title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"Has the angle of the rising sun in relation to due East altered at any point on the Earth in the past few years?"
] | [
false
] | More details here I know the surrounding assumptions are not your bag and you are skeptical of them but I was wondering if someone could confirm the empirical data and, hopefully provide a scientific hypothesis as to why this has occured (if it has). Thanks in advance guys. :-) | [
"Ok, you are simply refusing to answer any questions about your process or accept any suggested answer. You very obviously are an anti-science psuedo-intellectual. If you were interested in science you would take any criticism of your process, adapt your experiment to correct for that problem and improve the validi... | [
"Ok, you are simply refusing to answer any questions about your process or accept any suggested answer. You very obviously are an anti-science psuedo-intellectual. If you were interested in science you would take any criticism of your process, adapt your experiment to correct for that problem and improve the validi... | [
"Magnetic North moves around over time. Over the last decade or so it has been moving very rapidly, about 40 miles per year. This will not affect position of the sunrise, but it will affect your measurement when taken with a magnetic compass. ",
"(Relevant link.",
")"
] |
[
"Is there a phrase to describe the back-and-forth evolutionary process between organisms, e.g. predator and prey?"
] | [
false
] | I'm thinking of things like the prey evolves a particular defense, the predator evolves a counter to that defense, and so on. I seem to remember this sort of thing from high school biology, or just reading about it. Is there even a term of art for it? Or is there a good phrase to describe the constant process each ye... | [
"coevolution"
] | [
"Red Queen's hypothesis",
", in reference to the quotation by the Red Queen: \"It takes all the running you can do, to keep in the same place.\""
] | [
"Evolutionary arms race"
] |
[
"What happened to all the Aquatic Dinosaurs?"
] | [
false
] | I'm curious as to why the aquatic dinosaurs disappeared. I know there are a lot of theories and hypothesis as to why the land dinosaurs were wiped out, but it seems that sea life has been left out of this discussion. For example, the asteroid. How did that affect the ocean? | [
"First off, the obligatory \"Giant marine reptiles were not technically dinosaurs\" (some were actually pretty closely related to certain lizard groups, others were in completely different groups, none were dinosaurs proper)",
"Second: These marine reptiles tended to be large, active top predators. Life is alwa... | [
"Sharks saw a 20% species reduction. That says nothing for the populations though, which may have seen much larger reductions. And, as you point out - there are many small and deepwater species."
] | [
"Also, it is hypothesized that the meteor hit organic rich sediments which released large amounts of SO2 and CO2 into the atmosphere. SO2 keeps solar radiation from entering the atmosphere, thus cooling the earth rapidly. CO2 lets solar radiation into the atmosphere, but does not let it out. This causes warming.... |
[
"Some questions on the common ancestor of apes and humans."
] | [
false
] | 1) What did the common ancestor of modern apes and humans look like? I always imagine it looking like a modern ape but I can't really believe that to be the case. 2) Would that common ancestor be regarded as an ape if it would still exist (unchanged)? 3) Is there a book that focusses on the evolution of that ancestor t... | [
"I think I understand now, thanks.",
"So... we regard apes as a monophyletic group, that is we think that they all derive from the same common ancestor. Or to put it another way they form a completely self contained group if we were to draw an evolutionary tree of animals.",
"The principle observations for esta... | [
"1) well Humans are apes, so the last common ancestor between Humans and OTHER apes would be at the homo-pan split. The earliest species thought to be on the hominin lineage (or arguably before the split) are orrorin, ardipithecus and Sahelanthropus. Google them to get an idea of what it would look like. ",
"If y... | [
"For modern apes to form a group (clade) like they do, they must originate from a node at which there was an organism that was itself an ape. Otherwise you are looking at 5 instances of convergent evolution on the general ape phenotype (Lesser apes i.e. Gibbons, Orangutans, Chimps, Gorillas and Sapiens). ",
"On t... |
[
"Is interstellar space travel even possible considering the amount of random dust/matter out there? Wouldn't a collision with something the size of a grain of sand destroy the craft?"
] | [
false
] | If a space craft were travelling extremely fast through space, hundreds of thousands of miles and hour, and it came in contact with just a single stationary or moving molecule, dust particle, or something even larger, wouldn't that essentially destroy the entire craft? I know how utterly empty the vacuum of space is bu... | [
"I'll assume 0.5c is \"extremely fast\".",
"The (classical) kinetic energy of a bare proton at 0.5c is:",
"...which ain't much.",
"The objective answer to your question obviously depends on the parameters of the spacecraft and the debris encountered, but if we make some assumptions, you can get an idea. Let's... | [
"But wouldn't a third of a milliliter of water traveling at 0.5 C simply punch a tiny hole through the craft, like a bullet? After all, a bullet doesn't simply expend all its energy the moment it hits something. It often passes through and keeps going having expended little energy."
] | [
"That's for the engineers to figure out.",
"And being drunk, I'm not exactly in the engineer mindset :)"
] |
[
"How do deserts enrich the Earth's seawater?"
] | [
false
] | In "Our Planet", a docuseries produced by Netflix and narrated by David Attenborough, while speaking about the Arabian desert and the surrounding water he mentions that "dust blown from the land contains nutrients that fertilize the surrounding waters. So it is the desert itself that enriches the sea". What does this... | [
"The wind picks up the tiny sand particles which are then later on dropped in the sea. This mainly transfers iron to the sea (which clings on to the sand), so much so, that the iron in the Atlantic ocean is 70-90% iron which came from deserts (mainly the Sahara). ",
"Iron is necessary for fertilization of the sea... | [
"The parent means \"of the iron found in the ocean, 70-90% comes from the Sahara\""
] | [
"There are also many other inorganic nutrients present in sand, like phosphorus and nitrogen. These elements among many others are essential to life and get lost permanently due to sedimentation to the bottom of the oceans."
] |
[
"Do any unpowered lenses exist that can reveal a wavelength of laser light not otherwise visible to the naked eye?"
] | [
false
] | Is there a combination of laser light wavelength and transparent lens material that reveals the presence of laser light to a human observer without a powered system like an IR or NVG scope? Ideally the light wavelength would not be visible to the naked eye, but would be visible by the human eye looking through the lens... | [
"Non-linear optics",
" (which allows the incoming frequency to be different from the outgoing frequency) typically is only observed at super high intensities like from lasers.",
"This is how most green laser pointers work -- they double the frequency of an infrared laser diode using a Second Harmonic Generator ... | [
"chances are you are not going to be able to accidentally phase match a crystal with a laser you don't know is there."
] | [
"So, it's not the lens that allows you to see infrared light. The lens is just a normal lens - it concentrates light into a small area for the actual enhancement to happen...",
"Here is an article on how night vision goggles work: ",
"http://electronics.howstuffworks.com/gadgets/high-tech-gadgets/nightvision3.... |
[
"How long, without a nuclear detonation, until we can make Low Background Steel again with normal atmospheric gasses?"
] | [
false
] | As above really! | [
"That depends on the background level you want to reach. A dark matter detector (looking for a few events in tonnes of mass in several years) has much more stringent requirements than a Geiger counter where a few decays per hour and kilogram don't matter. For dark matter detectors: Probably never due to natural rad... | [
"It is just a matter of effort. ",
"This article",
" describes the effort to get an extremely low background for Xenon1T, one of the dark matter experiments.",
"Where possible they used copper instead of steel. The copper samples showed some natural radioactivity, e.g. from radium decays. They considered plat... | [
"What if the oxygen for the BOP was generated electrolytically from water or thermally from decomposing minerals? Arent't there also air filters for clean rooms that could remove particulates almost completely?",
"Is it just more economic to recycle low background steel than produce it with these methods?"
] |
[
"If a radioactive isotope is accelerated near c, will the decay slow down or remain the same relative to observer?"
] | [
false
] | I would assume the decay would slow down, but the more I think on it, the less I'm confident. | [
"It will be slower.\nFor example, when cosmic rays hit the atmosphere, they can produce muons. A muon is more or less like an big electron and its lifetime is only 2 µs.\nSo if you don't consider the time dilation, a muon cannot travel more than 2 µs times 300000 km/s = 0.6 km. So you wouldn't expect them to reach ... | [
"Yes, it's very common: around 10,000 muons per m² per s (at sea level). And since they are charged they are fairly easy to detect. So any student with a basic detector can see muons.",
"Actually, many experiments which try to directly detect dark matter have to run under a mountain to get rid of the muon backgro... | [
"Wow, that's an incredible example. Thanks for that.",
"How often can we detect cosmic rays producing muons in the atmosphere? Is it common?"
] |
[
"How large is the biggest (most massive) supermassive black hole we've discovered?"
] | [
false
] | null | [
"NGC 1277"
] | [
"Adding on to this, its mass is about 17 billion solar masses."
] | [
"what about NGC 4889?"
] |
[
"How did the human butt become an object of sexual interest?"
] | [
false
] | null | [
"This all sounds right but it'd be perfect if you had a few sources"
] | [
"This all sounds right but it'd be perfect if you had a few sources"
] | [
"Among primates, and many other mammals, the rump is used to indicate when a female is in heat. The \"female shape\" indicates a sexually nature, well nourished individual. "
] |
[
"Why are the inner planets smaller and solid, while the outer planets are large and made of gas?"
] | [
false
] | null | [
"Early in the formation of a solar system you have a large disk of dust (meaning all types of molecules, gaseous or solid) orbiting a protosun. The temperature in the disk depends on how close you are to the protosun. In the inner part of the disk the temperatures are so high only metals and rocky dust are solid. "... | [
"I believe we are still lacking in enough data to make such wide-sweeping statements. ",
"This is a recent update on Kepler's findings",
" (the percentages are the changes since their last version of the image) - you can see that they're finding more Neptunes than Jupiters, but the number of Earths and Super-Ea... | [
"and, in fact, may not even be common",
"Is there actually any indication of this? I was under the impression that the reason current instruments pick up gas giants orbiting close to their parent star is because they are more sensitive to this type of planet than a large, low-velocity gas giant such as Jupiter or... |
[
"Why is monosomy often lethal? Can someone break down this explanation?"
] | [
false
] | The explanation states "Many monosomic individuals don't survive because if just one of those genes is represented by a lethal allele, monosomy unmasks the recessive lethal that is tolerated in heterozygotes carrying the corresponding wild-type allele, leading to the death of the organism. In other cases, a single copy... | [
"Say an organism needs to produce a protein called LIFE to stay alive. Most organisms of that species will have 2 copies of the gene that acts as a blueprint for synthesizing the LIFE protein, but some will have one normal copy of the gene for LIFE, an one mutated copy which encodes the protein LOFE. Having only ... | [
"For the first case, a lethal allele means that it doesn't do what your body needs it to do and as the name implies having them causes you to die. They are usually but not always recessive simply because dominant ones will generally kill whoever carries them before they can have kids. The most famous example is the... | [
"Say you have fifty thousand genes. A handful of them will be bad versions - lethal versions. ",
"If they are paired up with another set of genes, which will certainly also have some lethal members, it’s extremely unlikely they will be the same ones as yours (unless the other set is from a close relative). Their... |
[
"Other than water and salt, are there any products that we eat which have absolutely no biological origin/ingredients?"
] | [
false
] | [deleted] | [
"Two examples I could think of are baking powder and various essential minerals in compounds, e.g. Iron(II) sulfate and Magnesium hydroxide.\nMany more chemicals that fit your description are probably food additives, like colours and preservatives."
] | [
"If you are Scandinavian you might well eat ammonium chloride, and use it as a flavoring in your baking. (If you didn't grow up with it you'll probably gag on it.)",
"Some antacids are essentially powdered rocks (calcium and magnesium carbonate.)"
] | [
"Additionally our body needs a wide variety of minerals to work; magnesium, iron, potassium, ect."
] |
[
"What are the differences between the modern Windows filesystem and the modern Unix filesystem? Where did those differences come from?"
] | [
false
] | In a computer science course I'm in, we covered that Unix file systems use a logical filesystem on top of the physical file system. I understand a bit, but it can get a bit confusing. As I understand it, the logical file system sometimes allows for smaller file sizes (via File Holes) and allows for easier mounting of s... | [
"This is really an issue of engineering rather than science, so I'm not sure it's on-topic, but I'll try my best to answer anyway.",
"The idea of a \"logical file system\" that you got from your class is fuzzy and conflates a bunch of different issues; it's not really a useful way of thinking about how operating ... | [
"logical filesystem",
"In Linux, we call it the VFS. I've never heard the term logical file system. The VFS is responsible for a number of features, and I won't get nearly all of them. The basic notion for question is to identify which specific file system driver (ext4, btrfs, vfat, etc.) can fulfill an IO reques... | [
"So when my professor said that Windows effectively lacked a virtual filesystem, and handled everything on the physical file level, was he wrong? Or am I still misunderstanding?",
"He is wrong, but you have to have some fairly low-level knowledge about Windows to know how it really works.",
"The paths in Window... |
[
"How can some animals live for several centuries without dying off from cancer far earlier?"
] | [
false
] | In an earlier thread on , many concluded that at some point cancer rates would overwhelm treatment. As we age, the risk of cancer increases due to likelihood of certain errors increasing with time. So, how do certain , with very long life spans, overcome this problem? | [
"First, the examples in your second link seem mostly to be ",
" lifespans, which is not the same as average lifespans. A single individual living far beyond the average lifespan isn't really indicative of anything, just that they're \"lucky\" enough to avoid mortal accidents, cancers, etc.",
"Next, many of the ... | [
"I thought I read that on reddit, but after searching I found this: ",
"http://www.livescience.com/9680-cancer-kills-wild-animals.html"
] | [
"Rule number one about science: Don't tell people what you think. Tell them what you've proven."
] |
[
"Why does my tv antenna work better when I stand near it?"
] | [
false
] | I cut the cord about 3 years ago and use an HD antenna to watch broadcast networks. In my latest move, my antenna was dropped and now works funky. Specifically, in SF when tuned to CBS 5.1, the antenna cuts out frequently (2 seconds of clear broadcast, 2 seconds of static and lost signal) when I watch it from bed or th... | [
"The human body acts as an antenna in, and of itself. The human body does conduct electricity (think salt water), and so it can be a pretty good antenna.",
"If standing next to your antenna all day doesn't suit you though you can ghetto-rig aluminum foil to help strengthen an existing antenna. "
] | [
"The body both conducts electricity well enough to act as an antennae while ALSO absorbing other radio signals, which may remove the competing static signals.",
"Humans are also surrounded by an electrostatic field of sweat."
] | [
"Maybe your body acts as a sort of RF filter. Does it matter where you stand around the TV? I presume you are standing on the side of the antenna that your broadcast is coming to achieving this?"
] |
[
"How close are we to having Star Trek like deflector shields?"
] | [
false
] | [deleted] | [
"You should stop replying in askscience if you have no idea what you are talking about. There is a reason why your posts keeps getting downvoted."
] | [
"Here",
".",
"Some of it seems rather recent. Apparently they came up with some sort of plasma bubble that protects the contents from radiation..."
] | [
"See also ",
"3M electrostatic wall"
] |
[
"How are some birds able to imitate human speech?"
] | [
false
] | Reading made me curious - how are birds such as parrots and mynahs able to imitate human speech when their "vocal" tracts are so different from those of humans? For example, birds do not have lips, so how are they able to produce labial consonants? Is it just that they are able to trick the human ear into hearing certa... | [
"In addition to a larynx, birds have a ",
", a complex two-part noise-making apparatus. By manipulating the numerous muscles that attach to it, they can create an incredible array of sounds, even several distinct sounds at once. Syrinxes are far better than larynxes for producing sounds-- in fact, Turkey Vultures... | [
"Is it just that they are able to trick the human ear into hearing certain sounds when only approximations of them are being produced?",
"In a certain sense, yes. As you may or may not know, speech isn't just pure tones - overtones (in a musical sense, not in a literary sense) give a sound a lot of important qua... | [
"I'm mostly kidding - we love our African Grey. He's a gas - but he is quite musical and talkative.",
"Actually, the worst thing he does are two specific sounds. The first is the sound of a backing up FEDEX truck - so every time we hear that we rush to the door - I think he gets a kick out of that (in fact, my y... |
[
"What is radiation poisoning and how does it work, also how is it treated?"
] | [
false
] | Specifically radiation from nuclear bombs, but anything else is appreciated. | [
"Hey, this is something I have to worry about at my job! Well, sort of, I have to worry about my dosage.",
"Radiation poisoning is radiation killing cells in your body. Specifically, it destroys or mangles your cells' DNA. There are three general bodily functions affected by radiation; gastrointestinal, hemato... | [
"Very interesting, thank you!",
"How would you treat having a higher dose of radiation, and what is occurring to fix the problems caused by the radiation poisoning?"
] | [
"You should read the ",
"Mayo Clinic",
" page on treatment. It'll be much more indepth than what I can offer. I also have the utmost respect and trust for the Mayo Clinic, and have had friends with exces radiation exposure be treated there(albeit for fairly low dosage compared to fallout)."
] |
[
"What factors have caused the more recent uptick in nut allergies among youth?"
] | [
false
] | I don't think I met anyone with a nut allergy until I was in my 20s and even now, most of the people allergic seem to be young children. Is this a built up immunity that we didn't worry about previously or something else? | [
"I do all those things and haven't been sick either. Correlation doesn't mean causation"
] | [
"Do you have a citation on this? The studies I've seen have shown correlation on a nation-wide scale, but negative evidence in actual experiments as to whether increased levels in the diet increases risk of allergies."
] | [
"Correct!!",
"It has nothing to do with \"manufacturers\" and their \"substitutes\", that's just silly pseudoscience. The prevailing theory of allergy prevalence is called the ",
"hygiene hypothesis",
", which suggests our immune system continues to attack perceived invaders, even in the absence of parasite... |
[
"Can adrenaline actually give you the strength to lift a car and how does it work?"
] | [
false
] | null | [
"here's a good breakdown",
". Basically the adrenaline gives your more blood and oxygen to your muscles which in turn allows you to be more effective. Like others have said, you don't suddenly gain super strength, but you ",
" suddenly able to use the full potential of your musculature. Your body normally preve... | [
"There was a 4 part mini series made by The Discovery Channel called ",
" in 2008 that has cool graphics and goes over this in the first episode. ",
"It was a really interesting and well made miniseries."
] | [
"The extra oxygen delivery gives you increased stamina but not strength. The epinephrine/stress/fight response gives you strength over what you’d normally expect. It’s most likely a combination of the increase in calcium release and increased signal potential ion that allows for more muscle to be recruited.",
"... |
[
"Can you improve your eyesight..."
] | [
false
] | by flexing your vision? For instance, you focus on something close to you, then focus on something far away from you, and repeating. | [
"Programs like that and the Bates Method exist(",
"http://en.wikipedia.org/wiki/Bates_method#Treatments",
"), but the results remain inconclusive and highly controversial. I wouldn't hold my breath about it.",
"A healthy diet and adequate vitamin intake, wearing sunglasses, and avoiding other life style risk... | [
"Just trying to help Ill be sure not to next time :D"
] | [
"Thank you for the reply. I have also heard that the more you use glasses you become more dependent on your glasses. Is that true?"
] |
[
"When light goes from a vacuum, into water, then back to a vacuum. At what speed is it now traveling ?"
] | [
false
] | Is it traveling at the speed of light through water? Or, is it back up to the speed of light in a vacuum? If so where does it get that energy boost from? | [
"It’s traveling at the vacuum speed again. There is no energy boost associated with the change back to vacuum; the frequency of the light stays the same. But the phase velocity changes because the index of refraction changes."
] | [
"Light actually goes slower in a medium.",
"This is because light in a medium isn't a pure electromagnetic wave anymore. Light in vacuum is just an oscillating electromagnetic field, whereas light in a medium is an oscillating electromagnetic field + oscillating electric dipoles (caused by motion of ions or elect... | [
"Just to add ... the speed of light, either through vacuum or through the medium, is ",
"inversely proportional to the electric permittivity and magnetic permeability",
" of the vacuum or medium. In a medium, these two constants have higher values than they do in free space ... consequently, the speed of light... |
[
"Do scientists have any opinion as to whether virtual particles occur only in vacuums or if they occur anywhere?"
] | [
false
] | Bonus question: Do virtual particles that spring out of existence from nowhere then annihilate themselves violate the conservation of energy principle? | [
"The ",
" place that I have ever seen a concrete description of a 'virtual particle' is in the context of Feynman diagrams, where it is nothing more than a term in an algebraic expression.",
"The idea is that something like an photon is a ripple or disturbance in the 'photon field'. Such photons interact with e... | [
"Do virtual particles that spring out of existence from nowhere then annihilate themselves violate the conservation of energy principle?",
"No. They don't come from nowhere. Even a vacuum has energy and virtual particles come from that energy."
] | [
"or is this based on the beliefs of the scientific community?",
"This isn't based on belief, but on evidence from experiments and quantum field theory."
] |
[
"What recent advances in your field are lesser known to the masses but could have significant impacts on our way of life in the next 5-10 years?"
] | [
false
] | null | [
"problems like?"
] | [
"problems like?"
] | [
"http://www.youtube.com/watch?v=1GhNXHCQGsM"
] |
[
"What is happening when I wake up starving, wait an hour or two and don't eat, and the hunger dissipates?"
] | [
false
] | I can't think of a good, concise way to word this question without telling it like a story. I usually wake up around 8 or 830 AM every morning. Some days I don't wake up hungry, but twice a week I'll wake up STARVING, like almost nauseous. I bear the hunger and by 9 or 10 I'm not hungry and can wait till about 1 PM to ... | [
"It's not starvation mode.",
"When you get this feeling, your body has burned off much of the free, easy glucose in the blood, liver and muscle, and is in a transition period where it decreases the rate of glucose metabolism and begins to rev up the burning of fatty acids. Until this process is complete, and the ... | [
"it stops because ",
" cells start ",
" breaking down glycogen (imagine a long chain of glucose molecule holding hands) and fat in your body. If you wait a little longer to eat (several days), they begin ",
" breaking down proteins ... this involves cells breaking down protein in muscles into amino acid whi... | [
"Does that mean skipping breakfast is a good idea if you're trying to lose weight?"
] |
[
"Do humans contain 'white meat' and 'dark meat' like poultry?"
] | [
false
] | null | [
"Mammalian muscles differ from avian muscles by having ",
"multiple muscle fiber types in each muscle",
". So avian muscles are generally either translucent pink or darker translucent pink, while mammalian muscles are much redder and grainier in appearance, and more opaque. The color in all cases comes from myo... | [
"Pork is pink to red",
", but while were at it, I'd like to know what cheetah meat looks like. I'm guessing a pale pink, since their fast twitch muscle fibers make up ",
"\"83% of the total number of fibers examined in the vastus lateralis.\""
] | [
"Why do pigs have white meat rather than red meat like other mammals?"
] |
[
"If all matter in space slowed to a stop, would there be any noticeable change?"
] | [
false
] | [deleted] | [
"Try this on for size",
"."
] | [
"Try this on for size",
"."
] | [
"Are you asking what would happen if ",
" stopped? I seek clarification on that, because metric expansion is not actually motion, though it sounds like that's the conceit behind the question.",
"The answer is that if metric expansion stopped all at once, tomorrow, we wouldn't know it for a very, very long time.... |
[
"Those black areas underneath the skin of potatoes - Toxic? Edible? Normal?"
] | [
false
] | [deleted] | [
"I used to own a restaurant that was famous for the fries that were sold. Due to the high volume I bought, the company that manufactured the fries wined and dined me for a couple of days, and gave me a tour of a farm and their factory. ",
"The dark areas commonly found on fresh potatoes are called sugar ends. ",
... | [
"Cool!"
] | [
"Thanks. On smaller scales, abrasive peeling is a thing, but you should check out steam peeling. ",
"It's even done with tomatoes, but with a twist, it's done under vacuum so it can be done at lower temperatures."
] |
[
"Is it possible to create a sound that dissipates unusually quickly?"
] | [
false
] | I'm imagining creating a sound that can easily be heard close by, but after leaving a certain range the sound grows inaudible very rapidly. Is it possible to manipulate a sound wave to do something like that, or is the rate at which sound waves die out only affected by the air it travels through? | [
"I think the easiest way to do this would be to change the source of the sound rather than the sound itself. There are specialty speakers and devices designed to do this - I know I've run into them at museums and other places.\nMost quality monitor speakers have a waveguide designed to create as wide a soundstage a... | [
"I can't think of a way to synthesize a sound that will dissipate unusually quickly when played through an ordinary loudspeaker. But a clever spatial arrangement of out-out-phase elements can create a significant near-field sound that dies out quickly. Tuning forks and wine glasses, for example, sound louder up clo... | [
"Yes. Of course sound can be focused! You could do this by creating a sound source that focused the sound instead of a wall that did it (imagine a parabolic speaker arrangement).",
"But even better is the ability to use ultrasound to do this. Ultrasound refracts and spreads less than lower frequency sounds. You c... |
[
"Is there an industrial or structural reason that any recyclable plastic bottle most always has a non-recyclable plastic cap?"
] | [
false
] | I have looked pretty far and wide for an answer. The only reason I could think of would be that bottle makers want a harder plastic cap, either for the threading or to prevent it breaking, but if high density polyethylene is strong enough for the container, why isn't it strong enough for the cap? Can you not dye HDPE? ... | [
"Both polyethylene and polypropylene are thermoplastic polymers. That is, they can be heated up and reformed, thus 100% recyclable. This is in comparison to thermosetting polymers like Bakelite, which cannot be heated up and reformed, as they will break down when heated.",
"The main reasons that you are told not ... | [
"Those need to be removed as well, otherwise they'll stay solid when the bottles melt! That's one of the main problems with scaling up recycling, there isn't an easy way to automate this. ",
"You should remove the ring when you toss out the bottle into the recycling bin. Most plants use people to manually sort th... | [
"What about the little plastic rings that stay on the bottle neck? Are they small enough that it doesn't matter, or are they filtered out somewhere in the process?"
] |
[
"A question about death"
] | [
false
] | Recently, my grandfather passed away and my nephew (age six) has not been told much. This got me thinking, at what age do children typically understand death? My gut tells me it would be formal operations, based off of Piagetian theory. Is this correct? Or can children comprehend death in concrete operational? | [
"He isn't asking what is death, he's asking at what age in development a child can grasp the concept of \"death\"."
] | [
"Why? This is a perfectly valid question for ",
"/r/askscience",
" . ",
"If only I knew the answer. "
] | [
"The way I see it, is that death is an explainable biological phenomenon (e.g. cessation of brain-function, respiration or whichever definition doctors these days use). ",
"Death can be caused by severe trauma, illness, or 'old age': cell division over the years shortens telomeres in the DNA, which in turn leads ... |
[
"If the door of an in flight commercial airplace was opened, would everything be sucked out a la hollywood films?"
] | [
false
] | Going even further, if somehow there was a small hole in the passenger section of the plane, would the suction immediately cause it to grow bigger and bigger eventually sucking out the passengers (again, as seen in hollywood films)? Thanks in advance! edit - commercial airplane* | [
"Watch the mythbusters episode, also commercial airline doors open in a little then push out making it impossible to open whilst the cabin is pressurized aka at altitude "
] | [
"It is impossible for the door to open in flight while the cabin is pressurized. The pressure differential keeps it sealed shut.",
"And being sucked out through a small hole is a myth. The real danger in an uncontrolled decompression is from hypoxia and hypothermia.",
"http://en.m.wikipedia.org/wiki/Uncontrolle... | [
"Others have stated the safety features of a passenger door. However, in the case of a ",
" the size of that door, the result is rapid decompression and ",
"major damage can occur",
".",
"A small hole won't cause catastrophic damage."
] |
[
"Why are certain programming languages more suitable for creating certain types of programs?"
] | [
false
] | So for example C+ is suitable for the creation of device drivers, Java is suitable for web applications, etc. What component of the software architecture makes one programming language more suitable for the creation of a certain type of program over another? What makes any one language more versatile than another langu... | [
"Programming languages have different design goals that tend to encourage certain kinds of programming. Be aware that every serious programming language can simulate any other serious programming language so you could technically write any possible program in any possible language (actually because of type checking... | [
"It's all somewhat of a subjective thing in most cases as to which languages are \"better\" at any task. Most modern languages can do almost everything.",
"However, in most cases when someone makes a statement like \"C is good for device drivers.\" or \"Python is good for databases\" we are expressing a subjecti... | [
"The OS isn't necessarily the lowest layer in a system. A hypervisor often runs underneath an OS, or multiple virtual OS's could be run on a single machine. There is also a BIOS, which is needed to actually start running the OS. ",
"So I don't think it breaks the definition to have an OS running on top of a JVM. ... |
[
"Why do some substances (metals, wax, etc.) lose density when heated, whilst others (egg, meat, etc.) tend to solidify?"
] | [
false
] | null | [
"Metals become liquids when heated because their particles gain energy and so they can move about. Eggs contain complex proteins such as Albumin. At a temperature higher than about 60 degrees Celsius, the complex molecules become denatured by the heat. They change into something else which happens to be a solid. Th... | [
"I wouldn't necessarily say that a new substance is formed in the egg case! Incoming pedantry:",
"All proteins are long chains of units called amino acids. What makes proteins special is that the units within these chains can interact, and so when folded you get things like hydrogen/ van der waal interactions and... | [
"Eggs contain lots of proteins, which are long chains of assorted amino acids ",
"twisted into complicated knots, pleats, and folds.",
" ",
"The covalent bonds holding the chain together are strong and will not break much until the egg starts to burn. The intermolecular forces holding the knotted chains in th... |
[
"Does Urine Therapy have any real scientific proof supporting its 'benefits'?"
] | [
false
] | I have met a few people who actually will drink a small cup of their own urine every morning, and they claim that the health benefits are worth it. One guy told me that after he started doing it he stopped testing positive for Hepatitis-C which he claimed to have had for 15 years. | [
"Straight off of wikipedia:",
" \"There is no scientific evidence of a therapeutic use for untreated urine.\" It links to some articles as well.",
"I'm currently looking around trying to find some peer-reviewed articles, I'll get back to you if I can find anything conclusive."
] | [
"http://www.skepdic.com/urine.html",
"A great search engine that would be useful to you to bust common myths is ",
"Skeptical Search Engine",
". It searches popular skeptics sights."
] | [
"Not to derail the specifically scientific discussion of urine composition, but I feel it's relevant to ask why your friend believed so strongly that urine therapy had any merit? I see this quite often (even within my own peer group) of people swearing by these (sometimes bizarre) alternative treatments based at th... |
[
"If I hold my hand to the back of a blow-dryer, will the rotor blades go faster or slower?"
] | [
false
] | [deleted] | [
"The rotor blades will move faster, because there is \"no air\" to offer resistance to the rotor blades. It works similar to a vacuum cleaner, when you cover its mouthpiece. It will spin up because you are removing the load from the motor. A similar effect can be seen in a car with a manual transmission. What happe... | [
"You are not creating \"no air\" on the front side of the rotor blades which push against the motor.",
"That is true, but that is not the way propellers work. They \"dig into the air\", on one side of the propeller and pulls through the air(or, in fans, pulls the air through). They don't dig into the air on both ... | [
"I am a bit confused by your statement. Are you saying that if the motor/propeller was not blocked, it would run faster?",
"Yes. ",
"If you put an even stronger vacuum behind it, it'll even spin backwards overpowering your motor -- just like a windmill does."
] |
[
"Do dogs really love their owners, or are they just really good at getting us to feed them?"
] | [
false
] | null | [
"Does it count if studies show both dogs and humans produce oxytocin when making physical contact?"
] | [
"Super subjective question and I’m no dog behavioralist, so this is speculative. Dogs are pack animals, the same as us. Love is a very strong emotion, and one of its primary functions is to bond members of a group together. Although we may experience more nuanced and complex versions of emotions, I believe that the... | [
"Yeah that would be pretty great starting evidence actually!"
] |
[
"How much lower were water levels during the time of Polynesia expansion ?"
] | [
false
] | null | [
"Wikipedia says that's 3.5-1 kyr before present? ",
"Not very different. Reconstructions say that global sea level has been fixed at modern values (to within 1-2 meters) for the past 4-7 kyrs. Furthermore, I can't think of any local changes in polynesia that would cause deviation from the global average over t... | [
"Yep, just to add a graph to this explanation, ",
"averages of different records of sea level, relative to modern sea level",
" suggest sea level was within ~2 meters of modern for the last ~5 thousand years. "
] | [
"Thanks for the response . I was curious maybe water levels were low enough that land was easier to find . "
] |
[
"How do other apes keep their nails short?"
] | [
false
] | null | [
"Hah, alright. How do orangutans trim their mustaches then?"
] | [
"Same way I do. "
] | [
"I always see my dogs chew them, and I've seen videos of primates biting them, among other animals with similar claws and nails. As I've witnessed caring for many different animals and observing others, active animals will use their claws and they'll break here and there from regular use. It's not like nail biting ... |
[
"Is there any way to improve intelligence or are we stuck with what we have?"
] | [
false
] | Barring implants, neural "cyborg-ification", etc. | [
"Richard Feynmann claimed that he wasn't exceptionally intelligent, but that he focused all his energies on one thing. Of course he ",
" exceptionally intelligent, but he makes a good point. ",
"I think one way to improve your intelligence is to actually try to understand things in a very fundamental way. Rathe... | [
"Well that depends on what you mean by intelligence. You can train your math skill, increase your knowledge, attain a knowledge-seeking attitude, have intellectual confidence(which imo counts for a lot) etc etc but improving your ability to learn might be tricky.",
"If you mean the average intelligence of our spe... | [
"I disagree, we derailed evolution and natural selection",
"No, we ",
" the outcome of natural selection. It is irrational to think that we aren't part of a process of natural selection. The only way we can conclusively not be part of natural selection is if we all die.",
"No matter how sophisticated our reas... |
[
"Is there a maximum and/or minimum possible wavelength for light to have?"
] | [
false
] | If so why? | [
"No. Since the Lorentz transformations are continuous in the velocity ",
", we can always boost into a reference frame in which a given light ray has arbitrary wavelength."
] | [
"You run into trouble at very long wavelengths - if dark energy is constant, then the part of the universe you are in causal contact with doesn't increase beyond limit. A wavelength longer than this part of the universe cannot be called radiation in a meaningful way."
] | [
"All wavelengths are possible since we can always just locally boost into a frame with arbitrary relative velocity to a given frame. As I already wrote, Lorentz covariance means all wavelengths are possible. "
] |
[
"Does it take the same amount of energy to run a mile at 5 minute pace that it takes to run the same mile at 6 minute pace?"
] | [
false
] | If a person was to run a mile at a fairly fast pace, they would expend X amount of energy. What if the same person were to run the same mile in the same conditions but at a slower pace... Would they expend the same amount of energy? | [
"For humans, yes. Energy efficiency of the human running gait is independent of speed. Search for \"human\" on ",
"this Wikipedia page",
".",
"Do note that this is true only if you are comparing running vs running (not running vs walking), and only in humans (as far as we know)."
] | [
"The faster you run leads to an exponentially increasing amount of heat generated.",
"Why do you think this is so? Isn't the heat loss constant per number of ATP produced?"
] | [
"From a basic thermodynamic standpoint, this cannot be true, while the wiki says that: \"it is commonly thought that the COT remains constant across all submaximal running speeds\"\nOne reason this cannot be true could be seen for energy used to cool yourself down: The faster you run leads to an exponentially incre... |
[
"If an object of large mass would suddenly appear 1 light-second away from you, would you feel the gravity instantly or with a delay of one second?"
] | [
false
] | [deleted] | [
"The speed of gravitational waves in the general theory of relativity is equal to the speed of light in vacuum, "
] | [
"Keep in mind that photons are massless - but they do have momentum. This means that photons will naturally follow the geometry of space-time.",
"Arm that with the knowledge that the more dense (massive) an object is, the more it distorts the geometry of space-time.",
"Also keep in mind that the gravity is alr... | [
"Keep in mind that photons are massless - but they do have momentum. This means that photons will naturally follow the geometry of space-time.",
"Arm that with the knowledge that the more dense (massive) an object is, the more it distorts the geometry of space-time.",
"Also keep in mind that the gravity is alr... |
[
"What happens when E=MC^2 is applied in a medium in which the speed of light is slower?"
] | [
false
] | [deleted] | [
"There is no medium in which the speed of light is slower. What's ",
" happening is that atoms in the material absorb and re-emit photons, and the delay between the two makes light appear to travel through it slower. It's often convenient to refer to this as slowing down the speed of light, but the actual speed o... | [
"c refers explicitly to the speed of light in a vacuum."
] | [
"No, c is a constant"
] |
[
"Why is Kelvin an SI base unit?"
] | [
false
] | Our chemistry teacher explained to us recently that temperature is just the avereage kinetic energy of all the particles in a sample. But then shouldn't temperature be measurable in Joules? Or Joules/mol? And if it is, then why is Kelvin a base unit if it can be derived from units of energy? | [
"Because different materials can have different amounts of energy in them per unit molar mass--molar heat capacity. If we defined temperature as energy per unit molar mass, for instance, then a glass of water in front of you could/would be at a different \"temperature\" than the table it's sitting on, even if they... | [
"From a thermodynamic perspective, temperature is much like fugacity. ",
"Temperature is a number associated with ability for flow of energy from one item to another item. Energy does not flow from high energy to low energy, but from high temperature to low temperature. Temperature and energy are different and th... | [
"Fugacity is basically just pressure but corrected for the fact that gasses are not ideal."
] |
[
"How is it possible for shampoo to smell so different from it's taste?"
] | [
false
] | null | [
"Because of the difference between \"taste\" and \"flavor\" from a scientific standpoint.",
"Flavor is the total sensory experience of something you put into your mouth, minus the somatosensory (touch, feel) aspect. This includes both taste (the chemical properties your tongue can detect, ie salty, sugary, bitte... | [
"So in short, your nose only smells volatile substances, but when you put something in your mouth, you get the dual action of your nose and your tongue, with the latter sensing both volatile and non-volatile. Yes?"
] | [
"Typically, the manufacturers will add something based on Denatonium to it, in order to prevent large-scale ingestion. It typically requires 10ppm to be functionally inedible. Bitrex is a common branded form, which (as is my understanding), is not volatile at all and as such, has no effect on the smell, but a huge ... |
[
"Why are thermal images so blurry? What is hard about making thermal imaging lenses?"
] | [
false
] | null | [
"Cost is the major reason. Most IR detectors have a resolution lower than even the cheapest cellphone camera. Thre IR detectors and lenses are very expensive\nThe Flir T660 has a 640x480 resolution, very high for IR cameras. The cost is $25000 to $30000"
] | [
"There's also pretty strict export laws (because an infrared camera is a pretty important piece of a heat seeking missile) ",
"So it might be that you're seeing blurry images from the lower-res versions that are legal to export, as the restricted ones are much more expensive. "
] | [
"Several factors that drive the cost up:",
"As many thermal cameras work in the wavelength range 8 – 16 μm, you need detectors that work with it, that are less common than silicon massively used with visible, so there's less economy of scale.",
"The wavelength also means that pixels can only be reduced to a sim... |
[
"Why is Intel still using 14nm in their cpu's when the technology for 5nm is already out?"
] | [
false
] | Intel's new rocket lake is using a 14nm and yet Samsung's new chip for its phones is using 5nm so the technology cleary exists. Is there no benefit for Intel to using a smaller node? | [
"Comparing process technology is very difficult. This is because there are many different tradeoffs (static leakage, dynamic power, and frequency being the main components).",
"The short answer is that you can't compare the numbers across companies (Intel's 10nm is (or will be) better than their 14nm, but Intel's... | [
"Just to add on here for any confused readers, the name of the process node doesn't actually correspond to any physical dimension on the CPU. It used to measure the gate length, but it hasn't done so for years. Now it's basically used as a marketing figure, justified by \"well these are all the ways we've improved ... | [
"Intel is trying to move to 10nm and 7nm but is having manufacturing problems (yield issues). This is 100% intels fault - they for years only released incremental upgrades to gain maximum profits as they would not have to reconfigure manufacturing lines. They failed to be innovative - they were looking at competi... |
[
"Why are melting Ice Caps causing the world water level to rise, when (correct me if i'm wrong) the higher percentage of the ice is in the water already and ice has a lower density than water?"
] | [
false
] | [deleted] | [
"Maybe in covered surface you're right but the volume of ice on land is far greater than the volume of sea ice. Sea ice is a couple of meters thick and the land ice on Greenland and Antarctica is up to 3 kilometers thick, that's a lot."
] | [
"This is correct but the bigger contributor to sea level rise is simply the fact that warm water expands. "
] | [
"Oceanography Undergrad here. Yes, you are correct. The rough number we use (if I remember correctly) if about 50% of the sea rise so far is due to thermal expansion. The other 50% being land ice. ",
"edit*\nWent back and read part of the IPCC report. Here is some additional data:",
"Over the period from 1961 t... |
[
"Is there a study that shows exactly how damaging chronic ibuprofen use is to the stomach lining?"
] | [
false
] | I used to know a kid that took 4 200mg ibuprofen 3X a day for years due to migraines/sinus headaches, and he also drank heavily during this time (it was in college). He didn't show any adverse effects like bloody stools or anything for the 3 years that I knew him. Is it just something that only affects certain people? ... | [
"Nothing in biology or medicine is 100%, so there will always be individuals who don't fit the standard mold. However, on the whole we know that NSAIDS like ibuprofen can lead to GI damage due to its effects on prostaglandins, which are protective.",
"The clinical presentation of NSAID gastropathy may range from... | [
"4x200, three times a day is actually below the maximum dose. Max dose is 3200mg per day. Also, there is no specific interaction between alcohol and ibuprofen at an allowable dose. They can both cause stomach irritation, but this won't necessarily be the case for everyone. "
] | [
"thanks!"
] |
[
"Do snowflakes spontaneously form from vapor? Or do droplets first fall then crystallize?"
] | [
false
] | Was trying to understand the origin of a snowflake and whether or not there is an instantaneous transition from water vapor or if the droplet forms and crystallizes during its descent. I imagine hail is just droplets freezing during descent? Is it the temperature difference that produces one over the other? | [
"I have a Master's degree in Meteorology, currently working on my Ph.D. Should probably take the time to get the flair, but eh.",
"The processes that form hail and snow are very different. Snow, or ice crystals, are formed in cloud regions where temperatures are uniformly below freezing. All snow is initially for... | [
"Great answer, but I'll just tack on a more basic summary in response to OP's question:",
"The snowflakes form directly from vapor for the most part. Very small dust particles (called ",
"ice nuclei",
") are of the right size/shape to start accumulating ice directly from vapor, and at the right temperature (t... | [
"So does the size of snowflakes depend on how much pollution is in the air or excess water vapor to build onto crystals?"
] |
[
"What is the difference between magnetism and electricity?"
] | [
false
] | Hi ! I was sitting in my Physics class today and my teacher told us we were beginning to cover magnetism and electricity. After the introduction to the topic, I made a comment that they were the same thing (I was under that impression) My teacher, who is a psychopath when it comes to students saying things, exploded te... | [
"Well, let's not be hasty. The teacher is correct that electricity and magnetism are not \"the same thing.\" There is a reason why you have to learn both, and not just one! The are indeed both aspects of the same thing (the electromagnetic field), but each aspect is important and distinct. It's just that they trans... | [
"Electricity and magnetism are intimately related, so much that they are considered one force--one of the four fundamental forces of nature--electromagnetism. A changing electric field furnishes a magnetic field, and vise versa (as per Ampere's law). Your teacher doesn't know what (s)he's talking about."
] | [
"One difference is that electric charge exists and magnetic charge doesn't... ",
"as far as we know",
"."
] |
[
"Blood typing O blood type"
] | [
false
] | Alright so I've been wondering this for a while. There are 3 different types of blood. A,B, and O. Each can mix with each other initially at birth (DNA gene) Anyways my question being the O type of blood is the most common. And around 50%ish. The A is about 27% and the B. being the least common of the 3. Now what I do... | [
"ABO blood types are different because of different proteins on the red blood cell surface. There is an A protein and a B protein. Blood type O is the lack of either of those proteins. So, if you receive the gene for A from your mother and O from your father, then you will have blood type A. So O is recessive becau... | [
"The thing is that dominance/recessiveness and allelic frequency are completely independent. I don't know the frequency of the A, B, and O alleles off-hand, but we can use some made up numbers to see how at least this is possible. ",
"So lets say that A is completely dominant over O, B is completely dominant over... | [
"There at least 30 blood group in humans. They have to do with the presence of antigens in the surface of red cells in the blood. O means the lack of them... you can read more here: ",
"http://en.wikipedia.org/wiki/Blood_type"
] |
[
"Is it possible for something to have negative mass?"
] | [
false
] | Is there anything in the universe that has properties opposite of gravity resulting from having the opposite of mass? | [
"The existence of negative mass would not cause any contradictions, and the mathematics work out in a self-consistent way, so it can't be ruled out. However, we currently have no reason to believe that anything with negative mass actually exists."
] | [
"Firstly when you derive E=mc",
" from the four impulse you actually get E",
" =m",
" c",
" +... which implies |E|=|m|c",
" >0. Secondly your argument is on the same level as form example this: Galileo transformation says x'=x+tv but SR says something else so SR is wrong. You cannot argue the non existenc... | [
"Negative mass would make either the Alcubierre drive possible, or would allow you to create / sustain a wormhole which GR tells us would allow communication into the past.",
"Either of these things (which are only possible with negative mass) would allow FTL communication, which thus breaks causality as you can ... |
[
"Do plants need gravity to grow?"
] | [
false
] | I was thinking how plants grow in outerspace (artificially of course). I know the ISS has some expirements going on where they grow plants but I was not sure how well they grow or what special measures need to be used. Thanks | [
"There was a news item here in the U.S. this past week about astronauts on the ISS eating vegetables grown in microgravity for the first time. From that perspective their main concern seems to be artificial lighting to mimic sunlight more so than gravity. "
] | [
"Before the food growing, they have probably done tons of experiments with plants before."
] | [
"I would be interested to know what effects gravity or the lack thereof would have on plants in space"
] |
[
"Is if more fuel efficient to add gas while going uphill?"
] | [
false
] | The road I drive on each day to work has many hills and slopes. Is it more fuel efficient to add more gas while going uphill or should I accelerate before the hill comes and add less gas while actually on the hill? | [
" slow down while rising up the hill, then allow your car to speed back up on the way down. Otherwise, you'd have to apply gas on the way up, only to apply the brakes on the way back down. ",
" get into an accident caused by abnormal driving behaviors that confuse/surprise other motorists. You'll be all over t... | [
"This is on the highway, and I'm driving against the traffic, so it's usually pretty clear. I never apply brakes on the highway unless someone cuts me off.."
] | [
"The amount of work done (and therefore the amount of gas used) will be the same with all other variables held constant... of course all other variables aren't constant. What you may be overlooking is that you can use the Earth's gravity to give you some momentum to get up the hills: Try to coast down hills (no nee... |
[
"If you know you have contracted a cold and it's still in its incubation incubation period, what proven steps can you take to lessen its severity?"
] | [
false
] | null | [
"I found this with a bit of googling",
"\n",
"http://www.sciencedaily.com/releases/2011/11/111101130200.htm",
"So I guess one thing someone can do is to stay warm. It gives some sort of boost to the body's mechanism for destroying infected cells. I don't know how much of an effect this'll have though. I think... | [
"I can't answer your question, so don't upvote this, but the common cold and influenza are completely different things. Influenza is caused by the Influenza Virus, whereas the common cold is usually caused by Rhinovirus.",
"http://en.wikipedia.org/wiki/Rhino_virus"
] | [
"Thanks for the clarification! I made the change."
] |
[
"What is the effective actual brightness in relation to the human eye of planetary objects in the distant solar system? What I mean is: are photos of Saturn the brightness they are due to long exposures or would they actually be relatively dim objects due to their distance from the sun?"
] | [
false
] | [deleted] | [
"You can see most of the planets with your bare eyes on a dark night, except Mercury (because of its small size and because it is usually only visible at twilight due to its proximity to the sun) and Uranus/Neptune (too far away, but you can see with a good pair of binoculars). Most pictures of outer planets are ta... | [
"For example, if I was in a spacecraft orbiting Neptune would it be as bright as most photos show?",
"This really depends on a few factors, including how close your spacecraft is to Neptune.",
"As a basis for comparison, think about how bright the light is from a Full Moon. If the Moon were twice as close, it w... | [
"For example, if I was in a spacecraft orbiting Neptune would it be as bright as most photos show?",
"This really depends on a few factors, including how close your spacecraft is to Neptune.",
"As a basis for comparison, think about how bright the light is from a Full Moon. If the Moon were twice as close, it w... |
[
"[x-post] Saw this in r/gifs and just want to know what causes this and how to replicate it? Link inside."
] | [
false
] | null | [
"My chem teacher did this. It is really easy to replicate. Get some rubbing alcohol, put it in a 5 gallon jug, close the top of the jug and shake the jug around. This will cause the alcohol to vaporize. Light a match take your hand away from the opening and quickly through in the match. It will do that but faster (... | [
"OMG you knew Richard Feynman! ",
"We used to put on magic shows — chemistry magic — for the kids on the block. My friend was a pretty good showman, and I kind of liked that too. We did our tricks on a little table, with Bunsen burners at each end going all the time. On the burners we had watch glass plates (flat... | [
"It is sometimes called the ",
"\"whoosh bottle.\"",
" I've done it several times with 70%-90% isopropyl alcohol with great success. Place less than 50 mL in a 5 gallon jug, swirl, ",
", and light with a match or grill lighter. ",
"If you try this, be sure to wear goggles and have both a metal object (pie p... |
[
"Since the universe began, has time been going the same speed?"
] | [
false
] | I understand how time is relative so this is a difficult question to explain. The big bang happened in an instant. If I was in the middle of the big bang when it happened would it still be instant? Does a second to me right now feel longer than a second would feel during the big bang (provided that I was in the midd... | [
"If a span of time objectively ",
" longer, that span would ",
" longer.",
"Time is measured according to the duration and frequency of time-dependent phenomenon. A ",
"second",
", for example, is defined as \"the duration of 9,192,631,770 periods of the radiation corresponding to the transition between t... | [
"Great answer. It's not called \"relativity\" for nothing."
] | [
"There isn't any way to be sure. However, since there is no reason whatsoever to suspect otherwise, we don't."
] |
[
"When I think of flight (as in an airplane) my mind perceives it as the wing creating a low pressure system above the airplane which basically allows it to float up into that space. How wrong am I?"
] | [
false
] | null | [
"Pretty much yeah",
"The shape of the wing causes a low pressure system to form over the wing. This is what creates the lift that keeps the plane in the air.",
"For science: ",
"http://en.wikipedia.org/wiki/Lift_(force)#section_2"
] | [
"if you remember basic classical dynamics, in order to create a lift upward the wing has to push something downward and air is all that is available. The fact that it is fluid dynamics does not invalidate the principle of the underlying microscopic theory.",
"He is correct."
] | [
"The lift generation comes out from the mathematical solution of the differential equations that describe the flight phenomenon. These are the so called Navier-Stokes equations. The Bernoulli principle is an ideal subset of Navier-Stokes that cannot fully describe the actual phenomena in a lifting body or airfoil o... |
[
"In the double slit experiment, why is coincidence counting needed?"
] | [
false
] | I know there are many different setups of this experiment. I'm referring to this one here: While I understand the overall experiment, I'm not sure what the coincidence counting is needed for. I've read elsewhere on the web that it's used to distinguish the entangled photons from stray light and background noise. Howeve... | [
"The coincidence counter is not just used to reduce noise, and is in fact critical to the experiment. This is because without the coincidence counter you will not see an interference pattern at all because the photons coming from the BBO (in contrast to coming from a single slit) are not spatially coherent . The pl... | [
"Thank you very much for this explanation!"
] | [
"Coincidence counting is the only possible way to detect light / photons. Every time you detect a photon, you destroy it and thus you have created a \"detection coincidence\". This is also true in everyday life, technically you count how many photons hit your retina. "
] |
[
"Why does paneer not melt?"
] | [
false
] | I was cooking some food today and I've always wondered, why doesn't paneer melt? Every other cheese I can think of gets more liquidy/greasy at high temperature. Paneer gets softer but retains its original shape even when boiled or fried. | [
"It is a hot acid cheese where the milk is heated and acidified for curding. Cheeses like mozzarella are kept below 110F to separate casein and whey. Whey needs higher temps to colagulate so this style is mostly casein. When made around 200F like the one you are asking about the whey is incorporated into the cheese... | [
"I don't think this is true in the case of paneer. It isn't a dry crumbly cheese. It's definitely higher moisture than something like cheddar, which melts easily. The texture of it is something like firm tofu."
] | [
"\"When you melt cheese, you're essentially softening the milk proteins and fats to varying degrees of pliability and usability. When a cheese is heated, the protein matrix — which trapped the fats and proteins in milk and helped form solid curd when the cheese was made — collapses, encouraging the flow of cheese i... |
[
"If the Earth were flat, how far would you be able to see?"
] | [
false
] | Assuming that gravity and atmosphere stayed the same, would you be able to, for example, see New York from England on a clear enough day? | [
"I'd think it would be more of a question of ",
"scattering",
". According to ",
"Wikipedia",
" you can see about 300km in the cleanest possible sea level atmosphere."
] | [
"Based on a human eye resolution of 1.2 arcminutes (I read that on Wikipedia), you could see the Empire State Building from about 1100 km away. "
] | [
"Just type \"1300 feet/(angle)\" into Goolge where (angle) is the minimum resolution."
] |
[
"American Chemical Society AMA: I am Gerry Wright, Director of the Michael G. DeGroote Institute for Infectious Disease Research at McMaster University and Associate Editor of ACS Infectious Diseases. Ask me anything about antibiotic resistance and antibiotic discovery."
] | [
false
] | Hi Reddit! I am a Professor of Biochemistry and Biomedical Sciences at McMaster Univeristy and Director of the Michael G. DeGroote Institute for Infectious Disease Research ( ). I have been working on antibiotic resistance and discovery for over 25 years. My lab uses a combination of chemistry, microbiology, biochemist... | [
"How far away are we from complete resistance to current antibiotics?"
] | [
"How much resistance is due to animal agriculture compared to overprescription/not finishing prescriptions? Does one seriously outweigh the other?"
] | [
"Hi Dr. Wright,",
"At our current rate of growing antibiotic resistance, how long can we expect our current arsenal of antibiotics to remain effective (say, 50% of the time)? ",
"As a follow-up, how far along are we towards being able to design rather than discover antibiotics?",
"Thanks for doing this AMA!"
... |
[
"Is cancer natural, or a result of modern world pollutants?"
] | [
false
] | null | [
"May I know what other 'theories' about cancer you are referring to? For a start I will say yes, cancer can occur naturally even without modern world pollutants. There are many 'natural' ways for mutations to occur and that is how evolution is possible in the first place."
] | [
"The main alternate theory she's looking at is here:\n",
"http://www.dr-gonzalez.com/history_of_treatment.htm",
"Basically, the idea (from the early 20th century) is that pancreatic enzymes are the bodies main defense against cancer. The treatment includes high doses of pig-derived pancreatic enzymes, a soecia... | [
"I would suggest to stick to research supported modern theories and medicine. Doctors are not perfect so if need be seek advice from more than one but please do not let 'alternative' approaches that are not backed with proper research replace modern treatments."
] |
[
"Some questions raised by a teacher..."
] | [
false
] | We had a substitute in math today named Dr. Handkins. He majored in both mathematics and physics for his undergrad, and minored in chemistry. He got his masters in Ministry and his Doctorate in ministry as well. He has been a pastor for 43 years now. Here are some questions he brought up: 1.) 25% of the universe is mad... | [
"He's an idiot and part of the reason why science education is failing in this country. He is not a scientist and does not understand science at all.",
"1) Just because we don't understand some of the universe doesn't mean that the parts we do understand aren't valid.",
"2) The odds that someone with his geneti... | [
"I was going to rage out at you and then I reread and realized that it was your teacher who said these things and not you.",
"Making claims on how we came about (the Big Bang) and calling it \"scientific or empirical evidence\" is at the very least pushing it, to me.",
"Calling the big bang a claim and then put... | [
"2.) The odds for the chain of mutations that occurred in evolution are so astronomically low that evolution seems much more complex and unlikely than God. Even with billions of years, the chances are still extremely unlikely.",
"The process of natural selection is ",
" equivalent to just picking mutations at r... |
[
"Is the well known image \"March of Progress\" OK to be considered acceptable as a symbol for human evolution?"
] | [
false
] | Its hard to explain exactly how I mean this. I have studied some and understand much more than before how humans evolved. I know that this image has been trashed to the side by most anyone with a better understanding of evolution because it presents itself as showing evolution as being a linear progress toward the end ... | [
"Well, it's not ",
" wrong, but it's \"wrong enough\" that it's probably best not to promote its use. The modern human population does have lineage we can trace back through time, and if you followed that lineage back you'd probably see something ",
" resembling what you see in that image, going from right to l... | [
"\"The march of progress is the canonical representation of evolution – the one picture immediately grasped and viscerally understood by all.... The straitjacket of linear advance goes beyond iconography to the definition of evolution: the word itself becomes a synonym for progress.... [But] life is a copiously bra... | [
"I couldn't agree more. I think its an image that will forever at least drive the conversation toward a discussion about evolution. And I don't care how small the knowledge an individual has or how set in their views against evolution they are, there is no way that any amount of discussion is a bad thing. I'll take... |
[
"What's the average temperature in the universe?"
] | [
false
] | null | [
"Are you talking about the average temperature of the matter in the universe? Or the average temperature of the radiation we observe?"
] | [
"The average temperature over the course of the universe's lifetime is 2.73K, which equates to -270C or -454F, according to ",
"this article"
] | [
"Average over space, the minimum/lower limit of the average temperature is the temperature of the Cosmic Microwave background with 2.73K. But there are galaxies, stars, hot gas around, so the average is going to be higher than that. ",
"When we average over time as well, <T(r,t)>, that's probably gonna be even hi... |
[
"Are any physical constants a power of 2?"
] | [
false
] | I've been fiddling with this problem for a while now, and I'm stuck because our units are mostly arbitrarily defined. My original goal was to find out if the speed of light was a power of two. I assume and would work as units, but given that these values are derived using the speed of light (where one Planck length di... | [
"If you use Planck units then many physical constants are 2",
" ."
] | [
"There are dimensionless and dimensionfull constants. The latter have values that change depending on what units you express them in, so you could just jigger your units until something looks like a power of two, but that's not very meaningful.",
"Dimensionless constants, or ratios of dimensionfull constants, hav... | [
"In plank units the speed of light is 1. (That's a power of 2, but not a particularly exciting one.)",
"2 as the base of a logarithm is a fundamental notion in information theory.",
"2 is also the size of the 'spin space' for spin-1/2 particles - for example there are two 'electron slots' per orbital, similar... |
[
"Would the trans-atlantic cable still be in existence?"
] | [
false
] | It was laid so long ago, Has anyone looked for it? Is it too deep or the currents moved it? Or has the saltwater corroded it into dust? Sorry if this may not be a suitable question for | [
"The transatlantic telegraph cable was insulated by ",
"gutta-percha",
". Wikipedia is lacking in detail, but from my Bell labs book (The Idea Factory) and ",
"here",
", the ",
"Teredo Worm",
" and several other species attacked gutta-percha. The steel wires and copper conductors will also have corrod... | [
"Sharks have what is known as electroreception. Basically the ability to sense electric fields. Living beings have electric fields too. You do the math on that one :)"
] | [
"Parts of the Atlantic that the cable crossed are so deep that decay happens very slowly. Witness the Titanic. I'm sure that it is still down there, although the condition is undoubtedly poor.",
"Fun and somewhat related fact, the wreck of the feared German WW2 battleship Bismarck has actually had a newer trans o... |
[
"How does the Aristotle's lantern (the jaw apparatus found in a sea urchin) work?"
] | [
false
] | Hello! I'm a non-scientist (obviously!) who is currently working on a design project. While doing my research, I came across the structure of the mouth of the sea urchin (known as Aristotle's lantern) and I'm really fascinated. I tried to read more about it on the internet, but due to my non-science background, I have ... | [
"Aristotle's lanterns are, at least in my opinion, some of the coolest and most unique structures in nature. I first learned about them in detail during my undergraduate invertebrate zoology course, where I also got the chance to ",
"dissect a sea urchin",
" (warning: potentially gross I guess). You can see t... | [
"Thank you so much for the detailed explanation, it really helped me a lot! Also the soil sampling device is very interesting :)"
] | [
"Was this course at Friday Harbor, by chance?"
] |
[
"Are blood transfusions between species possible?"
] | [
false
] | null | [
"Yes, in some cases, it just depends on whether or not the recipient has any antibodies against the donor blood.",
"\nBest example of this is dog blood being transfused into cats. Cats can receive a one time transfusion from a dog in a emergency. \nHere is review article about this subject:\n",
"https://www.ncb... | [
"Yepo. I've had about 12 patients undergo xenotransfusions (cats getting dog blood). All did fantastic for the transfusion itself, though the underlying disease process was sometimes fatal. ",
"This is a procedure most vets are still too nervous to do, but being a medicine resident at an exceptionally busy hospit... | [
"Hyperliteralism aside, no, blood from one animal is generally not compatible with another animal.",
"If someone receives incompatible blood in a transfusion, it means that the recipient's immune system doesn't recognize the antigens (sort of molecular surface features, determined by genetics) on the donated bloo... |
[
"Why do bug bites itch?"
] | [
false
] | null | [
"The short answer is ",
". The longer answer will seem unnecessarily complicated, so I've included some citations.",
"Pruritus (itching) as a cutaneous sensation (typically characterized as unpleasant) is frequently associated with irritation/damage secondary to dermatological conditions, systemic disorders [ge... | [
"So itchiness is a subconscious interpretation of pain?"
] | [
"Depends on what you mean by subconscious, but for practical purposes...yes. ",
"This",
" paper is a good overview if you're interested in liminality."
] |
[
"Everyone knows that sharks can smell blood in the water. But are there any air-breathing animals that can smell underwater? Or water-breathing animals that can smell in the air?"
] | [
false
] | null | [
"Otters blow bubbles with their nostrils underwater as they stick their nose in potential food. They then suck the bubbles back in, in-order to smell if the thing they are investigating will be tasty. It’s pretty cool."
] | [
"Star-nosed moles can smell and identify prey underwater. They also hold the record for fastest eater of prey. Also they are terrifying"
] | [
"This is also done by the star-nose mole.",
"EDIT: here's a video! The underwater smelling is at the end.",
"https://youtu.be/fio1NUxszhY"
] |
[
"What makes metals metal?"
] | [
false
] | With regards to elements, how is metal defined and what makes some but not other elements metal, without much 'pattern' to it? (In that after Hydrogen and helium in periodic table, there's 2 metals, then some nonmetals, 3 metals, some nonmetals, then a lot of metals etc, but all with inconsistent amounts in each cluste... | [
"There are no strict definition, but generally metals have de-localized outer electrons and thus high electric and thermal conductivities. ",
"Metalloids have some metallic properties and some non-metals become metallic under high pressure. Which elements are classified as metals, metalloids or non-metal are matt... | [
"Remember that the periodic table is a tool created by people, not a universally perfect arrangement of elements. So the lack of a pattern is because the periodic table was not arranged in such a way to prioritize the grouping of metals together.",
"Basically, metallic elements easily form cations (readily lose e... | [
"If you're asking why there's no transition metals until the third row, that's because the s and p shells fill up twice before it's more favorable for a d shell to fill up. After the d shell fills you get metalloids, as the shells get higher energy down collumns they get more mettalic as the electrons start to be s... |
[
"What technological obstacles need to be overcome to make solar energy viable?"
] | [
false
] | null | [
"As far as I see it, there are 3 major issues with solar energy. ",
"Initial cost- Solar panels aren't cheap. And while they do pay for themselves over a long period of time, it can take 10-15 years for a solar panel to have paid for itself. For many consumers, this period of time is too long for the payoff to be... | [
"At this point, money and political will are the only obstacles. See ",
"this",
" paper that just came out."
] | [
"Inexpensive batteries.",
"Solar panels work well, but only when the sun is shining. Large scale power systems need to match power generation to power consumption. The only practical way to do that with solar energy is to store the excess energy somehow and retrieve it when needed."
] |
[
"What cells in my body are making the spike protein after I get an mRNA vaccine?"
] | [
false
] | Is it all of them? Just the cells in the muscle that they injected into? Or is just white blood cells? | [
"Both the Pfizer/BioNTech and Moderna vaccines are being given i.m., so if you’d like to know what parts of your body are producing the coronavirus Spike protein antigen, the answer seems to be the muscle tissue at the site of injection, the lymphatic tissue downstream in your armpit on that side, your spleen, and ... | [
"Because that’s how the immune system works."
] | [
"Wow. Thanks for the write up!"
] |
[
"Does killing a stray ant in the home decrease the likelihood that more ants will appear in the future?"
] | [
false
] | Every now and then I see small ants in parts of my house. They are tiny and unobtrusive so I wouldn't mind letting a few just go and do their thing. But I also want to avoid a large number of ants appearing some day. When I've seen isolated ants, I've killed them under the belief that doing so would decrease the likeli... | [
"Ants leave scent trails to find their way and guide other ants, so killing one ant won't necessarily stop others from following, but it will impede the progress of their exploitation into your home. ",
"http://icouzin.princeton.edu/pheromone-trail-networks-in-ants/"
] | [
"So even if large numbers of the ants that go to a place never come back, they don't stop trying to explore there? That must be ",
" convenient for ant eating predators"
] | [
"They tend to go where the strongest scent is. An ant that goes and returns by the same trail effectively leaves two layers. Every other ant that follows the same path leaves a thicker trail. ",
"One path, followed only once is a relatively faint scent. "
] |
[
"If it is believed that Mars lost its atmosphere because it lost its magnetic field & lost its protection against solar winds/storms, why does Venus have such a thick atmosphere since it too has no intrinsic magnetic field to protect from the sun & is closer to any solar storm?"
] | [
false
] | I mean, Venus had such a think atmosphere, thicker than Earths & is so hot around the entire thing, yet is a similar size. It just baffles me that Mars potentially lost its atmosphere because no magnetic field, yet Venus never did. Finally, does Earth actually need a magnetic field to keep its atmosphere protected fr... | [
"It would appear that Venus’ atmosphere actually shields itself. As the solar wind interacts with the ionosphere, the charges particles can induce a magnetic field similar to earth’s and protect the lower layers of the atmosphere. Here’s an article explaining it.\n",
"https://www.jhuapl.edu/NewsStory/210603-Solar... | [
"I'll start with what is probably the biggest factor. Volcanoes on Venus have spewed out a lot more CO2 (and other gases) than those on Mars.",
"Terrestrial planets would have started with a primary atmosphere primarily made of hydrogen and helium accreted from the solar nebula. But the terrestrial planets were (... | [
"That is known as an induced magnetic field, and exists in plenty of bodies throughout the Solar System. It contributes slightly to the retention of the Venusian atmosphere, but then it should have had the same effect when Mars had an atmosphere. ",
"As far as I understand it, the number one factor for atmosphere... |
[
"Recently been interested by how the allies decrypted the German communications during world war 2. Can anyone answer these two questions?"
] | [
false
] | Hi all, I'm not sure if this is the right sub for cryptography but I can't find anywhere else to ask it. I recently visited bletchley park and looked around the codebreaking exhibits. However there are two things that I don't get... The British had enigma machines before the war as they were used in banks for encryptio... | [
"I can't speak to your second question, but I can answer the first: The Nazis did not send an identifier like this at the start of each message. The daily Enigma settings were distributed monthly on sheets of paper. Unless the Allies could get their hands on these sheets (which they occasionally did), there was no ... | [
"Hmm, the exhibits at the park said differently"
] | [
"Apparently they picked common words like eine or heil and added these to the encrypted message",
"It was more like, they assumed those words would appear somewhere in the message and used that to narrow in on certain encryption settings that are consistent with the appearance of those words.",
"There was a ",
... |
[
"How do psychologists distinguish between a patient who suffers from Body Dysmorphic Disorder and someone who is simply depressed from being unattractive?"
] | [
false
] | null | [
"To answer that question, you must know that Body Dysmorphic Disorder (BDD) is a compulsive disorder, in the same family as OCD. A diagnosis of BDD features a prominent obsession with appearance or perceived defects, and related compulsive behaviors such as excessive grooming/mirror-checking and seeking reassurance... | [
"Awesome and thorough explanation. ",
"How’s the DSM-V? I was still using the IV when I practiced. "
] | [
"Well, my center still technically uses the DSM-IV for coding, though we use the ICD-10 more commonly. ",
"I've just tried to get myself up to date on the DSM-5 for when we inevitably switch over."
] |
[
"Can someone explain why big bang theory is not an explanation of the creation of the universe but rather only the expansion"
] | [
false
] | Also what are some theories of the creation of the universe? | [
"It is not the goal of science to explain creation. Science wants to explain observable phenomena. We observe expansion, the Big Bang theory explains that. It is not like some scientist sit down on a Monday morning and decide that they should try to explain where everything came from.",
"Some people do hypothesiz... | [
"First cause is an unanswerable question; the big bang theory merely explains what happened after the big bang, not what caused the matter to be there in the first place. "
] | [
"It is not the goal of science to explain creation.",
"What? I'm sure a lot of scientists would love to know how the universe was created. "
] |
[
"Can someone please simply put the 2nd law of thermodynamics?"
] | [
false
] | null | [
"Assuming you googled and wiki'd that \"heat cannot flow from cold to hot without external help\" or \"heat cannot be converted to work 100%\", what do you mean by simply put? "
] | [
"The second law of thermodynamics states that for any spontaneous process, entropy increases.",
"Basically, if something can happen without you putting work into the system, the disorder in the system increases.",
"A good example: say I have a cup of really hot water. If I drop an ice cube into the hot water, t... | [
"the universe is always moving toward a greater state of disorder"
] |
[
"Other than lightning strikes and lava, how do fires occur naturally?"
] | [
false
] | null | [
"Well it's dependant on a fire already burning elsewhere but raptors in Australia have been noted to carry burning twigs to start new fires to flush out prey:",
"https://www.iflscience.com/plants-and-animals/australian-birds-of-prey-have-harnessed-the-use-of-fire-to-flush-out-their-prey/"
] | [
"Why am I not surprised that Australian wildlife is using fire to kill even more."
] | [
"It'd be a pretty unlikely event to occur in nature. Hay bales combust because they're packed tightly when damp,which allows bacteria that's exothermic to grow in the inner damp bits. They catch on fire when either the heat gets high enough to light the outer dry straws. I don't think there's be many non agric... |
[
"Do Prions exists among reptiles and birds?"
] | [
false
] | There is research that speculates that prions in mammals can arise because of cannibalism. Reptiles and birds are notoriously cannibalistic. | [
"Mammalian prions do not arise because of cannibalism, but can be spread by cannibalism.",
"Anyway, the prion-forming protein in humans is also found in nearly every other vertebrate, birds and reptiles included. However, prions are only known to cause disease in mammals. The reason is unknown.",
"http://biolog... | [
"I'm not sure if the specific mechanism is known yet, protein folding disorders are pretty tricky to determine the root cause of, especially when they're very rare. Here is a short review on general details of protein misfolding:",
"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3330701/#__ffn_sectitle",
"To put ... | [
"If there's anything that wasn't clear or got a bit technical let me know! I can try to adjust my explanations if you want.",
"I get you on the anxiety - learning all this stuff makes me equally paranoid and calm, because I learn a lot of stuff based on genetic and progressive diseases, so I both know what signs ... |
[
"Why are anticonvulsant medications used as mood stabilizers too?"
] | [
false
] | null | [
"PhD student in neuroscience here. That is a fantastic question, and quite honestly one that neuropsychiatrists are very much still attempting to answer. General consensus, and still very surface level is this:",
"Your brain is an electrochemical system, with tiny proteins known as ion channels. These ion channel... | [
"Further to ManNotTheBear's comments, many drugs are marketed with one indication but are then found to be effective for other indications in post marketing studies. One such example of this could be codeine. We use codeine to treat pain but it also causes respiratory depression and constipation - so in the UK it h... | [
"Yeah it actually makes sense now! Thank you very much for taking the time to answer"
] |
[
"Upon launch, what kept the Space Shuttle from tilting backwards towards the orbiter?"
] | [
false
] | [deleted] | [
"If the rocket nozzles generate a thrust that points through the center of mass of the shuttle, then it won't rotate."
] | [
"I'm a bit confused here and not seeing the boosters you're referring to. ",
"The external tank contained fuel for the orbiter's main engines, while the two tall white boosters mounted to either side of the eternal tank are entirely self contained solid fuel rockets which once lit simply burn through their fuel u... | [
"This is the ELI5 answer. In more detail, the mass of the external tank and solid rocket boosters is ",
" small. The empty weight of each of the SRB's was around 200,000 lbs, and 1.3 ",
" pounds while fueled. The empty weight of the tank was only 60,000 lbs, but it weighed ",
" million pounds fully fueled. Th... |
[
"Were astronomical phenomenon easier to see with the naked eye 5000 years ago than there are today?"
] | [
false
] | Did ancient Egypt, Mesopotamia, and the Indus Valley civilization see a different sky than we see today? How much easier was it for them to view astronomical bodies with the naked eye than it is today? Edit: Fuck, just looked at my title. *than they are | [
"Are you talking about light pollution? Yes, all light on earth obstructs our view of the stars. And it's probably safe to say that there is more anthropogenic light today than there was 5000 years ago just about everywhere. So they probably had a better view of the stars. Here's a ",
"picture",
" showing t... | [
"You don't even have to go back 5k years. A few hundred years ago at most, the sky was much better for astronomy at night.",
"With the introduction of electricity, light pollution became prevalent. That took off about 100 years ago. Dim stars become invisible because of the sky glow.",
"With the industrial revo... | [
"Say you are in a desert 300 miles from any light in all directions. You look at the sky. Then suddenly all light on earth goes out. You look at the sky again. Would the second look be any different?"
] |
[
"What is the fastest theoretical speed a planet (rocky or gas giant) or dwarf planet can rotate without breaking up? Also what is the timescale for one rotation in comparison to an Earth-standard day?"
] | [
false
] | null | [
"Depends on what the planet is made of, but in general, about 20-30 times faster than Earth rotates.",
"Let's assume that all layers of the planet rotate uniformly at all depths (which isn't always true). For a planet to begin to break apart, the centrifugal acceleration felt by the top layer of the planet at the... | [
"Yes to both. The faster you spin the planet, the less heavy everything on the surface feels. The speed that the grandparent calculated is when everything becomes weightless, i.e., it's the speed you need to be in orbit."
] | [
"Yes to both. The faster you spin the planet, the less heavy everything on the surface feels. The speed that the grandparent calculated is when everything becomes weightless, i.e., it's the speed you need to be in orbit."
] |
[
"Can kinetic energy be directly converted to light?"
] | [
false
] | Most forms of energy can be directly transformed into one another, like charging batteries, burning wood, wind turbines etc. However, I dont know of any example where light gets created directly from kinetic energy, and I had some science teachers say that its impossible. Is this true? | [
"Sorry if this is a stupid question, but do the electrons in our bodies emit electromagnetic radiation when we run, since we're accelerating them?"
] | [
"Sorry if this is a stupid question, but do the electrons in our bodies emit electromagnetic radiation when we run, since we're accelerating them?"
] | [
"Ok that makes sense. Thank you. "
] |
[
"Besides human activity, how is the carbon in fossil fuels returned to the ecosystem?"
] | [
false
] | Based on the biogenic theory of fossil fuels, the carbon locked into petroleum, coal and natural gas comes from millions year old biomass. Human activity releases that carbon in the form of carbon dioxide, which is then returned to the ecosystem. Besides humans burning fossil fuels for energy, how is that carbon return... | [
"A large portion of the petroleum in the ground gets released naturally over time; it isn't extracted and used/burned by humans. Still don't know, once it's released to atmosphere/the ocean, how it recycles back into the ecosystem other than micro organisms eating it. ",
"Doesn't quite support my statement in fu... | [
"When buried fossil fuels reach the surface, they can oxidize into CO2 in any number of ways, from coal seam fires to microbial action on deepwater oil seeps. But most fossil fuels do not return to the ecosystem in this way. There is also a lot of carbon locked up in carbonate rocks--this can also weather out in... | [
"Thanks for the response! I didn't know that any microorganisms were capable of handling it at all. I thought hydrocarbons were generally extremely toxic.",
"That would be a very slow release and return to the ecosystem, but since the creation of fossil fuels is equally slow, the system would be in balance over v... |
[
"Does reading improve your reaction speed and time?"
] | [
false
] | null | [
"Reaction speed to what?"
] | [
"the length of time taken for a person or system to respond to a given stimulus or event"
] | [
"This is a little too vague. Learning to read makes you faster at discriminating between different kinds if letters or words and makes you slower in some cases (as in the Stroop effect). It does not affect how quickly you can push a button when you see a light go on."
] |
[
"Pregnancies after 30? Is it a greater risk"
] | [
false
] | Hi guys I have heard that getting pregnant after 30 is a greater risk than before.So I am entirely certain that the people who propound this idea have no biology background or understand any physiology, But I am curious if there is any science behind this. My hunch is no.However is there any specific age after which pr... | [
"This",
" (PDF) shows that the risks of miscarriage and chromosomal defects does indeed increase as women age."
] | [
"Maternal age",
" is an independent risk factor for low fetal birth weight, in addition to daewangbo's information."
] | [
"It has long been recognised that ",
"increased maternal age is a risk factor for the foetus to have trisomy 21",
", a genetic condition more commonly known as Down syndrome.",
"Risk of stillbirth increases",
" as maternal age increases, however ",
"risk of placental abruption decreases with increasing ag... |
[
"Turing complete?"
] | [
false
] | null | [
"It means that by using the rules of magic the gathering, you can simulate a Turing machine.",
"A Turing machine is a hypothetical machine that manipulates data on a tape according to a set of rules. A Turing machine can be made to run any computer algorithm.",
"So this means that given enough time and space fo... | [
"Would chess then also be considered Turing complete?"
] | [
"I can't seem to find anything definite about the matter."
] |
[
"Why did the Sahara Desert enter an arid-green cycle?"
] | [
false
] | null | [
"Short answer: wobbles in the earth's orbit and rotational axial tilt cause variations in amount of solar radiation reaching the earth. During periods of less solar heating, the inter-tropical convergence zone moves north, allowing the tropical monsoon moisture to move into areas further north on the african contin... | [
"Global warming isn't about those random and temporary fluctuations, though. "
] | [
"Global warming isn't about those random and temporary fluctuations, though. "
] |
[
"Does HIV cancel out any allergies a person may have?"
] | [
false
] | From my (admittedly limited) understanding, HIV causes your immune system to fail nearly completely Allergies are an overreaction of your immune systems reacting to something that is not a threat to the body If you were allergic to cats as an example, contracted HIV, and somehow came into contact with a cat, would your... | [
"HIV does not really cause the immune system to fail completely. The immune system is extremely complex and has several different arms that are all necessary but not sufficient to protect us. HIV actually affects a relatively specific part of the immune system.",
"Allergy is a relatively nonspecific term. Allergi... | [
"Just to add to this, mast cells and eosinophils are the main effector cells of allergy, and they are largely unaffected by HIV. So long as one had the allergies already, most of the machinery will continue to work for a while. B cell longevity and memory is an interesting topic though, and I’d be curious to see ho... | [
"CD4+ cells (those which HIV targets) control the signal of the immune response so it's probably best to understand AIDS as a disruption to the normal immune function versus simply suppressing it.",
"An example is a fairly common symptom of AIDS, ",
"allergic rhinitis",
". But studies have found a variety of ... |
[
"Is there enough oxygen in the ocean for us to live in the ocean and breathe through a machine that extracts the dissolved oxygen?"
] | [
false
] | null | [
"No, no, no. Or at least: that is not what your links are saying.",
"To begin with, 34.3% is \"percentage of gases in sea water is based on the total gases dissolved in sea water at equilibrium with air\". The fact that 34.3% of the gasses dissolved in seawater is air is NOT THE SAME as saying that there is more ... | [
"You would then be able to recover at least a little energy, but that defeats the purpose if it just binds with oxygen, which is what you wanted to create. "
] | [
"The important thing isn't so much the concentration, it's the throughput of the machine. If the machine can suck up 100 gallons per minute and extract the oxygen at some efficiency rate, it's going to be a lot better than if it can only process 10 GPM"
] |
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