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1xp87d | - curling | It may be because I am under 60 years old but, what is curling and why is it in the Olympics? I don't understand the purpose of sliding a rock across ice and why its considered a sport. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1xp87d/eli5_curling/ | {
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"Archery is a sport and it's basically the same thing, with arrows. Golf is a sport and it's basically the same thing, with a stick. Croquet is a sport and it's basically the same thing, with wickets. Shotput, hammer, discus, and javelin throws are all sports, yet curling requires more precision as you're hitting a target rather than just going for distance. All of these sports are or have been Olympic events. Curling is like playing horseshoes with hockey pucks, it takes a lot of finesse and muscle control, and then there's a surprising amount of strategy in being a sweeper. A better question might be why you think curling shouldn't be an Olympic sport rather than asking why it should."
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9b6qp0 | Why did complex, increasingly centralized cultures seem to spring up almost simultaneously around the world? | We see civilizations with great levels of centralization and organization seem to pop up all over the world, in Mesoamerica, West Asia, China, and the Indian subcontinent. Why is it that they seem to have come about almost at the same time but probably had little contact with each other? (Especially Mesoamerica to the rest of them) | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/9b6qp0/why_did_complex_increasingly_centralized_cultures/ | {
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"I'm not sure if we're talking about neolithical, bronze age, or iron age cultures; or rather what exactly do you mean by 'great levels of centralization and organization'.In any case, given the neolithical transition from the hunter-gatherer society to an agrarian society, centralization and organization are a necessity to make the sedimentary lifestyle work. Are we talking about the development of agriculture, or development of language and script? What is the exact criteria?\n\nIn any case, the timeframes considered a 'start' for the locales you mentioned :\n\n**\\*Neolithic\\***\n\n*Mesoamerica* : 3500 BC, Tehuacan culture\n\n*West Asia* : 10000 BC, Jericho culture\n\n*China* : 7000 BC, Peigligang culture\n\n*India* : 9000 BC, Bhimbetka culture\n\n**\\*Bronze age\\***\n\n*Mesoamerica* : 1200 BC, Olmec culture\n\n*West Asia* : 3000 BC, Mesopotamia and Egypt\n\n*China* : 1600 BC, Shang dynasty\n\n*India* : 2200 BC, Harappan culture\n\n**\\* Iron age\\***\n\n*Mesoamerica* : never happened on its own, until the arrival of europeans around 1500 CE\n\n*West Asia* : 1600 BC, Hittite culture\n\n*China* : 1000 BC, Zhou dynasty\n\n*India* : 600 BC, late Vedic period\n\nAs you can see, it's very hard to say they come about almost at the same time, as practically none of these 'age starting' periods coincide ( the Olmecs and Shang Dynasty being whole 400 year aparts being the closest, and a huge stretch) with West Asia clearly leading the way in terms of technological development and mesoamerican cultures staying in Bronze age for 2700 years. Also, if we rearrange this table to be locale specific instead, we can see completely different time-technology development curve, with West Asia and India going through the neolithic period in some 7000 years, and Mesoamerica in 2300.\n\nSocietal and technological development is an effect of a million of factors ( like geography, climate, local flora, fauna, and so on), so even in a hypothetical situation that the developments of certain cultures would've coincided to be almost in temporal parallel, it couldn't be surmounted to anything more than a coincidence."
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5oe5ke | North-Western Europe today has some of the lowest corruption rates in the world. For how long has this been the case? | And would anyone care to discuss any important events that caused the downward trend? Is it purely due to wealth (which seems unlikely to me due to corrupt oil-states), democracy (which again seems unlikely, as many democracies have high corruption) or something else? I recognise these are both tricky questions. | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/5oe5ke/northwestern_europe_today_has_some_of_the_lowest/ | {
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"The short answer for Denmark would be since around the age og absolutism in Denmark. It wasn't as low as modern day Denmark but it was decreasing. This was due to a few new laws introduced to make sure the king held absolut power and that his authority was not to be doubted. It effectively removed many of the nobles whom had their own agendas and replaced them with either better nobles, clergymen or loyal and talented commoners.\n\n-\n\nLater the loss of a lot of territory united the danish people and the country became homogenous with almost only ethnically danes living in the country. This unification through loss meant that danes became more trusting towards each other. Also the country had become a democracy through reforms and had kept the tradition of reforms instead of revolution.\n\n-\n\nOnce again skipping ahead to the 1930s and the great depression effect on Denmark. Instead of squabbling amongst each other forever and letting the people suffer the largest parties came together and made “kanslergade forliget” a compromise starting the welfare state in Denmark. By not abandoning the people and creating the foundation for the modern welfare state in Denmark the idea of solidarity grew in popularity. This became especially true in the last half of the 1900s were the moderne danish state was made. It is stil one of the core values of most danes today.\n\n-\n\nOvertime this low corruption and unification of the danes have grown into trusting of one another which again made bribes and the likes less needed further boosting the growing trust. \n\n-\n\nIt’s important to remember Denmark haven't really been in many serious wars since the endless warring against Sweden except for 1864 were around 1/3 of the countrys farmland was lost. This relativ peace and stability created decent living condition. Not saying they were the best but enough to make sure rebelions an revolutions like the ones in france didn't happen.\n\n-\n\n**These are the most important things about the danish development of low corruption rates.**\n\n- Harsh laws against corruption during the Age of absolutisme\n- Fairly homogenous and unified population\n- Small country\n- “Hvad udad tabes skal indad vindes” (what is lost outward shall be won inwards)\n- Kanslergade forliget (The Kanslergade agrement )\n- Decent or above living standards\n- Social reforms\n- High social mobility \n\n-\n\nSources: \nMette Frisk Jensen - Korruption og embedsetik\n"
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3f85a2 | How do fuel tanks in spacecraft empty/pump effectively in zero G? | If a tank is upright on Earth, a pump at the bottom will always draw (liquid) fuel out as gravity pulls it to the bottom, right? So how do spacecraft keep the fuel from having air pockets or space next to a pump (as i assume this would ruin the thrust)? I have heard something about spinning the tank so centripetal (centrifugal?) force sends it to the outside, is this commonly used in spacecraft? Thank | askscience | http://www.reddit.com/r/askscience/comments/3f85a2/how_do_fuel_tanks_in_spacecraft_emptypump/ | {
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"Spinning might be used, but it is usually easier to give a short boost with your RCS (usually runs on compressed gas, so it doesn't have this problem) to settle the fuel in the bottom of the tank, after which the engines can turn on and the acceleration of the rocket will keep it in place.\n\nAnother method which is sometimes used is to fill the \"empty\" part of the tank with an inflatable bladder, usually by filling it with helium.",
"In rockets the fuel is kept at the bottom of the tank by the thrust of the engine. This obviously stops working once the engine is shut down, and as such most rocket stages cannot restart their engines. A few upper stages can, however, as do most satellites and spacecraft. They can use one of the following methods:\n\n* Propulsive venting: The Saturn V third stage burned once to put the spacecraft into earth orbit, and again to push for the moon. After the first burn the liquid propellant boil-off was vented backward, to provide a constant thrust. This thrust was tiny, but enough to keep the fuel at the 'bottom' of the tank.\n\n* Ullage burn: What /u/forhtur mentioned. Prior to the ignition of the main engine the spacecraft is given a small kick by either dedicated solid motors or it's RCS system. This properly aligns the fuel, and allows the main engine to start.\n\n* Surface tension: A common solution is to put all sorts of baffles and guide vanes in the tanks, to which the liquid sticks by surface tension. These are designed in such a way that even in microgravity conditions the engine intake will be covered in fuel.\n\n* Inflatable bladder: See /u/forthur 's reply.\n\n* Spin: many old satellites were made to spin throughout their entire lives. I suppose the centrifugal force is used to manage fuel in those satellites, but I haven't had a close look of the internals of one.\n\nThe first two solutions work for spacecraft of all sizes, but have some clear disadvantages. Propulsive venting can only be used for very short periods (such as one orbit prior to burning for the moon). Performing an ullage burn requires either dedicated rockets or a set of strong reaction control thrusters, which adds weight to your spacecraft.\n\nSurface tension is an elegant solution, but it is also weak. Hard movements and rotations will shake up the fuel, and the time it takes to restore order is proportional to the tank size. It is common for spacecraft and satellite tanks, but has yet to be applied successfully to a large rocket stage.\n\nBladder tanks don't work with cryogenic propellants (liquid oxygen, hydrogen). The boiling that occurs would create gas bubbles on the wrong side of the bladder, defeating the point. Unlike rockets most spacecraft and satellites use so-called 'storable' propellants however, making bladdered tanks a common solution as well.\n\nSpin stabilisation has become kind of obsolete with modern advances in control systems. The advantage of non-spinning spacecraft in terms of instrumentation, solar power and communication far outweighs the benefits of spinning. This also means that fuel management by centrifugal forces is no longer common."
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2q315u | Can birds fly backwards? | I've been thinking about this for too long. | askscience | http://www.reddit.com/r/askscience/comments/2q315u/can_birds_fly_backwards/ | {
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"Only hummingbirds can, due to their unique method of flight and wing structure. Other birds can *propel* themselves backwards by pushing against the air with their wings, but they cannot fly in the sense of sustained, controlled aerial travel."
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52toka | railroad crossings don't seem to have sensors or something to warn conductors of a vehicle/object stuck on the track, why? | We have sensors at traffic lights that allow the lights to know when a car is/isn't present so that it will/won't change.
Shouldn't we have something along those lines for the railroad crossings so we won't have to see anymore videos of cars and trains being destroyed. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/52toka/eli5_railroad_crossings_dont_seem_to_have_sensors/ | {
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"Small subway style trains might be able to stop within a .25 mile or so depending on their speed. A large freight train with hundreds of cars, some of of which maybe be carrying tankers of flammable or hazardous chemicals can not stop quickly.\n\nIt can easily take a mile or more for them to safely stop. An emergency stop might happen quicker but at great risk of derailment or damaging the tanker cars and causing a spill. Sometimes the safest option is to simply plow through the obstruction on the track.",
"Here is the bottom line. Money. You are proposing, some sort of system, that would cost millions, if not billions of dollars to implement, that would at best, warn trains miles ahead of a potential problem which would create a very high false positive system and at worse, warn trains just before an intersection about a problem they can do nothing about anyway. False positives are very bad. Every time a train stops it costs money. It's not just one train that is delayed, but the entire system is disrupted. The train that stopped is now 30 minuets late but the train that wants to use the same tracks but going the other way is also delayed 30 minuets and ect, ect.\n\nCars getting stuck on train tracks is very very rare. Spending that much money on such an irrelevant problem is not a good investment of cash. For a fraction of the cost you can just print signs and post them at every intersection saying, \"If there is a problem, call this number.\" Nearly everyone has a cell phone now, 99% of all calls will be accurate and does what an expensive automated system can't do. ",
"It takes 1 to 2 minutes to stop a train. That's the reason we don't take turns at crossings the same way we do at street intersections. It is hard to stop a train and the process must start 2 miles (3 kilometers) away. While we could create an early notification system, we in fact already have. We notify motorists that they are crossing train tracks and we notify them of the presence of an oncoming train. \n\nBlocked tracks are not a significant problem for safety. Bigger problems are people trying to race a train, people dodging the crossing guards to cross in front of an approaching train, or people walking on the tracks. Compelling a train to stop whenever anything is on the track ahead of it even at a distance would undermine the fuel and time efficiency that trains offer."
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300lnn | What is the processing speed of our brains? | Brains process information with the use of electricity that flow from neuron to neuron (I think). So it is safe to say that we process information as fast as the speed of electricity * space between nerve ending and brain, or are their other variables that take part? | askscience | http://www.reddit.com/r/askscience/comments/300lnn/what_is_the_processing_speed_of_our_brains/ | {
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"Cells are covered in a lipid bilayer, which is not conductive like most metals. Instead, neuronal conductance relies on voltage-gated ion channels for propagation of electrochemical impulses. There is no traveling of electrons along a neuron like you would expect in metal and thus impulses travel much slower than the \"speed of electricity.\"\n\nFirst, there is the issue of how fast axons conduct action potentials. This can range anywhere from [0.5 m/s to 120 m/s](_URL_1_), depending on thickness of the axon and mylenation. Thicker axons conduct faster and mylenated axons conduct faster (due to [saltatory conduction](_URL_3_)). For more information, you can read the classic studies by [Hodgkin and Huxley](_URL_5_) on the squid giant axon.\n\nNext, you have to consider the time for the information to jump from neuron to neuron. Most connections in the brain are [chemical synapses](_URL_4_) and can take up to 1-2 ms to go from one neuron to another. Some synapses are [electrical](_URL_6_) and are very fast (~200 microseconds), though these are more rare.\n\nOne further variable is the distance between structures that you're interested. This distance is both in terms of absolute distance and number of synapses. This is important if you're considering the processing of information. And this is also the most nebulous variable. We can talk about how fast an impulse can travel along an axon, but that doesn't address information processing. Information is processed in [neural circuits](_URL_2_), which aren't completely serial. There are feedback and feed-forward loops. There are small-scale networks (e.g., within a brain area) and large-scale networks (between brain areas). The simplest example of processing stimuli from sensation to behavior is [simple detection](_URL_0_.) (reporting the presence of a stimulus). Detection of auditory stimuli are quite fast (140-160 ms) while visual detection is a bit slower (180-200 ms). While these times seem very fast, consider all the processing that must be required (considering how fast our neurons conduct and transmit information). We still don't know exactly what goes on in the brain within neural networks for even these simple processes.\n\n**TL;DR: our brains don't have a \"processing speed.\"**",
"Just a small note to add to the other excellent responses: Electrical impulses are confined within a neuron. Neurons communicate to other neurons via [neurotransmitters](_URL_0_), and not via the [action potential](_URL_1_)."
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"http://en.wikipedia.org/wiki/Nerve_conduction_velocity#Normal_conduction_velocities",
"http://en.wikipedia.org/wiki/Biological_neural_network",
"http://en.wikipedia.org/wiki/Saltatory_conduction",
"http://en.wikipedia.org/wiki/Chemical_synapse#Signaling_in_chemical_synapses",
"http://en.wikipedia.org/wiki/Hodgkin%E2%80%93Huxley_model",
"http://en.wikipedia.org/wiki/Electrical_synapse"
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"http://en.wikipedia.org/wiki/Action_potential"
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ouxbj | what is "individual mandate" and what does it mean for the u.s.? | What is it exactly and why do people think it's bad or good. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/ouxbj/what_is_individual_mandate_and_what_does_it_mean/ | {
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"It requires people to buy some kind of health insurance, or pay a tax penalty if they don't. \n\nPeople think it's good because we want everyone to have medical care - but it is difficult to provide that care without everyone be required to pay into the system to spread both cost and risk. Other countries do the same thing by having national health care systems.\n\nPeople think it's bad because OMGWTFsocialismBBQ."
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20c4eh | How did Canada's cold war military spending compare to that of the United States? | Obviously the State's spending was much higher but by how much? In particular, was there a time during the Cold War when Canada's spending was similar to that of the US? Also, how much did Canada's Avro Arrow compare to American jet fighters of the time in terms of cost? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/20c4eh/how_did_canadas_cold_war_military_spending/ | {
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"Canada spent about two percent of GDP on defense during much of the Cold War. [See the chart on this page](_URL_0_). \n\nFor comparison, Canada had a GDP of about $700 billion (current dollars) in 1990, putting its defense budget at about $14 billion, while the US had a GDP of about $9 trillion and defense spending of $400 billion, about 4.5 percent."
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3zzox1 | why apple is switching to swift from objective c? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3zzox1/eli5why_apple_is_switching_to_swift_from/ | {
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"I do not code, but from what I've seen at the Keynote's, it is more efficient in terms of the amount of code you have to write, some things that used to take 5 lines can now be written in 1 line. \n \n**EDIT**: [Here is a short article listing 10 reasons.](_URL_0_)"
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1p0l0v | if everyone uses wikipedia, but everyone says it is unreliable, why doesn't wikipedia stop third party edits and edit themselves? | I understand third party editors edit Wikipedia usually and Wikipedia does not have enough editors to edit every page, but with a sight as popular as wiki don't you think they could throw an advertisement in there or ask for more donations to increase valid editors?
It's just a shame wikipedias reliability is always trashed by people. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1p0l0v/eli5_if_everyone_uses_wikipedia_but_everyone_says/ | {
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"The entire idea of Wikipedia is that it's a world wide, public collaboration. You might as well ask why Reddit doesn't stop letting people post links and just hire a team of professionals to post stuff instead.",
"Because the contributors are us. We are wiki. ",
"Because the number of people they would need to hire would make it simply unfeasible. They would have to add a ton of advertising to cover the extra salary costs, and the amount of new articles would drop drastically. As it stands, they have several algorithms that go through and get rid of ridiculous edits fairly quickly and they have some staff that goes through to verify the authenticity of certain submissions.",
"Actually, [its way more accurate](_URL_0_) than you think it is. It compared to other non-public sites like Encyclopaedia Britannica.",
"I consider Wikipedia one of the most reliable sources on the planet, *because* it has thousands of people reviewing it constantly."
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11aidu | Why does POV footage of running always seem so shaky whereas when I run, my vision remains quite steady? | [This video prompted the question](_URL_0_)
When I run (or walk for that matter), my vision doesn't seem as shaky as POV footage always is. And I assume that the camera moves exactly like his head does since it is attached to his head.
Why does this happen? Does our brain automatically do the "stabilizing" for us? | askscience | http://www.reddit.com/r/askscience/comments/11aidu/why_does_pov_footage_of_running_always_seem_so/ | {
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" > Does our brain automatically do the \"stabilizing\" for us?\n\nYes.\n\nYour brain does a lot of processing of the visual signals your eyes produce - it fills in blind spots, for example, and as you've noticed, also steadies the image. The [visual cortex](_URL_1_) is the single largest system in the human brain. \n\nHowever to do this processing, your brain relies on various other cues like your inner ear and [proprioception](_URL_0_) in general - \"the sense of the relative position of neighbouring parts of the body and strength of effort being employed in movement\".\n\nFor example, when you're walking or running, you're aware of where your feet are and when they're going to hit the ground. You're also aware (if only subconsciously) of where you head is point, where your eyes are pointing, etc. Your brain is able to synthesize all this information to provide you with a stabilized visual image of what you're seeing. It's quite amazing, really. \n\nEven though the raw images from a POV video may be similar to what enters your eyes when you're running yourself, your brain isn't getting the other signals that allow it to predict the image's motion and therefore smooth it out. So POV videos look jerkier than real life experience.\n",
"Bruce Hood gives a good description, explanation, and demonstration of the processes you're asking about in the Royal Institution Christmas Lecture 2011. You can watch the very short clip of the relevant section [here](_URL_0_).\n\n",
"Also another thing, since the camera is higher up and more forward than your eyes, movement will be magnified. As an example, hold a pencil at the tip and move it like a metronome. Compare the distance that the mid point makes from left to right to the distance the eraser makes from left to right.\n\nEdit: Also the difference in field of view, if the camera has less field of view it will look more relatively shakey\n\n",
"[efference copy and corollary discharge](_URL_0_)\n\n > When an efferent signal is produced and sent to the motor system, it has been suggested that a copy of the signal, known as an efference copy, is created so that sensory signals generated from external stimuli in the environment can be distinguished from sensory signals resulting from an animal's own actions.",
"What you're looking for is called the vestibulo-ocular reflex. We automatically compensate for head movement with our eyes.\n\n_URL_0_",
"I have an artifical left leg from a deformity from birth. I walk with quite a limp because of it. \n\nWhen I walk, as far as I can tell, I am walking perfectly level. \n\nOnce in a while, I'll see myself walking twoards a store, with my reflection in the window staring back at me, and I am in SHOCK at how much I am limping. I have no idea while I walk. The same goes for when I watch a video of myself recorded by camera. \n\nWhen I record a video while walking (even slowly), I have to be super careful to level the camera as I walk otherwise, the entire video will \"limp\" to the left as I step.\n\nI usually go at least a month or many months before seeing my reflection of me walking, sometimes a year, and it's always shocking at how much I limp, where as in my 1st person perspective, I'm walking perfectly level. I figured out the brain is leveling the world for me first hand early on because of my more 'extreme' experience :-).\n\nIf there is a way in the future for me to walk as level as a normal person, it would be interesting if my brain took some time to compensate for this, and would \"show me\" something odd in a transition period while the re-training took place.\n\nIf anyone has any questions about anything related to this, feel free to ask.\n"
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djeglx | what causes heart palpitations to actually be felt? what makes them different from regular heart beats that you can't feel at all? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/djeglx/eli5_what_causes_heart_palpitations_to_actually/ | {
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"For \"skipped\" heart beats, which is one type of palpitation, typically what happens is part of your heart beats out of sync. This causes your heart to beat inefficiently; it can't properly get all the blood out. So the *next* heart beat is extra hard - its pumping more blood than normal. That heart beat after is what you actually feel (although you might feel a slight delay, the beat after feels like your heart flipping or like a dropping feeling in your chest). Enough premature heart beats in a row and you might also feel a sense of dizziness or even shortness of breath. \n\n\nOther palpitations, where you feel like your heart beat is just more... Pronounced, when its not actually faster than normal or irregular, is often just more of an awareness of your heart beat. Some positions make the feeling more noticeable, like laying down. People who have palpitations are more likely to notice them in the evening and at night - when they're laying down and have little to distract them.",
"I've experienced atrial fibrillation after heart surgery, basically when the top chambers of the heart decides to beat faster than the ones below it. Not only do the other chambers in the heart beat harder to compensate, but you can also feel it in the lungs. Kinda like running a marathon while doing nothing. You dont think about it, but how you breathe is linked to your heart rate."
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dry9ul | Before the discovery of DNA and Genes, how did people explain heritable traits passed down from mothers and fathers? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/dry9ul/before_the_discovery_of_dna_and_genes_how_did/ | {
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"These two answers by u/restricteddata may be of some interest while you await a specific answer to your question:\n\n* [Before Gregor Mendel's work on heredity, how was the scenario of two dark haired parents producing a child with blonde hair viewed?](_URL_1_)\n* [What were people in ancient societies explanation of “genetics”? For example, was it widely understood that a man’s son would (to one degree or another) resemble himself?](_URL_0_)"
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"https://www.reddit.com/r/AskHistorians/comments/al3j3z/what_were_people_in_ancient_societies_explanation/",
"https://www.reddit.com/r/AskHistorians/comments/2wjsju/before_gregor_mendels_work_on_heredity_how_was/"
]
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||
drv2du | How do you convert a more million C degree plasma into electricity (ITER)? | After managing to stabilize and sustain the plasma at ITER, how will they convert the heat of stg that's more million Celsius into electricity? | askscience | https://www.reddit.com/r/askscience/comments/drv2du/how_do_you_convert_a_more_million_c_degree_plasma/ | {
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"They won't convert the heat of the plasma directly. Much of the energy from the reaction ends up in high-energy neutrons, which, because they're not electrically charged, aren't contained by the magnetic field which contains the plasma. They'll go straight through the reactor walls, and into a lithium \"blanket\". The blanket will heat up as it captures the neutrons, and that heat will be used to generate electricity. One of the key engineering challenges is building a structure which can hold up under continuous bombardment from high-energy neutrons.\n\nA major reason that lithium is used is that when lithium captures a neutron, one of the reaction products is tritium, which can then be recycled as fuel for the reactor.\n\nThe blanket will also absorb energy from good ol' fashioned electromagnetic radiation coming from the plasma, but by design, this radiation is kept as low as possible. One way that things can go wrong is if the plasma does strike the wall and cause ablation of material, that material can cause a runaway radiative collapse where the high-atomic-number elements which end up in the plasma rapidly radiate away the plasma's heat and stop the reaction."
]
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82knzx | why are other stocks effected so much when one stock crashes? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/82knzx/eli5_why_are_other_stocks_effected_so_much_when/ | {
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"When my supplier of wine goes out of business, I get cranky and people buy stuff from me less.\n\nCompanies have the same sort of relationship between themselves.",
"There are multiple reasons.\n\n1. Problems in one stock may indicate a problem in the entire industry. If all cows suddenly got sick, the milk company’s stocks suffer and also the cow leather company would have lower future income and investors would sell.\n\n2. Investors who lose their money in the crash may overreact and sell their other stocks (once bitten, twice shy). There are also stop-loss algorithms which sell all the investor’s stock when they suffer a significant loss, which might cause this.\n\n3. The crash of a major stock will lead to lower incomes for investors, and also potential firing of employees etc which leads to decreased economic growth. This will result in lower profits for other companies and is reflected by a overall market shift downwards.",
"Only part of a stock's price is based on actual company value. The rest is based on what people think about the future prospects of the company, its industry, and the economy overall. Not all of these feelings are based on logic and data, some of them are based on fear and greed. People invested in the market know this so they're constantly watching for signs that the tide of sentiment is turning. Nobody wants to be the last to see the signs so some people are always going to jump early."
]
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2f2cpf | I've been told that the banjo is an African instrument. How did it make it from Africa to the U.S., Ireland, etc.? And how was it traditionally played? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/2f2cpf/ive_been_told_that_the_banjo_is_an_african/ | {
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"hi! more input is always welcome, but do check out this post from a few months ago\n\n* [How did the banjo, an instrument of African descent, become a staple of Anglo folk music?](_URL_0_)\n\nalso, you may want to keep an eye out for a music documentary film that did the festival circuit a few years ago, *Throw Down Your Heart* (2008) ([IMDB](_URL_2_), [distributor site](_URL_3_), [trailer](_URL_1_)), in which American banjo player Béla Fleck travels across Africa to meet & play with musicians there. The trailer includes a few short clips."
]
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"http://www.reddit.com/r/AskHistorians/comments/22uisb/how_did_the_banjo_an_instrument_of_african/",
"https://www.youtube.com/watch?v=WDCxaQhhL0A",
"http://www.imdb.com/title/tt1185405/",
"http://www.argotpictures.com/throw-down-your-heart.html"
]
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||
1kbgq7 | How much do we know about a Dog's brain? | askscience | http://www.reddit.com/r/askscience/comments/1kbgq7/how_much_do_we_know_about_a_dogs_brain/ | {
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"\n\nThis has been removed because the question is too broad or too vague. If you’re still curious, please conduct some basic research and resubmit a more specific question.\n\nFor more information regarding this and similar issues, please see the [FAQ.](_URL_1_.)\n\nThis has been removed because questions based on personal anecdotes tends to invite unconstructive speculations.\n\nFor more information regarding this and similar issues, please see the [FAQ.](_URL_0_.)\n\n\n\n"
]
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"http://www.reddit.com/r/askscience/wiki/index#wiki_avoid_questions_about_personal_or_isolated_events",
"http://www.reddit.com/r/askscience/wiki/index#wiki_make_questions_as_specific_as_possible"
]
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||
3j86pv | what is the difference between fuel economy and fuel efficiency? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3j86pv/eli5_what_is_the_difference_between_fuel_economy/ | {
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"Although if you are having a conversation with a regular person, they are basically interchangeable, I think the difference is that while fuel economy means your cars mile per gallon, fuel efficiency is the percent of potential energy in the fuel a vehicle can turn into mechanical energy if that makes sense.",
"\"Economy\" refers to the efficiency of the whole system (vehicle). \n\n\"Efficiency\" refers to the effectiveness of converting fuel into power.\n\nThey are related, because the fuel efficiency of the engine will contribute to the overall economy, but the economy will also factor in vehicle weight, wind resistance, road and tire conditions, etc. "
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8afrs4 | how the government can/does seize a website? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8afrs4/eli5_how_the_government_candoes_seize_a_website/ | {
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"The find whoever is hosting it. Get a subpoena, and issue the subpoena to the hosting agency. The hosting agency then shuts it down and turns it over to the government.",
"The way website names work is basically a phone book. When you type in \"_URL_0_\", your computer goes to a Domain Name Server and asks it for the website's IP address (the equivalent of a phone number). Your computer then calls up that IP address, where the website's computers pick up and transmit the website data.\n\nThere's a non-profit corporation called ICANN that runs the whole name thing, and they designate control of each section (.com, .org, etc.) to a different company. The directory of .com sites is run by an American company called Verisign, for example, while the .uk directory is run by a UK-based non-profit called Nominet UK. \n\nIf the government wants to seize a website, they can get a court order to take control of that website's directory entry and change it to point to government computers instead of the website's computers, assuming they have jurisdiction for the company that runs that directory or they can cooperate with the country that does have jurisdiction. This is why The Pirate Bay was jumping from domain to domain- every time the record and movie industries convinced a country to take over their entry, they just registered a domain with a company in a different country.\n\nThey can also seize the physical computers that run the website, but if they don't also take control of the directory entry, the website operators can just get new computers and change the directory to point to those computers instead."
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1iw7ct | how does the canadian government and economy function compared to america's? | From a citizen's perspective, what differences are there? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1iw7ct/eli5_how_does_the_canadian_government_and_economy/ | {
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"We don't elect our Prime Minister directly. We vote for a member of parliament, and the leader of the party with the most members after all the votes are counted gets appointed Prime Minister by the Governor General. The GG is appointed by the Queen (but she always appoints the person that the current Prime Minister \"suggests\".\n\nElections can be called whenever the GG dissolves parliament. This will happen when the PM asks for that, or after five years have phased with no election, or if the government is defeated in a vote on supply (budgets, basically). So the government can fall, and that forces an election.\n\nThere's also a senate, which is entirely appointed. The current governing party wants to make it elected, but that doesn't seem to be going anywhere at the moment.\n\nAs for the economy, it functions much like the US economy. There are stronger regulations on banking and there's a much, much smaller health insurance industry, but it's very similar.",
"Economically, we're more socialist than the US, but not by as much as you'd think. The single largest difference is that health care is publicly funded here whereas it isn't in the US. Taxes are slightly higher. "
]
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48kiq4 | Do air-breathing animals born underwater ever drown at birth? | I am watching David Attenborough's reptile series and they just showed an anaconda birthing session. The snakes all seem to get up and breath relatively quickly, but is that instinctual, or the air inside them brings them upwards? | askscience | https://www.reddit.com/r/askscience/comments/48kiq4/do_airbreathing_animals_born_underwater_ever/ | {
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"text": [
"There is no air inside the egg during gestation. Just like humans in the amniotic sac, they \"breathe\" fluid. They only begin to breathe air once they are born and the air and atmospheric pressure drains the fluids to allow breathing."
]
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[]
] |
|
4dydar | why is reddit just coming out with an app and why did it take so long | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4dydar/eli5_why_is_reddit_just_coming_out_with_an_app/ | {
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"text": [
"Did I miss something? A new app? Is it better than \"reddit is fun\"?",
"What the heck is AlienBlue then?",
"I think they are inspired by the success of apps like Bacon Reader. Why did it take so long - no one but reddit team knows the answer but usually it's internal politics that slow things down. "
]
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96o6pk | How vital was the Allied victory in North Africa during WWII? | What would the loss of the Suez canal have meant for Britain? Was oil production in NA and the Middle East significant compared to other parts of Allied/Axis territory? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/96o6pk/how_vital_was_the_allied_victory_in_north_africa/ | {
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"The Allied victory in North Africa was very significant for quite a few reasons, the men fighting in North Africa were battle hardened veterans with years of experience, they had had resounding successes with limited resources, as Hitler didn’t accept North Africa as a primary theatre of war despite Rommel’s insistence, once the Allies had defeated the Axis they captured almost half a million Italian and German soldiers, this in and of itself would be a significant blow to the Axis. In his book “Panzer Commander” Colonel Hans Von Luck quotes Rommel as saying that the war was over (after the German defeat in North Africa) and that Germany should begin peace talks with the Allies.\n\nIn terms of oil production, if we look at The League of Nations reports for 1940 we can see that Iraq and Egypt only produce about 4.5 Mt of crude oil (Mt = million metric tonnes) every year German occupation would undoubtably disrupt the the efficiency of oil extraction causing these figures to be somewhat lower. If we compare these figures to those of the US 182.6Mt or the Soviet Union 30Mt you can see that the Middle Eastern oil production pales in comparison. Opening another front with the Soviets after victory in North Africa would be seen as far more important than seizing Middle Eastern Oil production. \n\nThe Suez Canal was very important. Erich Raeder believed that capturing the Suez Canal could lead to a German victory without the prospect of crossing the English Channel. He argued that once the Suez was in German control an advance through Palestine and Syria would swiftly follow, by this point the Axis would be at Turkey’s southern border, at this point with an Axis dominated Balkans to the West and German forces to the south Turkey would be forced to join the Axis or at the very least provide safe passage to Axis troops and supplies. The Germans could also have potentially pushed into Iran thus cutting off significant amounts of supplies sent to the Soviets by the Allies\n\n\nTLDR: North African and Middle Eastern Oil production/reserves weren’t really significant. Losing the Suez may well have opened another Front with the Soviets and potentially called Turkey into the war. Victory would also stop hundreds of thousands of Axis troops becoming POWs.\n\nSources: \n“Panzer Commander” Hans Von Luck\n\n_URL_1_\n\n_URL_0_"
]
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"https://www.theatlantic.com/photo/2011/09/world-war-ii-the-north-african-campaign/100140/",
"http://digital.library.northwestern.edu/league/le0280ah.pdf"
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14eejq | Considering the planetary changes that Earth will be going through due to climate change, where will the most temperate and desirable places to live in the world be in, say, 50-100 years? Geographically and climate-wise, not politically of course. | askscience | http://www.reddit.com/r/askscience/comments/14eejq/considering_the_planetary_changes_that_earth_will/ | {
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"Here is a picture new scientist published. \n_URL_1_\nand the blog it was stolen from (not read it yet, but thought i would add it anyways.)\n_URL_0_"
]
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"http://pol-check.blogspot.nl/2012/08/global-warming-what-will-change.html",
"http://4.bp.blogspot.com/--mfHbEFJ_Jc/UCp4e80Ht_I/AAAAAAAAAOA/rPMgacH0bYI/s1600/world_plus_four.jpg"
]
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||
10dypv | Is there any evolutionary evidence of other animals heating their food prior to eating it, or is the cooking of food an entirely human construct? | Not sure if this is the right subreddit, but I was curious | askscience | http://www.reddit.com/r/askscience/comments/10dypv/is_there_any_evolutionary_evidence_of_other/ | {
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"Well, there are [these](_URL_0_) monkeys, which leave the nuts they eat to dry in the sun to make them easier to crack.",
"I can't remember which thread it was in, but i think it was someone asking WHY we cook our food. Of course everyone assumes it is for sanitation, but apparently the real answer was making our food easier to digest, which is why Humans have a relatively small gut for a mammal our size. \n\nanyway...\n\nheating food prior to eating requires the ability to make fire, and we're the only animals that can do that, so no, i doubt their are other animals that cook their food.",
"If I may hijack your thread, here's a follow up question: \n\nWould this also imply human tongues have become less sensitive to heat than that of other animals?\n",
"Not cooking, but this [video](_URL_0_) shows Japanese macaques washing their sweet potatoes in salt water. Scientists believe this behavior is done to alter the flavor of the sweet potatoes. \n\nedit: spelling",
"There's a theory that cooking played a large role in our evolution as humans. \"According to Professors Wheeler and Wrangham and their colleagues, it is no coincidence that humans - the cleverest species on earth - are also the only species that cooks.\" [source](_URL_0_)",
" As I see it we are the only ones that have the skills required to cook food - Is there any evidence that shows some sort of preference among animals( mainly primates) towards cooked food?",
"Considering cooking as a method of breaking down structure to allow access to nutrients, there are some other methods which have the same effect: grinding, such as the gastric mill (gizzard) in birds, and rotting, which humans also use, intrinsic to some scavenger diets. Wrangham discusses these methods of food decomposition as well, particularly how they come to be used in the contemporary fad of \"raw\" diets.",
"While technically still human, there has been recent evidence showing that Neanderthal's did indeed [cook](_URL_1_) their food. There have been many recent [discoveries](_URL_0_) that point to modern humans and our close cousins having much more in common than previously believed.\n",
"There is a desert spider that uses hot sand to cook it's prey. I want to say it was called a spoor spider. It is a trapdoor spider that catches insects in its silk and then presses them against the burning desert sand until they die.",
"I think that to think about this question accurately, you need to separate the idea of \"cooking\", as in, to treat a food source in such a way as to expand access to the nutrients within, from \"heating\".\nAre we the only species that uses heat to expand our access to nutrients in food? Maybe. Probably. I don't know, but some one here might.\n\n\nAre we the only species that pre-treats food to expand access to nutrients? No, surely we are not. Ants collect plant matter and culture it with a fungus, harvesting the fungus because it is higher in protein than the leaf matter. Is this cooking? Depends on how you look at it. Tempeh is essentially the same principle: inoculating soy beans with fungus before eating, capitalizing on the fungi's ability to partially digest the soybeans and thus expand our access to their nutrients.\n\nBees and the collection of pollen and nectar to produce a more nutrient rich pollen (honey and royal jelly), though not through the secondary of a bacterial or fungal partner is the similar as well. The bees don't eat the pollen (I think they may sometimes consume nectar directly. Not sure here) directly. They process it into a more nutritionally dense product.\n\nTermites, another example.\n\nI wouldn't be surprised if there are also some animals (probably insects) that use bacteria to ferment dead animals to increase access to nutrients.\n\nI guess my point would be that the answer to you question depends on the nature of its phrasing. It depends what you consider \"cooking\" to be. Does cooking have to be done using \"heat\", or can it be done using a third party organism like a fungus or bacteria? How different is cooking from processing? ",
"Iguanas 'cook' the food in their gut with their belly heat. Also laying around on hot rocks all day will help em do that.",
"Although this is not my specialty, there is evidence that other hominids used fire to cook their foods (_URL_0_). Does human = all of our genus?",
"There are South American monkeys that use the sun to cook their food before eating it. They leave these large nuts out in the sun for about a week to allow them to dry out, what's interesting is that they keep track of which ones they have left out and pull them out of the sun when they are ready. [BBC did a video segment on them, it's really quite interesting](_URL_0_)",
"There is a bonobo that builds his own fires using matches and cooks two types of food. He was taught at least some of these behaviors. I don't believe any came about purely by imitation. The article, link below, states:\n\n\"He was also fascinated by the camp fires his keepers made to cook food. And he was encouraged to interact with humans and copy them. At the age of five, he was making small piles of bone dry sticks.\"\n\n[Pics, video, and an extremely un-scholarly article.](_URL_0_)\n\nDisclaimer: I am not aware of any scholarly articles done on this, and I am not a scientist of any sort. I just thought I would share.\n\nEdit: After watching the video, it seems he is assisted and heavily coached. Watch for yourself and decide. He does use a lighter and warms his marshmallow in the fire before eating it. He also put out the fire after being told to. Not as significant as I first thought, but still interesting.",
"Not exactly cooking but Marine iguanas bake in the sun after eating seaweed so that it heats up inside the stomach in order to aid digestion.\n\n_URL_0_",
"Cooking is just another example of humans using their intelligence to change their environment to their benefit.\n\nCooking allows us to expand our diet and eat things that otherwise wouldn't be edible to us. Essentially cooking is just a really specific example of problem solving and tool use. Which is something we excel at but is not unique to us.\n\nEssentially it's not that different to sea otters using rocks to crack shellfish that would otherwise be inedible to them or predatory mammals cleaning the poisonous hairs of a dangerous caterpillar or tarantula before eating them. Some ant species carefully grow, cultivate and mash edible fungus on a bed of chewed mulch. I don't know of any animals that cook but I know plenty that spend time preparing meals that would otherwise be impossible for them to eat.",
"Harvester ants make[ a type of bread](_URL_0_)?",
"I wrote a brief essay about how humans evolved to have smaller, softer teeth due to the advent of cooking. It helped our ancestors who are opportunistic feeders, eat more difficult to eat foods. For instance, things that required a lot of chewing / gnawing like raw meat once cooked is much easier to eat, rough starchy vegetation / fruits is now much more edible so our ancestors got more calories than a species that didn't cook the same food. Scientists believe this allowed humans to dedicate more resources to brain development making us \"smarter\". (ie: animals who eat low nutrient / hard to digest foods like grass spend significantly more energy digesting than anything else like cattle.) \n\nSo to indirectly answer your question, you'd have to look at the brain shelf size and teeth of animals to determine whether there is actual \"cooking\" going on and also some requirements to be able to cook (animals who have opposable thumbs, animals who know how to use tools, probably diurnal animals to see themselves start a fire). Off the top of my head, no, there aren't other animals (besides human ancestors) who consistently use cooking (on this planet) \n\nside note: I also used the paper to also make the argument that the increase in animal protein in the human diet (more calorie rich) alongside cooking also allowed for the increase in brain size just to stick it to vegans even though no one but my professor read my paper. :B :B ;B (he liked it. ) \n\nmy sources (copy pasta): Finch, C. E., Stanford, C. B. (2004). Meat-Adaptive Genes and the Evolution of Slower Aging Humans. The Quarterly Review of Biology, 79(1): 3-50 \n\nLucas, F., Perry, G. H., Di Rienzo, A. (2010). Evolutionary Adaptations to Dietary Changes. Annual Review of Nutrition, 30: 291-314\n",
"Since other species (other than humans) cannot make fire, cooking becomes unique to humans. Even if other animals, most likely monkeys, discovered cooking, they would have to wait around to use a fire that humans create and would normally put out. Given that the a huge chunk of time is spent foraging, monkeys and apes cannot be expected to \"wait around.\" There is one situation where some monkeys have been known to eat charcoal from nearby kilns (where cooking had occurred), but the the charcoal is used as a type of \"medicine\" to rid harmful toxins in the monkey's body. [Source.](_URL_0_) & I am studying biological anthropology in graduate school.",
"their is a bird that stakes its food on thorns or barbed wire to let it roast in the sun before it eats it. _URL_0_",
"Im not sure if this is at all true, and im on a european tour and i dont want to spend the megabytes googling whilst on the train.....but...\nMy grandfather mentioned to me that there are shrikes that will hang their prey on branches or things like barbed wire fences. HE explained this was to let the sun to dry the carcass to make it lighter to carry/easier to consume/last longer.\n\nWhile not cooking, per se - It seemed somewhat relevant. \n\nIf you want to google it, try something like 'shrike hangs prey on fences' or something. If i remember, i'll google and leave a note when i get back to the hotel.\n\n\n\n ",
"Well, if we are talking about applying heat to food in order to make it easier to digest, then humans are the exclusive users of this strategy. The control of fire was first used by *Homo Habilis*. Some even argue this trait triggered the evolution to *Homo Erectus* anmd eventually the modern form *Homo Sapiens*. An interesting read is [Catching Fire](_URL_0_) by Richard Wrangham. By cooking food, humans were able to devote less energy into developing extensive digestive systems for processing copious amounts of vegetation and put more energy towards the growth of the brain. In essence, cooking may have contributed to the encephalization of the brains of our ancestors. ",
"Monkeys also know to follow a forest fire to enjoy the cooked nuts, however they do not actively cook themselves.",
"This is a bit off subject but it you may find it [interesting to your topic. ](_URL_0_)",
"On a side note, homo sapiens are referred to as coqtivores because we are the only species that cooks its food. ",
"[This is a great documentary on the subject of cooking and humans](_URL_0_)",
"This isn't documented evidence that I know of, but when I was kid we went to Yellowstone National Park and I witnessed a Robin (bird) pull an earthworm out of the ground then go dip it into a steaming hot spring and ate it. Maybe it liked the flavor, I don't know, but it is something I will never forget.",
"what do you mean by \"evolutionary evidence\"?"
]
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],
[],
[],
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[],
[],
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"http://news.nationalgeographic.com/news/2012/06/120614-neanderthal-cave-paintings-spain-science-pike/",
"http://sydney.edu.au/news/agriculture/1272.html?newsstoryid=9638"
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[],
[],
[],
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"http://www.reddit.com/r/askscience/comments/10dypv/is_there_any_evolutionary_evidence_of_other/"
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[
"http://www.dailymail.co.uk/news/article-2080050/Now-thats-chim-PAN-zee-Meet-monkey-fry-burgers.html"
],
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"http://en.wikipedia.org/wiki/Marine_Iguana#Behavioural_ecology"
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[],
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"http://www.sciencedaily.com/releases/1997/09/970901072246.htm"
],
[
"http://unabridged-blogowitz.blogspot.com/2008/07/loggerhead-shrike-lanius-ludovicianus.html"
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[],
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"http://www.amazon.com/Catching-Fire-Cooking-Made-Human/dp/0465013627"
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1ggj2h | Why, with a sinus infection, does pressure in your sinuses/head build up whether you blow mucus put or suck it in? | askscience | http://www.reddit.com/r/askscience/comments/1ggj2h/why_with_a_sinus_infection_does_pressure_in_your/ | {
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"The paranasal sinuses are poorly innervated - pain tends to be vague and poorly localizable in the sinuses because the brain has a difficult time precisely interpreting what little sensory input it receives from the sinuses.\n\nWhen an acute bacterial sinusitis occurs, with all the inflammation and mucus production that accompanies it, inflammatory cytokines (signaling molecules) sensitize nervous tissue which innervates the sinus mucosa. Instead of the typical sensation of pain that you'd normally get from inflamed tissue, most will describe fullness or pressure, or just vague discomfort over the cheekbones, above the eyes, or near the bridge of the nose. [This \"pressure\" sensation can be present even when no blockage exists to allow pressure buildup](_URL_0_).\n\nThis can be thought of as analogous to myocardial ischemia (i.e., a heart attack) - pain due to ischemic heart disease is classically described as a dull \"pressure\" sensation (\"an elephant sitting on my chest,\" e.g.). The heart and other visceral organs are poorly innervated by sensory nerves as well, which is why internal pain can present as poorly localizable or with dull or vague discomfort, akin to sinus pain and pressure. "
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8zylan | why does sleeping in a particular direction unblock a blocked nose? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8zylan/eli5_why_does_sleeping_in_a_particular_direction/ | {
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"Stuffed noses are caused by mucous but also blood congestion in vessels in your nose due to inflammation. You'll notices that sleeping on your belly might cause congestion and thenoving to your back gets rid of it. Gravity rules all! ",
"When your nose is blocked, it's more often than not nothing to do with a blockage in the nasal cavity, but rather a buildup of fluid in the sinuses that 'pinch off' the airflow. When you lie on the opposite side, gravity redistributes these fluids, and the other side becomes blocked instead. ",
"Once upon a time there was a man sitting under an apple tree reading a book. His name was Newt. An apple from the tree branch above his head became too heavy, broke off the branch, and fell on his head. \"Ouch!\" He cried. He thought someone threw the apple at him, but no one was around. \"Wow...why did that apple just fall?\" He picked up his book and just curiously let go. It fell to the ground. Just like the apple! A lightbulb appeared above his head. \"What goes up...must come down!\" He began to pick up random objects and watched in amazement as they fell down. \"This is science! I shall call this amazing force of pulling things down towards the Earth's surface... GRAVITY!\" That night he stayed up late dropping things. He got a stuffy nose so he decided to go to sleep. His right nostril was very clogged. Newt said, \"I should not have stayed up late. Never again.\" His right nostril was building with pressure of snot, mucus, and boogers. \"I really wish something could help my nose.\" Then another light bulb popped on his head. \"By jove, I will use gravity!\" Newt turned in his bed to his left side. Instantly his right nostril started to drain due to gravity and it felt so good. However, now his left nostril was clogged. So he used gravity again and rolled to his right side. Gravity was Newt's friend, and for the rest of the night as Newt tossed and turned in his sleep gravity was always there to help drain his nostrils. Fin.",
"There are a few reasons. First, a lot of congestion is caused by mucus. Your nostrils don't stay separate for long: they merge into one big passage at the back of the nose called the \"nasopharynx\". The nasopharynx opens right over your mouth and throat. Gravity will make fluid run downward, so if you put the stuffy side up, any blocking fluid may run out of the way eventually.\n\nSecond, your body is about 60% water by weight. Because fluids including water and blood naturally follow gravity, any part of your body placed lower than another will have extra. If your nose is low compared to the rest of you, or one part is lower than another, you might get some congestion because there is extra fluid in the blood vessels and tissue around the nose. This is more pronounced in the nose than elsewhere, too, because you have a lot of blood vessels in some parts of your nose. (Your body works hard against gravity to keep fluid from pooling in places by pumping blood, but it isn't always perfectly successful).\n\nFinally, your nose has something called a \"nasal cycle.\" If you google a cross-section of the inside of your nose, you would see curled shelves of bone on the outer wall, called \"conchae\" or \"turbinates.\" These shelves are covered in tissue that can fill with blood when activated by a nerve, just like the penis or clitoris. This cycle moves from one nostril to the other every couple of hours, so if you stay on one side for long enough, eventually the top side will unblock. Not because of gravity, but simply because it was time to switch.\n\nIt's interesting to note that very small changes in the size of a tube, like your nose, can cause big changes in the ability for air (or water, or whatever) to pass through it. This is denser than necessary by ELI5, but Poiseuille's Law tells us that the radius of a tube increases or decreases flow by a power of four- that means small decreases in the space in your nose can have a huge effect on air flow. \n",
"I can't lay on my right side without my nose getting plugged up. As soon as I lay on my back or better lay on my left side I can breath through my nose just fine. It's irritating because laying on my right side feels comfortable since I always have to lay on my left.",
"Not evertime it's a blockage. Oftentimes it also the [nasal cycle](_URL_0_). I have this, it's annoying.",
"In addition to direction of side turn, there is one more variable to this; It is your chin position. If you tuck your chin in VS if you protrude your chin out. The effect is less pronounced than the turn. You can maximize the open-ness by varying this angle.\n\nI also find holding your breath for about 10 seconds speeds up the shift after I turn. And once the shift starts, short fast nostril breaths hasten the full opening. So glad I could share this !",
"thanks for this info, guys... i never knew about the 'nasal cycle' and was fully prepared to chop-off my left nostril as it is almost always stopped-up.",
"Lookup septum and turbinates. I had a deviated septum and turbinate reduction a few years back. But most of the other answers are correct about blood flow, fluid distribution and inflammation. I think someone also talked about our nose cycles. ",
"Gravity\n\nBlockage is mucous typically and it just moves around a bit opening up the passage giving the clear feeling of unclogged",
"It’s because of your turbinates. You have 3 glands in each nostril called turbinates that inflate like little balloons and cause congestion. They are there to humidify and regulate the temperature of the air entering your nose. Without them breathing would be painful and difficult. This is called (empty nose syndrome). They membranes are very vascular. When you sleep in your side, the blood can rush to that side of your head and cause the turbinates on that nostril to swell. \n\nSome people have enlarged turbinates or a smaller nasal cavity to where this becomes and issue and can cause chronic congestion.\n\nI know this because I’ve had surgery twice on my turbinates for this very issue. I was basically permanently congested and sleeping on my side would many times cause what your are describing. For patients where no medication is effective, surgery can be done to shrink them. ",
"I had this problem, turns out I had a deviated septum. Had the surgery, much better! haven’t slept so well since childhood. ",
"For the people struggling with inhaling through their nose, to the point where your life became a meme by bringing tissues everywhere;\n\nPlease go see an ENT Doctor to check if you have a deviated septum. It's a life-changing surgery and im recovering from one right now. Definitely worth it."
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ay3wis | Time dilation due to gravity AND due to velocity (are they multiplicative?) | So, in other words (and without the advantage of the Einstein field equations because they're over my head at this point).
& #x200B;
I understand that I can calculate gamma using Sqrt(1-v\^2/c\^2) for an object orbiting a planet of mass M. Whatever the orbital speed needed to orbit at altitude R will plug in and give us the time dilation due to velocity. BUT, at the same time another gamma = Sqrt(1-2GM/Rc\^2) because of gravity. Can you find total time dilation (relative to stationary earth observer) by multiplying both gamma's together?
& #x200B;
t = t\`(gammaGravity)(gammaVeloctiy) ?
Thank you to anybody willing to explain!
& #x200B; | askscience | https://www.reddit.com/r/askscience/comments/ay3wis/time_dilation_due_to_gravity_and_due_to_velocity/ | {
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"If you are slow and not close to a black hole you can treat them as separate effects and multiply. If these things are not true you need the [full formula from general relativity](_URL_0_)."
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30qt84 | what are a few of the most elementary financial scams, and how exactly do they work (e.g. exit scam, ponzi scheme, etc.)? | I've heard of an exit scam time and time again but I can't find an explanation. I know a bit about the ponzi scheme, but I'm sure there are other devious plots! Let's discuss! | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/30qt84/eli5_what_are_a_few_of_the_most_elementary/ | {
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"An exit scam is basically just selling things to people but not actually delivering once you got the money. More relevant in less-legitimate markets where trust is a factor in the transaction (since you won't be using a credit card/paypal/etc that could reverse the charge and you don't really want to bring attention to your purchase). You build up trust, people give you money, you send them product, then at some point you get as much money as possible from sales up to the point that you would actually have to deliver, and bail.\n\nPonzi scheme you \"invest\" money for people and promise them a return. You can pay investor A with money from investor B to make it look like they are making a profit, when actually all you did was pay the investors with their own money. As long as more and more people invest, you can continue moving money around to make it look like everyone is making money, but at some point too many people are going to take their money out or not enough new investors will add money to the pot so it will collapse and the last people left will lose all their money.\n\n",
"Pump and dump is a common one. You buy a little-known and little-traded stock. Then you go hyping the stock with false information, like on investor forums. You get people to buy the stock, the price goes way up, and then you sell your shares. Then people realize the company is crap, and try to sell their shares, but no one wants them, and the price tanks.",
"* Ponzi - pay current investor not with profits, but with the principle from new investors\n* Pyramid - investors make money not from the investment, but through recruiting new investors\n* Cashier's check - pay for goods or services with too large of a cashiers check, as for the difference back in cash, check turns out to be fake\n* Exit scam - set up business selling things for real, then stop shipping but keep taking orders\n* The Nigerian - hire someone to help you move money out of the country, make them open a shared back amount with some token minimum in it"
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3gdtfx | Wikipedia states that the Nazis often 'promoted premarital and extramarital sexual relations', what are some examples of this? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/3gdtfx/wikipedia_states_that_the_nazis_often_promoted/ | {
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"Could you provide a link to the relevant Wikipedia page?",
" > \"From its early days, the Nazi Party made a show of raw virility. 'I have seen the sex instinct deliberately aroused in many ways... At mass meetings, speeches dwelling on the copulative process of the Nazi male would send the Storm Troopers marching out of the hall all set for a demonstration. They never had to wait long for a partner. German women would wait outside the meeting places.' With Hitler intent on boosting the birth rate, newsstands displayed 'books and magazines filled with nude men and women...It was plain that Nazi Germany planned all this to but one end.' ... 'The word illegitimate must be blotted out of the German language,' Minster of Labor Robert ley declared... women who felt they needed more social respectability could legally take the name of a soldier who had died in battle.'...This created a class of women 'who clung to Nazism because the Nazi Party would protect their illegitimate children.'\" (from Chapter 11 of *Hitlerland*).\n\nIn addition, the Nazi party had the Lebensborn program that encouraged Aryan births, and accepted Aryan children into government financed homes. They encouraged children born to German soldiers with mothers from occupied nations, to have the children adopted by Aryan families, and they financially supported these children. The Lebensborn program, which was run by the SS, declared every SS soldier should father a child before going to war. Overall illegitimacy ceased being a stigma and became patriotic. \n\nGermans also made it easier to divorce, and 80% of new divorces were of men divorcing wives who were not fertile. Due to WWI, there were a lot more single women than single men. They planned to institute polygyny after the war ended, since World War II did nothing good for the male/female ratio, but they of course never got that far."
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2lkfge | interstellar and the science involved | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2lkfge/eli5_interstellar_and_the_science_involved/ | {
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"Normally you think of moving as going from point A to point B in a physical sense within our 3-dimensional world.\n\nBut many believe that we \"move\" through time in a similar way, that that's the 4th dimension. The only difference being that we're stuck going in one direction on this line (the future), and strangely, only able to see in the opposite direction (the past). It's kind of like we're driving backwards. There is no way to change the direction we are moving, the best we can hope for is to either #1, change the speed we move through it (which they did, although in this case it was an unwanted side effect) and #2, change the direction we can see along the line of time, which they kind of did with the \"ghost hand\", but the fact remained that it's a lot easier for the future to see us than it is for us to see the future.\n\nA 3rd option, to keep with this whole \"driving backwards\" analogy, would be to view the car from outside, which is where the 5th dimension comes in, allowing Cooper to see his timeline from another direction. Just like how a line on a piece of paper is 1 dimension, you can't really \"see\" the line for what it is when you're trapped \"inside\" of it (much as we are \"trapped\" inside the 4th dimension, time) but if you can look at it from the outside, that's when you can really see it and possibly even manipulate it.\n\nGravity is measured in meters per second squared, but do we really know what a second squared is? Well, if a line is one dimension and a square is two, and time is the 4th dimension, maybe time squared is the 5th dimension, which is why gravity is the only way he was able to manipulate it.\n\nI should have been in bed 6 hours ago and I'm loopy as all getout, so if this made any sense at all, it would be a miracle.\n\n"
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38uslm | why does having noise in the background (tv, music, etc.) make me feel safer when i'm home alone? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/38uslm/eli5_why_does_having_noise_in_the_background_tv/ | {
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"Your ears are sensitive through a wide ride of volumes. When it is very quiet, you hear faint noises you are unaccustomed to, which can be disconcerting. Background noise hides those sounds with ones more familiar to you, restoring your comfort level.",
"It tricks your brain into thinking you are with friends, which makes you feel like someone is less likely to sneak up on you or otherwise try to hurt you. ",
"I have had kids in my house for a lot of years, and it is rarely quiet, ever... So, when it is, and i am alone, it is disconcerting, unfamiliar. i do not feel scared, it just doesn't feel right. I usually put some music on and do my thing :)",
"I think people have a psychological dislike of silence. Because \"true silence\" is something that is actually hard to achieve. \n\nI recall reading somewhere that there exist some actual, acoustically soundproof rooms, that are so quiet that it's been known to actually make some people extremely uncomfortable if left in there for long periods of time.\n\nI also read an interview with a police interrogator once, who said one of the most powerful \"tricks of the trade\" is to just sit in an interrogation room with a suspect, and not say a word. Eventually, they will start talking, since, in his experience, people hate silence and need to fill the void with their own voice.",
"Keeps your imagination from working overtime trying to decipher every weird piece of background noise it picks up. \n\n\"FUCKING DRACULA!!!! Oh wait, no, that's the water heater turning on.\"\n\n",
"It's not about feel safer, it's the fact that many of us are unaccustomed to silence. We feel awkward, unsafe, and even scared when everything is all quiet. Because when everything is quiet we think more. And nobody wants to think anymore ",
"I agree with all the stuff that has been said about background noise being the normal.\n\nBut I think it goes even deeper than that and this deep-seated fear harkens back to the says in when humans lived in the wilderness and when something was too quiet, a predator may have scared off other animals and is stalking you surreptitiously.\n\nYou know, \"clever girl\" and all that stuff too."
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d3l1ou | Is it possible to get eye damage, or even a sunburn, from the moon's light? | If moon is just reflecting the Sun's light, then are the UV rays also reflected? And are the UV rays strong enough do damage or affect the human body at all? | askscience | https://www.reddit.com/r/askscience/comments/d3l1ou/is_it_possible_to_get_eye_damage_or_even_a/ | {
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"No, the intensity of the reflected moonlight from a full moon is about 300,000 times weaker than that of direct sunlight (the exact number depends on various conditions such as location on Earth, where the moon is in its orbit, etc...).\n\nSo in order to get the same amount of UV radiation as you'd get from 15 minutes of direct sunlight, you'd need to be exposed to the moonlight for 8.5 years. In this time, the skin's limited self-healing capabilities are easily able to overcome the damage.\n\nYour eyes are safe as well, because even looking directly into the moon is orders of magnitude less bright than looking at the sky on a cloudy day. It's even well below the intensity of dimly lit interiors.",
"If you look at it through a telescope at night with no moon filter, but not otherwise. Your eyes will be dilated at night, then suddenly filled with very bright light. Not immediate blindness, but not great for them long term.",
"No, but I'm kinda sure you could damage your eyes looking at the moon with something like a Dobson telescope, just because it's so bright.\n\nAfter a minute of looking, when you look away you notice you can't see much only still see a massive light resembling the moon, everywhere you look, just like staring into a strong light bulb for a while.",
"Is it possible to get eye damage when viewing the moon through a telescope? When I took mine out last full moon I was seeing spots if I stayed glued to the eyepiece for longer than a couple of minutes. If it matters, my telly has a 120mm lens.",
"I managed to almost do it but it required looking through an 18 inch refracting telescope. We were taking turns looking at different objects in the sky and decided to take a look at the moon. Since it was direct vision observing I was getting some pretty concentrated moonlight right into my eye, plus I was taking my time examining the surface. When I looked away I had a strong purple/green image of the moon flashing away in my retina for a good 15 minutes or so. I almost thought I'd damaged it.",
"UV damage is not proportional to intensity. It's worse.\n\nWhen a single high-energy UV photon hits an electron in a molecule, it knocks the electron away, but the electron is likely to come back, restore its bond, and result in no damage. When multiple UV photons hit electrons in a molecule, then those electrons are more likely to to escape, break a bond, or cross-link and bond with a neighboring molecule.\n\nThe chances of a molecule being struck by multiple photons, goes up nonlinearly with the number of photons in the vicinity. This is why intense sun is so dangerous, and sunscreen is so important. A small increase or reduction in intensity has a big impact."
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199lfp | Why are speed of light and phase velocity used interchangeably in wave equations? | I've noticed that some equations use v and sometimes the same equations have c, when their values are different. Can Reddit please explain whats the difference between the two and the reason for them being used in this manner. | askscience | http://www.reddit.com/r/askscience/comments/199lfp/why_are_speed_of_light_and_phase_velocity_used/ | {
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"The letter we use to represent something is arbitrary.\n\nWhat matters are the concepts.\n\nThe speed of light is the speed at which light travels in vacuum; it is a special speed of the universe, such that if something is traveling at that speed relative to one observer, it is traveling at that speed relative to every observer. Typically, we denote this speed, which has a special status, as *c*.\n\nEvery wave has a phase velocity. It's the ratio of the angular frequency to the wave number, or, equivalently, the product of the frequency and the wavelength.\n\nWhen light is traveling in a medium with index of refraction *n*, its phase velocity is *c/n*. In a vacuum, *n*=1, so the phase velocity is *c*, but in water, for example, the index of refraction is *n*=1.33, and so the phase velocity is *c*/1.33."
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6mwnz5 | how can certain areas of the world be so dominant in online gaming? | For instance why can Korea consistently have teams win against the rest of the world in Mobas, while Europe generally has the best CSGO players? Also how come different areas play the same game with different strategies? With enough experimenting shouldn't the same optimal strategy be found? I understand in some places professional gaming is more popular, like Korea, but if teams everywhere practice full time, shouldn't they be all similar levels of skill and technique? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6mwnz5/eli5_how_can_certain_areas_of_the_world_be_so/ | {
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"It's just popularity. Like if you grow up in Canada dang near everyone grows up playing at least a little hockey. If you're good you practice against other good locals. Go up a few levels and you're playing playing with the best of the best.\n\nIf you grow up in Florida maybe one in a few hundred plays hockey. The best of those practice with each other and eventually you end up with the Panthers.",
"As for why Europeans are good at CSGO, it probably has to due with PC gaming being significantly more popular in Europe than in the United States. Counter-Strike is one of the most dominant competative shooters in PC gaming history, so it's not surprising that a lot of European gamers play it. Korea has a huge gaming community focused in small area, and this creates a powerful and competitive culture around it. RTS and MOBA games in particular are very popular in Korea, so lots of youth participate very competitively. The more people you have playing, the more likely you'll get superstar players and teams from your areas."
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23hraa | What are your favorite recurring, blatantly inaccurate portrayals/themes in contemporary movies about ancient civilizations? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/23hraa/what_are_your_favorite_recurring_blatantly/ | {
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"Most of the world has proved incompetent at distinguishing anything in Latin America before 1650. It's all just one giant cultural chimera that manages to be everywhere at once on one and a half continents. I've got a stock set of answers for the frequent question, \"The Inca? They were like the Aztecs, right?\" Often, when told that Peru and Mexico aren't the same place, I get the \"Oh, well, close enough. They both speak Spanish.\"\n\nThe most recent screen blunder I can remember is in an episode of Agents of SHIELD earlier this year. The team goes to an archaeological site in the jungles of Peru. Of course, it's a giant Maya pyramid. That's like sending James Bond to Pakistan and chasing a villain into the Colosseum."
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7yj80j | So what was Mother Theresa really like. Was she a the charitable saint many Christians claim she is, or was she the monster that Hitchens described? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/7yj80j/so_what_was_mother_theresa_really_like_was_she_a/ | {
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"Hi, not discouraging other responses here, but you may be interested in some earlier threads\n\n* several flaired users in [AskHistorians consensus on Mother Theresa.](_URL_0_)\n\n* /u/Dice08 answers here [The top of r/All says that Mother Teresa never helped anyone. Is that true?](_URL_1_)",
"I appreciate /u/searocksandtrees citing me. That gets a lot of the work out of the way so I can just speak frankly:\n\nFrom everything I've seen surrounding her character it seems she is just the charitable person people claim of her and did so in the worst of conditions. However the scale of her work is heavily embellished and her notoriety surpasses the actual scale of her work. To make matters worse, she seemed to went to an extreme with her vow of poverty so it affected the quality of the work and living conditions (there is the oft mentioned story of her being given a free building for her people to work in NYC and her turning it down as the elevator that city hall required was too luxurious for her) but seeing as these standards and medical availability are an issue to the area she was working anyway it is questionable what was her doing and what was consequence of the area she was in. I'd redirect you to my post cited by /u/searocksandtrees for that detail. \n\nOverall, Hitchens' picturing of her as a monster doesn't hold to criticism but there is still much wrong to be said. Especially in what could have been done if she didn't apply her vow of poverty in that way. Contrast that to the current Pope Francis who also is under a vow of poverty but lives in the Vatican in the [Apostolic Palace](_URL_0_)"
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ai38o2 | How much information would a pre-modern army commander have about an opposing force (strength, composition, leadership, location, etc.)? | I watched the 3rd season of The Last Kingdom recently, and in the final episode there's a large battle where one army is ambushed by the other while it's on the march. Partway through the battle, two more armies join in, both of which were a surprise to the two armies already engaged.
Was this a common occurrence in the past? If not, how effective were scouts and pickets at relaying accurate information? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/ai38o2/how_much_information_would_a_premodern_army/ | {
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"As I've mentioned in [other threads](_URL_0_), Wessex during the period in which *The Last Kingdom* is set was actually studded by a fairly extensive and sophisticated network of look-out posts and signalling beacons connected with garisson forces at local *burh* fortifications. This network was also then extended into Mercia and into recaptured areas of the Danelaw. This system was designed specifically to curtail the Viking strategy of mobile warfare and afforded the English both the early warning and the use of the rivers and road network to respond rapidly to Danish threats. Indeed, significant victories such as the 911 Battle of Tettenhall come about because the English are aware of where the Danes are and where they are heading, and are able to outmanoeuvre and surprise them.",
"In addition to the excellent answer provided by /u/BRIStoneman in the context of Anglo-Saxon England and the Viking incursions, I may be able to shed some light on the nature of military intelligence and some of the methods by which it could be obtained in the context of feudal western Europe during the High Middle Ages, and to some extent the Late Middle Ages.\n\nFirst of all, I will approach your inquiry from the perspective of organisational stages: initiating the war, the strategy, and the tactics.\n\nSecondly, I will mention the restrictions that decided to what degree feudal combatants were able to achieve strategic and tactical surprise *before* going over the options of military intelligence available to them, as the former dictates the the latter.\n\nLastly, examples and sources I use in the following are local to my area, the western Netherlands, but can in most contexts be applied to much of feudal western Europe due to parallels in feudalism, Christian values, and the perception of knightly honour.\n\n**The (high) nobility operated in a very personalised international social network in which nearly everyone was acquainted in some way, making war a personal affair and therefore predictable in its initiation in terms of underlying reasons and the aimed objectives.**\n\nFrom the High Middle Ages onward, the nobility of feudal western Europe was a well-connected clique of acquainted individuals with vassal-liege ties, marriage ties, or some form of relation through (short-term) coalition or (long-term) alliance. As such, war between feudal combatants was personal: not rarely it involved raising arms against a liege, a vassal or indeed family, either by blood or in-laws. This also meant that wars were generally preceded by conflict in other areas, such as arguments over trade tariffs, the ownership of certain fiefs or rights, or simply over rivalries of some kind or another, leading to diplomatic or economic action that only resulted in war *if* a suitable compromise could not be reached. As such, the onset of war was readily apparent, as was the reason to wage a war.\n\n**The cumbersome nature of the organisation and mobilisation of feudal forces as well as of the logistic apparatus supporting them meant that it was nigh impossible to achieve strategic surprise.**\n\nThe military forces of feudal western Europe were structured on the local approximates of the levy system: the nobility and their retinues, and the common man, were summoned (the former by personal invitation of the liege, the latter by local representatives) and requested to converge on predetermined mustering locations where inspection of the assembled forces would take place. In the County of Holland the period of time allocated to reach these mustering locations was put at 14 days, a period of time that depended on the size of the territory. The levy itself could be fielded for 40 days (this was also true in other fiefdoms in the Holy Roman Empire, as well as in the Kingdom of England and the Kingdom of France), at which point a new levy had to be raised, in order to minimise the impact on the available workforce and therefore the economy. The combination of set periods of time between summoning and mustering, the troops assembling at predetermined locations, as well as the limited window in which military goals had to be realised, meant that there was no such thing as a speedily and/or covert build-up of forces. As a result, not only was the initiation of a war an obvious process, it also meant that the initial location of the enemy forces was a predictable one.\n\nFurthermore, the logistics coupled with fielding a feudal army were very observable: rations and supplies were purchased in large quantities in the cities, and carts and barges were commandeered and chartered to transport these goods. This meant that any local merchant or inhabitant was aware of what transpired, and especially knowledge in the hands of the former quickly found its way to colleagues abroad, something I will touch upon later. This also meant that it was rather easy to conclude what the military goal of a campaign was, as the nature and amount of goods hinted towards the strategy employed (i.e. oats for horses in large quantities suggested use of cavalry), as well as the envisioned goal (i.e. material for siege engines implied the capture of a castle or urban centre), which is coincidentally also the reason why receipts of these orders and transactions are some of the most trustworthy primary sources we have on warfare in the High and Late Middle Ages (there is little to no embellishment, for instance).\n\n**The dependency on civil elements in the military meant that passive military intelligence represented a relatively large portion of the available intelligence in comparison to active military intelligence.**\n\nNot only was the common man an integral part of the military in the sense of forming the bulk of the levy, the logistic apparatus also heavily involved the population of urban centres. This meant that it was relatively easy to obtain reliable intelligence on enemy actions. As I mentioned before, the merchants were an accessible source of information, as they relied on an international trade network that was by nature effective in spreading precise information relatively quickly. The active gathering of intelligence happened in two roughly distinctive methods: bribing local representatives or the clergy, and the use of couriers (spies). Especially the use of couriers in the period is well documented, with their costs and payments represented in accounts, often anonymously in order to protect their identity. Between these sources of information, lieges and their councils had the opportunity to be well informed about the strategic and operational intentions of their enemy.\n\n**Relatively primitive methods of communication restricted the coordination of complex tactical manoeuvres, limiting the available options, and simplifying the tactical approach in the field.**\n\nThe absence of a structural and dependable system of communication was a hindrance to tactical creativity, which was further enhanced during moments of *friction* (the appearance of phenomena that hinder plans, such as the weather or disease): a moonless night hampered vision in such a way that it was dangerous to manoeuvre military elements (i.e. two armies fielded by the Bishopric Utrecht failed to united on a night in October 1228, botching the planned offensive^(1)), so would fog or heavy rainfall. This simplification-by-necessity meant that the field of battle between feudal opponents was decidedly less a matter of surprise – which requires maximum communicative effectiveness – and more of cohesion – minimizing the needed communicative effectiveness. As a result, manoeuvring on the field of battle was relatively predictable. \n\nThere were of course exceptions to the rule, which only meant that tactical surprise was all the more devastating when it was achieved (purportedly the citizens of Utrecht thought they were surrounded by the Tartars rather than the West-Frisians in the dead of night in 1247^(2)), but by and large tactical success stories in this time period are occasions of non-feudal opponents, often using irregular forms of warfare, against feudal opponents using regular forms of warfare.\n\n*To conclude, the political and military realities of the period meant that information on strategic and operational intentions were relatively easily obtained, while information on the enemy tactics were more difficult to gather but oftentimes equally predictable. As such, feudal commanders in the High Middle Ages had the potential to be very well informed about an opposing force.*\n\n^(1 Quedam Narracio, Unknown Author, 1232)\n\n^(2 Croniken van den Stichte van Utrecht ende van Hollant, Johannes Beke, 1371)"
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"https://www.reddit.com/r/AskHistorians/comments/774amv/signal_pyres/dojaotb"
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536ob6 | besides the battery, what is keeping us from creating a full artificial permanent heart that can replace the organic one? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/536ob6/eli5_besides_the_battery_what_is_keeping_us_from/ | {
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"I think we still lack the material or coating material that is not rejected by the body. \nNowdays you would have to take Immunosuppressive medication and similar stuff to make your body hopefully accept the organ. \nThat reminds me of a documentary about the first time spider silk was synthesized in the lab and one application was for wound recovery and coating of artificial organs as it is antibacterial and had good properties to not provoke reactions from the body. \n(no expert opinion)",
"Not for this sub.\n\nConsider if you have **resting** heart rate of 70 beats per minute. That device needs to beat 4200 times an hour, 100800 times a day, 36792000 times a year. For the rest of your life. \n\nWith no stopping for repairs, adjustment or any other typical maintenance. Plus all of this has to be biologically compatible with your body, and roughly the same size and shape as your real heart. \n\nNot an easy task."
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2vunus | why do people hate thomas edison so much? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2vunus/eli5_why_do_people_hate_thomas_edison_so_much/ | {
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"Honestly, I don't know many people who \"hate\" Thomas Edison at all.",
"Most people tend to go on about the animal torture. That's a valid complaint, but I'm more opposed to the moral bankrupcy he demonstrated during the great phenol plot.",
"While Edison did create many things, he was also at the head of the Edison Corporation, or whatever it was called. When someone had an idea, he'd push it through until it was perfect, but then take ownership for the company. So many things that have Edison's name were not exactly his.\n\nHe also conned people into thinking alternating current (AC) was more dangerous than direct current (DC), which is what he was pimping. There's science, words, and Edison killing elephants in the [War of Currents](_URL_1_).\n\nHe discredited Tesla as well, turning him into a penniless madman at the time of his death. History has shown that Tesla was a far smarter man who would have probably [destroyed the world](_URL_0_), accidentally. A man after my own heart.",
"Topsy the Elephaant; killed by electrocution on January 4, 1903, at the age of 28 by Inventor Thomas Edison; who oversaw and conducted the electrocution, [and he captured the event on film](_URL_0_)."
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6y2igu | why does our body sometimes moves or shakes when we remember a cringy situation from the past? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6y2igu/eli5_why_does_our_body_sometimes_moves_or_shakes/ | {
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"If the situation triggers a flight or flight response, the body's first impulse is movement. \n\nA loud noise behind them will cause most people to start. This is your brain telling your body to fire up its muscles and get ready for whatever is about to happen.\n\nRemembering a sufficiently unpleasant situation could trigger a similar flight or fight response, firing off muscles for the hardcoded classic danger response that nearly all mammals share.",
"I'm hoping someone else can give a more detailed answer.\n\nIn my experience, as someone with clinical depression and general anxiety and having been on SSRI's to treat both, the stress I experience when initially exposed, or remembering the exposure, to something \"cringey\" feels the same as the kind of stress induced twitches I get from stress itself and from being late taking my medication.\n\nYour body processes stress through a number of neurotransmitters, each with their own effects, and some these will affect your muscles (there are studies being done demonstrating that dopamine, as an example, helps dictate how toned your muscles are). Different people show different symptoms for depression and anxiety, and I in particular have a greater tendency to show things like twitching or tense muscles, possibly even before I'm consciously aware that I'm stressed out.\n\nAs a final note, I handle cringe inducing humour very poorly. I find it makes me more uncomfortable than it does a typical person, and I sometimes feel so overwhelmed that I can't finish reading/watching/etc. the material.\n\nI hope some of this helps!",
"Just wanted to tell you guys that I'm happy not to be alone with these cringey memories!\nHappens so often to me and when it does I almost wanna leave my body.\nDoes someone know if people with depessive tendencies suffer more under that issue?"
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2naa79 | Shield wall primary sources | Can anyone recommend some good primary sources that demonstrate use of shield walls in combat? I don't really know when shield wall use was at it's peak, but any sources from around this area will be really helpful. Thanks! | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/2naa79/shield_wall_primary_sources/ | {
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"The sagas describe shield walls a couple of times - the only ones I can think of off the top of my head are *Egils saga*, during the Battle of Brunanburh, and *Sverris saga konungs*. You're not going to get a whole lot of detail, though, as the sagas weren't written like modern novels describing the push of the wall etc., but they *are* used and referenced there."
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1vlczv | Why does food smell better/stronger when being cooked? | It may be a stupid question but how does the cooking process "bring out" the smell of a particular item. For example, a cut of steak sitting cold on the counter does not have a strong odor, however after it has been cooked my whole house smells like delicious filet mignon | askscience | http://www.reddit.com/r/askscience/comments/1vlczv/why_does_food_smell_betterstronger_when_being/ | {
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"My anwser isn't very scientific, but here I go. It has to do with the heat. Heat makes particles move faster including the particles that create the smell. The particles can then diffuse through your house faster and then everything smells delicious. \n\nCan someone double check me though because my source is my 8th grade science class.\n ",
"There are two things going on here: one, the heat of cooking catalyzes reactions that produce those tasty-smelling compounds; and two, heat makes all the molecules in whatever you're cooking move around faster, making them more likely to evaporate and reach your nose.\n\nThere are many different kinds of new compounds that can be created through cooking: reactions between amino acids (in the proteins that make up meat, for example) and sugars can create a class of molecules called Maillard compounds that are responsible for much of the smells and tastes we associate with browned foods. Sugars can undergo caramelization reactions, too, which leads to the browning in onions, for example.\n\nThe molecules produced by these cooking reactions are called *volatiles*, meaning that they evaporate easily, which allows them to reach your nose and mouth so you smell them (and spread through the whole house). The heat of cooking increases their rate of vaporization, which is why once your meal has cooled, it still has the delicious cooked smell, but you're less likely to smell it across the house."
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6w9tmv | "American Chinese food" originates only from one city in China, Toisan. What was so important about this city that it influenced nearly all American Chinese culture? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/6w9tmv/american_chinese_food_originates_only_from_one/ | {
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"American Chinese food actually has a lot of influences beyond Toisan (or Taishan) and could be more properly encapsulated by looking at the 4 areas of Sze Yup (Toisan, Xinhui, Enping, and Kaiping), which refers to a specific region in Guangdong where many of the Cantonese speaking immigrants that originally came to America hail from. \n\nFor much of America's history, immigrants from this region as well as nearby Hong Kong made up the majority of the Chinese diaspora living in California, New York, New Jersey, Texas, etc. They came by the tens of thousands and settled in various Chinatowns, participated in the Gold Rush, worked on the infamous railroads, labored in sweatshops, built businesses, and faced much hardship along the way. By and large, these early Chinese immigrants were from the same towns and villages, all spoke Cantonese, and ate the same food. \n\nEven as late as 1987, it seems that a [whopping half of Chinese Americans still claimed Toisan heritage.](_URL_3_.)\n\nThus, it seems natural that the regional cuisine has a major influence on the development of Chinese American cooking. It isn't that the location of Toisan itself is regarded as important but the fact that immigrants who came to America were largely from the Sze Yup area and restaurants that catered to these clientele wanted to give them comfort food that reminded them of home. The lack of proper ingredients that forced cooks to improvise in the beginning of Chinese immigrant history is what created the eclectic fusion of cuisines. \n\nBut it would be wrong to say that Toisan is the main origin of all Chinese American food. I should use this spot as a disclaimer that origins of dishes or food history in general can be extremely divisive since many people/places/institutions can and do argue about the 'true' origin or creator of foods, drinks, styles, and everything else. So unless the creation or origin of something is very clearly documented, much of it is derived from oral or cultural histories where accounts can be muddy if not totally at odds with each other. Keeping this fundamental uncertainty in mind, let us continue!\n\nBy the mid 1990s, much of Chinese-American food that modern Americans would be familiar with had already changed a great deal from the earlier days of what the earliest immigrants would have been serving in their restaurants. The reason for this is two fold. First is that cuisine is not static and of course availability of ingredients, cultural tastes, the audience, and trends change as time passes. Second, the Toisan/Cantonese majority for much of Chinese-American history was displaced by the massive influx of Chinese immigrants during the 1980s and 1990s. \n\nAn aprox. 400,000 Chinese American population of the 1970s [nearly quadrupled in size by the opening of the 1990s.](_URL_4_)\n\nMany of these Chinese immigrants hailed from other regions of China whereas before it had been dominated by Cantonese speakers from southern Guangdong and its neighbors but also increased the populations of those nearby neighbors of Hunan and Fujian. Noticeably, Hunan and Fujian tastes and cooking traditions have also had large effects on what we consider to be Chinese-American cuisine today.\n\nFor example, the modern iteration of ['orange chicken'](_URL_1_) or 'sesame chicken' are generally attributed to Hunan cooks/regional cuisine rather than Toisan or the other venerable regions of Sze Yup, though some have claimed that the Xinhui tradition of being known for using oranges as aromatics has had influence on the development of some variations. \n\n[Chop suey restaurants and the food they serve](_URL_5_) have similarly evolved over time and created endless variations and derivations. Chop suey in and of itself is not a dish that has a set list of ingredients or form of preparation but is a general style of preparation for whatever bits and pieces are lying around in the kitchen pantry. The name itself 雜碎 in Cantonese literally means \"mixed pieces\", with 碎 in particular having a bit of a connotation of leftovers or inconsequential things. \n\nThis belies the history of when Chinese immigrants simply combined whatever was on hand (even if it was simply cheap scraps that most people would ignore or throw away) to make something edible. \n\nParallels could also be drawn to the [Korean dish of bibimbap](_URL_2_), which literally means mixed rice and is also a dish that is seen as a combination of odds and ends pulled together to make food.\n\n[Chow mein](_URL_0_) is similar in that it literally means \"fried noodles\" and the variations that were created in America have differed a great deal from place to place (especially East Coast vs West Coast) over time. While there are 'staples' for different areas, ingredients, preparation, and modifications can all differ greatly. \n\nFinally, with the broad acceptance of Chinese and Chinese-American cuisine, the line has been blurred a great deal as to what is simply Chinese cuisine and what is Chinese-American cuisine. This is because many Chinese Americans would return to their hometowns and either settle back down or visit on a regular basis. Some would bring back Chinese-American cooking derivations and these sometimes influenced mainland cuisine as well. But also because as newer iterations of dishes or cuisine are pushed out, it's becoming more and more difficult to say what is decisively Chinese or Chinese-American except by accepting various levels of arbitrary categorization.\n\nI hope this has been a helpful primer! Let me know if you have any more specific questions and I'll try to point you in the right direction even if I can't personally help you! \n"
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"http://www.nytimes.com/1987/11/04/world/taishan-journal-the-wellspring-of-chinatowns-still-bubbles-over.html?mcubz=0",
"http://i.imgur.com/IZCf1gb.jpg",
"http://www.galleryintell.com/wp-content/uploads/2016/07/Chinatown-New-York-City-1934.-Gelatin-Silver-Print.-Imogen-Cunningham-%C2%A9-Imogen-Cunningham-Trust.-Image-courtesy-Seattle-Art-Museum-e1468522670744.png"
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ymmh4 | magnetic door locks. how do they work? | So I get the basic concept. Magnets, force, etc. My question us more this:
At work, we have magnetic door locks. It's a fire code violation if they lock from inside. So to get out, you push the door and it opens. To get in, though, you have to scan your badge and it "deactivates" the locks. How does the door know if you're pushing or pulling? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/ymmh4/magnetic_door_locks_how_do_they_work/ | {
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"The magnet is a simple electromagnet. There is an iron block welded or bolted to the door on one side, and there's a mounted system with more iron bars on the frame of the door. When it's active, (you can't open the door) there is electricity going through the part mounted on the frame, which holds that part and the part on the door together. When you can open it, the electricity is off.\n\nThere's a switch on the inner jambar thingie (whatever they're called) which allows electricity from a unit that controls the magnet through. The controller senses that the bar has been pressed, and it deactivates the magnet. The same thing happens when you swipe your card or whatever method they have to deactivate it on the other side.\n\nIn the case of a fire, there's a place on the controller for the fire safety system to be wired in. When the alarm goes off, it is sending electricity to the controller like if someone was pushing the jambar or swiping their card, and it stays disabled until the fire safety system is turned off.\n\nSource: I've taken them apart and hacked around with them several times. They're neat."
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f7b21 | If a giant tube from Earth's crust to outer space were made, would our air be sucked out? | askscience | http://www.reddit.com/r/askscience/comments/f7b21/if_a_giant_tube_from_earths_crust_to_outer_space/ | {
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"No... the pressure differential would be balanced by the gravitational force, which is what holds the atmosphere in place in the first place."
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79padg | How to best teach someone about history? | My mother recently asked me to help her learn more about history. She knows very little about history and would like to learn more.
I don't have any idea where to start, and I don't think suggesting she read a textbook would be a good idea. Should I go chronologically and in depth? Start with a general overview and then go in depth? Just stick to the last couple of centuries?
Any ideas of what to do Historians? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/79padg/how_to_best_teach_someone_about_history/ | {
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"Hi there, I'm just an undergraduate so I don't have a lot of expertise on teaching (mods please remove this if this post isn't up to standards). But I am taking a course about Public History and as a result have spoken to numerous professionals, including historians, musuem curators, and National and State Park interpreters about how they engage with people about history.\n\nHistorians (at least those who work with the public like museum directors) do what is called interpretation of history. This is going beyond just learning about what happened when and where. Interpretation is about engaging the person and making them want to learn about it on their own, fostering an appreciation for the significance of what you're talking about. \n\nIn the case of your mother, I would recommend seeing what sorts of things she's interested in specifically. If its local history, see about taking her to a museum or finding pictures of the people and places in your area. If its something a little broader or farther away, perhaps see if you can find a book or a documentary that covers what she's interested in. Just make sure you're pointing her to stuff that she's interested in. Just \"history\" is too broad to explain, try to come up with specific questions about what she wants to learn about.\n\nYou could also try connecting it to things she's already interested in. If your mother likes to knit and sew like my mother does for example, you might try showing her demonstrations of historical spinning equipment or finding her a book about textile production in Europe or North America. If she likes to cook, see if you can find track down historical recipes in old cookbooks. Just make sure what you're showing her is relevant to her or she might find that she doesn't really care about what you're talking about.\n\nIn any case, I suppose what I'm saying is that you should work with her to find out what kinds of stories resonate with her and start there, and then use that as a starting point to get her exploring on her own. For example, someone who's interested in human stories about families separated in WWII might not be particularly interested in the planning of the Normandy landings. Both are part of the History of WWII, but are pretty different stories, and one might resonate more with someone. Find out what that is, and go from there.\n\nSo to summarize, find out what exactly she's looking to find out about, then try to point her towards things that can help her answer those questions. Try to explain things or find material that is relevant to her. This will help keep her interested and engaged with the history she's learning. Hopefully that helps at least a little, until someone a bit more qualified than me can chime in."
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54yyak | why are forests cut in square shapes in the us? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/54yyak/eli5why_are_forests_cut_in_square_shapes_in_the_us/ | {
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"These areas were logged at some point, notice the new growth in the areas that aren't as densely covered. I don't know if there is a specific reason for the grid pattern, I imagine it is just easier to manage that way.\n",
"In that particular example, various areas are designated scheduled to be and sold off to logging companies who come harvest the trees on a in certain areas while leaving other areas untouched to reduce impact on the ecosystem and ensure the forest remains renewable.\n\nIn other locations, there could be a other reasons. They could be cut along property lines, cut to make farmland (fields are usually square or rectangular), hit town/county/state boundaries, and so on.",
"Not sure about U.S. forests, but a classic way of managing forests, going back to before industrialization iirc, is to cut them into squares to manage the age of the trees for logging.\n\nLet's say you've got a kind of tree that takes 20 years to mature.\n\nIf you planted your land full of trees you'd have loads of trees in 20 years and then you'd have to wait 20 years before having trees again.\n\nNot a very sustainable business model, or good way to have a steady source of wood for whatever purpose.\n\nInstead you could cut your land into 20 squares. Each year you plant trees in one of the squares. After 20 years, you cut it down and replant. You then have a steady stream of trees to log every year. \n\nIt also simplifies it when you have, say, 4 different types of trees, which each take a different number of years to mature. You just designate a number of squares as relevant for each type, write it up on a map.\n\n",
"Other answers have explained why they're squares -- basically, surveying of land in the western US was done in the past 150-200 years in which surveying technology was advanced enough to do big squares instead of following topographic features quite as much.\n\nBut maybe you're asking about the \"checkerboard\" pattern? That's a peculiarity to how land was developed in Oregon, and we ended up with an alternating grid of land with 1/2 owned by a railroad and half managed by the federal government. It gets complicated but here's a history of how it played out: _URL_0_"
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2inqo3 | Is it possible to overdose testosterone? What will happen then? | askscience | http://www.reddit.com/r/askscience/comments/2inqo3/is_it_possible_to_overdose_testosterone_what_will/ | {
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"Depends on the administration route. Generaly there is no acute toxicity levels for testosterone.\n\nIf you take it orally (in the form of methyl testosterone) you will have acute hepatitis at a few grams.\n\nIf you take it IM you are restricted by the amount of oil your muscle can take."
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33p2ng | why is that so many people appear to be unaffected by a huge knife sticking directly into their brain, but almost always, a knife to the neck or chest will more than likely result in a fatality? | This question is due the large number of posts recently of people seeming nonchalant about a knife sticking out of their head | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/33p2ng/eli5_why_is_that_so_many_people_appear_to_be/ | {
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"Knife in brain guy? Is that you?",
"I suspect its more that people who survive shocking injuries to the brain are relatively rare and thus noteworthy.",
"Maybe because if the knife doesn't hit any vital part of the brain your main body funcions still work, breathing for example. (I've read about a guy who wasn't careful when placing dinamite in a hole for mining and the blow shot a metal pipe through his head. He lived on with a 2 cm diameter hole in his head.)\n\n\nI guess when you get stabbed in the chest or neck you bleed much more and lose all the 5L quickly...",
"There's not just one simple answer, as the systems involved are very complicated as well as the circumstances surrounding the stabbings are also unique to each case.\n\nPart of it might be some confirmation bias. You see so many people in ER waiting rooms or x-rays of people with knives, screw drivers, etc. sticking out of their heads. That's because it's such a bizarre sight. We think of the brain as this ever-crucial organ, so when someone walks into the ER with something sticking out of their brain, it's noteworthy and pictures of it are shared. You seldom get to see pictures of people who died from being stabbed/impaled through the brain. Many of them are DOA or do not sit in the waiting room for help. They get rushed to a trauma bay and emergency treatment is implemented behind closed doors. \n\nAnd then there's the misconception that a knife to the chest or neck is \"almost always\" fatal. This isn't necessarily the case. As I researched this, I came across one [source](_URL_0_) that finds that the mortality rate for stabs that penetrate the heart are around 15.5% and non cardiac stab wounds have a mortality rate around 2.5%. Now, you don't see many people in the ER with a knife protruding from their chest or neck, because even if they're stable there is a higher risk that the patient may start to lose massive amounts of blood, and they need a closer eye kept on them. If someone is relatively symptom free with an object in the brain, it's maybe not as critical of a situation and they may have to wait for treatment behind more serious cases.\n\nThen there are the circumstances of the stabbing. A knife to the skull will most likely get stuck in the bone, so it's a one and done sort of deal. It is far more likely to get stabbed multiple times in the chest and neck than it is in the head. The more holes you have in your body, the more likely you are to die from your wounds.\n\nFinally there's the anatomy of the organs involved. The brain is a very complex and large organ. Its functions are relatively compartmentalized, but there is also quite a bit of distribution of functionality. The more critical functions are located in the innermost parts, such as the parts that regulate temperature, blood pressure, respiration and heart beat. The chances of them getting damaged by a stabbing are fairly low. And the brain is resilient. Even if one part is damaged (from a stabbing or even a stroke), it can \"rewire\" itself to accommodate for the lost function. Someone with a damaged speech center, can sometimes relearn how to speak by using another part of the brain. So if the brain is stabbed and decent sized blood vessel is not ruptured, there is a good chance it will not be immediately fatal.\n"
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1a1cjs | The Sound from Krakatoa's explosion traveled around the Planet Seven Times. Would the sound be particularly loud at the exact opposite side of the World? | If sound travels outwards in every direction from its source the sound waves will travel in an expanding circle around the planet til it reaches the Antipode of its source where they will converge and travel back to its source again.
Will the sound at that point be particularly louder than surrounding areas as a result of that fact? | askscience | http://www.reddit.com/r/askscience/comments/1a1cjs/the_sound_from_krakatoas_explosion_traveled/ | {
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"Certainly. Although being in the exact spot would be difficult as fluctuations would occur as a result of the earth being an irregular shape.",
"I don't believe the sound from Krakatoa went around the world 7 times. At least not audibly. The time it would take for sound to travel through air would be 1 day and 8 hours.\n\n_URL_0_\n\nPerhaps you're referencing the seismic waves?\n\nAs to the second part of your question. If the sound did make it around, and the waves combined constructively, you would get a louder sound. If they combined perfectly destructively (not-likely), you could theoretically get no sound at all.",
"I just read that comment too. It said subaudible sound waves. So no... no loudness.",
"Somethings like [this simulation](_URL_0_)? Looks like it. \n",
"The sound would not be an audible 'bang!' but low frequency sound waves.\n\nOne interesting thing though is that the dust that was thrown up into the atmosphere did travel around the planet and created stunning sunsets. [These are the ones that Turner captured in a few of his paintings and are being used to calculate how much 'pollution' was in the air](_URL_0_)",
"What you have to understand is that point forces that propagate outward as the surface area of a sphere, such as EM fields, sound waves, etc. are governed by the inverse square root law.\n\nThis means that for every 1 step increase in r (the distance from the source) the power of an arbitrary subsurface of the sphere is proportional to 1/r^2 . The first thing you should notice about this factor is that it is never zero. The second thing you should notice is that the power decreases VERY quickly. \n\nSo what does it mean to \"travel around the world seven times\" if the power of the sound at any observer is never zero? It means that we have to define an arbitrary cutoff. For example, we could say that the cutoff is the power level that a human could hear with unaided ears. Another arbitrary cutoff is the level at which a recording device can distinguish an event. \n\nThe new question should be, at what distance from the point source (in this case, the Krakatoa explosion) is the power of the sound \n\nFinally, as for the constructive/destructive interference thing, i suspect that the sound wave generated from the explosion was comprised of many frequencies. Constructive and destructive effects in waveforms are proportional to the distance from the source and the wavelength (1/f) of the component of the sound; it is very unlikely that the sound would interfere in an overall constructive or destructive manner. ",
"Alright, I'd like to give a fuller answer to this question.\n\nYour intuition on this question is exactly right. Far away from the volcano, the sound will be ducted in the atmosphere, travel around the curvature of the earth, and refocus on the other side. 1/r^2 spreading, which a few others have mentioned, won't apply here because the geometry prevents isotropic spreading.\n\nThat said, there are a few complications that will come into effect. First off, there are other losses than spreading that you'll have to deal with. These losses are greater for higher frequencies. As a result, only very low frequencies, below the level of human hearing, will be able to make that whole trip around the earth multiple times. Second, the earth isn't a perfect sphere, so the \"focus\" of the sound will be a little bit spread out. This is exacerbated by the fact that the sound speed in the atmosphere is not the same everywhere. So, basically, the first time around the earth, the sound will focus pretty well, but each time later the focus will be less pronounced."
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2pgqbo | why is my smoke detector so sensitive to burned toasts but not to a burning towel left on the stove? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2pgqbo/eli5_why_is_my_smoke_detector_so_sensitive_to/ | {
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"Smoke detectors detect smoke particulate, not the presence of fire (usually they also have system that detects excessive heat). Burning toast tends to produce a nice cloud of smoke while a burning towel tends to burn more cleanly (not very much smoke), leading to less particulate for the detector to detect. You could have a roaring alcohol fire underneath a smoke detector and it wouldn't pick it up (assuming it doesn't get the device too hot) because there would be essentially no particulate produced. "
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6wpz8j | how were the japanese warned of the dprk missile? | I've been reading comments from Japanese people saying that they've gotten alerts on their cell phones from the government warning them of the missile heading towards Japan. And then another when it flew over, and another when it was confirmed that it was completely safe.
So how is it done? Does the government send a text message to everyone in the country? Does everyone have an app installed on their phones which issues the warnings? Is there something else? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6wpz8j/eli5_how_were_the_japanese_warned_of_the_dprk/ | {
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"They can send text messages to anyone but modern cellphones have options like AMBER. \n\nIn Japan especially, a lot of people have iPhones, and if you're american, they're an option in Settings > Notifications , scroll all the way down and you'll see \"AMBER alerts\" and \"Emergency alerts\". \nIt works the same way in Japan.",
"Modern telephone systems have these kinds of warning built in. One of the first integration between cell phone systems and warning systems were in Japan as they frequently have to warn people about Earthquakes and Tsunamis. The warnings are sent out as a kind of SMS but broadcast to all cell phones connected to a cell and not addressed to a specific cell phone. The phones might also interpret these messages differently to make them stand out and more noticeable. It is also possible to have such system for older cell phone technology by creating a list of every phone connected to a cell and then send an SMS to each phone individually.\n\nYou have a cell phone capable of receiving these kinds of messages and unless the cell phone tower you are close to are very old it also have the technology in place. But depending on how much the government is invested in this it may not be available. A lot of agencies are also careful not to issue warning unnecessary so you may not have received any. It is possible to test most of the system without actually sending out a mass message."
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r1cul | What's the history behind the development of quarantine practices worldwide? | Question came to me as I recalled, vaguely, of a line in Albert Hourani's _A History of the Arab People_ describing that the Ottomans still hadn't figured out the practice of quarantining ill people by the 19th century, which meant that plagues/pandemics would consistently cull the population every generation or so, slowing Ottoman growth. In contrast, the European nations that had been practising quarantining victims since the black death reaped the rewards of population growth and increased pool of talent.
But that's just a vague memory of mine, and the wikipedia page for the subject sheds little light. Is there truth in the above? And when did quarantining start/where did it spread to? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/r1cul/whats_the_history_behind_the_development_of/ | {
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"To my knowledge, during Tudor England, every time the \"sweating sickness\" (an epidemic that swept the cities every summer, probably brought over from France by Henry VII's army) came, there were methods similar to quarantining. They would tie some mark (I think it was a bundle of straw) to the door of the house to warn people to stay away. The family was discouraged from leaving the house and going abroad after the disease struck their home. and so forth. \n\nThere was also the horrific Lazzaretto Vecchio (_URL_0_) where Venetians with the plague or suspected thereof where shipped until they got better or croaked (I can't imagine the survival rate was very high in such a place). I think that island dates back to the 1400's.",
"There were some (very) meagre and mostly unintentional beginnings in the Middle Ages, during the time of the Black Death(1347 - 1351/3), for example there are sources that tell of people that were walled in in their houses after showing symptoms of the plague. This was partly based on the isolation of other victims of infectious diseases from society, particularly lepers.\n\nSame goes with access to cities, in Italy during the Black death people showing symptoms were refused access to neighbouring city states, and sometimes refugees without symptoms weren't let in, either - mostly out of fear, not out of calculation. People sometimes did catch on, that even non-symptomatic people could spread the disease, but they weren't able to capitalise on that knowledge. Then, of course, there was the fact that this particular disease is also spread by rats/fleas, and good luck keeping them out of your city.\n\nThe first real Quarantine (named after the amount of days it was instituted - 40) was the one OleWorms64 referred to, in Venice. Wiki has something:\n\n > The word \"quarantine\" originates from the Venetian dialect form of the Italian quaranta giorni, meaning 'forty days'. This is due to the 40 day isolation of ships and people prior to entering the city of Dubrovnik in Dalmatia - Croatia (formerly known as Ragusa). This was practiced as a measure of disease prevention related to the plague (Black Death). Between 1348 and 1359 the Black Death wiped out an estimated 30% of Europe's population, as well as a significant percentage of Asia's population. The original document from 1377, which is kept in the Archives of Dubrovnik, states that before entering the city, newcomers had to spend 30 days (a trentine) in a restricted location (originally nearby islands) waiting to see whether the symptoms of plague would develop. Later on, isolation was prolonged to 40 days and was called quarantine."
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3yv8tr | what's going on when we have a bad headache/migraine? is the brain telling itself that it feels pain or is the brain itself actually in pain? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3yv8tr/eli5_whats_going_on_when_we_have_a_bad/ | {
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"It's never your brain. The brain doesn't have pain receptors and can't actually feel pain. The membrane around your brain can feel pain, but the brain itself cannot. \n\nThe pain you feel is not your brain - it's usually blood vessels being either dilated or constricted in your head. "
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29me52 | What is happening molecularly when bleach gets on a dark cotton shirt? | Is the dye replaced? Or what? Whats going on when that happens? | askscience | http://www.reddit.com/r/askscience/comments/29me52/what_is_happening_molecularly_when_bleach_gets_on/ | {
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"Organic dyes are strongly coloured because they contain large networks of [conjugated double bonds](_URL_0_). One such example is [anthocyanin](_URL_1_), the molecule responsible for the colour of many plants. In general, the larger the conjugated system, the higher the wavelength of light the molecule will absorb.\n\nBecause a conjugated system requires double bonds at regular intervals, disrupting these double bonds will break the conjugated system. Bleach works by chemically altering the molecule to disrupt the conjugated system. When this happens, the absorption spectrum of the molecule will shift to a lower wavelength, possibly out of visible light range and into UV range. If that happens, the molecule no longer absorbs visible light and will appear white to us."
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iw8au | If we were to travel to a star 1 ly away, what is the earliest time we could arrive at there? | Assuming we could accelerate arbitrarily fast, from the destination star's perspective.
IE, if we see something cool 1 ly away, in what time frame would it be physically possible to reach there?
edit: arrive at there.... ugh | askscience | http://www.reddit.com/r/askscience/comments/iw8au/if_we_were_to_travel_to_a_star_1_ly_away_what_is/ | {
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"Time is relative. From the travelers' perspective, you could get the time arbitrarily close to zero, but from Earth's perspective the time could never be less than a year.",
"From the travelers perspective, one could arrive there arbitrarily fast. From earth's perspective, any amount of time greater than one year.\n\n For your actual question: Assuming the star is not moving relative to earth, then any amount of time greater than one year. If the star was moving relative to earth, it might not agree that it is 1 ly away from earth.",
"Let's assume you're traveling close to the speed of light. \n\nWe have three clocks: one on Earth, one on your spaceship and one near the star. When you leave we start the clock on Earth and the clock on the ship. We also send a light signal to the star, and when it's received the third clock starts. When you arrive your and the star's clock are stopped, and we send a signal back to stop the clock on Earth.\n\nIn the end, the clock on Earth will show 2 years, the clock at the star will show 0 years and the clock on your ship will also show 0 years."
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8xjg3n | Are our internal organs sexed so the differences between men and women are noticeable? | I don't mean our reproductives and plumbing, we know about those. I am referring to things the heart and lungs, digestive organs, lymphatic system, eyeballs, teeth, fingernails, veins, blood or boogers.
We're familiar with the skeletal differences (brow, cheekbones, jaw, hands and feet) and the general differences in metabolic rate, lung capacity, muscular and fat distribution but I was wondering if there were differences in say the liver, or the uvula, vomer or gall bladder, the things that don't normally come up as examples.
I was thinking of the push in recent decades to get more women in to Pharma testing as subjects and how cardiac pain can be missed in women if you're looking for the famous shooting pain in the left arm experienced by men.
Let me give a for instance. Could someone look at a liver, or tests results from it, and say 'Yep, it belonged to a man'. I'm using the liver because it's a fascinating organ.
Please and thank you. | askscience | https://www.reddit.com/r/askscience/comments/8xjg3n/are_our_internal_organs_sexed_so_the_differences/ | {
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"In regards to the liver, no. However, the cardiovascular system of a male is naturally larger than a females, but you couldn’t make more than a slightly educated guess as to whether a set of lungs belonged to a male or female. A completely average males lungs compared to a completely average females lungs will appear to be bigger, but sizes of people vary as does the size of someone’s lungs so it is not a definite thing at all."
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893fr7 | why do most nerve tracts crossover so that neurons in the brain's cortex innervate muscles on the opposite side of the body? | Functionally and from an evolutionary perspective, what is the advantage of having nerve tracts decussate to the contralateral side of the body? For example, the optic chiasm, the corticospinal tract, etc. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/893fr7/eli5_why_do_most_nerve_tracts_crossover_so_that/ | {
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"Asking this question in this manner rather obfuscates it. Perhaps to a community like the ELI5 it would be better to say: \"Why do the brain's hemispheres control the opposite side of the body?\" \nOr something to that extend.\n\nOne interesting theory I saw in [_URL_0_] is that it contributes to the flight response in limbed-animals. There the author argues that the crossover may benefit response and coordination during flight responses. Not a perfect theory, but the best one I can tell you. "
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8qsw23 | Why did pikes fall out of popular use in the ancient period, and why did they not return to popularity until the late middle ages? | From what I know, it seems pikes were quite popular in the ancient world, especially by the Macedonians. It then largely fell out of use for centuries before becoming the standard weapon for European infantry until guns made them obsolete. I have heard that the formation of the Roman legions countered pikes, but not how exactly. After the fall of Rome, and as cavalry became the dominant force on the battle field, why did it take so long for the pike, a great counter to cavalry, to return to use other than occasionally by the Scots and Flemish? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/8qsw23/why_did_pikes_fall_out_of_popular_use_in_the/ | {
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"Organised formations of pikemen were first used by the Macedonians in the second half of the 4th century BC, and were in use until some time in the 2nd century BC. During this period of less than 2 centuries, they were seen as the ultimate weapon on Mediterranean battlefields. Alexander's successes against the Persians are largely due to his army's dependable core of veteran pikemen. Any Hellenistic kingdom worth its salt would field its own pike phalanx, and states trying to assert themselves on the geopolitical stage (such as the resurgent Sparta of the late 3rd century BC) would sometimes abandon their existing fighting styles and reorganise their infantry as pikemen. For Greek hoplites, this would entail the replacement of their heavy double-grip *aspis* shield for a much smaller round shield suspended from the neck by a strap, and the replacement of their thrusting spear with a very long *sarisa* pike wielded with both hands. In Alexander's day the *sarisa* was perhaps 4.5m (15ft) long, but the advantage of greater reach caused a steady increase over time to a maximum of around 7m (21ft). These pikemen were arrayed in dense formations (typically 16 ranks deep) and presented an impenetrable front of gleaming spearheads.\n\nSo why did this warrior type go out of style? \n\nThe common answer is that the pike phalanx, while very effective in a head-on advance across level ground, was cumbersome and vulnerable from the flanks and rear. It relied on a dense wall of overlapping pikes, which could only be maintained in one direction at a time, and required terrain without obstacles in order to function properly. Quicker and more flexible troops such as the Roman manipular legion were able to exploit this by luring pikemen into broken ground and using small units to engage vulnerable parts of their formation. This led to notable Roman victories at Magnesia, Kynoskephalai and Pydna (among others), which gradually eroded the power of the Hellenistic kingdoms and eventually led to the abandonment of pike infantry and the incorporation of Hellenistic lands within the Roman domain.\n\nBut this is the kind of thing you hear on Youtube channels. It doesn't really look very hard at the question. Aristotle already remarked on the vulnerability of pike formations and their dependence on level ground to function; it clearly didn't stop them from becoming world-conquering troops. Alexander himself suffered the dissolution of his phalanx at Issos but still won the battle. It is from Polybios that we get the contrast between Hellenistic pikemen and Roman legionaries described above, but this is artificial and technocratic and his own accounts of the battles mentioned suggest that Roman victories were much more due to contingency and local decisions than to innate advantage.\n\nA couple of other factors are worth considering. The first is that the maintenance of a pike phalanx required immense investments of manpower and money. The typical pike phalanx was anywhere between 9,000 and 20,000 men strong; the men had to be professionals, carefully drilled and permanently available. The two ways to achieve this were either the establishment of a standing army at astronomical expense, or (the common Hellenistic solution) the allotment of very substantial lands to military settlers. These settlers were often (at least ideologically) Greek or Macedonian, which meant drawing on a rather small pool of immigrants to form a core element of Hellenistic armies. They often proved difficult as a political interest group and could destabilise empires as much as preserve them. Moreover, they were required not only to serve, but to maintain farms and families in order to replenish their own number over the generations. This could result in serious recruitment shortages if heavy losses were suffered in battle. Defeat at Panion in 200 BC proved such a demographic disaster to the Ptolemaic settler-pikeman class that the Ptolemies essentially gave up on fielding a pike phalanx altogether, and reformed their remaining military settlers into more flexible troop types such as *thureophoroi* or cavalry. The Ptolemaic kingdom was one of the richest Hellenistic states; how much more likely were others to keep their pike phalanxes up to strength?\n\nThe second point is that the Macedonian pike phalanx is essentially an overspecialised weapon. It is ideal for battle on level ground against heavy infantry, but practically useless in other situations. As long as the enemy is tactically or ideologically committed to fighting pitched battles on level ground, the pike phalanx is a war-winning weapon; this proved the undoing of the Persians, who had a strong tradition of fighting on prepared battlefields where numbers and cavalry would count in their favour. Similarly, the pike phalanx was both useful and necessary for Hellenistic kingdoms in their wars against each other, since fielding anything less in major pitched battles would be bringing a spear to a pike fight. Within its own self-contained tactical system, pikes begat pikes, and all major players needed a strong phalanx of their own. But Polybios already noted that it would be very unrealistic to expect any enemy to conform to the phalanx's preferred conditions for battle if they had a choice. Anyone who was not committed to fighting in the open with a main line of heavy infantry would be able to choose circumstances for battle in which the pike phalanx would be at a disadvantage. This would require Hellenistic kingdoms to depend heavily on the other arms of their forces, such as light infantry and cavalry - making the huge investment in the pike phalanx seem less attractive and less easily justified.\n\nThe third point builds on the previous two. Considering the extreme cost and the limited use of a pike phalanx, you may start to wonder why the Hellenistic states ever bothered with them in the first place. To explain this, it's important to bear in mind that the decision to adopt particular military technologies or customs is rarely guided by cold cost-benefit analysis alone. For the Hellenistic kings, legitimacy initially flowed from the ability to claim closeness and similarity to Alexander the Great; many of the features of Hellenistic kingship derived from the example he had set, which in turn built on Classical predecessors like Philip II, Iason of Pherai, Dionysios of Syracuse, and Evarogas of Cyprus. This included aspects of court life, relations with elites, cult of personality, the traits that defined kingship, and so on. It also included powerful manifestations of royal power. To put it bluntly, kings justified their status by showing off, and few things could show off power and wealth like a fleet of brand-new quinqueremes, a train of armoured siege towers, and a well-drilled Macedonian-style pike phalanx.\n\nThrough their phalanxes, kings communicated their power, regulated relationships with the Greco-Macedonian minorities in their territory, and established themselves as worthy rivals in wars with other Hellenistic rulers. The phalanx represented a coming together of Alexander-like symbols of power and harsh military necessities in the Mediterranean geopolitical system. As such, it had a brief moment of military dominance, but that its significance was far greater than its mere tactical success. It also meant that it had been steadily losing significance by the time the Romans started wiping the floor with it on the regular. Since the spectre of Alexander had faded, and the Hellenistic states had largely consolidated, and some states were simply no longer able to must significant numbers of Macedonian pikemen, the pike phalanx was already on its way out. If you couldn't impress anyone with a shiny new pike phalanx, and your enemies weren't playing the game, and all it did was drain your coffers, why bother? The Macedonians who fought Rome in the early 2nd century BC were the last to field a major army built around a core of pikemen, and their repeated defeats no doubt accelerated the demise of this way of war."
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1xwlnf | What did the Spanish want the Canary island for? | They didn't take any other of the Atlantic islands close to Africa or Europe, and I'm no farmer but this place (I'm on holiday in Tenerife) looks pretty arid
Edit: "islands" plural | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/1xwlnf/what_did_the_spanish_want_the_canary_island_for/ | {
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"In 1402, French adventurers Jean de Bethencourt and Gadifer de la Salle, who were nobles who owed allegiance to King Henry III of Castille, started conquering the islands. They wanted land. They got it. Bethencourt got the title \"King of the Canary Islands\", though he was still an under-king to Henry.\n\nIt took the Castillians until 1495 to finish conquering the islands. (They were also claimed by Portugal for a while).\n\nIn the early days of Spanish control over the Canaries they became one of the world's largest sources of sugar (Maybe the largest). Sugar was very valuable. Eventually, the Caribbean islands became bigger sugar producers than the Canaries.\n\nThe Canaries were also a key stop on the Spanish galleon route from Spain to the New World. Ships would stop there for water and provisions, as the islands were on the best (due to the prevailing winds, not the most direct) route from Spain to the Caribbean."
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qnst3 | Can black lights cause eye damage? | Black lights are a nice way of lightening up a party, but can they cause eye damage, especially if one stares directly at them for a long time? | askscience | http://www.reddit.com/r/askscience/comments/qnst3/can_black_lights_cause_eye_damage/ | {
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" > Can black lights cause eye damage? \n\n[Black light : Safety](_URL_0_) -- basically, not much risk of any kind.\n\nEDIT: The above only applies to \"Black lights\", not tanning lights and other kinds of UV lights which are dangerous to the eyes and skin.\n",
"Most of them are simply a fluorescent light bulb with a coating that only lets the UV light out. These are no more dangerous than a regular fluorescent light bulb.",
"You might be interested in knowing that we use a UV light as part of an eye exam procedure in our laboratory.\n\nAfter removing a device that looks like a large contact lens from the subject's eye, we need to make sure the cornea hasn't been scratched. We put a drop of fluorescent dye in the eye and shine the UV light to look for scratches."
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1jdhl6 | Can anyone tell me about the history of humans using weed? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/1jdhl6/can_anyone_tell_me_about_the_history_of_humans/ | {
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"“[PAGE 380] [description of a funeral] . . . And this is the Manner of the King’s Funeral. But when any other Scythian dies, his nearest Relations carry him about in a Chariot among his Friends; who receive and entertain the whole Company, in their Turn, setting the fame things before the dead Man as before the rest. In this Manner all private Men are carried about forty Days, before they are buried: And those who have assisted at these Funerals, purify themselves thus. When they have cleansed and washed their heads, they set up three pieces of timber leaning to each other, and laying a good number of Woolen Bags close together, throw burning Stones in to a hollow space left in the midst of the wood and bags. In this country a sort of HEMP grows, very like to flax; only longer and thicker; and much more excellent than ours, whether sowed or produced by Nature. The Thracians cloth themselves with garments made of the HEMP; so well resembling Flax, that a man must have great experience in those materials to distinguish one from the other: And he who had never seen this HEMP, would think their [PAGE 381] their Cloths were wrought out of Flax. The Scythians put the Seeds of this HEMP under the bags, upon the burning stones; and immediately a more agreeable vapor is emitted than from the incense burnt in Greece. The Company extremely transported with the scent, howl aloud; and this Manner of purification serves instead of washing: For they never bath their bodies in water. But their wives grinding the wood of cypress, cedar, and incense upon a rough stone, and infusing the powder in water, compound a thick substance, which they spread over all the parts of the body and face. . . . . “\n\n-herodotus \n\n[link] (_URL_0_) that goes more into detail.",
"Cannabis seems to be pervasive throughout Persian history from the pre-Islamic, Zoroastrian ancient era, through the Islamic conquests and Islamic \"Golden Age,\" up until today.\n\nOne of the few surviving books of the Zend-Avesta, called the Venidad, \"The Law Against Demons\", calls bhanga (marijuana) Zoroaster's \"good narcotic,” and tells of two mortals who were transported in soul to the heavens where, upon drinking from a cup of bhang, they had the highest mysteries revealed to them.\n\nCirca 1090-1124 AD in Khorasan, Persia, Hasan ibn al-Sabbah, recruited followers to commit assassinations and legends developed around their supposed use of hashish. These legends are some of the earliest written tales of the discovery of the inebriating powers of cannabis on the *hashashins* or assassins.\n\n*1,001 Nights*, an Arabian collection of tales, describes hashish's intoxicating and aphrodisiac properties quite specifically in the tale of the two hashish-eaters.\n\n > There was once, my lord and crown upon my head, a man in a certain city, who was a fisherman by trade and a hashish-eater by occupation. When he had earned his daily wage, he would spend a little of it on food and the rest on a sufficiency of that hilarious herb. He took his hashish three times a day: once in the morning on an empty stomach, once at noon, and once at sundown. Thus he was never lacking in extravagent gaity. Yet he worked hard enough at his fishing, though sometimes in a very extravagent fashion.\n\nThere are recurring references to cannabis throughout 1,001 Nights and I recommend reading either the original text or *The Arabian Nights: Tales of 1,001 Nights* by Robert Irwin, which provides fantastic contextualization and analysis."
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3zevmy | AMA: The Library of Congress Veterans History Project – 15 years, and 99,000 Collections of Veterans’ Voices from WWI to the Present | Hi, we are the staff of the Library of Congress Veterans History Project. Since we were established in 2000 via a unanimous act of Congress, we have been collecting oral histories and memoirs from US veterans, as well as original photographs, letters, artwork, military papers, and other documents. We have over 99,000 collections and that number is growing every day, making us the largest archive of this kind in the country.
We work with organizations and individuals around the country to grow our collections, but anybody can participate. All it takes is a veteran willing to tell their story, an interviewer to ask them about their service, and a recording device to capture the interview. Eligible collections will include either a 30 minute or longer interview, 10 or more original photos, letters, or documents, or a written memoir of 20 pages or more.
To ensure these collections are accessible for generations to come, we stabilize, preserve and securely store them for posterity, here at the Library of Congress. Our materials are available to researchers and the general public, either by viewing the original materials in person at the Library of Congress in Washington, D.C.. Additionally nearly 16,000 collections are available online at our website, _URL_1_.
The staff who will be answering questions are:
Col. Robert Patrick US Army (Ret.), Director of VHP
Monica Mohindra, Head of Program Coordination and Communication
Megan Harris, Research Specialist and Librarian
Andrew Huber, Liaison Specialist
From 9am-12pm Eastern today, please ask us anything about how we collect, preserve, and make available our collections, as well as anything about the individuals who comprise our archive and their stories, and of course questions about how to participate or any other aspect of the Veterans History Project. We will also try to answer questions about the Library of Congress in general, but keep in mind that it is a very large institution and we might not have specific knowledge about every detail.
Also, please sign up for our RSS feed [here](_URL_2_), and read our blog [here!](_URL_0_) If you don’t make it to the AMA in time to have your question answered, you can always email us at vohp@loc.gov.
EDIT: It's now 12:00 here and the official AMA has come to an end. However, I am still going to be monitoring this thread and will send any new questions to the appropriate staff member for an answer, but I can't promise quick answers anymore. Feel free to keep asking questions though, and remember you can email us anytime at vohp@loc.gov. | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/3zevmy/ama_the_library_of_congress_veterans_history/ | {
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"Thanks for doing both this project and this AMA! I noticed that only a few of the individual subject files are online; what are your plans for digitization and making them more easily accessible for folks doing research from home? Having worked with folks here for a few years, I'm constantly amazed at how many people are interested in history, but they don't typically have the resources to go to Washington, D.C. for their research. ",
"Thank you very much for being here!\n\nI'm curious to know more about your collection of First World War accounts. With the death of the last living veterans of the war, this repository has become more important than ever; what is the scope of its contents, how are they being preserved, and what do you have planned (if anything!) for 2017?\n\nThanks again.",
"I know that the Korean War is often also referred to as \"the forgotten war\". What steps has this project taken to address this problem, or how has this problem affected the project as a whole?",
"This sounds like a pretty amazing project! I'm sure that each of you have come across tons of amazing stories and recollections while working on it, but are there any particular ones that really resonated with you that you could share with us here?",
"Do you know of similar programs run for veterans in other countries such as the UK or Canada? If do, is any sort of cooperation between your projects?",
"I've been following your project for a long time and I think it's absolutely fantastic. Thank you for running something so amazing!\n\nWith that said, my question is that of minorities: How well-represented are minorities in your collections? Is there a particular minority that you have yet to see but that you would like to include in the collections? ",
"Talking about time in the war can be difficult for a lot of veterans - do you have any advice for conducting oral history around difficult memories? ",
"Hi! Do you have suggestions on questions to ask and how to approach an aging veteran to ask them about doing an interview? My grandfather is 93, served in WWII for the US and I know he was present during D Day(he says he watched the beach landings from a ship) and the Battle of the Bulge. He began in a mail room in England and volunteered to join an engineer group that moved through France and somewhere into Germany. Any suggestions are welcome for questions I could ask. He also has photos of Jewish camps in an album that he will not discuss, photos of ovens and stacks of bodies.",
"What is the thing that has surprised you the most when looking at your collection? \n\nHow do you organize such a collection?",
"Thank you for making those happen. My uncle's recordings have been on there for years and is a great way for us to get to know about his life and to share his amazing tales. \n\nAre the stories vetted in any way? Corroborated by other witnesses or documentation? Are there any stories that had to be edited due to classified content? ",
"Does the project also compile interviews from soldiers from the other side, such as Germany?",
"I have 600 letters from my Grandfather to my Grandmother, written from Oct. '41 to March '46. I'd be happy to contribute, but more pressing is how to efficiently digitize such a collection?",
"I work with the VHP through my job, as a staffer with a Congressional member in their district office. We usually try to get high school students involved with the project by encouraging them to talk to veterans in the community and in their families, though I've submitted several narratives on behalf of several veterans. I love this project, and I love that there is a place for their stories and the things that meant something to these veterans at one time (the diary for instance, and photographs.)\n\nThank you for all of the work you do!",
"Do you accept typed transcriptions of letters? My mom has hundreds of letters that her mom saved during WWII that were sent to her from my grandpa. I am going through them letter by letter and typing them up to preserve them for posterity. They are written in cursive as was the style at the time and the ability to read cursive, especially when it isn't good penmanship, is fading away.\n\nI think I'm getting close to being done with the letters and once my mom, aunt and uncle have a chance to read them we are looking at historical/veterans societies that may be interested in them. I don't know if my mom would part with the physical letters but they would be willing to share the typed manuscript.\n\nIf it helps, my Grandpa was drafted in 1942 into the Army and after training was assigned as a field medic to the 808th Tank Destroyer Battalion with which he deployed to Europe in September 1944 and saw combat including in Luxembourg during the Battle of the Bulge.",
"Guam has the highest enlistment rate in the US, and their soldiers have the unique identity of being US soldiers and living through a foreign occupation. \n\nSo why is Guam not on the states and territories list, even though you can find some of them if you search by race? \n\nAlso, how do you feel about Congress continuing to deny reparations to the locals of Guam from WWII?",
"I presume that in your work you come into contact with lots of ... shall we say \"negative\" stories. After all the saying goes, \"War is hell\". Does exposure to such stories take a mental toll on you? If it does, how do you deal with it? "
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75sbk8 | Kennedy assassination records may be fully declassified by the end of this month. Has anything significant come from previous releases of records, such as in July 2017, which impacted previously held views on the event? | According to [this site](_URL_0_), "The National Archives and Records Administration is releasing documents previously withheld in accordance with the JFK Assassination Records Collection Act. The vast majority of the Collection (88%) has been open in full and released to the public since the late 1990s. The records at issue are documents previously identified as assassination records, but withheld in full or withheld in part." A first batch of 3,810 records from the FBI and CIA were released in July of this year. While I read about the release in the news at the time, I have not heard anything about the contents since. Was anything interesting or significant found? The issue is in the news again today with the impending deadline at the end of this month for the final release of all the records.
Follow-up question: were there any big bombshells in the original release of the first batch of records in the 1990s which changed common thinking about the assassination? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/75sbk8/kennedy_assassination_records_may_be_fully/ | {
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"Can anybody recommend a solid, well researched book on Kennedy assassination ?",
"If we are talking, what's the historians view on JFK and the Unspeakable: Why He Died and Why It Matters by James W. Douglass? I tried to ask here but didn't get much.",
"To add on: as laymen are there historic detailed questions that would be fruitfull to ask? How could one make the best out of the declassification? And what will be worthwhile to look for in the debate on the new material in relation to old historic questions? ",
"Is there any truth to the allegations that some of the files have gone missing?",
"I'm disappointed that no one has addressed OP's initial question. Is there any expectation that the new files will bolster any of the theories behind the assassination? Did the earlier release of files add anything new? ",
"So this has been sitting for a day now, and I was hesitant to weigh in because, well, this *isn't* my area of study, to say the least, but I do think there are a few things which can be noted nevertheless. For the documents released in the 1990s, I really can't say anything specific on what they revealed, but any reputable work on the history of the assassination that has been published in the past 20 years will likely have incorporated them already, and there might have been bombshells at the time, but by this point that'd be old news, and someone on the younger side might be surprised even to learn that some of what was revealed only came out so late. Certainly, it can be said that the broad narrative - Lee Harvey Oswald was a single gunman, firing from the book depository - has never been impeached, and nothing that came out then did so either.\n\nNow, as for the 2017 documents? Well, as you note, some were released in July, and more will be coming out by the end of the year. [Politico did a write up just after the first patch a week after they came out](_URL_0_), and I think that their summation provides us with a few important points. Namely... don't expect anything to happen too quickly! At the one week mark, as they note:\n\n > JFK historians and the nation’s large army of private assassination researchers are still scrambling to make sense of the latest batch of tens of thousands of pages of previously secret CIA and FBI documents.\n\nWhich is to say, it is a ton of material. A *lot* of it is also useless. Many documents apparently are nothing more than duplicates of records already released. With the July Batch, nothing came out which was a bombshell. The core narrative remains essentially unchanged. There *does* seem to be some interesting material concerning internal communications of the CIA about their concerns of missing some key connection - the possibility Oswald was connected to Cuban elements in some way seems to loom large - *but that is only speculation*. There were some clues which they feel the Warren Commission didn't investigate thoroughly - a trip to Mexico apparently wasn't properly followed up on - but there is nothing in these documents which suggest there actually was a connection, only concern for the possibility that they *couldn't find one that might nevertheless exist*. Their concerns seem, at least in part, to stem from the fear that if that were true, it might have been in retaliation for their own activities against Castro and Cuba. But again, all that that documentation points to is some people in the CIA during the '70s navel-gazing in the wake of the Warren Commission, and in no way points to actual evidence in any way. The key thing that these documents reveal so far, to again repeat and this time give it to Politico, is that:\n\n > None of the files released last week undermines the Warren Commission’s finding that Oswald killed Kennedy with shots fired from his perch on the sixth floor of the Texas School Book Depository in Dallas’ Dealey Plaza—a conclusion supported by 21st century forensic analysis—and that there was no credible evidence of a second gunman.\n\nFor the documents still forthcoming, we can only speculate what they contain, but the chances of them changing the above are scant, and that is charitable. The best likelihood, *if* someone is able to really research these trails which went cold a half-century ago, is providing better elucidation into the motives of Oswald. The documents point to others who believed connections might be out there unfound, and maybe there is something to that or maybe not. But *any* really revelatory information that these might turn up isn't going to show up yet. It would likely take years of further analysis and research before you find any reputable historian publishing a new work, or revising their previous ones, to incorporate these documents even in a relatively mundane way, let alone in a manner which they believe offers new elucidation on the assassination.\n\nTL;DR: There are some tantalizing tidbits at the margin, which with a lot of *honest* investigative work could maybe let us learn more about Oswald's motives, but Oswald Did It, In the Book Repository, With the Carcano.\n\nIn any case, all the documents can be found [here](_URL_1_). The Politico article I referenced is [here](_URL_0_). They in turn highlight one of these internal CIA documents [here](_URL_2_)."
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6eo12g | what happens if you defend yourself against a bounty hunter? | Saw a news article and it made me think of what would happen if i successfully defended myself against a bounty hunter.
For instance: The perp has an outstanding charge and did not show up to court. A bounty hunter gets assigned and finds the perp. The perp defends himself against the bounty hunter which results in the death of the bounty hunter. Would the perp receive charges for the death of the bounty hunter(murder/manslaughter)? What is the threshold for identifying yourself as a bounty hunter or any LEO?
Thanks | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6eo12g/eli5_what_happens_if_you_defend_yourself_against/ | {
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"Could the defendant be charged with a crime? Absolutely. Bail bondsman, police officer, or any other civilian, a homicide happened. There's only a few select reasons to exempt a homocide from being charged, legal self defense being one of them. However a fleeing criminal can't use that as a legal defense against his pursuer. At the point in time when bounty hunter is on you, you have been charged and found guilty of failing to appear at the court hearing. Whether you are guilty or not of the original reason why you were summoned to court in the first place is irrelevant at this point. "
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3y5942 | how fast would a santa have to be to deliver all the presents to everyone in the world? | Yeah I know Santa isn't real. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3y5942/eli5_how_fast_would_a_santa_have_to_be_to_deliver/ | {
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"If we look at it as Santa only visits homes, and thus only has to make one stop per home. Additionally because of time zones we will assume he has a 24 period of time to stop at all the locations.\n\nThe best estimate I can find assumes there are about 900,000,000 houses in the world.\n\nWith these numbers, Santa would have to visit 10,417 homes every second to make the run. ",
"Data is incomplete, so we'll do some fast and loose maths.\n\nThere are [about 1.23 billion children under 10](_URL_2_). Obviously, we shouldn't count all of them since Santa only visits children who actually believe in him, not just metaphorically or as a holiday spectacle. But we *do* count both good and bad children since he has to give bad kids coal too.\n\nLet's start by excluding the two biggest countries that probably don't have many kids that *believe* in Santa. [~236 million indian children](_URL_14_) and [~160 million chinese children](_URL_3_). The next most populous country, Indonesia, only has [~44 million kids](_URL_4_), so the numbers will probably diminish quickly after that. I'm too lazy to add up a bunch of bar graphs so let's just call it another 200 million across the rest of the world.\n\nThat leaves about 600 million children under the age of 10 in countries that *generally* believe in Santa.\n\nBelief drops off dramatically by 9 years old. [Around 60% of 6-7 year olds and around 30% of 8-9 year olds.](_URL_6_). Recall from before that the under-10 population is more or less evenly distributed. That means only about 40% of children under 10 *in countries that generally believe in Santa* actually believe in him. But now we've racked up a whole lot of margins of error, so let's call it an even half to account for children that believe in Santa in the countries we just excluded earlier, and those who still believe past age 9.\n\nThat leaves 300 million children worldwide who believe in Santa.\n\nNow take into consideration /u/Dicktremain's point about homes. The [average household is about 3.5 people](_URL_0_) (it's missing data on a bunch of countries, whatever. and excluding china and india doesn't change much). Let's assume an average of 1.5 parents per household (because I can't find a good source). That means there are an average of 2 kids per household.\n\nWhich means Santa has to visit 150 million houses.\n\nStealing /u/DrImmergeil's estimate of time. The [sun rises at about 8:00 in the morning](_URL_8_). But Santa can't start right when the sun sets, he has to wait till kids go to sleep. So let's assume bedtime is 10:00p. That's 10 hours of night time that he can use. Plus 23 hours for every other timezone.\n\nSanta has to make **150 million stops in 33 hours, or about 1263 stops every second**. But how *fast* is he going?\n\nBecause [half of everybody lives in cities](_URL_1_), the travel distance is significantly shorter for some trips. I couldn't find any data on average world city sizes, but I did find [the average area of a US city is ~614km^2](_URL_17_). We do know that US cities tend to sprawl, and as a sanity check, the [largest Canadian cities and towns (excluding villes) is ~720km^2](_URL_9_). There's clearly a *bigger* bias here, but I don't know exactly how much.\n\nTrying to figure out exactly how far Santa has to travel in each city will be an impossible task, depending on the density of believing children. But we have an upper limit of about 500km^2 per city on average. Within the [~150 million km^2 total land area of Earth](_URL_7_), it might as well be a single point. But remember, fully *half* of Santa's travels are in these tiny little dots, so he travels *a lot* within them. Let's try to compensate for it some other way.\n\nLet's assume that the other half is evenly distributed around the world. Our hypothetical children in Antarctica should very adequately make up for the intra-city travel distances. What about the excluded countries of India and China? Well there's a bunch of countries we didn't exclude all around them, so you're still going to have to fly over anyway. Probably won't make a huge difference.\n\nSanta has to make 75 million stops spread over 150 million km^2 of land. Each stop sits on [almost 2km^2 of land](_URL_15_). Assuming a triangle because it's the easiest to calculate, each stop is [2.14km from each other](_URL_11_). That's a grand total distance of [160 million km](_URL_10_), with half of the stops evenly distributed among the world landmass and half the stops in a single point.\n\nSanta has to visit 150 million houses over 160 million km in 33 hours. Or an average of [**3.9 million km/h**](_URL_5_).\n\nThis is [36.5% of the speed of light](_URL_12_), a measly [warp 0.19](_URL_16_).\n\n/u/The_Dead_See asked about time dilation effects. At those speeds [there's barely any](_URL_13_). And it'll actually work *against* Santa. He'll experience *less* time than the rest of us, but he still has to get the job done in 33 hours of the at-rest frame of reference - that is, our time. For the 33 hours that we experience, Santa will only experience about 30. So he has to deliver all those presents and coals with 3 fewer hours in his frame of reference."
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"https://www.wolframalpha.com/input/?i=warp+factor&a=*C.warp+factor-_*Formula.dflt-&a=*FS-_**WarpSpeed.w-.*WarpSpeed.v--&f3=0.00365&f=WarpSpeed.v%5Cu005f0.00365&a=*FP.WarpSpeed.Series-_NG",
"https://en.wikipedia.org/wiki/List_of_United_States_cities_by_area"
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p56q8 | will someone please eli5 "dues ex machina" | I don't understand that saying. Is it a reference? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/p56q8/will_someone_please_eli5_dues_ex_machina/ | {
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"It's simply something written in by the writer that either explains away other things in the plot or makes it so that characters can conveniently escape their predicament. It typically means something that the writer sort of pulled out of their ass when they couldn't come up with a decent way to explain a situation.\n",
"I think of it as an \"out of context\" solution to a problem. It is as if (and this is how it was originally used) the problem was divinely solved. It can be very much like calling something \"ironic\" in the sense that pretty much anything can be argued as being in context (no matter what you call \"ironic\" someone will disagree).\n\nBut if you imagine a tense chase scene in a city and suddenly the bad guy is shot when a gun some random person is cleaning in their apartment goes off and kills them, saving the good guy. That whole \"WTF happened?\" feel is what I am talking about.",
"The essential element of a story is a character's struggle to achieve something. The ups and downs of the struggle is what entertains us. \"Deus ex machina\" ruins this by basically making the character's struggle irrelevant.\n\nLet's say it's a story about me as a struggling immigrant:\n\nI come to America and face prejudice and poverty. Then there's some happy moments when I get married and start a family. But then there's more struggle as I face problems starting a business, encounter racism, etc.. Then at my lowest point, I win the lottery (deus ex machina) and all my problems are solved and I live happily ever after. The story is ruined because there's no real outcome of my struggles. All my perseverance didn't really matter because it had nothing to do with the happy ending. ",
"* Movie starts\n* Plot has holes\n* *Deus ex Machina*\n* Profit",
"It basically means that whoever is writing a story took the easy way out of a plot conflict.\n\nSome seemingly inescapable conflict arises in the plot, and some external force which has possibly not even been referenced yet in the book \"swoops in\" and saves the day.",
"Deus ex machina: \"god out of the machine\"; plural: dei ex machina) is a plot device whereby a seemingly unsolvable problem is suddenly and abruptly solved with the contrived and unexpected intervention of some new event, character, ability, or object.",
"In ancient Greek plays, tragedies often ended with a God descending from heaven (lowered by a machine, of course) and bringing closure to the plot.\n\nHence the saying Deus ex Machina (*or* *God from the machine*). It is usually used when someone or something out of the blue brings a storyline to an end which would not have been possible otherwise.\n\nExample: In the final matrix movie, Neo makes a pact with one of the machines to kill Agent Smith. Without the help from that machine, this would not have happened and nothing in the film up to that point indicates that such an event was even a possibility.\n\nNote that the thing interfering in the plot line does not have to be divine or a machine to be called a Deus ex Machina, it simply needs to bring about an improbable change in the story."
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mfy9x | How do eye drops work? | askscience | http://www.reddit.com/r/askscience/comments/mfy9x/how_do_eye_drops_work/ | {
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"Can you be more specific as to what type?",
"Visine, ClearEyes or other OTC eye drops act to constrict the blood flow of vessels in the eye which causes the redness in the first place. \n\nMost eyedrops also add a \"simulated tear\" to naturally lubricate the eye to make dryness go away.\n\n\n",
"There are multiple types of eye drops.\n\nFirst, there are ophthalmic formulations of various medications, including antibiotics, antivirals, and corticosteroids. These are used for specific problems and require a prescription in the US.\n\nAs acj21 mentioned, many eye drops designed to reduce 'red eye' contain vasoconstrictors which shrink the blood vessels in the white part of your eye, making your eyes appear more white.\n\nThere are artificial tears which are used to deal with symptomatic dry-eye. The idea is that some people have aqueous tear deficiency (they don't make enough or lose too much of their natural tears) and so you replace them.\n\nIf you have really bad dry-eye problems, you can actually get serum tears made. This means a doctor draws a bunch of blood from you and spins out all the red blood cells in a centrifuge. The remaining serum is given back to you and used as eye drops.\n\nThere is one FDA-approved medication for dry eye, called [Restasis](_URL_0_). It contains a small amount of immune suppressant medication. The medication is slightly controversial, as some eye docs doubt the efficacy.\n\nOur actual understanding of dry eye is quite poor. We think that dry eyes have tears with an abnormally high osmolarity (too concentrated). This causes damage to the corneal epithelium (the outer layer of the clear part of your eye) which causes irritation and blurred vision.\n\nNote: I do research in dry eye. ",
"Can you be more specific as to what type?",
"Visine, ClearEyes or other OTC eye drops act to constrict the blood flow of vessels in the eye which causes the redness in the first place. \n\nMost eyedrops also add a \"simulated tear\" to naturally lubricate the eye to make dryness go away.\n\n\n",
"There are multiple types of eye drops.\n\nFirst, there are ophthalmic formulations of various medications, including antibiotics, antivirals, and corticosteroids. These are used for specific problems and require a prescription in the US.\n\nAs acj21 mentioned, many eye drops designed to reduce 'red eye' contain vasoconstrictors which shrink the blood vessels in the white part of your eye, making your eyes appear more white.\n\nThere are artificial tears which are used to deal with symptomatic dry-eye. The idea is that some people have aqueous tear deficiency (they don't make enough or lose too much of their natural tears) and so you replace them.\n\nIf you have really bad dry-eye problems, you can actually get serum tears made. This means a doctor draws a bunch of blood from you and spins out all the red blood cells in a centrifuge. The remaining serum is given back to you and used as eye drops.\n\nThere is one FDA-approved medication for dry eye, called [Restasis](_URL_0_). It contains a small amount of immune suppressant medication. The medication is slightly controversial, as some eye docs doubt the efficacy.\n\nOur actual understanding of dry eye is quite poor. We think that dry eyes have tears with an abnormally high osmolarity (too concentrated). This causes damage to the corneal epithelium (the outer layer of the clear part of your eye) which causes irritation and blurred vision.\n\nNote: I do research in dry eye. "
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aasmub | How were the internal borders of the USSR decided? | The borders of the republics and other subdivisions were ostensibly determined on the basis of ethnicity, but it seems like there were many arbitrary or illogical deviations (examples below). How were these borders determined and why?
More specifically:
* Why was Nagorno-Karabakh not joined to Armenia?
* Why were Kazakhstan, Tajikistan etc made republics while Tatarstan, Buryatia, Chechnya were not? It seems like not all republics were previously states (eg the Baltics) so why were some areas created as republics and others weren’t?
* What’s with the handful of enclaves near the Fergana valley?
* Why were North and South Ossetia not joined together?
* Why weren’t areas with large Tajik populations given to Uzbekistan instead of Tajikistan?
* On that note, why was Karakalpakstan given to Uzbekistan and not Kazakhstan?
* The borders for the central areas of Russia don't seem to follow ethnic lines of Tatars / Bashkirs / Mordvins / Mari / Udmurts very closely at all... | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/aasmub/how_were_the_internal_borders_of_the_ussr_decided/ | {
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"The internal borders of the USSR fall into two different categories: those that largely existed prior to the USSR/joining the USSR (so the South Caucasus states, the Baltics, arguably Ukraine); and those created within the USSR (Central Asia is the main example here), with some exceptions. I'll try and answer the specific examples you cited here, and then give a more broad overview answer:\n\n* Nagorno-Karabakh - While mainly populated by ethnic Armenians (then, and now), Karabakh is not easily accessible to Armenia, especially in 1920 when the Bolsheviks occupied the region. There is currently just one road connecting the two, a highway through the mountains that was only properly built in the 1990s and funded largely by the Armenian Diaspora (and is the reason Armenia occupies part of Azerbaijani territory not within the former Nagorno-Karabakh Autonomous Oblast, which was separated from Armenia by a strip of territory). In the 1920s there was no such road, and it was incredibly difficult to travel between NK and Armenia; however there are no mountains blocking the path to the rest of Azerbaijan, and the main road leading up to Russia (via Georgia) is to the east as well, and indeed is how the Bolsheviks first came to the region (they occupied Azerbaijan first). There was discussion on joining Armenia and NK together, but it was deemed impractical due to communications issues (see the road issue again), so they linked it to Azerbaijan, while making it autonomous. And until 1988 that largely worked.\n\n* Central Asia - First it should be noted that both the five Central Asian states (Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, Uzbekistan) and the others you mentioned (Tatarstan, Buryatia, Chechnya) are all republics, though the first five were made full *union* republics, while the others were merely *autonomous* republics within the Russian Soviet Federative Socialist Republic, and still exist in the modern Russian Federation. Now obviously you mean why did Kazakhstan et al become union republics (and later sovereign states), but I wanted to make sure that was clear. It had to do in part with the policy of state-building in the USSR: they were reluctant to create union republics unless the state had international borders. In part it was to entice local ethnic groups on the other side of the border to join the Bolshevik cause and allow for a stronger future claim for expansion, what Terry Martin referred to as the \"Piedmont Principle\" (after the region in modern France that was the origin of the Italian unification movement). The autonomous states obviously couldn't serve that purpose, so largely were left as they were. There is more to that, but I'm blanking at the moment and would have to look into it, so please ask a follow-up if interested.\n\n* Fergana Valley - This is something I can't actually answer, but I do know of a couple books that look at the Uzbek-Kyrgyz border, of which the Fergana Valley is part of. I'll mention them below.\n\n* North and South Ossetia - Situated right between the two Ossetia's are the Caucasus mountains, making it extremely difficult to travel between the two. The Russians built a military highway in the 1800s to reach Georgia, going through modern South Ossetia, but even then it was treacherous. The easiest way to go between the two is the Roki Tunnel, which was only finished in 1984. Thus it was easier to just keep the two places separate, though some argue that it was also done in order to antagnise the Georgians, who had the South Ossetian Autonomous Oblast (or region/province) to contend with; I would dispute that argument, and agree it was a more practical consideration.\n\n* Tajiks in Uzbekistan - I don't know what specific regions you are mentioning here, but it is worth considering that the modern ideas of ethnic Tajiks, Uzbeks, Turkmen, Kazakhs and Kyrgyz only dates back to the Soviet conquest of Central Asia. The people there largely did not identify as such, and the Soviets themselves largely created the ethnic identities based on a more rural-urban divide (with the Uzbeks being considered more urban). Thus it was considerably difficult to properly sort everyone into \"their own\" republic (yes, Tajik is a Persian language while Uzbek is Turkic, but even then Uzbek was only formalised in the 1920s, and Tajik was made distinct from Iranian Persian in that era; plus the people there were multi-lingual, so it was not easy to divide them that way either).\n\n* Karakalpakstan - I unfortunately don't know the details behind that at all, so couldn't really tell you.\n\n* Central Russian borders - Again, these people were only really identified and categorised in the early years of the Soviet era. While they had lived there for centuries (or more), they never identified as a specific group, and were largely named as one group or another by Soviet ethnographers. The borders for their territories were largely drawn to encompass their largest concentrations, though without ethnic cleansing that was near impossible (and the Soviets didn't do that in those regions; that type of thing began decades after the borders were drawn).\n\nIt is important to note that prior to the Soviet Union, many of the non-Russian peoples did not have a concept of a national identity as we understand it today. Many of them didn't even have a written language or literary tradition, which while not a definite factor in fostering a national identity, certainly helps it. The Soviets introduced these ideas to them, even though the very notion of nationalism was contrary to Marxist theory. However Lenin argued that these peoples were so backwards they needed to develop a national consciousness in order to advance to the point where they could move into the socialist phases. Thus the policy of *korenizatsiia* (коренизация; loosely translated it means \"nativization\") began, which Martin linked to affirmative action (non-Russian peoples were promoted to high government positions, given university spots, culture developed, etc). This also fed into the creation of national territories, which the Bolsheviks felt was important for their development (an idea not shared by other socialist groups at the time, but I digress). Ethnographers were sent out to figure out who lived in the Soviet Union, so they could be properly developed and advanced into the modern era, and then onto socialism. But of course no region is homogeneous, and thus things like the examples you mentioned happened. "
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2vzc00 | Can birds taste things? Does their sense of taste work the same way as ours? | I only ask as I just threw out some garlic bread and the birds loved it | askscience | http://www.reddit.com/r/askscience/comments/2vzc00/can_birds_taste_things_does_their_sense_of_taste/ | {
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"\"Birds do have a sense of taste, but it is not well refined. Depending on the species, birds may have fewer than 50 or up to roughly 500 taste buds, while humans have 9,000-10,000 taste buds. Birds can taste sweet, sour and bitter flavors, however, and they learn which of those tastes are the most suitable food sources. The sensitivity to different tastes varies by species, but most birds use other senses – sight and hearing most prominently – to locate the best foods.\"\n\nFound [here!](_URL_0_)\n\nNow I know! Your question prompted my knowledge. Thanks! :-) \n",
"Not positive on their specific tastes, but it is theorized pepper plants evolved capsaicin to deter mammals and have birds as their primary distributors since they do not register the chemical's heat response.\n\nFrom Wikipedia\n\"The seeds of Capsicum plants are dispersed predominantly by birds: in birds, the TRPV1channel does not respond to capsaicin or related chemicals (avian vs mammalian TRPV1 show functional diversity and selective sensitivity). This is advantageous to the plant, as chili pepper seeds consumed by birds pass through the digestive tract and can germinate later, whereas mammals havemolar teeth which destroy such seeds and prevent them from germinating. Thus, natural selection may have led to increasing capsaicin production because it makes the plant less likely to be eaten by animals that do not help it reproduce.\"",
"I recall reading about an approach for getting Canadian geese to stop coming to commercial office parks, eating the grass and shitting everywhere: apparently birds (or geese anyway) find the chemical that is used for artificial grape flavoring (e.g. \"sweet tart\" candies, koolaid, etc) extremely distasteful. The solution was to encapsulate grape flavor in small plastic microcapsules that could be sprayed onto the grass as part of a lawn treatment. Theory said it would keep the birds from eating the grass. Practice said it had to be applied too often in the growing and mowing season to be cost effective"
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2qpkde | I'm watching the show "Peaky Blinders" .. Is their depiction of English attitudes towards Northern Irishmen with regard to WWI conscription correct? | Peaky Blinders is a Netflix drama about the events concerning the "Peaky Blinders" gang in 1919 Birmingham. Chief Inspector Chester Campbell is an Irish policeman from Belfast called to Birmingham at the bequest of Winston Churchill to recover a large amount of stolen guns.
However one of the main themes of the show is the attitude of his police force towards him as it is revealed that he didn't go to fight in WWI. As far as I know, conscription was never introduced to Ireland so why did this English attitude exist towards Irishmen? Is the depiction of attitudes in the show correct?
**Edited: Forgot the 1920 Government of Ireland Act hadn't come into effect, Ireland was not yet partitioned.** | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/2qpkde/im_watching_the_show_peaky_blinders_is_their/ | {
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"Phillip is pretty wrong and obviously biased, both nationalists and unionists did not officially exist at the the time, those terms came about to describe those in Northern Ireland after its creation, the terms used would have been Republicans/rebels and Loyalists, both denominations fought in WW1, and were not discriminated against because of religious or political belief but purely because they were Irish commoner, who were looked down upon by the English gentry as well as most of the English population as they had always been in servitude to both English and even Irish landlords, much like the Scottish and Welsh were.\nMany thousands of Irish died during WW1 and the irish suffered the heaviest losses at the battle of the Somme, there is even a huge WW1 and 2 memorial in Dublin which was visited by Queen Elizabeth on her recent and first visit ( by any English monarch ) to the Republic of Ireland.\nConscription was never introduced in Ireland and the partition was never completed until 23 May 1921, when the free state was created along with the creation of a Northern Ireland.\nBe careful when asking about Irish history as ignorance and bigotry have prevented most people from actually Being unbiased!"
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26h1lk | how can weather forecasting website show so much detail of the weather, even for small cities? | I know they use satellites. But how is it possible to get wind speed, temperature, humidity, etc. of every city on earth by just taking some satellite pictures? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/26h1lk/eli5_how_can_weather_forecasting_website_show_so/ | {
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"Well, most of those things you mention are really not gathered by satellite, but instead through LOTS of weather stations scattered around the country/earth. Especially at airports. Those little weather stations measure lots of different things like temperature, humidity, wind speed, air pressure, cloud cover, etc... and by combining all that info together, along with historical trends, and meteorological theory, computers can make pretty good guesses at what the weather will be like in the future in any particular place.\n\nBut even then, computers don't have ALL the data or perfect equations to do their math with, and so even small inaccuracies can produce bad results, especially far into the future."
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11rvdd | How can planet hunters distinguish between a solar maximum/minimum and an actual planet transiting the star disc? | We know that Kepler and most other means of detecting extrasolar planets work on the principle of periodic dimming of the suspected host star. How do we distinguish between an actual planet transit and a periodic dimming of the host star due to a similar process as we see with the 11 year period of the solar maximum? | askscience | http://www.reddit.com/r/askscience/comments/11rvdd/how_can_planet_hunters_distinguish_between_a/ | {
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"The transit method of detecting exoplanets actually yields a significant number of false positives. [Here](_URL_0_), for example, is a paper discussing this problem.\n\nIf the transit method reveals a possible exoplanet, a standard next step is to apply the radial velocity method, to see if one can detect the slight Doppler shift in the stellar light, due to the wobble in the star's position induced by the planet. This is an independent measurement, and so can determine if a prospective exoplanet signal from decrease in light intensity corresponds to an actual exoplanet. Another benefit is that with a transit method and radial velocity measurement, you can determine both the size and the mass of the exoplanet, and thereby determine its density."
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4ph9fo | What was the difference between mandates, protectorates, dominions and colonies in the context of the 20th Century? | Can someone explain in simple words the difference between mandates, protectorates, dominions and colonies in the context of the 20th Century? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/4ph9fo/what_was_the_difference_between_mandates/ | {
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"Follow up. What's a territory as well in this context? How was say, Puerto Rico viewed as a territory and not a protectorate?",
"Generally speaking the four terms could be defined as follows.\n\nMandates - These were awarded to victorious powers after WW1 by the League of Nations (forerunner of the United Nations), for example France in Syria, Britain in what was then called the Mandate of Palestine. Ostensibly these were territories that had broken free of Ottoman rule but were thought incapable of governing/protecting themselves so Allied powers were called in as guardians. I'm not really qualified to speak at length at how benign or exploitative this 'guardian' relationship may have been, however most political maps would identify mandates the same way as any other sovereign territory held by an imperial power. These mandates had little, if any independence. The term 'Mandate' is still in use today to describe United Nations peacekeeping missions, although obviously these have a different character than the old, Post-WW1 mandates.\n\nProtectorates - Protectorates are similar to Mandates in that they're ostensibly weak or less advanced nations that require the assistance of a great power for economic, or military purposes. Generally they'd have some degree of local autonomy but their foreign affairs were handled by the protecting power. The distinction here is that protectorates weren't awarded by the League of Nations, they were formed (more or less) bi-laterally.\n\nDominions - This is an exclusively British term to refer to their former colonies which had achieved a degree of independence but still acknowledged British supremacy. In WW2 these were (essentially) Canada, Australia, New Zealand, and South Africa although Ireland, Newfoundland, and sometimes the then-British government of India have also been characterized as Dominions. Keep in mind that being a Dominion isn't just a matter of historical identification, it brings with it a degree of dependency on Britian and in the case of Canada, Australia, New Zealand (unsure on South Africa) it also means your Head of State is the British monarch. Therefore the United States of America was never considered a 'Dominion'. In modern times, there is a trace of this relationship in the 'Commonwealth of Nations' which is essentially an exclusive club for former British colonies and territories that form an extremely loose political and economic bloc.\n\nColonies - A Catch-all term for any non-European territory that an Imperial power held. It's also not mutually exclusive with the other terms - the British Dominions could all be considered 'Colonies'. I've also heard the French and British Mandates called 'Colonies' as well. This term doesn't necessarily mean that large amounts of immigration from the motherland to the colony in question took place, although of course there was usually at least a small amount."
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4062tj | What was the extent of glacio-isostatic depression in the last ice age? | How much did the earths crust warp (distance-wise) during the last ice age when covered with up to 1500m if ice? I am sure there is a way of working it out, but cannot find a solution! | askscience | https://www.reddit.com/r/askscience/comments/4062tj/what_was_the_extent_of_glacioisostatic_depression/ | {
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308cyq | what's stopping us from drilling to the center of the earth (other than economical reasons) | Hi I'm writing a book and was curious how would one get to the center of the earth. What roadblocks are we faced up against? Are there any limitations of modern technology? How would we get there, and what's stopping us from doing so?
Thank you for any responses. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/308cyq/eli5_whats_stopping_us_from_drilling_to_the/ | {
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"Well once you get through the mantle, the inside of the planet is molten magma. You can't drill through a liquid. Plus I think there's also an issue of lots of pressure (not sure on that one tho)",
"To put it simply, it gets too hot. The deeper you go the hotter it gets. Once you reach about 10 km (6 miles) down temperatures are already as high as 482F (250C). Once you're through the crust (about 30 miles down)and into the upper mantle, which consists of partially molten rock, you’re talking about temperatures in the range of 650-1200C (1200-2200F). . We don’t know exactly, but the Earth’s inner core is theorized to have a temperature of around 6000 Kelvin (5,700C, 10,300F)",
"If we forget the economical reasons, the main issue we face is heat. It gets really hot as you go down - 6000°C hot. At this temperature it is very hard to drill or do anything else. \n \nLet's assume your drill doesn't give a damn about the temperature; you have a massive amount of pressure to deal with. Specifically, the pressure is just under 3,000,000 times the pressure of our atmosphere - this is enough pressure to turn your human body into the size of an apple. \n \nFinally, you'll eventually be drilling through magma, and you probably know that drilling through a liquid is pretty impossible - you know, because it ain't a solid. \n \nYou'd have to find a way to drill quickly through the surface of the earth, with a drink that withstands all pressures and temperatures, and then throw some thick carbon nanotube walls around the magma so that you can continue making a tunnel without magma seeping in. You'd have to drain the magma from your tunnel, dispose of it somehow, and create a robot or force field that can withstand the massive pressure and heat of the core.",
"You're using reddit ELI5 to research a book? ",
"Apart from heat, there is pressure. Rock under high pressure get plastic and flows into the hole you just drilled."
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44s18x | A couple questions about the second Persian invasion of Greece (480 BC) | I've learned a bit about the historical truths to the invasion and the Thermopylae battle that were either false or left out of the movie 300. There some things that I still am curious about though.
1. When looking at [this map of the Greco-Persian wars](_URL_0_) it appears there were two routes the Persians took, one by land and one by sea, with the land route ending up at Thermopylae. Were the Persian forces at Thermopylae just the forces that took that long winding land route, or did ships from the sea route join there too? This map makes it look like the ships avoided Thermopylae and headed south.
2. Was there a particular reason that Persia had to land at Thermopylae in order to advance to Sparta? Why couldn't they have sailed to the south part of Greece and landed on the eastern shore there? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/44s18x/a_couple_questions_about_the_second_persian/ | {
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"Both your questions are asking the same thing. The Persian sea route was the route by which the fleet advanced parallel to the army. Thermopylae was not an action that took place in a vacuum, there was a naval battle at Cape Artemisium occurring simultaneously with the action at Thermopylae. ~~Most scholars would consider~~It's possible the battle of Artemisium was the more important of the two actions, as it ~~appears to~~may have been a true attempt to decisively defeat the Persian fleet, as opposed to the action at Thermopylae ~~which was intended to delay the army enough to allow the Greek land forces to assemble, as well as to support the fleet at Artemisium by preventing the Persian army from taking the harbors to their rear~~. As it was the battle of Artemisium concluded indecisively, resulting in the need to eliminate the Persian fleet at Salamis. But the Persians could not simply land troops in the Peloponnese (also, mind you, Sparta was not their objective, the Spartans were only one part of the Greek forces fighting against them) because the Greek fleet still existed"
]
} | [] | [
"https://upload.wikimedia.org/wikipedia/commons/thumb/3/3a/Map_Greco-Persian_Wars-en.svg/2000px-Map_Greco-Persian_Wars-en.svg.png"
] | [
[]
] |
|
9kqnuu | Were There Witches in the Old West? | Many rural communities in the US held belief in the supernatural for a long time, and Hispanic communities in Mexico and neighboring states have *curandero* folk healers and the like... were these practices considered "witchcraft" during the period of the Old West? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/9kqnuu/were_there_witches_in_the_old_west/ | {
"a_id": [
"e71o4fk"
],
"score": [
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"text": [
"The problem - as you hint - is one of terminology, namely, at what point do we call a practitioner of magic a \"witch.\" It is a difficult question to address, as expertly considered by [Monty Python](_URL_1_): throughout European history, practitioners of magic did not generally claim to be witches, nor did they look like what one might think they should (which is why Monty Python's peasants needed to change the appearance of a normal looking woman to make her look like a witch). Conversely, everyone has practiced some form of magic to affect themselves or others, even if it is as small as wishing on a falling star or when blowing out birthday candles. So does that make us witches? It depends on context: if the people around us say that someone who makes wishes on birthday candles is a witch, then that is the deciding factor.\n\nSo then the question is twofold: were people in the \"Old West\" practicing magic and did people regard at least some of these practitioners to be witches? \n\nThe answer to the first question is easy: of course they did - most cultures include some magical practices, so that's no surprise. Mary McNair Mathews in her autobiographical publication, Ten Years in Nevada (1879), describes curating her son's severed finger in a jar of brandy, because that was the only way to make certain the stump would not give the boy pain. Archaeologists at the African American Boston Saloon in Virginia City, found [altered coins](_URL_0_) placed beneath the floorboards, probably in 1866, as a means to encourage the business to profit. The 1877 artist for Harper's Weekly who depicted Chinese immigrants in Virginia City [\"Burning Joss Papers](_URL_2_) believed they were engaging in magical practices. And when Virginia City journalist Alf Doten repeatedly consulted a \"Dial\" - an 1860s counterpart to a Ouija Board - he and his friends were using magical practices to summon the dead (from the Doten dairies, which I am currently transcribing). This is a small sampler of the types of magical practices in one location in the nineteenth-century West.\n\nSo then, the question is whether anyone would have called the magical practices of other people (or their own) witchcraft. That's a difficult question to answer. The West was inundated with people from throughout the world, so it seemed that virtually every nation was represented. Did someone in that complex mix of cultures across the vast region and over the decades regard someone else's \"magic\" as witchcraft? It's hard to imagine the answer not being yes, simply because of the huge spectrum of possibilities. I would be thrilled if I could find an instance of that, but nothing comes to mind. I believe that we would need to conclude that among speakers of English - and in the documents they left behind - people generally did not conclude that witchcraft was being practiced in their midst. For the many other people who lived in the West, speaking a range of languages, the counterpart of that term may have been in use, but I am not prepared to address that."
]
} | [] | [] | [
[
"https://imgur.com/4ANdUp0",
"https://www.flickr.com/photos/27128624@N03/4656225270",
"https://imgur.com/BIXNl3m"
]
] |
|
65562l | I see the "no shirt, no shoes, no service" signs everywhere but I don't actually see anyone in public without shirts or shoes. Are these signs a relic? Were people more shirtless in the past? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/65562l/i_see_the_no_shirt_no_shoes_no_service_signs/ | {
"a_id": [
"dg7riwh"
],
"score": [
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"text": [
"Followup question(s): is there a reason why pants are never included in this list of items? Is it because nobody would dream of going out without pants on so it wasn't even thought of, or is it because it didn't fit the alliteration? Or both? Also, what about no \"shorts?\" Some places surely had rules against wearing shorts, but you never see those on these signs."
]
} | [] | [] | [
[]
] |
||
318f7l | why do i need to drink water more often than eat food? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/318f7l/eli5_why_do_i_need_to_drink_water_more_often_than/ | {
"a_id": [
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"score": [
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"text": [
"We use water for all sorts of things in our body, food is pretty simple, broken down and used or stored. food can be stored in different forms, water cannot be stored as easily. so we have to replenish more often because we cant store it as easily. "
]
} | [] | [] | [
[]
] |
||
6v8x5z | How did the various 60s experimental bands in Germany react to the rather unflattering term "krautrock"? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/6v8x5z/how_did_the_various_60s_experimental_bands_in/ | {
"a_id": [
"dlyj0dk"
],
"score": [
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],
"text": [
"Well, suffice to say that they were not flattered by the term. According to David Stubbs' book *Future Days: Krautrock And The Building Of Modern Germany*, 'no German musician of that generation accepts the word 'Krautrock''.\n\nStubbs prefaces the book itself by claiming that the term was invented either by the British music journalist Ian McDonald (author of the Beatles book *Revolution In The Head*) or by Richard Williams of the NME in the 1970s. So it wasn't a term that the German experimental bands of the 1960s and 1970s used to describe themselves.\n\nStubbs also points out that, in writing about this music at book length, he had to walk a careful line; in approaching the bands for interviews, he points out that he referred to their music as 'experimental German music of the sixties and seventies', and the subtext is that the bands won't be happy with the subtitle of his book. \n\nStubbs also provides several examples of members of these bands rejecting the title. The band Faust had a track called 'Krautrock' on their album *Faust IV*; the band used the term sarcastically, finding it 'insulting and injurious'. John Weinzierl of Amon Düül says that Julian Cope is on his blacklist for writing a book called *Krautrocksampler*, and that whoever invented the word is 'criminal'. Sleevenotes for the Harmonia album *Musik von Harmonia* say that 'careless critics and reviews tried to hide their lack of knowledge and expertise by pressing this ghastly label even on the few artists that wouldn't behave like those stoned dancing bears.' \n\n"
]
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[]
] |
||
4z0jze | how is code converted to software, how is graphics and code linked together? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4z0jze/eli5_how_is_code_converted_to_software_how_is/ | {
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"Code is a human readable set of computer instructions. You can for instance say that \"x = 1 + (2 / y)\" which is very easy for humans to understand. However computers are made up of billions of transistors and resistors that change currents in wires so to make it easier for computers to understand we compile the code into machine code. The above statement would be a sequence of numbers telling the cpu to \"read value of memory address 0x4893f5 into ebx, set eax to 2, run the division routine, add 1 to ecx, move value of ecx into memory address 0x4893a6\". There are thousands of these types of instructions that is part of the x86 instruction set (and even more for x86_64) and all of them is implemented by careful placement of transistors and resistors in the cpu.\n\nGraphics is just another piece of data like the machine code. However it is often used to produce an image to display on the screen. How this is done depends on the code of the software. A lot of applications use the gpu for this which is a special chip that is designed to work with large grids of data like images."
]
} | [] | [] | [
[]
] |
||
17so0k | If we stopped launching new satellites and servicing the existing ones, how long would it take for them all to eventually become non-functional? | askscience | http://www.reddit.com/r/askscience/comments/17so0k/if_we_stopped_launching_new_satellites_and/ | {
"a_id": [
"c88hrrv"
],
"score": [
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"text": [
"This is definitely an interesting question! But not so much a science question. /r/AskEngineers or another subreddit would be perfect for it."
]
} | [] | [] | [
[]
] |
||
1uwunm | Can someone tell me if this national park's ruins could have welsh origin rather than Cherokee Indian? | I have visited this park numerous times and there is a lengthy description near the walls that outlines the legends of a Welsh explorer who came to the Americas before Columbus. Is it even possible that he could have made this journey? Is there any evidence that the design of the structures could have been Welsh?
There are very interesting anecdotes and historical accounts of supposed 'tribes' speaking a language similar to Welsh and I find this to be very fascinating. Unfortunately I am not very knowledgeable on the subject of Native American history.
_URL_0_ | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/1uwunm/can_someone_tell_me_if_this_national_parks_ruins/ | {
"a_id": [
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"score": [
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"text": [
"It's actually unlikely that Fort Mountain was built by either the Cherokee or, especially, the Welsh. I've discussed [the alleged Welsh discovery of America](_URL_0_) before, with emphasis on their supposedly connection to the Mandan, but Fort Mountain gets a brief mention as well. The short of it is that the Welsh discovery of the Americas was a convenient historical fiction concocted by 16th Century British historians to justify their entry in the colonization of the Americas. They capitalized on a vague reference in Welsh folklore to the 12th Century prince Madoc emigration from Wales to an unknown destination, and transformed it into a voyage of discovery. Even if Madoc did hypothetically set sail for the Americas, he and his Welsh colonists were at least six centuries too late to build the Fort Mountain enclosure.\n\nThe idea that there were a prior wave of Welsh colonists in the Americas clung to the culture of the English-speaking colonists. From time to time, a colonists would describe the local language as sounding like or even being Welsh, despite being Siouan or Iroquoian languages for the most part (the Algonquian and Muscogean languages the make up the bulk of the remainder of eastern languages didn't attract much Welsh speculation). Any legendary people with unusual characteristics would soon be transformed into white Europeans in the minds of colonists. Of particular note here are the \"Moon-Eyed People\" that often associated with the Fort Mountain Site. This unusual description has led to speculation that 'moon-eyed' refers to the light color of their eyes, which is then used to cast them as having blue eyes and from there to being European. Going back to the Cherokee sources on the \"Moon-eyed People,\" its more likely that the description is intended to mean they were adapted to seeing during the night, as they were also said to be unable to go out in sunlight. They're not Europeans, but one of several other-than-human peoples that were thought to share the Cherokee's world.\n\nThe Fort Mountain enclosure fits into a series of hilltop enclosures built Middle and early Late Woodland period (about 2000-1500 years ago, give or take a century). These were important sites in the Hopewell religion that dominated the eastern half of the continent at this time. Fort Mountain area was largely outside the core Hopewell area, but still well within their sphere of influence. It seems the people inhabiting the region at the time picked up a few things, like hilltop enclosures, and gave them their own local flavor - the extensive use of stone, which was used sparingly to the north and west.\n\nAt the time, [the ancestors of] the Cherokee were living further north than Georgia, which didn't become part of Cherokee country until their territorial expansion in the 18th Century."
]
} | [] | [
"http://en.wikipedia.org/wiki/Fort_Mountain_State_Park#Ancient_wall"
] | [
[
"http://www.reddit.com/r/AskHistorians/comments/1ogxdg/is_there_any_solid_evidence_to_support_the/ccs0vl3"
]
] |
|
19tm3l | Plutarch: Parallel Lives | I am really interested in Plutarch's "Parallel Lives" writings. I found the readings online and read*The Life of Romulus* but do not have the time to go through and read all of them. Anyone know where I can found some summaries of his works? I would like to read his writing about Julius Caesar, Cato and Antony next.
Thanks! | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/19tm3l/plutarch_parallel_lives/ | {
"a_id": [
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],
"score": [
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"text": [
"It should certainly be easy to find full copies -- most or all of the Loeb Classical Library's pre-1923 editions [are available for download here.](_URL_0_)\n\nBut summaries? I'm not aware of any that have been made, I'm afraid. There's no Cliffs Notes nor SparkNotes for Plutarch."
]
} | [] | [] | [
[
"http://ryanfb.github.com/loebolus/"
]
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|
18482z | Do you think the Occupy Wall Street movements will be mentioned in the history books of the future? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/18482z/do_you_think_the_occupy_wall_street_movements/ | {
"a_id": [
"c8bg7y3"
],
"score": [
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"text": [
"Yes just like the Populist movement, prohibitionists, nativists etc. The tea party will probably be mentioned as well."
]
} | [] | [] | [
[]
] |
||
5w2lug | why does watching a movie on a projector instead of a computer screen feel like a more satisfying cinematic experience? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5w2lug/eli5_why_does_watching_a_movie_on_a_projector/ | {
"a_id": [
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"text": [
"The way that things are presented to you has a strong influence on how you feel about what is being presented. For example, companies go through extraordinary lengths to brand themselves in a certain way, have their stores look a certain way, and engage with the public in a certain way. They want you to associate their image with their products and that is not on accident. Similarly you've internalized what you perceive as an authentic cinematic experience as something that is being projected and that is why you find it implicitly more satisfying.",
"Focusing close-up is a cue to your brain that you're looking at something close-up. That detracts from the illusion of watching scenes that take place further away than your screen. In my view, watching stuff like close-up dialogue on a huge cinema screen suffers from the opposite problem."
]
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[],
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||
fu1inw | all light we see is a mix of three colors with our rods. is how we hear sound the same? | Specifically, we perceive color three-dimensionally, how many dimensions does our perception of sound have?
Edit:
I'm apparently having trouble expressing the question. I'm not asking about the physical mechanism, but the number of capacities of sensation. Many people have trichromacy, some have tetrachromacy. Is there something like that for hearing? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/fu1inw/eli5_all_light_we_see_is_a_mix_of_three_colors/ | {
"a_id": [
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"score": [
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"text": [
"Sound is perceived by hair cells in the cochlea. Each hair cell is sensitive to a specific frequency. There are thousands of hair cells. So yes, there are similarities, but sound is perceived by a much more high-dimensional system. \n\nAlso our perception of sound has far higher time resolution and much lower spatial resolution than our perception of light."
]
} | [] | [] | [
[]
] |
|
4fzxc6 | Why are so many organic molecules carcinogens/toxic? | askscience | https://www.reddit.com/r/askscience/comments/4fzxc6/why_are_so_many_organic_molecules_carcinogenstoxic/ | {
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"text": [
"There's a saying in toxicology, \"the dose makes the poison\". That is to say that almost anything is toxic at high enough concentrations, while anything eventually can be diluted enough that there's no toxicity any more.\n\nBut there is some truth to your comment, there are quite a few organic molecules that are toxic or carcinogenic. There are also a lot of inorganic compounds that are as well, so without specific examples it's hard to narrow down the differences. \n\nPerhaps a way to answer you is to describe things that organic compounds can do but inorganic compounds can't. Organic compounds can often bind tightly to a protein, driving some activity of the protein which can lead to downstream effects. Some organics can also be activated in a way that makes them reactive and they cross-link to DNA, which can make them carcinogenic. Organic compounds are sometimes also easier to get across cell membranes, so their permeability into cells can lead to higher toxicity than they might otherwise have.\n\nAt the same time, there's lots of organic compounds without a lot of toxicity, so it's really hard to generalize. Context matters in every case, so the specific compound and situation matters!",
"Most inorganic molecules/materials are toxic. It is just harder to eat them. Take the first column. Lithium salts are toxic. Potassium salts are toxic if too much are taken, etc.\n\nOn the right side, all halogens are toxic.\n\nI can't go on - almost every element I am thinking of is toxic."
]
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[],
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||
41qhv6 | Why did tricolours became the most common type of flag used by nations? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/41qhv6/why_did_tricolours_became_the_most_common_type_of/ | {
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"text": [
"The Dutch were the first to use the tricolour during their revolution, making themselves a republic. The tricolour then became a symbol of republicanism and became very popular during the French Revolution which shook the ground of Europe, inspiring republicanism in other countries to use the tricolour, for example the Irish tricolour during the easter rising. \n Another interesting fact is that the Russian flag was a tricolour when it was an absolute monarchy, it was because Peter the Great was inspired by Dutch ships to create a modern navy, he adapted the Dutch flag for the Russian navy since the Russian navy didn't have a flag at the time. The flag inspired the flag of pan-slavism which is why eastern european countries have those three colours in their flags (Slovakia for example) then became a symbols of Russia and made the national flag in 1894. Which is why eastern Euroean countries have a similar tricolour."
]
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[]
] |
||
avzu35 | why aren't charger/data ports in phones shaped more like a headphone jack? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/avzu35/eli5_why_arent_chargerdata_ports_in_phones_shaped/ | {
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"It might be related to the size and complexity of a headphone style jack, which has to grip the tip mechanically with a spring steel part.",
"Headphone jacks aren't really a great design, but they usually work OK if you only have a small number of signals. If you want to use a bunch of signals, making sure that each of them has a solid connection can get tricky. It's just not a great system from a mechanical point of view, and that can result in cruddy electrical connections. Particularly as things wear out. \n \nIt could also create more problems with crosstalk (interference). With a typical data port, you can keep signal wires from crossing. That gets a little difficult at the end of a round jack if there are a lot of signals. It also gets a little more tricky to keep the signal wires the same length, which is valuable with high speed signals. "
]
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[],
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||
4lmcd0 | What is the origin of adenosine to create cAMP and ADP/ATP in the body? | askscience | https://www.reddit.com/r/askscience/comments/4lmcd0/what_is_the_origin_of_adenosine_to_create_camp/ | {
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"text": [
"Your body has a constant supply of nucleosides, of which adenosine is one. You get most from the food you eat, but the body also [synthesizes its own, either through _de novo_ or salvage pathways](_URL_0_)."
]
} | [] | [] | [
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"https://en.wikipedia.org/wiki/Nucleotide#Synthesis"
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||
5simkl | why do all currencies undergo inflation over time? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5simkl/eli5_why_do_all_currencies_undergo_inflation_over/ | {
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"That's an over-generalization. The underlying resources that give value to a currency tend to expand over time. In the rare instances where they contract over the long-term - such as the Japanese population declining - currency can go in the opposite direction and deflate.",
"This is a very broad topic to talk about, however I shall do my best, I've included a tl;dr at the bottom if you want to skip. I've tried to keep it brief but I could literally talk for days about this all in detail. Please let me know if you have questions or disagree with anything I wrote, I love talking about this stuff and would love to share what I have learnt with you.\n\nIn order to understand inflation, first we need to distinguish money. Money in the modern day is fiat money - it is not backed by anything such as gold or other precious metals - and is just a generally accepted form of payment. It only has value because we are told it has value. During the times of the gold standard, yup, you guessed it, it was backed against gold.\n\nInflation occurs when the supply of money is increased to the point where the value of the money starts to decrease. This is because there is a greater abundance of the money and since value is normally related to the quantity of a good (I say normally since there are goods where price does not change regardless of supply, i.e. oil/petrol/diesel), the greater the quantity the lower the value and vice versa.\n\n - As a side note, this is based on the assumptions of neo-classical thought. A more accurate description of reality is presented by the Post-Keynesian School of Thought, and is often referred to as Horizontalism, Structuralism (which itself includes more than just money theory) or the Endogenous money supply.\n \nEven though there is an increase of money, there is no simultaneous increase of material goods or assets, because this is fiat money remember. This can get out of control and lead to hyperinflation (examples include Post war Germany and Zimbabwe).\n\nSince money hasn't got a real physical value, it cannot be exchanged directly for anything physical, it is instead a form of payment, or an IOU of sorts. When you run out or run low on cash, you turn to the commercial bank to draw credit and borrow from them. You can only receive credit if someone else has debited their cash into an account (at least in the Neo-Classical School of Thought). This demand for money (credit or borrowings) increases, and is matched by an increase of supply. \n\n - I should note, that this is also matched by the effect of the money multiplier, where a bank will lend out a certain percentage of a deposit to create a new debit, which is then lent out again, etc. \n\nBanks (commercial banks specifically), create money from the money they are receiving from the people (and yes it is essentially fraud but its up to interpretation really). I should also note that if you are curious of horizontalism then the causality is the opposite, the supply of money is anywhere between 0 and infinite at any given moment in time, and will be granted to anyone so long as they are creditworthy (known as credit rationing), which in turns causes a deposit later on. \n\nAs the supply of money increases, and inflation rises, the purchasing power of the money decreases. You can buy less goods with the same amount, for instance £1 used to buy you 5 Freddo's, now £1 will buy you 2. You could argue that this is just a price change by the manufacturers, however, the root cause is the reduction of purchasing power.\n\nThe reduction of purchasing power forces consumers to turn to the banks once more and demand more credit to support their lives and needs, which in turn causes inflation to rise. It is an endless cycle, however, it is in reality a slow process, and normally, inflation is targeted through interest rate targeting policies by the Central Banks (like the Bank of England).\n\nDo not get me wrong though, inflation does not spell disaster for an economy. Generally speaking, it is beneficial, as inflation equates to growth. It means more people are spending money encouraging expansion of industry and services, causing increased trade both domestically and internationally. Problems only arise when there is no change in physical goods. If people are spending more but not getting more then it is not a good thing.\n\n\ntl;dr - The current supply of money is exhausted by the consumer (spent or saved). Money is demanded by the consumer in the form of credit (i.e. borrowings or overdraft). Money supply is increased by the banks to match the increased demand. The value of the money drops, as there is a greater abundance of said money. Inflation increases causing a higher demand for money again. The cycle continues unless it is controlled."
]
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3z7hpc | Can we have lenses for sound? | So that we could derive information about our surroundings similar to what optical lenses provide. | askscience | https://www.reddit.com/r/askscience/comments/3z7hpc/can_we_have_lenses_for_sound/ | {
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"You could, but if it's a solid, the index of refraction will be huge, and almost all of the sound will be reflected. And if it's a gas, then it will just dissipate. You could use a heater to make sure the closer air is warmer, and therefore has a higher speed of sound, but any air currents will mess it up.\n\nAlthough apparently the speed of sound in rubber is lower than in air, so it might be possible to build a solid lens that works well.\n\nBut it's much, much easier just to [use a mirror](_URL_0_).",
"Not sure what you mean about deriving information about our surroundings, but [parabolic microphones](_URL_0_) are frequently used to capture sound from far away sources. You'll see them frequently on the sidelines of football games to isolate captured sound on the field from the ambient noise of the stadium. ",
"You are describing acoustic metamaterials, they are basically the acoustic version of an optical lens using periodic arrays of specific materials to manipulate sounds or other vibrations like phonons.\n\n\n_URL_0_",
"In the water (the ocean) sound waves traveling down into higher pressure will start to increase speed because of more tightly packed molecules and begin to curve back up towards lower pressure. If they increase in speed by more than 30 or so feet per second before hitting the bottom they will head for the surface and can converge in an annulus of sound hundereds of miles away.",
"I work with diagnostic ultrasound and our transducers use a 'lens' to focus the sound beam at a particular tissue depth. This technology employs a delay circuit to fire elements in the transducer in a pattern so that the beam wavefront is curved toward a focal point. The echoes from this tissue layer have the reverse of the delay applied to retrieve the signal strength information. Not really the process you were asking about, not really a lens, in fact not really much of anything other than me having an \"Ultrasound, yay!\" moment.",
"One huge issue you would have building an acoustic lens is that it would really only work over a relatively narrow frequency range. Just like light refraction in an optical lens results in chromatic aberration, different acoustic frequencies passing through an acoustic lens would refract different amounts and would have different focal lengths.\n\nFor visible light the total frequency range is about 400THz-800THz, a 2:1 ratio. Audible sound spans 20Hz-20kHz, a 1000:1 range. I'm definitely not an optics expert, but I imagine focusing such a wide range of \"audiochromatic aberration\" would be basically impossible, even if there was a good way to build a general acoustic lens at all.\n\n\nCreating a lens tuned for a particular frequency could work, but you would probably have to generate a stimulus at that frequency to gather any energy in the band of interest... And then you have the basic components of an ultrasound machine.",
"acoustic 'lenses' already exist in various forms, to do a few different things. The most obvious one is the outer ear.\n\nthere are also acoustic lenses used in live sound and loudspeaker design, such as those made by \n\nJBL\n\n_URL_2_\n\nL'acoustics\n\n_URL_0_\n\nReunkus Heinz\n\n_URL_1_\n\nThey all use the same basic ideas as optical lenses (diffraction, refraction etc..) and the same basic forms (convex and concave structures) to adjust the timing differences between sound waves. We also have 'horns' which are used to increase sensitivity and control directivity of sound waves\n\n_URL_3_\n\n\n\nWe also have 'interference tubes' as used in shotgun mics (without which, location audio in film and TV more or less wouldn't exist)\n\n_URL_4_\n\nAlthough I cant find a link at the moment, there is also the 'interference based' directivity control used in Martin MLA and EAW Anya products, which are crazily powerful.\n",
"The Exploratorium here in San Francisco has a giant [Fresnel Zone Plate](_URL_0_) exactly to demonstrate that sound beams can be focused by objects.",
"According to [this link](_URL_0_), a large balloon filled with CO2 is a sound lens. \"When you whisper behind the balloon, the audience will hear it, but it is very directional. So as you talk in a whisper from behind the balloon and slowly scan the audience, having them raise their hands when they can hear it and lower their hands when they don't, it looks like a wave of hands across the audience.\" ",
"You think of a lens as transparent, but we also use mirrors to focus light.\n\nIn that sense, waves are waves and you can focus sound quite effectively by shaping a reflecting surface, rather than refracting through another medium.\n\nA satellite dish focuses radio, but also focuses acoustically, using the same wave principles that apply to light and to the ripples on a lake. \n\nPut your mouth at the focal point and whisper. 100 feet away, another \"dish\" facing you will concentrate the \"parallel\" sound into a focal point where a friend can hear you about as well as standing alongside.\n",
"Others have addressed your exact question more precisely, but someone should add this: a physical device to focus sound waves is not necessary to derive information about our surroundings similar to what telescopes provide. A better and more common approach is to use an array of many microphones to record the sound at many points across a wide area. Then you can \"focus\" the recorded sound digitally with a computer and hear in any specific direction you want. This is how submarines do it. The calculation done in that computer is mathematically similar to what a lens does for you."
]
} | [] | [] | [
[
"http://www.hps.cam.ac.uk/whipple/explore/acoustics/parabolicsoundmirrors/"
],
[
"https://en.wikipedia.org/wiki/Parabolic_microphone"
],
[
"https://en.m.wikipedia.org/wiki/Acoustic_metamaterials"
],
[],
[],
[],
[
"http://www.google.com/patents/US5163167",
"http://www.renkus-heinz.com/upload/line-arrays-white-paper-1.pdf",
"http://www.jblpro.com/pub/obsolete/Acoustic_Lens_Family1.pdf",
"https://www.grc.com/acoustics/an-introduction-to-horn-theory.pdf",
"http://www.soundonsound.com/sos/dec13/articles/qanda-1213-01.htm"
],
[
"https://en.wikipedia.org/wiki/Zone_plate"
],
[
"http://demoroom.physics.ncsu.edu/tapl/archive/200807/241.html"
],
[],
[]
] |
|
2rr1wu | if you were to rip out a person's eyeball without snapping the optical nerve, and then made it face the other eyeball (aside from pain and whatnot) how would your brain put together the image? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2rr1wu/eli5_if_you_were_to_rip_out_a_persons_eyeball/ | {
"a_id": [
"cnifm7o",
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"score": [
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"text": [
"I assume it would try its best to make \"sense\" out of the information.\n\nYou might get two superimposed images and just see a \"single\" eye.\n\nYou can definitely do this with mirrors and some plywood. ",
"This actually happened to my mother when she was young, she was a trainer for thoroughbreds and she was bucked off and into a brick wall, her face was destroyed and one of her eyes was hanging out. Unfortunately, she can't really recall what it was like. She said that she wasn't able to see anything, but that eye was also covered in dirt. Add to that the body is pumping out all sorts of chemicals to help with the pain and I imagine things are pretty muddled and it's hard to get a straight answer on it. :/",
"If you push on one of your eyes so they aren't looking at the same thing you can get an effect that would probably be similar. Right now I'm looking at text on the screen and when I push on my eye I see two copies of the screen in different locations in my vision. If you were to point your eyes at each other I imagine you would see both eyes within your vision, but it wouldn't make any coherent image.",
"The fact that your eyes are looking at each other is not the critical part of the experiment, as eye A looks like just another object to eye B. There may be some psychological experiences, but you may also have to be on hallucinogens to fully appreciate the meta-ness of staring at your own eyes.\n\nThe physiologically interesting bit of it is how your brain compensates to the images in each of your eyes being very different. You do this a lot actually, when you close one eye, you are essentially getting a full image of your environment and a full image of 'black'. Your brain knows that it should favour the open eye in its 'calculations' and does. You can approximate this with holding an object very near your eye, like your phone. You can still see your phone with eye A and your environment with eye B. Your phone will be blurry if it is this close, but that isn't because you are only viewing with one eye. If close enough, you will literally see two images next to each other with the boundary between them seeing very blurry but that you can't quite focus on. Unfortunately, its not much more interesting than that.\n\nCarnivores (and omnivores) have two eyes facing forward to be able to sense depth, as that is crucial for catching prey. However, herbivores (with exceptions of mammals without natural predators) generally have eyes that face outwards (opposite). They don't need the depth perception, they just need to cover as much of their environment to ensure there are no predators. These eyes are often not even possible to face the same direction. They interpret completely different images. We don't know how animals construct images in their brains, but for some it is definitely stitched together as well, and others..."
]
} | [] | [] | [
[],
[],
[],
[]
] |
||
1bzv4p | Why do so many people seem to have insomnia to some degree? | It seems like every other person I know is taking some form of sleeping medication. Is this even a new phenomenon, or is it just more apparent because the medications are more readily available? Is this common world wide? | askscience | http://www.reddit.com/r/askscience/comments/1bzv4p/why_do_so_many_people_seem_to_have_insomnia_to/ | {
"a_id": [
"c9bofp8"
],
"score": [
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"text": [
"Insomnia is extremely common today, and [yes it is common worldwide](_URL_2_). When talking about this, it is important to draw the distinction between the [different types of insomnia](_URL_7_).\n\n* *Transient insomnia* is for a period of up to a week. This is experienced by virtually *everyone* at some point in life, due to stress, illness, etc.\n\n* *Acute insomnia* is for up to a month.\n\n* *Chronic insomnia* is for longer than a month.\n\nIn addition, note that [different definitions for insomnia exist](_URL_2_). Sometimes insomnia estimates are based simply on survey questionnaires such as \"Do you have difficulty falling asleep?\", which yield prevalence estimates of up to about 60%.\n\nInsomnia is medically diagnosed based on the inability to fall asleep, maintain sleep, or feel rested by sleep. This should be the case *despite* adequate opportunity to sleep, and should manifest with daytime impairments. Using that strict definition, there is thought to be a prevalence of [about 5-10%](_URL_1_) for [chronic insomnia](_URL_2_).\n\nInsomnia can have many causes. Often people use *primary insomnia* to mean insomnia that has no known underlying cause, and *secondary insomnia* to mean insomnia that stems from some other medical problem, e.g., pain.\n\nOthers suffer from [sleep state misperception](_URL_5_), otherwise known as *subjective insomnia*, where they objectively appear to sleep based on [polysomnography](_URL_0_) but do not feel feel that they are sleeping.\n\nIn general, insomnia is [more prevalent in women than in men and more prevalent in old age](_URL_1_). There are theories as to why these things are the case, including [sex differences in the intrinsic properties of the circadian clock](_URL_9_) and [age differences in the ability to maintain consolidated NREM sleep](_URL_11_), possibly due to [loss of sleep-regulatory neurons](_URL_6_) and [changes in circadian regulation of sleep with age](_URL_4_).\n\nIt is difficult to know whether rates of insomnia are on the rise, since there have not been stable diagnostic criteria used consistently over a long period of time. Nevertheless, we do know that many behaviors in modern society negatively affect [sleep hygiene](_URL_8_), leading to more difficulty falling asleep and maintaining sleep. These problems stem mostly from two causes:\n\n**1) Shift-work.** The timing of the human circadian clock is set by light. Those engaging in night shift-work are usually unable to fully adapt to the work schedule, due to strong effect of the natural light cycle, and the tendency to revert to more normal schedules on free days. The circadian clock is not able to very rapidly change its timing (this is why jet-lag occurs) and it strongly promotes sleep during what it considers to be the night. Shift-workers are therefore commonly trying to sleep at a time when the circadian clock is not promoting sleep.\n\n**2) Use of artificial light and light-emitting devices.** The human circadian clock is acutely sensitive to light during nighttime. Light before bed [suppresses natural melatonin production](_URL_10_) and also [delays the circadian clock](_URL_3_), resulting in the body wanting to go to bed later on both that night and subsequent nights."
]
} | [] | [] | [
[
"http://en.wikipedia.org/wiki/Polysomnography",
"http://www.sciencedirect.com/science/article/pii/S1087079202901863",
"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1978319/",
"http://en.wikipedia.org/wiki/Phase_response_curve#Light_PRC",
"http://informahealthcare.com/doi/abs/10.3109/07853899908998789",
"http://en.wikipedia.org/wiki/Sleep_state_misperception",
"http://informahealthcare.com/doi/abs/10.1080/07420520500545813",
"http://en.wikipedia.org/wiki/Insomnia#Types_of_insomnia",
"http://en.wikipedia.org/wiki/Sleep_hygiene",
"http://www.pnas.org/content/108/suppl.3/15602.short",
"http://en.wikipedia.org/wiki/Melatonin#Light_dependence",
"http://www.sciencedirect.com/science/article/pii/S096098220800804X"
]
] |
|
ft195s | how can factories that use specialized machinery to produce a certain thing quickly change production to a completely different thing. (i.e. automobiles to ventilators) | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/ft195s/eli5_how_can_factories_that_use_specialized/ | {
"a_id": [
"fm4fso0"
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"score": [
3
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"text": [
"It is never quick as you are thinking. You need to set up an assembly line for different components in a spare space and you need to order any needed assembly machines and you need to order the raw components going into the finished product and you need to assemble and train staff. You need te develop relationships with new vendors you have never dealth with before. That is all why I am thinking the auto manufacturers are the last place you would want to have building medical equipment you need quickly. The fastest and most efficient solution is to have companies already manufacturing the ventilators ramp up production. They already have trained staff. They already have assembly machines. They already have vendors that supply the necessary parts. They simply need to increase production by adding shifts or laying down a floor and putting up a tent and simply adding production lines. All this GM, TSLA, F stuff is simply political optics both for and against and terrible inefficient in reality."
]
} | [] | [] | [
[]
] |
||
14kbvu | What happens to the vitamins and minerals in an avocado as it ripens? (or similar fruits) | Let's suppose a ripened avocado is kept at ambient temperature.
1) What will happen to its vitamins and minerals as time passes and it ripens even more?
2) What about the carbs, proteins and fats? | askscience | http://www.reddit.com/r/askscience/comments/14kbvu/what_happens_to_the_vitamins_and_minerals_in_an/ | {
"a_id": [
"c7e83sg"
],
"score": [
2
],
"text": [
"Well considering that fruits taste sweeter as they ripen, the complex carbs in the fruit must be converting into sugars. So, less carbs more sugar."
]
} | [] | [] | [
[]
] |
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