q_id
stringlengths 5
6
| title
stringlengths 3
301
| selftext
stringlengths 0
39.2k
| document
stringclasses 1
value | subreddit
stringclasses 3
values | url
stringlengths 4
132
| answers
dict | title_urls
list | selftext_urls
list | answers_urls
list |
|---|---|---|---|---|---|---|---|---|---|
751bk6
|
On YouTube I can watch extremely detailed videos of ancient Roman battles that show what each section of the army did and at what time. How is this known, exactly? Was there just a scribe sitting on a hill recording the battle?
|
Example here: _URL_0_
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/751bk6/on_youtube_i_can_watch_extremely_detailed_videos/
|
{
"a_id": [
"do2raqu",
"do2xgq5",
"do3huhh"
],
"score": [
1274,
29,
5
],
"text": [
"Well yes, there were always reporters for the [*Novum Eburicum Tempora*.](_URL_0_)\n\nBut seriously, it is worth just looking at the source material for this. The reconstruction of Teutoberg is more complicated than most in part because batlefield archaeology has actually played a role in shaping our understanding of it, so instead I will use Cannae as one of the most famous battles of the ancient world and one that tends to feature in these sorts of battlefield reconstruction. From Polybius' *Histories* 3.113-116:\n\n > Next day it was Terentius' turn to take the command, and just after sunrise he began to move his forces out of both camps. Crossing the river with those from the larger camp he at once put them in order of battle, drawing up those from the other camp next to them in the same line, the whole army facing south. He stationed the Roman cavalry close to the river on the right wing and the foot next to them in the same line, placing the maniples closer together than was formerly the usage and making the depth of each many times exceed its front. The allied horse he drew up on his left wing, and in front of the whole force at some p281 distance he placed his light-armed troops. The whole army, including the allies, numbered about eighty thousand foot and rather more than six thousand horse. Hannibal at the same time sent his slingers and pikemen over the river and stationed them in front, and leading the rest of his forces out of camp he crossed the stream in two places and drew them up opposite the enemy. On his left close to the river he placed his Spanish and Celtic horse facing the Roman cavalry, next these half his heavy-armed Africans, then the Spanish and Celtic infantry, and after them the other half of the Africans, and finally, on his right wing, his Numidian horse. After thus drawing up his whole army in a straight line, he took the central companies of the Spaniards and Celts and advanced with them, keeping rest of them in contact with these companies, but gradually falling off, so as to produce a crescent-shaped formation, the line of the flanking companies growing thinner as it was prolonged, his object being to employ the Africans as a reserve force and to begin the action with the Spaniards and Celts.\n\n > The Africans were armed in the Roman fashion, Hannibal having equipped them with the choicest of the arms captured in the previous battles. The shields of the Spaniards and Celts were very similar, but they swords were entirely different, those of the Spaniards thrusting with as deadly effect as they cut, but the Gaulish sword being only able to slash and requiring a long sweep to do so. As they were drawn up in alternate companies, the Gauls naked and the Spaniards in short tunics bordered with purple, their national dress, they presented a strange and impressive appearance. The Carthaginian cavalry numbered about ten thousand, and their infantry, including the Celts, did not much exceed forty thousand. The Roman right wing was under the command of Aemilius, the left under that of Terentius, and the centre under the Consuls of the previous year, Marcus Atilius and Gnaeus Servilius. Hasdrubal commanded the Carthaginian left, Hanno the right, and Hannibal himself with his brother Mago the centre. Since the Roman army, as I said, faced south and the Carthaginians north, they were neither of them inconvenienced by the rising sun.\n\n > The advanced guards were the first to come into action, and at first when only the light infantry were engaged neither side had the advantage; but when the Spanish and Celtic horse on the left wing came into collision with the Roman cavalry, the struggle that ensued was truly barbaric; for there were none of the normal wheeling evolutions, but having once met they dismounted and fought man to man. The Carthaginians finally got the upper hand, killed most of the enemy in the mellay, all the Romans fighting with desperate bravery, and began to drive the rest along the river, cutting them down mercilessly, and it was now that the heavy infantry on each side took the place of the light-armed troops and met. For a time the Spaniards p285 and Celts kept their ranks and struggled bravely with the Romans, but soon, borne down by the weight of the legions, they gave way and fell back, breaking up the crescent. The Roman maniples, pursuing them furiously, easily penetrated the enemy's front, since the Celts were deployed in a thin line while they themselves had crowded up from the wings to the centre where the fighting was going on. For the centres and wings did not come into action simultaneously, but the centres first, as the Celts were drawn up in a crescent and a long way in advance of their wings, the convex face of the crescent being turned towards the enemy. The Romans, however, following up the Celts and pressing on to the centre and that part of the enemy's line which was giving way, progressed so far that they now had the heavy-armed Africans on both of their flanks. Hereupon the Africans on the right wing facing to the left and then beginning from the right charged upon the enemy's flank, while those on the left faced to the right and dressing by the left, did the same, the situation itself indicating to them how to act. The consequence was that, as Hannibal had designed, the Romans, straying too far in pursuit of the Celts, were caught between the two divisions of the enemy, and they now no longer kept their compact formation but turned singly or in companies to deal with the enemy who was falling on their flanks.\n\n > Aemilius, though he had been on the right wing from the outset and had taken part in the p287 cavalry action, was still safe and sound; but wishing to act up to what he had said in his address to the troops, and to be present himself at the fighting, and seeing that the decision of the battle lay mainly with the legions, he rode along to the centre of the whole line, where he not only threw himself personally into the combat and exchanged blows with the enemy but kept cheering on and exhorting his men. Hannibal, who had been in this part of the field since the commencement of the battle, did likewise. The Numidians meanwhile on the right wing, attacking the cavalry opposite them on the Roman left, neither gained any great advantage nor suffered any serious loss owing to their peculiar mode of fighting, but they kept the enemy's cavalry out of action by drawing them off and attacking them from all sides at once. Hasdrubal, having by this time cut up very nearly all the enemy's cavalry by the river, came up from the left to help the Numidians, and now the Roman allied horse, seeing that they were going to be charged by him, broke and fled. Hasdrubal at this juncture appears to have acted with great skill and prudence; for in view of the fact that the Numidians were very numerous and most efficient and formidable when in pursuit of a flying foe he left them to deal with the Roman cavalry and led his squadrons on to where the infantry were engaged with the object of supporting the Africans. Attacking the Roman legions in the rear and delivering repeated charges at various points all at once, he raised the spirits of the Africans and cowed and dismayed the Romans. It was here that Lucius Aemilius fell in the thick of the fight after receiving several dreadful wounds, and of him we may say that if there ever was a man who did his duty by his country both all through his life and in these last times, it was he. The Romans as long as they could turn and present a front on every side to the enemy, held out, but as the outer ranks continued to fall, and the rest were gradually huddled in and surrounded, they finally all were killed where they stood, among them Marcus and Gnaeus, the Consuls of the preceding year, who had borne themselves in the battle like brave men worthy of Rome. While this murderous combat was going on, the Numidians following up the flying cavalry killed most of them and unseated others. A few escaped to Venusia, among them being the Consul Gaius Terentius, who disgraced himself by his flight and in his tenure of office had been most unprofitable to his country.\n\nFrom this account you can get most of the details you will see in videos like the one you posted: the weak Carthaginian center that fell back to allow the double envelopment of the Roman lines, the cavalry action on the sides, the screening by the skirmishers, etc. What you *don't* see is the conceptualization of the army into neat \"blocks\" that tend to dominate [popular representations of battles.](_URL_1_) The Romans did organize their army in a way that could sort of allow that as the armies were dvided into named legions (~5000), cohorts (~600) centuries (~80) and conturbium (~10),^1 but it is very rare to see that reflected in battle literature unless a subdivision of the army did something remarkable (such as Cato's detachment during the Battle of Thermopylae). That is largely a modern convention, and someone more familiar with the development of modern military theory can probably comment on that better than I can.\n\n^1 These numbers are *very* approximate and vary across time and space, and the *conturbium* may not have been thought of as a tactical unit.",
"From the OP’s video, it sounds like the whole legion was destroyed. How long would it take for the Romans to find out what happened?",
"Can someone comment on the accuracy of this video? I've visited the (alleged) sites of this battle, and while the account in the museums there is generally similar, it does differ in details quite a bit. For example, I distinctly remember hearing about the roman \"trek\" being very drawn out and being attacked along a long stretch of road or path, alongside which a fence was supposed to have been built. Also, it seemed like there was a lot more doubt about how the events took place then this video communicates. When i was there a few years ago, it seemed like there was even still doubt about where the battle actually took place. And the beheadings and crucifixions seem a bit colorful to be taken at face value when only one side's sources are available in such an emotionally charged event. "
]
}
|
[] |
[
"https://youtu.be/kmF3VBA_RcM"
] |
[
[
"https://www.reddit.com/r/AskHistorians/comments/751bk6/on_youtube_i_can_watch_extremely_detailed_videos/do3ehgr/",
"https://upload.wikimedia.org/wikipedia/commons/f/f2/Battle_cannae_destruction.png"
],
[],
[]
] |
|
4mqakw
|
When surgeons "run the bowel" is there a specific strategy to how it's pulled out, and how it's put back in?
|
I've been watching a lot of House, and whenever they run the bowel in the show they just seem to pull out the bowel in a pile, then put it back in a pile. But isn't there a risk of tangling? Is gravity/orientation a factor?
|
askscience
|
https://www.reddit.com/r/askscience/comments/4mqakw/when_surgeons_run_the_bowel_is_there_a_specific/
|
{
"a_id": [
"d3yvf5n"
],
"score": [
3
],
"text": [
"Mercifully, real intestines aren't completely loose--they're tethered by tissue, called mesentery, which keeps them in some degree of order. You can pull bowel out to an extent, but it's not like one big loose rope the way it sometimes looks in movies/TV.\n\nThat said, bowel twisting on itself (volvulus) can still be an issue sometimes, particularly in the non-fixed parts of the colon."
]
}
|
[] |
[] |
[
[]
] |
|
1qskfr
|
why doesn't a lightbulb act as a short circuit?
|
I don't understand 100% what exactly consumes electricity and acts as a load. A lightbulb just heats a wire so why doesn't it act as a short circuit?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1qskfr/eli5_why_doesnt_a_lightbulb_act_as_a_short_circuit/
|
{
"a_id": [
"cdg0f7p"
],
"score": [
3
],
"text": [
"Well, it does, kinda.\n\nA light bulb has a very thin wire. You might think that filament is about a millimeter wide, but the filament is actually a coil of a coil of the actual wire. The wire is much finer than a hair.\n\nPushing electric current through that wire is hard. So only a small amount of electric current can flow. Pushing that current through the wire takes effort - work -Energy - and this energy ends up as heat. The filament gets hot, really hot, until it glows brightly."
]
}
|
[] |
[] |
[
[]
] |
|
1phz1o
|
why do some toothpastes produce a lot of foam and some produce non at all?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1phz1o/eli5_why_do_some_toothpastes_produce_a_lot_of/
|
{
"a_id": [
"cd2hgq5"
],
"score": [
3
],
"text": [
"Sodium Lauryl Sulphate. It is a detergent. It produces foam which carries off debris you scrub off your teeth. It also tastes kinda like mint and blocks all your sweet receptors which causes your OJ to taste bitter. "
]
}
|
[] |
[] |
[
[]
] |
||
7l95y5
|
Is there a benefit to building aerodynamic Spaceships?
|
By that I mean Spaceships that theoretically remain in Space, so no entering/exiting atmospheres.
|
askscience
|
https://www.reddit.com/r/askscience/comments/7l95y5/is_there_a_benefit_to_building_aerodynamic/
|
{
"a_id": [
"drm5nom"
],
"score": [
6
],
"text": [
"In a Low Earth Orbit (LEO) or close to any planet with an atmosphere, there is still a thin trace of gases. Sometimes it's called \"residual atmosphere\". For most practical purposes it's a vacuum: you can't breathe and water boils at room temperature, but it can still cause drag on vehicles moving at high speed. This is not negligible because satellites in LEO move really fast, 7.6 km/s. This drag causes orbits to slowly decay over time.\n\nThe GOCE satellite was only intended to be in space during its planned mission lifetime. But it had a particularly low orbit at 250 km. This required a very aerodynamic design, so it was sometimes called \"the Ferrari of space\".\n\nIn a much higher orbit, like geostationary, or in interplanetary space, it doesn't really matter."
]
}
|
[] |
[] |
[
[]
] |
|
e0wwie
|
how did currency exchange rates form in the very beginning?
|
I was wondering how exchange rates formed in the beginning. As in, when the first two countries came together to exchange a monetary deal, how did they know how much of their money equated to the other countries money.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/e0wwie/eli5_how_did_currency_exchange_rates_form_in_the/
|
{
"a_id": [
"f8istg1",
"f8j6elq",
"f8jb2tr",
"f8mcdob",
"f8pbcg8"
],
"score": [
12,
31,
7,
3,
2
],
"text": [
"Same way as the price for anything: both sides do their homework on how much stuff they can get with the other sides currency and then figure out how much of their currency you are willing to give for a given amount of the opposite sides currency. At some point both sides reach an agreement. If they cannot reach a mutually agreeable price for the opposing sides currency, there isn't a trade agreement.\n\n & #x200B;\n\nedit: the exchange rates aren't set by individual countries, they are floating based on how much different currencies are worth when doing international trade.",
"Countries often initially had their currencies locked to a precious metal (typically gold or silver). For example pound sterling (GBP) derives its name from when 20 shillings was literally a pound of sterling silver, under Anglo-saxon rule. These are pretty easily exchangeable because the international value of that coin is its metal content.",
"First they were set according to gold(or a rare earth metal) then world war happened.\nThen all of them were set according to USD which was set according to gold( I think it was the Brentwood agreement).\nNow it's like a free market depending on supply and demand it's called the forex market(foreign exchange market)",
"Precious metals.\n\nCoins were invented to simplify trading in precious metals. If someone showed up at an inn with a hunk of hacksilver, the innkeep had to judge the quality and weight to determine how much beer and mutton that would buy him.\n\nTo make it easier, someone (typically the state) would produce coins of a specific mass and purity. The coin would have some primitive security features so that a merchant could quickly determine that the coin was probably real and probably hadn't been shaved or altered. Now the barkeep can have an actual menu/price list: one of Lord Suchandsuch's pennies will get you 2 beers, 3 will get you a room for the night and so forth. If someone shows up with coins the innkeep has never encountered (eg: from Lord Soandso's mint), the innkeep had a few options. They could just say no and lose the trade. They could take the hacksilver approach and judge the value as best as they could. They could direct their customer to a moneychanger who knows all about coinage and assay to get the coin exchanged for currency that the innkeep is familiar with. As a side effect of this, the moneylender would develop a schedule comparing different coins: an 8g gold sovereign was taken to have the same value as one pound of sterling silver. A silver penny weighed 1/240th of a pound so 240 pennies was worth 1 sovereign (1 pound sterling). Other countries used other currencies. The Spanish real was about 1/150 lb so, assuming the merchant was familiar with the coin, one would be worth about 1.5 pennies. \n\nWhen governments traded, it was all gold and silver traded by weight. The actual shipment could be a mixture of bars and various coins..it didn't matter as long as they were of acceptably purity and the total weight was correct.",
"Ooh! Economics Major here. I can answer. \nMost of the answers given are right, but I wanna give the full picture for a more holistic answer. I assume that you're referring to today's economy with all different types of exchange rate systems (flexible, fixed, managed float, peg, dollarisation,...), and how these started. In that case, we have to see some major turning points in history, namely the Gold Standard and the Bretton Woods System.\n\nI won't start too far back as it doesn't really answer, but silver was widely used as the standard until the Bank of England decided to drive silver out of circulation (because it was running out of it).\n\nBut in 1870, the Gold Standard was established. This was sort of the beginning of \"exchange rates\".\nThis started with the British. With the industrial revolution, countries believed that a necessary condition to facilitate world trade was a stable exchange rate system.\nEach country set the value of 1 unit of their currency at a predetermined percentage of the weight of gold, or in others words, its value.\nFor instance, a British Pound was 0.23546% an ounce of pure gold, and the USD was 0.048379%. This made the Dollar-Pound exchange rate 0.23546/0.048379 = 4.867. \nThese values were fixed, and the gold standard required that each country adjust its domestic money supply in direct relation to the amount of gold it held. \n\nHowever, there were many problems along the way. WW1 caused the gold standard to be ceased for a while, but it came back. At one point in time, US and France held 70% of the world's gold alone, and this caused the other countries that adopted the gold standard to hike interest rates, which essentially led to the infamous Great Depression. At this point, people realized the gold standard actually caused many problems, and decided to abolish it.\n\nThis led to the Bretton Woods System. \nThe USD was pegged at $35 per ounce of gold, and all other countries under the Bretton Woods System pegged their currency to the USD. This was essentially a fixed exchange rate system. This also made the USD the international reserve currency.\nAlthough this was meant to promote growth and trade, Bretton Woods was formed on the basis of Capital Control and Financial Market Regulations (Impossible Trinity, if you're curious). This was bad in the time of increasing international trade. Hence, it eventually broke down for a few reasons, which I won't really explain to keep things simple.\n\nIn the end, the Bretton Woods System collapsed in 1973, and the dollar was delinked from gold. People also realized that fixed exchange rate systems weren't all too good an idea. This ushered in the era of flexible exchange rates, which grew to the myriad of systems we all know today."
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[]
] |
|
86ziqz
|
How exactly does the rabies virus control human beings (stop them from drinking)?
|
What is the mechanism the virus uses to control human behavior? Does it override programs in the motor cortex? Does it program fear of water in the amygdala? Or does it just block muscles in the throat? I find it very hard to understand how a virus can manipulate something as complex and deliberate as human behavior. [Video](_URL_0_)
|
askscience
|
https://www.reddit.com/r/askscience/comments/86ziqz/how_exactly_does_the_rabies_virus_control_human/
|
{
"a_id": [
"dw945dj",
"dw9b8i9"
],
"score": [
366,
24
],
"text": [
"Rabies infects neurones that control respiration and swallowing. \nThere is an automatic cycle you usually don’t notice around breathing and swallowing. \nThe rabies infection of the neurones controlling that cause it to become unreliable.\nAn infected person starts to have trouble swallowing and the negative reinforcement of trying to swallow and choking causes an involuntary anxiety or fear around doing it. ",
"[This thread] (_URL_0_) answers this question.\n\nIt has not been shown in the literature that behavioral aversion to water in humans increases transmission of the virus. Humans are actually a dead-end host for rabies so this makes no sense in terms of natural selection. \n\nAggression in animals, however, does increase transmission, so this is more likely an evolutionary adaptation of the virus to influence behavior to increase the chance of transmission to another host. "
]
}
|
[] |
[
"https://www.youtube.com/watch?v=OtiytblJzQc"
] |
[
[],
[
"https://www.reddit.com/r/askscience/comments/28jff7/why_does_rabies_cause_a_fear_of_water/"
]
] |
|
bf7j6d
|
why is nationalism bad?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/bf7j6d/eli5_why_is_nationalism_bad/
|
{
"a_id": [
"elbge2e",
"elbgjzk",
"elbh9pb"
],
"score": [
5,
5,
2
],
"text": [
"Because it’s moved past nationalism, and into jingoism. \n\nNationalism isn’t bad until it starts coming at the expense of others.\n\nEdit: had to double check definitions, and I was describing PATRIOTISM. I guess nationalism is defined as extreme patriotism coming at the expense of others.",
"Nationalism is “identification with one's own nation and support for its interests, especially to the exclusion or detriment of the interests of other nations.” the important part there is the detriment of other nations. Nationalists think their country and the citizens are better than others. The exclusion of others often leads quickly to racism as nationalists try to rationalize one country being better than others. Since nations ultimately are lines in the sand they often turn to racial lines as something more “concrete”.",
"Nationalism is defined as “identification with one's own nation and support for its interests, especially to the exclusion or detriment of the interests of other nations.” This means you put your country first no matter what. One of the side effects of this is a complete lack of care, empathy, compassion, or essentially any positive view of anyone who is from any other country. It essentially is the us and them mentality on steroids; us good, them bad. One of the common tactics of us and them is dehumanizing “them”. See terminology from current American alt-right, nazi germany, imperial japan. A common example is calling minority groups by animal terms, I.e. monkey, rat, pig, dog. This dehumanizing makes it easier for events like genocides to occur. It goes from “killing your neighbors and their children” to “removing the plague of rats and their spawn infesting the land”. \n\n\nTl;dr: nationalism feeds us and them mentality. Us and them mentality is us good, them bad. This thinking leads to the idea that “they” are just animals. Thinking of “them” as animals makes it easier to kill. Aaaaaannnnnnnnnnnnnddddddddddd you’ve just won an all expenses paid genocide."
]
}
|
[] |
[] |
[
[],
[],
[]
] |
||
1qze3o
|
why is beef tenderloin so expensive?
|
I went to the local market and saw beef tenderloin for $25 a pound. What makes this such an expensive cut? Is it the demand for it? Lack of supply?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1qze3o/eli5_why_is_beef_tenderloin_so_expensive/
|
{
"a_id": [
"cdi0gbv",
"cdi0ipc",
"cdi0nip"
],
"score": [
16,
5,
2
],
"text": [
"[Here](_URL_0_) you have a chart showing where different beef cuts comes from.\n\nThe more a muscle has worked in its lifetime the tougher the beef cut tends to become and the tenderloin hasn't done much work in compared to to the rest of the cow. You can serve it very rare and nice tenderloin will still almost fall apart in your mouth.\n\nSo you have a small amount of very nice and tender beef from each cow which of course drives up the price.",
"It's the most tender part of the animal, and therefore the most desired. It's more in demand.",
"The prices of meat cuts are rising due to the cost of raising livestock increasing. A Beef tenderloin, or a (eye) fillet for those outside of the states, is one of the most desirable cuts due to the muscle being used very little making it particularly tender.\n\nI do not live the US so I don't know how your local markets work compared to those held in my home country of Northern Ireland but I presume you still be straight from the farmer. If so that is actually pretty standard. $25 would suggest that the farmer is raising the livestock in good conditions."
]
}
|
[] |
[] |
[
[
"http://upload.wikimedia.org/wikipedia/commons/thumb/2/2a/US_Beef_cuts.svg/640px-US_Beef_cuts.svg.png"
],
[],
[]
] |
|
2elgzt
|
Hydrogen used as a energy storage system?
|
Why can't we use excess solar energy to break down water into hydrogen/oxygen which could be burned as needed for power during nights/overcast?
|
askscience
|
http://www.reddit.com/r/askscience/comments/2elgzt/hydrogen_used_as_a_energy_storage_system/
|
{
"a_id": [
"ck0rn0w"
],
"score": [
3
],
"text": [
"I'm not an expert on hydrogen production, but I have looked at industrialised hydrogen production for future nuclear application. Assuming the same processes would be applied I can answer the question, but obviously my answer is based on nuclear rather than solar energy sources. \n\nThe main problem seems to be that the industrialised production of hydrogen is currently based on the sulphur-iodine cycle, steam electrolysis or some hybrid of these. Each of these is a cycle which, as you say, splits water into hydrogen and oxygen. The problem is that they all rely on high temperatures and pressures to be industrially viable, and the *most promising* requires concentrated sulphuric acid to be heated to over 1000C. Materials in contact with sulphuric acid at that temperature have a very real problem is sticking around for any feasible length of time. When i originally looked at this a couple of years ago now, the 'record' was a 10 minute demonstration run, based on a rig fabricated from silicon carbide and teflon. "
]
}
|
[] |
[] |
[
[]
] |
|
3u8zxy
|
why do ships sink vertically?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/3u8zxy/eli5_why_do_ships_sink_vertically/
|
{
"a_id": [
"cxcvvyt"
],
"score": [
2
],
"text": [
"Its only if the breach in hull is only on one end or another. So when water start to fill up the ship one side gets heavier and goes down first. If the breack in the hull was all along one of the boards the ship would tilt towards that side before sinking and not vertically"
]
}
|
[] |
[] |
[
[]
] |
||
1twhai
|
basic beliefs of taoism
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1twhai/eli5_basic_beliefs_of_taoism/
|
{
"a_id": [
"cec6ubr",
"cec96cp",
"cec9vd3",
"cecakc7",
"cecckh0",
"ceccphs",
"cecdloj"
],
"score": [
9,
24,
2,
6,
11,
5,
4
],
"text": [
"The Tao of Pooh. Read it.",
"Taoism can be summed up pretty generally as it all focuses pretty much around nature and being a natural and forefilling person;\n\nDaoism (Taoism) 道統 (Daoism and Taoism are the same thing)\n\n- A way of life (in China may be referred to as a religion)\n- 'To go with the flow', be positive, to agree with most things, to enjoy - life to the fullest, to life the high-life.\n- Dao - translates to Way/A Way\n- Daoism is Chinese because it originates in Chinese culture and it is most clearly understood through the Chinese language and views of being.\n- Daoism is considered a 'religion' because it involves an orientation towards and relationship with, 'the sacred'.\n- Fundamental Daoist ideas/concerns include:\n~Wu wei : Effortless action, to behave in a completely natural and uncontrived way\n~Ziran: Naturalness\n~Zhenren: realized/perfected person, to be enlightened and aware of the world\n~Dao: Way, path, route, such as choosing the right path to take in life\n",
"/u/georgeisamazing has a good answer for the basic tenets of Daoism as laid out in its most important foundational texts, the *Zhuangzi* and the *Daodejing*. \n\nHowever, you should know that modern \"Taoism\" bears little resemblance to that....2,000 years of history has twisted it quite a bit, and these days Taoism as a religion in China is basically a collection of crazy superstitions and remedies for immorality (Zhuangzi and Laozi are probably rolling in their graves being associated with that nonsense).\n\nMore than most other \"religious\" systems, though, I'd say you'll have an easier time understanding Daoism if you actually read the foundational texts. For what it's worth, the Daodejing is really short and the Zhuangzi is pretty entertaining (although they both require a lot of thought to follow)",
"Everything is the Tao. Nothing is the Tao. \n\nThe Tao is nothing. The Tao is everything.",
"That which can be explained is not the true Dao.... (wooden flute blows)",
"The Tao that can be spoken is not the eternal Tao.",
"Read the Tao of Pooh, bst simple beautiful little book that explains it well. Winnie the Pooh is a taoist! Just Be! :-)"
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[],
[],
[]
] |
||
2hm2an
|
Why aren't sunrises fiery colors too?
|
Aren't sunrises the same process happening in reverse more or less? They almost always seem bland in comparison.
|
askscience
|
http://www.reddit.com/r/askscience/comments/2hm2an/why_arent_sunrises_fiery_colors_too/
|
{
"a_id": [
"ckuhfkt"
],
"score": [
2
],
"text": [
"Not an expert, but I remember hearing a lecture about this. I'm not sure I'd characterize sunrises as less fiery or bland, but there are certain atmospheric changes that make sunrises and sunsets different. Firstly, there are some physiological changes that may contribute. Sunsets can darken the sky faster than our eyes can adjust to the change in light. At sunrise, our eyes were adjusted for night vision, and this may contribute to observing fainter changes in the sky's color. Secondly, atmospheric effects from pollution accumulated throughout the day can make the sky at sunsets seem more colorful by dulling the orange/reds."
]
}
|
[] |
[] |
[
[]
] |
|
1z3nj9
|
how come when you crack your knuckles underwater, it is incredibly loud, but when you try and scream underwater, the sound is muffled to a whimper?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1z3nj9/eli5_how_come_when_you_crack_your_knuckles/
|
{
"a_id": [
"cfq75hr",
"cfqbqsv"
],
"score": [
121,
10
],
"text": [
"Water transmits sounds quite well, so if an action vibrates the water to make a sound, you'll be able to hear it clearly in the local area. However, sound does not cross mediums very well. When you're trying to talk (or scream) underwater, the sound is being generated by vibrating air in your vocal chords. When this hits the water just outside your mouth, only a little of that energy is transmitted into producing underwater sound waves. The rest is lost, reflecting back into your mouth.",
"To add on a bit to /u/KahBhume's answer:\n\nThe sound is also louder because water, a liquid, transmits sound waves better than air, a gas. As you may recall from basic science courses, both gases and liquids have free-moving particles and aren't rigidly structured like solids. That's why a spilled glass of water will spread out all over the table. However, liquid molecules are best friends- they stick together- while gas molecules are like a teenager on Maury- they go wherever they want whenever they want- and aren't always close to each other. \n\nThis is important because of the way sound waves are produced. Waves are formed when one molecule bumps into another, which bumps into another, which bumps into another. Your eardrum picks up these waves and your brain turns them into sounds. This is why there is no noise in space. In a vacuum, there are no molecules to bump each other, so there can be no sound.\n\nWhen the molecules are far away from each other, as in a gas, the molecules bump into each other less often. They still do, of course, because you can hear in your everyday, gas-filled life. In a liquid, the molecules are close together, so a moving molecule is much more likely to hit another molecule. This results in a better transmission of the wave, and therefore a better transmission of the sound. The density of the object (closeness of the molecules) is also why different gases can raise or lower the pitch of your voice.\n\nTL;DR: Liquid is more dense than gas, transmits sounds better."
]
}
|
[] |
[] |
[
[],
[]
] |
||
3zykkm
|
why is there such a large amount of rain falling across australia, when it is meant to be an el nino year and be very dry?
|
[deleted]
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/3zykkm/eli5_why_is_there_such_a_large_amount_of_rain/
|
{
"a_id": [
"cyq2dh2"
],
"score": [
2
],
"text": [
"El Nino is the summer part of the phenomena. In winter it becomes El Nina and brings more rain. I would guess that in the southern hemisphere the season are reversed."
]
}
|
[] |
[] |
[
[]
] |
|
4ux2y7
|
If honeybees are non-native to North America, won't the original (or other) pollinators flourish and fill in the gaps left behind by the decreasing population?
|
I'm assuming the original pollinators weren't completely displaced by the invasive european honeybee, but even then the other pollinators' populations will expand without competition from those bees. I haven't been able to find any articles addressing this whenever bee population articles come up.
|
askscience
|
https://www.reddit.com/r/askscience/comments/4ux2y7/if_honeybees_are_nonnative_to_north_america_wont/
|
{
"a_id": [
"d5u5r7i"
],
"score": [
12
],
"text": [
"[Apparently it's a bit of a myth that honey bees are non-native](_URL_2_).\nBut that could just be a red herring and I get your point. \n\n[This online handbook on insect pollination of cultivated crops](_URL_1_) mentions the loss of native pollinating insects. So does [this article](_URL_0_). So it's not just honey bees that we are losing, but all insect pollinators. It's a \"pollination crisis\" not just a honey bee crisis.\n"
]
}
|
[] |
[] |
[
[
"http://www.iatp.org/files/Pollination_Ecology_Plant_and_Bee_Interactions.htm",
"http://www.aces.edu/urban/forestry/documents/OnlinePollinationHandbook.pdf",
"http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=1544"
]
] |
|
4mu1x7
|
the uploader has not made this video available in your country.
|
Why? Just f**cking why????
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/4mu1x7/eli5_the_uploader_has_not_made_this_video/
|
{
"a_id": [
"d3yaft0"
],
"score": [
8
],
"text": [
"Its likely the video contains material that is not licensed for worldwide use. International licenses are significantly more expensive than licenses for a specific region. "
]
}
|
[] |
[] |
[
[]
] |
|
wrsuv
|
Why is spacetime a Minkowski space and not a Euclidean space?
|
I recently read that spacetime is a Minkowski space and not a Euclidean space. Is this true? It doesn't make sense to me, as I would think it possible to represent spacetime as either.
Is "time" represented by a continuum of real numbers? Someone recently said they wished they had an infinite amount of time, and I was about to say that the amount of time between two seconds is a continuum of real numbers, but I didn't want to make an uninformed statement.
I know some stuff about linear algebra, calculus, measure theory and graph theory so don't give me a mathless answer.
|
askscience
|
http://www.reddit.com/r/askscience/comments/wrsuv/why_is_spacetime_a_minkowski_space_and_not_a/
|
{
"a_id": [
"c5fvrfy"
],
"score": [
3
],
"text": [
"Euclidean space doesn't have a way to build a causal structure like Minkowski space does. In Minkowski space you can have vectors with positive, negative, or zero length. This allows you to define events that are timelike separated and which are therfore causally connected, events that are spacelike separated and therefore are not causally connected, and events that are lightlike separated and so sit on the path of a light ray. In Euclidean space all vectors have positive length so you can't make this classification.\n\nEDIT: Experimentally, because of length contraction and time dialation we know that euclidean length is not conserved when we move from one frame to another, while the minkowskian length is."
]
}
|
[] |
[] |
[
[]
] |
|
37o19j
|
how for example, gun laws are so different from state to state and why they just cant be the same all over the country
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/37o19j/eli5_how_for_example_gun_laws_are_so_different/
|
{
"a_id": [
"crocfn1",
"crocft6",
"croch4t"
],
"score": [
3,
7,
2
],
"text": [
"Basically the US Constitution says that anything that isn't specifically spelled out as belonging to the Federal government will be left to the states or to the people (10th Amendment). ",
" > The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people.\n\nThe 10th Amendment to the US Constitution (part of the Bill of Rights) specifically says that, outside of the powers *specifically* granted to the Federal government, the states are responsible for making laws.",
"In the US the Federal government only has as much power as the States give up to it. This means that everything not specifically set as a power belonging to the Federal Government is an issue for the States to control. Gun laws are one of these. "
]
}
|
[] |
[] |
[
[],
[],
[]
] |
||
2ycf5l
|
Why did Saddam's forces succeed in fighting the Kuwaiti forces, then lose to the American/coalition forces?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/2ycf5l/why_did_saddams_forces_succeed_in_fighting_the/
|
{
"a_id": [
"cp8au5i"
],
"score": [
10
],
"text": [
"Leaving aside the enormous issue of the obvious disparity between Kuwaiti and Coalition forces (both in scale and quality), Iraq's successful invasion of Kuwait benefited greatly from the experience of the Iran-Iraq War. Although the Iraqi military did not cover itself in glory in that conflict, the armed forces gained a modicum of experience and competency in carrying out specific missions. The Republican Guard had been retooled from an elite praetorian formation (and this was still an important component of their duties) into a force capable of both combined arms and night attacks. Although the Guard formations were not as proficient at these operations as Western forces, it was enough to overwhelm Kuwaiti forces. The prior war also underscored the need for accurate intelligence and the Iraqi Air Force's MiG-25s conducted extensive overflights over Kuwait in July 1990 and the regime disseminated the aerial photographs to ground units. Commercially available tourist maps also contributed to the Iraqi success. \n\nThe swift victory in Kuwait masked many of the flaws of the Iraqi armed forces. One of the fundamental problems of Iraqi military effectiveness was the compartmentalization of its armed forces into various satraps. Iraqi naval, army, and air forces often operated in the dark as to what other branches were doing. The Army operated under the assumption that the Iraqi Air Force would provide an air umbrella for its operations. However, the Air Force assumed that its attacks on Kuwaiti airbases would suffice and it kept a number of units on alert over Iraq itself to prevent any repeat of the Israeli 1981 bombing of the Osirak nuclear plant. The Kuwaitis did mount some airstrikes against Iraqi forces much to the consternation of Republican Guard commanders. The swift occupation of Kuwaiti airbases ended this threat, but the inability of the left hand to know what the right was doing was a precursor of the later disasters in 1991. The successful invasion of al-Qulayah Navy base by elements of the Iraqi Navy showed that the Iraqi forces were capable of acting with initiative and daring. The Iraqi commander Colonel Muzahim Mustafa occupied the harbor despite losing one missile boat and suffering equipment malfunctions. Yet Mustafa's bold tactical leadership was atypical of Iraqi forces; crucial mission leaders were often kept in the dark about their operations until the last minute. Air mobile helicopter pilots only had rudimentary training and were assured that the Air Force would eliminate Kuwait's Hawk missiles. The Air Force's failure to do so led to high helicopter losses and the rudimentary training in night formation flying also led to a large number of crashes. The Iraqi approach to operational planning inhibited tactical initiative as frontline troops barely knew the basic plan and had to focus great efforts on carrying it out, so improvisation when the plan went awry was less likely. \n\nUltimately, these defects were not as much of an issue given that the Kuwati response to Iraq was much more passive than it could have been. Civilian refugees prevented the effective deployment of Kuwaiti armed forces. The speed of the Iraqi assault prevented the Kuwaitis from exploiting the Mutla Pass as a defensive line, which was one of the few natural barriers in Kuwait. The result was that the Kuwaiti response was often in penny-packets that the Iraqi's could quarantine. Again, defects within the Iraqi command and communication system meant that Iraqi troops were often unaware sister unit's status, so it was up to the unit being attacked to deal with the Kuwaitis alone. Coalition forces would exploit this disjointed command structure in 1991 as they destroyed the Iraqi forces in a piecemeal fashion. \n\nIn short, the Iraqis were competent enough to take Kuwait, but lacked the ability to hold Kuwait against a military \nfoe like the United States. \n\n*Sources*\n\nAl-Marashi, Ibrahim, and Sammy Salama. *Iraq's Armed Forces An Analytical History*. London: Routledge, 2008.\n\nWoods, Kevin M. *Iraqi Perspectives Project Phase II. Um Al-Ma'arik (The Mother of All Battles): Operational and Strategic Insights from an Iraqi Perspective, Volume 1* (Revised May 2008). Ft. Belvoir: Defense Technical Information Center, 2008. < _URL_0_;. "
]
}
|
[] |
[] |
[
[
"http://handle.dtic.mil/100.2/ADA484530>"
]
] |
||
t1zek
|
philosophy, what is it and why do people study it?
|
ELI4
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/t1zek/philosophy_what_is_it_and_why_do_people_study_it/
|
{
"a_id": [
"c4iv1iy",
"c4iv2km",
"c4iv465",
"c4ivabm",
"c4iy4cj",
"c4j3pr3"
],
"score": [
8,
8,
2,
12,
2,
2
],
"text": [
"Philosophy would be very hard to explain to a four year old like you asked. \n\nI think the [first 2 sentences on wikipedia](_URL_0_) sum it up.\n\nAs far as why people study it, it can be very interesting and mind expanding.",
"Philosophy is basically really deep thoughts about everything.\n\nFor example: \n\n* How do I really know I'm here? When I see things, am I really seeing things? When I touch things, is my brain interpreting what I'm touching exactly correctly, or are things getting \"lost in translation\"? If none of my senses are working exactly perfectly, how can I know what the world looks like? If my brain isn't working exactly perfectly, how can I know that I exist if my thoughts aren't correct?\n\n* When we do something for the good of everyone, but one person gets hurt, is that still right? What is \"right\"? Is there one definition for what is \"right,\" or do we always need to compare it to \"wrong\"?\n\n* Does God exist? If there is evil in the world, and God can do something about it (he's \"omnipotent,\" right?), then why doesn't he do something about it? Does that mean he's not nice (\"benevolent\")? If being nice is one important part of being God, is God not \"God\" anymore?",
"Philosophy involves thinking about why things are the way they are and how can we be sure we really know things are that way. In the western world, over 2000 years ago a man called Aristotle decided to organize exactly how people should think about things like that. \n\nAnd up until the 1500s pretty much all science, education, religion, law, and politics in the western world was directly effected by the way he set up things. One important reason is that one of Aristotle's' students was Alexander the Great. When Alexander took over the known world and put his personal stamp on it, it was a stamp informed by his teacher.",
"**What is philosphy?** If you were to take a course an Intro to Philosophy course in college, you would learn about major schools of thought regarding human purpose, ethics, and rationality. The foundation of most of today's philosophy is based in Greek Philosophy -- the ideas of ancient philosophers like Plato, Aristotle, Socrates. Their timeless writings are still relevant and debated to this day. Their work has been built upon for many years and have gone in many different directions. Some of these schools of thought are in direct conflict with one another, such as utilitarianism (the ends justify the means) and deontology (the ends do NOT justify the means; it is about the best moral choice). \n\n~~Philosophy is considered a \"soft\" science, similar to sociology. This is different from a \"hard\" science like biology or physics because it deals in intangible social issues: things that are difficult to measure and prove with hard data.~~ Philosophy is full of a lot of debate and semantics (determining the exact meaning of a word -- such as \"morality\") that don't always end with conclusive answers. \n\n**Why do people study it?** People study philosophy to better understand the human condition. People want to better understand not only individual purpose (self), but collective purpose (all of humanity). People also want to better understand ethical issues, and argue for what they believe are the most moral choices. An example of a classic ethics debate is whether or not the \"needs of the many outweight the needs of the few.\" Such questions are not easy to answer because they heavily depend on the context. \n\nNonetheless, people spend a lot of time contemplating these questions. Anyone can sit around and read about and contemplate these questions--most people do at some point in their life. But academically (at Universities), it has to be more than wayward contemplation. Therefore, like anything in academics, it requires a deep knowledge of past and current writings on the topic to provide a foundation of supporting concepts and ideas. This creates a web of supporting data to transition and progress into new or modified ideas. \n\nAt the end of the day, people who study philosophy hope to understand themselves and their world a little better than they did before. There are not a ton of career options tied to philosophy -- many who specialize in it often become professors of the subject, or move onto higher education that is more focused on something like law. The study of law is often intertwined with philosophy due to its connection to morality/ethics. Therefore, a background in philosophy is not a bad stepping stone into law. \n\nMore often, philosophy as college curriculum is taken as a minor degree, or a class or two in supplementation to a seemingly unrelated degree. Example: someone who is specializing in biological engineering may be forced to take classes in science ethics, which is rooted in basic philosophical principles. This is so they are able to better make choices in a career field that is full of difficult, complex moral dilemmas that cannot be answered with a microscope. They are questions that require subjective introspection.\n\n**TL;DR- 42.**",
"There are a lot of areas one studies in philosophy. Not all scientist study biology, and not all philosophers study ethics.\n\nThere is metaphysics - the study of Universals and particulars; Objects, Entities; General and individual\n\nOntology - the study of existence, where things come from and what they are. It gets very confusing very fast.\n\nEpistemology - The study of Knowledge, which is traditionally defined as a \"justified true belief.\" How do we know what we know.\n\nEthics - The study of ought and should. Ethics isn't about logic (it might borrow or use logic), or something being rational. Many things that are considered unethical are still rational.\n\nLogic - An abstract system that defines other systems, most notably mathematics is the prime example. Logic is learned along side metaphysics usually. If you see a book \"how to think logically\" it's probably not about logic. If you see \"fallacy of 'x'\" it's talking about logic, but, most people are ignorant think that their petty human language and debates are actual logic. Symbolic logic is what undergrads study, specifically predicate logic. Modal logic adds a couple of more operators, but that's more of a graduate study.\n\nAnalytic and Continental philosophy. Both are poorly defined in their start, and are poorly defined now. But it's pretty easy to distinguish them.\n\nAnalytic philosophy - Without arguing who started it, lets just say Frege, Whitehead, Russell. (Note: Russell is ONLY real analytic philosophy when he writes the Principia Mathematica, his political mumble jumble is muddled pseudo philosophy. The whole \"Russell's Teapot\" is not real philosophy.)\n\nAnalytic philosophy is the study of Logic, Metaphysics, Language. Easier said: Universals, general terms, more than one kind of thinking. Objects that are shared, or are part of other things.\n\nContinental philosophy - Usually said to start with the three H's: Heidegger, Husserl, Hegel. Though, when I said things were poorly defined initially and now, Husserl kind of does analytic and continental, Hegel is now being studied by analytics, and Heidegger is more of the Nietzsche branch. It's very easy to see which philosophers are talking about Nietzsche, and which are talking about other areas of continental philosophy.\n\nNevertheless typically continental philosophy is the study of the subject, the existential, the phenomena.\n\nAnalytic and Continental really only serve as what schools focus in studying. But there is also American philosophy, and American philosophy is Pragmatic philosophy. Pragmatic philosophy was initially very similar to Continental, but then it became American Analytic. So analytic philosophy is usually thought of as Anglo-American. Continental is really \"French\" type of philosophy (European).\n\n*Language - Both continental and analytic philosophy study language. For analytic philosophy language is studied more in how it applies to the abstract, what words denote. In continental philosophy language is studied as a system as well, but more what it connotates, what people mean when they say.\n\nPeople study it for all sorts of reasons. The main reason people study it is because it serves two other humanities pretty well -- History and English.\n\nOther people who study philosophy, like me, tend to disdain much of philosophy (historically a lot of people did too). We prefer to describe ourselves closer to mathematics than to the humanities. Logicians, not philosophers. It makes sense too, most (important) logicians were mathematicians.\n\nPhilosophy was doing physics before our physics became good. It tries to describe a Universal theory of the World. Physics tries to do that now. If you read theoretical physics it's VERY similar to philosophy. Unfortunately, if you don't know the history of philosophy your physics will suffer the same problems we have already addressed.\n\nSo really, there is a convergence point. Most historical/ancient philosophy is dead. But you still need to know the history to know contemporary philosophy. Contemporary philosophy and science differs in terms of methodology.",
"Like you're four:\n\nScience is a field where you study the world with experiments and studies. Philosophy is where you study the things that can't be answered with experiments and studies. With science you can figure out things like how electricity works, or what happens in a black hole, or how ants communicate with each other. Even stuff like why humans fight wars are based in science. These are things you can see with your own eyes. But there are a lot of questions that you can't answer by watching or testing them with experiments. This is stuff like \"What is good and what is bad?\" \"What happens after we die?\" \"How do we determine what is beautiful and what is ugly?\" \"How do we know we're not actually dreaming right now?\" But they're not guesses...people have arguments, some of them very convincing, for their philosophical beliefs! \n\nPeople study philosophy because it makes sense of the world. Science is for understanding the world around us, and philosophy is for saying \"Well, what does that mean for us? How does all this knowledge impact how we live our life?\"\n\nEven asking \"What is philosophy?\" is a philosophical question! You're trying to make sense of the world, out of a concept that isn't scientific but is based entirely in the realm of human ideas."
]
}
|
[] |
[] |
[
[
"http://en.wikipedia.org/wiki/Philosophy"
],
[],
[],
[],
[],
[]
] |
|
8odvhb
|
Is James McPherson too critical of George McClellan?
|
I’m currently reading Battle Cry of Freedom, about 500 pages in, and McPherson seems to be highly critical of McClellan throughout. He seems to only credit him for doing a good job of organizing the Army of the Potomac and really inspiring his men at the beginning of the war.
He goes at length reveal his flaws and mistakes throughout. How he had contempt for Lincoln, his overly cautious tactics, his overestimation the enemy’s strength, and overall presents him to be pretty unlikeable (mostly by using his own words against him).
I know McPherson is well respected, but is their any legitimate criticism of his portrayal of McClellan?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/8odvhb/is_james_mcpherson_too_critical_of_george/
|
{
"a_id": [
"e03862g"
],
"score": [
13
],
"text": [
"Ethan Rafuse made a creditable attempt to defend McClellan in his 2011 biography *McClellan's War,* and while somebody other than I could better assess him as a tactician, strategist, or battlefield commander, I think Rafuse does manage to debunk some of the McClellan myths. The famous incident where Lincoln called on him and was turned away, for example, was much more likely to have been due to an attack of the malaria McClellan picked up during the Peninsula Campaign, not him being an egotistical snob. His supposed failure to pursue Lee after the Battle of Antietam is a great exaggeration: his army was exhausted, and the reconnaissance in force he sent across into Virginia after Lee was decisively repulsed.\n\nThere is a real problem with biography: we like stories of people to run like film scripts. An egotistical, snobbish, well\\-bred and incompetent McClellan makes a great contrast to a modest, progressive Lincoln or a hard\\-working, unassuming Grant, and Rafuse does show this is another case where the characters are not quite that simple. Grant was quieter than McClellan but no less ambitious, and also made mistakes that cost a lot of lives. And we have to also avoid a presentist bias: McClellan's Whig politics are now way out of line with what we would feel to be correct, but his compromising attitude towards the South was shared by a lot of Northerners, and would certainly be seen again after the War when the North abandoned the freedmen and Reconstruction. "
]
}
|
[] |
[] |
[
[]
] |
|
3gd1s4
|
how are babies born with "hardcoded" reflexes that they can do first time, without practice?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/3gd1s4/eli5_how_are_babies_born_with_hardcoded_reflexes/
|
{
"a_id": [
"ctwzp7c"
],
"score": [
3
],
"text": [
"Hardcoded is the exactly correct word to use.\n\nThey are born with neural pathways in their brains that will automatically respond to stimuli, residing in a more primitive part of their brain.\n\nFor many animals, that more primitive part of their brain is almost all that they have, so all of their behavior is hardcoded, and they have very little capacity to learn. For humans, the primitive brain is small, with most of their brain devoted to learned behavior."
]
}
|
[] |
[] |
[
[]
] |
||
f2w29z
|
how do people who suffer from epilepsy safely drive?
|
Some forms of Epilepsy can be triggered by flashing/flickering lights and when driving, especially at night, even driving on a motorway can cause lights to flicker due to oncoming traffic etc.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/f2w29z/eli5_how_do_people_who_suffer_from_epilepsy/
|
{
"a_id": [
"fhf1e9y",
"fhf3gu2",
"fhf5dpg"
],
"score": [
18,
2,
2
],
"text": [
"They can’t. Exceptions not withstanding (minor cases, controlled by medication,etc) Licenses can be denied over medical issues.",
"To begin with, people with certain medical conditions can't drive. In this example, it's having seizures. \n\nFrom there, it depends on the particular circumstances. For example, if the seizure was caused by certain drugs, severely low low sugar, it can be quickly and effectively managed by not taking those drugs, and managing your blood sugar. In these instances you should be back driving quite fast, maybe not even losing you license. \n\nNow if its cause is unknown, then they suspend your license until the doctors are satisfied that it's a one time event, not likely to happen again.\n\nThen we have people who are prone to seizures. They probably won't ever be allowed to drive. Again though, they take into account what causes these seizures. Flashing lights are just possible cause. And even then, it's not all flashing lights. An actual strobe light may cause a seizure, but those are not being used as much in emergency vehicles, they're mostly LED lighting which may not cause a seizure. Same with reflections on glass, or signal lights, or lights from a passing vehicle. That means the person may be still be safe to drive because what causes the seizure isn't likely going to be found while driving.\n\n\nIn short, just because someone may have seizures, doesn't mean they're caused by lights. And even if they are, the conditions have to be just right for it to happen, and those conditions may not be something you'll encounter while driving.",
"I used to date a girl with epilepsy. She was otherwise normal, but just wasn't allowed to drive. There really wasn't a work around. I was happy to give her rides though, and she would Uber/Lyft if no ride was available."
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
w9tqb
|
purpose of the f keys on the top of your keyboard.
|
Why are they there? What was their original intent?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/w9tqb/eli5_purpose_of_the_f_keys_on_the_top_of_your/
|
{
"a_id": [
"c5bhuch"
],
"score": [
10
],
"text": [
"Back in the bad old days, there was no such thing as a \"mouse\"- all you had was your keyboard. But some software still needed the \"menus\" that we take for granted in most every program we use today. \n\nSo, the F keys were implemented as a quick and easy way to access those menus. Programs could draw those menus across the top of the screen, along with the name of the key that would pull that specific menu up- and you could use the arrow keys, or letter shortcuts to navigate from there.\n\nNowadays, they're typically not used at all, except for shortcuts for advanced users. For example, F12 in Chrome brings up Developer Tools, allowing you to look at the base level of what each part of HTML code on the page you're viewing is responsible for."
]
}
|
[] |
[] |
[
[]
] |
|
bm96ad
|
What is the prevalence of assassinations in historical conflicts?
|
What is the point of large-scale warfare if the enemy leaders could simply be assassinated? Was it not done because it was harder than it seems, or was it seem as dishonorable, or were there other considerations?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/bm96ad/what_is_the_prevalence_of_assassinations_in/
|
{
"a_id": [
"emxwzu2"
],
"score": [
2
],
"text": [
"As required, I will provide a lengthy answer.\n\nIn the past assassinations were often an option, though like today most had some sort of security detail. An example of which (though perhaps an extreme one) can be found in the Mongol Empire, where Genghis Khan had a private defensive force called the Kheshig. The force was sizeable, being thought to be around 10,000 plus by the time Genghis died. This is perhaps why no Khan of Khans (leader of the mogul empire) was ever assassinated.\n\nIn less militaristic nations, or in nations with a smaller security detail, leaders often were assassinated. A prominent example being in Julius Caesar, though here it was his friend, Brutus who murdered him, and it was not for a war, but rather for political gain. The religious wars in the Middle Ages also claimed many monarch's lives.\n\nThe Order of Assassins or Hashshashin was an islamic group which terrorised the islamic world for the better part of two centuries until it was eradicated by the Mongols on their way through the Mohammedan Empire. Whilst they were still around, though, their ruling was generally accepted, and though many tried to defeat them, most feared that they would be assassinated should any move be taken against the great Hashshashin.\n\nThus in this respect, perhaps enemy leaders could be simply assassinated, and as history has shown, it can be an effective method if the leader can actually be reached.\n\nHowever, in modern times it is much harder to assassinate any leader of a major nation such as America, due to not only the massive security details and defences, but also because of the intelligence agencies which play a huge role in the protection of leaders. Obviously there are exceptions, such as the Kennedy ordeal, but such exceptions are just that.\n\n(Speculation) In terms of ending wars it is unlikely to do so in the modern age. This is mainly due to the fact that unless the enemy country in question is a dictatorship, monarchy or any kind of totalitarian state the influence of assassinations is probably minimal. This is because new leaders can be quickly appointed. Totalitarian leaders who feel under threat of assassination are probably less likely to continue fighting. In addition, in such totalitarian states the leader is often the one powering the war. Although, in many cases, even in such nations, a new leader with similar ideals and qualities (if not worse) is quickly appointed, as seen in General Gaddafi and Libya."
]
}
|
[] |
[] |
[
[]
] |
|
etp9zh
|
Why wasn't the Holy Roman Empire ever centralized?
|
Now I'm not an expert in history but from what I know in the 12th maybe 13th century countries like france and england were pretty decentralized like the HRE
but what led to the HRE not being centralized the way england and france did? I know the riechreform was about this but why so late?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/etp9zh/why_wasnt_the_holy_roman_empire_ever_centralized/
|
{
"a_id": [
"fiffzqj"
],
"score": [
3
],
"text": [
"I think I give a thorough answer, here: \n\n_URL_0_"
]
}
|
[] |
[] |
[
[
"https://www.reddit.com/r/AskHistorians/comments/f6byq6/why_did_france_succeed_in_centralizing_where_the/?utm_source=share&utm_medium=ios_app&utm_name=iossmf"
]
] |
|
7chqf0
|
What alleged psychodellic property or ingredient of nutmeg makes people high?
|
askscience
|
https://www.reddit.com/r/askscience/comments/7chqf0/what_alleged_psychodellic_property_or_ingredient/
|
{
"a_id": [
"dpr6xgg"
],
"score": [
5
],
"text": [
"Myristicin, an anti-cholinergic.\n\nLike other anti-cholinergic drugs it will cause dry eyes/mouth, confusion, headaches and nausea. In certain doses it can cause mild hallucinations.\n\nThe effects vary widely from person to person and can last for 2-3 days. I've frequently heard a nutmeg high being described as like a bad flu. I've only known one person to do it twice.\n\nInterestingly, Myristicin doesn't fully explain nutmeg's effects according to some literature. Elemicin, also in nutmeg, is potentially psychoactive as well. Some of nutmeg's effects may come from how myristicin alters the metabolism of other compounds found in the nutmeg seed."
]
}
|
[] |
[] |
[
[]
] |
||
17ljfh
|
why do objects in space tend to orbit in a disc-shaped pattern?
|
Why do Saturn's rings, our solar system, and, indeed, most every solar system and galaxy in the known universe tend to end up in disc-shaped orbits? My gut feeling tells me the answer is centripetal (centrifugal?) force, but that doesn't seem to account for why the shape is so common. It would seem to me that since space expands in all directions and gravity exerts its force in all directions, that there would be far more examples of celestial bodies with odd-shaped orbits than than are currently known (to me, anyway).
Just for a little bit of background on my line of thinking, this question occurred to me while I was watching a TED Talk about dark matter and based on what the speaker explained (and from what I knew about dark matter beforehand), dark matter does not seem to operate in disc-shaped patterns but instead exerts its huge amount of gravitational force in all directions.. And it was from this realization that I started questioning why "normal" matter does tend to exert its gravitational force on one primary plane. It's quite possible I could have misunderstood this concept and, considering the theoretical frontier that dark matter is on, I realize the answer to this question may not be as simple as I'm hoping it is. Nonetheless, thank you in advance for any answers you have.
Edit: My question was more or less answered by Imhtpsnvsbl, but feel free to discuss further or add anything you like.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/17ljfh/eli5_why_do_objects_in_space_tend_to_orbit_in_a/
|
{
"a_id": [
"c86lx0e"
],
"score": [
15
],
"text": [
"Conservation of angular momentum, basically.\n\nImagine a big cloud of particles, each moving with some random velocity. The cloud will have some well-defined center of mass, obviously, so each particle that makes up the cloud is going to be in orbit about that center of mass, the orbit determined by where the particle starts out and what its initial velocity is.\n\nEvery body in orbit around another body has some angular momentum. If you were to compute the angular momentum of every single particle in the cloud, you'd be able to add them all up. Many of the individual momenta would end up canceling out; there's a particle here that's moving this way with such-and-such angular momentum, but there's another particle on the other side moving in pretty much the opposite way, so those two momenta cancel out almost exactly.\n\nBut once you've added up all the angular momenta, you'll find that it doesn't *all* cancel out exactly. Instead, there's some *net* angular momentum. We can say that's the angular momentum of the whole cloud.\n\nHere's the thing about angular momentum: It *never goes away.* It moves around, adds and subtracts, and it can cancel out under the right circumstances, but it never just *disappears from the universe.* So if the cloud starts out with some net angular momentum, then it will *keep* that net angular momentum *forever.*\n\nSo if you let the particles move around for a while, you'll notice that they start interacting with each other. This one bumps into that one, these two graze each other, whatever. In each interaction, angular momentum *moves around* — this particle gains a little, that particle loses a little — but it *never just disappears.* Maybe occasionally a particle will bounce off another in such a way as to get knocked out of the cloud entirely; when that happens, it'll carry a tiny amount of angular momentum away with it. But in general, the total angular momentum of the cloud remains constant.\n\nAs the particles interact with each other over a long span of time, these interactions will have a net normalizing effect. That is, every particle in the cloud will tend to have its angular momentum \"nudged\" closer and closer to the net angular momentum of the cloud, divided by the number of particles. That's because a particle with *more* than the average angular momentum will tend — statistically, I mean — to interact with another particle in such a way that it gives up angular momentum. Particles with less than the average angular momentum will tend to gain angular momentum from their interactions.\n\nSo over a very long time, the particles will tend to get \"averaged out,\" so they approach uniform angular momentum.\n\nThat means they end up settling into orbiting in the same direction, and *in a plane.* Particles that are orbiting outside the plane of the cloud's net angular momentum will tend to get pulled back toward it by their interactions with other particles.\n\nSo that's why planetary systems, like our own solar system obviously, tend to form planes. Because the huge gas cloud that existed here before our solar system condensed out of it had a net angular momentum, and because angular momentum is conserved, the solar system that exists today has *pretty much* exactly that same angular momentum.\n\nDark matter doesn't tend to form disc-like structures, though, because dark matter particles *don't interact* with each other at all. They're completely transparent to each other, passing through each other like they're not even there. Without interactions to average out the angular momenta of the particles, clouds of dark matter tend to say … well, *cloud-like,* forming the galactic halos we observe when we look out into the night sky."
]
}
|
[] |
[] |
[
[]
] |
|
1zgvzj
|
why do we combine words together accidentally when speaking?
|
There have been times when I will have a conversation with someone and I will randomly combine words into one word. For example there was a time when I was comparing my residence water with my home water and I meant to say "nice water" but ended up saying wice... It's embarrassing when the other person looks at you like "what are you saying?" anyone else have this problem?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1zgvzj/why_do_we_combine_words_together_accidentally/
|
{
"a_id": [
"cftj73y"
],
"score": [
2
],
"text": [
"Your brain forms sentences by trying to put together words that represent what you're thinking. Sometimes your brain knows the words, but doesn't send the signals to the muscles in your face quick enough for your mouth to form each individual word correctly, so you blend a couple words together, and people wonder why you just said 'wice' instead of nice water."
]
}
|
[] |
[] |
[
[]
] |
|
f74668
|
how do rape kits/paternity tests work if sperm only has 50% of the father's dna?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/f74668/eli5_how_do_rape_kitspaternity_tests_work_if/
|
{
"a_id": [
"fi8zi72",
"fi9b3mp",
"fi9s4e5"
],
"score": [
13,
3,
2
],
"text": [
"Each sperm only has 50%. \nThere are many many millions of sperm. \nThe odds that all of them miss any part of the father's DNA is essentially zero.",
"I mean...spermatozoa contains 50% of DNA compared to the othet cells.\n\nBut 100% of this 50% DNA belong to the guy who ejaculated.",
"Even 50% of the DNA is roughly a shitload of data. You still got extremely much to compare with.\n\nSay that you are matching if two books are the same. Even if you only have every second word of one of the books. you can still make a pretty strong assumption on whether it is the same book or not."
]
}
|
[] |
[] |
[
[],
[],
[]
] |
||
2s9q4x
|
Why is recent history often excluded or extremely rushed in history classes?
|
I am mostly referring to secondary education but it has always seemed to me that any history since WWII, at least American history, is covered in a fraction of the time compared to other events in history. I'd be interested to know if this is also true in other countries.
I'm curious because IMO I feel most of our society has very little empirical knowledge (other than what our parents have imparted on us) of what has happened in the last 60 years. Educators tend to spend weeks on the revolution, the civil war, Jefferson, Lincoln and Washington but when it comes to Vietnam, political/racial tensions in the 60s/70s, Nixon, Reagan and even Clinton, the majority of younger people who didn't live through it really have no clue.
I'm very interested in the reasons for why this might be. Bias of the people writing the curriculum? Is the jury still out? While I love all history, it seems to me that some of the most important history is that which directly affects why our society is the way it is today.
Please let me know if this has been answered before or if this is suited for a different sub.
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/2s9q4x/why_is_recent_history_often_excluded_or_extremely/
|
{
"a_id": [
"cnnt6zp",
"cnnuw8n",
"cnnw82l"
],
"score": [
15,
6,
5
],
"text": [
"Historian James Loewen attends to this question in his book for popular consumption: \"Lies My Teacher Told me\". The short answer is: the recent past in too well known, and therefore too controversial. he studies the number of pages in history text books dedicated to to recent past, first in books from the 1980's, then a second sample from the 00's in order to compare how many pages they dedicate to the recent past. \n\n\"On average, the textbooks [from the 1980's] give forty-seven pages to the 1930's, forty-four to the 1940's, and fewer than thirty-five pages to each later decade. Even the turbulent decade of the 1960's -- including the civil rights movement, most of the Vietnam War, and the murders of Martin Luther King Jr., Medgar Evans, Malcolm X, and John Robert Kennedy -- got fewer than thirty-five pages.\"\nLowen p. 260\n\nAs you can see, when the 1960's was fresh in the minds of parents who had lived through it, history books devoted roughly 25% fewer pages covering it. However, when the 1960's faded from the recent past, textbooks began to give it a new emphasis of focus.\n\n\"Textbooks in 2006-2007 show quite a different approach. Now the 1960's are no longer recent history, so textbooks can give them the emphasis they should have received, fifty five pages. (That total is greater than for any other decade of the twentieth century.) But today's texts, published between 2000 and 2007, give short shift to the new recent past, the 1980s, 1990s, and 2000s. Now they devote forty-nine pages to the 1930's and forty seven to the 1940's, but fewer than twenty to the 1980's and 1990's (Even tossing in the first years of the new Millennium).\"\nibid\n\nThe unfortunate conclusion from this trend is to recognize that K-12 recent history will always be sterile and lackluster because of the socio-economic forces that shape the textbook publishing process. Conventional High School history is supposed to be non-political, but current events are always political and remembered as such. Textbook publishers don't want to take a side on current events because they don't want to risk alienating the parents of potential students. \n\n\"Some parents are Democrats, some Republicans, so what authors say about the impeachment and trial of Bill Clinton will likely offend half of the community.\"\nLowen p. 261\n\nThese political concerns, along with many others are ripe in the minds of textbook publishers as they endlessly revise their books in order to parade before skeptical school boards nation wide. This process is so politicized, and so lucrative, that the history that is allowed into K-12 history books could hardly be called history. All notes and evidence is take from James Loewen's Lies My Teacher Told me, and I encourage any with an interest in american history, or the history regarding the education of history, I invite you to check it out.\n\nLoewen, James W. Lies My Teach Told Me. New York: Touchstone, 1995, 2007.\n",
"The other answer is that we don't know what was actually important in recent history. We need time to pass to understand that.\n\nTake the Clinton administration for example. One of the initiatives that was pushed and passed was NAFTA. Was that good or bad policy? Was the increase of Mexican [emigration](_URL_0_) due to NAFTA? Was/is that emigration good or bad for the US and Mexico? It is just to soon to tell. You can make educated arguments one way or the other but when we haven't decided on how we are going to classify millions of aliens it is very difficult to draw a conclusion as to the success of a policy. And does the policy (or lack of policy) have any real significance in determining the direction of our country. We just don't know yet.",
"The other thing is that there's also just an issue of time. Most secondary classes that cover American history 1492-present are trying to get through a lot of material in a school year and if they fall behind at any point earlier in the course then they have to get through the later material faster-especially if they're an AP class and they practically need to finish the coursework by mid or late April to have a few week's review time. So by the end of the year(when recent history is covered) there's a rush just to get through everything. "
]
}
|
[] |
[] |
[
[],
[
"http://www.npr.org/2013/12/26/257255787/wave-of-illegal-immigrants-gains-speed-after-nafta"
],
[]
] |
|
brdapk
|
Did 'Population: ' signs actually appear outside towns in the American West? If so what was their purpose?
|
Edit: I get it, lots of american towns still have them. What I'm asking is why they originally came about.
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/brdapk/did_population_signs_actually_appear_outside/
|
{
"a_id": [
"eofjodb"
],
"score": [
156
],
"text": [
"American expansion always included strong elements of boosterism: wanting to believe that your town was bigger and better, or would soon be bigger and better, than other nearby towns. Because I’ve never seen any suggestion that population signs were posted for view by passing railway passengers, I believe the practice really arose in the early days of automobiles and cross-country motoring. In much of the nation, the new highway network was cobbled together from pre-existing county roads, including the section-line roads that run parallel at one-mile intervals. With so many routing possibilities, there was great rivalry among small towns to be on the new marked route that would attract motorists, and I speculate that booster clubs put up signs at junctions and crossroads touting their towns: listing the services such as hotels, repair garages, and tourist campgrounds to be found there, and also showing a population figure that would suggest a greater variety of eateries, services, and attractions. No doubt there was some inflation of those figures, and so state highway departments and their official signs noting entrance into municipalities became the trusted arbiter of such figures.\n\nSome states also show the altitude of towns on city-limit signs, a holdover from railway days when that was a figure of interest to both the drivers of the locomotives and travelers passing through. In the early days of motoring, altitude was also a factor in engine adjustment and performance, and useful for motorists to know.\n\nAlas, I’ve never found much in the way of sources on this topic, so its informed more by broader understanding of the rise of the automobile and civic rivalry in the early 20th century. The rivalry of towns wanting to be included on the pioneering coast-to-coast Lincoln Highway is chronicled in Drake Hokanson’s book *The Lincoln Highway: Main Street Across America.* John A. Jakle and Keith Sculle’s book *Motoring: The Highway Experience in America* gives a pretty good picture of the landscape that faced early cross-country motorists. The various papers in *Roadside America: The Automobile in Design and Culture,* edited by Jan Jennings, give more detailed insight into various aspects of the roadside culture."
]
}
|
[] |
[] |
[
[]
] |
|
6mg3ia
|
what is a w-4?
|
Like, I vaguely know what it is, but how does it work?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/6mg3ia/eli5_what_is_a_w4/
|
{
"a_id": [
"dk1b9gt"
],
"score": [
3
],
"text": [
"Essentially, the government requires that your employer collect your income tax on your wages and send that to the government. \n\nIn order to do that, your employer needs some way to estimate how much you'll pay in taxes. To do **that**, they need information from you about how much you expect to pay in taxes. \n\nSo you tell your employer if you're married or single, and if you have certain allowances that would be subtracted from your taxable income. (like having kids) You can tell your employer to withhold extra money, if you have special circumstances or if you're working two jobs. Your employer then uses that information to estimate your income taxes, and withholds those funds from your paycheck. "
]
}
|
[] |
[] |
[
[]
] |
|
4dd9t0
|
why do child victims of abuse gravitate towards people similar to the abuser?
|
Why *does it seem like* child victims of abuse gravitate towards people who also abuse them? Wouldn't they want to go in another direction?
I can't relate of course, but if I was beat up at a 4H convention I would make sure never to attend another 4H convention - not seek out more 4H members. Silly example I know.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/4dd9t0/eli5why_do_child_victims_of_abuse_gravitate/
|
{
"a_id": [
"d1pvrmy"
],
"score": [
4
],
"text": [
"Abuse is all about control. A lot of abuse involves making its victims feel worthless, like they can never do better, like they cannot find happiness or deserve happiness, etc. Control is part of how abusers keep their victims silent. \n\nVictims of child abuse often have little exposure to healthy relationships. They also tend to have lower self-esteem, and it requires a lot of consistent help and guidance and support to help victims. Victims can also potentially develop behavioral issues and can be difficult to deal with if people don't understand or know how to deal with it. This leads to more self-esteem issues, a tendency to revert back to what they know and what they've been told by the abuser. \n\nHelping a victim of child abuse doesn't stop with just removing them from the abuser(s)' home."
]
}
|
[] |
[] |
[
[]
] |
|
ctwhwy
|
how does uhaul/any other car rental company keep vehicles equally distributed across the country?
|
Shower thought I had.. how do they match the random sporadic demands of vehicles that you can’t predict? Do people get paid to drive them to different locations n such?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/ctwhwy/eli5_how_does_uhaulany_other_car_rental_company/
|
{
"a_id": [
"exogibf",
"exoju8l",
"exom2rl"
],
"score": [
13,
8,
7
],
"text": [
"Car rental businesses hire people to drive vehicles to other locations. I’m sure Uhaul has something similar in place.",
"They hire people to drive vehicles back to where they need to be to equalize distribution. Sometimes you can even get a really good deal on long distance rentals because they have vehicles that need to go to a certain destination.",
"U-Haul is pretty famous for pricing rentals differently to give customers reasons to drive the trucks where they're demanded. It can cost vastly more to rent a truck to go from a low supply city to a high supply city, than the other way. \n\nRental car agencies charge considerably more for a 1-way trip than a pick up and return at the same location trip. The rental cost likely includes the cost of transporting the car back to it's original location. \n\nWhen needed drivers can be hired to move vehicles."
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
285idr
|
How accurate is the Romanticized telling of the American Civil War?
|
When taught about the American Civil War, we were told it was very "brother against brother" and generally clean and fair. How accurate is this viewpoint of the war? Were any massacres or inhumanities committed similar to the atrocities in other civil wars throughout the world (El Salvador, USSR, Afghanistan, Mexico)? Also, how much more complex was the civil war than simple fighting about slavery, were there further ethnic or political disputes, did these lead to any dehumanization that resulted in brutality? In short, how clean was the American civil war in comparison to those in other parts of the world?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/285idr/how_accurate_is_the_romanticized_telling_of_the/
|
{
"a_id": [
"ci84pa0"
],
"score": [
5
],
"text": [
"\"how much more complex was the civil war than simple fighting about slavery\"\n\nThe short answer here is that it wasn't more complex than that. Slavery was absolutely the central political controversy of 19th century America. The southern states had enjoyed legislative and judicial power over the federal government for decades leading up to the election of Abraham Lincoln. With the loss of the White House to an avowed abolitionist, they realized that their stranglehold on the federal government was at an end so they revolted rather than honor the democratic process.\n\nThe single most poignant fact in the discussion of \"whether or not the Civil War was fought over slavery\" is that the Confederate Constitution banned the abolition of slavery. If the \"State's Rights\" argument is to be believed, then why would the Confederate government take away their own states' right to decide on slavery? After the War ended, southern apologists immediately began writing revisionist history that de-emphasized the role of slavery in their rebellion. Unfortunately their efforts found their way into many a history book and so today there is a sizeable portion of the American public who believe that the Confederate cause was one of self-determination and self-governance.\n\nThis is demonstrably false. The Confederacy formed because while males feared that their ability to own black people as property would be taken away from them, and they decided collectively that they would rather take up arms against their countrymen than let that happen. There are very few conflicts in human history where one side can be considered legally and morally in the wrong - the American Civil War is one of those few."
]
}
|
[] |
[] |
[
[]
] |
|
d8soga
|
How did the relative cost of a medieval knight compare to the cost of a modern battle tank?
|
I have been wondering how expensive medieval knights were & wondered if a modern battle tank was a fair comparison for cost.
[A modern battle tank is around USD$6-9 million to buy](_URL_0_). I have no idea on how much it costs to maintain/ fuel/ arm/ man a tank per year, but I assume it's significant. Maybe 10% of the ticket price?
All in all a battle tank represents a substantial investment, with [many countries not fielding battle tanks at all](_URL_1_).
Do we have an idea of how much a medieval knight cost? A knight would have required armour, weapons, horses, staff & presumably suitable property/ housing.
Is it possible to compare:
* cost of modern battle tank vs cost of modern infantry
* vs
* cost of medieval knight vs cost of medieval foot soldier?
I've been wondering about this idea but when I attempted to Google it I just got lots of MMORPG/ RPG results.
Any thoughts are appreciated.
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/d8soga/how_did_the_relative_cost_of_a_medieval_knight/
|
{
"a_id": [
"f1d8rr1",
"f1dy1oi"
],
"score": [
14,
42
],
"text": [
"I found this thread from 2 years ago:\n\n_URL_0_\n\ncredit to u/WARitter and u/Dashukta for answers",
"I mean the very terms \"medieval\" and \"knight\" are problematic in their own right as the medieval period is not particularly closely defined and knights can be anything from Hungarian riders to great lords of England and France. The latter would obviously spend vastly more money on their equipment than the former. The same is true for the term \"foot soldier\" which can be anything from a hastily raised levy of spearmen to dismounted men-at-arms, both are technically medieval foot soldiers but their cost varies a great deal.\n\nWith that in mind, say you are a Lord in 15th century England and you which to equip a retainer as a mounted man -at-arms. We assume that this man owns his own weapons but little else. He will need armor and a destrier. Let's assume he has his own courser already. Let's also, just for arguments sake settle for a harness of plates that is not custom made for him but rather made for a man roughly his size and modified to fit. Say you pay 6 pounds stirling for the armor and adjustments. You pay another 5 for the destrier (prices of war horses varied a great deal with time, demand and quality, if this figure is unreasonable I hope someone with more knowledge than me, like /u/waritter, will correct me). Either way, we end up at 11 pounds sterling for horse and armor.\n\nThis is the equivalent of one year and three months of labour for a skilled journeyman, half that for the man-at-arms himself. By comparison, a Main Battle Tank costs a whole hell of a lot more. $6M is the equivalent of 100 years of median income in the US, so, by very rough estimates, fielding a single main battle tank in 2018 cost about the equivalent of 80 men-at-arms in the 15th century.\n\nFor this case I assumed that you're fielding a normal retainer as a man at arms, not a titled and landed noble. For the man-at-arms you could expect to pay about 1 shilling per day plus food and lodging. I have no idea what the running expense of an active MBT is but I expect it is significantly higher given that you would also need a crew of 3-5, mechanics, infrastructure, fuel, ammo, spare parts etc etc. The crew alone would mean, if we assume that the tank crew member makes about the same as a skilled journeyman did in the 15th century, that wages alone are twice as expensive for the tank compared to a man-at-arms.\n\nEDIT: Pay updated, thank you /u/Rittermeister."
]
}
|
[] |
[
"https://www.quora.com/How-much-does-a-common-battle-tank-cost",
"https://en.wikipedia.org/wiki/List_of_countries_by_level_of_military_equipment#List"
] |
[
[
"https://www.reddit.com/r/AskHistorians/comments/56ccx9/how_much_would_a_suit_of_armour_from_1455_1485/"
],
[]
] |
|
22pb3m
|
Did businesses really flourish in the Nazi Regime?
|
I am interested in whether or not businesses did well under a Nazi Regime. Did they do well because of the capitalist system (as past of fascism) allowed them to do whatever they wanted (as part of a free market) or did they suffer because the totalitarian aspect of the state hindering their progress?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/22pb3m/did_businesses_really_flourish_in_the_nazi_regime/
|
{
"a_id": [
"cgp2tm7"
],
"score": [
3
],
"text": [
"Many businesses enjoyed an extremely close relationship with the Reich government. The most notorious one, [IG Farben](_URL_3_), --a chemical conglomerate formed in 1925 and made up of Bayer, BASF and others-- was so deeply implicated in committing crimes against humanity--being the supplier of Zyklon B, the poison used in the gas chambers--that it was abolished after the war, and many of its [corporate officers were put on trial](_URL_1_). \n\nPost war examination has shown that the Nazi economy --and indeed the entire [Nazi bureaucracy](_URL_0_) was a house of cards, built on the loot and plunder of conquered nations in the former, and a personality cult and backstabbing on the latter. German industrial production peaked in 1944 under the direction of Minster of Armaments Albert Speer. These improvements can be principly attributed to him untangling the mess created by other Nazis, in their effort to win Hitlers favor, carving out little bureaucratic empires for themselves. This is especially evident in the restructuring of the [Reichswerke Hermann Göring](_URL_2_), an enormous state controlled steel conglomerate, formally headed by Hermann Göring. \n\nSources: \n\nInside the Third Reich, Speer, Albert\n\nThe Rise and Fall of the Third Reich, Shirer, William"
]
}
|
[] |
[] |
[
[
"http://alphahistory.com/nazigermany/the-nazi-state/",
"http://en.wikipedia.org/wiki/IG_Farben_Trial",
"http://en.wikipedia.org/wiki/Reichswerke_Hermann_Göring",
"http://en.wikipedia.org/wiki/IG_Farben"
]
] |
|
1dvoz1
|
Why do American lawyers have such a bad reputation? When did disrespect toward lawyers start?
|
We all know the jokes, "50,000 lawyers at the bottom of the ocean is a good start, etc. This sort of tasteless joke would be unfathomable against doctors. And in Germany, I never encounter this sort of attitude, lawyers here get a lot of respect. So when did it become socially acceptable for Americans to slag off on lawyers as they do? How come?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/1dvoz1/why_do_american_lawyers_have_such_a_bad/
|
{
"a_id": [
"c9uby08",
"c9ufiu2",
"c9ufpgn",
"c9uq3u8"
],
"score": [
12,
9,
8,
3
],
"text": [
"A major issue is defense laywers. People don't understand that there is a difference between due process and guilty v innocent. A defense lawyer, regardless of whether or not the jury finds him guilty has to make sure his client has their rights observed. While this can be explained by say, a public defender (I just take the cases the state gives me) it doesn't work so well for private defense lawyers who (supposedly) know their client is guilty and still defends them. People like this are seen as \"without shame.\" \n\nFurthermore, it seems to me at first glace that a lawyers job is largely the same job of any academic: create a theory, support it with evidence, and then present your work to a panel of peers in hopes that it is approved. The problem is that a lot of people don't see Law like this, they see it as justice, and if you turn out to be a prosecutor who's plaintiff loses, or a defense lawyer who's client is found guilty BOOM you are an evil jerk trying to get away with (or wrongly label someone with) murder. \n\nThe reality is that few lawyers are courtroom lawyers, and few courtroom lawyers regular deal with \"big\" cases like murder, rape, major theft, etc. Most crimes that end up in courtrooms are pretty minor, and the importance of due process, rather than whether he was guilty or not, is what is going to take up people's time. \n\nIts the same with any sort of general case of technical skills and education are required to get a job and keep it. Those without the technical skills and education don't appreciate what you are doing, and perhaps even miss a lot of the skill. Most people don't stop and think that most Congressmen are lawyers, that all judges are lawyers, that people with their JD teach at law schools, at undergraduate schools, people who work in the Town Hall are lawyers, etc, etc. They just assume all lawyers are blood sucking defense lawyers who protect corrupt corporations, because stereotypes are fun and easy. ",
"Disrespect and low opinion of lawyers goes back to at least the colonial era for Americans, and I wouldn't be surprised if the origins go back to pre-colonial England.",
"To understand it, you have to split the American legal system up.\n\nIf you're a business person that hates lawyers, it may well be because of the worsening problem of patent trolls, and the fact that even in cases that are specifically rigged overwhelming in an employer's favor, legal cases can be hugely expensive. A business that does absolutely nothing wrong may still find itself eating tens or hundreds of thousands of dollars defending against frivolous lawsuits, brought by people who surely can never reimburse you if they lose. It can be because someone sues you over a patent for [1-click shopping](_URL_2_) or [shopping carts](_URL_3_), or an employee decides to accuse you of racial discrimination because you fired them for being an idiot.\n\nIf you're a victim of a crime and hate lawyers, it's probably because some crimes are notoriously hard to prosecute (rape and burglary) and easy to defend. Worse, rape victims get the double whammy of invariably being slandered at trial as a legal defense. If it's a corporation that's wronged you, they probably won't see any jail time, and the courts have become markedly more pro-business in the last 30 years.\n\nThen there are stories where lawyers managed to claim up to [$233 million per lawyer](_URL_1_) from the Tobacco Master Settlement Agreement between the states and the Tobacco industry. \n\nOn the flip side, corporate lawyers happily defame tort lawyers (such as the [Hot Coffee case](_URL_0_), which was arguably misrepresented) and vice versa.\n\nIn my experience, lawyers as a whole tend to be disrespected, but they are generally respected more on an individual level. But there is a growing feeling in America that the legal system doesn't work, and lawyers seem to bear the brunt of the blame",
"I work on the history of 19th century humour and I've encountered plenty of lawyer jokes in this period. Interestingly, American lawyers (and especially those from Chicago) were highlighted as being particularly unscrupulous shysters. This joke was originally published in an American newspaper, before being clipped out and re-printed by a British editor:\n\n > CHICAGO WOMAN: How much do you charge for a divorce?\n\n > CHICAGO LAWYER: One hundred dollars ma'am, or six for five hundred.\n\nThe joke is also made at the expense of women from Chicago, who were stereotyped in the New York press (and in London) as marrying and divorcing men at the drop of a hat. "
]
}
|
[] |
[] |
[
[],
[],
[
"http://en.wikipedia.org/wiki/Liebeck_v._McDonald%27s_Restaurants",
"http://www.cato.org/publications/commentary/great-tobacco-robbery-lawyers-grab-billions",
"http://en.wikipedia.org/wiki/1-Click",
"http://arstechnica.com/tech-policy/2013/01/how-newegg-crushed-the-shopping-cart-patent-and-saved-online-retail/"
],
[]
] |
|
f1ho5a
|
Did ancient civilizations have ancient civilizations?
|
Did any civilizations one could call "ancient" or "classical" (Egyptians/Romans/Mayans etc) have their own classical civilizations that they saw as "before their time" or a source of their own, contemporary culture? If so, how did they know about these civilizations - did they preserve the literature, art, and/or buildings or ruins?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/f1ho5a/did_ancient_civilizations_have_ancient/
|
{
"a_id": [
"fi5niaz",
"fh72p2m",
"fh7iqgb",
"fh7odh1"
],
"score": [
59,
1368,
56,
343
],
"text": [
"I hope this reply isn't too late for you u/urag_the_librarian. This is a fun question because, as is sensible enough...of course ancient peoples knew about *even more ancient* peoples. But how can we understand their level of knowledge? That is a much more difficult question. We are left with history (literacy and orality) and artifacts. And while this sub is dedicated to the literature side, I think it's equally as important to see the commonality of heirloom objects in the archeological record. \n\nSo as you're thinking, the Romans understood their \"cultural origins\" to be in the Aegean; whether they had come from the Trojans, or simply had adopted Greek “high culture.” Some other peoples around the world have also done this, this conceptualization of history is in its essence a form of \"translatio imperii.\" Literally, “the translation of empires,” the ideological tool that later peoples used to cement their political position through their supposed ancestry with an earlier golden age. The Aztecs believed their cultural origins were in the Toltec empire of a few hundred years prior, and controlled the narrative around the sacred usage of the even earlier site of Teotihuacan. See u/400-Rabbits answer [here](_URL_2_) for more details. \n\nAnd similarly, the Qin of ca. 100 BCE China believed their cultural origins to be in the earlier Shang and Xia dynasties. Sima Qian, *the* historian of this time, says the earliest Xia histories were about 2000 years prior to him and he is right; as these two \"dynasties\" roughly correspond to the Shang and Erlitou periods of the bronze age of the north Chinese plain, ca. 1000-2000 years before his writing. These periods were not necessarily “dynasties” but simply correspond to the “over-kingship” of a particular powerful city’s lineage in northern China central plain, first at the Erlitou site then Erligang, then at the Shang “capitals” Luoyang and eventually Anyang. The details Sima Qian gives about the rulers and chronology for both periods are probably entirely mythological, having been invented in the succeeding Zhou dynasty of the early iron age when this new state needed its own translatio imperii (i.e. the Mandate of Heaven). \n\n > ...Allan (1991) further suggests that the Shang may have had an ordinary myth of the Xia as a previous people who were their inverse, but not as a dynasty. This myth, according to Allan, was later transformed by the Zhou into the story of an historical dynasty which was conquered by the Shang. This new interpretation was made in the beginning of the Western Zhou dynasty [ca. 1000 BCE], in order to justify their conquest of Shang under the mandate of Heaven (Allan 1991: 57-73). These arguments are plausible given that no contemporary writing of the Xia has been found. At present, there is no way to prove the existence of the Xia as a dynasty, although there may have been a Xia people in oral tradition among the Shang and other contemporary peoples in the later second millennium BC.\n- [Li & Hong](_URL_3_)\n\nBut most peoples credit their ancient history to have been the establishment of their lineage/people by a great ancestor after the creation of the world...as you mention, the Maya, their stories are like this; or at least the Popul Vuh of the Quiche. \n\nI think we should give ancient peoples the benefit of the doubt. They were intelligent, and they knew (in some way) how to interpret ancient artifacts they found. I am in love with \"The Pessimistic Dialogue Between Master and Servant,” this bronze age Babylonian text has a master suggesting things, and then his supplicant servant supporting his decision even when he’s flip-flopping. It’s actually wonderful philosophy, but I’ll quote a segment which not only speaks to how they remembered their own history, but also how they remembered their deep unknown history. Translation by Robert Pfeiffer.\n\n > Master: I will do something helpful for my country.\n\n > Servant: Do it, my lord, do it. The man who does something helpful for his country, his helpful deed is placed in the bowl of Marduk. [The tablets listing men’s deeds were stored in Marduk’s bowl]\n\n > Master: No servant, I will not do something helpful for my country.\n\n > Servant: Don’t do it my lord, don’t do it. Climb the mounds of ancient ruins and walk about, look at the skulls of late and early [men]; who [among them] is an evildoer, who is a public benefactor?\n\nI find this a particularly beautiful statement of ancient wisdom, an honest reckoning with the realization that whether one is good or bad for one’s community is utterly obliterated by time. A process which, by their time, had already created “ancient ruins of early men.” We find a similar realization about death in Gilgamesh, when an enraged Inanna threatens to raise the dead (6.2), translation by David Ferry.\n\n > Give me the Bull of Heaven or I will go\n\n > to the Underworld and break its doors and let\n\n > the hungry dead come out to eat the living.\n\n > How many are the dead compared to the living!\n\nBrief references to situations like this give us a glance into how a bronze age person was conceiving their own past, even how they conceived of a deep and unknown past. Yet generally, as with the Mayans, Babylonians conceived of their history as a chain of events by culturally similar mythical kings who lived in the deep past soon after creation. And when Babylonians conducted archeological digs, and found ancient texts written in an archaic yet similar language; the evidence they had uncovered only confirmed this hypothesis. This is detailed in a wonderful paper by Irene J. Winter, [Babylonian Archaeologists of their Mesopotamian Past](_URL_0_). \n\nIn it, she gives an example of an iron age Neo-Babylonian period excavation at a bronze age Old Babylonian period temple. At this dig, the excavators found a fragmentary Old Babylonian tablet which had been placed there as a foundation deposit by a king some 1000-1500 years earlier. The tablet was restored, even going so far as to attempt to (incorrectly) write in Old Babylonian so as to restore the broken text. The foundation deposit was replaced, and the uncovered foundations were re-used for a new temple. In the eyes of the king who “restored” such ancient temples, he had simply replaced many planks in Theseus’ ship. Textual reconstructions of ancient languages were probably overseen by people such as Nabu-zer-lishir, who was in effect the “field director” of excavations under King Nabonidus. Historians today give him the title “scribe,” but specifically he was appointed to this position by the king because he was an expert in ancient languages. While their tradition of archeology and philology did not survive, and was re-invented by Europeans thousands of years later; it is heartwarming to know that we have a record of ancient people who were, as we are in this online forum, obsessed with understanding history. \n\nThis desire to physically recover the past, and using history to advise one’s choices during excavation is actually seen thousands of years earlier, by people at Catalhoyuk. As noted by Ian Hodder [here](_URL_1_).\n\n > ...in Building 1 retrieval pit F.17 was dug [in ancient times] to remove or retrieve a relief sculpture (only traces of which remained on the wall)...Given the large amount of erosion off the top of the mound that occurred in the millennia after the Neolithic occupation, we cannot know how deep these Neolithic 'archaeologists' had to dig, but it was at least 0.7m and probably substantially more. We do know that Building 1 had been filled and that any digging down implies a precise historical memory even if embedded within wider knowledge about where important sculptures were generally placed. Not all houses have major relief sculptures on the west walls of main rooms [where the retrieved sculpture was].",
"One of the best and most well-known examples of this is Classical Egypt and their understanding of the Pyramids, which were well over a thousand years old by that point. As such, I will refer you to older AskHistorians posts that address that specific piece of the answer.\n\n[_URL_0_](_URL_1_)\n\n[_URL_3_](_URL_2_)\n\nI expect that Chinese history from the same time period would offer additional good examples, but that is not something I'm very familiar with. Fingers crossed that someone with that expertise follows up with this post, because I'm interested in that as well.",
"A previous post about Xenophon and the assyrian cities in Anabasis by /u/Iphikrates\n\n_URL_0_",
"One of my older answers deals with this topic. Another user already (and very kindly) mentioned it, but I'll paste it up anyway, to allow anyone interested to ask follow-up questions:\n\nThe Greeks and Romans were aware that other civilizations were older than theirs. Egypt was a special source of fascination, as witnessed by evidence ranging from Herodotus' long description of Egyptian history and customs to Roman graffiti in the Valley of the Kings. Yet in the case of Egypt (and, as we shall see, more generally), they had a poor understanding of chronology. They tended to think that the Pyramids, for example, [were about 1500 years younger than they actually were](_URL_0_).\n\nWhen it came to ruins not associated with any living culture (which are, I think, more the focus of your question), it tended to be assumed that almost everything could be fit into a traditional mythological/historical schema that began around 1600 BCE (by our reckoning) and identified the Bronze Age with the age of heroes. When describing the ruins of the Mycenaean citadel at Tiryns, for example, Pausanias (who wrote in the second century CE) observes:\n\n\"The wall, which is the only part of the ruins still remaining, is a work of the Cyclopes made of unwrought stones, each stone being so big that a pair of mules could not move the smallest from its place to the slightest degree.\" (2.25.8)\n\nAnother Mycenaean wall, on the Athenian Acropolis, was associated with nebulous prehistoric Pelasgians (e.g. Hdt. 6.137). Chance discoveries of ancient burials, likewise, tended to be linked with the heroes of history/legend. The bones of a tall man found with bronze weapons on the island of Skyros, for example, were proclaimed to be the remains of Theseus. Later, an ancient burial exposed at Rome was decided to be the body of the legendary king Numa.\n\nThe Greeks and Romans, in other words, tended to assume that they knew what civilization/era ruins belonged to, even if they actually had no idea. Plutarch, for example, recounts what happened when the Spartan king Agesilaus decided to open a tomb traditionally thought to belong to Alcmene, the mother of Hercules:\n\n\"In the tomb itself no remains were found, but only a stone, together with a bronze bracelet of no great size and two pottery urns containing earth which had by then, through the passage of time, become a petrified and solid mass. Before the tomb, however, lay a bronze tablet with a long inscription of such amazing antiquity that nothing could be made of it, although it came out clear when the bronze was washed; but the characters had a peculiar and foreign conformation, greatly resembling that of Egyptian writing...\" (Mor. 577F-78A)\n\nAssuming that Plutarch's source is reputable, Alcmene's tomb probably belonged to a Mycenaean worthy, and the writing on the mysterious table was Linear A or Linear B. Agesilaus & friends, however, didn't know that - and so, since the writing looked more or less Egyptian, a Spartan was sent to Egypt with the tablet. There, a learned priest (who of course knew no more about Linear B than the Greeks) pretended to translate it.\n\nWhen in came to ruins in the classical world, in short, ignorance was no barrier to confident interpretation.\n\n\\[I'm on the road at the moment, but I'll address any follow-up questions later today.\\]"
]
}
|
[] |
[] |
[
[
"http://blogs.bu.edu/aberlin/files/2011/09/Winter-2000.PDF",
"https://www.academia.edu/12454074/History_making_in_prehistory_examples_from_Catalhoyuk_and_the_Middle_East",
"https://www.reddit.com/r/AskHistorians/comments/51qcj6/i_heard_that_the_aztecs_thought_teotihuacan_was/d7fal3n/",
"https://www.researchgate.net/publication/273293121_Rethinking_Erlitou_Legend_History_and_Chinese_Archaeology"
],
[
"https://www.reddit.com/r/AskHistorians/comments/a5ya3o/did\\_the\\_romans\\_know\\_that\\_the\\_great\\_pyramid\\_of/",
"https://www.reddit.com/r/AskHistorians/comments/a5ya3o/did_the_romans_know_that_the_great_pyramid_of/",
"https://www.reddit.com/r/AskHistorians/comments/19hrhe/how_did_the_romans_view_ancient_egypt/",
"https://www.reddit.com/r/AskHistorians/comments/19hrhe/how\\_did\\_the\\_romans\\_view\\_ancient\\_egypt/"
],
[
"https://www.reddit.com/r/AskHistorians/comments/5g326k/comment/dap70ii"
],
[
"https://www.reddit.com/r/AskHistorians/comments/a5ya3o/did_the_romans_know_that_the_great_pyramid_of/ebqjuwr?utm_source=share&utm_medium=web2x"
]
] |
|
4wrlje
|
if you wore an oxygen mask that simulates the elevation of 5,000 feet, would it make breathing at 6,000 feet easier, the same, or harder?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/4wrlje/eli5_if_you_wore_an_oxygen_mask_that_simulates/
|
{
"a_id": [
"d69bchq"
],
"score": [
3
],
"text": [
"I assume by \"oxygen man simulating 5,000 feet\" you are actually talking about a tanker full of normal air that has been pressurized to match that elevation, and not a tanker full of just oxygen. It would be easier. That is what any pressurized container meant for human life is trying to do. Airplanes are pressurized so they simulate ground-level pressure vs. the atmosphere at 20,000 feet up. Submarines are pressured so they simulate ground-level pressure vs. the ocean at 5,000 feet down."
]
}
|
[] |
[] |
[
[]
] |
||
oyl8p
|
the movie "primer."
|
Seriously -- my brain, she hurts.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/oyl8p/eli5_the_movie_primer/
|
{
"a_id": [
"c3l2roh",
"c3l36lu"
],
"score": [
2,
6
],
"text": [
"Not possible at all. I don't think it's possible to explain to a thirty year old.",
"In short: multiple time lines running parallel to each other. In long: See this image _URL_0_"
]
}
|
[] |
[] |
[
[],
[
"http://unrealitymag.com/wp-content/uploads/2011/09/primer-chart.jpg"
]
] |
|
2q5znk
|
Why can't the core of a star be "more" than iron?
|
Why for example we don't have mercury core stars or plutonium core stars?
|
askscience
|
http://www.reddit.com/r/askscience/comments/2q5znk/why_cant_the_core_of_a_star_be_more_than_iron/
|
{
"a_id": [
"cn3miwl",
"cn6iqfm"
],
"score": [
9,
2
],
"text": [
"A star is held up by the equilibrium between the inward force of gravity and the outward pressure of fusion energy. However, fusing iron or any heavier elements than iron doesn't produce a net output of energy, but rather extracts energy from the environment. So when that sort of reaction occurs in stars, it cannot sustain the equilibrium, and the star quickly collapses and undergoes a supernova, leaving behind a neutron star or black hole.",
"Elements heavier than iron *can* be produced by absorbing neutrons with a sufficient amount of energy.\n\nCertain nuclear reactions in a star produce high-energy neutrons. In small stars, the most common of these are:\n(1) H-2 + H-2 ---- > He-3 + n\n(2) H-2 + H-3 ---- > He-4 + n\n\nThese tend to be relatively rare compared to [other reactions involving hydrogen or helium.](_URL_1_)) In small stars, hydrogen-1 and helium-4 make up the overwhelming majority of the material in the star's core. \n\nIn stars appreciably larger than the sun, the main source of neutrons is one branch of the [C-N-O cycle.](_URL_0_) Note: The CNO cycle tends to account for most of the energy production in larger stars. \n\nThat is:\n(3) C-13 + He-4 ---- > O-16 + n\n\nIt starts out with iron absorbing several neutrons, then beta decaying into nickel, and so on.\n\nThis is known as the \"S-process\". typically, there is a time frame of several decades between each successive capture. "
]
}
|
[] |
[] |
[
[],
[
"http://astronomy.swin.edu.au/cosmos/c/cno+cycle",
"http://hyperphysics.phy-astr.gsu.edu/hbase/astro/procyc.html"
]
] |
|
60wmpy
|
How did the Soviet Union attempt to domestically and internationally justify plainly different standards of living between party leaders and ordinary citizens?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/60wmpy/how_did_the_soviet_union_attempt_to_domestically/
|
{
"a_id": [
"dfadvba"
],
"score": [
76
],
"text": [
"Followup and/or related question: how aware would the average soviet worker have *been* of the standard of living differences? "
]
}
|
[] |
[] |
[
[]
] |
||
3523up
|
Why do deep sounds seem to travel further?
|
With the same volume on speakers the bass and lows are always more audible and you can hear them farther is it designed like this? Do the sound-waves actually travel further, and if so why?
|
askscience
|
http://www.reddit.com/r/askscience/comments/3523up/why_do_deep_sounds_seem_to_travel_further/
|
{
"a_id": [
"cr0abhe"
],
"score": [
5
],
"text": [
"Low frequency waves are long. Quite long. Some take as much as 20-30 ft to fully develop. They go right through most walls, whereas high frequencies (very short wavelengths) get stuck in a pillow. It's the same reason why it takes so much more power to drive bass speakers than treble & midrange. "
]
}
|
[] |
[] |
[
[]
] |
|
1ylgjq
|
Why did all of the reptilian megafauna of the seas disappear?
|
askscience
|
http://www.reddit.com/r/askscience/comments/1ylgjq/why_did_all_of_the_reptilian_megafauna_of_the/
|
{
"a_id": [
"cflngec",
"cflngru"
],
"score": [
4,
2
],
"text": [
"Cretaceous–Paleogene extinction event was severe enough that highly specialized animals died out. Mammals survived because they were scavengers and could survive on a very broad died. Of course, other factors come into play. Large size always seems to be selected against during extinction events. Also, it is important to know that whales evolved [after the Cretaceous–Paleogene extinction event.](_URL_0_) ",
"A big chunk of their diversity was lost in the Cretaceous-Paleogene (K-Pg) extinction. A lot of marine reptiles like [mosasaurs](_URL_5_) and [plesiosaurs](_URL_8_) went extinct. The mosasaurs are interesting because they show up in the Early Cretaceous, exibit a big explosion in diversity, and then go extinct at the K-Pg boundary. \n\nHowever, the [ichthyosaurs](_URL_1_) and [pliosaurs](_URL_2_) (a type of plesiosaur), which get lumped in with other marine reptiles, are extinct before the K-Pg. \n\nSome marine reptiles make it through. Sea turtles first appeared at least as far back as the Cretaceous and are still around. [*Toxochelys*](_URL_4_) is an example of a Cretaceous sea turtle. [*Protosphargis*](_URL_3_) is even a genus belonging to the same family as the leatherback. \n\nSome crocodyliforms (crocodylians and their extinct relatives) survived, and a lot of them were pretty big. Crown-group crocs (Crocodylia) survived, but also groups like the [Dyrosauridae](_URL_0_), many of which were marine. [Choristoderes](_URL_7_) make it through and go extinct in the Miocene (~20 million years ago). We're not sure how choristoderes are related to other reptiles.\n\nWhales evolved after the K-Pg extinction. I wrote up a brief overview [here](_URL_6_).\n\n"
]
}
|
[] |
[] |
[
[
"http://en.wikipedia.org/wiki/Whale#Evolution"
],
[
"http://en.wikipedia.org/wiki/Dyrosauridae",
"http://en.wikipedia.org/wiki/Ichthyosaurs",
"http://en.wikipedia.org/wiki/Pliosaur",
"http://en.wikipedia.org/wiki/Protosphargis",
"http://en.wikipedia.org/wiki/Toxochelys",
"http://en.wikipedia.org/wiki/Mosasaur",
"http://www.reddit.com/r/askscience/comments/1k4j5e/does_the_hipbone_of_a_whale_have_any_function/cblbpfm",
"http://en.wikipedia.org/wiki/Choristodera",
"http://en.wikipedia.org/wiki/Plesiosauria"
]
] |
||
8x6blt
|
why when lying on my side, my brain prefers to watch parallel to the floor instead of parallel to my eyes?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/8x6blt/eli5_why_when_lying_on_my_side_my_brain_prefers/
|
{
"a_id": [
"e217ebw",
"e2191o5",
"e21bp4a"
],
"score": [
58,
57,
36
],
"text": [
"Your brain knows that you are lying on your side. It expects things to look rotated for the eyes. If they are not something is wrong.",
"Your brain is a very complicated machine that does a lot of things you're not aware of, especially with regard to processing images. Your brain figures out what's up and down based on visual cues and a special little gravity sensor inside your ear.\n\nFun fact, in an \\[experiment\\]([_URL_0_](_URL_0_)), a guy was able to completely adjust to seeing the world upside-down, through the use of mirrored glasses. It took the guy about a week, but when they took the goggles off, the \"normal world\" was as confusing and disorienting as the \"upside-down\" world had initially been.",
"Does it? I prefer to have it parallel to my eyes actually."
]
}
|
[] |
[] |
[
[],
[
"https://www.theguardian.com/education/2012/nov/12/improbable-research-seeing-upside-down"
],
[]
] |
||
1bd4yk
|
How close could a person get to the sun, realistically?
|
How close could someone get to the surface of the sun (in a space ship obviously) before heat or gravity destroyed him?
edit: Thanks for the replies, I've learned a lot!
|
askscience
|
http://www.reddit.com/r/askscience/comments/1bd4yk/how_close_could_a_person_get_to_the_sun/
|
{
"a_id": [
"c95tt60",
"c95u65v",
"c95vu15"
],
"score": [
5,
81,
23
],
"text": [
"That depends on the vessel, do you mean like in the space shuttle? ",
"I know the closest you can get to the sun on earth is mount chimborazo its not the tallest mountain in the world but it is the tallest one on the equator.",
"This is highly dependent on the space ship in question and how efficiently it can cool itself radiatively. At any rate, the [Helios II spacecraft](_URL_0_) currently holds the record for closest Solar approach by a human made artifact, at .29 AU (a bit inside Mercury's orbit). It wasn't carrying people, but it remained intact through many orbits (these orbits were elliptical, so .29 AU was closest approach)."
]
}
|
[] |
[] |
[
[],
[],
[
"http://en.wikipedia.org/wiki/Helios_(spacecraft\\)"
]
] |
|
3z6xr5
|
how exactly do we move our limbs and why don't we mimic our movement in robots?
|
I've always wondered what mussels have to move in my arm to pull my finger tendons and how that signal is sent from my brain, but can't seem to get a straight answer.
It seems pretty efficient so why don't we mimic it in robots instead of using motors?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/3z6xr5/eli5_how_exactly_do_we_move_our_limbs_and_why/
|
{
"a_id": [
"cyjpdxf"
],
"score": [
3
],
"text": [
"In order to move a muscle, we need to send a signal to a primary motor neuron. This specialized neuron controls groups of muscle fibers in one particular muscle, causing them to contract. When you want to consciously move a muscle you directly send a signal to the appropriate motor neuron which causes the action. We do it this way because we have other signals we want to control muscles; like reflexes or autonomous control. \n \nThe reason we don't make robots like this is because we already have motors that spin around an axis, but we don't have ones that constrict like muscles. We could build motors that function that way, but theres not a lot of incentive because the current system works as it is. I'm not an engineer or robotics expert so I can't get any more specific with this part of the question."
]
}
|
[] |
[] |
[
[]
] |
|
igblu
|
How do we determine when a common ancestor
lived?
|
For example: the last common ancestor between us and chimps is said to have lived between 6 and 8 mya, but a fossil of this animal has not (yet) been found, so we have got nothing to date. So how do we know it lived between 6 and 8 mya?
Also: if we want to know when, say, the last common ancestor between us and frogs lived, how would we determine this?
|
askscience
|
http://www.reddit.com/r/askscience/comments/igblu/how_do_we_determine_when_a_common_ancestor_lived/
|
{
"a_id": [
"c23ix1f"
],
"score": [
9
],
"text": [
"Using [molecular clock](_URL_4_) genetic dating methods, generally following [coalescent theory](_URL_5_). It basically works like this. If we take a chunk of DNA from a human and the same chunk of DNA from a chimp then the differences in these two strands of DNA is an approximation of the time depth of the ancestor of the two species. This difference is proportional to the rate of evolution of that chunk of DNA. \n\nNow, if we have some way of calibrating that rate of evolution we can turn this into a time estimate. There are two common ways of doing this. First is to use a fossil that dates some part of the family tree that neighbors the species we're interested in. So, for example, the next closest species to humans/chimps are Gorillas and then Orang-utans. If we have a fossil Orang at (from memory) 10-13 million years ago, and there are, say, 1000 changes in the DNA strands between humans and orangs, then we have a rate of about 1 mutation per 10,000 years. If we see 500 changes between chimps and humans then we can take the rate and extrapolate it. \n\nThe other alternative is to use a well-studied molecule where we have good estimates of the rate of molecular evolution. [Mitochondrial DNA](_URL_1_) is the most commonly used one for animals, and we have good evidence suggesting that it evolves at around one [transition mutation](_URL_2_) every ~6764yrs. So then it's just a matter of counting the changes. \n\nThings get much more complicated than that though, most people these days use some form of [Bayesian phylogenetic methods](_URL_0_) with a number of different \"relaxed\" clock models that handle variation in rates of change between sites in the DNA, or different rates across species, etc.\n\n(and we [do have fossil chimpanzees](_URL_3_), for the record)."
]
}
|
[] |
[] |
[
[
"http://en.wikipedia.org/wiki/Bayesian_inference_in_phylogeny",
"http://en.wikipedia.org/wiki/Mitochondrion",
"http://en.wikipedia.org/wiki/Transition_(genetics)",
"http://www.nature.com/news/2005/050831/full/news050829-10.html",
"http://en.wikipedia.org/wiki/Molecular_clock",
"http://en.wikipedia.org/wiki/Coalescent_theory"
]
] |
|
vhr4z
|
Why do you think people use the term "Native American" instead of referring to tribes individually? Is this fair?
|
I was recently reading a book by Edmund S. Morgan called *American Heroes* (really enjoying it so far by the way) and he has a chapter discussing Native Americans. In his book he points out that among the different Native American tribes, linguists recognize 375 different languages. We still, however, generalize all of these tribes into the category of "Native American." This sparked my curiosity. What do you think is the main reason that we do this? Is it simply for convenience or is it just generalizing history too much?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/vhr4z/why_do_you_think_people_use_the_term_native/
|
{
"a_id": [
"c54m1jf",
"c54mwt2",
"c54obyd",
"c54oh0o",
"c54rgqp"
],
"score": [
2,
2,
2,
3,
2
],
"text": [
"Well, for one, they are native to North America so the term fits in that sense. Secondly, the United States government recognizes [565](_URL_0_) different Native American tribes and having to memorize or distinguish based on this, especially when the physical differences between tribe are virtually non-existent (unlike the differences in race) makes it much easier to just use the blanket term, especially as it is still correct. One other reason could also be the lack of clearly defined regions and areas that Native Americans inhabit. While it is easy to define a Japanese person as hailing from Japan, and an Indian as hailing from India, the Native American tribes never had such defined borders and as such, cannot always be defined by where they lived. \n\nThis same usage of broad nomenclature is seen as well with people of Chinese descent but varying ethnicity. Despite differences in ethnicity, they are termed Chinese, most likely for simplicity's sake. ",
"Generally speaking there are far too many tribes to refer to them individually unless you are talking about an individual or a single tribe doing something. I think there are 500+ tribes recognized. ",
"Isn't the preferred term now American Indian?",
"I've taken to using the terms indigenous peoples or indigenous tribes when I'm not referring to a particular tribe or nation. This choice came after the realization that \"Native American\" was just as much a Euro-centric term as \"Indian.\" That being said, sometimes American Indian or Native American are simply the best terms to use because they can be easily recognized by a wider audience. ",
"The same reason we say European rather than be bothered naming every European country."
]
}
|
[] |
[] |
[
[
"http://en.wikipedia.org/wiki/Federally_recognized_tribes"
],
[],
[],
[],
[]
] |
|
75403n
|
astronomy question
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/75403n/eli5_astronomy_question/
|
{
"a_id": [
"do38oyq"
],
"score": [
2
],
"text": [
"Inverse square law-\n\nThe inverse-square law, in physics, is any physical law stating that a specified physical quantity or intensity is inversely proportional to the square of the distance from the source of that physical quantity. The fundamental cause for this can be understood as geometric dilution corresponding to point-source radiation into three-dimensional space.\n\n_URL_0_"
]
}
|
[] |
[] |
[
[
"https://en.m.wikipedia.org/wiki/Inverse-square_law"
]
] |
||
2gb3fm
|
What rules of the english language came into play when determining that some words had no plural form- e.g fish, deer, etc?
|
askscience
|
http://www.reddit.com/r/askscience/comments/2gb3fm/what_rules_of_the_english_language_came_into_play/
|
{
"a_id": [
"ckhnua0"
],
"score": [
7
],
"text": [
"Any \"rules\" of the English language are artificial constraints created a posteriori. English is the way it is because some people spoke that way and it became a *custom* (rather than a rule).\n\nThis becomes clearer when implementing [speech recognition and machine translation](_URL_0_). Rule based systems are brittle and don't work as well, while statistical approaches do much better. Statistical approaches basically work by compiling a huge database of how people actually talk and computing how common words and phrases *are* used (rather than how they are supposed to be used). "
]
}
|
[] |
[] |
[
[
"http://pangeamt.com/en/faq-about-machine-translation/q2-why-statistical-mt/#.VBT7_vldXwo"
]
] |
||
ebm4ns
|
In The Communist Manifesto, it's fairly accepted that Marx imagined the workers revolution to start in heavily industrialized nations. Yet the majority of former Communist States when their Revolutions happened were in primarily agricultural societies, why did this happen?
|
Specifically I think about how the Russian Empire at the time of the October Revolution wasnt as industrialized as the rest of europe. Or how China wasnt really industrialized at all with more examples in places like Vietnam and Korea. I Hesitate in including Eastern Bloc nations like Poland and Romania as they were sort of "coerced" into being communist states by the USSR.
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/ebm4ns/in_the_communist_manifesto_its_fairly_accepted/
|
{
"a_id": [
"fb7861k"
],
"score": [
8
],
"text": [
"I answered a [similar question](_URL_0_) a few months ago which talks about Marxism's application in the Russian Empire.\n\nThe short answer is that the October Revolution was almost entirely orchestrated in the nation's industrial capital, Saint-Petersburg (then called Petrograd) so Marx was right to a certain extent. Despite this, very few early Marxist thinkers (including Lenin himself) predicted that the socialist revolution would occur in Russia because of its largely agrarian society-- as you mention.\n\nLenin combated this diversion from Marxist orthodoxy by implementing certain language like 'rural proletariat,' to bring those outside the actual cities under the purview of his revolutionary aims. When that wasn't totally effective, the Bolsheviks just reverted to type and socialized the countryside by violence and coercion. There's several responses in that question beyond the initial answer that talk about this in pretty excruciating but I'm happy to answer any follow-up questions you might have."
]
}
|
[] |
[] |
[
[
"https://www.reddit.com/r/AskHistorians/comments/cykrhl/marx_predicted_workers_would_take_control_of_the/"
]
] |
|
3mqpfi
|
how alcoholic must your breath be to catch fire, and why does it even work?
|
[deleted]
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/3mqpfi/eli5_how_alcoholic_must_your_breath_be_to_catch/
|
{
"a_id": [
"cvh9p68"
],
"score": [
2
],
"text": [
"80 proof and above is generally flammable. Although I really don't see how this could happen, this would require actually inhaling some embers, which doesn't really happen when you smoke. \n\nFurther more, its going down different \"tubes\" the alcohol is going down through your stomach. \n\nSmoke goes through the respiratory system to your lungs, there wouldn't be much if any alcohol in your respiratory system to catch fire."
]
}
|
[] |
[] |
[
[]
] |
|
187h5b
|
why can't we capture light?
|
For example, why can't we take a perfectly round ball with mirrored insides and "capture" light. Or a cylinder and observe the light falling down with gravity as it circles around down the cylinder. I have a pretty firm grasp of physics and light so maybe not quite like I'm five. But this has always intrigued me.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/187h5b/why_cant_we_capture_light/
|
{
"a_id": [
"c8ca4nf",
"c8caul2",
"c8cbcvq",
"c8cc2le"
],
"score": [
4,
8,
3,
2
],
"text": [
"I'm a chemist, and not a physicist, so it's quite possible that I'll be wrong on some of these things. But I'll do my best.\n\nFirst, it is somewhat possible to capture light in the way you're suggesting, at least transiently. The problem is that matter absorbs light and turns it into an alternative form of energy. So the light bouncing around the solid will eventually all be absorbed and then... not be there anymore. You can make the box quite large, and then the light will \"last\" longer. After all, some light from the sun manages to travel millions of miles. I don't read much of the physics literature, but I'm sure somebody has published papers on the fabrication of a near perfect mirror for this application. \n\nAs for the second thing, I can think of two problems. First, you can't \"see\" photons. You see things that light reflects off of. If we could see light, then... well... we really couldn't see anything at all because our eyes would be overloaded. Light waves (and waves of all energies, too) are constantly whizzing around in every direction. Luckily, we don't see their motion. We rely on the fact that light bounces off of an object and goes into our eyes to identify things.\n\nAdditionally, I know that light is affected by mass, but you'd have to have A LOT of mass to affect it's trajectory. Ancient astronomers did beautiful scientific work while completely ignoring the fact that mass distorts the trajectory of light. A little metal ball or cylinder is hardly going to affect it. ",
"\"why can't we take a perfectly round ball with mirrored insides and \"capture\" light.\"\n\nThis was posted before in some science subreddit, and you could probably find it with a bit of searching. Even if you put light into a perfectly spherical mirror, it wouldn't be 'captured'. Some of the light energy would inevitably be converted to heat. \n\nYou can't beat the laws of thermodynamics. ",
"Okay, so you might now this already, but for others coming to this thread: photons (particles of light) aren't real. Not real like you or I or the ground or the air. They're something else entirely.\n\nThey come into being when an atom goes from an excited state into a less excited state. Technically, this is when an electron drops from a higher to a lower \"energy level\". These energy levels are strictly defined and electrons can only exist in one or the other, there's no in-between.\n\nSo when an electron drops from a high energy level to a lower one, it does so *instantaneously*, and creates a photon in the process. (Sidenote: the drop in energy dictates the wavelength, and thus the colour, of the light.) You might know that nothing can accelerate to the speed of light. Well, fortunately, from the moment that photon exists, it is *already* traveling at the speed of light, and it will continue to do so until it hits something. \n\nWhen it hits an atom, its energy is transferred into the electron/s, making them jump up an energy level (or two or three). Here's where we answer your question: the second law of thermodynamics says you can't have a perfect transfer of energy. When the receiving atom gets the photon, its electrons can't jump to a *higher* level, they can reach only the *same* or a *lower* level.\n\nSo, over time - and it would be a very short amount of time for any kind of vessel we would be building - the wavelength of the light would be getting longer and longer, and thus the energy would be getting lower and lower. Eventually, the energy of the light being emitted would be so low that it can't raise any electrons from their *ground state*, their lowest energy level.\n\n**But**, I hear you say, **but what about the conservation of energy? Energy can't be created or destroyed; it has to go *somewhere*.** Correct! It does.\n\nWhen a photon can't raise an electron from its ground state, all the energy is transferred into *heat*. Heat is really just atoms moving about on a small scale, so you can imagine the photons coming in and knocking the atoms about a little bit. So your vessel would be dark inside but slightly warmer.\n\nNote, because I can sense it already coming, that this is *not* infrared light. That's called \"radiant heat\", this kind of heat also has a name but it escapes me. Suffice to call it \"normal heat\". If the inside if your vessel is a vacuum, and I assume it is, then you inside it would not feel the heat; but if you touched the walls, you would. There would be a stage, when the wavelength of the light was becoming longer and longer, when some of the energy would be thrown around as infrared light, but after a while the energy is too low even for that. It ends up warming the vessel itself, not holding warmth *inside* the vessel.",
"Well I don't think I could give a satisfactory answer to a five year old, but maybe to a 10 year old?\n\nLight is a form of energy, and energy wants to disperse itself evenly throughout the universe (we call this idea entropy). If you put energy in a box, no matter how you make the box, eventually the walls will absorb the energy (you've never heard of a thermos that keeps things warm forever have you?).\n\nThe same applies to light. You perceive light energy with your eyes, and think of it as \"brightness\" but what you are really measuring is energy of a certain frequency. Like heat in a thermos, if you put light in a box, eventually it's energy will get absorbed by the walls of the container."
]
}
|
[] |
[] |
[
[],
[],
[],
[]
] |
|
7otdlw
|
What is the benefit to making new elements in labs?
|
Pretty much just the title. If these elements are not found in nature and are too difficult to create to have any practical use then why bother discovering them? Is it simply for the furthering of knowledge or is there another reason?
|
askscience
|
https://www.reddit.com/r/askscience/comments/7otdlw/what_is_the_benefit_to_making_new_elements_in_labs/
|
{
"a_id": [
"dsc4mov",
"dsckdr2",
"dscy84o"
],
"score": [
30,
2,
4
],
"text": [
" > Is it simply for the furthering of knowledge or is there another reason?\n\nIs that not enough?\n\nWe learn about nuclear structure, nuclear reactions, etc. If we can study them chemically, we can learn about atomic structure as well. These extremely heavy elements could have very interesting chemical properties.",
"There is a theorized \"island of stability\" for a few superheavy elements. The artificial elements that have been created and observed in the past few years have had extremely short half lives (MUCH less than a second), but some models suggest that even heavier elements will be more stable and will have longer half lives. These super heavy elements could have unique properties (since their density is likely to be much greater than elements we currently have access to). With unique properties comes unique applications. \n\nI would say that overall, however, this research is more for general knowledge and the prestige of pushing our limits. You get to name the new element, after all.",
"Some of the artificial elements found practical applications later. You might even have one in your house. Americium is used in some smoke detectors, among other applications.\n\nWe don’t have practical applications for elements with an atomic number over 100 today - but who knows what we will have in 50 years."
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
80riqs
|
active reading and why it's important to a reader
|
By the term "active reading", I'm referring to the reading technique that's usually done in English Literature classes.
I'd like to know what it is, what it involves, how one would mix it into their everyday reading, and why it is important.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/80riqs/eli5_active_reading_and_why_its_important_to_a/
|
{
"a_id": [
"duxniuc",
"duxnoqr",
"duxowiv"
],
"score": [
4,
2,
3
],
"text": [
"\"Active Reading\" is simply reading, but with an emphasis on paying attention to content and critically analyzing the text as you read, instead of just reading the words and moving on. \n\nIt's important as it gets a person to focus on the content of the text, it lets them identify unknown words or grammatical concepts to research further, it can arguably be helpful as a memorization tool since you are concentrating more on it, etc.",
"\"Active reading\" usually just means reading to understand what is important rather than just mindlessly reading. As for why it's important, I'm sure many of us have at one time or another read a page in a book a couple of times half heartedly before realizing we don't remember anything at all and putting the book down. That is the opposite of active reading and what happens if you don't read actively.\n\nThink of reading like a conversation. Which method makes you learn more; actively paying attention to the person talking to you or just zoning out while they drone in your ear? That's why active reading is important; it lets you quickly understand the parts of information in texts that are important and remember those instead of forgetting quickly.\n\nAs for techniques many of them are things many readers do already; things such as looking for key words, summarizing ideas in your head, or predicting what is going to come next can all work as active reading techniques.",
"One of my lit profs drilled into me that I needed to not only know what all the words on the page meant, but what they would have meant to the person writing them.\n\nI found a pocket etymological dictionary to be of invaluable help in understanding the correct period usage of words I was reading."
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
mv2l5
|
socialism vs. capitalism (and right-wing vs. left-wing)
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/mv2l5/eli5_socialism_vs_capitalism_and_rightwing_vs/
|
{
"a_id": [
"c342jf2",
"c3447l7",
"c342jf2",
"c3447l7"
],
"score": [
2,
2,
2,
2
],
"text": [
"Socialism is when the 'means of production' (factories, land, raw materials) are owned cooperatively. Either by groups involved in the production, or by the state on behalf of the people. either the products or the profits from their sale are distributed according to the group's plan.\n\nCapitalism is when the 'means of production' are privately owned. the product or the profits from its sale are distributed according the owner. ",
"At least in America, the Right Wing accuses the Left Wing of being Socialist as though it is an insult; and the Left wing accuses the Right Wing of being Capitalists as though it is an insult. My point is that in America these meanings are slightly warped when compared to how 'Socialist' and 'Capitalist' are used everywhere else.",
"Socialism is when the 'means of production' (factories, land, raw materials) are owned cooperatively. Either by groups involved in the production, or by the state on behalf of the people. either the products or the profits from their sale are distributed according to the group's plan.\n\nCapitalism is when the 'means of production' are privately owned. the product or the profits from its sale are distributed according the owner. ",
"At least in America, the Right Wing accuses the Left Wing of being Socialist as though it is an insult; and the Left wing accuses the Right Wing of being Capitalists as though it is an insult. My point is that in America these meanings are slightly warped when compared to how 'Socialist' and 'Capitalist' are used everywhere else."
]
}
|
[] |
[] |
[
[],
[],
[],
[]
] |
||
1xtzco
|
How does acidosis ( lactic, metabolitic etc) cause some one to go in to a coma?
|
It't should be a simple question but I can't quite get to the bottom of it. Any ideas?
|
askscience
|
http://www.reddit.com/r/askscience/comments/1xtzco/how_does_acidosis_lactic_metabolitic_etc_cause/
|
{
"a_id": [
"cfeo92s"
],
"score": [
10
],
"text": [
"I've looked into this for you, and the conclusion is this is poorly understood.\n\nWith that said, there are a quite a few apparent effects of acidosis that would likely contribute to neurological impairment, which I'll detail for you. \n\nThe first (and in my opinion most important in this case) effect of acidosis is on the heart, not the nervous tissue. There is a wide body of evidence that notes that blood pH falling below 7.2 results in a reduced cardiac contractility, and also bradycardia. This fall in the activity of the heart frequently doesn't meet the criteria for cardiogenic shock, but is an important factor. Compounding the decreased cardiac activity is systemic arteriodilation with hypotension. This leads to a circulatory collapse over the period of a few hours in a manner not attributable to shock.\n\nFollowing this circulatory collapse, acidotic patients are at risk of developing cardiac arrhythmias which would further decrease cerebral perfusion.\n\nThe factors discussed so far explain a reduction in cerebral blood flow, but the actual oxygen delivered by each unit of blood may be compromised, too. An increase in hydrogen ions and CO2 both shift the oxygen dissociation curve of haemoglobin to the right; they decrease the amount of oxygen bound to haemoglobin at a given partial pressure of oxygen. In practical terms, this means that haemoglobin is less able to carry oxygen to the tissues.\n\nThis paints the picture of inadequate oxygen delivery to the brain. In addition to this, it's likely that the brain is less able to generate ATP. The brain's primary source of energy is glucose, which is broken down by glycolysis. One of the key enzymes in this process is phosphofructokinase. The activity of this enzyme is pH dependent, and an acidic environment significantly slows its action. \n\nFinally, the excitability of neurones is decreased by an acidic environment. Putting all these factors together results in the brain receiving inadequate oxygen, inadequate nutrients, slow metabolism and then an inability to use what energy it has quickly. This surely results in impaired cognition and potentially lethargy and coma. "
]
}
|
[] |
[] |
[
[]
] |
|
2lyxx4
|
How much Western pop culture (movies, music, etc.) was allowed in the USSR and Warsaw Pact countries?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/2lyxx4/how_much_western_pop_culture_movies_music_etc_was/
|
{
"a_id": [
"clzfcpj",
"clzju8z"
],
"score": [
5,
4
],
"text": [
"I remember a thread about music in the USSR - _URL_0_",
"hi! you'll find some responses regarding films in these posts\n\n* [What was the public perception of Cold War films such as Dr Strangelove in the Soviet Union?](_URL_3_) - includes a link to a list of all foreign films screened in the USSR\n\n* [Were the best Soviet film directors such as Tarkovsky able to see films unavailable to the general public of the USSR?](_URL_1_)\n\n* [During the cold war, were American films available in the USSR, and vice-versa?](_URL_2_)\n\n* [What was the attitude towards non-political or left-wing foreign literature or movies in the USSR?](_URL_0_)"
]
}
|
[] |
[] |
[
[
"http://www.reddit.com/r/AskHistorians/comments/26z28q/theres_an_episode_of_doctor_who_set_on_a_russian/"
],
[
"http://www.reddit.com/r/AskHistorians/comments/1ym45b/what_was_the_attitude_towards_nonpolitical_or/",
"http://www.reddit.com/r/AskHistorians/comments/2bvakt/were_the_best_soviet_film_directors_such_as/",
"http://www.reddit.com/r/AskHistorians/comments/2gec6r/during_the_cold_war_were_american_films_available/",
"http://www.reddit.com/r/AskHistorians/comments/2hf2q4/what_was_the_public_perception_of_cold_war_films/"
]
] |
||
5wg44w
|
why do hdr videos require more processing?
|
Why does it require a good hardware for playback?
[edit] I was referring to the hardware required for playback
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/5wg44w/eli5_why_do_hdr_videos_require_more_processing/
|
{
"a_id": [
"de9stga"
],
"score": [
2
],
"text": [
"HDR is more information between the darkest and brightest points. The greater information per-frame means it takes longer to load, and better hardware to process."
]
}
|
[] |
[] |
[
[]
] |
|
39dafn
|
Does California's sinkhole problem magnify its precarious position on the fault lines as well as being in the subduction zone in speeding up its descent into the ocean?
|
It's an odd question I suppose, but I read this article today: _URL_0_ and it got me thinking if this would be additive or neutral. Also, I mean the article seems to indicate that man has a direct impact on this. Is the problem overstated?
|
askscience
|
http://www.reddit.com/r/askscience/comments/39dafn/does_californias_sinkhole_problem_magnify_its/
|
{
"a_id": [
"cs2untd"
],
"score": [
2
],
"text": [
"I'm not sure I understand the question... what subduction zone do you mean? And where in the article is any reference to fault lines? California is not descending into the ocean. \n\nThe drought might impact the San Andreas fault slightly as water can work as a lubricant in [strike-slip faults](_URL_2_) so there are more, but weaker earthquakes, which might mean fewer but larger earthquakes in the case of such a heavy and deep reaching drought. \n\nFurthermore, the water depleted valleys sink in relation to the surrounding mountains, but due to [isostatic response](_URL_1_), the region of the plate floats, so overall, California gets deeper valleys where the groundwater is depleted and the danger from flooding (due to heavy rains and snow melt) increases in these areas but the region will not sink into the ocean from it. Near the coast, there is also [saltwater instrusion](_URL_0_) that refills the aquifers with water that cannot be used in agriculture so those areas won't sink much from the missing groundwater. They might be flooded, however, by sea level rise one day. \n\nSource: Geohazards lecture a few years ago, so feel free to correct me. "
]
}
|
[] |
[
"http://m.motherjones.com/environment/2015/06/california-sinking-drought-ground-water"
] |
[
[
"http://en.wikipedia.org/wiki/Saltwater_intrusion",
"http://en.wikipedia.org/wiki/Isostasy",
"http://www.abag.ca.gov/bayarea/eqmaps/fixit/ch2/tsld003.htm"
]
] |
|
7bvtau
|
how does hydraulic fracturing work? and what are the pros and cons of the process.
|
[deleted]
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/7bvtau/eli5_how_does_hydraulic_fracturing_work_and_what/
|
{
"a_id": [
"dpl4x5j",
"dpl50o8"
],
"score": [
2,
2
],
"text": [
"You drill a hole into a rock formation containing tiny pockets of trapped natural gas. Then you pump a mixture or water, solvents, and tiny bits of sand into the hole. You pressurize the liquid at high pressure, fracturing the rock and wedging the little bits of sand into the cracks. When you let the pressure off, the natural gas comes out, and you capture that and sell it. It pushes the liquid out, so you store that and then pump it in again and again until you've cracked all the rock and release/harvested all the gas.",
"Water is incompressible, so if you have a cubic meter of 'stuff' (dirt, stone, oil, gas) and you force water (fracking liquid is mostly water) into it, you'll get out a slurry of stuff mixed with the fracking fluid out. You can then filter it to get the oil/gas you want. \n\nIt's a way to drill for oil/gas in deposits that are not easily tapped with traditional oil wells, but is more costly than normal oil well drilling and has some environmental concerns related to groundwater, small earthquakes, etc. That being said the price of oil is relatively low at the moment and fracking is not that profitable at this trough in energy markets, so you're seeing less fracking and thus less env issues."
]
}
|
[] |
[] |
[
[],
[]
] |
|
1ijh2m
|
If I replace multiple light bulbs at the same time why do they burn out at different times?
|
askscience
|
http://www.reddit.com/r/askscience/comments/1ijh2m/if_i_replace_multiple_light_bulbs_at_the_same/
|
{
"a_id": [
"cb5280v",
"cb53nfg"
],
"score": [
3,
2
],
"text": [
"Light bulbs are made to last within a certain tolerance. \n\nExample: 100 light bulbs are manufactured to last 1000 hours. But in reality most of those light bulbs won't last 1000 hours. Some will last more, some will last less. So you might get 90 of those light bulbs that last between 950 to 1050 hours. The other 10 are outliers.\n\nIt is nearly impossible to produce all light bulbs as equals. And even if you could they would have to fall within a certain range of \"hour life\", as statistically it can be proven that they chance of every light bulb lasting exactly 1000 hours is zero. ",
"Consider also *why* lightbulbs fail. When a tungsten filament is made, it isn't perfect. They are undetectable when the lightbulb is made, but over time these defects will grow under the stress of heating and cooling, and eventually will cause the filament to burn out. As a result, tiny differences between light bulbs can cause large differences in how long they last."
]
}
|
[] |
[] |
[
[],
[]
] |
||
9g181m
|
are all physical traits “inherited”, or are some of them random?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/9g181m/eli5_are_all_physical_traits_inherited_or_are/
|
{
"a_id": [
"e60nvqg",
"e60qglk"
],
"score": [
5,
2
],
"text": [
"Some of them are random - that’s actually how evolution works.\n\nThe way your body grows is defined in a set of rules stored in each cell, which is your DNA. When your body makes new cells (as you’re growing, or when you need to heal a wound), that DNA has to be copied to the new cell. Sometimes errors occur during this copying process, and these are known as ‘mutations’.\n\nSome mutations are good, such as an immunity to a deadly disease. Some mutations are bad, such as those which result in cancer.",
"When animals breed, they have mutations because the biological process is imperfect. Sometimes proteins get switched around or changed.\n\nIf those mutations (changes) don't kill anything, then they are passed down (maybe) to the next generation, in which case those changes become inherited, rather than an on-the-fly mutation.\n\nSome physical traits can occur in the womb during the gestation of the animal.\n\nbut in terms of evolution, mutations happen (imperfect system), and if there are beneficial mutations, say, a better immune system, they will be passed on and increased in frequency in the animal's population. Then they'll continue in the population to be inherited."
]
}
|
[] |
[] |
[
[],
[]
] |
||
1zw8uk
|
would an airplane be affected if it flew over land that was experiencing a massive earthquake (i.e. over 9.0)?
|
In other words, would the earthquake on the ground affect anything in the air that would affect anything in the sky?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1zw8uk/eli5_would_an_airplane_be_affected_if_it_flew/
|
{
"a_id": [
"cfxj81c",
"cfxmzgd",
"cfxnqx3"
],
"score": [
6,
2,
16
],
"text": [
"Earthquakes in maritim regions can cause floods and Tsunamis, which in turn have a strong influence on local winds. Those can possibly influence airplanes close to the ground. I can't imagine an airplane being affected by earthquakes when it flies at its normal transition height of around 10-15 km and neither when its above large areas of solid grounds.\nEdit: If the earthquake comes with volcaninc eruptions, it's another story. But in that case, we have one cause (volcanic eruption) and independent consequences (1: earthquake, 2: a lot of air movement above the vulcan, 3: etc.)",
"Unless you were flying low, the only time an earthquake could effect an aircraft is if there was a volcanic eruption as ash would be able to reach the altitudes that an aircraft flies at.\n\nPlanes have been effected before by this, for example, British Airways Flight 9.\n\n_URL_0_",
"Speaking as a pilot, and I am, the simple answer is NO. As soon as the plane is off the ground, the ground can shake all it wants. The air will be not be affected by the ground enough to cause any issue with the plane. So far the answers have been over thinking the basic question."
]
}
|
[] |
[] |
[
[],
[
"http://en.wikipedia.org/wiki/British_Airways_Flight_9"
],
[]
] |
|
ybvie
|
Does the discovery of the Higgs help create a better defenition of mass
|
As i understand it, the kilogram is a block in paris that we measure every once and awhile, but we don't have a succinct definition of what a kilogram is. Does the discovery of the higgs help us define this quantity?
|
askscience
|
http://www.reddit.com/r/askscience/comments/ybvie/does_the_discovery_of_the_higgs_help_create_a/
|
{
"a_id": [
"c5u6e63"
],
"score": [
2
],
"text": [
"Not really, for a couple of reasons: The Higgs field provides a mechanism for fundamental particles to have mass, but it says nothing about why diffenent particles have the masses they do. That has to be added by hand. Also, the Higgs field is not the only source of mass, and most of the mass of everyday things comes from QCD binding energy, not the Higgs field."
]
}
|
[] |
[] |
[
[]
] |
|
23rxvo
|
How hard would you have to press your fingertips together to kill the bacteria between them through sheer pressure?
|
Is it possible to "squish" a single-celled organism through human or mechanical strength? Or is there too much space between two surface to actually harm them? I'm curious.
|
askscience
|
http://www.reddit.com/r/askscience/comments/23rxvo/how_hard_would_you_have_to_press_your_fingertips/
|
{
"a_id": [
"ch04j0k"
],
"score": [
6
],
"text": [
"If you had a perfectly smooth surface, I don't see any reason why you couldn't crush them. However, what looks smooth to us is probably not smooth on the size scale of bacteria — most of them would probably be slid out of the way into crevices in the surface — think trying to crush M & Ms with a slotted spoon. "
]
}
|
[] |
[] |
[
[]
] |
|
1ej9sc
|
What are the largest animal populations on Earth?
|
askscience
|
http://www.reddit.com/r/askscience/comments/1ej9sc/what_are_the_largest_animal_populations_on_earth/
|
{
"a_id": [
"ca0rz14"
],
"score": [
2
],
"text": [
"Many insects have numbers in the trillions, and biomasses far surpassing ours. We have much greater numbers than any other large mammal. A few birds also outnumber us."
]
}
|
[] |
[] |
[
[]
] |
||
3am7sd
|
what is going on inside my phone that causes it to freeze?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/3am7sd/eli5_what_is_going_on_inside_my_phone_that_causes/
|
{
"a_id": [
"csdwbz0"
],
"score": [
2
],
"text": [
"There are a lot of different things, but basically it's the same reason computers occasionally freeze - lack of system resources or a critical error in core code. Because we keep pushing technology forward towards more features and more power, we never have time to optimize code and operating systems to remove ALL of the bugs that are in them, for perfect reliability. Intermittent issues that can be solved with a reboot is a price that consumers have shown they're willing to pay, so companies have little to no incentive to perfect systems."
]
}
|
[] |
[] |
[
[]
] |
||
2kc8i8
|
There's an episode of ST:TNG where Picard tells Wesley that before Marco Polo most people in Europe didn't know whether or not China really existed. That's not true ....right?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/2kc8i8/theres_an_episode_of_sttng_where_picard_tells/
|
{
"a_id": [
"clk4fqw",
"clk4vgw"
],
"score": [
11,
23
],
"text": [
"The Romans where aware of the Han Dynasty and traded Silk, wine and olive oil. What they knew about each other was limited by the sheer distance that separated them. The western Roman Empire probably did little trade with China the parts of Rome closer to Persia probably did most of Rome's trade with China. \n\n[A map of the world by Ptolemy, in the east of the map is \"Sinae\" China.](_URL_0_)\n\n[Chinese description of Rome and there products.](_URL_2_) \n\nAlso check this question out _URL_1_",
"Codswallop. Marco Polo's father and uncle had been to China before him; Venetian and other Italian traders had dealt in Chinese goods for centuries. Marco Polo was the just the first to write about it, exposing his travels to a wider audience. However, the popularity of his book also has to do with the fact that he made a lot if things up (admittedly, he also did some fairly remarkable things when he was there).\n\nFurther, as posters have noted below, some, sporadic knowledge of China had existed since Roman times."
]
}
|
[] |
[] |
[
[
"http://upload.wikimedia.org/wikipedia/commons/2/23/PtolemyWorldMap.jpg",
"http://www.reddit.com/r/AskHistorians/comments/2306e8/just_read_the_faq_got_intrigued_by_contact/",
"http://depts.washington.edu/silkroad/texts/hhshu/hou_han_shu.html#sec11"
],
[]
] |
||
lx4ki
|
What is the biggest earthquake the Earth is capable of producing?
|
askscience
|
http://www.reddit.com/r/askscience/comments/lx4ki/what_is_the_biggest_earthquake_the_earth_is/
|
{
"a_id": [
"c2wa8m6",
"c2wa8m6"
],
"score": [
12,
12
],
"text": [
"The largest earthquake every recorded was about a magnitude 9.5. Magnitude is largely controlled by the maximum stress rock can sustain. Higher magnitude quakes aren't really possible because the rocks will break before the stresses can build high enough to make a larger quake.\n\nThis topic was covered in detail in [this thread](_URL_0_) about 6 months ago.",
"The largest earthquake every recorded was about a magnitude 9.5. Magnitude is largely controlled by the maximum stress rock can sustain. Higher magnitude quakes aren't really possible because the rocks will break before the stresses can build high enough to make a larger quake.\n\nThis topic was covered in detail in [this thread](_URL_0_) about 6 months ago."
]
}
|
[] |
[] |
[
[
"http://www.reddit.com/r/askscience/comments/g1y4b/the_most_powerful_earthquake_in_recorded_history/"
],
[
"http://www.reddit.com/r/askscience/comments/g1y4b/the_most_powerful_earthquake_in_recorded_history/"
]
] |
||
3a0ruz
|
what happens in my brain when i get inspired?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/3a0ruz/eli5what_happens_in_my_brain_when_i_get_inspired/
|
{
"a_id": [
"cs8amsc"
],
"score": [
2
],
"text": [
"i don't know for sure, but it would make sense to me (again no idea on the science), but synapses fire that trigger parts of the brain that release endorphins which make you feel good and happy about it. the more inspired, the more synapses fire the more endorphins released"
]
}
|
[] |
[] |
[
[]
] |
||
5o5xj4
|
why do domestic trailers have less material than international ones? why not just use the international trailer for foreign and domestic audiences, especially when youtube exists?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/5o5xj4/eli5_why_do_domestic_trailers_have_less_material/
|
{
"a_id": [
"dcgu1kp"
],
"score": [
2
],
"text": [
"Trailers are often made to appeal to a specific audience.\n\nFor the most part, trailers for western countries will all be the same, but you may see some difference in trailers for Japan and China, as those audience have different tastes for films and content then western audiences, and if the film contains asian actors, they would often be incorporated more into the trailers, while they may not be given any additional time in the western ones. \n\n Other than that, if you do see other differences in western countries, they will be very minor, and again, just made to appeal to the audience who its target at."
]
}
|
[] |
[] |
[
[]
] |
||
43ypsc
|
What would happen if you frayed the ends of hundreds of small wires connected to two ends of a battery, and brushed them together?
|
askscience
|
https://www.reddit.com/r/askscience/comments/43ypsc/what_would_happen_if_you_frayed_the_ends_of/
|
{
"a_id": [
"czm2qge"
],
"score": [
11
],
"text": [
"You'd be creating a short circuit, with consequences possibly including a damaged battery, melting insulation / vaporized or molten wire / fire, and a chemical hazard, depending on the battery chemistry and the exact nature of your setup. \n \nTo start with, let's say that there's only one wire attached to each end of the battery. The wire happens to be two 6\" lengths of [22 AWG](_URL_2_), and is attached to the terminals of a 9 V (alkaline) battery. Looking at that table, we can see that the resistance of the wire (both pieces in series) will be 16.14 mOhms - that is, 0.01614 Ohms. [Ohm's Law](_URL_3_) tells us that V = I x R -- that the difference in electric potential (voltage) is equal to the amount of electrical current flowing multiplied by the resistance. \n \nIn this situation, V and R are known, and I can be calculated. In addition to the wire resistance, the 9 V battery has some internal resistance - about 1 Ohm, which saves us from complete disaster. So I = V / R, and the current is about 9 Amps. Going back to the AWG table, the wire shouldn't melt or vaporize (although it will probably become noticeably hot), and might melt through the cheaper types of insulation. The battery, since it's probably [not expected to handle 9 A of current](_URL_0_), will become very hot and unhappy, possibly igniting. If the battery didn't have any internal resistance, then we'd be looking at a current of well over 500 A - ten times what it would take to melt the wire! \n \nPulling that much current out of a battery / through a wire causes them to heat up, as the electrons try to move and collide with inconveniently placed atoms. More current ~ more collisions ~ more heat.\n \nAll things considered, alkaline batteries are fairly safe in this scenario - they'll (more or less safely) self-destruct instead of providing a ridiculous amount of current, and you probably won't be exposed to any nasty chemicals. A car battery, on the other hand, has a smaller internal resistance (~0.01-0.001 Ohms), and can handle lots of current. With a car battery, you'd easily melt the wires - although, if you short the car battery with large enough wires that can handle the current, you'll damage the battery and probably wind up with vented hydrogen gas and a good chance of a fire / worse. \n \nBack to your original question! Lots of tiny wires, random battery, and shorting the wires together. [Fire](_URL_1_). The wires will *probably* burn out quickly enough to avoid damaging the battery."
]
}
|
[] |
[] |
[
[
"http://data.energizer.com/PDFs/522.pdf",
"https://youtu.be/HjWSV1LY_so?t=1m8s",
"https://en.wikipedia.org/wiki/American_wire_gauge#Tables_of_AWG_wire_sizes",
"https://en.wikipedia.org/wiki/Ohm's_law"
]
] |
||
7utstl
|
the new memo release and what it means
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/7utstl/eli5_the_new_memo_release_and_what_it_means/
|
{
"a_id": [
"dtn2ubw"
],
"score": [
3
],
"text": [
" > Is this release as bad as they say?\n\nWho is \"They\"?\n\n > What does it mean?\n\nIt means we know nothing we didn't already know. The FBI used in part, a democratic-funded dossier as evidence to obtain warrants to conduct surveillance against Carter Page. Related information much later was found to be false Republicans claim that the dossier was a central part of why they obtained a warrant and thus the FBI is allowing democrats to (extremely) indirectly fund surveillance against republicans. The FBI is claimng this memo willfully omits key facts - which could include anything up to and including numerous other facts they had that would have justified surveillance making the entire issue a moot point.\n\nFurthermore, almost everyone involved in approving said surveillance was appointed by Trump so the concept that this is a Democratic plot relies on this idea that there's secret sub-organizations within the FBI so powerful that they're more powerful than the director, deputy director, etc etc etc - all appointed by Trump.\n\nSo basically the memo says things we already knew for months, and means absolutely nothing in and of itself. "
]
}
|
[] |
[] |
[
[]
] |
||
6hetvb
|
If there are magnetic field lines are there gravitational field lines also?
|
If there are what is the significance of them and how do field lines relate to the waves in electromagnetic and gravitational fields?
|
askscience
|
https://www.reddit.com/r/askscience/comments/6hetvb/if_there_are_magnetic_field_lines_are_there/
|
{
"a_id": [
"dixr0rt",
"dixr6hd"
],
"score": [
7,
65
],
"text": [
"In Newton's theory of gravity, you can definitely define gravitational field lines. The reason they aren't used very much is that they aren't as useful as magnetic field lines are, for two reasons:\n\n1. Magnetic field lines can be seen directly. For instance, plasma is often frozen onto magnetic field lines, as in this [example on the Sun](_URL_0_). You can use a magnet to force iron filings to align with the magnetic field. In contrast, the gravitational field is much less useful directly.\n\n2. Newtonian gravity has no speed limit. There was never any need to use a field to transfer the force from one place to another, because Newtonian gravity is instantaneous. Note that electrostatics (Culomb's Law) is also instantaneous, so electric field lines were not invented until after magnetic field lines were invented.\n\n3. (related to the second) There are no (Newtonian) gravitational waves. Fields become necessary (as opposed to just useful) when they carry significant energy independently of matter. Light is an electromagnetic wave which can only be understood classically in terms of a field. There are no free gravitational waves in Newtonian theory, because Newtonian gravity is instantaneous. ",
"Yes. Similar to how magnetic field lines give some indication of which way a dipole will orient at that location and how strongly, and electric field lines indicate the direction of force a positive charge would experience, gravitational field lines indicate the strength of gravitational force a mass would experience at a particular location. \n\nIn the case of the Earth, these gravitational field lines would point towards the center of the Earth, and converge(indicating more force) as a mass moves toward the surface.\n\nKeep in mind these field lines are just visual depictions of the field. They aren't \"real\" in the way gravity is real, just representations. "
]
}
|
[] |
[] |
[
[
"https://en.wikipedia.org/wiki/Corona#/media/File:Traceimage.jpg"
],
[]
] |
|
18v2sk
|
Why did some Jews get out of Germany before the WWII and others stayed behind?
|
Einstein was able to get out. Was it the rich and well educated? Was it the young and encumbered?
this piece give some detail but not really what I'm looking for _URL_0_
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/18v2sk/why_did_some_jews_get_out_of_germany_before_the/
|
{
"a_id": [
"c8i98m9"
],
"score": [
5
],
"text": [
"Many, many reasons.\n\nUnlike what the Nazis were claiming the \"Jewish\" people of Germany considered themselves to be just as German as non Jewish people considered themselves to be. It was their home. They had a stake in it. I say \"Jewish\" because there were laws which determined if one was Jewish or not and you didn't have to consider yourself as Jewish to be Jewish under the law.\n\nFor those who wanted to leave was the problem of being able to afford to do so, being allowed to do so and finding somewhere to take you. The US was a popular destination but the US had immigration quotas. Other countries in Europe were also in a number of ways antiSemetic (obviously not to the extent of the Nazis) and so limited the numbers of Jewish people they would take, if they would at all."
]
}
|
[] |
[
"http://www.ushmm.org/wlc/en/article.php?ModuleId=10005468"
] |
[
[]
] |
|
16s3o8
|
How did gold atoms coalesce into relatively homogenous nuggets rather than mixing with other elements as the solar system formed?
|
It's my understanding that gold atoms can only be fused in the heat and pressure from very large supernovae. Wouldn't these atoms form one by one randomly throughout the volume of the dying star? How is it that we find nuggets of gold rather than just random gold atoms interspersed throughout the crust of the earth? Do gold atoms attract each other when floating freely in space after a supernova or do large quantaties of gold atoms fuse together in pockets of just the right heat, pressure, and lighter elements as the star explodes?
|
askscience
|
http://www.reddit.com/r/askscience/comments/16s3o8/how_did_gold_atoms_coalesce_into_relatively/
|
{
"a_id": [
"c7yv9t1",
"c7yxzz0"
],
"score": [
3,
2
],
"text": [
"_URL_0_\n\nThose nuggets form later",
"When the early earth differentiated, almost all the gold was taken in to the core. The current gold on the surface is due to later meteorite bombardment, see _URL_0_ on how we figured that out.\nSo now we have random gold on the crust, but still too dispersed to be of any use to us. It has to be subducted and remelted to start the process of enrichment. \n\nAfter it is melted this way, it is in the the form of a pluton( a big hunk of magma that does not make the surface) or on the surface. It is still spread out in a very homogeneous way, we have to make real deposits for it to be economical. How do we do that? Lots and lots of hot water.\n\nThis water will essentially dissolve the gold from the original rock and move it to another area. What causes the gold to come out? The water either cools or come to some other chemical change that causes the solubility of gold in that water to change. It will start dropping the gold off there and start to make a deposit. This is the basic process for all gold deposits. You can further enrich the concentration of gold in something by weathering out the lighter stuff and using rivers etc to move that heavy gold even more concentrated.\n\nThe previous is our old understanding of gold deposits, but it has issues. A lot of current gold deposit work is going on the awesomely named field of geomicrobiology. They have found evidence that bacteria play a huge role in gold ore deposits, but honestly I know very little about how this process works."
]
}
|
[] |
[] |
[
[
"http://en.wikipedia.org/wiki/Ore_genesis"
],
[
"http://www.nature.com/nature/journal/v477/n7363/full/nature10399.html"
]
] |
|
68wq28
|
why dixon ticonderoga pencils can erase better than other pencils.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/68wq28/eli5_why_dixon_ticonderoga_pencils_can_erase/
|
{
"a_id": [
"dh1y01a"
],
"score": [
11
],
"text": [
"You kids should stop playing with rubbers.\n\nSerious answer, it has to do with the composition of the rubber. I've noticed that the rubber on those erasers rolls off it into little cylinders. This is important because it increases the surface area of the rubber. Imagine wiping up a desk with a Clorox wipe. You use one side until it's black. What do you do? You flip it over and use the other side! The rolling effect of the rubber flips the dirty side and the clean side, and because the rubber is strong enough to remain connected to itself, you can roll those little suckers around and wipe up your mistakes! \n\nOn other lower quality erasers, the rubber doesn't quite hold together and just kinda breaks apart and disintegrates(not a literal disintegration, but it gets the point across). Now you have all these tiny itsy bitsy chunks which in theory have more surface area than the cylinders from before because they can use their sides and front and back and top and bottom, whereas the cylinders can only use front and back. Buuuuut, because the chunks break apart and scatter (and because there is no compression force acting upon them) they don't do shit. They don't have the structural integrity to withstand the pressure you are applying to them, so they they turn into dust and make it even more difficult to erase things."
]
}
|
[] |
[] |
[
[]
] |
||
1xoo6e
|
if humans are really that bad a multitasking, how can people sing and play an instrument at the same time?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1xoo6e/eli5_if_humans_are_really_that_bad_a_multitasking/
|
{
"a_id": [
"cfd8bki",
"cfd8cyz"
],
"score": [
4,
3
],
"text": [
"They're *good* at multitasking if the two tasks can be done with different parts of the brain.\n\nThis is why you can drive a car and carry on a conversation with ease, but you can't tap two different rhythms with your hands.",
"Because to an experienced musician, both singing and playing an instrument come so naturally that they require very little conscious thought - or sometimes, the conscious thought all goes into the singing, and playing the guitar or piano or whatever just happens automatically.\n\nA good analogy would be having a conversation while driving a car. If you've been driving for 10 years, it's easy to have a conversation with someone even as you change lanes, put on a turn signal, adjust your speed with traffic, and so on. If you've been a professional musician for years and that's included singing and playing an instrument, it's easy to sing while playing an instrument too.\n\nAlso, note that the singing and playing are both the same song, and they're very much related. The musician has to think about the part to sing and the parts to play, but they fit together.\n\nSinging one song while playing another would be *very very* hard. Maybe not impossible, but it'd require lots of practice and probably wouldn't be very good. That's the kind of thing that's meant when we say humans are bad at multitasking.\n"
]
}
|
[] |
[] |
[
[],
[]
] |
||
45wrsq
|
What all did Einstein's theory of special relativity predict?
|
[deleted]
|
askscience
|
https://www.reddit.com/r/askscience/comments/45wrsq/what_all_did_einsteins_theory_of_special/
|
{
"a_id": [
"d00zcdm"
],
"score": [
2
],
"text": [
"Einstein's special theory of relativity, which he published in 1905, said nothing about gravity, black holes, etc. That all came from the general theory of relativity, which was published a decade later.\n\nSpecial relativity includes such effects as time dilation, Lorentz contraction, the relativistic velocity addition formula, simultaneity not being an absolute notion, and the notion of rest mass as a form of energy, among other things."
]
}
|
[] |
[] |
[
[]
] |
|
855tbh
|
why does gps need almanac data?
|
Been reading about GPS recently but this confused me a bit. Why isn’t time and ephemeris sufficient to triangulate position? Sure it gives the rough position of the satellites so that the GPS knows which signals to listen for, but can it not just listen for all satellites?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/855tbh/eli5_why_does_gps_need_almanac_data/
|
{
"a_id": [
"dvuxqca",
"dvuyews",
"dvv3kfr"
],
"score": [
3,
3,
2
],
"text": [
"It could, but that would mean a lot more processing. Almanac data is almost always available, so it is much more efficient to use that instead of listening to everything and then figuring things out from there.",
"You could listen for all the satellites at the same time, but it takes up a lot of signal processing power. GPS satellites transmit almanac data every 12 minutes so your GPS receiver knows which satellites to look for. In military applications it also makes it harder to spoof as military receivers can listen for an encrypted signal and will ignore signals from satellites that aren't supposed to be visible.",
"The problem with GPS signals is that they are extremely faint, and they are all transmitted on the exact same frequency using a \"spread spectrum\" approach. On top of that, the satellites are in orbit, so will have widely varying Doppler shifts affecting both the signal frequency and the code frequency/phase. The code sequence for each satellite is published in advance and built into the receiver firmware.\n\nYou cannot even detect a GPS signal unless you know the frequency, code and the code phase in advance. Once you know the frequency, code and code phase, you have to use a long (1 second+) averaging process to collect many signal samples and average them out to confirm a detection.\n\nIn practice, the code phase can't be known in advance. So you have to brute force search for the code phase. The problem is that each search requires a long averaging period. So, you really, really do not want to have to brute force search the frequency and code as well. So, having an almanac allowing rough calculation of which satellites are visible (and therefore which codes to check) and what their rough frequencies will be, can drastically reduce the search space. \n\nReceivers typically include a large number of signal search cores, so that the search can be done in parallel, but more processor cores increases cost and power consumption. However, these days, there is increasing demand for GPS receivers with very fast start and other features as a result, manufacturers are integrating huge numbers of search cores (multiple millions) which can complete a brute force search in about 30 seconds in good signal conditions, and 1-2 minutes in marginal signal conditions where longer averaging times are needed for confirmation.\n"
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
2wawkr
|
Would it be possible to put a human into a permanent hypothermic state instead of cryogenically frozen in order to slow down ageing for hundreds of years?
|
I know that surgeons sometimes operate on patients that are extremely cooled in order to prolong life long enough to operate, and to slow the organs and processes. Can this be done over a long period of time as in tens or hundreds of years? Providing the body with enough oxygen and nutrition to slowly continue to live during that period?
|
askscience
|
http://www.reddit.com/r/askscience/comments/2wawkr/would_it_be_possible_to_put_a_human_into_a/
|
{
"a_id": [
"cop5neb",
"cop8aei",
"cop8b0s",
"coq2zik"
],
"score": [
40,
24,
19,
3
],
"text": [
"this link maybe of intrest to you: _URL_0_\n\nThis is the next step in the \"cooling the body for surgery\" idea. This could also be a next step towards some sort of hibernation like we see in Sc-Fi film/games. Any state of 'stasis' that the human body is put in could have long term negative medical effects on the body, especially the brain.",
"NASA is currently doing studies for people lying in bed for 3 months without getting up. Test subject received $18,000. Results include fainting 8 min after once standing for the first time. I think we are capable of intentionally putting people in a coma and are testing for a duration mission trip",
"It would be difficult to keep microorganisms from destroying the person over time. Fungus, mold, and a billion other bacteria can function quite well at low temperatures. Just read an article that demonstrated HPV can survive in a liquid nitrogen bottle. So there would be some technical challenges to say the least. ",
"I'm not sure about prolonged stasis but there are pilot studies being conducted now that involve acutely cooling patients with major trauma, as well as post cardiac arrest. I don't believe any of the trauma trials have been completed yet, but hopefully there will be some good literature coming out soon. \n\nRegarding prolonged low-temp stasis though, it seems far fetched for the time being. There are lots of physiologic effects of deep cooling that are harmful and difficult to control: blood clots differently at low temp, cardiac arrhythmias, immunosupression, electrolyte abnormalities.... \n\nTL;DR: Prolonged stasis is still science fiction, but short term cooling in acutely ill patients is being studied actively. "
]
}
|
[] |
[] |
[
[
"http://www.newscientist.com/article/mg22129623.000-gunshot-victims-to-be-suspended-between-life-and-death.html#.VOSKXSy8rvo"
],
[],
[],
[]
] |
|
rnbn4
|
Physiologically speaking, how different am I from someone who lived 200 years ago? 500 years ago?
|
Are there any major differences in the human body between a human being that lives today compared to someone who had lived 200 years ago? 500 years? 10,000 years ago?
|
askscience
|
http://www.reddit.com/r/askscience/comments/rnbn4/physiologically_speaking_how_different_am_i_from/
|
{
"a_id": [
"c476cb0",
"c476o3k",
"c4771wk"
],
"score": [
8,
3,
9
],
"text": [
"We are a lot taller and fatter compared to people 100 years ago, they did not have anywhere as near as much meat on average compared to what we do now.",
"I happened to read [this article](_URL_0_) a few days ago... It looks like our teeth may have become more crooked in the last 10k years.",
"Please note that the differences mentioned here result from dietary and other health differences, not genetic differences."
]
}
|
[] |
[] |
[
[],
[
"http://news.sciencemag.org/sciencenow/2011/11/crooked-teeth-blame-early-farmer.html"
],
[]
] |
|
3vmemk
|
[Psychology] What's the science of obsession? Questions below
|
1. What's the clinical definition? What officially qualifies as obsession?
2. How does it develops?
3. How/if does it differ from addiction?
4. What's the best way to treat it?
Thank you for the responses!
|
askscience
|
https://www.reddit.com/r/askscience/comments/3vmemk/psychology_whats_the_science_of_obsession/
|
{
"a_id": [
"cxp6l56"
],
"score": [
2
],
"text": [
"I'm really surprised that no one has attempted to answer this yet.\n\n1. Obsession is defined in the DSM-5 as the following:\n * Recurrent and persistent thoughts, urges, or images that are experienced, at some time during the disturbance, as intrusive and unwanted, and that in most individuals cause marked anxiety or distress.\n * The individual attempts to ignore or suppress such thoughts, urges, or images, or to neutralize them with some other thought or action (i.e., by performing a compulsion).\n2. Obsessions usually develop under a somewhat specific set of circumstances. Internalizing stress can cause a person to develop obsessions. Physical and sexual abuse in childhood have also been associated with increased risk for developing OCD, a psychological disorder marked by severe obsessions and compensatory behaviors (compulsions) designed to alleviate those obsessions.\n3. The major difference is that generally addiction is pursued based on deriving some sort of pleasure from participating in the addictive behavior. Substances produce a pleasurable effect on the user, at least for some time. Obsessions are generally unpleasant in nature, causing distress (as defined by the first bullet point in my first answer).\n4. There are several ways to treat disorders that include obsessions. Cognitive-behavioral therapy is commonly used. Exposure therapy is also used commonly, but some people may have adverse reactions to the therapy. Anxiolytic drugs can also be prescribed to help keep symptoms under control while the client undergoes therapy."
]
}
|
[] |
[] |
[
[]
] |
|
36w9go
|
What is the difference between a scientific theory and law?
|
I read that laws are usually mathematical, such a f=ma, and that scientific theories explain the laws. However, Einstein's theory of relativity includes mathematical equations (Einstein's field equations), so I'm still confused on how that is. Why isn't something that's been proven time and time again "upgraded" into a law? What's their true difference?
|
askscience
|
http://www.reddit.com/r/askscience/comments/36w9go/what_is_the_difference_between_a_scientific/
|
{
"a_id": [
"crhn08q",
"crho1ph",
"crhoq9k"
],
"score": [
24,
4,
8
],
"text": [
"Someone asked a very similar question a few months ago, [and this is a fairly frequently asked question,](_URL_0_) so I'll copy paste what I wrote there, since that user specifically asked about 'Newton's Laws' vs 'Einstein's theory' as well.\n\n-----------------------------------------------------\n\nA lot of people make the mistake of thinking, \"Gee, I know what the words *law* and *theory* mean. You can't break *laws*, so those must be the things that are really solid, but a *theory* is just a like some kind of guess, I can come up with my own theory right now!\" So let's try to tease out why these people are wrong. To scientists, words like *law* and *theory* have very specific definitions, so we need to do some semantics.\n\n**A law is a declarative statement, based on observation, that seems to describe some behavior of some naturalistic phenomena.** Newton's Laws are exactly that. \"Objects in motion remain in motion, and objects at rest remain at rest unless acted upon by an outside force.\" This statement seems consistent with every observation we've ever made, and it has a great deal of predictive power. Basically, a law is a statement of a fact that can be experimentally falsified. One experiment that shows a body accelerating under its own volition, for no reason and with no discernible outside force, and this is refuted. \n\nNow for *theory*. I have a definition of theory that I like, and others are free to disagree. **A theory is a testable explanation of some set of natural phenomena that explains all the best currently available evidence.** Basically, a theory explains the laws or some bundle of them and it offers some *reason* for them. Einstein's *theory* is that we live in a four dimensional universe, and that space and time are related in some nontrivial way, and things get curvey which is the source of attraction between masses. The 'theory' provides a mechanism by which the 'laws' act. \n\nEinstein's theory explains the results of tons of experiments or makes predictions (mathematically) that are consistent with them, such as the Michelson-Morley experiment and Gravity Probe-B. The theory *explains* the facts. A bunch of laws, together, form the pillars that a theory stands on. If one of those facts turns out to be bunk, (like in Einstein's theory, that nothing goes faster than light), it will have to be modified or entirely replaced in order to account for this new evidence. \n\nFurthermore, now that we have our definition of a 'theory' we can see that a theory is a fundamentally different thing from a law, so it wouldn't make sense to take Newton's law of inertia and try to promote it into a theory, because it's just a single statement about *one specific type of observation.* \n\nAnother good example is evolution. Darwin's theory of evolution by natural selection is a *theory*. It explains the *fact* that organisms aren't the same as their parents, that new traits can emerge, and these traits can proliferate through the population over successive generations if they prove to be beneficial. Natural selection is the mechanism so maybe (as much as I hate the phrase) we should call 'survival of the fittest.' Species changing over time is the *evidence* from experiments and the fossil record, and Darwin's *theory* ties it all together. It's amazing that Darwin came up with his theory before DNA was even known about, but was found to be very consistent with the microbiological understanding of genes and mutations.\n\n\nBottom line: Theories don't somehow graduate into laws after they get proven, because they're different beasts entirely. Laws are statements about specific phenomena, and the laws, together with the evidence and facts, are explained in aggregate as theories. ",
"A law is a simple statement about an observational trend. It usually goes something like \"The more cars there are on the freeway, the more time it takes to get to work\" or something like that.\n\nA theory is a deductive argument in which the logical consequences of a small number of premises are deduced. So it goes something like \"IF the speed of light is constant, THEN we deduce that... < THINGS > \".\n\nThe < THINGS > themselves are laws and lesser theories, including laws and theories we have yet to observe, hence a theory's great predictive power. Laws have very limited predictive power.\n\nSince a theory is a deductive argument, not a simple observational statement, it's a totally different animal, and changing it to a law would not be an upgrade. Theories that consistently correctly predict the outcomes of experiments are called *accepted theories.* Accepted theory is as good as it gets in science.",
"Other posters in this thread in generally correct, but words can have different meanings in different contexts, and ignoring this can cause confusion or frustration when sticking to a rigid definition.\n\nFor example, in physics \"theory\" often means what other fields would call \"mathematical modelling\" and can also refer to specific mathematical techniques like perturbation theory or Hartree-Fock theory, rather then self-consistent evidence-based frameworks. You can also have physics theory that doesn't correspond to reality but are still interesting to study."
]
}
|
[] |
[] |
[
[
"http://www.reddit.com/r/askscience/search?q=laws+theory&restrict_sr=on&sort=relevance&t=all"
],
[],
[]
] |
|
2lv1n9
|
why do screens use red/blue/green pixels but printers use red/blue/yellow ink?
|
i know that my computer screen makes the colour white by combining red, green and blue light. but in art (and my computer printer), the 3 primary colours are red, blue and yellow?
these two setups seem so similar, but with one obvious difference. what gives?
i do remember being told that this difference exists in high school physics, but not "why". if you can ELI5, i'll be happy and a fair bit impressed as well!
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2lv1n9/eli5_why_do_screens_use_redbluegreen_pixels_but/
|
{
"a_id": [
"clyeo66",
"clyepjg",
"clyeskm",
"clyf10w",
"clymf3q"
],
"score": [
29,
11,
3,
9,
3
],
"text": [
"Inks subtract color, screens add. Basic ink colors are cyan, yellow and magenta. So cyan is white minus red, but on a screen it's constructed as blue plus green. It works like this because white light goes through ink, so the color comes from what is subtracted. On a CRT or LED screen, a pixel is a tiny lamp of red, green or blue color, so the color comes from what is added to black (screen off). Also, pixels are monochromatic on LCD screens even though they absorb light.",
"The inks used in printers are cyan, magenta and yellow (and black), not red, blue and yellow. This is called a subtractive color model, because adding ink to the white paper subtracts some wavelengths of light. If you add all three colors, you get black (but in reality you get something brownish, which is why black ink is also used). \n\nThe monitor on the other hand, does use red, green and blue pixels. This is called an additive color model, because wavelengths of light is being added to the otherwise black screen. If you add all colors, you get white. \n\nIn art, the base colors taught are usually red, blue and yellow. Why this is I do not know, but if I were to speculate I would say that at least a part of the reason is that it's much easier to get kids to remember \"red\" and \"blue\" rather than \"cyan\" and \"magenta\". ",
"It's the difference between additive and subtractive primary colors. Pigments are \"subtractive\" because when you look at red paint, it reflects red light that is shined on it and absorbs all other colors, \"subtracting\" them. Light is \"additive\" because shining two different colors of light on a (white) surface adds them together and doesn't subtract any color.\n\nAlso, technically speaking the subtractive primary colors used in printers are CMYK (Cyan, Magenta, Yellow and Black)",
"Printers don't actually use red/blue/yellow ink, but instead a mixture of four colours generally, you may have seen this written somewhere as CMYK, this just stands for cyan, magenta, yellow, and key (key being a fancy term for black, really a mixture of all of the others).\n\nBecause printers start with a white surface (something that gives off every colour of light) and cover up the white surface with certain pigments to create colour each pigment is actually subtracting from the origional 'full spectrum'. This is called \"subtractive colour model\". \n\nThese colours are approximated in art using similar colours, red being the substitute for magenta (a very bright pink colour, red is actually a mixture of almost equal parts magenta and yellow), blue being the substitute for cyan (a very blight almost baby blue colour, what we call blue or use as blue in art would really be a mixture of mostly cyan with some majenta in it) and yellow for yellow (again, the yellow used in art actually being a slightly more lustrous yellow than the somewhat pale looking yellow used in printing)\n\nWhen these colours are combined in different ratios they are able to remove certain wavelengths (subtracting them) until eventually with all of them being applied as thick as possible you would reach a theroetical 'key' (black) colour, this generally can't happen in a printer as they don't really apply a very thick amount so a key tone is added (black) to be used to 'darken' the image anywhere that needs to happen (somewhere that all three would be applied in equal amounts).\n\nFor example, to create a very pale red you would apply a fine amount of yellow and a fine amount of majenta, and this would subtract all of the colours other than the wavelengths between the yellow and magenta masks which would make the paper appear red. To darken it one could apply a mist of equal parts of each colour, or using black could simply apply a black mist and darken it much easier this way. \n\nScreens on the other hand are not natually white, they are black. They also use a combination of four colours really, the exact opposite of the colours used in subtractive model colour making. When equal parts of red, green and blue light are given off something will appear white. This is an additive colour model, the more wavelengths of light you want present the more colours of light you will turn on. The fourth colour is white, given off by your backlight, which is the opposite of key just to give you an idea of how the key would be used in subtractive printing. \n\nTherefore the one obvious difference is not so, in art the red and blue used are not perfect colours and limit the range that one can produce, but they are good approximations to create many colours and are often easier pigments to find and deal with at a more primary level. In reality there is a huge difference, they are totally opposite colours with the intention of completing totally opposite processes!",
"You've got a lot of great explanations here, but maybe this one will be a little simpler:\n\nFirst of all, when people told you in art class that the primary colors are red, blue and yellow... they lied. Sort of. Actually, those \"primary\" colors are magenta, cyan and yellow. Close enough for a beginner's art class to simplify as red blue and yellow, but not really true.\n\nWhy is this important? Because when you're talking about mixing pigments on paper or canvas in art, what's happening is you're mixing *reflected* light. Light bounces off the paint. Your TV is creating light-- it's not reflected, it's the actual light.\n\nThat's the easy answer, but here's a little more in-depth:\n\nOkay. So white light (not REFLECTED light, but the light itself) is made up of red, blue, and green. If you combine all three of those colors of light you get white light.\n\nBut what if you only combine two of them? Then you get another color-- Blue and red make magenta, blue and green make cyan, red and green make yellow.\n\nMagenta, cyan, yellow. Your \"reflective\" primaries.\n\nSo another way of looking at that is, say you take white light, and you subtract green. That means all you have is blue and red, which makes magenta.\n\nSo magenta is white light without the green in it.\n\nAnd when you paint on something, what happens is the white light hits the paper, hits the paint, and the paint soaks up the green light, leaving only magenta. That's why the reflective colors are different-- you have to take *away* light to make colors, since the light you're seeing is reflected off of something.\n\nWhereas with your computer screen, it's actually emitting the light itself, so it has to *add* the colors of light."
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[]
] |
|
c76vfq
|
why don’t we have fat and muscle surrounding our brains as an added protective layer over our skulls?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/c76vfq/eli5_why_dont_we_have_fat_and_muscle_surrounding/
|
{
"a_id": [
"esdfgek",
"esdhuhg",
"esdtcmp"
],
"score": [
25,
11,
3
],
"text": [
"Heat retention. The brain uses a large portion of our energy and the temperature range from normal to heat stroke is all of 3 degrees C. Also because of all of the blood vessels in the brain, a lot of the body's heat is pumped through your head.\n\nJust being hot makes you think slower and make more mistakes.",
"Muscle tissue has the sole purposes of enabling movement of the body and organs, fat tissue is mostly only for energy storage. So neither of those two tissues really qualify as a protective tissue and if we start thinking evolution it makes little sense for an individual to have increased reproduction rates because of two ridiculously energy cost intensive tissues around the skull which already protects the brain.\n\nTissues that are fit for acting as protective Barriers are bone, skin, and mucous membranes and those are already pretty solidly implemented into our heads at this point. Anything beyond that would probably just drive the cost-effect balance into negative and would decrease our fitness as individuals, thus leaving us more susceptible to natural selection which would lead to a relatively fast extinction of such a muscle-fat-head human.",
"We do, only the very top of the skull doesn't have skeletal muscle attached. There's a specialized type of skin called scalp that covers the skull, it's extra thick and tough for added protection. All skin has a layer of subcutaneous fat as well. Inside the skull there's several more layers of protection called the meninges, made up of three layers; the dura mater which it tough and thick, the arachnoid mater which is spongy and the pia mater which is thin and delicate. The brain itself also floats in a tub of liquid called cerebrospinal fluid that flows between the meninges and through the brain itself via a system of ventricles and canals, supporting it and further cushioning it."
]
}
|
[] |
[] |
[
[],
[],
[]
] |
||
6fqv7v
|
how did fentanyl become part of the illegal drug trade and is it here to stay?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/6fqv7v/eli5_how_did_fentanyl_become_part_of_the_illegal/
|
{
"a_id": [
"dikau7o",
"dikb4no",
"dikdpfv"
],
"score": [
6,
3,
3
],
"text": [
"Parmacist.\n\nEvery opioid has become apart of the illegal drug trade because they all cause euphoria when abused. Causing big issues. It's as unavoidable as gravity. But they're also irreplaceable in pain treatment. \n\nFentanyl in particular has several forms, like mucosal sticks and long-duration patches. No other drug has these formulas. Even if there were, patients routinely complain that only one type of thing alleviates their pain. So it's continues presence is also quite certain as it is a drug medicine needs.\n",
"It's synthetic and much more powerful than heroin, so it can be mass produced in labs at lower cost and marketed as a \"better\" high. It's also used to cut normal heroin. It's going to be a global problem for the foreseeable future. ",
"Fentanyl was completely uncontrolled in China until 2015, which meant that legitimate chemical companies were free to produce and sell it without restriction. That meant that a legitimate Chinese chemical plant could produce it and sell it to drug dealers in the US and, as far as the Chinese government was concerned, everything was completely legal. It also helps that Fentanyl is extremely cheap to produce - much more so than other opioids.\n\nIn 2015 China began regulating Fentanyl, but enforcement is fairly light. Basically, the Chinese government will only act when the US government complains about a specific supplier, and even then there usually isn't a punishment as long as the company stops producing Fentanyl for long enough.\n\nAnother factor is that ts possible to slightly alter the Fentanyl molecule so they you get something that is technically a different chemical, but which is so similar to Fentanyl that it behaves in the exact same manner and is just marketed as Fentanyl. The US considers those new chemicals to be \"analogues\" of Fentanyl and they are automatically treated identically to Fentanyl under US law.\n\nConversely, Chinese law treats analogues as being a completely new, and therefore unregulated chemical. China has been slowly banning Fentanyl analogues, but its a slow process that, again, only really starts occurring when the US begins complaining loudly enough.\n\nBecause of that, there is a large amount of cheap Chinese Fentanyl that is easily accessible to US dealers. "
]
}
|
[] |
[] |
[
[],
[],
[]
] |
||
axa7le
|
Can you determine the secondary/tertiary structure of a protein based solely on the amino acid sequence?
|
This has become a debate in my Undergrad Biochemistry class, so I thought I'd come ask here.
Some students are arguing that based on the environment and interactions with chaperones can lead to different final structures.
On the other hand is that a specific sequence will fold one way no matter what, so we can determine the final structure based only on the sequence.
Let me know what you think!
|
askscience
|
https://www.reddit.com/r/askscience/comments/axa7le/can_you_determine_the_secondarytertiary_structure/
|
{
"a_id": [
"ehs8ohy"
],
"score": [
5
],
"text": [
"If you know what patterns and properties to look for in the primary sequence you can make fairly accurate predictions about some features of secondary structure. Principally alpha helices. You can predict beta sheets as well, but since beta sheets, particularly parallel beta sheets, can form between amino acids that are on distant parts of the primary sequence, its much harder to accurately predict them. Additionally many proteins have loop, and unstructured regions, that are hard to predict. Many amino acids also undergo post translational modification which can affect their chemical properties. The ability to predict tertiary structure is much harder unless you have structural models of similar protein sequences to compare to. There are common domain structures like leucine zippers, zinc fingers, greek keys ect, that you could predict with a decent accuracy if you know what primary sequences to look for. \n\nBottom line there are features of protein structure that you can predict from the primary sequence, but you can't accurately model the entire protein structure de novo from the primary sequence. "
]
}
|
[] |
[] |
[
[]
] |
|
81zmtt
|
Resources on pre-modern/medieval warfare/armies in East Asia that are not in the recommended reading list? Specifically regarding Korea.
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/81zmtt/resources_on_premodernmedieval_warfarearmies_in/
|
{
"a_id": [
"dv6nd68"
],
"score": [
2
],
"text": [
"Specifically for Korea, the major event that has attracted most attention is Hideyoshi's invasion, 1592-1598. The resources resulting from that attention amount to 3 major books, and various journal articles and other books. Two of these books are in the reading list (but in the Imperial China section of the list):\n\n* *The Imjin War: Japan's Sixteenth-Century Invasion of Korea and Attempt to Conquer China* by Samuel Hawley (2005). One of the three main English accounts of the Imjin War, perhaps the only thing that comes close to a \"world war\" in East Asia. This is not the most comprehensive text on the war but it gives an excellent introduction. Hawley uses mostly Korean sources for this book and writes from a Korean perspective, so the book does suffer from a pro-Korean bias.\n\n* *A Dragon's Head and a Serpent's Tail: Ming China and the First Great East Asian War, 1592–1598* by Kenneth M. Swope (2009). The newest of the three books, Swope writes from a Chinese perspective and uses a lot of Chinese primary sources. Though his text has been criticized for providing flawed information, as a military historian, Swope gives an excellent account of the capabilities of the Ming military. It is best to read Hawley, Turnbull, and Swope together.\n\nThe third book, referred to in the comments on Swope above, but not in the list, is\n\n* Stephen Turnbull, *Samurai Invasion: Japan's Korean War 1592-1598*, Cassell, 2002. Turnbull depends on Japanese sources, Swope on Chinese sources, and Hawley on Korean sources. It's good to read all three.\n\nAlso useful is\n\n* Peter H. Lee (ed), *Record of the Black Dragon Year*, Univ of Hawaii Pr, 2000. This is a translation of a contemporary Korean popular history of the war.\n\nTwo books that cover the modernisation of the Korean army as a result of the Japanese invasion in the context of wider changes in East Asian warfare c. 1600 are:\n\n* Peter A. Lorge, *The Asian Military Revolution: From Gunpowder to the Bomb*, Cambridge University Press, 2008.\n\n* Tonio Andrade, *The Gunpowder Age: China, Military Innovation, and the Rise of the West in World History*, Princeton University Press, 2016.\n\nSee also\n\n* Tonio Andrade, Hyeok Hweon Kang, Kirsten Cooper, \"A Korean Military Revolution? Parallel Military Innovations in East Asia and Europe\", *Journal of World History* 25(1), 51-84 (2014)\n\nThere are also some sources on the US war in 1871:\n\n* Gordon H. Chang, \"Whose \"Barbarism\"? Whose \"Treachery\"? Race and Civilization in the Unknown United States-Korea War of 1871,\" *Journal of American History* 89(4) 1331-1365 (2003)\n\n* Carolyn A. Tyson, \"Marine Amphibious Landing in Korea, 1871\", _URL_1_\n\nSome sources on weapons and armour:\n\n* Sang H. Kin (trans), *Muye Dobo Tongji: Comprehensive Illustrated Manual of Martial Arts of Ancient Korea*, Turtle Press, 2000. Translation of a late 18th century Korean military manual.\n\n* Boots, J. L., \"Korean Weapons and Armour\", *Trans. Korean Branch Royal Asiatic Society*, XXIII, Pt. 2, pp. 1-37 (1934). _URL_0_"
]
}
|
[] |
[] |
[
[
"http://www.raskb.com/content/full-texts-volume",
"http://webarchive.loc.gov/all/20100407175236/http%3A//www.history.navy.mil/library/online/marine_amphib_korea.htm"
]
] |
||
5dbpkh
|
why microwaves don't explode with the pressure of accumulated steam from food.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/5dbpkh/eli5_why_microwaves_dont_explode_with_the/
|
{
"a_id": [
"da39tcn",
"da3b9mx"
],
"score": [
3,
9
],
"text": [
"The microwave is actually not air tight. There are air vents on the microwave itself. I also believe that the door itself is also not air tight. Microwave energy is also not kept inside of the microwave completely, given why pregnant women should not stand by the microwave. ",
"It has air vents. Microwave energy is prevented from leaving the microwave due to a metal mesh that surrounds it. [This mesh is not airtight, and doesn't need to be](_URL_0_) to function properly. "
]
}
|
[] |
[] |
[
[],
[
"http://1.bp.blogspot.com/-UNUVqRO5Fgw/Te0_pUJIjSI/AAAAAAAAQdM/xtrVIr1Xv3I/s1600/Tesla18Dalek10006Ft.jpg"
]
] |
||
284br3
|
weed smokers of reddit: what is the advantage of smoking marijuana instead of making pot brownies?
|
I mean, smoking is pretty bad for your lungs, and stuff, and brownies taste great, so why smoke it?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/284br3/eli5_weed_smokers_of_reddit_what_is_the_advantage/
|
{
"a_id": [
"ci79qkl",
"ci79x6r",
"ci7a2xw",
"ci7doki",
"ci7ejhm"
],
"score": [
2,
2,
2,
6,
2
],
"text": [
"But once it does kick in... :o",
"And there's just something inexplicable about the vibe and mood of blazing a joint somewhere isolated in nature.",
"Smoking, you need a somewhat secluded or private area, where as the brownies, you can eat pretty much anywhere without others being alerted to it.",
"Some of us actually appreciate the bud. We smell it. We inspect it. We look at it with magnifying glasses. We taste it delicately. We compare it to others. We seek out specific strains and specific features. We celebrate specific growers. We take notes. Ok, some of us do. \n\nFor all the reasons that some people drink wine instead of jello shots, we like to smoke finely cured buds, instead of eating sugary shit brownies filled with leaves and shake.\n\nYou're not appreciating the buds if you're just grinding them up into cake batter to get fucked up. Any crappily-grown weed or improperly cured weed gets thrown into edibles. To get a truly good *smoking* weed, the process really has to be done right from start to finish. Learning to appreciate that, and all the steps involved, is a huge part of my enjoyment.\n\nAnd you don't need to \"smoke\" it. I use a vaporizer a lot of the time. It's instantaneous and basically harmless healthwise. You can taste all the subtle characteristics of what you're vaping. It's really easy to find your favorites using a vape.\n\nI still hit the bong quite a bit because goddamnit, that's the way I was raised and nobody will ever convince me to give it up!\n\nI think edibles and concentrates are a waste of time, money, and bud. They're jello shots.",
"If you've ever eaten a pot brownie, you'd know. A high from smoking is virtually instant (latency is usually no more than 15s if you inhaled enough), and it doesn't last too long (likely no more than 45-60min, usually much less). Meanwhile, a brownie has a much longer latency (could be 45min-1hour), and then the effects last much longer (could be several hours). This doesn't accommodate proper functioning in society, while smoking can be a break in the day or just a nice chill at night. \n\nOn a side note, vaping, while still with some negative effects, would be much safer than smoking because you're not burning the plant so you produce less toxic chemicals in the process. "
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[]
] |
|
9oqgb5
|
- what is preventing the us government from making voting day a national holiday?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/9oqgb5/eli5_what_is_preventing_the_us_government_from/
|
{
"a_id": [
"e7vwoje"
],
"score": [
3
],
"text": [
"The US has no legal holidays where all businesses are required to give all workers the day off, it's a capitalist country.\n\nThere are about 260 working days per year. Adding another federal holiday thus costs about 0.4% of productivity. While it's a small number, 0.4% of the US GDP is a really big amount of money. Spending that money on voting day isn't perceived as worth it.\n\nWhen you suggest switching another existing holiday for \"Voting Day\", you get a lot of pushback. If you pick a day like Columbus Day/Indigenous Peoples Day that not everybody gets off, it costs a lot of money. If you pick a day most people get off, like Thanksgiving, then you get a whole new level of angry. "
]
}
|
[] |
[] |
[
[]
] |
||
61s5oi
|
how are paintings restored?
|
How are famous paintings restored without the restorer actually putting paint onto the surface to fix cracks? How does the process work?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/61s5oi/eli5how_are_paintings_restored/
|
{
"a_id": [
"dfh30cj"
],
"score": [
3
],
"text": [
"First they study the picture to see how the painting constructed. They use X-rays and ultra violet lights to see what paints and varnishes were used.and if any repairs have been done before. Also knowledge of the artists usual technique and of the time period are important.\n\nOnce they have this info they might put a new backing on the canvas to make it stronger. Then they use solvents and knives to gently clean away old varnish and previous restorations.\n\nThey do fill in the missing areas. But they use special compounds that can be easily removed in the future. As well as detailed records of the work that was done.\n\nThen they cover it with special non-yellowing varnish to keep it looking good. "
]
}
|
[] |
[] |
[
[]
] |
|
1tp2xp
|
How do they convert electric signal to type that our brain can read?
|
I always wondered how do they make it work...
How do they make electronic ear,nose or eye?
I am looking for more "engineering" answer because i am student of electrical engineer school and i am planning to specialise later in biological engineering.
Thanks for patience!
|
askscience
|
http://www.reddit.com/r/askscience/comments/1tp2xp/how_do_they_convert_electric_signal_to_type_that/
|
{
"a_id": [
"cea44s3",
"cea56qz"
],
"score": [
3,
2
],
"text": [
"Nervous systems already communicate with electrical signals. In fact, that's what your mechanoreceptors do: the hair cells in your ears, for instance, convert pressure changes into electrical signals which downstream neurons can then receive (the chemical synapse does utilize ligand/receptor kinetics, but all to the end of depolarization: electrical signalling).\n\nIn many experiments with neurons, a current is directly injected into the neuron to stimulate it. \n\nNow, how the brain (or specific nuclei in the brain) interpret it depends on that particular set of neurons and how the encode information. A very common kind of coding is rate coding, where the neuron spikes faster to encode more intense stimulus.",
"Electronic ear and eye work the same. They push current, biphasic, negative first, at currents up to the 1 mAmp range. It may go up to 6 volts in a volt representation over a 1 kohm lead, but most of the stimulation occurs at much lower currents than that. Safely in the 0.100 mA to 6 mA range.\n \nSuch currents are necessarily fairly dispersed because of the size of the contacts (hundreds of microns wide). "
]
}
|
[] |
[] |
[
[],
[]
] |
|
aa0dob
|
how do game anti cheats, like battleye or gameguard work?
|
What I mean is - I know they can check the processes which are running and are associated to the game that you're playing, but how do they know that those processes are actually cheating tools?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/aa0dob/eli5_how_do_game_anti_cheats_like_battleye_or/
|
{
"a_id": [
"eco0g43",
"eco0k0f",
"eco20mw"
],
"score": [
20,
12,
2
],
"text": [
"There are different flags that can be detected to assume someone is trying to tamper the game, such as debugging another process (the game in this case), accessing the memory mapped to that game, running the game in a virtualized environment, tampering the binary or assets and many more. \nAnti-cheat try to detect those abnormal behaviors targeting the game's process. ",
"They guess. \"We know about a cheat program, and it looks like *this*. You currently have something running that looks like it, so we're gonna assume you're cheating.\"",
"Different anti cheats employ different methods to combat cheating. Most of them keep these methods secret so that they can remain one step ahead of cheaters. Common methods include memory modification detection, the idea that when the cheat program modifies memory, some code will scan the binary (.text section) and find differences. This will flag the account for further investigation. Some anti cheats, however, use pattern detection. If someone with aimbot and esp is killing people through walls they can flag accounts and allow for further investigation. The goal of cheat makers is essentially to bypass these detection vectors and allow the cheater to continue cheating. Anti cheats have also gotten more complex over time because cheat makers have found more security holes in the OS and games in general. This led to Kernel level anti cheats which basically act like anti virus programs (have the same privilege level) and locate cheats that utilize better stealth. Even with these sophisticated anti cheats like BattleEye, cheaters can still remain safe for long periods of time due to how difficult detecting some cheats can be. To sum, the anti cheats basically scan memory for modifications, look for patterns both in the user and the program, or search through the PC for cheat related software that is present. "
]
}
|
[] |
[] |
[
[],
[],
[]
] |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.