title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"[Physics] Is it possible to have a photon so energetic that it doesn't interact with any material we know?"
] | [
false
] | I know that gamma rays do not interact and go through most materials, except lead for instance. That's my silly question, thx. | [
"More energetic photons are actually more likely to interact with materials (above a certain threshold), because it increases the likelihood of pair production.",
"This is essentially a graph of how likely a photon is to interact, vs energy",
"."
] | [
"Equal parts pair production and incoherent scattering."
] | [
"What band is the well near 10"
] |
[
"Higgs Boson, and inertial vs gravitational mass"
] | [
false
] | null | [
"No - intrinsically, the Higgs has absolutely nothing to do with gravity.",
"To understand this, pretend for a moment that there is absolutely no such thing as gravity. This is an approximation that is generally made in all of particle physics [1]. The \"Standard Model\" of particle physics does not in any way ex... | [
"Thanks for the detailed yet comprehensible explanation!",
"Does anyone know why inertial mass equals gravitational mass, then? (I.e., why everything falls at the same speed, in case I'm using the terms wrong.) Or is that still an unexplained coincidence? :-)"
] | [
"Thanks, I am glad that it makes some sense!",
"The equivalence of the two masses was one of the key facts that led Einstein to the theory of General Relativity. General Relativity (GR) starts with the implicit assumption that the two must be equal.",
"In GR, gravity is not really a force - nothing is really ac... |
[
"how does a cell know what it's \"body parts\" do? I mean how does the golgi apparatus know its function/what to do?"
] | [
false
] | null | [
"Putting it ",
" simplistic: it is all about (physical) chemistry. Molecule X binds to a receptor, which changes its form, which triggers another reaction, etc. ",
"It’s a huge chain reaction with some probability distribution (depending on binding strength, temperature, etc.)"
] | [
"So a protein is a very big molecule. It’s so big that parts of it are attracted to other parts and cling together, think of a balloon you’ve rubbed on your hair and stuck to a wall.",
"These self-stickiness gives proteins a folded shape. There’s still some charge, but since the protein is folded a specific way, ... | [
"That's a little like asking how does a taco truck know that its a taco truck. The truck itself doesn't know what it does, but inside it has the ingredients for tacos, a taco chef, and all the signage on the outside of the truck indicating its a taco truck.",
"The same works in cells. The golgi apparatus is essen... |
[
"What kind of mold might this be? (image included) Is there any way to save my stuff?"
] | [
false
] | Went to get the holiday decorations out of the basement and some how the container (which was ~3ft (-1m)off the floor) was wet inside. I cant seem to find any mold on Google that looks quite like it. Could just be the power of suggestion but I started feeling sick within minutes of exposure. Also, is there any way to... | [
"I did mould assessments for a couple years-First of all, the colour doesn't really matter, any mould is mould.",
"Anything paper based is pretty much gone, there is no saving it.",
"Anything inorganic (light strings, anything plastic or metal) give it a good scrub with some steel wool, soap, and bleach, and it... | [
"Almost certainly. Is it dangerous? Almost certainly not. Should they do something about it? Yes, because if somebody spends long times in their, they may get the mild symptoms i described above, but more importantly because it has a huge effect on the value of the building, and if they don't, costs will spiral ... | [
"Almost certainly. Is it dangerous? Almost certainly not. Should they do something about it? Yes, because if somebody spends long times in their, they may get the mild symptoms i described above, but more importantly because it has a huge effect on the value of the building, and if they don't, costs will spiral ... |
[
"Can lowering the temperature of molecules and reducing their excited state allow us to pack them in tightly and create superdense matter?"
] | [
false
] | Perhaps my concept of it is flawed but I remember reading that as matter moves through states, condensing as they get colder, molecules take up less space due to reduced excitement. If we now have the ability to cool things down so greatly that we can actually trap particles of light, could we keep feeding something ... | [
"Yes. But not for the reason you think. Read up on ",
"Bose Einstein Condensates",
"."
] | [
"Hi, that seems flawed to me. basically PV=mRT, so for a given mass at a given pressure, if you decrease the temperature, then R is a constant so V reduces, i.e. it crams into a smaller space.\nthe same mass in a smaller space = higher density\nyou can't trap light with temperature, because the light would hit the ... | [
"I'd been explaining some of the dangers of space to my daughter, and described some of the affects I'd heard of weightlessness.",
"That lead me to think about the big difference between space flight in fiction and science fiction. Gravity. They mention artificial gravity all the time, and you watch them all wa... |
[
"How does the black hole at the center of our galaxy affect our solar system?"
] | [
false
] | null | [
"The mass of the central black hole is about 4,000,000 times our Sun. The mass of the entire Milky Way is about 1,000,000,000,000 times our Sun. So the black hole is one 250,000th of the entire galaxy. If you magically removed it, nothing at all would change for the vast majority of the galaxy, including us.",
"T... | [
"Basically no, while there is a TINY bit of gravity exerted on use by it it would about same as the amount of gravity of a single molecule on the moon (But even that is likely a far bigger effect).",
"The gravitational pull of an object does effect everything else in space, but when you double the distance betwee... | [
"Thank you so much. That explains it very well."
] |
[
"Found this \"rock\" 15 years ago, finally trying to figure out what it is."
] | [
false
] | I found this about 15 years ago (the 33 sticker is because this was the 33'rd unknown specimen from my collection). It was located on the shore of Lake Ontario near Selkirk Shores (Pulaski, NY). The object itself weighs about 1.5lbs, is cloudy mostly but somewhat clear. It is full of air bubbles and one bubble shown e... | [
"It's glass. GIS for Conchoidal fracture or slag glass rock. Possibly from a glass factory (slag)."
] | [
"This is most likely a glass slag sample that was dropped in water and cooled very quickly. This would explain the fluid inclusions (most fluid inclusions in quartz are not visible to the naked eye, thus leading me to believe these inclusions are not natural in origin), and the conchoidal fractures. "
] | [
"This is certainly not calcite. Calcite has a cleavage plane when fractured, this is conchoidal. "
] |
[
"Is it possible we’ve permanently eliminated some strains of colds and flu with the year long quarantine?"
] | [
false
] | null | [
"Yes, maybe. There are a couple of strains that there have been zero reported cases of and scientists think they may have gone extinct. Which is good news for flu shot makers because they just hope they are right about which strains they develop vaccines for months in advance of flu season. Fewer types of flu str... | [
"There's a good explanation of this at ",
"StatNews",
". ",
"it appears that one of the H3N2 clades may have disappeared — gone extinct. The same phenomenon may also have occurred with one of the two lineages of influenza B viruses, known as B/Yamagata.",
"Neither has been spotted in over a year. In fact, ... | [
"The flu viruses generally have animal reservoirs. Things like bird flu and swine flu are named as such because those are the animals they cross over to humans from. For this reason they will come back once people stop with the various protection measures we are currently using."
] |
[
"Colonization of Venus"
] | [
false
] | On the Venus wiki page there is a small note about colonization of Venus. "Landis also makes a case for Venus as a target for human colonization. At 50 km above the surface, the temperature range is 0-50°C, the air pressure drops to 1 atmosphere, the gravity is 0.9 that of Earth, and the resources for life are plentif... | [
"This",
" article?"
] | [
"As I recall, the theory was to use balloons of some sort to keep one aloft amongst the clouds. The big problem was corrosion, something that I have yet to read a solution for. I'm actually curious about what one would do for food, colonial expansion, the initial costs to doing this, and harvesting resources from V... | [
"A chemical atmosphere! Oh no!"
] |
[
"What do you know that nobody knew 10 years ago?"
] | [
false
] | How far has your field advanced in 10 years? | [
"Strict control of blood sugar kills critically ill patients.\nCooling patients after cardiac arrest saves lives.\nIt doesn't matter which inotrope you use as long as its not dopamine.\nIt doesn't matter whether you use saline or albumin to resuscitate critically ill patients unless they have a head injury.\nSteroi... | [
"Optical stimulation barely existed 10 years ago...now you have awesome stuff like ",
"this."
] | [
"More like 13 years, but before 1998 people didn't know that the expansion of the universe was accelerating. Since then, WMAP has placed impressive constraints on the composition and history of the universe."
] |
[
"Would a star that’s about to supernova release an excess of gamma rays?"
] | [
false
] | null | [
"A star will show little activity as its death begins- there will be a whole lot of business going on with gamma rays and such when it goes off bang, but for a few hours before the actual event there is one marker we can detect of the coming supernova: neutrinos.",
"Since they pretty much ignore matter altogether... | [
"We'll get a few ",
" of warning time if the supernova is in our galaxy or very close, maybe a few hours more for a few selected stars nearby. We expect a supernova with advance warning time every few decades or so. Maybe every 10-20 years now with improved detectors, I don't know, but certainly not something fre... | [
"Are there any upcoming supernovas that we could see?"
] |
[
"Is Corn Syrup really worse for you than natural sugar? If so, why?"
] | [
false
] | [deleted] | [
"TL;DR - It's not resolved, and if it's real it has to do with HFCS making you feel \"not as full\" as sucrose does.",
"In vitro studies show that fructose doesn't stimulate the production of insulin like glucose does ",
"1",
" Therefore, consumption of fructose is going to give rise to a different metabolic ... | [
"You might be thinking of high-fructose corn syrup (HFCS), which is generally as bad as ordinary sugar, however has a higher amount of fructose as compared to sucrose. HFCS-55 is comprised of 55% of fructose and is used in beverages.",
"Fructose is the main issue here. Excessive fructose has been linked to; obesi... | [
"Agree - not fully resolved. What is pretty clear is most of us eat too much sugar of all kinds and that sugar in drinks is especially bad for us. Particulalrly from a weight gain perspective as many people don't process this sugar (mentally) as calories and thus our juices and cola contribute to overeating"
] |
[
"Why doesn't normal wet sand at the beach turn into (or gives the effects of) quicksand?"
] | [
false
] | [deleted] | [
"That's not really true; quicksand ",
" exist, it just doesn't behave the way that it does in the movies. So it's possible to sink into quicksand, but you wouldn't sink far enough to drown, and would be able to escape fairly easily. ",
"Sand grains tend to lock together fairly easily, so something has to cause ... | [
"Quicksand doesn't really exist. It's made up for movies. You're more buoyant than the sand and therefore don't sink. The sand is full of friction and holds itself together even under your weight. ",
"If for example something like a building was laying on some sediment with a bunch of sand and water underneath an... | [
"When I was young, quick sand was my biggest fear. I thought it was very common and people died from it all the time."
] |
[
"How many trees would each person have to plant for our civilization to become carbon neutral?"
] | [
false
] | null | [
"You could possibly substitute the question with: \"how many hectares of land would be need to grow biomass to replace our fossil fuel use\".",
"Global fuel use is somewhere around 160,000 Twh.",
"Miscanthus grass can ideally produce 17 t/Ha (more like 10 in reality) per year, each tonne delivering 3.6Mwh.",
... | [
"So... like 3?"
] | [
"Yes, they decompose but only after a long lifetime of drawing carbon from the air and building carbon structures. And after they do die, the carbon released is not automatically put back into the air. It fuels growth on top of them and can also go into the ground."
] |
[
"Is it possible to reach LEO by balloon?"
] | [
false
] | [deleted] | [
"He highest altitude free fall jump was ~19.5 miles (~102,000 feet, or 2.5 times the cruising altitude of commercial planes), I believe although I'm not certain, that this is also the highest manned balloon. LEO is ~1200 miles. ",
"While its theoretically possible to build a buoyant object to reach closer to thos... | [
"The important thing to understand here is that orbit isn't really about altitude at all—the important part is velocity. If you took a balloon up to ~225mi (where the ISS orbits) and jumped, you'd just fall the long, long way back to the ground. If the ISS came near you, it would whiz past at about 27000mph."
] | [
"Just read that the gravity pull on the ISS is 90% of the earth. Guess you still would need a big rocket to get the same speed though."
] |
[
"If gravity bends space towards objects, why does light bend around the sun?"
] | [
false
] | What am I misunderstanding? I think I'm getting caught up in semantics.. | [
"Nothing is pulled or pushed. Light travels in a perfectly straight line at all times, it's just that in the presence of a gravitational field (such as due to the Sun), \"straight\" turns out to mean what happens in the picture. ",
"Basically what I'm trying to stress is that light reacts to gravity because gravi... | [
"http://www.astro-photography.net/images/figure%202%20relativity_light_bending.jpg",
"Light that would hit the sun if you ignore gravity, still hits the sun. Light that is going around the sun and wouldn't hit the earth (ignoring gravity) will actually curve in a bit when you consider gravity.",
"It is not cur... | [
"No, I think that's exactly what I mean. So light from a star that we would not be able to see behind the sun (ignoring gravity), that would be traveling into space is \"pulled towards\" by the sun by gravity to hit Earth?"
] |
[
"Is the expression \"a hole in the space-time continuum\" meaningful in any way, or is it \"not even wrong\"?"
] | [
false
] | I've occasionally heard this expression in various movies or television shows. Does it refer to something that is theoretically possible, or is it just nonsensical jargon? Thanks! | [
"It's a pretty decent way of describing ",
"black holes",
" in non-technical terms.",
"Einstein found, while developing his theory of special relativity, that space and time are intimately related to each other. If I'm sitting on Earth and you're in a rocketship moving past the Earth, then we'll measure dista... | [
"Nice explanation. You should also mention that singularities have not been shown to exist. There is no evidence that black holes have singularities. All we know about black holes is essentially that they are very dense and non-luminous.",
"Edit: I guess you kinda said that towards the end. Anyway, good post."
] | [
"I touched on that but didn't make it explicit. Actually, I did mean to (and then forgot to) write a bit about what we do know about black holes, which is what you say: we've seen the gravitational effects of objects which are so dense that they probably can't be anything else."
] |
[
"how much force would it take to alter the orbit of a planet like earth or mars?"
] | [
false
] | So I was watching Futurama why not and in two episodes, Crimes of the Hot and A Farewell to Arms, Earth and Mars are pushed out of their orbits. Now obviously it's a cartoon, complete with disembodied heads and various other future-y crap but it got me thinking, what would it take to push or pull a planet in a stable o... | [
"The big question here is \"how much do you want to alter its orbit?\" Any amount of force will technically alter a planet's orbit, but unless it's a very large force, it won't be detectable.",
"That said, I saw the Futurama episodes, too...let's say we're trying to alter Mars' orbit to one that will be very elli... | [
"Your last parenthetical addition has a typo. e=1 is parabolic, you typed e=0 twice =P"
] | [
"Intrigued, a bit of googling got me ",
"this",
". The earth's orbit doesn't change, just that the redistribution of mass affects the earth's spin around it's axis. It's negligible, kind of like the nanoseconds of time dilation one would experience from traveling in airplanes."
] |
[
"Dear askscience: Developing a nuclear fusion reactor so we can ... heat water to generate steam to spin a magnet inside a copper coil seems like caveman overkill. Is there really no better way to generate electricity?"
] | [
false
] | [deleted] | [
"Turbines are easily the most cost efficient means of converting heat into electricity that we have. A supercritical water turbine can reach an efficiency of 50%. In comparison, even the most efficient high-tech solar cells we have only get about 40%, with your typical solar panel at 10%. In principle Stirling engi... | [
"I see a massive ammont of heat-energy being lost during these processes?",
"Yes. This is unavoidable due to the laws of thermodynamics. What happens in practice is that whereas you get a large quantity of waste heat, the temperature it is discharged at is quite low, and hence it cannot be efficiently converted i... | [
"There are plenty of ways to generate electricity. A steam turbine works because a voltage is generated when a magnetic field and a current carrying conductor are in close proximity to each other with relative motion. ",
"Several other ways to generate voltage are: ",
"piezoelectric ",
"http://en.wikipedia.... |
[
"What happens to a photon when it collides with solid matter?"
] | [
false
] | Do all photons reflect off the surface of dense objects, or do some of them "vanish" on impact? How does light interact with matter to heat up a surface? | [
"Yes, photons cease to exist when absorbed."
] | [
"No object has perfect reflectance, so some photons will be absorbed. If the energy absorbed is transformed into molecular motion, this will manifest as an increase in temperature."
] | [
"What properties of matter is it interacting with at tiny scales? Is it the electromagnetic force of the matter, its mass or something else?"
] |
[
"Abnormally Long Arm hair, Can Anyone Explain This?"
] | [
false
] | Hi everyone, ever since I was a kid I noticed this 1 hair on my arm that lacked pigment and seemed to grow without any limit and it grew relatively quickly. I used to pull it out, but as I got older I realized I needed to observe its true potential and see how long I could really grow it. I researched the world record ... | [
"C'mon guys, the rules are right over there ---->",
"Keep discussion on topic and focused on answering questions scientifically.\nPersonal anecdotes and layman answers are not acceptable posts.",
"I don't want to have to downvote any more of you."
] | [
"Thanks! but any ideas on why this hair grows significantly longer than any other hair on my arm? Also it feels different, I'm not sure why."
] | [
"Thanks! but any ideas on why this hair grows significantly longer than any other hair on my arm? Also it feels different, I'm not sure why."
] |
[
"Are there any materials we know of that absorb visible light while letting through infrared light?"
] | [
false
] | null | [
"Germanium is opaque to visible light but transparent in the mid-IR range. It's often used in IR optics.",
"See for example this commercial supplier of germanium lenses: ",
"http://www.tydexoptics.com/materials1/for_transmission_optics/germanium/",
"In general, in order to absorb light there has to be an elec... | [
"We often take advantage of silicon's transparency to IR light to align multiple layers of features in microprocessor fabrication between the front and back sides of the wafer.",
"Our own vision falls off with light around 0.7 microns in wavelength, and to see through silicon you need light of 1.1 micron waveleng... | [
"Yes! Germanium is commonly used for lenses on infrared cameras and is opaque to the visible spectrum but transparent in infrared. This link has some good information about some other materials which exhibit similar properties: ",
"https://www.rp-photonics.com/infrared_optics.html"
] |
[
"How can I tell if a bond will be ionic or covalent?"
] | [
false
] | I understand the difference between ionic and covalent bonds: With ionic bonds, an atom which pulls strongly on electrons (usually something from the right side of the table) steals an electron or electrons from an atom which pulls less strongly on electrons (usually on the left side of the table). Because the atoms (n... | [
"Simple answer: Ionic bonds require a metal. Sodium, Magnesium, something like that.",
"Longer answer: Bonds don't fall into two categories, it's more like a spectrum. Ionic bonds are on the extreme end of one side, and covalent bonds (in all their myriad forms) occupy the other 80%.",
"Think of it like this:",... | [
"A general rule of thumb is that if the electronegativity difference between two bonding atoms is 2.0 or greater, then the bond is considered to be an ionic bond."
] | [
"Cool, the longer answer was what I was looking for. However, I have one more question:",
"Let's say we've got Mg, which has two electrons. Let's say an F atom comes along and ionically bonds with the Mg, making Mg+ and F-. Now, my guess is that the Mg+ ion's electronegativity is higher. Is that the case?"
] |
[
"If I put a pair of telescopes in parallel, will the effect be multiplicative or additive?"
] | [
false
] | Suppose I have a pair of 15x zoom telescopes (for example, I separated a pair of 15x zoom binoculars) and laid them end-to-end. Naturally there'd be some loss of field-of-vision when looking through them both. But would the resulting zoom level be 15 (i.e. 225x)? Or 15*2 (i.e. 30x)? Or something else entirely? Or am I ... | [
"I think you mean in series..."
] | [
"Just bear in mind that the fundamental operation of a telescope is not zooming or magnification; it is light-gathering. One can only obtain so much usable magnification without enough light. So telescopes with larger apertures are used to gather more light.",
"So in fact there are now telescopes that are more li... | [
"Yes! Thanks, sorry."
] |
[
"What does Alzheimer’s actually do to the brain?"
] | [
false
] | Why is it slow acting in some cases and fast acting in others? | [
"The presence of neurofibrillary tangles and beta amyloid plaques (which recently have sparked controversy). Lead to the degradation of the cortex of the brain. Dementia is the term used to describe impaired cognitive status. The severity of the disease is typically generally attributed to the amount of neurofibril... | [
"There's some new research that looked into how sleep protects against Alzheimer's. \"A study published in the journal Science revealed that cerebrospinal fluid carries these waste products away from the brain during deep sleep, acting as a guard to cognitive function . . . There’s also mounting research to sugges... | [
"I was taught something similar in uni maybe 3 years ago, sleep and quality of sleep is huuuuge. It's been found that in people with lack of sleep, that there's an abnormally high level of specific plaques and more related to dementia etc.",
"Shift workers are getting funked over big time, can't imagine how bad 3... |
[
"Is there any study on wheter the increase of depression rate in the last decades is an actual increase or an increase on diagnosis only?"
] | [
false
] | null | [
"This article might be a good starting point for you:",
"Hidaka, B. H. (2012). Depression as a disease of modernity: explanations for increasing prevalence. ",
" 140(3), 205-214.",
"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3330161/",
"I think a fair summary is that as countries develop, we notice and di... | [
"They also loosened the definition of depression so mild sufferers can also seek medical assistance. Which is good. They’ve made it far more “mainstream” so obviously there would be an uptick. A decent study would take into account the times that the definition changed and show accordingly on their stats and would ... | [
"I think people would be interested if a psychologist could speak to how the publication of DSM-5 in 2013 changed the diagnosis of depression."
] |
[
"How do different kinds of objects cool in a vaccum?"
] | [
false
] | I have seen heated discussions in more than one thread about how, and how quickly, different things would cool in a vacuum. So, how fast would a human body, a solid metal object, or a large amount of liquid cool down in a vacuum, assuming there's no siginificant radiaition heating it up? | [
"A large solid object in a vacuum will cool via radiative cooling. Assuming it is hotter than the surrounding environment, it will emit more radiation than it absorbs until it comes to an equilibrium with the radiation in the environment.",
"A large amount of liquid in a vacuum will cool via radiative cooling as... | [
"Statistical thing. All objects radiate energy via black body radiation. Relatively warm objects will radiate more than they absorb."
] | [
"Good answer. I ",
"dug up",
" a ",
"couple videos",
" of low pressure water freezing for the skeptical."
] |
[
"Why don't true white light lasers exist? Or will they ever possible? I know we can make mock ones by combining a few elements, but it's not the real thing. Will we ever be able to combine many gasses to produce a whiter light?"
] | [
false
] | I read that you can combine Kr with Ar to produce a "white light laser", but it's not near true white light. Kr emits 11 different wavelengths, which is a lot but I was wondering how much more you could create. If you can combine Kr and Ar, can you combine large combinations of elements to produce even more wavelengths... | [
"It is possible to do this if you can find a gain medium that has a wide enough spectral width. So this would be essentially possible to do with a gas laser.",
"However, femtosecond pulsed lasers do exist with solid state gain media (Ti:Sapphire, as one example) and these do have quite large spectral widths. Acco... | [
"A ",
"krypton laser",
" can produce 11 wavelengths of light. It's a step function instead of all possible wavelengths, but I quoted \"white light laser\" for a reason.",
"My question is can you create a tiny, powerful beam of light, similar to that of a regular ol' laser you can pick up almost anywhere these... | [
"With the right gain medium how would you propose spacing the reflective surfaces such that all wavelengths add constructively? "
] |
[
"Does the airflow behave differently after Mach 1? If so, how?"
] | [
false
] | Hello there. Well, the question basically sums it up. I went to a technical school and kind of know how the air molecules behave or "flow" under certain circumstances, but I have no idea nor I was able to find any information about if it behaves in a particular manner after it surpasses the speed of sound | [
"yes it does, you usually split flows into subsonic (> Mach 0.8), transitional (0.8-1.2), supersonic (>1.2) and hypersonic (> 5). Search for gasdynamics, there you can find informations about it. You for example get heat effects and shock waves over mach 1.2. Under mach >0.3 you can even see most flows as incompres... | [
"The shockwave starts to behave differently at these speeds. My knowledge is limited to supersonic propulsion, but Ramjets are most efficient at transonic and supersonic velocities, and rely on slowing the airflow down to subsonic speeds before combustion and producing a supersonic exhaust and a ton of thrust. As w... | [
"Is there a qualitative change around mach 5, or is it just a more extreme version of supersonic flow?"
] |
[
"AskScience AMA Series: We're Heather Job, Corinne Drennan, Jonathan Male, and Yangang Liang from the Pacific Northwest National Laboratory. We use robots to advance energy storage and bioenergy, helping to speed up discoveries. National Robotics Week is April 3-11, help us celebrate. AUA!"
] | [
false
] | Domo arigato, Mr. Roboto! Hey Reddit, happy National Robotics Week! These days, robots are not just fodder for 1980s Styx songs. Nor are they always famously featured in TV shows or movies, like Rosie from The Jetsons. At the Pacific Northwest National Laboratory, robots are the workhorses that help our scientists adva... | [
"Probably too basic a question for this AMA, but i wonder where do you see energy storage, and bioenergy in 10 to 20 years? And what is your goal for those 10-20 years! ",
"On a side question I guess for anyone that would like to answer, how realistically is it for a battery in the \"near\" future, for example th... | [
"For energy storage, it has been identified as a key to climate change mitigation. Globally, only 3% of power capacity is being stored. The energy storage capacity needs to be doubled or tripled in 10-20 years. To realize this, we need low-cost and high-efficiency energy storage technologies. With the cost decreasi... | [
"If you had an ideal realization of your goals, what would it look like? How would you like to see the power grid advanced?"
] |
[
"How do muscles gain mass when you exercise?"
] | [
false
] | First post here and I have no idea whether I sound stupid or not, but how exactly do muscles gain mass when you exercise? Basically if I am to lift weights on a daily basis anyone would know that I'd eventually became stronger and my muscles will increase in mass but how exactly does it increase in mass? | [
"Muscles are filled with actin and myosin filaments that do the actual work of contraction. After exercise, the muscle cell releases signals that promote the synthesis of new actin and myosin filaments. This may partially be stimulated by breakage of existing filaments. Either way, the muscle cell ends up with more... | [
"Skeletal muscle stem cells reside under the basil lamina of each myofiber. Damage due to increased metabolism when pumping iron cause these stem cells to form myoblasts, which divide and fuse to existing fibers. You don't make new fibers, you just add more nuclei to make more contractile proteins."
] | [
"So you can tell when a muscle cell has been recently repaired due to the peripheral nuclei.",
"Actually recently/newly regenerated muscle cells have central nuclei. Peripheral nuclei are only in mature myofibers. "
] |
[
"How does this \"real\" invisibility cloak work?"
] | [
false
] | According to a camouflage company, they've created an . They've put up mockups of the design that apparently bend light around the material? But wouldn't that just make a sheet of that material invisible rather than the thing behind it? Can someone explain the physics/optics behind how this purported invisibility mate... | [
"Roughly speaking, you can make light \"stick\" to tiny periodic conducting structures and bend this sticky light around a surface and release it behind it in a way that removes all information of the surface as the light travels past the surface. I think such a device could actually be constructed for selected wav... | [
"How? It can't. This company normally manufactures ",
": ",
"http://www.hyperstealth.com",
"This is just a marketing ploy. Noone honestly things this company somehow secretly financed a massive high-tech research program to develop what amounts to an invisibility cloak like their pictures portray. It's all ph... | [
"They did demo it in person to the press. One reporter verified that the mockups are accurate.",
"\nEdit: I will admit that it could be a conspiracy/pyramid scheme though."
] |
[
"Could we heat up Mars?"
] | [
false
] | I keep on hearing talk of human exploration, and eventually possible terra formation of Mars. This got me thinking, is there anything we could do to heat up the atmosphere of the planet to above zero and free up the ice? It seems if you want to live on another planet have the temperature averaging -50C is going to be a... | [
"Thicken up the atmosphere, which would make the greenhouse effect start a positive feedback effect with the CO2 caps, gradually making the planet warming.",
"A load of different ways have been proposed to achieve this, but they all require technology we don't really have yet - smash some comets/asteroids into th... | [
"The northern region of Mars has has water deposits. Very pure water. ",
"Source"
] | [
"The surface radiation environment is about the same as LEO, measured by Curiosity. A bit of shielding shouldn't be a problem."
] |
[
"Is the incidence of genetically-related disease lower in those who would be considered 'two or more races' as compared to those who would be considered one race?"
] | [
false
] | I ask because I remember learning about how cross-breeding between two inbred types of corn created a more durable, disease-resistant type of corn. Can the same be said of humans? I.e., is someone who is, say, half-Chinese half-African more likely to be immune to certain diseases or have greater immunological resistanc... | [
"1) Race is rather arbitrary, irrelevant, and somewhat silly. There are no hard lines between human \"races\" everything very much exists along a continuum. With some populations (which again will have muddled borders) with higher levels of homogeny (people are more genetically similar) you may see elevated levels ... | [
"The idea of race is predicated on the idea of firm racial genetic boundaries that do not exist. "
] | [
"I realize this. You need to drop the notion of race as focus on the notion of population which is much closer to the genetic reality. The notion of population also prevents the arbitrary aggregation of divergent populations into a single 'race' based upon idiotic and arbitrary assumptions. "
] |
[
"Why do so many animals happen to have 5 fingers/toes on each hand/foot (or paw)?"
] | [
false
] | Why not 4? Or 6? | [
"Actually it started as eight. The fishes that were living in the shallows were working with a fin that had more bones. There are a couple of ideas about why they eventually ended up with five, but there's a ",
"gap",
" in the fossil record during this time and we're not quite sure yet. We need more fossils. On... | [
"Actually it started as eight. The fishes that were living in the shallows were working with a fin that had more bones. There are a couple of ideas about why they eventually ended up with five, but there's a ",
"gap",
" in the fossil record during this time and we're not quite sure yet. We need more fossils. On... | [
"This is actually just an historical artifact. It's called ",
"pentadactyly",
" (meaning five fingers). The first ",
"tetrapods",
" (meaning four legs) had five fingers, and the rest of us came from there. Some tetrapods have since evolved new traits like hooves, large columnar feet (like elephants), fins (... |
[
"Optical Fibre and light transmission"
] | [
false
] | Hi everyone Stupid doubt really. Is it possible for a light particle to shatter the optical fibre when it is passing through? I remember reading about Total Internal Reflection, but at that speed, wouldn't it be like a bullet piercing a bullet proof glass at a high enough speed? | [
"well it's beyond stupid to downvote because of something that dumb. ",
". we can argue whether that accounts for 95%..90%..97% of losses. Whatever it's a biggy. ",
"You can argue that the precise mechanism that causes TIR to fail is scattering. But fuck man. I could argue that Rayleigh scattering is the result... | [
"What do you mean shatter? Light can definitely escape an optical fiber.. light is re-amplified many times during communications... But, in that case, light leaves because TIR is not always satisfied.** ",
"I also think some energy maybe lost to coupling (if the evanescent fields get too close to something...)...... | [
" I mean it could go backwards and still meet TIR but that is highly unlikely. ",
"anyways this accounts for >95% of the losses. so yea it is due largely to TIR losses. ",
"and i may have not taken a laser class in awhile... but by awhile i mean 6 months. it's just absurd getting down-voted in askscience becaus... |
[
"Can Maillard reaction happen by boiling food in conditions that raises water's boiling point (e.g. salted water or high atmospheric pressure)?"
] | [
false
] | null | [
"While it is straightforward in a chemical lab to raise the temperature of steam to 140-165 C, the equipment to properly do so does not exist in a standard kitchen. Attempting to heat steam in a pressure cooker is the kind of thing that makes them explode."
] | [
"Maillard reaction occurs from 140-165 C. A high pressure cooker raises the temperature to 120 -ish C. So using current equipment the answer would be no. You could try using steam at high temperatures to see if you can create the Maillard reaction on food."
] | [
"As I understand you can achieve Maillard reactions in a pressure cooker by adding baking soda to change the ph value. The topic is discussed in an older reddit thread ",
"https://www.reddit.com/r/instantpot/comments/8n9v65/maillard_reaction_inside_a_pressure_cooker/?utm_medium=android_app&utm_source=share"
] |
[
"Are there weapons that have been studied that are more powerful than nuclear weapons?"
] | [
false
] | I know it's a scary question, but with today's technology are nuclear weapons the most powerful weapons we can produce? Or are there others that could be theoretically produced that would be even more powerful? By power I guess I am referring to sheer destruction potential. | [
"Teller-Ulam-style nuclear bombs can get extremely powerful, much larger than any that have ever been built. (Super-huge bombs are less useful, militarily, than a larger number of mere city-destroying bombs. So after satisfying themselves that absurdly large bombs were possible, back in the '50s, both the US and US... | [
"In the very distant past, in the Universe's very early life, it underwent a period called inflation, in which its scale increased by dozens of orders of magnitude in a trillionth of a trillionth of a trillionth of a second.",
"I guess you intentionally didn't use the accursed term \"Big Bang\", but for clarifica... | [
"In the very distant past, in the Universe's very early life, it underwent a period called inflation, in which its scale increased by dozens of orders of magnitude in a trillionth of a trillionth of a trillionth of a second.",
"I guess you intentionally didn't use the accursed term \"Big Bang\", but for clarifica... |
[
"Can we listen to the CMB?"
] | [
false
] | As I understand it, the CMB used to be higher energy radiation and has decayed over time. Is it possible to turn that data back into radio waves and then listen to it? | [
"You don't have to turn it back into radio waves. The CMB is currently peaked at a wavelength of around 2 mm, with the highest intensities between about 1 mm and 1 cm in wavelength. These are radio waves.",
"In fact, in an analog TV set, if you tune to a spot where there is no broadcast station, a fraction (if ... | [
"You could, but there's not much to hear."
] | [
"Yes."
] |
[
"Is solar power viable in the U.S.?"
] | [
false
] | null | [
"You roommate is making a blanket black and white statement. They are almost never correct. :) The truth is usually in the gray area. We don't have to only choose solar for the sole energy source of the USA. We can implement it where it will work and where it doesn't have to be transmitted too incredibly far and... | [
"Given that most power is generated locally, and the viability of solar is mostly dependent on the amount of sunshine a place gets I'd have to say your friend's reasons are bs.",
"http://sunfarmvt.com/wp-content/uploads/2012/08/photovotaic-solar-map.jpg"
] | [
"It'll become more and more competitive as scale increases. Mass production will drive down mfg. costs and technology advances will allow for improved efficiency. I believe these factors will make it more viable in the long-term than oil. Of course it is sustainable so big oil would rather you not invest so they ca... |
[
"Why does the earth's spin about it's axis effect the shape of the earth?"
] | [
false
] | [deleted] | [
"Take a bowl full of water. Spin it. The surface of the water changes shape and the water flies out. The spinning motion sends things away from the centre and this is what happens to the earth. As it spins, the force pushes the mass outwards and this is more obvious at the equator and the planet bulges slightly.",
... | [
"Ah, I see what you're getting at. That only happens due to acceleration and inertia. When something is moving at a constant speed with no thrust, there are no forces acting on it that could change its shape. The spin of the Earth is a constant thrust against its mass, it's motion through space isn't. ",
"Think ... | [
"Well, sure if you spin it it flings out of the bowl, but then if you throw the bowl across the room as well the water will also get pushed out of the bowl. The earth is moving through the galaxy at a tremendous speed, why does that not effect the earth while spin does?"
] |
[
"Is there a particle that is the opposite of a photon?"
] | [
false
] | It seems as if there is always an opposite for everything. Positrons and electrons, matter and anti-matter. So is there an opposite of a photon? If so what is it? | [
"Photons are their own antiparticles. ",
"Not all particles have a 'distinct' antiparticle, another example of a particle being its own antiparticle is the [; \\pi_0 ;] pion."
] | [
"I don't think two photons can be made to interact with each other since waves just pass through each other, right?",
"In fact, they can if they have enough energy. This gives rise to things like ",
"two-photon physics",
". The most obvious way for two photons to interact is in the time-reversed pair-annihila... | [
"I don't think two photons can be made to interact with each other since waves just pass through each other, right?",
"In fact, they can if they have enough energy. This gives rise to things like ",
"two-photon physics",
". The most obvious way for two photons to interact is in the time-reversed pair-annihila... |
[
"How does the collapse of a star decay the protons and electrons into neutrons?"
] | [
false
] | So the basic idea of the birth of a neutron star is that the incredibly massive ball of H, He, and other material implode to become a supernova after millions of years in fusion reaction as it consumed and fused the light fusion material into heavier matter. In this 10 seconds the protons and electrons are transmutated... | [
"Protons and electrons can be converted to neutrons through ",
"electron capture",
". This reaction, ",
", conserves lepton number since an electron neutrino is released in the process. This process is not unique to supernovae and happens in normal stellar activity in the ",
"second step of a proton-proton ... | [
"So that's why supernovae give off neutrinos that are detected in observatories. Brilliant, thank you.",
"Would there be any chance for the creation of exotic matter in similar events?"
] | [
"\"Exotic matter\" is a pretty broad term, so I'm not sure exactly what you're asking, but as with any ultra-high energy event, you'll see interesting interactions."
] |
[
"Could someone create sound on the moon."
] | [
false
] | The moon doesn't have an atmosphere so that for instance you couldn't hear your fart if you were on the moon. However, there is lots of moon dust which if stirred up would remain for some time above the surface until the moon's gravity pulled it back to the surface. During that time could one hear because of the dust? | [
"Yes and no. ",
"However. And this is #2. Sound is relative to the range that the human ear can hear. There are gasses in space, and there are gasses surrounding the moon. But the density of gas is so small it can not carry/transfer vibrations that we can hear with our human ears. But you certainly could with spe... | [
"Could someone create sound on the moon.",
"Yes. Sound can travel through solids. (But no to the dust thing.)",
"It actually travels ",
" through solids, if you're not too fussed about which frequencies are attenuated how much.",
"Put your ear to the wall and cover your other ear. You'll hear whatever's in ... | [
"An astronaut could \"hear\" a rocket land and takeoff with his helmet in contact with the ground, for some distance.",
"Or two astronauts could talk to each other by touching helmets and yelling. "
] |
[
"What happens to routers that they need reset all the time?"
] | [
false
] | null | [
"There's no one answer here, there are many things that can cause a router to lose connectivity in a way that ca be fixed by a reset. ",
"Off the top of my head:",
"Other reasons may exist. Ask if you want more detail on any of those. "
] | [
"Thank you for your submission! Unfortunately, your submission has been removed for the following reason(s):",
"If you disagree with this decision, please send a ",
"message to the moderators."
] | [
"The only decent consumer grade router I have owned that shipped with stable firmware was the Billion router I owned. I don't recall ever having to reboot it due to a software/hardware fault. However after 7 years of near constant use it overheated and died. I miss that router. "
] |
[
"How can evolutionary development occur among species which reproduce via parthenogenesis?"
] | [
false
] | [deleted] | [
"Occasional mutations still occur."
] | [
"Parthenogenesis is genetically equivalent to asexual reproduction as seen in all prokaryotes. Many biologists would be very surprised to hear that bacteria and other prokaryotes don't evolve."
] | [
"It ",
" work fine for multicellular animals, too. Natural Selection is still in effect and mutations are possible. However, change is slower per generation than by sexual reproduction.",
"You also can't say \"If X trait were better all organisms would have it.\" Species do not necessarily have the ability to e... |
[
"Is it possible to view surfaces of distant planets?"
] | [
false
] | What I mean is would it be possible for us to actually get a surface view of a distant planet without having rovers or other objects physically on the surface of that planet? With the distance we can see in the galaxy, what is restricting us from viewing the very surface of other planets from Earth? | [
"Extrasolar planets are small and dim and really far away and their light is swamped by the light from their nearby stars. Existing telescopes for the most part don't even have the ability to distinguish the light from a planet direcdtly as a dot, much less map the planet.",
"There is a proposal to devise a syst... | [
"So this idea they have still hasn't been approved to this date? Could the reason be because of what was listed in the article",
"After a quick google search I came across ",
"http://planetquest.jpl.nasa.gov/video/15",
"It seems that they still have several engineering hurdles to overcome. Thanks for the info... | [
"I don't know where it stands in the internal NASA processes, but this mission is mentioned in the ",
"NASA 2011 strategic plan",
", so it seems still under active consideration. "
] |
[
"What are some recent changes in science we may have missed out on from taking courses 10,20 etc. years ago?"
] | [
false
] | null | [
"One of the fields that have advanced the most in the last 20 years is ",
"COBE was early 90's and wmap was early 00's. These first proper looks at the cmbr gave leaps forwards in the understanding of the early universe the anisotropies in the cmbr were amazing new science. ",
"Although a bit before 20 years, 2... | [
"alot of stuff has always been a myth, until the internet came to the rescue. ",
"see list of common misconceptions in wiki. "
] | [
"the pluto thing is just a definition, is does not give new insight. ",
"I suppose new scientific discoveries are almost always very specific, so that most people outside that specific field dont know or care about it. "
] |
[
"People built a \"Z machine\" on Earth that creates a temperature of 2 Billion Kelvin. How can this temperature be generated and why does this temperature not melt the entire facility that creates it?"
] | [
false
] | For scale, this is approximately 100x hotter than the center of the sun. Given that the sun only has an outside temperature of 5,500K and easily heats up Earth to 300K+ over a distance of 150 million kilometers, shouldn't a temperature of 2,000,000,000K on Earth itself cause severe damage of some kind? | [
"It's a VERY tiny amount of matter heated to that extreme. It's a point temperature, they aren't making the whole earth 2B Kelvin.",
"Think of it like a welding torch. The spot of the weld is hit enough to melt the metal, but the rest of the object being welded stays solid."
] | [
"amount of heat",
"that's not an \"amount of heat\". it's just a high temperature and the point is that the total energy in the system isn't very big (certainly not enormous). heat is a way of transfering energy and since there's not much energy in the system, you'd find it hard to transfer much heat to the facil... | [
"The point you are missing is the fact that the smallness is a central part of the claim. The point here is not \"look at how hot we got something!\" It is \"Look at how small we made the collection of energy!\" If they made something so hot it ignited everything, that energy would still need to come from somewhere... |
[
"How do electromagnetic waves propagate through outer space and Earth's atmosphere?"
] | [
false
] | As I understand it, the force carrier for the electromagnetic force is the photon. Which leads me to ask if an emf wave is the result of photons being absorbed and emitted by the particles in the medium the wave is traveling through? And if not, can you tell us what the mechanism is that allows emf waves to travel thro... | [
"Forget that first part. It just adds confusion.",
"Changing electric fields generate a magnetic field. Changing magnetic fields generate an electric field. These two phenomena lead to a self-propagating wave of oscillating electric and magnetic fields, originating from an initial perturbation in (let's say) char... | [
"It's true that photons are the force carrier for Coulomb interactions, but those are virtual photons (virtual particles and force carriers are another topic), and it is not directly related to your question.",
"For photons there is no necessary medium or mediating particles through which they propagate in the cl... | [
"Why does this propagating wave move at c and not just stay in the same place?"
] |
[
"Spherical mirror and light."
] | [
false
] | So I've been wondering about this for years. If you have a Sphere that is made out of "one way" mirror so you can see into it and you had a light like flashlight or whatever and shined it into this sphere would the light escape? Would it become too bright to look at? If you turned the light source off would the light i... | [
"No such glass exists, or can exist. Let me explain.",
"One-way glass actually isn't what you think it is. Glass reflects about 4% of the light that hits it. That means that if you have a much brighter light on one side of the glass than on the other, then most of the light coming from the direction of the mirror... | [
"One way mirrors are never \"one way\". They are partially reflective on both sides, and purposefully kept darker on one side that then other. This way, the light reflected from the lighted side is much brighter than the little bit passing through from the darker side, and it becomes very difficult to see anything ... | [
"If it's made out of a one-way mirror and you can see into it, then that means that the light waves can come out from inside, but the one-way-ness of it means that no light waves will be able to get into it to be reflected!",
"In any event, by conservation of energy, the sphere would never emit more light than wa... |
[
"What happens if you eat a \"do not eat\" silica bag?"
] | [
false
] | null | [
"Haha I didn't actually eat one, was just curious. Thanks!"
] | [
"Haha I didn't actually eat one, was just curious. Thanks!"
] | [
"Thank you for your submission! Unfortunately, your submission has been removed for the following reason(s):",
"medical advice",
"/r/AskScience",
"guidelines.",
"If you disagree with this decision, please send a ",
"message to the moderators."
] |
[
"How would I experience the world around me if I were able to run at near the speed of light?"
] | [
false
] | null | [
"Time dilation works both ways, so while you're travelling at relativistic speeds, you will notice that the clocks of your surrounding running slower than yours."
] | [
"Your world would red-shift and everything would age faster around you.\n",
"http://www.youtube.com/watch?v=lPoGVP-wZv8",
"\nThis video is a really neat example, with Carl Sagan as the narrator. Visual effects are included."
] | [
"I'm pretty sure it'd hurt a lot (if you even had time to hurt before you vaporized) :D"
] |
[
"Does the \"time\" part in \"the curvature of spacetime\" refer to time dilation due to gravity? How is spacetime being curved different from just space being curved?"
] | [
false
] | Also, is there any fundamental difference between the overall curvature of the universe, and the local curvatures that we call gravity? It seems like I hear the overall curvature referred to as the "curvature of space," and gravity referred to as the "curvature of space ." What's the difference (if there is one)? | [
"In two dimensions, positive curvature is just a basketball. What this means is that any two lines - like the lines on a basketball - meet exactly twice. It also means that your surface is finite in size.",
"Bumping this up to three dimensions, does this imply that if you have two lines (say two laser beams) that... | [
"When you say \"the curvature of space,\" are you talking about the overall curvature of the universe? If this is the case, does that mean that the overall curvature of the universe is a function of mass/energy, and not just some intrinsic property of the universe?",
"When I wrote \"the curvature of space\" there... | [
"There are a lot of people who can craft beautiful and explanatory analogies around here, so I'll try and answer your questions in a short and to the point fashion.",
"There are two concepts that you seem to have not quite fully separated yet, and that is fine. Those two concepts are the local geometry of the un... |
[
"Do cities stop rivers from changing course?"
] | [
false
] | [deleted] | [
"Not sure if this is the question you're asking, but the Mississippi River has been trying to abandon its current channel and drain through the Atchafalaya River instead, and there's ",
"a system of floodgates",
" in place to prevent that."
] | [
"Shoreline stabilization is a typical component of urbanization along rivers. Bulkheads, rip-rap, and other engineered surfaces ensure that the river stays the course, often with certain predictable consequences. Without stabilization, this probably wouldn't happen; soil could erode from under buildings and topple ... | [
"This is actually a major contributor to coastal erosion in South Louisiana. Instead of depositing silt to build coastline the river is scouring it away. "
] |
[
"If I were able to stand next to Voyager I where it is now in interstellar space, would I be able to see it?"
] | [
false
] | I was wondering if there would be enough light (photons) out there to bounce off the spacecraft and hit our retina or if it would appear to be a silhouette against a starry sky? Or dimly lit. I got to thinking about this after watching Star Trek recently and wondering if there was enough light in deep space to make the... | [
"You can easily estimate how well is voyeger 1 illuminated. Direct sunlight is about 50,000 lux. Illuminance falls with distace squared. Voyeger is 125 AU far. So illuminance is roughly 50,000/125**2 = 3.2 lux. So Voyager is better lit than open terain in the light of the full moon, which is about 0.5 lux. Even in ... | [
"Wait you realize Maku is saying you ",
" be able to see it right?"
] | [
"To expand on this question wouldn't the background luminance from the milky way and other stars be enough? I'm pretty sure on a moonless night the ability to still see is primarily from starlight not an atmospheric reflectance of sunlight, but would love to know for sure. If it is starlight then you would be able ... |
[
"On a nice day, black objects will heat faster than white objects, but do certain colors behave the same way?"
] | [
false
] | I'm on a beach on a sunny day, will my blue shirt heat up faster than my red shorts if they are the same material? Is there a significant difference? | [
"and on top of this, remember that there remain a lot more light outside of our visible spectrum. Particularly things that may be more or less opaque in Infrared. Like Sand can get very hot even though it's a very light color. "
] | [
"True, to do a good experiment, you would have to test ONE material in several different colors, assuming that the material involved in pigmentation is negligible compared to the energy absorption due solely to color. Maybe different colored plastics or ceramics? Measure the surface temperature with an IR thermome... | [
"The simple answer to your question is that lighter colors reflect more energy Darker colors absorb more energy. Since light is energy, an absorption would increase a materials temperature. An object appears white if it reflects all colors, black if it absorbs all colors. Naturally there are gradients of color and... |
[
"Whatever happened to the hole in the ozone layer?"
] | [
false
] | When I was a kid that was all I ever heard about. "Beware of CFC's!" they said. Is this still an issue or has science proven otherwise and the concern now more focused on climate change? | [
"CFC's are no longer really manufactured, due to the ",
"Montreal Protocall.",
"Ozone depletion",
" is still an issue, but we no longer massively produce most of the chemicals that were making it worse. Now that we've stopped, there's nothing more to do."
] | [
"Antarctic ozone layer bouncing back after the phase-out of chlorofluorocarbons",
"Ozone data from 1955 to 2012"
] | [
"CFCs are ",
" effective at destroying ozone. As in, a single CFC molecule can destroy hundreds of thousands of ozone molecules. ",
"Back in the day, we were using CFCs all over the place, and pumping them into the atmosphere without regard for their impacts (largely through ignorance). ",
"The reason you don... |
[
"How do the arms of galaxy’s persist?"
] | [
false
] | Shouldn’t the nearest part of the arm rotate around the center of the galaxy faster than the furthest part of the arm- similar to planets all having different rotational periods around our sun? | [
"Yeah good catch! This is actually called the winding problem in cosmology. A commonly accepted explanation to solve this problem is density wave theory, though I believe it is yet to be confirmed. Definitely check it out it’s pretty cool",
"https://en.m.wikipedia.org/wiki/Density_wave_theory"
] | [
"Now I imagine the pattern you'd see if you recorded the galaxy from birth to today and played in within a few minutes"
] | [
"This lady (below) was one of the first to really dig into this phenomenon. There were others before her, but she got a break with a new technology that allowed a much higher precision in measurement of velocities.",
"https://en.wikipedia.org/wiki/Vera_Rubin"
] |
[
"What type of tissue is this?"
] | [
false
] | I thought it was simple squamous epithelium based on its structure and nucleus location. What is the tissue in the dotted area? And what traits did you use to determine this? Thanks in advance. | [
"My personal favorite, Adipose (or fat) tissue. The large white area is accumulated triglyceride and the surrounding tissue has blood vessels and what appears to be some fascia. The large uniocular lipid droplet with the nucleus pressed up against the edge of the cell is very telling of the adipocyte. Only in very ... | [
"That very well may be the case, I'm not particularly familiar with the effects of H&E staining on the contents of the lipid droplet, but it certainly makes sense.",
"I've always found nutrition and metabolism absolutely fascinating, so during my undergraduate, I joined a nutrition lab, which happened to be devot... | [
"I'm no expert in histology, but I believe the nucleus of simple squamous epithelium represents a much larger portion of the cell volume compared to the adipocyte. Adipocytes are significantly larger and have very little cytosol compared to the simple squamous epithelial cell type. If memory serves, simple squamous... |
[
"Why is playing games fun?"
] | [
false
] | I understand why eating food, or having sex can gives us pleasure, since it makes sense biologically, we need to do those things to survive and procreate, but why does playing games gives us "pleasure"? And to be a bit more general, why are some things satisfying and others aren't? Like watching a good movie and watchi... | [
"TL;DR: Games ",
" necessary for survival and procreation.",
"Games are essentially play acting at doing something more complex (usually). Consider playing house, a child is essentially emulating their parents or other role models into \"trying out\" tasks before they get older and do it for themselves.",
"Ev... | [
"Johan Huizinga's ",
" (",
") is considered to be the first seminal research on human \"play\" behavior. I would suggest reading this. ",
"You may also be interested in Jane McGonigal's \"Reality is Broken: Why Games Make Us Better and How They Can Change the World.\" I think it will probably not answer your ... | [
"This is an adaptive explanation for why we are motivated to play games. It could very well be right, but it's not a mechanistic explanation of why a human playing a game ",
" enjoys it. That kind of explanation would have to appeal to an understanding of reward centers in the mind/brain, probably how reward depe... |
[
"How come when viruses cross species they often become deadly (e. g. Ebola, H1N1,rabies, malaria, etc) to human, while relatively safer for the animal hosts?"
] | [
false
] | null | [
"I'm not sure if there's any one answer to this, but there are a few contributing factors.",
" If a pathogen is extremely deadly it can actually hurt it's ability to spread; ebola for example can become symptomatic in days and kill soon after. Because this is so fast the host often doesn't have many opportunities... | [
"The two googleable terms of art here are \"evolution of virulence\" and \"emerging pathogen\" epoxymonk's answer here is excellent but really the important point is the evolution of the microbe. Barring massively deadly pandemic events like ",
"Justinian's Plague",
", ",
"the Black Death",
", and ",
"th... | [
"To add - some viruses are 'unreachable' to out immune system - rabies, herpes. They sit in our nerve cells where blood cannot reach and thus our white blood cells can't as well."
] |
[
"What happens to the observable universe as you move through it?"
] | [
false
] | From my understanding, everything appears to be at its own center of the universe, with the most distant visible objects being aftermath of the big bang and the closest objects being ourselves. I know that the faster something moves through space, the less that object passes through time; and that the space within our... | [
"Neil DeGrasse Tyson uses the analogy of a ship on the ocean with the 2d observable horizon representing the 3d observable universe.",
"If you were in andromeda galaxy you would be able to see some of the universe the milky way couldn't see. However the milky way would be able to see some of the universe the and... | [
"Right now, the edge of the observable universe is a lot of protons with massive amounts of energy. What happens to those as we start moving at faster speeds?",
"Not much. The cosmic background radiation would be redshifted behind you and blueshifted in front of you.",
"and/or what does the end of the universe... | [
"Thanks!",
"Alright, so what we see now will always remain and age in our observable universe, which is technically different for any other individual point during the \"same\" time.",
"Right now, the edge of the observable universe is a lot of protons with massive amounts of energy. What happens to those as w... |
[
"If we put a telescope, say, 10 light years away, identical to kepler, looking at our solar system, what planets would it be able to detect?"
] | [
false
] | [deleted] | [
"Most of the planets Kepler will detect will typically be between about 100pc and 1kpc (1parsec=3.1 light years). So If someone had the equivalent of Kepler in a solar system at say 500 pc they could detect Earth. But... that star would have to be within about 1/2 degree of being along the ecliptic plane on the sky... | [
"It's not just a matter of the size of a planet, it's a matter of time. For a transit to be confirmed as a planet, it needs to be seen at least 3 times, so you need to look at the star for at least three times the orbital period of the planet. So to detect an object at Earth's orbital radius, you'd need to look for... | [
"Er, that's kind of how it works? Astronomy isn't done by staring through telescopes manually any more... But you can see more than one star at a time with each telescope..."
] |
[
"If kepler 22b is 2.5 times the size of Earth would theoretical humans living on the planet have to be 2.5 times the size of Earth humans due to gravity?"
] | [
false
] | How would "humans" be different if they lived on the planet? Suppose that a human species evolved in a similar fashion as we did but this process occurred on Keplar 22. *Suppose for the purpose of this question, Keplar's gravitational force is exactly 2.4x as great as Earth's. | [
"Kepler"
] | [
"Gravity is more dangerous to large creatures than it is to small creatures. An ant can fall from any height and have no ill effects upon landing. If they same conditions were placed on an elephant, it would explode upon impact. Only sea creatures can afford to be immense because they are suspended in water.",
... | [
"it is, we only know the size of the planet, not its density, so we don't know how massive the planet is. force due to gravity= G * Mass1 * Mass2 / (Distance between them)",
"or F= Mass1 g where g is the acceleration on the earths surface"
] |
[
"Do objects \"splash\" when they enter a planet's atmosphere?"
] | [
false
] | A thought occurred to me this weekend watching a youngster "splash" puddles... Specifically, that when one "stomps" a sufficiently shallow puddle, the water displaces to such a degree as to effectively "empty" the puddle. Can an object entering a planet's atmosphere have a similar effect? Does the entering object cause... | [
"The primary reason liquids 'splash' is because liquids are incompressible, so when something (like a toddlers foot) enters a body of water, that water has to go 'somewhere'. When you do the same with a body of gas, the gas on the leading edge can simply compress to take up less volume and make enough room for the... | [
"gasses escape our atmosphere all the time, that's why helium loss is a big concern. They're not really 'bound' to the earth so much as they don't have enough energy to escape unless that energy is supplied to them from something external (like a spaceship exiting the planet)."
] | [
"Yes and no. It is possible to \"skip\" along the atmosphere -- hypersonic waveriders are designed to exploit this nature of the upper atmosphere. There isn't a real ",
" however because the atmosphere compresses pretty well and just makes waves rather than actual splashes. ",
"For some \"data\" look at ",
"t... |
[
"What is the medical consensus on tourniquets?"
] | [
false
] | I'm not referring to ones used for surgery, etc. I'm asking if it's beneficial or harmful to use a tourniquet in a survival situation, miles away from medical attention. Also, is it beneficial to use a tourniquet for short-term blood stoppage. Like if you cut yourself and were waiting for an ambulance (although I'm sur... | [
"Prior to the Iraqi and Afghanistan conflicts, tourniquets were considered the fourth and last resort for uncontrolled bleeding (1. Direct pressure, 2. Elevation, 3. Pressure point, 4. Tourniquet) They were considered risky due to tissue damage and release of lactic acid and other toxins when removed. During the re... | [
"As long as they are removed within a reasonable amount of time ",
"How is that reasonable amount of time defined? 6-8 hours?"
] | [
"I'm not sure but 6-8 hours after a tourniquet can cause severe tissue damage. I believe that the safe amount of time for a tourniquet is somewhere between 2-3 hours. "
] |
[
"How strong of an environmental impact does discarded glass cause?"
] | [
false
] | I know that plastic causes a large impact on the environment, but what about glass? Glass isn't biodegradable, but you rarely hear about glass pollution. What sorts of negative impacts are caused by glass? | [
"It takes up space in landfills, but other than that glass is more or less harmless. Crush it up and you essentially have sand."
] | [
"Apparently ground glass melts at a much lower temperature than sand, plus saved materials, shipping, etc. Glass is probably only behind metal in recycling efficiency. Still, glass is essentially a transparent rock, so discarded glass is really only detrimental in that loss of recycling efficiency. "
] | [
"Weathered glass can make for a cool find on the beach.",
"Can anyone comment on the energy lost by not recycling? That is, how much energy does a single bottle have the power to save?"
] |
[
"Why prescription drugs are so expensive in US?"
] | [
false
] | null | [
"The free market functions for generics. After the patent period ends, anyone is free to manufacture the same drug under the generic name. A brand may still be sold as more expensive, since it has certain restrictions for the brand name (generic only needs to be within like 20% active drug accuracy).",
"Some drug... | [
"Not always. Colchicine, important for gout and available for well over 100 years, recently went from about $.10 per pill to about $5 per pill.",
"http://en.wikipedia.org/wiki/Colchicine#Marketing_exclusivity_in_the_United_States"
] | [
"But they did force people like me to buy out of Canada and ran a marketing campaign stating that the drug I've been buying for years was unsafe. And they did force other producers of the drug to not sell in the US."
] |
[
"why does water seem to stick to glass?"
] | [
false
] | More specifically the water I put in glass test tubes. When I pour it down the drain in notice there's still a noticeable amount left that's kinda difficult to get rid of. We use these other vials for testing and I've noticed the same thing with them too (they're made of borosilicate, not sure about the test tubes). I ... | [
"Adhesion.",
" Water \"seems\" to stick to glass because it does.",
"I don't seem to notice this when washing dishes at home though.",
"It certainly still does, but (a) possible you're looking at non-transparent dishes so you're not really noticing it, and (b) soap in the water will massively reduce the surfa... | [
"The short answer is that glass--an amorphous compound containing primarily silicon and oxygen--tends to form something known as silanol on its surface. These silanol groups are Si-OH formed when oxygen atoms dangling from the surface of the SiO4 matrix react with moisture in the air. They form hydrogen bonds with ... | [
"Adding on to this, with some liquids we see the opposite effect. Mercury in a glass beaker, for example, is repulsed by the sides of the container. As a result, the mercury on the surface forms a dome instead of the bowl shape we see with water."
] |
[
"If a projectile is fired vertically and then at an angle changing nothing else, do they both travel the same distance before they lose upward momentum?"
] | [
false
] | This may not be worded perfectly, but if you were to fire a projectile with a force known to make it peak at say 200', and then fire the same projectile with the same force, changing only the angle of the barrel, say 30 degrees off vertical, does the projectile still travel 200' before it begins to fall? | [
"No. Firing straight up will make the projectile go higher.",
"If you point the projectile straight up, all its energy is directed toward making it rise upward. If you point it at an angle, some energy is directed toward making it go horizontally-- which means less energy directed to making it rise.",
"To put i... | [
"I think you're misinterpreting the question. He's asking if the projectile has travelled the same distance through space relative to the cannon - that is, does the length of the straight line up and down equal to the arc of a projectile with a horizontal component."
] | [
"You might want to ask this in ",
"/r/learnmath",
" or ",
"/r/casualmath",
" instead.",
"Question clarification: You're asking if the ",
"arc length",
" of the ",
"trajectory",
" is the same, right? Just clarifying that you don't mean \"do they reach the same height?\" or something else."
] |
[
"How come we can't see the milky way with special goggles or glasses the way photographers and film makers use special filters to record and capture the night sky?"
] | [
false
] | [deleted] | [
"To get these incredibly vivid pictures of celestial objects, the photographers will have exposure times of anywhere from a few seconds to many hours (in addition to being in a place with minimal light pollution). So, in order to see these same images, you'd need to take all the light that falls into your eye over... | [
"Well first of all, you should learn about the pollution of light.",
"And of cause there are only a few times the milky way is as visible at pitch black night.\nSo, you would have to be anywhere far off other light sources, and you should check when the milky way is at best visibility.",
"So, filters aren't eve... | [
"The filters are used to pick up different wavelengths which our eyes cant otherwise detect...fair enough, but apart from that these photographers also use extremely long exposure times to make the image \"bright\" by capturing a lot more photons than you would in a normal snapshot of when you look at it with your ... |
[
"Dimensions: are they real? And if not, why do we postulate a center-less, edge-less universe?"
] | [
false
] | We can move left-right, up-down, and forward-backward. We can imagine a universe wherein objects lose one or two of these possibilities, as well as ones in which they gain extra possibilities for motion and length (4 and 5 dimensional universes). And to answer the question "does our universe have a center and an edge?"... | [
"Dimensions actually exist insofar as they are useful constructs to describe and communicate our observations about the world. Whether we consider the concept of dimensions \"real\" or not isn't all that important. What is important is their definition helps explain physical observation, i.e how to quantify the dif... | [
"I ",
" that show. I've tried to like it, but against all fiber of being, I find no joy in it."
] | [
"The big bang, despite its suggestive name doesn't actually describe the moment of creation. The big bang model describes the early universe quite accurately to just a ",
" amount of time after the initial state of the universe. For earlier times including t=0, we do not have a physical model and lack understandi... |
[
"Possible adverse effects of 1,3-dimethylamylamine?"
] | [
false
] | [deleted] | [
"Maybe ",
"this report from the Department of Defense",
" and ",
"this literature review",
" will help. They both give some of the history of the situation and a better understanding about from where the controversy originates.",
"The DoD article specifically mentions:",
"So, it's a bit related to the ... | [
"That's a lot of good info thanks! "
] | [
"i know nothing about this chemical but i am familiar with a host of others. firstly, meth(amphetamine) itself is a synthetic drug and secondly, just because a drug has 'meth' in its name it will not necessarily be relative in its properties to regular meth. MDMA = methylenedioxymethamphetamine, for example, and i ... |
[
"Why was Rhodium so expensive in the early 90s?"
] | [
false
] | null | [
"Rhodium has currently has very few industrial applications outside of catalytic converters for automobiles, which consumes about 80% of the rhodium supply each year.",
"The 80's saw legislation requiring all new vehicles to have catalytic converters, and the transition to the unleaded fuels that works best with ... | [
"My guess would be because Russia is the second largest exporter and that spike is during the collapse of the Soviet Union."
] | [
"This looks like a pretty reasonable explanation. Have an orangered."
] |
[
"How does a cell know where it is and what to do?"
] | [
false
] | How do we get our basic body shape? When we are forming how does a cell know that its on the arm and should turn into part of the hand? | [
"This is a complicated question that could be answered in a lot of different ways. I will try to keep it simple and mostly technically correct.",
"All of your somatic (body) cells have the same genes. Your body makes stuff by using genes to make templates for proteins. Not all of genes are \"on\" at the same time... | [
"Some cells are simply in what they can do based off their structure, this is called the ",
"potency",
" of the cell. Some stem cells have limited trees ",
"of what they can and can't become.",
" Other cells like embryonic stem cells have very large trees of potential progression.",
"However, that's not t... | [
"In Embryonic development, your body guides the differentiation of cells using signal compounds/proteins called morphogens. The morphogenic diffusion gradient (called a morphogenic field), is detected via amphiphillic receptor proteins, which then respond by activating or deactivating certain sensory/developmental ... |
[
"If very loud noises can damage your hearing and very bright lights can damage your sight, can very strong odors damage your sense of smell?"
] | [
false
] | null | [
"Loud noises and bright lights are damaging because of the energy they carry; scents, on the other hand, are merely particles suspended in the air. Sure, many chemicals could do serious damage to your olfactory receptors if you inhaled them through your nose, but it would be because of their reactivity, not their p... | [
"indeed, though the capacity of light to damage the retina also does not necessarily correlate with a strong sensation of vision. light beyond the visible spectrum in both directions is also capable of damaging tissues (including the retina). Similarly, noise, which is just pressure oscillation, can do damage beyon... | [
"Olfaction (scent) and gustation (tongue) are different and follow different mechanisms of detection. Both combine to form the percept of taste. In the case of the tongue, we have five distinct taste receptors that react to various stimuli:",
"There is some debate about 'mouthfeel' and the taste of lipids. ",
"... |
[
"Do fish make friends with eachother? Do they make friends with fish that aren't the same type of fish as themselves?"
] | [
false
] | Like, especially in a school of fish such as neon tetras, for a simple example. Do they have certain members of the school that they like or dislike, do they make friends and enemies? | [
"\"Friend\" might be too complicated of a concept for fish, and there is a huge difference in behavior between different species. But...",
"Yes, in general there are a lot of fish that will at least look like they've made friends with other species. Hang out in the same cave with each other, follow each other a... | [
"I'm going to go out on a limb and say that a fish like a Tetras life is pretty darn busy. probably a little too busy to make friends or form lasting relationships. One reason is they don't live very long, and they spend their entire life either looking out for predators, hiding or dodging predators, eating, mating... | [
"There’s actually an episode of an ocean documentary where a grouper and an octopus are friends with each other and have a well formulated hunting strategy together. The octopus covers a rock formation with its tentacles, trapping small fish inside. The small fish try to escape through openings where the waiting gr... |
[
"Why does switching the batteries around in a remote make it work for a little bit?"
] | [
false
] | This always seems to work with most electronic, battery-powered devices. The most obvious reference being a remote control. | [
"The electrical contacts on the battery and/or battery holder build up a thin layer of corrosion that resists current flow. Moving the batteries around scratches the contacts and exposes fresh metal, improving conductivity."
] | [
"I was merely addressing the \"one battery is more drained than the other\" question. A 1.1v battery and a .9v battery will always add up to 2v, no matter what order you put them in. "
] | [
"I was merely addressing the \"one battery is more drained than the other\" question. A 1.1v battery and a .9v battery will always add up to 2v, no matter what order you put them in. "
] |
[
"Linguists: Are there studies that look to find links between Asian language and Native North American speech?"
] | [
false
] | null | [
"The linguist Edward Vajda has proposed a link between the Na-Dené language family in North America and the Yeniseian languages in Siberian. (see ",
"https://www.uaf.edu/anlc/dy/",
" or ",
"https://en.wikipedia.org/wiki/Dené–Yeniseian_languages",
"). I'm not a linguist, so it's not clear to me how well-est... | [
"the link has also been genetically established",
"1) \"Genetic\" connections mean something entirely different in linguistics, FYI. It only refers to the likelihood of languages being related, not any current or past speakers via their DNA. I mention this because your comment as literally taken is actually false... | [
"I'm not a linguist, so it's not clear to me how well-established this connection is.",
"It's not well established, but it's not out of the question. If the connection does exist, there's also the debate about whether it means Yeniseian-speakers remained behind in Siberia as the Na Dene-speakers headed east into ... |
[
"Does chewing your nails increase your resistance to disease?"
] | [
false
] | I have the bad habit of chewing my nails, yet I have a very strong immune system and rarely get sick, and when I do, it's usually something mild enough I can go to work with. Since nails are a breeding pot for bacteria (many harmful) and I constantly get them in my mouth through chewing, does the body respond to them b... | [
"No, things you eat, including bacteria, are typically broken down by the acidity of the stomach. There is no positive correlation between nail chewing and immune system strength.",
"You can even cause ",
"Melanonchyia",
" which looks a little strange, but does have ",
"other",
" causes."
] | [
"It doesn't matter that you're not swallowing the chunks you tear off, you will be swallowing some of the material you chew, it's inevitable. And yes, the principle still applies, your mouth is a huge mucous membrane, the bacteria will mingle with saliva, which you swallow 1/4 cup of each day and still end up in t... | [
"I'm making a honest-to-goodness question. I don't think that ",
"/r/shittyaskscience",
" would be the right place to ask a genuine question like this."
] |
[
"How does NASA control rovers if theres like 5 minutes of delay?"
] | [
false
] | Because the radio wave thingies get sent at light speed and theres a delay, how does NASA control rovers with such precision? Sorry for being dumb and probably getting the flair wrong. | [
"It's not like a remote control car where you move it around and react to the environment, they send a series of commands to the rovers and they follow them.\nPlus there'll be an onboard AI in the rover to prevent it doing things like like falling down a ditch."
] | [
"Most of what the rovers do is automated. For example, that whole entry sequence all the way to the landing was pre-programmed so that the rover and its \"helicopter\" work without any human input. The only thing that NASA tells it to do is either to move to a location and to operate its sensors."
] | [
"Most of what they do isn't automated. The landing sequence and helicopter are automated because they have to be, no real other option. Once the rover is on the ground, it has stereo cameras to make a map. ",
"It does have an autonav mode using which it can detect obstacles and plan a path and move around, but it... |
[
"Is pouring cold water on yourself beneficial if the air temperature is significantly greater than your body temperature?"
] | [
false
] | null | [
"Evaporation uses a massive amount of energy, it's excellent at cooling you. Even if the water is quite hot it can still cool you."
] | [
"Evaporation is an endothermic process, and it removes heat from the environment. ",
"It's like a cold pack of water and ammonium chloride that you can buy from the shops to cool you down.",
"http://en.wikipedia.org/wiki/Instant_cold_pack"
] | [
"Heat and temperature are not the same thing. This might start to get a little complicated, but try to bear with me.",
"The water has a high ability to accept a lot of heat from another substance before it raises in temperature. The air has a lower capacity to accept heat before it raises in temperature. So, if y... |
[
"If you got shot, how likely is it you would actually bleed from the mouth?"
] | [
false
] | In movies you always see people getting cut down in a line of fire and then all of the sudden bleeding profusely from their mouths. How accurate is this to what would actually happen if you were shot? If it is indeed accurate, what happens to make this happen? | [
"I can't give you an exact probability, but if there is tissue damage to your lungs or anywhere in your upper GI tract, this can lead to hemorrhage which could result in blood coming from your mouth. If it is in the GI tract, it would more likely be vomiting blood. "
] | [
"Well if they're dying slowly, the character usually has something to say. Coughing and spitting up blood would make that difficult. "
] | [
"Just consider where it would be coming from. Your lungs are relative large and cover quite a bit of your torso. A bullet is likely to damage your lungs if you're shot in the chest, and you bleed out internally. As long as you're breathing, you're creating a cycle of negative/positive pressure in your chest cavity.... |
[
"How did the study linking MMR vaccine and autism come to be published in The Lancet if it was obviously flawed?"
] | [
false
] | I would have thought that a reputable journal of the calibre of The Lancet would vet any article submitted for publication very rigorously. | [
"So I want to preface this by stating that Wakefield's 1998 Lancet paper contained (essentially) fabricated data, and was probably influenced by unreported financial conflicts of interest, i.e. the paper is bunk.",
"HOWEVER, claiming that the paper is obviously flawed, as far as I am aware, is not accurate. It is... | [
"without making sure it was conducted the way it should be.",
"None of science works like this. I think there's an idea that when you do some $100,000 study on \"blah\" and submit the results to a peer reviewed journal that those peer reviewers, like, fly out to your lab and examine all your equipment and use $30... | [
"Nono, it didn't come across as know it all.",
"The big mistake your friend is making (and that a lot of people make) is thinking that one scientific paper by itself means anything. I'm about to say something that may seem very strange, but read it carefully: The simple statistical fact is that Wakefield's public... |
[
"After seeing a lot of sensationalist articles recently, what discoveries, studies or inventions are LEGITIMATELY out there right now that could make huge waves for humanity?"
] | [
false
] | null | [
"how it really amounts to a bunch of bologna",
"I don't have an answer, but I do need to point out that bologna = lunch meat. Baloney = nonsense."
] | [
"My Physics professor often tells us that the two fields with the most potential to dramatically alter our lives in the coming years are the fields of genetic manipulation and neuroscience. Michael Chrichton's (slightly overdramatic) sci-fi novel 'Next' is an attempt to describe the vast potential of gene manufactu... | [
"The ",
"national ignition facility",
" is a little behind schedule, but still has a good chance of producing the first economically viable fusion reaction. Success at NIF could potentially mean massive production scale investment in fusion power production in our lifetimes, which would eventually mean a drama... |
[
"When eyes adjust to the dark, is the iris just letting more light in, or does the brain behave differently too?"
] | [
false
] | null | [
"The pupil can adjust to let in about ten times more light from its smallest to its largest. But the eye can increase its sensitivity by roughly a million times-- so there's more at work than just the pupil. This is the part that takes 20-30 minutes to happen when your eyes \"adjust to the dark,\" and it is a ",
... | [
"A timely eg for you, sir.",
"http://www.iflscience.com/health-and-medicine/how-the-eclipse-gave-some-people-superhuman-night-vision/"
] | [
"Thanks! "
] |
[
"How can there be a separate vaccine for shingles?"
] | [
false
] | I am looking at a brochure for the shingles vaccine from my local supermarket/pharmacy. It says "If you've ever had chickenpox or the chickenpox vaccine you are at risk of developing shingles." What is going on with chickenpox/shingles? How is there a separate vaccine for shingles if it's the same virus that causes b... | [
"Chickenpox is the physical manifestation of the varicella zoster virus. Once it \"goes away\" it continues to live and replicate VERY slowly in your spinal nerve cells. The slight infection that continues is well contained by your immune system. Sometimes, as an adult, if your body is immunocompromised due to anyt... | [
"You can group immunity in the blood into two groups: Cell mediated and humoral.",
"Shingles happens when our cell-mediated immunity (to the VZV virus) is low.",
"Chickenpox happens if we don't have any immunity to VZV.",
"The shingles vaccine boosts our cell mediated immunity as it is a live virus. This redu... | [
"Thank you for answering. What you said makes sense but the brochure I have also recommends getting the shingles vaccine if you've had shingles to prevent future shingles or to reduce the severity of any future shingles. If the vaccine basically mimics a shingles episode then why wouldn't a ",
" shingles episod... |
[
"How does the body \"decide\" where to lose weight from?"
] | [
false
] | I recently lost a lot of weight, mostly due to eating right and a bit of cardio. Unfortunately it has been mostly around my neck, face, chest and breasts, leaving me still with larger legs and "love handles". So how exactly does the body "decide" where it should lose weight from? Thanks! | [
"One major factor is hormones. Men and women tend to store fat very differently. Men tend to store fat on their stomachs, while women tend to store fat on their breasts, hips, and rear. ",
"Interestingly enough, this is based mostly on hormones. Transgender people who undergo cross-sex hormone therapy eventually ... | [
"It's well documented that localized training does not affect fat burn in a certain area; that is, doing squats or oblique exercises will not get rid of your leg fat or love handles. Fat burn is more like peeling an onion, it comes off from the entire body rather than a single area. ",
"However, there are parts o... | [
"It doesn't! Working out certain parts of your body will not stimulate the breakdown of fat in that area alone-- fat will be broken down from stores all over your body to provide the needed energy. Certain areas of your body are more likely to accumulate fat, and each part of your body does not lose fat at the same... |
[
"Why are some people allergic to metal? What is the antigen?"
] | [
false
] | From the little I know about allergies, it seems that people shouldn't be allergic to metal (cheap metal usually). So what is really going on? Is it a true allergy or is it a similar reaction? | [
"I'm inclined to say its a \"true\" allergy, inasmuch as its the same immune response as most allergies. The response is ",
"contact dermatitis",
". There is T lymphocyte involvement and upregulation of immuno-related hormones.",
"Specifically, it looks like experimentation has repeatedly confirmed that ",
... | [
"How nickel turns on innate immune cells",
"Nickel hypersensitivity, an example of hapten-mediated ",
"allergic contact dermatitis",
"The 'antigen' is Nickel attached to a protein. Nickel, by itself, does not elicit an immune response; nickel is a hapten. The nickel ions from the jewelry gain access to dendr... | [
"I'd like to know as well."
] |
[
"How bright is a single photon?"
] | [
false
] | null | [
"The faintest light that a dark-adapted human eye can detect is ",
"about 90 photons",
", so a single photon is only 1% as bright as that.",
"By the way. The link is one entry in the ",
"Physics FAQ",
", maintained by John Baez at UC Riverside."
] | [
"From a classical optics perspective, 'brightness' is a measure of the intensity of light when it strikes a detector (like your eye). The eye isn't the greatest detector in the world because it's not quite linear (2 million photons isn't necessarily twice as 'bright' as 1 million photons after going through neural ... | [
"They found that about 90 photons had to enter the eye for a 60% success rate in responding. Since only about 10% of photons arriving at the eye actually reach the retina, this means that about 9 photons were actually required at the receptors. Since the photons would have been spread over about 350 rods, ",
",... |
[
"Why is there so much mystery shrouding the Oort Cloud? Do we know anything concrete about it's existence?"
] | [
false
] | A quick google search shows there isn't much consensus on the topic and it seems as if we're not even sure it exists. Some articles talk about it with certainty while others vaguely mention there being controversy among experts. What are the most up-to-date theories on the Oort Cloud and are there any interesting tidbi... | [
"You're right, in that it's still only a hypothesis - we can't observe it yet, since it's thought to be made up of billions of small, cold, and VERY diffuse objects with maybe a few dozen Earth masses' worth of material. Turning the Hubble Space Telescope outwards and hoping to find an Oort cloud object, for examp... | [
"The main reason is that the long period comets come in from all directions. A spherical distribution for the source of long period comets is the easiest explanation for this distribution.",
"If their source was the Kuiper belt they would all tend to orbit much closer to the ecliptic, which is the plane that all... | [
"They mean there are very few objects in a very large region of space."
] |
[
"How sustainable is our landfill trash disposal model in the US? What's the latest in trash tech?"
] | [
false
] | null | [
"Landfill mining is worth a look, essentially digging through existing landfills and sorting things of economic value, recyclables, biodegradables, fuel sources, etc. while creating more space in the process. It is of course a costly undertaking, but there are MSW sites in the US that have profitably implemented la... | [
"I work at a waste to energy facility, and would say the landfill model is sustainable. My plant reduces every 7 tons of incoming waste to 1 ton of ash that goes to the landfill as cover. Plus we have a system to recover metal out of the bottom ash and we sell that to scrappers for recycling. Then add in that our a... | [
"The plant I work at is in Florida, and I'm an operator there. It's an incinerator plant, we're permitted to burn about 500 tons a day. The plant has two units, each unit has an accompanying pollution control system with it. Our scrubber system injects a lime slurry into the flue gas (gas outputted from the combust... |
[
"Diesel Engines get better mileage than gasoline but do they produce less Carbon Dioxide doing so?"
] | [
false
] | I know that Diesel engines get better mileage by volume than gasoline. But Diesel is also a large hydrocarbon than gas so I was wondering if the mileage by carbon dioxide produced is also better for diesel or is it effectively the same or is it worse? Ignoring glittery tangents like biodiesel, does a gas engine or a di... | [
"CO2 emissions per chemical potential energy are almost identical between gasoline and diesel - around 73 g/MJ. Diesel engines are more efficient because they are \"lean burn\" (i.e. use more air and less fuel than dictated by the stoichiometric ratio), have high compression ratios, and no \"throttling losses\" (si... | [
"The problem with diesel is particulate emissions (think smog), not thatthey produce more CO2 than stard gasoline engines.",
"Improvements are being made to diesel in this area however.",
"Edit: ",
"http://thinkblue.vw.com/tdi-academy-clean-diesel-vs-gasoline/#cleandieselvsgasolinefuelsemissions"
] | [
"I didn't know that last one about diesels, so what exactly does a throttle do then?"
] |
[
"Why is it when some vaccines are administered, they require a follow up booster within a few weeks/years?"
] | [
false
] | As follow-up; what determines if a vaccine is "good enough" to not require a booster? Does the booster work differently than the original vaccine? Is there an ideal time between the original vaccine and the booster? | [
"The initial vaccination creates a bunch of T and B cells that fight off the infection, but these soon die off. They leave a small population of memory cells that can quickly recognise and mount a defence against the infection a second time. ",
"Memory cells do not proliferate without the infection to stimulate t... | [
"When mammals are born, they get passive immunity from their mothers (whether in utero or via colostrum after birth). That's great for protecting the baby, but the maternal antibodies can interfere with the baby's ability to generate their own antibodies in response to vaccines. Everyone's maternal antibodies wear ... | [
"(I don't know why I'm bothering to argue, but here's the counter argument for anybody else curious)",
"A) True, many vaccines are considered effective for a decade or so, but it can vary from case to case. Most of the time vaccines are effective for decades, or even life, but there are examples of them failing a... |
[
"Have we found any stars that are definitely without planets?"
] | [
false
] | Since we found a planet near Alpha Centauri it got me wondering, have we found a star system that we can conclusively say do have a planet orbiting it? If so how did we prove it? | [
"It's pretty hard to prove such a thing. We don't even know how many minor planets our own star has."
] | [
"This is correct. We simply don't know for certain. We can't, really. The odds of us spotting a planet orbiting a star aren't particularly high. We really have to be looking or get a lucky break.",
"Based on the observable space we've looked at so far, I would guess that the frequency at which a star exists witho... | [
"The most productive methods we currently have to detect extrasolar planets all rely on the orbital plane of the extrasolar planet be more or less in line with our line of sight. If the orbital plane is perpendicular to our line of sight, then most of the methods we use don't work as well.",
"If a particular sta... |
[
"When one stands on the moon, would the horizon appear to be closer, since the moon is so much smaller than earth?"
] | [
false
] | null | [
"Yes, it does. See ",
"here",
". But, there's another thing going on that's less obvious: the lack of an atmosphere. Without an atmosphere, there are few clues for the true distance of landscape feature. Lunar material is also in a limited sense self-similar (scale invariant), meaning that larger rocks and smal... | [
"If you look at a picture of a ",
"mountainous landscape on Earth",
", there's the additional clue for distance that mountains farther away look significantly bluer, because of the air in between. The mountains at the horizon at left for example don't show any details anymore.",
"Second, there's something whi... | [
"I believe that little speck 45",
" up and left of the satellite dish is the lander module."
] |
[
"Does a charged battery weigh the same as an empty battery, theoretically?"
] | [
false
] | null | [
"A charged battery will weigh slightly more, or as Warren puts it: ",
"Energy is stored in a battery in chemical form. In other words, the energy is stored in the chemical bonds between atoms, which involve electrons. A charged battery has many such bonds already formed, while a discharged battery contains the sa... | [
"You aren't taking relativistic in to account. "
] | [
"the total mass of electrons doesn't change, so the weight should remain the same. charged & empty states are just different configurations of where electrons are put."
] |
[
"Could you clone yourself by saving your semen then having a sex change and impregnating yourself?"
] | [
false
] | null | [
"No. Sex changes are a general term, but what you are probably referring to is genital reassignment, or “bottom surgery,” which surgically replicates the appearance of the genitalia of the opposite sex. It doesn’t actually change your biological sex. To become pregnant, you need a functioning uterus, eggs, etc. Tra... | [
"Alright thank you for the information. I'm a theoretical point of view, the if they could get a functional women's reproductive body parts, could you clone yourself?"
] | [
"1) I’m not aware of there ever having been a uterine transplant into a male, and ethically I don’t think any doctor would ever authorize it. Human Subjects Review Board would riot.\n2) Endocrine conditions in male bodies are fundamentally different than in female bodies, and aren’t able to change the way that wome... |
[
"How do calories actually relate to weight stored in your body?"
] | [
false
] | Calories are a unit of energy. How does that translate into the common idea that you gain one pound for every extra 3500 calories that you eat that you don't burn off? Where does this extra weight come from? | [
"The energy is stored in the chemical bonds of the molecule (protein, fat, carbohydrate). The breakdown of the molecules allows the body to harness the energy to phosphorylate adenosine diphosphate (ADP) to make adenosine triphosphate (ATP). ATP is the 'currency' that the body uses for energy.",
"The idea that ... | [
"In its simplest possible form, if your body absorbs more calories than it expends, it uses those calories to synthesize and store fat as a precaution against future calorie deficit. The mass comes from the food we eat, the chemical energy necessary comes from the process of digestion."
] | [
"I have a related question that I think is basically answered by the above, but I'm not certain of the details.",
"When weight is \"lost\", it's simply that the energy storage molecule has been broken up and the energy released. But the mass itself is still in the body. To actually lose weight, those molecules wo... |
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