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seongil-dn_mteb-eli5-with-reddit_perc

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[ { "id": "corpus-325435", "score": 0.7293028831481934, "text": "I think you'll find that Pauli's exclusion principle helps to explain in more detail why octets are the \"perfect\" state. The octet rule, though helpful in understanding the intricacies of bonding don't delve into much detail. In Quantum Mechanics, we use quantum numbers n (energy level/shell character), Azimuthal ℓ (Angular), Magnetic mℓ (describes orbital), and Spin ms (angular momentum). These describe various characteristics of nuclear particles. Take a look in more detail to the principles of quantum mechanics and particularly quantum numbers to understand in more depth why octet rules exist. Keep in mind, there are always exceptions, nature is fascinating that way. However for most particles they follow these basic (Actually quite complex) rules." } ]

[ { "id": "corpus-313364", "score": 0.6926883459091187, "text": "Keep in mind, that hydrogen can also just \"give away\" one electron to have an empty shell, which is also \"closed\" in some sense. Fl**uo**rine on the other hand, has quite some more electrons, which it will rather keep, so adding one more electron will be easier to fill its outer shell. Additionally Fl**uo**rine has quite some protons in its nucleus (9), while being comparable small (compared to other elements in its group, which also like to get one more electron) and is thus the most electronegative element. Edit: spelling ;)", "topk_rank": 0 }, { "id": "corpus-8737", "score": 0.691764235496521, "text": "It’s been a while since this lecture, so forgive me if I mess up a few points. From what I remember, every object on the planet has sort of a key number of electrons it likes to have. Objects that are known to be great conductors of electricity (copper for example) have a much higher key number than say humans do. So, whenever an object has a deficit of electrons, it takes all the electrons it can every time it makes contact with another object that has extra. They all have a tendency to want to remain at that key number. If something has an excess, they’ll give them away. If something has too little, they’ll take them.", "topk_rank": 1 }, { "id": "corpus-187243", "score": 0.691724956035614, "text": "Because the protons help the atom hold onto electrons. The configuration of these electrons controls how the element participates in chemical reactions. Most of the \"behavior\" you're referring to is chemistry.", "topk_rank": 2 }, { "id": "corpus-309961", "score": 0.6915946006774902, "text": "As I understand it the number of protons determines the number of electrons, thus making the protons more important. If you have a carbon atom (six protons, six electrons, six neutrons), and you take one electron away the carbon will become positively charged because the protons want to pull in electrons. So, for your oxygen analogy if you were to lose a proton ( I have no idea how you would even do that) you would have nitrogen. The nitrogen will become negative, and would then want to get rid of the electron; or bond with something (likely H+ because there is a lot of it).", "topk_rank": 3 }, { "id": "corpus-128755", "score": 0.691227912902832, "text": "Atoms have many electrons in shells around the nucleus. Some of those shells are full and others have only a few electrons in them. More interestingly, some metals share all the electrons in their outer shell, what are called free electrons, while others have some outer shell electrons bound to the atom. Each electron has a magnetic moment, because it is a current around the nucleus. When metals have an odd number of bound electrons, they have net magnetism and can be magnetized, what is called ferromagnetic. When they have an even number of bound electrons they can be paramagnetic (attracted to magnetic fields) or diamagnetic (repelled from magnetic fields). On a case-by-case examination, it's even more complicated than that because free electrons also impact these other behavioral types.", "topk_rank": 4 }, { "id": "corpus-254639", "score": 0.6910677552223206, "text": "> Atoms usually bond to have full valence shells, resulting in compounds Let me simplify this a little to clear it up- reactions in nature always take place to become more stable. This is in most cases resulting in 8 valence electrons. > But with the electric charge, the valence shell is not full, so would the Neon cation be able to bond with another atom, such as sodium or another alkali metal? If not, *why* not? (I haven't heard of NeNa before, so the latter question is likely the one to ask) Hypothetically yes but this pretty much doesn't happen for a couple main reasons. The first ionization energy is so high on noble gassed, neon and helium in particular, that it pretty much never forms ions. So, if there were a compound called NeNa, it would be synthetic.", "topk_rank": 5 }, { "id": "corpus-298718", "score": 0.6910415887832642, "text": "Depends on if you want it to be stable or not. We can create large atoms and perhaps arbitrarily large atoms but the vast majority of them decay immediately. If you're referring to relatively stable atoms, this may be worth a read: _URL_0_ e: Didn't notice the proton qualifier in your question. In that case, in a general sense you need to balance out the protons with electrons. Electrons reside in a \"shell\" (like an orbit). There's only so much room in each shell and as atoms get more protons, the additional electrons are forced into higher level shells. I think our heaviest elements have 7 shells and while it's theoretically possible to create 8 shell atoms, I think it's undetermined whether 9 shell atoms could exist so there may in fact be an upper limit.", "topk_rank": 6 }, { "id": "corpus-238511", "score": 0.6908788681030273, "text": "This has to do with orbital theory. Electrons are filling up d orbitals in that middle row, and electrons will always go to lowest energy configuration. Sometimes it's more favorable to fill other orbitals first and other times it's not.", "topk_rank": 7 }, { "id": "corpus-247104", "score": 0.6902579665184021, "text": "The answer to why things happen in the real world, is that energy always tries to approach a minimum. This is a consequence of the laws of thermodynamics, which, as far as we know, always hold. For chemical reactions (such as ionization, or bond formation), the energy that is minimized is known as chemical potential. It so happens, due to the nature of atomic force interactions, that chemical potential is minimized when molecules organize themselves to have full valence shells. It should be noted, that the valence shell idea is a general guideline for how lower atomic number elements act. With larger atomic numbers, the shells become more mixed, and valence does not play a significant contribution to the energy. However, the minimization of chemical potential is always the direction reactions take as they proceed in time.", "topk_rank": 8 }, { "id": "corpus-285558", "score": 0.6900897026062012, "text": "when using the term \"stable,\" one isn't referring to the activity of the electrons themselves, but rather the atom as a whole. An atom with a full outer shell is less likely to react with other atoms, especially other atoms with a full outer shell.", "topk_rank": 9 }, { "id": "corpus-306669", "score": 0.689782977104187, "text": "Tungsten atoms have an outer 5d shell with two electrons in it. This allows for strong covalent bonds to form with other tungsten atoms which requires a lot of energy to break. _URL_5_ _URL_4_", "topk_rank": 10 }, { "id": "corpus-151692", "score": 0.6894664764404297, "text": "It's all about the electrons and their configuration. In its outer shell, carbon has 4 electrons and has room for 4 more. Nitrogen has 5 and has room for 3. Those electron configurations are totally different and make different sorts of bonds. The thing that's really cool is instead of looking across the columns, look down the columns. These have the same electron configuration, and make very similar sorts of compounds. Carbon and silicon are similar; copper is like silver and gold; nitrogen and phosphorus act similarly, etc etc etc. You've also heard of the noble gases, halogens, alkali metals, etc. Each of these act in very similar ways based on their electron configurations.", "topk_rank": 11 }, { "id": "corpus-254529", "score": 0.689384400844574, "text": "Because Xenon is the heaviest of the noble gasses (excluding radioactive radon), its valence electrons will be the least tightly bound. Basically, because they sit further away from the nucleus, you have a lower energy penalty for losing the full electron shell configuration. This makes it susceptible to highly electronegative elements, like F [Compounds of Xe](_URL_0_)", "topk_rank": 12 }, { "id": "corpus-302966", "score": 0.6892991065979004, "text": "Carbon is ideal because it is the fourth most common element in the universe and can covalently form chains of itself (called [catenation](_URL_2_)). The four valence electrons also allows it access to a wide range of geometric forms, such as sp^3 tetrahedral (diamond), sp^2 planar (graphene), or sp linear (sort of, alkynes definitely exist but polyynes like carbyne are often unstable). This allows you to make *a lot* of stable structures out of just carbon. The main drawback to silicon is that it just doesn't catenate with itself well. Long chain silicon molecules are highly reactive with water, and often spontaneously decompose. Also aromaticity for silicon doesn't work in the same way as carbon. You can barely make a [benzene-like silicon molecule](_URL_2_), much less a sheet of slicon-based graphene (which wouldn't even be flat).", "topk_rank": 13 }, { "id": "corpus-248691", "score": 0.6888132691383362, "text": "Not everything strives to be neutral. This is not the driving force for why molecules or polyatomic ions form. The driving force for everything in nature is to *lower its energy*. Consider elemental (neutral) sodium. That is, sodium atoms in the [Ne] 3s^1 state. That extra unpaired electron in the 3s orbital is extremely unstable, because it is much more favorable (that is, lower overall energy) to have only fully occupied, fully paired orbitals. Elemental sodium is so unstable, in fact, that if you react sodium metal with an oxidizer (such as chlorine gas), you get an [exothermic reaction](_URL_0_), yielding table salt with every single sodium atom in the Na^+ state and every chlorine atom in the Cl^- state. All \"neutral\" atoms before the reaction have now become ionized, and a tremendous amount of energy was released. That released energy informs you that the starting compounds lowered their overall energy as a result of the reaction.", "topk_rank": 14 }, { "id": "corpus-300978", "score": 0.6883883476257324, "text": "It's not the number of protons that directly determines these things, it's the number of electrons which do the real interacting we call chemistry. Most elements will have roughly the same number of electrons as they have protons remaining electrically neutral.", "topk_rank": 15 }, { "id": "corpus-265121", "score": 0.6882256269454956, "text": "Fluorine is the most electronegative element on the table. In simpler terms, fluorine is a greedy little bastard and hates sharing. While it's satisfied at the octet rule in its elemental diatomic state, if it can find another source of easy to take electrons, its going to take them and not let go. It's not 100% that simple, but that's the general idea. The octet rule tends to breakdown with most halogens and its not a concrete law, rather just a guideline.", "topk_rank": 16 }, { "id": "corpus-315471", "score": 0.68792325258255, "text": "Protons attract electrons to them, so you get some degree of energy released whenever an electrons is pulled into an orbit around it, making the atom lower energy which is favorable. However, when you get more electrons around an atom they start to repel each other. There is a sweet point where the energy is minimized, with a finite number of electrons added to the nucleus. Electrons have spin. When their spins are aligned then they for quantum reasons (pauli exclusion principle) tend to avoid each other. They'll tend to be positioned further apart. A full orbital has a lot of these electrons aligned with each other, so the atom gains less energy from electron electron repulsion. This is called the exchange energy. If the electrons are constantly repelling each other they are easier to pluck out. As such, many atoms that don't have full orbitals could lose quite a bit of energy from chemically bonding to something that could give or take some electrons from it.", "topk_rank": 17 }, { "id": "corpus-302535", "score": 0.6879157423973083, "text": "The electron configuration is actually what matters. But to have a neutral atom with a given electron configuration, the proton and electron numbers need to match. So for an element proton number = > electron number = > electron configuration = > properties.", "topk_rank": 18 }, { "id": "corpus-236451", "score": 0.6878710389137268, "text": "That's not valence in the denominator, it's the number of electrons transferred in the electrochemical process. Voltage is J/C, which means a reaction that releases 1000 kJ spread amongst 10 electrons has a higher voltage than the same 1000 kJ spread amongst 20 electrons. That's all there is to it. Ion size, charge, and other specifics can be included in the equation, but they are minor correction factors that could give non-ideal behavior as predicted by the Nernst equation.", "topk_rank": 19 } ]

[ { "id": "corpus-325436", "score": 0.7200678586959839, "text": "Nope! We can see through the Milky Way well enough in various wavelengths to see what else is out there. Far infrared radiation, for example, can pass through obscuring dust in our galaxy to help us see outwards. There are [a bunch of dwarf galaxies orbiting the Milky Way that you may be interested in](_URL_0_), though." } ]

[ { "id": "corpus-313067", "score": 0.684043288230896, "text": "There's no reason it would be on the same plane as the Milky Way. The nebula the solar system formed in would have had matter going in all different directions unrelated to the direction the galaxy as a whole is spinning.", "topk_rank": 0 }, { "id": "corpus-301057", "score": 0.6836099624633789, "text": "That's a very good question, and the answer is pretty much no. The shape of a galaxy is its history, rather than its age; you can have a young galaxy that lived hard, and an old galaxy with a boring life. In more specific terms, you have something like the Large Magellanic Clouds, which are older than our galaxy, The Milky Way. The Milky Way though, is a much more \"mature\" galaxy in terms of galactic evolution, having undergone many mergers with other galaxies and having gobbled up many of its dwarf galaxy's.", "topk_rank": 1 }, { "id": "corpus-251817", "score": 0.6833263635635376, "text": "[This is a labled picture of Andromeda](_URL_1_) Almost every dot you see is a star from our own Milky Way galaxy, because they appear bighter to us than other distant galaxies. [Here is a picture of a galaxy cluster](_URL_0_) Almost all of these light sources are galaxies, with the black dots being stars that were taken out of the photo.", "topk_rank": 2 }, { "id": "corpus-660740", "score": 0.6832143068313599, "text": "If everything in the galaxy is expanding from one central point then how is it that our galaxy and the andromeda galaxy set to collide in the future? I have always heard that all the galaxies are moving away from each other.\n\nThanks", "topk_rank": 3 }, { "id": "corpus-307686", "score": 0.6831585764884949, "text": "Well, everything that's going to get in the way is in our own galaxy; beyond that space is vacant enough that it's not a problem. In order to get those mind-blowing Hubble Ultra Deep Field images that show thousands of distant galaxies, we had to point the Hubble towards the most vacant areas of sky we could find, and even then we ended up with a few Milky Way stars photobombing the thing.", "topk_rank": 4 }, { "id": "corpus-66717", "score": 0.6830800771713257, "text": "All the stars you see at night are part of the Milky Way. Most are \"close\" as far as stars go. The nearest major galaxy is 2,500,000 light years away, you'd never see an individual star at that distance without an incredibly powerful telescope. It's possible for a star to originate in one galaxy and get ejected in the direction of another, but we've never found one nearby that's carrying that much speed.", "topk_rank": 5 }, { "id": "corpus-299992", "score": 0.6830539703369141, "text": "You're exactly right; since galaxies contain so much empty space (the nearest star to our Sun is about 4 light years away, which is about 30 million times our Sun's diameter!) very few stars actually collide when galaxies do. What happens is they're tossed around gravitationally until they finally settle into a new position in the larger galaxy that results from the collision. A few unlucky stars are flung out so quickly that the galaxy can't recapture them, and they end up zooming out into intergalactic space. But on the whole, when the Milky Way collides with the Andromeda Galaxy in a few billion years, we shouldn't have too much cause for concern, other than a significantly shifting night sky.", "topk_rank": 6 }, { "id": "corpus-547011", "score": 0.6829541325569153, "text": "If we are inside of the milky way, and the galaxy is on a relatively flat plane, shouldn't we see a ring around us of the galaxy? Do we see this from space?", "topk_rank": 7 }, { "id": "corpus-275048", "score": 0.6825881004333496, "text": "There are a number of factors. Partly because lots of other galaxies are spirals, and the difference between spiral and elliptical galaxies is quite pronounced, in terms of the types of stars they contain. Plus the Milky Way looks like a disc-shaped thing plus a bulgy thing in the middle from side on. And nowadays, we can use parallax, doppler shift and all that to make a 3D model of the Milky Way, and the arms and bars are clearly visible.", "topk_rank": 8 }, { "id": "corpus-282730", "score": 0.6825615763664246, "text": "Yes, that's exactly why we look at things at large distances. Very distant galaxies seem to be quite different than galaxies today. We see them interacting with other galaxies more often, they form stars much faster, etc. In fact, one of the most \"distant things\" we can see is the radiation left over from the Big Bang, the so-called \"Cosmic Microwave Background.\" This light comes from the very beginning of the Universe, when things were much different than they are today!", "topk_rank": 9 }, { "id": "corpus-324048", "score": 0.6823749542236328, "text": "The [Antennae Galaxies](_URL_0_) are moving towards each other at hundreds of kilometers per second ([source](_URL_2_)). Andromeda, our closest large neighbor galaxy, is moving towards us at around 300 km/s ([source](_URL_1_)). Our galaxy is about 100,000 lightyears across, which means it takes light 100,000 years to cross it, so nothing will cross that distance in less time. For reference, the speed of light is about c=300,000 km/s, so at 300 km/s, Andromeda is traveling at 0.001c, so the crossing time will be about 100 million years.", "topk_rank": 10 }, { "id": "corpus-284835", "score": 0.682340145111084, "text": "The easiest to see clue is that when we look up into the sky (even with naked eye) we see a band of bright light with a small bulge in the mirror. This implies a disk shaped galaxy. 2MASS took [this picture](_URL_0_) of the sky. Another clue is the velocities and orbit of the stars. We can detect that there is overall rotational motion in the orbits of stars. This is a property of a spiral galaxy. Of course we compare our own galaxy with other spiral galaxies we can see to help us guess the shape of ours. As for our location. Again a clue is that we do see a bulge in the Milky Way in the sky. This implies that we aren't at the centre. Then we measure the velocities of stars orbiting near the centre, helping us determine the mass of the black hole (galactic core) as well as our own distance.", "topk_rank": 11 }, { "id": "corpus-294862", "score": 0.6823247075080872, "text": "Furthest away object is the Andromeda galaxy, furthest away star you could se under optimal conditions (apparent magnitude m=6) is about 15000 light years away. On average you can see maybe 500 light years or so. For comparison, our galaxy is about 100 000 light years in diameter. EDIT: Spelling.", "topk_rank": 12 }, { "id": "corpus-34878", "score": 0.6822793483734131, "text": "> I've also learned that every galaxy is moving away from every other galaxy as the universe expands. That's only *mostly* correct. It's not **every** galaxy moving away from **every other** galaxy. Only galaxies that are far enough away to not be gravitationally bound to each other are moving away from each other. The Milky Way and Andromeda are practically next-door neighbors, and the gravitational attraction between them is a bigger influence than the expansion of the universe.", "topk_rank": 13 }, { "id": "corpus-256341", "score": 0.6819573044776917, "text": "Galaxy clusters would be where I'd put the distinction. The local group, the galaxy cluster we're part of, is on the order of a few million light years in size, and it definitely isn't all expanding (the Andromeda galaxy, for example, will actually collide with the Milky Way in about 5 billion years) Going up to galaxy clusters, that's scaling up to tens of millions of years away.", "topk_rank": 14 }, { "id": "corpus-294867", "score": 0.6818891763687134, "text": "This is hypothetically possible due to gravitational lensing. Light from a distant galaxy gets bent by a closer galaxy and multiple images can get formed [like here](_URL_0_). There may be a situation where we see one image of a galaxy after a supernova has gone off, and in another image it hasn't gone off yet. This is considered a bit of a \"holy grail\" of observational astronomy.", "topk_rank": 15 }, { "id": "corpus-321689", "score": 0.681827962398529, "text": "Space is HUGE. Every star visible to you at night is within our galaxy, and they are VERY far apart. While stars don't hinder Hubble, other things can - nebulae, molecular gas clouds, etc. Even still, we have a very clear and relatively unobstructed view of the cosmos, and we've imaged galaxies tens of billions of light years away.", "topk_rank": 16 }, { "id": "corpus-319727", "score": 0.6812476515769958, "text": "There are stars and galaxies in all directions. However, the astronaut would only be able to see them if there was enough visible light coming from those stars and galaxies to light them up bright enough to be seen. And the light has to reach the astronaut in the first place too. So there are many more galaxies out there where the light just hasn't had the time to reach us. Also, there are other galaxies that are moving away from us, while we are also moving away from them. Both ours and the other galaxies are emanating light, but since both galaxies are moving away from each other, the light from one galaxy will never reach the other.", "topk_rank": 17 }, { "id": "corpus-309396", "score": 0.6808726787567139, "text": "Not significantly different. You have to remember how *empty* the galaxy is. Out here, the average stellar density is about one star per ten cubic parsecs, but even close to the galactic barycentre it's only about a hundred stars per cubic parsec. If we approximate that as a cube of stars five on a side — or 125 stars total, which is an *over*estimate by nearly half, if I remember right — that puts the stars more than half a light-year apart. The galaxy is big. We are small.", "topk_rank": 18 }, { "id": "corpus-42170", "score": 0.6807985305786133, "text": "30 miles? You can go out on a clear night and see the Andromeda galaxy 2.5 million light years away. How far you can see depends on the size and brightness of the thing you're looking at. And on the line of sight. The earth's curvature is the limiting factor for terrestrial objects but there are a few carefully chosen places where you can see over 200 miles in ideal conditions, from one mountain top to another. The longest lines of sight on earth rely on atmospheric refraction to make distant objects appear higher than they would if light moved a straight line.", "topk_rank": 19 } ]

[ { "id": "corpus-325437", "score": 0.8862839341163635, "text": "> I learnt today about in-memory databases and how now non-versatile memory makes them able to hold information even when powered down. Non-volatile, yes. > It got me thinking : that's just what SSDs do ! So the question is, why are SSDs considered as storage, and wouldn't a SSD database be a good compromise between price and rapidity ? SSD's *ARE* a form of non-volatile memory. Yes, they are frequently used in database applications. The distinction between \"storage\" and \"non-volatile memory\" is contextual and superficial." } ]

[ { "id": "corpus-55253", "score": 0.8105571269989014, "text": "RAM is what's termed \"volatile memory\"; as soon as it loses power, everything it's holding is erased. So yes, SSDs will still be necessary. They sacrifice access speed (so they're slower to read/write) in exchange for being non-volatile.", "topk_rank": 0 }, { "id": "corpus-57186", "score": 0.8052358031272888, "text": "Hard drives, and even the best consumer SSDs are extremely slow compared to RAM, in both maximum data transfer rate and latency. Ever noticed that when a computer is heavily using a page file, performance takes a big hit? Despite the cost per GB, a smaller amount of very fast memory, directly accessed by the CPU is a lot faster and desirable than non-volatile storage.", "topk_rank": 1 }, { "id": "corpus-119510", "score": 0.8005446195602417, "text": "The basic answer is that RAM and SSDs are different in the way they store data. SSD read/writes are (much) lower than HDD, a cost in exchange for speed (but not as much speed as RAM). The better term you are looking for in regards to SSD/HDD v. RAM permanence is volatility. RAM requires power to retain data, SSD/HDDs do not.", "topk_rank": 2 }, { "id": "corpus-26614", "score": 0.7885949611663818, "text": "SSDs are designed for speed. Flash memory is designed to be large in capacity and small in size -- sacrificing speed to get there.", "topk_rank": 3 }, { "id": "corpus-152724", "score": 0.7853322625160217, "text": "SSD's are made out of Flash memory, which is a form of RAM that is non-volative (e.g. it doesn't lose data when power is removed). It's the same type of memory in a USB stick. Flash memory can be made from both NAND & NOR gates, with different performance characteristics. NOR flash allow random access to the byte level & high read speeds, at the cost of density. NAND flash has to be accessed by blocks by has higher density. Most storage devices, including SSD's, are made from NAND flash as the performance benefits of NOR aren't worth the density trade off. NOR flash is used in niche areas when appropriate (for example, instruction memory in embedded devices). For the Vertical I'm not 100% sure what the technology is, but it's likely a production technique that either stacks Flash cells, or uses a different orientation (like FinFET) to increase density.", "topk_rank": 4 }, { "id": "corpus-42664", "score": 0.7833500504493713, "text": "SSDs are silent, use less power, and have a much faster read/write speed compared to HDDs. The tradeoff is that they are more expensive per GB of storage space.", "topk_rank": 5 }, { "id": "corpus-108476", "score": 0.7804794311523438, "text": "A hard disk drive (HDD) uses spinning iron platters to store information, while solid state drives (SSD) use flash memory (the same type your USB stick, or SD memory card uses) that's purely electronic, and involves no moving parts. Because of that, an SSD has much quicker read/write times, thus is popular for use as a system drive. Hard disk drives, on the other hand, does have the advantage of having incredible memory that's unmatched by SSDs, so is good for storage of everyday data that doesn't critically depend on being read/written to quickly.", "topk_rank": 6 }, { "id": "corpus-283659", "score": 0.780349850654602, "text": "Some applications will persist data to non-volatile memory (HDD, SSD). Office documents, open tabs in a browser, etc. You're not storing the total DRAM state of a running application, but information that can be used as configuration when it is run again.", "topk_rank": 7 }, { "id": "corpus-14994", "score": 0.7792452573776245, "text": "A SSD uses flash memory, a type of memory that does not lose its contents when turned off. Traditional hard drives use spinning magnetic platters to store data. SSD drives use less power and can read data much faster than hard drives. They are not affected by magnetic fields, at least not ones you'd normally encounter. There are no moving parts, they don't generate as much heat, and aren't as easy to break by sudden jarring movements. But, they are more expensive.", "topk_rank": 8 }, { "id": "corpus-119553", "score": 0.777607798576355, "text": "A traditional HDD has moving parts - a platter that spins around and a read/write head that moves over the surface of the disk to magnetize/demagnetize/read the value of bits on the surface. An SSD has no moving parts (that's what \"solid state\" means). It functions more like the RAM inside your computer (not exactly the same way, but kinda). It's presently still monstrously expensive to manufacture such drives, but as the technology develops, SSDs will eventually replace traditional HDDs.", "topk_rank": 9 }, { "id": "corpus-313593", "score": 0.7771077752113342, "text": "When it comes to primary storage its all about IO throughput. SD cards have an extremely low IO throughput (read/write is slow). SSDs have a much higher throughput. Just as RAM is much faster than NAND... just as you're processors cache is must faster than RAM. SD cards and SSDs at a basic level are pretty much the same technology however they are built differently. SD cards are so compact because they sacrifice I/O connections and most importantly they are not designed for heat buildup. The faster you access this memory the more heat builds up so they are throttled. If you tried to read/write from an SD card at the same speed you did your SSD you would just fry it.", "topk_rank": 10 }, { "id": "corpus-299651", "score": 0.7768023610115051, "text": "SSDs do NOT use the same basic technology as RAM. RAM is just a big array of flip-flops (or a capacitor and a transistor, in the case of DRAM). SSD uses FLASH memory. FLASH is memory with a floating gate, that uses quantum tunneling to store charge. The fundamental idea is similar to DRAM, but by using a floating gate instead of a connected capacitor, the leakage current is reduced to very, very low levels, such that the memory can be preserved for years. If I recall correctly, most SSDs are rated for a minimum of ten years without losing memory.", "topk_rank": 11 }, { "id": "corpus-135823", "score": 0.776451826095581, "text": "Basically: no. SSD and RAM use completely different technologies to store information. RAM uses capacitors to store information. Those capacitors can store and delete information very fast, but will lose the information almost immediately if powered off. An SSD uses flash memory. They use transistors to store information, thus being a bit slower, but able to store information even without power. Another thing that slows SSD drives is the connection that is used to access them. It is not built to be as fast as the connection to the RAM.", "topk_rank": 12 }, { "id": "corpus-192743", "score": 0.7745929956436157, "text": "In SSDs, you’re basically storing your bits of data in special transistors called floating gate. Electrons can get trapped in an area and stay there for a long time, even without any power. The SSDs have circuits that detect if there’s any electrons trapped or not in these floating gates. Obviously you need a ton of these transistors to be able to store som descent amount of data.", "topk_rank": 13 }, { "id": "corpus-2784472", "score": 0.7735898494720459, "text": "If an ssd is using nand flash technology why isnt it able to hold several terabytes of data? A single nand die can be over 128 gb and sd cards use the same tech so why doesn't an ssd hold more?", "topk_rank": 14 }, { "id": "corpus-188847", "score": 0.7729519605636597, "text": "Higher capacity SSDs are very similiar to lower capacity SSDs (for the same model), but have more flash chips to store data. The controllers in SSDs can access these chips in parallel, at the same time, and so can transfer more *total* data to more chips in the same amount of time, than they could with any chip individually.", "topk_rank": 15 }, { "id": "corpus-120015", "score": 0.7723132967948914, "text": "People do, look at Ramdisks. But there are two main downsides: 1. RAM is still expensive as hell per GB compared to SSDs. 1. (More importantly) RAM by its very nature does not store memory when it's not powered. This makes storing long-term data on it troublesome for consumer purposes.", "topk_rank": 16 }, { "id": "corpus-289452", "score": 0.771102786064148, "text": "In a solid state drive, there are arranged some number of memory cells whose states can be changed like flipping switches. If you have a row of light switches, and flip them to on or off in a certain sequence, they will make their respective lights go on or off. If you cut power to this system the position of the switches won't change, and the next time you supply power, the lights will illuminate the same way. Writing to a SSD is like going in and flipping those switches to a certain configuration that will produce in binary machine language whatever media you want to store. I don't know if they will degrade over time, but I do know that SSDs only have a limited number of writes before cells start to degrade and become unusable.", "topk_rank": 17 }, { "id": "corpus-24886", "score": 0.7707480788230896, "text": "RAM is orders of magnitude faster than the memory used in SSDs. You're paying for the MUCH faster speed.", "topk_rank": 18 }, { "id": "corpus-63929", "score": 0.7705301642417908, "text": "A SSD is a solid state drive and are must faster. they can read write at a much faster rate and never need to be de-fragmented. The down side of this is that they are very expensive in relation to storage size so its most computers only run a small one. HDDs are slower and Need to be De-fragmented every now and then depending on how often you delete stuff. On the upside the data in a HDD will last until the platter is physically broken and because of how cheap they are you can buy a 1TB for bulk storage relatively cheap.", "topk_rank": 19 } ]

[ { "id": "corpus-325438", "score": 0.7772318720817566, "text": "Theoretically there's no reason why they shouldn't. You'll need a 128-bit address space as soon as 16 EiB (the maximum for a 64-bit address space) isn't enough. I have no idea when that point will be reached, but it's unlikely to happen in the next decade or two. However, you can have 128-bit and 256-bit registers in a CPU (SSE and AVX respectively) which can hold one huge number or more typically a vector of multiple 32-bit or 64-bit words. The upcoming AVX-512 will supports 512-bit registers. Additionally, GPUs tend to have wider memory buses that can reach up to 512 bits wide. This lets them read multiple adjacent w\u0010ords in one go to improve memory bandwidth without cranking up the memory clock speed. The downside is more wires between the GPU and memory and the larger area requirements." } ]

[ { "id": "corpus-32715", "score": 0.737610399723053, "text": "2 to the 32nd power is about 4.2 billion, so that's the number of bytes that can be addressed. In a 64 bit computer, 2 to the 64th power is a lot more, so for the foreseeable future, that's more than enough addressing capability.", "topk_rank": 0 }, { "id": "corpus-321377", "score": 0.7367368340492249, "text": "Sure, and one cpu does just that. But 64-bit code has several advantages. For one the address space is bigger, so you aren't limited to using only 4 gigs (in practice closer to 2 gigs) of ram and can use up to terabytes of ram for a single process if you want. For another the 64 bit instruction set is a bit better and more \"powerful\" in general. There are more registers, for example, and this enables 64-bit programs to achieve higher performance on the same cpu.", "topk_rank": 1 }, { "id": "corpus-142274", "score": 0.7365745306015015, "text": "There are limits, but you just work around them. Cpus have kind of hit a wall with clock speeds so now they are more focused only multicore for example.", "topk_rank": 2 }, { "id": "corpus-594951", "score": 0.7359967231750488, "text": "With the RISC-V architecture, is it faster than 64-bit architecture if it were to be used with Linux (if there is a binary version for Risc-V).\n\nAdditionally is RISC-V not limited to 4GB of memory usage unlike 32-bit?", "topk_rank": 3 }, { "id": "corpus-2554", "score": 0.7349432110786438, "text": "Well if you've already hammered out your 64bit support before you need it for the RAM that's always nice, of course. There are some other advantages, though none I would imagine are Earth-shattering. 64bit CPUs would also generally use 64bit registers, which means you can potentially keep more useful information in the CPU at a time.", "topk_rank": 4 }, { "id": "corpus-1470757", "score": 0.7346674203872681, "text": "I mean a real x86 architecture PC not some crappy Windows CE system.\n\nThis is a theorethical question so we won't include shipping from a single place.\n\nWhatever I try I can't get a build under 300", "topk_rank": 5 }, { "id": "corpus-75427", "score": 0.7334443926811218, "text": "The difference is 32 bits... bah-da-boom.. Seriously, you are limited to 4G of RAM with only 32 bit OS (address limit 'cause you only have 32 bits to use). This also translates into how much info you can pass through the computer - like drinking a slurpy through a narrow straw. With 64 bits you get more memory to address and more info (or banana flavored slurpy) through your straw.", "topk_rank": 6 }, { "id": "corpus-257044", "score": 0.7328986525535583, "text": "They aren't, but a power of 2 is a round number in computing. If you have a 16 bit address, you have 65536 possible memory locations. You could have 64000 for instance, but that'd be weird. You'd have to do something sensible when addresses above 64000 are accessed, instead of just covering the entire range and having no such problems. With a power of 2, you get a [neat structure](_URL_0_) with no need to make allowance for special cases. Now once you have chips with sizes of powers of 2, it also works out very well to have powers of 2 of those. Meaning 8 x 1 Mbit chips, for instance. SSD drives actually tend to deviate from this, because they need to store extra data, and have some redundancy. So a 128GB drive might actually present itself as a 100GB one, and keep the rest for internal use.", "topk_rank": 7 }, { "id": "corpus-122659", "score": 0.7324292659759521, "text": "Imagine you're writing numbers on a piece of graph paper, with one digit per square. If you have, say, 20 squares per line, and you can't have numbers go from one line to the next, then you can only work with numbers up to 20 digits. Roughly, saying that a processor is 32- or 64- bit is effectively saying how many (binary) digits it can work with. I can give you a more detailed answer if you want.", "topk_rank": 8 }, { "id": "corpus-79790", "score": 0.7311583757400513, "text": "The bits are...like a highway. 32 bits means you have 32 lanes on that highway (all going the same way). 64 bits mean you have twice as many lanes. The lanes are what carry your data around your machine, between the CPU, RAM, motherboard, etc. It's also how much data the CPU can access at one time. That doesn't mean it's faster, just more accurate. For things that use tons of data, like science labs, movie studios, etc., the extra room does make processing faster. On your average home machine, you won't notice much difference. 64 bit software is made to take advantage of the extra room, and can't run on 32 bit CPUs where there's not enough room. 64 bit CPUs can run 32 bit software though, and even some 16 bit software, I think. This is just an interested layman's understanding though. I could be wrong about something here.", "topk_rank": 9 }, { "id": "corpus-282475", "score": 0.7310978174209595, "text": "I would have to say no. The 64-bit means that the processor uses 64 bit words in its instruction set. To make it simple, it basically allows there to be more addressable memory. The more addressable memory you have the more programs you can have running simultaneously. A 32-bit system can store up to 4GB of addressable memory (RAM) because 32 bits can store -2147483648 through 2147483647. I say it's not necessary because the programs run on a phone come no where close to maxing out the RAM. It just makes it future-proof. Maybe a couple years down the line we will see more advanced OSes and programs. Only then will 64-bit become necessary.", "topk_rank": 10 }, { "id": "corpus-2665618", "score": 0.7275950312614441, "text": "I'm thinking if Microsoft announced in 2020 that in 5 years the next Windows would be 64 bit only, what would reaction be? How feasible would that be? It would have a major impact on the industry that's for sure. What are y'all thoughts?", "topk_rank": 11 }, { "id": "corpus-1259047", "score": 0.7271028161048889, "text": "64 bit tech has been around for years, yet many VST's don't support it yet. Shouldn't we be moved on completely to 64bit by now. What am I missing? Sorry if there is a really obvious answer to this that I'm not aware of.", "topk_rank": 12 }, { "id": "corpus-165613", "score": 0.7262184619903564, "text": "A 64-bit computer does its computation using 64-bit numbers instead of 32-bit numbers. 32-bit numbers can go from 0 to 4 billion, but 64-bit numbers can go from 0 to 18 *quintillion* (that's 15 0's). But this is very technical. Practically speaking, what this means is that: * 64-bit computers can access vastly greater amounts of memory than a 32-bit computers, which gets important as we add more and more RAM to our machines. * 64-bit computers can more easily do math using larger numbers", "topk_rank": 13 }, { "id": "corpus-19963", "score": 0.7256547808647156, "text": "32 or 64 Bit describes the length of numbers in binary the processor calculates with, which means there's a maximum number the processor can handle. For 32 Bit that is 2^32 - 1 so about 4 billion. 64 bit means bigger numbers, bigger calculations. 64 Bit can handle 2^64 - 1, which is 9,223,372,036,854,775,807. But one of the bigger reasons to use 64 Bit is that the memory is also limited by that number length. 32 Bit means up to 2^32 Bytes can be adressed, that's roughly 4 GB of RAM. In today's age that is not much. With 64 Bit the processor can adress 2^64. So you could have up to 9 Exabyte or 9 billion GB of RAM. If you have the money that is :P Source: I'm studying a combination of CS & EE Edit: I'm sorry that seems more like an age 10 explanation. Edit2: As an addition: You also can see the 32 Bit limitation on flash drives with older file systems because they have the limitation that a file may not be bigger than 4 GB, because the file size only has 32 Bit.", "topk_rank": 14 }, { "id": "corpus-67187", "score": 0.7248973250389099, "text": "Plenty of people still have 32 bit machines, and 32 bit apps still work fine on 64 bit. The average person won't experience a meaningful difference between most 32 and 64 bit apps on a 64 bit machine, but everyone on a 32 bit machine will notice a 64 bit app they can't use. Also, it's sometimes slightly harder to develop a 64 bit app, if you don't expect to gain much for it but you'll lose a big portion of your audience by going all 64 bit, why would you do that?", "topk_rank": 15 }, { "id": "corpus-69544", "score": 0.7214682698249817, "text": "More often than not 64-bit architecture is more advanced (read:faster) than 32-bit architecture. So if you're capable of running 64-bit you're probably already doing better. There's something in machine code called SIMD - Single Instruction Multiple Data. Without SIMD, if you wanted to multiply 4 small numbers together, you would have to send 4 sets of instructions. With 64 bit instructions, you might be able to send 2 sets of instructions by packing 2 32-bit numbers into a 64-bit address. This would effectively speed up your computation time by 100%. In short, having twice as much instruction/data space to work with allows you to do certain things twice as fast or faster, but not all things will be sped up. Some of this also depends on the capabilities of the compiler, which might not be smart enough to take advantage of certain opportunities to use things like SIMD.", "topk_rank": 16 }, { "id": "corpus-29858", "score": 0.7214595079421997, "text": "If you run a 32-bit OS, then only the 32-bit version of the program will work. On a 64-bit OS, you're right, you get a choice. I can't speak to any particular application, but in terms of generalities, 64-bit apps tend to faster at raw computational tasks, but they can be slower at tasks that involve complex data structures (mainly because pointer size is higher).", "topk_rank": 17 }, { "id": "corpus-31716", "score": 0.7209047675132751, "text": "For most programs its really not that big of a deal, a 32-bit program only had access to 2gb of ram which is more than enough for most programs but more ram(avalible in a 64-bit application) could be helpful on more intense programs like video editing and heavy gaming. howtogeek has a good article on the topic.", "topk_rank": 18 }, { "id": "corpus-149486", "score": 0.720836877822876, "text": "Nothing about it's 64-bitness will likely make a difference in the WoW client. However, 64-bit x86 processors have *other* advantages over the 32-bit versions. If the software is compiled to take advantage of them, you might see an improvement.", "topk_rank": 19 } ]

[ { "id": "corpus-325439", "score": 0.7996302843093872, "text": "The next closest star is Proxima Centauri, 4.24 light-years away from the Sun. In spite of how close it is to us, Proxima Centauri is a very dim red dwarf - at magnitude +11 it's not visible to us on Earth without a decent telescope. Halfway to Proxima Centauri would put you 2.12 light years from the Sun. Proxima would be magnitude 9.5, still too dim to see without a telescope or at least a very good pair of binoculars. The Sun, meanwhile, would be almost 135,000 further than we usually see it, meaning it would be 135,000^2 times dimmer. That would place its brightness at magnitude -1.1, almost as bright as Sirius as viewed from Earth, the brightest star in the nighttime sky." } ]

[ { "id": "corpus-316223", "score": 0.7483721375465393, "text": "It would look like a bright but not super-bright star. It would be about half as bright as the Alpha-Centauri system, which is basically two suns.", "topk_rank": 0 }, { "id": "corpus-322369", "score": 0.7467366456985474, "text": "Here is list of the nearest stars to the Sun. _URL_1_ The apparent magnitude is how bright it will appear on Earth. The general definition is that anything dimmer than magnitude 6 (meaning the magnitude is greater than 6) is not visible to the naked eye under the best sky conditions. The absolute magnitude is if the stars were all put at the same distance (10 parsecs or 32.6 lt-yrs) away. Going down this list would give you 61 Cygni B which has a mass of 0.63 times the Sun. It's part of a binary system so you would also see its slightly heavier companion with it as well. _URL_0_ Actually Alpha Centauri A is 1.1 times the mass of the sun and is easily visible from the Southern hemisphere.", "topk_rank": 1 }, { "id": "corpus-292540", "score": 0.7396909594535828, "text": "Yes. The two Alpha stars together are about twice as bright as the sun, and the sun would have a magnitude of about 0.5, comparable to Vega as seen from Earth, from Alpha Centauri.", "topk_rank": 2 }, { "id": "corpus-316305", "score": 0.7393268346786499, "text": "[Here](_URL_0_) is a rough approximation of what the sun would look like from Pluto, which is only about five light hours from the sun on average. Stars that were several light months away would be dimmer, but still noticeably brighter than any other stars in the sky.", "topk_rank": 3 }, { "id": "corpus-310404", "score": 0.7356633543968201, "text": "If you traveled about 1.5 light years towards the brightest star in the sky, Sirius A, both that star and the Sun would have the same apparent magnitude (about -1.9).", "topk_rank": 4 }, { "id": "corpus-290466", "score": 0.7351475954055786, "text": "The effect of other stars is extremely small. The intensity of radiation falls off with the square of the distance, so an object that's twice as far will only receive a quarter of the energy through radiation. The Sun is at a distance of about 150,000,000 km. The next nearest star, Proxima Centauri, is a little over 4.2 lightyears away, or about 40,000,000,000,000 km. That's 260,000 times as far away. That means that the radiation received on Earth from Proxima Centauri would be 260,000^2 = 67,000,000,000 (67 billion) times as weak as that from the Sun, assuming Proxima Centauri would be just as bright as the Sun (it's not, Proxima Centauri is considerably smaller and dimmer). And that's just the nearest star (other than the Sun) to Earth.", "topk_rank": 5 }, { "id": "corpus-315088", "score": 0.7344925403594971, "text": "**Tl;Dr:** It depends. I haven't seen the movie, so I don't know how close to the star they were, how intrinsically bright the star was, or what they were observing the star through. For instance, the least luminous star known is 8000x dimmer than the Sun. The most luminous is thought to be about 8000000x brighter. That's a dynamic range of 64 billion, so a lot depends on the star. How close? In general, apparent brightness varies inversely by the square of the distance from the source. Move 10x closer, it appears 100x brighter, so distance matters. Finally, if I were them, I would only observe this star through some sort of optically dense window – 0.000000001% transparent to visible light, and 100% opaque to gamma rays, X rays, UV, SW IR, LW IR, heck, even radio waves. It could burn your face off, man.", "topk_rank": 6 }, { "id": "corpus-320856", "score": 0.7320424914360046, "text": "The density of stars near the galactic center will be higher. [Wikipedia](_URL_0_) puts it at 2 stars per cubic light year compared to the 0.004 stars per cubic light year near the sun. This corresponds to an average separation of ~0.8 light years between stars near the galactic center vs the ~6.3 light years between stars near the sun. This is assuming a locally uniform distribution of stars; the commonality of binary star systems should probably be taken into account for a better estimate.", "topk_rank": 7 }, { "id": "corpus-282621", "score": 0.7319222688674927, "text": "Here you go: _URL_1_ \"Ross 248, currently at a distance of 10.3 light-years, has a radial velocity of −81 km/s. In about 31,000 years it may be the closest star to the Sun for several millennia, with a minimum distance of 0.927 parsecs (3.02 light-years) in 36,000 years. Gliese 445, currently at a distance of 17.6 light-years, has a radial velocity of −119 km/s. In about 40,000 years it will be the closest star for a period of several thousand years.\" There's also a list of known stars that will pass within 5 light years of the sun over the next 2 million years. According to that, in 1.4 million years, [Gliese 710](_URL_0_) will be 1.01 light years from the sun. This may be the one you had heard about.", "topk_rank": 8 }, { "id": "corpus-302153", "score": 0.7309443354606628, "text": "The potential energy before is negligible, and upon collision it's -G\\*M^2 /(2\\*R) where M is the mass and R the radius of the sun. The potential energy has been converted to kinetic energy, which is 2\\*10^41 J for both stars, which means they both go at roughly .1% of the speed of light. I don't know what would happen on collision. I speculate that they would form a larger star after some time to settle down.", "topk_rank": 9 }, { "id": "corpus-319944", "score": 0.7281463146209717, "text": "The next brightest star is Sirius. It is 25 times as luminous as the sun but 540000 times as far away. That means the heat we receive from it is about 80 trillionths that what we get from the sun.", "topk_rank": 10 }, { "id": "corpus-325019", "score": 0.7259352207183838, "text": "According to [this article](_URL_0_), Voyager 1's encounter with another star will be in about 40,000 years. At that point it will come within 1.7 light-years from it. The star is Gliese 445, which is around 17 ly's from the Sun. I don't know exactly when the halfway point is but I guess that would be when it's closer.", "topk_rank": 11 }, { "id": "corpus-315498", "score": 0.7195801138877869, "text": "This is some fairly basic math: The Sun's diameter is about 1.4 * 10^6 , while the Earth's diameter is about 1.27 * 10^4 . So roughly, the Sun's diameter is 100 times bigger than the Earth's. So for both of them to be the same size, you would need to be about 100 further from the Sun than you are from Earth. This means there's a spheroid around the Earth with a radius of about 1/100th the Earth-Sun distance (which is about 150 million km / 100 = 1.5 million km, or 9400000 miles, which is about 4 times further from the Earth than the Moon is. So in short you'd be in empty space, about 4 times as far away from the Earth as the moon is; the exact distance depends on the angle between you, the Earth and the Sun. As for apparent brightness, I don't think there is such a point. The Sun is so much brighter than the Earth (which only reflects the Sun's light), that even on the surface of the Earth, the Sun is still brighter than the Earth.", "topk_rank": 12 }, { "id": "corpus-281126", "score": 0.7188459634780884, "text": "No. You would see the distance to the star contracted to 25.7 light-years, and the star approaching you at 0.86 *c*.", "topk_rank": 13 }, { "id": "corpus-833953", "score": 0.7180134057998657, "text": "So what if the star that we are observing has a star relatively close to it and it is behind it from our point of view. Could this star be larger and acting like an eclipse on the star behind it with sort of an overlap and the overlap becoming smaller as time passes.\nJust an interesting thought I was having.I know nothing about space but would something like that be possible to see if two Stars were close like that?", "topk_rank": 14 }, { "id": "corpus-317649", "score": 0.7177113890647888, "text": "There are more bright stars closer to the centre of the milky way and the stars are indeed closer together. Combined this does mean the average luminosity is greater in the middle of the milky way compared to where we live. Obviously the actual ambient light would depend on how near a bright star you were. Here are some lecture notes covering the topic for more in depth reading _URL_0_", "topk_rank": 15 }, { "id": "corpus-299410", "score": 0.71699458360672, "text": "A supernova is about 10 billion times as bright as the sun. Alpha Centauri is 250,000 times as far away as the sun. Brightness decreases with the square of distance. A supernova at that distance would be one-sixth as bright as the sun.", "topk_rank": 16 }, { "id": "corpus-1169287", "score": 0.7159553170204163, "text": "The light hitting ur eyes will have started from the object a long time ago\n\nThe sun is like 10 minutes away\n\nAlpha centauri is a few years away\n\nShit b kool", "topk_rank": 17 }, { "id": "corpus-273831", "score": 0.7119670510292053, "text": "[Yes.](_URL_0_) There would be one directly behind you whichever sun you were looking at.", "topk_rank": 18 }, { "id": "corpus-299640", "score": 0.7088537812232971, "text": "Voyager 2 is 104 AU from the Earth, so using an inverse square law it would be 1/104^2 times less bright. (0.00009245) The Sun is about 400,000 brighter than a full Moon at Earth's surface. so lets multiply them to get: 37 times brighter than a full moon. So one the side facing the Sun, can 100% see it, very well actually. Im not sure how well distant star light will illuminate the other side though, probably pitch black. Voyager 1 is even further away but its still way brighter than the moon comparatively.", "topk_rank": 19 } ]

[ { "id": "corpus-325440", "score": 0.8010886311531067, "text": "> Why are there no colourful fish in fresh water? [There are many colourful freshwater fish.](_URL_1_) In particular [Lake Mawali Cichlids.](_URL_0_)" } ]

[ { "id": "corpus-126864", "score": 0.7525514960289001, "text": "Water is a very light blue. It looks colorless in small quantities like a glass because the blue is too faint to be seen in small quantities. It is a deep blue in ocean because you are looking at so much faint blue that it looks darker. _URL_0_", "topk_rank": 0 }, { "id": "corpus-158925", "score": 0.7499262690544128, "text": "It has to do with the plant life and filtration of the body of water. Lakes can often suffer from large algae blooms from nutrient pollution. This would give the lake a darker, murkier look to it. Lakes are often freshwater, allowing for weeds and such to grow. The sea on the other hand is most likely salt water and won’t suffer from nutrient pollution or over vegetation.", "topk_rank": 1 }, { "id": "corpus-325374", "score": 0.7397377490997314, "text": "There are different types of water throughout the Earth. For instance, the Great Lakes are a Type II water. This means it's has 3 particular color producing agents (CPAs). These are chlorophyll (providing blue and green colors) , dissolved organic matter (providing dark yellow/tan/brown color), and suspended minerals/sediment (providing a red to deep brown color depending on the sediment type). So, you will get water color based on the individual concentration of each of these CPAs. For ocean waters there may be different levels or types of CPA, but I know in coastal regions of the oceans the three i mentioned are common, esp chlorophyll. On mobile so I can't get sources, however I am a freshwater remote sensing professional. Edit: here is a book on remote sensing of coastal waters _URL_0_", "topk_rank": 2 }, { "id": "corpus-313009", "score": 0.7357088327407837, "text": "> The color of water is actually blue due to the selective absorption of red wavelengths, an effect that increases with thickness. Also when certain materials or organics are dissolved or suspended in water, they can affect its color. Reflection of the sky comes into it, but when it's overcast the sea still looks blue, so we know it's not the whole story. _URL_0_ _URL_2_ _URL_3_ _URL_1_", "topk_rank": 3 }, { "id": "corpus-321952", "score": 0.7355904579162598, "text": "Water isn't colourless. It looks blue because it weakly absorbs red light. In oceans, there's also a large amount of dissolved minerals and particles that add to the scattering of light. In a glass, it looks colourless because the sample is thin enough that you don't notice the blue colour. _URL_0_", "topk_rank": 4 }, { "id": "corpus-17443", "score": 0.7301987409591675, "text": "The ocean isn't a stagnant pool, massive underwater currents constantly circulate the ocean. The different colors you see come from various sources, the depth of the water, temperate, algae, mineral content. Like you get that *gorgeous* light blue in the Caribbean because the water is shallow near the islands and is reflecting some of the blue tinted light off the white sand. (The light is tinted blue for reasons that I'm not smart enough to explain).", "topk_rank": 5 }, { "id": "corpus-62403", "score": 0.7295134663581848, "text": "This is kind of a broad question but I'll attempt it. All water has an intrinsic blue color, albeit faint, due greatly to the fact that it absorbs most of the longer frequency wavelengths of visible light (red, orange, green, etc), thus answering why oceans are mostly blue. The color of water can be changed greatly depending on the materials or sediment present in great quantity. A lot of silt can make it look brown or tan, a lot of plankton can make it appear greenish, a lot of iron can make it appear red. The CLARITY of oceanwater depends on location and conditions. Turbulent water and currents disturb more sediment, creating more murky water, and water further north tends to have a greater amount of microscopic life (plankton, etc), whereas water in warmer, tropical locations receive more sunlight, preventing the reproduction of plankton, resulting in clearer water.", "topk_rank": 6 }, { "id": "corpus-179810", "score": 0.7293227314949036, "text": "Water is blue because it absorbs the other colors of light, reflecting the blue light to your eyes -- or Blue light penetrates water the deepest. First is absorbs the reds and oranges and ultra violet and violet, then the yellows and greens. This is what you see at the macro-level when you view the ocean from far away. As you get closer, and see water that is closer to shore, there isn't enough water to absorb those yellows and greens so this is what will cause that blue-green hue to start showing up. When you scoop up a tiny bit of water, there really isn't enough water there to absorb a significant amount of light, which is why the water shows clear.", "topk_rank": 7 }, { "id": "corpus-113244", "score": 0.7280145883560181, "text": "Uh, the ocean is kinds green in most places. The color of water has everything to do with what exactly is suspended in it. Water with a lot of algae and other organic matter in it tends toward green/brown.", "topk_rank": 8 }, { "id": "corpus-129975", "score": 0.7273896336555481, "text": "You are talking about Cape Agulhas. The different colors come from different kinds of plankton living in the water. While it's true that pure water gets its color from refracting light, the ocean is not at all pure. Plankton living in the water has a major effect on the color of the ocean. The Indian and Atlantic Oceans have different temperatures and different concentrations of salt, so different kinds of plankton live in them. Different kinds of plankton reflect different colors, so when you look at the ocean from the shore you see different colors in the water. The bands and pockets of color appear because the oceans don't mix evenly. The uneven mixture is caused by a current called the Agulhas Retroflection.", "topk_rank": 9 }, { "id": "corpus-129059", "score": 0.7243989109992981, "text": "Water is inherently blue. It's just a very, *very*, **very** light blue. So light that you need a substantial thickness of it to see the actual blue tint. The opacity of the ocean is caused by all of the stuff dissolved in it. It's nowhere *near* being pure water.", "topk_rank": 10 }, { "id": "corpus-191867", "score": 0.7239419221878052, "text": "The minerals in different bodies of water vary and also the blue tint varies with the amount, imagine you’ve got a clear sheet of plastic with a 1% blue tint so it looks clear until you put it against a white tile or something. Now imagine you’ve got 100 of those sheets and if you stack them together and look through everything seems far more blue because you’ve got the added tint of 100 sheets. You may argue that the clearness should add up too but the addition of colour changes the appearance whereas the lack of colour does not. This make any sense at all..?", "topk_rank": 11 }, { "id": "corpus-235498", "score": 0.7230644226074219, "text": "> I was down at Lake Michigan and I noticed this extreme color difference in the water. Are you sure those are two different color waters, and it's not something underneath the water (like an algae plume, reef or shallow area)? > It's a clean cut line dividing the two colors of water. (Here's a picture _URL_0_ .) It's a cool picture! Where'd you take it, near the shore or far out to water? Where was land in relation to you, any other information you have could help. > What causes something like that and how does it stay so perfectly separated (at least on the surface)? Let's find out together! (No, seriously, I don't have the answer, but I'm curious - the questions I've asked might help me find the answer or someone else who has more information deduce it, though.)", "topk_rank": 12 }, { "id": "corpus-5136", "score": 0.7225133776664734, "text": "Large bodies of water like rivers, lakes, and oceans really are blue. Pure water with nothing else in it is transparent. But large bodies of water are not remotely pure. (They may be clean and potable, but they're not \"pure\".) You know how a bottle of maple syrup looks dark brown, but a small drop of it looks very light brown, almost transparent? Large bodies of water are the same. Take a small cup of it and it looks transparent. But look at a large volume of it and you're seeing through millions of gallons of it, and the tiny tint to the water makes it overall appear a light, medium or even dark blue. The main reason water is blue is because some of the particles in water absorb red light, so what's left is blue. But some lakes are also colored by algae. Finally, while not a primary factor, reflecting the blue color of the sky is sometimes part of what contributes to water appearing blue.", "topk_rank": 13 }, { "id": "corpus-279585", "score": 0.7221001386642456, "text": "For the same reason that ocean water is blue. Water and ice both [only absorb weakly in the visible spectrum.](_URL_0_) However this absorption is stronger in the red part of the spectrum and weaker at the blue end. As a result, the intrinsic color of water and ice is blue. The problem is that in order to see it you need light to travel through a sufficiently thick layer of water/ice for the color to become noticeable. That is why a glass of water or an ice cube will look clear, but the ocean or a thick sheet of ice will look blue.", "topk_rank": 14 }, { "id": "corpus-274640", "score": 0.7214373350143433, "text": "I want to link you to [this](_URL_0_). It does an excellent job of summing up the process in my opinion. In the most basic of terms, the \"lakes\" are made of salt water that has a much higher concentration of salt than the rest of the ocean. The ocean is very standard in it's salinity, at about 35 parts per thousand. The underwater lakes are three to fives times as concentrated and are therefore much denser, confining the super salty water to underwater wells and streams.", "topk_rank": 15 }, { "id": "corpus-9810", "score": 0.720718502998352, "text": "Well, this is the thing. Large amounts of water appear blue right? Oceans, lakes, icebergs, swimming pools, even a white bath full of water will look slightly blue-ish. Of course it's because water *is* slightly blue. You just need a decent amount of it before that can be seen. A glass of water doesn't have nearly enough to appreciate the colouration, so it looks clear.", "topk_rank": 16 }, { "id": "corpus-149115", "score": 0.7198805212974548, "text": "Fish from the coral reefs are, not so much open water marine fish. Coral reefs are bright and colorful places, so to blend in bright and colorful works. In freshwater, the common background colors to blend in with are earth tones or sometimes green.", "topk_rank": 17 }, { "id": "corpus-301909", "score": 0.7187685966491699, "text": "Tropical waters are very nutrient poor, and in those areas relatively shallow. Low nutrients means less things living there, less organic content floating around. Tropical waters are usually high sand, low silt too. Edit: Forgot to expand upon the shallow part. Blue light penetrates the shallowest, so the deeper you go the less blue light there is. That's why deep dwelling organisms tend to be reddish in color. The only light that reaches that deep is red, so they don't stand out.", "topk_rank": 18 }, { "id": "corpus-171286", "score": 0.7166744470596313, "text": "> what about freshwater fish, where everyone has a similar body shape and color, and everyone swims in the same murky brown water? What? No they dont. Freshwater fish vary widly in size, shape, and colour quite drastically. Also not every body of fresh water is brown and murky.", "topk_rank": 19 } ]

[ { "id": "corpus-325441", "score": 0.7522782683372498, "text": "Usually false-color. Images of nebulae typically include narrow-band filters which pick up only a specific emission line, such as H alpha or OIII. These filters are usually colored corresponding to where they are on the EM spectrum, so H alpha is usually colored pinkish or red because it's at 656 nm. [This site explains it very well and thoroughly](_URL_0_)." } ]

[ { "id": "corpus-159884", "score": 0.7137717604637146, "text": "They don't. Depending on where you live, you should be able to find Betelgeuse and Sirius in the night sky with any star chart app. They should be some of the brightest, anyway. Betelgeuse will have a very distinctive orange hue, even with the naked eye, while Sirius will appear more like a typical \"white\" star. As for the others, most are so small that it's difficult for our eyes to discern color without some magnification.", "topk_rank": 0 }, { "id": "corpus-272310", "score": 0.7137578129768372, "text": "It would be black, except if there are things on the planet that absorb that light and convert it to a visible frequency. Certain chemicals do this. You might see bioluminescence if any creatures exist. You might be able to see a little bit do to the starlight of other, normal stars.", "topk_rank": 1 }, { "id": "corpus-151079", "score": 0.7136526107788086, "text": "You might be mistaking a few things, lots of telescopes CAN capture colour, others do not. When you see a false colour image it isn't that the microscope is detecting something that we dont see, false colours are just substituted for other values to make things easier to see. For example, we cant see infrared radiation, but we can detect it with IR cameras, however in order to make sense of the data we colour different values of IR detection with different colours to create a \"predator vision\" type of image that can be useful to us. Similarly there are lots of telescopes that dont operate in the visual spectrum, they detect xray, or IR, or gamma bursts or microwaves, or some other portion of the electromagnetic spectrum, and we give these wavelengths false colours so that we can more easily visualize them.", "topk_rank": 2 }, { "id": "corpus-269287", "score": 0.7128888368606567, "text": "I used to do amateur astronomy and one thing you will quickly learn is that the bright and vivid photographs you see are only visible in photographs. The cones and rods in your eyes are not as good as a CCD camera. The cones in your eyes can detect colors, but not in dim lighting while the rods are more numerous and can detect dim light, but not color. With a telescope with a 4.5\" aperture, I'm not sure how much color you will see for planets, but you can try a couple of different methods to improve your chances. If your eyes become dark adapted, you become less color sensitive but if you are seeing the bands of Jupiter, that would mean you are seeing a difference in color and not brightness. Try to get dark skies, and try not to magnify too much in order to retain some of the brightness to keep your eyes partly color sensitive. Just don't expect to observe the vibrant colors that photographs show.", "topk_rank": 3 }, { "id": "corpus-657721", "score": 0.7112288475036621, "text": "I have a 6\" dobsonian tube (Orion StarBlast 6) with eyepieces 5, 10, and 25mm. I'm currently near Atlanta, GA in the U.S.\n\nI was wondering if there is a source I can consult in order to determine where to look for visible comets. I have Stellarium but I haven't found a feature or plugin for comets in it. Also, I don't yet have a good grasp on how to translate the magnitude scale into brightness (in an area of moderate light pollution) and determine if I will be able to see the objects through my scope or not. Anyone care to explain or point me to an easy to comprehend explanation on magnitude?\n\nI've looked at the moon, Jupiter and its moons, the Orion Nebula, Pleiades, and the double cluster to exhaustion, to name a few. I've tried seeing some others but unsuccessfully; probably due to light pollution or because they are too faint (like the Andromeda Galaxy which looks like a small star with a very faint smudgy haze around it). What other interesting objects are there to look at in my area this time of year I can locate them in Stellarium but I need to know what to search for.", "topk_rank": 4 }, { "id": "corpus-241959", "score": 0.7103755474090576, "text": "Chromatic aberration... at least that's what it's called when working with a telescope.", "topk_rank": 5 }, { "id": "corpus-834164", "score": 0.7091067433357239, "text": "I feel like I always see neutron stars colored purple or blue in artistic impressions - but are these actually the colors of visible light a neutron star would give off?\n\nIf you were able to fly out into space and get up close to a neutron star, what color would it look to the unaided human eye? And would you be able to see the jets they emit with your eyes? Or would you only be able to see them if they were pointed directly at you or shining through a medium that scattered their light, like a laser?", "topk_rank": 6 }, { "id": "corpus-286477", "score": 0.7085660696029663, "text": "The peak output given off by a red dwarf falls in the infrared part of the electromagnetic spectrum. Red is the color in the visible spectrum that is nearest to infrared, so that will be most pronounced of the colors that we can observe. But the light from red dwarfs also contains lights of higher frequencies (blue end of spectrum) to some extent. Something that is blue will still reflect a small amount of blue light falling on it. As long as our eyes can detect those blue wavelengths we will see it as blue in relation to other things. However, light will be much dimmer than sunlight on earth. If the planet was in the habitable zone of a very small red dwarf then the light would be very dim compared to what we are used to on earth. I have read that the luminosity would be similar to an incandescent light bulb.", "topk_rank": 7 }, { "id": "corpus-316394", "score": 0.7080453634262085, "text": "No, you won't be able to see exoplanets as anything other than points of light. JWST *will* be able to directly detect some exoplanets, and possibly take spectra of the planets' atmospheres, but you won't get a picture of the planet. Besides, JWST operates in the infrared (wavelengths greater than 1 micrometer), so blue and green (~450-550 nm) are outside of its wave band.", "topk_rank": 8 }, { "id": "corpus-835271", "score": 0.7076993584632874, "text": "I recently bought a Celestron Powerseeker 76 AZ telescope. I've mostly used it to look at the moon, and the viewsI got were amazing. However, I've also tried to look at Jupiter. The results I got there weren't very good. It kind of looked like a white orb and i think i saw some of the belts of the planet. I thought I would see colours and maybe a bit more details though. For all I knew it have just been some dust on the lens, but I'm sure it was Jupiter. It was very bright and didn't look like a small point in the telescope. More like a white dot. Does anyone know what I'm doing wrong or what the problem is?", "topk_rank": 9 }, { "id": "corpus-274109", "score": 0.7073416113853455, "text": "That is basically what the [Event Horizon Telescope](_URL_0_) is trying to do with the black hole in the centre of our galaxy. What it would actually see though is just a small localized dip in the brightness of a bright background.", "topk_rank": 10 }, { "id": "corpus-685075", "score": 0.7073221206665039, "text": "Hi,\n\nLast night I asked for tips on finding Orion Nebula. I ended up finding it and got a great view! \n\nNow, could you guys give me tips on finding Andromeda Galaxy? I know nothing about finding it. I have an Orion XT6 with a 25 mm eyepiece and a 6 mm.", "topk_rank": 11 }, { "id": "corpus-72588", "score": 0.7071849703788757, "text": "Most of the color you see in pictures of distant galaxies and nebula is added in. The images are typically created using electromagnetic waves outside the visible spectrum of light, but this will vary picture to picture. If you posted an example picture of what you're talking about, you're more likely to get the exact explanation for that specific picture.", "topk_rank": 12 }, { "id": "corpus-324594", "score": 0.7063987851142883, "text": "The [Chromoscope](_URL_0_) may be relevant to your interests. It lets you visualize the sky in various wavelengths.", "topk_rank": 13 }, { "id": "corpus-321077", "score": 0.7062647342681885, "text": "What you're asking about is the effect of optics, specifically the diffraction limits of lenses and mirrors. When you view or image a point source through an aperture with either a lens or a mirror the image of the point source will not itself be a point, it will be a diffuse disk. This is called the [Airy Disk](_URL_0_), and it has an angular size that varies with the wavelength of light imaged and the diameter of the aperture (multiplied by 1.22). For example, take 600nm as a typical wavelength of visible light. For humans in extremely dark conditions the pupil of the eye can open to a diameter of nearly 8mm, which gives an airy disk size of 9e-5 radians, or about 20 arcseconds. In contrast, the Hubble's theoretical resolving power is nearly a thousand times better. So, to answer your question, it depends on the instrument used.", "topk_rank": 14 }, { "id": "corpus-276741", "score": 0.7062243223190308, "text": "Nothing absorbs 100% of the light that is shined on it, except maybe a black hole. You will be able to make out shapes, but everything will look dark and green.", "topk_rank": 15 }, { "id": "corpus-322414", "score": 0.7057433128356934, "text": "The densest regions of molecular clouds reach particle densities of around a million particles per cubic centimeter. Assuming the particles are hydrogen, this gives an order of magnitude density of 10^-18 g/cc. Air is around 10^-3 g/cc, so even the densest regions of nebulae are diffuse enough that they're effectively vacuum compared with being on Earth. While you wouldn't notice the gas in your immediate vicinity, you probably would notice the sky around you looking darker due to the accumulated effect of looking through lightyears worth of dust. It would probably be similar to looking at the nebula from just outside, only you'd see it in every direction.", "topk_rank": 16 }, { "id": "corpus-305474", "score": 0.7055068016052246, "text": "It would look black with stars visible, just like everywhere else. Those pretty Hubble photos are for the most part false color, and often span lightyears in width. As for the number of particles, we actually don't know. There's already debate over the density of the interstellar medium outside our solar system, let alone a nebula thousands of lightyears away.", "topk_rank": 17 }, { "id": "corpus-288213", "score": 0.7048608660697937, "text": "They're real images from telescopes, but not real images as the human eye would see them directly. They'll take photos through various filters to enhance certain elements (green for oxygen, red for hydrogen, etc) and then merge these into one photo. This brings out detail that the human eye would not otherwise be able to see. They may also use filters to view wavelengths that the human eye simply cannot see. Infrared is a prime example. There's a lot of dust out in the galaxy, and dust blocks visible light quite well. However, infrared passes through it much easier, which lets us see through a lot of dust. When viewed in (mostly) visible light, the Horsehead Nebula looks like [this](_URL_0_). When viewed in infrared, it looks like [this](_URL_1_). You can see wayyyyyy more detail that way when the human eye just sees a black blob.", "topk_rank": 18 }, { "id": "corpus-290311", "score": 0.7047940492630005, "text": "It would be black except for the few galaxies that are visible to the naked eye, which are the Andromeda galaxy, the triangulum and the small and large megellanic clouds. You might also see the dwarf galaxies that are merging with the milky way, but that depends on whether you consider them part of the milky way or not.", "topk_rank": 19 } ]

[ { "id": "corpus-325442", "score": 0.8642264604568481, "text": "All planets' gravity affects all other planets. But it's possible for multiple planets to be in stable orbits within a single star's habitable zone, yes." } ]

[ { "id": "corpus-322258", "score": 0.8184353709220886, "text": "Basic answer is no. Even if there could be a very marginal and unusual situation where there was a planet with a smidge more mass than the star in the system, they would orbit the centre of mass, which means they would both orbit around a point between them, rather than one around the other. The planet would have to be far, far more massive than the star for the centre of mass of the system to be inside the planet, so in that sense it definitely isn't possible.", "topk_rank": 0 }, { "id": "corpus-322071", "score": 0.8117882013320923, "text": "I very briefly studied this a long time ago. The orbit is pretty stable as long as the distance between the stars is much smaller than the distance between the planet and the stars. I imagine the habitable zone would be similar to that of a system where just one star and an equivalent energy output. I don't see any particularly obvious problems with a planet supporting life around a binary system. There'd just a bit a lot of subtle differences. You'd probably get slightly different tides in the oceans, slightly different dawns/dusks, slightly different patterns in solar wind, etc. But really, light is light, heat is heat, gravity is gravity, one star or two.", "topk_rank": 1 }, { "id": "corpus-835237", "score": 0.8052342534065247, "text": "So I know that the best chance of finding other life on extrasolar planets is to look for terrestrial planets in the habitable zone of a star, the zone where water neither freeze nor boils, but stays liquid. I also know that the size and placement of the habitable zone depends on the star's size and color/temperature. I was wondering if it was possible for two terrestrial planets to form within the same habitable zone. If it is possible, will there be any addition effects to the two planets being 'close' (relatively) to each other?", "topk_rank": 2 }, { "id": "corpus-323848", "score": 0.798552930355072, "text": "There are a variety of orbital architectures that would allow a planet to stably orbit a binary star system, but perhaps the simplest configuration would be a close binary system with a planet in a more distant orbit. In fact, [the planet Kepler-16 b](_URL_2_) is a roughly Saturn-mass planet orbiting two very close low-mass stars. There are dynamically stable, habitable zones in binary star systems as well. You can see some animations of how such zones vary with time as the binary stars orbit one another [here](_URL_0_), and you can calculate your own habitable zones [here](_URL_1_).", "topk_rank": 3 }, { "id": "corpus-833537", "score": 0.7958537340164185, "text": "Can a planet touch a star or inside outer layer of a star and still could maintain a stable orbit? Thanks.", "topk_rank": 4 }, { "id": "corpus-319815", "score": 0.7943633198738098, "text": "It would be cool, but probably not. There are planets that orbit around two stars (aka a [binary star](_URL_1_)); these are known as [circumbinary planets](_URL_0_). However, they form an orbit outside the two stars, and since planetary bodies revolve around the planetary system's center of mass, both stars and the orbiting planets will orbit around their common center of mass. In addition, given the chaotic environment between a binary system, the most likely area for planet formation is outside the orbit of the two stars. However, there are mathematical models that suggests the plausibility of a figure-8 orbit (called a choreographic system because of its resemblance to dancing), but this has not been observed in space.", "topk_rank": 5 }, { "id": "corpus-322949", "score": 0.7915992140769958, "text": "Yes! But it's a little more complicated than. There are two types of habitable zones around a binary star. One is the normal temperature one that we're used to, but there's also a tidal habitable zone, inside which the varying tidal force is too extreme for habitability.", "topk_rank": 6 }, { "id": "corpus-305008", "score": 0.7845712304115295, "text": "Roughly half of the stars in the galaxy are part of a binary system. If the two stars are about the same mass, then they'll orbit around a common point in space between them. If one star is a lot more massive than the other, then the smaller star will orbit around the larger star just like a planet does. [Sirius, one of the brightest stars, actually has a little companion star that orbits it.](_URL_2_) Planets can exist in binary systems. Check out [Wikipedia's page on circumbinary planets](_URL_0_) for more. A few have been discovered so far, and [the Kepler spacecraft will probably find lots more](_URL_1_) as its mission continues. As for the possibility of life on a circumbinary planet, I've heard of binary systems having habitable zones just like one-star systems do, but I'm not sure how they'd be different.", "topk_rank": 7 }, { "id": "corpus-241737", "score": 0.7815703749656677, "text": "Yes, it's theoreticaly possible. For instance, a brown dwarf with 3% of the sun's mass would have a habitable zone 2 -3 times the star/planet's Roche radius. With smaller dwarfs, the habitable zone would fall within the Roche limit, so it must be sufficiently large to prevent this. Also, brown dwarfs fade relatively quickly, so the habitable zone would not be stable for more than a couple billion years.", "topk_rank": 8 }, { "id": "corpus-310360", "score": 0.778962254524231, "text": "It's perfectly possible to have a binary star system - either with the planet orbiting one star and the other star significantly more distant, or with the two stars relatively close together and the planet orbiting the centre of mass of the system. Systems like that have now [been observed](_URL_0_), so yes, it's perfectly possible.", "topk_rank": 9 }, { "id": "corpus-262556", "score": 0.7744790315628052, "text": "It depends on the system, but many are far enough apart that each could have its own system of planets independent of the companion star. According to the [Wikipedia page](_URL_0_) on Alpha Centauri, the companion star wouldn't have a significant affect on the climate of a planet orbiting either star, and they orbit at a distance comparable to Uranus from our sun. The other star would move like a planet through the sky, but be brighter than the full moon. If the stars were closer they could interfere though. Also, wobble is not the only way we can determine if there are planets around a star. The new KEPLER observatory measures brightness changes from planetary transits.", "topk_rank": 10 }, { "id": "corpus-5276", "score": 0.7727838158607483, "text": "Yes. There are plenty of binary star systems in the known universe. However, the planets orbiting them might not be habitable, as temperatures would likely vary greatly due to how the planet orbits the stars.", "topk_rank": 11 }, { "id": "corpus-290633", "score": 0.7682086825370789, "text": "If you mean an elliptic zone whose boundaries (min and max distance from the center of mass of the system) fluctuate, then yes. We'd only call the portion that is stable a 'goldilocks zone', though. If you mean a zone of physical parameters that allow habitability and actually orbits around and among the components, or (quasi-)periodically 'appears' from place to place, then that too is possible in principle, but the system probably (~certainly) wouldn't support a planetary orbit that follows such a zone. 'Habitable/goldilocks zone' implies stability over periods where life can spring up and evolve. From the only example we have, this means millions to billions of years. For your wording of \"zone always changing in position\", I'd therefore say: No. Goldilocks zones are stable (by definition).", "topk_rank": 12 }, { "id": "corpus-320401", "score": 0.7671693563461304, "text": "Sure there could be. The other poster attacks stable orbits. But there are [stable orbits](_URL_0_)! Some are odd! some are simple The simplest is a [circumbinary](_URL_1_) where it orbits both stars. There's about 20 known planets. Most are in the goldilocks zone. Some stars are also binary, but kinda far apart. Alpha Centuari is like this, where the stars are about as far as pluto from each other. There's stable orbits that exist where a planet could go around one or both!", "topk_rank": 13 }, { "id": "corpus-305935", "score": 0.7660413384437561, "text": "I think this is only one answer, but the habitable zone doesn't necessarily have to be based within that very specific area around a star. For example, there are geological processes that can create heat, or energy that life could develop with. Europa, a moon of Jupiter, has this going on as it is pulled against Jupiter and other moons. (I think, I'm not an expert I just watch a lot of shows about the Universe)", "topk_rank": 14 }, { "id": "corpus-274397", "score": 0.7597912549972534, "text": "No, there are no such stable orbits. (I notice lots of people don't seem to understand what \"stable\" means. A pencil balanced on its point is not stable, even though there is an equilibrium position there.) A couple of people have pointed out that there are some possible figure-8 orbits in which a group of objects of identical mass all move together in the same orbit. That's not what the OP is asking about. He/She wants a small planet in a figure-8 around two big stars. This is not stable.", "topk_rank": 15 }, { "id": "corpus-286450", "score": 0.7577112913131714, "text": "[Here](_URL_0_) is an article detailing the 10th, and most recent, discovery by the Kepler mission of a planet that orbits a binary star. Kepler 453b is actually in the habitable zone, too.", "topk_rank": 16 }, { "id": "corpus-317415", "score": 0.7571792006492615, "text": "Absolutely. Depending on the size and type of the star, the habitable zone can be quite large. If I remember correctly in our solar system Mars is just outside the habitable zone, and some have theorized that it used to actually be in the Sun's habitable zone. Since a stars intensity changes over time, so does the zone, and this would explain why, as some think, Mars *used to* have a large amount of liquid water. Mars is ~56 million kilometers away. [Here is a good image to demonstrate how it works](_URL_1_). This chart was made using real data. So you can see, Gliese 667Cc is just outside the habitable zone, while Gliese 581g and Gliese 581d are inside of the habitable zone. (note however that Gliese 667 and Gliese 581 are different stars) There is lots of information on how astronomers determine the habitable zone of a star on the wiki page for [circumstellar habitable zone](_URL_0_).", "topk_rank": 17 }, { "id": "corpus-313216", "score": 0.7567338347434998, "text": "No. It's an unstable equilibrium. Any perturbation, no matter how small, would cause the planet to accelerate away from the barycentre towards one or other star. Exactly what orbit it would then go into depends on the relative masses of the stars and the ellipticity of their orbits.", "topk_rank": 18 }, { "id": "corpus-1416056", "score": 0.7565787434577942, "text": "Specifically, I’m wondering about star systems with at least a few planets. Thanks!\n\nEdit: to clarify, I’m wondering how close they can get without disturbing each other", "topk_rank": 19 } ]

[ { "id": "corpus-325443", "score": 0.748132050037384, "text": "There's a terminology difference here that is probably confusing you. All organisms produce what are called [fatty acids](_URL_0_), some of which are essential fatty acids, ones that humans require to be healthy, but that we cannot make (enough of) ourselves. Fat is what animals make, and oils are what plants make, the main difference being their consistency, where fats are generally solid, and oils are more liquid. Both animal fats and plant oils are fatty acids. So to answer your questions: Yes fruits and vegetables make fatty acids, but they don't make fats. They make their fatty acids the same way we do, by using complex enzyme pathways to convert other similar compounds (triglycerides and phospholipids) into fatty acids. Yes, each fruit or vegetable as a (mostly) constant composition and amount of fatty acids." } ]

[ { "id": "corpus-154031", "score": 0.7101150155067444, "text": "Generally speaking, there are two types of fats: saturated and unsaturated. (Its actually much more complex than that but I'm keeping it ELI5) Saturated fats are the bad kinds you hear about that clog up your arteries and lead to a host of health problems - heart disease, hypertension, etc. Unsaturated fats, on the other hand, have been shown to have positive effects on your health. The help the body absorb vitamins, the can clean up your arteries and strengthen your heart. So, no. Not all fats are created equal. The fats found in things like avocado, salmon, nuts and other things are not only necessary but also beneficial to our health.", "topk_rank": 0 }, { "id": "corpus-643407", "score": 0.7079472541809082, "text": "I know avocados are more nutritious. But people say that olive oil is more than just not nutritious, that it actively clogs your arteries! So then why are things like avocados fine?\n\nIs all fat bad? Period? Some seem to think so. Perhaps I should avoid nuts, avocados, *anything* with a high fat content.", "topk_rank": 1 }, { "id": "corpus-93208", "score": 0.7060571312904358, "text": "It makes it much easier to isolate calorie dense portions of ingredients while removing all the fiber, water, or nutrient rich portions of ingredients, so processed food is much more likely to be empty calories. Take for example a simple process like extracting olive oil from olives. Olives have a huge amount of water (bulk that carries no calories) some protein, carbs, fiber and a relatively large amount of oil (fat). It even has a few trace minerals and some vitamins. Olive oil is 100% fat. 10g of olive oil has roughly the same amount of fat as 100g of olives. Almost every ingredient in a snack food is pure starch, sugar, or fat, with only a small amount of flavorings added. That means your eating food that has tons of calories per gram relative to something less processed even something you may consider more rich. For example, 100g of Cheetos has about 30% more calories than 100g of cheese (600 vs 450).", "topk_rank": 2 }, { "id": "corpus-2295855", "score": 0.7015645503997803, "text": "Dear /r/nutrition \nI decided to cook more healthy for variety, gains, and generaly my own good, and started to read about fat, proteins and carbohydrates (beginning with fats). I figured that unsaturated fatty acids seem to be more healthy than saturated ones and read that vegetable fats have them at mass. But at the same time I asked myself if it was possible to turn, say olive oil, into something you can brush on a bread and if it would have an impact on the \"healthiness\" it provides in a liquid state.\n\nsorry for any kind of bad english, it is not my first language, and thank you in advance.", "topk_rank": 3 }, { "id": "corpus-67458", "score": 0.7013463377952576, "text": "Putting fats on salads is good because it helps absorb the fat soluble vitamins in salad. Frying on the other hand isn't good because first off heating up fats to the point of frying isn't good for the fats and second off cooking food too much destroys food and produces carcinogens.", "topk_rank": 4 }, { "id": "corpus-1983907", "score": 0.6956338286399841, "text": "So lots of people watch out for high fat food and avoid but if you are getting your fat from natural sources like Greek yogurt, avocado, nuts, olive oil. is it actually that bad for you? \n\nI have a feeling that the perceived fear of fatty foods comes from the fact that lots of fatty food also contains lots of sugar and little nutrition. And therefore lots of people with high fat diets are undernourished or overweight because the fat is the 'wrong type' \n\nI eat quite a high fat diet (majority natural fat) and I eat very little processed foods and sugar, I'm 61.5kg and 5,7, do you think this will affect my health in the future and I should eat less fat?\n\nWhat's your view on this also- up for discussion!", "topk_rank": 5 }, { "id": "corpus-1478276", "score": 0.6867212057113647, "text": "I have noticed I get more definition with olive oil (mufas) as the primary source of energy. While when I eat butter or animal fat (saturated fats), I have some reactions, I get less energy and less definition, as well as some skin problems. Anyone can relate? I'm planning to eat just olive oil and completely exclude all the others (I may have some avocado and some coconut oil ocasionally). I will exclude also animal fat, I will just eat lean parts or fish. Please let me know what you think of this. If this is sustainable or not. Or if this can hurt my gains...", "topk_rank": 6 }, { "id": "corpus-143050", "score": 0.6847932934761047, "text": "Fruits are not 'fat reserves' for trees - they don't use them for energy. Fruits contain seeds which allow the tree to reproduce. In short, fruit gets dropped onto the ground, some animal comes and eats it and then wanders off. The animal then shits out the seeds (which are protected by a tough coat against the stomach of the animal) somewhere else and the seeds grow again. This allows the tree to spread its offspring far and wide.", "topk_rank": 7 }, { "id": "corpus-39807", "score": 0.6830140948295593, "text": "\"Fat\" is the name we give to a group of organic molecules that consist of long chains of carbon. Carbons like to make four bonds. In a saturated fat, every carbon is bonded to two other carbons (the ones in front and behind it in the chain) and two hydrogens. In an unsaturated fat, at least one of the carbon-carbon bonds in the chain is a double bond, so those carbons aren't bonded to two hydrogens. From a health perspective, it's commonly believed that consuming lots of saturated fats (found in meat, dairy, coconut oil, and palm oil) lead to a higher cardiovascular risk so you should try to use oils high in unsaturated fats, like olive, sunflower, canola, avocado, or peanut. Some newer research questions whether this is actually true or not.", "topk_rank": 8 }, { "id": "corpus-321275", "score": 0.681617259979248, "text": "Tropical oil crops (e.g palms) tend to contain reasonably high levels of saturated fat (compared to cold climate oil crops). However they are usually different molecules to those found in animal fat (there is some crossover though). There are over 50 molecules that are considered \"saturated fat\"(ty acids). A botanist or biologist will have to answer how and why tropical plants produce these molecules though.", "topk_rank": 9 }, { "id": "corpus-26463", "score": 0.6806180477142334, "text": "From what I understand of the ever-changing world of nutrition, no. Fat doesn't make you fat. Eating more calories than you burn in a day makes you fat. Where those calories comes from either doesn't matter, or only matters indirectly. But, fat is very dense in calories, and doesn't contain many (or any) other nutrients. This means that, often, diets that are high in fat are likely to also be high in calories. Thus, people who eat high fat diets often end up gaining weight because they are eating a lot of calories.", "topk_rank": 10 }, { "id": "corpus-324769", "score": 0.6778703331947327, "text": "Plants and animals make fats from glucose, with several intermediate steps. [here](_URL_1_), [here](_URL_2_), and [here](_URL_0_). (Warning, lots of chemistry).", "topk_rank": 11 }, { "id": "corpus-192063", "score": 0.6685906648635864, "text": "Take seed or fruit. Grind it. Collect oil. Vegetable oil Cooking oil is made from corn, sunflower, peanut, rapeseed (canola) Or alternatively rendered animal fat. Beef fat makes tallow, pig fat makes lard.", "topk_rank": 12 }, { "id": "corpus-325122", "score": 0.6681814193725586, "text": "That's not the way plants work. They make their own energy rather than taking it in from the environment in their \"diet\". Plants store their energy in the form of starch rather than fat. They use this starch to either grow or reproduce. Some plants store lots of starch in their roots (eg potatoes), but the concept of obesity just does not apply to plants in the same way as it does for animals", "topk_rank": 13 }, { "id": "corpus-98596", "score": 0.6673317551612854, "text": "Fat is like a carrier for lipophile aromas - like the essential oils in spices and herbs. That's why fat-reduced or fat-free products need to weigh this up with more sugar, salt and (artificial) flavouring - and still are less tasty than their fatty counterparts. Some scientists (Stewart et al.) assume that some people can also sense fat (like sweet, sour, bitter, salty and umami) We're also probably quite prone to liking fatty foods, as the high calorie density of fat once was the best thing to save oneself from starving. Garlic and onions contain lots of strong essential oils. When heated, two chemical processes , the Maillard reaction and caramelisation, happen, which intensify flavours, too. And once they're cooked, they become soft and mushy and thus make a great base for gravy and sauces, i.e. they make them a bit thicker and give them a nice, smooth texture.", "topk_rank": 14 }, { "id": "corpus-777583", "score": 0.6656674146652222, "text": "People always say fruit is healthy and different from sugar because despite the fructose, no one usually eats enough amount of fruit for it actually be an issue (even 6-8 servings a day seem fine).\n\nBut what about someone following an extreme diet like only/mostly fruit? Raw or frutarian vegans for example. I know they aren't exactly a large enough group for it to be worth having real scientific data, but do we have any reports/exams preferably from frutarians that indicate they have fatty liver/higher visceral fat because of the massive consumption of fructose? They don't look healthy, but are usually are extremely skinny despite consuming massive amount of calories and fructose.\n\nUsually people who drink and have high visceral fat, despite also being skinny, have a protruded midsection, but that isn't the case for frutarians.", "topk_rank": 15 }, { "id": "corpus-97613", "score": 0.6651237607002258, "text": "I can't remember a good enough explanation from the top of my head, so here you have a copy paste from one of the first results from Google: > For decades we’ve been warned that eating saturated fat, the type found in meat, cheese, and other dairy foods, can lead to heart disease. Instead, we've been told to choose healthy fatsfrom nuts, seeds, fish, and vegetable oils. > New research questions that belief. A recent review of 72 studies found no link between saturated fat and heart disease. The review also showed that monounsaturated fats like those in olive oil, nuts, and avocados don't protect against heart disease. Tl;Dr: there's no need to focus on saturated fats.", "topk_rank": 16 }, { "id": "corpus-315338", "score": 0.6650248765945435, "text": "Oil and fats, the purer the better. The traditional standard is 9 kcal/g of fat vs 4 per gram of protein or carbs and 7 for alcohol. Water and fiber mostly add weight without energy. So, drinking/eating olive oil, peanut oil, clarified butter, or anything similar is as much energy as you can get for a given mass. A slab of animal fat, while \"pure fat\" in one sense, actually has less than 9 calories per gram, as it has water and connective tissue. Butter also has some water and milk solids, so a gram of butter has slightly fewer calories than a gram of olive oil.", "topk_rank": 17 }, { "id": "corpus-58568", "score": 0.6649665236473083, "text": "Nope, natural products contain saturated fats, it has nothing to do with cooking. For example, olive oil contains about 13% saturated and 85% unsaturated fats. Butter, on the other hand, has a lot, and so does coconut oil.", "topk_rank": 18 }, { "id": "corpus-2272234", "score": 0.6631176471710205, "text": "When I first subbed here I wondered about the fuss with oils and why so many plant based humans advocate avoiding them. If you haven't checked the links in the sidebar, this page is pretty persuasive, especially its comparison of flax seeds and flax oil.\n\nFlax oil isn't something I had regular exposure to in the standard western diet. I'd only ever bought it to season my cast iron skillet. My biggest exposure was always to **olive oil**. From having it drizzled atop hummus or pizza, to using it in soups or as the _go-to_ starter every time people pick up a sauté pan, and of course being offered up on its own as a dip for bread at restaurants—it's quite ubiquitous and most folks don't even bat an eye. So I was curious to compare olive oil to the real deal in a similar table. Here's what I found:\n\n|| Green Olives (1 Tbsp) | Olive Oil (1 Tbsp) |\n| --- | --- | --- |\n| Calories | 15 | 119 |\n| Total Fat | 1.5g | 13.5g |\n| Saturated Fat | 0.2g | 1.9g |\n| Protein | 0.1g | 0g |\n| Carbohydrate | 0.4g | 0g |\n| Dietary Fiber | 0.3g | 0g |\n| Magnesium | 1.1mg | 0mg |\n| Potassium | 4.2mg | 0.1mg |\n| Vitamin A | 1% DV (39.4 IU) | 0% DV (0 IU) |\n| Vitamin E | 3% DV (0.4mg) | 13% DV (1.9mg) |\n| Vitamin K | 0% DV (0.1µg) | 7% DV (8.1µg) |\n| Calcium | 1% DV (5.2mg) | 0% DV (0.1mg) |\n| Sodium | 10% DV (156mg) | 0% DV (0.3mg) |\n\nSource: cronometer.com\n\nAnyway, I thought some folks might find that interesting.", "topk_rank": 19 } ]

[ { "id": "corpus-325444", "score": 0.7627571821212769, "text": "There is evidence that mineral content in water affects the flavor we perceive. Bottled water manufacturers add in the desired minerals rather than selling distilled water, which some say tastes \"flat.\" Here's a study about the chemometric analysis of bottled and tap waters that had been through blind taste tests. It was determined that many testers disliked the flavors of high concentrations of certain minerals and liked others. _URL_0_" } ]

[ { "id": "corpus-154252", "score": 0.7245371341705322, "text": "It doesn't (per se). Tasting actually uses more senses than just the taste buds. The smell of the room you're in, or even the psychological 'feel' of the room. The feel or texture of the vessel that you're drinking from, against your lips. The temperature of the liquid (hot coffee versus cold coffee for example). Even the sight of what you're drinking has a small effect on your enjoyment. In short, the chances are by the time you're drinking from a tap in the bathroom, you're using a different vessel than normal. You're probably not sitting comfortably, and most of all the bathroom is not considered the cleanest (or best smelling) of places, and therefore your senses are being manipulated in otherwise imperceptible ways.", "topk_rank": 0 }, { "id": "corpus-314921", "score": 0.724125325679779, "text": "There are several factors involved (and probably more): -The chemicals used in treating the water vary in different locations. If you've ever been hiking and treated water with iodine you may have noticed a weird taste. -The mineral and other material composition in the environment can be different. This would result in water in different areas having different compositions and different concentrations of substances. -The pollution in the local area. Sulfur compounds, carbon dioxide etc. can all alter the taste of water. -The microbes in the water may have an effect on taste (their reaction products) and the types of microbes can differ between environments", "topk_rank": 1 }, { "id": "corpus-189493", "score": 0.7226110100746155, "text": "Assuming that it's the same water and not from different sources which may contain different salts.. there are 2-3 major factors 1. The temperature itself. When water touches our taste buds, the temperature sets off slightly different responses to the brain. 2. The material. Chilled water may be stored in any container- plastic/glass/metal. Warm/Hot water is almost always used with metal and sometimes glass. So this is also a small factor. 3. Gases. The most important factor is gases. If a liquid surface is kept in contact with a gas, the gas WILL dissolve in the liquid slowly. The colder the temperature, the faster the gas will dissolve in liquid and vice versa. Boiled water is thus absolutely devoid of gases ( bud-bud-bud-bud bubbles, remember? ). That's why bottled water tastes sweet while boiled water tastes bitter. Oxygen.", "topk_rank": 2 }, { "id": "corpus-49536", "score": 0.7224942445755005, "text": "The water is \"going stale.\" The longer the water sits out, the more carbon dioxide gets mixed in with it, giving it a flat taste. There are also gasses that are dissolved into the water when you pour it, and they will off gas if the water sits. There is also the factor of your environment: Dust, air fresheners, whatever else floating around that will quite happily nestle into your drink.", "topk_rank": 3 }, { "id": "corpus-173045", "score": 0.7222439050674438, "text": "A couple of factors can affect the taste: Temperature: the water left out overnight will be at room temperature but fresh tap/filtered water is usually cooler since it comes from pipes underground. Much like how a warm soda/beer tastes different compared to a cold one, temperature can greatly affect the taste. Chlorine: tap water has added chlorine which is disolved in the water. The chlorine will slowly out-gas and leave the water over time. The water left overnight will have less chlorine taste. Other gases: other gases in the air will dissolve into the water and can affect the taste. For example, carbon dioxide disolved in water will make it more acidic. Living things: hopefully you haven't left the water out for too many days! Algae and bacteria can grow to large concentrations in the water if it's not replaced or cleaned. This is how water can \"go bad\" if not stored properly.", "topk_rank": 4 }, { "id": "corpus-167161", "score": 0.7214440107345581, "text": "Never tried it but I'm guessing it tastes a little sour. This could be due to CO2 reacting with the water to make carbonic acid. That would affect the taste.", "topk_rank": 5 }, { "id": "corpus-1333581", "score": 0.7207000255584717, "text": "Describe the taste of water in the most philosophical way possible", "topk_rank": 6 }, { "id": "corpus-192587", "score": 0.7200467586517334, "text": "Every water tastes different. But if you're referring to water and ice made from the same surce, you taste differently those 2 things because one is colder than the other, also during cristallizzation water traps gasses that would be expelled while in liquid form, which contributes to taste", "topk_rank": 7 }, { "id": "corpus-38524", "score": 0.7200226187705994, "text": "The taste you detect with your tongue is relative. Imagine you drink something with a lot of sugar in it and then eat some fruit. The fruit will not taste as sweet as if you had drunk water or tea before eating it. The taste of water depends on what you saliva tastes like. Saliva contains, among others things different kinds of salt. If you do not drink water for an extended period of time, your saliva will have a stronger taste because there is more salt etc. in it. When you then drink water, you will water down your saliva and this might give you the sensation of tasting sweetness.", "topk_rank": 8 }, { "id": "corpus-178488", "score": 0.7184950113296509, "text": "Cold suppresses the sensitivity of tastebuds. Try drinking a soda on ice and then letting it come up to room temperature. It would taste much sweeter and more acidic. The same applies to water. The less we taste, the more refreshing it feels. Also, the data aren’t exactly clear but it’s possible that a preference for cold water may be an acquired taste.", "topk_rank": 9 }, { "id": "corpus-181930", "score": 0.7183359861373901, "text": "There are a few reasons it might taste different. First is temperature. Water coming out of the tap will usually be a little cool. And cold can help mask the metallic flavor of the minerals in your tap water. Leaving a glass of water out lets the water warm up and changes its flavor. Next is aeration. Water coming out of your tap can have a lot of air dissolved in it from being under pressure. This is why there are some bubbles in your water. Those gases can have an effect on the taste. Letting the glass sit for a while gives the gases a chance to escape and changes the flavor. Finally, if 'for a while' means a day, the taste change is probably due to microorganisms that are starting to grow in the water.", "topk_rank": 10 }, { "id": "corpus-52452", "score": 0.7181701064109802, "text": "Two simple reasons: 1- the water in your car had time to soak up flavors from the container which most likely don't taste good. 2 - (more likely reason) Cold tends to dull your sense of taste and so your don't pick up the flavors as easily. Also, the water is freshly poured and so is aerated, so isn't totally flat like the hot water that sat in your car.", "topk_rank": 11 }, { "id": "corpus-85214", "score": 0.7177566289901733, "text": "Your taste buds are better at tasting at higher temperatures. At higher temperatures, you can more easily detect impurities in the water, and therefore will think it tastes worse than if it were cold.", "topk_rank": 12 }, { "id": "corpus-100872", "score": 0.7176076173782349, "text": "The taste of tap water is determined by your local geographical area. For example if you go to Las Vegas they have terrible tap water whereas where I live we have essentially tasteless tap water. The minerals in the rocks of the resivoir and rivers make that difference Bottled water is filtered water so it filters those minerals out. Also when you look at a bottle of filtered water and it says \"natural spring water\" that is a lie. I worked for Pepsi a few years ago and we just filtered tap water.", "topk_rank": 13 }, { "id": "corpus-2762910", "score": 0.7171258926391602, "text": "Today I drank some water that was carbonated but which had gone flat. I noticed that it still had the slightly bitter taste that carbonated water usually has. I had always assumed that it was the bubbles changing the flavor somehow, but this water today didn't have any bubbles left.", "topk_rank": 14 }, { "id": "corpus-323091", "score": 0.7171165943145752, "text": "taste didnt evolve to make us enjoy food but to help us distinguish what we are eating. If water had a taste you would be tasting it constantly, as your mouth is almost always wet. Water which is impure does have a taste which registers as either rancid, salty, bitter and so on.", "topk_rank": 15 }, { "id": "corpus-323872", "score": 0.7159352898597717, "text": "Do you have city water or a well? City water can contain things like chlorine that evaporates quickly (taste change in prob less than a day) or other longer lasting chemicals that may bind with things in the air to produce \"off tastes\" and other weird things. Really clean water will still taste slightly different but it is usually other things in the water reacting and making different tastes.", "topk_rank": 16 }, { "id": "corpus-141038", "score": 0.7156540155410767, "text": "Nothing, it does not trigger any taste buds (if it did, the water in your mouth would trigger them, so you'd taste it all the time).", "topk_rank": 17 }, { "id": "corpus-1495783", "score": 0.7155418992042542, "text": "Idk what it is but I just don’t like the taste of water (even tho it doesn’t even have a taste). Every time I go drink water, even if its just like a dl or two I gag and feel like throwing up. I only drink water when I’m really thirst and don’t have anything else at home. I usually just drink flavoured water or a soda or something else... I’ve been recently drinking about a gallon of water a day in hopes to get rid of my acne but I just find it really difficult. ):\n\nExcuse me if I made any mistakes while writing this, English isn’t my first language", "topk_rank": 18 }, { "id": "corpus-84011", "score": 0.7150513529777527, "text": "When water is splashed around, extra oxygen gets dissolved in it which makes it taste \"sweeter\". When water sits still for a while the dissolved oxygen floats to the surface and gets out, giving the water a flat taste.", "topk_rank": 19 } ]

[ { "id": "corpus-325445", "score": 0.8682892322540283, "text": "Yes, microwave ovens distort chemical structures in foods. The heat from the microwave energy causes proteins to uncoil and change their shape, causing their texture and flavor to change. This phenomenon is known as \"cooking\", and is the same whether you microwave, boil, bake, or fry food." } ]

[ { "id": "corpus-257522", "score": 0.813115656375885, "text": "> It changes the structure of water No. Not at all. If it was changed, it would no longer be water. Microwaves have *no* harmful effects on food. In fact, in some cases, they preserve nutrients better than oven-cooking.", "topk_rank": 0 }, { "id": "corpus-281814", "score": 0.8009024262428284, "text": "Very crazy, as Microwave radiation is not ionizing radiation, and can't cause cancer. and the only way it \"changes\" the chemical structure of food is by cooking it. Which happens no matter how you heat it.", "topk_rank": 1 }, { "id": "corpus-48833", "score": 0.7819328904151917, "text": "The microwave itself does nothing besides heating the water in food. There are zero residual effects. Your friend is a complete and utter moron. That said, there are a few very minor issues. Unlike ovens, microwaves allow you to heat food in plastic containers, some of which are not microwave-safe, and could leech chemicals into your food. Also, if you reheat improperly refrigerated foods, a microwave could be less effective at killing unwanted microbes.", "topk_rank": 2 }, { "id": "corpus-274494", "score": 0.7809358239173889, "text": "I am not a nutritionist, so I can't really speak about the health aspect of it. But in all of the articles you linked, the physics is wrong or worded in a deliberately misleading way. I'll make a few points here: * Yes, microwaves can leach harmful chemicals out of containers, but so can every other method of heating. This is not an issue specifically with microwaves. * The sun does not use 'DC' radiation. The fact that microwave ovens have a narrow spectral line does not mean its somehow bad for you. * One of those webpages somehow claims that 400 milligauss of 'radiation' is linked to leukemia, which is absurd. A gauss is a measure of magnetic field, and 400 milligauss is tiny. For comparison, Earth's magnetic field is around 600 milligauss. I can't tell you if microwaving food is good or bad. But I can tell you that those websites horribly are wrong.", "topk_rank": 3 }, { "id": "corpus-319272", "score": 0.7726362943649292, "text": "A microwave oven is essentially a localised radio transmitter. They emit electromagnetic radiation, in this case the eponymous microwaves, which are absorbed by water molecules which in turn give them energy in the form of heat. Bear in mind that the radio waves around you are a bit different; They are in no way a danger to you or others. Now, when you put something metal into a microwave, it acts as a radio antenna. It also absorbs the microwaves, but instead of converting them into heat, it converts them into electrical charge. This will then cause the object to heat up, but also, with aluminum foil and other pointy objects, electrical arcing can occur. This in turn produces ozone and nitrogen oxides which are unhealthy and can, in the case of thin aluminum foil, cause it to catch on fire.", "topk_rank": 4 }, { "id": "corpus-112103", "score": 0.7678802013397217, "text": "There's nothing bad about cooking with a microwave, it's the food we choose (TV dinners and ready-made meals). Many of these meals have a lot of salt (sodium), fat and/or sugar in them, too much to eat regularly. Take this tasty [chicken korma](_URL_0_) from Tesco for example. Each serving contains nearly half of the calories, salt and fat you are recommended to eat daily, all in one meal! For some further reading about microwave safety take a look at [this page](_URL_1_) and [this page](_URL_2_).", "topk_rank": 5 }, { "id": "corpus-307332", "score": 0.763046145439148, "text": "Microwave radiation is non-ionizing and not harmful to humans beyond it's ability to heat you up. In this way, a microwave oven is only as dangerous as a toaster or regular oven. Microwave radiation has a thousand to a million times less energy per photon than visible light. In other words, the light from a candle will heat you up quicker than a microwave beam containing the same number of photons. You are surrounded by microwave radiation and it is not harming you. Even if you lived in the jungle away from all technology, you would still be bombarded by the cosmic microwave background (CMB) radiation that bathes the entire universe. Now, if your microwave oven is falling apart badly enough that there are loose or faulty wires or circuitry, there could be a danger of electrical shock just like with any electrical appliance that is falling apart.", "topk_rank": 6 }, { "id": "corpus-306801", "score": 0.7607941627502441, "text": "It's the temperature that kills the bacteria, not specifically the microwaves, so the answer is: depends at which temperature and for how long you keep the food at that temperature. Given that cooking (or re-heating) time is much less in a microwave oven, it is 'safer' to just use a stove. What I always wondered though is: spoiled food makes you sick because of the bacteria or because of chemical byproducts of said bacteria? But this should probably be another ask science.", "topk_rank": 7 }, { "id": "corpus-77136", "score": 0.7596955895423889, "text": "They're bad for you in the same way that sticking your hand in boiling water is bad for you. Microwaves don't have any lasting effects, they just heat things up - there's no residual radiation or anything like that. If you're directly exposed to them, you'd get burned. It's generally a good idea to let things in the microwave sit for a minute. It lets any steam clear itself from the microwave, it also allows the heat to fully spread through the thing you're heating.", "topk_rank": 8 }, { "id": "corpus-325003", "score": 0.7589853405952454, "text": "Microwave ovens heat food by jiggling molecular bonds in water and fats. This process tends not to get foods to the elevated temperatures needed for the [Maillard reaction](_URL_0_) to take place and browning to occur.", "topk_rank": 9 }, { "id": "corpus-2312513", "score": 0.7544367909431458, "text": "Are they even unhealthy to use? Ive grown up around people and friends who swear microwaves are bad for you or use some type of harmful radiation. Etc. etc... So I've always been a little paranoid but also skeptical about these claims.\n\nIve been heating my oatmeal up in it ever morning for a few months because its so easy to do in the morning. Instant organic oats with water, milk and berries... 45 secs in and BAM! Am I going to die or a grow a tentacle or something?\n\nMy dad has been cooking grilled chicken strips in the microwave for about 15 years and he is still here lol.\n\nbut in all seriousness. Is there anything bad (besides the quality of the food you choose to microwave)", "topk_rank": 10 }, { "id": "corpus-286315", "score": 0.7534170746803284, "text": "Heat will thermally degrade some polymers into their constituent monomers and many of them are *potential* carcinogens. You are more likely to melt the polymer than break it down to monomers at microwave heat, however, so it isn't likely there is substantial contamination. Some contain plasticizers like BPA which may affect hormone signaling. If you want to know more about your specific polymer [this long PDF](_URL_0_) will educate you.", "topk_rank": 11 }, { "id": "corpus-186284", "score": 0.7530721426010132, "text": "No, and you are overestimating the benefit. The microwave ovens we have today stimulate one particular kind of molecule, the water molecule, which is often found in food. To use another band, you'd need to find another molecule that's as common in food as water, and stimulate that. The effect would still depend on where in the food the molecule was, with the ones on the outside being stimulated more than ones on the inside.", "topk_rank": 12 }, { "id": "corpus-319746", "score": 0.7516129612922668, "text": "[This thread](_URL_3_) contains quite a lengthy discussion on microwaves' effects on food.", "topk_rank": 13 }, { "id": "corpus-293787", "score": 0.7449039816856384, "text": "Microwaves in a microwave oven have a frequency somewhere in the range of frequencies that are good for exciting rotational (not vibrational) modes in **polar** molecules. Water is one example of a polar molecule. As for the second question, any ionizing radiation can break molecular bonds and produce free radicals in tissue. So by definition, any ionizing radiation can cause damage to your body.", "topk_rank": 14 }, { "id": "corpus-323605", "score": 0.7443897128105164, "text": "> The radiation produced by a microwave oven is non-ionizing. It therefore does not have the cancer risks associated with ionizing radiation such as X-rays and high-energy particles. Long-term rodent studies to assess cancer risk have so far failed to identify any carcinogenicity from 2.45 GHz microwave radiation even with chronic exposure levels, i.e., large fraction of one's life span, far larger than humans are likely to encounter from any leaking ovens. However, with the oven door open, the radiation may cause damage by heating; as with any cooking device. Every microwave oven sold has a protective interlock so that it cannot be run when the door is open or improperly latched. > There are, however, a few cases where people have been exposed to direct microwave exposure from malfunctioning microwave ovens, or where infants have been placed inside them, resulting in [microwave burns](_URL_0_). Buy 'em a new microwave oven - they are pretty cheap these days.", "topk_rank": 15 }, { "id": "corpus-274376", "score": 0.7443073391914368, "text": "They haven't published the research yet. And a single paper at this point, doesn't really mean much more than there might be something worth looking into. If you search for stuff on microwaves in general here, you'll find some threads where I've explained that there's little in the way of known mechanisms by which they could cause any significant damage to any living things (plant or human). Because the effects of microwaves on molecules aren't really very different from heating them. (as opposed to UV and gamma radiation, which is _very_ different) Without a mechanism or solid evidence that it actually _does_ harm, there's nothing to discuss, really.", "topk_rank": 16 }, { "id": "corpus-297649", "score": 0.7442708015441895, "text": "Highly unlikely. Microwaves can only generate increases in rotational modes, which relax by giving off heat. You have to get up into the UV before the photons have enough energy to generate electronic transitions that can lead to molecular rearrangements, which is what could potentially cause cancer. Microwaves can't do anything but generate heat.", "topk_rank": 17 }, { "id": "corpus-295251", "score": 0.7417725324630737, "text": "Microwaves don't \"irradiate\" your food. It expose it to micro waves that react with the water molecule to make them \"vibrate\" which make it heat. I don't think eating the microwaved food have an impact on the body.", "topk_rank": 18 }, { "id": "corpus-124250", "score": 0.7395771741867065, "text": "Microwaves just make water molecules wiggle around and heat up. Although the mechanism is different, the heat generated is no different than that of a conventional oven. Microwaves aren't ionizing rays like gamma radiation or ultra violet light, which directly cause DNA and other molecules to break down and mutate into dead bacteria. So if you heat things up enough, sure, bacteria will die, but in the same way that if you put the bacteria into a coal-fueled furnace.", "topk_rank": 19 } ]

[ { "id": "corpus-325446", "score": 0.7720116972923279, "text": "They can actually, but they are unstable and oxidize/burn/explode spontaneously in air to form silicon oxides (sand/glass/quartz, etc). The reason for this instability was already given by /u/Brainmold: the Si-H bond is much longer than the C-H bond due to the larger radius of the silicon atom, making the bond much weaker. Compounds consisting only of tetrahedral silicon and hydrogen are called [silanes](_URL_0_) in analogy to the alkanes (tetrahedral carbon and hydrogen). Silanes can form straight chains, branched chains, and rings just like alkanes, but there are much fewer silanes known because the larger silanes become increasingly unstable." } ]

[ { "id": "corpus-304842", "score": 0.7319350242614746, "text": "Other elements in the same group as carbon do share some of its properties and bonding characteristics, so it’s possible! Silicon is a noted possibility in some circles. As the elements get progressively heavier down the group, they become more unstable and difficult to incorporate into a life-form.", "topk_rank": 0 }, { "id": "corpus-321382", "score": 0.7308893203735352, "text": "The Si-O pi bond is considerably weaker than the C-O pi bond. There isn't as good of overlap between the Si 3p and O 2p orbitals as there is between the 2p orbitals of C and O. It's more energetically favorable for oxygen to form a double bond to carbon, whereas with silicon, it's more favorable to form a second single bond to another silicon atom.", "topk_rank": 1 }, { "id": "corpus-81636", "score": 0.7263807654380798, "text": "One of the aspects of carbon that make it so suited to life is the fact that it has 4 valence electrons that allow it to readily combine with lots of other different kinds of atoms in a vareity of ways. It is so versatile it has its own branch of chemistry known as *organic chemistry.* Based on how the periodic table is organized, all atoms in a given column have the same number of valence electrons. Silicon, being in the same column as carbon, but one row down, has 4 valence electrons. So a superficial comparison suggest that silicon would be a candidate. But there are other things to consider. Carbon is lighter and relatively abundmant, and silicon does make all of the kinds of molecular combinations carbon does. Also, even if they have the same number of valence electrons, bonds formed with carbon atoms are stronger than those formed with silicon atoms. There is no telling what silicon based life would be like, and it is purely (at this point) an element of science fiction.", "topk_rank": 2 }, { "id": "corpus-321492", "score": 0.7256094813346863, "text": "Basically it's because the silicon-oxygen bond is extremely stable, compared to pretty much everything except for silicon-fluorine. /u/coniform answers it more thoroughly: _URL_0_", "topk_rank": 3 }, { "id": "corpus-313629", "score": 0.7229461073875427, "text": "If it's chemical structure allows it to make bonds in such a way that you can make out a discreet unit that repeats indefinitely. Organic molecules are good at forming polymers because they involve chains of carbon molecules that have the capacity to make four covalent bonds. YOU can string them together indefinitely.", "topk_rank": 4 }, { "id": "corpus-309460", "score": 0.7223771214485168, "text": "It's highly doubtful. Silicon is under carbon in the periodic table, but their similarities aren't that great. Probably the most important property of carbon is its ability to form strong single bonds with itself. Silicon doesn't do that, and the bonds that it forms with either itself or hydrogen are very susceptible to hydrolysis by water, hydrogen fluoride, and ammonia, which are the three commonly proposed solvents for life-like things. Also, in your thinking, I believe you are mistaking siliconE for silicon. The two are very different. Silicones are chains of repeating [-Si-O-Si-O-] units that are coated in organic chains to keep them separate. Silicon is a rock. Silicon dioxide would only exist in the gaseous phase at temperatures that would utterly destroy any Si-Si or Si-H bonds that might form.", "topk_rank": 5 }, { "id": "corpus-30100", "score": 0.7220955491065979, "text": "All of our biological molecules (Proteins, DNA, fatty acids, carbohydrates, etc) are Carbon-based. This means Carbon forms the main component and \"backbone\" of all of these molecules. Without Carbon, these biological molecules (and hence known life-forms as we understand them) cannot exist. Because of its chemical properties, Carbon can form bonds to FOUR other atoms, which is a high number (e.g. Oxygen can only form two, and Hydrogen one, under normal circumstances). This ability to bind 4 other atoms makes Carbon particularly suitable in this \"molecule backbone\" role: it can form long chains of itself, or various shapes such as rings, while still providing bonds to all the other \"building blocks\" that make up the active part of the molecule.", "topk_rank": 6 }, { "id": "corpus-319594", "score": 0.7214899063110352, "text": "Silanes are the direct analogue of alkanes, with silicon replacing carbon. They are less stable than alkanes though, especially as the chain gets longer. Silicon can form many polymers, but the most common ones have oxygen in the chain - those are known as silicones. Polysilanes are like the silanes except longer and with organic side groups. And those have a tin analogue, the polystannanes.", "topk_rank": 7 }, { "id": "corpus-276974", "score": 0.7210650444030762, "text": "Silicon is able to form four covalent bonds much like carbon. Doping involves adding either boron (P-type) or phosphorus (N-type). When added, boron can replace a silicon in the crystal. However, boron can only form 3 covalent bonds, leaving silicon with a free bond. Phosphorus can form 5 covalent bonds, but silicon can only form four bonds. In this scenario, the phosphorus has a free electron that it is able to delocalised.", "topk_rank": 8 }, { "id": "corpus-325329", "score": 0.7188929915428162, "text": "Just to clarify, *silicone* is different from **silicon**. CPUs are mostly made of silicon, they don't have silicone in them. One key advantage rests on the fact that Si-Si bonds are weaker. It means that the Si lattice can more easily accommodate foreign dopant atoms compared to its carbon analogue. As a result, it is possible to vary the electrical properties of Si with relative ease. Not so with diamond, say.", "topk_rank": 9 }, { "id": "corpus-70510", "score": 0.7174121141433716, "text": "The closer the electrons can get to a nucleus, the more tightly held they are (\"shielding effect\"). That means carbon's valence electrons are held more tightly than silicon's, and so on. This is because the fact that there are all these electrons below them causes their attraction to the nucleus be slightly canceled out by the fact that electrons repel electrons (the same force holding the protons together doesn't really work at the distances electrons are at). Therefore they are easier to \"rip off\" than if they were the closest ones. This is why methane is relatively inert (unless oxygen and a match), but [stannane](_URL_0_) (the tin equivalent of methane) is one giant mess. It's the other electrons pushing them away that causes stannane's valence electrons to not be able to hold onto the hydrogen atoms.", "topk_rank": 10 }, { "id": "corpus-311942", "score": 0.7172375321388245, "text": "There are compounds called [Allenes](_URL_1_) which have multiple double bonds in a row. So if polyacetylene is -C=C-C=C-C=C- (alternating single/double) then allenes are like H2C=C=CH2 (propadiene). I don't know how long they can be. There are also alternating single/triple bonded structures (-C#C-C#C-) known as [polyynes](_URL_4_). From that page: > The longest reported (synthetic) polyyne to-date contains 22 acetylenic units and is end-capped with triisopropylsilyl groups Again, I'm not sure why you don't get polymers of these - difficult to synthesise, perhaps. edit: [Here is a short article with a good image](_URL_0_) - showing a polyyne in the role of a [rotaxane](_URL_3_). edit2: The page on [Linear acetylenic carbon](_URL_2_) claims a maximum chain length of 300 carbons for an allene-like structure.", "topk_rank": 11 }, { "id": "corpus-266503", "score": 0.7153750061988831, "text": "They do form covalent bonds, but the conductivity comes from the band structures of the solids. The band gap of diamond is too large to allow for conductivity.", "topk_rank": 12 }, { "id": "corpus-322856", "score": 0.713569700717926, "text": "It's more that carbon is such a flexible atom when it comes to making molecules. You can do so many things with it because it can take on so many different valencies, make so many different kinds of bonds, and arrange itself into so many different molecules. Metals typically do not have the same level of flexibility as carbon.", "topk_rank": 13 }, { "id": "corpus-318841", "score": 0.7126772999763489, "text": "There has been some theories of silicon based life. It is similar to carbon, but the bonds aren't quite as strong. Obviously there's no proof of it, but from what I've read it's the most probable element behind carbon.", "topk_rank": 14 }, { "id": "corpus-316309", "score": 0.7102181911468506, "text": "tl;dr - It's highly energetically unfavorable. _URL_0_ Most known quadruple bonds possess one sigma bond, two pi bonds, and one [delta bond](_URL_1_). Delta bonds require the use of d orbitals. However, in carbon, the lowest available d orbital (3d) is not filled, and is at a much higher energy level than the highest orbital normally filled in carbon (2p). It is highly energetically unfavorable to have an electron in the 3d orbital, and so any C-C bond involving d orbitals is super-duper unstable.", "topk_rank": 15 }, { "id": "corpus-264275", "score": 0.709501326084137, "text": "That extra pi bond between the two oxygen atoms makes a **big** difference in stability. To make a chain of oxygen atoms you'd need a chain of O-O single bonds. Molecules with O-O single bonds can be prepared, they're \"peroxides\" and are very unstable (even hydrogen peroxide needs to be kept away from heat and light to keep it from breaking down). I expect a chain of oxygen atoms would simply be too unstable to be found in nature. For example: [trioxidane](_URL_0_) (hydrogen peroxide with an extra O) can be detected but it breaks down very quickly to more stable products. The difference between oxygen and carbon is the electronegativity of the oxygen atom. These oxygen's simply prefer to take electrons from species OTHER than another oxygen if they can. Fluorine is a more extreme example, as F2 gas will react with nearly anything.", "topk_rank": 16 }, { "id": "corpus-302", "score": 0.7092559337615967, "text": "Silicon is the other element other than carbon that would form long complicated bonds that life could evolve around. Though it is almost certain that another life form would be carbon based this gives a way of creating a \"totally new life form\".", "topk_rank": 17 }, { "id": "corpus-306645", "score": 0.7091584205627441, "text": "If water is available, there's not much reason to believe they wouldn't use it - carbon and silicon have near enough identical chemistry with water. Otherwise, your options are quite limited. If it's too hot for water, you're really too hot for most simple liquids - you also don't really expect silicon at high temperatures, as its bonds are weaker than those of carbon, so it would run the risk of breaking apart. If it's too cold for water, you could possibly use some of the simple hydrocarbons (methane, ethane) if they were around in suitable quantities.", "topk_rank": 18 }, { "id": "corpus-304678", "score": 0.7089829444885254, "text": "In chemistry an element can often be replaced with an element that is below it in the table of elements and it will behave similarily. The lower you go to heavier elements, the more energy is required to start a chemical reation and the more energy is released in a chemical reaction. Silicon is below carbon. Slicon is similar to Carbon in the molecules you can buld with it structurally, but its heavier and if you replace carbon with Silicon the chemical reactions are slower because they need more energy to get a change. Earths crust is 60% SIliconoxydes and 1% Carbonoxydes. Speed/efficiency is worth using the rarer stuff.", "topk_rank": 19 } ]

[ { "id": "corpus-325447", "score": 0.7475635409355164, "text": "That's your phone call. Your speaker chords are made of metal and they're acting as a radio antenna and picking up your call. But since your call is digital, and encrypted, and transmitted at a frequency outside your hearing range, the ringing just sounds like noise on the speaker. We use this phenomenon all the time. It's how radios work. ;P" } ]

[ { "id": "corpus-172759", "score": 0.7101645469665527, "text": "Two reasons: The telephone line is optimized for human voices, which have a very limited range. most music falls outside of this range, so a lot of the higher and lower frequencies get distorted or cut off. In some cases it could also just be that the audio file itself hasn't been changed in years or is small to begin with, and lacking in quality there as well.", "topk_rank": 0 }, { "id": "corpus-268858", "score": 0.7101637125015259, "text": "You are modifying the local parasitic capacitances that form between the antenna/tuning circuitry and ground. This can have the effect of either detuning the receiver, and/or introducing/enhancing lossy signal paths (resulting in a decrease in signal).", "topk_rank": 1 }, { "id": "corpus-243958", "score": 0.7097816467285156, "text": "A few more interesting facts: 1) The earliest morse code transmitters used to establish the first intercontinental radio links were nothing more than rotating disc dragging a series of conducting plates across a metallic lead and generating a shower of sparks (google SPARK GAP TRANSMITTER). As discussed elsewhere here, the arcs have a wide noise spectrum. When fed to a tuned antenna system, the electrical noise centered around a single wavelength was actually transmitted thousands of miles. 2) The com and nav radios used in aircraft use AM (amplitude modulation) to convey the voice signal. Electrical noise is demodulated as interfering modulation and severely interferes with the intended signal. Land mobile radios and your FM stereo system on the other hand use FM (frequency modulation) to convey the intelligence. The receiver design ignores amplitude variations and is largely immune to this type of static interference.", "topk_rank": 2 }, { "id": "corpus-407", "score": 0.7097519040107727, "text": "Just like radio. There is a transmitter and a reciever. In the case of Bluetooth, the transmitter is something like a smartphone. Then the speaker recieves the signal, and amplifies it.", "topk_rank": 3 }, { "id": "corpus-43307", "score": 0.7096866965293884, "text": "Your screen is buzzing with an invisible harmless electrical charge. When your finger comes close enough to touch it, it begins to suck up all that electrical charge because your finger acts as a 'capacitor' And the phone knows where your finger is cause it measures the strength of the field and where it is weak is where your finger is, because your finger is drawing all the electricity away at that point.", "topk_rank": 4 }, { "id": "corpus-248367", "score": 0.7096675634384155, "text": "Probably for less than a second (assuming the nearby lightning bolt didn't fry your phone or the cell tower or whatever). The radio protocols between the phone and the cell tower are designed to be able to recover from brief interference like that, and the internet protocols between your phone's web browser and the remote web site are designed to recover from the occasional lost packet and silently retransmit it. But the RF noise from the lightning bolt would disrupt the transmission briefly, yes. If you were on a voice call you might hear a brief dropout or garble, since voice usually trades off occasional errors for lower latency.", "topk_rank": 5 }, { "id": "corpus-111707", "score": 0.7094566822052002, "text": "As a pilot, it is not really to do with it interfering with instruments. It's just polite for people to use airplane mode, as at 36,000 feet, if you have loads of phones searching for a phone signal (as phones don't have a signal they start broadcasting a stronger signal, in a bid to find service), that creates a lot of noise. You can hear this static in your headphones, and it's pretty annoying. **Edit:** This is why some companies have put wifi and cell towers on planes, so the phones don't look for a signal at max strength. **Edit 2:** This is a very simple form of it, but for more detail on how phone radios work read this comment: _URL_0_ **EDIT 3**: This answer explains why it was necessary in the past _URL_1_", "topk_rank": 6 }, { "id": "corpus-432925", "score": 0.709201991558075, "text": "My sound cuts between coming out of the main speakers and the ear piece speaker randomly and from reading online it isn't just a faulty model, it's super common and when people get their phones replaced it keeps happening. Does anyone here know anything I can do?", "topk_rank": 7 }, { "id": "corpus-303697", "score": 0.709098756313324, "text": "It’s not likely that your phone would cause a problem. However, If you have a 200 people, all with cell phones that are transmitting bits RF radiation across various frequencies, there is a chance of some interference. It’s a small chance, but the consequences are enormous, so why not just got to airplane mode and eliminate the risk?", "topk_rank": 8 }, { "id": "corpus-300526", "score": 0.7090662717819214, "text": "Just to add something here that may be a mis-understanding, waves are not \"interfered with\" in some permanent way but rather at a specific spot in space you can have destructive interference. This does not mean the propagating wave is actually changed. If two waves destructively interfere at a spot that doesn't mean that the wave has been robbed of energy or \"messed up\" or the likes. At any location other than the location of the destructive interference, you have no clue that this interference is occuring over yonder. The wave propagates to you the same whether or not there are spot where it adds up with another wave constructively or destructively to change its amplitude at the spot. That being said, radio signals are distorted in all manners of ways while being transmitted which is why your cell phone has a signal strength indicator.", "topk_rank": 9 }, { "id": "corpus-314654", "score": 0.7090482711791992, "text": "The amount of power consumed by the speakers is obviously higher if the volume is turned up. But the amount of power consumed to transmit data from the phone to the speaker is the same regardless of the volume settings.", "topk_rank": 10 }, { "id": "corpus-9886", "score": 0.708745002746582, "text": "Your cellphone also loses signal if it goes into a tunnel. Your cellphone is fm radio, pretty, nice, but weak signal. Plans are on lower frequencies, AM radio. Shittier quality but a much stronger signal strength.", "topk_rank": 11 }, { "id": "corpus-175251", "score": 0.708560585975647, "text": "Phone systems are optimised for voice communication and clip frequencies that are higher or lower than usually occur in the human voice. Music often has harmonic frequencies that get lost. Add to this that hold music is often over-compressed to save memory space in the system.", "topk_rank": 12 }, { "id": "corpus-25778", "score": 0.7084739804267883, "text": "Oh I see the confusion. The sound isn't created by the computer. The earbuds convert electricity to music. The computer outputs electricity that looks like the sound. The earbuds have a \"voice coil\" which is a coil of wire which floats inside a magnet. It looks like [this:](_URL_0_). The coil will move in and out because electricity flowing through a coil creates magnetism which will fight with the regular magnet that the coil is floating around. The coil has a little speaker cone at the end of it which pushes the air to make the sound. TLDR: there's electricity in the wires, not sound.", "topk_rank": 13 }, { "id": "corpus-42213", "score": 0.7084481120109558, "text": "Data streams for phone calls are actually extremely compressed -- sometimes lower than 20kbps. You don't notice it as much when someone is talking because the system is designed to carry voice. Music, on the other hand, it is not designed for.", "topk_rank": 14 }, { "id": "corpus-188900", "score": 0.7084423303604126, "text": "It's due to \"multipath interference\". On its way to your radio antenna, a radio wave can also bounce off various things (buildings, trees, cars, etc.). The reflected versions of these multiple paths take a little longer to get to your antenna than the most direct one, so they are out of phase with the original. (The peaks and troughs don't line up.) This can cause destructive interference to occur, degrading the radio signal. (It can also result in *constructive* interference.) If you move your car just a little bit, you change which reflections are hitting your antenna, and the destructive interference can be increased or reduced.", "topk_rank": 15 }, { "id": "corpus-172949", "score": 0.7081766128540039, "text": "Lightning is a high-voltage electrical discharge, and your wireless earphones are basically miniaturized radio receivers; the lighting is far more powerful than the radio transmitter in your device, so the electromagnetic interference the lightning causes briefly overwhelms the radio signal from the transmitter.", "topk_rank": 16 }, { "id": "corpus-433205", "score": 0.7081651091575623, "text": "I think it's great that my iPhone notifies me that I'm getting a text message while I'm in a call, but several things about the actual execution are supremely frustrating. At first I thought that the other party could hear it, too, since it was so loud, but that was debunked relatively quickly. Regardless, it's *loud*! The noise isn't so bad if I'm talking on speakerphone, but if I've got the phone held up to my ear, not only is it painfully loud but it temporarily blocks out what the other person is saying. Is there any way I can change the sound that plays? At this point I might even prefer turning it off altogether.", "topk_rank": 17 }, { "id": "corpus-431688", "score": 0.7080607414245605, "text": "When I turned on my car today (2018 Subaru Crosstrek), the audio from my iPhone 8+ was coming through the bluetooth with a strange crackle/distorted sound. I went from my audio book to soundcloud to spotify, same results. I thought it was my car, but when I plugged in my headphone I was getting a strange repetitive clicking noise and some odd interference. Funny enough, it sounds fine to me when played through the speaker. Anyone know of any solutions?", "topk_rank": 18 }, { "id": "corpus-348018", "score": 0.7079944610595703, "text": "I have a telephone set from Microtel and it has been going crazy since the last month. It plays its ringtone in very short pulses (beeps.) I don't know the exact cause of the problem but I think it is because of EMI. My cable tv line and phone line run parallel from the pole to my room. Also I have an ADSL connection but I have installed a filter/splitter.\n\nPlease tell me the solution.\n(PS It doesn't run on batteries, only on the power in the phone lines.)", "topk_rank": 19 } ]

[ { "id": "corpus-325448", "score": 0.7219209671020508, "text": "The Big Bang is the initial expansion of the universe, of space itself. Light moves across space. But we're talking about space itself expanding. Say you have a car that can drive 60mph on the ground. That's it's speed limit. Now I grab the Earth itself and stretch it apart. The car can be receding from me at more than 60mph." } ]

[ { "id": "corpus-319449", "score": 0.6858217120170593, "text": "The current idea is that the seeds of non-uniformity were produced during inflation, a period of accelerated expansion in the early universe. Quantum mechanics tells us that on very small scales there's fundamental uncertainty in things like a particle's position or its velocity. This means there's no real uniformity on those scales. Normally, these non-uniformities are fleeting and average out with each other on pretty short timescales, but during inflation the expansion was so rapidly accelerating that these fluctuations were blown up to cosmic scales, larger than the observable universe, before they had a chance to settle back down. When inflation ended, still only a mere fraction of a second after the Big Bang, these small fluctuations remained as the seeds of structures which eventually, under their own gravity, grew into stars and galaxies and cosmic structures.", "topk_rank": 0 }, { "id": "corpus-302523", "score": 0.6857969760894775, "text": "As I understand it, the steady-state model of the universe was largely dropped in the early 1980s. Penzias and Wilson's observation of CMB radiation put the Big Bang model in the scientific mainstream and the steady-state model ended up with too many things it couldn't explain to remain relevant. That being said, I don't know of any current theories about the formation of the universe that rival the Big Bang theory, but that's not saying too much in and of itself because there are still plenty of things that the Big Bang theory can't explain.", "topk_rank": 1 }, { "id": "corpus-313626", "score": 0.6857673525810242, "text": "Hundreds of thousands of years is actually quite a short period of time in astronomy. Even very short-lived stars last for millions of years. The distance to other galaxies is also much larger than their size. Andromeda, the closest large galaxy to us, is millions of light-years away. We can say many other objects that are *billions* of light-years away. On that scale, we definitely notice that closer galaxies are more evolved than more distant galaxies. But on the scale of an individual galaxy, a hundred thousand years is almost too small to notice.", "topk_rank": 2 }, { "id": "corpus-131605", "score": 0.6857212781906128, "text": "You can't travel faster than the speed of light,that's against the laws of physics. But if you look up the sky with a Teleskope and would find a mirror which is placed one light year away from earth, you could see the shit you have done in 2015. 😉", "topk_rank": 3 }, { "id": "corpus-302298", "score": 0.6857185363769531, "text": "The universe is by definition all of space and time. Any point that is *not space* would be outside the universe and thus inaccessible, meaning there is no way of saying whether there is matter there or not. Perhaps there is matter there, but there is no way of detecting that matter using another object (such as a photon or some other particle that we could bounce off it).", "topk_rank": 4 }, { "id": "corpus-166657", "score": 0.6857144236564636, "text": "It's unanswerable. That's what is wrong with it. It appears that time itself began with the Big Bang and so asking what happened before the Big Bang is like asking, \"What is north of the north pole?\"", "topk_rank": 5 }, { "id": "corpus-323535", "score": 0.6856569647789001, "text": "Expansion is not the universe is expanding away from a *single point* but rather, expansion is happening in all directions from the point of *any* observer and any very distant object (all distant points are expanding away from all other distant points). Expansion happens at extremely large scales and distances. At localized scales and distances gravity overcomes expansion and keeps things pretty much bound. This is why we travel with a local group of galaxies, etc... and why expansion really doesn't effect us at any personal level (our planet is not flying apart, etc). Edit: You can read more on expansion [here](_URL_0_)", "topk_rank": 6 }, { "id": "corpus-287607", "score": 0.6855778694152832, "text": "In neutron stars the speed of sound \"exceeds\" the speed of light. Obviously the speed of light takes over, but the speed of light ends up as the limit rather than interatomic forces.", "topk_rank": 7 }, { "id": "corpus-259304", "score": 0.6855775713920593, "text": "No, information cannot go faster than light. For the broomstick example movement would indeed ripple through it, at the speed of sound in the material. Gravity propagates (according to our well tested theories) at the speed of light.", "topk_rank": 8 }, { "id": "corpus-165115", "score": 0.6855297684669495, "text": "The space *between* matter can expand faster than light, and it has.", "topk_rank": 9 }, { "id": "corpus-135433", "score": 0.6855230927467346, "text": "We really don't know and our current scientific methods cannot get a definitive answer. But the thought is more or less: why would our own universe be unique? Couldn't it be just one of many, like our solar system is one of billions, as is our galaxy? Maybe the Big Bang wasn't a one time event, rather a regular occurence in a constantly boiling multiverse. I'm sure there is some high level math suggesting the possiblity, but that's way above my understanding.", "topk_rank": 10 }, { "id": "corpus-32339", "score": 0.6855111718177795, "text": "To the best of our knowledge, the entire universe is infinitely big. Therefore, the question makes no sense. However big an area you're looking at, whether it's something as small as our planet, as big as our galaxy, or something much, much, bigger, it would still be an infinitely small portion of something infinitely big.", "topk_rank": 11 }, { "id": "corpus-306016", "score": 0.685499370098114, "text": "When we look through a telescope we're also looking back in time. The Big Bang also happened everywhere. When we look at the edge of the observable part of the universe we're really looking back in time at afterglow from an infinitely sized explosion that was everywhere that is just now reaching us. If galaxies and intelligent beings have since formed over there, they'll look at where Earth is and see CMB and an opaque burning-hot wall of ionized hydrogen too.", "topk_rank": 12 }, { "id": "corpus-304694", "score": 0.685468316078186, "text": "> all matter was compressed into a space smaller than a proton It's the space that was compressed, not matter. The universe was probably already infinite and isotropic at that time. It was just denser (in space, not in matter) than it is now. Obviously, such densities elude our comprehension as we are not (yet) able to reproduce densities of 10^97 kg/m^3", "topk_rank": 13 }, { "id": "corpus-168145", "score": 0.6854615807533264, "text": "Because the faster something travels the more mass it has. At the speed of light, a single proton would have infinite mass, and would take an infinite amount of energy to move at the speed of light. So to get just one proton to the speed of light it would take more energy than we can see in the whole universe.", "topk_rank": 14 }, { "id": "corpus-53411", "score": 0.6853832006454468, "text": "The moon is 385,000 km away, and the speed of light is 300,000 km/s. So if the moon blew up, we'd see it in about a second. That's not much of a delay. If the sun blew up, it'd take 8 minutes before we saw it.", "topk_rank": 15 }, { "id": "corpus-317478", "score": 0.6853030323982239, "text": "To ask what happened \"before\" the big bang is ill-defined. The big bang was, for all intensive purposes, the (chronological) start of the universe. There is no \"before\", there is no \"from what\". The best we can hope to do is craft theories (which are independently validated) that might give us a theoretical \"glimpse\" at time zero, but there are no (serious) contenders. At any rate, we will never be able to make observations or conduct experiments to validate any such claims.", "topk_rank": 16 }, { "id": "corpus-268356", "score": 0.6852696537971497, "text": "That's not how time shifting works. Once you get the particles 'back together' as it were, they're once again in the same 'time frame'. The fact that the one on the spaceship effectively experienced less time because of relativistic effects is irrelevant. What I would like to know is: will faster-than-light communication eventually be possible? This would definitely be useful. Example: A human colony on another world about 10 light years from here could warn Earth about the fallout of a supernova they have witnessed, 10 years before we on Earth would be able to see it.", "topk_rank": 17 }, { "id": "corpus-79340", "score": 0.6852607727050781, "text": "At the furthest distances we can see, there are undoubtedly significant changes. However, when we're talking about stars, we're talking about billions, potentially even trillions, of years of lifespan. For much of what we can study in more detail (like objects in our own galaxy) the time delay isn't a significant part of the lifespan of such objects. That's not to say no changes could have occurred, its just likely that much of what we see is more or less still there. You are correct in your secondary post to assume that these objects are all in motion relative to one another, though, so teleporting yourself somehow to the observed location of some distant object is going to wind up off-target. Even the Earth is moving rapidly through space relative to some other object.", "topk_rank": 18 }, { "id": "corpus-170013", "score": 0.6851744651794434, "text": "If the universe is huge but finite, it would curve. We have detected no indication that it has any curve at all. So it's either at least as much larger than the observable universe as the observable universe is roughly larger than you or me, or it is in fact infinite. Future measurements may be able to detect curvature in greater detail than today, so someday the question may be answered, but until then the universe is practically infinite from our perspective.", "topk_rank": 19 } ]

[ { "id": "corpus-325449", "score": 0.7021962404251099, "text": "There is no speed limit on the rate of expansion of the fabric of the universe (space-time). During the first few moments after the Big Bang, if the theory of Inflation is correct, the volume of the universe expanded by a factor of 10^78 in a time span from ~10^-38 to ~10^-32 seconds. Edit - To add to this. The speed of light is the speed limit for which information can propagate (which therefore means anything with mass/energy). There is nothing, as far as we know, limiting the rate of expansion of the universe itself. Objects very far from us are actually travelling away from us at a speed greater than the speed of light since the rate of expansion between two points increases as you increase the distance between said objects. The consequence of this is that light from these objects will never reach us." } ]

[ { "id": "corpus-167811", "score": 0.6670842170715332, "text": "Basically the faster you go the more power you need to go faster. As you get closer and closer to the speed of light that power gets closer and closer to infinity. This is true of anything that has mass, so anything with mass can't ever reach the speed of light. Massless particles (including light) aren't limited by this, so they run around at the fastest speed possible, which we call the speed of light.", "topk_rank": 0 }, { "id": "corpus-275640", "score": 0.6670840978622437, "text": "Suppose you did have a colossal mirror for a second. Due to the inverse square law, light from Earth will be rather dim by the time it gets there. It will dim by many orders of magnitude again on the way back. Black holes are not that big either. There's some debate about how big Sagittarius A* (the largest one in the galaxy) really is, but the consensus is that the event horizon is smaller than the solar system. There's also a lot of gas and dust from here to there, and there would be light from many other stars swirling around it. So no.", "topk_rank": 1 }, { "id": "corpus-10826", "score": 0.6670753955841064, "text": "Time is relative to speed. The faster you go the slower time appears to go from your perspective. That's why there's a universal speed limit of the speed of light, because the closer to the speed of light you travel the slower time seems to pass. If someone is at the top of a tall mountain then as the world spins around on its axis they would appear to be travelling further and thus faster, so for them time would appear to move more slowly. It's slightly lazy writing though, they wouldn't age faster than the second, they'd just have experienced more time. In fact in terms of the biological process of ageing you'd probably age faster at the top of the mountain because there's less oxygen.", "topk_rank": 2 }, { "id": "corpus-313525", "score": 0.6670747995376587, "text": "A photon can be continuously redshifted if it exists for long enough passing through expanding space. However, there is no limit to the wavelength ans anything below a certain point (around 0.1m) is called a radio wave, even if the wavelength is hundreds of millions of miles long. Practically speaking though, it has so little energy that it may as well not exist, after a point our sensors are not accurate enough to pick these low energy photons up.", "topk_rank": 3 }, { "id": "corpus-311557", "score": 0.6670743227005005, "text": "Any point you pick would be the centre of its observable universe. The Big Bang didn't originate from a point, it occurred everywhere. The universe isn't expanding from a point, it's expanding everywhere.", "topk_rank": 4 }, { "id": "corpus-182451", "score": 0.667071521282196, "text": "It’s not that the energy is absent, it’s that it’s spread so thinly as to be useless for life. The universe itself is expanding in size, and our current theories state that this expansion is going to get faster and faster. You’re right that matter/energy cannot be destroyed, but it can’t be created, either, so there’s essentially a fixed amount of matter/energy in existence. As the universe expands, the matter/energy gets diluted, and eventually it will be so dispersed that we’ll never be able to use it.", "topk_rank": 5 }, { "id": "corpus-317104", "score": 0.6670050621032715, "text": "Certainly! The wavelength 800nm is really just an artifact of our visual apparatus, though, so scientists tend to be more interested in the distance at which the recession velocity is equal to *c*. This distance is known^(*) as the Hubble length, and the sphere of that radius around a given point is its [Hubble sphere](_URL_0_). ^(*)Well, sort of. The Hubble length is actually defined to be equal to what this distance would be in a particular cosmological model; if our universe doesn't work the way that model assumes, the actual distance would be different from the Hubble length. Complications.", "topk_rank": 6 }, { "id": "corpus-33467", "score": 0.6669990420341492, "text": "For the text: Hm, I think you misunderstood what the space-time is. It's not really \"space and time\", it's the \"fabric\" on which the universe is set upon. So basically, for all we can tell, it works the same way here, and it works \"there\". And time, as you describe it, goes by here the same as it goes by \"there\" (with a tiny difference due to relativity, but it isn't really that relevante). For the title: Yes and no. No because for a long time we assumed the universe to be an emptiness that's slowly being filled with \"things\", and without any drag, it would keep on growing forever, but then they realized gravity kicks in, and gravity is the drag. Yes because when we realized that what's growing isn't the volume of \"universe\" filled with \"things\", it's really the space-time that's expanding, and making the universe itself bigger, something like, growing from inside. Hope it helped!", "topk_rank": 7 }, { "id": "corpus-287293", "score": 0.6668514013290405, "text": "This is more of a metaphysical question because there's no possibility we could find out, ever. Even if we eventually build a spaceship that travels at 99.99% of c, it'd take us 13 billion years to reach what we think is the end (it's the limit for matter to be visible for us, because the universe is only so old, the universe is probably infinitely big). And by the time we'd reach that \"edge\" the universe would have expanded enough for us to neever reach it.", "topk_rank": 8 }, { "id": "corpus-86919", "score": 0.6668410897254944, "text": "First question, Yes. Second question, Yes, that's sort of what a light-year is (the distance light travels in one Earth year). So if you look at a star that's 7000 light-years away, you're looking at something 7000 years in the past.", "topk_rank": 9 }, { "id": "corpus-171691", "score": 0.6668156981468201, "text": "Time and space is uniform along very large distance that is why frieqency stays unchanged. However give it long enough time and frieqency will shift .this happened to lead microwave background radiation shifted from photons at big bang", "topk_rank": 10 }, { "id": "corpus-247914", "score": 0.6667760610580444, "text": "If you could *hold* yourself near the event horizon and look out at the universe, you'd see time speeded up. But you'd have to park yourself at 4/3 of the Schwarzschild radius from the singularity even to see the Universe go at double-speed. That's already absurdly close to the event horizon. The g-force there would be ridiculous. If you're flying through it at high speed and looking back, that would be different.", "topk_rank": 11 }, { "id": "corpus-118284", "score": 0.666743814945221, "text": "This is an effect predicted by Einstein's special theory of relativity. This theory works under the assumption that the speed of light is the same for *everyone*, no matter what. This is very weird: If you were \"sitting still\", you would measure the speed of light to be 299 792 458 m/s. But let's say you were traveling really fast: say, 200 000 000 m/s in a car, and turned on the headlights. You'd think that you'd measure the speed of light to be 99 792 458 m/s from your perspective. But it's not; It's still 299 792 458 m/s. We measure velocity as v = x/t. Einstein figured out that the only way to have any of this make sense was that as you get faster, time moves slower for you, and thus \"corrects\" your measurement of the speed of light so that it agrees with your friend's measurement who is sitting still. The universe seems to be conspiring against us to make sure the speed of light is the same for everyone!", "topk_rank": 12 }, { "id": "corpus-235850", "score": 0.6667416095733643, "text": "Would the new sun fizzle out? No. For a very ballpark sort of number, consider this. Voyager 1 is travelling at about 17 km/s and has exited what some might call the border of the solar system (this is really ambiguous). At that speed it would take 350,000 years to travel 20 lightyears, while stars live for billions of years. That number, even with near future technology, could certainly be improved upon by more than an order of magnitude (perhaps several).", "topk_rank": 13 }, { "id": "corpus-660157", "score": 0.6667333841323853, "text": "I'm fully expecting my proposition to be deftly and promptly nullified, but the apparent paradox has been bouncing around in my head recently so I thought what better place to give it the light of day than here.\n\nAccording to current scientific understanding; \"The universe began as a very hot, small, and dense superforce (the mix of the four fundamental forces), with no stars, atoms, form, or structure (called a \"singularity\")\". \nSo, the language suggests a state of singularity was already manifest *somehow* prior to the theorized \"quantum fluctuations\" that triggered a rapid expansion commonly known as the Big Bang.\n\nIs there a way to explain this \"event before events began\" as anything other than supernatural? \n\nIf this is so and therefore came from another state of existence (Keter, Godhead, insert mystical appellation), does this arguably demonstrate that material existence is not all there is? That there is a non material (spiritual, mystical?) state that (apparently) consciously projected material existence into being? \n\nHas science proven the existence of God? (hah)\n\n\nWould humbly appreciate any input.", "topk_rank": 14 }, { "id": "corpus-257960", "score": 0.6667299270629883, "text": "Physicists have known for a long time that gravity \"moves\" at the speed of light. According to Einstein's theory of relativity, nothing can ever move faster than c, not even gravity. Last year, physicists observed a neutron star collision that caused a gravitational wave and a burst of gamma rays to be detected at nearly the exact same time, proving that they travel at the same speed, c. [_URL_1_](_URL_0_)", "topk_rank": 15 }, { "id": "corpus-278123", "score": 0.6666725277900696, "text": "As we currently understand it, time and space are fundamental aspects of the universe. You do not need light to have time elapse. For example, a particle that decays (say, a muon) has a non-zero lifetime without needing any light present.", "topk_rank": 16 }, { "id": "corpus-170252", "score": 0.66666179895401, "text": "The furthest identified galaxy, GN-z11, is ~13.4 billion light years away. Due to the current expansion of the universe, if you left today traveling at the speed of light you would arrive in about 32 billion yers. It is very unlikely we will ever reach them barring some presently purely hypothetical method of transportation that exceeds the speed of light by a very large amount. Somewhat related reading: _URL_0_", "topk_rank": 17 }, { "id": "corpus-300857", "score": 0.6666153073310852, "text": "Strictly speaking, the big bang theory doesn't deal with where matter originates comes from and whether there was a single \"point\" in empty space or not. It only explains the evolution of the universe after that point. Also, the \"point\" didn't explode and it wasn't in \"empty space\". There was no empty space. The \"point\" was the universe, it just [got a lot bigger](_URL_2_). That aside, it is a good question. The answer is that on a quantum scale, energy and matter [fluctuates](_URL_0_), particles pop in and out of existence. Those small fluctuations on a small scale are magnified to a macroscopic scale as the universe expands, and the universe should actually be *more* asymmetric than it is if we only considered quantum fluctuations. The big bang theory explains the apparent uniformity of the universe with a period of [cosmic inflation](_URL_1_), where the universe expanded extremely rapidly in a very short period. EDIT: Fixed a link. Some reformatting.", "topk_rank": 18 }, { "id": "corpus-153638", "score": 0.6665932536125183, "text": "Yes, something happening 350 million light years away would take 350 million years for us to see. However, that doesn't mean it's irrelevant. Really the fact that it happens in the past is irrelevant.... it is so far away nothing will affect us. It is still plenty useful for science, as we can use that data to predict the future of objects much closer to us.", "topk_rank": 19 } ]

[ { "id": "corpus-325451", "score": 0.7493288516998291, "text": "Water content has a lot to do with it. The ability of bacteria to degrade the butter is controlled by the amount of water present. It has to do with the activity (in the chemistry sense) of the water. The available water is bound to other molecules and not available to bacteria that need it the water to survive. Water can also hydrolyze fats and proteins creating rancid flavors. Also, a lot of the compounds that taste good are easily oxidized and the oxidized forms can taste bad. Like that old ass jar of olive oil in your cupboard...it tastes like crap because it has gone rancid. It smells bad, but not because of bacteria. Often food will smell bad, but the bad smells are not the result of pathogenic bacteria and will not necessarily make you sick. I am a geologist, so this may be a little simple." } ]

[ { "id": "corpus-124278", "score": 0.7099165916442871, "text": "Heavy Cream is what is known as an emulsion. Basically tiny droplets of liquid suspended in another liquid and the two don't mix together. In the case of heavy cream, it's little droplets of fat mixed in with mostly water. When you shake or churn heavy cream with enough force, you make these little drops of fat stick together and separate from the buttermilk. Once that's done you press the fat together to squeeze out the rest of the buttermilk and what's left is butter. Now, salted butter can be left out because it is dense, relatively dehydrated, and salty which is a poor environment for bacteria. Heavy cream on the other hand is unsalted, very wet, and full of little bite sized pieces of fat for bacteria to munch on. It's a very good environment for bacteria to grow in. Plus, put the right bacteria in and you can have yogurt.", "topk_rank": 0 }, { "id": "corpus-151771", "score": 0.709359347820282, "text": "Cream is still an emulsion: fat particles suspended in water. Butter, on the other hand, is a solid at room temperature.", "topk_rank": 1 }, { "id": "corpus-113928", "score": 0.7090433239936829, "text": "They're generally made of nonfat milk, thickeners, and flavoring agents. For example, fat-free sour cream is basically just milk, corn starch, and other thickening agents (various gums) + flavoring. But cottage cheese isn't inherently made of milkfat or anything - it's just curdled milk, so it's fat + milk protein in general. Make it out of nonfat milk and you have fat-free cottage cheese. I have literally never heard of fat-free butter and I doubt you have either. There's no getting around the fact that butter's entire purpose is as a source of fat. Anything that claims to be a non-fat butter substitute probably just has the density artificially lowered so that they can round the amount of fat per serving to 0g.", "topk_rank": 2 }, { "id": "corpus-81379", "score": 0.7086367607116699, "text": "They *do* separate in milk straight from the cow - the cream rises to the top - but milk you buy from the store has been through a process called [homogenization] (_URL_0_). This breaks up large fat molecules in to smaller ones which don't separate out as much.", "topk_rank": 3 }, { "id": "corpus-324612", "score": 0.7083030343055725, "text": "Lactose is sugar. Sugar completely dissolves in the liquid. Cream is an emulsion (homogeneous mix of fat and liquid). Churning won't extract the sugar that has dissolved in the liquid, it will only separate the fat (butter) from the liquid (buttermilk). In the end, almost all the sugar will be still dissolved in the buttermilk and almost none in the butter (only a bit remains, because not all moisture will be extracted). That's why the percentage of lactose in butter is so low, and the percentage of lactose in buttermilk is higher than in cream (same amount of sugar concentrated in less mass because all the fat is gone). Edit: removed the practical example, it was too silly.", "topk_rank": 4 }, { "id": "corpus-103221", "score": 0.7077487111091614, "text": "Low temperature slows down bacteria growth which is why we refrigerate foods to begin with. Milk has an extremely short shelf life otherwise, so if you leave it out the bacteria in the milk very quickly multiplies until eventually there's enough of it to make you sick. When you're cooking food that contains milk, you're both rapidly heating it (which doesn't really give the bacteria time to go crazy) and generally heating it to the point that you're killing bacteria.", "topk_rank": 5 }, { "id": "corpus-339369", "score": 0.7076728343963623, "text": "So i tried to make home made sour cream. Ingredients were cream, vinegar and milk. I had cream in my fridge (it was only a day or two there) and i used it as an ingredient. The recipe says it has to stand for 24 hours at room temperature, not in the fridge. I was so worried that it might spoil since the cream came from fridge and was already chilled (I was thinking bacteria might develop or something if i let it stand outside). So i let it stand inside the fridge at the vegetable compartment since it was not too cold there.\n\nI tasted it after 24 hours and it does not taste sour. Nothing changed, so I decided to bring it out of the fridge and let it ferment outside. Upon checking after 24hours, I saw bubbles developed (it looks like the bubbles you see when you are trying to make starter for sour bread). \n\nTHe recipe said that after 24hours you'll see liquid separate from the cream and you just have to mix it. Mine didn't. It developed that bubbles. I tasted it and its not that bad. \n\nI am just worried that I might get sick if I eat or use it. Just wanna be sure. Is it normal? Thanks so much!", "topk_rank": 6 }, { "id": "corpus-152610", "score": 0.707168698310852, "text": "Cream consists of little 'bubbles' of fat surrounded by liquid. Whipped cream is a foam that also has little bubbles of air in the liquid. However, if you keep beating on the cream, then the bubbles of fat start to combine and crash out of the foam. Without the fat acting to 'stiffen' things the liquid can't keep the air trapped. This causes the fat to form butter, and the liquid to form buttermilk, and the air to escape.", "topk_rank": 7 }, { "id": "corpus-126490", "score": 0.706839919090271, "text": "Milk and (dairy) half-and-half don't have enough fat to bind with the proteins to get thick and creamy when whipped. When you whip cream it traps air, and that's what makes it into whipped cream. That's really all it is.", "topk_rank": 8 }, { "id": "corpus-6113", "score": 0.7066982388496399, "text": "Right on, and exposure to bacteria. Moisture without oxygen in a sterile environment won't generate bacteria. Once opened you have all three, by refrigerating you actually just slow the enzymatic breakdown and reduce the suitability for bacteria to grow on the food", "topk_rank": 9 }, { "id": "corpus-2009038", "score": 0.7061598896980286, "text": "I work in CPG food and one of my clients does powdered drink blends that include coconut milk. Specifically, it uses a powdered coconut milk / cream with 45% fat content. This powder is then mixed with other powders and is packed into airtight sachets. What is strange is that sometimes some of the formulas start to see the coconut cream powder start to go rancid, while under the same circumstances other flavors do not even when the coconut cream is from the same lot and production date and storage (cool, dry, low light) are the same. \n\nMost I have asked about this note that heat or light could drive the fat to go bad, but they are packaged in three ply packaging with no windows. Also this is happening with retained samples that have been kept in a dry air conditioned home.\n\nSo my question is - outside of light - are there ingredients interactions that can drive coconut cream powder to go bad or is it possible that there is just variation of product from the same lot# such as water content etc. \n\nAnyway curious if anyone has any thoughts.", "topk_rank": 10 }, { "id": "corpus-315299", "score": 0.7056268453598022, "text": "The same reason why syrup doesn't need to be refrigerated. Spoiling comes from growth of bacteria. Milk is an excellent host for bacteria. If your sugar concentration is at the level it is for frosting, then bacteria simply can't handle it, absorb too much sugar and die before being able to reproduce. Thats why a lot of things high in sugar or salt won't go bad and can resist spoiling.", "topk_rank": 11 }, { "id": "corpus-121253", "score": 0.7041611075401306, "text": "Milk spoils because microorganisms start eating it & exposure to oxygen in the air air causes it to break down. Refrigeration just slows down the growth of microorganisms & the chemical reactions - it doesn't stop them completely. Shelf-stable milk will be pasteurized at super high temperatures - this kills all the microorganisms rather than just \"most\" of them like regular pasteurization would. It's then sealed in a package that prevents any air or new microorganisms from getting inside to start the spoiling. As soon as you open it, however, it's going to spoil about as quickly as regular milk.", "topk_rank": 12 }, { "id": "corpus-2649841", "score": 0.7039171457290649, "text": "Here is the recipe\n\nThe thing is, doesn't fat normally go rancid within several hours of being left out at room temps? \n\nEDIT: This isn't my recipe, but I ran across it a couple days ago in preparation of buying my own homebrewing kit.", "topk_rank": 13 }, { "id": "corpus-551910", "score": 0.7036533951759338, "text": "So I remember having a mini-crisis when I moved to the UK and discovered that the stores sell eggs unrefrigerated. They're just left on shelves and my friends have told me they actually last longer if left on shelves than putting them in fridges.\n\nLater I discovered that it's actually in the manufacturing process of eggs that differs between Europe and the rest of the world, making it not only 'safe to put on shelves', but in fact, eggs are safer in Europe than the rest of the world in general. \n\nI moved to Belgium and discovered that stores here don't refrigerate milk! given my prior crisis, this must be because there is a superior production technique that makes it safe to do so. I don't know anything about milk or making of milk other than where they come from. Anyone here can educate me? Thanks!", "topk_rank": 14 }, { "id": "corpus-316617", "score": 0.7035173773765564, "text": "When ice cream is made, it is done using milk which is a colloid of fat dispersed in water. When freezing the ice cream, it must be constantly stirred to get the \"good\" consistency you expect when purchasing it. This ensures an even dispersion of the fat within the ice matrix of the water and helps the two phases to freeze at the same rates giving that nice gelatinous consistency. When you leave it sitting out, the heat unevenly transfers throughout the ice cream causing the water portion of the mixture to melt more rapidly than the fat. The fat that does melt comes to the top of the melt and forms that foamy junk on top while, when you try to stick a spoon into it, it is noticeably more difficult after refreezing because the refrozen liquid below the foam is mostly water. Basically, it comes down to the properties of colloids. They tend to separate when transitioning between the liquid and solid phases.", "topk_rank": 15 }, { "id": "corpus-124676", "score": 0.7021675705909729, "text": "Those things are both completely unrelated. It's *time* that makes milk go bad, not *heat* (as you have clearly found out through experimentation) - and keeping milk in the fridge will not *stop* it from going bad, eventually! All the organisms living in the milk are slowly making it go bad. Putting it in the fridge slows them down considerably. Heating the milk up doesn't make them work faster.", "topk_rank": 16 }, { "id": "corpus-56122", "score": 0.7019460797309875, "text": "These products are generally in air-tight jars. Before being filled, the jars are sterile - that is, there are no germs anywhere on them, due to whatever sterilization procedure is used (for at-home, this is usually boiling; I don't know off hand what the industrial process is). The food that goes in is either cooked or otherwise prepared in such a way that it also has no germs when it goes in. With no bacteria to grow, there is no reason to refrigerate (since refrigeration is primarily to slow down bacteria growth). Basically, so long as you don't open it, the food in that jar should theoretically remain good to eat until the seal fails so bacteria can get in.", "topk_rank": 17 }, { "id": "corpus-312718", "score": 0.7014868259429932, "text": "Because they have (if performed correctly) been sterilized and do not contain spoiling bacteria. Due to the impermeable packaging, they also have no risk of being exposed to bacteria. That's not to say chemical degradation of the food isn't possible, but that's mostly just going to make it taste bland and/or nasty, rather than rancid or harm you.", "topk_rank": 18 }, { "id": "corpus-325363", "score": 0.7014865875244141, "text": "In the case of bread, it's starch crystallization as /u/steinbergergppro mentioned. In the case of fats (which go rancid), it's oxidation by air.", "topk_rank": 19 } ]

[ { "id": "corpus-325452", "score": 0.7308629155158997, "text": "Hubble expansion only dominates gravity on the scale of galactic superclusters. Andromeda and the Milky Way will collide along with everything else within our local group eventually." } ]

[ { "id": "corpus-310515", "score": 0.6942750215530396, "text": "The Milky Way is part of the Local Group of galaxies. Andromeda (aka M31) and the Milky Way are the two biggest galaxies in it and the center of mass lies in between them. We are not orbiting it per se, but are more on a collision course with Andromeda and will collide in 300,000,000 years or so. [source] (_URL_1_) (pdf). Edit: M31 not M33 Edit edit: more info: The Local Group is part of the Virgo Supercluster and lies on its outskirts. The majority of the mass is in the Vancetti and Virgo clusters. We are currently moving away from the center of the Supercluster, but will probably be pulled into the Virgo cluster one day. [source] (_URL_0_)", "topk_rank": 0 }, { "id": "corpus-314494", "score": 0.6942341923713684, "text": "Objects that are close to one another (in universe-terms) experience gravitational attraction that causes them to \"drop out\" of the expansion of the universe. So, basically, the effect of gravity is greater between us and Andromeda than the effect of spacetime expansion.", "topk_rank": 1 }, { "id": "corpus-167684", "score": 0.6941834092140198, "text": "The expansion takes place over very long distances. Andromeda is, cosmically speaking, extremely close to the Milky Way.", "topk_rank": 2 }, { "id": "corpus-247535", "score": 0.6941356658935547, "text": "The oldest light we receive is the cosmic microwave background, and the distance we are receiving it from is growing with time. Because of this, fully formed galaxies and stars can't exactly pop into view, other than getting bright enough that we notice them(which is why gamma ray bursts are among the most distant events observed) If we had unreasonably powerful telescopes and computers to capture and analyze massive amounts of incoming light and watched for billions of years, we could theoretically watch the gas at the origin of the current background radiation collapse and form structures as the distant early universe exited the [dark ages.](_URL_0_) But for now we're stuck looking for the occasional short burst, or focusing our lenses on the same place for long enough that we can recognize the faint red splotch of a [young galaxy.](_URL_1_)", "topk_rank": 3 }, { "id": "corpus-832559", "score": 0.6940370202064514, "text": "I was wondering when the two galaxies eventually collide how long will it take for the two to merge? Are we talking a year or more like a millon years?", "topk_rank": 4 }, { "id": "corpus-307596", "score": 0.6939863562583923, "text": "It's possible, but most models which fit the data suggest this isn't the case. We know that the expansion is accelerating right now, and that will tend to dilute away things like galaxies too quickly for their gravitational influence to slow the expansion back down at all, much less slow it down so much that the expansion turns around and starts to contract. The only model I know of which does predict cycles of expansion and contraction, while allowing for the current acceleration, is Paul Steinhardt and Neil Turok's [cyclic model](_URL_0_), which gets around the issues I raised by invoking some funny higher-dimensional ideas from string theory.", "topk_rank": 5 }, { "id": "corpus-283193", "score": 0.6939540505409241, "text": "Yes. We can find the velocity of other stars relative to ours, and by extension our velocity relative to them, by looking at redshift and blueshift. I'm not actually sure how we find the mass of the galaxy, but apparently we've managed that. We're moving at 220 km/s, and escape velocity is 537 km/s, so we're not leaving.", "topk_rank": 6 }, { "id": "corpus-1543890", "score": 0.6937779188156128, "text": "I could've sworn there was one, but I can't find it. I've been binging on episodes trying to find it but have so far failed. It's the idea that because of the universe's rate of expansion, even if we traveled at the speed of light, we cannot escape the local group of galaxies", "topk_rank": 7 }, { "id": "corpus-299610", "score": 0.6935909390449524, "text": "In around four billion years our galaxy will collide with the Andromeda galaxy (Since galaxies are largely empty space with the odd solid bit - it won't be quite as violent as it might seem - probably). Assuming that the two galaxies subsequently go on their merry ways (imagine a comet having a close pass with the sun) then it is likely that the two galaxies will exchange some mass (solar systems) during the encounter. There are two parts of the interaction that are likely to be interesting: 1. The action of the centre of masses of the galaxies on solar systems. 2. The specific interaction when two solar system pass near each other. Both of these types of interaction can/will disturb orbits and could lead to a solar system (or part thereof) to be pulled into a new orbit.", "topk_rank": 8 }, { "id": "corpus-319177", "score": 0.6935586333274841, "text": "You got it right essentially. Light had to travel further because space is expanding. That 13.2 billion ly distance is called 'look-back distance'. That same galaxy is actually further away from us now.", "topk_rank": 9 }, { "id": "corpus-268370", "score": 0.6935555338859558, "text": "Other galaxies have been seen with telescopes for centuries. In fact, the Andromeda Galaxy, the closest neighboring spiral galaxy to the Milky Way, is four times wider than the full Moon in the sky (it's just so dim that you can't normally see it with your eyes). However, for a long time these were believed to just be clouds of gas inside the Milky Way, which was regarded as the extent of the entire Universe as far as visible matter was concerned. It was only in the early 20th century that new observations drove astronomers to the conclusion that the Milky Way is just one of many galaxies. There was an event called the [Great Debate](_URL_0_) which took place in 1920, where prominent astronomers argued each of the two opposing viewpoints of the time (that the Milky Way was the entire universe, or that it was just one galaxy among many). Further observations in the early 1920s established conclusively that other galaxies were too far away to be inside the Milky Way.", "topk_rank": 10 }, { "id": "corpus-303725", "score": 0.6931641697883606, "text": "[This](_URL_2_) illustration shows the merger. The frames in this image are based off of simulations (possibly [this](_URL_1_) or a similar simulation) of the event. As to your second question, Andromeda is only approaching at 250,000mph, so the only thing happening with the light is a doppler shift. [This](_URL_0_) is a where I got the information and image/video.", "topk_rank": 11 }, { "id": "corpus-323446", "score": 0.6925231218338013, "text": "I'll just add that you have to take into account the expansion of the universe, which is not limited by the speed of light. There can in fact be galaxies that are \"receding\" from us at faster than light speed.", "topk_rank": 12 }, { "id": "corpus-273159", "score": 0.6921482682228088, "text": "Supernovae in distant galaxies are not naked eye observable. The supernovae that have been naked eye observable have almost all been in the Milky Way; the one exception of which I'm aware is [1987a](_URL_0_), which was in the Large Magellanic Cloud, a kind small satellite galaxy of the Milky Way, about 170,000 light-years away. In addition, in 1885, there was a [supernova in Andromeda](_URL_1_) (Andromeda is around 2 million light years away) which might have just barely been naked eye visible, although I believe there is no record that anyone did see it without aid.", "topk_rank": 13 }, { "id": "corpus-24520", "score": 0.6921226978302002, "text": "Pick a galaxy, any galaxy (as long as it's not one that's really close by). You can measure an object's speed relative to you with [doppler shift.](_URL_0_) You can measure the distance from a galaxy with standard candles, supernovae, apparent size, and some other tricks. No matter what galaxy you look at, all of them (except for the very closest few) are moving away from us, and the speed that they are moving away from us is directly proportional to the distance from us. That is, every object that is 600 million light years away is travelling away from us at the same speed of 13000km/s (numbers estimated, but not made up). There are two ways to explain this. Either the universe is expanding and carrying everything away from everything else, or, your telescope just happens to be in the exact geometric center of the universe. The former seems more likely.", "topk_rank": 14 }, { "id": "corpus-301450", "score": 0.691666305065155, "text": "The Andromeda galaxy, which is relatively similar to the Milky Way, is visible to the naked eye from a dark location. Neglecting any correction for the somewhat smaller size of the Milky Way, and the fact that Andromeda only covers a small part of the sky (it sounds as if you'd like the MW to appear quite big!), one would expect the Milky Way to also be visible.", "topk_rank": 15 }, { "id": "corpus-87669", "score": 0.691662609577179, "text": "The chances of them colliding with each other during the initial collision is extremely remote. It's moderately likely that they will absorb one or more stars during the collision before they, like 99.99% of the other stars in each galaxy, pass out the other side unscathed. The courses of all the stars and massive objects in the Milky Way and Andromeda galaxies will certainly be distorted heavily and the shape of each galaxy disrupted as they slowly ocillate between 2 distinct galaxies and a single amorphous galaxy. Over many millions of years the 2 galaxies will eventually completely merge and it's likely the 2 black holes will one day merge after they eventually come within an very small distance (~1 light year which is tiny on a galactic scale) but there is no certainty that the 2 will end up in the exact same region until many millions, even hundreds of millions of years have passed.", "topk_rank": 16 }, { "id": "corpus-316478", "score": 0.6916503310203552, "text": "Our observatory (Subaru) make [this discovery](_URL_0_) recently - which was then confirmed by Keck and backed up by Hubble and Spitzer. This early galaxy is 12.8 billion light years away.", "topk_rank": 17 }, { "id": "corpus-238863", "score": 0.6916329860687256, "text": "There's not anything to see one light year away. The Very Large Telescope has an 8 meter lens and can see 300 nm wavelength, meaning we could see resolve 400,000 kilometers at that distance.", "topk_rank": 18 }, { "id": "corpus-276339", "score": 0.6915274858474731, "text": "You may be interested in [this paper](_URL_0_) which discusses misconceptions surrounding some of the issues you're asking about. Firstly, you are incorrect that we cannot observe galaxies that recede at faster than c. We can, and in current cosmological models, most of the observable universe (anything with redshift z > 1.46) is doing so. The point at which galaxies recede at greater than c is not a horizon. To answer your question, we never observe such events, because they happen too infrequently (human lifetimes are short compared to the universe. We never see anything cosmological happen in our lifetimes) and this would happen by the galaxies gradually redshifting to indetectability, not instantly winking out of the sky. So you're asking if we've ever seen a rare event that takes millions of years to happen.", "topk_rank": 19 } ]

[ { "id": "corpus-325453", "score": 0.8037455081939697, "text": "The lactose itself does nothing in people with lactose intolerance, they just can't digest it. The bacteria that feast on the undigested lactose that enters the intestine cause the problem. If you don't eat lactose for a longer period you'll have less lactose-consuming bacteria in your intestinal flora. If instead you eat lactose regularly your intestinal flora will contain more lactose-consuming bacteria. Which will result in a stronger reaction. So no real permanent damage but eating lactose will worsen it." } ]

[ { "id": "corpus-2011446", "score": 0.7427013516426086, "text": "Can lactose intolerance be severe enough that you can't even touch dairy like with some types of allergies?", "topk_rank": 0 }, { "id": "corpus-323406", "score": 0.7423645257949829, "text": "In addition to what DeePhlat said, lactose intolerance isn't an on/off phenomenon, it varies quite a lot by degree. Many with it can eat hard cheese without concern, some can eat any cheese, yogurt, or ice cream without problems. And the response also varies by degree, many people just get bad gas. Those who get diarrhea may get it rapidly or it may take many hours, so the milk product stays in the gut for a while, and things other than the sugars can get fully digested.", "topk_rank": 1 }, { "id": "corpus-1231494", "score": 0.741405189037323, "text": "So, my partner is doing an assignment and according to 'studies', research has found that breastfeeding reduces the risk of people becoming lactose intolerant. I just thought I'd ask it here as I am fascinated by this claim.\n\nI don't think I was breastfed and I am lactose intolerant.", "topk_rank": 2 }, { "id": "corpus-1498189", "score": 0.7307764291763306, "text": "I have had problems with milk recently, so I took a lactose intolerance test, which came back as negative. \nHowever, I have still noticed that no matter if I was constipated or had diarrhoea, it would worsen my symptoms. \nI recently took cow's milk instead of my usual oat milk because I was travelling and couldn't find any without added sugar (they always make me sick) and I have been constipated ever since. I haven't had a single bowel movement in two weeks, and no matter what I do, it doesn't change. \nIn an attempt to help my constipation, I had a latte macchiatto made with lactose free milk and had a bad reaction to it. \nAs soon as I finished it, I felt nauseous and could feel my bloating worsen. I've also felt an urge to vomit, but still haven't felt a bowel movement.", "topk_rank": 3 }, { "id": "corpus-1496969", "score": 0.7270285487174988, "text": "I'm 19 and still able to drink and digest milk, am I considered lactose persistent? Or will my lactose intolerance only will show up when I'm in my 20's?", "topk_rank": 4 }, { "id": "corpus-318909", "score": 0.7269859313964844, "text": "Yes. Lactose intolerant people can't digest lactose in their stomach or first part of the small intestine, but the bacteria in the later part of the digestive system can. Some bacteria break down lactose with lactase, but some also break it down through fermentation. At this point in your digestive system, you don't necessarily absorb all of the nutrients and calories. On top of that, the fermentation of lactose creates the nasty gases and bloated feeling. Your body washes out all of the waste product with water and that's why you can get some nasty poops. I don't know how many of the calories in milk are from lactose. Maybe someone else can help you with that. But I can say that it would be difficult to get an exact number of calories absorbed.", "topk_rank": 5 }, { "id": "corpus-97", "score": 0.7267179489135742, "text": "So, from what I've understood in the past, people who are lactose-intolerant aren't able to break down lactose. Their body doesn't produce enough lactase, which is an enzyme that breaks down lactose. So, depending on how much lactose is taken in, it usually is broken down by bacteria instead in the gut. This causes a bunch of side effects like, nausea, bloating, gas, and stomach cramps.", "topk_rank": 6 }, { "id": "corpus-1498282", "score": 0.7265827655792236, "text": "I was both lactose and gluten intolerant as a child but both passed and I had been fine for well over twenty years. It seems something has now changed again since I got a bad gut infection seven months ago. I haven't been the same since that day and experience almost constant bloating and pain. However I haven't experienced much diarrhea in this time; its occurrence is very rare and it's never that bad... apart from today.\n\nToday I had my lactose intolerance test and it answered with a resounding yes. My breath test readings were crazy high. I got numbers in the 250s for the 'PPM' values, whatever that means, but the nurse said the average should be around 20. The test also resulted in me having really bad diarrhea over there - diarrhea so bad I haven't experienced anything that bad in ages - as well as making me ridiculously bloated and windy.\n\nSo yes, I am profoundly lactose intolerant again somehow. Whatever stomach bug I got it was one real bastard because it's clearly changed me big time. I guess I'm kind of pleased with the result because now I know that I at least have some room for improvement as I'm obviously going to 100% cut out lactose from my diet. The thing is though that I have already experimented with cutting lactose out and it didn't seem to make that much difference. Maybe I wasn't strict enough but Idk. I also didn't have that much lactose in my diet even now anyway.\n\nI know now that lactose will never enter my system again. Best case scenario is that I go back to how I used to be but I'm not so sure I'll be that lucky, simply because I didn't see any profound difference when I tried a lactose free diet. Also I don't think constipation is a symptom of lactose intolerance, is it? Though I do usually shit every day, my stools are never complete logs anymore and are usually hard or broken into mini-pellets etc. Do you think that could be related to lactose intolerance? I'd really appreciate your thoughts on the matter.\n\nUpdate: next day now. Stomach still all bloated up after eating. Looks like lactose intolerance is just one of the new symptoms and not the defining one. Shit...\n\nI also had my Coeliacs disease blood test today and on the 12th I will also get a SIBO test and deliver a stool sample for the faecal calprotectin test (god please don't let me have Crohn's etc). Hope it all goes swimmingly, we'll see...\n\nThanks for reading.", "topk_rank": 7 }, { "id": "corpus-1495966", "score": 0.7250216603279114, "text": "I am only slightly lactose intolerant, but I have an addiction to oats/muesli\nI use oat milk/soy milk which sometimes only makes me feel a little bloated.\n\nIs there any long term side effects if I continue consuming these products?\n\nFrom what I've read there isn't, but I'd like peoples opinions and experience with this.\n\nThanks for your help", "topk_rank": 8 }, { "id": "corpus-112949", "score": 0.7250065803527832, "text": "Most dairy products have a type of sugar in them called lactose. Our body requires an enzyme called lactase to break down lactose. People who are lactose intolerant don't have nearly as much lactase, so they have trouble digesting things with lactose. Most cheeses are just made from the milk fat and don't have any of the sugars in them, so they actually don't have much, if any, lactose (always check the type of cheese first, though!). As a result, they don't cause as much trouble for many lactose intolerant people. Yogurt has some lactose in it, but not as much as milk or ice cream and the bacteria in yogurt actually help the body digest the lactose, so lacking lactase isn't as harmful. Since intolerance to lactose varies among individuals, some lactose intolerant people may be able to eat cheese and yogurt fine but not milk and others may have problems with all of it.", "topk_rank": 9 }, { "id": "corpus-322522", "score": 0.7248217463493347, "text": "The ability to metabolize lactose is dependent on a protein called lactase. Those who have a non-functional version or decreased levels of the protein would be unable to digest lactose, so it would instead be \"digested\" by bacteria in the gut, which would then produce gas in the form of methane. This explains the symptoms of lactose intolerance. The activity and presence of lactase varies significantly throughout your life. Most infants have the ability to digest lactose, but this activity decreases as you age. The great majority of the world adult population is unable to digest lactose in great quantities, such as that found in milk, with the exception of populations from Northern European origin, where presumably high levels of lactase activity evolved to allow milk drinking late into adulthood. Your example of intermittent lactose intolerance is not something I've heard of before, but almost anything is possible when it comes to the human body. TL;DR: Yes, probably.", "topk_rank": 10 }, { "id": "corpus-320992", "score": 0.724210798740387, "text": "Our bodies need a certain enzyme, lactase, to digest lactose. When you're lactose-intolerant, you no longer produce enough lactase to break down lactose. When you have enough lactase, lactose is broken down and absorbed into the intestines. When you don't, bacteria in your gut feeds on it and it ferments, causing gas, bloating, diarrhea, etc, etc.", "topk_rank": 11 }, { "id": "corpus-1497625", "score": 0.7185136079788208, "text": "I'm 22 and have been having acne problems from 14-15. My acne is not really bad but it still sucks. I was also eating a lot of sweets and drinking coke.\n\nSo few months ago i stopped drinking coke, started eating less sweets and drank started drinking more water (\\~1.5 L per day). Helped, but not i still had breakouts. After that i started using face oils ect.. Again, i think face oil helps me but not completely.\n\nThen i read about lactose intolerance. And damn, i use a lot of dairy products. Almost every day i eat white bread in morning (sometimes before bed). Also cheese and butter, and yoghurt. Not that much milk, because i only use milk in my coffee. I read that lactose intolerance cause bad gas and i indeed often have really bad gas and a lot of it.\n\nDo you think i might have lactose intolerance? How much do i need to go tryhard without using dairy? Like, can i eat slice of cake at holiday or just in general sometimes but not much.", "topk_rank": 12 }, { "id": "corpus-1496962", "score": 0.7175617218017578, "text": "What I mean by my question is can someone be lactose intolerant and not have the normal symptoms like diarrhea, gas, stomach cramps, etc. but instead have other more mild symptoms?\n\nI have eaten ham and cheese sandwiches and drinken lattes for breakfast all my life. More recently I noticed that everytime I do eat that I start feeling sick. I feel nauseous and extremely fatigued right after, but only that.\n\nToday I didn't eat anything and at atound 11am I had a ham and cheese sandwich and had a full glass of milk to test my hypothesis and I felt so sick right after I had to lie down and take a nap. I didn't feel my stomach rumbling or any of the more common symptoms people with lactose intolerance describe but is there a possibility I could have a lactose intolerance that manifests differently?", "topk_rank": 13 }, { "id": "corpus-2500009", "score": 0.7147160768508911, "text": "Just something I've been wondering lately because it's happened a handful of times now that I've switched to another brand of lactase pills. Lets say I have a 1000 Cal meal for dinner, and chase it with a litre of milk (640 Cal) (but I've either forgotten or haven't taken enough lactase) so I get explosive diarrhea a couple hours later.\n\nA few questions regarding this:\n\n1. Does this mean that I've deviated from my caloric count due to incomplete absorption?\n\n2. Can I still count the whole 1640 calories from the meal? or should I count only a certain percentage of it? \n\n3. Is there an ideal waiting period that I should wait after eating my meal to have milk, so that if I get the runs, it doesn't make me lose the caloric gains from the meal?\n\nThanks in advance.\n\nBasically what I want to know is whether or not I need to keep eating to make up for any hypothetical losses during the occasional times i get diarrhea.", "topk_rank": 14 }, { "id": "corpus-132486", "score": 0.7143375873565674, "text": "Milk is pasteurized (heated quickly to kill germs) before being sent out to market. This has nothing to do with lactose intolerance. Lactose is a type of sugar naturally present in milk, and it's that sugar that gives some people stomach problems when they drink it. For most of history, all mammals became lactose intolerant after being weaned. Several thousand years ago some human developed the ability to keep drinking milk after being weaned, which gave them a new, calorie rich food source that decreased their chances of starving, therefore increasing their chances to reproduce. So milk isn't bad for you, but it's also not necessarily good, especially whole milk, which is high in fat. If you're eating a balanced diet you don't *need* milk, but if you like it and budget for the calories it's fine.", "topk_rank": 15 }, { "id": "corpus-1496601", "score": 0.7142476439476013, "text": "I’ve been lactose intolerant since I was about 15 and have IBS. The problem is I LOVE milk. I’d usually be ok with a small glass but any more than that I was miserable. When pregnant, I was suddenly able to drink all I wanted with no consequences (good thing it’s the only thing I truly craved). \n\nAfter giving birth I got a stomach aches with a glass of milk, but it wasn’t a full blown reaction so I thought I would be fine. Didn’t really drink it much just because I don’t want stomach aches daily or to risk having a full day on the toilet while trying to nurse LO. LO seemed unaffected by that milk but he was only 2 weeks old. \n\nWell we got milk again and I had a glass yesterday. I never felt sick so I thought, great my tolerance has improved. BUT, LO was the fussiest I’ve ever seen him. His stomach definitely hurt, pulling his knees up and grunting. I gave him gas drops which seemed to help him produce gas and burps. I didn’t eat or drink anymore dairy and today he’s back to normal. \n\nIs it possible that my lactose intolerance is affecting him? I know it’s rare for babies to have lactose intolerance, and some kids have a legitimate allergy. But my baby doesn’t seem to mind when I have traces of dairy (in cookies and breads and things), just when I had milk (similar to how I’m triggered - too much dairy and I pay for it). \n\nAnyone have a similar experience?", "topk_rank": 16 }, { "id": "corpus-1497407", "score": 0.7141562104225159, "text": "Sort of new to lactose intolerance here. It happened suddenly around 6 months ago (maybe after a stomach bug?) and I thought it would have eased up by now but it looks like it's here to stay. TMI question here but I was wondering what happens to others after consuming lactose (which I usually do by accident since i haven't completely gotten used to this yet). I have the usual gas and bloating but the diarrhea is kind of weird for me. All night I have this uncomfortable urge to have a bm and I'll end up going maybe 5 or 6 times the rest of the night. It's not really full blown diarrhea but just sort of loose and really uncomfortable (and smells like sulfur?). It's like a feeling of incomplete evacuation. Obviously I'm doing my best to avoid dairy but it's hard since it seems like it's in everything and I end up having days like this all the time. Is this typical?", "topk_rank": 17 }, { "id": "corpus-1497886", "score": 0.7139610052108765, "text": "I'm trying to figure out if I'm lactose intolerant. I only ever drink milk if it's in hot chocolate or I'm going out to get iced coffee, never milk on its own because I think it's nasty. However, I LOVE cheese and eat a ton of it. Anyway, I noticed I would sometimes get painful gas, bloating and often violent sharts and shits (sorry but I have to be straightforward) after drinking milky coffee and chalked it up to just being coffee, but if I make black coffee or coffee with non-dairy creamer I'll be fine. Cheese has made me gassy for about a year or so, sometimes painfully so, but recently it's been causing me lots of pain. Most recently: Last week I ate a big plate of very cheesy macaroni and cheese and was farting like crazy for HOURS, and I do mean hours. Today I had 3 cheese quesadillas and I have been in such awful pain. I've been trapped on the toilet sharting plus having horrible gas and bloating. The past 2 months or so my possible lactose intolerance has gotten much worse and I'll often have 2-3 days a week when I am in pain plus frequent random diarrhea. \n\n\nAre these signs of lactose intolerance? If so should I try Lactaid? I don't care about milk but I don't want to give up cheese forever if I don't have to, thanks!", "topk_rank": 18 }, { "id": "corpus-1497698", "score": 0.7139521837234497, "text": "After decreasing my lactose exposure for roughly ~8 months, would it make sense that my body is now producing less lactase, and thus, more intolerant to lactose? Before, I could handle 3 slices of pizza without issue. Two nights ago, after those 8 months of lactose, I had less than half a pint of Ben N Jerrys and I was borderline-bedridden the next day.", "topk_rank": 19 } ]

[ { "id": "corpus-325454", "score": 0.8372416496276855, "text": "Every object reflects light; it is this reflected light that enters our eye and allows us to see the object. Mirrors are special in that they reflect nearly all the wavelengths (colors), and the substance doing the reflecting is very smooth on a molecular scale, so you don't have tiny scatterings of the reflected light in different directions due to microscopic bumps in the material." } ]

[ { "id": "corpus-316731", "score": 0.7937392592430115, "text": "It doesn't actually. Light is absorbed, and reemitted every time it interacts with an object, so when it \"bounces\" off the mirror, it is actually being absorbed and reemitted back the way it came.", "topk_rank": 0 }, { "id": "corpus-315388", "score": 0.7929631471633911, "text": "I believe it has to do with the mirror not being a perfect reflector. The photons get scattered and/or absorbed.", "topk_rank": 1 }, { "id": "corpus-29760", "score": 0.7925465106964111, "text": "Since the surface of mirror is smooth and shiny. The light rays bounce back without scattering thus resulting in a clear image... The mirror looks silvery because it is coated with silver/ aluminium or other \"silvery\" looking materials. The reflection takes place on that surface", "topk_rank": 2 }, { "id": "corpus-88007", "score": 0.7917171120643616, "text": "Mirrors have very, *very* smooth surfaces. This is great for 'bouncing' light (specifically: photons) back at yourself. When light hits a smooth surface like a mirror (or a lake), the photons get reflected at [roughly] *the same angle* as they left, allowing them to come back to your eyes. So you essentially see \"the same thing\" coming back at you. Unlike a plain glass window, though, mirrors have a shiny metal layer which is even *better* at reflecting the image.", "topk_rank": 3 }, { "id": "corpus-58953", "score": 0.7899336814880371, "text": "Because sometimes the mirror gets bent concavely or convexely. This even slight bend causes you reflection to distort a little. It's the same way that funhouse mirrors work. Also lighting in the room of whatever mirror you are looking into would affect how you look", "topk_rank": 4 }, { "id": "corpus-321813", "score": 0.7886788249015808, "text": "Mirrors actually reflect at all angles, it's the interference of the light waves that cause them to rebound like they do. If you think of the light as a wave moving in all directions from a point, you can see that if it hits a boundary it will bounce off. The way it does that is to have each point on the mirror act as its own light source ([huygens-fresnel principle](_URL_1_)) and the interference of light from all those points is what causes the wave to reflect as it does. A surface could be retro-reflecive if instead of being flat it were made of a bunch of tiny [corner reflectors](_URL_0_). if you want to get an excellent understanding of light you should read *QED: The Strange Theory of Light and Matter* by Richard Feynman", "topk_rank": 5 }, { "id": "corpus-181328", "score": 0.7863349914550781, "text": "Part of it is Surface roughness causing diffuse reflections. When you shine a flashlight at a mirror, the light will \"bounce. Almost all of the light that hits this mirror will bounce the same angle. If you shine it at a white piece of paper, a lot of the light will bounce, but it will scatter in to diffrent directions. Think of how you can use still water as a mirror, but when it freezes, air pockets add roughness and it scatters white light instead.", "topk_rank": 6 }, { "id": "corpus-303904", "score": 0.7853986620903015, "text": "Your eyes will pick up light that bounces off the mirrors, so you see reflections. For light waves that travel back and forth between the two mirrors (like a game of pong), each time the light hits the mirror, some of the energy of the light is imparted to the mirror. Eventually, the light's energy would dampen out due to these losses.", "topk_rank": 7 }, { "id": "corpus-291410", "score": 0.7847155332565308, "text": "Mirrors do not reflect light with complete efficiency. If you face two mirrors together you'll see the image gradually take on a green tint. This is because mirrors are a bit better at reflecting green light than other colors. Given enough reflections, the image would become completely green.", "topk_rank": 8 }, { "id": "corpus-832586", "score": 0.7845420241355896, "text": "Why don't they reflect objects at the distance they truly are? Is it actually better for mirrors to be this way? Is it safer?", "topk_rank": 9 }, { "id": "corpus-181084", "score": 0.7829952239990234, "text": "A mirror preserves the angle of the light which strikes it, while the white object does not. As a result, the mirror gives you a 'specular' reflection, or a mirror image. The white object gives you a diffuse reflection, the light striking it is scattered in many different directions, so you do not see a preserved reflected image. Note that an object will often have some amount of both diffuse and specular reflectivity.", "topk_rank": 10 }, { "id": "corpus-311152", "score": 0.7822891473770142, "text": "It’s because the direction of reflection isn’t preserved. White surfaces can be explained by light penetrating into the surface, scattering, and then exiting the surface in a random direction. With a mirror, there is no penetration and the incident angle is equal to the reflected angle.", "topk_rank": 11 }, { "id": "corpus-189400", "score": 0.7817298173904419, "text": "The smoother a surface is the less diffrence there is in reflection of light. Its the same thing when you take a standard sheet of steel and grind/buff it down to be extremely smooth. Youll have almost a mirror because most of the light is now reflected in a uniform manner.", "topk_rank": 12 }, { "id": "corpus-149466", "score": 0.7813244462013245, "text": "When light hits a boundary between one transparent medium (e.g., air) and another (e.g., glass or water), some is reflected and some is refracted. Usually only a small percentage is reflected, except at very shallow angles, but often even that small amount is enough to produce a visible reflected image. A good example is looking out a window at night, when it's dark outside but brightly lit inside. The window will appear to act as a good mirror. If you look out the same window in the day time the reflection is still there but it's much harder to notice because it's competing with the very bright view outside.", "topk_rank": 13 }, { "id": "corpus-45734", "score": 0.7809542417526245, "text": "Your line of sight has to travel the distance to the mirror, plus from the mirror to the object. The mirror simply redirects light. It's like looking straight at the object through a window. The distance is the same, not just a flat picture on the glass.", "topk_rank": 14 }, { "id": "corpus-316473", "score": 0.780147135257721, "text": "No mirror reflects 100% of the light that hits it. Some of the light is absorbed. Thus, the reflected images get successively dimmer. Eventually you'll be down to just a few photons -- not enough to make a whole image -- and then eventually even these will be absorbed.", "topk_rank": 15 }, { "id": "corpus-29932", "score": 0.7799903154373169, "text": "A mirror has two reflective surfaces, the front of the glass, and the back surface of the glass that is on some sort of metal backing. Light is always being reflected from both, however the back surface is much more reflective. If you angle the front surface differently from the back surface, then the two images will be reflected at different angles. At night, you simply change the orientation of the mirror so that you see the front surface reflection instead of the back one. This is a much dimmer image, and therefore suited to night driving so you don't get blinded by the headlights behind you.", "topk_rank": 16 }, { "id": "corpus-248658", "score": 0.7796590924263, "text": "One way mirrors, transmit light in both directions, the reason that they work is that the side you want to be a mirror is kept brighter than the other, so that the brighter reflection drowns out the transmitted dimmer light.", "topk_rank": 17 }, { "id": "corpus-314387", "score": 0.7790401577949524, "text": "Yes and no, a normal mirror reflects visible light and likely near IR and UV, but it's not optimized for anything past that. Mirrors can be made for most forms of light, though it gets far harder the smaller the wavelength gets, x ray mirrors have to be almost edge on to work well, much like how glass becomes more reflective when looked at from the side rather then straight on.", "topk_rank": 18 }, { "id": "corpus-52239", "score": 0.7785758376121521, "text": "Normal mirrors are not perfect. While most of the light that hits them is reflected, a small amount of it is scattered, meaning that it reflects in a random direction. This can happen if the glass or the metal layer isn't perfectly smooth, if there's dust on the glass, or because of tiny impurities within the glass. The red dot on the mirror is the light that is scattered in the direction of your eyes. Optical mirrors, which are used to direct laser beams, are much better in this regard. They are incredibly smooth, and don't have a glass coating. They can achieve reflectivity beyond 99,99% - you would not see a dot when pointing a laser at one of them.", "topk_rank": 19 } ]

[ { "id": "corpus-325456", "score": 0.7349718809127808, "text": "There's clear evidence that the expansion is happening and that it's accelerating. If we assume this will keep going then eventually all galaxies become isolated from each other and something like a [heat death](_URL_0_) occurs. But no one knows if the expansion will keep on going. We don't even have a good theory for the acceleration yet." } ]

[ { "id": "corpus-315840", "score": 0.6981255412101746, "text": "None yet. But the theory has made testable predictions for what it should look like if another eternally-inflating bubble universe should look like if it collides with ours. Most of these predictions have to do with looking at the structure of the cosmic microwave background, so these people are anxiously awaiting data being taken by the Planck telescope. Edit: [Here](_URL_0_) is a recent paper on the subject, where astrophysicists combed through the WMAP cosmic microwave background data looking for bubbles and didn't see any strong evidence for one. But they talk briefly about their hopes for more sensitive data from Planck.", "topk_rank": 0 }, { "id": "corpus-45153", "score": 0.6981086134910583, "text": "Not a scientist, but my basic understanding is that the big bang never stopped banging. The universe started expanding 13.whatever billion years ago and is still going, and as more stuff forms further away, it's light will eventually make its way back to us. So its both.", "topk_rank": 1 }, { "id": "corpus-660157", "score": 0.6979900598526001, "text": "I'm fully expecting my proposition to be deftly and promptly nullified, but the apparent paradox has been bouncing around in my head recently so I thought what better place to give it the light of day than here.\n\nAccording to current scientific understanding; \"The universe began as a very hot, small, and dense superforce (the mix of the four fundamental forces), with no stars, atoms, form, or structure (called a \"singularity\")\". \nSo, the language suggests a state of singularity was already manifest *somehow* prior to the theorized \"quantum fluctuations\" that triggered a rapid expansion commonly known as the Big Bang.\n\nIs there a way to explain this \"event before events began\" as anything other than supernatural? \n\nIf this is so and therefore came from another state of existence (Keter, Godhead, insert mystical appellation), does this arguably demonstrate that material existence is not all there is? That there is a non material (spiritual, mystical?) state that (apparently) consciously projected material existence into being? \n\nHas science proven the existence of God? (hah)\n\n\nWould humbly appreciate any input.", "topk_rank": 2 }, { "id": "corpus-169200", "score": 0.6975722908973694, "text": "The universe doesn't expand on the edges. It's just that more space is made. That being said, to the how we know this. You know how when you stand near train tracks as a train is passing by and the horn will xhange pitch as it passes you (happens to cars, also, which are way more common) from high to low. This is a frequency shift cause by moving objects. Well, this also happens to light. When things are moving away from us, their spectrum goes towards red (called the red shift, coincidentally =)). As we've had the ability to look at things through big telescopes for quite a few years, we've noticed the shift in spectrums and some very smart people did some very complicated thinking and figured these things =)", "topk_rank": 3 }, { "id": "corpus-186402", "score": 0.6974642276763916, "text": "That is not how expansion works. Space doesn't need to expand into anything else, and there is no \"edge of the universe\". * Expansion of space simply means, that the distance between any two points increases over time, and this increase is faster the further those two points are apart. * There is no \"edge of the universe\". The universe is either infinite or closed. Either way, there is no edge. * Matter is not expanding. Space is expanding, but gravitationally bound matter is resisting this expansion.", "topk_rank": 4 }, { "id": "corpus-169402", "score": 0.6973966360092163, "text": "It's not a point *in* the universe. It's the universe itself that's expanding. Nothing can move inside the universe faster than light, but the universe itself is expanding and there's no speed limit on that expansion.", "topk_rank": 5 }, { "id": "corpus-170192", "score": 0.6972126960754395, "text": "There most likely is an infinite amount but we can’t see it. The region of the universe that we can observe, fittingly called the „observable universe“, is finite though and contains finite amounts of everything, including matter.", "topk_rank": 6 }, { "id": "corpus-317947", "score": 0.6971756815910339, "text": "The universe is increasing in it's expansion, not slowing down. There will be no big crunch at the end but rather a fizzle as matter and energy is so spread apart that universe essentially dies. Now that I depressed you here's a picture of [a really big dog on a small chair.](_URL_0_)", "topk_rank": 7 }, { "id": "corpus-170141", "score": 0.6970496773719788, "text": "The universe itself is expanding still and doing so faster than the speed of light. Where nothing inside the universe can move faster than the speed of light, the expansion of it can. (In my very limited understanding) Where something was observed at point A and now at point B they can tell that the expansion is X.", "topk_rank": 8 }, { "id": "corpus-15655", "score": 0.6969618201255798, "text": "It is an argument against the universe being infinitely big *and* infinitely old. If it is infinitely big, then every line of sight will eventually land on a star. If it is also infinitely old, then there is enough time for the light from that star to reach your eye, meaning every line of sight should reveal a shining star, making the night sky pure white. Since the night sky isn't pure white, the universe is A) not infinitely big; and/or B) not infinitely old. Current cosmology leans very heavily toward B: the universe had a \"starting point\" of sorts, at least with respect to the stars (all the stars are no older than a certain point back in time). Since even though the universe is infinitely big, and every line of sight lands on a star, there hasn't been enough time for that light to reach us. Since the universe is also expanding, some of that light will never reach us. Since that expansion is increasing, the night sky will actually get dimmer as stars move far enough away.", "topk_rank": 9 }, { "id": "corpus-307596", "score": 0.6968411207199097, "text": "It's possible, but most models which fit the data suggest this isn't the case. We know that the expansion is accelerating right now, and that will tend to dilute away things like galaxies too quickly for their gravitational influence to slow the expansion back down at all, much less slow it down so much that the expansion turns around and starts to contract. The only model I know of which does predict cycles of expansion and contraction, while allowing for the current acceleration, is Paul Steinhardt and Neil Turok's [cyclic model](_URL_0_), which gets around the issues I raised by invoking some funny higher-dimensional ideas from string theory.", "topk_rank": 10 }, { "id": "corpus-317332", "score": 0.6966637372970581, "text": "No, the space between atoms, atomic structure, our planet, our solar system, our galaxy, is not getting bigger. Expansion effects are only seen on massive distance scales. One way to think of it is imagine two observers millions of light years apart - the two observers will find that they are moving away from each other. Basically, space, at massive scales, is increasing. [Here is a more detailed explanation](_URL_0_)", "topk_rank": 11 }, { "id": "corpus-251898", "score": 0.6965551376342773, "text": "There are no current *scientific theories* to the existence of other universes. However, there are a number of *leading hypothesis* - including M-Theory (Brane hypothesis), Special black hole hypothesis, and Penrose Cyclic Universe model (just to name 3 of the more popular). There are also the ripples in the CMB which may indicate a previous universe (more confirmation, one way or the other, expected in 5 to 10 years).", "topk_rank": 12 }, { "id": "corpus-141343", "score": 0.6965001821517944, "text": "No scientist believes that there is an edge of the universe, because no scientist has a good idea for how such an edge might work; what would keep you from going further? The predominant opinion currently is that it goes on forever. Some scientists think instead that it \"curls back\" on itself, like the surface of the earth does; that way it can be finite without having an edge.", "topk_rank": 13 }, { "id": "corpus-243210", "score": 0.6963629722595215, "text": "The problem with this question is that it's dealing with speculation, not science. Thus, officially, there isn't a way to say scientifically that we know everything... ever. That being said, there have been many times that physicists of the era said that there were no major discoveries left, only minor stuff. Then someone comes along and rewrites something huge. So it's good to be humble.", "topk_rank": 14 }, { "id": "corpus-143087", "score": 0.6962819695472717, "text": "it doesn't have edges; relativistic cosmology describes a universe that curves in on itself, it's just like asking what would happen if you drove your car far enough to go beyond the horizon. The best way to picture the \"expansion\" is like a balloon being blown up; draw two points on the surface of the balloon and they keep getting further apart.", "topk_rank": 15 }, { "id": "corpus-307884", "score": 0.6961663365364075, "text": "It's discussed [here](_URL_0_). The short version is that we can tell how big it is by looking at distant supernovae, we can tell how fast it's expanding from redshift, and we can find the age from both of those together. I think it's worth adding that the universe did not start off with all of the energy at one point and then expand into space. The redshift is not the Doppler effect. The universe is believed to have begun with the energy uniformly distributed, and the space itself expanded. The wavelengths of light that had been emitted expanded with it. This requires general relativity to explain, not just special relativity.", "topk_rank": 16 }, { "id": "corpus-297801", "score": 0.6960893869400024, "text": "Yes, there are predictions of the inflationary model that have been confirmed, namely the scale invariance of temperature anisotropies in the CMB. Also, inflation explains the flatness and horizon problems (though the theory was actually developed to solve them, so one could argue it doesn't count as additional evidence).", "topk_rank": 17 }, { "id": "corpus-305672", "score": 0.6960856318473816, "text": "It's fundamentally impossible to tell if the space between things is increasing or everything is getting smaller. We generally talk about space expanding because it's a simpler notion.", "topk_rank": 18 }, { "id": "corpus-101710", "score": 0.6959719061851501, "text": "NVM, figured it out. So galaxies and matter-y things are like toys scattered in different depths and position in a kids' ball pit, where balls are growing in size, pushing toys apart in all directions. And the balls here are spacetime. So it's just space between stuff expanding, not the toys/matter. So 3-dimensional center point in the pit, if it exists, has still little to do with expansion... or does it? For furthest of toys, it's most detectable, since they move away from this point relatively the quickest? Perhaps I didn't figure it out at all.", "topk_rank": 19 } ]

[ { "id": "corpus-325457", "score": 0.780836284160614, "text": "The impact that killed the dinosaurs was estimated to be around 100 *million megatons* TNT equivalent. By comparison, the Tsar Bomba was 50 megatons and the shock wave circled the world 2-3 times, detectable by standard instrumentation. The sheer amount of debris and the weather change would be quite noticeable to any naked-eye observer. Such an impact would be 2 *million* Tsar Bombas. Edit: I should have mentioned the Tsar Bomba is the most powerful nuclear bomb ever tested." } ]

[ { "id": "corpus-80233", "score": 0.7341397404670715, "text": "Compare it to the 2013 meteor strike near Chelyabinsk, in Russia. That one was much larger. It lit up the sky, significantly brighter than the Sun, for a few seconds, and exploded with the force of a big nuclear weapon- dozens, but not hundreds, of times more powerful than the Hiroshima bomb. You wouldn't have wanted to be near it when it fell, but if you were over the horizon from it, you probably wouldn't have noticed its effects.", "topk_rank": 0 }, { "id": "corpus-242380", "score": 0.7314733266830444, "text": "The meteor that is thought to have killed the dinosaurs hit Mexico with an energy equivalent of 100 teratons of TNT. That's about 2 million Tsar Bombas. The [impact crater from that meteor](_URL_0_) is only about 110 miles wide, which is obviously much smaller than the Middle East. Conclusion: a bomb big enough to create the pictured crater would likely vaporize all life on Earth.", "topk_rank": 1 }, { "id": "corpus-26170", "score": 0.7295453548431396, "text": "First, the largest problem that gets caused by an impact of that size is the ash thrown up, which causes and impact winter, and not the devastation in the immediate vicinity of the impact. This kills off plants, which starves herbivorous dinosaurs, which starves the carnivorous dinosaurs. Not many species could adapt themselves fast enough to these new conditions, so most of them died. That being said; some of the therapods survived and continued evolving, becoming today's birds.", "topk_rank": 2 }, { "id": "corpus-97240", "score": 0.7287527918815613, "text": "Imagine a really large meteor hits Earth. Like, the size that killed the dinosaurs big. Something from the ground might be sent from the impact that would be fast enough to escape the Earth and find its way to Mars. The reverse has basically been shown. There are Mars-rocks in the form on meteorites on Earth. They are rare, but exist as far as we can tell.", "topk_rank": 3 }, { "id": "corpus-276586", "score": 0.7274784445762634, "text": "Not on a routine basis. Of course, an asteroid impact like the one that caused the mass extinction event that eliminated tons of species including the dinosaurs has a dramatic effect on plants and animals. Indirectly, then, Jupiter nudging an asteroid so it heads into the Earth, would affect plants and animals. But I think that's something different from what you're asking about.", "topk_rank": 4 }, { "id": "corpus-276842", "score": 0.7241683602333069, "text": "The meteorite that killed the dinosaurs *did* fall into the ocean. This very likely resulted in some pretty impressive tsunami-like waves, but otherwise didn't make much difference. As I recall, the depth of impact was so great that I would have cratered a significant distance into the upper mantle, a few km of water is going to do next to nothing to something moving with those sorts of energies.", "topk_rank": 5 }, { "id": "corpus-350522", "score": 0.720583438873291, "text": "How would our daily lives be affected? What impact would the dinosaurs have on our society? Would humanity be the same as it would today?", "topk_rank": 6 }, { "id": "corpus-304311", "score": 0.719399094581604, "text": "The physical planet? Not a bit. The biosphere would likely be altered drastically (I'm not really sure even that would be too severe), but the planet itself would be completely unaffected. For reference, Wikipedia [provides values](_URL_0_) of 2.1x10^17 J of energy in the Tsar Bomba (the most powerful nuclear weapon ever tested) and 5x10^23 J for the impact that created the Chicxulub crater (i.e., the dinosaur killer). That is, you would need around 2 million of the most explosive nuclear weapon *ever* in order to reach the energy released in that *one* meteor impact. And the only affect that impact had on the planet was to leave a relatively minor dent.", "topk_rank": 7 }, { "id": "corpus-127118", "score": 0.7193189859390259, "text": "The meteor hit so hard that, in addition to causing a huge explosion that directly killed many living things, it also changed the climate of the earth. For many years after, the earth was very inhospitable to life, and many living things, particularly big animals that were not well suited to facing this more difficult environment, all died.", "topk_rank": 8 }, { "id": "corpus-320693", "score": 0.7164346575737, "text": "Many of the large meteor showers we see are caused by comet dusts, many of which have come from outside the orbit of Pluto, so while yes the Earth would clear some of it put of the way (the solar system used to be a much busier place than it is today), there would be a flow of new particles into the orbit to make up for it. On a human timescale, no, but on a cosmological timescale yes.", "topk_rank": 9 }, { "id": "corpus-87416", "score": 0.7154074311256409, "text": "The event that you are referring to is usually called the [KT extinction](_URL_0_). The current consensus among those who study the period is that there was a roughly 10km meteor that impacted Mexico, causing massive fires and a corresponding \"nuclear\" winter that made it difficult for life to survive in the sea and on the surface. Many species went extinct as a result of this, including non-avian dinosaurs. The dinosaurs that eventually became modern birds did not die, nor did many other species.", "topk_rank": 10 }, { "id": "corpus-317133", "score": 0.7131390571594238, "text": "\"Wiping out all life\" is a pretty strict condition. I'm not sure a meteor of any size could do it. You might completely blow Earth to bits and some bacteria might still survive in some pieces. Also, the extinction events we know about, like the one killing dinosaurs, were very far from wiping out all life. They only got something like 75% of animal species. 25% is still a lot of species that survived. So it'll have to be a lot bigger than that. Or of course you can alternatively make it hit a lot harder.", "topk_rank": 11 }, { "id": "corpus-309034", "score": 0.7129799723625183, "text": "Certainly. The amount of energy released would be on similar scales of magnitude (tons to megatons of TNT). The scale of destruction could be similar as well. Read about the Tunguska event. Of course the scale of destruction would depend on the size of the meteorite, the composition of the meteorite, the angle of impact. The major difference would be that a nuclear reaction will produce some heavy and unusual isotopes, which would not be found in a meteorite impact.", "topk_rank": 12 }, { "id": "corpus-321734", "score": 0.7126283645629883, "text": "We have [observed meteors striking the surface](_URL_1_), they would have formed a crater however in general they would be too small to be observed from Earth. [The explosions of the impact are visible](_URL_2_) but the craters are just too small. Probes orbiting the moon [can see the new craters](_URL_0_).", "topk_rank": 13 }, { "id": "corpus-282814", "score": 0.7119831442832947, "text": "Most likely a few big pieces (at least 10 km diameter) would be projected towards earth, enter the atmosphere and the impact would kill all life on earth. If that doesn't happen (unlikely) a large moon dust cloud would form around earth, block the sunlight for thousands/millions of years and therefore also destroy all life on earth.", "topk_rank": 14 }, { "id": "corpus-254626", "score": 0.7106764316558838, "text": "The Chicxulub impactor (this is the asteroid that killed the dinosaurs) hit near the Yucatan Peninsula, probably in deep water. This asteroid was about 9 miles across and when it hit the energy it delivered was about the same as the Hiroshima Atom bomb *times 10 billion*. It created a tsunami that was over 300 feet high that would have reached Texas and Florida, over 500 miles away. If it had landed in the deep sea, it would have created a Tsunami over 3 **miles** tall. The heat from the asteroids reentry would have vaporized the ocean ahead of it, so it would have essentially hit dry land. When it hit, it dug a crater 60 miles wide and 19 miles deep. The debris from the impact went into back into space and returned. It probably caused volcanoes to erupt around the world.", "topk_rank": 15 }, { "id": "corpus-323887", "score": 0.7093168497085571, "text": "Depends what you mean by giant. Given the expected frequency of getting hit by mass-extinction-causers like the one that killed the dinosaurs, we're not overdue for one or anything. The most recent asteroid to \"hit\" the earth was the [Tunguska event](_URL_0_) in 1911. It exploded in midair with a force equivalent to 15 megatons of TNT and leveled a huge area of Siberia.", "topk_rank": 16 }, { "id": "corpus-104050", "score": 0.7085026502609253, "text": "The global nuclear arsenal is 6,400 MT. The dinosaur killer impact let off 2,390,000 MT. So you'd kick up a lot of dust, but on the cosmic scale you're not even nicking the Earth.", "topk_rank": 17 }, { "id": "corpus-130066", "score": 0.7084551453590393, "text": "The same way a bullet can cause so much damage. Those meteors are moving possibly hundreds of kilometers PER SECOND. That much kinetic energy impacting on the surface of a planet causes massive devastation, and the atmosphere doesn't provide enough braking power.", "topk_rank": 18 }, { "id": "corpus-15015", "score": 0.7077065706253052, "text": "Well, it's a pretty safe bet that we wouldn't be here. But that meteor was a huge extinction event - thousands of species were wiped out over a very short time, geologically speaking. They would have lived and developed far longer, some going extinct naturally, some being lost in other extinction events (there have been a few ice ages since then, for example), some maybe surviving to the present day like sharks have. But that extinction event was the key to mammals becoming so dominant on the earth. Before the changes that meteor brought, mammals were mostly just small scavengers - we needed to lose the dinosaurs and such to develop into larger grazers, and even apes and humans.", "topk_rank": 19 } ]

[ { "id": "corpus-325458", "score": 0.7843236923217773, "text": "Plants have plenty of lipid molecules, just like like animals. They serve as a compact form of energy storage, in addition to parts of some essential cell components such as plasma membranes and the basis for some cell signaling molecules such as steroids. As a rule, most plant lipids are oils, which are liquid at room temperature, rather than fats, which are solid at room temperature. But in the functions they serve in the body and how the body processes them, the difference between fats and oils is mostly arbitrary - you body is not at room temperature anyways. And there are certainly examples of plant \"fats\", a good example being [cocoa butter](_URL_0_)." } ]

[ { "id": "corpus-317194", "score": 0.7424398064613342, "text": "Animal fat is not just chunks of lipid lying around but connective tissue composed mostly of lipocytes, or fat cells. These specialized cells store the actual lipid molecules as small droplets. You could similarly ask why all the water in animals (70-80% of body weight) is not just sloshing around :)", "topk_rank": 0 }, { "id": "corpus-74365", "score": 0.7387929558753967, "text": "As opposed to animal fat you mean? Vegetable oil is basically just plant fat but has less \"saturated\" fat than animal fat like lard (which has to to with the type of molecular bonding). But vegetable oil still has saturated fats, just not to the same extent. Vegetable oil (like canola or peanut) is better than say lard, but still can be problematic if consumed in large quantities.", "topk_rank": 1 }, { "id": "corpus-50321", "score": 0.7382779717445374, "text": "Nuts and seeds are made of more than one material. While you might not be able to digest the fiber, you can digest the protein, fat, etc.", "topk_rank": 2 }, { "id": "corpus-1001", "score": 0.7370840311050415, "text": "It's not initially human fat. Everything we eat is broken down by enzymes into smaller bits. Proteins become amino acids, and fats become glycerol and fatty acids (sugars just become another kind of sugar). Any of those can be used by cells to make energy. The thing about fatty acids is that if they're not used by our cells to make ATP at the time we eat and digest, they can simply become fat in our body when they are moved to our existing fat cells.", "topk_rank": 3 }, { "id": "corpus-310302", "score": 0.7345383167266846, "text": "The strips of \"fat\" you see in bacon is not just fat molecules, it is millions of fat cells. Fat cells store a lot of fat inside them but are also made of cell membranes, proteins, nucleus, etc... The layer of fat cells also have a system connections giving the matrix of cells a basic shape. Notice how you can model wax (pure fat) but you can't mold a piece of fat from an animal. The grease in the pan is mostly just the lipid molecules that escaped the fat cells (rendered). The cooked strips of \"fat\" still in the bacon consists of all these other compound of the fat cells and some of the lipid molecules that are still trapped inside the basic matrix giving the fat shape. After enough cooking time you can basically break down all of these other compounds which will let all the fat escape.", "topk_rank": 4 }, { "id": "corpus-57498", "score": 0.7339506149291992, "text": "The most common reason for an allergy is an allergy to a protein. Nuts have alot of protein. And nuts have weird proteins. It's protein from a *tree*. So it is quite foreign to our mammal body, and easy for our immune system to effectively say \"WTF is this weird protein strand that is like nothing else I have seen?\". *Peanuts are not from trees, but most other nuts are. Peanuts are technically a legume. But still chocked full of weird \"looking\" proteins.", "topk_rank": 5 }, { "id": "corpus-269104", "score": 0.7329625487327576, "text": "Well fat is composed of hydrogens attached to carbons. With saturated every carbon has 2 hydrogens (on the ends of the fat 3). This can lead to an incredibly large molecule as you would imagine. Proteins are composed of small amino acids which are linked together to form a polypeptide. Protein is a functional definition, meaning if it serves a function it's a protein, if not it's just a poly peptide. Fat is less dense than protein because often proteins are much larger. Generally a fat is about 20-30 carbons long. Because fats are non-polar (if you don't know what that means just comment), they aren't very dense. Amino acids are polar and based on their structure they are often more dense. If that answers your question great! If not comment and I can do a more in depth answer, cause molecular biology is rather complex.", "topk_rank": 6 }, { "id": "corpus-279616", "score": 0.7307396531105042, "text": "Your body makes its own fat... even when you eat animal fat, it is broken down and reassambled...", "topk_rank": 7 }, { "id": "corpus-34390", "score": 0.7293390035629272, "text": "A factor in this is that the seeds contain compounds that block enzymes. Enzymes are molecules that break down other molecules in the seeds. When the seeds get wet and these blockers are washed away, the seed starts breaking down itself. Things in the seed like fat are then used for energy and the seed sends out some roots. This stored energy means that seeds can start growing under ground, even without any energy from sunlight! This is also why some people suggest soaking nuts and seeds in water before eating them. The seeds start breaking themselves down and it makes them easier to digest. edit: nuts, not buts...", "topk_rank": 8 }, { "id": "corpus-48266", "score": 0.7280819416046143, "text": "From a very simplified chemical standpoint, fat is mainly made up of carbon and hydrogen. When you burn it, you're breaking it up and combining it with the oxygen you breathe. The carbon combines with oxygen to form carbon dioxide (CO2), which you breathe out. And the hydrogen combines with oxygen to form water (H2O), which can leave in multiple ways (piss, sweat, etc.)", "topk_rank": 9 }, { "id": "corpus-180240", "score": 0.7274615168571472, "text": "You breathe it out. Fat is a complex carbohydrate, made from carbon, hydrogen and oxygen. When you breathe out carbon dioxide, it's the carbon from fat that you're getting rid of.", "topk_rank": 10 }, { "id": "corpus-1480204", "score": 0.7265580892562866, "text": "So I've recently started gaining and have read on here that nuts are great for weight gain. \n\n\nWhat I don't understand is how they can hold so many calories for such a small amount of food. Is it really 500 calories per 100 g of mixed nuts?", "topk_rank": 11 }, { "id": "corpus-313815", "score": 0.7262090444564819, "text": "Most of these foods are vegetables, which don't have solid fat, but rather vegetable oils. These exist in the cells of the vegetables, and the amount of vitamins in these are relatively low by weight.", "topk_rank": 12 }, { "id": "corpus-39807", "score": 0.7258263826370239, "text": "\"Fat\" is the name we give to a group of organic molecules that consist of long chains of carbon. Carbons like to make four bonds. In a saturated fat, every carbon is bonded to two other carbons (the ones in front and behind it in the chain) and two hydrogens. In an unsaturated fat, at least one of the carbon-carbon bonds in the chain is a double bond, so those carbons aren't bonded to two hydrogens. From a health perspective, it's commonly believed that consuming lots of saturated fats (found in meat, dairy, coconut oil, and palm oil) lead to a higher cardiovascular risk so you should try to use oils high in unsaturated fats, like olive, sunflower, canola, avocado, or peanut. Some newer research questions whether this is actually true or not.", "topk_rank": 13 }, { "id": "corpus-73801", "score": 0.7256246209144592, "text": "Ever noticed that peanuts are way cheaper than other nuts? Peanuts are one of the few nuts that aren't technically \"nuts\", because they aren't a fruit, and they therefore grow on the ground like peas. Hence, \"pea\" + \"nut\" = \"peanut\". Most other popular nuts grow on trees, meaning 1. Yields are lower due to space constraints, 2. Harvesting is difficult to mechanize and thus 3. Harvesting is much more time consuming and 4. Nut trees are much more high maintenance (and climate and soil dependent) than peanut bushes. Also 5. Nuts like Cashews and Almonds have poisonous shells, which have to be carefully removed. All these factors and a few other things which I can't think of now, contribute to the price difference.", "topk_rank": 14 }, { "id": "corpus-321275", "score": 0.725021243095398, "text": "Tropical oil crops (e.g palms) tend to contain reasonably high levels of saturated fat (compared to cold climate oil crops). However they are usually different molecules to those found in animal fat (there is some crossover though). There are over 50 molecules that are considered \"saturated fat\"(ty acids). A botanist or biologist will have to answer how and why tropical plants produce these molecules though.", "topk_rank": 15 }, { "id": "corpus-337879", "score": 0.7245782613754272, "text": "Livers, some fish oil and some milk... I don't know other animal products with noteworthy concentration of antioxidants. I'm not sure if the cooking alone explains the difference... Maybe it's intrinsic to the biologies of plants vs animals? Or it comes down to plants not having livers like animals so nutrients are more distributed all over their *bodies*? Probably a dumb question...", "topk_rank": 16 }, { "id": "corpus-30907", "score": 0.7245078682899475, "text": "Peanut butter is an energy dense food, high in fat content. Lots of fat = lots of energy. Energy is one of the main reasons why animals ingest food, so evolution has made good energy sources like fat taste really good to our brains.", "topk_rank": 17 }, { "id": "corpus-140780", "score": 0.7221101522445679, "text": "I'm tired so I'm keeping this brief, but unsaturated (specifically, omega) fat is good for you. It's essential for body function. At least 10 percent should be fat (most people more, 20 percent) but almonds have great fats in them. And calcium, which is a huge bonus. Just saw your note - the junk we eat is typically saturated fat. Bad fat. And some people say 8 almonds is the perfect amount for a day, but if it stops you from eating a bag of chips, eat 100. Unsaturated fats are required in the body for immune response, healing functions, metabolic process, cell structure. Countless things", "topk_rank": 18 }, { "id": "corpus-317984", "score": 0.7213867902755737, "text": "[Seeds have reserves of energy-storing molecules (such as starch and fats) and micro-nutrients, supplying the growing plant with everything it needs for a short while.] (_URL_0_)", "topk_rank": 19 } ]

[ { "id": "corpus-325459", "score": 0.7500944137573242, "text": "I think [Tycho](_URL_2_), a young crater on the moon, is a good example of this. What is going on is that a large impact produces enormous pressure, well above the ultimate compressive strength of the rock. As a result, the rock behaves as a fluid, and you get dynamics similar to [droplets of water](_URL_3_). The impact spreads the rock out, but after that the rock flows back into the depression. The momentum creates a spike in the middle. As the pressure dissipates the rock eventually freezes in place. The larger the impact is, the longer the rock will be able to flow. So a small impact produces a [simple crater](_URL_1_) that looks like a bowl, because the rock never flows back to the center. A larger impact produces the [central peak](_URL_0_) as we discussed. Even larger impacts can produce a [central ring](_URL_4_) if the peak has time to flow back out. Again, all these intermediate stages appear in the water droplets." } ]

[ { "id": "corpus-1169875", "score": 0.7115386724472046, "text": "I just caught a great shot of the moon during Sunday Night Football and noticed, again, the incredible amount of visible craters. I know most of Earth is water, but given the difference in size (and therefore gravity) shouldn't we have had more impact events?", "topk_rank": 0 }, { "id": "corpus-143656", "score": 0.7111958861351013, "text": "Your basic premise is wrong. The far side of the moon has more craters than the near side due mainly to the crust being thinner on the near side allowing magma to fill in larger craters. The moon always faces one side toward Earth due to a phenomenon called \"tidal locking\" where gravitational differences between the Earth and Moon sap energy from its rotation. It does still rotate of course, just with a period equal to its orbital period.", "topk_rank": 1 }, { "id": "corpus-2502", "score": 0.7099155783653259, "text": "The moon has no atmosphere or running water, so there's no erosion. The craters on the moon today are the result of basically every single impact over its entire history. Impacts are still comparatively rare.", "topk_rank": 2 }, { "id": "corpus-185747", "score": 0.7092298865318298, "text": "1. The moon intercepts a lot of meteors and takes one for the team. 2. Earth has an atmosphere that causes many meteors to burn up before they reach land, or at least shrink to an insignificant size. 3. Meteorites still hit earth all the time. 4. Because there's no atmosphere on the moon, there's nothing to cover up meteorite strikes unless another one hits near it and knocks the dirt around. As a result, you can see impact craters that are *very* old. On earth, our surface is constantly changing erasing most old craters (and, of course, many meteorites land in the ocean or lakes leaving no crater to begin with).", "topk_rank": 3 }, { "id": "corpus-318466", "score": 0.7090707421302795, "text": "A lot formed during the Late Heavy bombardment, shortly after the moons formation. There have been a fairly constant stream since then. The reason you don't see the same cratering rate on Earth is that we have an atmosphere and active tectonics which recycle our crust, and erode the surface.", "topk_rank": 4 }, { "id": "corpus-324637", "score": 0.7089954614639282, "text": "Because earth has an atmosphere that destroys most impacters before they hit the surface, oceans that absorb impacts without creating craters, and weather, glaciers, volcanoes and plate techtonics that erase evidence of impact craters. When you look at the moon, you are looking at 4 billion years of impacts. On earth, it's rare to be able to find a crater a few million years old, and the ones older than that no longer really look like craters. The rest have been erased by a living planet.", "topk_rank": 5 }, { "id": "corpus-176639", "score": 0.7077205777168274, "text": "Because gravity is dependent on the mass, but also the distance square, so the distance play a even bigger role here. So yes, the Moon have less mass, but it's also smaller so you are closer to the center of mass of the moon. That's why you don't have 1.5% of the earth gravity at the surface of the moon.", "topk_rank": 6 }, { "id": "corpus-24671", "score": 0.7077035307884216, "text": "Yup! It's all about motion and gravity just on different scales. Also fun to think about, in all of these cases the \"point\" the orbit is centered around is not the center of the object we think of as being the center, but someone between the center of the two objects, as even the smaller object pulls in the larger one, just not as much. In other words the earth is falling towards the moon, just not as fast as the moon is falling towards the earth.", "topk_rank": 7 }, { "id": "corpus-270314", "score": 0.7069218754768372, "text": "Yes, we've actually [seen a brand new crater form](_URL_0_) on the near side of the moon. It's not very big, but it is new. NASA has a set of cameras aimed at the Moon designed to pick up faint flashes caused by meteors hitting the Moon. As it turns out, one flash in March 2013 was a lot brighter than most. Had a very keen-eyed person been looking at the Moon, they would have seen the explosion caused by the impact. The rock that caused this impact was about .2 meters across, about the size of a kid's shoebox. As it turns out, the [Lunar Reconnaissance Orbiter](_URL_1_) passed over the crater formed by the impact less than a day after it occurred. It found an 18 meter wide crater.", "topk_rank": 8 }, { "id": "corpus-73488", "score": 0.7058309316635132, "text": "A couple of points. 1. The Moon is really, **really** far from the Earth. [Here's a scale image of the Earth and Moon with the actual distance between them](_URL_0_). So objects can hit the near side of the Moon almost straight on without having to originate from the Earth. 2. The moon was not always tidally-locked with the Earth. That is, billions of years ago, the Moon rotated independently from the Earth, and did not show only one side to it. That, combined with the complete lack of erosion on the Moon, means that many of the craters facing us would have been formed back when that side *wasn't* facing the Earth.", "topk_rank": 9 }, { "id": "corpus-166059", "score": 0.7053681015968323, "text": "Two reasons. 1. The Earth has an atmosphere, so a lot of the things that might strike the earth burn up instead. 2. The earth has an atmosphere and weather, so things that do hit and cause craters erode over time, there isn't erosion on the moon and mars.", "topk_rank": 10 }, { "id": "corpus-144613", "score": 0.7048119306564331, "text": "The Moon has little atmosphere and no geologic activity. The vast majority of impacts on the Moon were very early in the Moon's life, since the early Solar System had *a lot* more crap flying around, and most of that crap that ever *will* collide with the Earth or Moon already has. Same deal with the Earth. It's covered in craters. However, we have all this geologic activity, forestation, wind, erosion, etc. and after billions of years the craters kind of get flattened out. On the Moon, they basically stay forever since it doesn't have any of these things.", "topk_rank": 11 }, { "id": "corpus-325401", "score": 0.7045508623123169, "text": "Partially right. It's mainly erosion, and many smaller things are lost due to disintegration in the atmosphere. Water, wind, ice, etc- they all work to reform the landscape, erasing evidence of impacts. But we still see plenty of craters in dry places or places with less erosional activity. Meteor crater in Arizona is a good example. Also, impacts in the ocean are much less likely to leave a crater (unless it's really big), and since oceans cover over half the surface area of the earth, that many less craters!", "topk_rank": 12 }, { "id": "corpus-150344", "score": 0.7036416530609131, "text": "Given the scale of the impact theorized there wouldn't really be a crater. We're talking about an object the size of Mars hitting the Earth. Had it not happened so long ago that gravity had once again smoothed out the Earth's surface, we'd notice a hell of a lot more than something like a crater. This theory is all about what we see on the moon and (mostly) not about what we see on Earth. The moon is made of almost the exact same type of stuff the Earth's crust is made out of in all the same proportions that the Earth has. However, the moon has almost none of the stuff found in the lower layers of the Earth. As such, it looks like the moon is made out of material from the Earth's crust. The most promising theory about how a bunch of the Earth's crust got 300,000 km away is that an impact blasted it out into space where its gravity caused it to collect and condense into the moon we see today.", "topk_rank": 13 }, { "id": "corpus-321733", "score": 0.7034941911697388, "text": "Most of the craters in our solar systems come from the [late heavy bombardment](_URL_0_) roughly 4 billion years ago. due to the lack of tectonics (and therefore conservation of craters) we can see that the chance for an impact are relatively small & #x200B;", "topk_rank": 14 }, { "id": "corpus-318532", "score": 0.7022235989570618, "text": "Because there isn't enough mass there to accrete into a planet. The asteroid belt for example only has 4% of the mass of the moon.", "topk_rank": 15 }, { "id": "corpus-308344", "score": 0.7022005319595337, "text": "Here's a paper that asked that question... > We calculate the current spatial distribution of projectile delivery to the Earth and Moon using numerical orbital dynamics simulations of candidate impactors drawn from a debiased Near-Earth Object (NEO) model. We examine the latitude distribution of impactor sites and find that for both the Earth and Moon there is a small deficiency of time-averaged impact rates at the poles. The ratio between deliveries within 30° of the pole to that of a 30° band centered on the equator is small for Earth ( < 5% (0.958±0.001) and somewhat greater for the Moon (∼10%) (0.903±0.005).  So the Earth's poles receive slightly less meteorites and impacts than the equator, and the effect is slightly more pronounced on the Moon. Ref: Gallant, J., Gladman, B. and Ćuk, M., 2009. [Current bombardment of the Earth–Moon system: Emphasis on cratering asymmetries](_URL_0_). Icarus, 202(2), pp.371-382.", "topk_rank": 16 }, { "id": "corpus-282172", "score": 0.7016661167144775, "text": "We do, it's just that down here we just call it ground. One of the biggest pieces of evidence pointing to the impact formation theory is the similar composition between the moon and the earths crust. Since we live on Earth, we have a bias towards it, so we say that we find traces of Earth up there, not vice versa.", "topk_rank": 17 }, { "id": "corpus-236408", "score": 0.6997352242469788, "text": "That's not a line of rocks, it's a line of impact craters, most likely from a comet or asteroid that broke apart before impact. There's no scale on those images, but based on the overlaid latitude grid, that line of craters subtends about the same distance as one degree of latitude, so it's about 30 km long. These features are called [crater chains](_URL_0_). Some comets and asteroids are thought to be very loosely held together, and if they pass too close to the moon they can be broken up into many smaller pieces due to tidal forces. These pieces all stay in pretty much the same orbit, but with very small variations, and those variations tend to spread them out in a line on the same orbital plane. If their trajectory leads to an impact with the surface, you have many small pieces impacting along the plane of their orbit as the moon moves beneath them, resulting in a chain of impact craters.", "topk_rank": 18 }, { "id": "corpus-121903", "score": 0.6977738738059998, "text": "Two reasons. 1 : It's an optical illusion. The closer the moon is to the horizon, the easier it is to compare its relative size. It seems bigger mostly because you can see it compared to landmarks when it's low on the horizon. 2 : Atmospheric distortion. The lower it is on the horizon, the more \"atmosphere\" the light has to pass through. I can't remember exactly how it works but basically it acts as a lens.", "topk_rank": 19 } ]

[ { "id": "corpus-325460", "score": 0.7513056993484497, "text": "There is a fixed amount of mass-energy - matter can become energy and energy can become matter, but none can be created or destroyed. The observable universe is not infinite, and since we can't \"see\" anything past the edge of the observable universe (there has not been enough time in all of history for light to get from there to here), that doesn't really matter. Just like the question of parallel universes or what happened before the big bang, it simply isn't in the domain of things that Science has the ability to know about. We do know that the density of the observable universe, when you look at it from a large enough scale, seems to be uniform. We don't know and don't care if it continues to be uniform past that horizon - anything out there is far far away, and thanks to the expansion of the universe, it is getting farther away at a rate faster than the speed of light - it cannot possibly have any impact on us, so we simply will never know." } ]

[ { "id": "corpus-2020521", "score": 0.7136552333831787, "text": "Is there a finite amount on earth? How it is produced ?", "topk_rank": 0 }, { "id": "corpus-166411", "score": 0.7134894132614136, "text": "The universe isn't expanding by way of new matter. Existing matter is simply getting farther apart.", "topk_rank": 1 }, { "id": "corpus-740461", "score": 0.7134342789649963, "text": "I have seen a lot of talk on this subreddit concerning very bizarre, polarized thoughts on existence in general. It comes in many forms most easily seen in the rhetoric of the .self posts. Words like \"oneness,\" \"consciousness,\" \"buddha,\" \"infiniteness,\" are commonly used but are entirely subjective and are effectively worthless in written or spoken communication. Reality is math and it came from nothing. It is possible to create something from nothing, the simplest way is in pairs. Theoretically, we can take completely empty space, which has some very weird properties on it's own accord, and manipulate it creating two completely equal, but completely opposite physical beings. This, surprisingly enough, does not violate the laws of physics. How many different ways can 0=0 be rewritten? Infinitely, 0-1+1=0+1-1 etc; super simplified, but that's the gist of the idea.\n\n Mathematics is the reason behind the perceived \"oneness\" with the universe. This \"oneness\" can be captured in concrete terms with a minor understanding of gravity, a.k.a. a physical manifestation of mathematical occurrence. Every piece of matter is gravitationally connected with every other bit of matter in the universe. The blinking of an eye will have effects on the farthest stars in the most distant galaxies, this effect happens to be extremely close to nothing and is generally reinterpreted by the rest of the universe on it's way to that distant galaxy, but it is an effect nonetheless. This is chaos theory.\n\nThe laws of physics are defined as such only if they remain consistent at every place in the universe. Another way to put this is that no matter which way you manipulate the universe, whichever direction you look, it will always look the same. This idea is known as self-similarity and is the basis of fractal mathematics. I do not claim to know all the answers as some do, and I really think you should approach this subject and dissertations on it with a heavy grain of salt and a strong dose of skepticism. You will see people's ideas that could have only been the result of a little confusion and a lot of tryptamines; \"mathematical equations\" that read, couldn't make this up, (exi)=(st). No joke, don't get slippery on me, friends, we can make progress but we don't have the time for quackery. I will include a personal favorite list in a suggested order as an introduction to fractals. The math is not hard, just gorgeous, and a high school education would be more than enough for it to make sense. I wish you all a fine time and hope I have provided you with the tools or maybe a stimulus for us to elucidate ourselves more in this most paraprosdokian of an existence.\n\nTeaser: \n\nmath 1: \nmath 2: \n\nColors of Infinite: \n\nWelcome, friend.", "topk_rank": 2 }, { "id": "corpus-308295", "score": 0.7130401134490967, "text": "In a related question that I don't think deserves its own thread, how settled is the existence of dark matter? Could it just be some sort of effect of regular matter we don't understand yet, or is it pretty confirmed that it does in fact exist.", "topk_rank": 3 }, { "id": "corpus-159617", "score": 0.7129313349723816, "text": "This is probably an unsatisfactory answer but the universe isn't really in anything. All that there is is 'in' the universe.", "topk_rank": 4 }, { "id": "corpus-255693", "score": 0.7129186987876892, "text": "First off, dark matter is in our universe, and isn't separated in any special way - it's actually mixed in quite happily with normal matter most of the time. Saying the universe is 80% DM, 20% normal matter is just like a cake which has 250g flour, 250g sugar and 3 eggs - they're all in there, but they're mixed together and not stuck in one part of it. > \"These WIMPs collide in space, annihilating and decaying into ordinary particles, including electrons and their antimatter counterparts, positrons.\" That's actually a pretty misleading thing to say when discussing WIMPs (although not wrong) - the main point of WIMPs (Weakly Interacting Massive Particles) is that they spend most of their time *not* doing any of those things (i.e. not interacting), hence why there can be so many of them around without being easily detectable, and not bumping into/bouncing off normal matter.", "topk_rank": 5 }, { "id": "corpus-312549", "score": 0.7129034399986267, "text": "I believe the answer to this question is a description of the OP's misunderstanding of solid matter. He sees solid matter as some arrangement of unconnected atoms suspended some way to form a mass. What he neglects to consider is *why* do atoms form solids in the first place? So we are held together by the electromagnetic force, which bonds atoms into molecules, and molecules together too. Even if the universe were completely static, we would fly apart into plasma if it were not for these forces. The dark energy is present inside the volume you occupy, but has very little force per unit volume. It pushes on you, your atoms \"push back\".", "topk_rank": 6 }, { "id": "corpus-278183", "score": 0.7129004001617432, "text": "\"The universe is commonly defined as the totality of everything that exists\" (_URL_0_) Therefore, by definition the universe is a closed system as a system which is not closed implies interaction/exchange with another system. As everything is part of the universe there are no other systems. However, according to quantum mechanics a closed system cannot necessarily be predicted and therefore the universe is therefore not necessarily deterministic. If a system is deterministic or not has little to nothing to do with whether it is closed or not. In classical physics (i.e. non relativistic, non quantum) every system is deterministic as even in open systems the rules of exchange of matter or energy with the outside are governed by the same deterministic rules.", "topk_rank": 7 }, { "id": "corpus-280048", "score": 0.7127962708473206, "text": "There is no edge, center, or end to the universe. The universe does not sit in some other space... it **is** space (and time).", "topk_rank": 8 }, { "id": "corpus-257027", "score": 0.712762176990509, "text": "> Does every single bit of data exist in a physical form(switch) somewhere in the world? What other forms are there for data to exist? Metaphysical? Spiritual? Your question reads as \"does every physical thing exist in physical form?\" which has the unenlightening answer of yes, by definition. > Is it currently or theoretically possible to have data without matter?\" There is more to the physical world than matter. There is also energy/fields. For instance, photons of light from distant stars carry to us data about the star, and yet these photons are not matter and do not rely on matter to continue on their way and continue to carry information. Similarly, the optical signals in fiber optics carry information and yet are not matter.", "topk_rank": 9 }, { "id": "corpus-317903", "score": 0.7124612927436829, "text": "> One rule of matter is it cannot be created nor destroyed. This is not true. It happens all the time. > wouldn't each meteor essentially add a small amount of matter to our planet thus making it bigger? Yes. > Would we be able to notice a change theoretically over 100,000 years? No. However, let me quote NASA: > [\"Scientists estimate that 44 tonnes (44,000 kilograms, about 48.5 tons) of meteoritic material falls on the Earth each day.\"](_URL_0_) This puts an estimated ~2.7x10^-11 % more mass on the Earth over 100,000 years. In comparison, the mass of the Earth is listed as 5.9722x10^24 kg [by NASA again](_URL_1_), to the significant figures this measurement is listed, such as change would fall far below being detectable.", "topk_rank": 10 }, { "id": "corpus-169891", "score": 0.7124221920967102, "text": "It's not expanding *into* anything, as far as we know. We are unaware of anything external to our universe, and even the concept of 'space' is part of that universe, so some exterior location may not even make sense. We don't know that the universe is infinite, but it is, as you note, currently the mostly widely held model. Over time, there is more space between any two given distant objects, ignoring their own motion. So there is more space over time. Or if you prefer, space is becoming *less dense* over time. Trying to picture space as 'an object in a room, getting bigger\" is simply thinking about it wrong.", "topk_rank": 11 }, { "id": "corpus-289335", "score": 0.7124103307723999, "text": "Basically, nobody knows. The idea is that all energy and matter (the two are interchangeable) have existed in some form since at least the big bang, and presumably before then, as well. Since we have a very poor understanding of what \"before\" the Big Bang might even mean, we are still largely in the dark about this. Since the universe is expanding, and the rate at which it is expanding is increasing, it seems plausible that the the heat death of the universe will mean that all energy will be 'spread out' and particles will essentially just whizz through space all alone for a very very long time. After that... we don't really know. Maybe nothing. [This Wikipedia article](_URL_2_) might help. Here's something from the US Department of Energy attempting to answer this question: _URL_2_", "topk_rank": 12 }, { "id": "corpus-58215", "score": 0.7123960852622986, "text": "well one way is by having sets of infinity. A fun example I like to use is from D & D. One place, an evil otherworldly plane named Baator (think Hell) is made up of nine layers. Each layer is a world to itself, and is infinitely vast. No matter how far you go you won't reach another layer without special means. But they're all connected. Compare that to another evil plane, the Abyss. Its layers are infinitely vast too, but it has an infinite number of layers. So it is a bigger infinite than Baator.", "topk_rank": 13 }, { "id": "corpus-300857", "score": 0.7123249769210815, "text": "Strictly speaking, the big bang theory doesn't deal with where matter originates comes from and whether there was a single \"point\" in empty space or not. It only explains the evolution of the universe after that point. Also, the \"point\" didn't explode and it wasn't in \"empty space\". There was no empty space. The \"point\" was the universe, it just [got a lot bigger](_URL_2_). That aside, it is a good question. The answer is that on a quantum scale, energy and matter [fluctuates](_URL_0_), particles pop in and out of existence. Those small fluctuations on a small scale are magnified to a macroscopic scale as the universe expands, and the universe should actually be *more* asymmetric than it is if we only considered quantum fluctuations. The big bang theory explains the apparent uniformity of the universe with a period of [cosmic inflation](_URL_1_), where the universe expanded extremely rapidly in a very short period. EDIT: Fixed a link. Some reformatting.", "topk_rank": 14 }, { "id": "corpus-166204", "score": 0.7123001217842102, "text": "They don't have zero volume and infinite density, because that's impossible. However we don't yet have the physics to work out what their volume (and hence density) actually is. We know that if we run the maths we get zero volume but few physicists believe that's really the case.", "topk_rank": 15 }, { "id": "corpus-319372", "score": 0.7122499942779541, "text": "I'm not sure this question can be answered. For any size of the Universe we can ask why is it so big? We can talk about why it is this size, but we can't use a comparison like big/small since we have nothing to compare it to. As for the size, it is a factor of the amount of energy/mass at the beginning and how long ago that was. Which isn't really an answer.", "topk_rank": 16 }, { "id": "corpus-274530", "score": 0.7120780944824219, "text": "With the flat topoly the universe has, it is most likely infinite, thus the question of the shape is meaningless. Perhaps the universe has a small curvature, but this doesn't seem to be the case (our measurements could be too inaccurate). Another possibility would be a flat universe with a finite size, but we don't have found any evidence (repeating structures) for that either. So for the best knowledge we have, the universe is a flat and infinite one. Note that flat doesn't mean it has the shape of a paper sheet (afterall it's threedimensional), but that it generally follows euclidian topology, or in other words it's flat like an airstrip or the surface of an table in any direction you would go.", "topk_rank": 17 }, { "id": "corpus-307418", "score": 0.7119265198707581, "text": "The size of the universe may have always been infinite, even at the beginning of the expansion. In fact, present data favors this situation.", "topk_rank": 18 }, { "id": "corpus-183297", "score": 0.7119132280349731, "text": "We don't know if the universe has a center because we don't know if the universe has edges or if it goes on forever. What we do know is that the observable universe, which is the part of the universe that we can see, looks pretty much the same everywhere in the sense that it has much of the same things that behave in much of the same way. If the universe is infinite, meaning it goes on forever in all directions, it would not have a center. If it has some type of shape, it might have a center but not necessarily. If it has finite mass, which is a limit amount of mass, then it does have a center of mass and a center of gravity. If it does have boundaries then we are tasked with the question of what the nature of those boundaries are. I imagine they might be imperceivable to us. In fact I personally think that might be the case.", "topk_rank": 19 } ]

[ { "id": "corpus-325462", "score": 0.807296872138977, "text": "This question has been asked [many times before.](_URL_0_) From what I remember the consensus is that the preference for cold drinks is mostly just a peculiarity of western culture." } ]

[ { "id": "corpus-63256", "score": 0.7653403878211975, "text": "This is a cultural thing. Many cultures prefer water to be warm, rather than cold. Same goes for other drinks. It's not at all uncommon for people to drink iced coffee, and ice tea is incredibly popular even in Western society.", "topk_rank": 0 }, { "id": "corpus-56259", "score": 0.7600566744804382, "text": "Our preference for cold drinks is likely to be very very old, something we evolved when we were just animals. If you're an animal, some kind of ape or whatever, there are no fridges, no piped water, no cans etc. If you're drinking, you're probably either drinking from a stream or river, or from a pond or puddle, something like that. Which is better? A small, cold, fast flowing stream is best. Ponds and especially puddles, standing water in general, is warmer, and is likely to be much less clean and is more likely to contain diseases or parasites. So we prefer cold drink if we can get it, because the room temperature water available when we were animals wasn't very safe to drink. Edit: Later, when we had fire and could boil things (which kills parasites), we would have got a taste for hot drinks. But still we like our drinks either hot or cold, lukewarm stuff still isn't that appealing.", "topk_rank": 1 }, { "id": "corpus-64277", "score": 0.759337306022644, "text": "Because we are comparing the drink's temperature, to the temperature we believe it should be. ie the coffee is colder than you want it to be, and the coke/pepsi is warmer that you want it to be", "topk_rank": 2 }, { "id": "corpus-109198", "score": 0.7586859464645386, "text": "People (cultures) may have evolved to prefer cold or hot (tea) water as opposed to room temperature water because cold water is often from a fresh frozen source recently melted and fast moving. Hot water is recently boiled and sterile. And room temperature water is likely stagnant and infectious.", "topk_rank": 3 }, { "id": "corpus-113445", "score": 0.7527024149894714, "text": "This answer isn't really about taste, but a good reason cold drinks are preferred: Stagnant water is often dangerous to drink because it's more likely that contaminants have concentrated in it and its low oxygen environment encourages the growth of dangerous bacteria and parasites. Safer, running water tends to be colder because its motion promotes evaporation which cools and oxygenates it. EDIT: Don't assume running water is safe; there could be a rotting carcass, a cemetary or a leaking drum of nuclear waste upstream of you. Thanks.", "topk_rank": 4 }, { "id": "corpus-14715", "score": 0.751707136631012, "text": "This is culturally subjective. Many Asian countries, China most notably, much prefer drinking hot water. There is a flavor difference and you find cold water tastier because that's typical for your culture, your \"normal.\"", "topk_rank": 5 }, { "id": "corpus-166944", "score": 0.7505878210067749, "text": "Your preference through years of conditioning. Plenty of cultures drink warm or hot water exclusively and aren't very thrilled about being served cold water.", "topk_rank": 6 }, { "id": "corpus-323398", "score": 0.7490173578262329, "text": "You're asking a subjective question. I prefer to eat almost anything cold, personally. I don't like to heat up left over pizza for example, but not because I'm lazy. Cool tomato sauce is sweeter, the cheese sharper, so on. People like different foods. The case here is that you like warmer food, and I think the reason for the preference is likely explained accurately by [pofo](_URL_0_).", "topk_rank": 7 }, { "id": "corpus-180287", "score": 0.74891197681427, "text": "Because how we usually think of them is hotter and colder respectively. You associate coffee with heat and soda with being cold.", "topk_rank": 8 }, { "id": "corpus-2762250", "score": 0.7483811378479004, "text": "I have been on a strict zero calorie cold drink diet for a while. Sprite zero tastes the same as regular and same goes with any other drink. So why do people still drink regular soda? That stuff also has calories in it as well!", "topk_rank": 9 }, { "id": "corpus-2762605", "score": 0.7474881410598755, "text": "This may be mostly just an American/Western World thing, but I hear people always talk about how if any kind of drink or food gets to be room temperature it's suddenly gross. Coffee and tea come iced or hot, no in between. One would eat ice cream cold, and meat hot. Snack food is an exception, but I can't think of too many else. I've heard the reason people like beer cold (with the exception of craft) is because it lessens our ability to taste and makes it not so bad, but with warm beer you get the full brunt of it. \n\nI was just wondering if their was some particular reason for this?", "topk_rank": 10 }, { "id": "corpus-58249", "score": 0.7466086149215698, "text": "It's more to do with how refreshing it makes you feel. Eg: its hot, you drink a cold drink to cool down, or it's cold morning/night so you drink a hot chocolate or a coffee", "topk_rank": 11 }, { "id": "corpus-192737", "score": 0.7442566752433777, "text": "You generally don't taste things as well when they are cold, so cold alcohol is a bit easier to take that warm. You actually taste it just a bit less. This is the same reason why melted ice cream at the bottom of the bowl is just so darn yummy. One of the theories behind this is: Your tongue sends signals to your brain. Warm food actually changes the way your tongue sends those signals at the level of the individual cells, so the signal is actually stronger with warmer foods!", "topk_rank": 12 }, { "id": "corpus-182143", "score": 0.7425877451896667, "text": "Depends on your definition of cold and personal preference. The only time I prefer cold water is when I'm exhausted and thirsty, usually from working out or something....at that point cold water helps cool me down and quench my thirst. Any other time I drink room temperature water and find it just as refreshing as what I consider cold water.", "topk_rank": 13 }, { "id": "corpus-80539", "score": 0.7418097257614136, "text": "Hot drinks are hotter than cold drinks are cold. Cold drinks are rarely colder than freezing, and are still refreshing in the 40^o - 50^o range. Also, if something is frozen solid, it takes extra energy to thaw it, which means extra time. You drink coffee at between 120^o and 140^(o), below that it starts getting lukewarm and bitter. That means a cold drink is ~20-35^o below room temperature, while a hot drink is ~50-70^o above. Roughly twice the difference, roughly twice the time.", "topk_rank": 14 }, { "id": "corpus-167498", "score": 0.7405087351799011, "text": "Coldness greatly reduces the taste of something (ice cream, for example, has a ton of sugar and flavoring because of the temperature its served at, but if it was eaten warm it would taste too sweet). Water has minerals and such in it that you can really taste when consumed at room temperature. When consumed cold, you can't taste the additives as much, so it tastes \"purer\".", "topk_rank": 15 }, { "id": "corpus-166405", "score": 0.7389423251152039, "text": "One reason is because the colder water stimulates the nerves on the top of your mouth more than the hot water and causes you to feel it more. Also, if you are thirsty, your body associates cool liquids to be fresher than warm water and causes you to feel more sensations, therefore it makes it taste better and more refreshing.", "topk_rank": 16 }, { "id": "corpus-132330", "score": 0.7376899719238281, "text": "A soda appears to be \"more carbonated\" when it's cold since the CO2 molecules are more thoroughly dissolved in the soda (the solvent), while when a soda is hot, the CO2 molecules are separate from the soda, making it seem 'less carbonated\". Such a difference occurs because gases are more soluble at colder temperatures. This occurs due to the fact that at higher temperatures the gas molecules have a greater average kinetic energy, thus enabling them to break the intermolecular forces which keep them dissolved. Also, at higher temperatures gases have higher vapor pressures which makes them less soluble (this is why manufacturers bottle soda under pressure-to keep the CO2 dissolved). This correlation is evident in the ideas gas law (PV=nRT), since increasing temperature also increases pressure.", "topk_rank": 17 }, { "id": "corpus-25177", "score": 0.7375766038894653, "text": "Part of it the taste from just what your mouth comes into contact. Glass will be colder than plastic, and glass and metal generally have less of a taste that plastic. Anothing thing to consider is the difference between drinking from a bottle and a glass. With a glass, your nose is better exposed to the drink, thus you are able to smell it, which affects the taste experience you get from it. This is why Beers, Wines, Whiskies etc are meant to be drink from large open glasses.", "topk_rank": 18 }, { "id": "corpus-22534", "score": 0.7375014424324036, "text": "The colder something is, the harder it is to smell/taste certain aromatics and dissolved minerals. So, besides being more refreshing, it actually tastes better because it tastes less.", "topk_rank": 19 } ]

[ { "id": "corpus-325463", "score": 0.8019156455993652, "text": "Yes, but not by very much. The the closer part of the galaxy is a more recent image of what's going on in that particular region of Andromeda, while the far side is an older one. This gives a slightly skewed or warped perception of the state of the galaxy as a whole, but it's minimal and doesn't cause anything that would significantly impact our perception of Andromeda's shape, or its composition, distance, etc. Despite the differences being potentially hundreds of thousands of light-years depending on what points you choose to look at, it needs to be remembered just how enormous galaxies are, how far away they are from Earth, and how slowly they rotate from the perspective of a distant observer. Combine these factors, and you realize that the distortion of the entire image of Andromeda is negligible." } ]

[ { "id": "corpus-94546", "score": 0.76033616065979, "text": "Not really. The human eye isn't that good at gathering light. The Andromeda Galaxy is a bit over 2 million light years from Earth. In the sky it is 6 Full Moons across. That's huge. Why can't we see anything more than a small smudge in the sky? Because the human eye sucks at gathering light. In space that wouldn't be much better. Those pictures you see of other galaxies taken through telescopes take hours to days to take and not because they're really far away and small but because it takes time to gather enough light to get the pictures.", "topk_rank": 0 }, { "id": "corpus-247535", "score": 0.757871150970459, "text": "The oldest light we receive is the cosmic microwave background, and the distance we are receiving it from is growing with time. Because of this, fully formed galaxies and stars can't exactly pop into view, other than getting bright enough that we notice them(which is why gamma ray bursts are among the most distant events observed) If we had unreasonably powerful telescopes and computers to capture and analyze massive amounts of incoming light and watched for billions of years, we could theoretically watch the gas at the origin of the current background radiation collapse and form structures as the distant early universe exited the [dark ages.](_URL_0_) But for now we're stuck looking for the occasional short burst, or focusing our lenses on the same place for long enough that we can recognize the faint red splotch of a [young galaxy.](_URL_1_)", "topk_rank": 1 }, { "id": "corpus-251137", "score": 0.7574532628059387, "text": "To some extent, this depends on what you consider \"seeing\". The Andromeda Galaxy is visible, 2.5 million light years away, outside our own galaxy in moderate/low light pollution. As far as I know, that is the most distant naked eye 'object' visible. However, it's visible as a collection, we can't resolve individual parts of it (the stars that make it up) so I don't know if this falls within your restrictions.", "topk_rank": 2 }, { "id": "corpus-320236", "score": 0.7572501301765442, "text": "They're not just depicted that way, they are that way! [This](_URL_0_) is a photo of the Andromeda galaxy. It's not an illustration or false color, it's just a photo. You can even see it with your own eyes if the sky is dark enough, in fact the only part you'll see is the bright center portion. Galaxies are densest at the center, so that's where the brightest light comes from.", "topk_rank": 3 }, { "id": "corpus-659539", "score": 0.7568415999412537, "text": "If it’s 50 million light years away aren’t we looking at light from 50 million years ago? Or am I way off?", "topk_rank": 4 }, { "id": "corpus-37278", "score": 0.7560313940048218, "text": "Keep in mind that when viewing a disc, you aren't generally seeing a galaxy edge on, so while it may be 100,000 light years in diameter, the near end isn't likely to be 100,000 light years *closer to you* than the far end, but some fraction of that. Beyond that, it *is* distorted, but the speed of the objects is slow enough that it isn't particularly obvious. If you saw Earth say 25-50,000 years 'out of place' with respect to the near end of the milky way, would you notice that fraction of its 250 million year orbit?", "topk_rank": 5 }, { "id": "corpus-317552", "score": 0.7541123032569885, "text": "Remember that the galaxy in question is traveling slower than the light that it is emitting; thus the light is reaching us know, but the galaxy will not arrive for some time. In the case of Andromeda, which is about 2.5 million light years away, it'll be somewhere around 4 billion years till it reaches the Milky Way because it is moving towards us at tiny speed compared to the speed of light.", "topk_rank": 6 }, { "id": "corpus-833913", "score": 0.7534617781639099, "text": "Maybe I am all wrong, but if the first light from the stars was emitted around 13 billions years ago, it means it has been travelling this entire time through the expanding universe while being redshiffted. This light is still reaching it since we can see it with HST and JWST in the future. My question is: will this infrared light from that age ever stop reaching us? Shouldn't we get \"younger\" light with each new second? Or does the expanding universe cancels out that effect?\nExample: We see the light from a Galaxy who is 13Gy old. The same light we see next year (or even of a second later)should be slightly younger, right?\nI know I haven't been really clear but I hope you understand what I am asking! Thanks!", "topk_rank": 7 }, { "id": "corpus-834879", "score": 0.7523126006126404, "text": "So, in 4 billion years the Andromeda galaxy is going to collide (or merge, as I like to say) with the Milky Way galaxy. From Earth at the moment, we see Andromeda as how it appeared 2.3 billion years ago... But since it moves towards us, 2.3 billion years ago it should have been further away than it is now. So, if I'm correct, does this mean that the Andromeda galaxy is actually closer to us than it appears?", "topk_rank": 8 }, { "id": "corpus-96337", "score": 0.7512323260307312, "text": "That's kind of like asking why you can see the moon, but why can't you see a grain of sand 100 yards away. The sand is much closer, but the moon is much bigger. Andromeda Galaxy is 220,000 light years across and contains a trillion stars. A typical star is 1.4 million kilometers across. That means a star is 0.00000000006726% as big as a galaxy. Also, Andromeda is \"only\" 2.5 million light years away - not billions of light years.", "topk_rank": 9 }, { "id": "corpus-7864", "score": 0.7465702891349792, "text": "First, it is important to level set on the distance. The closest galaxy to the Milky Way is the Andromeda galaxy. It is around 2.5 million light years away. A light year is the distance that light travels in a year. Since light travels at roughly 300,000,000 meters per second, a light year is a very far distance. Now to answer how galaxies such distances away can be viewed and photographed. Time. The universe has been around for billions of years and has been expanding during that time. This means that billions of years ago when the light was emitted from very distant galaxies and started making its way to Earth, it didn't have as far to travel. This is how we can see things that are farther away in light years than the age of the universe.", "topk_rank": 10 }, { "id": "corpus-302646", "score": 0.7462894320487976, "text": "Yep. The speed of light is the limiting factor here. When a photon is emitted from a distant galaxy, it will travel however many million/billion light years to arrive here, and also take however many million/billion years before it enters the optics of the telescope, so what we see is most certainly a 'view into the past'. But of course, if you were to instantaneously travel to the galaxy where the light was emitted, it would be a very different place, because to be quite honest with you, the speed of light really isn't all that fast, when you look at total size of the universe. For example, when you look at the Moon, you're really seeing it as what it looked light 4 seconds ago, because it takes light 4 seconds to bounce of the lunar surface and enter your retina. Likewise, if you were stupid enough to look at the sun, you would see it as it was 8 minutes ago, because the light took 8 light minutes to travel the 150m km between the Earth and the sun.", "topk_rank": 11 }, { "id": "corpus-35379", "score": 0.7458921670913696, "text": "Yup. You're looking back in time a million years ago when you're looking at stars in the Andromeda galaxy. Civilizations could have started and ended and you would have no idea. If an current Earth like civilization in Andromeda were looking at Earth right now, they would have no idea.", "topk_rank": 12 }, { "id": "corpus-298024", "score": 0.7457971572875977, "text": "I'm not sure I understand your question so let me explain how we observe galaxies. Andromeda is the largest galaxy in our local group of galaxies. With the naked eye it is visible as a [smudge](_URL_2_), not much more than a star. (Note that M31 = Andromeda in that picture.) However, with powerful telescopes we can do better than this. Since galaxies are so large - they typically contain hundreds of billions of stars - we are quickly able to resolve the galaxy itself rather than just a point of light. This is in contrast to stars, which even with our best telescopes remain not much better than smudges. Take a look at [this](_URL_1_) to get an idea for how much better a powerful telescope can do. This is the same galaxy, Andromeda, as in the last picture. So with galaxies, we can make out their large-scale structures directly. We observe many types of galaxies, like elliptical and dwarf and spiral. [Here's](_URL_0_) a schematic.", "topk_rank": 13 }, { "id": "corpus-282730", "score": 0.7454980611801147, "text": "Yes, that's exactly why we look at things at large distances. Very distant galaxies seem to be quite different than galaxies today. We see them interacting with other galaxies more often, they form stars much faster, etc. In fact, one of the most \"distant things\" we can see is the radiation left over from the Big Bang, the so-called \"Cosmic Microwave Background.\" This light comes from the very beginning of the Universe, when things were much different than they are today!", "topk_rank": 14 }, { "id": "corpus-260791", "score": 0.7446386814117432, "text": "No. Light takes time to travel from these galaxies to us, and we can basically see things where light was transmitted 13.7 billion years ago. At that time, universe had no galaxies, and only uniform hot dense plasma, roughly the temperature of the surface of the Sun.", "topk_rank": 15 }, { "id": "corpus-278081", "score": 0.7423398494720459, "text": "You might get controversial opinions on this, and I've been a little conflicted as I've been thinking about it, but I think I'm going to have to go with the Andromeda Galaxy in terms of overall structure. I think that telescopes at this point are so good that we can map out the interstellar medium (ISM) really well, the spiral structure, and we can see the whole thing. For the Milky Way, we have to look through foreground parts of it to see more distant parts, and this leads to unknowns in the spiral structure on the far side, the bar size, etc. And I think that even though we can study parts of the ISM up close here, the fact that you can map out the whole thing there in spatial terms and decent wavelength coverage, and that we can't quite do the same thing here over very long scales, means that Andromeda wins again. I could be wrong, though, and I'd love arguments for or against.", "topk_rank": 16 }, { "id": "corpus-835261", "score": 0.7421218752861023, "text": "So I have a basic understanding of the way light works in space. Other galaxies are so far away that it takes light an incredible amount of time to reach us. So the pictures we have of other galaxies are from a very long time ago, correct?\n\nSo if we could somehow construct a telescope that could see far enough, could we see what the universe was like in its very infancy? Or even the big bang?\n\nI understand that seeing that far into space is near impossible. Given the scale of just the known universe. But just in theory, is it at all possible?", "topk_rank": 17 }, { "id": "corpus-191818", "score": 0.7406807541847229, "text": "Astrophysics graduate here (as well as current engineering student but that's less relevant haha) 🙋🏻‍♂️ So when we look at objects in space that are a certain distance away (e.g. 1 billion light years) that's where that galaxy was 1 billion years ago. We can also observe something called a redshift for astronomical objects because the universe is expanding, and this number tells us how quickly the object is moving away from us. Using both figures together, we can calculate the _current_ distance from us within a decent margin - which seems to be further than the age of the universe.", "topk_rank": 18 }, { "id": "corpus-315535", "score": 0.7404959797859192, "text": "Well something a million light years away would look just about the same now as it does in the picture, because a million years is a really short time astronomically. If it was something many billions of light years away, then it would be nigh impossible to predict what a given galaxy would look like today, because what it would look like today would depend on, for example, how many and what kinds of merger events in underwent since it emitted the light we're seeing. However, we can say that an average far away galaxy would look today the same as an average galaxy in our local universe. So how different did galaxies look in the past compared to today? Well there's lots of differences, but I'm not really an expert so I can't summarize them all. As an example, the famous [Madau plot](_URL_0_) shows that star formation was most active in the universe when it was about one third its current size.", "topk_rank": 19 } ]

[ { "id": "corpus-325464", "score": 0.7050921320915222, "text": "Tattoos only need to be 2-3 layers deep...Only our top layer of skin really 'regenerates'. When a fresh tattoo heals, the top layer peels off like a sunburn, & the ink stays underneath. We can't get ink to stay in that thin top layer, because it sheds off. Feet & hands have more layers & are replaced faster, which is why tattoos don't stay as well in feet/hands. If you have a tattoo & get a deep cut or scrape, the ink is taken out, & will heal with a 'hole' in the tattoo." } ]

[ { "id": "corpus-45360", "score": 0.6681524515151978, "text": "The pigment isn't broken down by proteins in the skin. As the skin replenishes itself, the pigment is pushed up with it. The process isn't perfect. Bits of pigment are broken off every time it moves, and smaller fragments are absorbed by white blood cells and carried off. Tattoos do fade over time, but the process is so slow that for a whole tattoo to disappear by this process would take longer than a human lifetime.", "topk_rank": 0 }, { "id": "corpus-63594", "score": 0.6669082045555115, "text": "Tattoo ink becomes embedded in fibroblasts, cells that are very important in healing. Andi t just kinda stays there, the tissue they heal carrying the same color as the ink. It actually intentionally destroys a bunch of the epidermis tissue that was ther ebefore the injection. Unfortunately this does tend to over time migrate deeper into your skin, resulting in the faded colors you see in older tattoos.", "topk_rank": 1 }, { "id": "corpus-119111", "score": 0.6649540662765503, "text": "It couldn't flake off because the ink is not on the surface of the skin but several layers down. However, as the cells migrate and regenerate, the ink IS moved around a bit, and often deeper into the tissue. This is why very old tattoos (30, 40 years) often appear blurred and bluish. [This guy] (_URL_0_) did an excellent write-up on a summary of current understanding, but this has never really been extensively studied.", "topk_rank": 2 }, { "id": "corpus-7858", "score": 0.6635356545448303, "text": "Tattoo ink penetrates through the first layer of skin, the epidermis, into the deeper layer - the dermis. The epidermis is the layer that routinely sloughs off old skin cells. The cells of the dermis are far more stable and does not shed like the epidermis leaving the tattoo intact.", "topk_rank": 3 }, { "id": "corpus-281608", "score": 0.6631454229354858, "text": "The other answers get to the heart of what you're asking, but I wanted to address one thing in your post, namely > I was under the impression that the body slowly replaces all of its cells in a few years. This isn't true at all. There's high cellular turnover in some organs, like skin, but most of the body isn't like this. Entire organs don't get resculpted, generally speaking, and some, like the brain and muscle, are almost entirely comprised of tissue you developed as a very young child (including in utero). For the most part, the body is pretty static, and dying cells are often replaced with fibrous scar tissue rather than with similar cells.", "topk_rank": 4 }, { "id": "corpus-135981", "score": 0.662843644618988, "text": "I'm pretty sure it'll retain the color because the DNA in those grafted cells won't change. Much like the palm of my left hand still grows tiny hairs years after the skin graft from my upper arm. /not a doctor, but I've been to way more than my share for skin issues", "topk_rank": 5 }, { "id": "corpus-41307", "score": 0.662808895111084, "text": "Scars have a different composition from normal skin. When you get a cut, for example, your platelets and red blood cells form a clot. Slowly, your skin cells release proteins (collagen) to replace that clot. In normal skin, you have collagen in random layers (think spilling uncooked spaghetti in a pile). In scar tissue, all that collagen runs in one direction (uncooked spaghetti in a box). In addition, scars are mostly collagen, so they are generally harder, stiffer, and (because the fibers run in only one direction) shinier. The reason why you shed skin but scars remain is because your scar is not made of cells, it is made of protein. Therefore, it is not replaced (the cells around it are). Tattoos remain because they are in a deeper part of the skin than the part that is shed.", "topk_rank": 6 }, { "id": "corpus-82920", "score": 0.661799967288971, "text": "LIke someone said watch _URL_0_ Basically the ink has large metal clusters within the dye. Lots of the dye gets \"washed away\" by your skin cells but the metal chunks stay behind because they are so big. That's why tattoos fade but never really go away.", "topk_rank": 7 }, { "id": "corpus-152218", "score": 0.6616166234016418, "text": "Our skin is constantly growing and the outermost layer is constantly sloughing off. The skin you have now is not the skin you had a year ago. Plus, just under your epidermis you have blood flowing, and an army of cells designed to fend off the bacteria and whatnot that would cause it to rot.", "topk_rank": 8 }, { "id": "corpus-292985", "score": 0.6614952683448792, "text": "The ink isn't actually injected into your skin cells, its actually injected below the top regrowing layers of skin cells. The blobs of ink are too large for your body (white blood cells) to get rid of, so they just sit there. Maybe the UV in sunlight breaks some of them down (fade), but generally the blobs of ink don't go anywhere. When you get laser tattoo removal, the laser light zaps the big blobs down into tiny blobs that your white blood cells can gobble up and get rid of.", "topk_rank": 9 }, { "id": "corpus-129643", "score": 0.6608628630638123, "text": "They are replaced. The cells themselves aren't really being recolored or anything. The needle essentially pushes the ink in between skin cells. When you shed skin, the ink moves up, eventually most of the color will fade but it will still be there, just not as vibrant.", "topk_rank": 10 }, { "id": "corpus-115869", "score": 0.6602340936660767, "text": "The ink molecules in tattoos are too large for the body to flush away. It's buried deep enough that the ink isn't shed along with the top layers of skin, but the body also can't break down the ink to remove the ink through internal body processes. The reason tattoos fade over time when exposed to sun is that the UV light breaks apart some of the ink molecules, making them small enough for the body to remove. Professional tattoo removal is using specific frequencies of UV light to more efficiently and more quickly break down the ink depending on the color and ink composition. Some colors of ink are more difficult to remove than others.", "topk_rank": 11 }, { "id": "corpus-172004", "score": 0.6596457362174988, "text": "They can, but there are waiting periods. I believe 3 months to 6 months depending on the state. Source: have tattoos and have donated multiple times.", "topk_rank": 12 }, { "id": "corpus-246858", "score": 0.6595741510391235, "text": "This is not my field of expertise, so I'll keep my comment brief. Consider 2 groups. Group A gets 3 minutes of exposure to the Sun each day for 100 days consecutively. Group B gets no exposure to the Sun for 99 days, then is exposed for 300 consecutive minutes on the 100th day. Clearly, it's not entirely linear. The body obviously has some healing ability that can, given time, counteract damage done to it.", "topk_rank": 13 }, { "id": "corpus-154049", "score": 0.6594403386116028, "text": "Think of it like an elastic waistband. That thing can go a long time retaining its elasticity -- in my experience, ten, fifteen years. But eventually it hits that point where it's stretched too much. You pull to stretch, and it -- stays stretched. Basically it's run out of elasticity to return back to its previous shape. Skin has elasticity in the same way, but as we grow older, that elasticity decreases. Eventually it stops tightening back.", "topk_rank": 14 }, { "id": "corpus-102922", "score": 0.6594269275665283, "text": "Cells divide and multiply. The cells behind multiply in the direction of the material, the cells in front multiply away from it, this slowly pushes it out through the skin until it breaches the surface, where it will come out. Fragments of the right size in the right place, ink for tattoo for example, won't trigger this reaction, but are too large for white blood cells to remove, which is why they stay there.", "topk_rank": 15 }, { "id": "corpus-152510", "score": 0.6582345962524414, "text": "Its due to the same reason that we have normal scars. We only grow an initial set of design cells from a young age hence why scar from childhood will heal. Once these cells replaced by adult cells its kind of like photocopying a photocopy. When the cells are damaged or missing they are copied like that resulting in things like scars and cancers", "topk_rank": 16 }, { "id": "corpus-114562", "score": 0.6579574942588806, "text": "Tattoos are ink injected into/under the skin, so while they're technically 'part of your body', that's only in the sense that a replacement hip is 'part of your body' - tattoo ink isn't on the list of cells that die and are replaced naturally by your body. They will break down over the years (which is why old tattoos can look 'muddy'), but that's a property of the ink itself breaking down and, again, not part of your body's cell-replacement-action.", "topk_rank": 17 }, { "id": "corpus-2769716", "score": 0.6579463481903076, "text": "Hello guys, I just got my 1st tattoo done after 8 years (yeah I can't believe it's been that long either!) anyway, I opted for something way bigger than what I've had before, and my artist claims a 2 or 3, 3 to 4 hour sessions might be needed to properly shade and provide all its glory, anyway, I've heard some artists suggest sessions about a week apart from each other but judging from my previous experience it will take at least 2-3 weeks for the tattoo to properly heal, right?\n\nWhat's the best time to wait for session #2? I feel if I program it a week after the previous session with all the rubbing off new ink the scabs will come off and it will not heal very well... what do you think?", "topk_rank": 18 }, { "id": "corpus-141418", "score": 0.6578352451324463, "text": "because skin is continually sloughing off dead cells, the surface of your skin turns over every few days. its like writing in a notebook and then ripping out the sheet.", "topk_rank": 19 } ]

[ { "id": "corpus-325465", "score": 0.8517417311668396, "text": "Pesticides used directly on food crops are not supposed to resist rain, at least not to the extent that they persist and poison people. Pesticides are often washed away by rain which is often part of the guidelines for use - rain can shorten the preharvest interval that is needed before crops can be harvested. The pre harvest interval is needed to ensure that the pesticide levels are below maximum guidelines (Maximum Residue Limit) required by regulatory agencies. Normally the use directions will specify weather conditions suitable for spraying (such as avoiding spraying before a rain and during high winds). Also, a pesticide that can't be mixed with water would be pretty hard to apply." } ]

[ { "id": "corpus-129561", "score": 0.802204966545105, "text": "Being rained on does remove pesticides. As does wind, and it will degrade in the sun. That is why they apply pesticides multiple times to a crop.", "topk_rank": 0 }, { "id": "corpus-323804", "score": 0.7768713235855103, "text": "For a big part, yes. It mainly works for residues, which are on the outer layer of the vegetable skin, where normally the biggest part of pesticides is located. A lot of studies show further, that a acidic washing solution, eg acetic or citric acid, is way more powerful, especially for organophosphorus and organochlorines. Also, peeling and cooking also have a strong effect on reducing pesticide concentration. Anyway, normally fruits and vegetables are washed in the factory before selling and shouldn‘t have residues above critical limits, theres no need to be scared, at least if you‘re in a country with proper food safety regulations. Some Papers about the topic (there are much more): _URL_2_ _URL_0_ _URL_1_ _URL_3_ Edit: spelling", "topk_rank": 1 }, { "id": "corpus-265614", "score": 0.7762168049812317, "text": "Rinsing fresh fruits and vegetables is a good idea for getting rid of dirt. I'll let others handle the discussion of how it likely doesn't remove pesticides. Just make sure not to rinse them ahead of time--only just before eating. Many leafy plants wilt from getting wet after they've been picked.", "topk_rank": 2 }, { "id": "corpus-97777", "score": 0.7672010660171509, "text": "You're not cleaning off the pesticide. You're cleaning off dirt and other toxins that may have stuck to the wax they put on the fruit to make it shiny. Pesticides stick to the fruit, but they are also absorbed by the plant and end up within the flesh of the fruit.", "topk_rank": 3 }, { "id": "corpus-325343", "score": 0.7636086344718933, "text": "While pesticides/agrochemicals are generally much more soluble in organic solvents, rinsing with water and rubbing the vegetables will still help quite a bit. This is because most of the pesticides will be absorbed by the dirt/dust on the outside of the vegetable, and if you get this physically removable material off the outside of the plant the majority of the pesticides will go with it. In addition, many pesticides are somewhat water soluble, so rinsing will help directly as well. As to whether or not you are taking in a lot of pesticides, the answer is more up in the air than you think. I do work with sample preparation of fruits and vegetables for pesticide analysis, and it is very hit and miss. 99% of the real world samples tested have no pesticide residue, but the few that do have *a lot* of pesticide. There is a reason I purchase organic fruits and vegetables.", "topk_rank": 4 }, { "id": "corpus-158797", "score": 0.7564162015914917, "text": "In general you should eat the skin. The pesticides get washed off when they are thoroughly washed at the harvesting plants before being shipped to the grocery store and once again at many grocery stores (but not all). If you are worried about it you can wash it off before eating it.", "topk_rank": 5 }, { "id": "corpus-314565", "score": 0.7467407584190369, "text": "Sort of. It'll get rid of any pesticide residue and dirt on the outside, but it's not the best at removing bacteria. Bacteria aren't all that water soluble in the first place - there's a reason you use soap when washing your hands, and it's not because it smells good. Worse yet, a lot of produce has nooks and crannies that you can't really clean well just by rinsing it, most notably leafy stuff like spinach. There was just a big listeria recall for bagged, prewashed spinach. So, it's better than nothing, but not exactly sterile. The good news is that most produce is perfectly safe, and even if it isn't, it takes a huge load of bacteria to make it through your stomach to make you sick. With the Listeria above, it's unlikely to cause any problems, Listeria isn't much of a risk to anyone with a functioning immune system.", "topk_rank": 6 }, { "id": "corpus-2362997", "score": 0.7460548877716064, "text": "These leafy vegetables are treated with so much pesticide that I wonder if it isn't better to avoid them, when I can't have organic. If I, caring so much, sometimes feel I can't wash properly, I can't imagine some random person doing it better. What do you think?", "topk_rank": 7 }, { "id": "corpus-71007", "score": 0.7438526153564453, "text": "For: wash off pesticides, dirt. Against: why the hell would there be anything against washing your fruit.", "topk_rank": 8 }, { "id": "corpus-73464", "score": 0.736903727054596, "text": "The perfect pesticide stays where you put it, targets only what it's meant to and degrades quickly. Unfortunately currently we only have pesticides that only do two of the three thing. Also pesticides and fertilizer get into water because of people using more than nessicary to \"be safe\" or make sure it works but it does work at the recommended levels and the extra isn't absorbed and is added to runoff.", "topk_rank": 9 }, { "id": "corpus-309613", "score": 0.7367448210716248, "text": "It's not about the pests as much as shelf life. A lot of fruits will spoil faster once they've been washed, and the store does not want the produce to go bad before it sells. Check out [these guidelines for proper washing of fruits](_URL_0_).", "topk_rank": 10 }, { "id": "corpus-151359", "score": 0.7363028526306152, "text": "This has been asked a few times already: _URL_1_ _URL_0_ Tl;dr of those two posts is that the pesticides degrade before they ever reach your table. Usually the sun, air, and heat in the field is enough to degrade the pesticides before you even harvest.", "topk_rank": 11 }, { "id": "corpus-308736", "score": 0.731455385684967, "text": "yes, they do to an extent. many vitamins such as vitamin c are water soluble. the water leeches the nutrients out of the vegetable.", "topk_rank": 12 }, { "id": "corpus-2011393", "score": 0.7251440286636353, "text": "If you buy a candy apple from the supermarket, it has the ingredients listed because the candy part isn't an apple.\n\nPesticides should be treated the same way- they're not an apple, and I should know exactly what I'm eating. There are allergies to pesticides, there are valid health concerns, and any of the reasoning that applies to listing ingredients on a box of cheerios also applies to chemicals applied to produce- including inert inert or inactive chemicals in pesticides.\n\nChange my view- I can't come up with a compelling reason that pesticides aren't an ingredient.\n\n\nedit: all my replies downvoted, I guess you'd rather discuss whether or not pesticides are harmful than actually try to CMV.\n\nI'm abandoning thread and unsubscribing. I'm pretty surprised that trying to have a discussion gets downvoted, and I guess this sub isn't for me anymore.", "topk_rank": 13 }, { "id": "corpus-14446", "score": 0.7203954458236694, "text": "I normally use white distilled vinegar diluted with water to wash most of my vegetables and fruits. There are a couple other ways too. Vinegar is used as a cleaner a lot, the acidity is suppose to kill a lot of the bad stuff and take off some pesticides left behind.", "topk_rank": 14 }, { "id": "corpus-3953", "score": 0.7199981808662415, "text": "My old organic chemistry professor explained the smell of rain coming in class once. It's also on his [website](_URL_0_): > People often think that they can smell rain coming before it actually starts to rain. Strange, as we would be in rough shape if we actually could smell water as it makes up most of our bodies (imagine being able to smell your saliva!). > There is a simple explination [sic] that seems strange at first. Organic compounds are much more soluble in wet air than dry and the world is full of molds that produce organic compounds with aromas. Typically gust of moist air preceed [sic] the onset of a rain storm and this wet air brings with it the smell of the molds. TL;DR Rain-a-comin' = more humidity. Chemicals we can smell are dissolved in the water in the air, such as molds. More humidity, therefore more smelly chemicals. Hence, rain smell!", "topk_rank": 15 }, { "id": "corpus-148132", "score": 0.7190924286842346, "text": "Anything soluble in water can be washed away. That includes many chemicals like pesticides and contaminants like feces. Soap makes this washing away of things easier and more thorough, but water is much better than nothing. Water is sometimes referred to in chemistry as \"the universal solvent) because of the variety of things which can dissolve in water.", "topk_rank": 16 }, { "id": "corpus-7890", "score": 0.7153555750846863, "text": "The water is a problem because of bacteria. Bacteria will not survive being absorbed by the roots of a plant and turned into fruit. Water sprayed on the surface of fruit could potentially be a problem, but the bacteria that live in water wouldn't survive long out in the air and sun.", "topk_rank": 17 }, { "id": "corpus-292999", "score": 0.7093898057937622, "text": "It comes down to moisture. If you run a package of raspberries under the sink then shake it dry, its still going to much wetter then it was when you bought it and it still has a decent amount of spores/bacteria on it. Mold and bacteria require moisture to grow.", "topk_rank": 18 }, { "id": "corpus-847489", "score": 0.7083858847618103, "text": "It is very dry during summertime where I live, already over 70 days without rain. Does the trap produce digestive enzymes without the need for rain water, or should I make an effort to splash the traps with water? TIA", "topk_rank": 19 } ]

[ { "id": "corpus-325467", "score": 0.7420689463615417, "text": "The people who developed the classical model didn't exactly know how the electrons were moving around. They just noticed that the electrons were moving around the nucleus *somehow*. The development of the classical model was an extrapolation that fit with the data at the time. That's why classical electrons orbit the nucleus, travel in circular paths, and have defined positions, even though modern electrons don't. It was the simplest explanation. The physics of planetary movement, on the other hand, are accurate models. That's why all the intricacies have been developed and standardized. They actually act like the model. Electrons don't." } ]

[ { "id": "corpus-144204", "score": 0.7047440409660339, "text": "They do. That's what an orbit is: The planet constantly flying away at an angle, and being pulled back closer, which results in an elliptical orbit.", "topk_rank": 0 }, { "id": "corpus-321515", "score": 0.7031803131103516, "text": "Not all of them are circular, the F ring for example is eccentric. So eccentric rings are possible. However most of Saturn's rings are circular. Essentially, in circular rings, the orbits of the particles themselves around the planet are not circular, they are approximately circular but with a combination of a small eccentricity and inclination. This gives the thickness of the rings (around 100 m). The argument of periapsis (position of the closest point) is actually a uniformly distributed random variable, and this makes the rings circular, even though the single orbits are slightly elliptical. This \"thermalization\" happens because sometimes the particles can interact through collision and this \"spreads\" variables uniformly through their allowed set of values over the course of very long times.", "topk_rank": 1 }, { "id": "corpus-319657", "score": 0.7028719782829285, "text": "The result that closed gravitational orbits are ellipses and the more massive body is at one focus comes from Newton's Laws and Newtonian gravity (an inverse square law) being very good approximations of gravity in non-relativistic cases. You can see the math of how Newtonian gravity permits stable elliptical orbits at _URL_0_", "topk_rank": 2 }, { "id": "corpus-240656", "score": 0.7023108601570129, "text": "If the planets were all perfectly symmetrical spheres interacting only with a perfectly symmetrical sun according to Newtonian gravity, these angles would be constant. However, the various planetary orbits precess (i.e., their perihelion moves gradually over time) due to not meeting the above idealized conditions -- the planets and Sun aren't perfect spheres, the planets affect each other, and general relativity modifies Newtonian gravity -- and so these angles vary. The overall variation is quite small; Mercury's perihelion shifts by less than 1/6 of a degree per century, the other planets even less.", "topk_rank": 3 }, { "id": "corpus-310823", "score": 0.7022755742073059, "text": "Planetary orbit relies on a force balance: (mv^2 )/r = (G m m2)/r^2 m = smaller orbiting mass v = velocity of smaller orbiting mass r = distance between centers of small mass and large mass m2 = mas of larger mass (Sun) G = gravitational constant On the left is the centripetal force, on the right is gravitational force. Notice that the one on the left relies on the square of the velocity. So if you get something spinning fast enough around a massive object, it can counter the gravitational pull of that object. To clear up some discussion below, notice that the mass of the smaller object (m) is on both sides of the equation so it can be cancelled out. The period of the orbit (and consequently the orbital speed) doesn't depend on mass of the smaller planet, only the mass of the bigger planet and the distance from that planet. I really wish reddit had tex", "topk_rank": 4 }, { "id": "corpus-247306", "score": 0.7022421360015869, "text": "Bohrs atomic model is commonly used as a more intuitive teaching tool to teach basic chemistry. While [it fails to explain some things](_URL_0_), it's sufficient as an introductory model and adequate for most purposes the same way Newtonian mechanics are still relevant. We don't have to invoke quantum mechanics or general relativity for most calculations. Still, they shouldn't be animated as orbiting the nucleus. Where did you see that?", "topk_rank": 5 }, { "id": "corpus-56224", "score": 0.7022028565406799, "text": "No, and no. The model of atoms as being small solar systems with small things rapidly spinning around a larger things is a simplification that is wrong. It's called the Bohr model, and is considered outdated as far as I know, though I'd say it does have it's merits, as it is illustrative. \"How does it work, then?\" Well, I don't really know. I'm bad at physics, so hopefully someone may come along and flesh out the answer.", "topk_rank": 6 }, { "id": "corpus-289898", "score": 0.7021803855895996, "text": "That question played an important role in the development of quantum mechanics. You commonly see it listed as a shortcoming of the Bohr model of atoms (last entry [here](_URL_0_), for example). The answer is that electrons aren't orbiting the nucleus in any classical sense: the [picture of the small ball orbiting a bigger one](_URL_1_) is just wrong. The better way to describe atoms and electron requires quantum mechanics, and it would be difficult to summarize here if you have no knowledge of it. I would advise you to learn QM directly if that interests you.", "topk_rank": 7 }, { "id": "corpus-320805", "score": 0.6992445588111877, "text": "The term you're looking for is precession. Orbit's precess for a number of reasons: the oblateness of the sun (it's not a perfect sphere), gravitational interactions with other planets, and General Relativity are the biggest (only) contributers. The oblateness of the sun affects all planets the same way; however their varying distances mean that the precession rate likely wouldn't be the same. Gravitational interactions with other planets are also going to make each planet's precession unique since the relative distainces to the other planets are unieque for each planet. Lastly the GR will again be highly distance dependent. Mercury is the only planet in the solar system that sees significant contributions from GR effects. So no the shapes of planets aren't always the same.", "topk_rank": 8 }, { "id": "corpus-291457", "score": 0.6991754770278931, "text": "That orbit does not exist. The photon sphere is well beyond the regime where stable orbits exist, let alone Kepler's laws apply. You really cannot speak of elliptical orbits. You'll just fall in.", "topk_rank": 9 }, { "id": "corpus-291592", "score": 0.6988661289215088, "text": "Yes, they both “orbit” around the center of mass. But just like a planet orbiting around a star, the center of mass is approximately the center of the star (the nucleus). When you solve the Schrodinger equation for the hydrogen atom, this is accounted for by splitting the Hamiltonian into a center of mass part and a relative part.", "topk_rank": 10 }, { "id": "corpus-168981", "score": 0.6987890601158142, "text": "I'm sorry, I don't think I follow. Where do you get that planets always have \"circular masses\" at the poles? And what circular masses do you mean? Are you referring to polar ice caps?", "topk_rank": 11 }, { "id": "corpus-835368", "score": 0.6981483697891235, "text": "All pictures show the planets on the same level or plane. Is that true or is it simplified for the general public? Or do the planets circle the sun with each planets orbit following it's own path?\n\nIf they do orbit the sun on the same level is that because the sun causes them to rotate along a certain axis? \n\nSorry if it's been explained before but I couldn't find the answer to my actual question(s). Thanks in advance", "topk_rank": 12 }, { "id": "corpus-313082", "score": 0.697651207447052, "text": "Interesting question isn't it? Well, most importantly, electrons don't *actually* orbit like planets around a star. The electron inhabits a diffuse region around the nucleus characterized by a wavefunction. This system does not possess angular momentum outside the intrinsic angular momentum of the electron and the nucleus. Geometrically, the angular momentum plays to introduce angular dependence in the wave function--basically the shapes get more and more exotic as you introduce more momentum into the system--you get access to a lot of different modes.", "topk_rank": 13 }, { "id": "corpus-304098", "score": 0.6974585652351379, "text": "According to the simple inverse square laws: yes, absolutely. They are mathematically governed the same (just with different constants) and so orbits should be possible in both. Classically speaking, this is what we believed, and indeed it is a good approximation of the truth for nonrelativistic speeds. Relativity puts a dent in the classical picture though, and both gravitational and electric orbits actually emit waves due to the accelerating reference frames that cause them to lose energy and spiral inwards. This effect is usually quite small for gravity. Of course, quantum mechanics also puts a dent in the classical picture, so if we are talking about a proton and an electron then quantum mechanical effects would dominate and no it wouldn't make sense to describe the electron as orbiting the proton.", "topk_rank": 14 }, { "id": "corpus-263480", "score": 0.6968338489532471, "text": "Electrons do not orbit the nucleus, because electrons behave quantum mechanically. The effects of gravity between protons and electrons are too insignificant to measure, and indeed we can correctly describe the behaviors of atoms using electrostatics, essentially Coulomb's law for the electrostatic potential V. Although there are no other forces, it's impossible to calculate how atoms work without using Quantum Mechanics. Classical physics doesn't apply to this kind of system.", "topk_rank": 15 }, { "id": "corpus-320242", "score": 0.6955054998397827, "text": "Planets and stars are generally spherical (to a good approximation at least) because gravity acts in all directions. There's no other shape for it to be! Now if you take a spherical blob held together by gravity and rotate it, it will bulge outward. In fact, the Earth does this: it is fatter at the equator. It's just that the rotation is relatively weak compared to how compact Earth is. With something like a galaxy or the Solar System, the bodies are more loosely bound, so this bulging is much stronger, making it approximately a disk. Note that in the center of most spiral galaxies, the core is spherical. This is because the rotation is weaker there: the centrifugal force gets weaker as you go toward the middle because your tangential velocity is less.", "topk_rank": 16 }, { "id": "corpus-281011", "score": 0.6953324675559998, "text": "They aren't, at least not in the same way the Earth orbits the Sun. It's taught as such because it's a comforting inaccuracy that still allows students of chemistry or physics to make many physically meaningful calculations without mucking about with the insanity that is quantum mechanics. Electrons are a smear of probability whose overall 'shape' of the cloud is defined by the quantum states it occupies. We know this to be the case because it's possible to directly probe atomic structures and make very precise measurements of energy and mass. If you're more interested in how the basic structure of atoms was discovered than I invite you to read upon Rutherford's now-famous gold foil experiment and it's descendants. These experiments solidified the notion that atoms had an extremely small positively-charged core and and nebulous negatively-charged outer structure.", "topk_rank": 17 }, { "id": "corpus-279714", "score": 0.6952264308929443, "text": "Earth's orbit may be elliptical, but it's not very eccentric. It's very close to being a circle.", "topk_rank": 18 }, { "id": "corpus-322894", "score": 0.6949545741081238, "text": "Any two planets can align themselves such that one (the closer) is in front of the other from the perspective of Earth. I don't know exactly the periods of this occurring, but it is a geometric problem to understand that it does.", "topk_rank": 19 } ]

[ { "id": "corpus-325468", "score": 0.8563215732574463, "text": "Sort of. It wouldn't exactly be a figure 8 pattern because the planets would be orbiting each other, so the moon could only switch orbits during certain alignments of the three bodies. More likely, you would have two stars with a planet that switches orbits between them." } ]

[ { "id": "corpus-323106", "score": 0.7876570820808411, "text": "I can offer some theory. Lets skip the explanation of how they get into these orbits and just look at the short and long term mechanics of the system. Short term: You can have binary planets at any radius apart by changing the orbital velocities, so yes a figure 8 is possible. Same for stars / moons etc Long term: Tidal forces of the sun-binary system would over long peroids slow the binary system down resulting in a collapse to a one planet system. A competing planet-planet tidal forcing effect could cause them to separate and maintain a binary orbit. These effects can be observed with the tidal locking of the moon with the earth and also the slight yearly increase in moon orbital velocity. Which effect dominates depends on orbital radii and axial rotation of planets. Can these binary planetary systems form in nature? Are there forces other than gravity that could affect this system?", "topk_rank": 0 }, { "id": "corpus-318027", "score": 0.7770677804946899, "text": "The figure eight orbit isn't possible. Binary star systems are common, though, and they can have planets if the two stars are fairly close and the planets are far enough away. Another alternative would be a small star orbiting a large star far away, like if Saturn were big enough to be a star. In that case you could have planets around the big star, _and_ planets around the small star. A stable configuration might have a sun somewhat larger than our own, say twice as large, and then something at probably Saturn's orbit, but at least 100 times the mass of Jupiter. This star would be about 1/10th the size of our sun, and so could obviously have planets of its own, larger than the moons of Jupiter or Saturn.", "topk_rank": 1 }, { "id": "corpus-319815", "score": 0.775287926197052, "text": "It would be cool, but probably not. There are planets that orbit around two stars (aka a [binary star](_URL_1_)); these are known as [circumbinary planets](_URL_0_). However, they form an orbit outside the two stars, and since planetary bodies revolve around the planetary system's center of mass, both stars and the orbiting planets will orbit around their common center of mass. In addition, given the chaotic environment between a binary system, the most likely area for planet formation is outside the orbit of the two stars. However, there are mathematical models that suggests the plausibility of a figure-8 orbit (called a choreographic system because of its resemblance to dancing), but this has not been observed in space.", "topk_rank": 2 }, { "id": "corpus-323623", "score": 0.7675049901008606, "text": "There is no reason why it couldn't, its just going to be hard to get the orbital mechanics to be perfect, but there are systems with 7 stars in creative orbits around each other so it could happen. Since the two moons will be relatively close together in mass they will likely orbit each other similar to a binary star system and the pair will orbit the planet. It would make orbital dynamics in the region rather creative, but I can't find anything that explicitly excludes the occurrence. One reason we haven't found anything like that yet is because we have a hard time picking up planets outside of our own system, and most of the planets we have found are Jupiter sized. Spotting even a Mars sized moon around that planet will take a while longer, and spotting a moon around that moon even longer. We are getting there, but since ~90% of the moon we know about are Jupiter's and Saturn's and we discovered a new Jovian moon in 2011, we still have a ways to go before we start picking up exomoon", "topk_rank": 3 }, { "id": "corpus-317517", "score": 0.7584693431854248, "text": "I think most science fiction art like that assumes the view is from a moon, and you see the planet and other moons. But to answer your question, technically yes, planets can form in a way that brings them very close in their orbits. The problem is that these orbits are very unstable, as the planets will gravitationally disturb each other and eventually either move farther apart or crash into each other, as is thought to have happened between earth and theia to form the moon.", "topk_rank": 4 }, { "id": "corpus-271869", "score": 0.7522965669631958, "text": "Yes, it's possible for one body to orbit two, provided the two central bodies are close together and the third body is far away, like a distant planet orbiting a tight binary. Additionally, for any two body system there are a set of points called Lagrange points where a third body can orbit the central body along with the planet. Figure 8 orbits are generally unstable, that's likely to get ejected from the system.", "topk_rank": 5 }, { "id": "corpus-264394", "score": 0.7521109580993652, "text": "I believe the typical arrangement is where the planets revolve around BOTH stars, not between. Day and night would be nearly identical to our own arrangement. The stars orbit a common point very close to each other. Gravitational pulls in this arrangement would be similar to our own as well. More interesting would be a planet with multiple MOONS where the tides would be timed much closer together. Alternatively, there are theoretical BINARY PLANETS where two planets could \"dance\" similar to a planet/moon arrangement. There you would have interesting eclipses everyday.", "topk_rank": 6 }, { "id": "corpus-280343", "score": 0.7516749501228333, "text": "If the bodies collide, or even just come close, at slow relative speed, then their gravity certainly cause them to properly collide and the effects will be devastating for both. Even if you magically place the two so that their surfaces just touch at zero relative speed, they will very quickly merge and become a single blob of something once you remove your magic from the picture. So then you could maybe think of something where the two planets orbit each other at an extremely close range. This still won't work. Just the tidal forces alone are enough to rip the planets apart even without them ever touching each other. In fact this is thought to be one way a planetary ring can form. A moon for some reason gets so close to the primary planet that the tidal forces break the moon apart. See [Roche limit](_URL_0_).", "topk_rank": 7 }, { "id": "corpus-314320", "score": 0.7476347088813782, "text": "This couldn't happen, because a gas body is quite large. You could end up with a gas binary planet system, with bodies of similar size, but not anything of the size disparity to be considered a moon/planet system. Either the moon would dissipate or it would be consumed by the planet. If you had something the size of Neptune orbiting a huge gas giant, I think that would still be considered a binary planet system, it if were even possible due to the gravity of the gas giant. A similar question is answered here: _URL_0_", "topk_rank": 8 }, { "id": "corpus-274397", "score": 0.7426338791847229, "text": "No, there are no such stable orbits. (I notice lots of people don't seem to understand what \"stable\" means. A pencil balanced on its point is not stable, even though there is an equilibrium position there.) A couple of people have pointed out that there are some possible figure-8 orbits in which a group of objects of identical mass all move together in the same orbit. That's not what the OP is asking about. He/She wants a small planet in a figure-8 around two big stars. This is not stable.", "topk_rank": 9 }, { "id": "corpus-323248", "score": 0.7404660582542419, "text": "While you can find a [mathematical solution](_URL_0_) for such an orbit, it requires such precise positioning and starting momentum for every object in the system that even a tiny pertubation will shove it into an orbit of one of the two planets. I wouldn't expect to find any natural objects in such an orbit, and even an artificial object wouldn't stay on it for long. If you're willing to relax that requirement, what you could have is a moon orbiting the common barycenter of a pair of planets, similar to a planet orbiting a binary star system. In that case you'd probably expect the moon's orbital radius to be no closer than a bit over the separation distance between the planets. In this case, the moon would essentially behave as if it were orbiting one planet with a mass equal to the total mass of the two planets. For the period of that orbit you can refer to Kepler's 3rd law.", "topk_rank": 10 }, { "id": "corpus-322894", "score": 0.7377116680145264, "text": "Any two planets can align themselves such that one (the closer) is in front of the other from the perspective of Earth. I don't know exactly the periods of this occurring, but it is a geometric problem to understand that it does.", "topk_rank": 11 }, { "id": "corpus-324138", "score": 0.7355493903160095, "text": "There is no planet like this, but [Pluto](_URL_1_) and its moon [Charon](_URL_2_) have this property. They are mutually [tidally locked](_URL_0_).", "topk_rank": 12 }, { "id": "corpus-309633", "score": 0.7351540923118591, "text": "There is indeed a figure 8 orbit, but it is not stable. _URL_0_ The object will, if perturbed, orbit one body or the other.", "topk_rank": 13 }, { "id": "corpus-318613", "score": 0.7343058586120605, "text": "Yes, this is called a barycentre. Pluto and Charon are examples of a binary system orbiting about a common barycentre.", "topk_rank": 14 }, { "id": "corpus-834566", "score": 0.7340720891952515, "text": "For example;\n\nCould one planet have a atmosphere large enough to maybe share it with a moon? Or would this mean the gravity would be too strong and pull a moon down to it’s surface?", "topk_rank": 15 }, { "id": "corpus-296917", "score": 0.7340136170387268, "text": "In terms of natural satellites, yes. The moon and earth share this relationship. It's called 'tidal locking'.", "topk_rank": 16 }, { "id": "corpus-177340", "score": 0.7333779335021973, "text": "Theoretically, it is possible. There are 5 points, known as LaGrange Points, where an object can rest relative to a planet and a star without moving relative to those two. L1 rests in a straight line between the planet and the star (solar eclipse). L2 rests behind the planet along the same line (lunar eclipse). We know of natural examples of 3 other Lagrange points, but I don't know if there are any known at L1. Edit: made a mistake and added info. Per Wikipedia, we don't know of any natural objects at L1 or L2, just the three co-orbital points.", "topk_rank": 17 }, { "id": "corpus-321540", "score": 0.7300208210945129, "text": "In the ideal case that the planet is perfectly spherical and doesn't have a moon, then yes this is technically possible, although such a system is basically impossible to form. However, small variations in the planets gravitational field due to surface imperfections or the presence of a moon that can raise tides on the planets can allow the planet to transfer (negative) angular momentum into its rings, which will gradually lower their orbits until they crash into the planet (assuming the rings are much less massive than the planet), so such a system is not stable.", "topk_rank": 18 }, { "id": "corpus-244166", "score": 0.7279859185218811, "text": "Both the moons are very close in inclination. Relative to each other their orbits are only tilted by less than 1 degree. So they can appear right next to each other in the sky, and it is possible to have one moon block out the other. There's actually a video from Curiosity of this happening. _URL_0_ So you could see both moons and the sun align. You could see this from anywhere somewhat near the equator on mars.", "topk_rank": 19 } ]

[ { "id": "corpus-325469", "score": 0.76295405626297, "text": "Yes. Current co2 levels are just over 400ppm. Most plants will grow more with co2 levels up to 1200-1500ppm. When getting higher co2 they do better in slightly warmer conditions than if they are getting normal amounts of co2. I dont think this will make it harder for humans to live or go outside though." } ]

[ { "id": "corpus-133051", "score": 0.7247722148895264, "text": "2^o C doesn't seem like a big deal unless you think about it worldwide. That means that over the entire planet, the average temperature raised 2^o Without climate change, there would be an average temperature and so some areas would get warmer and some get colder. The same thing would happen in this case, but that would mean some areas would have temperatures say 10^o higher than ever seen to make up for the areas that stayed the same or only saw a 1^o change. It isn't enough to send panic in the streets, but it does show that things are getting warmer.", "topk_rank": 0 }, { "id": "corpus-2675106", "score": 0.7242709398269653, "text": "In the recent decades, global warming has been rapidly speeding up. For some reason, the only way to stop it is to save the plants. Why? Wouldn't mass producing oxygen solve the crisis better?", "topk_rank": 1 }, { "id": "corpus-313365", "score": 0.7230212688446045, "text": "It's not only conceivable, [it's happening](_URL_0_). The tricky part is that the species that are able to rapidly respond to the increase in available carbon will become predominant. The end result of increased carbon, nitrogen, phosphorus, etc. due to human activity will be, at least initially, an overgrowth of opportunistic species that can quickly convert the new material into living organisms.", "topk_rank": 2 }, { "id": "corpus-315059", "score": 0.722552478313446, "text": "While I don't know of any studies that have looked at forests directly, there have been a number that have looked at increases in crop yields due to an increase in the concentration of CO2. Given the underlying biology behind it, it would seem likely that plant life in general would be positively affected. More info: _URL_0_", "topk_rank": 3 }, { "id": "corpus-296127", "score": 0.7222394943237305, "text": "Basically almost any form of plant based life will flourish with higher CO2 concentrations. This fact has been used for many years to increase their growth rates in green houses and similar controlled enviroments. _URL_0_ As you may know, plants use CO2 as a source for carbon which is used, for example in photosynthesis, to build more complex organic molecules.", "topk_rank": 4 }, { "id": "corpus-2385987", "score": 0.7219526171684265, "text": "So, I was speaking to a friend about global warming and CO2-uptake. We were talking about planting trees. \nAnd he mentioned to me that it isn't a good solution as everyone thinks, as trees in a changing climate might not be the CO2-sinks people believe they are. \nHe explained to me that when temperature rises, tree respiration also rises, but photosynthesis remains the same, thus offsetting the CO2-uptake. \nAs an example he told me that in parts of Scandinavia where warming was largest the trees are already net producers of CO2. \n \nHow much of this is true? How should I see this in context? \nIt feels very counterintuitive.", "topk_rank": 5 }, { "id": "corpus-46512", "score": 0.7205249071121216, "text": "Do you have a source for the fact that it does? It can make certain plants grow less just because they need a certain ratio in the atmosphere. So overall it could produce less if the plant was smaller. But global impact wise there are a lot bigger issues than any minor impact on crop nutrients. I work in the field of environmental engineering and I never hear that mentioned.", "topk_rank": 6 }, { "id": "corpus-292401", "score": 0.7196874618530273, "text": "Yes. It may only take about 100 years to increase the temperature and pressure enough to support plant life. It would take much much longer to get enough oxygen in the air for us to breathe, but we could walk the surface with just a mask for o2. Edit: added a source below.", "topk_rank": 7 }, { "id": "corpus-116751", "score": 0.719046950340271, "text": "The amount of carbon in our atmosphere directly relates to the temperature. If the carbon is too low (less than 2 parts per million) the earth would get cold because not enough heat would be trapped in. If the carbon gets too high (6 parts per million) then heat would be trapped and we would be stuck in a cycle of heating and trapping heat from the sun. The increased heat would melt the polar ice caps causing the sea level to rise. The increased heat would also cause droughts and dust storms. Source: Cosmos", "topk_rank": 8 }, { "id": "corpus-60191", "score": 0.7181511521339417, "text": "CO2 levels will increase from the Canadian Wildfires. But not by much. There are greater fires happening right now all across the world (mostly in rainforested areas) which the public and the media just tend to ignore. However, as well as just the fire burning all the greenery up, the loss of this greenery will mean that less CO2 is being stored by leaves for them to make energy (from photosynthesis). However, since the area of the fire isn't really that large in planetary terms, it really isn't significant either.", "topk_rank": 9 }, { "id": "corpus-2592648", "score": 0.7179850339889526, "text": "You read about climate change and how even just a 1 or 2 C increase can lead to wide scale disasters and bad climate change. Maybe I'm misunderstanding how this works.\n\n1 or 2 degrees C is equal to about 2 to 4 F. I fail to see how Increasing the average temp of a climate biome by 4 degrees is that big if a deal. Of course I beloved in climate change and the effects, I just dont understand how that works.\n\nIf \"normally\" the temp would be say 87F and due to climate change it is instead 89F, i fail to see how that produces more monster hurricanes and expands the deserts and all the negative effects of climate change.\n\nHope someone can help me understand", "topk_rank": 10 }, { "id": "corpus-38016", "score": 0.7163363099098206, "text": "the small increase is really the result of wild swings of very high temperatures in some places and very low temperatures in other places, or a wild mix in the same place... and all those wild swings almost, but not quite, balance out... so the net change is \"only\" 1 or 2C, but there is lots of mixing and stirring going on and that mixing and stirring has a tremendous effect on local conditions.", "topk_rank": 11 }, { "id": "corpus-560230", "score": 0.7154784202575684, "text": "It may sound stupid to ask, but pretend I'm five for asking it.\n\nDoctor Who just had an episode where the number of trees across the whole world was much, much greater than double, but I want to start with a basic idea.\n\nAgain, pretending I'm five, if trees take in CO2 and spit out oxygen, does that mean the CO2 would get shaved down, proportionately, from being \"sucked up?\" And the oxygen would increase? I don't know how the nitrogen would get affected by the process if at all, so if its own level remained stable, it would just lower but likely not get dialed down into being a minority gas.\n\nIs it even possible to offset it? Or would it all balance out from other environmental variables? (Perhaps it would balance over time but the overnight thing would throw a wrench into that?)", "topk_rank": 12 }, { "id": "corpus-304893", "score": 0.7147904634475708, "text": "Not an expert, but our CO2 concentration and global temperature used to be much higher than they are now. See the [Azolla event](_URL_0_). Until we get back to those conditions (which would be very disruptive if it happened), I don't see how we could have anything more catastrophic.", "topk_rank": 13 }, { "id": "corpus-307477", "score": 0.7146157026290894, "text": "Your idea assumes that plants are limited by CO2. That if given more CO2 they will grow more and thus take up more CO2. While some plants do show short term bursts of growth when given extra CO2, plants are ultimately limited by water, nitrogen, phosphorus, and light. You can give them as much CO2 as they need but they cant do much without more of these other basic ingredients.", "topk_rank": 14 }, { "id": "corpus-127904", "score": 0.7140704393386841, "text": "higher CO2 will lead to increased temperatures, among other problems. This will lead to may issues including melting of ice caps and ocean levels rising. This is the whole basis behind concerns about climate change, if you're unaware of the current terminology.", "topk_rank": 15 }, { "id": "corpus-252450", "score": 0.7140189409255981, "text": "There isn't a risk insofar as it would be easily reversible (putting CO2 into the atmosphere is easier than getting it out). But if for some reason CO2 dropped way below pre-industrial revolution levels and we decided not to reverse it, you'd get a cooling effect (probably also some slowdown in plant growth). Though I don't really see how we could do that without massive industrial investments into carbon sequestration and storage. Just planting trees won't do it, you'll run out of space to plant new trees eventually (unless you also figured out a scheme to store the wood, after harvesting quickly grown trees, so they wouldn't rot the next few tens of thousands of years).", "topk_rank": 16 }, { "id": "corpus-249220", "score": 0.7131764888763428, "text": "The limiting process for plant growth for many species is CO2 diffusion, which depends on the CO2 concentration. If the gas in the hyperbaric chamber has the same composition as air, then the increased pressure will mean an increased CO2 concentration, which will speed the growth process. This may not be as straightforward if the plant under consideration uses some kind of alternative carbon fixation pathway, such as the CAM or C4.", "topk_rank": 17 }, { "id": "corpus-305625", "score": 0.7125886678695679, "text": "There is a [several ppm seasonal change in the stable background CO*_2_* concentration](_URL_0_) driven by seasonal hemispheric differences in vegetation, overlaid on a long-term increase in CO2 concentration driven by fossil fuel consumption.", "topk_rank": 18 }, { "id": "corpus-192093", "score": 0.7124155163764954, "text": "Well, CO2 isn't really like food for trees, but that's not the point. Trees (all photosynthetic organisms really) can only consume and utilize a certain amount of CO2, sort of like how once you eat to the point of being full, you can't eat any more no matter how much food is on the table (not to reinforce the idea that CO2 = food). We're dumping way more carbon into the atmosphere than all the photosynthetic organisms on the planet can use, so it's building up. If we planted vast areas of trees, then they would use more CO2. That's a very real and feasible possibility for curbing global warming if we actually did it **and also dramatically cut CO2 emissions.**", "topk_rank": 19 } ]

[ { "id": "corpus-325470", "score": 0.7356560826301575, "text": "Another important concept to understand is that nothing in the universe is *traveling* faster than light. Galaxies moving away from us at 400,000,000 m/s aren't actually moving through space that fast. What is happening is the \"metric expansion of space time\". In other words, space itself is what is growing. As an analogy, imagine a 4x4 grid that is 1\" per unit at t=0. You are at (0,0) and there is a planet at (2,2). We can see with the Pythagorean theorem that the distance to that point is sqrt(8) inches away. Now, the way to think of metric expansion is that at time t=1s, you are still at (0,0) and the planet is still at (2,2). We would say that the planet isn't traveling right? But now our initial 4x4 grid is 2\" per unit. And our new distance is sqrt(32) inches away. The object is now 4 times further away, but its actual position on the grid is the same. What has changed is the *size of the grid (space) itself*." } ]

[ { "id": "corpus-307606", "score": 0.6988062858581543, "text": "> I believe the expansion was so fast that the mass of our universe expanded faster than the speed of light It does not make sense to assign a speed value to the expansion. The only relevant parameter is \"speed per distance\", or \"speed for an object at a particular distance\". As Robo-Connery said already: The big bang was not an event in space. You cannot point to a location and say \"there it happened\" - it occured \"everywhere\". There is no \"light event horizon\", only a limit of the observable universe for every single observer.", "topk_rank": 0 }, { "id": "corpus-290461", "score": 0.6987899541854858, "text": "To add to /u/astrokiwi's answer. The specific way to do the calculation is to solve these two equations for an expanding universe (note X*_0_* refers to today's value): > T(t) = T*_0_*(1+z) = T*_0_*/a(t) (for radiation) > da/dt = H*_0_*√(W*_R,0_*+W*_M,0_*a+W*_K,0_*a^(2)+W*_L,0_*a^(4)) Where, > a = expansion factor, how rulers stretch > W*_R,0_* = radiation density today > W*_R,0_*= matter density today > W*_L,0_*= dark energy density, constant in time > W*_K,0_*= 1 - all other density = spatial curvature, close to, if not exactly, zero All the density terms are normalized to the total density and thus are all < 1 individually. If you integrate this equation for the expansion factor (today a=1), you get that when the universe is around 30 billion years old, the radiation temperature will be about 1 K. In that far future, dark energy will vastly dominate expansion. Asymptotically our universe behaves like a de Sitter universe. The solution of a(t) to such a universe looks like e^(Ht).", "topk_rank": 1 }, { "id": "corpus-259490", "score": 0.6986379027366638, "text": "Because even though inflation did increase the size of the Universe significantly, it lasted only an extremely short period of time. Or put another way, even though inflation made the Universe many orders of magnitude bigger than when inflation started, it still left the Universe absurdly tiny in comparison to its size today. So when you're calculating the age of the Universe, it's essentially negligible. Similarly, the Universe increased greatly in size during the next cosmic era, when radiation dominated the expansion. This lasted for about 80,000 years, but because that was such a tiny period of time in comparison to 13.7 billion years, you can ignore it and still get a very good estimate for the age of the Universe. The important eras to consider are the next two, matter domination and dark energy domination, as those each lasted a few billion years.", "topk_rank": 2 }, { "id": "corpus-325456", "score": 0.6985983848571777, "text": "There's clear evidence that the expansion is happening and that it's accelerating. If we assume this will keep going then eventually all galaxies become isolated from each other and something like a [heat death](_URL_0_) occurs. But no one knows if the expansion will keep on going. We don't even have a good theory for the acceleration yet.", "topk_rank": 3 }, { "id": "corpus-72171", "score": 0.6985613703727722, "text": "The idea is that, while the universe is expanding in size, the amount of matter and energy in it is finite. That whole, can't be created or destroyed thing. What happens when you have a set amount of something in a container that's getting bigger? Eventually the universe will be so massive and stretched out that there'll be mere ones of atoms per cubic kilometer. Not much of a universe at that point, is it? Certainly not one full of stars and planets and junk.", "topk_rank": 4 }, { "id": "corpus-126421", "score": 0.6981357932090759, "text": "The growth of the universe is not limited by the speed of light. That is the speed limit inside the universe but the universe itself can expand faster", "topk_rank": 5 }, { "id": "corpus-321171", "score": 0.6980539560317993, "text": "I don't believe that things getting smaller accounts for red shift. Remember that light from distant galaxies being redshifted by an amount proportional to their distance from us was (is) the primary evidence for an expanding universe. Things getting smaller doesn't account for this.", "topk_rank": 6 }, { "id": "corpus-127520", "score": 0.6978781223297119, "text": "Good question - we don't know for sure. But, actually, it probably doesn't matter. If the current expansion of the universe continues, you would keep traveling in a straight line forever because the space ahead of you would keep expanding away from you.", "topk_rank": 7 }, { "id": "corpus-304996", "score": 0.6978569626808167, "text": "The big bang wasn't an explosion in space at a point, away from which we're now flying. It was the expansion of *all* of space. For several hundred, thousand years after the initial singularity, the universe was too hot and dense for light to travel. Any time it was produced, it would immediately be absorbed by something nearby. But around 370,000 years after the initial singularity, the expansion caused the universe to cool sufficiently that neutral atoms were able to form. When that happened, light was emitted from *everywhere* in *all directions*. The light we're seeing as the CMB today comes from points that were so far away at that time that their light has taken 13+ billion years to reach us. Light from closer points passed us earlier, and light from more distant points will reach us eventually (except for some *really* distant points from which light may never reach us).", "topk_rank": 8 }, { "id": "corpus-261644", "score": 0.6977713704109192, "text": "The universe didn't start from one point exactly. The light we're seeing now is from an area of the universe that is now very very distant from here.", "topk_rank": 9 }, { "id": "corpus-251548", "score": 0.6977342367172241, "text": "It's because the big bang happened everywhere in the universe, not at a specific place. So at a given distance, we're seeing light from the very early universe, or maybe put a different way - there's always some distance where light reaching us is from any time in the history of the universe you want to see.", "topk_rank": 10 }, { "id": "corpus-312136", "score": 0.6977285146713257, "text": "This is a consequence of the observable universe having zero curvature and the critical density of matter. In the absence of dark energy, such a universe would expand forever and the expansion rate would decrease towards zero. (With dark energy, however, the expansion accelerates). _URL_0_", "topk_rank": 11 }, { "id": "corpus-832601", "score": 0.6976855993270874, "text": "Hello Askscience, I just watched a talk by Lawrence Krauss which he gave 3 years ago (link to the video right here. In it, he talks about the Big Bang, the nature of the Universe, how we know what we know, and the implications from that. I have a few lingering questions about our universe, so if there are any astronomers or cosmologists or quantum physicists out there, I would appreciate any insight you can give me.\n\n1. Krauss explains that we live in a \"flat universe\" with total energy zero because the force of gravity allows for there to be both positive and negative energy. This also allows for it to have begun from nothing. However, he also says that our universe is expanding at an increasing rate, which is characteristic of an open universe. In addition, he says that from our measurements, the total mass in the universe (including dark matter) is only about 30% of what is needed for the universe to be flat. So I just want this point to be clarified for me: the universe *is* flat, but its expansion is accelerating like an open universe because 70% of that remaining *stuff* is dark energy, meaning there is not enough matter to slow the expansion of the universe to a halt. Is my understanding correct here? (Any further comments are welcome, and if you are interested, 32:20]( and [40:30\n\n2. My next set of questions touches upon the implications of the possibility of getting \"something from nothing.\" After listening to this Krauss' talk, I know that it is possible, and in fact I even understand it on an elementary level. Krauss explains that if you start with absolutely nothing, quantum fluctuations will *necessarily* produce something (like an entire universe), and the force of gravity allows for the presence of negative and positive energies which will cancel out to be zero.\n * My first question is: if it is possible for stuff to be produced from nothing due to quantum fluctuations, why hasn't more stuff been generated from the remaining pockets of nothingness? Why have we not observed new universes popping up from nothing?\n * My next question is: when this happens, what is the effect on time? Did the Big Bang induce time to start? Did this process in some way determine our Universe having 3 spatial dimensions and 1 time dimension?\n\n3. Lastly, I would like a clarification on the process by which the forces in the universe developed. From my understanding, the four fundamental forces were not always the same throughout the lifetime of the universe (I remember this vaguely from an astronomy class, but please correct me if I am wrong. Did the two nuclear forces at some time split into two different forces?) Anyways, my question is: Did gravity exist before the Big Bang, and has it always been the same throughout the 13.72 billion year lifetime of the universe? If so, a follow-up question would be how could it have existed? Was there not (theoretically) complete nothingness before the Big Bang?\n\nThank you for reading and discussing, and I recommend checking out Lawrence Krauss' full lecture if you have the time.", "topk_rank": 12 }, { "id": "corpus-833643", "score": 0.6975087523460388, "text": "Another way of framing the question for clarity:How much faster do the galaxies at the expanding edge of the universe travel, and how much does the relativity of time change from there to slower parts of the universe?", "topk_rank": 13 }, { "id": "corpus-251026", "score": 0.6974027752876282, "text": "The universe is believed to be infinite. Even if it is finite, space would be wrapped up in itself so it is not \"pushing outwards\" like a growing sphere. When people say the universe is expanding they mean that the fabric of space itself (picture it devoid of matter) is stretching. The energy driving this is known as 'dark energy' but the nature of it is currently unknown. If it runs out the universe may collapse on itself or approach a steady state, but it looks like it is actually increasing which will eventually stretch space so much it will basically become a cold dead void with huge distance between any matter edit: or rip all matter apart.", "topk_rank": 14 }, { "id": "corpus-303931", "score": 0.6973655223846436, "text": "The accelerating expansion of the universe isn't due to a gravitational pull between galaxies. The space itself between galaxies is expanding. Which is why we view objects farther away from us as traveling faster away from us. The more distance in between, the more space that gets in between, so the faster it looks like its moving away. The speed of objects traveling away from us differs from the local speed of objects due to a gravitational acceleration from another object.", "topk_rank": 15 }, { "id": "corpus-290950", "score": 0.6973394751548767, "text": "> Since we all started at a central point This is not the case. There is no central point of the universe, rather all points are moving away from all other points. The light from the CMB has traveled 13.7 billion light years to us. This does incorporate the expansion of the universe.", "topk_rank": 16 }, { "id": "corpus-165449", "score": 0.6972848773002625, "text": "Nothing. Since the Universe is all that exists, there is nothing outside it and nothing for it to expand into. It just gets bigger. This might not make a lot of sense, but that's how things are when you start examining really big things, like galaxies and the Universe itself, or really really small things, like the individual particles that stuff is made of. Things stop making sense, because \"sense\" is formed by the things we see around in our daily lives, like throwing a ball and running around.", "topk_rank": 17 }, { "id": "corpus-310485", "score": 0.6971973776817322, "text": "It depends on the energy content of the universe. In our universe, we have 30% matter (dark and baryonic) and 70% dark energy, so the graph you are looking for is the dashed one in [this plot](_URL_0_). It approaches an exponential function. The inflationary period can be ignored in this case, since it lasts only a fraction of a second. Yes, the expansion is accelerating due to dark energy, so it will be faster in the future. And yes, at some point our local group, the Virgo cluster, will be completely isolated from the rest of the universe, if I remember correctly. If dark energy had a particular property (w < -1 for the pros), the scale factor would actually blow up in finite time and rip everything apart, even protons (Big Rip scenario). But this doesn't seem to be the case, so gravitationally bound objects will stay that way.", "topk_rank": 18 }, { "id": "corpus-316532", "score": 0.6971080899238586, "text": "The expansion of the universe and the speed of light have different units, therefore you can't compare them. The Hubble Constant is the fraction by which a given parcel of space will grow in a given amount of time. It has units of inverse time, s^(-1). The speed of light, of course, has units of distance/time, m s^(-1). The Hubble Constant is usually given in units of kilometers per second per megaparsec, but the two distance units just cancel out and you get the result that the universe expands by about 0.00000000000000002% per second. > Also, if that happened, would we at one point not be able to see any other galaxies because they're receding from us faster than their light can reach us (assuming we'll be here, of course)? There will eventually come a time when there are no other visible galaxies in our observable universe (except for nearby ones that are gravitationally bound to us).", "topk_rank": 19 } ]

[ { "id": "corpus-325471", "score": 0.7521138787269592, "text": "Cyanide can be ingested, inhaled, or absorbed through the skin. It acts by blocking the cytochrome C oxidase enzyme which is an essential part of intracellular oxygen utilisation. What this means is that the cells can no longer use oxygen at a tissue level, no matter that they are being supplied at adequate amounts. Thus you are in effect suffocated. This explains why it acts so quickly - it is a small molecule that can be absorbed easily, and its mechanism of action is on oxygen utilisation." } ]

[ { "id": "corpus-38170", "score": 0.71415776014328, "text": "There's a chain of chemical reactions that your body uses to convert sugar (glucose) and oxygen into ATP (the chemical which the cells use for energy). Cyanide binds to one of the enzymes necessary for this chain of reactions which means the whole process is interrupted. The cells in your heart and central nervous system rely heavily on that specific process to make ATP, so they quickly stop functioning properly. The size of a pill is quite misleading since there are a lot of molecules of cyanide in a single pill. A single pill could easily contain *quintillions* of cyanide molecules whereas you only have trillions of cell in your entire body. That's enough for there to be around a million cyanide molecules in every cell.", "topk_rank": 0 }, { "id": "corpus-1871481", "score": 0.7075734734535217, "text": "Cyanide is preferred as a gold extraction method over mercury yet they are both very poisonous and toxic substances. Why is this the case?", "topk_rank": 1 }, { "id": "corpus-24885", "score": 0.6930364370346069, "text": "It's lethal because it blocks a key enzime in the cycle of muscle contraction. The cause of death is paralysis of diaphragm, the muscle responsible for respiration. Antidotes exist, but you need to deliver them as soon as possible, because respiratory arrest ensues fast.", "topk_rank": 2 }, { "id": "corpus-130922", "score": 0.6907861232757568, "text": "Cyanide is different from other Carbon and Nitrogen containing compounds. It is made of a single Carbon and single Nitrogen atom, which make up the anion CN- This ion binds to and inhibits the function of an enzyme in the body that is vital to aerobic respiration, which your heart and central nervous system heavily depend on", "topk_rank": 3 }, { "id": "corpus-176254", "score": 0.6903488039970398, "text": "Altitude sickness, as you already stated, is caused by low levels of oxygen in the atmosphere and therefore the cells. Cyanide on the other hand, inhibits cytochrome oxidase, and therefore the electron transport chain of mitochondria. This means that it inhibits respiration and the body’s ability to actually use oxygen. So, the similarities are due to the fact that the body cannot use oxygen to produce energy (ie create ATP)- be it because there is no oxygen to use (altitude sickness) or because the structures that are able to use available oxygen are impaired (cyanide poisoning)", "topk_rank": 4 }, { "id": "corpus-272656", "score": 0.6883167028427124, "text": "Cyanide closely resembles Oxygen (O2) in terms of molecular orbitals, therefore will bind to the Iron centres in haemoglobin and more importantly in mitochondrial proteins involved in respiration. Cyanide being an anion forms complexes are both kinetically and thermodynamically very stable, as such Oxygen is unable to displace cyanide resulting in it blocking aerobic respiration pathways. It doesn't matter what atoms a compound/ molecule is made up of, its how the species behaves that is important. The elements that make up your body are never found in elemental form, pretty much always as fairly inert organic molecules. There are plenty of examples of Carbon and Nitrogen species that would be poisonous to cells.", "topk_rank": 5 }, { "id": "corpus-275228", "score": 0.6877748370170593, "text": "You might want to start with the [snopes](_URL_0_) article on this one. Basically, the cyanide won't kill you in the amounts you eat, even if you chew them considerably. However amygdalin, which is found in peach and apricot pits, is [quite toxic](_URL_1_). It's converted to cyanide in fairly high concentrations. There was a belief some years ago that this compound helped fight against cancer, but it's actually pretty harmful. > Based upon the rather flat LD,0 curve, it is reasonable to assume that the toxicity of orally given amygdalin in humans will vary greatly from person to person. This may explain why presumably some have ingested amygdalin and noted no toxic effects, whereas others have become symptomatic and a few have died of cyanide poisoning, one adult dying after ingesting as little as 10.5 grams of amygdalin", "topk_rank": 6 }, { "id": "corpus-317084", "score": 0.6871103048324585, "text": "Apple seeds do contain a small amount of a chemical that turns into cyanide when metabolized. This isn't typically harmful unless you do something like deliberately eat an entire bowl of apple seeds. ([Ref](_URL_1_)) Cyanide is not a cumulative poison. Chronic exposure can cause problems, but you need to be constantly eating sub-lethal quantities of cyanide or cyanogenic chemicals (cassava root as a carbohydrate source being one of the main possibilities). > [Cyanide does not accumulate or biomagnify, so chronic exposure to sublethal concentrations of cyanide does not appear to result in acute toxicity. However, chronic cyanide poisoning has been observed in individuals whose diet includes significant amounts of cyanogenic plants such as cassava. Chronic cyanide exposure is linked to demyelination, lesions of the optic nerve, ataxia, hypertonia, Leber's optic atrophy, goiters and depressed thyroid function.](_URL_0_)", "topk_rank": 7 }, { "id": "corpus-1670913", "score": 0.6860371828079224, "text": "If it bites you and you die, it's venom. If you bite it and you die, it's poison. But cyanide is a poison. Would it become a venom If a snake had its regular venom replaced with poison?", "topk_rank": 8 }, { "id": "corpus-241215", "score": 0.6737374663352966, "text": "HCN is a pretty weak acid, so it's not likely to cause the sort of disfiguring burns you see with strong acids like HNO₃ or H₂SO₄. It *is* very, *very* toxic though, so even if we pretend it was as caustic as something like AR or a piranha, there's absolutely no chance you'd survive contact with enough of it to eat your face off and not die from the cyanide poisoning itself.", "topk_rank": 9 }, { "id": "corpus-5935", "score": 0.6730108261108398, "text": "The atoms that make it don't matter in this case. What matters is the shape of the molecule they make together, and how that mixes with other shapes in the human body. Imagine that some molecules are locks, and others are keys. There is one particular lock that is necessary for your cells to produce energy, which you need to survive. When the one molecule that is shaped right fits that lock, it allows the cell to produce energy. Then it comes out, and you can do it again. Cyanide is like a mis-cut key. It fits in the lock, but doesn't produce energy. Worse, it gets stuck, and won't come out. When this happens to enough of the locks, you no longer produce enough energy. That means your muscles stop working, which stops your lungs, heart, etc.", "topk_rank": 10 }, { "id": "corpus-286732", "score": 0.6719560623168945, "text": "If death doesn't immediately follow the decrease in osmotic pressure in all your cells simultaneously due to a large volume of DNA inside of them vanishing then I think death by [histotoxic hypoxia](_URL_7_) is a possibility. Histotoxic hypoxia occurs when your body is unable to utilize oxygen for respiration, as in the case of cyanide poisoning. Since mitochondria divide much more frequently than their host cells, and have shorter half-lives and shorter lived proteins the loss of mitochondrial DNA will possibly have a more immediate effect than the loss of nuclear DNA, and if your mitochondria can't function then you can't respire.", "topk_rank": 11 }, { "id": "corpus-776190", "score": 0.6691718697547913, "text": "Ive heard apple seeds have cyanide in them, if so how much would even be a lethal ammount to consume?", "topk_rank": 12 }, { "id": "corpus-181686", "score": 0.6682196259498596, "text": "movies are movies. you do not die instantly, however, the hart and breathing stop, your blood stops flowing, in a matter of seconds you black out, in 5 minutes your dead. by breaking the neck, you break the nerves to the body, making it limp, it appears dead. however, it is not instant. even decapitated heads blink for a few seconds, the only way to jnstantly kill someone is to destroy the brain quickly. edit: what causes the fast death in breaking the neck or cutting off the head is the stop of bloodflow. your brain starves.", "topk_rank": 13 }, { "id": "corpus-8269", "score": 0.6672151684761047, "text": "It depends on the drug. Every substance (from water to cyanide) has what they call an \"LD50\" that is the dosage (in mg per kilo of mass of the subject) that will result in the deaths of 50% of the subjects. LD50 = Lethal Dose 50% So without asking about a specific substance, we can't really tell you what's happening.", "topk_rank": 14 }, { "id": "corpus-340273", "score": 0.6655607223510742, "text": "I have eaten so many apricot seeds in my life and my mom too. Nothing happened to us. When I googled it says you cab get cyanide poisoning. Is this true?", "topk_rank": 15 }, { "id": "corpus-79507", "score": 0.6653828620910645, "text": "Your body is pretty sensitive to some things, and the ratio of mass isn't always the best way to make it work. You're a lot bigger than a bullet, too. The botulism toxin is one of the deadliest poisons, in part because it doesn't get used up, and affects nerve cells - one molecule can kill a cell and move on to the next one, and it doesn't take many dead nerves to cause trouble. Polonium-210 is extremely radioactive, so it's essentially shooting tiny bullets at your cells from the inside. And the bullets themselves are alpha particles: so small, that even tiny amounts of polonium can release billions, and each one can wreck a cell. If its ingested, it will pass through your system, firing all the way through, and hitting many different bodily functions.", "topk_rank": 16 }, { "id": "corpus-2008699", "score": 0.6633797287940979, "text": "\n\n**Wild Almonds also contain high amounts of cyanide. Around 20 can kill an adult.**", "topk_rank": 17 }, { "id": "corpus-31967", "score": 0.6616132259368896, "text": "the reason you die from electrocution is it is an ongoing, continuous, current. The current will immobilize an muscle tissue it passes through, keeping it contracted for as long as the current is present. This includes your heart and lungs, to name a few. So basically you die because it stopped your heart / breathing / etc. A lightning strike, is pretty fast, lasting only a split second. Can still kill you but the chances are lower.", "topk_rank": 18 }, { "id": "corpus-2597064", "score": 0.6596714854240417, "text": "Hello people smarter than me. I’m confused with this concept, can anyone clarify?\n\nUWorld says nitroprusside can lead to cyanide poisoning.\nFirst Aid however states nitrates are used to TREAT cyanide poisoning (by inducing methemoglobinemia).\n\nI am confusion.", "topk_rank": 19 } ]

[ { "id": "corpus-325473", "score": 0.8725217580795288, "text": "This is an appropriate question for askscience. Anyways, a fixed refresh rate makes sense for LCDs. They hold their images between refreshes, so they don't \"flicker\" like CRTs do. You want the entire LCD screen to refresh at the same time, to eliminate \"tearing\" of the image, but you don't know exactly how fast the image will be coming it. So the solution was to create a maximum frame rate, and to always refresh at that rate. A variable refresh rate wouldn't have any real advantages, except for possibly very minor energy savings." } ]

[ { "id": "corpus-189185", "score": 0.7900668978691101, "text": "It's a mix of display connection limitations and marketing. Before displayport and higher versions of HDMI, the display cable that could transfer the most data was Dual Link DVI. The initial 120 Hz refresh monitors were at 1080p resolution. 120 Hz made sense because it was double 60 Hz, the standard monitor refresh rate and divisible by 24, the movie frame rate. Monitor manufacturers wanted to distinguish their monitors so they pushed the limits of Dual Link DVI. It turns out 144 Hz at 1080p was close to the maximum supported data rate for the cable. So monitors came out with 144 Hz refresh rate and 144 > 120. The number kinda got stuck as the new threshold so most high refresh monitors set that as the standard.", "topk_rank": 0 }, { "id": "corpus-325474", "score": 0.7799886465072632, "text": "_URL_0_ This is a decent source to read and answers your question. Anyhow, CRT frame rate was is better than your average LCD monitor now days. CRT monitors were usually equivalent to 75hz - 85hz. LCDs on average are 60hz. The source I posted stated that it has to do with the electrical standards of America. Ignore what people say about the human eye and mind when it comes to refresh rate. There is a lot of false information out there in regards to this. The human eye sees way more than 60fps. The human eye can also perceive things to be smooth even with things at something much lower, like 24fps. This is explained in the article I linked as well.", "topk_rank": 1 }, { "id": "corpus-43946", "score": 0.7740340828895569, "text": "Old TVs had the refresh rate locked to the frequency of the ac, so 60hz in North America and 50hz in most other places. Newer technology can run at much higher frequencies but 60hz has been kept as a default.", "topk_rank": 2 }, { "id": "corpus-106922", "score": 0.7694306373596191, "text": "Monitors often have higher resolutions and refresh rates.", "topk_rank": 3 }, { "id": "corpus-175582", "score": 0.7656061053276062, "text": "It has to do with the refresh rates of the camera versus the refresh rates of the monitors. Many cameras record at 24 frames a second, whereas most computer monitors refresh at 30 or 60 frames per second. This means that when a television camera is recording, it sees the screen while it's in mid-refresh. It's less noticable with LCD than it is with CRT, as there's a constant source of light from LCD monitors.", "topk_rank": 4 }, { "id": "corpus-1210731", "score": 0.7622596025466919, "text": "Is there a rhyme or reason? Why doesn't it just double/triple etc? \n\n\nI ask because from 60hz to 144hz seems to arbitrary. Is there a reason why it's not a even number or incremental (ie 60, 120, 180, 240) instead of theses odd jumps (ie 60, 75, 90, 100, 120, 144, 155, 165, 240)? \n\n\nIs it based on the screen's refresh rate capability, or the hardware doing the work to create the image translation to the screen? A random question, just wanting to know for my own knowledge.", "topk_rank": 5 }, { "id": "corpus-137146", "score": 0.7590011358261108, "text": "Just about no monitor natively runs at 40/56/etc by default. The vast majority of monitors run at a default maximum of 60hz, so it makes sense that if a set framerate is required, that 60fps or 30fps (since it is a factor of 60) is used.", "topk_rank": 6 }, { "id": "corpus-43041", "score": 0.7583200931549072, "text": "Most televisions above 60Hz use something called \"predictive imaging\" to smooth out the action. Basically, the TV's computer looks at two consecutive frames and figures out what an additional (nonexistant) frame *should* look like between those two and makes up that frame. If you look at the same HD imagery on a 60Hz TV and a 240Hz TV, you will notice that the 240Hz TV's image is substantially smoother flowing. A number of people I know have commented that the smoother video on the high refresh rate screens looks unnatural. All that aside, the 600Hz you are referring to is only on plasma TVs, and is the only refresh rate you'll find for that type.", "topk_rank": 7 }, { "id": "corpus-70690", "score": 0.757706344127655, "text": "The standard analog television signal used in the US is 30 frames per second interlaced (meaning it gets half the frame 60 times per second). This was chosen by committee in 1940. Consoles were designed to work with TVs, so they used the same frequencies. Because TV signals came in at that rate, most TVs have a refresh rate of 60Hz or 120Hz. If you have a 60Hz TV and play something at 30fps, the screen will update once every two refreshes. If you have 60Hz and 60 fps, the screen will update every refresh. But if you have 45Hz, the screen updates once every 1.5 refreshes, and you end up with [screen tearing](_URL_1_), where the image doesn't line up right because the frame was updated in the middle. Games made for PC have a V-Sync option to hold the frame update until the screen refresh is finished, but games designed for consoles are trying to get every last bit of power out of a fixed amount of hardware, so they take the shortcut of locking the frame rate.", "topk_rank": 8 }, { "id": "corpus-2795034", "score": 0.7535914182662964, "text": "Do OS' s have a set refresh rate? Does it depend on cpu clock speed?", "topk_rank": 9 }, { "id": "corpus-281017", "score": 0.7535573840141296, "text": "Although the theory involving refresh rate is a commonly held one, in this case (and most cases involving LCDs) the strange effect is caused by having the fine grid of pixels displayed on the fine grid of pixels in front of you now (your computer/tablet/phone screen). If you zoom in, the effect will change/disappear. edit: spelling and clarification.", "topk_rank": 10 }, { "id": "corpus-23263", "score": 0.7511826753616333, "text": "The reason specifically 60 is currently used is because high definition televisions and computer monitors, particularly LCDs, are designed around 60 hertz signals as a common base capability. _URL_0_", "topk_rank": 11 }, { "id": "corpus-241255", "score": 0.750663161277771, "text": "Tangential questions: How can CRT monitors which run at a maximum of 60-ish Hz able with image fade better able to control the time an image is displayed than the 120+ Hz LCD/LED displays that we have these days?", "topk_rank": 12 }, { "id": "corpus-87945", "score": 0.7491900324821472, "text": "This is because not all LCD panels are made the same. Some panels, like the inexpensive TN panels, have such poor viewing angles that colors and contrast literally become inverted, when viewed from extreme angles. The upside of TN panels is their speed: 144+hz TN panels are easily achievable, even for really high resolution displays. Other panel types, like IPS and PVA, have very little contrast shifts when viewed off-angle. However, these panels are much more expensive, and high refresh rates are rare.", "topk_rank": 13 }, { "id": "corpus-85137", "score": 0.7482978105545044, "text": "Most TV refresh 60 times a second. Therefore if you give it a 60 fps feed it will display each image once. Nice smooth picture. If you give it a 30 fps feed it will display each image twice. Steady but not as smooth. If you give it a 45 fps then it displays the first image once, the second image twice, the third image once and the forth twice... This leads to an unsteady image that feels worse than the 30fps. Many monitors have displays that refresh more than 60 times a second or can adapt their display frequency. Therefore 45 fps on a monitor might look better than 30fps but this is not true of most TVs.", "topk_rank": 14 }, { "id": "corpus-1985706", "score": 0.7473110556602478, "text": "Isn't this technically impossible? 1000ms divided by 60hz would give a result of 16,6ms per frame. So it would take 16,6ms before the next frame is shown. How come alot of monitors still advertise with the 1-5ms?\n\nEdit: if you're gonna downvote atleast state why.", "topk_rank": 15 }, { "id": "corpus-65703", "score": 0.7462109327316284, "text": "This question is like the other question that was asked when LCDs first came out. (Why doesn't my LCD monitor have a Hz rating?) Response Time is a function of the LCD and LED environments. It's job is to estimate how long it takes for a particular section of the monitor to go from (standard is) all white to all black or vice versa. There is gray-to-gray, don't wanna touch on that. CRT (Cathode Ray Tube) uses Hz, this tells you how many times it has to refresh each individual pixel in a second. 60 Hz means each pixel is refreshed 60 times in one second. A pixel on a CRT monitor or TV is made up of Yellow, Green and Red \"lights\" that light up as a result of an electron being fired from a gun in the back of the TV (why there's that big ass end on CRTs.) **TL;DR** Response time measures how long it takes to change the image, not how many times it updates that image in a second. Hz (Hertz) is the standard of measurement for CRT.", "topk_rank": 16 }, { "id": "corpus-2093320", "score": 0.7445939779281616, "text": "I learned this the hard way. I used an expensive 60hz gaming monitor for about 4-5 years before buying a 144hz that came with a DP cable instead of the HDMI I had used before. Low and behold, my old monitor was a 144hz monitor with a cable that did not allow more than 60hz. It was a real bummer, knowing how much I missed out on, and also more or less wasting money on an expensive second monitor. I had no idea the type of cable you used could limit refresh rates, and I was too young to know what I was buying when I got the monitor...", "topk_rank": 17 }, { "id": "corpus-316112", "score": 0.7435232400894165, "text": "The image on-screen refreshes at a different rate from the number of frames per second the camera. Most computer monitors refresh in a range from 60Hz-120Hz; cameras work at 50 frames per second. Because camera and monitor are out of sync, your picture takes at fewer images per second. source google search", "topk_rank": 18 }, { "id": "corpus-254943", "score": 0.742385983467102, "text": "You only need about 60Hz to achieve the effect. Most electrical grids cycle at 60Hz and old CRT monitors / TVs commonly refreshed (at a minimum) at that rate. Some people however are sensitive enough to be bothered by the flicker, also if you where to look away or via the corner of your eye it might be easier to perceive the flicker.", "topk_rank": 19 } ]

[ { "id": "corpus-325474", "score": 0.8289002180099487, "text": "_URL_0_ This is a decent source to read and answers your question. Anyhow, CRT frame rate was is better than your average LCD monitor now days. CRT monitors were usually equivalent to 75hz - 85hz. LCDs on average are 60hz. The source I posted stated that it has to do with the electrical standards of America. Ignore what people say about the human eye and mind when it comes to refresh rate. There is a lot of false information out there in regards to this. The human eye sees way more than 60fps. The human eye can also perceive things to be smooth even with things at something much lower, like 24fps. This is explained in the article I linked as well." } ]

[ { "id": "corpus-189185", "score": 0.7847231030464172, "text": "It's a mix of display connection limitations and marketing. Before displayport and higher versions of HDMI, the display cable that could transfer the most data was Dual Link DVI. The initial 120 Hz refresh monitors were at 1080p resolution. 120 Hz made sense because it was double 60 Hz, the standard monitor refresh rate and divisible by 24, the movie frame rate. Monitor manufacturers wanted to distinguish their monitors so they pushed the limits of Dual Link DVI. It turns out 144 Hz at 1080p was close to the maximum supported data rate for the cable. So monitors came out with 144 Hz refresh rate and 144 > 120. The number kinda got stuck as the new threshold so most high refresh monitors set that as the standard.", "topk_rank": 0 }, { "id": "corpus-26009", "score": 0.7825167775154114, "text": "The electrical grid in the US is alternating current at 60Hz. This made it much easier for CRT displays to cycle at 60Hz or multiples.", "topk_rank": 1 }, { "id": "corpus-43946", "score": 0.7784063220024109, "text": "Old TVs had the refresh rate locked to the frequency of the ac, so 60hz in North America and 50hz in most other places. Newer technology can run at much higher frequencies but 60hz has been kept as a default.", "topk_rank": 2 }, { "id": "corpus-268271", "score": 0.7742965221405029, "text": "Long story short, NTSC uses a 60Hz refresh rate because the power supply runs at 60Hz. Similarly, the European PAL standard runs at 50Hz because of their power grid frequency. This is especially relevant for old analog tube TVs. The TV's circuitry would use the AC frequency as a timing signal to control direction of the sweep of electron beam inside tube. Whenever you tune to a station, the incoming signal usually won't be in sync with the sweep and it has to realign the two. That's why your TV screen flickers whenever you change channels. It needs a short time to synchronize the picture. Hope this helps!", "topk_rank": 3 }, { "id": "corpus-63204", "score": 0.7739277482032776, "text": "In CRT displays this was due to the AC power cycle being 60 Hz. But with newer displays it is tradition and there are display standards like 144 Hz which are not multiples of 30.", "topk_rank": 4 }, { "id": "corpus-838681", "score": 0.7681888937950134, "text": "I've compared a regular LCD monitor, a CRT monitor with a passive hdmi-vga adapter, and a CRT TV with an active hdmi-scart adapter. The results I got at first using a mini SNES were in line with my expectations: 90-100 ms on the LCD (the standard in modern games), 55-65 ms on the CRTm, and 100 ms on the CRTtv (I guessed the 30-40 ms you gain from the crt are counterbalanced by the processing of the active scart adapter).\n\nBut then I've made another test this time connecting my pc and the results were completely different: I've got 55 ms on the LCD (very odd considering 50 ms was the standard for an original SNES and my monitor is quite cheap), and 80 ms both the CRTs (when on the previous test the CRTm gave the best results and the CRTtv+adapter the worst).\n\nDo anyone have some explanation for that? The test was made counting the frames from the button pressed all the way down to the character starting the jump animation using a 240 fps camera and taking the average results on 10 jumps.", "topk_rank": 5 }, { "id": "corpus-255170", "score": 0.7654950618743896, "text": "This is answered on the [Wikipedia article for Display Resolution](_URL_3_): > Few CRT manufacturers will quote the true native resolution, because CRTs are analog in nature and can vary their display from as low as 320 × 200 (emulation of older computers or game consoles) to as high as the internal board will allow, or the image becomes too detailed for the vacuum tube to recreate (i.e., analog blur). Thus, CRTs provide a variability in resolution that fixed resolution LCDs cannot provide. There was also [a discussion](_URL_2_) on this subreddit previously that better addresses the limits of resolution.", "topk_rank": 6 }, { "id": "corpus-2049259", "score": 0.7641746997833252, "text": "I've never understood this. I use a 1987 13\" TV in my bedroom, and a 13\" IBM CRT monitor from the mid nineties for my computer, and both have a great, sharp image. Like, I can make out every individual pixel just fine. Meanwhile, people make \"CRT Filters,\" i.e. simulated CRT appearance, for LCD screens, that are full of lines, blur, and other such weirdness. So what I don't get, is why is this?", "topk_rank": 7 }, { "id": "corpus-2359262", "score": 0.7633242607116699, "text": "I mean, I know higher resolutions and cell phone lobbyists vying for the bandwidth used by small broadcasters and public access were big factors, but framerate was also a major selling point. \n\nI know there's a visible difference between 60fps on a CRT and an LCD, but if everything's going to run at 30fps, I'd rather play it on a CRT. Looks better that way.", "topk_rank": 8 }, { "id": "corpus-107752", "score": 0.7629890441894531, "text": "Because that's how a CRT monitor *really* looks. A CRT draws one horizontal line at a time, top to bottom, many times each second. To you eye, it smears together, giving the illusion of a solid looking image. But to a camera recording 20-30 frames a second, the part of the screen that just got drawn will look brighter than others. And when played back, you lose the what happened between frames, which breaks the illusion.", "topk_rank": 9 }, { "id": "corpus-254943", "score": 0.7599924206733704, "text": "You only need about 60Hz to achieve the effect. Most electrical grids cycle at 60Hz and old CRT monitors / TVs commonly refreshed (at a minimum) at that rate. Some people however are sensitive enough to be bothered by the flicker, also if you where to look away or via the corner of your eye it might be easier to perceive the flicker.", "topk_rank": 10 }, { "id": "corpus-175582", "score": 0.7574907541275024, "text": "It has to do with the refresh rates of the camera versus the refresh rates of the monitors. Many cameras record at 24 frames a second, whereas most computer monitors refresh at 30 or 60 frames per second. This means that when a television camera is recording, it sees the screen while it's in mid-refresh. It's less noticable with LCD than it is with CRT, as there's a constant source of light from LCD monitors.", "topk_rank": 11 }, { "id": "corpus-87945", "score": 0.7572216391563416, "text": "This is because not all LCD panels are made the same. Some panels, like the inexpensive TN panels, have such poor viewing angles that colors and contrast literally become inverted, when viewed from extreme angles. The upside of TN panels is their speed: 144+hz TN panels are easily achievable, even for really high resolution displays. Other panel types, like IPS and PVA, have very little contrast shifts when viewed off-angle. However, these panels are much more expensive, and high refresh rates are rare.", "topk_rank": 12 }, { "id": "corpus-70690", "score": 0.7571377158164978, "text": "The standard analog television signal used in the US is 30 frames per second interlaced (meaning it gets half the frame 60 times per second). This was chosen by committee in 1940. Consoles were designed to work with TVs, so they used the same frequencies. Because TV signals came in at that rate, most TVs have a refresh rate of 60Hz or 120Hz. If you have a 60Hz TV and play something at 30fps, the screen will update once every two refreshes. If you have 60Hz and 60 fps, the screen will update every refresh. But if you have 45Hz, the screen updates once every 1.5 refreshes, and you end up with [screen tearing](_URL_1_), where the image doesn't line up right because the frame was updated in the middle. Games made for PC have a V-Sync option to hold the frame update until the screen refresh is finished, but games designed for consoles are trying to get every last bit of power out of a fixed amount of hardware, so they take the shortcut of locking the frame rate.", "topk_rank": 13 }, { "id": "corpus-151733", "score": 0.7561435103416443, "text": "its the other way around. Computer monitor LEDs/LCDs have a way higher pixel and screen resolution density than any television on the market, excluding 4k TV's", "topk_rank": 14 }, { "id": "corpus-130298", "score": 0.7546473145484924, "text": "That used to be the case with CRT (cathod ray tube) displays on older TVs. Here each pixel was generated by beaming it onto the screen, and leaving the same image for too long would literally burn the screen. Nowadays with LED technologies this is no longer a problem.", "topk_rank": 15 }, { "id": "corpus-20727", "score": 0.7530537843704224, "text": "A lot of televisions have high *input lag*, while computer monitors try to minimize this. This isn't related to the *refresh rate* of the screen, which is what you mean by \"Hertz.\" (Hertz are the unit, but \"inch\" isn't the same as \"length.\"). Slow controls aren't really a problem when you're just watching television after all.", "topk_rank": 16 }, { "id": "corpus-43041", "score": 0.751495897769928, "text": "Most televisions above 60Hz use something called \"predictive imaging\" to smooth out the action. Basically, the TV's computer looks at two consecutive frames and figures out what an additional (nonexistant) frame *should* look like between those two and makes up that frame. If you look at the same HD imagery on a 60Hz TV and a 240Hz TV, you will notice that the 240Hz TV's image is substantially smoother flowing. A number of people I know have commented that the smoother video on the high refresh rate screens looks unnatural. All that aside, the 600Hz you are referring to is only on plasma TVs, and is the only refresh rate you'll find for that type.", "topk_rank": 17 }, { "id": "corpus-280347", "score": 0.7508284449577332, "text": "There's a lot of analog circuitry in a CRT, and analog things are generally less \"stable\" over time as compared to digital. Your CRT appears to be failing where it can't keep the image centered (it's supposed to); this problem was solved long ago for CRTs.", "topk_rank": 18 }, { "id": "corpus-23263", "score": 0.7495092749595642, "text": "The reason specifically 60 is currently used is because high definition televisions and computer monitors, particularly LCDs, are designed around 60 hertz signals as a common base capability. _URL_0_", "topk_rank": 19 } ]