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[ "The first thing to start with is that it isn't light that's special, it's the speed *c* that's special. (We'll come back to why light travels at the speed later.)\n\nIt's a principle of the universe -- a principle that we can assert, but as of now we can't tell you *why* it's true or reduce it to a more basic principle -- that there is a certain speed which is the same relative to every observer (no matter whether those observers are moving relative to each other or not).\n\nIn the Newtonian view, something would have to be moving at an infinite speed in order to be traveling at the same speed relative to every observer, but Special Relativity teaches us that the special speed is finite. We will call that speed *c*.\n\nThe first thing you should notice is that this means if something is traveling at that special speed, everyone will see it traveling at that special speed. That means, for example, that it can never be made to go faster or slower or be brought to rest; otherwise we'd be violating the underlying principle.\n\nLight happens to travel at this speed, so it was in the context of light that we first encountered the notions of Special Relativity.\n\nI know you have other questions, but I thought I'd at least get this part of your answer posted.", "Alright, so you are asking some advanced questions and I'm going to preach what I learned in undergraduate quantum physics and then you can move on from there, or ignore this completely and listen to someone else, or whatever.\n\nWhy do photons have different energy states? So yeah this now moves into the idea of Energy as a whole. Everyone knows classic Einstein's E=mc^2 but most do not know that the full equation which leads to an answer to your question is E^2 = (mc^2)^2 + (pc)^2 where m is rest mass and p is momentum. Rest mass is the mass that objects inherently have. If you or I was floating in space we would have a rest mass of some tangible value. Photons have no REST mass. That's important. \n\nNow that we know all of this we find that the energy of a photon is thus E = pc. So energy is dependent upon the momentum of the of photon. But how can a photon have momentum, doesn't momentum have to do with mass. Yes. Also no. Debroigle was all like hey I'm going to do some math and you guys are going to save a lot of headache. You have already mentioned you heard of the wave-particle duality of light. Debroglie was the man who is well known for giving a mathematical representation of this relationship. So Debroglie said hey, you know what I get that electromateic waves have no rest mass, but I'm pretty sure they still have energy and stuff. So he came up with E = hv where h is Plancks constant and v is the frequency of the light. So now were all like yes, yes, this is good, we are starting to understand some things. Everyone quickly went and said hey! HEY! Frequency and wavelength are related to speed! OMG! So now we know light moves at c and that its energy is related to frequency and we have another energy equation too so now we can make things equal each other. Thus if you follow:\n\nE = pc with 0 rest mass \n\nE = hv for electromagnetic waves \n\nlambda*v = c for photons (known relationship between frequency, wavelength, and velocity)\n\nThus: p = h/lambda \n\n\nSo light has energy which can have different 'states' as you called it, which all change based on the frequency. (Or wavelength, they are inherently related, it just depends on what you want to talk in, I like frequency because common culture talks about EM in terms of frequency and not wavelength).\n\nSo yeah different energy based off frequency. To add to this monstorous question, I also want to mention that you will probably come to the conclusion that photons still have mass based on these equations and yeah there is a relationship between them but the physics world deems this relationship to be a 'relativistic' mass. Relativistic mass of photons is related to its wavelength and planck's constant and speed of light and stuff. \n\nWoooo second question is a bit easier to explain conceptually. I will not even remotely try to explain the math behind it. So let me just say that space and time are related. They are so related that the theoretical grid which incorporates all celestial bodies is known as the space-time continuum. Now when light moves it moves directly along lines in this grid. So picture for me a flat grid. Its flat. It has lines. It looks like a checker board or whatever. Cool. Ok, now gravity. Gravity bends the space-time grid. Gravity causes dips and slopes in this grid depending on the mass of objects. So think about a bed sheet which is held flat and tied to something at each corner at the same elevation. Now put a bowling ball in the middle. The sheet dips a lot. Put a tennis ball in there, it doesn't dip so much. Same thing happens in the space-time grid. The sun is pretty big. So it makes a big dip. Thus, the space-time grid bends. Light still moves along the lines of the space-time grid so it 'bends' around massive objects. It's not bending as much as taking the path of leach resistance.. in a sense. As opposed to breaking off the grid and going in what we would call a straight line, it follows the dip and moves along. So light is not being pulled by the attraction to the massive objects, it is in fact the environment that is bending. Weird. \n\nYour third question is not so much a question as it is your misunderstanding of the speed of light is. The speed of light is not a speed, I mean it is, but it is more importantly the maximal relationship between space and time. Its a constant for a reason. It is the relationship between space and time. More in depth study will give you an idea of why space and time are related and how intricate it is; read that if you want but as a basic concept the speed of light is the proportion to relate space and time. Cool, so now that we know that it is the maximal balance between space and time, lets ask why. Well, in short, the math works out that way. Lets go back to E = mc^2. So for something with rest mass we can solve this. \n\nRest mass = 1 then energy = 1*c^2 . \n\nNice. So how are energy and speed related to mass. Keeping in mind c is a constant. \n\nE/c^2 = m\n\nSo as mass approaches 0, we need more and more and MORE AND MORE AND MORE energy to make the equation work. In fact we actually need infinite energy for something with 0 mass. (which is why the the pc is so important in the equation to find the energy of light) To continue since I brought up E^2 = (mc^2)^2 +(pc)^2 we can reduce this to E = mc^2 + pc. So at 0 rest mass, like a photon, pc controls the energy. The bigger p is, the more energy we have. Since we know p=h/lambda we can see that as wavelength decreases, momentum increases. Thus, like your assertion of adding more speed as opposed to mass, wavelength decreases to increase energy. This is of course up to the maximal amount which is of course bound by space-time since labda*frequency = c. Lols. See how its all related?!?! Nice.\n\nLight sails are beyond me, but one of my TA's talked about it once and I distinctly remember him talking about how momentum is the driving factor. Makes sense. I mean take E = pc. Photons have momentum based on frequency. All light sails do is take that momentum/energy from the photons to propel the vessel. What harnesses the energy, I don't know. I guess some sort of material which resonates at a particular frequency. Ask someone smarter. \n\nSpeed of light asymptotically we already approached. I guess I forgot to mention that the p in the equation is meant for single particle considerations, not like p = mv in classical physics. But then again, we would talk about Einsteins equation outside the context of single particles (most cases) so its kinda inherent. Yeah, anyway.. so E^2 = (mc^2 )^2 + (pc)^2 . rearrange a few things and m = sqrt((E^2 / c^4 )-(p^2 / c^2 )). So you can see how energy increases as mass increases. The second part of the question I kinda already explained, but yeah, not a defining force, but inherent relationship between space and time. Word up. \n", "The concise answer: in order for the laws of physics to behave the same in all reference frames, things (like light, but not *only* light) that have speeds which depend on the properties of space must travel at a single constant velocity, which happens to be C." ]

[ "It depends on the temperature of wherever it’s at but generally because ice carvings are so large they are more resistant to heat. Even still, popsicles don’t turn into liquid the second you take it out of the freezer.", "As the outer layer of ice melts and turns into water, it absorbs heat to do so. It absorbs this heat from its surroundings, including both the air AND the underlying block of ice. This makes the underlying ice even colder, which means it takes even longer before it too melts. \n\nEverything above 0K (-273C) contains heat energy. Therefore even frozen stuff like ice contains heat. As a matter of fact, there is more heat energy in an iceberg than there is in a fresh piece of toast!" ]

[ "You have just named two chemicals. What concept do you want explained here?", "Alcohols are a category of chemicals that all have the structure X-OH, where X is some number of carbons in a chain. So you have:\n\nMethanol: C-OH \nEthanol: C-C-OH \nPropanol: C-C-C-OH \nButanol: C-C-C-C-OH \nPentanol: C-C-C-C-C-OH \nHexanol: C-C-C-C-C-C-OH\n\nAnd so on. Chemically they're similar to each other, but not completely interchangeable. Ethanol and methanol are *not* interchangeable as drinks: ethanol gets you drunk but methanol makes you blind." ]

[ "Since you can't remember much of your past life, only the really important parts and stuff that stands out, you tend to only remember a few years worth of content. So if you have 5 years worth of memories after 50 years, it can feel like those 50 years went just by as quickly as you expect the next 5 years to take.", "I think I'm with the OP here. None of these answers here actually seem to legitimately give a cause for this to happen.", "The longer you live, each day is taking up a smaller and smaller percentage of your life, which makes it feel shorter, and overall makes life pass pretty quickly.", "Since you can't remember much of your past life, only the really important parts and stuff that stands out, you tend to only remember a few years worth of content. So if you have 5 years worth of memories after 50 years, it can feel like those 50 years went just by as quickly as you expect the next 5 years to take.", "I think I'm with the OP here. None of these answers here actually seem to legitimately give a cause for this to happen." ]

[ "There's computer software you can use. Rapid Evolution is fairly good.", "If it's a modern song, the bass usually plays the root note on the one beat, making it easier to isolate.", "The best way of doing it is to simply figure out which notes are being played in the song, then see which scale they follow. For example, if all the tones in the melody are simple A,B,C,D,E,F,G, then the song is probably in C-major, because those are the notes in that scale.", "As long as you have a musical ear, it's fairly simple. You try to play along with the music on piano, guitar or whatever. Once you're hitting some right notes, listen out for the 'home note'. So, if it sounds like G is the home note, play the chord of G. By playing the chord, you should be able to hear if it's the root or a fifth, etc. If it's not right, keep trying. You can also figure it out based on the notes /accidentals you play that sound right. ", "A song usually starts and finishes on the chord in the 'centre' of the key. Grab a keyboard or guitar, listen to the first/last chord of the piece and try to match it on the instrument. When it sounds the same, you've found your key. Remember, it could be major or minor, so try both.", "If you have no information, then it takes a good ear. If you are experienced with solfege (The Do, Re, Mi system), it is *way* easier. What I do is listen and figure out which pitch is Do.\n\nThere are a few clues to help you. The leading tone, Ti, the seventh scale degree, leads up into Do. Fa (4th degree) falls down to Mi. The other strong pitch is likely Sol, the 5th scale degree. \n\nIf it's a minor key, you'll hear Me instead of Mi (the difference is Me is a half step lower) and instead of La (6), you have Le, which acts similar to the way Fa lead to Mi, but it leads to the stronger Sol. Ti might be Te (half step lower) or remain Ti; it's easy to hear the Le-Ti gap, so that's a major hint in a minor key.\n\nWhen you figure out in your head which note is Do, you can hum it into a tuner or find the same note on a piano. For major/minor, you look first at Mi vs Me, La vs Le, Ti vs Te. Sometimes a song changes key or briefly tonicizes(makes it sound like Do) another note, typically Sol.\n\nThe only way to get good at this is experience. Sing simple tunes in Solfege to build your ear skills. Practice intervals; songs are rarely just steps. ", "Not strictly how to find the key, but the root note is generally whatever note the song *seems* like it should end on. ", "TIL that there's no explaining anything in music theory like one is five. However, I'll try to give it a shot.\n\nIf you have the sheet music, a quick and easy way is the key signature. Every possible combination of sharps and flats has an equivalent major and minor key. This has to be memorized by rote, there is no other way.\n\nIn the context of rock music, the key is almost always the first chord in a \"riff.\" This is a fast and loose rule, but let's look at a basic three chord progression of G-C-D. This would be in G major. Or Am-F-G-D, the key is A minor. \n\nThis is not always true, but the best way I can explain it is to listen for the \"tonic\", rather, the dominant-sounding chord in the riff. I can't really tell you how to do this one other than \"you know it when you hear it.\"", "Figuring out which _scale_ a song uses is not to hard. Play some notes on an instrument (e.g. guitar, piano) whilst listening to the music. Remember which notes sound terrible when played with the song, remember which ones sound good. (There's only different 12 notes, so it's easy for a musician to remember).\n\nOnce you've got a set of notes that sound good, it's usually easy to find the 1 or 2 that sound \"best\". These will be what musicians call the root and fifth, and they'll basically pinpoint which scale the song uses. \n\nThe key is a bit more complex. *Scale* is a different thing from *key*, as *scale* simply says what notes are used, but not how they're used. A *key* defines a *home note* -- the note which the musical *key* centres around. A normal C scale is \"C,D,E,F,G,A,B\". But you can technically play in that scale by using the Key of *G Mixolydian*, as well as the plain old key of *C Major*. Don't worry to much about the word Mixolydian, in plain terms it just means the G isn't the start note of the *scale* used, and tells you which note in that scale it was. (Mixolydian is the name for the 5th).\n\nTo most human beings there's no hearable difference between a C Major and a G Mixolydian. Musicians can figure out if the key is C Major or G Mixolydian etc by looking at the different chords used and how often a song uses a particular note, and when it uses it. That's the tricky bit.\n\n", "I usually just start playing a scale along with the song. If it sounds like crap, I move up half a step, and repeat. Once it \"sounds right\" for the whole scale, you've found it. I'm sure there is a better / more technical way, but oh well.\n\nThough, there are quite a bit of songs that change keys throughout the piece... that kind of sucks because then you have to do it again.", "Clarifying question from someone that isn't good at music notes. Is the key the note that makes you feel like the melody is \"finished\"? Like if you hum the song, you end it on a note of that key? I don't know if I'm making sense because my music vocabulary is very limited.", "To find the key for much of today's popular music: Find the \"home\" note, the note that feels like the main note, a.k.a. the \"tonic.\" A key is a perceptual series of note relationships proceeding from that \"home\" note. Often times, these note relationships follow what we call \"the major scale,\" so once you find the \"home\" note, you have generally found the key. If the main note is C, odds are you will be in the key of C major. Major keys have a very distinct feel, what many would call pleasant or \"happy.\" This is an over-simplification, but it does the job most of the time. The name for what music theory people call the feeling or mood of the piece is tonality. Major tonality is the dominant tonality in popular music today.\n\nThe real music theory explanation: The major scale is not the only kind of tonality. There are other commonly found tonalities; they arise as often as you can discern a different scale. Minor scales, the blues scale, the pentatonic scale (minor or major), different modes of those scales (same note relationships overall but proceeding from different degrees functioning as the \"home\" note), ranging all the way to non-western and/or microtonal scales.\n\nOnce you identify the home note, you can figure out how the other notes in the song relate to it by matching them by ear or on an instrument. Write all of the notes in the song down, and figure out their relationships to the home note. This series of relationships from the home note up the scale will usually be Whole-Whole-Half-Whole-Whole-Whole-Half (whole and half steps), the major scale. This is good enough most of the time. But the relationships will reveal other scales from time to time. Reading up on the different kinds of scales/modes people use opens up new worlds. I highly recommend it.\n\nThe only problem I see in all this is that the western system for writing and talking about music is hundreds of years old. The benefit of this is that western music theory people have de-constructed and and put back together much of the music in the history of the western world again and again, contributing amazing insights and spurring on massive innovation. The disadvantage of this is simply that music is never in the past, but it is now. It is a transient, fleeting thing, and often defying expectations or \"rules.\" Using an old system to describe music can lead someone to miss some of what's conceptually present in music that was written outside of it (\"world\" music, songs written by people like Thom Yorke who can't read sheet music). Thus, thorough transcription needs to fit the piece, the composer intentions (wherever discernable from their previous work), and other contextual clues like genre... and my personal opinion is that the Italian system of old is no longer doing the job. It becomes tedious when trying to transcribe dubstep rhythms with note heads, or blues solos in traditional staff notation. Music has always been sound, not words and symbols. And conceptually, music has always been bursting at the seams. On a related side note, I am working on a new system to roll out on a music theory/guitar website I am launching someday hopefully in 2012.\n\nWhy I am commenting: I am a music theory teacher. I have studied western music theory and world music theory. Baroque harmony, species counterpoint, microtonal stuff, non-western transcription methods, and all that. Bachelor's degree in Ethnomusicology from UCLA. Scored 5 on the AP music theory exam (which isn't saying that much but whatever).\n\nTL;DR - Find the main note, call it \"[main note] Major\" and you will be right most of the time.\n\nEdited to mention my favorite comments and expand some brief thoughts. Konrad4th's explanation in solfege is great. Only issue with it is you need to embark on the challenge of ear-training which everyone should do if they haven't. Relative pitch opens up music in a whole new way. Lizard's comment is also very informative if you have access to a piano.", "There's computer software you can use. Rapid Evolution is fairly good.", "Depends on how much information you have. If you just have the audio file, try looking up a chord chart or a lead sheet online, and go from there. If you can't find a chart, you'll have to use your ear to find the chord. The basic rule is whatever chord the song starts on, and ends on is the tonic, and you can use that to figure out the key. For example, if the first chord is an Em7, chances are it is in the key of Em (this rule is quite often broken, depending on the complexity of the arrangement, but it's a good starting point).\n\nIf you have the sheet music, then the key signature should be there, and you can easily work it out from that.\n\nHope this helps. ", "If it's a modern song, the bass usually plays the root note on the one beat, making it easier to isolate.", "The best way of doing it is to simply figure out which notes are being played in the song, then see which scale they follow. For example, if all the tones in the melody are simple A,B,C,D,E,F,G, then the song is probably in C-major, because those are the notes in that scale.", "As long as you have a musical ear, it's fairly simple. You try to play along with the music on piano, guitar or whatever. Once you're hitting some right notes, listen out for the 'home note'. So, if it sounds like G is the home note, play the chord of G. By playing the chord, you should be able to hear if it's the root or a fifth, etc. If it's not right, keep trying. You can also figure it out based on the notes /accidentals you play that sound right. ", "A song usually starts and finishes on the chord in the 'centre' of the key. Grab a keyboard or guitar, listen to the first/last chord of the piece and try to match it on the instrument. When it sounds the same, you've found your key. Remember, it could be major or minor, so try both.", "If you have no information, then it takes a good ear. If you are experienced with solfege (The Do, Re, Mi system), it is *way* easier. What I do is listen and figure out which pitch is Do.\n\nThere are a few clues to help you. The leading tone, Ti, the seventh scale degree, leads up into Do. Fa (4th degree) falls down to Mi. The other strong pitch is likely Sol, the 5th scale degree. \n\nIf it's a minor key, you'll hear Me instead of Mi (the difference is Me is a half step lower) and instead of La (6), you have Le, which acts similar to the way Fa lead to Mi, but it leads to the stronger Sol. Ti might be Te (half step lower) or remain Ti; it's easy to hear the Le-Ti gap, so that's a major hint in a minor key.\n\nWhen you figure out in your head which note is Do, you can hum it into a tuner or find the same note on a piano. For major/minor, you look first at Mi vs Me, La vs Le, Ti vs Te. Sometimes a song changes key or briefly tonicizes(makes it sound like Do) another note, typically Sol.\n\nThe only way to get good at this is experience. Sing simple tunes in Solfege to build your ear skills. Practice intervals; songs are rarely just steps. ", "Not strictly how to find the key, but the root note is generally whatever note the song *seems* like it should end on. ", "TIL that there's no explaining anything in music theory like one is five. However, I'll try to give it a shot.\n\nIf you have the sheet music, a quick and easy way is the key signature. Every possible combination of sharps and flats has an equivalent major and minor key. This has to be memorized by rote, there is no other way.\n\nIn the context of rock music, the key is almost always the first chord in a \"riff.\" This is a fast and loose rule, but let's look at a basic three chord progression of G-C-D. This would be in G major. Or Am-F-G-D, the key is A minor. \n\nThis is not always true, but the best way I can explain it is to listen for the \"tonic\", rather, the dominant-sounding chord in the riff. I can't really tell you how to do this one other than \"you know it when you hear it.\"", "Figuring out which _scale_ a song uses is not to hard. Play some notes on an instrument (e.g. guitar, piano) whilst listening to the music. Remember which notes sound terrible when played with the song, remember which ones sound good. (There's only different 12 notes, so it's easy for a musician to remember).\n\nOnce you've got a set of notes that sound good, it's usually easy to find the 1 or 2 that sound \"best\". These will be what musicians call the root and fifth, and they'll basically pinpoint which scale the song uses. \n\nThe key is a bit more complex. *Scale* is a different thing from *key*, as *scale* simply says what notes are used, but not how they're used. A *key* defines a *home note* -- the note which the musical *key* centres around. A normal C scale is \"C,D,E,F,G,A,B\". But you can technically play in that scale by using the Key of *G Mixolydian*, as well as the plain old key of *C Major*. Don't worry to much about the word Mixolydian, in plain terms it just means the G isn't the start note of the *scale* used, and tells you which note in that scale it was. (Mixolydian is the name for the 5th).\n\nTo most human beings there's no hearable difference between a C Major and a G Mixolydian. Musicians can figure out if the key is C Major or G Mixolydian etc by looking at the different chords used and how often a song uses a particular note, and when it uses it. That's the tricky bit.\n\n", "I usually just start playing a scale along with the song. If it sounds like crap, I move up half a step, and repeat. Once it \"sounds right\" for the whole scale, you've found it. I'm sure there is a better / more technical way, but oh well.\n\nThough, there are quite a bit of songs that change keys throughout the piece... that kind of sucks because then you have to do it again.", "Clarifying question from someone that isn't good at music notes. Is the key the note that makes you feel like the melody is \"finished\"? Like if you hum the song, you end it on a note of that key? I don't know if I'm making sense because my music vocabulary is very limited.", "To find the key for much of today's popular music: Find the \"home\" note, the note that feels like the main note, a.k.a. the \"tonic.\" A key is a perceptual series of note relationships proceeding from that \"home\" note. Often times, these note relationships follow what we call \"the major scale,\" so once you find the \"home\" note, you have generally found the key. If the main note is C, odds are you will be in the key of C major. Major keys have a very distinct feel, what many would call pleasant or \"happy.\" This is an over-simplification, but it does the job most of the time. The name for what music theory people call the feeling or mood of the piece is tonality. Major tonality is the dominant tonality in popular music today.\n\nThe real music theory explanation: The major scale is not the only kind of tonality. There are other commonly found tonalities; they arise as often as you can discern a different scale. Minor scales, the blues scale, the pentatonic scale (minor or major), different modes of those scales (same note relationships overall but proceeding from different degrees functioning as the \"home\" note), ranging all the way to non-western and/or microtonal scales.\n\nOnce you identify the home note, you can figure out how the other notes in the song relate to it by matching them by ear or on an instrument. Write all of the notes in the song down, and figure out their relationships to the home note. This series of relationships from the home note up the scale will usually be Whole-Whole-Half-Whole-Whole-Whole-Half (whole and half steps), the major scale. This is good enough most of the time. But the relationships will reveal other scales from time to time. Reading up on the different kinds of scales/modes people use opens up new worlds. I highly recommend it.\n\nThe only problem I see in all this is that the western system for writing and talking about music is hundreds of years old. The benefit of this is that western music theory people have de-constructed and and put back together much of the music in the history of the western world again and again, contributing amazing insights and spurring on massive innovation. The disadvantage of this is simply that music is never in the past, but it is now. It is a transient, fleeting thing, and often defying expectations or \"rules.\" Using an old system to describe music can lead someone to miss some of what's conceptually present in music that was written outside of it (\"world\" music, songs written by people like Thom Yorke who can't read sheet music). Thus, thorough transcription needs to fit the piece, the composer intentions (wherever discernable from their previous work), and other contextual clues like genre... and my personal opinion is that the Italian system of old is no longer doing the job. It becomes tedious when trying to transcribe dubstep rhythms with note heads, or blues solos in traditional staff notation. Music has always been sound, not words and symbols. And conceptually, music has always been bursting at the seams. On a related side note, I am working on a new system to roll out on a music theory/guitar website I am launching someday hopefully in 2012.\n\nWhy I am commenting: I am a music theory teacher. I have studied western music theory and world music theory. Baroque harmony, species counterpoint, microtonal stuff, non-western transcription methods, and all that. Bachelor's degree in Ethnomusicology from UCLA. Scored 5 on the AP music theory exam (which isn't saying that much but whatever).\n\nTL;DR - Find the main note, call it \"[main note] Major\" and you will be right most of the time.\n\nEdited to mention my favorite comments and expand some brief thoughts. Konrad4th's explanation in solfege is great. Only issue with it is you need to embark on the challenge of ear-training which everyone should do if they haven't. Relative pitch opens up music in a whole new way. Lizard's comment is also very informative if you have access to a piano." ]

[ "Largely countries do their testing now underground, which limits the amount of fallout. Fallout is about radioactive particles getting into the atmosphere then falling back down. If you do your testing underground, there's not much fallout.\n\nThere's still radiation, but then you just keep people away from those locations (hence doing it in the middle of nowhere, like deserts)", "If you bury a nuclear device test deep underground or under a mountain you can contain all the radiation. North Korea uses this method. You can also eliminate fallout on the ground by detonating the blast sufficiently high off the ground. ", "Since 1963, a treaty has been in place that bans testing of nuclear weapons in space, air, ground, water - everywhere EXCEPT underground.\n\nAnother treaty calling for a complete ban on testing was introduced in 1996, but has not been adopted yet by all parties.\n\n\n_URL_0_", "They used to do it out in the open, before they realized the full extent of the negative repercussions of nuclear fallout. So they used to test the bombs in the middle of the desert where there weren't many people around in the US. And the largest number of US tests were in the South Pacific, around the Bikini Atoll, using bombs many times more powerful than those used in Hiroshima and Nagasaki. At the time of the tests in the 1950s, the native inhabitants of the area were forced to leave by the US government, with the understanding that they'd be able to go back in a short while to their homes. However, they're STILL not back there because it's still radioactive. \n\nWhen it was realized how serious the damage caused by nuclear testing was, countries started doing their testing underground, so as not to pollute the atmosphere with more radiation.\n\nAs for safety nowadays if major cities are attacked: it would certainly be safer there than it would be closer to the cities. However, it's been theorized that a large nuclear war involving many powerful weapons will cause major damage to the earth that will wipe out a large amount of life on the planet. It is hypothesized that it will cause \"nuclear winter\"--a worldwide cooling brought on by all the smoke and debris that are thrown up into the atmosphere by the bombs and prolonged fires afterwards. This will result in crop failures and death. There will also be a lot of radiation in the atmosphere that will pollute the earth and can cause sickness and mutations. So a true global thermonuclear war might end up killing most of life on earth. ", "So many very incorrect responses here. I was kind of afraid of opening this thread for this reason, but here goes...\n\nFallout is a concern when you detonate nuclear weapons on the surface. Even small nuclear weapons can produce considerable contamination downwind. The Trinity shot of 1945, for example, [created quite a large plume](_URL_5_). You wouldn't want to be someone who lived in that plume; close-in to the site, it could actually kill you or give you radiation sickness. Further out, it raises cancer rates.\n\n[The huge contaminating plumes from multi-megaton bombs](_URL_3_) did contaminate the test sites they were set off in, and people did have to be evacuated, and many people who lived near the test sites did contract cancers, have higher rates of birth defects, etc. \n\nIn the United States, people living due-east of the Nevada Test Site (e.g. in Utah) [did pick up significant levels of radiation from the drifting clouds](_URL_2_). Individually this adds up to a small dose; over a large population this means an increase in cancers. Various estimates have been made by the number of people, worldwide, who got cancers from US nuclear testing. As one source concludes:\n\n > \"As a result of fallout from U.S. atmospheric testing between 1945 and 1963, an estimated 70,000 to 800,000 people in the United States and around the world have died or will die prematurely from a fatal cancer attributable to the testing (a comparable number of fatalities would be attributable to the Soviet testing program).\"\n\nThis is from Arjun Makhijani and Stephen I. Schwartz, \"Victims of the Bomb,\" in Stephen I. Schwartz, ed., Atomic Audit, 395-431, on 395. \n\nThe US has paid out [over $1 billion USD](_URL_4_) to over 20,000 people who were \"downwind\" of the Nevada Test Site during the era of US atmospheric nuclear testing there (1948-1962), who themselves or their relatives came down with diseases attributable to fallout exposure. This probably _under_estimates the effects a bit but I just want to emphasize that the answer to your question is not \"they made it work perfectly safe and it wasn't a problem,\" the answer is, \"they exposed huge populations of people to radioactivity, and justified it by arguing that the safety of the nation was worth their collective sacrifice.\"\n\nAfter 1962 the US, USSR, and UK did all of their testing underground. China and France continued to test in the atmosphere for some time afterwards. Today nobody but North Korea has tested since the late 1990s, and so far they've been testing underground (but there are worries they may test in the atmosphere).\n\nAs for a nuclear war scenario, it depends on what you assume \"the enemy\" will do. Nuclear attacks on cities are often presumed to be more or less fallout-free because the goal will be \"medium\" destruction and not \"heavy\" destruction and that tends to involve setting the bombs off high-enough that fallout doesn't occur. However if you imagine \"the enemy\" will attack US missile silos in the midwest, which are buried deep underground and are \"hards\" targets,\" then you are imagining a lot of surface burst weapons and that creates a lot of fallout. So fallout maps will vary by the assumptions you make (including about weather behavior). Here is an estimate [for the mid-1980s by Oak Ridge National Laboratory](_URL_0_) — you can see that being downwind of cities, and of military bases, is a dangerous proposition. By comparison [here is one from the 1960s](_URL_1_), which has more realistic weather patterns.\n\n\"Safe\" is always relative here. If you know how to take shelter from fallout and have shelter facilities available to you, in many cases you can be reasonably safe from it. The destruction of cities and infrastructure will have other impacts, of course, that will make life post-attack \"less safe\" (e.g., disrupting your food and energy supply)." ]

[ "One of the problems is that most species (I've read up to 90%) are not known or not catalogued.", "Yes, there are places like [the American Museum of Natural History](_URL_0_) that have repositories of endangered or extinct species' DNA. Whether or not we should is a normative question that probably doesn't have a definite answer. Personally, I'm still hoping for Jurassic Park to happen.", "I believe others have adequately answered the question of \"are we ?\". The question of \"should we ?\" though is trickier and is in my opinion a question of ethics more then science.\n\nJoel Determan once said, \"The tree of life is self pruning\" if a species goes extinct not from human interference but because it simply can't compete I feel we have no reason or responsibility *to* save it. Human selection/intervention will only change the macro-evolution of an ecosystem and it would be arrogant to assume we know what is best for an environment.\n\nThe flip-side would be cases of extinction in which we are the culprits, a la dodos, in which case I'm not entirely convinced that we have a responsibility to maintain said species. If in the wild a new predator and/or parasite moves into a new area and then successfully out competes the local prey it may doom itself from it's own success. I can't remember the full details they always give in the undergraduate text books but I recall a story about feral cats on a pacific island that hunted the local fauna to extinction which then in turn lead to the extinction of the cats. Much the same can be said of humanity if we drive enough species to extinction we may ourselves be doomed to extinction.\n\nObviously we should strive for our own survival and to that end conservation is extremely important but ultimately evolution doesn't give a fig if we live or die. We are simply not that important and even if we go super villain and decide to take as many species down with us geology has shown us time and time again that life is remarkably resilient. And all devastation we cause to biodiversity will slowly disappear after our own extinction.", "I think acts of conservation are ultimately anthropocentric. Since the inception of evolution, Darwin recognized that the tree of life has no distinct branches without negative space (extinction). Life has a long history of adapting to drastically different environments (e.g. aerobic metabolism). Life'll be fine in the long run. There's no need to think we're doing nature a favor by protecting it. Lots of things die. Humans may too.\n\n\nShould an organism go extinct today, and should we manage to preserve it prior to extinction, its genotype will be adapted to our current environment. Depending on the sensitivities of the genotype to the environment, it may or may not be a successful species in the future. Or, there's always the chance it'll be immensely successful, e.g. a temporally invasive species.\n\n\nSay oceanic acidification causes many species of crab to go extinct. We forsee this problem and place the crabs' genomes into safe keeping. The oceans acidify, the crabs go extinct, and natural selection continues. Newly adapted crabs fill the niches formerly occupied by the now-extinct crabs.\n\n\nImagine some really bright scientists find a way to revert the oceans to previously held pH levels. Do you reintroduce the extinct crab population into the oceans?\n\n\nSome believe woolly mammoths went extinct due to human hunting. Given the capability, should we restore woolly mammoths to the wild? How well would they fare in a world that has already selected them for extinction? (Oops, trick question. We should because it'd be sweet.)", "Your focus was probably more on animals, but for plants there's the [Svalbard Global Seed Vault](_URL_0_)." ]

[ "Many do. The rotors are attached to small charges to blow them off just before.", "Can't tell if OP is serious or not, but that was hilarious and is getting an upvote.", "helicopters generally operate too close to the ground to make parachutes practical. \n\nin addition, helicopters are very delicate machines. even compared to other aircraft. although ejectors have been done in helicopters, in most cases the intricate technologies required to do it would come at too high a cost in terms of weight, space, and performance.", "They aren't called 'Choppers' for nothing...", "Because whack whack whack is not just the sound the rotors make through the air... very similar sound when going through your neck.\n\nReally though, the ELI5 answer is to try jumping on your bed into the ceiling fan", "Would an ejection system that ejects the pilots from underneath the helicopter work?", "You guys are idiots. You don't always have to go RIGHT ABOVE THE HELICOPTER. What about out the sides or something? I'm pretty sure OP isn't retarded.", "The vast majority of military helicopters fly with more than a pilot and copilot on board. No one I serve with would ever punch out and leave passengers/crewmen behind.", "They do. There are a couple variants. One was posted below (blowing the rotor off). Another fires the ejection seat down and to the side.", "Your username is mildly relevant." ]

[ "We don't use a base 10 system for measuring movement on a circle though. Revolvers are kind of clockwork devices. They require a precision in their design that is less complicated than the clocks I'm using as an analogy or the mechanisms of their more modern autoloader counterparts. Even the simplest of revolvers requires a gear calibrated to allow a cylinder to rotate enough to move the next round in between the barrel and the firing pin or \"hammer.\" You can see the complicated design of Samuel Colt's first revolving rifle [here.](_URL_0_) Other design concerns include the width of the round, the rod the cylinder moves around, and the amount of material needed to make sure the rod, cylinder, and frame can withstand multiple firings. All of that needs to fit onto a handle that will fit securely in the palm of your hand.\n\nEdited per editor's request.", "Size and weight. A revolver cylinder would have to increase in diameter to add extra chambers and at some point it's just too much. Especially with larger bore rounds like say .44 and .45 calibre. Smith and Wesson managed to fit seven chambers into their 686 revolver, their smaller j-frame pocket guns use five round and the large n-frame like the trr8 have eight round chambers (all in .357). They also make a smaller 5 shot .44 mag and a regular size 10 shot .22.\n\nIt's all to do with the size of the gun, a fatter cylinder with extra chambers is more bulky and heavy", "It's interesting you mention the 5 or 10. I don't know if that influenced the decision or not, as opposed to the size and weight considerations, but...early revolvers had 6 chambers, not necessarily shots. In most cases, one chamber was empty, giving you 5 shots and a safe place to lay the hammer.", "For the same reason that cell in a beehive are hexagons- that is the most efficient way to rotate holes (to put the bullets in) around a central shaft. Some revolvers have fewer in order to be smaller.", "It's a function of size, weight, caliber and chamber pressure. The chamber size, the overall cylinder size are factors and the chamber pressure is a factor because there must be adequate cylinder strength to keep it from exploding. \n\nAs the cylinder size increases, so does the gun's width and weight. \n\nContrary to the comments about 6 being the best number of rounds numerically, it's much more than that. \n\nFor example, I own a 10 shot revolver chambered in 22LR. This works because the chamber size for 22LR is much smaller as is the chamber pressure. There are 9 shot, 7 shot, 6 shot, 5 shot revolvers in 22LR. I believe the French made a 20 shot revolver but I don't know the caliber BUT it must have been small caliber or the gun would be huge. \n\nOn the other hand, I also own a 5 shot .357 magnum which has a a fairly high chamber pressure and caliber so you can't squeeze in many more rounds, 6 would likely be a good balance as the gun would get heavy or the cylinder would be too weak to be safe. ", "It was the result of the best ratio of diameter of the cartridges in use at the time to the acceptable fatness and also expense of the gun.\n\nThe cartridges can only be placed around the perimeter or the cylinder, so you have to make it dramatically larger, heavier, and most importantly, more expensive and use more materials to make it hold more shots. There must be enough metal between each hole/chamber in the cylinder to contain the pressure of the powder going off so the gun doesn't blow up in your face. So adding more shots is a case of diminishing returns. There is nothing technically preventing anyone from doing it, and there wasn't even at the time. It's just impractical.\n\nIt's worth mentioning that not all revolvers were or are six shooters, either. Five is/was also common. Earlier \"pepperbox\" guns, the arguable precursor to revolvers, commonly held four. There were some small caliber revolvers at the time that held *more* shots as well, since the smaller diameter cartridges took up less space along the circumference of the cylinder.", "There were 20 shot revolvers made. Google it. They had an inner and outer ring of chambers.\n\nI have a 5 shot revolver. 5 used to be quite common amongst small frame revolvers. Once you increase the frame size you can increase the cylinder size giving room for an extra bullet. Size and ability to be concealed is a factor for why the high capacity, large caliber revolvers fell out of favor. ", "There is nothing special about 6 shots, revolvers hold as many shots as can fit given the quality of steel the cylinder is made from and the size of the gun and bullets. \n\nNo one buying a gun for self defense has ever said they wanted fewer bullets and not more. ", "Educated guess for a 5yo reddit child: I believe that the chosen caliber drives the design. Let's take a look at the boundary (extream) conditions and use between 20 & 2 bullets. Okay, grab your grapes and we will do this together.\n\nNot those grapes, the grapes in your lunchbox. Place 20 bullets (grapes) in a ring. Now place one grape in the middle for the central pivot. There is a lot of room in the middle! Much more than is needed.\n\nNow place two grapes side by side with one grape in between for the pivot. Now there is a lot of room around the ring. \n\nHow much room is on that ring? Room for 4 more bullets for a total of 6. \n\nCould there be 5 or 7, sure but from a machinists perspective, striking three equally spaced lines through a center point is much easier than 5 or 7 equally spaced lines. Durring the time of the iconic six shooter, machining was more difficult so anything that would save time/math was favorable. This leads us to a little history.\n\nHEY, pay attention you little shit!\n\nSamuel Colt was on the forefront of mass production, up to that point a firearm was made by a single worker/artisan start to finish. Due to advances in tolerancing, Colt could mass produce parts knowing that they would be a relatively close fit. This allowed for assembly by less skilled workers lowering costs and pushed revolvers into more hands.\n\nOkay, back to the design. In addition to holding the bullets, the cylinder is also the chamber where the ammunition fires so a certain amount of material is needed to contain the explosion.\n\nAlso, gearing is proportional to number of bullets and would be a thin ring about 1/4 bullet diameter which is why I chose a full grape rather than a raisin for the central pivot. And as I stated at the beginning, this is all reative to the caliber of the bullet as it can be scaled up or down. \n\nNow eat your grapes.\n\nEdit: Thank you kind stranger.", "Just seemed to work out that way as the best compromise between calibre, weight, size, etc. Other ones were made or tried, if you are a fan of the Forgotten Weapons channel Ian has covered [many revolvers](_URL_1_) with differing amounts of chambers, 5, 7, 8, 10, 12 and even a [ludicrous 20 shot one](_URL_0_).", "Something that most people haven't addressed - maximizing area.\n\nA revolver cylinder is a circle by cross section, but if you think about it as more of a hexagon, you end up with a series of equilateral triangles. This means that circles - which the cross section of ammo also is, fits efficiently within them. The ammo size was functionally set.\n\nNow we can't maximize the entire area, originally there may have been some machining limitations but since the bullet is effectively fired from inside the cylinder chamber, it also needs to be tough enough to retain those forces so the wall of the chamber have to also be a certain size.\n\nHowever we could imagine trying to make revolvers with more chambers. As we add chambers, the interior angle of the section gets smaller to hold the width of a bullet and its required housing you have to move further from the center and the size of the entire construct gets much more unwieldy.\n\nI believe that because of these things, functionally 6 chambers is the point at which you don't have to make the cylinder much bigger than any previous numbers of chambers. I did some checking and there are plenty of other sizes made over time, but also it seems 6 was not immediately the standard. However there's enough advantages from an engineering standpoint, combined with 6 being pretty good from a number of shots standpoint for most of the realistic self defense needs, that I think people just settled on it.", "Mostly convention based on experimentation. Designers tried all kinds of crazy things in the early 1800's until the sweet spot of 5 or 6 rounds was found. Theres a great youtube channel called \"forgotten weapons\" that chronicles some those very interesting ealry designs. \n\nIn general, more shots means a bigger cylinder, higher bore axis, and an overall heavier gun. There comes a point where people have trouble using it because of the size, weight and recoil characteristics.", "One of my favorite geometric coincidences here! (This is fun) Take 7 coins of the same size - 7 pennies, if you will. put one on the table, and arrange the other 6 in a circle touching and surrounding it. Perfect, eh? So, six shots is coincident with the order of the universe, and the setup of machinery." ]

[ "These lyrics take a highly Afro-Centric stance towards the role of Africans and their descendants. It also greatly simplifies several of these topics into an issue of just race within the context of the present (or at least in the context of late nineties race relations.)", " > The Punic Wars began 264 B.C...The first genocide of history\n\n[Ben Kiernan, a genocide scholar agrees.](_URL_0_) But that's not something you're going to find consensus on." ]

[ "Indeed it can, the sun is opaque yet photons can slowly travel up to the surface from the core by being absorbed and re-emitted by atoms within the substance.\n\nWith many materials though like steel the energy required to do this would evaporate it if the steel was too thick.", "Somewhere in [this video](_URL_0_) they demonstrate light penetrating a solid surface and bouncing back out again. I highly recommend you watch the whole thing though, as it's extremely cool.\n\nTo give a more direct answer to your question, it is a general property that the amplitude of a wave driving a linear medium dispersively will decay exponentially with penetration depth. That is, if the medium is opaque to the color of light you're bombarding it with, then the intensity of the light will decrease by a fixed factor in each successive centimeter of depth (see the [Beer-Lambert Law](_URL_1_)). According to this model, the intensity never truly reaches zero, but it does approach zero very rapidly. Unfortunately for us, the transmitted intensity only depends linearly on the incident intensity, which means that if you increase the thickness of your material by a fixed amount, you need to increase the incident intensity by a fixed *factor* to get back what you saw coming out before you increased the thickness. \n\nSo in short, it depends on the electrical properties of your medium, how thick of a material you use, and what you consider a \"shadow\" since in most cases the transmitted light will be attenuated somewhat. Some objects may become transparent to some degree with bright enough light, and others will just melt or vaporize before you ever see an appreciable amount of transmitted light from them (metals for example, which are good reflectors). \n\nFinally, increasing the intensity beyond a certain a point for some materials may give rise to nonlinear effects, in which case the frequency of the light you get out will not be the same as what you put in. These new frequencies may be attenuated just like the original incident light, or they may pass right through. In these cases, you *really* need to know what kinds of electrical properties the material has before you can predict whether or not an appreciable amount of transmitted light in a frequency you can detect will be observed.", "I'll also mention this happens in many doctor's offices in an X-Ray Machine. The light penetrates flesh and the bone leaves a shadow." ]

[ "Not all contaminants are alive. Boiling kills \"germs\", you still need to remove poisonous chemicals.\n\nYou could potentially take boiling a step further, though, and distill the water. Boil the water, capture the steam, allow to cool and re condense into water.", "1. Boiling water just kills the microbes. If it is contaminated with some chemical, that chemical is still there.\n2. Boiling water takes lots of energy. It is not practical to boil large portions of the water supply.", "I was watching some weird reality tv show about a post-apocalyptic world once, and on that episode they captured rain water or found water, poured into a column of sand or something like that to filter out the particulates, then bubbled Ozone through the water - apparently this was more efficient boiling enough water to use (the ozone part). \n\nDoes this actually work? What about the metal and chemicals?", "same reason boiling minestrone soup doesn't make it drinking water" ]

[ "People are pretty out of shape compared to the fitness level we evolved with, so I would think less supporting musculature? Maybe we sporadically lift heavier objects than we were evolved to as well. We certainly have more stuff to move around now too, versus as someone said hunting and gathering activities.", "Someone already addressed the mechanics and physics involved. As far as why it's still vulnerable after millions of years of evolution, that most likely comes down simply to how evolution works. Few people have debilitating back injuries before reaching reproductive age, especially without hard industrial labor (which obviously hasn't existed for millions of years). Having a bad back is a common problem only for older individuals. This means that the current structure is for the most part \"good enough\" because reproduction rates aren't very strongly effected. As you probably already know as a med student, evolution doesn't have an end goal for some kind of ideal or optimized design but instead only passing on genes to the next generation. There is a variety of human traits that are good examples of this.", "It's likely a side-effect of bipedality, combined with the necessity of carrying heavy objects. When you carry an object in front of you (i.e. not in line with your spine), the action of your erector spinae muscles prevents you from rotating forwards. These back muscles have very little leverage since they are just an inch or two from the hinge point of the spine, so the force they have to exert to keep you from rotating forward is many times the weight of the object you're carrying. This counter-rotational force applied by your back muscles also compresses your spine. \n\nAs a numerical example with made-up numbers, let's say your erector spinae muscles have a line of action 2 inches from your spine. If you hold a 10-pound weight 20 inches in front of you, this means your back muscles must exert a force of 100 pounds to keep you from rotating forward (10lb X 20in = 100lb X 2in). The total compression on your spine is equal to the force of the carried weight plus the force applied by your back muscles; in this example, that means carrying a 10 lb. weight results in a compressive force on your spine of 110 lbs (most of which, obviously, comes from your back muscles).\n\nThis is why in many third-world countries you will see people carrying enormous weights on top of their heads. The net compressive force applied by an object carried directly in line with your spine is much less than that applied by a much smaller object carried away from your body (for example, if you carry a 50 lb. weight on top of your head, that only places your spine under 50 lbs. of compression).\n\nQuadripedal animals do not generally have this type of spinal compression injury, as their back muscles don't usually need to apply this type of counter-rotational force." ]

[ "Here's the 10th Doctor explaining it definitively (from Blink): _URL_0_", "They work in whatever way is convenient to the plot at the moment." ]

[ "Black holes don't just appear out of nowhere. They are super dense balls of matter. If there is not one in our solar system now, there will not be one any time soon.\n\nIt is believed that the center of our galaxy, and most galaxies, is a supermassive black hole.\n", "As noted already, we already know of black holes in our galaxy, and how they are formed as the remnant of a supernova. A black hole \"appearing\" would be an extragalactic rogue ejected from its original galaxy, or even this one, by gravity slingshot resulting from a close pass with another object of similar or greater mass. As the space between stars is not actually empty, we would see such a rogue black hole from a great distance from the x-rays produced from the interstellar dust it was consuming, along with its effects on stars it passed. It would be as easy to see as a skier on a lake while he was on fire, at night, while watching from shore.\nIncidentally, galaxy and solar system are two hugely different scales. It is like asking about the odds of a five-legged flea existing in either the state of Texas or your left nostril. The first is highly likely, the second, well, you'd already know.", "Despite what it has already been stated\n here, there are a lot of mini-blackholes created even in our own atmosphere. The main actor in their creation are cosmic rays. Nonetheless, blackholes have an \"halflife\" some how proportional to their mass. Since their gravitational pull is usually smaller that the interatomic distances in the upper atmosphere, they cannot grow, and thus \"evaporates\" in the span of picoseconds" ]

[ "The number of the beast appears in our earliest fragment of Revelation, [the Oxyrhynchus Papyri](_URL_0_), as 616, not 666 and both numbers were used by the early church. \n\nIt is thought the numbers are derived from giving numerical values to letters, as a code, and the two different values come from the different Greek and Latin spellings of the name and title \"Nero Caesar\". \n\nAcccording to Bruce M. Metzger in *\"A Textual Commentary on the Greek New Testament\"*: \n\"Perhaps the change was intentional, seeing that the Greek form Neron Caesar written in Hebrew characters (nrwn qsr) is equivalent to 666, whereas the Latin form Nero Caesar (nrw qsr) is equivalent to 616.\" \n", "To build and complement two quite good answers:\n\nThe text this is derived from is Revelation 13:18, I quote below the Greek and an English translation:\n18 ὧδε ἡ σοφία ἐστίν· ὁ ἔχων νοῦν ψηφισάτω τὸν ἀριθμὸν τοῦ θηρίου, ἀριθμὸς γὰρ ἀνθρώπου ἐστίν· καὶ ὁ ἀριθμὸς αὐτοῦ ἑξακόσιοι ἑξήκοντα ἕξ. \n\nHere is wisdom: let the one that has understanding calculate the number of the beast, for is a human number: and its number is 666.\n\nGreek numbers can be represented by words, as in this edition, but it was more common to use letters to symbolise them. P47 reads χ̅ξ̅ϛ̅ whereas a manuscript such as P115 reads χ̅ι̅ϛ̅. The former works out to 666, the latter to 616. Overall the textual tradition for 666 is relatively stronger than that for 616. \nMost attempts to explain the number centre on three methods: (1) That it is purely symbolic, and so should be taken just ‘as is’; (2) that it is chronological, indicating some kind of duration of the beast’s reign, (3) some use of Gematria, in which the correspondence of letters and numbers is used to represent words by the sum of their numerical equivalents.\n\nIn the case of 666, the most common attempt is to identify 666 with Nero. But this depends upon transliterating the Greek form of Nero Caesar into Hebrew and then performing the calculation with this spelling, nrôn qsr. And even this spelling is generally considered a defective form of nrôn qysr, with the letter yodh missing (which is permissible, but not well attested in Hebrew texts with the name of Caesar in them.\nYou can see that this is getting problematic: it assumes that readers, at least some readers, have knowledge of Hebrew not only Greek, and would choose both the right name to transliterate and the appropriate way to transliterate. A lot of contingencies.\n\nA host of other name possibilities, generally in Greek, have also been suggested. \n\nAnyway, I am getting a little beyond your question. In short, there was a base-10 system in use, the number would have been represented with Greek letters (and is in the earliest manuscripts), and 666 is a superior textual tradition.\n\n", "As a follow up, have humans generally used base 10? and is it for the obvious reason that we have 10 fingers?" ]

[ "The good folks at _URL_0_ have an unreasonably large collection of Marx and Engels. So it's odd to me that searching this phrase, \"retrograde races,\" pops up only detractors with third or fourth-hand citations to old newspapers, but *not* to original Marxist works. And most of it is wacky New World Order or anticommunist Christian work. I'll keep looking, but I'm very skeptical he said anything of the sort.\n\n[Here is a similar phrase.](https://www._URL_0_/archive/marx/works/1873/01/indifferentism.htm) The sarcasm is so clear, however, in the whole context.\n > In expectation, therefore, of this famous social liquidation, the working class must behave itself in a respectable manner, like a flock of well-fed sheep; it must leave the government in peace, fear the police, respect the law and offer itself up uncomplaining as cannon-fodder.\n\n[Here's Marx responding to the same accusation, interestingly enough.](_URL_2_) In this case his own bourgeoisie background is coming through a bit, but he's being hyperbolic about an internal Party political struggle.\n\n > Klein really does wield some influence over the Solingen workers, and they are the best in the Rhine province. I, pour ma part, have never, either drunk or sober, expressed the view that the workers are fit only for cannon-fodder, although the louts, among whom little Klein is evidently coming to rank himself, are, to my mind, barely fit even for that. It would be as well to treat little Klein with your accustomed discretion as a tool that may perhaps (?), in time of action, be of use to us.\n\nI'm not finding \"retrograde races\" or comparable anywhere in Marx's work. Except in a fit of extreme sarcasm (which he was prone to) this doesn't match up with the rest of his philosophy. To Marx, members and cultures of the proletariat were distinguished by their time and place (following Hegel's similar line of thought) but were far more united than divided. [I mean, hell, even Lenin was on that same boat:](https://www._URL_0_/archive/lenin/works/1911/jun/11.htm)\n > The difference in the attitude of the two bourgeoisies was not due, of course, to the “characteristics” of different “races”, but to the different levels of economic and political development which caused one of them to fear the “younger brother”, and made it vacillate impotently between deprecating the violence of feudalism and censuring the “intolerance” of the workers.\n\nIt would be a very interesting turn of events for Marx to support the destruction of the Slavs, when panSlavism is inevitable in the discussion of Stalinism and Bolshevism at large.", "[Here is a letter](_URL_0_)from Marx congratulating Lincoln on the emancipation proclamation. I'm by no means an expert but I'm currently reading capital volume one, and in it he says that slavery, along with feudalism, is an inferior economic system because (among other reasons) they retard economic growth by disincentivizing innovation of and investment in labor saving technology. Capitalism is superior bc it is always trying to reduce labor time and thus becomes increasingly productive. " ]

[ "When you say 'We', you are referring to many westernized countries. There are some countries in the world that don't value life as much as \"we\" do. I don't think it's a matter of us valuing each and every person, but more for the fact that if we didn't value every single person, it would be hard for society to be structured when we can't even maintain the basic function of life.", "There are seven billion humans, but most people are not merely humans. Most people care about some hundred or thousand friends, family, and neighbors. This has always been the case. " ]

[ "Boiling water will generally kill most pathogens that are harmful. What you'd have to worry about at 70C is spores from bacteria like clostridium (Tetanus, Botulinism, C.diff, gangrene) and bacillus (b. cereus, anthrax). Those are more likely to survive temperatures up to 120C. Do you know why your city is under a boiled water advisory?", "This is the temp and time required for pasteurization: \n\n63ºC (145ºF)1) \t30 minutes \t\n\n72ºC (161ºF)1) \t15 seconds\n\n89ºC (191ºF) \t1.0 second\n\n90ºC (194ºF) \t0.5 seconds\n\n94ºC (201ºF) \t0.1 seconds\n\n96ºC (204ºF) \t0.05 seconds\n\n100ºC (212ºF) \t0.01 seconds\n\n138ºC (280ºF) \t2.0 seconds\n\nEDIT: this is for milk", "No matter what you set your water heater to, that is the maximum temperature it will reach. It does not guarantee all the water going through it reaches that temperature. So even if your heater could go high enough to be safe you'd still be just one long shower away from possible contamination." ]

[ "A server ( any pc is good if have a raid disk) can host an almost illimitate amount of documents. \nAlso, the paper is not forever, if you need to edit the document you need to print it again for all the users.\nAlso, you probably will need a shelf for all the paper you needand keep it at a suitable temperature for the users.\n\nWhere i work the introduction of electronic storage have litterally emptyed 4 rooms from all the paper.", "Thought experiment time:\nAll documents fall into 4 categories based on these two possible attributes.\nRate:\nLow retrieval rate\nHigh retrieval rate\n\nDistance:\nLow distance retrieval\nLong distance retrieval\n\nHard-copy:\nLow retrieval rate \nLow distance retrieval\n\nDigital:\nHigh retrieval rate\nOR\nLong distance retrieval\n\nIf you put these attributes in a 2x2 square you will notice that 3 of the 4 possible squares have ether Long distance, or High retrieval rate as a property.\nDigital systems provide benefits to both those situations while hard copy only really works in a low distance low retrieval rate situation.\n\nRemember the energy \"price per page\" on electronic documents is really low. The energy \"price per page\" on hard copy is high. \n\nIf your document is low retrieval, low distance, then keeping a system running to maintain this document makes little sense but we don't dedicate single systems to documents, we consolidate. So the energy cost of a single digital document is distributed. This is not the case with a hard copy document.\n\nDefinitions:\nA low retrieval rate document is some thing you only need to check once in a while\nA low distance retrieval document is something you can keep on hand and do not need to send out for processing.\n\nA high retrieval rate document is some thing that needs to be accessed and or utilized often.\nA long distance retrieval document is some thing that needs to accessed from far away and or by multiple entities that are separated by distance." ]

[ "To be nitpicky, orbital *velocity* is changing constantly, because velocity is a vector quantity. It has both magnitude and direction. An object in orbit is under constant acceleration so its velocity *has* to change by definition. In a theoretical perfectly circular orbit the orbital *speed* (the magnitude) doesn't change but *velocity* still changes because the direction changes.", "As has been pointed out elsewhere, an orbit involves a velocity that is constantly changing direction, and is therefore accelerating. Don't accelerating masses emit gravity-waves and thus lose energy? Yes, I realize it's negligible--but it's nonzero. (Overwhelmed by other factors, of course.) Perhaps someone would care to calculate this...", "Orbital velocity is a function of the mass of the object being orbited and the distance from that object.\n\nV = sqrt(GM/r) \n\nThe sun is losing mass over time, and orbiting objects are slowly drifting away due to tidal forces sucking energy out of the system. So M is getting smaller and r is getting bigger. \n\nSo over time, orbital velocity is decreasing and the planets are moving away from the Sun." ]

[ "A similar question was asked here.\n\n_URL_0_", "I would like to add related question:\n\nWhy did Serbia stay Christian (Orthodox) with very small number of converts, while in Bosnia there was significant part of population that converted to Islam under Ottoman rule?" ]

[ "Riflings work similar to how [this device](_URL_0_) works.", "Bullets have a concave back, so when it is fired the edges expand against the barrel of the gun. A copper or lead bullet is much softer that steel, though eventually you will wear out the gun barrel. \n\nThe smooth bore would be slightly faster due to less surface area, but the accuracy is so lousy that the speed difference is worth it. It is like throwing an American football without spin. " ]

[ "Reddit has anti-spam measures, like the fuzzing of votes. These ghost up/downvotes prevent people from realizing their mass upvoting isn't working as it should.\n\nThe specifics are a company secret. Reddit wouldn't want the spammers to know exactly how they prevent spam.", "I have, on more than one occasion, switched accounts to Upvote self posts for visibility. They all show up. ", "Cause... ain't nobody got time for that.", "What good would that do? It's not like you can exchange your Internet Points for something that's worth the time and effort.", " > but i think that wouldnt work because everyone in my dorm uses the same connection.\n\nI would hope you all have different IP addresses. \n\n > whats to stop me from getting my whole dorm to upvote me?\n\nThe admins can see who upvotes what, and you'll get banned very quickly for using the same account to upvote everything.", "Honestly I believe that Reddit is already controlled by an army of bots by people who want to hog the front page...", "They don't, but in all honesty, if you're spending your time logging in and out of different accounts to upvote your own comments, you're the one who is being screwed..." ]

[ "You still have to pay property taxes, and there might well be local laws requiring some minimum standard of upkeep as well.", "Have you ever owned a house? If you can't sell your money pit, it becomes a money black hole.", "As Detroit keeps shrinking, it's likely that services to many such areas will be cut off, meaning your house will decay and rot and you'll eventually be left with nothing but a tax bill.", " > Even for the slight chance that property houses might rise in the next 100 years?\n\nJust because the house and lot is sold for $1 doesn't mean that the city is going to value the property for that much. So you pay $1 for the house and end up paying property taxes for some unknown amount.", "There's probably a lot of back taxes that you'd have to pay to actually buy it, and probably some overdue utility bills that you might have to settle to get service turned back on. ", "If you think it's a good investment, then buy it. The reason people aren't buying them is because nobody thinks it is a good investment. \n\nI don't know how the real estate market works in the US, but in Britain buying a house is more expensive than just the cost of the house - there are legal fees, estate agent fees, stamp duty etc. I imagine spending $1 on the house may well run into thousands of dollars before you actually have the deeds in your hand. So if the house is worth $1,and you've spent $3,000, the house owes you a lot of money already.\n\nYou know you're not going to be able to rent it out for the foreseeable future, so it's not going to be looked after. So do you want to insure the house (in case the roof collapses?). Paying a premium every month on an empty house is crazy. If you don't pay the premium and the roof does collapse, are you going to spend $10,000 fixing the roof on a property that's only worth $1. Just in case it does become worth it in 20 years? \n\nAs I said, if you think it's an investment, then go ahead and buy it. Personally, I'd leave it well alone. ", "It is likely that this house is in such poor condition that it would have to be demolished (hard to tell from one photo). If the demo/removal costs are higher than the value of the lot, you've got yourself a bad investment", "_URL_0_\n\nThis video sums up why. ", "because the property is a pure liability. it has no market value at all (which is why they're basically being given away). the amount of money you will lose before you even have an opportunity to profit is enormous. and its not even a good chance at a profit. Detroit only looks to be getting worse, not better. would you be willing to sit on a property, losing money every month, for an indeterminate period of time, for an unknown chance at maybe making money?", "You can murder a couple people in Detroit and get away with it. Miss a payment, fuck up on a property code, piss off the tax man and you will be hounded and hunted down by the man for all eternity.", "Why not buy the houses, tear them down and sell the scrap? These houses are old, and some of that old timey trim can be resold at a good price. Then sell the empty land after you're done.", "I'll ask my own question, OP.\n\nDo ***you*** want a house in Detroit?", "because a house listing isnt a legally binding contract, once they get peoples attention with the teaser listing, the seller finds out who is willing to pay the most.", "Some are, I know a guy who picked up 250 of them. The back taxes costed him a lot but he plans on renovating them.\n\nI should add he is Chinese and bought them all sight unseen.", "Look at the listings for the sub-$100 houses. Property taxes are still upwards of $3000 annually. On top of that you have instant liability once you own it. If kids get injured on your property, you can be sued. If you dont' maintain the property, the city can fine you. If crackheads move in and you don't know because you're not paying attention, they can claim adverse ownership and you could lose your entire $1 investment. ", "Because they are located in Detroit.", "I'd like to know why they're not razing the buildings and plowing and planting the lots. I'll take $100 of those houses please to start my new farm.", "If you ever spent any time in Detroit, you would know exactly why you would never buy a house in that part of town. Yes, they are cheap, but so are all the other houses around it and either filled with crackheads or in a very high crime area. If you buy the house, refurb, pay all the taxes, you still wouldn't be able to rent it or you wouldn't want to live in it...neighbors are everything in Detroit\n\nAnd all the points made below about cost of taxes, refurb costs, upkeep and dealing with the city are very true. I lived there for 3 years and was lucky enough to be in a nice neighborhood where all the cops and firemen lived. They are required to live in the city in order to work for the city\n", "Ok Certified Residential Appraiser here from the Metro Detroit area. i dont do many appraisals in the city for many reasons but i guess ill throw my 2 cents in on why people do not purchase these properties.\n\n#1 Properties like these are typically negative value. This is due to extremely low property values along with the cost to demo a home with 0 remaining economic life(Cant live it anymore)\n\n#2 Property taxes will occur but upon sale of the home will be back to zero. This property is owned by Fannie Mae who is responsible for the back taxes. And Typically they will be forgiven by the city government or paid off as a stipulation of the sale.\n\n#3 Who the hell wants to buy a property is Detroit. This is probably the largest reason behind the 1 dollar sale. Fannie Mae is trying to get this property off their books asap so they are not responsible for the property taxes. Hence the 1 dollar asking price. \n\nAnd i guess this probably isnt the place for a rant about Detroit and all the misleading press out there as to why it is failing. The reason it is failing has nothing to do with who is running the city or pensions plans. Thats a laugh. It has everything to do with the Great White flight in the 70's where we had an explosion of people move to the suburbs attempting to escape the race riots. This created a wealth vacuum in Detroit where property value decline drastically. The only reason their is 700k people still living within the City limits is due to their lack of education and they are just poor. Sorry to offend anyone but facts are facts. Anyone from the city that has received and education leaves immediately, thus leaving the city with more and more prevalent uneducated population.\n\nThere are signs of life though in Detroit as our Campus Martius area and the surround stadiums, along with the Wayne State campus have create a Central Artery in the city where economic development is booming. Condos that could have been purchased for 40k 2 years ago are selling in excess of 200k and we have many new companies, include one that 1 work for moving their head quarters downtown. I know the city is broke and is building a new stadium, but the future benefits of building that stadium far outweigh the cost now. I'm betting in 10 years from now we slowly see a creep of economic development for the Woodward corridor in Detroit, hopefully bring some new economic development and gentrification to the city. \n\nEdit-Thanks for the gold kind fellow Redditor!!!\n\nEdit-spelling not campus marcus. My bad", "its basically a pile of old rotten wood that somehow looks like a house still. Wood that u have to pay huge taxes on. Nothing works inside, and you'd have to spend tens of thousands of dollars to make it livable.... in probably the worst neighborhood imaginable. And taxes obviously. ", "Another important factor, beyond the unknown costs and liability factors, is safety. Many of these very inexpensive houses are part of neighborhoods that are completely blighted. Last summer, I was in Detroit and decided to tour some of these areas, and it was super sketchy. In these areas, about one in every five homes has been boarded up, burnt out, stripped by thieves, or seemingly abandoned. There are people wandering the streets at all hours doing who knows what, street signs have been uprooted, mongrel dogs are roaming around, there aren't many street lights at night. Combine the above with the fact that Detroit is bankrupt and that the average time for police to show up to your house for a 911 call is about an hour. Consequently, it is very dangerous to live in these areas. ", "Having lived in Detroit for years, and having left in 2007, I can confirm that it's because the houses are in Detroit.", "Extremely high taxes. Extremely high crime. Squatters. Almost non-repairable condition. Water damage. Houses stripped of all copper plumbing or have exploded from cold weather.\n\n\nThey just aren't worth it. Even for $1. You are almost trading $1 for tens of thousands worth of work just to turn around never be able to resell it because the area is shitty.\n\n\n\nI don't know how this problem can be fixed aside from the city leveling entire blocks and starting new communities by forcing all of the current residents out - but I guess that's racist so it is just going to stay the way it is until they leave on their own.", "lets not forget the Obvious. \n\nCondition. I had a friend of mine that buys houses in our town and renovates them for rent. He thought the same thing you did. WOW.. a $1 house!!! NO BRAINER!!!!\n\nHe even figured that some of these old houses may even be worth the cost of tearing down, just to get the Woodwork, Flooring, Trim, doorknobs, doors, ect... basically, buy the house,, and part it out, then pay approximately $25000 for demo. \n\nHe lined up a Relator,,, drove to Detroit,, He went and looked at them.\n\n#1. some of these houses were in such bad neighborhoods the relators wouldn't even go with him to show him the house. if the relator won't go to the house with you.. this is a REALLY good sign that all of your tools, trailers, vehicles, ect.. are in danger of being stolen while you spend 3 weeks ON SITE gutting the house. you can't make money If you are robbed blind while working.\n\n#2. upon inspecting over 30 homes,,, NONE.. NOT ONE had copper left in it. they had been stripped of every copper pipe. many had the old radiators stripped and caused water to be leaked all over. Some even had the copper WIRING literally pulled out of the walls THROUGH THE PLASTER!!.. Around here, this is part of the cost you can recoup from demo'ing a house is to sell the copper.. the crackheads beat him to it.\n\n#3 only two of the homes were even in salvageable shape. but they were too modern to get high end woodwork out of . they need to be earlier than 1940's to have the GOOD woodwork. the ones that were old enough, had vagrants and druggies that had lived in them. shit and pissed everywhere,, and for some reason took great joy in completely destroying any and all salvageable wood work and doors, ect.\n\n#4. someone already beat him to the \"good stuff\"... some prior owner, or crew had already removed all of the items of value from the home,, you were just buying a shell.\n\n#5. Liability - it was already talked about, but also remember, insurance companies know these neighborhoods and will charge you MORE if your house is located in one.\n\n#6. Taxes - already discussed\n\n#7 no market to sell the property. no one wants the empty lot. in other towns / cities. you can recoup money by selling the empty lot.. there is no market for them in these neighborhoods.\n\n basically... if it made good business sense... there would be a BIG business doing it now.\n\n", "I'm talking out of my ass and I'm sure I'm missing something obvious, but I wonder if you could create an LLC, buy some of the \"best\" properties for next to nothing (i.e. in what were once excellent downtown neighborhoods) and then just sit on it. Let the taxes accrue over the years, they'd just put a lien on the title of the house. If the value comes back, the back taxes come out of your profit. If they never come back or some hobo trips on your gate and sues, the LLC takes the hit.\n\nIsn't that how LLCs work? Cue Kramer suggesting you simply \"write it off.\"", "This is one of the worst ELI5's I've ever seen. Yes it's a crappy area with a high crime rate and poor economic outlook, but that's not what stops people from buying these $1 properties. What stops them is the liability, starting with the thousands if not tens of thousands owed in property taxes. That doesn't simply go away simply because the property changes hands, no matter what the yahoos in this thread seem to think. Then as soon as your name is on the property you're on the hook for whatever goes wrong there, including homeless that move in and then hurt themselves.", "Lead Paint, Asbestos, Taxes, Crime, Bankruptcy, Hopelessness, and Racism.", "I'm thinking this could be a good charitable project. \n\n1. Buy up a block of houses. Given administrative overhead, legal, etc. I'd make a totally uninformed guess that this would be $500 max. \n2. Fix up the houses into a \"campus\" -- say education buildings or something. Given the state of things I've seen describe below, I'd make another uninformed guess of a half million dollars, hopefully less (allowing for EPA regulations, zoning queries, etc). \n3. Start up classes, services, whatever. As a charitable organization, this could be crime prevention classes, or church related, or a \"community center\", whatever. Maybe this could be one of those ~~Urban garden~~ City Farm things I hear about on *Splendid Table* sometimes. \n4. Let this \"beacon of light\" improve the surrounding property value\n\nEdit: City Farm, not Urban Garden. See [here](_URL_0_) for an article on this. ", "Because they're not houses, they're lots with a pile of rubble on them. These houses are in such poor condition that even for $1, it wouldn't be economical to buy them.", "Detroit is a shithole. Sorry people living in Detroit, but that's my opinion having lived there. I spent 3 years in the area, and all I saw was overpriced areas and areas that were reminiscint of Escape from NY.", "1. There are tousands of dollars in back taxes on the property.\n\n2. The demolotion costs.\n\n3. The neighborhood is anything but lovely. ", "1: You have to pay back taxes owed on the property.\n\n\n2: The house is likely condemned. You'll need to demolish it.\n\n\n3: The neighborhood shows no signs of improving any time soon.\n\n\nDollar for dollar it only *looks* like a high potential, low risk investment. \n\n\nWhat I *really* want to know is why the federal government has turned a blind eye to Detroit. Damn city used to be called the Paris of the United States. *Paris*. How many billions of dollars go to foreign aid and pointless wars when we can't even take of our own? \n\n\nActually, no, don't answer that. I don't want to give the government an excuse to sink their claws into more business they should have none of. ", "ITT: Reditors suggesting a \"on the sly\" improper disposal of asbestos that redditors would likely complain about if done by a large company.\n\ntl;dr: being a dick in business is ok if you aren't a large faceless corporation", "Brb, buying houses in detroit", "I can tell you why that particular house hasn't sold. A lot of the houses in Detroit are the same way.\n\nFirst, that house is a foreclosure. It was foreclosed on in 9/28/2010 and immediately put on the market for $1. They've removed and relisted it several times, but for never anything more than $1000. This means the house has been on the market for three years for insanely cheap without *any* takers. This alone will turn off many buyers.\n\nSecond, that house is in incredibly poor condition. It was built in 1915. There's a huge hole in the roof, which means that rainwater's been leaking into it for who knows how long. The wiring into the house has been stripped. Most of the windows are broken, and the roof's siding is rotting. There's no garage. Someone buying that property has the option of sinking thousands of dollars into that home to get it liveable, or tearing it down and building anew.\n\nWhich brings me to the third point -- take a look at the [property values of the other homes in the area](_URL_0_). They're around $15,000 to $25,000 at most. Because the property values in the area are *so* low, and that house needs *so* much work, the best return an investor is going to get for fixing and flipping that house is *maybe* $5,000 if you do the bare minimum of fixing.\n\nNow, $5,000 may not seem like a bad chunk of money, but consider that you have to deal with contractors in Detroit, the rampant crime in Detroit, and the overall lack of city services in Detroit. This means that a restoration project on that property will easily take a year, and maybe two or three. At that rate, you would've been better off using your time to work at McDonalds. There's really no money to be made there.\n\nBut couldn't someone buy that house to fix it up and live there? A lot of the other houses on that street are occupied, after all. But again, there's the problem that the house is in such terrible shape and needs so much work. Anyone moving to the area, and there are few, would be better off buying a house that's not insanely messed up.\n\nThis doesn't even take into account that there are probably utilities and backtaxes to take care of. Once you take into account all the associated costs, a $1 house gets very expensive.\n\n**TLDR**: A $1 house is $1 for a reason.", "This is easily answered.\n\nThe house costs a dollar at auction, but you are responsible for all of the back taxes (liens) on that house. So, you are actually buying the privilege of paying whatever is owed on the house for $1.00. What is owed on the house could be tens of thousands of dollars. \n\nEven if the house doesn't have a large cache of back taxes owed, they are usually in highly undesirable neighborhoods where you wouldn't live yourself and you wouldn't be able to find a renter for the property. ", "Looks like we have a winner. But thought I'd relate a story anyway, as this is occasionally a considerable deal: My boss bought his house in Baltimore for $1 back in the '70s. It's part of what's now a very nice area, right next to the convention center and the stadiums. He put in about $30K (it needed a roof, after all) but it's quite sizable and he just recently got a low estimate of over $300K.", "Many of the houses have thousands owed in back taxes that the buyer may get stuck with\n", "buy a city block of $1 houses, hire some thugs to burn them all down, ........, profit", "The neighborhood is a squalid hell hole. ", "Look at the nearby crime - _URL_0_", "This video gives a pretty good example of Detroit, although I don't think it does it justice. I used to live around Detroit, and I've seen areas worse than in this video. In fact, most of where they're driving, would be safe to drive in. There are areas that aren't even safe to drive in. I live in Denver now and hear people talk about the ghetto, they don't even know...\n_URL_0_", "Let me tell you guys a little something about Detroit, and having friends that are contractors that work there...\n\nDetroit is the most crooked city in this United states. The shit the city officials pull to get by is obscene, It is hilarious how everybody here is \"oh well, building code and asbestos and safe demolition.\" None of that shit matters in the D, seriously. All you have to do is slip the right official a $100 bill and that problem goes away, EVERYBODY who works for the city is crooked, EVERYBODY can be bribed, nobody gives a shit about how serious their job is, the major intentionally ran the city into the ground for his personal gain, then went about declaring bankruptcy as if it was something he tried to avoid, it was entirely part of the plan. The reason why people don't buy houses or property for $1 comes down to a) taxes and b) the fear of it never turning around (which it won't). Nobody in their right mind is going to build a new house in an area where if by themselves on the street they will get shot for looking at someone for a few seconds too long. Especially in a city where there isn't enough money to hire adequate non-corrupted police enforcement. The city itself will absolutely never come back, those houses will sit forever, until they fall over on their own accord, and when they fall over, nobody will pick up the mess, because nobody wants to, and nobody wants to pay to have it done. \n\nIt is an absolute shame, because some of those houses are absolutely gorgeous. \n", "Because they're $1 \\* \\*\\* \\*\\*\\* \\*\\*\\*\\* \\*\\*\\*\\*\\*\n\n\\* Plus taxes. \n\\*\\* Plus maintenance to code \n\\*\\*\\* Plus HOA maintenance, to requirement \n\\*\\*\\*\\* Plus back taxes and other fines \n\\*\\*\\*\\*\\* Placeholder for more costs", "Did I miss it, or are there zero Robocop jokes/quotes posted in this thread?! It's setup too well, $1 things in Detroit that's going Bankrupt...", "I imagine it's kinda like that local bar that does $1 drink night; it attracts a certain, unfavorable crowd so those that can afford to pay the normal prices elsewhere avoid the bargain. ", "If no one is taking action to buy them, there's GOING to be a good reason; people like making money.\n\nIf the $1 houses aren't being bought up, it's because the investment sucks. For many reasons that have been posted before:\n\n- High land taxes, (other taxes too)\n\n- Maintenance costs and costs to bring the building up to certain government standards for living is going to be pretty outlandish given their conditions.\n\n- Not maintaining the houses means you're going to be liable for problems that could occur on the property, regardless of whether people are allowed to be on the property.\n\nWithout the liability and government \"fees\", I'd buy one up even though I'm in Canada, just so I could say I own a place in the states.\n\nAs the cliche goes, you couldn't pay people to get rid of them.", "You ever play Fallout?\n\nIt's kind of like that. Piles of rubble which have already been looted of everything of value, save for the occasional hidden bottlecap. Superfund levels of contamination in the soil that become your problem. Plus wasteland raiders who will shoot you to steal your bottlecaps and ammo.\n\n$1 is worth it if you have a Super Mutant companion. Unlimited rounds on a laser-gatling is win.", "Houses decay frighteningly fast when they're abandoned. Banks don't know much about real estate, a bank-owned house is not maintained much at all. Nor are they likely to pay property taxes on it. And in some cases, the bank would rather pretend the house is worth more than they would ever sell it for. Why would they pretend? Because they're insane and need to see the doctor, but nobody can make them.\n\nSo at some point the value of the house actually slips BELOW 0, from a combination of property taxes owed and the work to make the house livable again.\n\nPlus the neighborhoods these houses are in is scary and full of crime.\n\nGenerally if there's a good deal on a good house, it sells pretty quick. If it's selling for $1 and nobody is buying it, there are hidden costs that will pop up once you buy it.\n\nReally I think an FDR-type gubmint project where you take unemployed people and set them to demolish those houses (plus you can train them for a construction job, even abestos abatement) wouldn't be a bad thing IMHO. Kill two birds with one stone - reduce unemployment and build a base for Detroit's RE market to recover.\n\nMaybe you could also train them to build houses too, and give them a cleared lot that they could use to build themselves a new house?\n\nI'm not holding my breath though.", "It's not $1. That's the nominal price of the house, and many of them have fees that will put you negative the instant you buy the house. You then have responsibilities and liabilities which will cost you real money. And if you want to do anything at all to the house, it will cost you a lot of money.\n\nA new $1 cellphone is also a nominal price. You won't get it without a contract.", "What I want to know is how does a formerly nice house get to that condition? Was it abandoned and then trashed by vagrants and vandals? Or were the previous owners really that neglectful? \n\nIt makes me sad that there are so many homeless people in this country, and houses like this are just sitting there...", "many of these $1.00 house situations come with a price. \n* they are in very un-desirable neighborhoods\n* you MUST qualify for a mortgage of around $150,00.00 (this is a common amount)\n* you must use that money to renovate the home\n* home must be your primary residence for said period of time (normally 2 years)", "Because, Detroit. You couldn't pay me to live in that shithole!", "Detroit: come to where the hookers pay *you* for sex.", "several reasons: \n* it is Detroit \n* crime in the area is horrible \n* despite the ignorant optimism, things will never improve there \n* extremely high local muni taxes for little to no muni services \n* the homes are rarely habitable \n* the neighborhoods are rarely habitable \n* there is nothing positive about owning property in Detroit - the city council will destroy your hopes and dreams with their ignorance and racism ", "Have you been to Detroit?", "#1. Danger - Who's going to live there...you? What's the rental rate for that property?\n#2. Taxes - That \"Free house\" is going to cost you $4,000 per year\n#3. Fines - Once you buy it, you're subject to all of the regulations the city puts on your home. \n#4. Liability - Now that you own your $1 home, if a homeless guy or druggie wanders in, stubs his toe on a rusty nail they can sue you. \n#5. Fixup - Now that you've got your $1 house it's going to cost you $60,000 to get it to a state where it's inhabitable....and you can buy an inhabitable home for $30,000. ", "Because noboby wants them. Their burnt out, dilapidate houses that would cost thousands to make livable. Nobody wants those houses for a reason.", "People are allergic to bullets. ", "Because it's detroit ", "I don't understand this entire business with back taxes.\n\nWhy can the bank just decide \"You know what, fuck the taxes. We'll let whoever buys it from me deal with that shit.\"\n\nIf a person makes that same decision, wouldn't he be in a world of hurt?", "Because who would ever willingly live in Detroit? ", "Hopefully the hivemind can help me out with the feasibility of this plan:\n\n* Step 1: Buy several city blocks in Detroit for cheap.\n* Step 2: Bulldoze. EVERYTHING.\n* Step 3: Build a giant castle, complete with walls and a moat.\n* Step 4: Offer free housing and enjoy your new role as King of a city within a city.\n\nHow much do you think this would cost?", "If people were buying them they wouldn't be $1.\n\n:)", "Because that would require people wanting to live in Detroit", "- Off Topic-\n\nAfter reading all the responses, I would propose this:\n\nThat the local Government/Council/City buys them up.\n\nThey could start by creating jobs tearing down the old houses - Bringing real employment to impoverished area. Then there is the rebuilding process. Invest in training up the Unskilled workforce, so they can help rebuild the areas they live in.\nAnd finally, give them priority purchase of the properties, through collections direct from wages, for a discount price. \n\nWith a little investment, they could turn the slums around. It would lower the unemployment rate, increase the number of skilled workers, and allow the least fortunate to become property owners. . . something that a lot of people aspire to be.\n\nMost importantly though, getting people to engage in the local community, getting them into full time work, builds a level of respect for your community and yourself. If you invest time and effort into something, you are more likely to care for it. ", "Because they're in Detroit...", "I work as a realtor in and around Detroit and 90% of my clients are investors. Most people from well-populated cities don't understand that the $1 house may be the only house on that entire block. If you are from a normal city, you can't fathom the amount of blight, neglect, vandalism, etc that exists in some of the neighborhoods. You just don't have a frame of reference for it. \n\nSo most people think,\" It's a house, it's got to be worth SOMETHING?!\" But value is based on what can be done with a property: either renting it out, or selling to a family. If there is little to no life in a neighborhood and you can't do anything with a house, it would be best NOT to buy it, even if they were giving them away. \n\n\nPS. I've sold many houses for $1. If they are bank-owned foreclosures, you still have to pay pro-rated taxes and closing costs. So you rarely get away paying $1. Lol", "Location location something something", "I made the mistake of doing this. I bought 50 vacant lots in the city of indianapolis for a couple hundred bucks each. made the further mistake of putting them in my own name instead of some not for profit shell corp.\ngot sued 54 times, for stuff like flowers growing or somebody else littering.\nhad a nervous breakdown, during which i lost all my money because i had been in the middle of a stock deal. 12 years later, i'm slowly getting my shit together. sold a few of the lots to make back what i paid for them, but too much hassle. after a lifetime of being a revolutionary, drug dealer, arms importer, etc., what they got for me for was growing flowers and somebody else's littering.", "My Dad moved from the UK to Detroit a few months ago cause he runs a business doing just this. He buys cheap houses, renovates them and puts a tenant in. Then he'll just sell it on.\n\nPlug - _URL_0_", "The amount of asbestos, lead, the gangs of scavengers that take anything they can sell in a scrap yard makes those $1 houses not such a great deal. The people that do try and make one of these homes livable usually have everything stripped the night the stuff was installed.\n\nNot to mention cops barely respond to 911 calls, no joke, they just don't show up. EMS half their fleet doesn't run. It truly is survival of the fittest in the area that have $1 houses.\n", "The cost of moving them long distances is prohibitive.", "Abandoned Detroit homes are best suited for fire department practice.", "In some blocks of Detroit:\nNo utilities\nNo police service\nNo fire department service\n\nYou would have to get a generator for power, a shotgun for home defense, and some fire extinguishers. And then you wouldn't be able to leave.\n\nBut you would still pay the full tax rate.", " > EDIT: I've never made front page before, yay! Can someone give me reddit gold for hitting front page? It's my cake day today.\n\n*Seriously?*", "Put it this way, if someone wants to sell you any kind of real asset for $1, they are looking to pass off ownership (and liability), not gain one dollar. \n", "Because they're in Detroit.", "I can't comment on Detroit specifically, but two general reasons why you might not want to buy $1 property are:\n\n(1) If it catches on fire and a neighbouring house burns down, you're liable. If someone squats in it and gets hurt, you're liable. You have to take out insurance to cover these possibilities and dozens of others.\n\n(2) You have to pay rates on it (a kind of tax to the city council). Depending on the area these can be quite exorbitant. In my area large-ish commercial properties can pay $70K/year in rates.\n", "It predicts property will rise 4.3% meaning in a year it'll be worth $1.043. Whoa! I'm buying ", "Because they're in Detroit. ", "A lot of this has been covered - but its because the cost of taking possession of the house is significantly greater than $1, and absolutely no guarantee that your property will ever be worth anything substantial.\n\nSure, there have been examples of \"homesteading\" programs that were successful - like in Baltimore in the late 1970s when they sold row houses for $1 around the Inner Harbor (whose redevelopment had already been announced) under the condition that the purchasers rebuild/restore the homes. In that example - it was a very specific program and a limited area.\n\nIn Detroit - you'd basically be throwing a dart at a map of shitty neighborhoods and hoping that a decade from now, Bruce Wayne decides to build a hospital on your land and pay you to acquire it.\n\nThis is pure speculation - not investment. Stick $10,000 in a domestic stock index fund and congratulate yourself in 10 years instead.", "[The house's tires are worth more than everything combined!](_URL_0_)", "Because a $1 house in Detroit is still a house in Detroit.", "High taxes. Criminal environment. No police presence.", "because at a dollar they are overpriced", "Most of the one dollar houses are all in extreme disrepair and have been stripped. Plus they come with a tax bill. A colleague bought up some to use as rentals a few years ago and it was a disaster. He had trouble getting and keeping good tenants because who wants to live in a house on a bombed out block with no city services? Eventually he started telling tenants that if they lived there for a year and paid their rent he would GIVE them the house. He still had trouble getting rid of them. ", "47% of them can't read the ads.", "Because Detroit is fucking awful.", "Apparently in Detroit you can be robbed at gunpoint by police so maybe people just do not want to live in Detroit?\n\n_URL_0_", "Decided to google earth / map for a bit down the streets. On the street corners with open places that were getting delivery.. armed guards (for booze and bread and crap) .. Also a lot of these houses and buildings that have been abandoned or recently abandoned seemed to of had some modifications by their previous owners;\n\n\n Iron gates on all doors (the doors seem to always be of the steel plate/concrete/plate variety. Then on top of this which gets me the most is these placed have had their windows bricked up and just have little slits for windows now. A place is so freakin bad you have to build a fortress? Christ they probably dont even have pear magners at the stores around there, could you imagine?", "excuse my ignorance of MI property laws etc\n\nwhat is stopping a massive company like, say Google, from buying up vast tracts of land and building a \"model city\" showcasing innovations in technology and basically moving their entire operation to a new \"campus\" basically built from the ruins of detroit?", "It's Detroit. Nough said. I grew up there and now live in Kentucky. Trust me, no one wants to own anything that ties them to a crime infested and falling city. Just saying :). ", "TIL you could buy a house for $1 in detroit", "I'm not a real estate Broker or anything, but I know that it is listed as $1 because it is an auction. This is not what the house is going to be sold for.", "I'm sure taxes are the main issue. A house may cost $1 but the back taxes could end up costing thousands. Still it is a home flippers paradise, some flippers buy homes by the dozen.", "Because of the cops who rob people at gunpoint?", "Because they are in Detroit", "they are in 100% black ghetto areas. You wanna live there? Neither do they. Good luck!", "They should just evacuate the city and use it as a set for a Fallout movie. ", "I heard that if you buy 5 houses in a row you can upgrade them up for a hotel. ", "It's almost entirely because of back taxes. Let's say the land is worth 100k and the house used to be worth 500k. Assuming a property tax of like 5%, you would have to pay 25,000 a year in property taxes. \n\nHere's where it gets messy. The bank may own the mortgage to the house, but it'll dice it up and sell it in parts in what's called a CDO or Collateralized debt obligation. After dicing this up, and selling it multiple times, it has no idea who the house belongs to. This causes the foreclosure process to be extra messy and lengthy. It may take years to get this house off the market. All this time, this house is vacant. Looters come by and strip the copper wiring. There's water damage. It becomes overgrown. The house rots and literally the only valuable thing is the plot of land. After 5 years, you have a plot of land that used to be worth 100k, but now has 100k of back taxes that the new owner would have to pay. And there you have the reason why people don't buy 1$ houses. \n\n*Massively oversimplified but that's essentially it. ", "/u/oceanlifetime broke it down nicely in this thread\n_URL_0_\n\n > There are strings attached. I'm a Baltimore Investor and we have similar houses. Now assuming there isn't a large tax bill attached to it and assuming the bank gives it to you fee simple, you are not in for an easy ride.\nFirst of all the inspector is going to be very aggressive in making you get the house rehabbed. Someone dumps trash in your yard? That's a $100/day fine,. The grass is overgrown that's a $100/day fine. You are dealing with a bankrupt city that is desperate for revenue, they will come after you.\nSo you think, ok I won't be a slum lord, I'll fix up the house and rent it out. Soon though you realize that the house will cost more to fix than it would be worth. You think, ok I'll board it up and wait for the market to recover, then I'll be rich!\nSlow down, soon those old nosey ladies are going to be taking pictures of your house as a vacant, calling you a slum lord, and trying to get it condemned. The city will start fining you with some new law they passed just so they can make money off of you, maybe send you threatening letters.\nOk I'll bite the bullet and fix it you think, I'll be a white knight turn this neighborhood around. Nope, the city will stand in your way every step of the way. Charging you for a permit here and there, taking their time, delaying your rehab. The police will ignore people breaking into your house and stealing your appliances and copper.\nThis is too much! There is value in the land so I'll demolish the structure, land is still good right? Wait until you see those costs, easily in the five figures.\nThis was supposed to be so easy you think. Well guess what, you are not the first person who thought about buying cheap houses from the city. If it was really so simple then experienced investors would have bought up all those blocks of $250 houses a long time ago. Those areas are abandoned for a reason and all the good intentions in the world won't change the situation.", "Because ghost dude. No one wants to live in a haunted house ", "You answered your own question.", "Becuase Robocop needs to come in and clean up the streets.", "Look at the owed back taxes. You pay those too", "As someone who lives in Australia, is it possible for me to buy one of these pieces of property? What would I have to go through for it to make it happen?", "can i buy it with bitcoins ?", "I live in Detroit, and people are buying these houses. Not in droves, but people ARE buying them to live in, and my job is turning some of them into pieces of art, or places for artists to work in. \nMost of the houses are sadly being bought up by investors from other cities and other countries, who are betting on the turn around of Detroit. But then those houses just sit and rot, and nobody who actually lives here can do a thing about it except keep them boarded up so that they don't become drug houses.\nAlso, I've lived around the country, and so have many of my friends here. People move here every day from other places. Our neighborhood is my favorite place to live in the country. Great mix of people, great early 19th century archetecture, our house looks like a castle, I have a farm up the street on some city owned land, and I can ride my bike everywhere from here. ", "Ermagherd erts hernted O.o", "what starts with n and ends with r that you never want to call a black person? neighbour. That's why." ]

[ "In my understanding, it's because your muscle fibres are literally breaking after heavy use. They're replaced with stronger fibres, but that takes a couple of days. This is why you get physically stronger and can lift more weight.", "This usually happens to me after using gardening equipment all day. I'm completely unable to lift my arms (can't even hold up a book to read), and it usually lasts 24-48 hours. \n\nI'm not sure how accurate it is, but this is how it's been explained to me: \n\nMuscle tissue is made up of fibers. Strenuously exerting your muscles actually tears those muscle fibers. Torn muscle fibers cause weakness in the muscle and require time for your body to repair. \n\"Building\" muscle is actually torn muscle tissue being repaired over and over (think repeatedly lifting weights at the gym). \n\nHope this helps! \n" ]

[ "I am certainly not a chemist - just have a freshman uni class; I know next to nothing about fulminates. I also know AskSci has a justifiably jaundiced view of anecdotal evidence, but my first-hand story is quite relevant to the topic.\n\nI'm a motion picture property master. (Coincidentally, I've even worked for Vince Gilligan, the show's creator and Exec, but that doesn't enter into the story.) Among many other things, I'm responsible for providing actors' rings and watches, and any jewelry used as a story point or to move the plot along.\n\nSeveral years ago, one night at about 11 PM, I was in the workshop of an old and experienced custom jeweller. It was on the 3rd floor of a very old stone building; several other custom jewellers also had workshops there.\n\nMy jeweller had been an important contact for many years. On this night, he was producing a large and complex rush order of pendants for me. I was at his shop late because they were playing first thing next morning, so I needed them in my hand before I knocked off, and a few things had delayed their completion. While Harry was setting the last stones, I was working at the buffing wheel, just so we could get out of there. For a propmaster, pitching in at a supplier's, at midnight, often comes with the territory.\n\nAs we worked, we heard a muffled thump, and saw a lot of glass fall past the window onto the street below. We looked at each other and said, \"What the hell was that?\" Then we heard a godawful noise from the hall leading to the shop. Seeing nothing untoward on the monitor, we opened up - it took a while, being low-tech, high-security. When we checked the corridor, we saw a man crawling down the hall, using his hands to orient himself to the wall. His face and shoulders were a bloody mess. Not quite \"Gus-after-the-explosion\", but getting there; pieces missing. There were smears down the old stairway and all along the wall and floor. He was hollering like hell. My guy recognized him as a young jeweller who had recently moved into the shop directly above his. We got him sitting down, and while Harry attended to his airway, I called 911. The guy looked like he'd been shotgunned, so I assumed he'd been robbed, and I asked for police on a possible 10-72 (firearm present), as well as an ambulance.\n\nWhen the cops came, we took them upstairs, where the injured man's shop lay wide open. It was a wreck. Small bits of stuff were embedded deep in the plaster walls. Broken glass everywhere. Explosion, clearly. Not as big as \"Tuco's office\", but a significantly destructive boom, enough to demolish most of a room of about 600 square feet. If it hadn't had windows, a wall *might* have come down. But nothing was burning, and the large safe was intact. I gave my statement and numbers to the police, grabbed my nearly-done pendants and split. Harry stayed on because he had much more info for the police.\n\nI got the story two days later, when I called to hear what had happened. Turns out Harry, the old hand, had recently demonstrated to the young jeweller how to use mercury fulminate to flash-plate jewelry findings and stuff. Although he emphasized how dangerous it was, and that the young guy should only do it under supervision until he learned what he was doing, he had tried it on his own anyway. Got the mix *and* the volume wrong. Blew his shop to hell. \n\nFound out even later that they saved his jaw, but he lost a retina and half his tongue, and was in the hospital for two weeks. Of course, by the time he got out, the landlord had evicted him. Harry picked his stuff up from the alley and stored it, but that was the end of the guy's career as a jeweller, I guess.\n\n**TL/DR:** Mercury fulminate. Serious fucking stuff.", "Also, before he leaves, he states that it is mercury fulminate with a little chemistry tweak. So I'm guessing that it wasn't all mercury fulminate. " ]

[ "[Apollo 15 Hammer and Feather Drop](_URL_0_)\n\n", "if you throw it in a vaccum on earth rather than say in orbit, it will follow a parabolic arc, just like a rock thrown at the same velocity.", "thank you fine gentlemen for assisting me" ]

[ "If you mean sample rate, then none. The eyes don't work like that. This was actually on here a couple of days ago but I can't find it, maybe you can though.", "Check out:\r\n\r\n_URL_0_\r\n\r\nand\r\n\r\n_URL_1_", "Closest thing to a frequency might be [flicker threshold](_URL_0_). But even that is not really the same thing." ]

[ "There are new colliders being put together, _URL_1_ (\"visit general public website\" has some good info)\n\nAnd there are old accelerators being used for precision measurements rather than looking at energy frontiers, _URL_0_\n\nIt's important to note that the LHC uses old accelerators as booster stages to get the protons up to 7 TeV. Maybe one day the TeVatron at Fermilab will be used as an injector into a larger machine (though probably not, as we're near the point of diminishing returns for circular colliders)", "There is one other operational hadron collider currently: RHIC (Relativistic Heavy Ion Collider). It collides at various energies from 30-200 GeV per nucleon pair, and is also the only collider that can collide polarized protons. It is useful for studying the Quark Gluon Plasma via heavy ion collisions, and proton structure due to it's polarization capabilities. They are about to shut it down for some upgrades and the addition of a new detector which should be online around 2018-2019 I think." ]

[ "Yes, as there is a further distance for the signal to travel...\n\nIt's not quite that simple though, there are a couple of factors which increase the time it takes to transmit...\n\n1. Physical distance, radio signals, like sound move at a set speed... being further away affects the time it takes for it to travel, however the speed is so fast, the impact is rather small\n\n2. Places where the signal stops - so the signal needs to stop and be processed each step of the way, and sent back on it's journey again. Each time this happens, it takes time (again very small amount of time) to process the data, and re-transmit it.\n\nTL;DR Yes it does... why, because the signal has further to travel, which takes longer, and each time stop the signal makes, takes time to be processed. ", "Sort of, but the delay is short.\n\nIf the two phones are within the same vicinity and same carrier, they'll use the same cell tower to send and receive texts. When they're far apart, the message has to be routed to the correct cell tower to deliver the text. That means that it has to go through the carrier's server, which has to search for where the receiving cell phone is, and get that message to it.\n\nIt takes a little bit longer to interconnect between carriers.\n\nHowever, the delay is actually pretty short.", "Many others have already provided excellent answers, as far as SMS are concerned. On the other hand, things are quite different if a server-based IM platform is used (as it is more and more often the case). \n\nIn this case, the answer is NO, it doesn't always take longer to send a message to someone that is farther from you and, in some cases, it takes even shorter!\n\nServer-based IM services use, as the name suggests, a server that receives the messages from the senders and forwards them to the receiver.\n\nAmong the basics of networking, there is the explanation of which are the main causes of delay in any communication: the whole thing can be summed up in three main points: the time it takes for the sender to \"push\" the data on the channel, the time it takes for the channel to transfer the data from point A to point B, and the time it takes in-between nodes to elaborate and forward the data. \n\nOf these three delay causes, the second one depends on the physical distance between source and destination (s = v*t, v being c - or, actually, less than that; usually values around 2/3 of c are accepted). \n\nSo, long story short, the total time it takes your message to go from you to the receiver depends on the distance between you and the server, and the one between the server and the receiver. \n\nThis means that if you and the receiver are close to one another, but far from the server, the total delay is roughly twice the time it takes you to connect to the server. \n\nOn the other hand, if either you or the receiver are close to the server, although far from one another, the total time will be shorter (and, shorter still if both of you are close to the server - that's why most IM providers, as well as any other service provider try to have as many servers as possible dislocated around the globe). \n" ]

[ "[.50bmg is a BIG bullet.](_URL_0_) This means it takes up more room in magazines and is heavier to carry around. \n\nThe most famous gun to use that round, the Barretta M82 (better known as the Barrett .50) is for the US army legally an anti-material rifle. It is supposed to take out things like bombs, enemy weapon stockpiles, or unarmored vehicles from a safe distance (although it can and often is used against humans directly). The range these kinds of guns are used at rarely require that many shots immediately, so the Barrett only has ~~five~~ TEN round magazines.\n\nHowever, in video games, many smaller caliber sniper rifles/dedicated marksman rifles that can accept larger magazines often only accept a few bullets for balance reasons. An absolutely realistic war video game [would be both heavily unbalanced, boring beyond belief, and absolutely frustrating](_URL_1_).\n\nEdit: Correction", "It's a sniper rifle, not an assault rifle. 1 (maybe 2 or 3) carefully placed shots, and done. No need for a large capacity magazine.\n\nAlso, as stated by others, sniper rounds are heavy. Why carry more than you need?", "Whenever a sniper takes a long range shot, they almost always do it while laying down with either a bipod, or the front of the rifle propped up on something. If you use a smaller capacity magazine, you can have a shorter box sticking out of the bottom of your rifle. That makes it easier to get a comfortable low position.\n\nHere is an [M16 with a 30 round mag] (_URL_1_).\n\nLook how much lower this [Remington 700] (_URL_0_) is in comparison.", "Because typical \"sniper\" rifle ammunition, such as .308, .300 winchester magnum, .338 lapua magnum, .50 bmg, etc. are long, heavy rounds compared to standard \"assault\" rifle ammunition such as 5.56, 5.45x39, or 5.8x42. A 30 round magazine of .50 bmg, .338 lapua, or .300 win mag would all be ridiculously long and heavy. In the field, this directly implies a much lower amount of ammunition on the individual level, and the unit as a whole. More bullets in hostile territory is more better." ]

[ "Cavities have more to do with diet than brushing! I recall one study where a dentist went to a very remote village in Africa or Asia and they didn't have tooth brushes. He cleaned teeth and was amazed that after cleaning teeth that were completely black with built up plaque, there were no cavities or any real issues. \n\nSugar rots our teeth. Soda drinkers and candy eaters tend to have more cavities, even with religious brushing. People who eat \"clean\" (ie less refined sugars) tend to have fewer cavities even if they brush less frequently. \n\nBrushing is important, especially if you eat sugar, but diet is a bigger factor.", "For my first year in medschool i had a few classes on dental hygiene and other crap, i learnt that having cavities is about 50% not brushing your teeth and having a bad diet (eating sugary stuff and very acidic) and 50% genetics.", "I am 63 and never had a cavity. Same with my mom. I was told years ago by my dentist at the time it had to do with calcium in saliva. I have no idea if that is true. What I do know is it was not the amount of sweets. People my age were raised on kool-aid and candy and soda's were a staple part of the diet. My brother, who was raised the same as me, had plenty of cavities." ]

[ "If you shoot positrons into matter (or electrons into large amounts of antimatter...), most of them get slowed down before they annihilate. A typical kinetic energy of a few eV does not matter in the annihilation, it just increases the energy of the photons a tiny bit.\n\nIf you look at electron/positron annihilation in particle accelerators, for example, things are different, and your photons get much higher energies.", "That's for if they're not moving very fast. In particle accelerators, they sometimes smash particle-antiparticle pairs together because they're easier to move in opposite directions, but they're moving so fast that the energy from the particle-antiparticle annihilation is dwarfed by the kinetic energy.", "You are correct. Energy/momentum must always be conserved. So when positions annihilate with electrons (even though your post cites 'particles', 511keV is only the e+/e- rest mass, so not generalizable to all particles), the corresponding photons aren't, in general, guaranteed to have 511keV and aren't guaranteed to be going in exactly opposite directions.\n\nAs to the why this value (and the implicit opposite equal/opposite directions of the photons) are given in your answer sheet (and used so pervasively in fields such as medical physics), you can see from the [equation](_URL_0_) used to calculate the cross-section for *annihilation in flight* (term used to describe annihilation of positrons while they still have appreciable kinetic energy) scales as rougly 1/gamma. \n\nThis means that the cross section becomes smaller as the positron's kinetic energy increases. Contrast that with a stationary (i.e. non-relativistic, room temperature position) which effectively has an eternity to wiggle around until it hits an electron, and it becomes immediately apparent that as a rule of thumb, non-collinear annihilation photons pairs, with energies greatly deviating from 511keV, will mostly be a small perturbation to the 511keV photons you can generally expect to see from this type of interaction." ]

[ "[Dr. John Craven](_URL_1_), former Chief Scientist of the Navy's Special Projects office.\n\nHe contributed extensively to the development of deep submergence technology. He also helped create the Natural Energy Laboratory of Hawaii.\n\nI highly recommend his book [The Silent War: The Cold War Battle Beneath the Sea](_URL_0_)", "I never knew who [J. Willard Gibbs](_URL_0_) was until I took thermodynamics in college. Dude was a giant of science.\n\n > He devised much of the theoretical foundation for chemical thermodynamics as well as physical chemistry. As a mathematician, he invented vector analysis (independently of Oliver Heaviside).", "The average citizen doesnt know about [Paul Dirac](_URL_0_), who predicted the existence of antimatter, and formulated a theory dealing with the behavior of fermions among other contribution to early quantum mechanics.", "The book \"A Short History of Nearly Everything\" by Bill Bryson mentions a number of scientists who were intimately involved with important work, but who (usually for personality reasons) were overlooked when the credit was assigned. It really emphasizes the unfortunate human element of attaching names to things.\n\n[Henry Cavendish](_URL_0_) is a good one. \"Because of his asocial and secretive behaviour, Cavendish often avoided publishing his work...Examples of what was included in Cavendish's discoveries or anticipations were Richter's Law of Reciprocal Proportions, Ohm's Law, Dalton's Law of Partial Pressures, principles of electrical conductivity (including Coulomb's Law), and Charles's Law of Gases.\"", "[Dr. John Craven](_URL_1_), former Chief Scientist of the Navy's Special Projects office.\n\nHe contributed extensively to the development of deep submergence technology. He also helped create the Natural Energy Laboratory of Hawaii.\n\nI highly recommend his book [The Silent War: The Cold War Battle Beneath the Sea](_URL_0_)", "I never knew who [J. Willard Gibbs](_URL_0_) was until I took thermodynamics in college. Dude was a giant of science.\n\n > He devised much of the theoretical foundation for chemical thermodynamics as well as physical chemistry. As a mathematician, he invented vector analysis (independently of Oliver Heaviside).", "[John Bardeen](_URL_0_). He invented the transistor which is responsible for pretty much all modern technology. He's also the only person to have won a physics Nobel Prize twice. \n\nYet for some reason I've never met anyone outside of the University of Illinois who knows who he is.", "The average citizen doesnt know about [Paul Dirac](_URL_0_), who predicted the existence of antimatter, and formulated a theory dealing with the behavior of fermions among other contribution to early quantum mechanics.", "The book \"A Short History of Nearly Everything\" by Bill Bryson mentions a number of scientists who were intimately involved with important work, but who (usually for personality reasons) were overlooked when the credit was assigned. It really emphasizes the unfortunate human element of attaching names to things.\n\n[Henry Cavendish](_URL_0_) is a good one. \"Because of his asocial and secretive behaviour, Cavendish often avoided publishing his work...Examples of what was included in Cavendish's discoveries or anticipations were Richter's Law of Reciprocal Proportions, Ohm's Law, Dalton's Law of Partial Pressures, principles of electrical conductivity (including Coulomb's Law), and Charles's Law of Gases.\"" ]

[ "Feels good. Try having someone scratch your head or use one of those [weird head wire thingies](_URL_0_). Plus, probably something along the lines of \"positive reinforcement for evolution of social benefits.\"", "Helps remove parasites and most animals cant reach there or see it. So it's probably evolution push this social behaviour.\n\nHumans have that too btw." ]

[ "I think it's because how the Nervous System interacts (or doesn't) with these things. \n\nFor example, rejecting an organ is not a Nervous System response, but rather a biochemical response. In the same sense, the NS is not linked directly to the ways in which the heart frequency changes (release of hormones?).\n\nThe actions you can control, on the other hand, can be controlled by the NS directly.", "I rarely understand what type of answer a person is looking for when they ask \"Why\" the body functions the way it does. From a scientific standpoint, the human body is not a product of intelligent engineering, so the answer can't be \"Oh, well the R & D team decided to put in an extra fail safe so that you can't accidentally kill yourself by shutting down respiration or cardiac functions\". Are you looking for an evolutionary answer? If so, I'm not the person to provide one, but I can tell you that evolution doesn't function based on logic; it all comes down to selective pressure and these types of things just don't have the selective pressure. Beyond that, I'm not sure how to answer the question of \"why\"... that's just how the body works. " ]

[ "It's a website where people link to articles or pictures on the internet and can comment on them.", "The bathroom wall of the internet." ]

[ "This American Life has a couple of fantastic programs on this very topic. I highly suggest you seek them out if you're interested in learning more about the financial meltdown.", "So ShittyBank offers loans to people buying homes (mortgages.) The bank writes you a mortgage, buys your home for you and lets you live there as long as you make monthly payments to pay off the loan. ShittyBank does this hundreds of thousands of times all over the country.\n\nNow ShittyBank turns around and says \"hey, we've got all these mortgages providing a stream of income. Anyone wanna buy a piece of them? If you buy a piece of them, you'll get a portion of all the payments made on them for the next 30-45 years.\" The bank is selling \"collateralized debt obligations\" or CDOs--huge bundles of active mortgages, organized into tiers according to the creditworthiness of the person paying off the mortgage. You buy a CDO, and you get a piece of the payments for every mortgage contained in that CDO.\n\nThe problem is, ShittyBank now has to pay anyone who purchased its CDOs, even if the people holding the original mortgages fail to pay. The bank doesn't want to be left holding the bag if a bunch of people decide to stop paying their mortgages.\n\nSo the bank decides to get some insurance. It goes to an insurance company--let's say, AIG. AIG says \"pay us a little fee, and if your mortgage borrowers default on their loans, we'll step in and keep paying out to those who bought CDOs with those loans in them.\" This is a *credit default swap.* \n\nMake sense?", "This American Life has a couple of fantastic programs on this very topic. I highly suggest you seek them out if you're interested in learning more about the financial meltdown." ]

[ "Its in the bible. Specifically, [Isaiah 14:12](_URL_0_). Here, it talks about the angel who wanted to put himself above God, and it calls him \"Light-bringer\" or Lucifer.", "In biblical lore, before Satan was cast from heaven, he was the leader of the angels and the most favoured angel in heaven. But a rift between God and Satan resulted in Satan being cast down to earth.\n\nIn history, the Babylonian king referred to himself as the first star. Kings always think very highly of themselves, and the first star of the morning is impressive. But this title of first star of the morning comes from an scene that occurs on many clear mornings. This scene is the shining of a star as the sun rises. That is, it is the last star visible before the sky is flooded blue. The light bringer refers to this star, also known as the first star of the morning, or the morning star. \n\nLucifer is a Roman translation that means morning star. This was apt for early Christians because they considered Satan to be the first among the angels, or the leader of the angels.\n\nHowever, the morning star to which they are referring Venus. Venus appears as the brightest star on the morning depending on the time of year. This is because it is relatively close to earth and reflects the light of the sun easily. It's usually the last star to disappear form the morning sky as the sun rises.\n\nSo when Isiah was referring to Lucifer, he was in fact referring to Venus. The later Roman translation creates Lucifer, which became the name of Satan, as a means to identify a fallen star, or the great first star among the angels, or the angel that was cast from heaven. The translation was wrong, and Lucifer as Satan was born.", "It's interesting to note that the figure of Satan/Lucifer is actually an amalgamation of three figures in mythology.\n\n1) The Serpent in the garden of Eden. A figure of corruption. \n\n2) Ha-Satan, which means 'The Adversary.' Think of him as a celestial District Attorney that lays out your sins when you die and stand before God and are judged. He also has a spot in Heaven and converses with God on a regular basis.\n\n3) Lucifer, fallen Angel, which others here have covered very well.\n\nThey all sorta got mashed together over the last two thousand years. ", "It's been a while since I did my degree (theology) but I focussed heavily on the Satan myth in my dissertation and if I had pursued academia further word have been the basis of any doctoral work. If memory serves the simple explanation is the character is actually a mix of translational issues, biblical references, pagan artifacts and several apocryphal stories that have all been amalgamated into one overarching narrative. \n\nSatan in either Hebrew/Greek/Aramaic (can't remember the language for the source text) is actually a title, the correct term being something like 'Hasatan' or 'Hashaitan' (it was 10 years ago I did the research, bare with me). This title was actually a political stab at some infamous despot or another at the time. I think the literal translation is 'the adversary'. This was interpreted by early scholars as a proper name and was characterised into this malevolent persona. Over time it got swept together with things like the serpent myth in Genesis, Origins poems, the signs of the first rapture in Daniel and the second in Revelations, Hades from Greek myth, Zaroastrian Angra, Chernobog, Djinn Legends from Persia, Enoch's story of the Fall and a thousand other cultural influences into this broad overarching narrative. Satan itself just represents 'that which we are opposed to', whereas the Lucifer tale of the fallen angel comes from Enoch, Dante, Blake and Milton. \n\nIt's important to remember that there is no one 'Bible' there are thousands of texts, written across hundreds of years by thousands of authors in dozens of different languages (most of which we can only guess at reading). What you commonly think of as the Bible is just what a few old dudes decided they wanted to cram together into one book at Nicea, or under King James or in some church or university somewhere. What one you refer to just depends on your chosen breed of insanity/sun worship. There isn't really one Satan story because the story is actually a cultural phenomenon. It's a persona we invented as a society over two thousand years of culture. \n\nI'm sorry if that's a bit of a tangled mess to follow, but I'm skimming over a lot of detail from my memories of research I did a decade ago. \n\nFun fact: Of all the characters associated with Satan in the NRSV edition of the Bible, not one of them ever tells a lie. The devil always tells the truth (which probably had a significant impact in tying him to the Lucifer story from Enoch).\n\nNinja Edit - Forgot about my boy Dante Alighieri", "Hmm, I fell under the assumption that Lucifer, like Prometheus, carried this name because he \"tricked\" Adam and Eve into eating the fruit of knowledge of good and evil. Lightbringer being synonymous with enlightenment, it would make sense that Satan would be referred to as such since he is thought to be the one that brought understanding to mankind. I haven't actually formally studied this, so take this with a grain of salt. ", "Satan in Hebrew is just \"adversary\" or \"accuser.\" There is no one Satan in the Old Testament, it's just a title; the New Testament is where the singular Satan/Devil is developed as a figure. That's important to bear in mind because there are so many misconceptions about Satan. \nLucifer is attached to Satan because of a prophecy in Isaiah 14 regarding the king of Babylon at the time who is sarcastically referred to as the \"Shining Morning Star\" in translation. For some ignorant reason, despite the text quite literally prefacing the statement by saying it's about the king of Babylon, people have relentlessly attached it to Satan because of speculation about his origin. Tradition is a powerful thing and it's not helped by the influence of various religious groups, especially Gnostics, on contemporary understanding of pseudo-religious myth. ", "At the Bible college that I attended, one of the OT professors said that the first tie-in of Lucifer and Satan was contributed by Jerome, of Vulgate fame. \n", "I'm not sure what the origin is, but it is interesting, because \"lucifer\" in roman refers to the morning star. \n\nThe last thing that Jesus says in the book of revelations is, \"I am the bright and morning star.\"\n\nI kind of see it as a commentary on the duality of man, but I'm no biblical scholar.", "2 Corinthians 11: \n\n > 13 For such are false apostles, deceitful workers, transforming themselves into the apostles of Christ.\n\n > 14 And no marvel; **for Satan himself is transformed into an angel of light**.\n\n > 15 Therefore it is no great thing if **his ministers also be transformed as the ministers of righteousness**; whose end shall be according to their works." ]

[ "American Civil War:\nThomas Jackson was call \"Tom Fool\" by his VMI Cadets (I personally like \"Old Blue Eyes\"). His cousin William Jackson was called \"Mudwall\". Lee was called the \"King of Spades\" because he preferred a defensive stance as the war drew on and this involved digging in. George Gordon Meade was once called a snapping turtle. Jubal Early was \"Bald Old Man\" or \"Old Jubilee\". Turner Ashby (Stonewall's cavalry commander) was the \"Black Knight of the Confederacy\". William \"Extra Billy\" Smith. There were a few Fighting Joes and Fighting Dicks. \n\nNot sure if it's a modern nickname or not but Henry K. Burgwyn is known as the \"Boy Colonel\" because he was just 21 when he was killed at Gettysburg and had been promoted to Colonel a few months shy of his 21st birthday. I've been able to visit his grave in downtown Raleigh where he has a monument on a hilltop in the Confederate section of the yard.", "This may not be a nickname, but Emperor Magnus Maximus can be translated as 'Big, Very Big', 'The Great Important', etc." ]

[ "[MTPT](_URL_0_) and [MPPP](_URL_1_) (desmethylprodine) are two. Actually, MTPT is a potential byproduct and is the core of MPPP, which is an opiate like designer drug. The story behind the mixup is pretty tragic, an intrepid makers wanted to make the recreational drug and wound up making MTPT, which is processes to MTT+ in the body and is an extremely strong inhibitor of complex I in the body. This graduate student self injected the drug, giving himself symptoms of Parkinson's, later giving an effective model to study the disease in animal models. ", "Ethanol and methanol. If you chop off a -CH3 you go from drunk to blind.\n\n > I was thinking something crazy like sugar and cocaine.\n\nWas that intended as an example? The two aren't all that structurally similar.", "Dextromethorphan and Levomethorphan. They are composed of the same number of the same atoms and are literally mirror images of one another yet levomethorphan is an opioid painkiller similar to morphine and dextromethorphan is a cough suppressant, NMDA receptor antagonist, serotonin reuptake inhibitor, dissociative / psychedelic drug and cough suppressant commonly found as the active ingredient in Robitussin! Interestingly, although both have cough suppressant properties, the mechanisms by which the two suppress the cough reflex are entirely different, with opioids/opiates working by suppressing the \"cough reflex\" part of your brain in an area called the medulla and with dextromethorphan having a more complex (hypothesized) effect involving sigma receptors which I don't pretend to understand) (Citation: Debonnel G. Current hypotheses on sigma receptors and their physiological role: possible implications in psychiatry. [Review]. J. Psychiatry & Neurosci.. 1993;18:157-172.) Dextromethorphan and levomethorphan could not be more similar in structure and could not be more different in effect!", "Testosterone-\n\n_URL_0_\n\nAnd Estradiol-\n\n_URL_1_\n\nSo incredibly similar, but those tiny differences mean so much to our bodies.", "As rlee89 pointed out, sugar and cocaine aren't even close to being structurally similar.\n\nThat being said, I'll add my example.\n\nD-glucose and L-glucose. Although both taste sweet, L-glucose can't be metabolized and can have laxative effects.", "Psilocybin, tryptophan, tryptamine, serotonin and Dimethyltryptamine.\n\n_URL_2_\n\n_URL_0_\n\n_URL_4_\n\n_URL_3_\n\n_URL_1_\n\n\nSome are powerful psychedelics, an essential amino acid, or essential to brain chemistry.\n\nVery similar molecules.\n" ]

[ "Popular discussions of the Pacific Theatre usually covers the naval action, the battles on the small islands and atolls on the strategy towards Tokyo. \n\nI wouldn't go so far to being neglected, but I would like to know also. The Korean War is a real clincher of the 20th century, but most people I know couldn't tell a fact or two about it to save their skin. ", "In my opinion it is neglected because of the more racial sensitivity going on in the war in the Pacific. We were very racist against the Japanese and Asians in general. This makes the moral narrative of good versus evil harder to square up as it was in the war against Germany.\n\nIt also might be the most barbaric front of the war outside of the Soviet/German Eastern Front clashes. Which makes it harder to put on a bumper sticker for a cursory glance through history.", " The US strategy in the Pacific was to island hop until they could get a good postion to break the Japanese war effort through decisive naval battles and direct destruction of industry and population centers in the \"home islands\" of Japan. Everywhere else such as Indochina, India, China...etc were basically secondary to this goal, and thus had little priority for US involvement. Less involvement usually means less staying power in the popular memory which is likely what happened here. \n\n\n", "There weren't any gigantic decisive battles, a la, Iwo Jima, or Normandy, that the U.S. was involved in. I think it's why it's forgotten.\n\nI think it's sad that it's forgotten, though. Joe Stilwell, Orde Wingate, and Chiang Kai-Shek are all really, really interesting characters, and all the stuff that happened in the CBI theater really set the stage for Sino-American relations for thirty years after.\n\nAlso, your grandfather doing an IAMA (if possible) would be amazing.", "To add to everyone else,\n\nI'd imagine it is a forgotten theater because of the lack of operations or units in the theater. By no means do I believe that was the case, but compared to battles in the ETO, where battles were very distinguished on a map, battles in the PTO and particularly the backwaters of the CBI theater were very brutal and sloppy. Units would be engaged all along the front, if there was such a concept in a particular region. And where the PTO had large surface fleets or assault forces being deployed, a very minimal amount of resources were placed into the CBI theater, hence the lack of recognition. \n\nThe Flying Tigers got recognition for being some of the first Americans being engaged in combat (with the added prestige of being a mercenary squadron that civilians saw as interesting) but IIRC, were largely forgotten once America officially got into the war, thus removing the small amount of interest that the region got :/", "For what it's worth it's totally forgotten about in Britain as well and we provided the majority of the soldiers that fought across Burma. My grandfather served there, yet you'd be hard pressed to find a regular non history fan in Britain who'd know that Britain fought Japan in Burma. Hell I imagine most people of my generation wouldn't even know about Singapore these days." ]

[ "This is definitely one of the hard problems for general relativity to answer. A point particle isn't *exactly* a billiard ball of zero radius and some finite mass. But (from what I hear at least) putting a quantum field into the stress-energy tensor doesn't return good curvature fields.", "It's been explained by other commenters, but to put some of it together, there are two problems. 1) they aren't really points, they are represented by waves with some nontrivial spatial spread and 2) GR (gravity) and quantum (everything else) don't play nice, so you can't really work gravitational questions out on those length scales.", "Your logic is fine. Your premise is wrong. Particles aren't points. That's just a classical approximation.", "This is definitely one of the hard problems for general relativity to answer. A point particle isn't *exactly* a billiard ball of zero radius and some finite mass. But (from what I hear at least) putting a quantum field into the stress-energy tensor doesn't return good curvature fields.", "It's been explained by other commenters, but to put some of it together, there are two problems. 1) they aren't really points, they are represented by waves with some nontrivial spatial spread and 2) GR (gravity) and quantum (everything else) don't play nice, so you can't really work gravitational questions out on those length scales." ]

[ "There is a job called 'Pentester', i think, who are hackers for a job and on a legal base. They get hired by companies to test their networks and softwares for weaknesses.\nI hope i could answer your question ^^", "Let me rephrase the question:\n\nHow come hay distributors have to wait for professional needle hunters to find the needles in their haystacks instead of just finding the needles themselves before shipping the hay?\n\nHopefully that puts the scope of the problem in the correct frame of reference. Hay distributors are not trained to find needles, and don't need to be, as 99.98% of all hay has no needles in it.\n\nOf course, looking at it the other way, ALL software has bugs in it; there are more possible logic paths that can be taken than a software developer can test for before publishing. If they followed all logical paths and accounted for them, it would be faster and cheaper to do the task manually than to use computer software. So developers pick some arbitrary point in testing as \"good enough\" and some set up a bug bounty reporting system for post-publish discovery.", "Software companies find 1001 vulnerabilities and close them before anyone knows about them. Most before its ever released. But ultimately developers are people and people don't always see everything, especially when it comes to their own works. \n\nSo hackers find the 1002nd vulnerability and exploit it. \n\nGood developers never stop looking for those holes in their software but you can't expect them to think of every scenario. There are far more hackers than any one developer group has developers so it only makes sense that they can sometimes find holes before the developers can. ", "It's a nice concept in theory, but sometimes it's just not practical. You and I might want a perfectly bug-free application, but sometimes the goal is just to be first to market. If the product doesn't sell, then you scrap it and you didn't waste time fixing bugs to begin with.\n\nAnd obviously a thorough coder will try to cover any security holes as they are able, but another set of eyes will reveal things the author will not see...extend that out to the worldwide hacking community and there's bound to be *somebody* that will find a hole the company never would have on their own.", "You write a program\n\nYou write it 99% bug free, there are 1% issues now.\n\nYou have peer reviews when you're checking it in, they catch 99% of issues, you're now at 0.01% issues.\n\nYour QA team checks it over and Pentesters try to break it, they find some other bugs and remove 99% of the remaining issues. Your code is now 99.9999% bug free. Yay!\n\nYou release it into the wild.\n\nIf it is only somewhat popular and doesn't contain anything really valuable maybe no one every finds the bugs\n\nIf its really popular or contains/protects/operates something really valuable you're now a huge target. There are now hundreds or thousands of software engineers pouring over your code trying to find a breach. It is possible for there to be 10-1000x as many people searching for a breach once its out in the wild as touched it when it was in production. You have way more eyes looking at it from so many different perspectives that someone will find something.\n\nNo code is 100% bug free, and its not possible to ensure that it is. Sometimes built in functions provided by Windows or core HTTP functionality gets broken and there is nothing you can do to stop that.\n\nSecurity is about the most effective protection for the most reasonable cost. If you are a small software developer you will never successfully defend against a nationstate attacker so if Russia wants to breach your system they're getting in so you just focus on making it fairly secure so the average script kiddy isn't going to get through", "Finding and fixing bugs costs money. Finding all would cost a fortune. You also have to ship the product - delays means costs. \n\nSo you ship buggy code or you go out of business. ", "There is a more fundamental problem than others have mentioned. If my business goes offline because Windows had a bug that allowed a hacker to shut me down, I suffer damage, but Microsoft does not. \n\nEconomically, the people who buy the software are the ones who have the incentive to make it hack-proof, but they have no ability to do so. The developers, who get to choose how much time and effort they spend making their software hack-proof, have very little incentive to do so.\n\nUntil at least some of the economic harm caused by hackers falls on the companies who write the hacked software, they will always under invest in making their software bullet-proof.\n\nI am *not* saying they put no effort in, but ask any senior person in any software QA group in any company, and they will tell you that QA is underfunded in their company.", "There's an old story about a programmer that found the most obvious bugs in his software, then passed it over to his beta-tester.\n\nPart of the game took place in a cafeteria, and the programmer had written a 'red herring' into the game: the player could take a napkin from the dispenser on the table, but the napkin had absolutely no use anywhere in the game.\n\nThe tester submitted a bug report that said, 'Game crashes when taking more than 999 napkins from the dispenser in the cafeteria'.\n\nThe tester had done something that apparently serves no purpose; since it was a text-only game, that meant that the tester had sat at his keyboard and typed 'get napkin from dispenser' 999 times in a row, for no real reason.\n\nThe programmer later said, 'I hadn't bothered to test the dispenser, because it never occurred to me that someone might actually attempt to take a thousand completely useless objects.'\n", "They don't, they definitely do find vulnerabilities in house. You just don't hear or care about these cause nobody reports \"software development going according to plan, all is alright\".", "While everyone else here is going to give you broad answers, the difficulty involved, and much with the uttering of statistics and the doing of things, etc. The truth is more complicated. This is not a problem with security not being given due attention per-se, but rather a consequence of our field's lack of practicing good engineering. Let me explain from an example in a different field: Construction. On 9/11 two planes much larger than the engineers had ever foreseen crashed into them. Despite an event that critically wounded the tower, it remained upright for about half an hour. But they overbuilt the towers, they stayed up long enough for many to escape. The lessons learned from that collapse are now considered in future designs -- many planned skyscraper builds went back to the drawing board after, to be redesigned to account for this. \n\n\nSome of the very first laws in human history detail building codes -- \"If a builder buildeth a house, and it collapses and kills its owner, the builder shall be put to death.\" All of our buildings are built upon the knowledge of previous failures. Their designs are open to public inspection. There are libraries upon libraries filled with analysis and standards. All work (should) be inspected, and engineers cross-check with each other at every step of the design process, and even during construction. The towers stayed up as long as they did because humanity has had over 8,000 years of engineers learning how to build better buildings, and all of the lessons they have learned, we can learn today. \n\n\nIn my field... none of this happens. Designs are black boxed, considered trademarked, trade secrets, copyrighted, patented -- the point is, most of our technology is most certainly not available for public inspection. Consequently, when it fails we learn nothing. So why not? Because corporations don't want to admit to wrongdoing, so they blame esoteric reasons far removed from this truth. And so our community learns nothing about the failure, cannot conduct a root cause analysis, and cannot share this information with anyone so our mistakes are learned from. \n\n\nWorse, we have to redesign things from scratch most usually every time. Our software isn't modular (like buildings are). We rarely incorporate well-tested previous designs. In fact, the industry is actively averse to using a proven design because by the time its proven, it's considered \"out of date\". Put another way: We reinvent the wheel with every new model of car. \n\n\nBecause of all of these things, a person in our field, no matter how gifted, can only rise to the level of their own competence. They have no shoulders to stand on, and, being human, and unable to communicate with very many other humans for the aforementioned reasons, there are inevitably mistakes. \n\n\nThis is why \"hackers\" will win in every contest. Security is only as strong as the weakest link, and with all of these problems, it's almost a statistical certainty they will find not just one, but very many. The problem isn't that companies design badly, or that they didn't invest enough in security. The problem is that no matter how much of an effort you make... it's *your* effort only, not the collective efforts of hundreds of thousands of people. And so we are left with things like cell phones that can catch fire and kill us. We're left with hospitals all over Europe right now that aren't functional because of a \"cyber attack\". Everything that has a microprocessor in it has bugs. And as our society becomes increasingly dependent on information systems, this problem will only increase exponentially. \n\n\nWe don't need 8,000 years to fix these problems. Aviation is a relatively new field -- we only started a hundred years ago, and yet thanks to proper engineering *practice*, by applying first principles, it is now the safest way to fly. But until we start applying those principles, our technology will continue to with increasing frequency and severity. Security is defined properly as \"the computer doing what you want it to do, and not doing what you don't want it to do.\" Whether it's a hacker or an \"oops\" -- the end result is the same. And proper engineering would prevent both. \n" ]

[ "Facebook was around eight years before Snapchat. It's been evolving ever since that day, and no one is going to sue a company for having similar features unless code and designs are literally stolen. \n\nThere's no patent on social media features. ", "Lots of apps have similar features. If one company is able to independently arrive at a similar feature without any proof of actual infringement on the patent, then there is no case." ]

[ "It might be a result of \"dryness\" in the pleural space (area between your lungs and interior wall of your chest), any friction on internal organs is incredibly painful.", "Heartburn, maybe? What's your diet like?" ]

[ "At least partially because having to process a payment using a card costs the retailer a fee.", "There are transaction fees associated with credit card transactions, generally in the 2-2.5% range. If I'm buying a $10,000 item, the person selling it to me would get $9800 and the credit card company would get $200.\n\nIt's also possible something shady's going on, and they're wanting cash payment to avoid there being a record of the transaction with the intent of evading paying taxes on this.", "When you buy something with a credit or debit card, there's typically a delay between when you leave with the product you're buying and when the seller receives the money. Additionally, there's always the chance that something could happen (such as the payment failing to process or an insufficient funds issue), though with faster processing of payments those issues are becoming less common. By paying cash, many sellers of large items, especially ones that people don't buy frequently, such as larger TV's and furniture, are willing to lose a small amount of profit in exchange for having the money right tf now. I remember my stepdad getting $300 off a $1500 TV by paying cash. I once saved $180 on a recliner (it was tagged for $600, I talked them into taking $500 and including delivery)" ]

[ "You'll have to clarify this one. It doesn't make much sense at the moment.", "Because the phone is able to remove the output signal from the input signal. Noise cancellation. ", "Sound is made up of waves of energy. When waves intersect, they can exhibit constructive or destructive interference. When the high energy peak of one wave hits the low energy trough of another, the two waves cancel out (this is destructive interference). \n\nThe speaker on your phone knows what wave it is putting out, and the microphone knows what it is getting in. There is a chip in the phone which subtracts the outputed wave from the inputed wave. This creates destructive interference which \"crosses out\" the other end of the conversation.", "Basically, check out this [diagram](_URL_0_). What it's showing is that two identical but ‘opposite’ signals will cancel each other out and result in no signal at all.\n\nYour phone can compare the sound coming from your speaker with the sound coming in from the microphone and turn one of them ‘upside down’ (polarity reversal if you want the proper term) so that the words coming out the speaker cancel themselves out but leave the rest of the signal intact.\n\nIt's one of the times when noise cancellation is useful - a lot of the time, it can be frustrating when signals we *do* want cancel each other out.", "You've probably heard that sound is what happens when the air vibrates. Technically, sound means \"fast changes in pressure.\" Pressure is either positive or negative, never both. \n\nOne thing that's very easy to do with sound, once it's been put into a computer, is to \"flip\" it upside-down, like a picture of a mountain range -- every peak becomes a valley. The cool thing is, you can then make the sound go away by playing back both at the same time -- ever time the first sound tries to make a peak, the other sound makes a trough, so there's nothing left.\n\nYour phone obviously knows what sound it's making, so it can very easily take whatever it's hearing, add a flipped version of its own sound, and end up with just the sound that wasn't coming from itself -- your voice.\n\nNow, this process isn't perfect, since the phone's sound will be very, very different once it's bounced around the room and come back, so there are a few more tricks the phone can do -- like noise gating.\n\nNoise gating means that everytime the phone talks, it stops listening to itself for a very, very short period of time. That way, it won't record itself. It also does the reverse -- whenever you talk, it lowers its own voice so that it doesn't try to speak over you. The cool thing is that you barely notice this, since your hearing kinda works like that anyway.", "A chunk of the people's answers in here are correct. The only way to avoid a loopback from a speaker is to identify the voice and remove it. How to do this can vary, but a basic answer...\n\nFor an ELI5... Think of a jump rope being waved up and down. Normally you see those waves go all the way to the end of the rope. If you've ever had someone move the rope on the other end, you may recall the waves in the rope doing some crazy things. If they were to move the rope exactly the same as you do, when they meet in the middle, they'd actually cancel each other out.\n\nNoise cancellation does something similar to this. The phone memorizes the last few sounds it heard, then takes the new sounds and asks itself, \"gosh, part of this sounds familiar!\" and takes the part it's heard before (aka your voice), and subtracts it.\n\nELI21 - Sound waves are saved as digital points on a phone, using an Analog to Digital Converter. To remove noise, you need to identify the noise somehow, then mathematically subtract it from the new signal. Since voices are measured in both frequency and magnitude, removing a sound of a particular frequency from a voice call isn't as destructive as it might sound. Ex. A tuner on a stereo. This removes/amplifies frequencies it receives.\n\nIt's all a rather fascinating subject, feel free to PM with any specific questions." ]

[ "In previous discussions on this topic I had defended the use of the term in certain areas and contexts, because there are most definitely subspecialties which use the term. Like everything in the social sciences, very little is concrete, to include my own recent views on the matter. Still, I hope I’m able to at least make something of a case for the flexibility of the term “tribe”. We’ll see how that goes.\n\nTo give some background, I am an anthropologist/linguist working around Myanmar. I won’t give too much information on the specifics, for the sake of maintaining some degree of anonymity.\n\nIn previous discussions with /u/estherke and /u/commustar, I defended the use of the term “tribe” in at lease some contexts, arguing that in certain areas of the world, Northeast India for one, it’s an actual term of political organisation, while in other areas, it refers to a degree of political organisation, such as in the United States where tribal affairs councils are still in many cases the organising and administrative body for a large part of the aboriginal population. Likewise, in China you will find the term *buluo* used in places like Manchuria, Inner Mongolia and also in Taiwan’s many aboriginal settlements. It is a term which I think we can safely translate as being equivalent to “tribe” in English. It is in place names throughout the continent where Chinese is spoken.\n\nOf course, the term is not without issue even in my part of the world. As one example, In *Clan, Dialect and Tribe Identity: Emergence of Crosscutting Identity among the Zo People in Manipur*, the case is made by L. Lam Kan Piang that the term “tribe”, when used in the region, is still very much the result of an application by the British colonial institutions which was then carried over by the Indian government in the post-colonial period. I've recently started to feel more negatively toward its use, but I'll get to that further down. First, some background on the use in the areas I conduct my research:\n\nIn India the term has been codified, particularly in the context of Scheduled Tribes and Scheduled Castes. These terms confuse people at first, misunderstanding what “scheduled” refers too, but it really just means “listed”. The Scheduled Castes are what have been called the “untouchables” and refers to marginalised castes in India’s semi-recent history. The Scheduled Tribes are effectively all groups of people who otherwise fell outside the caste system. Generally this means those in Northeast India, where most of the Scheduled Tribes exist. I won’t get too much into the history of the region because it’s incredibly complex and very politically loaded. Quoting the government can’t be contentious though, right? The scheduled tribes are classified as such based on four main points. 1) They’re geographically isolated in “remote and inhospitable areas”. 2) They’re “backwards”, relying on “primitive” means of subsistance. They are highly illiterate and in poor health. Nevermind that many of their languages lack orthographies or educational support… 3) They’re distinct. This one gets me because assimilation is definitely a goal of the State. 4) They’re “shy”. Basically they’re isolated, again. Or really they’re suspicious of outsiders coming in and mucking around. I can’t imagine why. This is all quoting from India’s Labour Bureau by the way.\n\nIt starts to make sense why people such as Piang (cited above) take issue with the term. The problem is that it *is* codified, and it’s the term the tribes themselves use. In places like Arunachal Pradesh where English is the *de jure* lingua franca, “tribe” is what you’ll hear being used. The lines usually follow linguistic lines, not causally but just as a fairly obvious parallel to the development of group identity otherwise.\n\nI just want to tack on to the end of this comment an important note: In the course of going through some of the literature of the past week, I've actually come to more strongly detest the term than I previously had. It's a term that had a fairly understood specific meaning to me as used in my area, referring to a specific type of political organisation subordinate to ethnic affiliations and which was independent of the village. It has a well understood meaning free of judgement. The term is used probably in large part due to the legal codification, and in part I'm sure to tradition as well. I'm just feeling less comfotable in its use than I had before.\n\nThere have been a number of passages I've red this past week by authors in India which have made the use of the word \"tribe\" seem not so great. As just one example, the following is pulled from the Preface of *Encyclopaedia of Scheduled Tribes in India* by P. K. Mohanty, who says the following about \"tribal people\":\n\n > [they live in] …remote areas… whose style of life is quite different from the present day civilized men… [they] are termed tribal, to distinguish them from other people of the world.\n\nYeah, screw that.", "Well, I will begin by saying a \"tribe\" is a voting bloc in the assemblies of the Roman Republic, perhaps because there were originally three (*tria*) although the etymology is disputed. So needless to say *all* of you actually use the term wrong.\n\nBeyond that, \"tribe\" is often used as a translation of the Latin term *civitas*, which means \"citizenry\" or \"community\" but may best be translated as \"commonwealth\". It is an often problematic usage because it implies distinctions in communal organization that isn't actually in the Latin, but I suspect this will be handled more fully by someone else here.\n\nRather, I would like to describe it in the context of the Roman East, where the social historian Andrew Smith laid out a very interesting use of the term in his description of Roman Palmyra as a translation for the Greek term *phyle* (race/people). The term is taken from ethnographic studies of the Bedouin, and serves as a loose translation of the Arabic term *ʿashāʾir*. At its heart it describes a kin group, a large collection of families that share a common sense of interrelation within the broader communal framework of Palmyrene society and its Arab, Aramaic, and Amorite ethnicities. It was also more than just a familial group, cutting across class lines and not really claiming common descent, as a \"clan\" might.\n\nHowever, it was of utmost importance to the Palmyrene self identity, and tribal identity manifests in both the geography of the necropolis, with certain tribes buried in certain areas, and in the religious practice and nomenclature. In fact, the three deities of Palmyra, Yarhibol, Aglibol and Malekbal seem to have come about from a fusion of the deities worshiped by the tribes before they came together in the creation of Palmyrene society.\n\nI'm not entirely certain about the usage of the word tribe, although Smith is fairly rigorous with his consistency in application. What it does get at, however, is the degree to which Palmyra had a very distinct social organization than even the rest of the Roman East. It essentially maintained the division that preexisted the city, and particularly in the Early Imperial Period it seems to have been organized almost as multiple communities within the same walls. This is despite the fact that the Palmyrene's themselves had an extremely strong sense of the Palmyrene identity, maintaining non-classical styles of epigraphy and art. It may in fact have been the maintenance of this highly multiple identity that allowed Palmyra to maintain such notable cultural independence, as its elites never really behaved in a way that was truly comprehensible to the Roman mainstream.", "I think my answer is pretty straightforward. For Africanists, \"tribe\" carries the baggage of colonial-era designation systems that were reified and naturalized by a combination of governmental and individual selection. More than that, however, it carries the connotation of primitivism and atavism (as befits its ethnographic origins as a stage of sophistication) as well as a lack of \"civilization,\" and so it is inherently prejudicial. People from Africa use tribe in English primarily because this is what they've been taught to use; the real terms in vernacular are closer to nation or community (e.g., isizwe in isiZulu). The reality was that affinities were multiple and overlapping, and patron-client relations (even relative to centralized states) were far more important as identifiers and might change over time.\n\nIt's not analytically a precise or useful term, when there are others that give much more detail (or at least not less) without the historiographical baggage. So among Africanists, it is definitely a term in eclipse. Where the term persists academically, it persists entirely because of colonial-era inertia and a lack of systematic challenge / broad education to change the perception. But then, that last bit is common to a lot of subjects connected to Africa.\n", "I will go ahead and offer an Africanist perspective. \n\nThe term Tribe was used among historians of Africa from at least the 19th century up until the late 1960s or early 1970s. Since the 1970s, Africanist historians and anthropologists have engaged in a good deal of discussion within their fields about the term. The resulting consensus has been that Tribe is not a useful term to use in an African context, for several reasons. For organization purposes, I will list a few reasons as headings, and provide a little more context under each heading.\n\n**the term was over-applied, so that 'tribe' has no clear meaning**\n\nMany, many different societies in Africa have been described as Tribes.For instance, there was talk of [the Yoruba tribe](_URL_0_), of [Zulu and Kikuyu tribes](_URL_2_), and also of [\"bushmen\" (San) tribes](_URL_1_). \n\nThe problem with applying one term to all of those societies is that the social organization of these groups are completely different. In the 1950s, soon after the article about the Yoruba \"tribe\" was written, a greater proportion of Yoruba speaking people were living in cities than the population of Canada. Historically, Yoruba modes of subsistence was based on agriculture (this changes in the 20th century), while the Kikuyu were a pastoral-agricultural people (ditto), and the San have been hunter-gatherer peoples. \n\nAdditionally, it we look at recent population figures, there are roughly 40 million Yoruba people in Nigeria and Benin, perhaps 12 million Zulus, 6 million-or-so Kikuyu, and 90,000 San. Somehow, tribe is meant to describe a largely urban population larger than Canada, and also a hunter-gatherer population in the tens of thousands.\n\n**It promotes notions of timeless identity and social organization**\n\nThis is connected to the problem of over-application. In the popular imagination it seems that not only is every society in Africa a tribe, but that tribes began with dawn of man. [See this recent biology article](_URL_3_) as demonstration. \n\nAs a corollary, it is often thought that tribal identity can be traced back through the centuries. That is, someone who identifies as a BaLuba today had ancestors who identified as BaLuba in the year 1890, and ancestors further back who identified as BaLuba in 1700. \n\nIn the past few decades, historians and anthropologists have come round to the idea that identities are situational and overlapping. \n\nSo, to come back to our Baluba example, a person in rural Katanga province might identify much more with their village or family or occupational identity. They might even identify as non-baluba ethnically. However, when they move to a city like Kinshasa with a diverse population, it might be that they identify to others as Baluba, and the other identifiers become less pronounced.\n\n **the term promotes the idea of primitivism**\n\nThe usage of the word Tribe to describe African societies is deeply tied to the era of European colonization of Africa. In the context of the 19th century, it was understood to draw a connection between Africans and ancient Germanic and Gallic tribes encountered by the Roman Empire. The assumption made was that societies develop along a path from bands - > tribes - > chiefdoms - > kingdoms - > empires, and that African societies had only progressed to the tribal stage of development.\n\nMore recently, when phrases like \"tribal based conflict\" is used to describe political violence, it promotes the idea that such conflict is intractable and the \"ancient hatreds\" are incomprehensible to sensible, modern westerners. Thus, talk about \"tribal violence\" becomes a convenient shorthand to avoid delving into political, economic, or philosophical causes of violence.\n\n----\n\nWhat words are used now?\n\nIt can get tricky. In talking about identities, it is frequent to refer to ethnicities, i.e. \"from the Hausa ethnic group\".\n\nOf course, it can be troublesome to assume modern ethnicities can be applied retroactively to the past.\n\nWhen in doubt, I sometimes resort to identifying people by the language they spoke. I can speak of \"swahili speaking traders\", even if I have qualms over whether they would consider Swahili as an ethnicity, or would rather view themself as simply a muslim, or viewed themself as a Shirazi through their grandfather.\n\n\n\n", "My use of 'tribe' has mostly to do with the Germanic peoples of the Roman and Early Medieval/Dark Ages. The distinction here is also from the Romans, but different from what Tiako described. The Latin word for these various peoples that we now call the Germanic tribes, so the Jutes, Batavians, Cimbrians etc., was 'natio', whereas they would have been part of the Germanic 'gens'. By the first century or so, the Latin meaning of these words is thus quite different from their original meaning, but which have something to do with 'native birth' or 'relations'. For Free Germany, it is thus different from a 'civitas', which is a Roman administrative unit; when Romans come into an area, they try to turn a 'natio' into a 'civitas'.\n\nSo the term 'tribe' is a means of political organisation. Conveniently, this is also how anthropologists used the term (as a developmental stage in power centralisation, or in other words, a description of an organisational structure). This has as an implication that according to (a simplistic reading of) Tacitus, or other Roman geographers (ethnographers), a 'tribe' is some sort of homogeneous political actor, roughly equivalent to a modern state. In this sense, scholars have seen it as a description for a 'proto-state' (something on the ladder towards state organisation). This use, while common just 20 or 10 years ago, is now totally outdated.\n\nA more nuanced studying of social organisation in Germania both during and after the Romans actually shows that in many instances, the 'tribe' is not a primary political actor. Instead, you see groups of warriors who between tribes enter alliances or confederations, or who fight amongst themselves within what should be a homogeneous tribe. Similarly, a tribe does not have a single leader, but rather a 'class' of 'kings', seemingly aristocrats. However, it is unclear what the role of this class of rulers is in tribal organisation: do they really have power over a tribe (and limited to the tribe), or are they only concerned with certain aspects of society (warfare, defending against foreigners, perhaps guaranteeing traders, or simply giving the local youth something to do so they don't stir up trouble).\n\nThe old view, that tribal units in some way correspond to cultures (people with certain distinct habits, which should be visible in material culture, ie. archaeological artefacts), is still used by some, but in my opinion too flimsy to really hold water, once you look into the actual data that these people use to support their ideas.\n\nSo if it's not as simple as 'tribe=army', nor 'tribe=culture', then how can we distinguish the boundaries between the political entities within Germania? There are basically two ways. One is to look for natural boundaries between settled areas (in German called 'Siedlungskammern', or a settlement area). In some contexts, this can be very useful. The boundaries of the tribal units in Sweden, such as the Svear, are very nicely reflected by the edges of settled area surrounded by unsettled woodland. Similarly, the absence of settlement (and the inferred presence of woodland) has been used with some success in Southern Jutland to identify boundary areas. However, within Germany (and the rest of the North European lowland area) this is more difficult, as most of this area would have been settled in some way, without clear empty zones between settlements. Especially within Denmark, for example, no natural boundaries can be seen, as all arable land was in contiguous use (though there are differences between landscape types, so grazing-lands are different from arable land or coastal zone). Similarly, islands (such as the Danish islands, but also the insular marsh area of the Netherlands) have so many 'natural boundaries' that assuming they all are tribal boundaries is problematic.\n\nA second way (and the one I use in my PhD project) to see boundaries between political units (which I here call 'tribes' in Tacitus' sense) is to look for who was employed in infrastructural works. The assumption here is that you don't work for something to which you don't have a motivation to use, that is, you won't build your neighbour's fences for him. So every politically independent unit would built its own fortresses and fortifications, possibly between or in an offensive location in relation to their 'enemies' (and hence the different tribe). Tacitus gives a good example of one of those when he describes that during Germanicus' punitive campaign, Arminius' confederation of the Cherusci retreats at a wall built between the Angrivarii and themselves. While this wall has not been found yet, there are a number of other 'walls' (linear earthworks, long barricades etc.) thoughout Northern Germany and Jutland, but also in Southern Sweden. Similar structures are also built by the Saxons in Britain, and they are still (or again) in use in the Medieval period as well. Offa's Dyke and Danevirke are two examples built in the early 9th and late 8th century respectively, and both explicitly built to separate one ethnic/political unit (the 'Danes' in the 10th century and the Mercians in the 9th) from another. It is remarkable that the Romans seem to adopt this habit of building long earthworks in the 2nd century in Scotland, where Hadrian's and later the Antonine walls are similar parallels.\n\nHowever, the closer we study these earthworks, the more problematic it is to simply classify them as tribal boundaries. When we do apply the previously mentioned archaeological criteria for distinguishing tribes (contiguous settlement and differing material culture), these earthworks seem to be located right in the middle, not between, these tribal areas. Similarly, if you would expect these earthworks to be boundary defenses, they should be in relatively marginal areas, away from other things. Instead, we consistently find them barring busy traffic routes (roads, river crossings etc.), and also in landscapes with significant other prehistoric monuments (mostly bronze age burial mounds, because they were also built near roads continuously in use since that time). If we then take a look at how people like Offa or Hadrian or Antonius Pius used these walls, we get a different picture. Rather than being boundary/frontier markers, these structures are used by foreign occupiers to divide a tribal unit, and to control traffic (and communication) between allies within a political group. \n\nIn my own PhD project I try to look at other fortifications than the linear walls, such as hillforts, to see whether these have any relation to what we recognise as tribal areas.\n\nSo then what archaeological evidence do we really have left to identify tribes in Germania? Not much, so we should reevaluate what exactly is meant with this term. It seems that tribes are not really meaningful when talking about the division of the general population in the Germanic world, but rather only seem meaningful in certain context: primarily, when groups organise themselves for war. A tribe then collects around a particular leader (or a small group of leaders). This might be why so many of the tribal names, when we look at them etymologically, seem to refer to some warlike activity ('the smashers', 'the howlers', 'the spearmen'). The tribal unit seems to have been a term reserved for armies that could be activated when there is an opportunity for them, either in a situation of defense (when there are foreign invaders) or an opportunity for offense (when people go on a campaign). This is also an explanation for why tribal names seem so inconsistent over the centuries, or why tribes move around so much, or why sometimes names refer to different organisational scales: the tribal name seems to have been flexible, and can arise, disappear, slumber, or be invoked when there is a political opportunity.\n\nAs I said, the academic consensus about these things is changing, with old authorities like Ulf Näsman or Peter Heather being representations of the 'old' tribal definition, and Chris Wickham or Guy Halsall proponents of the 'new' idea.", "In anthropology we use the word tribe in certain contexts but it is a HUGE debate as you might imagine. \n\nSo first, there is a technical definition that shows up in every introductory textbook. For example, just grabbing an intro text at random from my shelf I got *Cultural Anthropology* 3rd Edition by Nancy Bonvillain, which is from 2013. So fairly recent. There is a whole section dedicated to tribes with this as its definition (I'm going to condense it a little):\n\n > Tribes: Societies with some degree of formalization of structure and leadership, including village and intervillabe councils whose members regularly meet to settle disputes and plan community activities. Tribes differ from bands in the degree of structure and organization contributing to group cohesion and community integration. Tribal societies may have more formalized organizational procedures than those found in bands.\n\nIt goes on to point out that subsistence patterns, environment use, and size vary quite a lot. But there are some cross-cultural similarities for this category: groups come together periodically for rituals, trade, festivals, etc. Kinship is usually unilineal (patrilineal or matrilineal) and social inequality may arise often centered around family ownership of resources. Non-kin society associations are often important which provide ally groups outside the kin group. Confederacies are at times created. And age grades/sets can become important. \n\nIn general, the textbook definition is fairly vague so that they can include everyone from the Cheyenne of the Great Plains to Scottish clans to Berbers to Dani of New Guineau. And it is arranged in relation to other social group formations. In this sense, we can see the influence of early anthropological attempts to classify the ways that different societies arranged themselves and, historically, find a lineal progression. While the progression portion is highly modified/adjusted and is no longer about some end goal it is still hard to understand tribe without looking at band and chiefdom. It is also still not a terribly precise term.\n\nSecond, the influence of historical attempts at classifying groups has led to those groups self identifying as being part of a tribe (or not) even if their contemporary situations would no longer qualify them as such. Tribe has become a symbol and a term for claimsmaking, (de)valuing, and drawing borders. In the past and even today it is sometimes lobbied at groups to indicate they are backwards or lesser than in some way. This makes identifying and describing communities using the term quite problematic at times. There was a period where anthropologists avoided the term as best as possible, but that could at times mean we were avoiding a term that our research groups preferred to be called. Now, cultural anthropologists working with contemporary groups tend to use the term only when the groups they work with self identify as such. Of course this leads to other interesting issues such as the Mardi Gras Indians, who are members of the black community in New Orleans who practice an Afro-Caribbean parading and secret society cultural tradition but do so as \"tribes\" with chiefs and self identify as \"Indians.\" The positioning, cultural politics, and performance of a black Louisiana man singing \"Indian Red\" and initiating a song battle with another \"tribe\" of black Mardi Gras Indians is complex and fascinating and damn difficult to explain to outsiders at times (as is the tradition of black New Orleanians painting their faces black and dressing in stereotypical \"African\" garb for Zulu.) How do you talk about cultural appropriation that is old, deeply sacred, and symbolic of a community in a useful but sensitive way? And how should you use the term \"tribe\" - quotes or no quotes? qualify it or not? explain it or let it stand as is?\n\nEdit: A good example of how complex this can get (and which doesn't violate our 20 yr rule!) is looking at works like this: \n\n* Lovett, Laura L. \"\" African and Cherokee by Choice\": Race and Resistance under Legalized Segregation.\" American Indian Quarterly (1998): 203-229.\n\nwhich explore how Native American-ness was appropriated by and claimed by many African Americans in a variety of ways for a variety of reasons. Mardi Gras Indians were just one such example, but because they are sacred the terms and usage are much more sensitive all around. I can give reading suggestions there too but I'm afraid most aren't historical or written 20+ yrs ago." ]

[ " > GRU Defector Stanislav Lunev said in his autobiography that \"the GRU and the KGB helped to fund just about every antiwar movement and organization in America and abroad,\" and that during the Vietnam War the USSR gave $1 billion to American anti-war movements, more than it gave to the VietCong. Lunev described this as a \"hugely successful campaign and well worth the cost\". According to Time magazine, a US State Department official estimated that the KGB may have spent $600 million on the peace offensive up to 1983, channeling funds through national Communist parties or the World Peace Council \"to a host of new antiwar organizations that would, in many cases, reject the financial help if they knew the source.\"\n\nThis is from his book: Through the Eyes of the Enemy: The Autobiography of Stanislav Lunev\n\n[Wikipedia](_URL_0_)", "The FBI has the VENONA transcripts, most/all of which are available online. Also check out the work of Frank Cain and David McKnight who are Australian historians who studied communist espionage and anti espionage in Australia, Britain, America and I think Europe.\n\nAlso have a look at the COMINFORM as it is often described as little more than a spy and foreign command structure. I think Earl Browder was also found to have been a spy for the USSR so look him up too.", "I don't believe the KGB worked through the CPUSA after the 1940's. Throughout much of the history of the Cold War, the FBI kept EXTREMELY close tabs on them, and practically every known member had a huge file on them. Much of their movements were tracked, they were regularly wiretapped (often illegally), and couldn't sneeze without a Fed handing them a handkerchief. \n\nThe KGB, who were FANTASTIC spies, I mean really really good at their jobs, to the point Stalin knew just about everything about the Manhattan Project outside of how to actually build a bomb, would not have been so careless as to use the CPUSA as a front. They more than once I'm sure used them as patsies and decoys, but never would have used them as direct spies or worked with them at any point after the 1940's. The Cold War was to hot at that point, and J. Edgar Hoover had to much of a free hand to act how he saw fit.\n\nAfter the 40's, much of the espionage carried out in the U.S. was done on individual levels and usually run from the KGB directly through handlers.", "I suspect you've seen it, but [Wikipedia's Summary](_URL_0_) is a quick read, and is a fantastic hub for finding related reading." ]

[ "Most people close out of torrents as soon as they're completed. By remaining as a peer with a large percentage of the file completed, the torrent is \"healthier\". Also, you're in a queue for a very specific sequence with few peers able to service the request, who also have many other requests to fulfill.", "Torrents download files by downloading small pieces of the files in your download. Seeders host many pieces on their machines for download.\n\nWhen your download starts, any piece of the torrent available can be downloaded. As the torrent goes on, it's seeking more and more specific pieces instead of being able to download almost anything that is available.\n\nAlso, over time as the torrent is seeded and leeched, some pieces become more common than others so there's a smaller pool of peers for some pieces. Not all peers who are seeding have 100% of the file, many are waiting on the less common pieces.\n\nWhile most clients download in a random order or just what is available, some better clients attempt to download the rarest pieces of a torrent first, but over time will still slow due to the search for specific pieces.\n\n[How torrents work](_URL_0_) \n", "The answers so far are no more than partly correct. There *is* a real effect caused by a lack of 100% seeders, but it's not the main effect in play here. You don't mean a gradual slowdown, like in the last 10-20%, but rather your DL rate cutting to almost nothing in the last 0.25-0.50%, right? I know what you mean. \n\nUsually, when you're downloading, you're getting chunks from peers at a *lot* of different speeds. One peer might be sending you chunks at 2mbps, one at 500kbps, and 3 at 10kbps each. Now suppose you're in the last 1% of a download, and you're downloading all the remaining chunks at once from these peers. The chunks from the fast peers finish quickly, and you're left with just a couple of chunks from the slow peers - and so your download rate slows dramatically. \n\nIn theory, a client could just drop the chunk from a slow peer, and download it again from one of the fast ones, but I don't think any of them do this and it's considered a bad practice - I could see it messing up the ratio tracking a lot of trackers do. ", "Torrents let you download from multiple sources, some send you parts of the middle, some from the end and so on. When the File is almost done, usually some sources have sent their part faster and the remaining bit isn't large enough to establish new connections, so you have only one or two slow sources left. This is why the speed decreases in the last seconds.", "Picture passing around the pieces of 1000 1000 piece puzzles in a group of 1000 people. Some people have a complete puzzle, and others are still collecting pieces. \n\nAt the start, you have nothing and so literally all 999 other people can give you stuff and you'll fly through the first percentage points. Eventually though you'll reach a point where if 900 of the other people are also still working on the puzzle, you will start looking for pieces many people don't have. That's okay, there's a hundred or so people that do have that piece, but they are also helping the other 900 so you need to wait in line. Eventually all you have left is those pieces that only the 100 people have and there's 900 people standing in line. You'll get them, but it is just going to take a bit longer." ]

[ "The more active an animal is, the more energy it requires.\n\nThe more energy it requires, the more food it must consume.\n\nThe more food it must consume, the more they have to salvage/hunt.\n\nThe more they hunt, they more chances of them being injured from the hunt/the more they salvage, the more chances of them being hunted.\n\nThe more chances of them getting hurt, the more chances of them dying.\n", "- Sleep is the period during which the body and brain rest and process things. This is an important thing for both body and brain, as we quickly notice ill effects when we do miss sleep. \n\n- Sleep is also a period during which an animal moves less and therefore uses far less energy. That is a good thing. Energy conservation is an important thing for many animals, especially the ones that are not always going to be able to obtain new food. An animal that is constantly awake will need a hell of a lot more food which is not in that animal's best interest. \n\n- And finally, evolution is not about creating something perfect. Evolution simply occurs via random mutations. There is nothing controlling those. Even if something is 100% an advantage, that still doesn't mean a random mutation has to occur.", "Evolution doesn't work that way. It's not directed. It's a series of *random mutations* which, if beneficial, have a *slight chance* of passing over to the next generation and then a *slight chance* of becoming permanent. And this all takes place over *tens of thousands* of years *or more*. \n\nAs for cats, their ability to sleep that long, and thus conserve energy for hunting, is a huge advantage. \n\nAlso, it should be noted that many organisms (even some mammals) have developed some interesting ways of sleeping, wherein only *half of the brain* sleeps at a time. Dolphins, for example, do that. ", "Because it is more advantageous to have bursts of high energy follower by periods of rest than to have sustained moderate energy use without rest, at least for most animals but especially hunters.", "Evolution requires generations of specimens without that trait to die and have fewer offspring. Nobody is dying from lack of enough sleep, so there's no evolution of the species that require less sleep", "Article: Why Do Humans and Many Other Animals Sleep?\n\n_URL_0_\n\n\nTL:DR; Scientist don't know why we sleep, many animals don't sleep, humans sleep to prevent the following: impaired memory, reduced cognitive abilities, mood swings and even hallucinations (after long periods of no sleep)" ]

[ "Very simply, we have potential and kinetic energy. You have a car up a hill and the breaks are engaged, this car has potential energy. You release the breaks and the car runs down the hill and hits a tree, this is converting potential to kinetic. \n\nTo store \"power\" with the car example, you simply push it up hill and turn on the breaks. \n\nWe store electricity by transforming it into potential energy in the same way. \n\nFor day to day usage, we store electricity via batteries. This is done by turning electric energy into potential chemical energy. \n\nThe standard battery looks like this. \n\nCathode + \nElectrolyte \nAnode -\n\nElectricity wants to flow from the anode to the cathode but cannot due to the electrolyte blocking it. Placing this battery into a device completes the circuit and allows electrons to flow from the anode, through the device and into the cathode. This in turn powers said device. \n\nBut batteries (chemical energy) represent a very small proportion of how energy is actually stored on a societal scale. For that we use pumped hydroelectric storage. \n_URL_0_\n\nWe essentially use electricity we have now to pump water up into a reservoir. This \"stores\" the energy, when we need said electricity, we simply allow the water to flow via gravity through turbines which can generate power. \n", "_URL_0_\n\nSimple terms, its a hydroelectric plant that fills its reservoir with pumping.\n\nWhen demand is low such as overnight the turbines pump water up and when demand increases such as needs for air conditioning in the hot afternoon hours the water comes back through under gravity and provides some extra megawatts for the grid to cover peak load needs.", "While there are many ways to \"store electricity\", most of them don't store electricity directly. This is only useful for very small amounts and a very small time and not feasible for real power applications like buffering solar and wind power fluctuations.\n\nInstead, electricity is converted into another energy form, stored as such, and then converted back. And there are numerous ways to do this:\n\n* Batteries turn electricity into chemical energy while loading, and chemical energy back into electricity when unloading.\n* Water reservoirs are used to pump water uphill when electricity is cheap, and lead through turbines when it is needed.\n* There are plans for hydraulic storage, where water is pumped into an underground cylindrical room with a large and very heavy piston on top of it, and the pressurized water can generate power when run through a turbine again. Basically the water reservoir idea for flat landscapes.\n* Another short term electricity storage system used to e.g. cover the gap between a power outage and the starting of the generators are flywheels. Energy is stored as rotational energy, and the motor can be turned into a generator by the flick of a switch. The flywheels have magnetic bearings and are vacuum sealed to reduce friction losses.\n* In California (IIRC) they turned an old mining railway into an electrical energy storage system. When power is available, a locomotive pushes a heavy train up a steep track leading to an abandoned mine, and when power is needed again, the train rolls back down, using its engines as generators." ]

[ "_URL_0_\n\nOriginal look", "On a similar note, how can people change their arrows to something else? Like a circle or something. I've seen it before and just assumed it was, like with all technology, magic of the dark arts.", "I always assumed it was so it wouldn't block you from seeing what you're clicking on... as much." ]

[ "The brain isn’t a computer. neurons aren’t switches. We don’t really understand how it all works.", "Let’s start with what a “digital” recording is. You may store a picture in a digital medium - this requires something called “encoding” in order to make computers understand what they’re looking at in order to display it. A simple example is a map; let’s say you wanted a picture of a checkerboard. You could encode this as an 8X8 grid, with (say) the number 1 for white and the number 0 for black, ending up with something like this:\n\n1 0 1 0 1 0 1 0\n0 1 0 1 0 1 0 1\n1 0 1 0 1 0 1 0\n0 1 0 1 0 1 0 1\n1 0 1 0 1 0 1 0\n0 1 0 1 0 1 0 1\n1 0 1 0 1 0 1 0\n0 1 0 1 0 1 0 1\n\nThe computer reads this information and draws a white square every time there’s a “1” and a black square when there’s a “0” - at the end you should have a checkerboard pattern that you recorded. Congratulations, we have “encoded” then “decoded” a simple image!\n\nNow that was a very simple example, normally you’d have to encode all kinds of shapes, colors, and in the case of video, many pictures in sequence (24-120 a second), each with their own shapes, colors, and values. In the computer world, this makes encoding much more complicated, and so you need special programs installed to see recordings of videos and such. If you ever used a computer and saw that you “need a codec,” this is what they are talking about - “codec” is short for (en)code-dec(oder). \n\nWhew, ok but what about human memories? In fact, you can get a sort of “map” like the above in a very specific part of your brain: your eyes (yes, there are parts of your eyes that are considered to be part of your brain! Fun fact.). Light enters your eyes and the image of what you are looking at is projected onto what’s called the “retina” which is just rows upon rows upon rows of specialized brain cells that “encode” much like we did with the checkerboard example above. However, if you think about it, this isn’t a memory. The memory is formed when this image is conveyed to your brain, where it undergoes a much more complicated, biological “encoding” much like more complicated videos that have to have special codecs on computers for recording or viewing. When others say we don’t understand how the brain works, this is part of what they mean - we don’t know enough about the biological “codec” that stores these memories.\n\nSome more fun things to think about is that the way we store memories isn’t purely visual; we store memories in multi-sensory ways, which means yes, we remember what we saw, but also what we smelled and heard, what we touched and possibly tasted. We also store along with that some less obvious things, like what we felt at the time, what it means, etc. A cool part about a human memory is that it’s kind of a self-contained model of the world that’s NOT just a image - you can easily change some details of the memory and still have it make sense. You can extrapolate what might have happened if things did not occur as you remember them. Example, let’s say you had a cheeseburger with your friend Mark the other day. You can imagine what would have happened if you had a chicken sandwich with Mark instead (provided you’ve ever had a chicken sandwich). Moreover, you can imagine a lunch with an entirely different person, at a different location, in a different context - and your brain will pull from other memories, or even stored abstract knowledge to help you fill in the details. Think about what daydreaming entails. What fantasizing is. It’s no small wonder we have trouble figuring out how our brain stores this stuff because it is, on a very basic level, so very different from what stored “data” on a computer is. At best with very large, high-quality computer files, our codecs let us store a large amount of video/audio data in an efficient amount of space; in our brains, every last item within a memory is linked to other memories, ideas, and concepts the extent of which we have only begun to discover. \n\n(That said, we’ve made some huge leaps that sometimes get us very blurry images of things that we have seen in the past... but only really in cases where we already know what to look for and with the aid of repetition on trained algorithms that absolutely would not work outside of a lab setting - but I’ve already done and awful job of ELI5 so we’ll just leave it here)", "We don't understand how memory is stored in the human brain.\n\nEven if we did, we don't understand how to build devices to electrically \"talk\" to the brain and extract the memories.\n\nEven if we did, the process might be too dangerous for healthy humans.\n\nThis tech is probably at least 100 years away from being practical, although that doesn't stop Elon Musk from [trying](_URL_0_)." ]

[ "Follow-up question: what exactly is the standard for translating names in academia? I've seen it done all different ways (for instance, I've definitely read published papers where Charles V is written as Carlos V, and my grad profs have never complained as long as I'm consistent. Is there a resource that outlines the conventions for this?", "In earlier times it has been more acceptable to translate the names/nicknames of foreign rulers. It's not just Dutch that does it, either - look at the names of the Eastern Roman emperors in English, for example. Not all of them are localized, but in English you'd use Basil, Constantine, John, Michael etc instead of the original Greek names.\n\nTranslating proper names has been studied quite a bit and it's a pretty relevant question in translation studies, specially in the field of literary translation. There are different ways of doing it, too. For example, in [this](_URL_0_) paper (which actually focuses on translating names in children's literature), the author names names conventionality as one of the possible translation strategies. In his own words:\n > This final procedure occurs when a TL [*target language*] name is conventionally accept ed as the translation of a particular SL [*source language*] name. It is commonly used with names of historical /literary figures and geographical locations. \n\nIf you're looking for examples, the Finnish names of any historical figures provide plenty of them. The Finns have a thing for localizing everything and it really seems like they do it more than most other people (though it's partially caused by the Finnish alphabet typically having one letter per sound). They speak of *Arkhimedes*, not *Archimedes*, and *Rikhard I Leijonamieli*, not *Richard I Lionheart*.\n\nThe same thing happens with geographical names. Languages tend to have different names for locations/nations they're more familiar with, because the names were adapted to the target language and culture. A great example would be the many names of Germans in other European languages.\n\nI guess in modern times it's usually assumed that the recipient knows enough of the topic to recognize foreign names and associate them with the correct people/places/etc. Nowadays people tend to value accuracy over sounding nice in the target language." ]

[ "Because the most visually appealing clothing are small sizes. It caters to the hopes and aspirations of people who wish to be thin. They visualize in their mind how appealing the clothing looks on a thin person, even though they will choose the XXXL size when they buy the product.", "They do it with shoes and bras as well. \n\nMy size four shoes should be at the bottom where I can get at them dammnit." ]

[ "Human life isn't impossible in Pripyat. It's just not necessarily advisable, since you would experience a potentially increased risk of radiation-linked ailments like certain cancers. The overall background radiation in the region is not 'immediately human destroyingly' high.\n\nEdit: To more directly answer your question: In the same vein, heat can destroy human dna and make human life impossible. But what matters is *how much heat.* Not just any amount of heat or radiation is immediately destructive. You are *always* exposed to radiation, every day. But your body can generally handle low amounts. ", "Radiation is energy traveling in the form of waves or particles. All life is constantly exposed to radiation. These waves and particles are very small (smaller than atoms) and have the potential to strip electrons from other atoms (called ionization). This ionization of atoms is what ultimately can cause damage to biological systems.\n\nRadiation dose is measured in a unit called the \"rem\" which measures risk. 1/1000 of a rem is a milli-rem or mrem. People are exposed to about 1 mrem of radiation every day from background sources which include radiation from sources in and on the earth and radiation from sources from space. There are two types of risks from being exposed to radiation. Deterministic (if you receive a radiation dose on your skin of 200 rem you **will** get a burn) and Statistical (if you receive a radiation dose of 1 rem you increase your chances of contracting cancer in your lifetime by 0.08%).\n\nin order for radiation to cause damage to biological systems a **huge** number of ionization's must occur to the atoms in a cell and that damage must be damage that is unable to be repaired by the cells natural repair process. \n\nThe potential for damage is also dependent on the type of biological system being exposed. Rapidly dividing cells are more sensitive to radiation exposure. So a developing fetus is much more likely to suffer from radiation exposure than an adult. Your reproductive cells are more likely to be damaged by a radiation dose than your nerve or brain cells are. Trees, flora in general, are not rapidly dividing and are not complicated systems. You can physically cut a chunk out of a tree and it will repair and survive. You could shoot a bullet through a tree and it will repair and survive. \n\nI looked up some of the exposure numbers at Pripyat and, in 2009, the exposure rate, at the highest level, was about 1 mrem per hour. So spending 5 hours at this level would be about the same as the excess radiation dose you would receive by flying from New York to Tokyo. And people do that all the time without worry.\n\nAnother factor is that the statistical increase in your odds of contracting cancer increases as you grow older. Animals in the wild may have an increased chance of contracting cancer as they grow older, but they have a much lower life span, in effect making the cancer odds irrelevant. \n\nEverything I've said is with the assumption that the radiation exposure is external to your body. Ingesting, or breathing, something radioactive deposits the radioactive material into your body where the radiation can irradiate the cells around the deposition for a long period of time. The risk involved from an intake of radioactive material is much greater than the risk from being exposed to the radiation outside your body. That is why researchers who enter these areas will take precautions to prevent intake while simultaneously being much less concerned about the radiation dose from external radioactive material.", "Pripyat is a bad example. Human life isn't impossible there, but they were forced to leave. Some people did stay. Also, animals survived there just fine.", "It might be relevant to point out that a swath of trees did die from the radiation at Chernobyl. \n\n[Red Forest](_URL_0_)\n", "Not impossible - humans could live in Pripyat. What would happen is that they would have much higher rates of cancer, and more birth defects. But if people lived there, had kids and whatnot and just ignored all the additional cancer and birth defects, the population would increase - because even if you have a ton of people dying from cancer from age 35 and up, there is still plenty of time to breed. ", "As someone that works in a nuclear field (uranium enrichment) I haven't seen the specific reason why trees aren't hurt as much by radiation. /u/drewal79 has a good answer about why cancer doesn't affect trees as drastically. My answer explains why tree cancer is unlikely in the first place.\n\nIt all boils down to how quickly the cells divide (plants have a relatively slow growth rate/metabolism compared to animals). The slower the division, the more resistant to chronic exposure's effects. All cells can suffer from a large, immediate exposure to radiation. What is happening in these contaminated zones is low level chronic exposure.\n\nThere are three basic results from any exposure:\n\n-Immediate cell death\n\n-Cell sterilization\n\n-Cell damage that can be translated during division (cancer)\n\nThe likelihood of these results depends on the type of radiation (ionizing is the worst) and the energy level of the radiation (higher is worse)\n\nSolar radiation causes cancer using these same principles. Severe sunburns are similar to severe radiation exposure (except high energy exposure will penetrate deeper).", "The radiation break down DNA, so it effects cells that rapidly divide the most, aka ones replicating that DNA. Tree cells do not rapidly divide. ", "Most of these answers are incomplete. You, and many of the people answering your question, are confusing *radiation* (which generally comes in 3 flavors, alpha, beta, and gamma) with *radioactive material* (which generates the 3 kinds of radiation).\n\nWhen Chernobyl exploded it dumped massive amounts of radioactive material, or fallout, into the surrounding environment. That radioactive material is composed of unstable atoms which gives off alpha (high energy helium nuclei), beta (positrons), or gamma (high energy photons) radiation. That initial burst of fallout was so radioactive (that is it emits a large amount of radiation) that anything, be that animal, plant, or human, coming into contact with it was likely to get radiation burns and die in a short period of time. But that fallout was spread very unevenly via wind. It has also become less radioactive with time (ie: it puts out fewer high energy particles per unit of time) as the atoms degrade into more stable, but still radioactive, isotopes. Since that material was spread unevenly, there are a lot of places in Pripyat where the amount of exposed radioactive material is very low, and thus the levels of radiation are very low. It's safe enough in those areas for plants, animals, and people to live pretty much normal lives. There are other locations with high concentrations of fallout. In these locations, nothing can grow.\n\nThe true danger with visiting Pripyat isn't that there's a lot of radiation being emitted by the fallout there. The danger is in breathing in or ingesting that fallout. If you get radioactive material into your lungs or intestines, it's like placing a tiny atomic blowtorch there. Larger pieces (say the size of a grain of sand) can actually burn through your tissue. Smaller pieces (a fleck of dust, down to just a few plutonium atoms) will stick in your body and deal damage consistently over time as the atoms degrade over and over again. These smaller pieces of fallout will cause cancers.\n\nAnd that last piece is why radioactive fallout is more dangerous to you than it is to a tree. You have lungs. You have intestines. A tree doesn't. A tree doesn't have large cavities inside itself where lots of air, or food has the chance to deposit some bit of highly radioactive material. Trees also don't move, so if they weren't exposed to fallout in the initial explosion, or by the early contaminated winds, they're unlikely to have been exposed later. That means that in locations with low concentrations of fallout, plants have been able to grow quite well in the past several decades.\n\nNote that trees *do* take in significant amounts of water, and that water can have fallout suspended in it. That fallout can then be deposited into the bodies of the plants. This will kill some plants, while others are relatively unharmed. This was actually a vector for the irradiation of humans. Many people drank milk contaminated with fallout (radioactive iodine in this case) which was milked from cows which had eaten grass downwind of the Chernobyl disaster. That resulted in an increased incidence of thyroid disease in that population." ]

[ "It is to stop the bruising, vaseline was used to stop the bleeding and protect the cuts but now they use a chalk like stick which looks like its metal.\n\n\n-_URL_0_\n", "Some use blades to release the blood pressure which reduces the swelling.", "Fighter/cornerman here:\n\nThat is a knot-knocker.\n\nAs was said elsewhere, it is used to reduce swelling. It is kept cold, and the combination of cold and pressure can help reduce, or least stall, swelling. Swelling is dangerous because it can reduce vision, and when you cannot see, then you cannot defend well.\n\nA typical cornerman bucket has two sides--a dry side, and a side filled with ice. \n\nThe bucket is prepped an hour or so before the fight, and the knot-knocker is placed in the ice to get really cold (we keep the water bottle on the cold side too).\n\nThe dry side will have vaseline, q-tips, coagulants (when allowed--some state athletic commissions do not permit the use of coagulants), and random other stuff (maybe scissors, extra athletic tape, etc)." ]

[ "We are dealing with a steady state problem which is governed by a simple rule, mass flow in must equal mass flow out. Massflow is defined as density * area * velocity. In order to balance the two sides you have to tweak the values involved.\n\nSo, when you talk about a turbo jet coming out you are discussing velocity. So the other two terms are what we have to play with. You can decrease the density, but its difficult and not particularly practical. On the other hand, decreasing area is pretty easy.\n\nAs far as pressures go, you actually don't have to do anything with the pressures. The pressure on two sides don't affect each other with the sole exception of a pressure driven flow. Even in that case the above mass flow considerations apply and are usually simpler ways to manipulate flows.\n\nSource: conservation of mass in a fluid flow. ", "Mass conservation: stuff that comes in must equal stuff that comes out if nothing is being accumulated inside the system. In fluid mechanics, this is represented by density*area*velocity=constant for the intake and exit.\n\nThere are two things going on here, in order of importance: \n1. Look at the area difference between the intake and the exit. The intake is larger than the exit. \n2. Temperature difference between the two sides. The exit air is going to be hotter than the intake air. Hotter air means lower density, as the pressure at both ends is atmospheric and the composition hasn't changed (the gas constant is the same at both ends). P=rho*R*T\n\nSo at the intake density*area is larger than at the exit. To keep mass conserved (or from being accumulated inside the hairdryer), velocity at the exit must be higher than the intake." ]

[ "To a reasonable extent, houses are built to withstand the weather likely to occur in that place. In areas that have a high risk of flooding, the houses are built so they can be emptied before a flood, and hosed out and repainted afterward. In hurricane zones, homes are built to higher building standards that will survive all but the most extreme storm. But at a certain point, the cost to build the building any stronger, balanced with the inconvenience of living in a house built like a bomb shelter, outweighs the risk of damage to the house in an extreme weather event. Beyond this point, there's insurance.\n\nAs to tornados - 99% of houses in a tornado zone will never experience a tornado. Building those 99% any stronger would be a total waste. For the other 1%, they would be severely damaged no matter what you do, unless you build a concrete dome that no one would want to live in. So they build a shelter to keep the people safe, build a normal house, and for the rest, insurance.", "Too expensive.\nEven if the house survive the disasters it would likely cost more to repair safely the damage than building another cheap house.\nAnd what if you build tons of nice eartquake proof house but no earthquake happen ? Waste of money.", "I like the tank analogy, why don't you ride a tank around instead of a car? Because it is expensive and inconvenient." ]

[ "It's both.\n\nPeople who are mentally challenged, suffer development issues, etc are kind of predetermined to an extent. \n\nMost people who are 'dumb' could be smarter. But it takes studying and effort, practice. \n\nOf course some people are savants, genius, and are more likely to be intelligent. But that can be squandered by laziness or disadvantage.", "The intelligence quotient (IQ) is based on one of the most common concepciotn of intelligence that divides it into two entities: fluid intelligence and crystallized intelligence.\n\nFluid intelligence is believed to be majorly determined genetically - it's your cognitive potential i.e. pattern recognition, spatial manipulation, algorithmic processing etc. (good nutrition in early years is supposedly able to slighty enhance this type of intelligence). But in general you are stuck with what you get.\n\nCrystallized intelligence is acquaried . It's knowledge - things you know. And this isn't so easy either - one learns faster, another slower. One is more determined to keep learning others are less. Those qualitative differences that influence how much knowledge you will acquire are dependant on many genetical and environmental factors. Hoever free will can make the biggest difference here.\n\nHaving both types of intelligence at a high level is being considered as being smart.\n\nPlease mind, that this explains cognitive abilities only in the realm of \"things\". The other realm is considered to be people - here emotional intelligence playes a much bigger role. And it's a different story.\n", "Intelligence is a result of biology and personality.\n\n & #x200B;\n\nOn one hand, you can say it is how fast a person learns. This is due to the brain's ability to retain and process information. This can be genetically and biologically influenced.\n\n & #x200B;\n\nOn the other hand, you can say intelligence is how much a person knows. Given enough study time, most people can learn anything. It's a matter of how much effort, discipline, access, etc. This is mostly a result of habit, personality, and environment.\n\n & #x200B;\n\nSo when you get the ultimate combination of ability and environment, you get some crazy smart people.\n\n & #x200B;\n\nBut you also get crazy smart people when you have less than optimum genetics but highly focused and dedicated effort.\n\n & #x200B;\n\nInterestingly enough, you tend to see a balance between these two factors. People who are biologically gifted find school easy, so they tend away from focus/dedication/discipline and later in life may be discouraged from intellectual challenge. The opposite is also true. So a person generally benefits an outside intervention - such as parents and teachers who nurture a gifted child to greater potential.", "On top of what others have said here explaining a genetic basis and environmental basis, I would also like to note that the acquisition of information is somewhat a compounding process, like a snowball rolling downhill. If you know more things, it becomes easier for you to learn new things by making connections with things you already know. Therefore, the more things you know, the faster you can learn new things, thereby increasing the amount of things you know, which increases the rate which you can learn (up to a point of course). So often when you hear stories of incredibly gifted or intelligent people, it is reported they displayed signs like this since an early age. This could just mean that some people begin learning earlier, and have had more time to compound their intelligence (which can have genetic and environmental components influencing the pace with which your brain forms and its resultant structure). It is true that when you are a child, your capacity to learn is much higher, meaning that time put into learning as a child is likely to have a higher payoff than time spent as an adult. The adult brain still has a great capacity for learning, however. \n\nFor this reason, I have always held the belief that the only bad time to practice learning is never. Every day that you learn new things you are increasing your ability to learn more things tomorrow, and the earlier you dedicate your life to learning, the greater you will maximize your intellectual potential. It is just like a savings account. If you don't have one, you will never accrue interest, and delaying having one only reduces the total interest you could have theoretically compounded on the account. ", "This has been tested thoroughly over the years, especially by the military. They have learned that no amount of training will make a person more \"intelligent\". But you can train a person of average intelligence to do certain specific jobs very well. So anybody can still grow and learn, but you will likely never increase your IQ more than a point or two. ", "In general, you can predict someone's adulthood intellectual capabilities with reasonable accuracy before they even enter school.\n\nThere are some impediments that can make otherwise smart people *seem* dumb, though. For example, deaf or blind children have a hard time demonstrating their intelligence in many cases. The underlying intelligence is there, but people are looking at the wrong things when they check for it.\n\nIn terms of the implied nature vs. nurture issue, it's both. You are far better at learning as a child than you are as an adult. So when it comes to certain foundational types of learning, a failure to accomplish it as a child probably means you'll never be particularly good at it. The two most common examples are language and mathematics.", "One the biggest areas of very recent study is emotional intelligence. This has to do with relationships with people. Two general conclusions from this area of study are: 1. Anyone can improve at any time, and 2. There are more types of intelligence that are just as important as the one that people typically think about. There hasn't been a single case in these studies that suggests there is anyone that can't improve, even if only a little. This includes developmental disabilities.", "The answer to the nature vs. nurture debate is not clear, except both matter. Some thoughts:\n\n*You can think of it as seeds. If you take two sunflower seeds (let's say they are from the same plant with all the same factors) and give one optimal growing conditions and one terrible growing conditions, the one nurtured will obviously have superior results. Environment matters. But if you take a bean seed, no matter what you do, it's not going to be a sunflower and that's okay because we need diversity. Genetics matter too.\n\n*In the case of influential people they often had a double dose of initial intelligence passed through their parents DNA and those same smart parents providing opportunities to build their intelligence as they grew.\n\n*In general, things that happen earlier in life matter more than things that happen later. For example, good nutrition as an infant has greater effects on intelligence than good nutrition in your 40's. \n\n*Intelligence is a tricky thing to measure and define.\n\nSo in short, yes you can grow your mind, but how much is limited by innate ability, age, and opportunity. It may not be possible to reach the same heights as someone who has superior genetics and early experience, but you can certainly get somewhere. For example, I do not have an aptitude for physics I think due to natural ability and lack of interest as a child. I'm in my 30's and could certainly learn it now, but it would take significant time and effort. Practically, I could never catch up with my sister who excelled in the subject." ]

[ "A virus that is actually an image or video won't do much as images won't be executed. You will sometimes see malware that is named to look like an image or document but is actually an executable file.\n\nExcel files (and other Microsoft Office formats) can contain embedded code in the form of macros, and you don't want to run code from untrusted sources. When a file is opened in protected mode, macros won't be executed, so it should always be safe to open a file in protected mode.", "Its possible to take one program, well call it \"safe_application\", and write a new program which contains safe_application and malicious_application which runs both. The malicious one would run in the background, and the safe_application you were expecting runs fine in the foreground. This is how most trojan horses were setup. This is also why many download sites would post the md5 checksum of the program. If the program was changed in anyway, the checksum would no longer match. So you could download the program from a mirror, then run the checksum for piece of mind that it was the safe_application. As mentioned before occasionally a vulnerability in windows was found where you could actually get code to execute anytime an image or other type of executable was opened. These types of vulnerabilities are generally patched quickly though. There were a few cases where people viewed images on websites or emails and were infected way back in the day.\n\nAnother way they were commonly spread is via vulnerabilities in browsers and browser plugins (like actionscript microsofts version of javascript which had too much power).", "For offices files, such as Excel files, the format is designed to allow for executable code. Modern office programs are designed to not allow this code to run automatically, especially if the file originated from outside your computer. \n\nFor other file formats, such as an image or video, which do not contain executable code, the \"virus\" or malware is exploiting a vulnerability in the program that is used to read the file that can trick the program into executing executable code. I remember reading about an exploit in Adobe Reader (I think) that could cause Adobe Reader to execute executable code when doing the normal rendering of the file. However, if the same vulnerability does not exist in a different program that is capable of reading the file, then the malware is useless against that user." ]

[ "Frostbite or hypothermia? In hypothermia, or low body temperature, you rewarm slowly because a rapid change would put stress on the heart.", "Because the amount of oxygen (blood flow) a cell needs is directly proportional to how warm it is. When you warm someone up by putting them in warm water or in front of a fire you warm them up from the outside in. Their body's core temperature is still low so their blood vessels in their extremities will still be constricted even if you warm their hands up. Their hands are warm and need blood flow but their core is still cold and wants to conserve heat so it will still reduce blood flow to the hands which will result in more cell damage.", "When your extremities are very cold, your body restricts the blood flow to them, but at the same time, the cold also slows their cell's metabolism, almost to a stop. If you heat the area up too quickly, the cells wake up, but because they have no supply of blood, they die. Heating the frostbitten area slowly makes sure blood flow returns in time.\n\nA similar thing happens with hypothermia. Your body restricts blood flow to the surface to maintain warmth in your core. If you heat someone up too fast, the blood travels through those surface areas and brings the cold back to your core where it can damage organs.", "I’ve been frost bitten before. Putting your hands under running water feels like getting hit repeatedly with hammers. Horrible pain.", "Weird, now I'm wondering if I believe an urban legend. I was taught it was because frostbite is frozen tissue and ice crystals at a cellular level can cause havoc. So you thaw out the frostbite so it melts rather than having jagged crystals moving. Some cells rupture from water expansion while freezing and without the ability to move anything your body can't repair or mitigate freezing damage." ]

[ "Yes, epic waves are possible. The Lituya Bay tsunami was estimated to be several hundred meters tall.\n\n_URL_0_\n\nThis doesn't address the original question though of what the physical limit on the height of a wave might be.", "The limit of wave height is the depth of the ocean underneath it. A wave breaks when the bottom can't match the top i.e. the wave is symmetrical below the water, and the bottom hits the seabed.\n\nIf throw a pebble into a lake, you get a splash - which isn't a wave - and after that, waves form." ]

[ "I think the increase in variables from having captalisation is far greater than the loss in variables of knowing that at least one letter must be capitalised. Without the requirement, the vast majority of users would use no capitalisation at all in a password, making it much easier to crack.", " > By making it essential to add a capital letter to my password, doesn't that narrow the amount of options a hacker has to go through to get my password?\n\nIn theory, yes. But in practice, you'll find that on a side that doesn't require you to have a capital letter most people will not capitalize any letter in their password out of convenience - and those that do may put more effort in creating a hack-proof password anyways and are not really the main target of hackers then.\n\nSo then you have the scenario where a hacker just needs to search through all uncapitalized passwords instead - which is a much more narrowed down set than any passwords with at least on capitalized letter.", "On a website that allows capitals but doesn't require a capital, the hacker will try all possible combinations, but they will prioritize their guesses based on typical password patterns. \n\nIf you split the set of all possible combinations into two groups. The first has no capitals and the second has one or more capitals, that second group is much larger than the first group. \n\nIf the hacker knows capitals are not required then they will prioritize their guesses to the group that doesn't have capitals. Given the low likelyhood of users to use a capital if not required, the hacker has a good odds of finding the password in that first smaller group.\n\nRequiring capitals does eliminate that first group, but the much larger group still remains and now the hacker has lost the ability to prioritize. This makes the odds that the hacker will find the password earlier in the search much less.\n\nOf course this brings up a great point for sites that allow capitals but don't require them, a user increases their security by having a capital in their password because they are now in the set that isn't prioritized. \n\nBasically anything a user does in their password that is different from what most other users do will decrease the chance their password is cracked.\n\nBut cracked passwords aren't the only way in. It's best to use strong passwords that are changed often. (+ two factor and password manager etc etc)\n\n\n", "Because trying to crack your password means trying all different combinations of letters from A-Z, numbers from 0-9 and symbols. If you add capital letters, that makes two sets of letters from A-Z, those in lower case and those in upper case. It essentially makes it much harder to crack your password." ]

[ "The air is applied to a large gasket that pushes on an acutator rod. That in turn pushes a lever attached to a rod that goes into the brake drum, the rod has a double ended cam shaped like an S that forces the brake shoes into the drum", "Air brakes are essentially regular drum brakes on steroids. Disclaimer: I’m an auto insurance adjuster, not a mechanic or engineer. I know the systems; you may not get the perfect technical language but I’ll probably describe them in simpler language. The way a drum brake works is like this:\n\nImagine that you have a cup, like a regular cup for drinking. Stick your hand into that cup, but not enough that you can’t turn it. Now imagine that cup is spinning quickly and your hand is just hanging out in there not really creating any friction with the inside walls of it. Now imagine that you form a fist with your hand and the friction between your expanded fist with the inside of the spinning cup causes it to stop spinning. \n\nIn this analogy the cup is the Brake Drum. Your hand is the Brake Shoes, and the actual skin on your hand that makes contact is the Brake Lining. In a drum brake system the Shoes and Linings are two horizontally opposed plates that remain stationary attached to a backing plate, while the Brake drum they’re inside of spins with the wheel. The Shoes and Linings don’t contact the Drum because a Return Spring keeps them tight. When you press the brake pedal, brake fluid travels through the brake lines, though the Master Cylinder and Power Booster, where it becomes pressurized, and enters a Wheel Cylinder (piston) between the Shoes and Linings, that pushes them out. They make contact with the Drum, like that fist in that cup, and that friction stops the vehicle. \n\nNow, the stopping mechanisms on an Air Brake system are generally the same with a few exceptions. Instead of hydraulic brake fluid, pressurized air is used. This is achieved much in the same way that an A/C systems work: a compressor, series of lines, and receiver-dehydrator to keep it all dry. Instead of a wheel cylinder (piston) pushing the Shoes and Linings against the Drum, a push rod activates a lever attached to a cam, which pushes the Linings out. The Cam looks like that meteorologist symbol for a hurricane, it just sits in there and turns when activated, pushing out the brake Shoes and lining against the Drum, like your hand in that cup." ]

[ "Humans have destroyed most of their habitat. They are a fairly delicate species that wasn't exactly taking over the world even *before* people cut down the plants they live in.", "Habitat destruction and habitat fragmentation, caused by human development. This is a common cause of vulnerability in animals today. They don't have enough land, and what land they do have is scattered, further separating their populations, making it difficult for them to maintain viable numbers. ", "This [comment](_URL_0_) by [u/99trumpets](_URL_1_) in a related thread may be helpful: \"The panda is in trouble entirely because of humans.\" The post is well worth reading." ]

[ "Capital punishment presents a stark contrast, an official 'good' killing, when the taking of life is widely presented as a barbaric and evil act. The trend over time has been to push for techniques believed at the time to be less painful, and more humane. I would expect this serves dual purposes, to avoid inflicting needless harm, and to thereby help convince the population that its actions are therefore less barbaric and more just than retaliatory, but that's debatable of course.", "So that the person who \"kills\" the prisoner is not traumatized from the fact that he just killed a man for the same reason war veterans suffer from physiological issues to having shot down many people in war. Killing a person is not easy and is not in human instinct to do, but if all the executioner has to do is give a prisoner a shot of poison the executioner might not suffer from it, compared to axing his head off, and shooting him in a firing squad.\n", "Michael Portillo did a very good documentary on execution for the BBC and he looks at inert gas asphyxiation. \n\n_URL_0_\n\nWhen he challenged an expert professor about the method, which is very effective and painless, and asked him what he thought, the professor answered \"I think it's terrible...Punishment should be painful.\" This mindset is barbaric but doesn't seem to be uncommon in many countries that have the death penalty. Why not use death by a thousand cuts? That's effective, and cheap. Sharp knives are everywhere. They could even make a machine that does it for them to sooth their consciences. \n\nIf you want to sentence someone to a painful death then sentence them to a painful death and let the world see it for what it is.\n\nI'm against the death penalty regardless of method (life without parole is enough) and I'm happy that nobody will sell them the tools they need. ", "The US Constitution says that the government cannot do \"Cruel and unusual punishments\", but it doesn't set exact standards or rules for what is \"cruel\". The courts are left to figure out the details and revise the details as time goes by. This creates a perpetual cycle of arguments and rulings. Rulings are typically compromises that move the argument a little bit at a time as opposed to going all one way or the other. \n\nMost silly rules are the result of some compromise. Instead of doing things efficiently one way or the other, everybody is forced to do things in some backasswards way. \n\nUS executions fall into this category. You cannot just completely skip executions and you cannot just put a bullet in somebody'e head. So you end up with medical killings because they have to be as humane as possible and conform to too many rules." ]

[ "Think of it this way, you're paying for commercials on cable channels (just not channels like HBO, but you pay for channels like AMC and E!). If you're not willing to sit through a Hulu commercial because you feel it doesn't have the value to you that Netflix does, you shouldn't pay for it.\n\nThey're two different products that operate differently.", "By subsidizing their costs with commercials, they can charge less for subscriptions. ", "Different choice of revenue streams. Both are perfectly valid ways of doing things, and both are probably maximizing their profits. What makes you think one is more greedy than the other?", "Higher costs for recent shows.", "Hulu has agreements with the tv networks to air their stuff usually next day. The networks want money for this. Probably a hefty sum. So Hulu pays, and in return has to charge you for a sub. But to subsidize the cost paid to the various networks and still provide a reasonable sub rate, they have to show commercials for the extra income. ", "What I haven't see here is this.\n\nFor syndication and other purposes, it's much easier to get that for old shows than shows that have just been aired.", "As far as I remember, HULU only implemented the pay-to-watch system recently, when they expanded off just the web. They made an announcement about just this issue, can't find because work net won't let me get there, which basically said that the providers were charging so much for content that they needed additional revenue on top of just adds or subs, they need both, just to keep paying for the the content from the major networks.\n", "I keep getting political attack ads on mine. Nothing pisses me off more than trying to watch Community and having to wait 30 seconds so the Koch brothers can tell me that my congressman is an evil, horrible person bent on destroying the world. I'd complain to Hulu for playing political ads, but meh, I'm lazy. " ]

[ "So what happens when we run out of SSNs? Do we recycle the old ones or add new numbers?", "In Canada, you can go into any Service Canada and ask them what to do with the card. I believe it can be mailed into the government and a hold/notice will be placed on the account to prevent identity theft.", "Social Security Numbers are not reused. But just because someone is dead doesn't mean that their ssn is irrelivant. Often a person's social security benefits continue to be paid out to a family member, generally a widow until that person dies.\n\nThe actually number itself can be used to reference a person through the social security administration and it is entered into something call the SSDI (Social Security Death Index).\n\nThere are still plenty of available numbers, I think the estimate is that the feds won't have to add an additional digit until 2055-2060.", "They go to some shady hotel in Miami where all the mexicans I work with go to get their \"papers renewed\"\n\none named gustavo had the SSN of a blonde, 9 year old boy. he got deported :(", "After someone dies (when some time has passed) the IRS locks that social security number so that nobody can use it for tax purposes when e-filing. ", "The system used by banks and employers to check the validity of an SSN is \"e-verify\". _URL_0_\n\nSSNs are SUPPOSED to be unique, and they do not get reused. In fact, part of the \"birther\" controversy is due to the assertion that the presidents own SSN could not pass the e-verify check. ", "The mob uses them for insurance fraud. ", "They are used to vote shitty people in to office.\n\nSource: [Black Sheep](_URL_0_)", "It is called the [Social Security Death Index or SSDI](_URL_0_). When a person is reported as deceased - when a death certificate is issued, that death is reported to the Social Security office wherein they retire that Social Security Number, and that SSN then becomes part of a public record.\n\nCredit reporting bureaus get regular updates of the SSDI database, and therefore credit card companies and all other associated agencies all get updated/notified of a death within 30-60 days. Those creditors will then start closing those accounts and proceed with determining the final disposition of those accounts.", "They start casting votes in Chicago", "It gets recycled in voting ", "As an Australian, what are Social Security Numbers? ", "Since there's only a finite amount of numbers we can conceive of, we try to re-use them for people born after the original owner died. In the case of followers of Eastern Mysticism we try to link a soul's earlier SSN to their reborn identity.", "I use them to keep getting their social security checks. ", "It's assumed by undocumented migrants for a nominal insidious fee", "The SS# feels immense heartbreak. After an eternity of depression, alcohol, drugs and not being able to find another soulmate. The SS# lights himself on fire, never to be seen or heard from again.", "This is the kind of question a smart ilegal alien would ask.", "Like with ancient Chinese kings, they are buried alive with the body out of respect.", "So, I did a look for my late grandfather. It said that his SSN was issued in the state of Illinois, does that mean he born in Illinois, or that was a state where applications for a Social Security Number were sent??", "I used a fake name and SSN to get phone and utilities all through college and a few years beyond. No one seemed to check, and if you memorize everything and rattle it off, no one ever checks.\n\nWhy? It doesn't cost them anything to believe you. \n\nNo one even noticed that the payment checks were coming from a totally different person, either. They only care if they DON'T get their money.", "This reminds me of a fun story. \n\nWhen I was 12 or 13, my parents decided that they should upgrade my bank account from some type of \"child\" account to some sort of \"teen\" account. I think the difference had something to do with my ability to see my funds and use the website, I don't really know. My parents put all of my allowance funds in here, rather than giving it to me physically, which really irked me, as I couldn't use those funds to buy whirly gigs and gadgets, but rather had to save for *college*. \n\nSo anyway, my mom took me into the bank, and told the banker that they were looking to close my current account. The banker pulled up my account, and all of the sudden got very stone-faced and somber. She treated my mom with kid gloves for the next half hour or so. I was just playing gameboy like a boss. My mom thought something was wrong, but simply ignored it. \n\nThe banker ended up bringing the branch manager in to talk to my mom. He said \"Mrs. 11, I'm really sorry we have to meet under these circumstances. I'm sorry for your loss.\" \n\nMy mom freaked out, she had no idea what was going on. At this point, I was paying attention. This shit was better than Pokemon. My mom asked what they meant, and the banker simply said, \"we're just offering condolences on jefferino11's death.\" \n\nMy mom just turned to me very confused, and said \"he's right here!\" I waved. \n\nTurns out my parents had messed up one number on my SSN when they filed the original paperwork. Since it was a child's account, they never bothered to check the SSN against the database, and simply kept it on file. The person whose SSN was in the computer had passed away two weeks earlier. \n\n**TL;DR: Went into the bank. They told me I was dead.** ", "Please note that SSA records are more than just the Social Security Death Index. \n\nThe Numident is the home of the Social Security Number (SSN).\n_URL_0_\nA new numident entry is generated each time a social security card is issued. A final entry is generated when a report of death is received. Coding is based on the source of the info. \n\nFor example if SSA gets info from a state registry about a death it will not be released on the Social Security Death Index. Where as if a funeral home reports a death on an SSA-721 or using an Electronic Death Reporting system, or a death certificate is provided; then it will end up in the SSDI. \n\nThere are so many varied reports of death and SSA records all of them, Some create disclosure potential other don't. The SSDI is a service that is constantly under review because it does not serve the core mission of the Social Security Administration (SSA), why blow money informing other of what SSA spent time collecting (the death reports). \n\nRemember that the SSN is a number generated by SSA for its own purposes. There is nothing stopping other from using the SSN, for really any pupose. like the way aa school assigns it students a number, SSA assigns workers an SSN. \n\nPlease refer to:\nYour Social Security Number and Card\n_URL_1_\n\nGeneral Info about the SSN:\n_URL_2_\n\n\n ", "They somehow vote for Obama.", "What if someone goes missing but is never found? Do they retire the number after x number of years?", "They get counted as votes/members to the Republican party.", "While some people believe that Social Security numbers are just retired, never to be used again, the truth is actually much more interesting. First, immediately upon the death of the owner, a special team is dispatched to retrieve the number. This team is recruited from the most kind-hearted of mathematicians who are strong of limb, swift of feet and of greatly reverential attitude. Upon arrival, the team wraps the Social Security number in mylar and attends to its grief. Next, the number is taken to The Great Counting Place. There, all numbers reach their final reckoning, from simple bar tab totals to huge national deficits. Most are dispatched quickly to ignominious ends. However, Social Security numbers are accorded a much better fate given their unique natures and delicate dispositions. They are first treated to a celebration of their owner's life and then commended on their own performance. It is a time of both solemnity and joy. Then, their own reckoning is scheduled. At the appointed time and with great fanfare and hoopla, the Social Security number is divided by zero. There's a brief flash of light and the number slowly fades into undefinition. As there is nothing at all left, no further action is required and the team slowly withdraws into quiet contemplation to wait for their next assignment. ", "so now you have enough info to put your plan into action.", "A Mexican slave laborer deploys it to secure a sweatshop/grill job." ]

[ "Autoimmune diseases come in two flavors: “kill everything” and “nah, bro.” We don’t know why it happens, but they’re starting to understand how they work. ", "I can answer this as I have a very rare one. Either at birth, or sometimes through trauma, medicine, etc, our immune system gets switched from \"auto\" mode to always on mode. In the always on mode, the cells including white blood cells, work on a specific part of your body, constantly trying to destroy it. We combat this by taking immuno suppressant drugs and steroids to tell our immune system to \"relax, have some red wine with dinner\". You will often see this in organ transplants, even in the closest matches, the body often sees the new organ or tissue as a foreign invader and try to \"reject it\".", "To answer your second question. Yes, exactly. Cancer does a good job pretending to the immune system that there's no problem. The whole answer to this question is that there are a few immune cell types that are usually good at nipping cancer in the bud, just that the worst kinds of cancer will bypass these immune cells by being tricky and either prevent immune cells from initiating apoptosis (signaling the cancer cell to kill itself) or from being recognized as a harmful cell in the first place. A very recent therapy called CAR-T cells used in some leukemias overcomes the limits of not being able to recognize lymphomas. Basically they pull out your own T-cells (aka killer cells), use some gene editing to place receptors to the cancer on the surface of those T-cells, and when put back in your body the T-cells go gangbusters, dividing rapidly and killing cancer while ignoring other healthy cells. They can do this because these cancer cells will have one thing different on the surface of their cells, and \"training\" a T-cell to see this will allow it to safely kill cancer cells without an autoimmune reaction. \n\n & #x200B;\n\nThe answer to your first question is complicated. Like some of the other answers, there is often a genetic predisposition to getting autoimmune diseases followed by an initiating event. And because this is good practice for me to remember immunology I'll break it down in a few examples with painful ELI5 detail(I'm still going to leave out a ton). \n\nType 1 diabetes:\n\nYour pancreas makes insulin to lower blood sugar. Cells that make insulin are called ß islet cells. In adolescence there's an inciting event (inflammation), and a cell (probably lots of cells, really) called a Natural Killer cell arrives in the pancreas destroys all the ß islet cells in a case of mistaken identity. Now you can't make insulin and need an insulin pump. Without it you starve to death.\n\n & #x200B;\n\nRheumatoid Arthritis: \n\nYou've heard of antibodies, maybe. These aren't cells, they're just sticky proteins that have an amazing quality. They stick to 1 type of thing only. But when they do they can signal immune cells (there are a few types) to come and attack whatever they're stuck to. B-cells make antibodies. Sometimes bad B-cells that recognize normal human cells or harmless human proteins get made by the body, and worse, they mature. When a harmless protein comes in contact with that 1 lone B-cell, that B-cell will divide, throw out more antibodies, and keep dividing. In the case of Rheumatoid Arthritis, that \"harmless protein\" is simply another antibody (called IgG). When an antibody sticks to another antibody, it forms a complex, and gets stuck somewhere. And these complexes stick together, growing larger and larger, all winding up in the tissue of the joints, which is usually pristine and smooth. \n\nStill with me?\n\nComplexes use a special chemical pathway called complement to call for help from two types of immune cells that do damage, Macrophages and Neutrophils. The complement pathway marks cells for destruction, and since all this complement is sitting in joint tissue, the macrophages and neutrophils arrive by the bloodstream and start destroying the joints. This leads to painful joints that will start to deform as more and more damage ensues. The treatment is to use drugs that prevents immune cells like Macrophages and neutrophils from growing/dividing, or preventing these from entering the tissue space (aka extravasation). But there's no cure, because those B-cells won't stop. And as you can imagine, RA is a terrible disease. \n\n & #x200B;\n\nand finally\n\nLupus:\n\nYou get a sunburn. That kills some of your skin cells, inside which there is your DNA and some nuclear material, which spills out into your body. Unluckily, you have one of those bad B-cells that makes antibodies that (absolutely randomly) recognizes that DNA and nuclear material from your skin cells. Antibodies from that B-cell complex with the DNA/nuclear material. \n\nBy a twist of even worse fate, some of that antibody-DNA complex is consumed by a Dendritic cell. The job of a Dendritic cell is to stand guard against invaders by eating things and presenting the chewed up remains to... B-cells. Normally this is the signal that expedites the process of ramping up an immune system against a bacteria. In Lupus, it causes all the problems. Now the B-cells make even more antibodies and start cloning themselves. More antibody complexes start depositing in places where sunburn/skin damage happened first, in the skin, causing a butterfly rash (google an image). But eventually this process can cause larger clumps complexes to deposit throughout the body, particularly areas that are thin and membranous where these complexes physically get stuck, like the kidney or the brain, blood vessels, the heart valves, the tongue, the lymph nodes. Just like Rheumatoid Arthritis, complexes activate complement, calling for immune cells to visit and start killing normal tissues. \n\n & #x200B;\n\nThere is a ton of nuance with these diseases, which have different processes and origins. This is because the immune system really isn't one \"switch\". Its a lot of switches that work in harmony to make sure that bad infections are dealt with, cancer cells are eliminated, and normal cells are not killed. For something to go wrong, multiple factors are usually at play, many I haven't mentioned. But hopefully this gives you a better picture of what an autoimmune disease is, rare and devastating. \n\n & #x200B;\n\n & #x200B;" ]

[ "try /r/mindfulness or /r/meditation for more info.\n\nMeditation lets you train your mind to empty itself of thought and emotion.", "Maybe some humans are capable of hibernation even just for a few minutes/hours by lowering the core temperature? There might have been occasions during blizzards where people get caught outside with nobody around so they just curl up into a ball until a few hours later where they are found still alive but in a hibernated state. ", "If that happened, you wouldn't be aware of it, making it impossble to test. No? \n\nMaybe it would be possible to measure brain activity in areas responsible for conscious thought? I have no idea if we have this kind of knowledge/technology in regards to the brain, but my gut says no.", "The other day i was messing around in the pool, trying to see how long i could hold my breath; when i pushed myself to the point that i was passing out, basically drowning. The last thing i remembered before that was that i was in the pool, and i didn't really remember coming up. for that 10 or so seconds, i had no thoughts in my head, it was beautiful.\n**tl;dr** tryed drowning myself, lost consciousness, alive and thoughtless. oxygen deprivation works" ]

[ "Not sure if anyones said this yet but [Tardigrade](_URL_0_) or water bears are pretty damn resilient.\n > they can survive extreme conditions that would be rapidly fatal to nearly all other known life forms. They can withstand temperature ranges from 1 K (−458 °F; −272 °C) (close to absolute zero) to about 420 K (300 °F; 150 °C),[7] pressures about six times greater than those found in the deepest ocean trenches, ionizing radiation at doses hundreds of times higher than the lethal dose for a human, and the vacuum of outer space.[8] They can go without food or water for more than 30 years, drying out to the point where they are 3% or less water, only to rehydrate, forage, and reproduce.", "No earth organism would thrive on Mars. Some organisms may potentially be able to survive, but none would thrive. The concern about contamination isn't about contaminating *Mars*; it's about contaminating the instruments we use to detect whether or not there has ever been life on Mars.", "There's been research into the viability of halophilic and methanogenic bacteria in simulated Martian sub-surface conditions; as long as they're far enough below the surface that they have access to liquid water (most likely a below-freezing brine), it seems like they're viable.\n\nWhat I don't know is if they tested for Martian radiation levels, or if radiation is even a significant factor at the depths in question.", "Bad water basin is a good example of an environment that might be analogous to a Mars environment. So we might want to look for gamma sulfur bacteria but they would need hydrogen sulfide as a reducing agent. Good chance that we may find analogs of this bacteria as fossil in Mars rocks. ", "Surface conditions are out-and-out uninhabitable (large temp swings, vacuum, radiation).\n\nSubsurface water/brines are a possible locale. We have good evidence to suggest that [salty brines are present beneath the soil](_URL_2_). Less saline water may also be present sufficiently far below the surface, as geo(are?)thermal heat would push temperatures up; the rock would also shield from radiation and temperature swings. With liquid water, dissolved nutrients would be readily available for biological processes. Given the [presence of atmospheric methane](_URL_3_), it is possible that methane seeps may exist; along with [hydrogen sulfide](_URL_1_), there is evidence of suitable chemical energy to serve as a food source.\n\nWe have similar conditions on Earth; both with [lithophiles](_URL_4_), and more accessibly, [ocean brine pools](_URL_5_) are known to contain a [selection of extremophiles](_URL_0_). Life that can survive via chemisynthesis, under great pressure, at temperatures between 0-4 ^o C, in super-saline brines is probably the best we can ask for.\n\n", "Tardigrades are found on the outside of space craft, and \n\n > are known to be able to survive a host of harsh environments. They can survive extreme temperatures (slightly above absolute zero to far above boiling), amounts of radiation hundreds of times higher than the lethal dose for a human, pressure around six times more than found in the deepest parts of the ocean, and the [vacuum of space.](_URL_0_)\n\nThey could survive for a while but there's no food on Mars or free standing water or super heated hydrothermal vents that we know of for thermophiles. There may be sulfur containing soil for [Sulfate-reducing bacteria](_URL_1_) to survive, but they also need moisture. ", "I actually do life detection research for potential future Mars missions in graduate school. Terrestrial life in the Atacama desert is our best analog for life that could survive on Mars. My favorite example is halophilic, endolithic organisms (life that likes salt and lives in rocks). There are salt crystals in the desert that deliquesce (pull enough water out of the air to dissolve in it and become liquid) and we have found microbes that live in this salty brine. There are seasonally changing features on the Martian surface called RSL that a lot of scientists think are periodicity recurring, really briny water tracks that happen in the summer by salts deliquescing water out the atmosphere. If a terrestrial, halophilic organism got to an RSL, it is conceivable that there would be seasonal blooms of them during which they thrive. ", "You should read the Mars Trilogy by Kim Stanley Robinson, he takes a hard sci-fi look at stuff like this in the larger context of human terraformation of Mars. Probably my favorite books, not just in sci-fi but in general.", "Even if any of our microorganisms could survive on Mars they shouldn't risk taking any there. Just incase they mess life for any possible life already on Mars. That would suck so much if we found the only life on Mars and ended up destroying it.", "Probably the tardigrades which are notable for being perhaps the most durable of known organisms: they can survive extreme conditions that would be rapidly fatal to nearly all other known life forms. They can withstand temperature ranges from 1 K (−458 °F; −272 °C) (close to absolute zero) to about 420 K (300 °F; 150 °C), pressures about six times greater than those found in the deepest ocean trenches, ionizing radiation at doses hundreds of times higher than the lethal dose for a human, and the vacuum of outer space.They can go without food or water for more than 30 years, drying out to the point where they are 3% or less water, only to rehydrate, forage, and reproduce.", "Yes, lots of plants and bacteria would work. They might not all grow as fast as on Earth, but it's definitely possible and an area of study for a lot of people. It's hard to be sure until we try, but there is plenty of energy to sustain life.\n\nLichen has been shown to be able to survive extreme conditions without damage.\n\n_URL_0_\n\n_URL_3_\n\n_URL_4_\n\n_URL_1_\n\nThis might be interesting, there were 500 seeds flown around the moon then returned to Earth and planted all around the world. _URL_2_", "So this is actually really interesting! I recently came across an article about organisms that could thrive in subterranean environments (with hydrogen present, I believe) by utilizing electrons stripped from surrounding metals. [Quanta Magazine article] (/_URL_0_)", "Lichens, both cryptoendolithic (growing inside rocks' crystalline structure) and chasmoendolithic (growing inside cracks in rocks). There are a couple of species of extremophile lichen from Antarctica which may do the trick.\n\nSource: am a geologist who did his undergraduate senior thesis on terraforming Mars' atmosphere.", "The annual IGEM competition in synthetic bio had a team that was designing plasmids using earthly genes to make a \"survival pack\" of genes needed to survive Mars that could be transformed into bacteria we chose. That is if there isn't any life for us to contaminate. _URL_0_", "Don't know... but would likely have to be some organism that could survive subsurface. Low pressure of Mars (1/100th of earth) means water can obly be in ice or vapor form above surface (I.e. triple point). Mud can sorta form, until the water in it boils away.", "Idk about thrive, but Tardigrades could put themselves in an indefinite state of stasis where they don't need nutrients. They could probably just wait on Mars until it gets terraformed in a few hundred years and then carry on as usual. " ]

[ "Altitude effects pressure which is connected to temperature. Higher attitude, less pressure, lower temperature.", "ELI5: The once-hot air that's now on top became cold while it was rising. \n\n\n---\n\n Parcel theory:\n\nA \"blob\" of hot air begins to rise. As it rises, the pressure exerted on it decreases and the blob expands. This causes the blob to cool as it gets higher. It will continue to rise until it becomes colder than the surrounding atmosphere." ]

[ "a lot of confusion here is stemming from thinking of objects AS waves or/particles. in the case of a photon or electron we use waves and particles in order to model and predict their behaviour.\n\nphotons are a way to quantise electromagnetic radiation for the purpose of calculation, so all electromagnetic radiation can be measured in terms of photons. photons have no mass\n\nelectrons are different in that they are a fundamental particle with mass and charge, electrons do still exhibit wave particle duality.\n\na good read for this is:\n_URL_0_\n\nas with anything that edges into quantum mechanics there is a lot of wishy washy hand waving because a lot of the phenomena is not properly understood/explained, it is also counter intuitive when compared with classical mechanics.", "Atoms are more magnetic when electrons do not have an opposite spin partner. One electron without a second electron spinning in the opposite direction will contribute to a material being magnetic. The last +1/2 or - 1/2 in the Quantum numbers will indicate spin.\n\n", "I'll try to answer all the questions you ask and add a bit for clarification. \n\nFirstly, my background is mechanical engineering, but my field is Superconductivity which deals with complex solid state physics and the ways in which electrons move through metals. Additionally, it deals with large magnetic fields, so I have a fairly good understanding of the energy properties of electrons and electromagnetics in general. \n\n > As far as I understood, photons are the particles that \"spread\" the force in electromagentism, as electromagnetic waves. \n\nMore accurately they are the quantized energy that occur from an electron changing it's energy level. (Edit: it turns out that photons can actually arise as something called a virtual particle... Virtual particles ARE known as force carriers) A photon's energy is determined by its wavelength and defines its momentum. A photon is simply a particle (or wave) of some specific energy, and that energy determines its designation as a type of EM wave (light, x-ray, gamma ray, infrared, etc.) For example, two charged particles can feel attractive forces to one another without emitting any photons and magnetic fields can exist without the movement of electrons, it will simply induce the movement of electrons if it is moved past a conductor. \n\n > I also know that electrons have electric charge and moving electrons cause a magnetic field. Does that not mean that electrons are also an \"electromagnetic\" particle? Following up, does the wave particle simultanity principle hold for electrons as it does for photons?\nDoes that mean electrons are also \"electromagnetic waves\"?\n\nYou are right that moving electrons cause a magnetic field, but electrons themselves are not generally called electromagnetic particles. That term is usually designated for photons which vary in their properties from electrons in very significant ways, namely that electrons have mass and photons do not. \n\nThis is not to say that electrons do not express themselves as waves. They do, but this has to do more with a quantum effect called the uncertainty principle, and is not necessarily related to electromagnetics. \n\n > Additionally, why do we call \"light\" or photons \"electromagnetic waves\"? \nAre all photons electromagnetic waves or does it depend on wavelength/energy or the source?\n\nWe call photons electromagnetic waves because they exhibit a property called wave-particle duality. This means that photons are both a wave and a particle. I can't explain this thoroughly without going into great detail. Suffice it to say that the important concept is that photons are basically pure energy that manifests as a mass less particle or wave. \n\nAlso, yes, all photons are electromagnetic waves, and that designation does not depend on wavelength or energy. \n\n > Thank you for any corrections and clarifications of my thoughts.\n\nNo problem. I hope I've done a good job. If a physics PhD finds this comment, please elaborate if you think I've missed something. \n" ]

[ "There used to be; it was called the Concorde. You can read all about why it was retired [here](_URL_0_).", "They are very expensive to operate and maintain compared to sub-sonic jetliners (which ain't exactly cheap, either).\n\nGround control issues would develop with the faster aircraft being integrated with the sub-sonic aircraft esp. in terminal control spaces. That would also cost money to deal with.\n\nThe public seems happy (!) with what they currently get in terms of travel. There's not financial incentive to upgrade speed of current routes to supersonic speed. ", "It's against federal US law to fly over land and break the sound barrier. Not really an explanation, but rather an interesting fact." ]

[ "Home loans. They don’t pay for it in cash.", "You borrow the money from a bank. This is called a \"mortgage\". Typically a mortgage loan will be paid off over about 30 years. So for a $300,000 home, a homeowner might pay $1600 a month to the bank; after 30 years, that adds up! They will have paid quite a bit more than the $300,000 cost of the home -- the bank keeps the extra as a profit.\n\nIt may be strange to imagine paying for something over more years than you've been alive, but hundreds of millions of people are doing it right now, and there's a good chance that someday you will be one of them.", "Loans.\n\nA bank buys the house, and then you pay them back with interest every month. For a $300,000 house at today's rates, you'll pay ~$1400 a month to the bank for 30 years.\n\nDoable on $50k, but a little lofty.\n\nYou may notice that $1400/month for 30 years adds up to way more than 300k, because banks aren't a charity.", "In most cases, people who buy homes do so by using what's called a mortgage. This is a loan from a bank, in which the bank pays the full value of the home to the builder (or to the previous owner), and then you pay the bank back over a period of time. Mortgage loans can usually be found at a lower interest rate than other kinds of loans because the bank has a built-in fallback: If you don't pay them regularly, they can just take the house back and kick you out. This is oversimplified, but essentially true.\n\nMost mortgages are spread out over either 15 or 30 years. So if you're buying a $300,000 house with a 15 year mortgage, then you might expect to pay $20,000 a year, or $1667 a month. However, that's not taking interest into account. The bank needs to make money in order to make this transaction worthwhile for them. So you end up paying more than the $300,000 that the bank paid to the builder, for the privilege of paying over time. For example, if you borrowed that $300,000 at 4% interest for a 15 year loan, you would actually pay the bank $2,219 a month, for a total cost of $399,431.\n\nThere are many other factors -- most people pay a down payment, which is a bunch of cash up front to reduce the mortgage amount. And very common are adjustable rate mortgages, in which the interest rate is not set in stone but can vary from year to year in response to how the economy is doing. But that's the basic idea.", "You could mortgage a duplex and live in one half and rent the other. The incoming rent will pay very large chunk of your monthly payment. It is work, though.", "You pay for a house over decades. Some mortgages can be upwards of 30 years, not to mention banks will allow you to remorgague your house after a certain period of time. So a single years income is irrelevant. \n\nAdditionally interest rates on mortgages are typically as low as you can get because the asset in question are stable values that almost always go up so the bank doesnt take much risk when loaning you hundreds of thousands of dollars. \n\nHousing is typically considered to be upwards of 30% of your income so as long as 30% of your income can generate enough payments to equal hundreds of thousands of dollars over the next 20-30 years, your good. \n\nBased on this 30% rule someone making 50k would accumulate 450k in 30 years and that's assuming they stick to only 30% for housing. If they have no other debt they might be able to allocate even more than that, although banks would consider that to be a risk factor and may deny them as a result or ask for a higher interest rate.", "Well, I am just closing on a house, so I can tell you.\n\nFirst of all, pay your bills. If you do not have good credit, this is difficult.\n\nSecond, you will need some money for the down payment. Now, 200k is not a cheap house. You may want to start with something a little lower. So, let's say 150k.\n\nMy bank qualified me for a 3% down payment. That is $4,500. You will also probably have closing costs, they vary by State. If you have a good real estate agent, they may be able to get the seller to pay the closign costs. Otherwise, maybe another $4,000.\n\nSo, you will need to have roughly $10k in cash for the purchase.", "1) Most people pay for the house as a couple. Most singletons can't afford a house of their own. \n2) They get a loan that lasts almost their entire adult life - 25 years, but 30+ isn't unheard of either. Start paying at 20, you won't have finished paying at 50, necessarily. \n3) On that loan, you may end up paying something like 4.5% interest. So by the time they finish paying for it, you have paid 1.5-2 times the price of the house when you bought it (30 years @ 4.5% per year = over $364k paid in total on a $200k loan). \n4) You need to put down a deposit, something like 5-10% or more of the total price. So you have to have been able to \"pay off\" or own 5-10% of the house before you even get given anything else. \n\n\nFact is, if you want to buy a house you have to save. You probably won't be able to afford anything much unless you club together with others (friends is often a bad idea, long-term partner is the usual route) or have a particularly good job. Then over your life you'll pay that back probably nearly twice over. But miss one payment in that time and the bank could start taking \"your\" house back from you. \n\n\nGenerally, in the UK, they won't lend you more than 5 times your combined income. So you might be able to get $250k if you earn $50k. If you're lucky. More likely you and your partner will have to both take out a mortgage together, and then it'll be for 5 x what you both earn - and your partner will own half that house/debt. \n\n\nSave money. Lots of money. If you want that $250k house on $50k a year you're going to need about $25k in the bank before they will even look at you. Then you'll need to be able to pay something like $1000-1200 a month for the next 30 years out of your money. That means you'll be paying something like $12,000 out of that $50,000 you earn every year into your house debt (which is what a mortgage is). \n\n\nI've owned a couple of houses in my lifetime, never long enough to pay them off (splitting up with people, etc.). I earn good money now. The banks will give me enough that - where I live - I can just about own a 1-bed apartment so long as it isn't anywhere too nice. If I started now, I'll still be paying it off when I'm 70. I would have to retire at 65, and still keep paying that same payment on the mortgage on that 1-bed apartment if I want to keep living there. \n\n\nSave now. Save early. Save lots. Or you run the risk of not even being able to afford your own tiny apartment in your lifetime, not to mention that even if you don't \\*own\\* a place, you'll still have to \\*rent\\* a place anyway - so you'll still be paying$1000 a month to someone else and get \\*nothing\\* for it (in effect, all you're doing by renting is paying \\*their\\* mortgage off for them.", "Guy who makes $50k checking in.\n\nYou don't. Unless you can get a loan (called a mortgage). But they usually want you to put down a bunch of money up front for it. Traditionally, 20% of the selling price of the house, but in some cases less. So when you take out a loan, the means you gotta pay it back in payments over the next 30 years until it's paid off. Each payment that you make adds to the equity of the house (basically, how much of the house you own in dollars).\n\nYou can actually take out a loan against the equity of the house for things like putting in solar panels or a pool or something like that but you still have to pay it back. Or... you can use that equity as the down payment on a different house so you're not stuck in the same house for 30 years.\n\nBut the most important thing is the down payment. If you don't have money saved up, coming up with a random $40,000 to use as a down payment is tricky. I'm going through this right now.\n\nI make $50,000 per year. I have $2000 in saving, another few in a 401k. I'm 36 and my job is in Southern California. My expenses match my income almost exactly down to the dollar so I don't get to save money. Unless someone in my family dies and leaves me a bunch of money or the economy taks hard, I don't get to own a house.\n\nThis is actually a pretty direct result of the politics in my country. Please vote.", "They don't. They take a mortgage out, but there's no way they could either a) afford the mortgage or b) even be approved with such little income.\n\nMost have their parents money who \"helped them\", an inheritance, or some other form of income that they aren't telling you about or large sums of money they received elsewhere.", "Gentle reminder that who's and whose are different words. Who's means \"who is.\" The word you're looking for is whose.", "You are young. Try not to stress out. Don't let these worries rob you of the joy of youth/possibilities in front of you. People find a way to muddle through just fine. The good news is that small positive steps you take today and just avoiding some typical mistakes will set you ahead of the curve. r/PersonalFinance is a great resource of information. I've self taught myself a lot over the years. Below is a summary of things I've found helpful.\n\n & #x200B;\n\nBasic calculus for financial health, learn how to calculate the following. You can find these as Excel Formulas but I like Amortization tables for visualization. You can play with the variables and see their impact:\n\n(1) Present Value (\"PV\" in Excel) = will return the $ size of a loan assuming a certain interest rate, loan term, and monthly payment amount\n\n(2) Loan Payment (\"PMT\") = the monthly amount you would have to pay assuming a starting $ balance, interest rate, and loan term\n\n(3) Loan Term (\"NPER\") = the number of months it would take you to pay off a loan at a certain interest rate, monthly payment, and starting balance.\n\n(4) Create a monthly budget = Income - Taxes - Fixed Expenses (like rent/insurance/utilities/debt payments) - Savings - Variable Expenses (food/transport) = remainder fun $\n\n & #x200B;\n\nRules of Thumb:\n\nCreating a monthly budget is the first step to see what you can afford and balance wants vs. needs to achieve your goals. It's hard when first starting out but try to keep the cost of rent < 30% of your net income in order to not feel squeezed. Unfortunately I don't remember where I found the below % but it's worked pretty well for me to budget and reach goals.  \n\n Proportion/Net Pay \n 10%\t wants \n 50%   needs \n 15%\t debt repay \n 25%\t save \n\nTraditionally for healthy finances you should never use your credit card as an emergency fund. Rather you just as a cashflow tool of bridging a couple of days until you have the cash. You should always try to pay off your credit card in full every month to avoid interest charges/fees. Minimum payments are basically just interest forever without really reducing the balance.\n\nIf you get student loans, it's ok to try to get the longest loan term possible to start out with. To the extent possible try not to accumulate more than your potential first year salary for your future career. Avoid private loans where possible, and try to pay any interest while still in school or grace period to avoid being added to the principal balance (i.e. \"capitalized\") whereby interest accrues on top of interest. When you graduate and get your first job will be a good time to shop refinance options to possibly lower your interest rate or extend your loan term to something manageable. The goal is to be able to repay it within 15 years as you get raises.\n\nWhen you are young, building up an Emergency fund of at least 3 months worth of expenses should be a priority. As you get older that amount will need to increase for various reasons. But this will save you in case of the unexpected. It's \"emergency\" for a reason. Not to be confused with your regular savings for known upcoming things.\n\nStart contributing to your retirement savings (IRAs/401k) as soon as possible. Target 10% of your gross income if you start in your 20s. But just getting started the earlier the better is important, even if you can only afford 1%. You don't need to get fancy, a target date retirement fund or SPY ETF is fine to start and you can read more later about diversification.\n\nCar loans should only take up to 5 years to be paid off. If you have to take 7 years, either the car is too expensive or your interest rate is too high because you have bad credit, so it's the only way they are able to convince you that it is a reasonable monthly cost.\n\nBuying a place depends on a lot of things, and I find this site does a pretty good job at factoring them in. Generally a manageable mortgage amount is < 4 times household income in the U.S. \n\n[_URL_0_](_URL_0_)", "OP, curious question. Which country are you from, if it is safe for you to tell us?" ]

[ "One interesting thing to note about the Panther tank was that the pre G models (and even a number of Gs due to production problems) came with a shot trap on the gun mantlet. The gun mantlet was theoretically impossible for a 75mm gun on the Sherman to penetrate. However, due to the shot trap, a hit on the lower part of the gun mantlet could ricochet downwards onto the top hull armour which was only about 15mm thick. This was if the Panther turret was facing forwards, which it would probably be due to tanks usually facing what they're engaging.\n\nHowever, as talked about below, Shermans didn't come with the best optics so hitting a target like the gun mantlet (I'm not aware if the Allies were aware of the shot trap) on purpose would be a tall order at range. ", "There is something getting rather lost in this thread.\n\nTanks are not like fighter aircraft whose sole or main purpose is to destroy other aircraft and binary comparisons of one tank's armour, for example, against another is a very superficial analysis.\n\nTanks are a part of the combined arms weapons system. Real life is not World of Tanks. There is infantry, aircraft, barbed wire, inclines, infantry, artillery, mine fields, infantry, anti-tank ditches, logistics, infantry, production costs, ease and speed of construction, infantry, reliability, maintainability, infantry and infantry. \n\nDid I mention infantry? Because that's what matters in war. Only infantry can occupy and hold ground and the primary function of all other facets of combined arms warfare is to allow the infantry to occupy and hold ground.\n\nThe efficacy of any tank must therefore be measured in a holistic manner, and not in a reductionist stats analysis. For example, one contributor states\n\n > A Panther threw it's standard AP round at twice the velocity of the standard 75mm Sherman AP round (936m/sec vs 519m/sec).\n\nAnd? So what? Is the velocity of the main armament the principle determinant of how good a tanks is? Is armour penetration even the principle determinant of how good a tanks is? And the answer is obviously \"No\". \n\nIf this was the case then the 2pdr and 6pdr guns on early to mid war British tanks would have imbued them with a firm superiority. In fact, these guns were totally unsuitable as tank guns because they could not fire a meaningful HE round and were thus ineffective against infantry, artillery, and just about anything else on the battlefield that wasn't a tank. \n\nNot only that, but these uber high velocity improbably long boom-sticks that the Germans mounted on their late war tanks were a liability in close terrain (hedges, forests, urban areas), while the muzzle blast kicked up dust, stripped leaves from bushes and trees, and were a menace to any supporting infantry who might be in the vicinity.\n\nSo a very high velocity gun is useful for shooting up armour, but its less useful for everything else. And how important is shooting up other tanks? Well, analysis conducted by the western allies indicates that only around [14% of all tank casualties were caused by other tanks](_URL_0_) which is about the same as losses to panzerfausts. \n\nWhich simply reinforces the point that primary purpose of a tank is otherwise than killing other tanks. Again, this was a central pillar of pre-war British armoured doctrine and it was proved horribly misguided.\n\nSo in evaluating how good a certain tank was against another we need to evaluate everything. Including speed and cost of production, ease of supply, ease of maintenance, reliability, transportability, and value as an infantry support tool.\n\nAnd in all of those factors, the Panther and the Tiger fall flat on their faces. Hell's teeth, would you buy a new car if the manufacturer estimated it would suffer a catastrophic transmission failure before your first visit to the petrol station? Or a car that had to be fitted with an automatic fire extinguisher in the engine bay because of the frequency of engine fires? Of course you wouldn't, yet this was the kind of design feature built into the Panther.\n\nSo while the Panther and Tiger seem good on paper in the world-of-tanks reductionist-stats-analysis kind of way, actual events showed that the rather more humble allied tanks like the T-34, Churchill and M4, were a better weapons system overall." ]

[ "Because while in the oven, they reach an internal temperature of over 160° F (hopefully), killing food borne pathogens that may have been in your raw ingredients. \n\nFun fact, you can actually store your butter at room temperature. I know I do, at least for a couple days. ", "Butter doesn't really need to be refrigerated if you're going to use it in the next few days. It's all fat. Refrigeration keeps the quality high over time.\n\nBacteria--at least, the food poisoning kind--don't thrive in low moisture environments, and most baked goods are low moisture enough for this. Also most bacteria already in the ingredients are killed in the oven. Bacteria also don't thrive in highly acidic, highly salty, highly fatty, and, to some degree, highly sugary foods. This is why you can leave bread and most cakes, jerky, cooking oil, and ketchup out on the counter. Some (commercial) baked goods also have stabilizers/preservatives like potassium sorbate added so that baked goods like pumpkin pie can go unrefrigerated at least until you cut into it. Following a recipe's instructions about refrigeration or not is usually the best course." ]

[ "He probably does. He just knows you can't scratch his ears via Skype and there's no treats either.", "Not sure about the lack of voice recognition, but dogs and cats see screens differently than we do. In order for us to detect fluid motion/activity on a screen, there needs to be around 15 frames per second. Think of it like a film reel. There aren't any major differences when you look at adjacent frames, but when they're played through a projector, they string together and we get the \"motion picture\". Dogs and cats require a higher frequency of frames in order to detect fluid motion (around 60ish). So, what we see as fluid movement on a screen is just still shots to them." ]

[ "Could a country run its economy in such a way there there are no formal \"jobs\"? Certainly. Even today, many positions that appear to be jobs are actually contractor positions. There's no theoretical reason this couldn't be taken to the extreme.", "Sure. In fact, for most of human history, our entire population was self-employed. It was called hunting and gathering. Later many converted to farming.\n\nWhat you seem to be suggesting is, \"If one day all of our products and services are created by some sort of fanciful AI, can everyone still work?\" and of course ,the answer is no - if we did, then not all our products and services would be created by some sort of fanciful AI.\n\nAn easier way to think about this possibility is just another in a long line of efficiently improvements that have reduced the # of humans needed to produce something we want/like/need.\n\nAt every stage, we have a collective opportunity to either a) work less, since less work is required or b) work the same amount but consume more. Note that when I say collective, I'm not implying any sort of political system, I'm simply saying, \"the species as a whole\". How those decisions get made could be one individual at a time, could be a giant committee, a vote, or something in between.\n\nIf we were, through some political mechanism, decide that we were going to work less, instead of consume more, then you've solved your problem." ]

[ "humans are largely made of water, and do not readily ignite. Human spontaneous combustion is a myth. It generally could occur as a result of outside, explosive chemicals like fertilizers. Other things that CAN catch on fire such as clothing are more likely to catch on fire.", "If you're thinking of \"total human combustion\" , then that's been pretty well explained as the wick effect. Spontaneous human combustion, as in, ignition without an external heat source, that happens in certain chemicals, it's been known to happen in grain, but in humans it's a myth, there needs to be an ignition source external to the body." ]

[ "There are at least three countries in North America, and one of them disproves your thesis.\n\n", "Well, Australia's capital was going to be either Melbourne or Sydney but because nobody could decide, we decided to stick it in a little town geographically the same distance from both cities and now we have Canberra. There really is nothing in Canberra and its the most depressing capital in the world. \n\nLike MrMarbles2000 said, it was basically built from scratch to BE the capital as opposed to being the cultural centre of its nation. ", "The capital of Massachusetts is Boston, which is easily the largest city in the commonwealth, and it always was the capital. Also:\n\n* Montevideo, the capital of Uruguay, is not only the largest city in the country, but contains over *half* of the country's population.\n\n* Paramaribo, the capital of Suriname, is not only the largest city in the country, but contains over half of the country's population.\n\n* San Salvador, the capital of El Salvador, is the largest city in the country, and its metro area contains about two-fifths of the country's population.\n\n* Ascunción, the capital of Paraguay, is the largest city in the country, and its metro area contains about two-fifths of the country's population.\n\n* Santiago, the capital of Chile, is the largest city in the country, and contains almost a third of the population of the country.\n\n* San José, the capital of Costa Rica, is the largest city in the country, and its metro area contains a third of the population of the country.\n\n* Guatemala City, the capital of Guatemala, is the largest city in the country, and its metro area contains about a third of the population of the country.\n\n* Buenos Aires, the capital of Argentina, is the largest city in the country, and its metropolitan area contains about a quarter of the population of the country.\n\n* Lima, the capital of Peru, is the largest city in the country, and it contains about a quarter of the country's population.\n\n* Georgetown, the capital of Guyana, is the largest city in the country, and it contains about a quarter of the country's population.\n\n* Panama City, the capital of Panama, is the largest city in the country, and it contains about a quarter of the country's population.\n\n* Mexico City, the capital of Mexico, is the largest city in the country, and its metropolitan area contains about a fifth of the country's population.\n\n* Caracas, the capital of Venezuela, is the largest city in the country, and it contains about a fifth of the country's population.\n\n* Bogotá, the capital of Colombia, is the largest city in the country, containing about a sixth of the country's population.\n\n* Managua, the capital of Nicaragua, is the largest city in the country, and it contains about a sixth of the country's population.\n\n* Tegucigalpa, the capital of Honduras, is the largest city in the country, and it contains about an eighth of the country's population.\n\nOn the American continent, only Canada, the United States, Ecuador, Belize, Bolivia, and Brazil do not have a capital city that is not the largest city in the country. Almost three times as many countries have capital cities that are not only the largest city in the country, but in many cases contain a disproportionately huge percentage of the country's population.\n\nEdit: I forgot Paraguay. Turns out it's like most American states: the capital is the largest city.", "I am not a historian or an urbanologist, so you should probably take the following with a grain of salt, but...\n\nWhat I think you may have noticed is that some countries, like the UK and France, have a primate city, which is when one city serves as the political, financial, cultural, and population center of a nation. Here's the wikipedia link to a list of primate cities with some background info on the concept:\n\n_URL_0_\n\nAs you can see, there really isn't an old world/new world split when it comes to primate cities/no primate cities. The US and Canada don't have primate cities, but Mexico and Chile do. England and France have primate cities, but Spain and Italy do not. I know this wasn't exactly your question but I hope this helps.", "Dzukian pointed out that American states often have their largest city as their capital.\nI'd like to note that several European states have their capital not in the largest city:\n\n* the Rhine-Ruhr metropolitan area has twice the population of Berlin\n* Istanbul (the largest city in Europe) is three times more populous than Ankara\n* Zurich, Geneva and Basel are all larger than Bern." ]

[ "They don't actually slow the car down, they wake the driver up, or pull him away from texting etc. They are an engineered-in warning system.", "By annoying the driver, who slows down to reduce the vibration and noise that the rumble strips cause." ]

[ "It is possible for it to condense, but it will not happen as readily compared to hydrophilic surfaces. While surfaces generally aids the formation of droplets, the rule of thumb is the stronger the interaction the better. If the surface is highly hydrophobic then it won't be that much more favorable to form on the surface than it is for water to simply just form a droplet on its own. \n\nWater typically prefers surfaces like glass, metal, some plastics, etc that are hydrophilic. ", "Water may condense more readily on a hydrophilic surface compared to a hydrophobic surface at the same temperature due to the high surface energy required to form beads.\n\nIn many applications such as lenses for cameras or swim goggles, it is much better to have a thin layer form on a hydrophilic layer compared to beads forming on a hydrophobic layer. \n\nThe beads are bad optically because they act as tiny lenses, which causes light to refract in several different directions. The thin later on a hydrophilic layer is almost perfectly optically transparent." ]

[ "I own one of these as well. It is basically ensuring that the note will be legal tender once the South won the war. Since this never ended up happening and the signs were looking dire after Gettysburg, many began disregarding them near the last years of the war, causing massive inflation.\n\nYou can read more about Civil War money here: _URL_0_ ", "I'd like to see photos just for the sake of seeing such a cool peice of history. ", "Is 'obverse' a fancy way to say 'front'?", "To expand a bit on /u/a_sage_chair's answer, note the other text on the bill: \"The Confederate States of America will pay TEN DOLLARS to bearer\"; that is to say, you can exchange it for a certain amount of gold. The CSA (and the USA, and practically everyone else in the world) were on a gold currency at the time: The bill is not \"really\" money, but it can be exchanged for \"real\" money and is much more convenient to carry around. But because the Confederate government needed its actual gold reserves, such as they were, to pay for guns and whatnot, their paper money had the hedge; \"you can get the gold, but only two years after the war ends\". The US chose instead to suspend payment in gold entirely, and issued \"greenbacks\", which were not redeemable for gold. These are both financial methods, ie accounting tricks, to mobilise the real economy, consisting of loaves of bread and young men. " ]

[ "It's only a certain type of goat that does that. They're generally bred that way then included in herds so that if a predator comes, that one collapses and distracts it while the others can get away.", "There is a breed of goat that does this, no one knows 100% why but the running theory is that they have deficiency in an ion channel. This prevents the \"go\" signal in neurones connected to muscles from reducing during times of stress. so when the animals are frightened they have constant active muscle neurones and so their muscles all contract at the same time and they seize and fall over.\n\nThere are other theories about their muscles not clearing calcium properly however I think there was some group studies showing a link to ion channels in the nerve cells.\n\nEdit: spelling (some dayum hot clearing;)" ]

[ "American aircraft carriers use something called a catapult to launch its jets. What this means is the jet's front wheel is attached to a steam powered track that launches the jet at high speed to the tip of the carrier and the plane has enough speed to achieve lift-off.\n\nBritish aircraft carriers use something called a ski-jump. There is a ramp at the end of the carrier which helps the planes get enough height to achieve lift-off.\n\nYou can read about this here: _URL_0_", "They have different launch methods. American carriers use catapults, British (invincible-class) carriers use unassisted launch. Ski-jump ramps help to increase the maximum takeoff weight of the plane compared to flat unassisted horizontal launch. Russians also use ski-jump ramps. \n", "The other posters are right, the ramp helps planes take off, but it also reduced the amount of space you can use to park aircraft, so larger american carriers that don't need them leave them off. American carrier designs, since as far back as the 1920s, have always sought to maximize deck space.", "The real question is which is more effective?\n", "American aircraft carriers use something called a catapult to launch its jets. What this means is the jet's front wheel is attached to a steam powered track that launches the jet at high speed to the tip of the carrier and the plane has enough speed to achieve lift-off.\n\nBritish aircraft carriers use something called a ski-jump. There is a ramp at the end of the carrier which helps the planes get enough height to achieve lift-off.\n\nYou can read about this here: _URL_0_", "British carriers are designed for Harrier jets which can take off under their own power off a sloped deck. Their engines can be turned downward to assist takeoff.\n\nUS aircraft are launched off the carrier with a catapult that accelerates the plane from zero to flying in 2 seconds. US carriers can fly a range of aircraft using this system.", "They have different launch methods. American carriers use catapults, British (invincible-class) carriers use unassisted launch. Ski-jump ramps help to increase the maximum takeoff weight of the plane compared to flat unassisted horizontal launch. Russians also use ski-jump ramps. \n", "The other posters are right, the ramp helps planes take off, but it also reduced the amount of space you can use to park aircraft, so larger american carriers that don't need them leave them off. American carrier designs, since as far back as the 1920s, have always sought to maximize deck space.", "The real question is which is more effective?\n" ]

[ "The simplest test to distinguish species is whether or not they can produce offspring together. Both Lebron and DeVito would be capable of impregnating a standard human woman so they're the same species.\n\nThere's some weird edge cases & exceptions but they're not really important for your questions.", "Species are defined in reference to a common ancestor and not solely on similarity. In humans the differences in height are not substantial enough to define a different species. The bears are distinguished as separate species a) since all brown bears can potentially reproduce and are isolated from mating with black bear b) they are defined or identified using other traits besides \"color\" (which are shared derived traits according to Biologist). ", "To be the same species you need to be able to produce fertile offspring. 2 Humans no matter what ethnicity mating can produce fertile offspring. \nSome species can mate and produce offspring, but their offspring are infertile, such as when a horse and a donkey mate they produce a mule, which is infertile therefore they are different species. \n", "A few people gave pointed out that one of the defining characteristics of a species is the ability to breed and produce fertile offspring. I'd like to add that the physical differences, from a biological perspective, between Danny Devito and Lebron are pretty minor. Overall body size, skin color being the obvious ones. Take a look at an animal like the angler fish to see how completely different members of the same species can be. As a species humans are actually lacking much genetic diversity.", "Well, there are a [few](_URL_0_) different ways to define a species. That list is a little long, so here are the three main definitions, in order of least to most likely to result in defining a new species.\n\n* Phenetic: Determined by differences in morphology, aka visual differences, between the individuals.\n\n* Biological: Determined by whether or not the individuals are able to produce viable (fertile) offspring.\n\n* Phylogenetic: Determined by evolutionary history of traits that may or may not be visible, such as a coloration pattern or the ability to produce a specific protein.\n\nThese all have trade-offs, but the biological species concept is the most-used. When you're talking about something like bacteria, however, other species definitions like the phylogenetic concept become much more useful.", "There's also a sociological component to your question that can't be ignored. There was historically a time when (white) people did argue that Lebron James' ancestors were essentially a different species from (some) if Danny De Vito's and were treated very differently. There has been a social pressure to move away from that kind of thinking because biologically, mentally, spiritually, etc. Lebron and Danny are similar enough that you can't justify treating them differently as a function of the few ways that they're different. The science of speciation is really interesting but the question you're asking isn't about science but about society.", "If Danny had a son and James had a daughter those two could have a child together. ", "Shut up deandra\n\n", "Tuned in to this thread to learn things and stuff, pleasantly surprised to not find any racist comments (yet).", "Well if Lebron and Danny really love eachother. They do a special handshake, and nine months later Arnold comes out. But then Arnold needs to be able to have a special handshake of his own and make babies of his own for Danny and Lebron to be considered the same species.", "There are differences between two black bears that we aren't accustomed to notice, just like I'm sure that all humans would look the same to a bear.", "Obligatory \"Twins\" joke. I feel old now.", "There's a lot of different answers in this thread but it looks like what comes out of it is a bit of subjectivity when classifying species and that humans don't necessarily play by the rules when it comes down to classifying themselves. Another big part is the actual similitude between the 2. A lot of species that look similar can actually be quite different : for instance, despite looking the same, black bear and brown bear's common ancestor date from [5 million years ago](_URL_0_) ( almost as big of a difference as the [7 million years that made the split between chimps and us](_URL_1_) ).\n\nThere's actually a short [wikipedia page](_URL_2_) going over some debate regarding human classification. Sorry that it's not so much ELI5 but worth checking out if you're really wondering.", "To put it simply, it all depends on how you define species. Scientists can't agree on one single definition because most hard definitions end up resulting in humans being considered different species, which is the most politically incorrect thing a scientist could suggest.\n\nIf we use genetic similarity, since we already consider chimps and bonobos different species, we'd have to consider humans different species (since the difference between chimps and bonobos is similar to the difference between different human groups).\n\nIf we use shape and size and looks, humans come in extremely different forms, enough to warrant calling them different species.\n\nSame for social structure.\n\nAnd if the test is the fertility test (can they produce fertile offspring?), we have members of different species producing fertile offspring.\n\nSo scientists have decided to agree to differentiate species based on what's most acceptable to the fashions of the age. Nazi scientists would say there are different species, others would say we are all the same.\n\nPersonally I think the whole argument is foolish. It's all just bickering over a name. The differences are there regardless of what we call the different groups of humans; different sub-species, races, ethnicities or populations of similar genomic structures.\n\nWhenever there is a bickering over a name, someone's agenda/politics is being threatened. There is no bickering on whatever the fuck we call the sun or the moon, because nobody gives a shit what you call them. But when it comes to race, some people stand to gain and some people stand to lose (or think they stand to lose), and so all hell breaks lose.\n\nAnd the most intelligent among us reserve our right to think whatever the fuck we want, leaving the bickering over names and labels to idiots.", "Because if lebron fucked danny's daughter they could make babies that could reproduce. It's the same with a Great Dane and a toy poodle.", "May be a bit late to the discussion, but here's my take:\n\nThe definition of species takes many different forms, both in biology and in our understanding. The most commonly accepted definition is: Can these two organisms procreate and produce an offspring that can also procreate. (all that matters in biology is sex/babies)\n\nThis can be stopped/prevented in two forms, either Pre-zygotic or Post-zygotic methods. Let's go through each one:\n\nPre-zygotic (literally meaning *before baby is created in womb*):\n These are restrictions such as geographic boundaries (opposite sides of a canyon), mechanical boundaries (that male part doesn't fit in the females), or behavioral differences that will prevent two organisms from even having an opportunity to actually attempt procreation. These will sometimes be overwhelmed in specific circumstances (mostly human interaction), but, if overwhelmed, will, in most cases, result in an \"unviable\" organism. (can't produce another baby, remember what Biology is all about)\n\nPost-zygotic (after the baby is *created in womb*):\n These are restrictions that arise after the two \"species\" have had sex and created a fetus. Whether it be chromosomal differences, the inability to form gametes, or the fact the subsequent infants become less and less viable. (yes, even if the first set is viable, if the next ones to come aren't, it's also considered unviable. called Hybrid Breakdown.) The point is, this type of speciation is the fact that although reproduction can occur, it does not better the species in itself, and is, because of that, not significant (in terms of biology)\n\nThese definitions only arise because they give us as humans at least some way of categorizing all the organisms on earth. Although prizzlies exist and are viable, they are very rare to occur in natural situations, and because of stark differences in \"race,\" are seen as unique. (behavioral, geographical differences).\n\nJust like most scenarios in the natural sciences, it's always about perspective. Sometimes it's easier to accept a specific understanding simply because it prevents further confusion and is sufficient in most cases. \n", "Human language, and peoples feelings. \n\nThats pretty much it. The laws we write for nature don't apply to us, because someone will always want to make it a negative. And hurt some groups feelings. I'm not saying any race is better. But I'm fairly certain there's no reliable racial studies simply because someone either will end up at the bottom. Or they'll feel like they have. \n\nThen you have racism/classism all over again.", "Think of it more like dogs. Danny D is a pug. LeBron J is a self centered baby.", "Beware of relativism inherent in your own species. A wild brown bear would perceive Lebron James and Danny Devito as big and small humans but isn't going to make much more of a distinction on an initial encounter. Put it in a room with a black bear and it will immediately perceive that it is very different to one of its own sloth. The smells and communication techniques will be different enough for it to register as a very different beast. \n\nThis is for the same reason that I was recently plagued by white guilt when I confused two GPs as the same person because they were both of Asian descent. Essentially, the closer you are to a species the easier it is for you to perceive differences. ", "That's because Lebron and Danny devito could breed and the bears can't. ", "It's worth noting that polar bears and grizzly bears are a bit more seperated evolutionarily then different ethnicities of human.\n\nI believe that it's only about 100,000 years between human ethnicities, yet p. bears and g. bears are closer to 7-10 million.\n\nHow two things look and behave can be a poor measure of speciation. \n\nBiological species definition (Can they make fertile babies?) is also pretty flawed. It only really works for animals, and even then it's pretty hit and miss (Asexual reproduction, yo! Also plants. Plants are batshit insane). \n\nAll in all, I am a bit biased towards phylogenetic evidence! I'd load up some key regions from Lebron and Danny's genome (Why, I have them right here! (Not really)) aswell as some sequences from the p. bear and g. bear and compare them for differences. \n\nThe problem here is when do call two things different species? There isn't a set date where after x years two things become different species.\n\nSpecies definition all in all is only really useful for a snapshot at one particular timepoint. It serves to make it easier to talk about species, but the concept of a species is a very hard one to solidly define. Too many just break the rules. \n\nIn the end of the day, it's kind of whatever we want to label them based off of what's practical. ", "There are a many contributing factors (this is by no means a complete list):\n\n* Taxonomy, the naming of species, is in a process of change from old physiological techniques (bone size and shape, mating habits and viability of offspring etc...) to more recenct DNA techniques. \n* Species definitions are not always agreed upon. \n* There are major social and cutural ramifications of classifying the human species, especially splitting it up into multiple species.", "Because James and DeVito are practically identical, and two different species of bear are very different.\n\nBecause we are very social creatures, identification of different people is very important to us. This means that our brains focus on differences between people, exaggerating them. But we don't care about differences between bears, so we tend to ignore most of them unless we train ourselves.", "Haha, oh man. I had a biology teacher in high school who pointed this out, but instead used the shortest girl in the class and compared her to the tallest, beefiest guy he could find. That teacher also jumped from table to table screaming like a chimp one time. He was awesome.", "Sounds like OP also listened to Chris Ryan's podcast!\n\nedit:\n\nAnd you should too. He's the best.", "Can't the supermod hire someone from /r/askscience to tight up things around here? I don't want to read someone's shitty jokes.", "copied this from the joe rogan podcast, they used Shaquille O'Neil & another small actor as a reference", "A brown and black bear can't interbreed, but LeBron and Danny can.", "Danny DeVito should print out this question and have it framed.", "A female Danny DeVito and a male Lebron James could mate and produce fertile offspring, the bears could reproduce but the offspring would be sterile.", "Because Lebron James and Danny DeVito can have a baby together.", "A better comparison would be a black bear that is very \"athletic\" and really good at hunting, and another black bear that is fat and sits around all day making bad jokes. ", "A species is a group of animals that can have viable offspring that can also reproduce upon successful breeding. So someone from Mr James's family could have a child with someone from Mr DeVito's family and they would have perfectly healthy children. \n\nBut in the known cases of a Black bear / Brown bear hybrid the offspring were sterile and often unhealthy. \n\n_URL_0_", "Because brilliant scientists who spent their entire lives watching bears or digging up lizard bones want to have discovered a species all for themselves and not commit suicide because their life is pointless. ", "I'd presume because the genetic makeup of a brown bear is not the same for a black bear.\n\nEven though physical traits (phenotypes) may be similar their genes (genotypes) can be wildly different. Just like how certains flowers, trees, and insects can looks similar, but be completely different species.", "There is so much misinformation in this thread! Hopefully you will see this.\n\nBiological species concept (aka \"species much produce fertile offspring\" thing everyone is spouting out here) is hugely outdated. The generalized lineage concept is currently accepted by those up-to-date in the field.\n\nSure, two individuals of different species *tend* to be unable to produce viable offspring, but this is a property, not the definition of a species. Nowadays, scientists can use statistical methods to delimit species based on divergence date estimated through sequencing DNA. It's not as subjective anymore as most of these people are claiming. Since Lebron James and Danny DeVito's ancestors diverged not too long ago (on a geological time scale) they are absolutely the same species.\n\nSee any papers by Kevin de Queiroz. Try this one: _URL_0_", "Well the species known as human are made up of many sub species such as:\n\ncaucasoid (homosapien + neanderthal)\n\nnegroid (homosapien)\n\nmongoloid and other smaller sub species such as pacific aboriginal etc.etc.\n\nit's not racist, it's just science, we are all human but with that there are sub species as well all enjoy different characteristics which are innate. \n", "Lebron James and Danny DeVito can mate (or at least, mate with each others' sisters) to produce probably nonsterile offspring.", "Both Lebron and DeVito have the same homologous structures that the rest of humans share with other animals, which also correspond to other species with similar structures. For instance, whales and birds share a similar bones structure where the bird's wing is and where the whale's flipper is, however they don't operate for the same purpose. While Lebron and DeVito may have different sized femurs, they are both used for the same purpose meaning they are most likely the same species.\n\nNote: This is just one of the many ways that species can be compared, and it is by no means the most accurate. You can also differentiate species through fossils, DNA testing, interbreeding (many reasons that it won't work), and probably some other ways that I'm forgetting. ", "The way you ask the question is a little misleading, since you're taking opposite extremes. Lebron James is taller than 99% of men, while Danny Devito is shorter than 99%. When you intentionally take two very different looking people, of course a question like yours will arise. When you look at the averages, though, and ask something like, \"How are Brad Pitt and Tiger Woods considered the same species?\", the answer becomes a little more obvious. ", "The spaniards BANGED the Mayans and turned them into Mexicans.", "The same reason a great dane and a toy poodle are the same species.", "Phenotype is not genotype", "The difference between those two people is the same difference between blue and brown eyes, or large or small ears. They can breed with members of the same species and produce viable offspring. Bears of different species cannot, their differences are like us and chimps.", "What about how all dogs are considered the same species? ", "Danny DeVito and Lebron James aren't as different as you think. Human brains are hardwired to recognize human faces and notice details that would seem obvious to us, but would be completely unnoticeable to others. There's a [disorder](_URL_0_) where one cannot recognize faces; their brains aren't hardwired like that. So, to someone with Prosopagnosia, they just might see Danny DeVito as a short guy and LeBron James as a tall guy, just as you could see in different black bears. To them, Lebron and Danny would be a lot closer than a black bear and a brown bear.", "Well, think of it this way.\n\nIt's not like Species are what they are, and that we discovered that fact. We made the shit up. We decided, and we could easily undecide it if we wanted to.", "Those are exceptions than the rule (your bear example). The 'exception' rule should be considered as important since the tests for species were pretty loose before genetic diversity tests came in.\n\nForget about other animals, humans don't have enough genetic diversity to classify different races as different species. That's the scientific reason.\n\nPolitical reasons, humans are intellectually evolved to the point where classification of races as species (even if it were scientifically true) would be very controversial and polarizing.", "It's all in the biology, they just don't split up humans into seperate species\n\nalso, brown bear (Ursus arctos) (genus = Ursus) (species = arctos) is from the same genus as black bear (Ursus americanus), but it's species (americanus (hehehe it says anus) ) is different because members of one certain species can reproduce fertile children, while members of the same genus but different species cannot produce fertile children\n\nhumans are all 1 species, because one human can mate with every other human of the opposite sex to produce fertile children (you shouldn't try tho)\nso to get to your example: Lebron and DeVito can both mate with, lets say, Angelina Joly (but Bratt wouldn't be happy with that) and get a fertile baby (if nothing goes wrong of course).\n\nto give you an example:\ndonkeys can mate with horses (in either way, so male horse + female donkey or male donkey + female horse) which gives you mules, but mules aren't fertile, they can't get children themselves.\n(horse (Equus ferus caballus) / donkey (Equus africanus asinus) they are same genus, but different species)\n\nsource: biology in highschool and a bit of wikipedia (mostly for the right names)", "it's a matter of politics", "I think their offspring has to be able to reproduce in order to be considered the same species. So we'll only know if Lebron and Danny try to make a baby.", "It is worth noting that human brains are particularly good at picking out human differences. They are less good at picking out bear differences.\n\nNow I'm not claiming that Lebron James and Danny DeVito are more similar than a black bear and a brown bear, but the bears are almost certainly more different than one would assume from casual observation.", "Even species aren't that well defined. People say if two animals can't have an offspring then they are of different species. But one has ring species, where adjacent populations can breed with each other but if two populations are too far away from each other they can not. So species is on a continuum. A great evidence for evolution btw.", "Danny Devito already made a documentary about this with Arnold Schwarzenegger called \"Twins\" ", "Do you mean like a Poodle and a Mastiff? ", "Brown bears taking all our jobs. ", "LeBron James and Danny DeVito should breed.", "I think different races sub species. We're all houman and we can all reproduce with eachother, but most races are adapted enough to their native ranges that they should be considered sub species. Of course there's the issue that labeling races as sub species would give racists and supremacists something new to mess around with.", "I must have stumbled into the \"Explain Like I'm a Scientist\" sub-reddit.", "To refine infocide's response to a degree: \nIt all depends on your criteria! \nIn fact, even within biology and biochemistry, there are multiple ways to categorize animals. When making general distinctions, there are methods that divide species according to anatomical, reporductive, and genetic differences as pointed out. \nHowever, on a day-to-day basis, the same biochemist/biologist, may argue for a relation of two species based on their genomes (DNA), transcriptomes (RNA or expressed genes), or their proteomes (actual proteins manufactured and incorporated in cell structure and function). \nPhylogenetic trees (those stickly diagrams that show proposed organisms on various \"branches\" that diverge from common ancestors) are generated by statistical comparison of sequences of DNA, RNA, and proteins. These can all be very different and employed to relate species you wouldn't think are the same at all depending on which aspect of life (or cell function) you are studying/comparing.", "two organisms are consitered the same species if they can mate and produce fertile offspring, assuming one is male and the other is female", "Historically \"species\" has been used to mean the largest group that can reproduce to produce fertile offspring. Since all humans can reproduce and produce fertile babies, we are all classified as the same species (Homo sapiens sapiens). ", "I feel like this question borders on violating the \"not for literal five year olds\" rule. The genetic difference between a short white guy and a tall black guy are extremely tiny compared to the genetic difference between 2 different species of bears. The definition of species is obviously not based on what looks physically similar to an untrained human eye, especially since the human brain is wired to notice small differences between humans.", "if Lebron James banges Danny DeVito's sister they have the ability to obtain a fertile child. So by definition they are the same species ", "If Lebron James had sex with a female version of Danny DeVito they could produce a fertile child. That's what same species means. If a black bear and brown bear can't produce fully fertile offspring then they're different species.", "I've always kind of assumed the various races of humans to be different human species. Is this incorrect?", "Haha I was listening to a podcast this morning and for awhile they discussed the same thing. They talked about how if an alien race came to earth and never saw humans before and the first they saw were Shaquille oneal and a white female dwarf they would certainly think they are of a different species. ", "Because a black bear can't reproduce with a brown bear, yet if you take to very different looking humans, male and female, they can reproduce. Hence, being the same species. ", "The human race, when comparing to other species, is incredibly un-diverse. Technically, \"race\" is just a social construct and has no genetic backing. People always say \"oh yeah? well skin is different colors and hair is different!\" and blah blah blah. But these very superficial differences may be easy to see, but they actually don't represent much. Pacific Islanders or South Indians have skin colors similar to some Africans, East Asians and Europeans both have lighter skin - the list of superficial similarities is just as long as superficial differences, despite likely differing genetic origin. Everything is just an adaptation, and human populations (to our knowledge) have not experienced natural selection to a great enough degree to create what could scientifically be defined as different \"races\" - let alone different species. In fact, due to multiple founder effects (i.e., genetic diversity decreases as small populations move farther from the original population - that is, as humans migrated away from Africa) if you were to divide humans into what would be closest to genetically defined \"races\" (although I hate using that word because, scientifically, there are no human races), there would be 3-4 races: Two races of entirely African populations, and a 3rd of everyone else. Some human genomics researchers also advocate for a 4th genetic race, which would be constituted of Pacific Islanders and Aboriginal Australians. \n\nThere's also the complicated fact that speciation is defined by sexual isolation. But the line between the ability and inability to interbreed is slow to be created, and evolutionarily, could take millions of years (and many generations of isolation, or continued interbreeding where more \"pure\" species members are more fit to survive). Because the line between species can be hard to draw - not only genetically, but physically - ancient humans interbred with \"different species\" of humanoid creatures that lived at the same time, like homo erectus (giggle), Denisovans or what are known as Neanderthals. These \"mixed species\" humans were not mutants, and many survived - we know because of the distinctly Neanderthal, Denisovan and other early humanoid genes that are found within our modern human DNA. Some humans, especially Europeans, are significant portion Neanderthal (fun fact: red hair/\"gingerness\" is a Neanderthal trait! so if you're a Catholic and think only humans have souls...)\n\nSAUCE: studied genomic perspectives on human evolution in school so... My professors!\nedits: clarifying and grammar" ]

[ "The Riemann integral is *defined* as a limit of Riemann sums - you need them to prove properties of the Riemann integral, such as linearity and the fundamental theorem of calculus.\n\nThere are other ways to define an integral, such as the Lebesque integral, which is defined for a larger class of functions than the Riemann integral (and is equivalent to the Riemann integral for Riemann integrable functions). The Riemann integral is usually introduced first since it doesn't require measure theory.", "The Reimann series is the eli5 for integrals. It's just way to teach the concept of an integral to someone who doesn't understand it yet.\n\nIt's also a good numeric approximation that's easy to implement. If you are computationaly challenged, it's easier to calculate a bunch (but still finite number)of areas and add them together than it is to actually do the calculus." ]

[ "Testicular torsion can happen and is insanely painful. Luckily for the most part the connective tissue in there keeps them from moving out of place much. ", "It is entirely possible to tangle them. It’s a condition that can really hurt. However for the most part, you have connective tissue that consists of fat and ligaments that keep everything in place. Almost every organ in your body has the same thing that’s why your organs don’t go flying around your body when you go on a rollercoaster for example" ]

[ "Because champagne is under pressure due to carbonation. Wine is not bottled with any pressure intended. ", "Follow-up question: if a wine cork had a top, would it be removable by twisting?", "Conventional wine is flat, sparking wine (champagne, prosecco, etc.) is not, and therefore, has a significant amount of pressure buildup. The flared single use champagne cork is necessary to keep that pressure in, while a traditional cork would simply shoot out of the bottle. An analogy would be water bottles vs soda bottles. You can't use the thinner plastic and shorter cap design on a soda bottle because the carbonation would cause it to burst." ]

[ "I believe it is because the first person has built up the static but hasn't become grounded where the second person is and so receives the shock.\n\nIt would be like putting your hand in a toaster, it isn't hurting the toaster as it is just passing through into the person for the real shock.", "When you become statically charged, electrons gather at the **surface** of your **skin** (or ON TOP of it). They distribute all across your body equally. When you touch someone, the charges have a means to travel. All the electrons gather at the point of contact, and travel **through** (or IN) the other person. \n\nSo, in this sense, one person has charge ON them, one person has charge IN them. The person with the charge IN them will experience the shock. The shock is felt at the point of contact, because this is the bottleneck of electrons that travel IN to the person.", "I'm kind of shocked this didn't immediately turn into a pun thread..." ]

[ "From my understanding, breast size is more to do with displaying age than anything else. [Larger breasts are more easily identified as \"old\"](_URL_1_) than smaller ones. [This helps men identify fertile females](_URL_0_), hence the mild preference for larger breasts.\n\nThe breast size has little to do with milk production or even energy reserves, but was sexually selected for as a measure of youth and fecundity. \n\n", "Thought these articles were interesting and raise some new points. \n\n[How men perceive breasts based on social sexual orientation ](_URL_1_) \n\n[Men tapping into maternal bonding wiring through foreplay](_URL_0_) ", "[Gluteofemoral fat](_URL_0_) is actually strongly correlated with quality, and somewhat correlated with quantity, of breastmilk. The findings in the study linked show that the particular kind of fatty chains stored in big booties are particularly nourishing to neonatal brains, and that woman with an ideal WHR (waist-hip ratio; basically that hourglass figure that women strive to have) has more neuro-developmental resources to offer her infant. \n\nBreasts do grow in size somewhat during pregnancy because the milk ducts are filling with colostrum, the \"first milk\" that women produce. It's incredibly calorie, fat, and nutrient dense, and a middling yellow in colour, as opposed to the more traditional whitish milk needed by more mature infants (past the first week or so). ", "As many people have already pointed out, breast size does not correlate to milk production. A woman's breasts (non-pregnant, non-nursing) are basically entirely fat tissue. The actual glandular tissue doesn't start to hypertrophy until prolactin levels rise during pregnancy. That is why they grow, but the size prior to prolactin has nothing to do with milk production. Interestingly, humans are some of the only mammals that develop and maintain breast tissue in the absence of lactation. Breasts form initially in response to the elevating estrogen levels of puberty and are considered a secondary sex characteristic. " ]

[ "To follow up on the two other posts, the changes in precipitation will be effected by where you live. Not everyone will experience the same thing. \n\nIn general there will be more seasonality to rainfall - more rain will fall in a short period of time (restricted to a few months) and then perhaps no rainfall for many.\n\nPlaces which already experience water stress - either to ecological factors (they are in a desert) or human ones (the population is too big to sustainably extract local water resources) will only get worse, probably not better.\n\nFor instance, I live in Canada - we have a lot of fresh water compared to our population size. However, most of it is glacial. This will be a big problem as glaciers retreat, this will reduce the amount of spring water melt that we rely on to fill our dams for water consumption. Also, in the prairies water is expected to get more seasonal - which isn't exactly ideal for crop growing. It can involve very wet spring and a very hot and very dry summer.\n\n\"...It must also be kept in mind that while a rise in temperature may mean a longer growing season and arable area, it will also have other, adverse affects. Current trends indicate that the prairie climate of the future will feature increased temperatures, a lack of moisture and increased rates of evaporation. These factors could result in severe droughts, while hot, dry temperatures will create more favorable conditions for weeds and insects. There will also be a risk of poor herbicide performance.Climate change will modify rainfall, evaporation, runoff, and soil moisture storage. With a warmer, dryer climate, there will be increased pressure to develop crop varieties resistant to drought\" - from agriculture and agri-foods canada.\n\nThis will probably be the same for the crop regions of the USA. Drought heat and seasonal rains will be typical.", "This is a very broad question. I'll rattle off a few ways that come to mind, but a thorough answer would fill a book.\n\n- Many people get their water from glaciers; the world's glaciers are shrinking, and if they disappear, many people will lose their supply of fresh water.\n\n- Rising sea level due to warming of the oceans means that ocean water will find its way further inland, turning some coastal wells brackish.\n\n- As global weather patterns change, precipitation will change in many places. The Sahara will get even less rain, whereas areas like the Caribbean and the west coast of the US will get more.", "To follow up on the two other posts, the changes in precipitation will be effected by where you live. Not everyone will experience the same thing. \n\nIn general there will be more seasonality to rainfall - more rain will fall in a short period of time (restricted to a few months) and then perhaps no rainfall for many.\n\nPlaces which already experience water stress - either to ecological factors (they are in a desert) or human ones (the population is too big to sustainably extract local water resources) will only get worse, probably not better.\n\nFor instance, I live in Canada - we have a lot of fresh water compared to our population size. However, most of it is glacial. This will be a big problem as glaciers retreat, this will reduce the amount of spring water melt that we rely on to fill our dams for water consumption. Also, in the prairies water is expected to get more seasonal - which isn't exactly ideal for crop growing. It can involve very wet spring and a very hot and very dry summer.\n\n\"...It must also be kept in mind that while a rise in temperature may mean a longer growing season and arable area, it will also have other, adverse affects. Current trends indicate that the prairie climate of the future will feature increased temperatures, a lack of moisture and increased rates of evaporation. These factors could result in severe droughts, while hot, dry temperatures will create more favorable conditions for weeds and insects. There will also be a risk of poor herbicide performance.Climate change will modify rainfall, evaporation, runoff, and soil moisture storage. With a warmer, dryer climate, there will be increased pressure to develop crop varieties resistant to drought\" - from agriculture and agri-foods canada.\n\nThis will probably be the same for the crop regions of the USA. Drought heat and seasonal rains will be typical." ]

[ "In every place I know of, roads are named by the government. But if the road was privately built, often the government will just keep the existing name.", "My mom's friend did this so I don't have many details, but basically she would pick names out from a big book of street names. She said it was sorted by groups that we see like types of trees, etc", "I worked at an engineering firm a few years back and when we designed a new development for a company we got to write in whatever street names we wanted. The company we were doing the work had to approve the names and then they had to be approved by the government. The government essentially just made sure the names didn't actually mean anything bad or there wasn't a street already named that in town. I don't remember how often the names went through to become the actual street names, I only remember one time the customer vetoing the street names when a guy tried to get all of the streets in the development named after violins.", "I guess it depends on where you live and what kind of street is. Also, some countries want to privatize the streets, as some political parties in Germany are trying to do right now to earn some money. In these cases you can literally just buy the street (or part of a street, this law luckily didn't get through) and then you can name it whatever the f--- you want.\n\nWhat I personally experienced is that a newly built street could also just be named by the people that live there, or that are going to live there, this happened to two of my relatives.\n\nA new neighborhood was going to be built, and after all the houses were sold, the local government decided to leave the decision to the future owners. Basically they did an election deciding on the prettiest sounding name, although this probably only happens in suburban streets. \nBut maybe I'm wrong and a Mister Fifth Avenue is very happy that the Times Square is on his very own street.\n\nPersonally I think this is the best way, as the streets actually get beautiful-sounding names.", "well this will depend entirely on the jurisdiction, tradition etc. reddit is an international site, why do people never mention where they are talking about?\n\n\nIn the UK, streets named pre-victorian era will have just had traditional names based on geography or function. The high street, the market street, the river lane, the Manchester Road, the London Road etc. These stuck when addresses were formalised. \n\nAnyway generally in the UK: developers can decide on street names but they are approved by local government", "...just completed a housing development in Australia creating new streets and a cleverly worded letter was put to council that street names were to be named after the main investors children in respect of his valued financial investment in the state. \nSo There you have it a lasting legacy for generations to come. " ]

[ "For medieval history, [RI-Opac](_URL_0_) is the best database I've used so far. Just type in the relevant keywords and it will find the articles/monographs related to that topic, even various PhD/MA theses. It also arranges them by date of publication, so it is super useful for finding recently published stuff. I use Google Scholar sometimes too, but it often brings up irrelevant hits in my experience. Another good way to look for recent scholarship is to find the most recent book on the topic you are interested in and look through the bibliography; this is especially useful for finding articles written in other languages.", "I use my library. Literature is on the 6th floor, history on the 4th. The catalog is online. If I have one reference number I know where to go and can shelf read.\n\nThere are also a number of sites online that have translations or the original text like Perseus or Livius or The Latin Library." ]

[ "As a librarian this question intrigues me, because I have a whole repertoire of shushes. I've consulted the Oxford English Dictionary, which has \"shush\" going back to 1925 (with one notable use being in Edna Ferber's 1929 novel *Cimarron*). But shush is an alternate form of hush, and hush goes back to the 16th century, with a notable use being Viola in Act 5 Scene 1 of *Twelfth Night* remarking \"My duty hushes me.\". The OED notes that \"hush\" derives from Middle English words like \"hussht\", with a notable use being in Chaucer's *Canterbury Tales* (The Knight's Tale).", "My Latin textbook in highschool (Cambridge purple book, I think the 4th iteration of their program) had \"sst\" as an interjection being the equivalent of the English \"shh,\" so I would say it's thousands of years old.", "As a follow-up question does the shush we use to tell others to be quiet and the shush we use to comfort babies come from the same place?" ]