coloured dinosaurs? | [
"They've found that some dinosaurs were black, white, and red-brown! They worked this out by ",
"investigating the structure of dinosaur feathers",
". They may have also been ",
"iridescent",
".",
"Anything apart from that is purely speculative. Dinosaurs have often been portrayed as brown/green probably ... | [
"That's really interesting. It was actually a peacock that got me wondering about this. If you found a peacock fossil but had never seen a peacock would there be a way to tell it was coloured the way it is? So it seems you would be able too? "
] | [
"Outside of the pigments we've found in feathers (which, as I recall, is a relatively recent development), we really have fairly little idea of what colors dinosaurs actually were, which is why there are ",
"so many",
" ",
"different interpretations",
" ",
"of what dinosaurs",
" ",
"looked like.",
"... |
[
"Do we know what the tallest mountain ever was?"
] | [
false
] | null | [
"Various flavors of this question are very popular on AskScience, so it might be worth checking out one of the more ",
"recent times a similar question came up",
".",
"With respect to our specific ability to determine what the tallest mountain ever might have been (or more generally, our ability to reconstruc... | [
"This is indeed a fun back of the envelope exercise, but fundamentally ignores some very basic aspects of how mountain ranges are built and supported. One of the best discussions of this is the classic ",
"Molnar and Lyon-Caen, 1998",
" paper (and ",
"here is a link to a PDF outside of a paywall",
"). The t... | [
"/u/CrustalTrudger",
"'s answer is more in depth than I could ever write, I'll just mention a point made by one of my teachers in uni giving some insight to your first question: how high has the tallest mountain on earth has ever been. This was an example he gave on the relevance on back-of-the-envelope calculati... |
[
"How do deciduous trees know when to drop their leaves? What would happen to them if winter never came?"
] | [
false
] | Obviously temperature is super important to this process, but what actual patterns trigger dormancy, and how can these get messed up? | [
"It's not temperature that causes trees to lose their leaves, it's hours of sunlight.",
"Trees, as you can imagine, are pretty good at using sunlight. When they notice the hours of daylight per day start to get below a certain number, that triggers them to go into dormancy.",
"If winter never came, if temperat... | [
"I recalled from my biology classes the phenomenon is called photoperiodism and experimentally proven that the receptor cells respond to night length.",
"To simplify things The photochemical Messengers generated requrie uninterrupted darkness to avoid being reverted to their base/inactive state . ",
"https://e... | [
"Isn’t it the length of nights that matter rather than daylight ?"
] |
[
"Would it be possible to invest so much money into a bank that it couldn't support the amount of interest it would owe you or wouldn't be in the banks best interest, as it would be too expensive?"
] | [
false
] | Do banks ultimately have an infinite supply of money? I'm thinking the answer would be that in theory, it's possible, but no one has that much money. What about if you went to a small rural town bank? I may be missing something completely obvious, but was just a thought I had. | [
"The more money you give to a bank, the more money they have to make investments and earn money.",
"So, assuming the bank was competent at making investments, no, you couldn't bankrupt a bank by over-investing."
] | [
"Depositing a huge amount of money into a bank will cause problems, but not necessarily the one you're thinking of, because of the aforementioned need for a bank to earn money with your money, so they can pay you interest.",
"The bank needs to find people/firms to lend your vast amount of money to. To encourage t... | [
"You have to remember interest you gain from the bank is lower than inflation. They don't even have to gain value from investing with your money to be able to pay you back."
] |
[
"Is there a limit to the size a planet can be and still be considered habitable?"
] | [
false
] | I mean could a planet be the size of jupiter and have life on it, under conditions similar to earth (water, oxygen, sunlight etc...) | [
"It could certainly sustain bacterial life and probably protozoans too. The question of more complex life is harder to answer.",
"Let's take Jupiter from your example. Gravitational acceleration at its surface is 24.79 m/s",
" or about 2.53g, where g is the gravitational acceleration on the surface of the Earth... | [
"Related question - does this mean that there is an orbital distance from Jupiter where you would have exactly 1g of gravitational force, so that if you had a space station orbiting in that orbit, you'd have earth-like gravity?",
"No. There is some altitude above Jupiter where the gravity would be exactly 1 g, bu... | [
"So you don't have an actual source, just common sense?"
] |
[
"Do people actually die from a 'broken heart'?"
] | [
false
] | [deleted] | [
"Severe stress can actually cause a weakening of the muscle walls of the heart, which can lead to death.",
"Called Takotsubo cardiomyopathy"
] | [
"Confirmed, I see this regularly in my line of work. Impressed this was in the first comment :-)"
] | [
"There is also something called \"Failure to Thrive\" and a lot of older people get diagnosed with it after losing a significant other. ",
"Wiki",
"\n*Edit formatting "
] |
[
"Can weight lifting create more hormones in your body?"
] | [
false
] | null | [
"Yes, proper exercise with resistance will increase the levels of \"good\" hormones. Not only is there a increase in serum testosterone levels, but in Growth Hormone and IGF-1, a couple of other important anabolic hormones. A study published in ",
"Int J Sports Med. 1991 Apr;12:228-35",
" showed this hormonal i... | [
"Likely what you're experiencing is an increase in testosterone (T). This is probably in response to your weight lifting activities. T is also important in libido, which is why you're seeing an increase in sex drive. T is converted into estradiol (E2, which is the same hormone in women) and dihydrotestosterone (DHT... | [
"Alright, this is going to sound stupid, but would this be able to promote facial hairgrowth aswell as an extention of the greater amount of testosterone?"
] |
[
"What's preventing us from curing diabetes?"
] | [
false
] | Aside from things like lack of funding, what are some of the scientific/medical field obstacles? Are we just not at a high enough level of understanding? Does bioethics come into play anywhere? As a type 1 diabetic with some, albeit little, knowledge, I'm more than curious as to what's stopping us! Edit : To everyone who has participated, I am unbelievably grateful for your time. All this information is extremely helpful! Thank you! I have so much love and respect to everyone who has, has lost, or is losing someone to, diabetes. Love every second of your lives, guys. I'm here for anyone who is effected by this or other correlated disease. I am but a message away. | [
"Type 1 diabetes is an autoimmune disorder. This means that the patient's own immune system is attacking the cells in the pancreas that produce insulin. Why the immune system does this is related to genetic and environmental factors.",
"Because these cells are destroyed, the pancreas cannot make insulin, but the ... | [
"The primary reason is that the disease we commonly think of as \"diabetes\" is actually a middling large ",
" of diseases with a shared primary symptom - chronically high blood sugar. But each one of them is in fact the result of a different metabolic failing or external factor. Some of the best know factors an... | [
"Research is certainly happening in that area, but the whole reason ",
" and ",
" ones' various organs even go about producing hormones ",
" is not well understood. Not the least reason for our current state of knowledge is that most hormones - including insulin - are ",
"chemically very complex",
", and ... |
[
"If something travels at faster than speed of sound without generating any noise, then still there will be sonic boom?"
] | [
false
] | By something i mean anything like some rocket or airplane etc. but it is important that it must not generate any noise like from engine. | [
"A sonic boom isn't generated from the propulsion system of any machine.",
"Sound is pressure waves. A supersonic object creates a pressure cone where it is splitting the air. The boom you hear is when the cone intersects your ear. A supersonic bullet has a miniature sonic boom without producing any other noise. ... | [
"Supersonic is only 0.34 km/s. Orbital velocity is 7km/s so no, most supersonic things will just slow down and hit the ground. You are correct that in space, you can go as fast as you want without creating a sonic boom per se. There is very diffuse gas in space, but drag or pressure waves will be insignificant."
] | [
"More specifically, it produces a shockwave by forcing the air in front of it to 'move aside' faster than the speed of sound causing a density spike. There is also a second shockwave originating behind it as the object leaves a partial vacuum behind it that collapses.",
"I suspect you could make an extremely tape... |
[
"Why do notes in chords fit together"
] | [
false
] | I'm doing a project in school which all students must do for their senior year in Sweden. The question I have chosen to answer is; I have a theory that it has something to do with the waves fitting together in some way. But other than that I don't know much. I don't really know how to proceed or how to test this. I also would need some easy-to-find literature on this subject and maybe some studies for validation. | [
"This is a good place to start. ",
"http://www.edly.com/mtfpp.html"
] | [
"I don't feel comfortable answering this question for you since it's for a school project. However, here are some keywords you can read about on wikipedia to get started: ",
"dissonance",
", ",
"acoustic beating",
", ",
"harmonics",
", and ",
"octaves",
".",
"Basically, whenever any of the harmoni... | [
"I would start by reading up on the Harmonic Series. "
] |
[
"Are NASA spacecraft transmissions encrypted?"
] | [
false
] | Could a layman intercept the signals from nasa satellites and get all the information? Or is it all done with.some secret protocol or something? | [
"This varies. In the past, information was transmitted in the clear. This reduced complexity and thus increased reliability. You would still need to figure out the communication protocol and/or file formats to understand what the information means.",
"However, there were several incidents in 2007 and 2008 when... | [
"I can't speak for NASA, but at ESA most spacecraft don't have any kind of encryption. There's an authentication mechanism though, which is standard and public. The only non-public thing is the signature of the spacecraft.",
"It is just too hard (and of very little value) to hijack a satellite. You need a ground ... | [
"In the early days, it was PR point that NASA missions were in the clear.",
"\nPR was cuz USA is 'free', USSR wasn't. (I dont know if they encrypted). The\nreality was that computers weren't fast enough to do it on the fly, especially not\nthose on the spacecraft. For manned missions, so little was controlled f... |
[
"The Rio–Antirrio Bridge spans the Gulf of Corinth in Greece. The Gulf expands by 30mm each year. How long could the bridge stretch to before breaking?"
] | [
false
] | It's a 2880m bridge now, how long would it be before it becomes unsafe? 2880.5m? 2900m? What technologies allow bridges to be "stretchy"? The does mention there being "provision for the gradual expansion of the strait over the bridge's lifetime". Does that mean that the bridge is expected to reach the end of its lifespan due to other factors before the expansion becomes an issue? What tends to be the limiting factor on longevity of bridges? | [
"Normally metal bridges are mounted on rollers on one side. Otherwise they would experience extreme forces due to normal thermal expansion and contraction which would increase the strength requirements significantly. "
] | [
"I have crossed this bridge and i have noticed at some points it has a link between sections like 2 steel combs facing each other. Kinda hard to describe, but it only leaves some small rectanlge gaps if you stetch the bridge, which you can drive over with no issue. I thought it was pretty clever."
] | [
"Good find, thank you! Wikipedia mentioned the supports being on top of gravel bases on which they can shift slightly, but my intuitions fail me when I try and consider what happens when you stretch another 8 or 9 centimeters out of each 100m length of driving surface."
] |
[
"Would pushing an object that weighs 100 pounds feel the same as pushing an object that weighs 1000 pounds if they are on a surface without friction?"
] | [
false
] | [deleted] | [
"The heavier one would move slower and appear bulkier/heavier to you and \"give way\" less to your pushing. Both would be pushable. Just the larger one would require more work to get it to an appreciable speed. This is because of inertia.",
"The funny thing is that if this were a truly frictionless surface in ... | [
"The explanation above explained what inertia is, with out using a technical and difficult word like inertia. Who cares what a word is, as long as the concept is communicated?"
] | [
"If there is no friction, does pushing the blocks feel the same? Yes, in the sense that, no matter what push force you exert, however weak or strong, the block will begin to move. In other words, there is essentially zero effort to get either of the blocks moving, regardless of how massive they are. You can sneeze ... |
[
"Why do neutrons interact differently with nuclei depending on their energies?"
] | [
false
] | So I was doing some reading on neutron radiation detection and shielding, and it appears to me that depending on the material used and the energy of the neutron, the neutrons are either bounces off the nucleus or is absorbed. What is the principle behind this? | [
"This is not only true of neutrons, it's true of photons and charged particles as well. In fact, I think a better question would be \"Why ",
" interact with matter the same way at different energies?\".",
"If you shoot a bullet at me it will hurt a lot, but if you throw it at me it won't. So even in very simple... | [
"It was that last line that made it really clear to me, so now I have some good starting points for further reading.",
"Thanks a lot!"
] | [
"This same line of reasoning is why radio waves travel so freely (low energy) while visible light (higher energy) is so easily reflected off surfaces."
] |
[
"What does it mean for the Higgs field to be \"tachyonic\"?"
] | [
false
] | null | [
"To answer this question, one has to first understand something about how masses are determined in quantum field theory.",
"In quantum field theory, a scalar field like the Higgs field has a potential energy function. The vacuum is the state that minimizes this function, and so the field will settle throughout s... | [
"*sombrero (not science, but this is as much as i can help :)"
] | [
"Man. That was approachable and well-explained and it still hurt my brain."
] |
[
"How do I explain to someone that the relationship between the 3 sides of a right-angle triangle are the same across the whole universe?"
] | [
false
] | [deleted] | [
"...sure that if we took a circle on their planet, measured its circumference, measured its radius, and divided the two, we would get pi just like we do on Earth.",
"It should be said that we ought to separate theory from observation - in the presence of spacial curvature, circles ",
" have this property. Lite... | [
"There are two different questions here - would an alien species necessarily discover all the same laws of mathematics we have, and are the constants like pi the same across the universe?",
"The first can be answered in the negative; aliens may have a dramatically different culture which emphasizes different thin... | [
"Well, we do assume that the laws of physics are the same everywhere.",
"The question is really more about the nature of math than about physics. Euclidean geometry relies on a small set of axioms, from these axioms everything that we consider euclidean geometry can be proven. The axioms of euclidean geometry see... |
[
"About 410-290 million years ago the earth's atmosphere was 35% oxygen. If modern man existed in this era could our lungs breathe in this air?"
] | [
false
] | null | [
"Yes, oxygen toxicity is a documented problem for divers. It begins to occur when the partial pressure of oxygen being breathed is greater than 1.6 atmospheres. Because the pressure at sea level is only 1 atmosphere, even a pure oxygen atmosphere would be breathable to humans on Earth."
] | [
"thanks doc."
] | [
"That number is too high, oxygen can cause pulmonary damage at lower partial pressures too. 1.6 atmospheres is merely where the damage goes from being mainly pulmonary to being mainly cerebral.",
"The limit for pulmonary damage is about 0.5 atmospheres.",
"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2688103/",... |
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