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 |
|---|---|---|---|---|---|---|---|---|---|
8imcpc
|
why is it that 8:30-5 or 9-5:30 seem to now be the most common working hours? growing up i was always told 9-5 (thanks dolly). is there a reason for the extra half hour? i work in the u.k. if that helps.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/8imcpc/eli5_why_is_it_that_8305_or_9530_seem_to_now_be/
|
{
"a_id": [
"dysv8m0",
"dytehzw"
],
"score": [
14,
2
],
"text": [
"Usually it's that you're entitled to a break by law, but they don't have to pay you for your break. So the shift is 8.5 hrs even though you only get paid for 8. Doing it on 8s is usually easier for HR/payroll to deal with",
"It's basically whether or not you get a paid lunch. These days most companies opt for not giving you a paid lunch so an 8.5 hour day would have a half hour unpaid lunch, 9 hours day with an hour unpaid lunch are also common. 9-5 is a 7 hour workday with an hour paid lunch."
]
}
|
[] |
[] |
[
[],
[]
] |
||
2je5pj
|
why does your body want to keep changing position at night?
|
When I'm lying on my right side in bed at night after a while I feel as if the world will end if I dont switch to my left side. Why is this?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2je5pj/eli5_why_does_your_body_want_to_keep_changing/
|
{
"a_id": [
"clav201",
"clav2tx",
"clav7y2",
"clavv2h"
],
"score": [
7,
27,
62,
2
],
"text": [
"I too would like to know this, because apparently I'm not the best cuddler after I fall asleep.",
"'Cause the right side of your body has a fricken body lying on top of it, so it's like \"alright, this is getting a bit heavy now, left side you can take over.\"",
"Lying in one position for a long time can cause pressure points on certain areas of the body which may then cause the tissue to break down from lack of blood flow. The wounds are called pressure ulcers and you see them frequently in people who are not able to reposition or move around while in bed. I believe your body A) moves around to try to find a comfortable position that also reduces pressure areas and B) once you have been in one position for too long your body will signal you to move and thus put the pressure on different areas of the body. I am sure there are other mechanisms involved as well, but this plays a large part. ",
"The amount of times I have smacked my self in the face with my asleep arm.."
]
}
|
[] |
[] |
[
[],
[],
[],
[]
] |
|
537ht7
|
During the tenure of great composers like Mozart, Bach & Beethoven, would it be common to hear their music played outside their country or did music spread slower?
|
For instance, Bach's Toccata and Fugue in D Minor, would this have been played by organists throughout Europe at the time? Or did the spread of composers' music accelerate at a later date?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/537ht7/during_the_tenure_of_great_composers_like_mozart/
|
{
"a_id": [
"d7qmsk8"
],
"score": [
3
],
"text": [
"Mozart traveled [A LOT, even for the standards of our time](_URL_0_). He also published his music, he was known in many countries.\n\nBeethoven's works were also published in different countries. His 9th symphony was commissioned by the Philharmonic Society of London in 1817. [He was known even across the Atlantic](_URL_1_).\n\nMost of Bach's music was not published during his life. He was nowhere near as famous as Mozart or Beethoven. \n\nMusicians did travel during the Baroque period, and there were some super stars touring all over the big cities. Publishing was a good way for music to spread, and we find music traveling across Europe even before the Baroque, but it was nowhere close what was seen during the 19th century. \n\nMusicians did come in contact with music from other countries, and even traveled to pick up some things and use them in their own music. "
]
}
|
[] |
[] |
[
[
"http://www.mozartways.com/content.php?m=2&lang=en&m_id=1290&id=1290",
"http://americanbeethovensociety.org/exhibits/americasbeethoven/newspapers.html"
]
] |
|
8l1e3j
|
Who are the Spanish descended from?
|
Are modern Spanish descended from Visigoths or the Romans? Or were the majority of the population was there before the Romans?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/8l1e3j/who_are_the_spanish_descended_from/
|
{
"a_id": [
"dzc2n6q"
],
"score": [
3
],
"text": [
"The Iberian Peninsula was inhabited long before the Romans occupied it, and the PaleoHispanic people's had lived in northern and Western Iberia since the Stone Age (35-40,000 BCE). Modern Spanish are descended from a rich mixture of Roman, Visigoth, Vandal, Muslim, Celtic and the PaleoHispanic, but all of these ratios are different depending on where you go in Spain to look at the population. Portugal is rich in Muslim and Roman influence because of the importance of the region for trade, whereas the North in places like Basque remained pretty culturally and linguistically solid even through Roman and Muslim occupation. Besides that, in the South East there's even influence from the Greeks and Phoenecians. So ultimately the peoples of Spain have many different origins, so it really depends on where you want to focus on."
]
}
|
[] |
[] |
[
[]
] |
|
2s4ty1
|
what is a "thinktank" company?
|
How do this work? What do they do? How do they get paid? How is it a viable business?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2s4ty1/eli5_what_is_a_thinktank_company/
|
{
"a_id": [
"cnm84dl"
],
"score": [
6
],
"text": [
"\"Thinktanks\" are in the business of generating solutions to problems - basically, they are like a consultancy, but admittedly the scope and type of problems they work on can be unusually difficult and very specialized. For instance, whereas consultancies e.g. Aon-Hewitt; Bain's Co, for businesses, may instruct or advise customers about company restructuring, marketing strategy and the like, \"thinkthanks\" in the form of non-government organisations work on say, how to prepare and best structure Afghanistan for a viable democracy, or how to raise popular awareness of seasonal drought in some third-world country. Thinktanks may also often have a visible bias, which may in fact be packaged as part of their company mission to attract customers, versus consultancies which front a more transparent, objective image - for instance, in the US you'll have publicly \"Conservative\" thinktanks which try to study government policies and criticize them specifically from a Conservative POV and think about how aligned they are with Conservative practice.\n\nPeople attached to thinktanks then are luminaries who typically have had loads of experience in the field they are working at - like politicians, scholars, and they make use of a great deal of interdisciplinary thinking from the sciences to humanities to construct solutions for scenarios and crises. There are for-profit and non-profit thinktanks, so they may be paid per-assignment by clients, or exist by generous academic grants and private donations. As I mentioned earlier, the people who run thinktanks may themselves already be well-recognized in their original fields of specialties - this means that money ain't as much a concern for them so the need for a \"viable business\" part is diminished. They may run thinktanks as a \"hobby\", a \"side interest\" of sorts - to provide themselves a public platform for their political and social views, or they may just be wealthy enough to fund it themselves."
]
}
|
[] |
[] |
[
[]
] |
|
2uv2rz
|
In his day was Leopold von Ranke (and his ideas about history being science) as harshly criticised as he is nowerdays by my history department?
|
Seems strange quite how immediately most of what I hear in lectures is dismissed.
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/2uv2rz/in_his_day_was_leopold_von_ranke_and_his_ideas/
|
{
"a_id": [
"coc4m4s",
"cocmgpx"
],
"score": [
7,
2
],
"text": [
"My knowledge of this is pure historiography, so maybe a historian of the period can elaborate, but the answer is no. Leopold von Ranke is largely credited with creating the discipline of history itself, so for much of his career he was unassailable. Late in his life there were some critics of his methods, but he was, for his day, pretty revolutionary.\n\nI'm not sure what kind of criticism you're seeing in your department, but I don't know if I would categorize modern historiography's take on Ranke as 'harsh'. The discipline has grown and evolved, mostly for the better, and Ranke is an important figure even if his ideas are no longer applicable.\n\nSource: Any historiography book ever. I referenced *From Historical Methods* by Powell and Prevenier because that's what I have on the shelf next to me.",
"Historicism is closely tied to the general thought and ideas of the 19th century. After world war 2 we didn't only start to see its flaws, but also \"lost\" the fundament on what it was built.\n\nMaybe that's why it seems strange to you."
]
}
|
[] |
[] |
[
[],
[]
] |
|
1kwyhx
|
how do people get stuck inside of fridges and freezers?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1kwyhx/eli5_how_do_people_get_stuck_inside_of_fridges/
|
{
"a_id": [
"cbtga6r"
],
"score": [
2
],
"text": [
"The first refrigerators that were produced for home use had actual latches on the door. This was decades ago. People would throw them out and, apparently, kids would climb in and lock themselves inside. But, for the last 40-50 years, refrigerators haven't had the latched doors. It's an old wives tale about kids getting locked in refrigerators now. "
]
}
|
[] |
[] |
[
[]
] |
||
dfj0zo
|
why does most graffiti have the same generic style/look that we have come to expect from vandals
|
[deleted]
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/dfj0zo/eli5_why_does_most_graffiti_have_the_same_generic/
|
{
"a_id": [
"f33dy2h",
"f33eack"
],
"score": [
6,
5
],
"text": [
"Speed, if you take too much time spraying it on the walls you will be caught doing it so speed is essential.",
"It's a lettering style designed to take up as much space as possible with color, leaving as little blank space as possible. And it's fairly easy to make with spray paint."
]
}
|
[] |
[] |
[
[],
[]
] |
|
3hhxyx
|
Is there anywhere that models predict will get nicer to live because of climate change?
|
Every time I read about the impacts of climate change, it's stories of ecological collapse, droughts, hurricanes, and so on. Is there anywhere that models predict the climate will get more moderate, the land more arable, and with more abundant fresh water?
To put another way, what's the best place to move to minimize the negative impact on my family?
|
askscience
|
http://www.reddit.com/r/askscience/comments/3hhxyx/is_there_anywhere_that_models_predict_will_get/
|
{
"a_id": [
"cu7qhwx",
"cu7raxf"
],
"score": [
20,
3
],
"text": [
"First off, \"nicer to live\" requires individual value judgements because not everyone is the same in what they like. By conventional metrics, most places are going to be losers in climate change but if the mean temperature was a bit warmer there will be some places which will generally be considered more pleasant places to live. Canada and Russian will be warmer but they will still have long dark winters. New York will get more like Miami and some people love Miami. It's known we are altering the climate but exact predictions of regional details are not as certain. It's not yet time to be homesteading new places based on predictions of climate 100 years in the future.\n\nRainfall and precipitation are also important factors in quality-of-life. While rain is inconvenient for picnics it essential for agriculture. Climate change is going to alter rainfall patterns but it's not as predictable which places will get hotter and drier and which get hotter and wetter. Storminess is also expected to increase for most places in the mid-latitudes. Timing of rainfall is also important - does it all come in winter or is it spread out through the year? It is unfortunately those places which are already struggling (Africa, Southeast Asia) which are forecast to have some of the worst negative effects on agriculture.",
"My understanding is the regional impacts of climate change have not been determined. It isn't completely clear when, or even if, the thermohaline circulation will stop. If it stops in your lifetime, you are likely to experience an ice age in short order. If it doesn't stop, Ohio is more likely to feel like Georgia in 2050 than be frozen. \nI think the really scary things are the political and economic impacts. What happens if the Sierra Nevadas can no longer supply summer irrigation water to the California agricultural valley? What happens if Hansen is right when he speculates about 10 feet of sea level rise by 2065? Do the Feds cover the relocation costs of north of 30 million Americans? Where does that money come from? What happens when Bangladesh has to move 50 million + people whose homes are now under sea water? Does India just absorb them, likewise with the refugees fleeing Africa to Europe right now? Does Europe just absorb millions of uneducated desperately poor Africans? These are the questions (and all the ones I haven't thought of) that worry me. \nUgh. I can't write anymore. This is depressing. Learn to garden. Learn to make your own energy. Try to live someplace with access to protein (like wild animals.) We are in trouble. "
]
}
|
[] |
[] |
[
[],
[]
] |
|
62oki0
|
why do android phone manufacturers not force carriers to use the same software like on ios?
|
For example with Samsung, each carrier has their own version of the software. Would it not be more efficient to make all carriers have the exact same software and just update that like on iOS?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/62oki0/eli5_why_do_android_phone_manufacturers_not_force/
|
{
"a_id": [
"dfo52ur"
],
"score": [
3
],
"text": [
"Because the manufacturers have very little power. If Samsung gives the carriers a hard time, they can immediately switch to HTC or another brand that's quite similar.\n\nBy contrast, if Apple gives the carriers a hard time, there is no very similar substitute they can choose, so they tolerate it."
]
}
|
[] |
[] |
[
[]
] |
|
j4y4n
|
explain how 0.999 recurring = 1 (li5.)
|
This was explained in class when I was younger. Never got my head around it.
Edit: Well and truly explained. Thanks.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/j4y4n/explain_how_0999_recurring_1_li5/
|
{
"a_id": [
"c29969x",
"c296htp",
"c296j0w",
"c296kr0",
"c296xsz",
"c29730k",
"c29969x"
],
"score": [
2,
15,
28,
3,
6,
3,
2
],
"text": [
"Do 1.00000000... minus .99999999...\n\nYou'll get 0.00000000... which is a neverending string of zeroes. You will naturally want to put a 1 at the end of all the zeroes, but there is an infinite amount of them. There *is* no end to stick a 1 onto.",
"A simple way is this: (let's assume the 0.333 and 0.999 are infinite)\n\n1/3 = 0.333 repeating\n\n1/3 + 1/3 + 1/3 = 1\n\nTHEREFORE\n\n0.333 + 0.333 + 0.333 = 1\n\nAND ALSO\n\n0.333 + 0.333 + 0.333 = 0.999\n\nThere are other, more complex ways, but this is probably the simplest.",
"All the numbers can be ordered on a very, very big line, like on a gigantic ruler. Now, if two numbers are different, that just means that there is some space on this ruler between them. That space is full of numbers, too. So, for example, 2 is a different number than 4, because (for example) 3 is between them. In fact, you can find more numbers than you could write a piece of paper between *any* two different numbers. Try it!\n\nNow, 0.99999... = 1 is just another way of saying that there are no other numbers between them. It makes sense once you try to come up with such a number yourself: Obviously it would have to start with 0.99999 as well but then be a little bit higher. But there is no such number that's still smaller than 1. ",
"I have a pretty simple algabraic proof that obviously a 5-year-old wouldn't understand, but you might:\n\nx = 0.999...\n\n10x = 9.999... (both sides multiplied by 10)\n\n9x = 9.999 - 0.999 = 9 (the small number subtracted from the big number)\n\nx = 1 (dividing both sides by 9)\n\nIt's just confusing because of the ways we represent numbers in various bases and as functions (i.e. fractions).",
"People who study math for a living (we call them \"mathematicians\") tell us that decimals (0.999, for example) can be transformed into fractions (1/4, for example) while still being the exact same thing. Say, for example, that you have a quarter — You can say that you have twenty-five cents (0.25) OR that you have 1/4 of a dollar, and BOTH ways are correct.\n\nMathematicians discovered long ago that there are some fractions that look really funky when converted into decimals. The fraction 1/3, when converted into a decimal, is 0.333333333... (the threes repeat forever). So let's imagine you have a loaf of bread, and it is cut into three equal pieces. The first slice is 1/3 of the loaf, the second slice is 1/3 of the loaf, and the third slice is 1/3 of the loaf. When you put them together, you get 1 loaf (1/3 + 1/3 + 1/3 = 3/3 = 1). But if we take the decimal counterparts, it looks like this: 0.33333... + 0.33333... + 0.33333... = 0.99999... \n\nWe didn't actually LOSE any part of the loaf of bread when we counted with decimals instead of fractions, so instead, mathematicians tell us that 0.999 recurring equals 1. ",
"If 0.999... did not equal 1, then there is a number between it and 1.\n\nWhat could that number be?",
"Do 1.00000000... minus .99999999...\n\nYou'll get 0.00000000... which is a neverending string of zeroes. You will naturally want to put a 1 at the end of all the zeroes, but there is an infinite amount of them. There *is* no end to stick a 1 onto."
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[],
[],
[]
] |
|
axcj73
|
Why is CBD's action on the 5HT-1A receptor non psychedelic, compared with e.g. LSD's action on the 5HT-2A?
|
[deleted]
|
askscience
|
https://www.reddit.com/r/askscience/comments/axcj73/why_is_cbds_action_on_the_5ht1a_receptor_non/
|
{
"a_id": [
"ehvguv7"
],
"score": [
4
],
"text": [
"So to begin, CBD is a partial agonist which is not the same as LSD, which is a full agonist. Partial agonism is jargon in that the drug binds quite well, but only exerts say 40% of an effect compared to a full agonist, which would give 100% of effect.\n\nAs well as this, we don't really know why certain drugs like LSD and substituted amphetamines cause hallucinations via activation of these receptors as we have drugs in our arsenal that are agonists at many of these receptors but without the psychedelic properties of LSD etc.\n\nTo make this a bit clearer for you (nothing to do with CBD but fascinating nonetheless) - Buprenorphine is a partial agonist of mu receptors for the treatment of opioid addiction. Because of its partial agonism it has a 'ceiling effect' (going back to partial agonists only being able to activate a receptor so much) meaning its abuse potential is greatly reduced as it cant give the high morphine can.\n\nThe reason Bupe works so well in the context of addiction is very interesting, and I'll tell you why. So, when both a full agonist (morphine) and partial agonist (buprenorphine) are present, the partial agonist actually acts as a competitive antagonist (consider the opposite of a agonist, it reverses or blocks the effects), competing with the full agonist for receptor occupancy and producing a net decrease in the receptor activation observed with the full agonist alone. This is why Buprenorphine is fantastic in what it does, because it, in a biological sense cock blocks morphine to those mu receptors it desperately wants to bind to.\n\nI am a pharmacology student so I would be more then happy to answer any q's you may have (especially in regards to psychopharmacology) as I love the subject and love to help people understand pharmacology. :) \n\n\n"
]
}
|
[] |
[] |
[
[]
] |
|
1jhgju
|
why do some tennis players grunt loudly whenever they hit the ball?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1jhgju/eli5_why_do_some_tennis_players_grunt_loudly/
|
{
"a_id": [
"cbepa7h"
],
"score": [
5
],
"text": [
"Tensing the torso allows maximum rigidity and power transfer to the strike. This tends to push air out of the lungs and produce a grunt, and grunting can be a way to focus on maintaining that form."
]
}
|
[] |
[] |
[
[]
] |
||
2eecq9
|
Could chemoautotrophic bacteria live in the hostile environments of another planet?
|
Not entirely sure if this is the place to ask this question, but I was recently watching [this video](_URL_0_) on Vimeo, and got curious.
Bacteria have been known to thrive in some of the most hostile places on earth. Places where we don't think life could possibly exist because of lack of oxygen, light, and other things deemed necessary for life, yet they still do.
So I was wondering, if it would be possible for bacteria that use nitrogen as an energy source to survive in other planets with high levels of radiation and toxic gases.
|
askscience
|
http://www.reddit.com/r/askscience/comments/2eecq9/could_chemoautotrophic_bacteria_live_in_the/
|
{
"a_id": [
"cjz0lrx"
],
"score": [
6
],
"text": [
"The discovery of extremophile organisms like bacteria has certainly broadened our understanding of life, and the sheer strangeness and lengths it can go and survive.\n\nSo, the answer is yes. There definitely *could* be organisms on other planets, even those that we might have traditionally thought of as being too hostile to life to support it. \n\nThe discovery of such extreme organisms has led some scientists and more than a few science fiction authors to speculate about the possibility of life on Europa, one of Jupiter's moons, or on Titan, one of Saturn's moons. Both are rather extreme compared to earth, but it might just be possible. "
]
}
|
[] |
[
"http://vimeo.com/channels/staffpicks/103389185"
] |
[
[]
] |
|
supox
|
Shimmering on roads.
|
When I drive on paved roads, occasionally there is this shimmering effect, like the road is made of some sort of liquid. It generally only happens when I'm changing elevation. What is this phenomenon?
|
askscience
|
http://www.reddit.com/r/askscience/comments/supox/shimmering_on_roads/
|
{
"a_id": [
"c4h4yqf"
],
"score": [
4
],
"text": [
"It is caused by the refraction of light when traveling through a density gradient in the air. The air near the surface is being heated by the hot pavement, and therefore expands reducing the pressure, resulting in less density. Light coming in from the sky is bends upwards when traversing from the colder and denser air above to the hot and thin air near the surface in a rather smooth arc and coming to meet your eye from a strange direction. You'll see more refraction when looking at pools of hot air from a shallower angle, hence why it's more apparent when you are changing elevation and can look along the tangent of a hill.\n\nHere's a quick picture demonstrating this: [_URL_0_](_URL_0_)\n\nIn fact, if you turn the picture upside down it resembles light bending downwards as it moves from less dense air, to much denser water (that is, each step is like an upside-down water surface, light doesn't arc like this when entering water). The deep reason behind this and other phenomena is the peculiar fact that light tends to go along paths that take the least amount of time. Rather than trying to get to you by slugging along through the colder air, it would rather dip down and zip through the hot air."
]
}
|
[] |
[] |
[
[
"http://i.imgur.com/Giv0T.png"
]
] |
|
1e01r2
|
As Historians, how can we utilize novels and literature as research?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/1e01r2/as_historians_how_can_we_utilize_novels_and/
|
{
"a_id": [
"c9vh9uk",
"c9vklyp",
"c9vlsz6"
],
"score": [
9,
6,
3
],
"text": [
"Well, certainly you can use period literature to provide evidence for a lot of things -- social norms, changing attitudes, the values and morals of the time, as well as a great source of linguistic data for language evolution. \n\nBut if you try to use say, a Mary Renault novel as evidence of Alexander's campaigns, you're probably going to have a bad time. ",
"This is a contentious area, to be sure. It gets deep into historical epistemologies and is a major source of contention in some faculties. \n\nThe problem is one of reliability of source material. This gets into questions of memory, post-modern inclusion, basic democracy in history, and many other things.\n\nFor example, let's say you wanted to research rice field slaves in the early 18th century. Typical sources might include things like purchase receipts, slaveowners' documents/diaries, some newspaper accounts, and other typical sources. (See Walter Johnson's fantastic *Soul by Soul* for a solid example of the use of these sorts of documents.) \n\nBut this is a history provided and lived by the slave owner. Any information gleaned here with respect to the slaves themselves will be imposed upon them; it will not be their own story. \n\nHow do we then \"get to\" the slaves' own story? Here is where it gets very messy. Sure, there are a few slave narratives out there (some of dubious genealogy,) but those are almost certainly the exception -- not many slaves made it out of those hell holes, much less wrote about the experience. \n\nSo what then? How do you get to the lives of those who did not produce documents in the most-known sense? The only way is to go thru oral histories, shared stories, and yes, some novels. \n\nThis then open up massive questions. Most folks will agree that over time, details in oral histories get embellished, forgotten, romanticized, demonized, etc., depending on the story. How does a historian reconcile this with the (supposed) quest for some sort of objectivity, some sort of \"factual\" basis for the conclusions the historian draws? \n\nFor some, there is no reconciliation. Certain schools of thought simply do not allow for the use of non-\"empirical\" sources. I don't mean to imply any sort of racism or hegemonic behavior, it's just that some folks can't wrap their collective heads around a definition of truth that is as variable as the winds. \n\nOthers, focused (often) on subaltern or antipodean cultures, embrace this challenge and see it as a way to allow previously unstudied peoples to be included in the grand historical narrative. Those who allow for these sorts of non-traditional sources are moving the historical authority from the narrowly-defined source to a very open-ended source base that ends, finally, at the beginning: the person for whom the material matters. These folks will argue that perceived truth is what matters, not the received truth that originates with the educational hegemon. They would argue that because truth varies from person-to-person, what we learn in history classes is just an agreed-upon-fiction. That is, more simply put, they would argue that the story Toni Morrison tells in *Beloved* is as real to those who lived the lives described by the characters as a bill of sale describing the purchase of a slave. \n\nI hope this rambly response makes some sense. There are a number of fine works out there that get into this sort of question. Many books on racial formation and race theory have fantastic explanatory introductions. Among them are Thelma Foote, *Black and White Manhattan,* Bruce Dain, *A Hideous Monster of the Mind,* and Tiya Miles *The Ties that Bind.*\n\nSome perhaps less theoretically-laden books include James Epstein, *In Practice,* James F Brooks, *Captives and Cousins,* and Claudio Saunt, *A New Order of Things.* \n\nMost of these works are underpinned by a strong current of post-modern (post-structural,) philosophy, relying on, among others, the work of Foucault, Derrida, and Bourdieu. \n\n",
"This is a major concern of the relatively new/resurgent subfield of travel history, which has been rising since the early 90s but has really taken off in the past 10-15 years. Travel accounts are plentiful and diverse going back centuries but straddle the line between literature and historical accounts. On the one hand many (but not all) travel accounts depict real encounters and real journeys, but they also display undeniable literary qualities that often get them compared with things like novels, which fall much more solidly on the literature side of things.\n\nGranted I'm no Mary Louise Pratt (hugely influential historian in the travel field and beyond) but I see the whole process as an extra sensitive exercise in careful source criticism. Take a travel account and you have to perform many of the same checks as other sources. How accurate is the account compared with external sources, what are the intentions/biases of the author, who is the intended audience, can the events be verified, and so on. But travel accounts also require additional literary categories of analysis, taking into account the use of metaphors and plot devices, treatment of the accounts \"characters\" (people not the author or narrator), contemporary writing conventions, publishing practices, etc. It can be an extremely complex process but it can also yield extremely interesting results given that travel accounts are intimate portrayals of cultural exchange and perceptions. Monumental authors like Pratt and Edward Said both relied heavily on travel accounts to produce great research on power negotiation between imperialists and colonized peoples, and numerous scholars since them have sought to expand on this type of work.\n\nWhere I'm going with this is that like travel accounts (which resemble literature in several ways), novels and similar works of intentionally fictional writing can serve historians quite well when treated correctly. Though not nearly as simple as I'm about to make it sound, this process involves incorporating not only historical but literary methods of deconstruction. What's more, though, I think the use of such sources serves as an important reminder to historians of just how tricky their sources can be, and not just the literary ones. As Cosmic_Charlie mentioned in his post, \"typical\" sources can too often be thought of as unproblematic, implicitly if not explicitly. Not only does this make historians complacent but it also leads to the casual dismissal of more blatantly problematic sources like travel accounts. Not that long ago the default position for historians was to dismiss all travel sources as either fictional, as told by inexpert fools or liars, as lesser history, or all of the above. As if unproblematic and pure sources existed. To me, novels and literature, like travel accounts, are highly useful but temperamental, requiring a cautious and strict style of analysis that keeps the greater historical community on their toes."
]
}
|
[] |
[] |
[
[],
[],
[]
] |
||
2um650
|
Why not make smaller turbojet engines instead of a larger turbofan with high bypass ratio?
|
I'm curious about this after some casual browsing on wikipedia about jet engines.
Wouldn't a high bypass ratio be inefficient in terms of both physical size and compression efficiency from the turbine? Why waste fan energy by bypassing it around the engine?
|
askscience
|
http://www.reddit.com/r/askscience/comments/2um650/why_not_make_smaller_turbojet_engines_instead_of/
|
{
"a_id": [
"co9ybrw",
"co9z0gy"
],
"score": [
3,
6
],
"text": [
"Turbojets are designed to create thrust by turning thermal energy into thrust directly, in the form of a high velocity exhaust stream. As long as the exhaust is moving faster than the speed of the vehicle, it will generate thrust. As long as the total thrust of these engines is greater than the aerodynamic drag on the vehicle, it will accelerate. \n\nThe turbine engine within a turbofan is designed for a completely different purpose - it's not designed with the goal of generating thrust directly by generating a reaction force, but rather for generating mechanical power which then drives a fan. Don't think of a turbofan as just a turbojet with a fan attached, because the turbine inside is designed with different parameters in mind - mechanical power output being prioritized over thrust output, which changes the way the turbine is built. We use turbofans for the vast majority of jet airplanes for the same reason our modern helicopters use turbines, as do our modern tanks: purpose-designed turbines are a great way to generate mechanical power.\n\n\n\n\n\n\n",
"I think /u/throwhooawayyfoe's answer, while correct, misses the point.\n\nJet engines, like rocket engines, work by generating negative momentum and putting it onto some propellant, which gets discarded out the back of the vehicle. Since momentum is conserved, the leftover positive momentum remains in the vehicle -- the engine has applied some thrust! Jet engines differ from rocket engines only in that they grab material from the surroundings, to use as propellant.\n\nThe problem with both kinds of engine is that putting momentum on matter costs energy. The momentum of a piece of propellant rises like ( mv ) -- it's proportional to how fast you push the matter out the back. But the energy on that piece of propellant rises like ( 1/2 m v^2 ) -- it is proportional to the *square* of the speed you push it.\n\nSo the faster you push the propellant out the back, the less energy efficient it is: the ratio of propellant kinetic energy to propellant momentum grows like v, so the faster you push the propellant, the more energy it costs you for each little bit of momentum.\n\nIn a rocket, the big deal is that you want to get as much momentum on as little propellant as possible, since you have to carry the propellant with you -- so you push the propellant as fast as possible. That maximizes propellant efficiency (how much thrust you get for each kg of propellant you throw out the back), but minimizes energy efficiency (much thrust you get for each joule of energy you expend).\n\nBut in a jet, you get propellant for free -- you can harvest it from the surroundings. So you want to put your momentum on as much propellant as possible, to reduce the amount of energy you have to load onto that propellant. Propellant is free, but energy costs money.\n\nThat's why high bypass ratio engines are more efficient: they push more propellant (the bypass air), so they can get away with loading less total kinetic energy onto it. That means they don't have to burn as much fuel to produce the same amount of thrust.\n\nA side effect of that is that high-bypass engines are quieter. That's because the extra kinetic energy from low bypass engines' exhaust gets dissipated as noise. Since the designers of military fighter jets care more about compact form than about fuel efficiency, fighter jets generally use low bypass engines with high speed exhaust. That's why they're so damn loud compared to large passenger jets.\n\n**tl;dr concentrating momentum onto a small amount of propellant costs energy. Using more propellant (in a high bypass engine) reduces the total amount of energy needed for the same thrust.**"
]
}
|
[] |
[] |
[
[],
[]
] |
|
3q49zn
|
Was Aristotle ever right?
|
Just curious, somewhere I heard the assertion that "Nothing Aristotle ever said was correct". Ever since then, I haven't found a single example of a correct statement by Aristotle. Maybe I just suck at searching though.
(And naturally, I'm just talking about hard science facts, I'm not considering theology/philosophy/etc.)
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/3q49zn/was_aristotle_ever_right/
|
{
"a_id": [
"cwccaeh"
],
"score": [
8
],
"text": [
" > I'm just talking about hard science facts\n\nThis only works if you believe science is an accumulation of facts. Instead, it might be useful to think of science as a project to model nature ([see Thomas Kuhn](_URL_0_)). For instance, Newtonian physics is a model that has retained much of its predictive power even as its assumptions about the nature of reality have been questioned by subsequent physicists.\n\nOn that understanding of science, Aristotle offered some models that were very useful until more precise and predictive models came along. For instance, the idea of elements with inherent tendencies can be useful. It makes sense of fire reaching upward, water settling into holes, and the incredibly regular motion of heavenly bodies. Ultimately, every Aristotelian model of nature that I'm familiar with has been replaced by more precise models with very different assumptions about the nature of things."
]
}
|
[] |
[] |
[
[
"https://books.google.com/books?id=3eP5Y_OOuzwC&printsec=frontcover"
]
] |
|
19ma6e
|
what is the point of rooting android products and jailbreaking apple products.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/19ma6e/eli5_what_is_the_point_of_rooting_android/
|
{
"a_id": [
"c8pb6n1"
],
"score": [
2
],
"text": [
"Rooting on Android gives you administer access to the device, letting you install custom software, overclock the hardware, delete built in apps, and allow apps to have functionality they otherwise would be denied.\n\nJailbreaking on iOS installs a second app store known as Cydia that lets you download and install software not approved by Apple. These apps also do things normal appstore apps dont, such as allowing you to tweak the functions of the OS and customize it. "
]
}
|
[] |
[] |
[
[]
] |
||
1se26q
|
Did Shakespeare and His Plays Cause Any Naming Trends?
|
Given many Americans name their children after stuff they see in the media (celebrity babies, Game of Thrones characters), did Shakespeare's popular plays trigger any naming trends after characters? I.e. were there booms of little Hamlets (other than his kid) and little Mirandas due to the Bard? I guess this could be ascertained through looking at the baptismal records, but I am too lazy to look through them.
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/1se26q/did_shakespeare_and_his_plays_cause_any_naming/
|
{
"a_id": [
"cdww09t"
],
"score": [
36
],
"text": [
"Probably the most influential names invented by Shakespeare were (and are) Jessica and Olivia. The following is from *The Merchant of Venice* (Arden Shakespeare, 3rd Series) Act 2, Scene 4, Lines 19-20:\n\n > LORENZO:\n\n > Hold here--take this, tell gentle Jessica\n\n > I will not fail her; speak it privately.\n\n\nWhat you just read is the earliest known appearance of the name Jessica with its modern spelling. Jessica was the most popular name for girls in the United States in the 1980's and 1990's and was the United Kingdom's most popular name of 2005.\n\nHere is the first appearance of the name Olivia in *Twelfth Night*:\n\n > DUKE ORSINO:\n\n > ...\n\n > O, when mine eyes did see Olivia first,\n\n > Methought she purged the air of pestilence!\n\n-TN, 1.1.19-20 (Arden, 2nd Series)\n\nOlivia became very popular throughout the English-speaking world in the 1990's and chances are pretty good that you've met one.\n\nBut that doesn't completely answer your question. You asked about Shakespeare's influence on naming trends in his own time and in the years following his death.\n\nShakespeare began his career as an actor some time in the 1580s. His debut as a playwright came some time between 1589 and 1591. In 1594 - 1595 a string of popular hits begin to make Shakespeare's career take off and by ~1599 - 1606 (what used to be called his \"great\" period) he was a minor celebrity and the plays of the Lord Chamberlain's Men were in very high demand.\n\nSo let's look at the most popular names for girls in England from 1600 to 1630. I'll be using [Names and Naming Patterns in England, 1538-1700](_URL_0_) by Scott Smith-Bannister, Oxford University Press, 1997:\n\nThe top four were (in order of descending popularity) Elizabeth, Mary, Anne, and Margaret. Alice, Jane, Joan, Agnes, Susanna, and Catherine round out the top ten. All of these were very common in the late 1500s as well, so Shakespearean names didn't crack the top ten until a few decades after he died.\n\n**However**, *Much Ado About Nothing* opened (supposedly) in the fall - winter of 1599 and was very popular in its first run. The name Beatrice appears in the top 20 English baby names in 1600-1610 for the first time in many years and then drops off again until 1680. This correlation of the debut of *Much Ado* with the spike in the popularity of Beatrice suggests (but does not necessarily prove) that Shakespeare did indeed influence naming trends in his own time."
]
}
|
[] |
[] |
[
[
"http://books.google.com/books/about/Names_and_Naming_Patterns_in_England_153.html?id=UoFY4ahN0u8C"
]
] |
|
14dge2
|
What does the spin on a bullet do for the pressure wave it creates? Does it change its nature much compared to as if it was not spinning and simply translating?
|
askscience
|
http://www.reddit.com/r/askscience/comments/14dge2/what_does_the_spin_on_a_bullet_do_for_the/
|
{
"a_id": [
"c7c6gjl"
],
"score": [
2
],
"text": [
"I'm not sure if this is what you're looking for, but [here is an image](_URL_0_) of a gun being fired underwater. You can see the cavitation caused by the bullet is twisted because of the bullet's spin. A similar thing should happen in air."
]
}
|
[] |
[] |
[
[
"http://also.kottke.org/misc/images/firing%20a%20gun%20under%20water.jpg"
]
] |
||
5nhwtc
|
how are we able to sense where our body parts are in space without actually looking at or feeling them?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/5nhwtc/eli5_how_are_we_able_to_sense_where_our_body/
|
{
"a_id": [
"dcbna8q"
],
"score": [
3
],
"text": [
"That's called proprioception, or kinesthetic awareness. It's also somewhat tied into reflexes, like catching or dodging a ball. You can increase the sensitivity with practice, too. Sadly, though, the “spider sense” is just for comics and movies for now."
]
}
|
[] |
[] |
[
[]
] |
||
68sv33
|
is there any situation in which the mathematical median can be higher than the mean?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/68sv33/eli5_is_there_any_situation_in_which_the/
|
{
"a_id": [
"dh0z9g2"
],
"score": [
4
],
"text": [
"The relationship between the mean and median are based on how skewed the data is, and in what direction the skew is. Generally speaking, things that we are familiar with tend to be skewed right, so we get that the mean is greater than the median. But if the data is skewed left, then the median will be greater than the mean. Consider the following data set:\n\n{1,100,101}\n\nWhat is the median? 100. What is the mean? 67-ish.\n\nIt is just that data tends to not really look like this in most familiar situations."
]
}
|
[] |
[] |
[
[]
] |
||
28s3il
|
can someone explain whether obesity is only present in humans or other mammals too have this disorder within their species?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/28s3il/eli5_can_someone_explain_whether_obesity_is_only/
|
{
"a_id": [
"cidwj9e",
"cidwog7"
],
"score": [
3,
3
],
"text": [
"I've seen some fat ass cats and dogs. ",
"Other animals can get fat, too. Pets often become obese; lab animals can gain too much weight if their diets aren't carefully adjusted. Among wild animals, morbid obesity isn't particularly common, because animals that are too fat to run away from predators usually either lose weight or get eaten."
]
}
|
[] |
[] |
[
[],
[]
] |
||
2dt6u1
|
do/can animals in nature outside of human contact get fat or even mordidly obese?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2dt6u1/eli5_docan_animals_in_nature_outside_of_human/
|
{
"a_id": [
"cjstavg",
"cjsts2f",
"cjsuc4h",
"cjsuu6i",
"cjswaiz",
"cjsx956",
"cjsxcxv",
"cjszhhm",
"cjt0gee",
"cjt3v7x",
"cjt4aaa",
"cjt5443",
"cjt57vj",
"cjt5cvo",
"cjt5eh3",
"cjt5ouc",
"cjt6862",
"cjt8mtg",
"cjt8ytk",
"cjtafql",
"cjtaj3h"
],
"score": [
140,
821,
2,
64,
37,
2,
17,
7,
4,
3,
21,
69,
2,
2,
12,
15,
2,
2,
2,
2,
2
],
"text": [
"Pandas are the only one I can think of. All animals can become obese but they dont.",
"They don't become obese due to limited food resources. Even if they could eat all they wanted, being fat would slow them down and increase their chance of becoming prey to something bigger and faster. Bears are the only thing I can quickly think of the eat to excess, but that is because they are storing energy for their winter hibernation. That, and they are an apex predator. The only thing that hunts them are humans. ",
"I have seen obese animals in the wild. It just depends on the readily available resources. If they don't have to forage much and have little competition they'll get fat. ",
"Depends on what you mean by \"fat\". As mentioned, bears bulk up for hibernation. Ocean going mammals have a layer of blubber. They are literally fat, but not unhealthy. Morbidly obese is a better term, meaning fat to the point that you are killing yourself. No, I don't think wild animals can get to that point without human contact, because they do not have access to enough food to get to that point, and if they could, they themselves would be food for something else. ",
"Many marine mammals are extreemly fat. Elephant Seals, Whales, Walruss, etc. \n \nAnimals that hibernate fatten themselves up first. \n \nAnimals that hunt or get hunted cannot afford to get fat as it leads to an inability to hunt or avoid being hunted so the problem takes care of itself. \n \nMany birds get fat such as penguins an puffins. This is partially to insulate against the cold and partially because it is easy to catch fish for them so getting lots of food is not a problem. ",
"I'm not sure about morbidly obese, but there's a 17 year cicadas invasion in a few places that results in some very full animals. EDIT :not sure why the down votes but ok.",
"This question reminds me of this video. \n_URL_0_\n\nEdit: added original creator. ",
"I know this isn't exactly what you asked but I saw a documentary recently about some people who keep moneys as pets. It said many pet monkeys are becoming sick, overweight and getting diabetes when they are being fed human food. There are no known cases of a monkey in the wild having diabetes. ",
"I don't think morbidly obese, but many animals get fat for the onset of winter. Studies have shown that even if hibernating animals are DENIED FOOD when fall comes around, they still grow fat and simply move less (due to less energy from less food); the fat growth is a biological imperative that won't be circumvented, apparently. Then, despite what they are fed after winter is over, they will shed that fat like crazy and return to their normal weight. \n\nThere might be some instances of animals being born that do not have hormone regulation and thus become fat or even morbidly obese in the wild. I've personally never seen anything like that, though. Scientists have mucked about with hormones in animals for testing purposes and the animals have become fat or stayed very lean accordingly, though.\n\nBut in most instances, not really. The growth of fatty tissue is usually brought about by eating simple carbohydrates (which raise your insulin levels, which promotes fat storage), and most animals do not target those as the main source of their food (carnivores eating meat, most herbivores eating grassy shit, etc).",
"There used to be a really fat squirrel that came around. Yes people feed them, but he was a lot fatter then the rest. He would also eat things the others wouldn't, like salt and vinegar chips.",
"Not sure if this qualifies as human contact, but I have seen rats in a pet food warehouse eat themselves essentially to death. They would tear open a 50 pound bag of dog food and eat so much there legs would no longer work. Their stomachs got so fat that their feet didn't touch the ground anymore. \n\nAlso remember that old youtube video of the squirrel that got into the bird feeder and ate so much he could no longer get out? This is what those rats did.\n\n_URL_0_\n\nSo there are two examples of animals getting to obese it became morbid.",
"Yes. As elephant seal pups enter the weaning period they will sometimes choose to start nursing on a different mother that recently had her pup, pushing the much smaller pup to the side. Elephant seal milk is very rich, 60% fat, so this pup will become morbidly obese. By doing this the pup loses out on the crucial period where it learns to swim and hunt. Ironically it will eventually starve to death.",
"Diddly do yes they do.",
"At the very least, I know there are animals that have suffered brain damage in a way that keeps them from knowing that they are full; this results in them eating themselves to death, if they can. (You could argue that humans are often to blame for serious injuries to wild animals, but theoretically it's possible without humans.) Similarly, though perhaps not quite what you meant, there are certain domesticated species that will supposedly eat themselves to death *without* humans to stop them--such as sheep--but again you could blame humans for making those species dependent on them in the first place.",
"There are vultures who have gotten morbidly obese after terrible events that led to mass deaths. The vultures got fat to the point that they can't even fly.",
"[sure](_URL_0_). All it takes is an overly abundant food supply, but those are hard to come by in nature.",
"Some animals have genetic condishuns that make them beautiful no matter how obese they are, shitlord.",
"University of Michigan squirrels.\n\nEnd of story.",
"The problem is that it's already difficult for any creature to get the calories it needs to function and to breed. Having an excess intake of calories will almost never happen. Humanity itself had only (widespread) access to plentiful calories in the last century or two. Being overweight was a sign of great wealth in all of humanity's history before that.",
"The raccoons behind the pizza Hut I work at are. ",
"The limiting factor for most animal populations is the availability of food. If a food-limited population of animals had access to enough food that they could become obese, their numbers would increase until that was no longer the case. \n\nIn a population with a different limiting factor (e.g. crowding) you might see some weight gain, but it's hard if not impossible for most species to become obese by eating the diet they're adapted to in its natural form. You usually have to feed them a more energy-dense mix of foods than they're adapted to."
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[],
[],
[
"http://youtu.be/yltlJEdSAHw"
],
[],
[],
[],
[
"https://www.youtube.com/watch?v=evRGIOj7nko"
],
[],
[],
[],
[],
[
"http://37.media.tumblr.com/tumblr_lowjxcz0cb1qzt6iio1_500.jpg"
],
[],
[],
[],
[],
[]
] |
||
1vt1bg
|
why do i keep getting acne when i have showered every day for 4 years and have a healthy diet/work out? im a 18 year old male
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1vt1bg/eli5_why_do_i_keep_getting_acne_when_i_have/
|
{
"a_id": [
"cevioz5"
],
"score": [
2
],
"text": [
"Not a doctor here, but maybe you should see a dermatologist if you haven't already (not that this is strange, but they can really help).\n\nA lot of acne in adolescence is caused by androgens being released in the body, such as testosterone (this is released in *everybody* during puberty, regardless of sex). Sometimes acne is deep in the skin tissue (cystic acne). Sometimes, acne can be caused by bacteria in the skin, not just hormones or unhealthiness or uncleanliness. If this appears to be the case, a dermatologist might prescribe an antibiotic such as Minocycline, or Isotretinoin (Accutane). However, a doctor would not prescribe Accutane unless you had severe acne and they'd tried basically everything else. It has nasty side effects. If the acne is not caused by bacteria, you will probably just be using some sort of topical cream (versus using a cream and an antibiotic).\n\nRemember that there is no cure for acne -- there are only things you can do to prevent it."
]
}
|
[] |
[] |
[
[]
] |
||
2o5t9x
|
what exactly the 10nm, 14nm, 22nm, etc nodes mean in semiconductor processing
|
I am having trouble understanding what those nodes represent. At first I thought they wetr the size of transistors but more research shows it has something to do with photolithography. Can someone explain it please? Thanks
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2o5t9x/eli5_what_exactly_the_10nm_14nm_22nm_etc_nodes/
|
{
"a_id": [
"cmjyx5n"
],
"score": [
4
],
"text": [
"Well, it's a bit confusing even to people in the industry. The devil's in the details. \n \nIn the distant past, the geometry of the \"node\" meant the size of the smallest transistors. But a while back it started to refer more to the pitch of the tightest metal layer (usually metal 1), where \"pitch\" means the width of the line plus 1/2 the space on either side. It was claimed that this was a better metric for how tightly things could be packed together. Marketing had crept into the engineering domain. \n \nThere is no single accepted standard now; different companies use different ways to measure their process geometry, and one company may change their definitions a bit at different process nodes. All are a bit deceptive, because *both* the transistor pitches and the metal pitches are important in determining how many circuits can be put in some area. \n \nTo really know about any fab's geometries, you need to dig into the details of all the different layers. For example, a process might have very tight pitches for transistors and metal 1 and 2, but very loose pitches for the higher layers of metal. So in theory you can pack transistors tightly...you just can't very efficiently hook them up to each other. It is possible for one company's 16nm process to be better at getting transistor density than another company's 14nm process. "
]
}
|
[] |
[] |
[
[]
] |
|
90enba
|
Nixon courted southern Democrats with the Southern Strategy. Prior to that, what common cause did these people have with northeastern elites like FDR and Kennedy?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/90enba/nixon_courted_southern_democrats_with_the/
|
{
"a_id": [
"e2r8a89"
],
"score": [
4
],
"text": [
"Roosevelt's biggest contribution to American politics was the establishment of the New Deal Coalition. Roosevelt united the traditional Democratic base (conservative Southerners, northern immigrants and Catholics, liberal northerners) along with expanding into traditionally Republican groups (such as blacks and Midwesterners) by promising an end to the Great Depression. The New Deal brought electricity, modernization, jobs, and most importantly, hope, to the South, the Midwest, and America at large. Basically, Roosevelt created common cause by improving people's lives across the board. \n\nThe tradition of the South voting Democrat (no matter what) for most of the party's history, boosted by the New Deal Coalition, made it so Southerners kept voting Democrat as long as they held a prominent position in the Democratic Party, and as long as those northeastern elites turned a blind eye to race relations. Despite being a New Yorker, Roosevelt was still 'their guy,' in the same way the northeastern elitist Mitt Romney was 'the guy' for the South in 2012.\n\nThe differences began when Kennedy *didn't* turn a blind eye. He didn't promise total desgregation or anything, but he discussed civil rights enough that it made the Southern base upset. It's somewhat inaccurate to compare Roosevelt and Kennedy for relations with the South, as in 1960, Kennedy had one of the worst performances of a Democrat in the Southern states, losing Virginia, Florida, Kentucky, and Tennessee to Nixon, and Alabama and Mississippi to Dixiecrats."
]
}
|
[] |
[] |
[
[]
] |
||
9d3dzo
|
When a sufficiently sized star dies and collapses into a black hole, does the gravitational attraction that it yields change?
|
askscience
|
https://www.reddit.com/r/askscience/comments/9d3dzo/when_a_sufficiently_sized_star_dies_and_collapses/
|
{
"a_id": [
"e5faj2r",
"e5fqp2k"
],
"score": [
24,
3
],
"text": [
"Either \"no\" or \"it might go down\" depending on what you mean.\n\nAt large distances, old fashioned classical gravity is accurate for both. The force of gravity is proportional to the mass. So if all the mass is retained, then gravity doesn't change. But in a supernova, a lot of mass is thrown out, so the resulting black hole has a lower mass than the star, and has *weaker* gravity*.\n\nThat said, when you get close to a black hole, weird general relativity stuff does start to happen - stuff that doesn't really happen in a star. This is because the mass is concentrated in a smaller region, and you can get much closer to the centre of mass (without being *inside* the object) and feel stronger gravity.\n\nBut if you're a planet orbiting a star, and that star magically turns into a black hole, your orbit won't change. ",
"Yes it will. It will actually go down. The collapse itself produces a supernova in all cases I'm aware of. This event is highly energetic and causes a lot of light and matter to be blasted away from the core of the star. This means that a black hole will always have less mass than the star that formed it. \n\nThe surface gravity of the object however changes dramatically. The surface of a star is actually very far from its center of mass, thus the gravity is lower (by the square of the radius). Meanwhile a black hole's event horizon is much tighter, held very close to the center of mass. If you stand at the same distance from the star and from the resulting black hole, the star would have more gravity because it had more mass. You can stand a whole lot closer to the black hole, and every time you half the distance, you quadruple the gravity."
]
}
|
[] |
[] |
[
[],
[]
] |
||
15o2rq
|
Was Gandhi actually a positive influence on the development of India as a country?
|
It seems to me that Britain Relinquished control over many of her colonies voluntarily post WWII (Mostly due to economics and it's own internal de-colonization movement).
So did Gandhi actually do much to help India's independence movement and did his legacy(which turned out to be rampant corruption, cronyism and economic stagnation) offset whatever good he had accomplished?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/15o2rq/was_gandhi_actually_a_positive_influence_on_the/
|
{
"a_id": [
"c7o7htd",
"c7o91b3"
],
"score": [
2,
3
],
"text": [
"This is one of the most hotly debated issues that I've ever encountered. A lot of people blame Ghandi for effectively bringing back the caste system. Honestly I'm not well read enough on the subject to go into much on the subject though. Hopefully a specialist will chime in on this one, as I'd like to hear what they have to say myself.",
"It's complicated; if you're not already aware of it there's a three hour long three part [BBC Documentary on Gandhi](_URL_0_) that covers a lot of his life and legacy. while it doesn't attempt a final judgement it does show various sides to the man and his actions.\n"
]
}
|
[] |
[] |
[
[],
[
"http://www.bbc.co.uk/programmes/b00n7sf1"
]
] |
|
mizm8
|
what generates the messages in computer errors?
|
Not being great at computers myself, I've always wondered where some of the strange error messages come from.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/mizm8/eli5_what_generates_the_messages_in_computer/
|
{
"a_id": [
"c31b0kk",
"c31b1dx",
"c31b9os",
"c31b0kk",
"c31b1dx",
"c31b9os"
],
"score": [
2,
3,
6,
2,
3,
6
],
"text": [
"I'm not sure what you mean by this. Each individual program has the ability to throw an error message. The operating system can throw them, as well. Can you be more specific with your question?",
"Error messages are usually for the programmer, not the user. This means they use jargon and probably only make sense in the context of the code.",
"Computer programmers write the error message into their software. \nSometimes they do so for their eyes only as a way of fixing their code.\n\nIt's like walking in a forest and making a mark on each tree.\nIf everything goes right, you will not ever see the mark again.\nBut if you are lost, you can look for the mark that you made to see where\nyou went wrong.\n\nComputer programmers make lots of marks in their code, so they can \nfix/debug their code later.",
"I'm not sure what you mean by this. Each individual program has the ability to throw an error message. The operating system can throw them, as well. Can you be more specific with your question?",
"Error messages are usually for the programmer, not the user. This means they use jargon and probably only make sense in the context of the code.",
"Computer programmers write the error message into their software. \nSometimes they do so for their eyes only as a way of fixing their code.\n\nIt's like walking in a forest and making a mark on each tree.\nIf everything goes right, you will not ever see the mark again.\nBut if you are lost, you can look for the mark that you made to see where\nyou went wrong.\n\nComputer programmers make lots of marks in their code, so they can \nfix/debug their code later."
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[],
[]
] |
|
48yb5a
|
how did scientists first hypothesise that an meteor killed the dinosaurs?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/48yb5a/eli5_how_did_scientists_first_hypothesise_that_an/
|
{
"a_id": [
"d0nk510",
"d0o32u3",
"d0odppp"
],
"score": [
69,
2,
4
],
"text": [
"It was proposed by [Luis Walter Alvarez](_URL_0_) after he noticed a thin layer of clay in the geologic record between the Cretaceous and Tertiary (now called the Paleogene) periods. After further investigation of the composition of the clay (in particular, the high-levels of iridium), Alvarez and his team proposed it may have originated from an impact from space.\n\nLater, finding evidence of an impact crater in Mexico along with the relatively quick demise of many species (including the dinosaurs) led credibility to the theory.",
"The fossil record tells the story. Rock layers deposited before the iridium layer contained fossils from many large dinosaurs. But the layers of rock above (the younger layer) contained none. His conclusion was to associate the dinosaur extinction event to the iridium. \n\nThe theory wasn't popular until a crater from an asteroid impact was found in the Yucatan by oil companies drilling in the Gulf. The impact event coincided with the iridium and the abrupt change in the fossil record. In addition, there were some serious volcanic events from that time period that may have exacerbated the situation. The extinction event wasn't simply an overnight affair - it actually may have taken more than a million years (relatively short for geology but a little long if you were looking for a knock-out punch). \n\nThe theory of an asteroid the size of Manhattan crashing into the sea off the coast of Mexico 65 million years ago remains the best explanation we have to date of what happened to Mister Rex and Miss Triceratops. Twas ever thus.",
"The start of it all was the discovery and study of the [Cretaceous–Tertiary](_URL_0_) (K–T) line. It's a visible layer between the cretaceous and the tertiary earth layer. Every dinosaur fossil ever found was under this layer. The exceptions are fossils that get found because of the constant moving underground layers piling up which brings those fossils back to the surface or close to it. \n\nThe scientists then asked themselves what happened. What caused this relatively abrupt end to the dinosaurs? Why do we find every dinosaur under this visible line? They studied the layers before and after the event and came up with the first theories.\n\nThat said, it's still a mystery how it exactly went down. If it was for example caused by the meteorite impact itself or more the aftermath of the impact."
]
}
|
[] |
[] |
[
[
"https://en.wikipedia.org/wiki/Luis_Walter_Alvarez#Dinosaur_extinction"
],
[],
[
"https://simple.wikipedia.org/wiki/K/T_extinction_event"
]
] |
||
2yowba
|
what is going on in your brain when you stare? why are you so focused on one thing you can't look away?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2yowba/eli5_what_is_going_on_in_your_brain_when_you/
|
{
"a_id": [
"cpbkd1s"
],
"score": [
3
],
"text": [
"I am not a psychologist, but generally it is because you are seeing something your brain considers valuable or possibly dangerous. If a man stares at a woman with large breasts, then it is because his brain considers it something valuable and wants it. You will focus more easily on something or someone that you find inherently valuable compared to something you consider important like math. Your brain wants the large breasted woman so it will encourage you to focus on that object and retrieve it.\n\nNow if you see something out of the ordinary like a kid wearing some crazy braces with a head set for their jacked up teeth, then you brain is assessing it for possible danger. You inherently won't trust it even if you consciously know that the 12 year old with extreme dental issues is not a threat to you. \n\nEither way you are assessing whatever you stare at and your brain considers it too important to just glance at and look away."
]
}
|
[] |
[] |
[
[]
] |
||
3dgjiy
|
Who made the bombs for the IRA?
|
Was it just one man? Or numerous men? I'm also curious as to how they got bombs into mainland England. And one last thing why were the South Armagh brigade so hard to deal with for the British army, I heard a lot about them and how British army forces wouldn't even enter certain villages.
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/3dgjiy/who_made_the_bombs_for_the_ira/
|
{
"a_id": [
"ct56srl"
],
"score": [
10
],
"text": [
"Early on the bombs were mostly homemade using Ammonium Nitrate fertiliser. While the process is simple it does take skill to get it right and there were several people who specialised in it. The explosives were often made in ordinary houses or sheds.\n\nThe provision of Semtex from Libya in the 1980s gave the IRA a lot of flexibility as it is more powerful and useful.\n\nRichard English, *Armed Struggle* is probably the best history of the IRA. You could also look at James Bowyer Bell or Tim Pat Coogan. Coogan is a journalist with good sources but his historical analysis is very poor so be warned."
]
}
|
[] |
[] |
[
[]
] |
|
s8w2p
|
What can you tell me about pirates?
|
So i read that post a while ago about the pirate code and it got me into this subreddit. I was wondering if anyone had other cool facts about pirates or other naval combatants of the time because lets face it those guys were cool.
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/s8w2p/what_can_you_tell_me_about_pirates/
|
{
"a_id": [
"c4c1qei",
"c4c3zil",
"c4c7l0b",
"c4cm183"
],
"score": [
5,
14,
5,
3
],
"text": [
"Apparently they helped [prevent global warming](_URL_0_). That's a cool fact.",
"Pierre Le Grand (_URL_0_ Legendary Pirate who captured a Spanish treasure galleon with 28 men and a leaky boat.\n\nL'Olonnais(_URL_6_) - Allegedly ate a man's beating heart out of his chest to intimidate prisoners.\n\nDu Pointis - _URL_2_ captured 20 million Livres and defeated one of the greatest forts in the Carribean.\n\nGrace O'Malley (_URL_1_) - Irish queen and pirate.\n\nJean Bart (_URL_5_) Born a fisherman's son, died an admiral.\n\nBlack Bart (_URL_3_) captured 470 ships.\n\nWoods Rodgers (_URL_4_) started off as a legitimate businessman, became a pirate, and later broke the back of the Golden Age Pirates as governor of the Bahamas.\n\n\nThese are some of the lesser known among most people pirates who were actually pretty bad ass and more successful than the likes of Blackbeard and Kidd. I'm a bit tired, so I may come back later and add some more here.",
"That's a pretty broad question, especially considering the scope of piracy. If you're looking for a good comprehensive book, I (and my prof who studies pirates for a living) recommend Peter Earle's *Pirate Wars*. \n\nOther than that, feel free to ask me anything and I will do my best to answer. ",
"It's interesting to look into the East India Company, there's a lot of articles arguing that were just licensed pirates of the English government."
]
}
|
[] |
[] |
[
[
"http://upload.wikimedia.org/wikipedia/commons/d/de/PiratesVsTemp%28en%29.svg"
],
[
"http://en.wikipedia.org/wiki/Pierre_le_Grand_(pirate)",
"http://en.wikipedia.org/wiki/Gr%C3%A1inne_O%27Malley",
"http://en.wikipedia.org/wiki/Raid_on_Cartagena_(1697)",
"http://en.wikipedia.org/wiki/Bartholomew_Roberts",
"http://en.wikipedia.org/wiki/Woodes_Rogers",
"http://en.wikipedia.org/wiki/Jean_Bart",
"http://en.wikipedia.org/wiki/Fran%C3%A7ois_l%27Olonnais"
],
[],
[]
] |
|
5lb3ld
|
why do humans need to be taught about sex while other animals just know what to do?
|
So a rabbit reaches sexual maturity, he knows exactly what to do. However, if a human reached sexual maturity and has never been exposed to anything of a sexual nature, he would have no idea what to do with another human being. To be clear, the question is not why humans aren't naturally good at sex, but why humans wouldn't know the basic mechanics without "taught" about them first.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/5lb3ld/eli5_why_do_humans_need_to_be_taught_about_sex/
|
{
"a_id": [
"dbub64d",
"dbub7vn",
"dbubc7z",
"dbufwfv",
"dbufyhh",
"dbum8po"
],
"score": [
12,
30,
21,
11,
2,
3
],
"text": [
"This is a very vague and not conclusive answer, but: Humans instinctively know more about sex than you think, and animals instinctively know less about sex than you think.\n\nHave you seen those videos where dogs or cows or turtles or whatever are just humping away at random inanimate objects and also even other species of animals? ",
"Humans don't *need* to be taught about sex. In fact, sex education is hardly *at all* about the mechanics of sex. It's about safe sex, and other bodily functions that are peripheral to the actual act. \n\nSome of it is stuff that people *would* figure out on their own, but why not take a short cut and learn about it *before* it's an issue? ",
"It's a recent development. For nearly all of human history, humans learned about sex the way rabbits or any animal would: Seeing it happen. Plenty of mammals mate out in the open, allowing anyone to figure out how it works. Even after humans moved indoors, the one-room dwelling was standard, and parents weren't likely to stop having sex for fear of offending the kids. It's only with modern social customs that sex was hidden from the view of young people, requiring them to learn about it some other way.",
"Humans don't need to be taught about sex any more than a rabbit does...if you want humans to have sex like rabbits. The rabbit, however, is not going to be concerned about things like consent, contraceptives, STDs, and pregnancy, while humans are. Humans need to be educated about those things more than about how to just make sex happen.",
"My understanding is that hiding sex behind closed doors and teaching it is recent. Centuries ago (decades? - someone correct me) people were having sex when they hit puberty. \n\n14 for Juliet in Romeo and Juliet, for example.\n\nAnd did Romans not have their own boys and girl prostitutes. ",
"We *are* naturally competent at sex. We just want to do it in a way that is more civilized and controlled than animals do. Animals don't use consent and birth control, they use estrus cycles and genital arms races and other such evolutionary tactics. Many animals are pretty much forcing themselves on each other, and the female just has to have some biological filter of sorts. (Keep in mind humans are one of the few species to be able to get it on anytime, anywhere. Most animals go into heat or lay eggs or some such.) Even the animals who dance or otherwise impress a mate into sex often don't care past having babies. \n\nWe have a sense that we can't just try to take a mate; we have to obtain permission for it to be moral, and so on. We are curious creatures as well and want to know not just how sex works, but why. What we teach isn't how to have sex, like how to put the penis in the vagina -- we can figure that out just fine -- but rather why it feels good, what the biological parts are doing, how to know proper consent, how to control when you have a baby, etc."
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[],
[]
] |
|
3b4qln
|
Why don't salamanders bleed to death when they lose limbs?
|
It seems to me like a human who lost a limb would bleed to death without medical care long before the whole regenerating or scarring thing became relevant. Why isn't that a problem for salamanders and other animals capable of regenerating limbs?
|
askscience
|
http://www.reddit.com/r/askscience/comments/3b4qln/why_dont_salamanders_bleed_to_death_when_they/
|
{
"a_id": [
"csjhyr7"
],
"score": [
2
],
"text": [
"If you chop off a person's limb they don't just fountain blood out of the open wound. At least not initially. The blood vessels constrict during trauma which buys valuable time for treatment. For salamanders I think the process is similar only the surface area of the wound is much smaller and it has time to clot before they would bleed out."
]
}
|
[] |
[] |
[
[]
] |
|
12nizu
|
When energy is converted into heat and then dissipates, how is energy conserved?
|
askscience
|
http://www.reddit.com/r/askscience/comments/12nizu/when_energy_is_converted_into_heat_and_then/
|
{
"a_id": [
"c6wlb7g"
],
"score": [
4
],
"text": [
"When heat dissipates, it doesn't disappear; it just spreads out."
]
}
|
[] |
[] |
[
[]
] |
||
4ccfgg
|
what is ethereum, and how does it have a monetary value?
|
I understand basically that it's a cryptocurrency, but what exactly is my GPU doing that is worth actual value to someone? I used to do Folding@Home, but that was more research purposes than anything else. How is this different?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/4ccfgg/eli5_what_is_ethereum_and_how_does_it_have_a/
|
{
"a_id": [
"d1gz9lr"
],
"score": [
5
],
"text": [
"I can't speak about Ethereum specifically, but I can give you a generalized explanation of bitcoin and hope the information is useful to you. The processing power used to generate a new coin is not *useful* or *practical* to someone in the same way as Folding@Home. The processing requirement to creating new coins is a means of creating and regulating scarcity. If each coin requires a certain amount of work to be produced, and there is a finite amount of work available, then the amount of new currency entering the market is restrained, which is extremely important for a currency. Cryptocurrencies do not have inherent value. Their valuation is merely what other people are willing to value it at, similar to other FIAT currencies used by nations around the world.\n\nThe American dollar's availability is controlled by the FED and the willingness of the public to purchase US bonds, and its value stabilized by the petrodollar. Bitcoins' availability is controlled by inherent restraints in software, and their value is somewhat intentionally not stabilized to encourage the development of a commodity trading economy. I reiterate that I don't know much about Ethereum, but I imagine it's quite similar."
]
}
|
[] |
[] |
[
[]
] |
|
92mh31
|
How far is it between solar systems in a galaxy? What is there in this space between solar systems and planets?
|
I read something about a probe leaving our solar system. That made me think about this. Is there just "empty" space between solar systems, only dark matter and dark energy etc?
|
askscience
|
https://www.reddit.com/r/askscience/comments/92mh31/how_far_is_it_between_solar_systems_in_a_galaxy/
|
{
"a_id": [
"e38uelj",
"e39opfu"
],
"score": [
3,
4
],
"text": [
"In the disc of the Milky Way (ie where we are) the average seperation between two stars is about a parsec, although this will vary drastically depending on the region (ie the stellar density near the galactic centre will be much higher than this).\n\nBetween stars/planets you have the Interstellar Medium (ISM). The ISM consists of diffuse gas with a typical density of a couple of atoms per cubic centimeter. However you also get higher density regions such as Giant Molecular Clouds (GMCs) and HII regions (such as the Orion Nebula), which have densities of a few million atoms per cubic centimeter. However, even these relatively 'high-density' regions are still extremely diffuse relative to Earth atmosphere, which has a typical density of 10^19 atoms/molecules per cubic centimeter - that number is 10 followed by 18 zeros!",
"There's also a huge number of rogue planets, comets and asteroids out there that get ejected from their orbits around their host stars and wander the galaxy, [100 billion freely wandering Jupiter-mass planets](_URL_3_) in our galaxy according to a recent study, but your chances of running into one are incredibly slim since space is so vast and we [only recently observed our first interstellar visitor](_URL_7_) as it passed through the solar system. There's also [cosmic dust](_URL_9_), which has the interesting property of being able to [spin at microwave frequencies of 10-60GHz](_URL_0_) due to the tiny size of the dust grains, emitting microwaves at it's rotational frequency, plus there's [all manner of molecules](_URL_5_) out there and various exotic ions that aren't stable on Earth and free protons and electrons and bare atomic nuclei, which are a radiation hazard to astronauts and behave like subatomic bullets that whizz through their bodies and rip electrons from atoms, damaging their DNA and cellular machinery. But by far the vast majority of the stuff out there is plain old hydrogen and helium in various forms of ionisation. Altogether, this mix of stuff makes up the [interstellar medium](_URL_1_), and it's from this gas and dust that stars and planets form when the conditions are right for clouds of it to gravitationally collapse and form compact objects, as happens in [molecular clouds](_URL_8_).\n\nWhen an article says that a probe has left the Solar system, it also depends on your definition of Solar system. Sort of like how we discover water on Mars every other week, because to one person, uncovering a patch of ice under the soil is discovering water, and to another person you've only discovered water when it's liquid water and ice, dew, transient dark streaks on crater rims and patches of frost don't count, so you get a new 'discovery' for each one. \n\nNo probe has even passed through the [Kuiper belt](_URL_4_) yet, and it'll be thousands of years before our probes reach the [Oort cloud](_URL_6_), the cloud of comets that surrounds the Sun and extends as far as 1 light year away, but [Voyager 1](_URL_2_) has passed through the Heliopause where the solar wind slows down and merges with the interstellar medium, so in the interest of attracting readers and getting advertising dollars, you'll have seen articles saying that Voyager left the solar system when it passed through the termination shock and articles saying it left the solar system a few years later when it passed through the heliosheath and more articles saying the same thing a few years after that when it passed through the heliopause, because such is journalism."
]
}
|
[] |
[] |
[
[],
[
"https://en.wikipedia.org/wiki/Spinning_dust",
"https://en.wikipedia.org/wiki/Interstellar_medium",
"https://en.wikipedia.org/wiki/Voyager_1",
"https://www.nature.com/news/the-hunt-for-rogue-planets-just-got-tougher-1.21445",
"https://en.wikipedia.org/wiki/Kuiper_belt",
"https://en.wikipedia.org/wiki/List_of_interstellar_and_circumstellar_molecules",
"https://en.wikipedia.org/wiki/Oort_cloud",
"https://en.wikipedia.org/wiki/%CA%BBOumuamua",
"https://en.wikipedia.org/wiki/Molecular_cloud",
"https://en.wikipedia.org/wiki/Cosmic_dust"
]
] |
|
5gwy15
|
Would Genghis Khan be considered a "bad guy" of history?
|
He started what would become the largest civilization that the world ever had. Of course this civilization had to come through war, lots of deaths, and warmongering. Even with the obvious bad, he managed to control this vast of an empire, preserve some cultures, etc. So, do historians view him as a disgusting person? Maybe not to the extent of Hitler, Stalin, etc., but still a villain of history?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/5gwy15/would_genghis_khan_be_considered_a_bad_guy_of/
|
{
"a_id": [
"dawl2rt"
],
"score": [
3
],
"text": [
"Potentially better follow up: Do historians actually view anyone as villains? I had got the impression that the more general sociocultural factors were being considered instead of individuals in good historical work. "
]
}
|
[] |
[] |
[
[]
] |
|
cczzqn
|
Why does a small amount of antenna extension in devices such as portable radios and satellite cellphones make such a big impact on quality of reception?
|
askscience
|
https://www.reddit.com/r/askscience/comments/cczzqn/why_does_a_small_amount_of_antenna_extension_in/
|
{
"a_id": [
"etrge9r",
"etsukxz"
],
"score": [
7,
2
],
"text": [
"Old ‘brick’ cell phones used a frequency around 800mhz. The wavelength, ~14 inches, would make a full wave antenna cumbersome. However, a half wave length antenna (that is normally stowed inside the phone) does work pretty well while being compact. \n\nNewer phones use higher frequencies, which combined with lower power signal and better signal processing, leads to an antenna that fits inside the phone (or IS the phone, in the iphone’s case).",
"Mostly because it gets the antenna away from your head. Your head, being made of mostly water, absorbs all the RF energy going in one direction. Extending the antenna gets it further away from your head, and thus allows more of it to radiate out into the atmosphere, and hopefully towards the base station (or satellite)."
]
}
|
[] |
[] |
[
[],
[]
] |
||
2brt23
|
What can you tell me about this Roman stone my neighbours dug up?
|
It was found in Montenegro, Europe, near the archaeological site of "Municipium S". From what I can read it says "SILVAN AVC SACR" but the V and A in the first word are connected. Any clues about its meaning or significance would be appreciated.
Pic #1 (_URL_1_)
Pic #2 (_URL_0_)
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/2brt23/what_can_you_tell_me_about_this_roman_stone_my/
|
{
"a_id": [
"cj89yd9"
],
"score": [
4
],
"text": [
"\"AVG SACR\" is short for \"AUGusto SACRum\"; \"SILVANO\" was a woodland deity. Basically it's dedicated/sacred to Silvanus and Augustus.\n\nSource: Silvanus in Salona p161 _URL_0_"
]
}
|
[] |
[
"http://imgur.com/CtWLkmH,F4Cp7Nz#1",
"http://imgur.com/CtWLkmH,F4Cp7Nz#0"
] |
[
[
"http://www.scribd.com/doc/151878038/Silvan-u-Saloni-S-Bekavac"
]
] |
|
32dj02
|
If visible light and radio waves are all forms of electromagnetic waves, can we emit visible light by emitting radio at a different wave length?
|
askscience
|
http://www.reddit.com/r/askscience/comments/32dj02/if_visible_light_and_radio_waves_are_all_forms_of/
|
{
"a_id": [
"cqa9h5r",
"cqa9mve"
],
"score": [
4,
5
],
"text": [
"No. The definitions of visible light and radio waves depend on their wavelengths. Visible light have a wavelength typically in the 100s of nanometer range, radio waves typically defined as larger than about a millimeter or so.\n\nLight can be [Doppler shifted](_URL_0_), which will change the wavelengths, but when you take into account the [relativistic version](_URL_1_), you have to be going very, very close to the speed of light to get between such large shifts in wavelength.",
"As you said, light and radio waves are both electromagnetic waves. They are simply at different frequencies/wavelengths, so are kinda different things. Human eyes can perceive only a small fraction of the different wavelengths that are out there. \nRadio waves have a longer wavelength (or lower frequency) than visible light. There are also infrared, ultraviolet, gamma rays, x-rays, etc. which cant be seen, like radio waves. \nEM wavelengths range from the size hugely, while we can only see roughly 380 nm (violet) to 750 nm (red) wavelengths, I think it is.\nSo by changing the wave length of a radio wave to make light like you said, would have to change the wave length drastically! \nIt would no longer be a radio wave you're emitting at that point :) \n\n"
]
}
|
[] |
[] |
[
[
"http://en.wikipedia.org/wiki/Doppler_effect",
"http://en.wikipedia.org/wiki/Relativistic_Doppler_effect"
],
[]
] |
||
18r17t
|
Why do you get shocked when you lick a 9 volt but not when you lay your finger across both leads?
|
askscience
|
http://www.reddit.com/r/askscience/comments/18r17t/why_do_you_get_shocked_when_you_lick_a_9_volt_but/
|
{
"a_id": [
"c8hb7mv"
],
"score": [
3
],
"text": [
"Different resistance values between your tongue and your fingers. Electrons can travel easily through your wet tongue from negative to positive but your fingers have a higher resistance hindering the passage of electrons."
]
}
|
[] |
[] |
[
[]
] |
||
6ptsku
|
How is the Dead Sea the lowest point on Earth ( 400m) if the Grand Canyon has a depth of 1800m?
|
askscience
|
https://www.reddit.com/r/askscience/comments/6ptsku/how_is_the_dead_sea_the_lowest_point_on_earth/
|
{
"a_id": [
"dksibd9"
],
"score": [
34
],
"text": [
"You are comparing depth with altitude - they are not the same thing.\n\nThe Dead sea is the lowest point on Earth at an altitude of -400 m **relative to sea-level**.\n\nThe maximum depth of the Grand Canyon is measured from the surface, in the middle of the continent. The actual altitude relative to sea-level of that point is about +730 meters."
]
}
|
[] |
[] |
[
[]
] |
||
8z4fs1
|
Does split brain lead to split consciousness?
|
Perhaps I’m not completely certain what consciousness is meant by in this study, but I don’t understand how consciousness can be shared if the left and right hemispheres are unable to communicate. Could someone help me understand if this is absolutely the case of if it’s still up for debate, and if it is the case, how could this be possible?
_URL_0_
|
askscience
|
https://www.reddit.com/r/askscience/comments/8z4fs1/does_split_brain_lead_to_split_consciousness/
|
{
"a_id": [
"e2g4qn1",
"e2hep6c"
],
"score": [
7,
2
],
"text": [
"A “split brain” is not really 100% split: we use the term to describe patients who, for one reason or another (usually surgery), have lost the functionality of the Corpus Callosum. The Corpus Callisum is a dense bundle of neurons in the middle of the brain that is the primary structure responsible for coordinating and spreading activity between the left and right hemispheres, which is why we remove it in epileptic patients: it prevents seizure activity from taking over the entire brain. \n\nThe brain has a few other auxiliary connections between the hemispheres, however, called the Commissures. In the absence of the CC, these structures are apparently able to keep some semblance of hemispherical coordination intact. There are a few other phenomenon that can influence things, since, as you can imagine, neuroscience has exceptions to every rule, but in general it’s safe to say that split-brain patients still have some communication between their hemispheres.",
"[This](_URL_0_) is a fantastic video on the “split brain” condition. Its a bit sensationalist toward the end, but a very interesting topic and does use a lot of studies. "
]
}
|
[] |
[
"http://www.uva.nl/en/content/news/press-releases/2017/01/split-brain-does-not-lead-to-split-consciousness.html"
] |
[
[],
[
"https://www.youtube.com/watch?v=wfYbgdo8e-8"
]
] |
|
20fgk6
|
What was the scientific and cultural legacy of Achaemenid Persia?
|
We seem to know a lot about Greek contributions to philosophy, art and science but with the vast Persian empire existing concurrently, is there any mark they similarly left upon our culture?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/20fgk6/what_was_the_scientific_and_cultural_legacy_of/
|
{
"a_id": [
"cg2puv8"
],
"score": [
3
],
"text": [
" > First, I am going to assume that \"our culture\" refers to western culture. But this is a dangerous assumption to make, so please be sure to avoid such generalizations in the future. This is an important distinction to make because the reception of the Persians in the West is much, much different from the reception of the Persians in, for example, modern Iran. These are just two extremes in a the wide spectrum of modern societies that have studied and analyzed materials and documents from Achaemenid Persia.\n\n > All that being said, I want to point out just one major document that has impacted Western culture: the Cyrus Cylinder. Since its discovery in the 19th century in Babylon, the Cyrus Cylinder has often been heralded as a document of peace, magnanimity, and the universal tolerance of mankind. It has been argued that in the document, King Cyrus the Great guaranteed the freedoms and liberties of all citizens of the Persian Empire.\n\n > Of course, reality is much different (and less exciting). The document was merely a dedication to the gods of the rebuilding of a sacred temple in the city of Babylon. In the text, Cyrus stated numerous platitudes about being destined to be king, and to protect these gods of Babylon, and to do the bidding of the gods, etc. But there is no \"universal charter of mankind\" in this document.\nNonetheless, scholarship in the early 20th century focused heavily on this early interpretation of the text, and Cyrus was aggrandized into an ancient guardian of liberty and freedom. The modern state of Iran has also developed and furthered this legend, even placing an image of the Cyrus Cylinder on some official documents and currency. Of course, there are also the biblical connections, with Cyrus being tied to the return of the Jews to Israel. Of course, the Cyrus Cylinder itself is silent on the Israelites, but his supposed magnanimity and his mention in the book of Isaiah 45 tied the Cyrus Cylinder to this growing legend of Cyrus 'the Great.'\n\n > For further reading, I recommend Irving Finkel's The Cyrus Cylinder, which has compiled all of the most recent research and thinking on the document and its history and reception. \n\nThis is from [my previous comment on the topic](_URL_0_)."
]
}
|
[] |
[] |
[
[
"http://www.reddit.com/r/AskHistorians/comments/1yx5ie/what_was_the_scientific_and_cultural_legacy_of/cg2n6c9"
]
] |
|
15rmxd
|
Different Base Numbers?
|
I hope i don't offend anyone for asking this here but I would like a more intelligent answer then r/askreddit might otherwise give.
So lets pretend I was writing a sci-fi novel about an alien race who used a different base number besides 10. Perhaps 6, 8, or 12. How could you go about this? And how could you maybe say that this system of counting is better then what we use now?
In other words I am only decent at math and have no knowledge whatsoever of other base number systems and have a hard time wrapping my head around other number systems.
Edit: Also I would like to ask how any other numbering system would be used outside of computers and how it would be useful. Once again I'm clueless, but if we used a different base number system in everything from base counting, to physic, or quantum equations, how would this make a difference?
Edit 2: Thank you for the very helpful and informative answers.
|
askscience
|
http://www.reddit.com/r/askscience/comments/15rmxd/different_base_numbers/
|
{
"a_id": [
"c7p66i5",
"c7p7n7j",
"c7pepu3"
],
"score": [
2,
2,
3
],
"text": [
"It's really not that hard to go about using other base systems, it just means that you go to the next place value at whatever your base is. For example, in hexadecimal, or base-16, you count up to 15 then roll over to the next place; obviously, that doesn't work perfectly with our normal notation of numbers, so we use the first six letters of the alphabet A=10, B=11, and so on, so 27 in base-16 is 1B. If you wanted to go into greater detail on your alien system, you should create your own symbols, in my opinion, to reduce clutter on the page. Lower bases (less than ten in this case) are easier to work with for us because, they don't need new characters, but the theory is the same, just roll over one before your base, 27 in base 6 is 43.\nI really can't make any judgement as to what base system is better or worse because it depends on a couple of factors:\n1. We use a base ten system partly because we have ten fingers, if your alien's form is radically different, then they would most likely have a system that they can count on their body.\n2. While some higher bases can be useful, I don't think it's realistic to see base-72 because you would have to remember 71 unique numerals, which is stupid, even though it would use much less space. So ",
"Numberphile did a vid resently\n\n_URL_0_\n\nAlso this guy set a challenge where astrobiologists and mathmatitians had to decode a totally alien message. The guy used a new concept of number based on radians rather than a linear scale.",
"_URL_0_\n\nYou may enjoy this. Balanced ternary has many computational benefits over binary."
]
}
|
[] |
[] |
[
[],
[
"https://www.youtube.com/watch?v=U6xJfP7-HCc"
],
[
"http://en.wikipedia.org/wiki/Balanced_ternary"
]
] |
|
729yma
|
- what makes peanut butter stick to the roof of your mouth, and throat?
|
I’ve always wondered why I got that split second feeling like I was gonna choke on a peanut butter sand which, but don’t get that feeling with Other foods .
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/729yma/eli5_what_makes_peanut_butter_stick_to_the_roof/
|
{
"a_id": [
"dniealk"
],
"score": [
3
],
"text": [
"Peanutbutter is viscous. The viscosity of peanutbutter means that it will take longer to flow than other fluids. Aside from that, peanutbutter is not only viscous, but is able to squish between nooks and crannies in a surface, allowing it to act like a glue. It's a good adhesive.\nOn top of that, peanutbutter is made mostly of fats, so it's not very soluble in water, and water doesn't want to interact with the fats in peanutbutter, so it takes time to go down with the help of friction from your tongue and esophagus.\n\nAlso, peanutbutter should be one word. It's one thing, and it's easier to type it that way. I vote 'yes' on *peanutbutter*."
]
}
|
[] |
[] |
[
[]
] |
|
h8etm
|
Is there any evidence that "sugar rushes" actually occur?
|
askscience
|
http://www.reddit.com/r/askscience/comments/h8etm/is_there_any_evidence_that_sugar_rushes_actually/
|
{
"a_id": [
"c1tedj7",
"c1tefqu",
"c1tem8f",
"c1teqfd",
"c1tffjv",
"c1tggyk"
],
"score": [
3,
5,
2,
3,
2,
4
],
"text": [
"There is some evidence that food dyes can cause hyperactivity in children which you can read about [here](_URL_0_).",
"Why are sugar rushes so popular, then, if there's no scientific evidence backing it up?\n\nIt seems pretty simple to me. Caffeine is a stimulant and gets you wired...sugar is not a stimulant and exhibits no stimulant effects.\n\nWho got confused and invented 'sugar rushes'? I'd love to know.",
"if you're mostly asking with regards to little kids, you also have to remember that children are suggestible, so all their parents saying \"don't eat too much candy, you'll get hyper!!\" can MAKE them be hyper when they do eat the candy. i agree about the dyes and all that, plus kids are just mental and parents want to have explanations for that. parents pass on \"info\" to parents and so on and so forth. i think we as Western society (can't speak much for the other side of the globe) tend to serve sweets at gatherings where there are a lot of people, which would get kids runnin' around and playin' and such. just my thoughts here.",
"Yes. The thing about hyper kids is probably over-exaggeration but the carbohydrates will give you a temporary energy boost followed by an insulin spike and subsequent crash. Kids may have little tolerance to this cycle and could be more sensitive to it.",
"What about blood sugar?",
"In social psychology they taught us much of the supposed \"sugar rushes\" children have are actually due to the environment. For example, a child at a birthday party in a new environment surrounded by other children and activities will naturally be more stimulated, though parents usually fall back on the old \"the cake is making Johnny hyper\" excuse."
]
}
|
[] |
[] |
[
[
"http://www.cspinet.org/fooddyes/"
],
[],
[],
[],
[],
[]
] |
||
3ojels
|
does location determine skin color?
|
My camp counselor said that dark skinned people are dark skinned because they settled in hotter places (e.g Africa). However I disagreed because a white person in South Africa over generations and generations will never have black offspring. Vice versa. Who is right in this?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/3ojels/eli5does_location_determine_skin_color/
|
{
"a_id": [
"cvxrc29",
"cvxrf5i",
"cvxrqnv"
],
"score": [
5,
2,
2
],
"text": [
"Dark skin protects against ultraviolet radiation from the sun. But solar radiation is also necessary to stimulate production of vitamin D. In the higher latitudes, where there is less solar radiation, there is both less need for protection and more need for the radiation. Accordingly, there is a natural selection pressure (meaning people are healthier and more likely to have children) toward darker skin near the equator and light skin further to the north or south. This is also the reason that you get tanned after lying in the sun.\n\nHowever, this takes tends of thousands of years to have any real effect on the genes of a population. Light-skinned people living in South Africa today are descendants of people from Europe. Maybe if they and their children live in South Africa another 10,000 years, they'll get darker skin.\n\nSo you're both right, in a sense. In the short term, where you live doesn't really matter. But in the very, very long term, it does.",
"The camp counselor is closer. The color of your skin is determined by the amount of melanin it contains. The more melanin, the darker the skin. Melanin protects you from UV rays emitted by the sun. However, some of those rays also need to get through to aid in vitamin D synthesis. So in sunny regions darker skinned people are selected for because they need to block out most sunlight to shield against harmful UV rays emitted by the sun. In darker regions pale skin is selected for because there's much less sunlight, so you need to let it through in order to synthesize vitamin D.\n\nIf you gave it enough time, and if that white colony in Africa was significantly reproductively disadvantaged by sun exposure, they would eventually have darker skinned offspring. And vice versa. Of course, they may not be reproductively disadvantaged because we can correct many problems today using things like vitamin D supplements or sunblock, in which case there'd be no advantage to gaining or losing dark skin color. ",
"You're right, if white people in South Africa only ever interbreed with other white people, they'll almost all still have white skin after any number of generations.\n\nBut that's not how natural selection works, though. Dark skin helps protect against harmful UV radiation, which is helpful in very sunny places (like the tropics). Light skin does the opposite, it absorbs as much UV radiation as possible in order to synthesize vitamin D, which is necessary in places that don't get much sun (like northern Europe).\n\nSo even though white people might live in South Africa, they won't be well-adapted to its climate. We humans are smart and have invented things like clothes and umbrellas and sunscreen to counter those effects, but absent those factors, over the long run all the white people in South Africa will die off from skin cancer or severe sunburn, and only dark-skinned people will be left. As it happens, some of those dark-skinned people might actually be ancestors of the white South Africans who have developed genetic mutations to produce more skin pigment. Because they're better adapted to the African climate, they've survived, so in that sense in the long run location will determine skin color."
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
16hlln
|
What drives the molecular change in catalytic enzymes?
|
The example I'm specifically thinking of is the F1 domain of the ATPase, which creates ATP from the proton motive force. The translocation of protons causes rotation of the the F1 domain subunits. Which drives a conformational change between tight, loose, and open binding conformations and these have different affinities for ATP
My question concerns the driving force for ATP synthesis. I read that there is a low gibbs free energy of for the reaction which means it'll happen spontaneously. Does this mean that in the tight conformation the ADP & Pi are held close so that there is less steric clash if they combined to form ATP.
Basically I understand the mechanism used by the protein by I don't understand why it drives ATP production.
|
askscience
|
http://www.reddit.com/r/askscience/comments/16hlln/what_drives_the_molecular_change_in_catalytic/
|
{
"a_id": [
"c7w4r3w"
],
"score": [
3
],
"text": [
" > tight conformation the ADP & Pi \n\nThat's pretty much the idea. The ADP and Pi are pushed so close together (in just the right conformation) that they can't help but react. "
]
}
|
[] |
[] |
[
[]
] |
|
t709s
|
Watching Cosmos...questions about light...brain hurts!
|
Longtime Carl Sagan fan, but I've somehow avoided watching Cosmos. Awesome, awesome series, but I have all these questions about light now and I'm really hoping you guys and gals can help me out. Forgive me if these questions are ridiculous. I'm assuming that I'm missing some pretty basic concept here and I'm not really expressing it correctly. The unfortunate thing about Sagan is that goofballs like me start getting interested in science with pretty much no appreciation for the basic concepts of physics...
1) Do all wavelengths of light move at the same speed? I have a very hard time making sense of the speed of light. In episode 8 Sagan talks about redshifts and blueshifts and I realized that I've never heard the speed of light described in terms of anything but the visible spectrum. What happens in the non-visible spectrum at the speed of light? This concept of red/blue shifting seems to imply that some parts of the spectrum move slower than others (I'm probably misunderstanding...). But if so, it seems like it would technically be possible to move faster than the visible spectrum while still remaining below the "true" speed of light. So maybe the best way to say this is, can you help me understand the speed of light, especially with regards to how relativity impacts the non-visible spectrum?
2) Okay, bear with me here...light is constantly emitted by the stars. Eventually it reaches us and we perceive the visible spectrum in terms of the light that is reflected by the material objects around us (am I on the right track so far?). But we also perceive the light as it reaches us when we look directly at the sun or stars. In these cases, it hasn't been reflected so we perceive it as bright, piercing white light, which I assume is because no part of the visible spectrum has yet been absorbed so it is all hitting our eyes. But light from stars is not emitted on a single line...it's emitted in three dimensions and at all times. "New" light is constantly arriving from all directions since there are start in all directions. Why is the sky not ALWAYS a wash of bright white? Has the light from distant stars been impeded somehow so that it doesn't all reach us? another way of stating it, why does it matter how far away a light source is? does light lose something (momentum/strength...not sure of the right term) during its trip through space?
3) Lastly, when light is reflected off of a material object, it's reflected in three dimensions as well...not on a single track (man, I hope someone is still reading this mess). So, here's where I get locked up...is the light emitted/reflected on a fixed trajectory and is it right to think of light as having a trajectory? If so, why aren't our eyes constantly bombarded by a combination of all portions of the visible spectrum from all of the things around us? It seems like we should see nothing but pure white all the time since there is a constant stream of incoming light from the sun and stars, and a constant stream of outgoing light (at least a portion of it) reflected off of the material objects around us. why doesn't the incoming and outgoing portions of the visible spectrum wash out and leave us blinded?
...as an aside to sort of help explain where I'm coming from, I've wondered (probably mistakenly) what it would REALLY be like if we were able to freeze time. My thought is that freezing time would be awful, because we only perceive the world around us due to the MOVEMENT of various portions of the visible spectrum of light. Were time to freeze, light would freeze in place and our eyes would be immersed in all portions of the spectrum. Wouldn't our eyes perceive nothing but the glare of pure white as if we were staring at the sun?
Man, I hope this makes sense. I've wondered about this for a long time and never thought to ask about it.
|
askscience
|
http://www.reddit.com/r/askscience/comments/t709s/watching_cosmosquestions_about_lightbrain_hurts/
|
{
"a_id": [
"c4k2rih"
],
"score": [
2
],
"text": [
"1) All light moves at the same speed in space. Period. The redshift is the change of *wavelength* of light. In the electromagnetic spectrum, light has different frequencies/wavelengths, but not speeds. Maybe someone can elaborate.\n\n2) [Inverse square law](_URL_0_). A certain amount of light is emitted from a star. As that light gets further and further the same amount of light is covering much more area in space (like the surface of a sphere). So when it hits us it is effectively diluted. The sun is close so it hasn't spread its light out and is still bright.\n\n3) On a microscopic level everything is bumpy so light hits it and is spread out, but on flat surfaces you can get most the light to reflect one way because more of the area the light hits (even on a microscopic level) is facing the same way. But light does bounce off in a straight line with a specific angle that you can measure.\n "
]
}
|
[] |
[] |
[
[
"http://en.wikipedia.org/wiki/Inverse-square_law"
]
] |
|
289lv3
|
If you flash freeze water, will it still expand in the same way as 'normal', gradual freezing?
|
One of the main issues for cryogenic freezing is that the water is the blood expands. The blood vessels housed in the haversian and volkman canals in turn expand and cause microfractures throughout the osteons.
It is often quoted that flash freezing is a way to overcome this, but is that entirely true?
Would it not be more effective to find a way to safely introduce an antifreeze chemical like that seen in some Arctic fish species?
|
askscience
|
http://www.reddit.com/r/askscience/comments/289lv3/if_you_flash_freeze_water_will_it_still_expand_in/
|
{
"a_id": [
"ci8wrpi"
],
"score": [
2
],
"text": [
"Water will expand regardless of how it is frozen; however, what changes is the size of the average ice crystal. When you slow freeze water it tends to build one giant crystal over time since water can slowly collect and arrange itself to form a unified solid. When you flash freeze each water molecule basically has to grab the nearest neighbor and as a result the average ice crystal tends to be significantly smaller since they don't have enough time to diffuse and order itself. \n\nNow as far as the biological side of this I remember hearing about it a long time ago because my sister did her master's work on this topic, but I sorta tuned it out since I lean towards the physics side of the science spectrum instead of the bio side. Not enough math for my interest. :)\n\nIt could have something to do with the formation of large ice crystal can also cause sharp ice to form which can tear tissues. But this is just conjecture so I'll defer to someone who is a little more knowledgeable on the subject. "
]
}
|
[] |
[] |
[
[]
] |
|
2selxp
|
why is it better to eat actual sources of protein (eggs, fish, meat etc.) than consume protein powder?
|
what are the negative side effects of consuming protein powder
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2selxp/eli5_why_is_it_better_to_eat_actual_sources_of/
|
{
"a_id": [
"cnosxwz"
],
"score": [
3
],
"text": [
"It isn't the protein itself that is bad. It is the other stuff that comes with it. You aren't consuming pure protein when using that powder, and a lot of that is things like instant milk which contains oxidized cholesterol, which is very very very bad. And there are many more issues, such as your body requiring certain balances of things in order to absorb the protein properly. When you eat things like meat, the meat itself comes with things like specific minerals and vitamins and amino acids that your body needs so that the protein can be used properly. They always say that animal meat is 'complete' protein.\n\nGenerally speaking, it is always better to eat natural things over artificial things. Protein powder is a good supplement, not a replacement."
]
}
|
[] |
[] |
[
[]
] |
|
36m2kz
|
how long does it take to be a professor?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/36m2kz/eli5_how_long_does_it_take_to_be_a_professor/
|
{
"a_id": [
"crf3zva",
"crf4jfb"
],
"score": [
3,
2
],
"text": [
"Depends largely on the school, faculty, and discipline.\n\nThe typical route is:\n\n- Undergraduate (bachelor's).\n\n- Postgrad (Master's).\n\n- PhD.\n\n- Lecturing and getting published.\n\n- Getting tenure.\n\n- Associate Professor.\n\n- Professor.\n\nTimescales vary - a bachelors and a masters can take anywhere between 5 and 10 years to do, depending on whether it's done full time, and by thesis or coursework. A lot of places also count first class honours in a bachelor's as part credit towards a masters.\n\nPhD is typically 3-7 years, again depending on how you do it and what the research and publishing is based on.\n\nTenure usually takes about ten years to get between lecturing and getting published. As academics get more senior, their role usually shifts to less teaching, and more getting publications and grants for their faculty.\n\nAssociate professorship to full professorship largely depends on the school and the discipline. I'd say 5-10 years on average between one and the other.",
"There is a lot of variation across fields. I can only speak for science.\n \nBachelor degree: 4 years\n\nMaster's degree: 2-5 years\n\nPhD: 4-10 years. Some schools let you start a PhD program without having a master's degree, like mine did. I spent 6.5 years in graduate school getting mine, but I never got a master's. The average time to get a PhD in science is about 7 years. \n\nPost doc: the average time people spend doing post docs is about 10 years these days. A classmate of mine got a tenure track position after only two years of post docs, but he had over 30 publications before he finished grad school, so he was an anomaly. I know another guy who spent 15 years as a post doc before getting a tenure track position. \n\nHere is where your question gets a little bit vague. When you begin a tenure- track position, your title is \"assistant professor.\" Given this, you are a professor at this point. Sometimes post docs are given the title \"research professor\" or some variant of that. I spent a couple of years as an \"adjunct research assistant professor.\" After you get tenure (which is usually 7 years) you are an \"associate professor.\" To become a full professor, where your title is just \"professor\" takes many years after tenure. Some people go their entire careers without making full professor. \n\nThis time line assumes that you make it through each step. At my school, about 10-20% of people who start a PhD program do not finish - maybe they weren't smart enough, maybe they didn't work hard enough, maybe they couldn't handle the stress, maybe they got sick of it or life got in the way. Lots of people don't make it through the post doc stage. Only a few percent of people with a PhD in a science ever get a tenure track position - there are just way more people who want the jobs than there are jobs. The percent who eventually get tenure is even lower. I know of at least one school that hires more assistant professors than it has tenure spots for. The lucky few get those spots and the rest probably never get tenure anywhere. Even if you are smart enough and creative enough, you have about the same chance of making it big in Hollywood as you do becoming a full professor. \n"
]
}
|
[] |
[] |
[
[],
[]
] |
||
297rkb
|
when a mosquito is sucking blood from my arm, where does its proboscis go after i kill it?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/297rkb/eli5_when_a_mosquito_is_sucking_blood_from_my_arm/
|
{
"a_id": [
"ciic70k"
],
"score": [
2
],
"text": [
"you probably pull it out when you brush the body away. otherwise it's still in there. not a big deal, though. the things are as thin as hair and your body has ways of dealing with stuff like that. "
]
}
|
[] |
[] |
[
[]
] |
||
1fk7rh
|
Why do nuclear armed countries need such massive investment in conventional military?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/1fk7rh/why_do_nuclear_armed_countries_need_such_massive/
|
{
"a_id": [
"cab416d",
"cab9om9"
],
"score": [
6,
3
],
"text": [
"I dabbled in nuclear strategy, tactics, and the general science of nuclear warfare a few years back, so let me try to answer.\n\nI'm going to assume based on your comments and questions that you're exclusively asking about the United States, but this probably applies to most nuclear weapons states with significant conventional forces.\n\nNuclear weapons are tremendously powerful, but lack granularity and staying power. They are fine as strategic deterrents and powerful battlefield weapons, but their utility largely ends there. Modern conventional militaries allow nations to engage in (comparatively) more subtle military actions such as invasion and occupation of non-nuclear states, anti-piracy efforts, gunboat diplomacy and showing the flag, and as aid during disasters. Many nuclear powers are also major conventional powers because they have an interest in these missions, and generally in possessing more subtle forms of power projection than a nuclear strike.\n\nAnother major reason is probably a political one - not only is a professional army seen as mandatory for a nation-state by the general public, but disbanding a large military would be unpopular among unemployed bureaucrats and soldiers. When you examine how many citizens are employed by the PLA or DoD, it becomes clear that the elimination of those agencies would be controversial to say the least.\n\nBut you have realized something important - the nuclear weapon is a potentially liberating tool from the need to support a massive defensive establishment due to the unacceptable political cost (not to mention damage) of being struck by one. States like North Korea and Israel clearly agree, as shown by their actions.",
"In the years immediately after World War II, it was imagined that the United States would be able to slash its conventional military budget considerably and rely on nukes alone as a means of deterring Soviet aggression. The idea was that the US would more or less go back to a \"peaceful\" footing as it did before WWII.\n\nThis was politically popular until the detonation of the first Soviet bomb. At this point it became fairly clear that nukes alone did not present the flexibility required for a modern military force, even in strict deterrence situations like that between the USA and the USSR. That is, if your only option is \"start a full-flung nuclear war,\" then you appreciate having some intermediary steps, because otherwise it becomes a game of \"how much does it take before you decide to lose a major city?\" Yes, a full-flung Soviet invasion or preemptive attack, but what about a Berlin blockade? What about a rigged election? What about a small incursion through proxy forces? \n\nIt quickly became clear to American policymakers — though this was not necessarily obvious from the beginning — that nukes _couldn't_ be used. This is the case even without the fear of retaliation. If the USA had used nukes in Korea, for example, there would have been little likelihood of the Soviet Union nuking the USA. But the political costs would have been immense: the USA would have lost its UN sanction, it would have lost its allies, and the Soviets would have gained from that arrangement. Furthermore, if the nukes didn't provide victory — and it wasn't at all clear that they could — then all of that would have been for very little in the end. \n\nFrom the 1960s onwards the US military sought to make a variety of nuclear options that would still increase variability without necessarily leading to all-out nuclear war (tactical nuclear weapons, for example), but the opinion has always been mixed about whether such conflicts would escalate, and whether such weapons would actually be worth the political penalties that would come from their use.\n\nLastly, the United States is a heavily interventionist state. It attempts to establish spheres of influence and regional hegemonies. It invades other nations on a regular basis. You cannot do these things with nukes; you need \"feet on the ground\" to project real force."
]
}
|
[] |
[] |
[
[],
[]
] |
||
21smmf
|
Chicago Footnote Help
|
Hi,
I'm doing homework for my master's and I'm running into problems with my footnotes, how do I include multiple sources such as a letter quoted in an encyclopedia, or government documents included in a collection of government documents, or an essay quoting a letter inside an encyclopedia? I've never had to do more than one level of citation before and traditionally I would rip the primary source out of the collections, but I do not think that is what my professor is looking for.
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/21smmf/chicago_footnote_help/
|
{
"a_id": [
"cgg5fbd"
],
"score": [
4
],
"text": [
"Yikes, those are the tricky ones.\n\nOkay gov't documents, you sort of cite it like any other books, but you usually include the volumes. Let's look at the gov't docs I used for my own research from the Pennsylvania Archives\n\nPennsylvanian, Commonwealth of. *Minutes of the Provincial Council of Pennsylvania, from the Organization to the Termination of the Proprietary Government. Colonial Records of Pennsylvania.* 10 vols. Philadelphia and Harrisburg: Theophilius Fenn & Co., 1852.\n\nThe author here is the state (since there isn't a given author), according the latest edition of Chicago. Include the title and series name. Volume number. Publisher, etc.\n\nNow, the other ones. If I understand you correctly, if you're using a quoted source within another source, then you need to state that you're using an indirect quote. \n\nName, of Author, \"Their Letter,\" in *Encyclopedia* and then give the rest of the citation for the encyclopedia. Repeat as needed. I think [this](_URL_0_) page might be of some service to you.\n\nI think you can do that for the last one too, but I'm wary of suggesting that as I'm pretty sure it's kind of frowned upon to quote three different sources. Is this for an exercise?\n\n\n"
]
}
|
[] |
[] |
[
[
"http://library.menloschool.org/content.php?pid=262726&sid=2298716"
]
] |
|
p1u97
|
the drug enforcement administration (dea)
|
How exactly does this agency work and whats the controversy behind the DEA's policy of raiding of medical marijuana dispensaries?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/p1u97/eli5_the_drug_enforcement_administration_dea/
|
{
"a_id": [
"c3ltbpo"
],
"score": [
2
],
"text": [
"The DEA is a federal law enforcement agency under the Department of Justice tasked with enforcing federal laws (primarily the Controlled Substances Act) on the use, manufacture, and smuggling of drugs in the United States. In some ways like the FBI, the DEA has \"special agents\" who they employ and who must pass a rigorous background check—if an applicant has *ever* used drugs, they are excluded from employment by the DEA. These special agents investigate, arrest, and detain drugs and those suspected of selling drugs.\n\nIn states where medical marijuana dispensaries are legal under state law, the DEA has been enforcing federal drug laws to shut them down. In the past, the federal government has been reluctant to enforce federal drug laws in states which chose to legalize medical marijuana. Pro-MMJ advocates say that the federal government has no authority to regulate the use and sale of medical marijuana that is fully within the state's borders. More broadly, the argument is that federal drug policy towards marijuana is shutting down legitimate businesses that help sick people, and that treating users and sellers of medical marijuana in states where it is legal like they are criminals is enormously bad policy."
]
}
|
[] |
[] |
[
[]
] |
|
b9dx6q
|
How did Taffy 3 actually pull off the defense of the Lette landing force in WWII?
|
I know there was outstanding bravery shown by the USS Johnson's, USS Samuel B. Roberts', and many other ship's captains and crews had an effect, but did admiral Korita retreat truly because he believed he was outmatched? Did he ever give a reason for retreating? Since he could see the force he was facing, I don't know how he could have thought he was outgunned, unless he thought for some reason the main US aircraft carrier force was nearby, but I would have figured he would have gotten word that they were busy trying to destroy the IJN decoy aircraft carrier fleet several hundred miles away. I also thought that this was pretty much a last ditch effort by the IJN to stop McCarthur's island hoping campaign. Wouldn't Kurita basically have had orders to "fight to the death" at that point? Lastly, was admiral Korita disciplined for withdrawing when he (at least in hindsight) had such a huge advantage and could have done serious damage to the US ground forces at Leyte?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/b9dx6q/how_did_taffy_3_actually_pull_off_the_defense_of/
|
{
"a_id": [
"ek7klod"
],
"score": [
3
],
"text": [
"Expanded from [an earlier answer of mine](_URL_3_)\n\nThe actions of Kurita at Samar are still somewhat controversial among naval historians. Kurita in theory should have acted with daring given that the *Sho* plan called for a fight to the death, but he vacillated throughout the engagement. On a more tactical level, there is the question of why did *Yamato* and *Nagato* turn northwards at ca. 0755 which pulled the ship away from Taffy 3 and the carriers when the two battleships were relatively undamaged. Second, there is the Kurita's overall withdrawal for the IJN forces at 0920 away from the American escort carriers and transports. Both decisions by Kurita earned him a degree of opprobrium at the time and in the postwar period with one common metaphor employed casting Kurita as Hamlet unable to make a decision until after the die had been cast. \n\nOf the two decisions, the *Yamato* turn is the more explicable. Lookouts had sighted torpedoes from an earlier torpedo attack and Kurita's battleships faced two choices to \"fan the torpedoes\", a turn to port (north) or starboard (south). The starboard turn would have kept the fleet into contact with Taffy 3 but posed two disadvantages. Firstly, it would have been steaming into the torpedo line, risking a hit. Second, it meant that both battleships were in serious danger of colliding with the battleship *Haruna*, which had been steaming in a line parallel to Kurita's division. This particular aspect of the division's decision is one that only very recently become apparent. Older historiography on Samar such as Morrison tended to place *Haruna* in a different location than more recent work like Robert Lundgren or John Prados which triangulates the battleline more closely using surviving Japanese and American accounts (and note, this still is reasonable conjecture, but still a hypothesis). The officers in charge of the ships' maneuvering instinctively chose the course that minimized damage, with the result that the two most powerful surface units at Samar were now seven miles out of position and its commander lacked even more situational awareness. \n\nThis uncertainty shines some light onto Kurita's second turn away from battle. When the US Strategic Bombing Survey (USSBS) interviewed some of the surviving Japanese naval officers, they gave some inkling that they knew after the battle that the opposing naval force was much smaller than they first thought at the start of the engagement. [*USSBS NO. 170 The Battle off Samar*'s interrogation of Commander Otani Tonosuke](_URL_2_), Operations Officer on the Staff of CinC Second Fleet has a very instructive portion on this very issue and how Japan's lack of air cover contributed to the fog of war:\n\n > Q. What type of carriers did you believe they were?\n\n > A. We gave that question much consideration, but never fully made up our minds. We found ourselves perplexed by your carriers because they did not correspond to their photographs, and first we thought that they were regular carriers; but after the battle, we decided that they were auxiliary or converted carriers. Also we received word from the tops that there was another formation, and at that time we wondered if we were not confronted by 12 or 13 carriers in all; but this was not ascertained on the bridge.\n\n > Q. Was there any attempt to engage in battle with the second group?\n\n > A. First, we would encounter the first group, and then take on the second.\n\n > Q. What damage did you inflict upon the first group you engaged?\n\n > A. One carrier sunk, one light cruiser, one heavy cruiser and one destroyer. There was some confusion between the high gunnery control platform and the bridge. There may have been a repeat report which was understood as two carriers sunk; the bridge concluded that one carrier was sunk. Again from later reports which may have contained duplication, we concluded that we had sunk four carriers, two or three cruisers and two or three destroyers. That was the total result of the day. I now think this is rather accurate, and from a report of search planes at about 1100, we received information that one battleship was severely damaged and dead in the water.\n\nAs Commander Otani's interrogation made clear, the IJN's attempt to ascertain the reality of the combat situation was made difficult by the reliance upon visual sightings from surface ships and the constant Allied air attacks on Kurita's fleet. [Kurita's USSBS interview](_URL_0_) likewise suggested that visual surface sightings were inadequate to give the IJN admiral a proper estimate of the situation:\n\n > Q. What type of aircraft carriers were the American carriers present? Were they the ESSEX or ENTERPRISE class? Did you recognize them?\n\n > A. I don't remember. Starboard bridge structure was all I could tell. There wasn't enough visibility nor adequate reports from the scouting planes.\n\nAlthough he was not available for a USSBS interview because of his foolhardy Kamikaze mission. Admiral Ugaki Matome's diary entries for the Leyte battles also notes that Allied air attacks and poor Japanese reconnaissance doomed Japan's efforts to throw back the Leyte invasion. Although Ukagi's diary took Kurita to task for confusing orders, he placed a good deal of blame for Japan's defeat on the inability of the Philippine's airbases to provide the surface fleet any form of cover or information. His 24 October entry noted that:\n\n > Unless we get enough cooperation from our base air forces, we can do nothing about [concentrated American air attacks], and all of our fighting strength will be reduced to nothing at the end. In such case we should perish by fighting an air battle, hoping it to be a decisive one. \n\nOnce the gravity of the defeat off of Samar sank in, Ugaki's 25 October entry pinned responsibility for failure \"in some respect to [the operation's] planning, [but] mostly to the extreme inactivity of the base air forces. Probably hindered by bad weather.\" One of the themes of Ugaki's remaining entries for October and November was lambasting Japan's lackluster efforts to produce as many aircraft as possible to turn back the Allied tide. \n\nAlthough Kurita asserted in his interview that he did not expect air cover from land-based aircraft, Ugaki's diary entry indicates that at least some IJN officers expected an effort to be made by land-based planes. Otani placed a great deal of onus on the *Sho* operation's failure to poor coordination between Kurita and Japanese air assets:\n\n > Q. Where do you think this whole operation broke down? Why did it fail?\n\n > A. I feel that from the very beginning that the cooperation between the Task Force (OZAWA) and the Surface Force (KURITA) and the land-based Air Force was bad from the beginning.\n\n > Q. What do you feel caused this poor coordination?\n\n > A. Coordination between the Surface Force and the (carrier) Task Force was almost impossible due to the restrictions on communication and the need for radio silence; therefore, the plans for cooperation were not carried out. This lack of information from OZAWA was one of the main factors in the failure of the operation, but perhaps the biggest factor was the lack of protection from our land-based air against your (carrier) Task Force. I feel also that the original plan was too complex and inflexible to work properly. \n\nIn this context, Japanese commanders focused much less on the small size of Sprague's CVEs and instead more on the number of failures of Japanese planning and execution as the reasons for defeat. The effectiveness of the CVE's air attacks, which Otani observed were some of the most effective air strikes despite their small size, further underscored the disadvantages of surface ships operating in an environment where the enemy held complete air superiority. Combined Fleet CinC Admiral Toyoda Soemu's [USSBS interview](_URL_1_) defended Kurita's actions to retire because of this material disparity:\n\n > Q. Under the circumstances as they are now known, in your opinion what that decision of KURITA to turn back a correct one?\n\n > A. Looking back on it now, I think that withdrawal was not a mistake. At the time I did not have and Combined Fleet Headquarters did not have information regarding the details of the engagement. Later, when we learned that Admiral HALSEY's Task Force was further south than we thought it was, I believe that Admiral KURITA then would have been within the range of air attack from your Task Force, so that it was not unwise for him to have turned back at that time.\n\n > Q. You would not criticize his action now in turning back?\n\n > A. I would not criticize. \n\nWhile some zealots like Ugaki saw defeat as an urgent reminder for Japan to redouble her war efforts to achieve victory (upon hearing of Hiroshima his 7 August entry expressed a wish that Japan should develop an atomic bomb of her own), other IJN officers adapted a more fatalistic attitude towards the war. "
]
}
|
[] |
[] |
[
[
"https://www.ibiblio.org/hyperwar/AAF/USSBS/IJO/IJO-9.html",
"https://www.ibiblio.org/hyperwar/AAF/USSBS/IJO/IJO-75.html",
"http://ibiblio.org/hyperwar/AAF/USSBS/IJO/IJO-41.html",
"https://www.reddit.com/r/AskHistorians/comments/4mxjpi/what_was_the_japanese_reaction_to_the_defeat_at/"
]
] |
|
3pif4o
|
What lies behind the military success of the Ottoman Empire in the period from the 1400s to the 1600s, and would they have fared equally well against western European powers?
|
Were the Christian realms in southeastern Europe easy prey for some reason or another? Was there something revolutionary about the Ottoman military? Please shed light on all possible explanations you are able to comment on!
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/3pif4o/what_lies_behind_the_military_success_of_the/
|
{
"a_id": [
"cw6jgmb"
],
"score": [
3
],
"text": [
"A search brought up [this](_URL_0_) post, which mentions the importance of gunpowder and speaks of \"superiority of Ottoman weaponry\". Could someone elaborate on that? How advanced were the Ottomans in the field of weaponry, how big of a role did that play and why did it not matter at later lost battles like Vienna?"
]
}
|
[] |
[] |
[
[
"https://www.reddit.com/r/AskHistorians/comments/33esbq/how_did_the_ottoman_empire_become_from_the_most/cqkc21y"
]
] |
|
31luty
|
How did tyrannosaurus drink water?
|
I tried to Google the answer, but apparently the internet cannot take this question seriously. I am curious because apparently t-rex couldn't lean that far down due to a poor center of gravity, so how did this giant beast get liquid nourishment? One guess I had was that they lay on their sides like when they sleep, but seems super inconvenient and would leave the them vulnerable. If anyone has a real answer or theory to this it would be much appreciated.
|
askscience
|
http://www.reddit.com/r/askscience/comments/31luty/how_did_tyrannosaurus_drink_water/
|
{
"a_id": [
"cq2xhbe",
"cq2yamn"
],
"score": [
48,
5
],
"text": [
"T. rex probably drank like most birds, by bending down and taking a mouthful of water, then tilting its head back to allow the water to run down its throat. Tyrannosaurus also has a ling and heavy tail that can be used as counter weight when it leans forward.",
"Anyone know how much they would drink on average a day?"
]
}
|
[] |
[] |
[
[],
[]
] |
|
gzkn9
|
Does negative mass repel objects?
|
topic :)
|
askscience
|
http://www.reddit.com/r/askscience/comments/gzkn9/does_negative_mass_repel_objects/
|
{
"a_id": [
"c1rhdx2",
"c1rifca"
],
"score": [
9,
3
],
"text": [
"Negative mass is *completely* hypothetical. Your question is like asking \"do unicorns like to eat carrots?\". If unicorns existed there's a chance that they would like carrots, but, unicorns don't exist, so it's not a useful thing to think about. If negative mass existed, then yes it might have the property of repelling other objects. But the question doesn't contain any physics at all.",
"The closest thing, conceptually, to \"negative mass\" that exists is simply pressure. And pressure gravitates in the same manner than mass does."
]
}
|
[] |
[] |
[
[],
[]
] |
|
1hwxvo
|
What makes salt flat so flat?
|
So, I get that [these places](_URL_0_) are all that remains of ancient lakes, and the surface is largely made of the biological detritus of millennia of fish and other aquatic creatures, but shouldn't the original lakes have had their own topography?
|
askscience
|
http://www.reddit.com/r/askscience/comments/1hwxvo/what_makes_salt_flat_so_flat/
|
{
"a_id": [
"caytsyk"
],
"score": [
4
],
"text": [
"Lakes are very low energy environments. So while the hole in the topography they filled will have been irregular, over the long periods (thousands, perhaps even up to millions of years) that the lake is present, fine sediment gets settled out relatively evenly across the basin. The builds up a flat bottom. Once the water is evaporated, you're then left with a salt flat."
]
}
|
[] |
[
"http://en.wikipedia.org/wiki/Makadikadi_Basin"
] |
[
[]
] |
|
2hio8g
|
How is Gavrilo Princip viewed in Serbia today?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/2hio8g/how_is_gavrilo_princip_viewed_in_serbia_today/
|
{
"a_id": [
"ckt1spa"
],
"score": [
19
],
"text": [
"Although this question is likely violating the 20 year, the WWI centennial has caused some focus on the expressions of commemorations and historical memory. NPR had a good report, [*The Shifting Legacy Of The Man Who Shot Franz Ferdinand*](_URL_1_) and *Smithsonian* magazine had an article in 2000 [\"Searching for Gavrilo Princip](_URL_0_) that takes a long view of Princip's legacy. "
]
}
|
[] |
[] |
[
[
"http://beacon.salemstate.edu/~cmauriello/pdf_his102/princips.pdf",
"http://www.npr.org/blogs/parallels/2014/06/27/326164157/the-shifting-legacy-of-the-man-who-shot-franz-ferdinand"
]
] |
||
1v6y6h
|
how would brass instruments be different if they were made from different metals such as steel?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1v6y6h/eli5_how_would_brass_instruments_be_different_if/
|
{
"a_id": [
"cepb7ng",
"cepbavr",
"cepbq5g",
"cepcdlo",
"cepgrun",
"cepgvrp",
"cepol32"
],
"score": [
68,
2,
13,
11,
4,
6,
2
],
"text": [
"The timbre would be slightly different, and they would be much harder and more expensive to manufacture.\n\nWe already have some instruments that are made in different metals - one example that comes to my mind is the flute. Leaving aside wooden types and thinking only of modern flutes with keys and all that, it's very classy and good-sounding to make a flute out of solid silver. It's also expensive as hell. A less expensive and less good-sounding option is a silver-plated brass flute, and the budget option is made from (I think) nickel-plated brass.\n\nBut the flute is straight, and the brass instruments are all bendy. One of the reasons brass instruments are made from brass is that it's soft enough to bend the tubes reasonably easily. I saw an episode of \"How It's Made\" about brass instruments, and it was pretty fascinating. If the tubes were made of steel, it would be harder to bend them, and the bells and such would be harder to spin (although it could be done).\n\nAnd I have seen (and even played for about five minutes) a silver cornet - it sounded beautiful.\n\nAnother thing to think about is that any kind of steel which is ductile enough to bend well is also going to be prone to rust - and playing brass puts a LOT of moisture into the tubes.\n\nLong story short, brass is easy to work with, comparatively inexpensive, resistant to corrosion, and traditional. There are other options, but they are much more expensive, although they do sound lovely.",
"We already have silver (usually plated, as far as I'm aware) instruments... which many think have a warmer tone. Mostly just tone / timbre would change, for better or worse.",
"A flutist named Georges Barrère had a platinum flute made in the 1930s. He asked Edgard Varèse to write a solo piece of music for the first performance.\n\nVarèse called the piece \"Density 21.5\", since platinum has a density of 21.5 grammes per cubic centimetre.\n\nI think it's fair to assume that the platinum flute has a good sound.",
"My band teacher had a collection of war time instruments that were made out of tin or other common metals because brass wasn't available at the time. They all sounded terrible and were very hard to play. ",
"I don't see it mentioned yet, but the brass composition and plating affect the sound tremendously. High copper content \"rose brass\" is reported to produce a much warmer sound as opposed to silver plating and is often seen on flugelhorns and such. Not that I've ever played one, but gold plated instruments are also available. See Canadian Brass, who use gold plated instruments exclusively. \n\n[_URL_0_]",
"One thing that people are missing is that brass vibrates very easily and produces a very musical sound and can quickly change between frequencies.\n\nI have seen (and played) \"brass\" instruments made from different things; plastic, wood, glass, steel, have all been tried. Most of the \"alternative\" materials don't have a good balance between resonance and tone. The amount of air required to get the glass trombone I saw to resonate is ridiculous.\n\nBrass is just a nice balance for all the criteria. Within Brass though you can have different types of brass that offer different tones. (Rose brass, yellow brass, gold brass, silver plated brass, gold plated brass, etc.)",
"your band is going to have bigger arms than the football team."
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[
"http://canadianbrass.com/about/ourinstruments"
],
[],
[]
] |
||
3nrw9i
|
what is the point of unmarked police cars if they are still very easily spotted?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/3nrw9i/eli5what_is_the_point_of_unmarked_police_cars_if/
|
{
"a_id": [
"cvqpp5e",
"cvqqh05",
"cvqrk5t",
"cvqrpzf"
],
"score": [
5,
2,
2,
2
],
"text": [
"This is a form of confirmation bias sometimes known as the toupée fallacy. Take the following sentence:\n\n > All toupées look fake; I've never seen one that I couldn't tell was fake.\n\nSuch a phrase can only be said about bad toupées — ones that look fake — and not actually all toupées. Put simply, if you saw a convincing one you wouldn't have noticed it, because you think it isn't one.\n\n",
"What you're thinking of as \"unmarked\" police cars are the ones driven by plainclothes detectives and such. They're not actually making any attempt to conceal that it's a police car, they're just not *marked* like a patrol cruiser. If nothing else, the car is identifiable by having a government license plate.\n\nThe *real* undercover cops drive cars that are indistinguishable from civilian cars, they may drive beat-up old vans, juiced-up pimpmobiles, whatever the assignment calls for. They have ordinary license plates, and if the assignment is critical enough, the plates are not traceable back to the cops.\n\n\n",
"I did a community patrolling class a couple of years ago, and here is how the chief explained it. \n\nThe cops have three types of cars. Undercover, unmarked, and marked cars. The marked cars have wrap and light bars put on them so you can clearly see they are cops. It makes the public feel better when the public calls for a cop, and lights and sirens are going when a car arrives and you see the wrap on the car telling you what department the cop is with. You can even get the car number and call in and comment about the cop.\n\nThen you got unmarked cars. These may be used by patrol supervisors, detectives, police sergeants, etc. These are the guys that usually don't do traffic patrols or are the first responders. They don't need the markings and wraps because busting speeders isn't their primary purpose. They show up to your house if you are making an insurance claim or need a damage report. No need for lights or sirens then.\n\nFinally, there are undercover cars. They may be cars from the impound lot or seized vehicles and are used for a specific purpose. ",
"Think of it as higher managers or an undercover store cop. By wearing the employee uniform, they would always be asked about where the toy section is or if they sell X stuff and by refusing to help, they would give the store a bad image.\n\nUnmarked cars don't have the letters so the cops can focus on other tasks than showing police presence. They can focus on violations that are harder to catch like cellphones, or other offences that need more discretion while not being hailed or approached for by distracting people. \n\n\nComplete undercover cars that aren't botched usually are not the usual cop car and is fitted with radios and lights that are hidden so even while walking by, you should not recognise them. \n\nOf course some PDs are cheap and will be having the lights at the base of the windshield and back glass as discreet enough.\n"
]
}
|
[] |
[] |
[
[],
[],
[],
[]
] |
||
3exkem
|
how come man made light (leds, etc) can't really replicate the way the sun or fire lights up stuff?
|
I've seen all kinds of lights (LEDs, florescent, incandescent, etc), and none of them really accurately light up stuff the same way the sun (or even fire) does.
Why?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/3exkem/eli5_how_come_man_made_light_leds_etc_cant_really/
|
{
"a_id": [
"ctjbj2m",
"ctjbjk2",
"ctjn60q"
],
"score": [
4,
4,
5
],
"text": [
"Sunlight contains all colours of the spectrum, and artificial lights don't. There are actually light bulbs that radiate the full spectrum that are available on the market, but the main reason why you don't see this type of bulb everywhere is because they're expensive to make. It takes different materials in the bulb to produce different parts of the spectrum, and the cost and feasibility of building a single bulb that can produce the entire spectrum would be costly and impractical since most people only want the visual part of the spectrum :)",
"We can do this. There are full spectrum fixtures of nearly all bulb types available. The most common is fluorescent but I have seen metal halide bulbs in particular that can do \"full spectrum\" lighting At that point it's about adding enough bulbs to replicate the intensity. As I understand it, LED bulbs just require an array/combination of different colored bulbs to mimic full spectrum lighting. \n\nI've had experience with both metal halide and fluorescent bulbs in saltwater aquaria/reef keeping. ",
"The Sun and an incandescent bulb both produce light based on the same principle of [thermal radiation](_URL_2_) - the spectrum of thermal radiation depends on the temperature of the object generating it - see for example [here](_URL_0_). The surface of the Sun is at around 5800K, while the tungsten filament in an incandescent bulb heats up to around 3000K.\n\nThey both produce a full spectrum of light, but with a different distribution across the wavelengths, which we perceive as a shift in the color of the light - an incandescent light will produce a warmer light than the Sun, due to its lower temperature. \n\nHowever using thermal radiation is not a very efficient way of generating light for illumination, as a lot of the energy is wasted generating light outside the visible part of the spectrum (between 400 and 700 nm on the graph above) - especially in the infrared (IR) part above 700nm which you can feel as the heat radiating from the incandescent bulb (or the Sun).\n\nThe alternatives like LEDs and fluorescent lights use different phenomena which generate light with much more narrow spectrum, often with one or several distinct narrow peaks around certain wavelengths (a typical fluorescent spectrum might look like [this](_URL_4_)) - but without much energy being wasted outside the visible spectrum.\n\nSo really the fact that energy efficient light is not full spectrum is a feature - it is what makes it energy efficient. We don't really currently have an energy efficient process that can generate only the full visible part of the spectrum. We cheat by combining different specific methods (gases, phosphors, etc.) that each produce a peak of light at one specific wavelength to fill in as much of the visible spectrum as we can (an example spectrum from such \"full spectrum\" fluorescent bulb looks like [this](_URL_1_))\n\nThe reason this works reasonably well is that human vision is not actually capable of sensing the full visible spectrum either - we have what is called tri-chromatic vision, with only 3 types of cells (cones) in the eye, each capable of [detecting light in a relatively narrow range of wavelengths](_URL_3_) - typically identified as red, green and blue. So if your source of light can generate some wavelengths in all 3 areas, it will appear as reasonably white to us - although there will be noticeable differences in certain colors illuminated by any light that is not full spectrum. You can see the 3 main peaks in the fluorescent spectrum I linked above around 440, 550 and 610 nm)"
]
}
|
[] |
[] |
[
[],
[],
[
"https://upload.wikimedia.org/wikipedia/commons/thumb/a/a2/Wiens_law.svg/720px-Wiens_law.svg.png",
"https://upload.wikimedia.org/wikipedia/commons/thumb/7/78/Spectra-Philips_32T8_natural_sunshine_fluorescent_light.svg/1489px-Spectra-Philips_32T8_natural_sunshine_fluorescent_light.svg.png",
"https://en.wikipedia.org/wiki/Thermal_radiation",
"https://upload.wikimedia.org/wikipedia/commons/thumb/1/1e/Cones_SMJ2_E.svg/287px-Cones_SMJ2_E.svg.png",
"https://upload.wikimedia.org/wikipedia/commons/thumb/8/8d/Fluorescent_lighting_spectrum_peaks_labelled.svg/1268px-Fluorescent_lighting_spectrum_peaks_labelled.svg.png"
]
] |
|
1ml7ns
|
Why 1^∞ is undetermined? Why is it not 1?
|
Also why is 0*∞ also undetermined? I mean if it is the sum of infinite zeros then surely it's just 0?
|
askscience
|
http://www.reddit.com/r/askscience/comments/1ml7ns/why_1_is_undetermined_why_is_it_not_1/
|
{
"a_id": [
"ccaao5y",
"ccaauij",
"ccab48p",
"ccab7fd",
"ccaempb",
"ccaft1m",
"ccajghr",
"ccakkto"
],
"score": [
211,
44,
10,
53,
15,
2,
2,
2
],
"text": [
"It needs to be reminded that infinity isn't directly a number but rather a concept of numbers going on forever, depending on the infinity, 1 can be affected in a different way compared to real numbers. It's like trying to do 2^Pineapple. It's just not going to work because we don't know directly what pineapple is and if it can actually be substituted as a number.\n\nAs for 0*Infinity, similar to the above statement, you can't multiply a number by a number that might not actually be a number, trying to multiply, add, subtract, divide, power, root etc. of anything that's not directly a number is complex stuff and even makes my brain hurt sometimes. Overall, infinity needs to be treated as a concept rather than a direct number because infinity can be multiple different types of numbers as there are many types of infinities.",
"You are treating infinity as if it were a number. That is not the case. Infinity is a concept that only exists in the limit. As that is the case, you can only really express it as lim(n → ∞) 1^(n), which actually does have a limit of 1.\n\nSimilarly, 0 * ∞ is probably not what you're really thinking of. What you mean is two functions, one of which, say f(x), has a limit of 0 as x goes to infinity, and the other, g(x) having the limit of ∞. When they are multiplied by each other, it's not clear what the limit will be. Say f(x) is (x+1), and g(x) is 1/(x-1). Then the limit of the product is neither 0, nor infinity, but rather 1. You can construct scenarios in which it goes to any number or 0 or infinity. (I'm not sure if you can make it not have a limit at all.) So the form in the abstract sense is indeterminate without more information about the limit.",
"I believe the understanding of indeterminate forms is somewhat skewed. \n\nThe form 1^∞ does not mean \"multiply one by itself an infinite number of times\". \n\nGiven some functions of x, f and g, we can take the limit as x - > c of f^g. If lim x - > c (f) = 1 and lim x - > c (g) = ∞, then this limit (lim x - > c (f^g)) is considered an indeterminate form.\n\nNow consider what this really means. As x goes towards c, f goes towards 1, but never reaches it. That is the key idea. (It is the same for g; it never reaches a value of ∞ since that doesn't even make sense). 1^∞ might be equal to 1 if you define it as such, but 1.0 ... 01 or 0.99 ... 99 raised to a very large exponent is most certainly not equal to 1. \n\nf getting closer to one decreases the value of the expression f^g, while g getting 'closer' to 'infinity' increases the value of the expression f^g. The behaviours of f and g in the limit as x - > c imply different outcomes. This is why it is considered indeterminate. The question becomes, which of f and g approach their limit faster? The derivative of a function is the measure of how quickly it changes, so the derivative of a function near some value c is how quickly that function is changing near c. This is the reasoning/motivation behind L'Hôpital's rule.\n\nFor the 1^∞ case, if f approaches 1 faster than g approaches ∞, then f 'wins' and the limit is defined (usually 1, but also depends on how much faster f approaches 1 than g approaches ∞). Conversely, if g is increasing faster, then it 'wins' and f^g continues to grow and grow and never stops growing, so we call the limit ∞ (or more properly, we say the limit does not exist).",
"The symbol ∞ does not represent a number, so writing \"1^(∞)\" isn't any more meaningful than writing \"1^(Reddit)\".\n\nThat said, there *are* infinite numbers: in fact, there's a lot of them! These are the \"transfinite cardinals\", and they measure the sizes of infinite sets, the same way that the ordinary cardinals (like 3) measure the sizes of finite sets. For example, 3 is the number of things in this set: {A, B, C}. The smallest transfinite cardinal, ℵ0 (read \"aleph null\"), is the number of things in this set: {1, 2, 3, 4, …}. It's actually perfectly intelligible to write down 1^(ℵ0); it turns out that this is equal to the number of *functions* from the set {1, 2, 3, 4, …} to the set {1}, which is 1.\n\nedit: Hebrew characters in Unicode apparently force right-to-left rendering. Can't seem to fix it. Oh well.\n\nedit edit: Got it. Thanks, /u/WanderAndTheColossus!",
"I always try to be very careful when I talk about limits and indeterminate forms to my students. And I make it very clear that one should never write things like \"3*∞ = ∞\" or \"∞ +1 = ∞\" even when it could make sense.\n\nThe point is that we say \"1^∞ is undetermined\" when we talk about limits. So let's try to understand what it means to be undetermined for limits.\n\nYou have limits of functions, for example, you know that the limit of a function f at a certain point p is L. (This has a precise meaning, and this does mean that you can write f(p) = L) And you have another function g for which you know that the limit at p is L'. The question is :\n\n What can we say about the limit of the three new functions f+g , f\\*g , f^g at this same point p.\n\nFor some case, depending on what L and L' are, we know exactly what the new limits will be.\n\nFor example, if L and L' are both real positive numbers (so only finite numbers), then the limits of the the three functions will be L+L' , L\\*L' and L^(L') respectively. This is the baby case in some sense.\n\nSome cases where limits could be infinite are also easy to deal with. For example, if L is a real number and L'=+∞ then the limit of f+g is +∞. Another example is that when L=L' = +∞ then the limit of f^g is +∞.\n\nIn all previous cases, only the values of the limits are important. I don't need to know what the functions really are. These are the **determined**.\n\nNow, can I do this for any possibilities of L and L' ?? The answer is No. In some cases for L and L', the values of the limits alone will not suffice to be able to give the limit of f+g (or f*g or f^g).\n\nFor example if L=+∞ and L'=-∞ then I cannot tell you the limit of f+g without knowing f and g. Meaning that with f(x) = 1/x^2 and g(x) =-1/x^4 at the point p=0 we get that the limit of f+g is -∞. However, taking f(x) = (3+1/x^4 ) with the same g gives a limit of 3. And I could get any other limit with other functions (including no limit at all). So sometimes we say (with this awful abuse of notation) that \"+∞ - ∞ is an undetermined form\". \n\nThe same thing happens when L=1 and L'=+∞ when we try to find the limit of f^g . I cannot tell you the limit of f^g without knowing f and g more precisely. I could give you examples where the limit would be 1 and other examples where the limit will be 3 or whatever you like . That's why we use this awful abuse of notation \"1^∞ is undetermined\"\n\nI hope that was clear. The use of ∞ is limited to sentences talking about limits (or in other contexts, talking about cardinality)",
"A value exists and is known when three criteria are met, the limit as x approaches from the left equals the straight substitution of x equals the limit as x approaches from the right.\n\n\nIf you graph y=x^n, where n is a very large number and x is positive, you will see that y is a very small number when x < 1, 1 when x is one, and a very large number when x > 1. Using infinity, it is zero when x < 1, and infinity when x > 1. Since those two do not match, 1^infinity is undefined.\n\n\nLikewise for 0 times infinity. With y=x*n when n is a very large positive number, y is a very large negative number when x < 0, and a very large positive number when x > 0. Since the two do not match, it is undefined at x=0.",
"It's because you can, using limits, you can actually get any answer you want. 1^x, as x goes to infinity, is infinity. That makes sense.\n\nBut something like (2-x)^(1/(1-x) as x goes to 1, (which is practically equal to 1^infinity) gives you e.\n\nIf you do it in different ways, you can get any answer. So we have to conclude that the real answer can't be determined, so we call it undetermined.",
"The form 0 * ∞ is considered in limits. We are not considering 0 itself but a function which tends towards zero. If we have something growing towards infinity and multiply it by something shrinking towards zero, the answer depends on which is shrinking or growing faster, indeterminate because we don't know which is the case. That's where L'Hopital's rule kicks in."
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[],
[],
[],
[]
] |
|
weu2b
|
the us system of government
|
So you have a president, but he's not the leader of a political party and he can't nessessarily pass the laws he wants? What's the difference between the senate & congress? And then each state has it's own governor and senate?
Could someone give me a run down of what all these pieces are and how they relate to each other?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/weu2b/eli5_the_us_system_of_government/
|
{
"a_id": [
"c5cpji7",
"c5cq7ot"
],
"score": [
6,
3
],
"text": [
"The US Government is best viewed as 3 branches.\n\nThe executive branch is in charge of carrying out laws and running the government's operations. The President is the head of the executive branch. He is elected by the people.\n\nThe legislative branch is in charge of making laws. Congress (the Senate and the House of Representatives) is the legislative branch. Senators and Representatives are elected by the people.\n\nThe judicial branch is in charge of resolving disputes and challenges to laws or government actions. The Supreme Court is the head of the judicial branch. The Supreme Court is appointed by the President, subject to Congress's agreement.\n\nAll three branches have checks and balances that make it hard for another branch to sieze power. Each branch has a way to override another branch's powers.\n\nThe President can veto a law passed by Congress. The President also appoints Supreme Court justices. Congress can override a President's veto, with a 2/3 majority. Congress can override a Supreme Court decision, by passing a constitutional amendment (with help from the state governments). Congress can also impeach (kick out) the President or a Supreme Court justice. The Supreme Court can strike down a law passed by Congress, and can prohibit the President from doing certain things.\n\nThat's how it works!",
"In most democracies, the person in charge of the legislature (the group of people who pass laws, like a Parliament or Congress) is also the \"head of government,\" meaning that person is in charge of the details of how laws get enforced.\n\nIn the US those two rolls are separate. The Congress can pass laws, but does not have the power to enforce them. The **President** must follow the laws Congress passes but is in charge or filling in the details about how it is enforced. All the bureaucracy and government agencies report to the President, not congress.\n\nNow **Congress** is made up of two parts, the **House of Representatives** (made up of 1 Congressman/ ~720,000 people) and the **Senate** (2 from each state no matter the state's population). For a law to \"pass\" both the House and the Senate must pass the exact same law with the exact same language. Each chamber does that a little differently but it can not be \"passed\" unless every word is the same between both sides.\n\nThen, because the US is based on common law not civil law, there is a **judicial branch** made up of judges that can change laws and policies. If someone gets arrested for a law they think is unconstitutional, they can bring the case to a judge and they decide either yes the law/government action goes against the constitution or no the law/action is within the power of government. The only time judges can stop laws is if it violates the constitution or if there are two laws that violate each other. They can not pass laws and the can not enforce them, but they can clarify which ones are constitutional. The Supreme Court is 9 people and it is the final word on what is and is not constitutional, there is no way to appeal a Supreme Court decision to another judge.\n\nThese three parts (the President, the Congress and the judiciary) are known as the **three branches of government**. They each have their own kind of power, but they are set up so that no one branch can overpower the other two and take complete control of the government. Each has at least one way of overpowering the other, and each has at least one way of being overpowered by another.\n\nFor example; after Congress passes a bill, the president must either sign it (when it instantly becomes law) or veto it (where none of it becomes law). So if congress passes something the president doesn't like he can veto it, but he must veto the whole bill (that's why small projects sometimes get bundled into more popular bills). But, if Congress *really* likes the bill, they can vote again and if they get 2/3 to vote yes the veto is removed and the bill is law. There are dozens of ways like this that the branches interact but the important thing is that it is designed so that the different branches stop any one from becoming an all powerful branch.\n\n**States also have these three branches** at the state level (except they call their equivalent of a \"President\" Governor), each independent and accountable to their state's constitution. There are some small differences but mostly they are based on the same model as the federal government. There are some things states can not do because only the national government can do it (raise an army, print money, and others). But there are some things that *only* states can do, things the federal constitution say is up to the states (education and others).\n\nSo that's basically it. **President, two-part congress, and judiciary**. One enforces laws but can't pass them, one writes laws but can't enforce them and the other judges if the actions being taken in writing and enforcing the laws is constitutional. States have the same basic system and power between states and the federal government is split up so that one can't dominate the other in everything."
]
}
|
[] |
[] |
[
[],
[]
] |
|
330c7a
|
Does honey contain protease?
|
askscience
|
http://www.reddit.com/r/askscience/comments/330c7a/does_honey_contain_protease/
|
{
"a_id": [
"cqglpqf"
],
"score": [
6
],
"text": [
"\"Protease\" isn't just one substance - there are many enzymes that can cleave proteins. (They're proteins, too, but generally don't contain sequences that they're vulnerable to themselves!) Honey has very little protein in it, only about 0.5%. I haven't been able to find out if any of that protein is, in fact, any sort of protease enzyme, but I also wouldn't expect any enzymes in honey to be in any sort of properly folded state, since the water content is so low. So they'd be expected to be inactive, even if present.\n\nJust out of curiosity, why do you ask the question?"
]
}
|
[] |
[] |
[
[]
] |
||
30ru5r
|
when someone asks if i've seen a particular movie or not, most of the time i can answer yes or no with extreme accuracy, so why can i not accurately remember every movie i've ever seen when not prompted with a title?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/30ru5r/eli5_when_someone_asks_if_ive_seen_a_particular/
|
{
"a_id": [
"cpv8bra"
],
"score": [
15
],
"text": [
"Psychological term called priming. When you hear something your brain activates or \"primes\" related topics. Hearing the title of a movie usually activates the memories associated with that movie."
]
}
|
[] |
[] |
[
[]
] |
||
2bq5zj
|
if women make up near equal percent of gamers, why are more games not being directed at female or neutral gender audience
|
As a marketing major, and with many feminists and gamers in my life, I've often had it brought up how unfair and biased gaming can be towards women. I assumed it was because it was more profitable to market towards males. After all, if it was equally profitable to market to females surely this would be happening, but I was directed to statistics claiming it's about a 50/50 split. So Reddit, why are so many games targeted at males as opposed to females?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2bq5zj/eli5if_women_make_up_near_equal_percent_of_gamers/
|
{
"a_id": [
"cj7suje",
"cj7tihy",
"cj7upi1"
],
"score": [
5,
16,
3
],
"text": [
"I'd like to see those statistics. I'm fairly confident that among FPS-style games, males outweight females fairly heavily. But, if you take into account a similar gender skew in favor of females and puzzle-style, browser, and mobile games, perhaps, then you can end up with a statistic that says it's a near even split.\n\nBut, I think you're imagining FPS-style console and PC games, and I'd really like to see some of those 50/50 statistics if you have a link to them.",
"because these statistics count in people playing farmville, candy crush and the like.\n\nif you leave casual games out the audience is much more male dominated.",
"I dunno if I necessarily agree with the games being targetted to males. Cars, guns, violence, sports yes stereotypically very male but certainly not anti-woman. \n\nWomen like these types of things just like men do. "
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
bqr01c
|
if exercising makes your heart stronger why are amphetamines and anxiety bad for your hear?
|
Increasing your heart rate makes it stronger. But drugs like cociane, meth and disorders like anxiety that increase your heart rate are bad for your hearts health. Shouldnt it make the heart stronger?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/bqr01c/eli5_if_exercising_makes_your_heart_stronger_why/
|
{
"a_id": [
"eo6xg5x",
"eo8adpy"
],
"score": [
6,
5
],
"text": [
"Increasing you heart rate is like a car going faster: through exercise is like using the gas pedal normally to control the acceleration of the car; amphetamines, anxiety, drugs like cocaine is like your car going off a cliff to go faster. You’re going faster, but you’re probably going to die in the end.\n\nCheers.",
"When exercising, you’re not just increasing your heart rate. The blood vessels throughout your body also dilate to allow better blood flow to your heart muscles and other organs\n\nUsing cocaine and amphetamines, even though your heart is beating fast, the drugs causes arteries to constrict, restricting blood flows. So your heart is made to work harder without good blood flow. On top of that, the blood pressure exerted in your brain is vastly increased which can lead to a stroke."
]
}
|
[] |
[] |
[
[],
[]
] |
|
bhbpkn
|
Why don’t former Italian colonies, such as Libya and Somalia, speak Italian?
|
I understand that the cultures and languages of those nations were already firmly rooted, but that was pretty similar to Algeria and Morocco who still ended up using French (and in Western Sahara, Spanish) quite extensively to this day. Why was this not the case in the Italian colonies?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/bhbpkn/why_dont_former_italian_colonies_such_as_libya/
|
{
"a_id": [
"elsheuv"
],
"score": [
23
],
"text": [
"I'm just going to respond regarding Somalia, since I'm not as well read regarding Libya and other Italian colonial territories.\n\nThe short answer to your question is that Italy's footprint in Somalia was light for most of its colonial history, and just as the Italians were ramping up assimilation efforts, WWII came along and stripped the colony from them.\n\nThe area became a protectorate of Italy in 1888 when Sultan Yusuf Ali Kenadid of the Majeerteen Sultanate signed a treaty with Italy. Kenadid's rival and neighbor, Sultan Boqor Osman Mahamuud of the Sultanate of Hobyo, signed a similar deal the next year, forming a continuous territory.\n\nIt was not, in some ways, a traditional colony at first in that the Italians had limited interest in most of the arid Somalian landscape - they were mostly interested in the strategically important ports on the shore, which gave them access to the Suez Canal and the Gulf of Aden.\n\nThe Italians provided arms and money to the sultans in return for this protectorate status, but they held little direct control beyond their coastal strip. Even here, the Italian population was mostly military officers and colonial officials, with few settlers.\n\nIt wasn't until the early 1930s that a two successive Italian Governors - Guido Corni and Maurizio Rava - started actively trying to assimilate the Somalis into Italian culture. The Italians began to build out hospitals and schools around the capital, Mogadishu, around this time, and more Italians began to arrive as permanent settlers. By 1930, there were 22,000 Italians living in Mogadishu and its immediate surrounding territory, but they were still a light footprint on the ground.\n\nBy 1935 that number had grown to 50,000 Italians settlers, 20,000 of who lived in Mogadishu, representing just under half of the city's population. Over the course of the colonial governance of the territory, the succession of sultans which controlled much of the inland territory occasionally proved disloyal, and over time the Italians started taking more and more direct control of the hinterlands of the territory as a way of ensuring better control. \n\nIf things had continued like this for a few more decades it's very likely that Italian language and culture would have become inculcated, at least around the coastal areas where Italian presence was heaviest, but Italy joined the Axis during WWII. They lost Somalia to a British attack in the spring of 1941. After the war the UN made the colony a trusteeship, and it was granted independence in the 1960s.\n\nWhen Siad Barre became president of Somalia in 1969, he enforced a policy of promoting the Somali language and enforcing it in government use. He adopted a new Latin alphabet for the language. Somali was the only language allowed to be taught in schools. His stated reason was to erase the gap between those who fluently spoke Italian and English and those who did not, as well as to help foster a thriving Somali culture.\n\nAs to the Italian colonists, some started leaving after WWII, but the exodus picked up after independence. There were several anti-Italian riots in Mogadishu around this time in which multiple Italians were killed. Many returned to Italy or migrated to the US, though there was still a small Italian population in the city through the 1990s.\n\n**Sources:**\n\n* Barrington, Lowell, After Independence: \"Making and Protecting the Nation in Postcolonial and Postcommunist States.\"\n* Baker, Bruce. \"Escape from Domination in Africa: Political Disengagement & Its Consequences.\""
]
}
|
[] |
[] |
[
[]
] |
|
16b7l9
|
what does alzheimers do to the brain? if a "cure" was invented would it help current sufferers remember?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/16b7l9/eli5_what_does_alzheimers_do_to_the_brain_if_a/
|
{
"a_id": [
"c7ugize",
"c7uhoal",
"c7uhyf8",
"c7ujh1l",
"c7ukp8f"
],
"score": [
13,
2,
2,
5,
3
],
"text": [
"As I understand it, Alzheimer's causes proteins to take the wrong shape in the brain. To put this in context the majority of proteins need to be the right shape in order to work. \nFor instance, enzyme's are used to break down your food much more quickly. Biologists describe the process using either the lock and key model, where only one shape of key can fit into a lock, or the hand in glove, where the enzyme changes shape to fit the hand. If what is required to be broken down doesn't fit nothing happens. \n\nThe protein in question is required for brain repair, as you age every part of your body slowly gets damaged and without the ability to repair you quickly accumulate damage. \n\nThat's about as simple as I can get it, if anybody can improve upon that please do. ",
"Well there's many theories, but one of them is that plaques form in the brain. These plaques are caused by the protein known as Beta Amyloid (hence why they are called *amyloid* plaques) and form the plaques by depositing tangled amyloid fibers into the brain. Thus causing the brain to start losing its ability to 'talk' to the other various parts of the brain, especially those involved with memory. ",
"Alzheimers disease is a form of dementia. A dementia is a \"wasting\" illness of the brain. The brain is made of billions of special brain cells called neurons. The neurons connect to each other in many complex links to form pathways; this is a little bit like the connections between roads at a very complicated crossing. On a road when you come to where 2 roads cross, you have 2 or 3 choices of pathways to take. In the brain when neurones meet there be many pathways to take, and after each crossing there will be another crossing. Very complicated pathways can be formed. In the brain, pathways of connections and crossings are used to store information such as memories. \n\nIn Alzheimer's disease specific parts of the brain break down and waste away. As the brain breaks down, it can do less. Memory is one job of the brain that is particulalry affected. Memories are kept by the brain like a computer stores files, you can save a memory today and come back and see it again tomorrow. The brain stores memories by creating those specific pathways of brain cells. So if you eat ice cream in the park, the brain will create a special connection of neurons to form a pathyway which will be where the memory is stored.\n\nWhen a pathway breaksdown, the memory is also lost - so if you have that memory of eating ice cream in the park, you will \"forget\" that memory if the special brain pathway storing it goes; so if the brain cells in the area die or waste away the memory is lost. This is what happens in alzheimers - the memories are lost because the brain cells are wasting away and those complex pathways are being lost.\n\nThere is no cure for alzheimers at present. If a cure is found, it is unlikely to undo the damage and bring back all lost memories. A cure would stop the wasting disease. The brain may be able to repair itself a little, and some memories (where the damage to the pathway is not too bad) may come back, but other memories will be lost forever. The key to curing alzheimers is finding a way to find the disease very early on and stop the disease progressing. There is alot of research going into this now and it is hopeful a cure will be found in the future.",
"Ok I'll try to explain it as simply but not nessarly as accurately as I can manage:\n\nThinking and memory relies on flashes of electricicty traveling along highways called neurons. these are very small and thin. they need to be supported and usually they're suppored by the right substance. \n\nSometimes your body starts to malfunction and starts making the support for these highways out of Taffy rather than concrete ( a more appropriate support for highways). As these highways are so tightly packed all the taffy starts to stick together and create yucky sticky balls that the electrical signals struggle to drive through. That's why it's hard to remember things.\n\nCurrent treatment relies on making the signals stronger, but treatment cannot untagle these taffy-based sticky tangles of neurons that prevent signal transmission. So the treatment can slow the memory loss but not prevent it. \n\nHope my clumsy analogy helps!",
"[Here](_URL_0_) is a very accurate short video about Alzheimer's.\n"
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[
"http://www.youtube.com/watch?feature=player_embedded&v=7_kO6c2NfmE"
]
] |
||
5c771z
|
how does a ship force a submarine to leave an area?
|
[This article](_URL_0_) says that a Dutch submarine was detected spying on the Russian fleet in the Mediterranean. Without using weapons how can a ship force a submarine to leave an area?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/5c771z/eli5_how_does_a_ship_force_a_submarine_to_leave/
|
{
"a_id": [
"d9u65vk",
"d9uo1g3"
],
"score": [
7,
2
],
"text": [
"The only thing a submarine has is stealth. It uses the depths, different thermal layers and silent operations to hide in the background ocean noise.\n\nGetting detected means the submarine is pretty much a sitting duck. It reflects either a mistake made by the submarine crew, or the skills of the surface fleet at anti submarine warfare. Attack submarines following or monitoring enemy fleets, even during peace time is common.\n\nWhen they get detected, enemy attack subs do things like blast their sonar, surface ships and aircraft drop sonar buoys over the location of the detected submarine. So the detected submarine gets chased away, and will most likely try to follow again without getting detected again.",
"Find it, ping the area, get in position where you could drop a depth-charge, and if they haven't freaked out and GTFO'd yet, you drop a depth-charge and send their souls to the depths. ...depther depths? \n\nThe sonar ping is not subtle. It's essentially shouting \"HEY\" on the surface and seeing if anything bounces back. The sub knows the boat is running active sonar pings, and knows exactly where the boat is. If they hear a ping, and then they hear a closer ping, they know the boat found them and could kill them all in short order. "
]
}
|
[] |
[
"http://www.bbc.co.uk/news/world-europe-37928222"
] |
[
[],
[]
] |
|
1harxt
|
If East Asians invented movable type well before Gutenberg, why didn't it take off as well as it did in Europe? Was it because of the number of characters? Economics? What?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/1harxt/if_east_asians_invented_movable_type_well_before/
|
{
"a_id": [
"casjx5o",
"caskjap",
"casoxlf",
"casplj1"
],
"score": [
8,
7,
3,
6
],
"text": [
"I know there are some excellent 'asia-specialists' on here who can probably answer your question more completely, but I figured I'd just get things started. \n\nI believe the social structure in China prevented the widespread use of the printed word. In China there was a far bigger devision between poor workers/farmers and the governing elite. There was no 'middle class' which was developing in Europe at the time printing was on the rise there. \n\nThis means there were less people to produce books (middle class people produced books on fasion, etiquette, the best ways to trade, make clothing etc) and less people to produce books for. (simply not enough people who can read.\n\nI would also add the fact that right at the time when printing was coming up in Europe, the reformation happened, which was the biggest religious conflict the continent has ever seen. Both sides used print as a weapon, which made sure that a lot of texts were produced. \n\n(source: Europe, a cultural history by Peter Rietbergen.)\n\nEdit: As one of you correctly pointed out. I misrepresented my source. The source I mentioned describes in great detail the development of print in Europe. The comment about Chinese social structure is not from this work. My apologies for the inaccurateness.",
"Ease of use, primarily. Remember the Latin alphabet only has about 26 characters. \n\nFrom the producer's point of view, the benefits of movable type are compounded when you can create any word using just 26 print shapes. \n\nFrom the consumer's point of view, the opportunity cost of learning how to read (as opposed to working to earn a living) is significantly lower if the system can be learned in a short amount of time and with little effort. This lower opportunity cost compounds the reduced cost of the product itself (i.e. the book) which is the result of mechanised printing.",
"This thread seems a bit geared towards China when it comes to the printing press, but what would it be like in Korea with the creation of Hangul? I'd imagine as a true alphabet, Hangul would be a natural choice for a printing press. Does anyone have any thoughts about this?",
"So, we are hung up a bit on the importance of movable type over the importance of any printing mechanism. Printing is the key here, and it took off tremendously in China, Korea, Vietnam and Japan. \nSo, let's deal with movable type - by the time it was invented, in the 11th century, the first major book culture revolution was already over 100 years old. It was based on the highly effective carved woodblock system. Movable type was indeed less useful than the woodblocks because the 1000's of individual characters required several skills to re-arrange, and for these other reasons: \n1. literacy and organization - whomever was managing the machine must have a pretty serious organization system to locate and properly place the words. In addition, this person must be literate. Woodblock cutters, by contrast, could be talented copyists without being literate. \n2. massive printing runs - the numbers were immense by the 11th century. Having ready made blocks for these printings runs was essential. The books could then be re-run without the hassle of re-arranging 1000's of characters. \nThat's pretty much it, there was no economic reason to switch to movable type, because the boom was already on, and woodblocks were extremely effective. \nThe ideas that literacy was lower, and that the middle class was smaller are demonstrably false. Literacy was ridiculously high in the 11th-12th centuries compared to everywhere else on earth (conservatively 20-30%) at the time. Additionally, the merchant class was absolutely booming, with a burgeoning middle class in all areas. Much of this was based on the mobility that literacy could provide. There are texts on all manner of quotidian things - local gazeteers for tourists, simplified law-books for pettitfoggers, simplified religious texts for lower level (not buddhist or daoist affiliate) practitioners. all sorts of DIY guidebooks for building boats, furniture, etc etc etc. \nSo, the answer is: printing took off just as much if not more than in europe 500 years later, but not movable type as the mechanism. "
]
}
|
[] |
[] |
[
[],
[],
[],
[]
] |
||
2ct2zo
|
how can a pc game be developed for years? don't the constantly emerging new hardware capabilities far outrun what the game (engine) started out with?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2ct2zo/eli5_how_can_a_pc_game_be_developed_for_years/
|
{
"a_id": [
"cjipd9j",
"cjipedm",
"cjipf6o",
"cjiplp7",
"cjipose",
"cjiqand",
"cjix3v8",
"cjj23ag",
"cjj5cqw",
"cjj7fwe"
],
"score": [
16,
5,
55,
2,
2,
2,
5,
2,
2,
2
],
"text": [
"Developers don't design for the cutting edge. The aim for the middle of the market. So they aren't worried if hardware changes (assuming its still compatible with their game/code) because the cutting edge doesn't matter.\n\nAll that matters is what the average or majority are using. ",
"Most game engines are fairly independent of hardware. That's why things like the Unreal engine are still in use today. As hardware improves, you can just keep telling them to render at higher resolutions, giving them models with more detailed polygons, giving them higher quality textures, etc.",
"There is a lot to a game besides it's interaction with hardware, essentially everything about game design is independent of hardware, save for things like user interface or graphics.\n\nBut you can write an entire game which outputs with blocky models and low resolution textures in a boring 3D world, but then relatively easily replace all those with better models/textures/lighting later in development without a huge cost. Add to that the fact that most development machines are very powerful and you have a situation where it's not hard to develop with the expectation that hardware will be able to do more in 2-3 years.",
"Generally speaking its much harder and takes longer to make the actual game than it is to spice up the graphics such that the graphics are cutting edge. Any PC upgrades other than graphics will make the game faster but these days PCs are fast enough already that video games don't max out the CPU or anything anyway. Those that do max out the CPU could be optimized to be faster, but since the hardware is so good the devs don't bother. Basically, they make the game first and then see where the hardware is and adjust accordingly. Also note that big companies can afford to have all the latest gadgets on a single test computer whereas most consumers won't have the newest stuff until years after it comes out. Most gamers probably have a gaming PC that is 2 to 5 years old and can still run new games that come out today. Until we see the next generation of gaming (I'm talking about you Oculus Rift) we've kind of peaked in terms of video games in that computers have more power than devs know what to do with (without being wasteful).",
"Short answer: you are only thinking the short-term.\n\nLong answer: you have to factor in (in no particular order):\n\n* Planning\n* Base Sketching\n* Pre-development\n* Casting and Acting (these two if voice actors)\n* Architecture/Hardware available\n* The actual development of the game\n* Funding\n* Marketing \n* Several other things that may be mentioned by other users\n\nMuch of the planning in there may take 2 years, or even 3+ in the worst of cases. The first three cases can be the longest if gone unchecked.\n\nOften, companies will work with the stuff they already have, and may build up from there. In prominent cases, like the Crysis series, they may get extreme-end PCs to work on so they can see how the engine will work, and then go the end-user. I do not think it is a matter of whether or not the market will catch up and pass them quickly; I believe that is an exercise in futility.",
"New hardware capabilities\" aren't as \"constantly emerging\" as you think. Compare, say, the most common consumer processors for gaming this year to the one from last year: they're all Ivy Bridge quad-core Intel x86-64 processors in the i5 or, less commonly, the i7 range.\n\nBefore the Ivy Bridge products, the market was dominated by Intel processors with the Sandy Bridge architecture, which from a casual standpoint is almost identical.\n\nOn the AMD side of the processor market, the story is the same: every few months we get a brand-new AMD offering that's almost a carbon copy of the one before it and the one that will come after it.\n\nThis is because improvements in spaces like the PC hardware market are incremental. Anecdotally, I often hear persons unfamiliar with technology opine about how brilliant engineers are breaking new ground on a daily basis, advancing computing at a breakneck pace. Obviously that isn't the case, or else your one-year-old laptop would bear no resemblance to the one you just bought.\n\nShort version: Hardware doesn't move as quickly as you might have been lead to believe, and the hardware from a few years ago pretty much does all the same stuff the new gear does.",
"Ever wonder what madman would buy 3 $2500 video cards for SLI?\n\nA game engine developer, getting ready for what will be in a single $250 card/console in 3-5 years.",
"Graphics are usually one of the last things nailed down for a game in development. Case in point, it is not at all unusual for alpha footage of Blizzard games to end up on the box art for their games. The Warcraft 3 box featured catapults being pushed by peons and a highly polygonal human tower which would never make it into the actual game. \n\n\n\nFurthermore, very few games represent a coherent *cutting edge* of graphics. In any given year you might see three titles that become *the* benchmarking title because they typically don't represent the kind of financial success a game like World of Warcraft, Starcraft, Farmville, Pokemon, ect, represent. Take a look at the 20 most profitable games ever made and most simply did not feature graphical fidelity as a selling point. Games like Starcraft and WoW intentionally chose graphical styles that were inferior in terms of hardware usage but looked *good.*\n\n\n\nBut yes, the constant evolution of hardware and engines do put games in early graves. Blizzard's Starcraft: Ghost title was canned, even though Blizzard acquired Swinging Ape Studios just to develop the game, because by the time it was getting close to that end phase the GameCube / PS2 / Xbox era was drawing to a close. Unwilling to commit new resources to translate the games into stronger hardware, and partially because the game was just, \"meh\", the game got postponed indefinitely. \n\n\n\nGames *do* tend to look their best near the end of the life cycle of a particular piece of hardware for a reason though. ",
"Everquest 2 used to have a pop up when you set it to the top two graphics levels warning you that even todays best gaming rigs would have trouble running at those settings.\n\nThey planned for the future.\n\n",
"I make 3D models, and I can tell you that it takes for EVER to make a realistic model like the one in videogames, and I make single, non animated object, I can nearly imagine how hard and time taking It is to make hundreds of thousands of single animated objects and converting them into an enjoyable environment. The only thing that limits our creating a better and realistic models is the size and how powerful a computer is, if you make a game that is too big the computer might not be able to render it or make your computer lag, which is not a very enjoyable problem to have while playing a game that you've put so much work into."
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[],
[],
[],
[],
[],
[]
] |
||
ca0qxb
|
what is it that causes cysts/spots to rupture with such force?
|
When you squeeze toothpaste, it doesn't squirt out.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/ca0qxb/eli5_what_is_it_that_causes_cystsspots_to_rupture/
|
{
"a_id": [
"et4ycyc"
],
"score": [
4
],
"text": [
"The spot is visible because of pressure build up so when you pop the skin the small amount of pressure that there is, forces the gunk out. With toothpaste the only pressure comes from your fingers so it will come out as hard as you squeeze"
]
}
|
[] |
[] |
[
[]
] |
|
34gj3t
|
Good sources for an essay on Pompey?
|
I have to write an essay "critically analysing the leadership and legacy of Pompey the Great." Any helpful primary and secondary source recommendations would be greatly appreciated as I have to include historiography and don't want to rely completely on articles i've found on the internet that, whilst relevant, are not written by anyone highly regarded amongst historians.
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/34gj3t/good_sources_for_an_essay_on_pompey/
|
{
"a_id": [
"cquuba5"
],
"score": [
2
],
"text": [
"So this period is the most documented in Roman history. The primary sources are vast. Plutarch's Life of Pompey's already been mentioned, but Pompey comes up in several Lives. Cicero discusses Pompey in numerous letters, and gave several speeches specifically addressing Pompey (De Imperio, for instance). Caesar wrote a history of his war against Pompey. After that, the imperial historians chime in - Appian's *Civil Wars*, Cassius Dio, the fragments of Diodorus Siculus. All of these are free in English on the internet if you look for them. You could make a career of studying the primary sources for Pompey.\n\nAnd then there's the legacy. His son Sextus was a pain in the ass for Octavian for quite a while. He gets a good reception in Virgil, and I'm sure there's more out there. Depending how far you want to take it you might get as far as Shakespeare.\n\nGood luck!"
]
}
|
[] |
[] |
[
[]
] |
|
24app5
|
why are people scared by and fascinated with seemingly supernatural occurences?
|
I just spent the better part of an hour reading people's personal supernatural stories. I am thoroughly freaked out, but at the same time, I plan on going and finding more stories once I post this question. Why do people believe certain occurences are supernatural (i.e. they perceive something to be a monster in a dark room) and why are people so fascinated by these occurences?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/24app5/eli5_why_are_people_scared_by_and_fascinated_with/
|
{
"a_id": [
"ch58ym8",
"ch5atuz"
],
"score": [
3,
3
],
"text": [
"Basically? Evolution. Back in the day (the era of evolutionary adaptation) our ancestors that heard noises in the dark and assumed the worst (that must be a predator!) outlived the ones that just went back to bed. Long story short, we confuse correlation for causation, and draw connections where there are none. ",
"The evolutionary response by /u/thesnack is the most direct answer. But abstractly, as far as the fear is concerned, people fear what they don't understand. Fascination is a positive, constructive, response. Supernatural conclusions are illogical and out of ignorance."
]
}
|
[] |
[] |
[
[],
[]
] |
|
2w9aqa
|
why does cheating in a sport, i.e. the biogenesis scandal, deserve a 4 year prison sentence?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2w9aqa/eli5why_does_cheating_in_a_sport_ie_the/
|
{
"a_id": [
"cooq0n5"
],
"score": [
5
],
"text": [
"It doesn't necessarily. However, falsely posing as a doctor and distributing a controlled substance, in this case testosterone, is a crime. Similarly, winning a game by murdering the entire other team would also likely give you a lengthy prison sentence, but not on account of cheating to win."
]
}
|
[] |
[] |
[
[]
] |
||
6w8490
|
how do aircraft stabilizers actually "stabilize" the aircraft?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/6w8490/eli5_how_do_aircraft_stabilizers_actually/
|
{
"a_id": [
"dm6esda"
],
"score": [
3
],
"text": [
"Aircraft wings create a force perpendicular to the chord of the wing, called Lift. They also create a nose down torque. Both of these change with airspeed. \n \nTo keep the wings from rotating forward you can either:\n \n1) apply an upward force ahead of the wings by using a small set of wings called a canard. This was the configuration of the Wright Flyer, and is more efficient, but is also difficult to design because the aircraft will tend to be dynamically unstable in pitch. \n \n2) sweep the wings/ delta configuration\n\n3) apply a downward force behind the main plane by using an tailplane. This is less efficient because the aerodynamic force is downwards, meaning that the main plane has to lift the weight of the aircraft + the downward force from the tailplane. However, this is inherently dynamically stable. \n \nMost aircraft are of the latter design; modern airliners reduce the inefficiency, which ultimately equates to higher fuel burn, by pumping fuel into the tail so that the downward force required is kept to a minimum. \n\nTailplanes also help to damp out short term pitch oscillations, and provide a convenient way for the pilot to change the angle of attack of the wings in order to manoeuvre the aircraft. "
]
}
|
[] |
[] |
[
[]
] |
||
15lw49
|
Historians, what do you think the North Korean people were told about WWII?
|
I am aware that Japan did invade Korea at one point in time. I'm just curious what you historians speculate/find out what they were told.
**Edit for the Mods:** [As per this post,](_URL_0_) from the Mod: /u/estherke, please read /r/askhistorians [rules](_URL_1_)
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/15lw49/historians_what_do_you_think_the_north_korean/
|
{
"a_id": [
"c7npcu6",
"c7nu9i4",
"c7nuxyv",
"c7o2cbx"
],
"score": [
2720,
8,
39,
3
],
"text": [
"We actually don't have to speculate too much about it. While we don't have access to everything that's been written or published within North Korea, South Korea has a ministry that collects North Korean publications and media, and both Korean and Western scholars have been able to establish what the dominant narrative in North Korean culture has become. While it's frustrating not to have every detail, it's fairly obvious how and why that narrative has come to exist.\n\n**What the North Koreans are told:** Kim il-Sung and his band of freedom fighters bravely forced the Japanese to relinquish the Korean peninsula, conducting brilliant attacks from a secret base on the sacred Mount Paektu. During the struggle, the future Dear Leader, Kim Jong-Il was born, and he fired at retreating Japanese as early as age three. Sometime in the middle of all this, the freedom fighters also found the time to carve predictions of Kim il-Sung and Kim Jong-Il's eventual greatness into 13,000 trees in the forest surrounding Paektu. The secret base, chairs, cups, and trenches used by Kim il-Sung were miraculously preserved and are available for tour by appointment. When he had time off from slaughtering the Japanese, Kim also wrote several revolutionary operas that are performed in North Korean theaters to this day.\n\nForeign visitors tend to have problems keeping a straight face on the rare occasions when they're taken to these sites. Some of the more obvious \"slogan trees\" referenced above were also quietly removed in the late 1990s when a visiting Japanese arborist asked how it was possible for 60-year old carvings to exist on 30-year old trees.\n\n**What actually happened:** This narrative is really only accurate in the sense that Kim il-Sung fought against the Japanese, but I have yet to find any historian -- Korean, Russian, Chinese, or otherwise -- who's argued that he was anything other than a fairly minor figure in a widespread anti-colonial struggle. In fact, he didn't fight in Korea at all, but rather Jiandao province in Manchuria (the northeast portion of China that has a sizable Korean-speaking minority), leading companies and battalions of the Second Corps in what became known as the Northeast Anti-Japanese United Army. While not the highest-ranked officer in the Corps, he seems to have been competent, and by 1935 the Japanese had put a price on this head. At that point he'd been harassing them for about 4-5 years, and he lasted another 4-5 before things got too hot and he had to run for it. He sat out World War II and the rest of the fight against the Japanese occupation in a Red Army camp in Siberia. Kim Jong-Il was actually born there in 1942, and not in Korea at all.\n\n**Small interjection:** Most of what we know of this period has been constructed from old Soviet, Chinese, and Japanese records, and Kim wasn't sufficiently important to merit mention at every turn. By necessity, there's some guesswork involved, and we don't have as much information as we'd like about Kim's actual record in (X) battle, or when Kim left Manchuria, etc.\n\nBy the time Kim returned to Korea with the Red Army in 1945, he'd been out of the country for something like 20 years and spoke Chinese much better than Korean. He was tasked with giving a speech in Pyongyang -- the Soviets were on the lookout for someone they could install in local government to help control the peninsula, and he seemed like a good prospect because he took orders well and had credibility as an anti-Japanese fighter -- and Soviet Koreans not only wrote the speech for him but had to coach him on pronunciation. This was only the first of many speeches he gave, and both these and the initial run of propaganda (again, largely written by other Soviet Koreans) were heavy on gratitude to the Soviets for their assistance in driving the Japanese off the peninsula and the Chinese for having supported the anti-colonial movement.\n\n**How and when this changed (i.e., we have always been at war with Eurasia):** Now, the most interesting thing about North Korean propaganda is tracing how and when it changes (subtly or otherwise) to reflect contemporary political needs. As far as the NK government is concerned, their history is flexible and can be made to serve whatever ideology they need to push at a given time. This has even extended to archaeologists going on the hunt for ancient tombs in central Pyongyang in order to prove the city's classical importance. But that's not really what you're asking about.\n\nAnyway:\n\n - **During the early 1960s and Khrushchev's tenure in Moscow, references to Soviet aid before and during World War II start to vanish from both North Korean history books and records of Kim's speeches.** Why? Because Khrushchev was trying to reform both the Soviet Union and its client states away from the Stalinist model (something to which North Korea was heavily wedded), and he also ridiculed both Mao and Kim's personality cults. While Kim had always been the figure of primary importance in the North Korean narrative concerning World War II, he changed from being the beneficiary of Soviet generosity who used resources wisely to being someone who struggled without any serious help from other nations.\n - **References to Chinese aid wax and wane too.** To the best of my knowledge, they, too, have largely vanished from the North Korean narrative of World War II, and they are definitely not acknowledged as the people who were really running the army in which Kim was an officer.\n - **Nothing is said of American or Allied involvement in the fight against Japan in the Pacific.** Unfortunately, I don't know what, if anything, is said about the European theater.\n - **References to the *juche* doctrine start appearing in Kim il-Sung's speeches about 15-20 years after they were actually given.** IIRC, Kim's actual mention of the doctrine dates to 1961 at the earliest, but *juche* starts showing up everywhere in the mid-1960s to early 1970s. Why? Because Kim Jong-Il was starting to build a power base for himself in the government, and needed a concrete contribution with which to be identified; they couldn't really pass him off as a major freedom fighter when he'd been all of 3 as the war ended. So *juche* was it. The actual architect of the policy was Hwang Jang-Yop, who defected to South Korea in 1997, but Kim Jong-Il expanded on it, wrote papers, essays, and books (or, just as likely, had someone write them for him), and *juche* mysteriously started being peppered in speeches Kim il-Sung had given two decades earlier in order to establish an unbroken line of thought concerning North Korea's need for economic self-reliance. *Juche* is not the only idea to have been given this treatment; in fact, scholars \"mined\" Kim il-Sung's speeches for pro-capitalist sentiments when the government needed a way to justify its tolerance of private markets in the 1990s and 2000s.\n\nI'm trying and failing to remember if there's anything else that jumps out about North Korean education on World War II, but I think that addresses the most important stuff. \n\n**As a TL:DR,** North Koreans are told that Kim il-Sung conducted a brilliant guerrilla campaign from a secret base on a sacred Korean mountain and that he sent the Japanese packing off the peninsula. They aren't told that he wasn't really a significant figure in the anti-colonial resistance, they aren't told that he never fought in Korea itself, they aren't told that he sat out World War II in Siberia, and whatever they do know about Soviet or Chinese (much less Allied) involvement is severely underplayed where it exists at all. Overall, the North Korean narrative of its own history is whatever the government wants it to be in order to serve a contemporary political need.",
"From what I've read on the propaganda available, much attention is focused on the anti-Japanese partisan struggle led by Kim Il Sung, so much so that you would think the whole war depended on it. Japanese rule over Korea is demonized as one of the greatest atrocities of human history aside from the American invasion of North Korea. Kim Il Sung is the main focus and he is portrayed as the great leader always brave, tireless, and paternal to his soldiers. What we would consider minor skirmeshes such as at Pochonbo are descibed as epic great battles with Kim leading the fore although many of them do take place along the border with northwest China. There are some mention of Chinese help but there is no mention of Soviet intervention at all, the Soviet Union is mentioned as destroying Hitlerlite fascism at Stalingrad and America's fight against Japan is immediatley glossed over with the mention of the atomic bombings. At the end of the war, the occupying Japanese villians are just replaced with Americans ruling over South Korea.",
"This thread got bestofed and as a consequence is attracting many new readers. I would like to take this opportunity to direct all new users to our [rules](_URL_0_). Please have a look at them before posting.\n\nContentless comments are being and will continue to be removed. ",
"great question. this and more is covered in the book \"history lessons\", which takes other nations' history books and covers the major events in US history from their perspective. fascinating reading. the NorK view of WW2 is just one example.\n\n_URL_0_\n\nhighly worthwhile reading. "
]
}
|
[] |
[
"http://www.reddit.com/r/AskHistorians/comments/15lw49/historians_what_do_you_think_the_north_korean/c7nuxyv",
"http://www.reddit.com/r/AskHistorians/wiki/rules"
] |
[
[],
[],
[
"http://www.reddit.com/r/AskHistorians/wiki/rules"
],
[
"http://www.amazon.com/History-Lessons-Textbooks-Around-Portray/dp/1595580824/"
]
] |
|
252v3t
|
When the astronauts looked at the earth from the moon, could they see the stars as well?
|
The title may not be the best way to phrase my question.
I was looking at this photograph:
_URL_0_
and wondering if the astronauts could see stars behind the earth that didn't show up in the picture (due to the limitations of cameras).
|
askscience
|
http://www.reddit.com/r/askscience/comments/252v3t/when_the_astronauts_looked_at_the_earth_from_the/
|
{
"a_id": [
"chdjg6h",
"che5s83"
],
"score": [
5,
2
],
"text": [
"Considering that the Moon's atmosphere is so tenuous that it might as well not exist (as far as this question is concerned), they actually would have been able to see the stars a lot better than we can here on Earth. Most photos from the Moon (well, from anywhere, really) tend to lack stars because the cameras' exposure times aren't anywhere near long enough to detect objects so faint.\n\nBasically, a longer exposure equals a brighter image - this would reveal the stars if it was long enough, but also completely wash out the Lunar surface. And keep in mind that the human eye is sensitive to a MUCH wider range of luminosities, so stars look brighter to us than they do to cameras.",
"Armstrong reported that he did not see any stars, but Gene Cernan (Apollo 17) said:\n\n\"It was also generally true that, when you were on the surface in the LM's shadow, there were too many bright things in your field-of-view for the stars to be visible. But I remember that I wanted to see whether I could see stars, and there were times out on the surface when I found that, if you allowed yourself to just focus and maybe even just shielded your eyes to some degree, even outside the LM shadow you could see stars in the sky.\"\n\nSo while the glare from the sunlit landscape makes it difficult, it's just possible to see the brighter stars from the Moon's surface during the day. At night you could see them easily."
]
}
|
[] |
[
"http://www.fromquarkstoquasars.com/wp-content/uploads/2014/01/earth-from-the-moon.jpg"
] |
[
[],
[]
] |
|
ofs7w
|
Does a photon have to be absorbed in order for it to have been created in the first place?
|
Inspired by this: _URL_0_
I say that a photon can be emitted if it is not absorbed. yel02 disagrees with me.
I did a quick google search but didn't find an answer. It seems obvious to me that photons don't care about whether or not some mass is there to hit but I'm more than open to a good explanation as to why I'm wrong.
|
askscience
|
http://www.reddit.com/r/askscience/comments/ofs7w/does_a_photon_have_to_be_absorbed_in_order_for_it/
|
{
"a_id": [
"c3gxuc6",
"c3gyyco"
],
"score": [
29,
4
],
"text": [
"A little bit about quantum mechanics that's important to understand:\n\nThe real physical object is the wave function. A particle is only the manifestation of the wave function when it gets collapsed (when you observe it).\n\nTherefore, the wave function of the photon exists regardless of wheter it is observed or not ( being absorbed is being observed ). The photon itself only exists when the wave function is collapsed, hence when it gets absorbed.",
"Photons don't decide whether they are emitted or not, the field equations of QED do. And from any observer's point of view, there will be a greater than zero time between absorption and emission.\n\nWhat you are probably thinking of is that a photon doesn't experience any proper time passing between emission and absorption. This just means that a reference frame moving together with the photon is ill-defined and you can't do any physics there."
]
}
|
[] |
[
"http://www.reddit.com/r/askscience/comments/of8pf/when_a_photon_leaves_a_star_what_are_the_odds/c3gtsbc"
] |
[
[],
[]
] |
|
4rrcvw
|
Did ladies really faint all the time in the past?
|
In a lot of fiction about the past, you see scenes where something unexpected and shocking is revealed and some fancy lady faints. I know this is definitely a little hammed up, but you see is so often that it makes me think there must be some truth to it. On the other hand, I know a bunch of ladies and have heard a lot of shocking things and never seen one of them faint.
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/4rrcvw/did_ladies_really_faint_all_the_time_in_the_past/
|
{
"a_id": [
"d542jc1"
],
"score": [
36
],
"text": [
"Well, first of all, we must wave away fiction (as we sadly often have to do...) when it comes to history. The idea of women fainting at the sight of terrible things or even their mention is not as old as history. We have no suggestions (to my knowledge) of medieval French women, ancient Egypt women or Mayan Mesoamerican women fainting at the sight of blood, spiders or hearing that the priest has seduced a local teenager. \n\nIndeed, this occurrence took place mainly in the Victorian area and was a combination of several different things. For it is true, women did feint at regular and irregular occasions during these years but the reasons aren't simply as vague as \"the female mind\".\n\nLet us start with corsets.\n\nIn the nineteenth century (and other time periods) the corset was extremely popular among women who could afford choking and being immobile to look pretty. As such, this was primarily something for bourgeois women and upwards, as female farmers, factory-workers, nurses and what not would find it impossible to work in the corsets of the 19:th century.\n\nWorn around the chest (and thus the lungs and the intestines) corsets were often made out of wool or leather, tightly woven and supported to so called \"boning\", which were vertically placed \"ribs\" of a sort made out of whale-bone, ivory or in the cheaper kind, wood. The purpose of the corset has varied, sometimes it's produce a curvier look, sometimes it's to suppress said curvier look. During the Victorian era it was definitely the former.\n\nGirls did not start wearing corsets as they became women (which might seem logical, because that's when you start getting curves) but rather girls started wearing them at a -very- young age. As in, pre-teen age. Take a look at this [nifty commercial](_URL_0_) from the time-period.\n\nSo, what happens if you wear something that presses on your chest in general and your ribs in particular for a great part of your life, including growing up when you form said rib-cage? Well, they get permanently displaced, that's what happens. As a result, lungs get compressed, intestines get shoved around, hearts struggle to function properly as the body struggles to function properly.\n\nEating disorders followed, as there simply wasn't enough room to eat anything but the mere minimal.\n\n------------------------------\n\nWith that said, it's highly likely that a lot of the swooning and fainting was put on display. It was simply a fad, it was lady-like, it was proper and it was considered nice. A lady that did not feint and swoon was no lady at all. Finer houses all included a so called 'feint-room', which was a pretty neatly set up room in some distant, silent corner of the big house. It had a feinting couch, soothing light, probably a bit to drink and so on and so forth. It was a social retreat where you could bring one or two friends with you while excusing yourself for a moment.\n\nAdditionally, -some- of the wealthier houses could afford a midwife or a doctor to help treat 'hysteria' which was a very common diagnosis at the time. In 1859, physician George Taylor for instance made the claim that 25% of all women suffered from hysteria. Hysteria had several treatments, including high pressure cold showers and other shock-therapies... But the most commonly accepted one was that it stemmed from sexual desire. As such, midwives or doctors could be working around the clock in these \"fainting-rooms\", offering pelvic massages to women who needed to take a break. As such, there was a pretty decent incentive to suddenly feel a need to feint and withdraw to hang out with your two best friends, have a cup of wine and get some... massage. There are reports of doctors filing complaints of pained wrists and fingers due to having to work with as many patients as they did (once again to underline here, this really was NOT a problem for poor people, who could not afford fainting rooms or doctors to staff them). \n\nThe sexual treatment of hysteria lead up to the development and invention of the vibrator who at first required medical personnel to handle but sooner rather than later (to the doctor's great lament!) became hand-held and easy to use on their own. The fad eventually grew out of fashion and the corsets of today are quite comfortable and women seldom feel the need to feint when watching the SAW movies. A more commonly accepted behavior is to gasp or simply avert your eyes when you encounter something shocking.\n\nSources: *Tystnadens historia* (History of Silence) - Peter Englund (2005) \n\nEDIT: Before we go bananas on corsets, I'd like to underline that 21:th century corsets are fine, even comfortable at times."
]
}
|
[] |
[] |
[
[
"https://s-media-cache-ak0.pinimg.com/564x/43/53/29/435329a26dfc6912a8af21206e64a812.jpg"
]
] |
|
gx76z
|
The higgs boson doesn't actually constitute most of the mass to our bodies, right?
|
So apparently the higgs boson is the reason elementary particles have mass. However, we're made up of neutrons, electrons and protons. Electrons weigh 2000 times less than neutrons, so the higgs mechanism is NOT what constitutes most of our mass, right?
|
askscience
|
http://www.reddit.com/r/askscience/comments/gx76z/the_higgs_boson_doesnt_actually_constitute_most/
|
{
"a_id": [
"c1qydjo"
],
"score": [
6
],
"text": [
"You are partially correct. The electron does owe all of it's mass to the Higg's mechanism. However, protons and neutrons are a little bit different as they are composite objects (they are made of quarks). Quarks also have mass, given to them by the higgs mechanism.\n\nBut there is a caveat. The up and down quark have (approximately) the same mass...somewhere around 3 MeV/c^2 (I think that's near the upper limit of the u/d quark mass...). Each proton has three \"on-shell\" quarks, and so we would predict our proton to have a maximum mass of somewhere in the neighbourhood of 9 MeV/c^2. If you look up the actual mass of the proton, you find that the proton weighs ~900 MeV/c^2. So the mass given to the quarks by the Higgs mechanism only adds up to about 10% of the overall proton mass!\n\nIt turns out that in general, only 10% (or so) of our mass comes from the Higgs mechanism. The other bit of our mass (and the rest of the proton's mass) comes from what is called quark confinement. The strong nuclear force that holds together the quarks into things like protons and neutrons is incredibly strong (duh!), and some of the energy of that force actually goes into increasing the mass of an object.\n\nSo yes and no, the Higgs mechanism **is** responsible for giving us mass, but most of our mass comes from quark confinement in the strong nuclear force. \n\nEDIT: okay, I got off my lazy ass and actually checked out the quark masses. Up quark is around 1-3 MeV/c^2 and down quark mass is 4-6 MeV/c^2. So our proton (two up, one down), would be around 12 MeV/c^2 maximum...still much much less than the actual proton mass..."
]
}
|
[] |
[] |
[
[]
] |
|
6a95xy
|
why does the usa seem so obsessed with race more then other countries?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/6a95xy/eli5why_does_the_usa_seem_so_obsessed_with_race/
|
{
"a_id": [
"dhcof8c",
"dhcp2u8",
"dhcpfje",
"dhcq35t",
"dhcutyp"
],
"score": [
11,
3,
6,
5,
5
],
"text": [
"Because of (1) yes slavery and (2) the USA has a more mixed population, with more immigrants from more countries and backgrounds, than nearly any other country.",
"Many countries don't have multiracial populations nor did they have the kind of legalized discrimination that the US did. I see you slinking away, South Africa....",
"Because, back in the 1600's, when North America began to have a large population of indentured servants (white) and slaves (black) these people noticed that neither group was being treated very well. \n\nThey banded together in what's been Bacon's Rebellion (after their leader Nathaniel Bacon) If Nathaniel had not died of an intestinal disorder, they might have captured much of the eastern seaboard.\n\nAfter the rebellion was put down, the rich landholders had a meeting, and decided to set the indentured servants against the slaves. Over time, they made the lives of slaves harder, and made laws that prevented Blacks from rising in society. They also made an effort to elevate the White servants, by reminding them constantly that they were \"better\" than the Blacks, their former allies.\n\nSo, now the lower classes of Whites put all their effort into putting down people of African heritage, rather than try to elevate themselves. (Look at statistics. The most racist states are also the poorest.) \n\nIf you want to learn more, read the book White Cargo. Bacon's rebellion is near the end. It will turn your world around. ",
"It's not as bad as you might think. The media is horrible and makes more of than what is really going on. ",
"There are many reasons for this listed already, but allow me to add my two cents in.\n\nThere are people who benefit from having high tensions between people of various races and groups. \n\nThe media is one of them. They get viewers by covering every single potentially racially charged situation. A black man is shot by the police? Wall to wall coverage. Some blind girl accidentally leaves dog poop on the steps of a Black Cultural center in a college? Instant scandal and around the clock coverage. More people watching means more ad revenue for networks, and sensational race-related stories get people to tune in. \n\nThen there are individual activists who thrive on racial animosity. The likes of Al Sharpton and Jesse Jackson have made themselves filthy rich by hyping up every real and perceived injustice faced by blacks in America. If blacks no longer saw themselves as victims of white oppression, they would have to actually get real jobs and earn their money.\n\nAnd then there are Democrat politicians who continue to enjoy 90% of the black vote and a majority of the Hispanic (and other minorities) vote. They have convinced blacks and other minorities that white people are all racist and that the only ones who are going to protect them from being put back in chains are the Democrats. \"Vote for us because we'll protect you from the racist Republicans\" is their mantra. Former VP Joe Biden even told a group of black voters, \"Republicans will put y'all back in chains.\" \n\nIf a magic wand was waved and racial tensions went away in America tomorrow, there would be a significant portion of people in positions of power who would find themselves without a job or at least have a harder time making money. When people gain from promoting unrest between racial groups, they have every incentive to continue to stoke the fire of racial tension, and unfortunately this message is well received by groups who want to see their collective failures as caused by external evil instead of any self-destructive behaviors within their own community."
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[]
] |
||
6xgjzi
|
why is it that every lighting bolt is shaped differently?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/6xgjzi/eli5_why_is_it_that_every_lighting_bolt_is_shaped/
|
{
"a_id": [
"dmfr560"
],
"score": [
3
],
"text": [
"A lightning strike is basically an electrical charge in the air trying to reach the ground. Electricity always tries to find what's called the *path of least resistance*, or the easiest way down. That's going to vary based on lots of different factors - air pressure, humidity, finding a nice tree or an unwitting golfer to zap... the charge is always [searching for the best path to take](_URL_0_) until it can find the best one and hit ground.\n\nAnd since there are millions of tiny variations that can affect that path, every lightning bolt will be a little different."
]
}
|
[] |
[] |
[
[
"http://i.imgur.com/e9cPao4.gif"
]
] |
||
bv23rd
|
how does decriminalization of drugs reduce drug abuse and crime in the countries that have done it?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/bv23rd/eli5_how_does_decriminalization_of_drugs_reduce/
|
{
"a_id": [
"epka1i2",
"epkaasc",
"epkabpf",
"epkas7f"
],
"score": [
3,
2,
3,
3
],
"text": [
"Decriminalization or legalisation allows drug sales to be more controlled, meaning you know what is going into the drugs and people are more informed about safe drug use. It also means that drug supply can be more easily controlled, and you can more easily limit how much people get. It makes people more likely to seek help if they have drug issues and makes help easier to get. Addiction levels fall, which makes drug related crime fall. \n\nDecriminalization also allows police to focus on more pertinent issues, while also removing the violent crime that goes with illegal drug supply. It also reduces organised crime which is largely funded by drug supply.",
"if you’re looking purely at statistics, think of any crime that is done by many people legal all of the sudden. that would obviously instantly bring the number of people doing something illegal down because now the people that used to be doing something illegal are only doing something legal.",
"Instead of giving people jail time, therapy is offered to drug abusers. This gives a more open environment in a populace to accept that drug abuse is a disease that can be cured and not a crime that can easily be solved by jailing all drug abusers. When offered jail time, drug abusers would just go underground and the state will exert more effort in rounding them up. However, once you treat it as a disease, people can voluntarily submit themselves to therapy for cure.",
"Jailing addicts doesn't actually do anything for them. Being in prison doesn't make them want to use less, and usually they will go back to using once they get out. Except now they have no community, money, and likely cant find a job.\n\nBy decriminalizing you can bring the market out of the shadow and into the light, where it can be monitored and controlled. You can do things like set up clean needle dispensaries and places they can get their drugs checked for impurities. This essentially gives addicts a safe place to get high around medical staff instead of ODing in a bathroom somewhere. You can then take all that money that you spend on funding drug policing and put it into state sponsored rehab programs and mental health therapy instead.\n\nAddicts have problems outside of being an addict, and as long as those problems persist they are going to keep on using. Throwing them into jail just adds more problems and results in them being fearful of looking for help when they actually want it."
]
}
|
[] |
[] |
[
[],
[],
[],
[]
] |
||
9mnuma
|
why do you continue to try and vomit/dry retch when you have drank to much, even after your stomach contents have completely vacated your body?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/9mnuma/eli5_why_do_you_continue_to_try_and_vomitdry/
|
{
"a_id": [
"e7fz02r",
"e7fzx3x"
],
"score": [
10,
3
],
"text": [
"The vomiting is your body’s response to an excessive amount of alcohol in your system, not just your digestive tract ",
"It's not just when you've drunk too much but when you're sick as well you also dry heave after vomiting that's because the nerves that cause you to vomit are still coated in what cause you to vomit in the first place."
]
}
|
[] |
[] |
[
[],
[]
] |
||
9va4v4
|
do rgb led's have the ability to display a wide range of colors. what causes the color to change, is it the voltage?
|
I am planning to build an Arcade Cabinet and I have been thinking of wiring up led's to the Joysticks and Buttons. For the life of me, I can't understand what makes the led's change colors. There is so much information out there but I seem to be having trouble understanding it.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/9va4v4/eli5_do_rgb_leds_have_the_ability_to_display_a/
|
{
"a_id": [
"e9ahd8b"
],
"score": [
9
],
"text": [
"An RGB LED is actually 3 LEDs in one package. One each of Red Green and Blue. But changing the intensity of each of the 3 LEDs you get a unique color from the single bulb. The human eye doesn’t see the individual colors but a mix into a single color.\n\nLots more details: _URL_0_"
]
}
|
[] |
[] |
[
[
"https://randomnerdtutorials.com/electronics-basics-how-do-rgb-leds-work/"
]
] |
|
3kfd05
|
apple airport express shows xbox one speed 270mb, xbox network stats says 30mb.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/3kfd05/eli5apple_airport_express_shows_xbox_one_speed/
|
{
"a_id": [
"cuwxwt7",
"cuwxxxw"
],
"score": [
3,
3
],
"text": [
"I'm not sure, but maybe the units are different.\nApple airport express must be showing in Mb(Mega-bits) and Xbox network stats must be using MB(megabytes).\n8bits=1byte!\nSo that explains 30MB=240 Mb.\nLeft 30Mbs in apple express is just a difference of 3MBs.",
"You're confusing M**b**ps (mega**bits** per second) with M**B**ps (mega**bytes** per second).\n\nThere are 8 bits to a byte, so 270Mbps = 33.75 MBps."
]
}
|
[] |
[] |
[
[],
[]
] |
||
45m62t
|
How often were peasants used in Middle Age battles? How were they trained? How were they equipped? Who paid for their equipment?
|
Any answers are appreciated.
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/45m62t/how_often_were_peasants_used_in_middle_age/
|
{
"a_id": [
"czzei6x",
"czzifdm",
"czziuoq"
],
"score": [
5,
2,
2
],
"text": [
"Could you clarify what you mean, do you mean in the sense of any peasant class individual participating in a war or do you mean armed mobs with no training at all?",
"In Mughal North India, peasants were used as infantry, they were the cannon fodder in battle, many also worked supporting roles such as coolies, carriers, cooks, servants, etc. The main warriors were from kshtriya castes, professional soldiers who were officers, cavalry, elephant riders, general's, etc.\n\n\nUnder Akhbar the Great there was the Mansabdari system, every government official was expected to maintain an small army according to his rank, peasants, mercenaries etc were hired or conscripted and trained. The Mughlas were Turks and not Indians, so not a lot of them trusted locals, so they brought in adventurers and mercs from Persia and Central Asia. Akhbar however made alliances with the Rajputs, a tribe of ass kicking war lords belonging to Kshtriya Caste. Their society was a war like one, every able bodied man was expected to go to war. Thus since most of the armies at the time were composed of professional soldiers, peasants usually played a supporting role, unless there was a shortage of men. \n\nI'll look for sources later.",
"For high and late medieval Western Europe, I think the definition of 'peasant' is important, because Medieval social structures had multiple de facto (and de jure) classes of untitled people, who could have very different material circumstances.\n\nIf by peasants, you mean 'the lower classes of serfs/villeins/tenant farmers, u/MI13 deals with their (non) use in the later middle ages [here](_URL_0_)"
]
}
|
[] |
[] |
[
[],
[],
[
"https://www.reddit.com/r/AskHistorians/comments/4248f4/if_peasant_conscripts_made_up_the_bulk_of_armies/"
]
] |
|
22w7h0
|
When roman emperors were divinized posthumously, what did that mean to the surviving population? And were the divinized emperors endowed with "powers", like Neptune/Poseidon's power over the sea?
|
I can understand giving an emperor a nice tomb (certainly his successor would want the same treatment upon his own death). I can even understand the careful treatment of his busts and statues and paintings, for posterity. But why divinize them? That seems excessive. It's not like they were a genetic lineage, many of the roman generals were adopted by their predecessors.
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/22w7h0/when_roman_emperors_were_divinized_posthumously/
|
{
"a_id": [
"cgr7649"
],
"score": [
3
],
"text": [
"Hi, that's a very interesting question, I have never questioned the 'why' in that way before. The answer goes back to Julius Caesar, the persona and the events around his death. \n\n > \"He died in the fifty-sixth year of his age, and was ranked amongst the Gods, not only by a formal decree, but in the belief of the vulgar. For during the first games which Augustus, his heir, consecrated to his memory, a comet blazed for seven days together, rising always about eleven o'clock; and it was supposed to be the soul of Caesar, now received into heaven: for which reason, likewise, he is represented on his statue with a star on his brow.\" (Suet. Jul. 88) \n\n > \"They afterwards erected in the Forum a column of Numidian marble, formed of one stone nearly twenty feet high, and inscribed upon it these words, TO THE FATHER OF HIS COUNTRY. At this column they continued for a long time to offer sacrifices, make vows, and decide controversies, in which they swore by Caesar.\" (Suet. Jul. 85) \n\nAnd a tad too long to quote, [this section](_URL_0_), which shows how popular Julius Caesar was among to common people. \n\nLooking at the above quotes, we can tell that Julius Caesar was divinized because the people wanted it and because of certain divine circumstances following his death. Starting with the comet, an understanding of the superstition of the Romans is necessary. I made a quick search on the subreddit and [this](_URL_2_) discussion shows upon the problems with using the term 'superstition', so I'm not going to analyze that further. What I wanted to say though is that the Romans were very aware of things such as birds in the sky, comets, how healty animals were, and so on. A comet showing in the sky for seven days following the death of such an important man as Julius Caesar, that's got to be important, and Suetonius shows us that. \n\nSecondly, having cults around a person was by no means a new invention. Scipio Africanus was said to have had a cult created around him in Iberia following his successes in the Second Punic War (Polybios, 10, 40). Cults around the Persian kings, the Egyptian Pharaohs and even Alexander the Great, had also been well established before this time. What was new here was the political situation. Caesar had won the civil war and had the people on his side. When he was murdered chaos ensued and one of Marcus Antonius (Mark Anthony) moves was to suggest that Caesar was to be divinized. \n\nSo, this is a bit of the background to why Julius Caesar was divinized, let's get into the deeper parts of your queries. The Romans were fans of continuity. As you can see above, Caesar's divination wasn't something completely new because it had been done before (in a way) with Scipio Africanus, except Scipio only had a cult, he wasn't divinized. This continuity along with the legal adoption of Gaius Octavius (henceforth Augustus) meant that it wasn't questioned whether or not Augustus was a *divi filius* (son of a god) or not. Because Julius Caesar became *divus* Julius after his death it was obvious that Augustus must be *divus* Augustus *divi* Julius. \n\nNow, if you look at the book titles [here](_URL_1_.), you can see that far from all emperors were in fact divinized. Suetonius died early in the 2nd century AD so there are a few divinized emperors missing there, but as you can see there are a lot of missing *divus* titles. \n\nStarting with Augustus, all emperors were actually titled *divus* < name > during their lives. Supposedly also the empresses considering the Livia was divinized in 27 AD and thus became *diva* Augusta, but that's the only example and thus hard to tell. Anyway, looking at the structure of the Imperial Cult, we can deduce that living emperors had the title *divus* (except Tiberius who refused to be seen as divine), which became *divi* after their deaths. However, just like with the case of Julius Caesar, the *divi* appointment actually had to be voted after the emperor's death. Meaning that just because you were a *divus*, which can be explained as a-god-to-be, there was no guarantee that you'd in fact be divinized after you died. You had to deserve to be made a god. \n\nThe last part of course sounds really strange to us. That also begs the question of what kind of god the emperors actually became. During my own research of the subject I created three categories of gods to separate them. The first category was the great gods like Jupiter, Mars, Neptune, etc., Olympian gods with unquestionable powers. The second category was smaller gods, such as Roma (the personification or Rome) or Mithras, gods that weren't omnipotent. The third category is then where the emperors fit, along with ruler kings and such. As far as I have seen, we don't have a single source explaining what kind of powers the emperors had after they died, which is why the above categorization is necessary. \n\nHowever, the emperor had a unique trait, the *numen* on top of the *genius* that everyone had. I wrote this a little while ago so I'll just copy-paste: \n*Numen*: The emperor's life spirit. Only the current living emperor had a *numen* as far as I've understood it. Meaning no one else than the emperor even had a *numen*. Genius: Today we like to describe it as the soul. However that's a really easy explanation and isn't quite correct. Soul is a christian term. Everyone had a *genius*, but what made the emperor special was that he had both a *genius* and a *numen* and they were both worshipped differently. \n\nSo, on to the last part of your queries (unless I have missed something, feel free to ask) - \"what did that mean to the surviving population\". This is something that might be rather hard to tell since we don't have writings from the general population about it. We do however have inscriptions on tombstones of dead priests in the Imperial Cult. Those tombstones show us that the cult of a dead emperor was abandoned or neglected as soon as a new emperor was divinized. This was, the divinzed emperor was a sort of god after his death and they weren't un-divinized, but when there was a newer divinzed emperor, whom the living were more familiar with, they turned to him instead. There is one exception to this. Because of the short life-span of Titus (he was only emperor for 2 years), the cult around *divi* Vespasianus stayed strong a lot longer than might have been expected when Titus also was divinized. \n\nAn ending note is that the Imperial Cult wasn't just a religion, it was politics and propaganda. Therefore it follows that the older the divinization of an emperor is the less it's worth in current times, for the current Imperial family. The Flavian family had no reason to keep the Augustan Imperial cult alive and likewise the adoptive emperors (Nerva-Pertinax) didn't strengthen the Flavian cult, especially after Domitianus reign. This explains in part why the cult of a previous emperor died out as soon as there was a newer one. \n\nSources: \nSuetonius, *The Lives of the Caesars*, translated by Alexander Thomson. \nPolybios, *Histories*, translated by Evelyn S. Shuckburgh. \nTaylor (1931), *The Divinity of the Roman Emperor*. \nFishwick (2002), *The Imperial Cult in the Latin West, Studies in the Ruler Cult of the Western Provinces of the Roman Empire*, III 1, III 2. \nFishwick (2004), *The Imperial Cult in the Latin West, Studies in the Ruler Cult of the Western Provinces of the Roman Empire*, III 3."
]
}
|
[] |
[] |
[
[
"http://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.02.0132%3Alife%3Djul.%3Achapter%3D84",
"http://www.perseus.tufts.edu/hopper/text?doc=Perseus%3atext%3a1999.02.0061%3alife%3djul",
"http://www.reddit.com/r/AskHistorians/comments/1mklxr/why_were_the_romans_so_fearful_of_forests/ccabr3m"
]
] |
|
7ocreb
|
In terms of evolution, do beneficial traits often get passed down with irrelevant/negative traits?
|
As a made up example, a genetic trait makes mice super fertile (beneficial) but also gives them lighter pigment spots in their fur (irrelevant).
What is the implication of this in humans? When a gypsy tells you that you have a short life line on your hand could she actually be telling you that you have a high risk for heart disease? Are there any noteworthy ones that we know about?
|
askscience
|
https://www.reddit.com/r/askscience/comments/7ocreb/in_terms_of_evolution_do_beneficial_traits_often/
|
{
"a_id": [
"ds8ta9v",
"ds8ujsw",
"ds8ztah",
"ds9246s",
"ds93ngc"
],
"score": [
2,
10,
3,
9,
3
],
"text": [
"It’s possible that a single gene can have multiple phenotypic effects (I can’t think of any but it’s possible), but it is much more likely, and common, that a particular phenotype is the result of multiple genes. Any two given genes, and even different mutations within a single gene, can sort independently. Even if there were one gene responsible for multiple traits, it’s possible that mutations at different points in the gene are responsible for the different traits, and can sort independently at very very low rates. \n\nEdited for fat fingering.",
"What you mean is generally called gentic draft or hitchhiking effect and it can cause all kinds of interspecies (and sometime intraspecies) variation.\n\nAs a simple example from [wikipedia](_URL_0_)\n > The Y chromosome does not undergo recombination, making it particularly prone to the fixation of deleterious mutations via hitchhiking. This has been proposed as an explanation as to why there are so few functional genes on the Y chromosome.\n\nI can explain more if you want to :)",
"The general answer is yes, there are traits that tend to be correlated. \n\nThere are two mechanisms for this.\n\n & nbsp;\n\nThe first is linkage. Genes are linked if they are on the same chromosome, and traits associated with genes close together (closely linked) tend to be inherited as a group. For example, red hair, freckles, and pale skin are closely linked traits in humans. \n\n & nbsp;\n\nThe second mechanism is pleiotropy, which is when a single gene affects several traits. So the alleles you have for that gene might have some effects that are beneficial, some neutral, and some detrimental. \n\nThe textbook example of pleiotropy where one trait is good and the other is bad (this is called antagonistic pleiotropy) is the sickle cell allele. One trait associated with that allele is defective hemoglobin, which leads to sickle cell disease if you have two copies of that allele. But it also confers resistance to malaria. So depending on the environment (i.e. if malaria is present), that allele may be a net benefit or a net detriment within a population. \n\nInterestingly, some cystic fibrosis alleles may operate the same way, conferring resistance to cholera, but causing disease when two defective alleles are present.",
"Something to consider is that sometimes what looks like a negative trait can actually have benefits that may increase the likelihood of it being passed on.\n\nFor example, Sickle Cell Anemia is a genetic condition that causes your red blood cells to be the wrong shape, and causes chronic pain and vessel blockages. This sounds like a pretty obvious negative trait, BUT in Africa it is surprisingly common in the population.\n\nTurns out that the different shape of the red blood cells makes you resistant to malaria, which is also common in Africa. What seemed to be a negative trait actually had a hidden benefit.",
"Certain traits can be linked together. For example selection for tameness in many domestic animals has also selected for floppy ears and a characteristic coat pattern (white stripe or patches on the head). This is probably because these traits are all influenced by the way the head/brain develops in the embryos [Source](_URL_0_). However domestic animals are a pretty special case since they have undergone very strong selection in a very different direction than natural selection in a relatively short amount of time. I can't think of any similar such traits in the human population, besides more obvious and direct correlations such as light skin predisposing one to skin cancer. In your example it would be very hard to imagine how heart health could be linked to palm lines, especially since the length of palm lines have very little influence from your genes (identical twins do not have identical palm lines)."
]
}
|
[] |
[] |
[
[],
[
"https://en.wikipedia.org/wiki/Genetic_hitchhiking"
],
[],
[],
[
"http://www.genetics.org/content/197/3/795#sec-2"
]
] |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.