title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"Is there an animal that primarily subsists on eating members of its own species/cannibalism?"
] | [
false
] | null | [
"This isn't viable due to ",
"trophic levels",
"/06%3A_Ecology/6.05%3A_Trophic_Levels). Each consumer needs a food source with roughly 10x the biomass of the consumer population to be sustainable, so a population of animals that subsisted on cannibalism would shrink rapidly."
] | [
"No. If there was, it would run out of food and die. Different animals have varying degrees of willingness or ability to engage in cannibalism, but there's no species for which cannibalism is the ",
" source of food."
] | [
"Cannibalism becomes more common when there is overpopulation but it will inevitably lead to a lower population and will never remain stable through cannibalism. The overpopulation phase is always fueled by an abundance of some other food source."
] |
[
"Do black holes cast a shadow?"
] | [
false
] | If I could place a black hole invetween the sun and the Earth (and presuming it wouldn't annihilate everything), would it cast a shadow on the Earth? | [
"This is not taking in effect gravitational lensing. ",
"If the original beam of light is wide enough and the position of the black hole relative to the surface and light source is correct, light bent by the black hole can light up the area were a shadow would be cast by a regular object. "
] | [
"Some light will curve around the black hole but there will still be a part where light is blocked (",
"like this",
")."
] | [
"So, depending on where you, the light source and the singularity are in relation to one another, you'll see more of a distortion than a shadow? "
] |
[
"I have some questions about something I read about: the habitable epoch of the early universe. Could you answer one or more of them for me?"
] | [
false
] | From this paper: I don't have much of a background in astronomy, physics or biology, I think I understand the gist of this theory, but I'd like a little more in-depth understanding. From what I gather, according to this astronomer, around 10-20 million years after the Big Bang, the background temperature of the univers... | [
"Oh boy. This paper is quite a stretch. Basically, it is saying that because we know the universe was very hot at the beginning, and is only 2.7K now, it must have been ~300K at some point in the past. This is true, and would have happened when the universe was 10-20 million years old. No one will debate that given... | [
"Yeah, the author (Avi Loeb) is a theorist who is pretty well known for doing this stuff sometimes. It's not 'crackpot', because the theories are usually logically sound, but they are often also extremely speculative bordering on impossible. Which can be extremely good for the field in pointing out new paths most p... | [
"From what I gather, according to this astronomer, around 10-20 million years after the Big Bang, the background temperature of the universe was warm enough for liquid water to exist in a lot of places, so it's theoretically possible that primitive life could have appeared on rocky planets",
"10 to 20 million yea... |
[
"How significant are asymptomatic COVID-19 infections to the transmission of the disease?"
] | [
false
] | I know vaccines like Pfizer were shown in clinical trials to be quite effective at preventing symptomatic infections. What about asymptomatic infections, though? How big of a deal are they at this time, esp. with the rise of the Delta variant accompanied by waning vaccine effectiveness? | [
"There’s older data suggesting that anywhere from 30-50% of cases are transmitted from people who are asymptomatic ",
" Some of those people remain asymptomatic, but many of them were simply pre-symptomatic as you can transmit the virus up to 3 days before symptoms. ",
"Source: I had to write a medical assessme... | [
"With the Delta variant, it is definitely unclear how significant asymptomatic transmission is. The CDC updated mask guidance a few weeks back after a study of an outbreak in Connecticut showed a few hundred positive cases resulted with vaccinated and unvaccinated patients having similar viral loads. Viral load has... | [
"The CDC updated mask guidance a few weeks back after a study of an outbreak in Connecticut showed a few hundred positive cases resulted with vaccinated and unvaccinated patients having similar viral loads. Viral load has been correlated with transmissibility in other studies, ",
"I've seen this repeated ad nause... |
[
"Why do you blow out different temperatures of air?"
] | [
false
] | null | [
"Human Body"
] | [
"Human Body"
] | [
"Thank you for your submission! Unfortunately, your submission has been removed for the following reason(s):",
"/r/AskScience",
"To check for previous similar posts, please use the subreddit search on the right, or Google site:reddit.com",
"/r/askscience",
" ",
"Also consider looking at ",
"our FAQ",
... |
[
"How do we measure the temperature of stars and quasars up to 100,000,000°? How do we know it's that hot?"
] | [
false
] | null | [
"The color of the light! I'm a material scientist not an astrophysicist so I eagerly await being told exactly why this is incomplete. The peak wavelength of a star indicates its surface temperature, it's called Wien's displacement law. The wavelength is inversely proportional to the temperature.",
"https://en.m.w... | [
"You're talking surface temperature of course, which is cooler than the zone where fusion is occurring, but we in a sense don't need to be able to measure this temperature directly because there is a requisite temperature to overcome the Coulomb barrier to create nuclear fusion within a star (or elsewhere). It's us... | [
"It's close enough for extremely hot objects that the OP asks about.",
"If you can use the spectrum to estimate the temperature to within even 10pc for such distant objects, that is a good enough result for astronomy."
] |
[
"Light Thrust?"
] | [
false
] | This is my first question in AskScience so forgive me if its been asked before. My question pertains to the properties of light, particularly its very special property of always finding the shortest travel distance. Why does this happen ? Also, I was just pondering ideas about how no object can attain the speed of ligh... | [
"Fermat's principle isn't that light rays ",
" the quickest path. It's not like light ray knows it will leave A end up to B and then optimizes to take the quickest path there. It's that the path that light rays that do reach B happen to ",
" is the quickest. \"Find\" and \"take\" are very different words. ",
... | [
"But this \"law\" annoys me. It isn't true, because mirrors obviously violate the principle (unless you specify that light must bounce off the mirror, but now you are adding extra rules).",
"Isn't that covered by the restriction that the rule only applies locally? The paths followed are the shortest in the sense ... | [
"The answer to your question on the distance light travels (optical path length) is a bit too hefty for me to get into at the moment, but I can answer your question about force.",
"Our most intuitive understanding of momentum comes from objects with mass - a truck is heavier than a car, so it has more momentum at... |
[
"What causes the crust to form 20-30 miles below the surface?"
] | [
false
] | Why isn't there molten lava everywhere just maybe 50 feet below the surface? What causes the crust to begin forming 20-30 miles below the surface? | [
"There's a lot of things right here, but there are also a couple clarifications I'd like to make...",
"While we don't get literal layers of molten rock anywhere, partial melting is extremely common in areas of mantle upwelling. It's not nearly as rare to have partial melt as I think you're implying.",
"The Moho... | [
"Well, there isn't molten lava everywhere because except for the outer core of molten iron-nickle, almost the entire planet is solid. This includes the mantle - it is almost entirely just dense rock such as peridotite, with only a very tiny percentage of melt.",
"Secondly, the crust doesn't \"form\" 20-30 miles d... | [
"Even including partial melting, most estimates for the fraction of the mantle that is liquid (that I've seen) at any given time is ~0.5% - 2%. There are certainly areas where molten rock is concentrated, and from what I understand most modern models predict a very tiny amount of melt to exist between many crystals... |
[
"How did we find out that 4% of the universe was the matter that we see?"
] | [
false
] | I'm not asking how we came to the theory of dark matter and energy, but how we came up with the measure of 4% | [
"The short answer is that the best results come from the ",
"Planck mission",
"'s measurements of the cosmic microwave background radiation. The results come from looking at the unevenness in that background, comparing that to the predictions of standard cosmology (predictions that depend on the relative amoun... | [
"Thank you, this was very helpful."
] | [
"Glad to help."
] |
[
"Is the Heisenberg Uncertainty Principle derived or experimentally found?"
] | [
false
] | Title says it all | [
"It's basically a theorem about Fourier transforms. If you do a Fourier transform on the waveform representing the position of a particle, you get a waveform representing the momentum. If you do a Fourier transform on the air pressure, you get pitches of musical notes. The same principle applies in both. If a music... | [
"It is derived from the principles of quantum mechanics."
] | [
"Those are good examples, but it's worth noting that the uncertainty principle is broader than applies for variables which are not canonical conjugates. For example, in the case of the hydrogen atom, position and energy share an uncertainty relation. See ",
"this",
"."
] |
[
"Is this sensationalist garbage? Or is Micho Kaku right when he says, \"We came close to losing Northern Japan\" ? (link in comments)"
] | [
false
] | I initially asked this in , but apparently you're not allowed to ask questions there. | [
"Sensationalist garbage. Micho Kaku has done very well for himself churning out vast swathes of bullshit. I don't know how he can look his academic colleagues in the eye."
] | [
"He does not specifically say it was a bomb, he says that the area would have been rendered uninhabitable due to radioactive material. This is the case around Chernobyl and Pripyat, so given that amount of material in the reactors would it have been enough to create a similar type of exclusion zone in northern Japa... | [
"But it wouldn't have say... blown up?"
] |
[
"What is the difference between chaotic systems and stochastic systems?"
] | [
false
] | From what I understand, chaotic systems are sort of a 'middle ground' between completely deterministic processes and stochastic ones because they're governed by deterministic equations, but because they're so sensitive to initial conditions it's impossible to predict exactly what's going to happen after a certain amoun... | [
"To put it pithily, stochastic processes are about ordered behaviors emerging from random systems, while chaos theory is about complex, random-seeming behaviors emerging from deterministic systems."
] | [
"\"Emergent\" behaviors can occur in both stochastic and chaotic systems. The core distinction is that stochastic systems have a random component while chaotic systems do not—they're classical deterministic dynamical systems that exhibit surprisingly complicated behaviors."
] | [
"this is more of how i understood it. you're describing emergent behavior, yes?"
] |
[
"Why does the body \"need\" 8 hours of sleep?"
] | [
false
] | The reason I put "need" in quotes is because not everyone needs 8 hours, but that's the recommendation. What I'm wondering is, why is it this long? Is there some process that our body is doing that takes hours to accomplish? Metabolizing something or storing memories perhaps? EDIT: I should probably clarify, the main p... | [
"There has been a lot of questionable information posted about sleep recently on askscience, so I want to clarify using peer-reviewed, cited sources. I hope other comments will respect the askscience guidelines.",
"1) Why do humans sleep roughly 7-8 hours? Why do animals need sleep?",
"Sleep is a relatively you... | [
"Please read the ",
"AskScience guidelines",
" before posting. Top level comments are reserved for expert panelists or comments that provide factual evidence with appropriate sources. ",
"Thank you!"
] | [
"Please read the ",
"AskScience guidelines",
" before posting. Top level comments are reserved for expert panelists or comments that provide factual evidence with appropriate sources. ",
"Thank you!"
] |
[
"How are the calories in beer counted?"
] | [
false
] | This is less of a scientific question... more of a procedural question. I was considering how beer, the best thing in the world, is marred by its high caloric content, and knowing the procedure typically used to measure calories, I wondered if these measurements are accurate. Foods are (precisely) tested for caloric co... | [
"we only net 215 kJ/mol of the 1325 kJ/mol, or about 16.2% of the energy",
"No, that's just a theoretical lower limit which assumes that all of the ingested ethanol is incompletely metabolized.",
"The standard energy density assigned to ethanol in nutrition information labels is ~7 kcal/g (not kCal, btw)."
] | [
"It sounds like FlyingSaggittarius helped you make the link with the piece of information that you were missing, but since it sounded like there was also a calorimeter procedural question:",
"Beer labels (at least in the U.S.) aren't regulated by the same FDA rules that govern other foods and require nutrition la... | [
"There is almost no chance that any acetic acid is excreted instead of metabolized or used in some acetylation reaction. From a cell biology perspective, that's some good shit. ",
"I argue that the acetate from ethanol metabolism should be counted as fats in calorie counting because its metabolism is more like ... |
[
"What happen when an infected cell replicate itself ?"
] | [
false
] | Hi, So what i'd like to know is this, if a cell is infected by a virus or ""infected"" with mRNA from vaccine for example. What would happen if the cell replicate ? Would the new cells contain the virus or mRNA ? I'm thinking about this cause when you do workout you accelerate the replication process (I suppose since c... | [
"The mRNA from the vaccines is gone within a few hours. mRNA is very unstable, and mostly has a half-life of a few minutes. That's one reason mRNA vaccines took a while to become practical. The current versions are generally modified to be more stable, but that only gives them a few hours of survival. (Obviously, t... | [
"I would also like to add that muscle tissue, if that’s what you are worried about, doesn’t replicate. All the muscle cells you’re born with, you’ll carry around until your death (ish). \nWhen working out, the damage to parts of the muscle fiber is light, is mostly intracellular, and is repaired by hypertrophy, mea... | [
"Well there are 3 types of muscle tissue namely smooth, cardiac and skeletal. Smooth Muscle can replicate, however Skeletal Muscle And Cardiac Muscle can only do hypertrophy(increase the size)."
] |
[
"CDC and health departments are asserting \"Ebola patients are infectious when symptomatic, not before\"-- what data, evidence, science from virology, epidemiology or clinical or animal studies supports this assertion? How do we know this to be true?"
] | [
false
] | I've been a mod of for several months. We have a science issue coming up repeatedly, every day we cannot answer. Please help. All around the world we're hearing the same, repeated message: "Ebola patients are only infectious when they are symptomatic" A significant fraction of the controls, contact tracing, follow u... | [
"u/nallen",
" asked me to weigh in here, and I've been combing peer-reviewed articles and literature to see what we actually know about transmission while symptomatic. I have found a couple of sources, with the following caveat: 1) this kind of work has NOT been done in humans during a real-time infection. Everyt... | [
"Great post. Thank you. This will help me in explaining to my friends and colleagues that there is no need to nuke Dallas."
] | [
"Yeah, the idea of nuking Dallas gets categorized as \"landscaping improvements\" in most of Texas. "
] |
[
"How can QD help forensic scientist to determine the age of a fingerprint?"
] | [
false
] | Dutch scientist are busy with a technique to determine the age of a fingerprint with the use of quantum dots. I have tried to contact them, but they can't help me with anything since it's still a running project. I was hoping someone here could tell me more about how it is done. In short (and from my understanding) the... | [
"The researchers obviously didn't have definitive answers to that themselves when they wrote this:",
"In order to develop this technique we will first establish which biomarkers provide significant information about the time a fingerprint is deposit on a surface.",
"It's an ongoing research, so would we could... | [
"The premise of identifying the age of the fingerprint would be possible if a compound were used that degraded in air at a known rate into a different chemical. In the simplest scenario, the initial chemical may fluoresce a type of light that excites a nearby quantum dot and this emits visible light A. The chemical... | [
"Damn, thanks this is exactly what I need."
] |
[
"What happens during near-death experiences?"
] | [
false
] | null | [
"The skeptic in me is coming out, so forewarning: I don't want to sound like an a-hole. ",
"I'd like to see a source about DMT. The only source I have been able to find on the internet is from a ",
"a book (warning PDF)",
" but not much of anything in peer-reviewed journals. Additionally, even on wikipedia, ... | [
"First off: there isn't all that much known about NDE's apart from anecdotal experience.\nChemically, it is often said that during an NDE, there is a release of certain neurotransmitters in your brain, including the powerful psychedelic compound DMT. This is often used as the explanation of the NDE, and the effects... | [
"Strassman, the author of The Spirit Molecule himself said that there was no proof of DMT being released during death/sleep."
] |
[
"Do the air bubbles in boiling water get hotter than 100C?"
] | [
false
] | null | [
"They're actually water vapor bubbles instead of air, which is mostly nitrogen and oxygen. The water is at 100C and as the molecules gather more heat energy they turn to vapor, also at 100C. The temp is the same but the vapor just has more energy to be in the gaseous state. The only vapor that could reach a higher ... | [
"Gases are slightly dissolved in the water, but as you heat it up, more of the gases escape.",
"When you reach boiling, the majority of the bubbles you see in water will be water. That's why when the bubbles reach the surface and escape, they condense after meeting with the cool air and form a rising, misty colum... | [
"From what I understand from your response: Heat from the pot (>100C) transfers energy to water vapor - by minute amounts - since the water can't heat it any higher. I have a hard time believe there no other molecules mixed around in the (distilled) water. Nitrogen and Oxygen molecules don't fit between H2O molecul... |
[
"Hypothetical Exoplanet Analysis"
] | [
false
] | What are some features of this artists conception of an exoplanet are scientifically inaccurate and/or impossible? Also, is there any truth to this picture? Source: | [
"Off the top of my head, the simplest example in that image of a mistake that I think would stand up is that it shows a star in the sky that is either very large or pretty close - and the brightness from it would certainly drown out the other stars in the black sky there.",
"Even the moon photos with their lack o... | [
"The lack of an atmosphere would sort of ruin the chances of having liquid water i would think. What would the temperature be like without a prominent atmosphere and a sun at such a distance?"
] | [
"I sort of assumed that there would be one which would allow for the liquid water, but left it at the sky being the wrong color :)",
"I don't know if there is a mix of gasses that could make an atmosphere which remained pretty dark/invisible even during a bright day (having such a large star nearby) but given the... |
[
"Would including more virus strains make influenza vaccine more likely to be effective in a particular year?"
] | [
false
] | Is there a biological limit on how many strains can be included in one vaccination? How about using a series of shots? | [
"\"Traditional flu vaccines (called “trivalent” vaccines) are made to protect against three flu viruses; an influenza A (H1N1) virus, an influenza A (H3N2) virus, and an influenza B virus. There are also flu vaccines made to protect against four flu viruses (called “quadrivalent” vaccines). These vaccines protect a... | [
"Actually each strain added reduces the chance of developing a successful immunity. ",
"Source, the vaccine website. "
] | [
"Yes, and the time to grow and produce several hundred million doses, so it has to be done well before flu season, and the strains active are apparent.",
"And the expense of producing hundreds of millions of doses extra in case of a major outbreak, and panic, many of these most years will simply be thrown away."... |
[
"On paper, wavelengths in the electromagnetic spectrum are often represented as looking like sine waves, is this actually how they are structured, or is it just a decent 2D approximation?"
] | [
false
] | Are they really 2-dimensional constructs like they are represented on paper, or is that just a rough cross section or something? What would a more accurate image look like, if there is one? | [
"sine/cosine functions are perfectly good, exact solutions to Maxwell's wave equations. One thing i will note though is that the 2D representations you are describing are a special case known as \"plane\" polarisation. In general light is elliptically polarised, and the more commonly known \"plane\" and \"circular\... | [
"Well they have two perpendicular components: the electric and the magnetic field. So ",
"this",
" is a bit more accurate. However, those fields don't actually extend into space: the arrows represent the strength of the magnetic or electric field, not how far they extend."
] | [
"Something I've never understood about these figures is what's going on just to the right or left of that axis. Or above the axis for that matter. I guess I'm not explaining this too clearly. The wave in this figure is one dimensional, so what's going on a foot above that line, for example? Do the electric and magn... |
[
"How come the skin of people that lift heavy objects with weird parts of their body doesn't rip out?"
] | [
false
] | So I was watching episode of GMM and I was wondering. How can you lift so much weight with your tongue \ eye lids? | [
"Well, not that I know the answer, but to clarify your question a bit... "
] | [
"Skin and muscle good tensile strength. Muscle fibers split along the direction of contraction, but the tongue has fibers running multiple directions, so it's less likely to tear. Skin is generally stretchy to a point, then resists further stretch. As long as the hole is made by a round point and the weight applied... | [
"Not a biologist or medical expert but I know that skin has pretty good tensile strength. But it's not just the skin, when people pull stuff using random body parts (say, their ear lobes) the force is distributed to the tissue underneath too. Muscle tissue also has good tensile strength."
] |
[
"What are the health detriments of LSD or magic Mushrooms? (Long term and short term)"
] | [
false
] | null | [
"Sources?"
] | [
"One of the dangers of hallucinogens is becoming agitated by the hallucinations and hurting yourself or others."
] | [
"Pfff thats a tall order, even though it does happen, it's usually due to underlying mental illness that exacerbates the drugs effects. Now, short term? Memory loss, depression, anxiety, aftershocks or \" flashbacks \" of the trip, sweats, paranoia and a few more. Long term: HPPS (hallucinogenic persistent percepti... |
[
"Why is magnetic attraction more powerful than gravity? Also, is there such things as \"magnetic waves\"?"
] | [
false
] | null | [
"The answer is nobody has any idea ",
"http://en.wikipedia.org/wiki/Hierarchy_problem"
] | [
"To my knowledge it is not well understood why the electromagnetic force is stronger than gravity. I'm sure there are hundreds of theories, but there's no compelling evidence for any of them. Right now, it should just be taken as a fact.",
"Magnetism and electricity are coupled together such that a magnetic wav... | [
"Can somebody tell me why the above comment is being downvoted? It is correct, and nearly identical to the other two."
] |
[
"[[Medicine]] How do tests for viruses works?"
] | [
false
] | [deleted] | [
"There are a lot of possible techniques, but one of the easiest test to produce is done through a technique call quantitative polymerase chain reaction or qPCR. In terms of protocol, the DNA and/or RNA of the sample is first extracted. If it's RNA it gets reverse transcribed back in to DNA. We'll then add two thing... | [
"A really simple way of explaining is...",
"Swab your nostril",
"Get the viruses genes from the swab (it’s RNA, not DNA)",
"Turn that RNA to DNA",
"Make a shit ton more copies of that DNA",
"Stick a bunch of sticky light up things that will stick to the DNA. ",
"These sticky things will only light up if... | [
"Those letters are DNA bases, think of them like binary code in a computer (except there’s 4 not 2). They code for information which codes for the organism, in this case the virus. What the test does is it looks for a piece of that code which only this virus has. It would be like looking for the part of the code th... |
[
"how can we test string theory?"
] | [
false
] | everything I've heard about string theory sounds like an interesting idea. IDEA. not a theory. how can we test the postulates of string theory in order to confirm that it is a viable ? | [
"It seems to me like you're hitting the standard \"but wait\" after learning about string theory and its limitations. It seems to me that a lot of people learn about it and go \"aw that sounds really cool.\" Many stop here. Then some people say \"but wait it can't be tested, why does it have all this press, isn't i... | [
"Absence of evidence isn't evidence of absence. It is, however, a good argument for not spending much time worrying about string theory."
] | [
"We can't, yet."
] |
[
"Is Tobacco on its own actually harmful or is it just the chemicals used by Companies in their Cigarettes?"
] | [
false
] | [deleted] | [
"According to available scientific literature, it looks like both tobacco on its own as well as the additional chemicals inhaled by smoking a cigarrette are considered to be carcinogenic.",
"Non-smoked things like chewing tobacco and snuff are associated with cancer risk, especialy oral cancers",
". While it ha... | [
"Inhaling smoke is bad for you, regardless of the plant being burned.",
"The additives do make it worse."
] | [
"Indoor air pollution is major health risk in developing countries WHO: ",
"Indoor air pollution and health",
". Paraffin candles, gel wax candles and scented candles also release carcinogens to the air. ",
"It should not be surprising that Inhaling smoke directly to your lungs is bad. "
] |
[
"What happens to the reaction mass from a rocket firing (prograde) in orbit?"
] | [
false
] | Presumably, it loses enough velocity that it ends up on a suborbital trajectory. But what then? Does it dissipate into space? Does it stay in an elliptical orbit and threaten other spacecraft that might pass through it? Does it fall through the atmosphere and burn up? Does it fall through the atmosphere and burn up? Wh... | [
"If a rocket is burning in a low enough orbit then what you presumed is correct, the exhaust gas ends up in a suborbital trajectory. (An exception would probably be thrusters with a very high specific impulse, which means an exhaust speed much faster than escape speed, or rockets in very high orbits).",
"But when... | [
"I think you're using prograde in the wrong sense. Burning prograde (towards the direction you're going) will increase your velocity. Burning retrograde (opposite prograde) will reduce your velocity. Orbit velocity differs at different altitudes. ",
"For an example, let's use the ISS. The ISS currently orbits bet... | [
"I'm curious about the spent reaction material though. If the ship is burning prograde, then it stands to reason that the reaction mass is being ejected on a retrograde vector at high velocity. The ap",
"apsis of the ship would increase, but the periapsis of the spent material should come down a long ways, especi... |
[
"How important is social interaction in our everyday mental health?"
] | [
false
] | null | [
"In social psychology we talk about a concept called the ",
". This is the desire to form and maintain close relationships with some other individuals and we call it a need because when we lack belongingness then we suffer more than just an unhappiness. People who are lonely in addition to mental health problems ... | [
"The way to investigate this is to read up on the effects of social isolation ",
"http://www.livescience.com/18800-loneliness-health-problems.html"
] | [
"not as important as an indivudual might think. this fights in to Maslow's Hierarchy of Needs where (in order of importance) it is, food and water, safety, love and belongingness, gaining the respect of others, self actualization. so in more simple terms, social interaction is more important to us (according to mas... |
[
"If a human body was cut in half by a long blade that is of 1 atom thickness, would he/she die shortly after?"
] | [
false
] | [deleted] | [
"Forcing atoms apart by 1 atom would cause cell death in the vast majority, or at least a signifigant number of the affected cells. The splitting of proteins, lipids, membranes, and nucleic acids by a single atom is still a substantial change, and these molecules would not spontaneously self-heal.",
"However, ev... | [
"Forcing atoms apart by 1 atom would cause cell death in the vast majority, or at least a signifigant number of the affected cells. The splitting of proteins, lipids, membranes, and nucleic acids by a single atom is still a substantial change, and these molecules would not spontaneously self-heal.",
"However, ev... | [
"I'm not so sure about this. Molecules larger than a single atom pass through cell membranes all the time without significant damage, so I don't think that cell membranes would be compromised; another lipid would just slide into its place. I think that the majority of the damage from the atom cutter would occur to ... |
[
"We generally count in base 10, computers use base 2 and hexadecimal, is there some orderly relationship among the various constants of physics that suggests nature has a preferred \"base\"?"
] | [
false
] | Part of the motivation for this is the question "Are we living in a simulation?" If so, we might expect some indication of the physics engine's architecture to show up in our physics. | [
"No. The base used to represent a number is just an arbitrary choice. The number itself has its own meaning, independent of how you choose to represent it. If you'd like an imperfect analogy, it is like writing a word in one typeface or another; the choice of typeface does not change the word."
] | [
"Base e has the lowest radix economy",
"Where \"radix economy\" is a term that the author of that Wikipedia article made up and which nobody takes seriously."
] | [
"There is no interesting and useful property of numbers that depends on the number base. The base is just a way to write down numbers. It doesn't change the number in any way. ",
"Edit: Apparently many people don't like my blanket statement. The truth is these types of questions pop up on this sub fairly often be... |
[
"Why Do We All Generally Agree On What Creatures Are Cute or Grotesque?"
] | [
false
] | [deleted] | [
"This might interest you.",
"TL;DR: Things that have large eyes and round, soft bodies are more likely to elicit the response because they remind us of our own babies and make us release certain hormones. Even inanimate objects can be seen as cute if they have the types of features we look for. It then becomes a ... | [
"There’s one group of animals not everyone agrees on: insects. Most people in advanced societies are repulsed by the idea of touching bugs, but in areas with low access to food, insects can be a delicacy, and they’re an excellent source of protein (grasshoppers are becoming more popular for consumption in the west)... | [
"There's a lot of spiders that ",
"a fair amount of westerner's find cute.",
" Mostly ones with big ole eyes. The depiction is also important. Most people find snails in real life to be gross, but animated ones like the ",
"den den mushi from One Piece",
" or snails from Spongebob like Gary can be found to ... |
[
"Do we have any idea of how to make \"artificial gravity\"?"
] | [
false
] | [deleted] | [
"Any form of acceleration is indistinguishable from gravity. So a spinning ship causes an acceleration pointing \"inward\" (ie you don't keep traveling in a straight line, you keep getting pushed toward the center). There are some limits here as to how fast to rotate it and whatnot so as not to make people sick. If... | [
"Any form of acceleration is ",
" indistinguishable from gravity. I make that nitpick only to observe that that nicely explains away the fact that spinning drums must be of a certain minimum size. Too small, and the \"locally\" part of \"locally indistinguishable\" is smaller than your ",
" Which is a problem."... | [
"Please, always feel free to nitpick away. I think I was referring to the nausea from rotating around too quickly, but I guess that would also fall under the jurisdiction of this local indistinguishability? (ie the acceleration on your inner ear doesn't exactly point toward the \"floor\" or something)"
] |
[
"If differences in human phenotypes such as skin colour, hair colour, etc. are due to clinal adaptation, what clines lead to the development of East-Asian slanted eyes?"
] | [
false
] | Since there is good evidence to suggest we radiated from Africa, I presume that primitive humans did not have slanted eyes, but I guess a possibility is that primitive humans did in fact have slanted eyes, and the change to non-slanted eyes is actually an adaptation. In either case, why/how did this happen? EDIT: Also,... | [
"The explantation for epicanthus is that Central Asian steppes, the area where proto-Mongoloids origated, were very dusty with common dust storms and the epicanthus helped them to protect their vision. But it's also possible that it was a random mutation and an example of the founder effect.",
"Because epicanthus... | [
"http://www.nytimes.com/2013/02/15/science/studying-recent-human-evolution-at-the-genetic-level.html?_r=0",
"The gene that controls for it, also does for other asian physcal traits (teeth shape, less breast tissue etc...) Several of these would seem to reduce energy requirements as well.",
"Edit; misremembered ... | [
"The trait you are speaking of is called the ",
"Epicanthic fold",
" and the evolutionary basis for it is not well understood, but it is often attributed to acting as ",
"a sun visor protecting the eyes from overexposure to ultraviolet radiation or as a blanket insulating them from the cold.",
". "
] |
[
"Is there a mathematical object analogous to a matrix with more than two dimensions?"
] | [
false
] | I guess it would resemble a stack of matrices. What would such a thing be used for? | [
"A multidimensional array with rank (or order or degree) greater than 2. ",
"Tensors",
" are an example."
] | [
"Tensors are actually a subset of what was asked about. In general any n-dimensional array would generalize a matrix; a tensor, however, is an object that ",
" In other words, a tensor is invariant under coordinate transformations. So if I have a (0,2) tensor, it would take two vectors and give me a number. If I ... | [
"A tensor.",
"What you're referring to as \"dimension\" is actually called ",
".",
"The rank of a tensor describes how many indices you need to specify an element of the tensor.",
"A scalar is a rank 0 tensor.",
"A vector is a rank 1 tensor.",
"A matrix is a rank 2 tensor.",
"As far as I know, there a... |
[
"Is there an exact number of atoms in the Universe?"
] | [
false
] | And if yes, then do we know roughly how many? | [
"That's by the way the number of atoms in the observable universe. The universe is much bigger than the observable universe, and evidence indicates that it's actually infinite. Unless the Copernican principle in really, really wrong, the density of the universe is approximately constant, so the number of atoms sh... | [
"At any given time the number of atoms is changing. For instance, in stars you have four hydrogens becoming one helium.",
"However, you can assume that the vast majority of atoms are hydrogen, and use this to calculate approximately how many atoms are in the universe, and it's about 10",
" ."
] | [
"evidence indicates that it's actually infinite.",
"I find that fascinating. I don't understand how it could have a beginning if it's infinite in size. Could you explain?"
] |
[
"Would it be possible to see the Earth in the sky from a different location millions of years ago?"
] | [
false
] | null | [
"But the stars don't stay in the same spot for all that time right? What we see now is the light of stars a million years ago, wouldn't they have moved since then? "
] | [
"Fair enough. At some point in the distant future, is this scenario possible? "
] | [
"Can you rephrase the question? What do you mean by seeing the Earth in the sky? ",
"I think you may be talking about going 1 million light years away and looking back at what the Earth looked like 1 million years ago. If you were 1 million light years away and had a telescope powerful enough to pick out the deta... |
[
"How are photons created/emitted?"
] | [
false
] | I know they're related to the electron, i'm just not sure how... | [
"I know this question doesn't make sense because of relativistic principles/Heisenberg, but if you could imagine watching an electron release a photon what would it look like? Or what would we imagine it to be visualized as? A radial propagation of an EM wave from the spherical electron?"
] | [
"Specifically to do with electrons, it is when they transition from the conduction band to the valence band through a loss of energy (the energy difference between the bands known as the band gap). This energy loss can happen in a non-optical fashion, for example as a wave through a crystal lattice (phonons), or op... | [
"Photons are emitted when there discrete changes in electric (or magnetic fields). The most common example is an electron moving from one energy level around an atom to a lower one."
] |
[
"What radio signals would travel into space?"
] | [
false
] | I am mainly asking if our radio signals from earth would theoretically be detectable from other places in space. Would our TV or internet signals leave earth? | [
"true but there is still a very low change for earth catching any other signal, it would be like trowing a single sand spec at another single sand spec yes there out there but them both hitting each other is not likely"
] | [
"true but there is still a very low change for earth catching any other signal, it would be like trowing a single sand spec at another single sand spec yes there out there but them both hitting each other is not likely"
] | [
"Following the laws of physics, any wave will travel as farther they can. So yeah, all waves we have produced, either it's radio waves, gamma rays or microwaves, all have travelled to space and will continue to do go farther. However, the intensity of the wave will decrease exponentially as it flees away from you."... |
[
"if the earth is constantly rotating AND orbiting the sun then HOW is the north star always due north?"
] | [
false
] | null | [
"Technically, the north star (",
"Polaris",
") is not ",
" due north: it's current angle is about 0.5 degrees away from the true celestial north pole. If you take ",
"a long enough time lapse",
", you can see that over the course of the night Polaris does make a very small circle around true celestial nor... | [
"Incredible answer. Thanks!"
] | [
"Hi PaddyAtomic thank you for submitting to ",
"/r/Askscience",
".",
" Please add flair to your post. ",
"Your post will be removed permanently if flair is not added within one hour. You can flair this post by replying to this message with your flair choice. It must be an exact match to one of the fol... |
[
"Can cement be liquified after setting?"
] | [
false
] | [deleted] | [
"Not through any approach that you would think of as common. As the cement component of concrete (which is cement plus aggregate materials) hardens, calcium silicate forms. The solubility of calcium silicate in almost every solvent is very poor, so you can't dissolve it again without a large amount of acid. Its mel... | [
"Is disposing of used/old concrete a problem then?"
] | [
"Old concrete can be crushed and introduced as aggregate for subsequent concrete mixtures."
] |
[
"How is it that we can determine the size, velocity, distance, AND chemical makeup of distant stars?"
] | [
false
] | It seems like one would need to know at least one of these variables to derive the others, given that distant stars only show up as a point of light. I understand the concepts of red and blue shift, and I would think that it would complicate the determination of velocity and chemical makeup. i.e. Is the star red becau... | [
"And from the chemical make up of a star we can determine its age (or period of a star's life cycle) which gives information on size, temperature distribution and many other physical properties."
] | [
"Red/Blue shift isn't used in determining star's makeup. Elements emit light in very narrow, specific spectral bands; so every chemical/compound has a distinct signature. Starlight can be analyzed for its wavelength makeup, based on that data scientist can then start assigning dominant species present. "
] | [
"So for example, a young star would still have lots of hydrogen and not much heavy elements. An older star would have more heavier elements and less hydrogen. Luminosity tells us its size and with those two things, we can determine age. With all that we can determine how much red/blue shift there is that is making... |
[
"In mathematics, is it ever possible to prove that you can't prove something?"
] | [
false
] | null | [
"In ",
"mathematical logic",
" such proofs are routine. Some examples:",
"Gentzen's consistency proof of Peano arithmetic",
"non-Euclidean geometries",
"Cantor's continuum hypothesis",
"Closely related to this there are also ",
" proofs, which can refer to two different kinds of thing:",
"Gödel's c... | [
"Not quite. The incompleteness theorem (a version of it) states that you cannot prove Con(T) from the theory T (under certain assumptions on T). This is an example of a proof that something is not proveable. ",
"There are many more examples: having the mild assumption that predicate logic is consistent, every fal... | [
"There are. One is Gödel's incompletness theorem\n",
"http://en.wikipedia.org/wiki/G%C3%B6del%27s_incompleteness_theorems"
] |
[
"What do + and - mean when talking about the metric of spacetime?"
] | [
false
] | [deleted] | [
"As ReverendBizarre said, it's a convention to tell you whether you put a minus sign on the time coordinate (in the metric) and a plus sign on the spatial coordinates, or vice versa. Generally people working in relativity like -+++, and particle physicists like +---, because they're weird. I suppose it's because if... | [
"I really can't see a way to explain this in a non-mathy way without losing a lot of the meaning... so here goes some basic definitions with a follow up example. The + and - refer to the 'characteristics' of the four dimensions. The metric of spacetime is expressed as a scalar product of characteristic 1 (or 3 an... | [
"That's usually called the signature, sometimes written as (-+++) or (+---). What this means is that the line element of the spacetime is written as (let's use flat space as an example),",
"ds",
" = -dt",
" + dx",
" + dy",
" + dz",
"or",
"ds",
" = dt",
" - dx",
" - dy",
" - dz",
"This differ... |
[
"Is there actual evidence that essential oils such as rosemary acts as insect repellants?"
] | [
false
] | I'm concerned about household pests, namely bedbugs, and I'm looking for cost-effective preventative methods. I've found anecdotal references to essential oils like rosemary, lavender, and peppermint being used to repel insects. Is there evidence that these are actually effective? | [
"A line of marching pharoh ants will absolutely turn and run from lavender oil. I see it every time summer rain drives them inside my front door. But the concentration of lavender oil vapor that works would be hard for a human to tolerate, and expensive. You can't bomb your whole house with enough lavender to wo... | [
"http://www.animal-fences.com/downloads/COMPARATIVE%20EFFICACY%20OF%20INSECT%20REPELLENTS%20AGAINST%20MOSQUITO%20BITES.PDF"
] | [
"I actually did a small research project on this in Rutgers University's Department of Entomology -- \"The Essential Oils of Plants as Mosquito Toxicants\". Well, it's not terribly relevant to repellents, but I can confirm that ",
" essential oils non-trivially kill second enstar mosquito larvae (while others, li... |
[
"How do we know that all of the continents were once all connected?"
] | [
false
] | [deleted] | [
"Lots and lots of corroborating evidence. Palaeomagnetism and oceanic crustal dating are two of the most important.",
"When some rocks form they preserve a record of the magnetic field present at the time. THis can happen in igneous rocks, as iron-rich mineral crystals grow in allignment, or even sedimentary rock... | [
"Rock samples from the edge of each continent match up with each other. ",
"Edit: Plants, soil, etc. Anything else of merit you can think of too, but rocks are the most obvious and intact evidence."
] | [
"There are multiple proofs for that. As far as I know, the main point is certain fossils, which were found on two different continents far away from the other. These fossils 1. couldn't just fly over that huge distance and 2. were that similar, it was nearly impossible for them to have developped by their own.",
... |
[
"Why does nicotine take away hunger momentarily, but when the effect stops the sense of hunger is even stronger?"
] | [
false
] | null | [
"Hi kemmuli thank you for submitting to ",
"/r/Askscience",
".",
" Please add flair to your post. ",
"Your post will be removed permanently if flair is not added within one hour. You can flair this post by replying to this message with your flair choice. It must be an exact match to one of the followi... | [
"Chemistry"
] | [
"'Chemistry'"
] |
[
"What is the origin of Ebola?"
] | [
false
] | null | [
"Likely transfer from fruit bats in or around the Kitum Cave region in then-Zaire (which gives its name to the most dangerous case-death strain) and modern Congo/Gabon. High monkey populations around this area function as a reservoir for Ebola Zaire."
] | [
"Ebola (or ebola hemorrhagic fever) is a zoonotic viral disease which has resurfaced multiple times in separate \"spillover\" events from its animal reservoir species, which likely includes bats and nonhuman primates. There's more than one ebolavirus, and multiple strains have been implicated in outbreaks, with the... | [
"More terrifying. Ebola Zaire had a 90% case fatality rate when discovered."
] |
[
"How do \"veins\" of precious metals occur?"
] | [
false
] | Since elements like gold, silver, etc. cannot be formed within the planet, whatever is in the planet has existed since the planet's formation, plus the occasional meteorite. While densities would surely come into play during planetary formation, it seems that those elements would be fairly evenly distributed throughout... | [
"Not an economic geologist but I have a geological background, so I'll welcome any corrections by a real expert. Veins of metals, ore minerals, or even plain quartz and mica can form by hydrothermal deposition in an already-existing crack. ",
"This means that you have some mineral source--a magma body, say--wit... | [
"Finite. Atoms of heavy elements (including gold, silver, platinum, and all other precious metals) are created by nuclear fusion in the hearts of dying stars. (Traditionally this meant supernovae, but more recent studies suggest ",
"colliding neutron stars",
" are to blame.) When the interstellar dust cloud ... | [
"I wonder; do you know if these precious metals are finite? Or can they be chemically created?"
] |
[
"How can a whole galaxy form within the first 600 million years of the universe?"
] | [
false
] | This is in response to a recent link today on . This galaxy is thought to have formed within the first few hundred million years from the big bang. A question I've always had regarding this is - how can a whole galaxy form in such a short time. We may not, at first, think of 600 million years as a short time span, but ... | [
"A question I've always had regarding this is - how can a whole galaxy form in such a short time.",
"The answer is that 600 million years is more than enough time to spontaneously concentrate mass, trigger thermonuclear fusion in individual stars and create spiral formations out of those stars.",
"The fact that... | [
"One explanation is that the mass density in the early universe was such that the time scale for galaxy formation was radically different.",
"Remember that, for spacetime to have the flatness it appears to, the cosmological expansion rate would have to stay at or near escape velocity, which implies a much greater... | [
"As ",
" said, rotations and collisions have nothing to do with it. You could just as easily say \"our galaxy hasn't even rotated 60 times since it supposedly formed, so there's no way it can be 13 billion years old\". The two aren't related. Also, one would hope that the currently held theory of early galaxy ... |
[
"If a venomous snake bites it's self is it immune to its own venom?"
] | [
false
] | null | [
"It varies snake to snake but is ",
"not definite",
". The venom needs to enter the bloodstream to be effective. Snakes that fight within their species tend not to bite each other so there isn't much pressure to develop protection against their own venom. There are snakes that are immune to the effects of other... | [
"I'm sure this came of question from the .gif of a snake head biting it's dismembered body.",
"Someone mentioned difference of injection versus ingestion. Ingestion wouldn't cause any complications unless it had a wound inside itself for it to enter the bloodstream.",
"Also I think someone said snakes tend to \... | [
"But doesnt any ingested food eneter the bloodstream anyway after it is broken down? Why would the venom not enter the bloodstream like normal food molecules?"
] |
[
"What is the ticking that you hear after a car has been turned off?"
] | [
false
] | null | [
"Nope, look up Antimony cooling instead. There seem to be very few videos of the phenomenon, but even the wiki page states that Antimony makes more pronounced versions of that sound."
] | [
"Additionally, different alloys will shrink at different rates as they cool. If they're bolted together you'll get that ticking sound. "
] | [
"Additionally, different alloys will shrink at different rates as they cool. If they're bolted together you'll get that ticking sound. "
] |
[
"Can anyone simply explain the mechanisms that protect the small intestine from the digestive juices released by the biliary system and pancreas?"
] | [
false
] | [deleted] | [
"I will assume that you are talking about the acidic chyme that comes out of the stomach after its digested all of the food. In this case there is a small tube that is between the stomach and the actual beginning of the intestine, it is called the duodenum. When the chyme (The mixture of the acid, food and the othe... | [
"Ok but thats the mechanism that neutralizes the acidic mix coming out of the stomach. You asked specifically about protection from the digestive substances from the pancreas and biliary tract... "
] | [
"Ok but thats the mechanism that neutralizes the acidic mix coming out of the stomach. You asked specifically about protection from the digestive substances from the pancreas and biliary tract... "
] |
[
"Why is gravitational force so weak?"
] | [
false
] | null | [
"This is a difficult question to answer. I assume you're referring to the fact that gravity is the weakest of the four fundamental forces. Is your question why it is weakest? If that's your question the answer is basically \"because it is.\" One of the forces had to be the weakest and it happens to be gravity.",
... | [
"The fact that gravity is weakest of all the four forces is the statement of the gravitational coupling constant in the 4 dimensions that we perceive, G_4, being much much smaller than the coupling constants of other forces. This discrepancy is usually termed as hierarchy problem in physics.",
"There are multiple... | [
"As Victor Stenger points out, the gravitational force is no weaker than the electrostatic force. That is, 1 N of gravity is just as strong as 1 N of coulomb force.",
"Anyone reading this post probably knows that in the particular example of an electron and a proton spaced a certain distance apart, the gravitati... |
[
"Why can we freeze embryos for IVF but not adult humans? What makes it possible for embryos?"
] | [
false
] | null | [
"Hello! Not an expert in freezing and thawing live specimen but well practiced in freezing and thawing dead specimen while keeping organs and microstructures intact. The major concern with freezing biological matter is the formation of ice crystals. Water forms crystals and expands when frozen and can result in bur... | [
"Speed and perfusion. Big problems both during freezing and thawing:",
", water is the enemy. It expands and forms crystals as it freezes, which together rupture cell membranes and effectively ravage tissues. If you just drop someone into a cryonic vat as-is, the brick of icy cellular mush you get will be far too... | [
"There are multiple types cryoprotectants and while they are generally supposed to be non-toxic it is only to a certain extent of concentration and exposure time. Extended exposure will interfere with daily bodily functions and metabolism. So unfortunately impossible to walk around with it indefinitely. The wolveri... |
[
"High Tides vs Low Tides"
] | [
false
] | I am going on a trip to the Gulf of Mexico sometime in August and to prepare properly I need to know what the pros and cons of high tides and low tides are.. I have already looked up a but of course I am having trouble understanding it. To my understanding if I go to the beach during low tides, there will be more 'stuf... | [
"Should I take it this is your first time at the sea side?",
"High and low tides will have different behaviours at different places, depending on the seafloor topography and coastline shape at that point. There's no golden rule.",
"All that chart is telling you is what level the tide is at at any given time of ... | [
"Indeed this is my first time, I guess I will just go and have a good time. I was just trying to get the most out of my vacation. Thanks for replying!"
] | [
"If it's a rocky beach below a cliff, you don't want to be there when the waves are crashing into the rocks/cliff. If there's sand as far as the eye can see (the most likely case for the gulf of mexico), you don't have to worry about it except riptides and things.",
"Low tide can be lovely and super cool to expl... |
[
"Realistically, When will we run out of oil?"
] | [
false
] | null | [
"Never. As oil gets rarer and harder to extract, it will get more expensive until almost nobody uses it anymore, but we won't ever run out."
] | [
"basically this. A lot of the reservoirs that are deemed 'dry' and have stopped production, can have as much at 50% of the petroleum left, it just became much more costly to extract it. There's a really good business opportunity for an engineer somewhere. ",
"We are also working on getting new, unconventional res... | [
"We won't, technically. What'll happen is that as scarcity increases, the price will rise, and eventually it'll be priced out of range of practicality. We'll never actually squeeze the last drop of oil out of the planet.",
"Predicting a date for that \"practicality\" point is pretty much impossible, as new dev... |
[
"Why do some animals eat their own young?"
] | [
false
] | Seems counter-intuitive from an evolutionary perspective, yet several species will eat their own young, or the young of other parents (which I can understand slightly more -- trying to protect THEIR specific genes rather than the species as a whole). Either way though, I find it hard to understand why an animal would e... | [
"There several scenarios, most having to do with bet-hedging and resources allocation, consider the following:",
"Female mice will reabsorb their embryos when the dominant male has been replaced. This is believed to be aimed at limiting female investment in offspring which will be destroyed at birth by the new do... | [
"Wonderful response, thank you :)",
"Edit - Very interesting question as I have asked this myself in the past. It's almost an accepted view of cannibalism. I assume it's natural selection taking effect in it's unusual ways. The weaker mouse's DNA is literally eaten alive whilst the new stronger dominant mouse spr... | [
"Yep - while putting those resources unto constructive use. It is highly adaptive behavior."
] |
[
"What do physicists mean when they say \"information\"?"
] | [
false
] | My physics professor was once telling us in passing (was not the subject of the lecture) about the holographic principle, where the amount of information that a black hole can consume is dependent on the surface area of the black hole rather than the volume. He never said matter or anything like that and I felt like si... | [
"The holographic principle itself is something more general, but what your professor was talking about is a closely related concept called the ",
"Bekenstein entropy bound",
". This is the idea that the entropy in a certain region of space is limited to a certain value, which you can calculate using the size of... | [
"The guy you're thinking of is ",
"Claude Shannon",
". But this doesn't answer OP's question. I will leave it to an actual physicist to talk about the information content of black holes."
] | [
"These bits have on and off, occurance and non occurrance, conformations that flip depending whatever the thing is.",
"Quantum bits have more than just on and off -- they can take any linear superposition of on and off. So for example they can be (loosely speaking) half on and half off, or one quarter on and thr... |
[
"How do stains work on the molecular level?"
] | [
false
] | How are the particles that become stuck on clothing so difficult to remove? And as a follow up question, how do stain removers work? | [
"I can tell you how bleach works on some types of stains. So some Compounds have color because of the molecule is a conjugated system. Meaning that more than 8 groups of alternating double then single bonds in a row all share electrons. When light hits this conjugated system it absorbs then releases energy that we... | [
"So my washed clothes are still dirty? "
] | [
"It's a matter of what the stain likes more: water or cloth? Stains usually are made up by fatty molecules (oils, fats, etc) that don't mix up with water (think oil and water, they don't mix together and form an emulsion). This means the stain likes to stick on cloth, rather than getting dissolved into water...unle... |
[
"If one were able to stand on a planet the size of Jupiter, what would the horizon look like?"
] | [
false
] | I've been asking myself this today and I can't quite visualize it. On Earth, the curvature of the horizon is always less than five miles distant on the surface, but Jupiter is many times larger. | [
"This can be calculated with some geometry. The equation is that ",
"distance=sqrt(height(height+2Radius)).",
"The answer to this for jupiter is about 16.7 km. It would look ",
" flat to you. It would also seem to take up a little bit more of your field of view because your angle to the horizon would be a lit... | [
"Why would it ever look like a bowl?"
] | [
"Sort of like standing in a bowl, then. That would be a really weird optical illusion."
] |
[
"Why can we determine the lifetime of short-living particles up to femtoseconds and less, but for the neutron we are unsure on the order of seconds?"
] | [
false
] | I just read , and in the last paragraph it says And the team is already designing its next-generation experiment, which aims to nail the neutron lifetime within 0.3 seconds. Compared to the lifetime of the Higgs, which is on the order of 10e-22s, this is a pretty large error. How come there is such a huge difference? ... | [
"The way that you measure the lifetime of the neutron and of extremely short-lived particles like the Higgs is totally different. There are different systematic uncertainties involved.",
"You don't directly measure lifetimes of things that live for 10",
" seconds; instead you look for resonances in scattering o... | [
"The intrinsic linewidth of something that lives for 10 minutes is on the order of 10",
" eV, which is far below the energy resolution of any experiment. These kind of indirect measurements are really only amenable to things with very short lifetimes. Direct measurements of the lifetime are preferred when possibl... | [
"That makes a lot of sense, thank you. In the article, they talk about a \"bottle\" method, where you put a certain amount of neutrons into some kind of container, wait some time, and then look how much neutrons are left. The other method is detecting the protons the neutrons are decaying into. Using the principle ... |
[
"Is there an instance in recorded history of an infection going from first outbreak to an endemic disease?"
] | [
false
] | If so, when did people decide to just give up on containing it? | [
"People do, but they don't really understand what's happened since the media stopped reporting on it at some point.",
"I consider myself pretty science literate, but I wasn't sure off the top of my head what ultimately ended up happening with H1N1. When I read your response I realized I personally have no idea i... | [
"“",
"” ",
"It’s only been in the last 20-30 years or so that “containing it” became an actual option. Before that, surveillance was not advanced enough to identify a disease before it was widespread. ",
"Compare HIV in the 1980s to SARS in 2003. HIV was already globally widespread before it was recognized a... | [
"Do people really not remember the H1N1 pandemic of 2009/2010? It was literally ten years ago."
] |
[
"Can you implant the nuclear genome of any cell into a sperm and have it fertilize an egg?"
] | [
false
] | If yes, is technology like that even in practice? | [
"the DNA in sperm is haploid, i.e. it has one set of chromosomes, while the DNA in a \"normal\" cell is diploid"
] | [
"http://en.wikipedia.org/wiki/Haploid#Haploidisation",
"Thanks for pointing me in the right direction."
] | [
"Let me clarify that with an example: Subject A wants a child, yet lacks functional gonads, could he use a donor's sperm cell?"
] |
[
"How come blood vessels and nerves are not pinched when we bend our elbows/knees and other bend parts?"
] | [
false
] | *Bendy parts. Sorry for title typo. | [
"Well, depends on how you define pinched. They aren't really pinched because they aren't in the joint barring major trauma. They can, however, have slight pressure on them at maximal flexion (particularly if you are a bit big) that you would experience as \"pins and needles\" and eventually pain over time. That w... | [
"To add to this, it's useful to consider that limbs do not completely compress when bent. If you imagine a garden hose, when you bend it , a crease forms which compresses the water stream. The hose construction is relatively stiff compared to the 'body'. The 'body' of the hose is only water, which deforms easily... | [
"Blood vessels definitely can be partially or completely pinched off as joints flex. Veins operate at lower pressures than arteries so they are more likely to be occluded. Our body gets around this by forking arteries/veins to create collateral paths which may eventually join up again. ",
"Here is the arterial ci... |
[
"What did people feed babies before mushed up store bough food in jars? Did mothers used to chew the food and then give it to their babies like birds do?"
] | [
false
] | null | [
"Complete speculation here, but they probably also breast fed for significantly longer than most modern societies. In modern poorer cultures, some mothers breast feed children at 5 or 6 years old."
] | [
"Unlike birds, humans don't need to chew food to mash it up. We have hands and tools such a mortar and pestle. Softer foods were cooked and pureed or mashed into a paste-like consistency, much like what you find in bottles today."
] | [
"People use mashing tools to mash up food for babies, and sometimes for themselves - mashed potatoes for example. Probably most people now living do not buy baby food in jars at the store."
] |
[
"Does angiogenesis really help against cancer? And what are the newest results about what food does help?"
] | [
false
] | null | [
"I think what you are looking for is anti-angiogenesis, the inhibition of the growth of new blood vessels. These studies (",
"Study 1",
", ",
"Study 2",
", ",
"Study 3",
" show that anti-angiogenesis can be useful in reducing the size of tumors in patients. However, this is effect is not uniform across... | [
"Also ProTip:"
] | [
"Thank you for the help. As far as I've understand the conclusions is that further research is needed and there can't be made any definite statements about it yet - just like you already said in your first comment.",
"The TED talk is kinda missleading or seems to be more promising while what they're actually doin... |
[
"If C02 is heavier than air then how is it causing global warming?"
] | [
false
] | I understand that CO2 isn't much heavier than air so a slight breeze would move it around pretty good but wouldn't the wind cause a pretty even distribution of the gas at all altitudes? I don't see how CO2 is holding in excess heat when its evenly distributed. | [
"CO2's ability to trap heat has nothing to do with its distribution. CO2 absorbs solar energy and turns it into heat more efficiently than, say, the nitrogen that makes up most of our atmosphere."
] | [
"Yes. However CO2 is not the only factor. In fact, methane traps heat ",
" 72 TIMES better than carbon dioxide. Also, it must be realized that the Greenhouse Effect is not a bad thing, it actually has been a main component in the survival of the organisms on this planet. Although, too much CO2 can accelerate the ... | [
"This is called the Greenhouse Effect, right?"
] |
[
"Can someone explain this madness?"
] | [
false
] | Just found this pair in my pensil pouch. Its like the Bic pen had melted around the Boxy eraser. I live in Iceland so the chance of leaving the pouch in a car during summer time and getting the pen hot is almost impossible. After removing the eraser, the material left behind was soft to the touch but definetly not ink... | [
"Solvent in the eraser dissolved the plastic in the pen. "
] | [
"Acetone?"
] | [
"I would guess hexane but that is just a guess."
] |
[
"Does quality of sleep differ significantly if induced with a sleep aid (i.e. melatonin or an antihistamine) compared with sleep that occurs naturally?"
] | [
false
] | null | [
"Sleep induced via melatonin should be the same size melatonin is produced endogenously any time you sleep, and the way you get it (probably) doesn't matter. Sleep induced by a antihistamine or sedative is of a lesser quality, though I can't remember the titles of the papers I read on it. IIRC, these drugs tend to ... | [
"Good post, thanks!"
] | [
"So those are very different ",
"Melatonin doesn't make you sleepy, it regulates your body clock - specifically it increases at night. It can help you sleep properly, especially if you have poor sleep hygiene, because it can help overcome other \"zeitgebers\" or time cues (like light and stimulation) that are te... |
[
"Is comet 67P's gravitational pull strong enough for me to remain standing on it without floating away?"
] | [
false
] | [deleted] | [
"Comet 67P/Churyumov-Gerasimenko is so small that its gravitational pull is several hundred thousand times weaker than on Earth. For this reason, the Rosetta lander had to touch down at no more than a walking pace. It also needed a harpoon to safely anchor it to the comet’s surface and prevent it from bouncing back... | [
"Even though it touched down at a walking pace, it still bounced several hundred meters. It's quite weak. "
] | [
"Thank you!"
] |
[
"How is Ballistics Gelatin an Accurate Representation of the Human Flesh?"
] | [
false
] | I know that Ballistics Gel is the same density as human flesh is, therefore allowing a somewhat accurate representation. However, I also noticed that when using ballistics gel dummies/torsos, the gelatin is significantly thicker than human flesh would be. Wouldn't the thickness, despite being the same density, affect t... | [
"Before ballistics gel, pigs were used, as they were found to be similar density to human flesh, and are pretty much the same size and weight, for repeat testing. Not completely sure, but I think ballistics gel is mixed to the same density as pig flesh still, but that's one of the main reasons to use ballistics gel... | [
"I wouldn't say \"rather than\" damage, since the behavior of the bullet is what indicates what type of damage it may cause when fired into a living person.",
"For example, what you think of as a \"standard\" (full metal jacket- lead interior with copper alloy jacket) bullet such as 8mm Mauser is a comparatively ... | [
"At the extreme loading rates imposed by bullets, the depth of gelatin blocks doesn't really matter. The dynamics of a cue ball falling onto a chunk of gelatin are significantly influenced by the thickness of the gelatin because stress transmitted through the gelatin can find it's way to the other side and push bac... |
[
"Is it possible to destroy the sun?"
] | [
false
] | null | [
"Thank you for your submission! Unfortunately, your submission has been removed for the following reason(s):",
"For more information regarding this and similar issues, please see our ",
"guidelines.",
"/r/AskScienceDiscussion",
"Please see our ",
"guidelines.",
"If you disagree with this decision, pleas... | [
"Half the questions on here are hypothetical... we have info on the sun and info on nukes. Are you suggesting someone can't work something out about this? "
] | [
"This question would be better suited for our other subreddit: ",
"/r/asksciencediscussion"
] |
[
"In the night sky, why do the stars twinkle/shimmer, but the planets do not?"
] | [
false
] | [deleted] | [
"Stars are nearly points of light in the sky. They hardly have any dimensions, due to their sheer distance from earth. Planets, on the other hand, have a visible width from earth. Even when looking through a reasonably good backyard telescope, stars still are simply points of light in the sky, while planets have a ... | [
"Stars are essentially point sources of light and planets are small discs. Atmospheric disturbances are refracting the point sources more noticeably than the larger planetary discs, where the twinkling gets averaged out over a larger area of the sky."
] | [
"Short answer: it's a wave-interference phenomenon. Starlight is coherent, but light from planets is not. With an incoherent light source, any interference fringes get washed out. (Light from a point source is always spatially coherent.)",
"The fast twinkle is actually a ",
"Fresnel Biprism",
" effect, whe... |
[
"Due to the constant expansion of space, is it possible at some point in the future that stars would cease to be visible in the night sky? If so, how long would that take?"
] | [
false
] | null | [
"No, because the expansion is irrelevant on the scales of collapsed structures like galaxies and galaxy clusters. Our solar system isn't expanding, the stars in our neighborhood aren't expanding away from us, and don't let anyone tell you otherwise!"
] | [
"I might be wrong, but I always understood it that because of the accelerating rate of expansion eventually the rate of expansion will be strong enough to overcome gravitational bonds within galaxies, and eventually even to overcome the strong/weak nuclear forces and electromagnetic attraction. I always understood ... | [
"Sorry, I ignored several complications here. The stars in the night sky will never leave due to the expansion of the Universe. However, at some point in the future we ",
" expect the night sky to become empty. Eventually - after about 100 trillion years - stars will cease forming, and all that will be left will ... |
[
"Can animals get STDs too?"
] | [
false
] | null | [
"YES. ",
"A particularly interesting one is 'canine transmissible venereal tumour' aka dog's bollocks cancer. It's a cancer that's passed on by cancer cells colonising individuals other than their original host through close contact. ",
"The only other cases of these transmissible cancers are Devil facial tumou... | [
"Yes. Here is an article on it. ",
"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1045078/pdf/brjvendis00066-0022.pdf"
] | [
"It's a cancer that's passed on by cancer cells colonising individuals other than their original host through close contact.",
"Well that's terrifying and interesting. There's no such thing in humans... right?"
] |
[
"'Chemistry' How does one speed up the oxidation of iron?"
] | [
false
] | I am trying to make an artsy rust pattern in some iron, however I was hoping that I could speed up the process that iron turns to rust. I assume this is done through oxidizing agents, is there a household one that works quickly? I've been trying hydrogen peroxide, however leaving a piece of iron in a tray of peroxide a... | [
"Salty water will do it. As explained ",
"here",
", salt in water boosts the rusting process.",
"\nAlternatively you can heat it up to around 600 C or more fo the oxidation to occur faster."
] | [
"This sounds like a good idea. To a lesser degree than aluminum (but similar), iron can have a passivation layer of iron oxide that protects the bulk of the underlying metal from being oxidized. Getting rid of it allows the oxidizing agent to come into contact with fresh iron, greatly speeding up the oxidation pr... | [
"Wrapping it in copper tubing/wire would speed up galvanic corrosion enormously in salt water."
] |
[
"What are the effects of rising atmospheric CO2 other than warming the planet?"
] | [
false
] | I was just reading this article: In it i states:> NASA said the planet was warming because of greater levels of carbon dioxide in the atmosphere as a result of human activity, mainly the increased combustion of fossil fuels. In 1880, the first year of the temperature record, “the carbon dioxide level in the atmosphere ... | [
"One major effect is that it increases ocean acidity due to a shift in the equilibrium point of ",
"this reaction",
". One of the most immediate effects of this is on ",
"Coral",
", which are already almost gone in many parts of the world. Coral are being hit by many factors (temperature, pollution, eventua... | [
"Davecasa's is absolutely correct in pointing out the ocean acidification. Here's a few time series of ocean pH taken from some subtropical locations: ",
"Ocean carbon dioxide and acidity",
"In regards to plants if we ignore the effects of higher CO2 on the climate, a number of experiments have been done in con... | [
"I hope you don't mind this correction/clarification. The only estimate of the amount of net primary productivity (i.e. photosynthesis and accordingly O2 produced) that I know of is from ",
"Field et al. 1998",
" which pegs the proportion of O2 produced in the ocean at about about 46.2% with land being 53.8%."... |
[
"Can we ever reach 0 degress Kelvin?"
] | [
false
] | I was watching a video on Linus Tech Tips showing a quantum computer. He said that the unit gets down to .015 Kelvin. What ways could we achieve 0 degress Kelvin, and if it's not possible why? Also, why does a quantum computer need to operate at such a low temperature? | [
"The third law of thermodynamics disallows cooling a system to absolute zero."
] | [
"An ELI5 statement of the third law is just \"You can't cool something to absolute zero.\""
] | [
"Technically, no. Practically - we can approach it incredibly close. In fact, cooling something becomes progressively easier as you approach zero, because heat capacity drops as T",
" around 0K.",
"A deeper question is, what you consider a good enough approximation for 0 K? Is 10",
" K good enough? Then we ar... |
[
"What do electrons do with/to an atom when they're not bonded to anything?"
] | [
false
] | null | [
"Remember that electrons aren't just particles, they also have wave properties (they are sort of complicated wavy/particly things that are best described with math and metaphors which rely on human experience tend to fall short). When an electron is bound to an atom it is basically in a standing wave on top of that... | [
"Can you clarify your question?"
] | [
"My main idea for the question came from the fact that (last time I checked,) alpha particles are basically helium without the electrons, which made me wonder, what are the electrons actually doing besides bonding to other elements?",
"Tl;DR, what do electrons do when they're not used in bonding with other elemen... |
[
"How genuine are Dr. Mehran Keshe's claims that the Earth will soon be hit by mega earthquakes which will claim around 40 million lives and will divide the continents?"
] | [
false
] | null | [
"As Das_Mime pointed out, this is complete nonsense. Let's ignore the fact the author is a fraud and look at the article:",
"He said: \"The South American continent is the starting point of the weakness. There will be earthquakes of 10 to 16 here and in one location 20 to 24.\"",
"I don't know what he means exa... | [
"To use a technical term, it's horseshit. ",
"Such earthquakes would be totally unprecedented, and there's no reason to even think that they're possible, much less that they're likely. ",
"The very article you linked admits that there is absolutely zero evidence backing up such a claim, and that Dr. Keshe has n... | [
"Run the formula given above on those two numbers and subtract the result. "
] |
[
"How does salt preserve food?"
] | [
false
] | null | [
"To my understanding it causes an environment that isn't as easily habitable for microorganisms. Some bacteria can actually live in a high salt environment, ones that can cause foodborne illness at least. Not 100% sure on that but I learned something like that in a food safety and sanitation class. The same would g... | [
"High salt concentrations kill most bacteria through osmotic pressure, the same way salt kills slugs. Since the concentration of salt outside the bacteria is higher than inside, water rushes out to equalize the concentration. This dehydrates and kills the bacteria."
] | [
"The main thing is that it dehydrates the food. Sugar will have the same effect (i.e. dried fruit). In any form of food preservation, the goal is to remove or freeze the water from the product."
] |
[
"What do we actually sense when we feel that something is wet?"
] | [
false
] | As far as i know there aren't any specific receptors for 'wetness' and sometimes it feels like something is wet but as soon as you enter a warmer environment the sensation is gone. I also heard that mercury doesn't feel wet although it's liquid. How does that work? | [
"The typical sensation of wetness is related to the coolness of the evaporative effect. When we are wet, either from sweat or an external source, the water is immediately drawing heat from our skin as it evaporates. Hot or warm water splashed on us feels different at first because it's actually adding heat. It feel... | [
"I believe the precise answer to this question is an area of active research, but I'll do my best.",
"I would disagree with Hagenaar that the coolness that we sense is related only to the evaporative effect. Instead, I would point to differences in ",
" that would likely explain part of the sensing that is goin... | [
"Liquids also have the effect of reducing friction. So when your finger feels cool and when you touch something that feels slippery, you know it's wet. "
] |
[
"Why are string theory dimensions smaller and not larger? (more in description)"
] | [
false
] | Why couldn't another dimension in our universe be too big to observe? At one point (in a TED talk) it was stated by Brian Greene that the remaining dimensions yet to be discovered in our universe are smaller and smaller in size. He also provided the idea that these smaller dimensions are the avenue for interaction wi... | [
"It loops back around itself on a small lengthscale. The universe in an Asteroids game has a finite size; you could leave one end of a rope somewhere, fly across the edge with the other end, tie the ends together, and pull it tight: it's not wrapping ",
" anything, but it still can't shrink past a certain point; ... | [
"If I'm understanding your question correctly..",
"One of the main reasons any higher dimensions must by necessity be \"small\" rather than \"large\" is that we observe the intensity of gravitation, electromagnetism, sound etc all obeying an ",
"inverse square law",
" when you move away from the source - beca... | [
"Because larger dimensions are obvious, like our 3 dimensions (which may be infinite in size), because you can move around in them. "
] |
[
"Why do painkillers work for specific kind of pain?"
] | [
false
] | [deleted] | [
"Aspirin and ibuprofen are both anti-inflammatory analgesics, which work by inhibiting production of prostaglandins, a group of lipid compounds which produce soreness and inflammation. They do not target specific pain, but rather circulate until they encounter a location which is producing prostaglandins, where the... | [
"work by inhibiting production of prostaglandins, a group of lipid compounds which produce soreness...",
"and yet...",
"targeting specific pain is likely a result of the placebo effect",
"Could you elaborate?"
] | [
"I'm sorry, I should have been more specific.",
"The first segment that you've highlighted is an explanation of why exactly these drugs cannot target specific pain - their pharmacological mechanism simply cannot allow this to happen. Aspirin cannot be better at dealing with back pain than headache, for example. G... |
[
"Does calcium stop being stored in human bones after a certain age? If so, when?"
] | [
false
] | [deleted] | [
"Bone resorption beats out bone formation depending on more than one factor though age is an important one. For women their chances of this happening and leading to osteoporosis increase dramatically after menopause or around 50+. This doesn't mean that bone formation isn't happening just that bone resorption is hi... | [
"No, hydroxyapatite (bone) is made up of calcium phosphate and a few other minerals/elements. Osteoclasts are cells that \"eat\" bone releasing these factors into the bloodstream. Osteoblasts(different type of cells) secrete these factors into a matrix that makes bone. Lacking calcium would result in no bone format... | [
"No, hydroxyapatite (bone) is made up of calcium phosphate and a few other minerals/elements. Osteoclasts are cells that \"eat\" bone releasing these factors into the bloodstream. Osteoblasts(different type of cells) secrete these factors into a matrix that makes bone. Lacking calcium would result in no bone format... |
[
"Can anyone help explain to me Ultracentrifugation"
] | [
false
] | [deleted] | [
"I think you are asking about density gradient centrifugation rather than ultracentrifugation.",
"Ultracentrifugation is just spinning very, very fast. Using this ",
"technique",
" you can pellet down specific cellular components by spinning at different speeds. For example, spin at 21,000g to pellet large or... | [
"You got the separation of materials based on size/density correct. That is important because it can be used as a method to separate out substances and therefore purify whatever substance you are trying to collect--usually DNA or proteins. For instance, in research this summer, I used an ultracentrifuge to purify... | [
"[Feel free to correct me if I'm wrong!]",
"OK, so you have the whole centrifugation thing down I think. You spin a tube with stuff in it super fast and all the components separate out into layers. Thing is, plain old centrifugation isn't able to separate as well as ultracentrifugation. You can get blood to separ... |
[
"Is boric powder a useful substance to get rid of German Cockroaches?"
] | [
false
] | My house has been crawling with German cockroaches and I heard online that boric powder would work. I need a scientific explanation for this. | [
"Not in my exp. Those little fkrs can breed so fast. ",
"I stopped an infestation from happening by going to my local DIY Pest Control place. Spent $50 on two products. A spray that kills the egg sacks that stay attached to the mothers. The other product was a poisonous gel that the roaches eat. The females who d... | [
"Disclaimer: source involves close up of a roach, and is therefore quite gross.",
"I think they're quite beautiful actually.",
"And the video is extremely interesting! Not so much because of the grooming, what I find far more interesting is the re-attempts the cockroach makes at grooming the restrained antennae... | [
"Disclaimer: source involves close up of a roach, and is therefore quite gross.",
"I think they're quite beautiful actually.",
"And the video is extremely interesting! Not so much because of the grooming, what I find far more interesting is the re-attempts the cockroach makes at grooming the restrained antennae... |
[
"Why does the color black attract more heat than other colors?"
] | [
false
] | null | [
"i would turn that explanation around; it's not that black things absorb more light - blackness is a perceptual property, not a property of a physical surface. a material ",
" black ",
" it absorbs so much of a broad (visible) spectrum of incident light."
] | [
"i would turn that explanation around; it's not that black things absorb more light - blackness is a perceptual property, not a property of a physical surface. a material ",
" black ",
" it absorbs so much of a broad (visible) spectrum of incident light."
] | [
"This is one of the clearest explanations I've heard, thanks"
] |
[
"How do we account for the gain/loss of time in a day due to earthquakes and tectonic activity?"
] | [
false
] | I'm aware of how earthquakes, such as that last big one in Japan, can cause the earth to spin faster, but I'm wondering how we can account for these moments in time. | [
"Through ",
"leap seconds",
". They are added every few years to account for the slowing of the Earth's rotation from the moon's tidal friction and internal tectonic processes."
] | [
"Yes. The minute takes its name from the Latin ",
", meaning \"small part\". The second is the ",
", the \"second small part\", and the minute can then be called more fully ",
", the \"first small part\". I don't know if it comes from court something something; ",
"Wikipedia",
" mentions medieval scientis... | [
"Sometimes, yes. ",
"On occasion, a very massive earthquake can bring a whole bunch of Earth's mass closer to the core",
", which has the impact of slightly increasing the speed of Earth's rotation. To use the most common analogy: it's exactly the same as when an ice skater brings their arms inwards, increasing... |
[
"Why are things like vanilla extract advised NOT to be stored in the fridge, and away from light?"
] | [
false
] | [deleted] | [
"With regards to Vanillin, I do work with it and can attest to the fact that it can crystallize and drop out of solution at refrigerator temperatures. "
] | [
"Recrystallization, a basic concept for those working with organic chemistry :P it's true for every compound, i'd say. Any solvent dissolves better when it's hotter, and when it's colder, certain compounds will precipitate and crystallize.\nIt's beautiful :D"
] | [
"For some reason I can't see 3 of the 4 comments there seem to be here so i'll give my view anyways.",
"It makes absolutely no sense that a molecule will decompose faster at lower temperatures, that much is obvious I would say. ",
"So the question is if by \"vanilla extract\" you mean vanillin, or if you really... |
[
"Why don't we shoot atomic waste into the sun?"
] | [
false
] | The question may be a bit silly, but I was talking to some friends and some of us said the reason is purely financial, because nobody would pay the millions necessary to shoot tons of waste into the sun. Other said it may be certain effects that the radioactive waste would have. What is true? Why don't we do it and g... | [
"Your friend who said the reason was purely financial is right … but may have failed to make the point strongly enough.",
"The Earth is in ",
" around the sun. That means the Earth, and everything on it, is moving through space at about seventy thousand miles an hour. In order to drop something into the sun, yo... | [
"To begin with, ",
"this",
" is one reason."
] | [
"That's like making a chainsaw out of wood!"
] |
[
"How do invertebrates, like the octopus, protect their vital organs?"
] | [
false
] | [deleted] | [
"The octopus brain is behind its eyes, and yes it is fairly small. Octopi have a very developed intelligence, and as we refine methodologies for studying octopus behaviour and intelligence their intellect is becoming very apparent. They can change the shape of their bodies quite dramatically, with the ",
"Indones... | [
"Eg, I could imagine, if I was designing an organism, it might make sense to have an \"arm brain\" for each arm that could control the arm, respond to impulses",
"Funny, you just described....an octopus! 2/3 of an octopus' neurons are in its arms, and the ",
"nonsomatotopic organization",
" of its nervous sys... | [
"Do any invertebrates have a \"decentralised\" nervous system (for lack of a better phrase)? Like could an organism distribute smaller \"computing clusters\" (again, lack of good phrase; ganglia/nodes) that pre-process sensation or post-process commands for action? ",
"Eg, I could imagine, if I was designing an o... |
[
"A fundamental property of bosons and fermions is that their wavefunctions are symmetric and antisymmetric respectively in terms of exchange of particals. Why is this so, and how do we know it?"
] | [
false
] | null | [
"Why spin works/transforms the way it does? I'm not sure anybody really understands spin. ",
"I do not think that spin is so mysterious. In terms of the representations of the lorentz group it is pretty clear what spin is (a very good explaination is in Weinbergs QFT books) "
] | [
"A common (but somewhat bogus) argument is that since particles are indistinguishable, then exchanging two particles can only make the wave function differ at most by a phase factor (e",
"), as changing the overall phase of the wave function is the only change you can make that will not change any observable prop... | [
"So spin statistics theorem shows that integer spins are symmetric and half integer spins are antisymmetric...",
"Yes.",
"also shows that bosons are integer spin and fermions are half integer spin",
"I'm not sure what you mean by that. How do you define bosons and fermions? You can either define them by the s... |
[
"Question about Carl Sagan Quote and Carbon atoms."
] | [
false
] | So I've always heard that "This is something carbon atoms do after 13 billion years"... I'm sure I got the quote a little wrong, but that's beside the point. My question is: what kind of atoms decay into carbon atoms? Can the quote be taken literally? Wouldn't most carbon atoms have decayed into something else by now?... | [
"To summarize the science part of it, the big bang basically only created hydrogen with a little helium (and trace amounts of Li, Be). All the heavier elements (up until Fe) are made by fusion in stars, and all the elements heavier than Iron were made from supernovae of dying stars.",
"Now as others carbon isn't... | [
"The actual quote is:",
"\"These are some of the things that hydrogen atoms do given fifteen billion years of cosmic evolution.\"",
"It's from the last episode of Cosmos. It refers to evolution, in that hydrogen atoms formed stars, which created all other elements (including carbon), which formed self-replicati... | [
"Oh, cool! Thanks for the info, guys, including the essay and the comic. ",
"So, next quick question: when an atom decays, doesn't it create a different atom? ",
"If so, is carbon never one of those atoms?"
] |
[
"Are young men more likely than young women to die of heart disease?"
] | [
false
] | A close family member recently lost a young nephew aged 19 to an undiagnosed heart condition. My mother and I had a conversation where we realised how prevalent it seemed to be - we could think of several instances of our seemingly-healthy male acquaintances who passed away suddenly where the cause of death was undiagn... | [
"This is not saying that heart attacks are becoming more common in younger people. It is saying that there are more ",
" of young people with heart attacks, especially young women. This could be related to increased surveillance, better understanding of heart attack signs/symptoms especially in women, healthcare ... | [
"EDIT: Ignore this post for now. The numbers I gave you are percentages, not absolute numbers so it is not going to accurately answer your question",
"",
"I'm not sure you are asking the question you want to ask. The answer to the question in your title is simple: the CDC reports causes of death by gender and ... | [
"Actually in general heart attacks are becoming more common in younger people, especially women — source:",
"\n",
"https://www.ahajournals.org/doi/full/10.1161/CIRCULATIONAHA.118.037137",
" "
] |
[
"Would the Bat-Signal work in reality?"
] | [
false
] | Could a projection system such as a spot light produce a clear enough image on a cloud landscape similar to how the Bat-Signal works? Why hasn't anyone tried it? | [
"Yes it works and is done from time to time. ",
"http://i.imgur.com/1TPkP.jpg"
] | [
"That looks more like a laser than a spotlight."
] | [
"Pirateparty logo Arrrrr =)"
] |
[
"What would happen if we can completely modify our DNA?"
] | [
false
] | null | [
"Thank you for your submission! Unfortunately, your submission has been removed for the following reason(s):",
"For more information regarding this and similar issues, please see our ",
"guidelines.",
"/r/AskScienceDiscussion",
"Please see our ",
"guidelines.",
"If you disagree with this decision, pleas... | [
"Thank you for your submission! Unfortunately, your submission has been removed for the following reason(s):",
"For more information regarding this and similar issues, please see our ",
"guidelines.",
"/r/AskScienceDiscussion",
"Please see our ",
"guidelines.",
"If you disagree with this decision, pleas... | [
"Thank you for your submission! Unfortunately, your submission has been removed for the following reason(s):",
"/r/AskScienceDiscussion",
"Please see our ",
"guidelines.",
"If you disagree with this decision, please send a message to the moderators."
] |
[
"If it is impossible to go the speed of light, couldn't we figure out that \"stopped\" is in our universe?"
] | [
false
] | If we somehow, theoretically, went fast enough that we started to see noticeable, recordable effects from approaching the speed of light, then went the other way and did the same, couldn't we figure out what the speed of light is relative to? I've always wondered this because while we can't go the speed of light, it pr... | [
"This is actually the core problem that special relativity answers.",
"You can't go faster than the speed of light relative to ",
" frame of reference. At the same time, the speed of light is always the speed of light relative to everyone.",
"This works because the classic velocity addition formulae you learn... | [
"That is ",
" what Michelson and Morley tried in 1887, to pinpoint the direction of motion of the ",
"luminiferous aether",
". To their dismay, they found no preferential direction of motion, which in turn led to the founding principle of special relativity: the speed of light is the same in any inertial fram... | [
"We routinely accelerate things to over 99.99% the speed of light relative to Earth. Just tiny particles, not spacecraft, but the concept is the same. Let's say you would be in a spacecraft that moves at 99.99% the speed of light relative to Earth. Now what? For you Earth moves at 99.99% the speed of light while yo... |
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