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fh5p7a
|
how does anyone know the long term effects of medication that's been invented in the last 20 years?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/fh5p7a/eli5_how_does_anyone_know_the_long_term_effects/
|
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"They have indications, but they don't \"know know\". But...consider a few things:\n\n1. The \"invention date\" of a drug is really a very, very long time before the launch date. During that process there is a lot of testing that goes on and that testing produces data. Not 20 year data, but the _average_ amount of time to get through FDA approval is 12 years. You probably haven't even heard of a drug before it's been had by others in a controlled environment for 10 years. \n\n2. The long term effects also err on the side of warning you. so...lots of \"May\" statements (this may cause that) are based on understanding a mechanism of action and then looking at impacts of that mechanism known from other drugs, other research and so on. so...warnings get folded in based on how a drug works.\n\n3. Lots of drugs are variants of existing drugs - e.g. a slight modification (for example \"time release\" isn't a change to the drug, but is to its delivery). so...a drug may be older than you think.",
"Drugs go through rigorous testing for ~10 years before even going public. This involves preclinical animal dose finding and toxicology before moving to human clinical trials. The drugs are pretty well studied before even going public.",
"The truth is: They don't. Just ask anybody with [tardive dyskinesia](_URL_0_) who got it after using popular drugs like Seroquel or Abilify."
]
}
|
[] |
[] |
[
[],
[],
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"https://en.wikipedia.org/wiki/Tardive_dyskinesia"
]
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||
2bg4gh
|
why does my wireless network connect status say 72.0mbps, yet when i do a speed test, it shows an average of 30mbps?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2bg4gh/eli5_why_does_my_wireless_network_connect_status/
|
{
"a_id": [
"cj4zwep"
],
"score": [
6
],
"text": [
"Your uplink to your ISP is 30 Mbps. \n\nThe link between your computer and your wireless router is 72."
]
}
|
[] |
[] |
[
[]
] |
||
yo21p
|
What were the medieval legends about the roman empire?
|
I was thinking about this as I was reading through the Two Lives of Charlemagne, comparing the more realistic contemporary biography of someone who lived with Charlemagne, vs the more fantastical legends of someone who came 100 years after his death.
It made me think about what fantastical legends they told about ancient rome back in medieval times.
Unfortunately, I don't even know where to start. What were some of the legends medieval people said about ancient rome? If any? Or were they entirely focused on hagiographies of late roman saints?
Are there books anyone can recommend?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/yo21p/what_were_the_medieval_legends_about_the_roman/
|
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"Are you referring to Western Europe and how inhabitants of the Western European kingdoms viewed the Western Roman Empire before its collapse in 476AD, or are we talking about sentiments towards the Eastern Roman Empire/ Byzantine Empire in Western Europe?",
"This isn't precisely my field, but I know there are wacky descriptions of the Roman/Greek origins of Britain in the works of Geoffrey of Monmouth, as well as a portion of Le Morte D'Arthur where Arthur goes and conquers Rome. Not to mention the can of worms of Arthur possibly being partially inspired by a Late Antique Roman commander in Britain. If nothing, a place to start.",
"Here you go: There is a theory that the hoard at the center of the [Nibelungenlied](_URL_0_) (MacGuffin, some might say), is in fact the treasure chest of Varus' doomed legions, lost in [Teutoburg Forest](_URL_1_) in 9 AD. Siegfried is Arminius, the mile-long Roman column is the serpent-like dragon.",
"I would generally say the general view of the Roman Pagan empire in medieval Europe (excluding Rome itself and its rival Italian city-states - which is too complicated for me to even think about) was shaped by the Bible - especially the New Testament in which Romans plays an essential part as the colonizers of the parts of the world where Jesus lived.\n\nIt would seem the Roman Catholic (and probably Orthodox Catholic) church had to do a great deal of damage control to divert blame for Jesus' death away from the Romans (after all, the Church was Roman and for whatever reason did not want to entirely denounce the pagans who preceded them) and onto the Jews.\n\nBut even the least educated people in medieval times would have been very well aware of Rome via Sunday Sermons. Among the more educated, knowledge of Pagan Rome would have increased a great deal DURING the middle ages as the pagan Greek and Roman works of literature were rediscovered and became the basis of most european educational systems.\n\nI'm not sure how much consciousness existed about Romans from the days when the pagan Romans colonized a vast swaths of Europe. It seems when Christianity was being spread throughout Europe in the 'dark ages' most writing that might have still existed in Europe from those days would have been destroyed.\n\nOne interesting play to read and think about the subject from a Renaissance perspective is Shakepeare's Cymbeline (set primarily in pre-Christian Pagan England under Roman occupation)."
]
}
|
[] |
[] |
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"http://en.wikipedia.org/wiki/Nibelungenlied",
"http://en.wikipedia.org/wiki/Battle_of_the_Teutoburg_Forest"
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[]
] |
|
3034px
|
how come the human body performs poorly at repairing the spine when it's damaged ?
|
Looked up spinal cord injuries and it said often cases result in a permanent changes in strength.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/3034px/eli5_how_come_the_human_body_performs_poorly_at/
|
{
"a_id": [
"cpooafs"
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"text": [
"It has to do with how complicated the spinal cord is. There are just too many connections that all have to be made exactly as they were before in order to be repaired.\n\nIt's better to leave it severed than to attempt an improper repair. At last that's what our bodies think."
]
}
|
[] |
[] |
[
[]
] |
|
3uy4r7
|
Why was medieval Europe and Asia so advanced while Native Americans, African tribes and Indigenous Australians were virtually stuck in the stone age for thousands of years?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/3uy4r7/why_was_medieval_europe_and_asia_so_advanced/
|
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"Here are two pertinent answers:\n\n_URL_0_\n\n_URL_1_\n\nAnd you can find more in the FAQ. The general gist of these answers is that there's no reason to expect that they should have followed the same developmental path as Europeans or Asians, and despite that some of these societies did make many of the same advancements, as well as making completely different advancements that didn't happen in Europe or Asia.",
"1) Tribes is a term that is not accepted by Africanists, as the [term has a problematic history](_URL_0_) and [gets applied so loosely that it carries no real meaning](_URL_1_)\n\n2) Africans were not 'stuck in the stone age'. The Nok culture of Nigeria demonstrated iron-working by 500 BC, perhaps earlier. Iron working had spread all the way to the Limpopo river in South Africa by 1000 AD. \n\nMany African states including Mali, Songhai, Ethiopia, Swahili, Nubia, Great Zimbabwe, etc. were engaged in trade or intellectual exchange with the wider world for centuries before Portuguese exploration began in the 1400s.",
"There have been a few posts (since removed) that have recommend Jared Diamond's *Guns, Germs, and Steel* or a recent CGP Grey video based on that book. Most of these posts were removed for breaking our rules ([\"Avoid only recommending a source – whether that's another site, a book, or large slabs of copy-pasted text\"](_URL_1_)), but in general we at /r/AskHistorians do not regard *Guns, Germs, and Steel* as a reliable source of history (see [the relevant section](_URL_0_) of our FAQs).\n\nThat said, at least an aspect of what Diamond is writing about is at play here - namely diffusion, the process by which ideas and materials spread from culture to culture to culture. For example, the gunpowder spreading from China where it was originally invented (by alchemists attempting to invent something else entirely) all the way to Spain by the time Columbus sets sail. Another example would be corn spreading out from southern Mexico, heading south into the Andes and the Amazon and north toward the Great Lakes. According to Diamond, of all continents, Eurasia was best suited for allowing ideas to spread far and fast.\n\nThere may be a kernel of truth here, but the situation is far more complex than that. Diamond severely underestimates how quickly ideas can spread in the Americas, for example (wheat spreads across Europe from the Middle East around the same time that maize spreads from Mexico to Peru). \n\nThere's also the issue of whether, once exposed to a foreign concept, a culture actually adopts it. Australia wasn't nearly as isolated from the rest of the world as people like to think. Around 4,000 years ago there was wave of migrants from India that left their mark in Australia's genetic tapestry; traders from Southeast Asia were sailing off the northern coast of Australia for at least hundreds of years prior to European colonization; and for thousands of years, Torres Strait Islander peoples have been mediating trade between Papua and Australia. Despite that, there are no bows in Australia. Bows had been invented in Africa *after* the ancestors of the Australians and the Americans had left. Americans likely developed some version(s) of the bow independently but these models didn't really catch on until bows that ultimately descended from the original African concept, crossed into the Americas with the Inuit and Yupik. In Australia, the bow reached Papua and the Torres Strait, but seems to have stopped there. The people of Cape York certain knew of the bows used by their neighbors to the north, but they didn't adopt them for themselves. Between the woomera [spear thrower] and the boomerang (both of which come in a variety of forms across Australia) likely filled the \"projectile weapon\" niche in such a way to make bows redundant. \n\nOn a similar note, prior to the arrival of the Spanish, the Aztecs knew of bronze and how to make it - they just couldn't do it because the neighboring Tarascan State to their west had a monopoly on the resources needed to do so and weren't in the mood to share with their enemies. Regardless, even if the Aztecs could secure access to the tin and arsenic they needed to turn copper in into bronze, they might not have used it to make weapons. Metals throughout the Americas were generally funneled into other projects (ceremonial and ornamental for the most part) rather than utilitarian purposes because the cultures valued these materials differently than their Eurasian counterparts.\n\nAgain, the FAQs have a lot of threads on this and related topics and there's the post series at /r/IndianCountry that I mentioned elsewhere in this thread that will help illuminate this topic."
]
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[] |
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"https://www.reddit.com/r/AskHistorians/comments/1aggse/the_native_americans_and_several_other_cultures/c8x977d",
"https://www.reddit.com/r/AskHistorians/comments/260od1/why_did_the_australian_aboriginals_never_progress/"
],
[
"https://www.reddit.com/r/AskHistorians/comments/31o2nt/monday_methods_definitions_of_tribe/cq3hm52",
"https://www.reddit.com/r/AskHistorians/comments/31o2nt/monday_methods_definitions_of_tribe/cq3iz1x"
],
[
"https://www.reddit.com/r/AskHistorians/wiki/historians_views#wiki_historians.27_views_of_jared_diamond.27s_.22guns.2C_germs.2C_and_steel.22",
"https://www.reddit.com/r/AskHistorians/wiki/rules#wiki_do_not_just_post_links_or_quotations"
]
] |
||
bczj9g
|
how can we still keep seeing proposed ridiculous laws pop up at the state level dealing with abortion. hasn’t the supreme court multiple times decided you can’t make it illegal to have an abortion?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/bczj9g/eli5_how_can_we_still_keep_seeing_proposed/
|
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"It's politics as usual. You introduce or pass laws that gain you favor with your constituents or moneyed interests (or, arguably less likely, because you actually believe in the thing). In this case, you can write or vote for a law and say that you're \"tough on abortion\" or \"tough on crime and drugs\" or \"free healthcare for everyone\". It doesn't matter if it doesn't pass or if a court tosses it out, because you proposed it or backed it. You support this thing, and you were stopped by the other party or government with their laws and rights and courts and silly stuff like that. It doesn't change the fact that you believe this way and are willing to stand up for it.\n\nAnother thing to consider are single issue voters. Voting can be complicated, and idealism can be very strong. If a candidate supports one issue that you feel strongly about, you may vote for them because of their stance on this one issue. Gay rights, gun ownership, abortion, and tax rates are examples of modern causes that have motivated single issue voters."
]
}
|
[] |
[] |
[
[]
] |
||
7wawka
|
why do treasury bond yields have such a profound impact on the equity market?
|
I searched this ELI5 up, couldn't find anything..
From what I'm hearing, the lower the value of a bond gets, the higher the yield. So that means your paying less money and getting a higher return, right? This should make bonds more in demand...but right now they're still not?
How do these yields tie into:
a) Interest rates and inflation
b) The equities market
This is based on the chaos in the market right now, I would love to fully understand this. Thanks in advance
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/7wawka/eli5_why_do_treasury_bond_yields_have_such_a/
|
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"Bonds are issued for a specific life (5 year, 10 year etc.) and have a built in interest rate. So if Treasury bonds are being sold today at 5% rate, the marketplace adjusts the price to that rate. Tomorrow, Treasury bond rates drop to 3%. Suddenly the 5% Bonds are worth more than before and there's a run on purchasing the 5% therefore price rise. Same token - bond rates rise to 8%. The 5% bonds are worth less overall since they don't make as much money in interest over the life. \n\nThe bond prices and rates are correlated. Higher rate, higher price. The goal is to make the yield (aka your total profit) static on it by the market lowering the price on the bonds with the lower return",
"Let's start things simple. Bonds are debt instruments, meaning every time you buy one somebody owes you the total money you gave them plus interest. That interest rate is set by the central bank. \n\n\nSo when you owed by someone lets say $100 and you will get paid 5% for it ($5) until the debt expires the value of your investment is basically worth $100 + $5 = $105. If you then decide to sell that bond before it expires you should theoretically receive an amount around $105.\n\n\nIF the central bank changes the interest rates, by let's say reducing it from 5% to 3%, then the bond you hold pays more than what the NEW bonds will pay. Therefore your bond must worth more to offer the same % returns as the new bond. The same works if the interest rates are increased, then the $105 dollar bond should decrease in value to match the returns of the new bonds that pay better. \n\n\nHOW DOES THAT AFFECT THE STOCK MARKET:\n\n\nFOR MANY years countries around the world have been reducing interest rates essentially to zero as a way to battle the 2008 GFC. \n\n\nThere are two things you must consider:\n\nFirst is, if interest rates are going up after all these years, the new bonds are more attractive than the older ones, therefore making investors that like safer investments to buy them instead of stocks. \n\nSecond, when interest rates go up that indicates few things such as that the inflation is increasing and that the cost of debt will now increase, meaning that companies that borrowed money will now have to pay more for their debt as well as seeing increased costs caused by inflation resulting in their profits to drop and as a result of the stock prices to decrease. "
]
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|
[] |
[] |
[
[],
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g11afj
|
if heat causes things to expand, why does using the drier cause delicate's to shrink?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/g11afj/eli5_if_heat_causes_things_to_expand_why_does/
|
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"text": [
"Cotton is made of cellulose which has long stranded fibers that curl up when dried quickly. As the water is forced out of the little \"tubes\" full of water dotted all over the surface, the water at the top evaporates first and the water more in the center pulls toward the top to fill the space. The process is reversibleish by soaking the clothing in question and gently pulling it into shape, as the water lubricates the fibers. \n\nThe tumbling action also doesn't help it essentially pushes the clothing into a smaller ball. \n\nI used to run an appliance store."
]
}
|
[] |
[] |
[
[]
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||
dcaixk
|
if all carbohydrates get broken down to their most simple form, sugar, why is it unhealthy to just eat tablespoons of sugar?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/dcaixk/eli5_if_all_carbohydrates_get_broken_down_to/
|
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"A few reasons:\n\n1.) The amount of carbohydrates you get per-pound from more complex foods is much less than the amount from processed table sugar, and it also takes more time to digest. So, it's more difficult to overeat. A pound of table sugar will be stored mostly as fat, while a pound of chicken will need to be broken down and digested first. Whatever sugars are extracted will mostly be used, and only a minimal amount will be stored.\n\n2.) Table sugar has virtually no other nutrients or minerals, so you won't be getting any of those either.\n\n3.) It can be killer for your teeth, since bacteria *love* sugar.\n\nSugar itself isn't bad - in fact you need it. *Added* sugars are bad, because too much will cause your body to store it. This can lead to weight gain, heart disease, and a whole slew of other problems primarily caused by overeating.",
"Most of the dangers come from the glycemic response to these various foods.\n\nPure sugar with nothing to slow the absorption rate will spike your blood sugar. This causes your pancreas to release Insulin to counteract that spike, which in turn reduces your blood sugar below normal levels, so your body releases glucose into the blood stream to compensate, which spikes it again, causing your pancreas to release more insulin... Lather, rinse, repeat until your glucose levels have hit a steady baseline.\n\nThis yo-yo effect taxes your pancreas significantly, as well as has other downstream effects on your body. \n\nThe more effort it takes your body to absorb the sugars, the healthier it is for your system when consumed in moderation.",
"What does it mean \"unhealthy\" exactly? It's a very vague term. A tablespoon of sugar is just too much sugar to be used immediately by the average human, so most of it becomes stored as fat. If that is what you consider unhealthy, then yes, it's unhealthy. But if you need the carbohydrates, because you are doing heavy work, then a tablespoon of sugar is \"fine\".",
"Not all carbs do. Some fibers get broken down to component parts only by the bacteria in your colon, at the very end of the digestive tract. Others are somewhere in the middle but are still used mainly by bacteria without resulting in sugars that get absorbed. These bacteria are very important for your digestive and nervous systems as a whole.",
"\"Sugar\" is a slightly problematic term, because it is a term for a class of compounds. \n\nTable sugar, which is normally what we have around, is sucrose, which is made up of two simple sugars stuck together. Your body has no issue splitting them up, so each molecule of sucrose becomes 1 glucose and 1 fructose.\n\nMost sweet foods contain either sucrose directly, or \"high fructose corn syrup\" which, is a mixture of fructose and glucose all mixed together.\n\nCarbs are mostly just long chains of glucose, and enzymes happily cleave off glucose from the chains and use it. So carbs become sugar, but mostly, become glucose. This is energy for the whole body, every cell.\n\nThe difference comes with fructose.... remember the sucrose is a source of it.... When your liver processes sugars, it makes fats and cholesterol. This is \"de novo lipogenysis\" which is just the fancy latin way of saying \"the creation of new fat\".\n\nThe thing is, remember how I said glucose is food for your whole body? Because of that, only a small percentage < 10% ever gets processed by the liver.\n\nFructose however is not an energy source for every cell. Fructose is processed in the liver, and 90% of it goes there. [Fructolysis](_URL_0_) is the process:\n > Unlike glucose, which is directly metabolized widely in the body, fructose is almost entirely metabolized in the liver in humans, where it is directed toward replenishment of liver glycogen and triglyceride synthesis.[1] Under one percent of ingested fructose is directly converted to plasma triglyceride.[2] 29% - 54% of fructose is converted in liver to glucose, and about a quarter of fructose is converted to lactate. 15% - 18% is converted to glycogen.[3] Glucose and lactate are then used normally as energy to fuel cells all over the body.[2]"
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4rz1wo
|
How do we know that our mathematics will translate all over the universe and not just our world?
|
askscience
|
https://www.reddit.com/r/askscience/comments/4rz1wo/how_do_we_know_that_our_mathematics_will/
|
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"Math is fine. It's like a board game, we invent the rules that we have to follow when we want to play it. Board games are not reliant on where you play it. Math is always the same everywhere because it is nothing more than an idea.\n\nBut many of the rules of math that we have invented have been fine tuned to approximate reality to some degree of accuracy, this is what science does. The statement that this approximation will be good all over the universe is the [Cosmological Principle](_URL_0_). From our observations of large scale objects, like the Cosmic Microwave Background, the Cosmological Principle appears to be valid.",
"Let's start with something simple, like [Peano arithmetic](_URL_0_). It has five axioms:\n\n1. Zero is a number.\n\n2. If a is a number, the successor of a is a number.\n\n3. zero is not the successor of a number.\n\n4. Two numbers of which the successors are equal are themselves equal.\n\n5. (induction axiom.) If a set S of numbers contains zero and also the successor of every number in S, then every number is in S.\n\nMust this be true in every reality? First let's ask, is this true in our reality? Is zero a number? Have you ever seen a zero? I haven't. I've seen the numeral 0, but that's just a symbol. It's not something that has successors.\n\nIt's nonsense to ask if those axioms apply to numbers in a given universe, since numbers aren't material objects. You can have zero of something, but what it really comes down to is that how many of something you have follows those five axioms. Most systems do not follow those five axioms, but the ones we do follow all the theorems that follow.\n\nAnd even when you do find something where it applies, it's still generally not perfect. For example, it might seem like those axioms are true for numbers of apples, but you can't always have another apple. At some point, there won't be room in the universe to fit another apple. The second axiom does not apply. And as a result, a lot of the theorems don't.",
"Math does not necessarily have to anything to do with the real world, even though it is useful for modeling the real word. So it is not affected by the state of the world, universe, etc.\n\nNow physics is a different story, because the purpose of physics IS to predict the behavior of the actual universe. So in fact we do know of places in the universe where our current physical theories are incomplete and would give wrong predictions, e.g. center of a black hole.\n "
]
}
|
[] |
[] |
[
[
"https://en.wikipedia.org/wiki/Cosmological_principle"
],
[
"http://mathworld.wolfram.com/PeanosAxioms.html"
],
[]
] |
||
hy1kt
|
Instead of the universe expanding at an increasing rate which is accounted for with the term dark energy, could there be an outside force pulling the universe and as the galaxies get closer the pull gets stronger, causing them to speed up?
|
askscience
|
http://www.reddit.com/r/askscience/comments/hy1kt/instead_of_the_universe_expanding_at_an/
|
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"text": [
"Yes. You can imagine that by chance we are just living in an underdense region, which would expand faster than the rest of the Universe.\n\nThe problem is that the expansion seems to be isotropic (=the same in all the directions). So it would mean we are almost at the center of this bubble. It's highly unlikely and cosmologists don't like to assume our position is special. But it's a possibility we should consider and try to rule out from the observations."
]
}
|
[] |
[] |
[
[]
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||
5l0ord
|
Any good source about the Seleucid Empire?
|
I've been looking over Wikipedia and some other websites for information about it, but it doesn't seem to be very deep.
I'm looking for books, webpages, posts here on Reddit, whatever that helps me to get information about the Empire, military, administration and society, everything I can get. Thanks.
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/5l0ord/any_good_source_about_the_seleucid_empire/
|
{
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"text": [
"Well, there is a lot out there on the Seleucid Empire, though some aspects of the empire are better known and researched than others. The [Wikipedia article](_URL_5_) and the links found therein are a good start. The [Livius page](_URL_3_) is also good, especially if the follow the rabbit hole and click on any links that might interest you. Livius is especially useful for providing information regarding Near Eastern documents.\n\nAs for books, there are decent chapters in most general histories of the Hellenistic World. Peter Green weaves information of Seleucid kingship throughout [his book](_URL_4_), but you need to slog through entire chapters in order to find information specific to the Seleucids. I greatly prefer Graham Shipley's[ book on the Hellenistic world](_URL_1_), which has its own chapter on the Seleucid kingdom.\n\nThere are more specialized books out there, but you may need access to a university library in order to find some of these books. Susan Sherwin-White and Amelie Kuhrt made a splash amongst ancient historians when they published [*Samarkhand to Sardis*](_URL_2_) nearly twenty-five years ago. The book was the first book-length attempt to situate the Seleucid Empire in a more Near Eastern context, with particular focus paid to primary sources in languages other than Greek and Latin. While the book is a bit dated now, it is a must-read for any serious historian of the Seleucids.\n\nMore recently, Paul Kosmin published [*The Land of the Elephant Kings*](_URL_0_). This book is a good attempt to reconstruct the intellectual and royal levels of society within the Seleucid Empire. The research is top-notch and up-to-date, and I highly recommend it.\n\nIf you have any particular areas of the Seleucid Empire that you wish to more know about, let me know. The academic scholarship is immense, even if much of it is not available to the general internet."
]
}
|
[] |
[] |
[
[
"https://books.google.com/books?id=ABihAwAAQBAJ&lpg=PP1&dq=the%20land%20of%20the%20elephant%20kings&pg=PP1#v=onepage&q=the%20land%20of%20the%20elephant%20kings&f=false",
"https://books.google.com/books?id=sAoiAwAAQBAJ&lpg=PP1&dq=graham%20shiplet%20greek%20world&pg=PP1#v=onepage&q=graham%20shiplet%20greek%20world&f=false",
"https://books.google.com/books?id=IZ65PED6ykMC&lpg=PP1&dq=samarkand%20to%20sardis&pg=PP1#v=onepage&q=samarkand%20to%20sardis&f=false",
"http://www.livius.org/articles/dynasty/seleucids/",
"https://books.google.com/books?id=1QOvJ14Jxv8C&lpg=PP1&dq=Peter%20Green%20hellenistic&pg=RA1-PR9#v=onepage&q=Peter%20Green%20hellenistic&f=false",
"https://en.wikipedia.org/wiki/Seleucid_Empire"
]
] |
|
uu4er
|
why haven't other species on earth reached the same level of consciousness of humans?
|
I'm not talking simply about intelligence like in dolphins or some species of ape, but complete self aware and conscious beings. Does it have to do with evolution? Can there only be one self aware species on a planet as the top predator?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/uu4er/why_havent_other_species_on_earth_reached_the/
|
{
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"Some corvids have passed self awareness tests, as well as some primates.",
"dolphins are self aware. There have been tests where a mirror is placed in the tank, instead of getting bored or thinking it is another dolphin in the mirror, the dolphin acknowledges that its a reflection, they will marvel for great lengths at a time and will check themselves out. Its more in the matter that we ourselves, truly dont know what they are thinking or what other animals have high levels of consciousness.",
" I can't guarantee you everything I'm about to tell you is right or that I'm even answering your question, but here it goes.\n\n The problem I think you're running into is assuming that our level of consciousness is somehow the next step in evolution, or that it is somehow the best place to be at. Sure, for us it is, but we're a bit biased don't you think? The only reason (Based off of evolution) that we have this level of consciousness is that it somehow benefited us and made us more likely to survive and pass on our traits to our offspring. \n\n In my mind, there is not anything preventing any other species from reaching the same level of consciousness at some point in their evolutionary progress, but the environment in which the live has to have the right conditions to get them there. \n\n Not really sure how much that helped or answered anything, but feel free to ask clarifying questions. In the meantime I'll see if I can't find the post to which I was referring. :]",
"It is because evolution is not aimed at any goal of intelligence or any ideal species. It is just a response to life attempting to exist via survival and reproduction. Whether that is hiding underground for 17 years followed by a few days of mating and death, becoming intelligent enough to use tools and pass on y knowledge with developed language, or setting up shop in the brain of another species and trying to send offspring off to find another one before killing it. No one system is any better than another.",
"Dolphins are completely self aware. we just don't care because we can't communicate with them but scientists are learning their language now and hopefully one day we'll be able to tell them all about the miracles of Jesus! ",
"Humans are special in a couple of big ways. \n\nFirst, we have fingers and thumbs, like monkeys and apes, who are primates like us. This makes us very good at working with small objects and using tools. Because we have hands, we can build big things like skyscrapers and cars and rockets. \n\nSecond, we have language. This is mostly because we walk on two feet instead of on all fours. Animals who walk on all fours can mostly make vowel sounds like \"ah\" and \"ee\" and \"oh.\" \n\nWhen we started walking upright, we had to bend our heads down towards our feet in order to look forward. When we bent our heads, we also bent our throats, which allowed us to make sounds like \"k\" and \"g\" and \"r.\" With the sounds we make from bending our heads, we got enough sounds to have a useful spoken language. \n\nSpoken language allowed us to talk about what to eat and where to go and how to kill big animals. We could understand plans and instructions without having done things ourselves. We could also talk about each other, and more importantly for your question, we could talk *to ourselves*. We eventually learned how to talk to ourselves without making any noise, which is the same thing as thinking. When we think about ourselves, or think about thinking, we experience that as consciousness. \n\nLanguage and consciousness are separate from tools and building. For example, ants can make big, complicated houses for themselves, and they can make farms of leaves and bugs, but individual ants can't think about themselves. \n\nDolphins can talk to each other, and they can recognize themselves, but they can't build anything, because they don't have hands. That's why humans normally think of dolphins as less advanced. But we don't know for sure. We don't understand their language, so we don't know what they're talking about, or whether they think, or whether they think about themselves and experience consciousness. \n\nAnother thing to think about is reading and writing. When we read, we think pretty hard, and when we write, we share what we're thinking so that anybody can find out later. Reading and writing let us share our consciousness across time and space, and we can only do that because we have both language and tools. Other animals with language don't have tools, and so they can't record their ideas and share them later. \n\nSome scientists think that there might be advanced intelligence on other planets, but it might be in animals like dolphins, who can talk to each other but can't use tools. Those aliens would never be able to build spaceships and come visit us, but they would have interesting and valuable lives. \n\nSo, to answer your question, right now we think we have a special kind of consciousness because we can't talk to other animals. But some other animals, like dolphins and whales and gorillas and crows, are really smart, and maybe we can eventually figure out how to talk to them and how they think.\n\n(Source: most of my understanding of the evolution of consciousness and language comes from \"Consciousness Explained\" by Daniel Dennett. [**EDIT:** The [book's bibliography](_URL_0_) is available in the middle of the \"Click to look inside\" pop-up. It's not a science book, but the author is reputable.] The speculation about extraterrestrial intelligence came from a brief article I read several years ago and cannot find.)",
"What are you talking about? [Didn't you see the documentary that came out last year?](_URL_0_) ",
"One guy claims it is because of monkeys who stumbled Into a patch of psychedelic mushrooms. ",
"Brains require a tremendous amount of energy to operate. Unless the intelligence helps the animal acquire more food, it will be selected out.",
"I got to explain this to another person not long ago: All animals have a certain degree of intellectual development,from the snail to us humans. And along the line comes self-awareness, which is not really a trait but a spectrum of characteristics that we like to say define \"being self-aware\". \n\nNow, why haven't other species reached the same level as us? Well because they don't need to . Their path on evolution has led them to specialize on other things, which doesn't necessarily include being smart enough to develop was we did.\n\nThink about it this way-- Imagine a shark could talk, and asked you **why the hell don't you have more teeth??!!** -- For the shark that means long life and supremacy underwater.",
"you're asking too many questions here. 'complete self aware and conscious beings' vs 'self aware species'\n\nfirst, there's only a small handful of humans who are completely self aware and conscious, historically. i mean that from an 'understanding of self' perspective, in the buddhist sense of humans having a mind that interferes with true perception of reality. \n\nbut in the sense that humans don't know how our brains and bodies work, you could argue we are not all that fully aware. \n\nsecond, just because we are smart doesn't mean we are aware of other intelligence. large hives of insects and other groups exhibit an intelligence distributed across their thousands of constituent parts - our intelligence is mostly localized to individuals, but via politics and culture we too have a distributed group intelligence. \n\nalthough, when you consider what we're willing to do to our surroundings, i.e. pollute, we may not be that advanced after all"
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[],
[
"http://www.amazon.com/Consciousness-Explained-Daniel-C-Dennett/dp/0316180661"
],
[
"http://youtu.be/f8D2NIGEJW8"
],
[],
[],
[],
[]
] |
|
6fy2q8
|
in terms of weight and calories what is the difference between binge eating a food such as a tub of ice cream all at once and eating it incrementally?
|
For example hypothetically say a tub of ice cream is 800 calories and you normally eat 1800 calories a day to lose weight is there a difference between eating the whole tub of ice cream in 1 day rather than over 4?
When trying to lose weight at slimming clubs I've gone to they award points to different foods and when talking people generally seem to say I at this in the week this is why I gained, even if they cut ha k on points other days.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/6fy2q8/eli5_in_terms_of_weight_and_calories_what_is_the/
|
{
"a_id": [
"dilz35i"
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"score": [
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"text": [
"There's none. If you have a strict diet but over the course of a month you eat one tub of ice cream, you will have gained as much weight at the end of the month even if you ate all the ice cream on the first day. Assuming you keep your diet otherwise exactly the same.\n\nThe problem is most people don't keep their diet otherwise exactly the same. If they eat an entire tub of ice cream in one day at the beginning of the month, they're likely to eat another tub of ice cream in one day another time during the month. So if you spread it out the changes are more gradual and 'feel' like they last longer.\n\nThat said, exactly when and how you gain the weight-- really everything about it-- is slightly more complicated and depends on lots of things.\n\n"
]
}
|
[] |
[] |
[
[]
] |
|
35f78z
|
What did the Europeans trade for African Slaves. I know Africans traded Slaves before Europeans. African Kings would use Slaves as currency. ?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/35f78z/what_did_the_europeans_trade_for_african_slaves_i/
|
{
"a_id": [
"cr46343"
],
"score": [
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"text": [
"Concerning the Europeans' payments to the African slave traders, the slave ships usually departed for Africa with a rather varied array of trade goods. Prices differed by region and time period and there was always some small concern that they wouldn't have on board what the African traders wanted. Obviously, back then, it was impossible to have recent and accurate information within a time period short enough to make adjustments to your trade supplies, and one African merchant might be interested in very different things than the next one 3 miles down the road (so to speak).\n\nThe most prevelant trade supplies were a bewildering array of textiles, firearms, gunpowder, copper and metal pots, pans and cups, various tools, iron bars and bracelets ('manillas'), buckets and other various metal objects (which were often smelted down by African smiths to make, well, whatever the hell they wanted).\n\nThen there were the kauri shells, a rather common means of payment throughout some of the slave regions on the African west coast. The kauris were not unique to Africa either, being used in other parts of the world as 'money'. The Europeans obviously had no use for the kauris, but many African traders wanted payment in kauri shells, so the Europeans were forced to engage in multi-money systems to procure kauris for trade. The Maldives were a large 'procurement point' for kauris for the Europeans. The Dutch VOC ships would use kauris as extra ballast for their ships on the return voyages to and from the East, then sold in Europe for the slave trade on West Africa. \n\n\nThe book about the slave ship Leusden by Leo Balai makes mention of an extensive list of trade products listed in the administration of the VOC. The Leusden was a rather 'successfull' slave ship, having made nine full round trips on the triangle-route, before the ship foundered and sank at the mouth of the Marowin river on her tenth voyage. This means the Leusden's travels are relatively well documented.\n\n\nIn any case, the list of trade goods, which would've been very indicative for the Dutch West African slave trade in the early part of the 18th century, as mentioned in the book,\n\n\nTextiles\n\n\nAnnabas/Fustian, a strong fabric often patterned, used for sheets, blankets. \n\nAtlas, a fine silk; striped\n\nBaftas, fine cotton cloth\n\n\"Broulissen\", coloured linen from India\n\nCaffa, decorated silk or cotton\n\nCassa, loosely woven fine form of cotton, often from the Bengals\n\nChits, a painted cloth, cotton or silk, made on the entire Indian subcontinent\n\nCora cloth, a fine woven silk\n\nGuinees, a coarse and heavy cotton, very popular in Africa to the extent that it gains the nickname \"negroskleed\" ('negroscloth').\n\nLemianasses, European cloth, blue with white stars\n\n\"Linguettes\", a type of cord used in the seams of clothing\n\n\"Perpetuanes\", a very strong 'sergelike' fabric from Portugal\n\nPlatilles, a fine, veil-like fabric\n\nRaw Guinees, unbleached cotton fabric\n\nSaai (Dutch for 'boring'), a woolen fabric from Leiden's sheetindustry, a cheap and simple sheet\n\nSalempouris, a textile named after Salempors or Serampore on the Coromandel coast. \n\n\"Sleepsheets\", used sheets. For some reason the Dutch sheets specifically were quite wanted, even the French and English bought them for their slave trade. \n\n\n\nMetal products:\n\nArmbands, also called 'manillas', that were open on one side. Originally intended as jewelry, they were later also used as 'money' and as raw material as African smiths melted them down.\n\nFirearms, estimates range from 180.000 to nearly 400.000 of firearms introduced into Africa yearly by European slave traders.\n\nCopper bars, used by African smiths to make jewelry\n\nKnives, rather self-explanatory :P\n\nCopper or tin bowls, used for a variety of things (it's a freaking bowl)\n\nSpanish bowls, more bowls, but smaller.\n\n\n\nOther goods:\n\nAlcoholic drinks! French brandy (eau de vie) was very popular, but Dutch brandy (jenever) also sold well. To this day, old Dutch jenever is still very popular in Ghana.\n\nGunpowder, not just for war but also as a general 'tool'. In Ouida (modern day Benin), the price of a slave in 1725 was equal to 300lbs (136kg) of gunpowder. \n\nBeads, many forms of beads, self explanatory\n\nMirrors, highly regarded ever since the Portugese started the slave trade, remained popular throughout\n\nFlints, for rifles\n\nThe Kauri shells\n\n\n\nAs you can see, it's a pretty extensive list. Having a large assortment of goods was a form of 'safety net' for the traders, because buying slaves wasn't always easy.\n\n\nOne interesting thing that keeps popping out is the prices for slaves. Even today, the end-of-voyage accounting numbers are impressive, with 6 digit numbers from the sale of a few hundred slaves. \n\nThis was very much a big business."
]
}
|
[] |
[] |
[
[]
] |
||
1s7gwi
|
how much data can fit in a qr code?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1s7gwi/eli5how_much_data_can_fit_in_a_qr_code/
|
{
"a_id": [
"cdunolu"
],
"score": [
3
],
"text": [
"Around 2,953 bytes or 7,089 numbers or 4,296 Letters but that is an extremely big one at 177 pixels by 177 pixels. It would be easier to use a web address and download the content at that point."
]
}
|
[] |
[] |
[
[]
] |
||
472l3c
|
Did people know Hitler only had one testicle during WWII? Or was the song "Hitler Has Only Got One Ball" just a coincidence?
|
During WWII there was a British song called "Hitler Has Only Got One Ball." Was this due to common knowledge, or just playful mockery that happened to be true?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/472l3c/did_people_know_hitler_only_had_one_testicle/
|
{
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"text": [
"I don t think it is even true about the testicle. In italy everybody used to say mussolini only had one ball so this is just a little bit to much of a coincidence. Is there any convincing source over this monoball thing?",
"Ok, to be completely honest, I haven't seen the alleged evidence Mayo and Cragie put forth for this although an article in the Guardian claims it comes from medical records taken down after Hitler's arrest subsequent to the Beer Hall Putsch attempt.\n\nHowever, this is a fairly new development and the 1940s song about Hitler's testicles was to a degree of almost certainty not based on this information. This especially so as Hitler's childhood doctor, Eduard Bloch, had emigrated to the US in 1938 and had testified to American interrogators that everything was fine with Hitler's genitals.\n\nSources:\n\n* Eduard Bloch: My Patient Hitler. In: Collier’s Weekly, March 15. and March 22. 1941.\n\n* Eduard Bloch: The Autobiography of Obermedizinalrat Eduard Bloch. In: J. A. S. Grenville and Raphael Gross (Eds.): The Leo Baeck Institute Year Book, XLVII (2002)\n\n* Office of Strategic Services, Hitler Source Book, Interview With Dr. Eduard Bloch March 5, 1943."
]
}
|
[] |
[] |
[
[],
[]
] |
|
50jwui
|
why didn't canada fully adopt the metric system in the construction industry like european and oceanic countries?
|
The Canadian construction industry is 100% imperial. You can find a few things here and there in metric, but almost nobody is measuring decks in metres. And yet we all use kilometres and litres and even starting to use kilograms a bit more. Engineers with feet (no pun intended) in multiple industries have to constantly switch between imperial and metric. Why is the construction industry in particular slow to change?
Edit: For anyone else curious, [this comment](_URL_0_) from 9 months ago in a similar ELI5 sums up the overall metrification problem nicely.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/50jwui/eli5_why_didnt_canada_fully_adopt_the_metric/
|
{
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"text": [
"Not an expert. But maybe because Canada is next to the US?",
"Changing standards is not as easy for every industry. Some Canadian industries are doing a lot of trade with the US side and it only creates a lot of issues if one were to change standard. And it takes time to redo everything. Even the European construction industry have not switched completely away from imperial units. Most wood still come in the old inch standard but rebranded in cm. 2x4 is just as common in Europe as in the US and is still called 2x4. This also goes the other way. Your standard 2 feet cabinet is actually 600mm as that is a global equipment standard.",
"I'm old enough to remember when the metric system was imposed by the government and the reason was to make us more competitive in foreign markets.\n\nSince one of our biggest exports was lumber, and 90% of it went to the US, lumber was an exception."
]
}
|
[] |
[
"https://www.reddit.com/r/explainlikeimfive/comments/3txu8v/eli5_why_do_canadians_or_at_least_where_im_from/cxad2tp"
] |
[
[],
[],
[]
] |
|
1iyhzx
|
Do hybrid cars (such as a Toyota Prius) have larger carbon footprints than conventional cars, due to the pollution caused during production?
|
One of my professors brought this up, and I couldn't find any solid research on the subject through Google.
Basically, the idea is that the "carbon footprint" of a car can be modeled by this equation:
> "Size" of carbon footprint = Amount of GHG emitted during production + (Amount of GHG emitted while driving per mile * Mileage)
So since hybrid cars cause more pollution through production but less through operation, there must be a certain mileage point at which the carbon footprints break even. At the average mileage for a given car, what is the "ideal" car if you want to absolutely minimize GHG emissions?
|
askscience
|
http://www.reddit.com/r/askscience/comments/1iyhzx/do_hybrid_cars_such_as_a_toyota_prius_have_larger/
|
{
"a_id": [
"cb9do55"
],
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8
],
"text": [
"Short answer: No.\n\nLong answer: Hybrids have a marginally higher pollution and energy cost to produce, but the difference is made up very early on in the car's lifetime (around 10,000 km, if you crunch the numbers in the following source), and the lifetime numbers favour hybrids. The [UCLA](_URL_1_) found that hybrids incur 35% less pollution than a comparable conventional car over the course of its lifetime, and use 34.2% less energy. The [Argonne National Laboratory](_URL_0_)'s GREET model, another lifecycle analysis, has results consistent with the UCLA's work.\n\nEDIT: Vehicle production as a proportion of the car's overall emissions and energy use is negligible compared to what it incurs during operation. From the UCLA's link, 96% of a conventional car's pollution (91% for a hybrid) happens in operations, as do 95% of a conventional car's energy usage (89% for hybrids)."
]
}
|
[] |
[] |
[
[
"http://www.transportation.anl.gov/pdfs/TA/378.PDF",
"http://www.environment.ucla.edu/media_IOE/files/BatteryElectricVehicleLCA2012-rh-ptd.pdf"
]
] |
|
6ci7mo
|
How would large scale fires be stopped in ancient cities? Did Rome, for example, have firefighters?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/6ci7mo/how_would_large_scale_fires_be_stopped_in_ancient/
|
{
"a_id": [
"dhv5uen"
],
"score": [
3
],
"text": [
"My knowledge on this is very slight, but there is a tangential reference in [Strabo's Geography (5.3.7)](_URL_0_) about how Augustus was particularly concerned by Rome's susceptibility to mass fires and so organised a group of freedmen who would help protect against this. Augustus also set limits on how tall buildings could be and there's a line of argument which suggests this too was an anti-fire measure as much as to prevent them from collapsing: since we believe higher floors in taller buildings tended to be built with cheap materials (read: flammable wood) because landlords wanted to maximise their potential profits from their plot of land. Therefore, in limiting the heights of buildings Augustus may have been indirectly trying to target buildings which were the most problematic with regards to spreading fires across the city. (Source: Yavetz, Z. The living conditions of the urban plebs in Republican Rome, pp.173-4)"
]
}
|
[] |
[] |
[
[
"http://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.01.0239%3Abook%3D5%3Achapter%3D3%3Asection%3D7#note-link7"
]
] |
||
1lna4l
|
Is there a school of thought that combines psychological analysis with historical studies?
|
Not the history of psychology, mind you. I mean for example, the psychological examination of the people involved in the American Revolution. Simply looking at history through the eyes of a psychologist. I am looking for the specific name for this concept, as well as who to read if there is anything published with this view.
Thanks y'all.
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/1lna4l/is_there_a_school_of_thought_that_combines/
|
{
"a_id": [
"cc0wdym",
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],
"score": [
11,
4
],
"text": [
"Psychohistory (I think Asimov nicked the idea for his Foundation series) is what you're looking for. It had its heyday during the 1960s/70s but died out pretty much by the 1980s as it was essentially speculative fluff. It surfaces now and then (cf Heiko Obermann's shouting at Richard Marius' biography of Luther) but as a fundamentally unsupportable position, it doesn't make for great history.\n\nLacey Baldwin Smith wrote a psychohistory of Henry VIII in the early 70s that got quite popular iirc.",
"Sure. It's called Psychohistory. It's more a method than a field, and it is highly controversial. It was more prominent a couple of decades ago than it is now. \n\nTwo books that rely on this method from my field of study are Erik Erikson's *Young Man Luther* and William Bouwsma's *John Calvin: A Sixteenth Century Portrait.*"
]
}
|
[] |
[] |
[
[],
[]
] |
|
3fu0oa
|
Did the Byzantine Empire continue to use Legions, if they stopped, when and why?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/3fu0oa/did_the_byzantine_empire_continue_to_use_legions/
|
{
"a_id": [
"ctsr8nm"
],
"score": [
4
],
"text": [
"Diocletion began to phase out the legion system well before the Byzantine Empire/Eastern Roman Empire was a standalone state. Instead of one massive, infantry-driven army, he split it into *limitanei* (frontier garrisoned soldiers) units and *comititenses* (legion-ish mobile line soldiers) units. He also put an increased focus on the use of cavalry, possibly due to the superior cavalry forces of the Sassanid empire, Hunnic forces, and various other nomadic hordes who used cavalry as the main wing of their army (The Byzantines actually more or less switched to this around the 7th-8th century). "
]
}
|
[] |
[] |
[
[]
] |
||
2u034j
|
Mass-energy equivalence, Why doesn't everything have infinite mass?
|
OK, so I'm just a teenager who's been reading online, but a couple questions occurred to me about mass-energy equivalence.
1: Does gravitational/magnetic potential energy increase mass. If so, why doesn't everything have infinite mass from all the stuff in the universe, and if not does that mean mass disappears?
2: When something is going at speed, it has kinetic energy. This energy increases its mass, which should in-turn increase the kinetic energy etc. Why does this not result in infinite mass (from a different reference frame, obviously)
|
askscience
|
http://www.reddit.com/r/askscience/comments/2u034j/massenergy_equivalence_why_doesnt_everything_have/
|
{
"a_id": [
"co46nzo"
],
"score": [
3
],
"text": [
"1. It increases the mass of the whole system, not the individual object. The mass isn't infinite because the potential energy isn't infinite. \n\n2. Relativistic kinetic energy is calculated based on the rest mass of the object. This is also one of the reasons why we got rid of the idea of relativistic mass, which states that the mass increases the faster you go. "
]
}
|
[] |
[] |
[
[]
] |
|
6m8wfq
|
how do theoretical physicists find solutions to the biggest and smallest answers to the universe using math alone?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/6m8wfq/eli5_how_do_theoretical_physicists_find_solutions/
|
{
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"text": [
"They don't.\n\nThey have centuries of observations to draw upon, they are trying to find math that is consistent with those observations. Sometimes that math takes them beyond what can be shown with experiments, but by no means are they using math alone.",
"So, the underlying thing here is that *math is never wrong*. The physical law that uses math to describe itself may be wrong, but the math itself isn't flawed.\n\nSo, when you have a given theory, you stretch that theory to it's mathematical limits in order to predict the existence of a given phenomena. If you then search for that phenomena, and find it, that is one more bit of evidence that the underlying theory is correct. If you don't find it (assuming you know that you *should* have found it), then you know the theory is wrong, because the things the theory predicted didn't come to pass.",
"As others have mentioned, physicists have lots of observation to draw upon and they then use math to obtain or find more concrete proof. A good example of this is Michael Faraday and James Maxwell. Both are highly regarded, yet Faraday didn't include much math (if any at all) in his papers. He used basic algebra or trig, but his findings were mainly based on observation. Later, James C. Maxwell took Faraday's findings and developed equations to sum up and model them.\n\nBoth are very famous physicists, but they are very different. Faraday was essentially a librarian who later became a lab assistant and then went on to describe his observations.",
"Theoretical physicists make models, not solutions to answers. In practice the models are much more complicated than my example, but the idea is very much so the same.\n\nSay you're playing a game and what to know your win rate. You know how many games you won and how many games you played. The formula for your win rate (# of wins)/(# of games played)=winrate.\n\nNow, when you look at that formula you see that you can use it to determine any 1 of those variables so long as you know the other two. You also notice that your win rate is only dependent on those 2 variables, and only those three variables. It's not dependent on the moon phase, not dependent on the time of day, or anything besides those 2 variables. In this particular example that's obvious, but in general that kind of thing is not obvious.\n\nSo, just by creating an obvious formula we discovered that your win rate is only dependent on 2 things, and we were able to make predictions with that formula (eg how many games it will take to win 50 games with a 70% win rate)."
]
}
|
[] |
[] |
[
[],
[],
[],
[]
] |
||
2rt1m3
|
How does distilled water expire?
|
I really had to buy some and I noticed there is an expiration date, but with nothing in it but water, how does it expire?
|
askscience
|
http://www.reddit.com/r/askscience/comments/2rt1m3/how_does_distilled_water_expire/
|
{
"a_id": [
"cnjeeqj",
"cnjgcq0",
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],
"score": [
3,
3,
2
],
"text": [
"The expiry date is a social thing, not anything physical to do with the water. A date is stamped on the label and when that date is reached and passed the object is said to be expired. It doesn't mean that anything has happened to the water.\n\nHowever, water can go off, usually by growing micro-organisms. It can do this at any time, either before or after the expiry date. Generally, warmer temperatures will promote the growth of micro-organisms. Micro-organisms growing in a product are generally not a good sign, however they are not necessarily bad.",
"Distilled water might not have a shelf-life, but the container around it certainly does. In the case of plastic bottles, these slowly leach compounds into the water (plasticisers and additives, rather than polymer). Over a long time, the build up of these compounds could become enough to make the water exceed contamination levels. Even then, it probably wouldn't be toxic, but to ensure that it stays within the legal limits manufacturers will place an expiration date that occurs well beforehand. This is also the reason why it's usually suggested to not reuse cheap soft-drink bottles as water bottles.",
"Even though it's distilled, it's unlikely there's \"nothing\" in the water. Contamination from particles in the air of the processing facility can make it into the water. Even boiling water vapor can carry vaporized contaminants from the source water into the distilled water. If either of those sources includes algal spores you could eventually grow algae, although this situation is very unlikely because of the low concentration of nutrients present."
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
s7zml
|
Can someone with a background in neurology take a look at this?
|
Can you shed some light on this? Is there something to it?
_URL_0_
|
askscience
|
http://www.reddit.com/r/askscience/comments/s7zml/can_someone_with_a_background_in_neurology_take_a/
|
{
"a_id": [
"c4btgtp"
],
"score": [
11
],
"text": [
"Yes, that's nothing new. We've known for YEARS that depression has nothing to do with a serotonin deficiency. The current theories suggest that serotonin may improve symptoms of depression by improving the health/functions of certain neurons. But the idea that serotonin is deficient in persons with depression (aka, the serotonin hypothsesis) was essentially disproven a long long time ago. "
]
}
|
[] |
[
"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1277931/?tool=pmcentrez"
] |
[
[]
] |
|
44wnz1
|
why doesn't type ii diabetes curb weight gain?
|
If insulin mediates fat uptake, and proper functioning of these receptors/GLUT2 is what stores fat in adipocyte tissue, doesn't that mean less fat would get stored when that mechanism is disrupted?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/44wnz1/eli5_why_doesnt_type_ii_diabetes_curb_weight_gain/
|
{
"a_id": [
"cztffyk"
],
"score": [
3
],
"text": [
"You are right that it can cause weight loss. In fact, unexplained weight loss is one of the first signs of undiagnosed diabetes. This happens because of the mechanism you described, but also because diabetics urinate out sugar. But it also stops cells from getting enough energy, which makes people hungrier so they eat more. Also, when people take insulin as treatment for diabetes, it can lead to weight gain. \n\nIt's important to visit a doctor regularly to keep from gaining or losing too much weight when treating diabetes. (Also, don't forget that there is a good weight loss and a bad weight loss. Good means you lose fat. Bad means you lose muscle too.)"
]
}
|
[] |
[] |
[
[]
] |
|
2sp8hh
|
Would it be possible to simulate the entire universe, all its laws, and its characteristics, with a quantum computer?
|
askscience
|
http://www.reddit.com/r/askscience/comments/2sp8hh/would_it_be_possible_to_simulate_the_entire/
|
{
"a_id": [
"cnrvk2i",
"cnrw3ka"
],
"score": [
11,
4
],
"text": [
"We don't even know if the universe is finite. If it is infinite then the answer to your question is no, as we cannot simulate a world with infinate size.\n\nIn the case that the universe is finite, to build a computer to simulate all of it would require as much state as can phisically be contained within the current universe (imagine trying the emulate the n64 on the n64, you typically need a computer many times more poweful than the computer you are emulating), which would leave no room for any logic components of the computer.",
"This question touches on [Laplace's Demon](_URL_0_).\n\nFTA\n > There has recently been proposed a limit on the computational power of the universe, i.e. the ability of Laplace's Demon to process an infinite amount of information. The limit is based on the maximum entropy of the universe, the speed of light, and the minimum amount of time taken to move information across the Planck length, and the figure was shown to be about 10 to the 120th power bits. Accordingly, anything that requires more than this amount of data cannot be computed in the amount of time that has elapsed so far in the universe.\n\n > Another theory suggests that if Laplace's demon were to occupy a parallel universe or alternate dimension from which it could determine the implied data and do the necessary calculations on an alternate and greater time line the aforementioned time limitation would not apply. This position is for instance explained in David Deutsch's The Fabric of Reality, who says that realizing a 300-qubit quantum computer would prove the existence of parallel universes carrying the computation."
]
}
|
[] |
[] |
[
[],
[
"http://en.wikipedia.org/wiki/Laplace%27s_demon"
]
] |
||
a8qdwz
|
If a males testicles are removed before puberty occurs does the male grow to be the size they would have been if the testicles were still there?
|
To add to my question, would the removal of the testicles before puberty cause the person to be uninterested in sex after they would have otherwise gone through puberty?
|
askscience
|
https://www.reddit.com/r/askscience/comments/a8qdwz/if_a_males_testicles_are_removed_before_puberty/
|
{
"a_id": [
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"ecebhb6",
"ecegzcg"
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"score": [
26,
32,
118,
27,
3,
5,
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"text": [
"I am by no means an expert on this subject but I read in a book titled \"Mutants\" by Armand Leroi that \"Boys that are castrated before puberty grow up to be tall\"( page 199) and also discusses the Italian Castarti who where a troop of singing men that where castrated. The entire book is a fascinating read about deformity.\n\n & #x200B;",
"To the “uninterested in sex” question: I took a course called “Sex and Endocrinology” and one class we had a discussion about the ethics of whether sex offenders (rapists, molesters, etc.) should be required by law to take either a pill or injection to stop the synthesis of testosterone (T). As of right now they have a choice whether to take them or not (consent is required). For males: blocking, or inhibiting, T from being formed and reacting with receptors does decrease sexual desire, erections, and wet dreams (there are research articles about this, I’m not sure about the data on females), overall they feel less inclined to preform sexual acts. Therefore, removing the testicles and stoping a large amount of T production will most likely decrease sexual desire. If they are removed, injections of T can “replace” the testicles’ function, if so desired. \n\nEdit: there are many sex studies involving mice that are interesting and dives in much deeper on this subject. If you are interested, I suggest going to Google Scholar to find research articles about this. Have fun learning and discovering :)",
"I can't quite say much with regards to humans, but as an owner of ferrets one of the interesting facts about them is all ferrets in, at least in Canada, legally must be Spayed/Neutered.\n\nThis has interesting side effects, as the operation is done when the ferret is very young. One effect that has been documented well is the ferrets go through significant changes in growth and behavior.\n\nYoung ferrets are far more social, friendly, curious, and less aggressive. As they mature normally, they become more food dominant, aggressive, and of course sexual with each other. Normal growing ferrets will become seclusive as well.\n\nHowever, if Neutered/Spayed, they don't go through these changes nearly as much. These ferrets, which are called 'Sprites', will basically stay in their childlike phase (temper wise) for effectively forever.\n\nThey also don't grow as big, and stay social. Sprites are much more cuddly, they are perfectly fine cuddling together in piles (behavior normally only seen in baby ferrets), and they continue to be playful and non-aggressive for their entire life span.\n\nNow, since Ferrets and Humans are both Mammals, I wouldn't be surprised if similar phenomena occur with us as well.",
"Maybe look for the singers back in the old days who were castrated for singing? There were a lot of them. I guess finding their height etc isn't very documented but it'd be interesting to see if they were short.\n\nThey do have data that shows testosterone causes male vocal cords to grow 63% \n\nHere's a book on it too \n[_URL_0_](_URL_0_)",
"I read about this in a medical physiology book in college when I was studying kinesiology for my minor. They actually grow to be taller. We learned this from studying Chinese slaves who were neutered and had an abnormal average height than their piers who weren't. This is also partially why steroids can stunt one's growth. I don't remember the mechanism but testosterone has an influence on one's height in development, by inhibiting it.",
"It depends on whether they go on to experience an estrogen-dominated puberty (most commonly because they’re intersex) or whether they never experience puberty at all. \n\nTowards the end of puberty, your epiphyses harden, which is what makes your limbs stop growing. If a person has a testosterone-dominated puberty, they’ll grow more before these harden than in an estrogen-dominated one, so the hypothetical intersex individual would likely end up shorter. \n\nHowever, the individual who never went through puberty at all would never have their epiphyses harden, so their limbs would keep growing, albeit quite slowly, and they could potentially end up taller. That said, several descriptions of historical examples describe them as short - this may be for diet-related reasons, though. \n\nI’d like to be able to say no one would perform orchi on a child, but that’s not true; surgical reassignment of intersex infants is still common practice in much of the Western world. However, this generally involves hormone replacement therapy. Children not going through puberty at all is a dead practice now, and has been since the advent of modern medicine, so we have very little hard evidence and hard records of how it ends up. \n\nAll that said, if you’re interested in the subject, it used to be done in the musical world. The practice declined in the early 1800s and had died out entirely by the 1860s, when it was banned in Italy. However, a small handful of recordings survived; Alessandro Morechesi’s recording of Ave Maria is worth looking up! \n\nTl;dr: if they go through estrogen puberty, they’ll be shorter. If they don’t go through puberty at all, they’ll probably be shorter, but on a purely theoretical level may be taller. ",
"Part of my Music History classes in college talked about Opera during the time that castrati were particularly common.\n\nYoung boys before their voice change would keep their high voice but with the thick and broad timbre of male vocal folds.\n\nCastrati are also talked about in general having both masculine and feminine features. They would be slim and light of frame, but tall and very long-limbed. Likely as a result of the biological processes talked about in other comments.\n\nAs to desiring sex, we get to a weird spot.\nRecords show that during that time, we begin to see the idea of \"gender as a spectrum\", with the *center* being the most ideal. Angels in scripture were described with neither or both genders' traits, so the castrati were seen as the closest mortals could get to godliness. Letters and records from nobles at the time also talk about how much status and renown one received for having had a sexual encounter with a castrati, Lords and Ladies alike."
]
}
|
[] |
[] |
[
[],
[],
[],
[
"https://www.amazon.com/The-Castrato-Reflections-Natures-Lectures/dp/0520279492"
],
[],
[],
[]
] |
|
avqlqg
|
what does serotonin do exactly and how does it work?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/avqlqg/eli5_what_does_serotonin_do_exactly_and_how_does/
|
{
"a_id": [
"ehgzvno",
"ehhiq63"
],
"score": [
4,
2
],
"text": [
"Low serotonin levels have been linked to depression. Serotonin is an important chemical and neurotransmitter in the human body. It is believed to help regulate mood and social behavior, appetite and digestion, sleep, memory, and sexual desire and function.\n\nHere’s a definition. ",
"Whoever is able to answer this question in detail will probably win a Nobel prize. We understand some of the broad strokes of how neurotransmitters work but it is becoming more and more clear that there is a great deal of complexity that we don't understand yet."
]
}
|
[] |
[] |
[
[],
[]
] |
||
hkmcp
|
How long do germs "live" to pose a health threat? Suppose I get some toilet-water splash-back, will the germs that might be on the floor live for a really long time?
|
askscience
|
http://www.reddit.com/r/askscience/comments/hkmcp/how_long_do_germs_live_to_pose_a_health_threat/
|
{
"a_id": [
"c1w4h3c"
],
"score": [
7
],
"text": [
"It depends on the organism. Most die relatively quickly. It can range from minutes up to centuries for spores. "
]
}
|
[] |
[] |
[
[]
] |
||
9ls8ms
|
If female babies are born, on average, with 2,000,000 eggs, then why do they go through menopause. Dont they only excrete one egg a month after puberty?
|
In 2018 the average life expectancy of a female is 84 years. On average, girls start thier menstrual cycle at age 12 and start menopause at age 51. That leaves 39 years of menstruation. If each year has 12 months, then, on average, each female has 468 menstrual cycles. If, from what I've been taught, every female loses one egg every month, then why do they go through menopause at 51?
|
askscience
|
https://www.reddit.com/r/askscience/comments/9ls8ms/if_female_babies_are_born_on_average_with_2000000/
|
{
"a_id": [
"e7bad85",
"e7dvh8z"
],
"score": [
15,
8
],
"text": [
"Because women lose many more eggs than the ones they release during ovulation. Roughly 11,000 eggs die every month before to puberty. A women will only have a few hundred thousand eggs remaining by the time she reaches her mid teens, and from that point on, roughly 1,000 egg die each month without ever making through the ovulation process. ",
"I know this is a day old but no one has given you a very good answer. The reason is that the follicles, each which contain a single undeveloped egg, are being constantly 'recruited' in batches, which means that they go from being dormant, to developing. However only one of the follicles in the batch will ever develop a mature egg, the others play a supporting role, for example producing hormones. After several weeks after being recruited, the 'chosen' egg in that batch will be mature and ready to be ovulated. However it will only be ovulated if the hormone balance is right, ie the woman is at the right part of her cycle. If so, the egg is ovulated, if not, the follicles are all reabsorbed, ie die. Remember I said follicles are being constantly recruited? That means that the batches of eggs are developing constantly throughout the menstrual cycle, and different eggs will be reaching maturity at different times, but only the one that is mature at the right time will be ovulated, with hundreds of others never being ovulated. This even happens during pregnancy, eggs continue to be recruited, but the hormone balance will never be correct for ovulation, due to the presence of the feotus. So as you can see from an egg point of view the entire process is rather wastefull! But as I said, the follicles containing the eggs are needed to produce hormones is order to drive the correct hormonal cycling, so its not pointless. The process also ensures that there will be a mature egg ready to be ovulated as soon as the hormonal environment is right. "
]
}
|
[] |
[] |
[
[],
[]
] |
|
jnkgu
|
why smoking cigarettes is bad for you?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/jnkgu/eli5_why_smoking_cigarettes_is_bad_for_you/
|
{
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"text": [
"Cigarette smoke contains many poisons that damage your lungs (which are crucial for breathing) and other important body parts",
"It's only bad for you physically.\n\nIt's fantastic from a psychological point of view. ",
"- Nicotine is addictive and by nature *bad*\n\n- Many of the ingredients in a cigarette are straight up poison, as mentioned by Samicom, which have different effects on the smoker, almost all of them are only made to get the user buzzed\n\n- Smoking can eventually cause a controlling grip on the user, which usually settles right around the time the user begins saying \"I need a cigarette\" for the first time. It becomes a habit. A necessity. The hand motions pulling in and out several times a day become familiar to the brain and also make it normal. This makes quitting harder.\n\n- The list goes on. Tooth and gum decay/bad breath, dirtying the inside of a car....there are way too many side effects that are just plain awful. You know, like cancer.",
"It's a bit difficult to read, but [this](_URL_0_) should answer your question.",
"Cigarette smoke contains many poisons that damage your lungs (which are crucial for breathing) and other important body parts",
"It's only bad for you physically.\n\nIt's fantastic from a psychological point of view. ",
"- Nicotine is addictive and by nature *bad*\n\n- Many of the ingredients in a cigarette are straight up poison, as mentioned by Samicom, which have different effects on the smoker, almost all of them are only made to get the user buzzed\n\n- Smoking can eventually cause a controlling grip on the user, which usually settles right around the time the user begins saying \"I need a cigarette\" for the first time. It becomes a habit. A necessity. The hand motions pulling in and out several times a day become familiar to the brain and also make it normal. This makes quitting harder.\n\n- The list goes on. Tooth and gum decay/bad breath, dirtying the inside of a car....there are way too many side effects that are just plain awful. You know, like cancer.",
"It's a bit difficult to read, but [this](_URL_0_) should answer your question."
]
}
|
[] |
[] |
[
[],
[],
[],
[
"http://www.tricountycessation.org/tobaccofacts/images/partsofcigarette.gif"
],
[],
[],
[],
[
"http://www.tricountycessation.org/tobaccofacts/images/partsofcigarette.gif"
]
] |
||
620nm1
|
how people can be spiritual and not religious.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/620nm1/eli5_how_people_can_be_spiritual_and_not_religious/
|
{
"a_id": [
"dfiqujh"
],
"score": [
2
],
"text": [
"It's like being able to believe in something bigger than yourself, without all the crazy garbage that comes along with it. A belief in 'god' without necessarily believing in a burning bush or walking on water, being spiritual is having a general faith without having all the craziness about the religion dictated and shoved down your throat. "
]
}
|
[] |
[] |
[
[]
] |
||
4or9iy
|
starting from where you are, travelling in a straight line in the universe at the speed of light for 13 billion years, and then doing a 180 to go back to the point you started, would you get there in 13 billion years and would it be the same spot you left from?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/4or9iy/eli5starting_from_where_you_are_travelling_in_a/
|
{
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"score": [
2,
3
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"text": [
"Well, seeing as nothing would actually stand still while you're travelling, no. \n\nThink of it this way - if you go outside and point something at the moon which will then travel in that straight line at 100MPH... it will likely never each the moon, because the moon hasn't just stood still for that entire time. ",
"No, because space itself is expanding, so the distance you covered in the first 13 billion years would be smaller than what becomes of the same distance over the second 13 billion years."
]
}
|
[] |
[] |
[
[],
[]
] |
||
2io3y9
|
how do people manage to hack scores on iphone game leaderboards?
|
It seems like every time I look at leaderboards, even for very unpopular games, there are several hundred legitimate scores that are steadily better and better, there is a huge jump up, and the top ten or so have ridiculous, unachievable scores.
Lots of commas.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2io3y9/eli5_how_do_people_manage_to_hack_scores_on/
|
{
"a_id": [
"cl3uepo"
],
"score": [
2
],
"text": [
"Depends on how the leader-board is implemented. Varies case by case. Generally going to be an oversight in programming by the game devs that allows arbitrary scores to be reported, or a flaw in the game that allows for points to be gained when they shouldn't be. "
]
}
|
[] |
[] |
[
[]
] |
|
1swieb
|
why does cheese 'sweat'?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1swieb/eli5_why_does_cheese_sweat/
|
{
"a_id": [
"ce1ympg"
],
"score": [
15
],
"text": [
"The 'sweat' is actually oils from the cheese.\n\nThink of the cheese like a sponge holding in water. When its freezing, the water stays in the sponge. When it thaws, the water starts leaking out.\n\nOil has a different boiling and freezing temperature than water. When you keep cheese in the refrigerator, the oils stays in the cheese easier (Although is may sweat a little over time). When you take it out, the oils start leaking out. However, because oil evaporates much more slowly than water, the oils tend to just sit on the surface of the cheese."
]
}
|
[] |
[] |
[
[]
] |
||
on6hw
|
Can someone explain why big bang theory is not an explanation of the creation of the universe but rather only the expansion
|
Also what are some theories of the creation of the universe?
|
askscience
|
http://www.reddit.com/r/askscience/comments/on6hw/can_someone_explain_why_big_bang_theory_is_not_an/
|
{
"a_id": [
"c3iiwmj",
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],
"score": [
2,
3
],
"text": [
"First cause is an unanswerable question; the big bang theory merely explains what happened after the big bang, not what caused the matter to be there in the first place. ",
"It is not the goal of science to explain creation. Science wants to explain observable phenomena. We observe expansion, the Big Bang theory explains that. It is not like some scientist sit down on a Monday morning and decide that they should try to explain where everything came from.\n\nSome people do hypothesize about possible solutions to current problems in cosmology which may imply some sort of Big Bounce scenario, but that is currently all speculation."
]
}
|
[] |
[] |
[
[],
[]
] |
|
b6srwu
|
what is radioactive fallout and why is it so dangerous?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/b6srwu/eli5_what_is_radioactive_fallout_and_why_is_it_so/
|
{
"a_id": [
"ejmwv7d",
"ejmzmzq"
],
"score": [
5,
4
],
"text": [
"In a nuclear explosion or fire involving nuclear materials, radioactive particles gets thrown into the atmosphere and the fallout is when the radioactive particles fall back to earth.\n\nIt's dangerous because it is airborne (breathing in radioactive material is very hazardous) and is nearly impossible to contain.",
"When a nuclear bomb (or any other fission reaction) blows up, the \"ashes\" of the fission reaction are a mixture of different elements, most of which are anywhere from medium radioactive to extremely radioactive. (The more radioactive, they faster they decay, making the radioactivity goes away)\n\nIf a nuclear bomb blows up high in the air, most of the radioactivity will dissipate up in the atmosphere. However, if it blows up near enough to the ground (with the fireball touching the ground), bits of sand and dirt will get coated with radioactive elements. It will then *fall out* of the sky and become... fallout. This is more dangerous because a large area downwind of the nuclear explosion will be coated with highly radioactive dust. However, after some weeks, the radiation is much diminished. It's a total myth that nuclear bombs make the landscape deadly radioactive for years or centuries, unless they are deliberately set up to make the most radiation possible. "
]
}
|
[] |
[] |
[
[],
[]
] |
||
9j4hmd
|
What happens if an electron on the "outermost orbit" of an atom absorbs energy (dunno if this is physics or chemistry) ?
|
Hello, I m not a native english speaker, and in my native language i couldn t find anything on this (or didn t know what i was looking for). (Also, there was something about energy levels, but the orbit thingy in the title sounds better than saying "what happens when electrons with the highest energy level absorb energy"). Anyhow, since i didn t have any chemistry class since 5 years and in my new (apprenticeship? Training? Some sort of school where i learn a job, anyway) we began with pretty basic stuff, like atomic models. My question is, since electrons "jump up" if you make them absorb energy, what happens if you do that to electrons which cannot jump, since there is no further energy level
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askscience
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https://www.reddit.com/r/askscience/comments/9j4hmd/what_happens_if_an_electron_on_the_outermost/
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"text": [
"Strictly speaking, there is no highest bound orbital. But the level density becomes very high at high excitation energy, and the energies of bound orbitals are bounded above. If you give an electron enough energy, it will just transition into a continuum state, where it is no longer bound the the atom. In simple terms, you just knock the electron out of the atom, and it moves freely away."
]
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174uto
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kugelblitz & event horizon
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I have virtually no knowledge of astrophysics (or whatever field this would be classified in) but recently heard these terms in a video, and became very confused.
Would really appreciate if someone could explain these to me while I have no background in the field.
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explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/174uto/eli5_kugelblitz_event_horizon/
|
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"An event horizon is a boundary in space across which two things can't affect each other.\n\nHere's a room with a chair and a lamp. The lamp's controlled by a switch on the other side of the door, outside the room. I want you to go into the room and sit down, and when you see the light come on, I want you to say the word \"banana.\"\n\nWe've just established what scientists call a \"causal relationship\" between you and me. At some point, whenever I decide to, I'm going to flip the switch. Electricity will start flowing down the wires, eventually reaching the lamp. The electricity will heat the bulb causing it to start emitting visible light. The light will move across the room to your eyes, where it'll tickle molecules in your retinas that give you the sense of sight. When you see the lamp come on, you'll say \"banana.\"\n\nEach of those steps takes time. When I flip the switch, the lamp won't start emitting light *instantly.* It'll take time for the electricity to reach the bulb. Not a *lot* of time, mind you, cause the distance the electricity has to travel is very short. But still, it'll take a little time. Similarly, you won't see the light from the lamp the instant it starts coming out, because it takes time for light to cross the room and enter your eyes.\n\nThe important point here is that my flipping the switch *must come before* your saying the word \"banana.\" The two things cannot happen at the same instant. The effect can follow the cause so quickly that it's *essentially* instantaneous — as would happen in this case — but it can't ever be exactly instantaneous. There will always be a minimum time that must elapse between a cause and its effect.\n\nNow … what is that minimum time? Obviously it varies, depending on how the cause causes the effect. If I told you to say \"banana\" when you catch the ball I'm about to throw at you, you can't say \"banana\" any faster than the time it takes for the ball to move through the air from me to you. But there's still an absolute minimum, can't-ever-be-faster amount of time that has to elapse between my cause and your effect. That absolute minimum time is set by the speed of light. Nothing can move between two points any faster than the speed of light, so nothing I do *here* can ever cause an effect *there* in any less time than the time it would take for a ray of light to get from here to there. The closer we are to each other, the less time it takes for light to get from me to you, meaning the minimum possible time for me to affect you is smaller.\n\nCause-and-effect, then, is intrinsically related to time, and time is intrinsically related to space. Whether two events have have a \"causal relationship\" to each other depends on how far apart those events are in time (how much time elapses between them, that is) and how far apart they are in space.\n\nIf you pick two events that are quite close together in time but quite far apart in space — say, one second apart in time but a quarter of a million miles apart in space — those two events *cannot* have a causal relationship. Because a ray of light can't get from the first point to the second point in so short a time. If you either pick a *closer* point, or pick a point that's the same distance away but that happens later, then those two events can have a causal relationship.\n\nAn event horizon, basically, is the dividing line between events which can have a causal relationship and events which can't. If two points in space and time are sufficiently close together in space that a ray of light can get from one to the other in less time than the time between those two points, then those two points can have a causal relationship. If they're farther apart in space than that, or else closer together in time than that, then they can't have a causal relationship; one of them is \"over the horizon\" from the other, and you can't get there from here.\n\nMost of the time when people talk about event horizons, they're talking about black holes. A black hole is a hellishly complex thing, and I won't try to explain it here. But suffice to say that black holes are surrounded by event horizons. Nothing outside the event horizon of a black hole can ever affect anything inside the event horizon.\n\nA \"kugelblitz\" is a long-discredited hypothetical idea from physics. The original idea was that it might be possible to put enough light into a small enough volume for a black hole to form there. Later this idea was extended to any kind of energy in the electric field (since light is just one particular type of electric energy). But this idea turned out not to be correct. As we came to understand more about quantum mechanics, we learned that if you put a lot of energy into the electric field, that energy will tend to \"leak out\" through something called pair production. Basically, when there's enough energy in the electric field at one point, it becomes possible for that energy to spontaneously transform itself into matter. Particles pop into existence at that point and radiate away, carrying energy out of the electric field as they go. So it isn't possible to put enough energy into the electric field in order to make a black hole; the energy in the field will radiate away long before that happens."
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1rhuaj
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will watching porn in the uk be illegal or just harder to access?
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explainlikeimfive
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http://www.reddit.com/r/explainlikeimfive/comments/1rhuaj/eli5_will_watching_porn_in_the_uk_be_illegal_or/
|
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"Come to Scotland, we're voting on independence soon and can't wait to tell Cameron to fuck off.",
"Harder to access.\n\nTo dispel a common myth, you probably won't have to actually call up the ISP in most cases (although it will vary between ISP's).\n\nIn the internet settings page that ISP's provide, there will be a box asking if you would like pornographic material to be blocked. That box will by ticked to 'yes' by default. If you login to the settings page and untick the box, you'll be able to watch all the porn you want.\n\n(Source: _URL_0_)",
"If the government's involved, expect it not to work anyway."
]
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"http://www.bbc.co.uk/news/technology-23403068"
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335wtz
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what is the difference between negative symptoms of schizophrenia and depression
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Hello friends in /r/explainlikeimfive/. Honestly at first I am a patient diagnosed with schizophrenia in February 2014. I had been hospitalized but now is stable and recovering, taking medicine (antipsychotic) daily. Actually I don't think I experienced the so-called "negative symptoms" at most of the time. But in recent weeks I find my mental condition seems is changing. I find myself have to take antidepressant (currently venlafaxine, without prescription) to alleviate recurring drowsiness and lack of motivation caused whatever by drug or by health. The doctor still treat me as a schizophrenia patient tough, but I will discuss this situation soon (in 4/24) with him.
So my questions now are: What at all is the difference between negative symptoms of schizophrenia and depression? Is negative symptoms of schizophrenia related with depression? And am I probably experiencing depression or negative symptoms of schizophrenia?
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explainlikeimfive
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http://www.reddit.com/r/explainlikeimfive/comments/335wtz/eli5_what_is_the_difference_between_negative/
|
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"I guess you removed and posted your question again, so I'll re-post my original reply:\n\nA lot of the negative symptoms of Schizophrenia do share similarities with depression (e.g. social withdrawal, loss of motivation and interest in activities, etc.) and many people with schizophrenia may be found to have depression.\n\nMost people who have depression don't start developing speech problems though, but impoverished speech is a relatively common negative symptom of schizophrenia (i.e. where your speech becomes difficult for others to understand and make sense of).\n\nAlso, people who are depressed don't necessarily have flattened affect (i.e. loss of emotion). They may have mood swings where they are angry or irritable, for example, but only people with severe depression start losing emotional feeling completely. It's not uncommon though for people with schizophrenia to experience complete emotional flattening (where there is almost no sign of emotion or personality)."
]
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49j9q4
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why are there weight classes for boxing? i understand people at lower sizes face disadvantages, but isn't intervening in this comparable to having height classes for basketball or swimming events?
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[deleted]
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explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/49j9q4/eli5_why_are_there_weight_classes_for_boxing_i/
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"text": [
"Basketball kind of does. Each position is a height and weight differential. A 7 footer can't be a point guard and so forth.",
"It would be, if all that was being taken into account was the victory itself.\n\nWhen you're talking MMA or Boxing a 100 pound difference (100 pounds of muscles, mind you) usually means a very onde sided event where one person get the shit beat out them, and might be hospitalized or even die from it. The reason it only exists in fighting is because an unfair advantage on a sport like this could mean serious injury to the smaller dude.",
"The reason is that in boxing (and other fighting sports) muscle mass is way more important than technique, so people with good technique have no chance against people in higher weight classes (as opposed to just a disadvantage). The advantage is so extreme that a legless dude has been the state wrestling champion somewhere - it's *more of an advantage* to lose your legs and squeeze into a lower weight class than to, well, have legs.\n\nOf course, we do have mens and women's sports, and varsity, junior varsity, and intramural, so there are similar ideas.",
"If you've ever fought/wrestled/weight lifted in competition, you'd realize VERY quickly that a weight advantage is almost insurmountable.\n\nWeight is muscle. It's power. It's strength. It's inertia. Taking on someone more powerful than you are is an incredible task. Taking on someone nearly the same size makes for a fair and entertaining competition.\n\nBasketball is not a contact sport, it's not 1-on-1. A small and fast player can beat a larger player, and vice-versa. Everyone has a specialty, and they come together into a complimentary team. Size and strength won't change your ability to get a ball in a hoop or read movement and position yourself well, nor does it interfere in teamwork.\n\nFor swimming, larger bodies have more resistance. They might have more muscle, but they have more to overcome as well (same can be said of almost all track & field events, a big runner is disadvantaged against a lean runner). Again, it's not a 1-on-1 event, and there's no contact, they're competing against the same rules, conditions, and measurements as everyone else.",
"It has a lot to do with safety (which sounds strange, I know, when you're talking about an activity where two men get into a ring and poiund on each other). A 6'2,\" 250 lb. guy is very likely to do quite a bit of damage to an opponent who's 5'9\" and weighs only 170 lbs."
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3ewy5t
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What's the smallest a communications satellite can be?
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askscience
|
http://www.reddit.com/r/askscience/comments/3ewy5t/whats_the_smallest_a_communications_satellite_can/
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"Depends on what you mean by communications. I know someone who has done work with [CubeSats](_URL_0_) which are 10cmx10cmx10cm. They were running Android and broadcast on amature radio frequencies. \n\nIf you're thinking about something for transferring thousands of overseas phone calls, you're going to need something bigger with big fat solar panels so it has enough energy."
]
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"https://en.wikipedia.org/wiki/CubeSat"
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1l6h5e
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Why can my eyes adjust fairly quickly when I go from a dark place to a light one, but take a long time to adjust when I do the reverse?
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askscience
|
http://www.reddit.com/r/askscience/comments/1l6h5e/why_can_my_eyes_adjust_fairly_quickly_when_i_go/
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"text": [
"It's the photoreceptor portion of dark adaptation. The receptors (cones and rods) in your eye generate a photopigment which increases sensitivity to light in dim conditions, but these pigments are decomposed in bright light. It takes ~7 minutes for cones to reach maximum sensitivity and up to an hour for the rods. For me, I see this often when I'm woken up by my phone and have one eye open to look at it. The eye first gets fuzzy dark vision back after a few minutes and only much later can I see in full detail.\n\nThere are physical and neural changes too, but those should occur instantly compared to the chemical changes. ",
"There's two moving parts to consider here:\n\n1. Your pupils (the openings that let light into your eyes)\n2. Your photoreceptors (cells that line your retina at the back of your eye; it's their job to convert light into signals that get passed on to your brain).\n\nBoth of these take a little time to adjust to new circumstances, but the speed of adjustment (and the consequences of not being adjusted) differ.\n\nYour pupils can adjust pretty quickly- often taking less than a second to reach the right diameter.\n\nThe photoreceptors themselves have essentially two states. Photoreceptors that have not been exposed to light recently are ready to fire a signal. Photoreceptors that *have* been exposed to light recently are not ready to signal, and they take really surprisingly long (on the order of minutes) to reset themselves back to the ready state.\n\nSo let's go through the sequence of events when you go from a dark room to a light room:\n\n1. Your pupils adjust within a second, contracting to let less light in.\n2. Your photoreceptors are already ready to fire! You're good to go.\n\nBut when you go from a light room to a dark room:\n\n1. Your pupils adjust within a second, expanding to let more light in.\n2. Your photoreceptors, having been recently exposed to light, take a few minutes to get ready to signal again.",
"I have a somewhat related question, I heard that women tend to see better in the dark than men do, is this true?",
"I have a related question, when I go from dark to light very quickly the light hurts my eyes. Can my eyes be damaged by exposing them to a bright light suddenly? Like if I were in a pitch black room for several hours and then walked outside where it is sunny while keeping my eyes open. ",
"The top comment here does a good job of explaining the \"how\" of adjusting to light more quickly than adjusting to dark, but not they \"why.\"\n\nRemember that organisms tend to have the capacity to do the things that help them live longer; that's just the result of natural selection driving evolution. So why does it take you longer to adjust to darkness than to light? \n\nThe best answer I've found is that over the millions of years that land mammals, and our ancestors, have been evolving, there was very little need to adjust to darkness quickly. After all, darkness tends to appear very slowly, with the setting sun. This was not always the case, of course, but it usually was. So no need, so no adaptation. Light, however, appears every time you open your eyes and it's light out. So it makes sense that eyes evolved in this way over time. Being able to see your surroundings quickly certainly makes your chances of surviving, and hopefully reproducing, higher than individuals who cannot. We are the beneficiaries of that, but now we have artificial lighting to change the equation. \n"
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mre2h
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Do particles on a spinning disk experience time dilation?
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Suppose I have a disk which is a meter in circumference, and I spin it up to 149,896,229 rotations/second. Now if we put a clock on the edge of that disk while it was spinning, would it run slower then an ordinary clock sitting on the wall?
What if I went smaller, what if I made a device that took a single atom and just rotated it in place at a ridiculously high speed, would it experience time dilation even though it wasn't moving anywhere?
|
askscience
|
http://www.reddit.com/r/askscience/comments/mre2h/do_particles_on_a_spinning_disk_experience_time/
|
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"Yes. This was tested when they flew two atomic clocks in opposite directions around the Earth, and is important for calculating positions using GPS satellites.",
"Yes. This was tested when they flew two atomic clocks in opposite directions around the Earth, and is important for calculating positions using GPS satellites."
]
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[],
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4bvyia
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why we can't have surgery when the blood pressure is high? and also isn't it possible to decrease the pressure by draining some blood?
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explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/4bvyia/eli5why_we_cant_have_surgery_when_the_blood/
|
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"Having high blood pressure increases the risk of a cardiovascular event happening during surgery. The anaesthetist will judge how comfortable she is with managing that risk, if the risk is judged too high then surgery will be postponed. \n\nAs to lowering blood pressure through bleeding, the cardiovascular system is set up to keep blood pressure at a constant at the expense of blood volume. This means if you lose blood the vessels will contract to keep pressure up. This situation breaks down when you get to very low blood volumes, at this point the blood pressure starts to fall rapidly. ",
"High blood pressure is rarely a reason to delay a surgery. \n\nElective procedures may be delayed due to high blood pressure to reduce the chance of complications (such as heart attacks, strokes, or medication interaction and adverse reactions) as many anaesthetics have the side effect of increasing blood pressure. \n\nDuring any procedure an anesthesiologist will monitor the patient's vital signs and administer corrective drugs accordingly. The main idea is that if they do not have to do the surgery, why not want until a time when the patient requires less drugs in their system and the surgery would be safer. \n\nHave a great day! :-) \n\n"
]
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6ds027
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How did the kings/Queens of England 'lose' their powers?
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My assumption is that a couple of hundred years ago the monarch was all powerful, but now they have exactly zero real power.
How did that change happen?
Was it a set of small changes of certain privileges/laws that eventually allowed for the removal of all the powers?
Or was it a deliberate change, (maybe instigated by the monarchs themselves).
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/6ds027/how_did_the_kingsqueens_of_england_lose_their/
|
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"I can chime in concerning the Stuart Crown, which ruled over Britain during the 17th century. During this period, the monarch not only lost certain powers and privileges, but was periodically abolished altogether. It is an incredibly complex period, and subject to much revision, in which political, religious, economic and social disagreements between King and Parliament eventually led to civil war and execution of Charles I. However, I will try to focus on the on the conceptual conflict behind this period, as an explanation to your question. \n\n\"Why\" Kings and Queens lost\" their power is a great question. In the case of the Stuarts (James I, Charles I, James II and Charles II), it was certainly not a deliberate change on behalf of the monarchs. It is also worth noting that they were not \"all-powerful.\" Certainly, the Stuarts retained prerogative powers during their rule, which theoretically allowed them to rule without impunity. However, in practice, this was not the case. Parliament maintained its own authority as a constitutional body, and was not afraid to question royal authority. \n\nI think it is important to understand how and why Kings and Queens ruled with absolute authority. To summarize briefly, the King ruled by divine authority, which is supreme above all institutional powers and laws. So, he can, by that logic, carry out policies and laws without earthly consequence. After all, he is only answerable to God. However, the idea that he rules by divine authority becomes complex, and contentious for that matter, in conjunction with Parliamentary institution. Indeed, how can a King retain absolute power while having to remain within the confines of civil law? As such, the Stuart Kings largely operated in a grey area concerning their absolute power. For example, James I tried and executed Guy Fawkes by using the Star Chamber, an arbitrary court which operated under royal prerogative. However, given the context of the offense, trying to blow up Parliament, no one questioned his authority in doing so. Conversely, when Charles I used the same court to controversially mutilate dissenters as a punishment for printing 'seditious' works, he was met with stark opposition within Parliament which eventually led to the abolition of the Star Chamber itself. Yet, if we examine the two cases, both were perfectly within their right, under royal prerogative, to employ the Star Chamber. As such, a key part of how the Stuart Monarchy lost certain privileges and eventually collapsed is that, when examined in depth, the relationship between an absolute monarchy and a constitutional parliament is problematic. \n\nThus, to answer your question in part, a couple of hundred years ago, the Stuart Monarch was not \"all-powerful\" in practice. In fact, a great deal of tact was needed to employ the presumed absolute power of monarchy without butting heads with Parliament, as the above example illustrates. Charles I made the fatal mistake of presuming and acting as if he had absolute authority, which in short, led to a civil war and his eventual execution. This is a broad, and incredibly in-depth question, so I would happily answer further questions concerning the Stuart Crown. For further readings, I would consult works by Tim Harris, particularly Rebellion. Additionally, Woolrych, Britain in Revolution, is another key work and incredibly in-depth. Other authors that I highly recommend are Mark Kishlansky and David L Smith."
]
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bwlqwc
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why do so many low-quality youtube videos loop over from the beginning midway through the video?
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Is it some sort of way to escape copyright infringement? Some quirk of a video recording software?
Do people do it intentionally, to pad the length of the video? Why, what does that accomplish? I've seen it even for videos that show part1 part 2 of some old TV show for example. Each part plays twice.
Sometimes the looped-over second run doesn't have sound.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/bwlqwc/eli5_why_do_so_many_lowquality_youtube_videos/
|
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"To pad the runtime and try to make more revenue. Longer videos = more money. 10 min YouTube videos make the most per ad click for the time they are. Short videos don’t make as much. \n\nLonger videos make more money than shorter videos, given they have the same number of subscribers and views. \n\nSolved!"
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9ukkxp
|
can someone really o.d. from potassium, and if so, how much would someone have to have to cause negative side effects?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/9ukkxp/eli5_can_someone_really_od_from_potassium_and_if/
|
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"Your blood is at a constant level of sodium, potassium and calcium. Cells require this constant level (in a certain range) to function properly. Outside of this range, you get funky effects like your nerves misfiring, or your muscles not working properly. The most dangerous is when it affects your cardiac muscles, which can cause your heart to beat in a rhythm that's not good for pumping blood, and can even cause it to stop.\n\nYour potassium is normally 3.5 - 5 mmol/L of blood, and levels higher than 6.5 mmol/L of blood are considered to be severe hyperkalemic (severely high potassium). The LD50 for potassium in a rat is 2600mg/kg, assuming a 70kg normal male, that's 182grams of potassium ingested to kill him (50% of the time).",
"The LD50 (the dose that'll kill 50% of people) for potassium is 2.5 grams per kilogram of body weight. For a 80kg person, that is 200 grams.\n\nA banana contains around 0.8 grams of potassium. If a 80kg person were to eat 250 bananas, they'd have a 50% chance of dying.\n\nHowever, the body naturally excretes potassium. Assuming you're well-hydrated and very healthy, your kidneys can filter out around 18mg of potassium per kg of body weight each hour. Our 80kg person would be reducing their potassium by 1.4g per hour, meaning that each hour you lose nearly 2 bananas worth of potassium.\n\nIf you managed to eat 1 banana every five minutes (and keep it all down), then after an hour you'd only retain 10 bananas worth of potassium, not 12. So, if you were to constantly eat bananas for 25 hours, non-stop, you would stand a good chance of dying from potassium intake."
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koicu
|
why ftl implies backward time travel
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I understand how FTL travel can imply forward time travel, but not backward.
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explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/koicu/eli5_why_ftl_implies_backward_time_travel/
|
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"text": [
"I fail to understand how FTL implies time travel in any direction.",
"it is a sci-fi show cliche for one thing... in theory, the faster you go, the slower time goes for you and it approaches zero as you get closer to the speed of light. So, based on that logic, if you go faster than the speed of light, you go into negative time. Supposedly, matter can't go faster than the speed of light and the energy required to even get close is huge.\n",
"Light is the fastest transmitter of information known to humans, and according to physicists this sets the whole stage for how events play out in forward time. Having a FTL postal service that can go faster than light it implies you can paradoxically receive a letter before it was sent, so you could stand next to your FTL mailbox and wait for a letter from your future self that reveals tomorrow's lottery numbers.",
"I fail to understand how FTL implies time travel in any direction.",
"it is a sci-fi show cliche for one thing... in theory, the faster you go, the slower time goes for you and it approaches zero as you get closer to the speed of light. So, based on that logic, if you go faster than the speed of light, you go into negative time. Supposedly, matter can't go faster than the speed of light and the energy required to even get close is huge.\n",
"Light is the fastest transmitter of information known to humans, and according to physicists this sets the whole stage for how events play out in forward time. Having a FTL postal service that can go faster than light it implies you can paradoxically receive a letter before it was sent, so you could stand next to your FTL mailbox and wait for a letter from your future self that reveals tomorrow's lottery numbers."
]
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xtaic
|
How did my juice become carbonated? I'm afraid to drink it now.
|
Here is the story:
-bought a bottle of V8 Splash Tropical Blend
-drove up to hike in the Sequoias
-car broke down and ended up keeping in the trunk at a repair shop for five days
SO the only altitude change it had was from like Fresno to whatever it is in the mountains, than it went from the 80-90ish degree weather to about 65-70 where I live. How the hell did it become carbonated?? This is crazy!!
|
askscience
|
http://www.reddit.com/r/askscience/comments/xtaic/how_did_my_juice_become_carbonated_im_afraid_to/
|
{
"a_id": [
"c5pdvpd"
],
"score": [
2
],
"text": [
"The heat in the shop frermented the sugar, its probably alcoholic too.\n"
]
}
|
[] |
[] |
[
[]
] |
|
5vs1ze
|
why does it seem that a typical blade of grass lives for years?
|
Yes, I know grass can die. But in a front yard, for example, the grass can remain green year round and for 10+ years. Does it not die simply from "old age" if no other factors are taken into account?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/5vs1ze/eli5_why_does_it_seem_that_a_typical_blade_of/
|
{
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],
"score": [
2,
3
],
"text": [
"Plants usually live for thousands of years where animals dont. We aren't 100% sure what causes death naturally however. That's the best I can give",
"Plants aren't alive in the same way as you or I. When a person or animal dies, it's usually because something stops working, usually the heart. Plants don't have organs though, at least, not in the sense that we understand them. That, coupled with the fact that they have extreme regenerative abilities (you can chop of the majority of a plant, but if just a part of the root survives, the whole thing comes back) means that a lot of plants are close to immortal."
]
}
|
[] |
[] |
[
[],
[]
] |
|
1wu3sc
|
would i be using more data setting up a hotspot and browsing reddit on my computer than just browsing reddit on my phone?
|
I have an iPhone and a Mac if that makes a difference. I feel like the answer is obvious
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1wu3sc/eli5_would_i_be_using_more_data_setting_up_a/
|
{
"a_id": [
"cf5e3fi"
],
"score": [
2
],
"text": [
"For the site itself there might be a tiny difference, if any..\n\nBut if you're browsing on a Reddit app made for your phone then you're likely to save data as it's going to be optimised for mobile.\n\nAlso, if you tether to the phone then who's to know what other requests are being sent out automatically (in the background for the most part) by the computer simply because it's got a network connection."
]
}
|
[] |
[] |
[
[]
] |
|
1cfujk
|
I've heard a lot of conflicting anecdotes and studies on the connection between violent video games and aggression, what do we KNOW?
|
Everything I've seen on Reddit thus far has been very dismissive of anything suggesting that there is a connection or correlation between the two. Many even claim that violent video games allow one to release anger, but I'm pretty sure the catharsis theory (taking it out on something/"venting some steam") isn't actually valid in the realm of psychology.
What I've learned is that exposure to aggressive material can give a kid a social script. See aggression - > more likely to be aggressive. The psychology textbook I've read is a little outdated and there has likely been new research since then.
Is this something we should actually take seriously or is my limited psychology education just plain wrong?
|
askscience
|
http://www.reddit.com/r/askscience/comments/1cfujk/ive_heard_a_lot_of_conflicting_anecdotes_and/
|
{
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"Please don't take me for a professional source - I am just a student who is currently studying History of Games as part of her major, as well as Game Theory.\n\nBut may I ask why are you restricting it to *video* games, rather than 'games' in general, including physical games such as various forms of the 'football' archetype, as well as physical prop games such as chess, hockey etc. In general, [this](_URL_0_) and similar readings are what I'm taking my definition of 'gaming' from and applying it to all forms of play - digital and physical.\n\nWhat I learned in my classes, or at least the structure with which they are presented, is that the theory behind games and the willingness 'to game' in general is universal, with video games being the latest form of the common pastime of the 'game'. The medium is very different from actual physical games, yes, but often than not, it is a cosmetic difference - for example, chess played physically and chess played digitally are the same game through different mediums.\n\nIn the chess example, of course that's a *direct translation* of a game into another medium, no different from a book being available as a digital book. I suppose you would be more interested in games made exclusively in the digital realm, aka fully fledged 'video games'.\n\nAgain however, I must ask why restrict to digital games, when there are the presence of violent and physical sports games around the world. For example, football, rugby, hockey, tennis etc. In some ways, they are not considered violent if played according to the rules, however we cannot deny the presence of violence within the sports in actual practice.\n\nIn those cases, have there been a thorough study whether or not there is a link between the aggression displayed in the players and in them outside of the field of the games? If so, is it linked to the nature of the games themselves, or to the physical exertion that is actually happening when these games are played? Comparing to their digital counterparts, does this same aggressive tendency also show? Or without the actual physical component that would cause actual biological changes during play, is there in fact *less* effects on the players of the digital game?\n\nHas there been equal studies on the effects of physical play compared to virtual play? Otherwise, what warrants more concentration and study on virtual play when the violence and actual physical aggression present in physical play has been accepted for millennia?\n\nI'm sorry if this muddies your question, but I've been studying gaming *as a whole*, and found that the division of physical and virtual play has been more often due to bias, rather than any actual reason why they should be categorized any differently. If one is studying whether virtual games have different effects on a person compared to physical games, that is fine. But for example, the idea of 'cathartic release' is accepted (and indeed, cited as a positive) with physical sports, and their universal cultural presence around the world has led to noone questioning their place in human society; yet often this same reason of 'cathartic release', is portrayed negatively when used for digital games, and I have to question why?\n\nEdit: Perhaps a more specific study would be; does a virtual interface and situation affect the brain differently, compared to learning it through physical means? How does kicking a ball in real-life compare to 'kicking a ball' virtually? Does shooting a man in real-life and shooting a man virtually register differently in the brain?\n\nAnd perhaps a final question would be - even if a correlation is found, is it to the extent that it is a cause for concern? Human society has survived with the existence of violent physical sports and games in various cultures and around the world. Injuries, deaths directly contributable to these sports still exist. Violence linked to these sports (for example the latest riot in Newcastle when their team lost to Sunderland) still exist. In the context of these games, it is accepted as the 'norm' - not desired and not common, but not unusual when they do occur. In the context of virtual games, actual direct death is not the 'norm' due to the lack of actual physical confrontation. \n\nIn that sense, isn't the potential/current influence of violent virtual games grossly overestimated in the context of how the human society continues to function with the presence and influence of truly violent physical games?",
"There are two large meta-analysis by Anderson et al done in 2001, and then again in 2010 as a follow-up.\n\n\"Violent video game effects on aggression, empathy, and prosocial behavior in eastern and western countries: a meta-analytic review.\"\nAnderson C.A. (2010)\n\nThe result abstract reads:\n\n**The evidence strongly suggests that exposure to violent video games is a causal risk factor for increased aggressive behavior, aggressive cognition, and aggressive affect and for decreased empathy and prosocial behavior. Moderator analyses revealed significant research design effects, weak evidence of cultural differences in susceptibility and type of measurement effects, and no evidence of sex differences in susceptibility. Results of various sensitivity analyses revealed these effects to be robust, with little evidence of selection (publication) bias.**\n\n**EDIT:** I also found some criticism against Andersons studies, that might be of interest:\n_URL_2_\n\n**EDIT2:** Even more criticism of Andersons research\n_URL_0_\n**EDIT3:** Some more criticism of Andersons research: Block, J., & Crain, B. (2007). Omissions and Errors in \"Media Violence and the American Public\". American Psychologist, 62(3), 252-253. doi:10.1037/0003-066X.62.3.252\n\nDepending on your school of psychology, there's a number of different explanations for this.\n\nI'm prone to accept the social-cognitive explanation of \"observational learning\" - meaning that regardless of reinforcement, punishment etc, people will learn just from observing others. You've probably heard of Banduras experiment with \"Bobo the doll\". \n\nBandura, A. Ross, D., Ross, S.A (1961). Transmission of aggression through the imitation of aggressive models. *Journal of Abnormal and Social Psychology*, 63, 575-582\n\nI might be biased though, as I prefer soc-cog explanations to most things, they account for so many outer, inner and cognitive factors, that other perspectives just don't come close too. \n\n\nThen again, what you have to remember that most kids some time in their life is probably going to play violent video games, and very few are actually violent. This might mean that there's some mediating factors/variables we need to account for. Especially violent/aggressive kids are more drawn to violent video games, which in turn makes them even more aggressive. This is what Bandura, again, would call reciprocal determinism.\n\n_URL_1_\n\nHere's a picture of the model. \n\nThe environmental factors might for example be aggressive parents (observational learning), and violent video games.\n\nThe personal factors might be a biological proneness to aggression, neurobiochemicals, certain kind of schemas for dealing with trouble - for example someone annoying the child. Everything that happens inside the kid basically. \n\nThe behaviour is the outcome of these two factors, and in turn, influences the other two factors. \n\n\nThese three factors, behaviour, personal factors and environment interact in other words, and may be the basis for an explanation to why some kids get violent, and some others don't when growing up playing violent video games. You have to remember that these studies only deal in comparing means of groups, and can only say something about a group, not an individual. \n\n",
"I am curious what the difference is between frustrating games and violent games. I think frustrating games would probably be far more psychologically damaging. Probably any frustrating activity would be the same."
]
}
|
[] |
[] |
[
[
"http://nideffer.net/classes/270-08/week_01_intro/Caillois.pdf"
],
[
"http://www.reddit.com/r/askscience/comments/1cfujk/ive_heard_a_lot_of_conflicting_anecdotes_and/c9gebeu",
"https://wikispaces.psu.edu/download/attachments/41095606/Slide2.JPG?version=2&modificationDate=1267291569000",
"http://www.ncbi.nlm.nih.gov/pubmed/20192554"
],
[]
] |
|
1b1095
|
why can nfl players "walk away" from contracts?
|
Isn't the point of, say a five-year contract, to ensure that the player stays for those five years?
It seems like players (e.g. Revis) are able to just hold out without penalty until the team either renegotiates or cuts the player.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1b1095/eli5_why_can_nfl_players_walk_away_from_contracts/
|
{
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"c92lqae",
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"text": [
"Players who hold out pay a fine for each week they miss, the fine is a set rate and isn't chump change, so generally only the star players can afford it. They also of course do not get paid for any missed time. \n",
"If a player is under contract, they will suffer serious penalties if they hold out. One player, Ashley Lelei, actually *lost* money, because the penalties exceeded his salary, he had to pay the team to come back."
]
}
|
[] |
[] |
[
[],
[]
] |
|
4l1icq
|
I was told that a sword purchased in the medieval era would cost the equivalent of a million pounds in today's money, is this true?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/4l1icq/i_was_told_that_a_sword_purchased_in_the_medieval/
|
{
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"d3jkkeh"
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],
"text": [
"No, not unless it was jewel encrusted and basically ceremonial. According to [this website]\n(_URL_1_) a basic peasant's sword was 6 pence in 1340. Using an [inflation calculator](_URL_0_), the range it could be worth is pretty impressive but on the very highest end, you still get £910 - a far cry from a million. More likely, it would be the equivalent of £340.\n\nNow, of course, this is for a peasant sword which would be pretty basic and rudimentary (think \"off the shelf\" today versus \"bespoke\"). A nobleman's sword would be a great deal more - upwards to £10,000 - with most costing about half that or less. Still, not anywhere near the million mark. :-)"
]
}
|
[] |
[] |
[
[
"https://www.measuringworth.com/ukcompare/relativevalue.php?use%5B%5D=CPI&use%5B%5D=NOMINALEARN&year_early=1340&pound71=&shilling71=&pence71=6&amount=0.025&year_source=1340&year_result=2016",
"http://www.luminarium.org/medlit/medprice.htm"
]
] |
||
ft9l1w
|
how do endangered species who successfully reproduce in zoos / captivity help the population in the wild?
|
Edit - I broke rule 6, so I reposted with out the question.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/ft9l1w/eli5_how_do_endangered_species_who_successfully/
|
{
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"Zoos have special training programs for baby animals. They have the animals forge/hunt for food in a bit of a simulated habitat before releasing them to the wild. For species that tend to live in groups, the zoos often locate nearby groups to release the baby animals near. This allows the animals an extra chance to learn to live in their natural habitat.",
"For endangered species, it is sometimes very difficult to find a mate (because there are so few of them) and to have healthy offspring (because of inbreeding). \n\nZoo’s are a great help because their reproduction programs tackel both these issues. Unfortunately, animals are hardly ever released back into the wild. But if you measure the success of a species by their numbers, zoos are a huge boost for the endangered ones.",
"In several ways. The first is education. Someone may come in to see the rare baby orangutan, but a keeper comes up and talks about palm oil and how deforestation to get this palm oil is making orangutans go extinct. You feel bad for the cute baby apes and buy sustainability sourced snacks instead, \n\nThe second is release to the wild. In the northwest, the black footed ferret was thought to be extinct. They discovered a few individuals, however. Zoo breeding programs worked together and the black footed ferret has greatly increased in numbers. This is probably the answer you were looking for. The zoos may also give their captive bred endangered species to programs in their native countries so they can breed there and be released. \n\nThe third is by supplying other zoos. This one doesn’t seem as relevant anymore, but it is. A few decades ago, many animals in zoos were taken from animals. Every animal you see in a zoo is descended from one that was captured and put in captivity, from pandas to meerkats. By breeding these animals and sending them to other zoos, they ensure wild populations can remain where they are, and captive born animals are happier in captivity than wild caught ones. \n\nThe final way is through donations. When you go to the zoo to see that baby orangutan, you pay $15 at the front. You slip $2 into the donation box. While your ticket price and donation will not Be enough to help the orangutans, hundreds of thousands of people also go to this zoo each year. The zoo uses most that money to pay their staff, care for the animals, and improve the zoo, but they also donate millions to help the orangutans in the wild."
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
ezf6gx
|
Can the human body function without saturated fats in the diet?
|
askscience
|
https://www.reddit.com/r/askscience/comments/ezf6gx/can_the_human_body_function_without_saturated/
|
{
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"fgqyx9b"
],
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"text": [
"Yes. Small amounts of saturated fats are important for cell membrane structure. However, your body can make saturated fats from scratch via fatty acid synthase. \n\nBut, you should still consume some fats for a healthy diet. Dietary fat keeps you fuller for longer. The healthiest sources of dietary fats are plant or fish based unsatirated fats.\n\nI highly recommend Harvard's Nutrition Source for science-based nutrition information. _URL_0_"
]
}
|
[] |
[] |
[
[
"https://www.hsph.harvard.edu/nutritionsource/"
]
] |
||
2clxfl
|
how does throttling netflix (or any data for that matter) benefit verizon?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2clxfl/eli5_how_does_throttling_netflix_or_any_data_for/
|
{
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"Because netflix represents 1/3 of total internet traffic in the U.S. (downstream, to consumer). So...by controlling the rate with which data from that single site is transmitted you can reduce the demand on your entire network by A LOT. That means verizon is paying less money to their peering networks, has to have less total capacity within their network and so on. In short..it saves them money.\n\nAdditionally, most of the companies who provide connectivity at least toy with the idea that network connections themselves will be commoditized and that they need to find revenue streams - content is an easy one to imagine. So...if you can make a shitty experience for other content then you're more likely to be successful at your own. This is more true for comcast than verizon.\n\n",
"Many ISPs don't like Netflix because the way the internet works is that, by example, you and I both have a network. We both want to communicate with servers beyond our network boundaries, and so we agree to pass each others network traffic through our own networks. This is called peering. ISPs don't charge one another for the bandwidth used, I'm going to use some of yours and you are going to use some of mine, and the agreement is mutual. Sometimes, your traffic is going to be heavy, so I'll make accommodations for you, knowing you'll do the same for me.\n\nNetflix is a network, but they have almost no inbound network traffic. They're almost exclusively outbound. So there's no \"peer\" aspect. Here I am, getting my bandwidth consumed like crazy, because video streams saturate bandwidth, and I'm getting nothing in return.\n\nNetflix knows this, and they're offering to place caches in-network, closer to their customers, and it will minimize traffic over the network boundaries, but there is no financial incentive for any network to agree.\n\nSo it's not that there is all that much benefit for an ISP to play nice with Netflix because there's nothing to gain from doing so. Since the ISPs can't get bandwidth and peering out of a relationship with Netflix, they've suggested they would charge Netflix for bandwidth usage, making them not a peer, but a high bandwidth customer. I find this fair, but people blur the distinction between peer and customer, and the implications of these relationships, and throw a hissy fit.\n\nIf Netflix were a customer, and paid for their usage, the cost for their subscription would go up. Way up. Their subscription is so cheap because they're milking the \"peer\" relationship. Being an ISP customer is bad for you and me, but is the only compensation the ISPs would get.",
"Another thing that hasn't really been mentioned, is that most ISPs are not only selling their customers internet, but also typically sell their customers TV service as well. This service costs them virtually nothing to provide to you, because it typically does not involve an increased investment in infrastructure if they can already provide internet. Many consumers consider Netflix to be a viable alternative to traditional television and thus Netflix can cost them huge sums in subscriber revenue. However if Netflix is slow, and rarely providing HD video, you are more likely to continue watching (and more importantly, paying for) your traditional HD TV streams."
]
}
|
[] |
[] |
[
[],
[],
[]
] |
||
8xgm1r
|
the difference between a restricted and unrestricted free agent in the nhl.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/8xgm1r/eli5_the_difference_between_a_restricted_and/
|
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"A unrestricted free agent can sign with whoever he wants. The team he used to play for has no special rights as compared to any other team in the league.\n\nA restricted free agent on the other hand, if another team makes an offer to him (called an \"offer sheet,\") his current team has a window of time to respond to the offer sheet. If they match the offer sheet, the player stays with that team. If they decline to match the offer sheet, the player gets signed to the new team, and the new team has to give up a draft pick (or picks) as compensation. ",
"An unrestricted free agent is free to sign with whichever franchise he desires for whatever compensation and term he is able to negotiate.\n\nMany unrestricted free agents reject higher offers in order to play in a more desirable location, such as one closer to home or with better marketing/endorsement opportunities. John Tavares recently signed with the Toronto Maple Leafs for far less than he was offered by other teams.\n\nRestricted free agents are players that have finished their entry level contract but do not yet qualify for unrestricted free agency. The duration of an ELC is age dependent. An ELC for a player between the ages of 18 and 21 is 3 years in length, an ELC for a player that is 22 or 23 is 2 years in length, and an ELC for a player that is 24 is 1 year in length.\n\nA player qualifies for unrestricted free agency when he has either played in the league for 7 years or reaches the age of 27. Since the minimum draft age is 18, no player can reach unrestricted free agency (except under one condition) before they hit the age of 25.\n\nIf a player signs an ELC at the age of 18 and that ELC expires when the player is 21, the player would be restricted for four years after which they would have played in the league for 7 years.\n\nIf a player signs an ELC at the age of 24 and that ELC expires when the player is 25, the player would be restricted for two years at which point they would be 27 years old.\n\nRestricted Free Agents can negotiate with whichever franchise they desire, and negotiate whichever terms they desire, subject to the franchise that gave them their ELC trying to retain them.\n\nIn order to retain negotiating rights, the franchise that the restricted player signed their ELC with must extend at least a qualifying offer to that player. A qualifying offer is for a one year contract with a prescribed minimum increase in salary. If a qualifying offer is not made at all, the player becomes unrestricted. If a qualifying offer is made and rejected, the player remains restricted.\n\nIf the qualifying offer is rejected, the restricted player may seek offers from other franchises, called an *offer sheet*. The player may also negotiate a better offer with his existing franchise. If another franchise's offer is accepted, the franchise that retains negotiating rights through a rejected qualifying offer may match that other franchise's offer within one week. If the franchise declines to match the other offer, the player becomes a member of that franchise. The franchise that lost the player receives a compensatory draft pick based on the new salary."
]
}
|
[] |
[] |
[
[],
[]
] |
||
28eqrn
|
why cars only have 6 gears while bikes have 21?
|
Most bikes have 21 gears while most cars have 6. Why don't cars have more gears, wouldn't it be more efficient to have more gears?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/28eqrn/eli5_why_cars_only_have_6_gears_while_bikes_have/
|
{
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"text": [
"technically CVT's have infinite gears. but for standard transmissions trucks have 21 gears. for cars, you can put more gears, sure, but do you really want to be shifting all the time? it would just add bulk and complexity. we want to keep it simple. for bikes, there're more gears b/c we as humans are limited to how many rpms we can put out. but for a car, it can go from 1k to 9k or even higher depending on the engine. a human maybe can go at most to 150 rpm (just a guess, i average 60 rpm on the cycle machine)",
"Because gears in a car's transmission take up way more space than gears on a bike, gears on a bike are actual gears that are different sizes while gears in a car's automatic or manual transmission are far more complex and each \"gear\" is comprised of several gears that convert the engine's power into power that can be used by the wheels. Yes having a 21 speed car would be more efficient power wise but a 21 speed transmission for a car would be very large and heavy and also very complex mechanically. But however some large trucks can have as many as 18 gears.\n\nIf you want to know more about how transmissions work look [here](_URL_1_) for how an automatic transmission works and [here] (_URL_0_) for how a manual transmission works.",
"People in average shape are comfortable pedaling at a very narrow range of speeds. Much faster or slower and you will tire out very quickly. Having a lot of gears means you can go the speed you want while pedaling at the frequency that works for you.\n\nCars would benefit a bit from more gears (that's effectively what a CVT helps with), but adding gears to a car tremendously increases the weight, complexity, and cost, compared to a bike (where the gears are under fairly little stress, and aren't constrained for space as much).",
"Too many complex answers. Here's the simplest: Humans can't create as much torque as an engine. If you could put out 180hp & torque you wouldn't need gears 1-7 on your bicycle.",
"TL;DR: cars have 6 gears because adding more would make them more expensive and not much more efficient, and bicycles have 21 because as an effect of how bicycle gears work, not because they need them, and many of the 21 gears are not usable or useless.\n\nNone of the answers so far are really complete or correct, I suspect because no cyclist has answered so far :-)\n\nLet's start with cars. Modern cars have usually 5-8 gears, with a ratio from the lowest to the highest gear of about 5. That means that at fixed engine RPM, top gear gets you about 5 times the speed of 1st gear, and about 5 times less torque on the wheels. The gears are more-or-less evenly spaced across that range, and having 5-6 gears is sufficient for most applications. Having more gears would make it a little more efficient, but the benefits get smaller as you add gears, while the gearbox gets more complicated and expensive.\n\nA typical mountain bike also has a ratio from first to top gear of about 5. Road bikes typically have a smaller ratio.\n\nBecause you have to pedal yourself and can't rely on an engine doing the work, you'd want to have gears spaced a bit more narrowly than in a car, so that you can always select \"the right gear\" for your fitness and preference. That explains why there might be \"a few more\" gears, but not why there are in excess of 20 (I think 33 is the current maximum).\n\nThat's due to the mechanics of bicycle gears. A bicycle basically has two gearboxes in series: the (typically three) chainrings in front, and the (typically 7-11) sprockets in the back. The are independent of each other, and \"multiply\" each other. That is required to get the wide range from first top top gear - one gearbox alone would not be able to achieve the wide range required.\n\nThe reason that only the front or back gearing would be insufficient is that the size difference between the individual sprockets can't be too big or the chain won't change smoothly from one sprocket to the other, and adding more sprockets won't work because the stack of sprockets would become too wide and won't leave any space for the wheel.\n\nThis is not a problem in cars because car transmissions work very differently - google \"synchromesh\" for an example.\n\nAs an effect of the two multipliers in bicycles, you get a large number of gears: for 3x7 you get 21, and for a 3x11 a whopping 33 gears.\n\nThe problem is that many of these gears are not usable (e.g. when the chain goes \"across\") or not useful (the same or very close to another gear) - they are just a side effect of how bicycles are built. You don't get more than maybe 12 significantly different ratios from a 21 speed bicycle.",
"Its all about Gear Ratios. the number of \"gears\" isn't the actual number of sprockets, its the number of possible gear ratios between the powerplant (engine or pedals) and final drive (drive wheels). On a 21 speed bike, there are 3 sprockets in the front and 7 in the rear. It is possible (though not recommended) to have 21 combination, as each rear gear could be selected with each of the front... the reason this isn't recommended is because 1- cross chaining, where the chain runs diagonally, say between the most outward front gear and most inward rear. You're actually supposed to shift both front and rear to keep the chain as straight as possible. And also, if you actually ever do the math, if you were to use all 21 combinations, a lot of gear ratios would be repeated (or repeated within 10% or so)\n\nSo really, if used properly, a bike with 7 rear sprockets has 7 gears.\n\nCars are the same way- the transmission has way more then 4, 5 or 6 gears, but they are set up in such a way that when you select 1st gear or 3rd gear, etc, you are aligning the transmission sprockets in one of 6 gear ratios that has been engineered to be most appropriate for a given speed. \n\nEdit: To compare cars to bikes a little more, we should talk about \"power band\" In an engine, the power band is the RPM range in which the engine is most efficient, putting out the most power with the least fuel comsumption (relatively, if you hit the redline, yea, the engine is putting out a ton of HP, but fuel efficiency takes a dive). The human equivalent would be pedaling cadence- the muscles in your legs will work most efficiently if you pedal at a specific and relatively constant RPM. In both cases, the 4-8 gear ratios you have to choose from are engineered to keep the engine RPM or pedaling cadence as constant as possible, within the power band, at any speed"
]
}
|
[] |
[] |
[
[],
[
"http://auto.howstuffworks.com/transmission.htm",
"http://auto.howstuffworks.com/automatic-transmission.htm"
],
[],
[],
[],
[]
] |
|
41wh2c
|
[Medicine] Realistically, how deadly is tuberculosis if it is treated properly?
|
The title says it all really.
|
askscience
|
https://www.reddit.com/r/askscience/comments/41wh2c/medicine_realistically_how_deadly_is_tuberculosis/
|
{
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"cz5sayn",
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144,
3
],
"text": [
"It depends. If you have a drug-resistant strain of tuberculosis, very. If you have an immune system disorder (such as AIDS), very. If you are otherwise frail (perhaps due to age), very. But if you are healthy, TB is detected early, it's a strain that still responds to drugs, and you are able to follow a treatment regimen that typically involves daily drugs for several months followed by several-times-a-week drugs for several more months, then I guess TB is no big deal. ",
"I work in a very high volume TB public health diagnostics lab, and let me tell you, TB is serious business. The WHO declared last year that TB now rivals HIV as the leading cause of death due to infectious disease worldwide. The treatment itself is no picnic for several reasons, which is why people are so quick to abandon it, leading to relapse and drug resistance. If all cases of TB were treated exactly as they should be maybe the problem would not be so dire, but this is all too often not the case. Not everyone tolerates the antibiotics well, they must be taken diligently for months, and in so many parts of the world they are too expensive for families that are often dealing with multiple cases, among other reasons. Many of these problems could be lessened if more money was pumped into public health facilities, which are usually stretched too thin. I'm not sure when those of us who haven't seen the devastation that TB can cause will wake up and tackle the problem in a sensible way, but I hope it's now, because soon it might be too late. \nAn excellent book that addresses the complexities of TB prevention and treatment is Infections and Inequalities: The Modern Plagues by Paul Farmer. I highly recommend it, it's a sobering and eye-opening read. "
]
}
|
[] |
[] |
[
[],
[]
] |
|
48n5r4
|
How accurate is Gilbert Beckett's comic history of Rome?
|
I love Victorian humour writing so I'm thinking of reading Gilbert Beckett's Comic History of Rome. I know it's meant to be silly and is far from scholarly, but is it accurate enough that I as someone who knows relatively little about Roman history can safely assume that anything in it that isn't obviously a joke is generally true, or has our knowledge of Roman history changed enough since the 1840s that I should read it as essentially historical fiction?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/48n5r4/how_accurate_is_gilbert_becketts_comic_history_of/
|
{
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"d0lbqzx"
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"Considering that Beckett was not a Classicist and was writing when Classics as an academic study was still in its infancy, I wouldn't expect very much accuracy from it. I haven't read it personally, but 1852 is well before pretty much all of the fundamental scholarship on Roman history. Hell, it's two years before the publication of Mommsen's history of Rome (and nearly three decades before most of his important academic work) and it's almost a hundred years earlier than people like Syme or Cary who pretty much totally replaced Mommsen's work. Mommsen was outdated even by Syme's day, and though he and his contemporaries laid the groundwork for real academic study their work is largely irrelevant to modern scholars now. Hell, even scholars like Syme, on whom the orthodox view of the late Republic is based, are no longer totally up-to-date. A *lot* of scholarship has happened since 1939, when Syme wrote *The Roman Revolution*, and even more has passed since Mommsen and Beckett. Already by the 50s we knew and understood infinitely more than the Victorians ever did--in the study of the late Republic alone such crucial concepts as the precise meaning of the *nobiles* (not properly until Gelzer's studies on the later Republican magistracies) and even the way elections worked were not understood in 1852. "
]
}
|
[] |
[] |
[
[]
] |
|
c22rk0
|
how come acid containers does not disintegrate when in contact with its super acidic contents?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/c22rk0/eli5_how_come_acid_containers_does_not/
|
{
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"text": [
"Acids react with compounds to produce other compounds, which is where the \"disintegration\" or \"melting\" effect comes from. However, acids can only do this with compounds that react with them. \n\nExamples: \n\n- Sulphuric acid reacts with metal, but not with glass.\n- Hydrofluoric acid reacts with glass, but not with plastic. \n\nThe container that the acid is kept in has to be made of the right material to avoid a reaction from occurring.",
"Acids can't dissolve everything, they can only react with chemicals susceptible to chemical attack by that acid.\n\nSo while they'd have no trouble disintegrating a container made of steel or cheap polyethylene, highly chemically resistant materials like glass or polytetrafluoroethylene (teflon) can shrug off most acids.",
"Acids are one of those things that most people don't realize how they work because Hollywood has produced a lot of really bad misinformation.\n\nThere are a couple of different technical definitions of the term acid which change their meaning somewhat, but in simple terms acids break down other substances by reacting with free pairs of electrons in that substance. If a substance has a very stable configuration of electrons, and doesn't have free pairs to react with, then the acid will not dissolve it.\n\nSometimes materials that can resist acid seem more flimsy than the materials that are not affected by acid. One of the more accurate examples from Hollywood is in Breaking Bad, where plastic tubs that would have resisted the acid we're not huge, and instead the acid was poured into a metal bathtub, dissolving right through."
]
}
|
[] |
[] |
[
[],
[],
[]
] |
||
56bn4b
|
Did Islamic leaders throughout history have a disincentive to convert non-Muslims due to the value of Jizya?
|
I've heard this claim a few times, that Islamic authorities consciously avoided the pursuit of conversion (past the earlier period of Islamic growth) in the face of the lucrative Jizya tax. Does this have any basis in historical understanding?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/56bn4b/did_islamic_leaders_throughout_history_have_a/
|
{
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" > consciously avoided the pursuit of conversion (past the earlier period of Islamic growth)\n\nActually it's kind of the other way around, unless you mean earliest period of expansion inside Arabia itself. Not only did the early conquest period outside of Arabia not feature mass or forced conversion, it was not actually possible to convert unless you became a *mawla*, an Arabized tribal client.\n\nThe jizya in this period is also misunderstand. Poll taxes on conquered peoples, and indeed as a primary method of taxation, were common in the ancient world and were practiced by both the Byzantines and the Sassanians. The jizya (not to mention other tax arrangements that were simply kept in place) was not substantially different from tax systems already in place, which is probably why we have no record of anyone complaining about it.\n\nThe idea of the jizya as it is now understood \"a discriminatory tax on non-Muslims\" doesn't become policy until the reign of the Ummayad caliph Abd al-Malik. It's also around this time period that the religion seems to have been universalized, so for instance Abd al-Malik builds the Dome of the Rock, almost all of the inscriptions of which seem to be intended at proselytizing new believers or otherwise reinforcing the faith in the truth of Islam in a mixed Abrhamic context.\n\nUnsurprisingly it's around this time in the late 7th century that the problem you enumerated arose. There are a few methods rulers might have hypothetically adopted: \n\nThey could make conversion difficult, which as I mentioned was the original notion, but which they moved away from, seemingly for ideological reasons in seeking to promote the faith. \n\nThey could reinforce the distinction between conqueror and conquered. This after all was kind of the point insofar as these taxes were supposed to be disseminated to pay the rolls of the soldiers doing the conquering. It may also be why the Arab conquerors tended to establish new communities separated from the major cities in the area. But no empire in history prior to the advent of nationalism was able to keep up that kind of stark divide for centuries. Eventually conquerors settle down and migrate and set up shop. Or the conquered move into the new cities where the real power is. Which is of course exactly what was happening.\n\nThe third option, which is what ended up happening, was (to borrow a phrase from Robert Hoyland) to \"reduce the benefits package\" of conversion. This was initially done by some regional governors simply by imposing the Jizya on new converts regardless, who then apparently apostatized, and that idea was apparently nixed by the central government. Ultimately the solution was to simply impose other forms of taxes on Muslims, including the reorganization of *zakat*, the annual \"charitable\" donation paid by Muslims, into what was effectively a mandatory tax, as well as the imposition of a non-denominational land tax. The other change was to the reward structure of the army, which was regularized into a fixed salary.\n\nIn addition, as an administrative matter, many of the tax collectors were simply kept on from the ancien regime, or remained among the dominant local culture seeing as how the conquerors had no experience in administration. Which raises the question of whether Christian tax collectors would *really* have carried out a tax policy designed to discriminate against their brothers in the faith and reward people they viewed as apostates.\n\nAll of this being said of course, practical tax collection is not a straightforward process in the late antique period, and particularly for the early era of the conquest the relevant evidence shows a complete jumble of practices that makes the theoretical policies somewhat irrelevant, though this regularized over time.\n\nThis is perhaps a separate question but there were of course also states like Egypt where the policy of the jizya may simply not have mattered as much because so much of the state's revenue was generated from other forms of taxation, particularly on trade.\n\nFor more information I would read either Robert Hoyland's *In God's Path* or Fred Donner's *Muhammad and the Believers*."
]
}
|
[] |
[] |
[
[]
] |
|
2qww0d
|
why does my phone screen look multicoloured when the screen is on if i look at a reflection of it?
|
If was on a blank white page and I look directly at the screen I can't see even the faintest colour but if I look at it through a window or any other shiny surface I can see very strong colours
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2qww0d/eli5_why_does_my_phone_screen_look_multicoloured/
|
{
"a_id": [
"cnacc4a"
],
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3
],
"text": [
"This has to do with the polarization of the screen. This fillers out specific waves of lights and then you add another mirror to that filtering (because mirrors don't reflect perfectly EVER) and you got yourself these cool colors"
]
}
|
[] |
[] |
[
[]
] |
|
qlqp2
|
When you hold an item (such as your finger) close to your face and focus on an object in the distance, why does light seem to "bend" around the item close to your face?
|
askscience
|
http://www.reddit.com/r/askscience/comments/qlqp2/when_you_hold_an_item_such_as_your_finger_close/
|
{
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"c3ykdz4"
],
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2
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"text": [
"I observe the same thing when looking through a small hole. In my case, I see this effect if I look through the hole in my blinds that the string goes through (not between the slats, I mean the oval-shaped hole with the string through it.) Looking through the hole has a magnifying effect on the screen of the window behind the blinds.\n\nI've wondered why too.\n\n"
]
}
|
[] |
[] |
[
[]
] |
||
15spxh
|
How important were stirrups to mounted warfare? What, other than stirrups, could have led to the rise of shock cavalry?
|
I was reading up on post-classical, pre-feudal social organization for Germanic aristocrats when I noticed several conflicting statements about their use in warfare. This brought up an inconsistency I've seen before and I figured *someone* here should be able to give me a little more information.
In most of ancient history, armies did not use shock tactics with their cavalry, it seems. They acted as mounted skirmishers, scouts, a screening force, or pursuit force. Even well-armored cavalry, such as the elite of the Persian empire, used javelins rather than lances. According to numerous sources I've seen in places like public school, popular books, and websites, shock cavalry came with the invention of the stirrup. Sometime in the 6th-9th centuries, the stirrup arrived in western Europe, and the Frankish nobility went from riding to battle and fighting dismounted to remaining mounted and using shock tactics. This being the origins of medieval knights.
But there are some holes in this explanation. For example, central Asian nomads employed *heavily* armed and armored lancers as shock cavalry as far back as the 3rd century BC. The Parthians who conquered the Iranian plateau spread these tactics to Persia, and the Sarmatians who overran the Pontic Steppe spread them to eastern Europe. The Macedonians were using shock cavalry of their own under Philip II, Alexander the Great, and their successors. The Hellenistic successor kingdoms even added heavy armor after encountering central Asian cavalry. The Romans also adopted heavily armed and armored cavalry from the Sarmatians and Persians.
So, if cavalry without stirrups are so poor for shock tactics, why were cataphracts so effective? If stirrups are unnecessary for shock cavalry, why did so few people use them and why the sudden rise of shock cavalry in postclassical history?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/15spxh/how_important_were_stirrups_to_mounted_warfare/
|
{
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"If you look at reproductions of [Roman saddles](_URL_0_)(scroll down a bit) you'd notice the really prominent horns that do a pretty good job of holding the rider on despite being knocked around a bit. I've read some arguments that stirrups really weren't a major factor at all in enabling shock tactics in cavalry compared to other elements of design like the above, but I have no idea how well-supported those arguments are so I don't think I'll discuss them in a top-level post.\n\nThat only addresses one of the culture you mentioned. I know nothing about saddles in other places.",
"I'm not an expert in this area but I'll provide you with some of my own knowledge on the subject.\n\nThere was enough use of shock cavalry use so I'll just pick one of your examples and expand on it. Alexander's Companion cavalry are regarded as some of the most effective cavalry the west had seen or would see for a very long time so don't get bogged down in thinking they weren't effective.\n\n\nPhilip (not Alexander) was the one to really institute the use of cavalry shock tactics into the Macedonian forces. It was uncommon enough among the Greeks that Philip could capitalize on this dramatic form of attack to deadly effect during his battles with them. Anyway, we want to talk about stirrups, which the companions didn't have. This means their legs couldn't be braced against impact and their lance could be neither thick nor supported under the arm. Regardless of this the Companions would indeed smash into their enemy and skewer them, though the thin lances often broke upon impact. The lance was mostly used to break up formations and a switch would then be made to swords to finish the job. One thing to keep in mind is while the Companions lacked stirrups their enemies did too and the Companions tended to be more lightly armored than their Eastern counterparts. A heavily armored horseman was more likely to be unseated by such an impact. Riders were expected to steady themselves by holding onto the mane and this did help a bit when it came to balance. Philip's force of mounted scouts had a lance so long it took two hands to wield and horses were guided with the pressure of their knees as modern equestrians still do. This wasn't some far flung experiment either; this two handed style survived long into the future and was adopted by Russian cavalrymen and Scythian nomads. \n\n\nThink of stirrups to horses as a crossbow was to a long bow; without it people simply had to hold on tighter and be more skilled than they were post-stirrups."
]
}
|
[] |
[] |
[
[
"http://www.limebrook.com/saddlehistory.html"
],
[]
] |
|
21huh2
|
gods in hinduism
|
I understand (or I think I do) that in Hinduism there are many deities, but that ultimately they are all just representations of the single unifying Brahman. However, I've just discovered that in the Rigveda there are many gods such as Yama, Indra, Agni etc, deities that I've never heard of before. What I'm confused about is where the more modern ideas of gods in Hinduism, the ones I was told about in school such as Vishnu, Ganesh, Kali etc. come from, and how they relate to these 'older' deities. Can someone explain this to me? Thanks
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/21huh2/eli5_gods_in_hinduism/
|
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"Hinduism is different from religions like Christianity, Islam and Buddhism by a simple fact that Hinduism has no founder. As humans evolve their belief system changed. Hinduism encompasses these evolution for the last 3000-5000 years. \n\nAt one point of time humans worshiped the elements. These elements are represented in Rig Veda:\n\nVaruna: Air\nAgni: Fire\nIndra: Rain\nYama: God of Death\n\nAs time progressed humans felt the need of more personified gods. In this period across civilizations more human like gods appeared. Vishnu, Ganesh, Kali are representation of those.\n\n",
"There is no such thing as Hindu dogma, as there is for every other major religion. There is no one holy text or religious body that dictates the Hindu religion. Hinduism just kind of started and, as it encountered other cultures and religions, it evolved and absorbed them, in a way. Hinduism is an inclusive religion, so when it encountered another religion, it could just say, \"Yeah, your god is totally cool, too.\" \n\nThis was particularly key to its survival as different Indian cultures were invaded or conquered by both foreign powers as well as other Indian kingdoms. So what you get is a mishmash of a bunch of view points under the umbrella of Hinduism. That's why \"older\" deities and \"modern\" deities seem so confusing, and kind of contradictory. They originated in different belief systems at different times, but were all co-opted into Hinduism at some point.",
"Just thought I'd add to the already insightful comments.\n\n\"Gods\" isn't the same kind of term as other religions. As some others have said, there isn't a central system of belief or dogma. Many Hindus, by definition, are atheists. They don't believe in a \"God\" which is a living entity as such, but more as a tool or concept to focus on. \n\nTo explain further, anthropomorphizing aspects of our lives are an easy method for us to be able to manipulate them in our minds eye for a variety of uses e.g. the pursuit of academic study (there's a god for that), however, in place of anthropomorphization, symbols such as mandalas can be used instead, among other devices (think Pentagrams and other occult symbols). When I say manipulate, what I refer to is firstly, assigning a symbol (e.g. a god's name) which describes a concept, so upon recall of the symbol, you're recalling everything the concept entails and secondly, focusing on this symbol through meditation which, for a variety of psychological reasons would be beneficial for your personal advancement towards that concept. Hinduism and the occult have much in common.\n\nThis is a reason why Hinduism has 330 million \"gods\" - they are just 330 million identified aspects of our universe for us to manipulate in our minds eye.\n\nHowever, as previously stated, there is no centralized order in Hinduism and as it's pretty old, followers have had all sorts of involvement with it. For example, for many believers, Hinduism isn't much different to the Abrahamic religions - it can be dogmatic, prejudice etc. And as always, there's always going to be somebody along the way to use said belief system as a form of control for the masses - Hinduism is no different.",
"Hinduism is a collection of ideas and stories. It does not have centralized figure for god. Every god is related to other gods in some way. In one story one god can be a seen as the superior, and in other story the same god can be seen as the inferior. ",
"Hinduism is a psychonautical philosophy with a front of a religion. You are that.",
"There are no definitive answers to this question :-)\n\nWhy? Because *Hinduism* is not a Religion in the sense that Christianity/Islam etc. are. There is no well-defined origin point. It is basically the name given by others to a whole cornucopia of Philosophies, Belief Systems, Traditions and Culture of the various people inhabiting the Indian subcontinent. Originally the various gods were representative concrete models of abstract concepts in the people's philosophy/belief systems. Thus every god/goddess stands for some specific characteristic which a group considers important enough to model. Given the diversity (on dimensions of language, regional differences, culture etc.) of the peoples of India, it stands to reason that each distinct group would model and name what it feels as important and when you take them all together you get a dizzying ensemble of deities! \n\nToday, Hinduism is conflated with the dominant Vedanta philosophy/religion though strictly speaking, it does not have to be. When you study the various Hindu scriptures belonging to different schools, you will find very different self-consistent world views which are admirable in their own right (eg. Samkya/Yoga vs. Vedanta).\n\nThe best comparison to Hindu schools of philosophy are the ancient Greek schools of philosophy who had a similar breadth of thought and a corresponding pantheon of deities.\n\n\n",
"This speaks to an evolution from an agrarian/nature-dependent society who saw the gods in the elements (Agni = Fire, etc) to a more urban society with time for fellowship and existential musings. A lot of these earlier Vedic gods were subsumed by later versions, such as elements of Rudra being seen in Shiva, and other gods were just made less important. The shift to the Bhakti tradition is where you get the Trimurti (Brahma, Vishnu and his avatars, and Shiva). \n\nThe wheel on India's flag points to a great descriptor of Hindu belief which is enlightenment is like the center of the wheel around which everything revolves, and the spokes are the many (or infinite) paths to enlightenment. Some say there are as many gods in Hinduism as there are Hindus, as it is a very personalized form of worship. Most worship either Vishnu in one form or another, or Shiva in his forms. Kali worship is also a popular albeit regional practice. \n\nAnother interesting analogy shows that some people practice Hinduism as neither a monotheism or polytheism, but rather a monism. An old man at a nearby temple once told me that he worships GOD. All three of the trimurti are as one to him, and he says it is because our state of being requires a Generator (Brahma), an Organizer (Vishnu), and a Destroyer (Shiva). Then the cycle starts again.",
"I'd like to explain this from the eyes of an outsider. The way I've interpreted it as well as takings from people I've met here along the way.\n\nMost Gods personify virtues - are metaphors for the goings-on around us. Life begins with creation - it needs to be sustained; protected and groomed, and finally ends with destruction. The holy trinity of Hinduism are the source of all creation, sustenance and destruction - namely, Brahma, Vishnu and Shiva. To answer the question of chicken-and-egg, Brahma is said to have sprung forth from the Lotus of Lord Vishnu's navel. To me, this makes sense in that all creation springs from a protector, a benefactor's presence. Just like a seed needs a kind terra to provide it with the nourishment it needs to grow and bear fruit and give birth to other trees. Life flows through its stations and the protector (Vishnu) guides man through it. In the end, when the time is right, the culmination is death, in which Shiva - the eternal truth and emotion - the sum of beginning and the end, would invite the true believer. Since Shiva is to bring about balance to life - with destruction, it would happen when the time is right. As with all things, it's incorrect to assume that destruction is always evil. Sometimes, for life to continue, destruction is needed and this God of all things does exactly that. \n\nEvery aspect of human life is given a \"God\" to help people cross over from birth to death. This is done to make things easier to visualize and understand. For example, Lord Ganesha is said to be the God of knowledge and wisdom, the destroyer of Evil and of Misdeeds, the one who consumes all that is bad and troublesome. For such a God, it's fitting that he has the body of a human with the head of an elephant. An elephant which is large, which is alert, which remembers everything - representing everything that knowledge and wisdom stand for. Like too much of a good thing being bad, every God is shown to be benevolent or stern/harsh, depending upon the mood of that God. Rather than blame the God when in dire times, the believer is asked to appease the God - now rather than taking it literally, it should be taken as a way to patiently wait for the calamity to pass over...\n\nIt's a way of life with lots of examples and metaphors. Like in Christianity, a lot of those metaphors have been lost. However, by thinking for himself/herself, every Hindu will reach the state of final salvation when he/she integrates with the divine consciousness or the \"Brahman\" (not to be confused with Lord Brahma). The Brahman is the primordial pure essence of all existence - hence, the ultimate truth of our lives (maybe, akin to the superdense universe *just* before the big-bang?)\n\nTrue Hinduism is all encompassing - I've never seen anyone flinch when I've visited temples, rung bells there, or when I've asked the priests to bless me - across the breadth of India. There's some serious tolerance in-built in the system (along with a lot of adoration for white skin). There's a lot for everyone to learn from true Hindus - I have and still am learning every day that I'm here. Cliches aside, they did have a civilization going here when the rest of the world was crawling out of the moors of barbarism.\n\nTL;DR: The roots of Hinduism are common-sense, respect, tolerance and acceptance - anyone who is tolerant and accepting of others and uses his/her common-sense as a moral compass is doing what a true Hindu should be doing.\n\nP.S: I'm not here to tread on anyone's toes. If you're offended, well, I'm sorry that you are. It's my viewpoint, though, and I'm learning everyday. My God knows that I'm pretty comfortable being an atheist and a believer at the same time. ;) Common sense. ",
"In southern India, every village has a village deity (Grama devata). Most families have a family deity or social deity ( Kula devata/daivam). Each individual has ones favourite deity (ishta devata/daivam). As per the festive occasion, there are celebrations hosted for popular deities. One is allowed to seek ones own path, and join others as long as they show reverence to others beliefs.\n\nThen there are cults/sects that adore humans claimed to be of divine nature. There are worship systems that are 'goal' driven (yagnas, kritus). The objects worshipped can be inanimate (stone/rock formations swayambhu, mountains, hills, or man made sculptures/idols); can be animate (snakes, cows, humans); can be abstract ideas (scriptures, manasa puja, advaita philosophy, sacrifice, charity/daana); can be forces of nature/natural phenomena (seas, rivers, celestial bodies)\n\nIn modern times, one is free to choose, but ancient times made a big fuss (saliva vs vaishnava, jain vs Buddhist schools) and fought wars. Rigveda speaks of natural forces of fire-agni, varuna-rain/water, yama-time/death, indra-prime among gods. While not very common, I have seen Christ, Buddha adorning the same altar in room of worship (puja room).\n\nAs you may realise, it is to much to explain every nuance, then there are anecdotal stories with inconsistent time lines, old wives tales. The folk lore is as fascinating as Greek mythology\n\nI don't want to quote wiki, but it has a very good definition.Hinduism is set in a diverse system of thought with beliefs spanning henotheism, monotheism, polytheism, panentheism, pantheism, monism, and sometimes in forms of atheism or non-theism (see advaita) among others.[1][2][3][4] It is often aptly termed monistic theism and even open monotheism by some scholars, but is not purely polytheistic as outsiders perceive it to be.",
"In addition to all that has been mentioned, I will give you a slightly more direct answer in terms of how the \"modern\" and \"older\" deities are related.\n\nIt is hard to pinpoint which god was mentioned where first. In fact, as a hindu I have never made a differentiation of modern and old. To me all these gods are part of our culture. The ones which you call modern, are in my view the \"mainstream\" gods. Many people tend to believe in them as a primary god. The \"older\" gods are secondary gods in terms of worship. \n\nLet me explain the various differences under two headings:\n\n1) Daily Life and Worship\n\nMost households have a primary god they worship. This is often dependent on the area they are from. For example, most households in Bengal, worship Kali as their primary god. \n\nEach god has its own story and legends. So they are usually associated with specific actions. So, if one holds a ceremony including a havan(sacrificial fire), the god being worshiped is Agni, the god of fire. Similarly, Ganesha, is considered the god of good beginnings. So his name is taken before any momentous task and he is usually the first god worshiped in a ceremony. \n\nAll primary gods have their own specific festivals which are celebrated on specific days. The secondary gods are usually worshiped during the event related to their specific domain.\n\nOf course there are groups of people who do worship Agni, Varuna(water god) etc as their primary god.\n\n\n2) Hindu Mythology\n\nHere I will mostly draw from the Mahabharat and the Ramayan. This is the literal relation/hierarchy.\n\nThe holy trinity is composed of Brahma, Shiva and Vishnu. Hindu mythology is spread out over millenniums. So many of the gods encountered in the accounts are avatars of the above mentioned three. But they are still worshiped individually, often because of the specific qualities they represent. For Example:\nRama and Krishna are both avatars of Vishnu. Rama is worshiped for being the perfect man. Krishna is worshiped for being the solver of problems.\n\n\nGuardians of the directions:\n\nEast - Indra (King of Gods)\n\nSouth - Yama (God of Death)\n\nWest - Varuna (God of the Seas)\n\nNorth - Kubera (Lord of Wealth)\n\n\nElemental Gods:\n\nAgni - Fire\n\nVaruna - Water\n\nVayu - Wind\n\netc etc.\n\n\nNote that there is no specific hierarchy. \"Modern\" gods such as Krishna etc consider any god they meet their equal and even their superior. The only real hierarchy you can draw is that all gods respect the Holy Trinity. It is believed they were all born of them. \n\n\n\n//Hope I helped. Sorry if its a confusing. First time answering. Happy to answer any questions.\n\n~Edit: Fixed formatting a bit.",
"One interesting, and important, bit about the Gods of Hindhuism is that they are not removed from making mistakes.\n\nmany of the stories revolving around Gods, Devas, Asuras, etc. involve them falling prey to ego, pride, greed, lust, etc., and finding punishment for it.\n\nGrowing up I always thought this was to remind us that no one is above morality and good behavior - e.g. there is a story that tells of Vishnu and Brahma finding a pillar of light. They race to see who can find the end. Neither do, but Brahma lies and says he does. Shiva then appears out of the pillar, accusing Brahma of the lie, and cursing him to not be worshiped - thus the lack of Brahma-centric rituals. \n\nThe Asuras are known for this - the name itself indicates someone who has a great desire for pursuit of power. Many of the asuras are granted boons by a God for their dedication in meditation, prayer, etc. The Asura Hiranyakashipu who was blessed with many boons by Lord Brahma. But in his arrogance, he struck out against his son, a loyal devotee of Lord Vishnu. And thus Hiranyakashipu was slain, despite his boons.\n\nMany of the stories in Hindhuism have this sort of underlying trait - humans constantly and consistently make mistakes, as do Asuras and Devas, and even the Gods in some cases. These mistakes often revolve around the over-indulgence in base desires, or an excess of ego/pride that leads us to deal harm to others and engage in Adharma (that which is not in accordance with the law/duty). The punishment varies, but in the end, those who are most rewarded are those who can commit to a life of dharma without falling prey to ego, pride, etc.\n\nThere is a lot of philosophy in addition to the religious aspects that are sometimes ignored or unknown. Many times I've argued with other Hindhus who are completely against the tenents of Mimamsa or Samkhya philosophies despite their roots in the Rig Veda, or have not even considered the ideas expressed in the Brihadaranyaka regarding the identify of the individual.",
"Modern day Hinduism has only a distant relation to Vedic gods. This can be attributed to the gap between the decline in the Vedic period (around 400 BCE) and the revival during the Bhakti movement (8th century AD - 15th century AD). The Vedic philosophies and rituals were kept alive by Brahminical sects who were spearheaded by Adi Shankara (700 AD) and who later blended themselves into the Varnas (class system) around the 4th century AD. \n\nEven today, only the Brahminical sects follow the rigidly followed ritualistic practices that invoke the Vedic gods. "
]
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2y0oyj
|
How widespread was the belief that a reunited Germany in 1990 would attempt to seek hegemony again?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/2y0oyj/how_widespread_was_the_belief_that_a_reunited/
|
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"Charles David Powell was a key foreign policy advisor to British PM Margaret Thatcher. He wrote a letter to the private secretary to the Foreign Secretary Stephen Wall detailing a conversation between Margaret Thatcher and French President Mitterrand\n\nFrom the letter it is clear that both Thatcher and Mitterrand were worried about German domination of Eastern Europe (including a reference to them becoming 'bad Germans').\n\nHowever those leaders were isolated - they did not have support from the rest of their governments to put pressure on Germany (and Mitterrand believed that pressure would anyway not succeed). Therefore no action was taken.\n\nThe text of the letter is available here: _URL_0_"
]
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|
[] |
[] |
[
[
"http://news.bbc.co.uk/nol/shared/bsp/hi/pdfs/11_09_09thatcher_unification.pdf"
]
] |
||
fwtxlb
|
time it takes to save something onto the hard-drive vs deleting it
|
How does saving something onto the hard drive (or moving from one hard drive to another) take a long time, whilst deleting it takes a couple of seconds?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/fwtxlb/eli5_time_it_takes_to_save_something_onto_the/
|
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"Saving something on the hard drive is like writing 10 pages in your diary.\n\nDeleting something from the hard drive is like writing an X next to a diary entry in your table of contents. (The X is a shorthand note to your future self that the diary entry's garbage you don't care about any more. So you can erase whatever''s on them if you start running low on blank pages.)\n\nIt's a lot quicker and easier to write a single X than it is to write a 10-page diary entry.",
"When you’re saving it, it’s changing the code in the free space to match the code of the item, however when deleting, the last digit of the code has a 1 changed to a zero or verse vice.",
"When you store a file you do have to write all the data that in content to the disk and update the file table with a file name, what blocks on the drive the file is stored at, and some other information.\n\nWhen you delete a file you do not touch the data but just update the file table and remove the file from it and say that the blocks are no longer in use and can be overwritten.\n\nSo deleting a file is just removing the information of where it is the data is still there and there are programs that can recover the information. The data is lots when the next file uses the same block and overwrite them."
]
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[
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|
14lq1q
|
how is the internet connected?
|
In the "guide to the galaxy," there was a post about "what is the Internet?" The answers only explained what the Internet *is*, not how it works, etc.
I'd assume there are some kind of underground wires from country-to-country, or wires from country-to-headquarters (Google now either thinks I'm retarded or a terrorist for searching "internet headquarters").
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/14lq1q/eli5_how_is_the_internet_connected/
|
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"There are big cables under the sea, between the continents. The cables are by far the weakest point in the whole internet, and if you cut a few wires a whole continent can lose access to the internet. This actually happened a few years back with a fishing both and the cable to Africa. \n\nAnd then you have smaller cables between nodes within countries (and between countries). ",
"[It's a series of tubes.](_URL_0_)\n\nEdit: It's also NOT a big truck.",
"Read [Tubes: A Journey to the Center of the Internet](_URL_1_) by Andrew Blum. It's written by a journalist who asked the same basic question as you and then went on a bunch of field-trips to see the physical components that make up the internet. I really enjoyed it.\n\n[Here's](_URL_0_) an interview from NPR with the author.",
"Upvoted for being a very nice question.",
"I'll take a shot at this.\n\nLet's first think of the network you have set up at home. You have your router which is hooked up to the internet. You probably also have a few computers and maybe even a tablet hooked up to the router. All of those devices get an IP from the router so that they can \"converse\" if you will. If you copy Dora the Explorer S03E11 from computer A to computer B, your router knows exactly where those computers are and how to access them. Let's stop there before we get into the nitty-gritty of TCP/IP.\n\nBut let's blow this model up. Like, a lot. You may have heard how domains get translated into IP addresses BUT HOW DO YOU KNOW WHERE THOSE IP ADDRESSES ARE?? So the internet is run by big, important companies (we'll call them tier 1 networks) that run HUGE networks (In fact, here's the very short list of them: _URL_2_). Between them, these companies know where every single IP address goes to (whether it's a specific server, computer, or even another network), just like your router. Now, they may not know that a certain IP goes to a certain server somewhere but they do know that that IP address \"belongs\" to another network which is below the tier 1 networks. We'll call these \"lower-level\" networks tier 2 networks and there A LOT more of them (some big data centers might be classified as tier 2 if they provide bandwidth for their servers). BUT WAIT, there's [another layer](_URL_1_)! This last layer is called a tier 3 network and that will be the one that you get your internet from.\n\nTo wit, here's how it goes after you want to access a website and you already have their IP address:\n\nYour router: \"Hey, tier 3 network that I'm connected to, do you know which network this IP address belongs to?\"\n\nTier 3 (your ISP): \"Heck yes! I'll route you to this tier 2 network which I know will either be the destination or at least knows the next place to look for that IP.\"\n\nTier 2: \"Sorry bud, I can't route you directly to that IP but I know a tier 1 network who will know where you need to go. I'll transfer you over to them now.\"\n\nTier 1: \"Oof, sorry dude, I don't know which tier 2 network this belongs to but I know this other tier 1 network will know that. And here's the name of that network: ASxxxxx\"\n\nAnd it kinda just goes back the other way for the return trip back to your router.\n\nWHOAH, WHOAH, WHOAH. HOLD UP HERE. WHAT'S THIS ASxxxxx STUFF??\n\nGood question. All these networks (since there's not millions of them like there are IP address) have IDs and are identified with AS and then some 3-5 digit number. It's called the [autonomous system](_URL_0_) and Wikipedia does a much better job of explaining them than I can.\n\nIt's also worth noting that those big, tier ~~3~~1 networks don't pay for bandwidth between themselves because they transfer A LOT of data (more than you can probably even imagine) and it would get very expensive, very fast. However, tier 2 networks pay money for bandwidth to tier 1 networks and tier 3 networks pay money for bandwidth to tier 2 networks. And that's why you have to pay money for your internet.\n\nI hope this has helped as I have never, ever come across an explanation which involved the explanation of these tiered networks which I feel is basically essential when you discuss the subject. Otherwise, it's just the basic \"here's how your computer get the IP of a website and your computer knows how to magically get to that IP address.\" If you have anymore questions, I would be more than glad to try and answer them!\n\n**Edit:** formatting, minor fact editing",
"1. So first, you have machines that just connect computers to each other: *Switches*. You may have one of these in your home to connect your computers to each other or to your Xbox or cable modem.\n\n2. When you are going to connect a bunch of those together, you want a machine that can organize them into groups, so it's not just a a thousand devices babbling at each other all the time. Sort of like breaking a building up into rooms. Not everyone crowds into the same room at the same time - that would be loud and confusing. If you want to talk with someone in another room, you need to figure out which room they're in and go there to talk to them. These \"walls\" come from connecting your switches together with *Routers*. At this point, you have a *Network*.\n\n3. Now you've got a few separate buildings and you want to connect them, so people can go from one building to a totally different building (probably owned by a different company). So you build a road between them (and you probably have locks on the doors and security guards and whatnot). This - where you've connected two or more networks together, is an *Internetwork*.\n\n4. Now Texas is full of roads and buildings connected to each other, so is New York, and California, and Florida, etc. So now we build interstate highways. Maybe one at a time - a big one from NY to FL, then another from TX to CA, etc. Maybe the one in Texas is run by their toll authority, maybe the one in Florida is run by the federal government, and the one in NY by the state government. Maybe at first, the only good way to get from NY to CA is to take the highway down to Florida, then over through Texas. Then someone builds an NY to IL highway, and IL to WA, and eventually you have a choice or two, or three how to get there. This Interstate Highway System as a whole is no longer referred to as *an* internetwork, but as *the Internet*.\n\nTL;DR: \n\nComputers connect to Switches (usually with the regular cables you have at home), which connect to Routers (usually with fiber optic cables over long distances), to form a network. Networks connect to each other to form internetworks. When the biggest Internet Service Providers connect all their networks to each other, we call that one \"the Internet\".",
"It's just like how all our homes are connected with roads."
]
}
|
[] |
[] |
[
[],
[
"https://www.youtube.com/watch?v=_cZC67wXUTs"
],
[
"http://www.npr.org/2012/05/31/153701673/the-internet-a-series-of-tubes-and-then-some",
"http://www.amazon.com/Tubes-Journey-Internet-Andrew-Blum/dp/0061994936"
],
[],
[
"http://en.wikipedia.org/wiki/Autonomous_system_%28internet%29",
"https://www.youtube.com/watch?v=EUDjnbOJcdg",
"http://en.wikipedia.org/wiki/Tier_1_network#List_of_tier_1_networks"
],
[],
[]
] |
|
a8mqej
|
why is imitation crab meat in everything instead of real crab meat?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/a8mqej/eli5_why_is_imitation_crab_meat_in_everything/
|
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"Why is there sawdust in my cornflakes?",
"Purely because of the cost. If it tastes *similar* and can be had for 1/10th the price, most people are ok with imitation crab. ",
"Real crab meat is really expensive. Getting big chunks like king crab or jumbo lump is like $30+ per pound. "
]
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|
[] |
[] |
[
[],
[],
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] |
||
1typwi
|
[Middle Ages] When did different classes of people wake up and go to sleep?
|
Follow up:
i) Which major events throughout the history (e.g. industrial revolution) changed the time people woke up and went to sleep.
ii) Before mechanical alarm clocks came around, did they use any other "waking" devices.
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/1typwi/middle_ages_when_did_different_classes_of_people/
|
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"I can speak about monks.\n\nAccording to the Rule of St. Benedict, which almost all of western monasticism followed, monks had to be awake for prayer at: midnight for Matins/Vigils (1.5 hours), 3am for Lauds (approx. 45 min), and 6am for Prime (approx. 45 min). On the other end, they had to say Vespers at around 6pm, and usually said Compline at 9pm before bed. This would change a bit in the winter - Lauds is theoretically tied to sunrise, and Vespers to sunset.\n\nThe monks would usually be awoken by the tolling of the bell.\n\nFurther reading:\n\n* Harper, John. *The Forms and Orders of Western Liturgy from the Tenth to the Eighteenth Century: A historical introduction and guide for students and musicians.\"* Oxford: Clarendon, 1991",
"Pre Industrial revolution people had an entirely different sleep schedule than modern people. Most people had 2 sleep periods broken up by an awake period in the middle of the night. A typical schedule would involve sleeping for 4 hours or so, waking up for an hour and a half to two hours, and then sleeping again for another 4 hours or so. \n\n In the medieval period the main clock for people on farms was the rooster, or other farm animals waking and creating noise (a cow that is used to daily milking will get pretty noisy if their human goes off schedule). In cities the ringing of the bells in church towers was the alarm clock and workday regulator. Running the chimes was a position of great responsibility and trust, because various chimes called people to work and ended the work day. \n\n After the 13th century invention of the mechanical city clock these large tower clocks were the city dwellers alarm clock. These clocks were enormously expensive, took years to construct, and regulated the work day. They were also tied closely to social agreements between different classes. Fiddling with the timing of these chimes directly impacted the day to day life of everyone in the city. There are examples of wealthy individuals attempting to change the schedule of chimes on these clocks to get more work out of their employees and the employees becoming extremely perturbed and demanding change.\n\n The history of time pieces is fascinating. It impacts much of what we consider critical to the development of the modern world. The Swiss invented the standardization of parts and assembly line techniques to gain efficiency in their time piece industry. Modern navigation depended on accurate portable time pieces. Modern astronomy was also developed by time pieces that allowed for more accurate measurement of observations. I already averred to the way management of public clocks affected social contracts between workers and employers, this is key to the development of modern labor relations. \n\n If you want to study this more I can't think of a book better to read than David Landes Revolution in Time: Clocks and the Making of the Modern World. Great book, very illuminating and very good read as well, I recommend it without any reservation to anyone with an interest in history."
]
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[] |
[] |
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[],
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|
5pnqra
|
Without behavioural cues, are birds with little or no sexual dimorphism able to distinguish a male from a female?
|
A thought popped into my head this morning as I was walking to work and I saw a pair of galahs. Male and female galahs are nearly identical, with the only difference being eye colour (the male having black eyes and the female having a deep red, which is quite hard to see). I then started thinking about the many species of Australian birds I know of which display little or no sexual dimorphism (cockatoos, lorikeets, rosellas, magpies..).
I know that most birds tend to have poor senses of smell. In bird species displaying little or no sexual dimorphism, how is a bird able to tell a male bird from a female? Must it rely on behavioural/auditory cues? Do birds ever mistake a male for a female (or vice versa) with potentially amusing consequences?
|
askscience
|
https://www.reddit.com/r/askscience/comments/5pnqra/without_behavioural_cues_are_birds_with_little_or/
|
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"text": [
"I would attribute it to them knowing the tiny differences and being extremely sensitive to them. Remember their eyesight is key, so being able to resolve minute details that you aren't keen to is on their list of advantages they have.\n\nEven without that, animals are generally very acute at recognizing members of their own species. Sheep know every other member of their flock even though their eyesight is poor compared to birds and they can easily look identical to any other animal. Like humans they actually have entire specialized sections of their brain dedicated to resolving each other.\n\nBirds in general have less complex social neurology and rely on \"sign stimuli\", so for instance the bird you mentioned with sexually dimorphic eye color would first identify the shape of the bird as one I'd itsown, and then look at the eyes (red hues are extremely pronounced in birds who scavenge, so this would be glaring to them) in order to determine the rest of their behavior. [[relevant citation]](_URL_0_)",
"As u/Ohzza points out, most animals are finely tuned to recognize sublte differences in members of their own species, so even subtle dimorphism may be obvious to the birds themselves.\n\nSecondly, birds can see further into ultraviolet than humans, and many birds which appear identical to us show sexual dimorphism in the UV spectrum [[ref](_URL_0_)].\n\nFinally, birds can be 'mistaken' for the opposite sex, but this isn't always a mistake - in fact [sexual mimicry](_URL_3_) is a relatively widespread phenomenon in which (typically) males 'pretend' to be females in order to sneak copulations while avoiding aggression from more dominant males. The [ruff](_URL_1_) in particular has taken this to the extreme, with [genetically-determined](_URL_2_) male 'types' including female-like \"faeders\"."
]
}
|
[] |
[] |
[
[
"http://psycnet.apa.org/psycinfo/1955-00376-000"
],
[
"http://onlinelibrary.wiley.com/doi/10.1111/j.1469-7998.2012.00931.x/full",
"https://en.wikipedia.org/wiki/Ruff",
"http://www.nature.com/ng/journal/v48/n1/full/ng.3443.html",
"https://en.wikipedia.org/wiki/Sexual_mimicry"
]
] |
|
1vbxg0
|
Why were blacks in Spanish and Portuguese colonies (especially Brazil) able to preserve their religion better than blacks in English Colonies?
|
a
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/1vbxg0/why_were_blacks_in_spanish_and_portuguese/
|
{
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"text": [
"Related questions: \n\nWere most slaves in North America taken from the Caribbean instead of directly from Africa?\n\nHow common was the smuggling of slaves to Brazil after the British abolished slavery but before Brazil did?",
"I think its a sort of things. But most important: were landed more africans in South America (Brasil indeed) than North America. For example: Salvador, Bahia's capital, has the largest black population outside Africa. Naturally, with a greater number is less difficult to preserve their culture.\n\nSome comparasion in America slavery \n _URL_1_\n\nWell known fact (from _URL_0_):\nThe enslaved were forced to convert to Roman Catholicism, but their original religion, Candomblé, has survived in spite of prohibitions and persecutions. The enslaved Africans managed to preserve their religion by attributing the names and characteristics of their Candomblé deities to Catholic saints with similar qualities. Still today all Candomble sessions are conducted in Yoruba, not Portuguese.\n",
"The difference is that the Spanish and Portuguese were Roman Catholic. Roman Catholicism has always lent itself well to religious syncretism. Catholicism itself consciously employed syncretic techniques throughout its early history in an effort to win converts.\n\nCatholicism, with its panoply of saints, its rituals and iconography was an excellent match and cover for slaves continuing to practice their traditional religions. Not so easy to practice a pantheistic religion within the confines of Protestantism. The Afro-syncretic religions are mixtures of various traditions, but the Yoruba pantheon is the predominate one found in these practices.\n\nIt wasn't just the Spanish and Portuguese either. Remember, the French were also Roman Catholic. So you'll also find syncretic survivals in the Voodoo of Louisiana and the Vodun of Haiti, both of which honor the Yoruba pantheon.\n\n_URL_2_\n\n_URL_1_\n\n_URL_0_\n\n_URL_3_"
]
}
|
[] |
[] |
[
[],
[
"http://en.wikipedia.org/wiki/Salvador,_Bahia",
"http://www.digitalhistory.uh.edu/disp_textbook.cfm?smtID=2&psid=3044"
],
[
"http://www.newadvent.org/cathen/14383c.htm",
"http://www6.miami.edu/iccas/afro2.pdf",
"http://www.historytoday.com/matt-salusbury/did-romans-invent-christmas",
"http://www.atitlan.net/maya/mayan-religion.htm"
]
] |
|
1l41nh
|
why do banks not allow more than a 4 digit pin ?
|
There is a chance of 1 to 3333 to guess the right PIN with trying 3 times. Actually that´s better than playing lottery.
Chances to guess the right one with 8 digits would be 3/10^8 and pretty secure. So why doesn´t my and many other banks allow this ?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1l41nh/eli5_why_do_banks_not_allow_more_than_a_4_digit/
|
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"text": [
"They do allow it, or at least some do. ",
"While it's greater than winning the lottery, it's still really small. There are millions of people playing the lottery, and that's the only reason anyone wins. If you stole a credit card each day for 5 years, the odds of getting one would still only be slightly over 50%. So they don't really need any more. \n\nThe biggest risk is by far people writing down the pin code. And if you make it longer, more people would need to write it down. Which would be a much bigger risk than someone randomly guessing the code. ",
"Over here, it can be between 4-6 digits. You're crazy not to opt for a 6 digit pin.",
"Because it's two-factor authentication. You might be able to guess the right PIN in one out of 3000 cards (possibly a little better than that with social engineering and \"dictionary\" attacks), but guessing the right PIN **and** getting 3000 cards in the first place is fairly difficult.",
"i'm assuming you're talking about your ATM (debit) card PIN, right? actually a 4 digit PIN is very safe.\n\n* first of all, a thief has to PHYSICALLY steal your card which in itself is a somewhat hard task.\n* then guess your 4 digit PIN in 3 tries WITH a security camera pointed DIRECTLY at your face.\n* additionally, there's generally a withdraw limit and if you want to withdraw more in a bank (not at the ATM), you'll need to provide an ID & Face that matches the card.\n* lastly, if everything fails, your money is insured."
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[]
] |
|
2hr420
|
how come asphalt sometimes looks blurry or distorted from a distance?
|
Title.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2hr420/eli5_how_come_asphalt_sometimes_looks_blurry_or/
|
{
"a_id": [
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"score": [
3
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"text": [
"Heat coming from the asphalt distorts your vision. Same concept as desert mirages."
]
}
|
[] |
[] |
[
[]
] |
|
u7v5y
|
Why do eunuchs have a longer life expectancy than women?
|
_URL_1_
_URL_0_
If testosterone causes reduced life expectancy, why do eunuchs live longer than women?
If a man were castrated and received testosterone injections, would he have a longer life expectancy?
|
askscience
|
http://www.reddit.com/r/askscience/comments/u7v5y/why_do_eunuchs_have_a_longer_life_expectancy_than/
|
{
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"text": [
"I'll let someone with expertise in the field address the mechanistic part of your question, but I just wanted to note this:\n\n > The historical record is not good enough to determine if eunuchs tend to outlive normal healthy men, but some sad records suggest that they do. A number of years ago castration of men in institutions for the mentally disturbed was surprisingly commonplace. **In one study of several hundred men at an unnamed institution in Kansas**, the castrated men were found to live on average 14 years longer than their uncastrated fellows. Nevertheless, I doubt that many men—myself included—would choose such a drastic remedy to buy a few extra years. \n\nBecause the study was based on such a specific population, it is extremely difficult to extrapolate findings to the population at large. In this case, we don't know if their increased longevity was related to the castration itself or the reasons for castration (perhaps certain diseases that led to castration also result in increased longevity), or due to other confounders (perhaps they were treated better and were thus healthier). The other evidence the article cites is with neutered pets, which is both similar affected by confounding variables, as well as difficult to apply to humans.\n\nSo before trying to figure out why eunuchs live longer than women, it might be good to verify that that is in fact the case."
]
}
|
[] |
[
"http://geronj.oxfordjournals.org/content/24/4/395.extract",
"http://www.scientificamerican.com/article.cfm?id=why-women-live-longer&page=2"
] |
[
[]
] |
|
hxc5t
|
Would it be possible to create a material that only lets heat pass through it one way?
|
I think that it would be possible via, for example, constructing it on nanoscale from layers of grid-aligned atoms, every next layer having particles bound stronger, so they can't vibrate strong enough to pass their force to next layer, while being close enough to previous layer to get heat from it.
A material built of millions of layers(perhaps 5-10 unique-density layers, repeating in a saw pattern) would let certain amount of heat in, and after enough heat is in it, it would start releasing it the other way, while only a tiny bit of heat would escape back.
Would it be possible this way? What about other potential possibilities?
|
askscience
|
http://www.reddit.com/r/askscience/comments/hxc5t/would_it_be_possible_to_create_a_material_that/
|
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"text": [
"Have you read about [Maxwell's demon](_URL_0_)?\n\nThat idea aside, I'm not quite sure how your proposed structure works. You have one layer that absorbs some level of heat, and a next layer that is harder to excite, and so forth. At the end of the day though, you have one energy barrier, largely defined by the \"least excitable layer.\" Heat flow in either direction only needs to overcome this barrier.",
"I really don't understand the mechanism for this device as you've described it, but the sort of material you're describing is [Maxwell's demon](_URL_0_) itself. In order to avoid breaking the second law of thermodynamics, such a material would have to produce an increase in entropy somewhere in the system that was greater than the decrease in entropy caused by the material's ability to separate hot from cold.",
"At room temperatures no way. The vibrational spectrum is too broad for all but an infinitely complicated structure to act as an acoustic diode. However, people have postulated designing materials that have a significant acoustic bandgap, possibly encompassing the audible range...",
"Doesn't that violate the 2nd law in that you're making a heat pump that doesn't need any work input and is 100% efficient?",
"This sounds similar to a diode, which has greater resistance to electrons moving across it in one direction than another. ...the question, then, is what happens if you stick a diode on (...err... between) a straight length of wire. Since some electrons will randomly pass through, and it's more likely in one direction than the other, could you build up a net charge? \n\nWell, according to wikipedia, this is an electrical analogue of a [Brownian ratchet](_URL_0_). The \"why it fails\" section of that article is pretty good.\n",
"[Found one!](_URL_0_). From the abstract:\n\n\"We demonstrated nanoscale solid-state thermal rectification... ...The effect cannot be explained by ordinary perturbative wave theories, and instead we suggest that solitons may be responsible for the phenomenon...\""
]
}
|
[] |
[] |
[
[
"http://en.wikipedia.org/wiki/Maxwell%27s_demon"
],
[
"http://en.wikipedia.org/wiki/Maxwell's_demon"
],
[],
[],
[
"http://en.wikipedia.org/wiki/Brownian_ratchet"
],
[
"http://www.sciencemag.org/content/314/5802/1121.short"
]
] |
|
bnnw83
|
how do companies like coca cola, pepsi, google keep a lid on their trade secrets with such an enormous amount of people involved
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/bnnw83/eli5_how_do_companies_like_coca_cola_pepsi_google/
|
{
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"text": [
"Usually it’s not really a secret. It’s more the risk of litigation if some uses a patented process/formula that prevents the use."
]
}
|
[] |
[] |
[
[]
] |
||
35sebe
|
Is the greek language of antiquity and the one used in modern Greece the same? Could Aristote engage in a conversation with modern clubbers on the island of Mykonos?
|
Could anyone speaking modern greek understand the inscriptions in Athens, Ephesus, Pergamon or any ancient greek cities?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/35sebe/is_the_greek_language_of_antiquity_and_the_one/
|
{
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"cr7dxer"
],
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"text": [
"hi! you may be interested in this similar question\n\n* [How similar is the modern Greek language with the Greek spoken in the Classical Period? Would they be able to understand each other?](_URL_0_) - featuring /u/Ireallydidnotdoit\n\nif you have follow-up questions on this post, ask them here & mention the user's username so they'll be auto-notified"
]
}
|
[] |
[] |
[
[
"http://www.reddit.com/r/AskHistorians/comments/2fr74g/how_similar_is_the_modern_greek_language_with_the/"
]
] |
|
s6n11
|
Is water required to form granite and other felsic rocks?
|
How does granite form? What does "felsic" mean? I have read that Venus' highlands are composed mostly of felsic rocks and granite is prime among those.
|
askscience
|
http://www.reddit.com/r/askscience/comments/s6n11/is_water_required_to_form_granite_and_other/
|
{
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"text": [
"Felsic means a rock that has a high silicate content. On Earth we find felsic rocks in the crust since silica differentiated out towards the Earth's surface. When rocks are poor in silicates they are known as \"mafic\", and rocks from deeper in the Earth (i.e. the mantle) are generally mafic. Granite is a felsic igneous rock which is formed when silica rich melts solidify slowly, so that the large crystals that you see in granite can form. Igneous rocks that solidify quickly from melts with the same composition are what we find around volcanoes on Earth (i.e. rhyolite and obsidian) since they have to be cooled very fast.\n\nI'm guessing the high temperatures and active volcanism on Venus promote the formation of granite there.",
"It means that it is high in silica and feldspathic minerals. Granite is formed through r e-melting of surrounding host rock and a process of fractional crystallisation. It certainly doesn't require free water. \n\nMy geochemist colleagues would also do me bloody murder if I didn't point out that 'granite' is a specific chemical term for a particular type of rock which has a certain percentage of quartz and potassium and plagioclase feldspars, identifiable only under thin section or by geochem analysis. A broader term is 'granitic', which you can identify in the field. 'Basalt' and 'basaltic' have a similar relationship."
]
}
|
[] |
[] |
[
[],
[]
] |
|
29bjgm
|
how come i can remember every single embarrassing moment of my childhood but manage to forget someones name right after they tell me?
|
Im sure everyone has had this problem one time or another. Youll meet soneone new and they tell you their name and even if you make a point of remembering their name for some reason your brain is just like "nah this persons name isnt important enough to remember" and you forget it istantly. So my question is why can I remeber things that happen decades ago but not the most important thing about meeting a new person?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/29bjgm/eli5_how_come_i_can_remember_every_single/
|
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"text": [
"Embarrassing moments make an impression worthy of remembering. People's names, however, are usually last on the impression making list, unless your name is Sir Dick Phok. ",
"Your brain will see the embarrassing moments as big important things that really affected you - where as someone telling you there name doesn't exactly make you internally freak out like when you did something embarrassing when you were younger, so obviously the times something bad's happened are going to be made a priority when little things like names are easier to just forget as they aren't seen as important",
"A person's name is not a novel experience that changes your life.\n\nHaving something embarrassing/life-changing is a much more significant memory because you feel the need to remember it. You don't want to be in those embarrassing situations again, so you remember them in an effort to prevent them from happening again.\n\nMaybe you were pants'd in school; you will wear a belt in school now so you don't get pants'd again...you don't want to be embarrassed because it makes you look weaker/less alpha than those around you. This stops you from attracting a mate, which, deep down inside, is your ultimate goal. You want to attract a mate, survive, and be healthy...so your brain does what it can to make you a more desirable mate.\n\nGo ahead and think about why you do everything that you do for a second... \"Why do I go to school?\" \"Why do I want to beat this kid in a race?\" \"Why do I want to be happy, have a job, and make money?\"",
"Remembering names is simply a matter of what you're *consciously* giving your attention to. My guess is that when you are meeting a new person, you are focusing inwardly, maybe worrying about how you seem to this new person rather than their name. "
]
}
|
[] |
[] |
[
[],
[],
[],
[]
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|
2yi671
|
How does the Mauna Loa Observatory manage to get accurate representative CO2 readings for Earth's atmosphere when it's in such a close proximity to multiple volcanoes?
|
I've tried running through this in my head a few times and I've tried to look it up online but nothing is coming up. The volcanoes are active, but do they only emit significant amounts of CO2 during large eruptions? Does CO2 emission have to do with the type of volcano/lava and its silica content? It would seem to me that because Mauna Loa is located in such close proximity to these volcanoes that the CO2 readings that it receives would be higher than the total global average.
|
askscience
|
http://www.reddit.com/r/askscience/comments/2yi671/how_does_the_mauna_loa_observatory_manage_to_get/
|
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"To start with, it's important to realize why a place like Mauna Loa is a good spot to try to measure CO2 trends in the first place. As a gas that is emitted in large quantities by various human sources (e.g. cars) and is drawn down by plants at different times during the day, you want to try to measure global CO2 someplace mainly devoid of plants and far away from humans, like on top of a mostly barren volcano. Mauna Loa also has the advantage of essentially being in the middle of the ocean, so the air masses being sampled likely represent a reasonably well mixed bit of air. The main page from [NOAA has some good discussion of how the measurements are made and why (along with a comparison of significantly more noisy data from a mid-continent site)](_URL_1_).\n\nOnto the question, the short answer is that usually the prevailing winds are such that emissions from the volcanic vents do not impact the measurements, but when this is not the case, the measurements are very noticeably influenced and can thus be filtered out. It's important to consider that CO2 is not the only gas being measured and is not the only gas released during eruptions (e.g. SO2), so it's reasonably easy to track when measurements are being messed up by a local volcanic source. Here is a rather long and technical discussion of [this process](_URL_0_). \n\nFinally, this is not the only place that is largely devoid of plants and is far away from humans that have been collecting long-term measurements of CO2 and they all [pretty much show the same thing](_URL_2_), suggesting that after filtering the data as described above, volcanic emissions are not grossly affecting the long-term results."
]
}
|
[] |
[] |
[
[
"http://web.archive.org/web/19980114152259/http://mloserv.mlo.hawaii.gov/publish/steve/VolcCO2.htm",
"http://www.esrl.noaa.gov/gmd/ccgg/about/co2_measurements.html",
"http://www.skepticalscience.com/Measuring-CO2-levels-from-the-volcano-at-Mauna-Loa.html"
]
] |
|
9yu7yh
|
we say that only some planets can sustain life due to the “goldilocks zone” (distance from the sun). how are we sure that’s the only thing that can sustain life? isn’t there the possibility of life in a form we don’t yet understand?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/9yu7yh/eli5_we_say_that_only_some_planets_can_sustain/
|
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"Yes, but how would you know what to look for with a life form we know nothing about?",
"Well, to be clear, the \"Goldilocks\" zone is not a hard and fast rule. \n\nIn the story \"Goldilocks and the Three Bears\" there were still creatures who ate the porridge and slept on the bed that was too hot or too hard. So the notion is simply that this zone has the greatest opportunity for life, not that it is the only possible place where life exists.\n\nI mean, we are pretty sure there is life on the various moons of Jupiter, Uranus etc... and they are well outside that zone. \n\nBasically, at this point in our ability to scan the universe, it makes more sense for us to focus our efforts on this \"Goldilocks zone\" rather than expend a higher level of effort searching out these other areas where life is less likely. ",
"Totally. But we have no idea what \"other life\" would look like. We could be staring it right in the face and we might have no idea that we could call it \"life.\" So until we have compelling evidence that some other form of life can exist, it's best to limit our search to \"Earth-like\" life, because at least then we actually know what we're looking for.\n\nHell, for all we know, there are living rock monsters on Venus that breathe the horrible sulfur gases in that atmosphere that would kill us. But if we were to see that in some future observation, we'd probably say \"Huh, there's some interesting effect that these rocks are having on the surrounding air, it makes them move around. We should study that a bit.\" It wouldn't occur to any of us to call that \"life\" at first glance because we've never seen anything like it.",
"\\ > **Isn’t there the possibility of life in a form we don’t yet understand?** \n\nAbsolutely.\n\nThe problem is we don't understand what we don't understand, and have no real way of searching for that kind of life. It could be the most common form of intelligent life is superconducting crystal on worlds near absolute zero. Or gas-filled balloons in the atmospheres of Jovial planets. Or any of a thousand other possibilities we barely understand, we just don't know. What we do know is how earthlike life looks like, and how it might appear to us from distant planets. ",
"Basically the only life we know is on earth, without knowing other life we can only assume other life is carbon based and therefore have same limitations on earth. Then you look at constraints that would make even the most resilient living organism die, like for example too close to sun and you boil, too far and you freeze, not enough of a protective shell your atmosphere blows off. The goldilocks is the region where a planet can be without getting too cold or too hot.",
"I believe this assertion assumes that water in a liquid form is the key element in having a chance for life. So the goldilocks zone is really just saying there will only be LIQUID water in the universe when a planet is X distance from an object that releases Y heat.\n\n & #x200B;\n\nEdit: a word",
"On top of what others are saying, the Goldilocks zone isn't even the only space in a star system which might have liquid water. It's just the only \"basic\" location which might.\n\nAs an example, you could have a gas giant which is orbiting outside the GZ with a planet sized moon, the tidal forces on this moon increase the heat in the depths of the moon which can result in increased surface temperatures. Couple that in with a decent dose of greenhouse gasses and you can have a liquid-water temperature across large swathes of the moon.\n\nReally the trick with the GZs is that they are the easiest ones to find with our current technology.",
"When you get right down to it, all life relies on chemistry. And in order to facilitate that chemistry, we need a few very basic things that are hard to replace.\n\nFor starters, we need a building block. Something versatile that can be combined in many different ways like a lego block. I'm sure you've heard the phrase \"carbon-based life\" in sci-fi or science sometimes. All Earth life is carbon-based. Carbon has the ability to bond with four other atoms at the same time, that makes it key to creating incredibly diverse and complex molecules.\n\nTo use the lego analogy, carbon is that super versatile block that makes a staggering variety of builds possible. It's not unimaginable that extraterrestrial uses some other base, but out of all known atoms, none are as versatile as carbon. So any known alternative wouldn't support the complexity of molecules that gave rise to Earth life.\n\nSecondly, if you want to facilitate chemical reactions, you need a neutral medium for the ingredients for that reaction to mix in. For Earth life, that's water. Water is a perfect solution for chemical reactions and it's plentiful to boot. Just like carbon, it's hard to find a substitute that is as plentiful or useful for the purpose as water.\n\nFinally, life needs to be able to generate energy. And and the most effective simple means of generating energy is through the chemical reaction of combustion, which requires... oxygen! Sure, there are other ways of generating energy but they're usually more complicated and more limited in scope. Which in turn limits how complex life can get using those alternative methods.\n\nSo it's not like life is impossible without those components. We just have a pretty good idea why those components provide the best opportunity for life.\n\nThe reason those goldilocks planets are so interesting is that they have the key components for *complex* life. If you had to search the entire galaxy for signs of life, would you focus on the factors that are most likely to result in life... or would you search for that one bizarre outlier where some microbe managed to come into existence with suboptimal building blocks, a suboptimal medium for chemical reactions and a poor man's way of generating energy?",
"To elaborate on a concept being expressed here:\n\nYes the Goldilocks zone is looking for conditions that could potentially enable life of the kind we know about. Yes, it is possible other kinds of life exist.\n\nBut, based on some well-reasoned supposition, life of other kinds existing is not as equally likely as our own kind of life existing.\n\nConsider the statistical case. We have a sample size of just one - *us* - but that's still not nothing. It is far more likely that our kind of life utilizes many of the most common mechanisms of life in the cosmos, rather than a rare kind. \n\nBut beyond that, the chemical case. Life of the kind we know and care about is dynamic, sitting on the edge of changing it's form and maintaining it, which means it can both make itself into a complex order, and modify that order over time. \n\nThe carbon atom itself seems to offer the most optimal version of this - carbon bonds are stable, but not too stable. And can chain together to form links of indefinite size to create a wide variety of complex molecules with distinct chemical and catalytic behaviors. Silicon might behave similarly, but silicon bonds (if i'm not mistaken) are stronger and thus change how much energy is necessary to change and alter the materials. Other chemicals could very well serve a similar purpose. But they are less likely to. So looking for carbon is a big part of looking for other life.\n\nBut the main thing looked for is the presence of conditions necessary for liquid water. Water is a very impressive material. Not only is it abundant, but it serves as a great solvent. Life cannot exist on solids alone. No significant chemical activities occurs between solids, and no complicated chemical pathways can be controlled at small scales. You *need* some kind of fluid. Being in a fluid means that materials get circulated around and distributed. You can get access to a large, diverse amount of materials and control the concentration through compartmentalization. You get access to the many resources in your environment in a more reliable and consistent way. \n\nThink about having a pile of salt sitting on your left hand and a pile of sulfur sitting on your right hand. Contrast that with floating in water that contains salt and sulfur. If you skin cells could make use of these materials somehow, all your cells would have access to both, rather than two places being super-saturated and the rest left to starve. Then also consider the likelihood of sulfur or salt being brought to you in the first place. Maybe if you're lucky and some wind blows some dust over you? Far more likely to get the material you need in a puddle of water, where various chemicals can be leeched out of the surrounding rock in far greater quantities than what's available from surface-contact.\n\nHaving liquid water also means moderate temperatures. A really hot place like Venus is liable to break down most bonds, so you can't get large stable molecules to stay together. Meanwhile somewhere like Titan is so cold that chemical processes would occur exponentially more slowly, limiting the rate of development of life, and also leaving too high of an energy barrier to break apart molecules that haven't themselves frozen into inaccessible lattices.\n\nThere's no hard and fast rule here, but as a general supposition, you really do *need* a working fluid to get any life of significance going. And water is abundant and ridiculously convenient in it's ability to serve that role. Maybe a gaseous atmosphere could support such a thing, but then the life would evolve to be buoyant and likely unable to work heavy materials necessary for any sort of exotic material process for electronics, or to utilize significant chemical or nuclear power for industry. Thus they'd be unable to advance to a technological state where they harness lots of energy and can communicate or interact with the rest of the galaxy. Sentient Dirigibles on another planet would be cool, but since light-years are currently a physically insurmountable distance, if they don't have radio, they're not nearly as useful to know about.\n\nSo it's not like we're looking for blue planets just because our life developed on a planet that's blue, as though a Mars or a Venus or a Jupiter would be equally capable of life and we're just biased. Our prejudice towards liquid-water-bearing planets is based not only on us being aware that that environment *can* work, but by having good reason to believe it is far more *likely* to work than other forms. Especially to work in a way that permits the development of non-trivial life that could potentially develop sapience and industry.\n",
"There aren't a *lot* of chemicals that make life possible like water does. Ammonia might be one, methane might be another. But water is chemically simple and does a lot. It dissolves enough chemicals in itself to act as a chemical transport mechanism, but it dissolves other chemicals slowly enough so that it doesn't destroy *everything* it touches. Having *liquid* available is important to life as we currently not only understand it but even as we realistically *imagine* it might be. Water works well for this, and we know it well enough. \n\nBut other liquids *might* work, but a lot more liquids probably won't. Alcohols probably won't work, because too many things break down in their presence. Oils probably won't work so well because they *don't* dissolve other things. Liquid carbon dioxide *might* work, but the temperature band between where it's not frozen solid (life can't happen if stuff can't move) or a gas (also can't really happen if it blows away in the wind) is pretty narrow. Ammonia and methane/ethane are best bets, but those are liquid at *roughly* the same temperatures as water anyway.\n\n**TLDR** Life *probably* needs a liquid to enable movement of chemicals and stuff in organisms, and that liquid needs to not destroy the life in the process. This leaves relatively few chemicals, such as water, ammonia, ethane, and methane. Most of them are liquids at similar temperatures, so a planet or body in space would need to be within a zone that allows those temperatures to not boil or freeze our life.",
"Yes. It is possible. It's just not very likely, compared to carbon-based life relying on water as a solvent and medium. Carbon is uniquely flexible. It wants to form four bonds, and easily forms double bonds. The next-best candidate, silicon, also wants four bonds - but it's big, which makes it less likely to form double bonds.\n\nIts size has another drawback - heavier elements (broadly speaking!) are less abundant in the universe than lighter elements. There is roughly [an order of magnitude more carbon](_URL_1_) in the universe than silicon. (To quote [Wikipedia](_URL_0_): \"Of the varieties of molecules identified in the interstellar medium as of 1998, 84 are based on carbon while only 8 are based on silicon.\")\n\nThe relationship between abundance and mass has another consequence for this conversation - there's lots of hydrogen around, so hydrogen compounds are comparatively easy to make. Carbon and silicon both bond well to hydrogen, except silicon-hydrogen compounds (silanes) tend to be very reactive with water, while hydrocarbons tend to not be very reactive with water.\n\nAnd water, like carbon, has some unique properties that make it an excellent medium for complex chemistry like life. It's the next best thing to a universal solvent, but saturates quickly for most solutes. Its liquid phase encompasses a very broad temperature range - liquid nitrogen, for example, is only liquid over a \\~15° C range, liquid methane only exists in a \\~20° C range - and a liquid medium is crucial for chemical reactions to occur.\n\nSimilarly, it has a large thermal capacity, meaning that its temperature is comparatively resistant to change - and a stable medium is conducive to complex chemistry.\n\nAnd we come back to the relative abundance issue here, too: oxygen is twice as abundant in the universe as carbon, and hydrogen is seventy-five times as abundant as oxygen. So the building blocks of H2O are about as common as possible, it's a very easy compound to form, and it's a relatively hard compound to break.\n\nThe point being that carbon and water are really, really good candidates for making something as complex as life. They're chemically well-suited, and they're very common.\n\nThis doesn't, obviously, mean there can't be life based on silicon or liquid methane or what-have-you, but it seems like the easiest building blocks of life are also the ones we happen to know have formed life.\n\nWhich makes it the best candidate to search for, since we have to pick what it is we want to look for.",
"Sure, it's certainly possible, practically guaranteed that there are possibilities of life that we don't yet know about. But, we know for a fact that Earth can sustain life, so if we want to find life, let's check the places we know are capable of having life before we start exploring unknown areas. ",
"Yes and no.\n\nLife requires complex and well organized chemistry. Complex and well organized chemistry can only evolve in an environment that's neither too hot nor too cold. The chemical building blocks of life don't have to resemble Earth's, but it's still simply impossible for complex molecules or any kind of biological structure to evolve in extremely cold or extremely hot conditions.\n\n[Extremophiles](_URL_0_) exist, but it is assumed that such forms of life originated from moderate environments and later adapted to extreme surroundings.\n",
"we are not sure and its totally possible that other forms of life exist and thrive outside the goldilocks zone.\n\nif we knew of 10 planets that had life on them, we could make much better guesses about where in the universe life might exist.\n\nBut we only know of 1 planet that has life. So we are only able to make somewhat poor guesses about where in the universe life might exist. still those poor guesses are much better then completely random guesses.\n\nIf mars and earth are the only planets in our solar system to have life then that will strengthen the goldilocks theory.",
"They always say it's \"perfect\" circumstances how we evolved but what if we adjusted to what the circumstances were? What if we're thinking of it in an opposite way, how life adjusted to what it's given ",
"To think it couldn't would be naive I think. In the same way an ant can't grasp nuclear physics, we don't know anything beyond our observable universe. Our entire universe could be one of billions of quantum particles that make up a much larger object or living organism.\n\nThere could be different dimensions we are not capable of accessing or undestanding with completely different laws of physics.\n\nWe could be in a simulation that is coded using rules and elements that may only be a subset of many more, or may not even exist in the non simulated world.\n\nBasically we don't know how much we don't know, but the possibilities are near infinite. Of course it entirely possible that our observable universe is all there is and life as we know it exists under the most propable conditions. \n\nHell there could even be a God and life as we know it is just one of many vastly different experiments or creations of his/hers/its. There is no way to disprove this.\n\nYou may have only existed as you for the last 10 seconds and all your memories created to make it seem you have been here for your whole life. In 10 seconds could wake up as different organism in a different reality with different rules and new memories and never know any different.\n\nIt all sound fantastical and a little out there, but all these scenarios are possible, and perhaps even equally likely. We have no way of knowing otherwise. ",
"It confuses the fuck out of me because there's some bacteria that live in absolutely _insane_ temperatures. I'm not a scientist but I feel if some form of life can exist in extreme heat / extreme cold it's possible that something exists outside of the zone",
"This is a big argument for a lot of Christian apologists. That life on Earth couldn’t exist within precisely the parameters that it exists here, and that’s why we know for certain there’s a God. \n\nSo I’m a Christian. I believe in God. But that argument is silly to me, because OF COURSE life would need the current parameters to exist. These are the parameters life evolved to exist in. Our environment matches us because we evolved within this environment. If life has arisen under different circumstances, we’d say the same thing about the incredible coincidence of circumstances being exactly what we needed to survive.\n\nThe Goldilocks zone is “just right” for us. It’s not necessarily indicative that anything that can be called living must live in the same type of zone. "
]
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|
[] |
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"https://en.wikipedia.org/wiki/Hypothetical_types_of_biochemistry#Non-carbon-based_biochemistries",
"http://periodictable.com/Properties/A/UniverseAbundance.html"
],
[],
[
"https://en.wikipedia.org/wiki/Extremophile"
],
[],
[],
[],
[],
[]
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||
11g71p
|
Can a plants' growth really be affected by different types of music?
|
askscience
|
http://www.reddit.com/r/askscience/comments/11g71p/can_a_plants_growth_really_be_affected_by/
|
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"Well plants have no way to hear anything, so it is really in the vibrations caused by playing the music that may affect the growth rate. This is a common science experiment in 5th grade or so, which is ironic because we really still don't have any real answer. Some are leaning towards classical and slower or calmer music would be best for a plant because the vibrations would be less intense, but really that would be a volume issue, and that leads into different levels of bass and a whole bunch of other factors. So I guess the short answer would be we don't fully know right now. Sorry.\n\nHope this helped a little."
]
}
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[] |
[] |
[
[]
] |
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3wcsbv
|
why swinging the hands in the right way can make one run faster/more comfortably?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/3wcsbv/eli5why_swinging_the_hands_in_the_right_way_can/
|
{
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"When you run, your pelvis is twisting as you move each leg. This causes each step to go slightly off-center from your running direction - when your right leg goes forward, it twists your pelvis to the left, causing a change in your angular momentum, thus a change in your direction. In order to maintain your course and not wobble side to side, you'd have to use a lot of extra energy to redirect each step to make sure you keep running in the right direction.\n\nUnless, of course, your upper body twisted in the *opposite* direction from your lower body on each step. By swinging your arms opposite your legs, you are twisting your upper body opposite your lower body to cancel out the change in momentum from your pelvis, thus keeping your direction in a straight line instead of wobbling as you run.\n\nPro tip: don't swing your arms wildly when you run, as that over-compensates. If you keep your arms in a straight line, you'll run more efficiently.\n\n(I apologize if this is not worded very well. It is late and I am failing to go to bed appropriately.)"
]
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[] |
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[
[]
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5bhazb
|
How does helium affect instruments?
|
If instruments were played in a chamber filled completely with helium (or other non-oxygen gas), how would it affect the pitch/timbre of the instrument? Would it affect different instruments (wind/string/percussion) differently?
I'm a musician & sound engineer, so I understand specifics of music, instruments, and basics of the physics of sound.
|
askscience
|
https://www.reddit.com/r/askscience/comments/5bhazb/how_does_helium_affect_instruments/
|
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"It would affect the pitch of wind instruments. Frequencies would be about sqrt(29/4) = 2.7 times as high because of the difference of standing waves in the resonating columns of gas in the instruments.\n\nOf course, there would be problems with reeds, enbouchures, etc. Instruments would be difficult to play.",
"Instruments that vibrate a column of gas (woodwinds, brass) would be affected. Those that have fixed tuning (anything with valves; closed-cavity percussion such as kettle drums) would produce out-of-tune higher pitch and be basically unplayable. Those that have variable tuning (for example, slide trombone) could still be played, but their range would change. I suspect that the musician's embouchure would be affected as well.\n\nInstruments that vibrate the instrument body (strings; non-cavity percussion, such as triangle) would still be able to reproduce their normal pitch, but for some of them timbre would be affected by the changing speed of sound within the instruments, depending on how much the timbre is determined by the air inside the body of the instrument.",
"The speed of sound in helium is about 1000 m/s, while the speed of sound in air is about 340 m/s. \n\nThe equation relating speed of sound frequency and wavelength is v = λ*f in which λ is the wavelength and v is the speed of sound.\n\nIn brass (I only know of brass instruments) the lowest note that can be produced (n=1) has a wavelength of twice the length of the instrument. \n\nThis means that because the instrument does not change and therefore the wavelength stays the same that the frequency will increase giving the instrument a higher pitch",
"Interesting question! Some instruments wouldn't be affected noticeably, but any instrument with a resonant cavity would be affected. As others have pointed out, the speed of sound is about 3x higher in pure helium at STP compared to air. A resonant cavity resonates at a fixed wavelength (or set of wavelengths). Since frequency times wavelength must always give the speed of sound, that means resonant cavities will produce higher 3x higher frequencies. \n\nAll wind instruments rely on resonant cavities coupled to some source of vibration, so they would be affected. Your lips would still vibrate at the same pitch, but you might have trouble finding the notes on a trumpet because the lowest note you could play would be shifted up by 3x from where it normally would sit.\n\nString instruments (mostly) couple the string vibration to a resonant cavity underneath. A violin string would produce the same pitch when bowed (this is determined by the tension in the string), but the violin would sound quiet and off because different pitches would resonate in the body of it. In contrast, a harp or piano wouldn't be affected much.\n\nDrums are another special case because the head of the drum, much like the string, wouldn't be affected. You might not hear any difference for a snare drum. But for something like timpani you rely on some resonance underneath to produce the right sound, so you would expect the sound to shift. A xylophone would produce the same notes, but if it uses resonators the notes won't be sustained for as long."
]
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|
3gb1jh
|
I would like to know more about Mongolia in the 1300s, I've got a few questions!
|
I've been binge watching the Marco Polo series and I'm really enthralled with the clothing designs and decor. I'd love to find more resources and illustrations about all of the beautiful colours, textures and clothing. What material is it, is there symbolism in the colours etc?
The Blue princess' bodyguard mentions that he is of 'the third sex', what is he referring to?
I've vaguely heard of Batu, grandson of Genghis Khan, how did he impact Mongol life/culture?
Khutulun seems to be deep into wrestling - how common was it for Mongols to wrestle? How common was it for women to join in battle, be warriors or be involved in wrestling/hands on activities?
How common were harems, how does marriage and courting go down with Khans? Everyone seems to have 3 wives and a buttload of women in their harems.
Tl;dr - Getting into Mongols, want to know more.
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/3gb1jh/i_would_like_to_know_more_about_mongolia_in_the/
|
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"I can answer some of the questions:\n\n1. Marco Polo is set at the time of Kubelai Khan, grandson of Genghis Khan. By this time the Mongols had already conquered large swathes of China and the Mongol nobility had integrated a lot of the fashions and practices of Chinese nobility (the Mongols didn't really have a nobility as such before). So the majority of materials and designs would have been Chinese, i.e. Silk and Song dyntasty patterns.\n\n2. Most likely a Eunuch. Eunuchs were often used to guard important women because they would not be able to do certain things with them, and would have no long term ambition (i.e. establishing a dynasty) due to not being able to produce heirs.\n\n3. Batu lead the Golden Horde which had a huge impact on the societies and cultures in Central Asia, particularly what is now Russia and the Turkic states (all the -stans of today). I actually read an article, the name escapes me now, which proposed that the Ottomans were pushed into Persian territory fleeing the Golden Horde, bringing about their empire (just a theory, but interesting nonetheless). \n\n4. Don't know much about Mongol recreation, but many warrior cultures use forms of physical contact and mock fighting as a way of both recreation and training, so it's possible, hopefully someone who knows can shed some light here.\n\n5. Don't know about this. \n\nThere are many good books about the Mongols out there, but just be weary, there is a new movement trying to portray the Mongols as kind of historic good guys. Every society has its pros and cons and submitting history to such a subjective light can often sacrifice historical accuracy. "
]
}
|
[] |
[] |
[
[]
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|
1mad8y
|
why some large displacement engines (eg 5.7l hemi) don't produce nearly as much power and torque as many other smaller engines in production vehicles?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1mad8y/eli5_why_some_large_displacement_engines_eg_57l/
|
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"For any engine, power is limited by how much air can flow into the cylinders. To a first approximation, this is the product of displacement, rpm, and turbo boost. That engine has huge displacement, but can't run at very high rpms and has no turbocharger.",
"It's cheaper to just make engines with more displacement. The equation for horsepower is directly related to RPMs, so smaller engines need more RPMs to get more power. More RPMs needs lighter, strong parts. Car companies have to maximize intake and exhaust and spend more time designing the chambers for efficiency and power. It takes more time and research to maximize smaller engines than just build a larger engine. ",
"There is a lot more involved in horsepower than just displacement. For example, a smaller engine with a turbo charger can produce as much if not more horsepower than a larger engine without a turbo because the turbo increases the amount of oxygen being taken in by the motor. If you delve deeper into the mechanics of an engine there are even more differences in the quality of the parts being used and the specific tuning. Another example is the type of motor used in Nascar. They use a 358 cubic inch engine that puts out nearly 900 horsepower. Meanwhile, there are consumer level motors with the same displacement that struggle to produce 300 horsepower. Nascar engines don't use turbos or super chargers, but their parts are more finely tuned and of a higher quality. Their parts are lighter, stronger, and there is no concern for emissions. In contrast, consumer engines are made to be cost effective and low emission (although the two often contradict eachother). Their parts aren't as finely designed and are not as precisely manufactured. Then add on things like mufflers and cats and you loose a lot of potential power. ",
"Almost every answer on here is wrong. Some more than others. Internal combustion engines are very complex and giving a simplified ELI5 answer really doesn't do it justice.\n\nRemember that when a manufacturer reports horsepower, they are reporting *peak* horsepower, meaning the most power the engine makes over it's rev range. To avoid getting too heavily into technical terms, imagine this... Try flooring your car at 1500rpm, then try it again at 4000rpm, since your car most likely has a power curve that makes more power at higher RPM's, you will accelerate more quickly when you floor it at 4000rpm. That is because your engine is making less power at 1500 rpm. Saying that two cars make \"300hp\" is not very telling if one makes 300hp at all revs, and the other produces 300hp at a very high rev and doesn't make much power at other times.\n\nThere are many reasons why some manufacturers choose to use large displacement engines. One of the best reasons is what we just went over, often times a large displacement engine can produce a more even power curve. This is not always true, but it is easier to make an engine with a large displacement have a balanced power curve. This is great for all kinds of driving because being able to accelerate quickly from a low rpm is useful for road driving and racing.\n\nAnother reason is simplicity and weight. Weight? What? I thought that bigger displacement meant heavier! Not quite. Smaller displacement engines often use turbo chargers to help boost their power and efficiency. This is good, but turbo chargers add their own weight, take up space, and usually come with supporting units like inter coolers that take up more weight and space and will affect the car's center of gravity as well as a host of other driving characteristics. \n\nThe third reason why large displacement engines are used is because they usually place less stress on components. Without diving into the combustion process, understand that making a small displacement engine produce the same horsepower as a large displacement engine makes it more \"high strung.\" Components are exposed to higher pressures and higher stresses. This with the added complexity of turbo chargers means that they can wear out more quickly (2.0L turbo charged Mitsubishi Evolutions are a good example of this) and be less susceptible to adverse conditions. Since the components are less stressed in a large displacement engine, they can also be made cheaper, making service cheaper. Furthermore, a relatively unstressed engine is easier to modify to produce more power while an already high strung engine might be at the peak of its abilities without heavily sacrificing reliability.\n\nLarge displacement engines have drawbacks, they often use more fuel and produce more emissions. A turbocharger that they might lack increases efficiency. However, do not confuse large displacement with exterior weight or size.\n\nThere is much more to this. Notice that I try to use \"usually\" as much as possibly because there are very many exceptions. Engineering an engine is a complex process and like all engineering, compromise is the key.\n\nSource: Automotive Mechanical Engineer"
]
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[] |
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||
f20v6s
|
from the moment my town picks it up, what happens to the soda can, glass bottle and stack of papers i’ve recycled?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/f20v6s/eli5_from_the_moment_my_town_picks_it_up_what/
|
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"Cleaned, broken down to base material and remade into new products. Glass and aluminum would be melted, while paper probably shredded and soaked, pressed, and dried into new paper.",
"depends on your town. I live in a major city in Southern California and even though recycling is required for residents, about 15% of it ends up in a landfill.",
"It also depends on how contaminated the lot is. A lot of items are not recycled and are incinerated or sent directly to landfill because there are either unrecyclable items mixed in with the lots (like polystyrene) or they are simply too dirty. This is the case for a lot of plastic items.\n\nIt isn't economical for a recycler to accept a load of plastic that is covered with food waste, for example. Pizza boxes are not recyclable because they're soaked with grease.\n\nItems which can be sold on are sold to middlemen who sell them to companies which process the material into usable material - usually by breaking them down at industrial scale. Those companies then sell the recycled material to manufacturers who process them into new products.",
"If you live near me it goes straight into the landfill. All of it, with the possible exception of clean aluminum.",
"In Poland they get mixed and stored at open dumps, then \"accidentally\" burned down to save the trash mafia (yes, this is a real thing and no, it's not funny) money on actual recycling.",
"Is there a way to find out the recycling practices of the area you live in?",
"In the UK it gets taken and piled up massive stacks at 'recycling centres'.\n\nThen eventually it catches fire, somehow.",
"In Germany you pay 25 cents extra as 'Pfand' and return empty cans and bottles to the shop. Don't know what exactly happens to the cans but bottles get recycled and about 1 out of 4 is made into a new bottle",
"Here is the best best ELI5 answer from my perspective (many other comments alluded to this). \n\nIt depends where you live! What can they recycle? A lot probably ends up in a landfill because it’s not easy to clean it up and recycle. \n\nI advocate using compost materials when possible because these break down. And a few communities I’ve lived in promote compost instead of recycle."
]
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2a82kb
|
Voyager I is travelling at ~61000 km/h away from the Sun. While the Sun is travelling at ~72000 km/h. Is Voyager I's speed relative to the Sun?
|
askscience
|
http://www.reddit.com/r/askscience/comments/2a82kb/voyager_i_is_travelling_at_61000_kmh_away_from/
|
{
"a_id": [
"cisg6vq"
],
"score": [
5
],
"text": [
"What did your source for the 61,000 km/h say? It should say what the velocity is relative to. When dealing with space craft, always pay attention to what any velocities are relative to, if it isn't obvious from the context, otherwise the velocities don't really mean much.\n\nAnyway, Voyager 1 has a Sun relative velocity of about 17 km/s which is about 61,000 km/h. I have no idea what your figure of 72,000 km/h for the Sun is relative to though. Sun's velocity relative to the galactic centre is about 250 km/s, or 900,000 km/h."
]
}
|
[] |
[] |
[
[]
] |
||
1fj4hu
|
how does family guy, robot chicken, and other shows like them get away with using other people's copyrighted characters in sketches without being sued?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1fj4hu/eli5how_does_family_guy_robot_chicken_and_other/
|
{
"a_id": [
"caard0q",
"cab6d29"
],
"score": [
26,
3
],
"text": [
"Fair use.\n\nMaking a parody of something else isn't illegal.",
"In short, as has been answered elsewhere in this thread: Fair Use. American (and I believe a lot of international) copyright law, allows for use of copyrighted material for the purpose of critcism and parody. That is to say, Any use commenting on or making fun the original work, characters and what have you. \n\nSatire is a bit more of a grey area, and can in some cases get you into legal trouble. Satire is where you use copyrighted material for the primary purpose of mockng something unrelated to the copyrighted material, usually something in a real world political context. Like say, you make a cartoon where the characters from Willy Wonka and the Chocolate Factory make fun of the president. \nI've heard opposing claims about this, but on the whole my impression is that satire can get you into legal trouble (as you're not really commenting on the work, just using it to make your points) whereas parody usually won't.\n\nThough in the particular cases of Robot Chicken af Family Guy, stuff like their Star Wars specials are actually endorsed by Lucasfilm, the copyrightholder of the material, so in those cases the point is moot."
]
}
|
[] |
[] |
[
[],
[]
] |
||
b379g2
|
Why does angular velocity and angular momentum follow the 'right hand rule' for direction?
|
I've scoured youtube and did a cursory search here and on EI5 but i can't find a good explanation. Every youtube video i look up just says "yeah use the right hand rule to find direction!" (of L and w) without ever explaining WHY we use it. WHY does the direction of angular momentum, for example of a "spinning ice skater" (classic example) who is spinning clockwise when viewed from above, point DOWN? Nothing is actually going down! (is it?!)
I watched one video and some guy said it's just a convention we decided on. But then i watched professor Lewin's demonstrations and it can't just be a convention because the objects actually follow these rules in the real world. Did we just decide to use this convention so it matches observation?
Can anyone explain why ang. momentum and ang. velocity vectors have these odd directions?
|
askscience
|
https://www.reddit.com/r/askscience/comments/b379g2/why_does_angular_velocity_and_angular_momentum/
|
{
"a_id": [
"eixzzoz"
],
"score": [
22
],
"text": [
" > I watched one video and some guy said it's just a convention we decided on.\n\nIt is indeed a convention. Angular momentum is what is called a pseudo-vector which means they do not change direction under coordinate inversions,\n\n* x → x' = -x\n* y → y' = -y\n* z → z' = -z\n\nTrue-blue vectors, also called polar-vectors, change their direction under such a transformation. Coordinate inversion is one type of \"improper rotation\" which are rotations combined with reflections. In contrast, the pseudo-vector does not change direction.\n\nA pseudo-vector is usually defined as the cross product of two polar vectors, for example angular momentum is,\n\n* **L** = **r**x**p**\n\nUnder coordinate inversion, both **r** (position) and **p** (momentum) acquire a minus sign which cancels out leaving **L** unchanged. Ultimately this is related to the fact that the cross product's orientation in space is non-unique as there are two possible vectors (left and right handed orientations) which are perpendicular to any two non-parallel polar-vectors.\n\n > But then i watched professor Lewin's demonstrations and it can't just be a convention because the objects actually follow these rules in the real world. Did we just decide to use this convention so it matches observation?\n\nNah, we wrote down the dynamical equations of motion to accommodate the right hand rule. If we wrote down mechanics using the left hand rule, any physics equation which has a psuedo-vector, would acquire a negative sign. A good example would be the Lorentz force equation for charges in the presence of magnetic fields,\n\n* **F** = q**v**x**B** (Right handed)\n\n* **F** = q**B**x**v** (Left handed)\n\nwhere **v** is velocity (polar vector) and **B** is magnetic field (pseudo-vector) and we took advantage of the fact that **a**x**b**=-**b**x**a**. As the force **F** is a polar-vector, it can't physically change direction which is good because the acceleration of my electron shouldn't care which convention I use. This also reveals another aspect of the cross product in that a pseudo-vector cross a polar-vector is a polar-vector.\n\nThere's a deeper connection to orientation of the Euclidean coordinate system. We know we have x, y, and z unit-vectors, and we know they are all perpendicular to one another, but it is ambiguous given two Cartesian unit-vectors which way the third points. In other words,\n\n* **x-unit** = (1,0,0)\n* **y-unit** = (0,1,0)\n* **z-unit** = **x-unit** x **y-unit** (Either Left or Right, you pick.)\n\nYou can switch between Right and Left handed orientations by a single coordinate reflection,\n\n* x → x' = -x\n* y → y' = y\n* z → z' = z\n\nIf the unprimed coordinate system is Right-Hand orientation then the primed coordinate system is Left-Hand orientation. **Edit:** To add, the Lorentz force, and all the dynamical equations are unchanged if you either\n\n1. define a RH-coordinate system and stick with the RH-rule or you\n\n2. define a LH-coordinate system and stick with the LH-rule\n\nIn both the above two cases, the Lorentz force is just given as,\n\n* **F** = q**v**x**B** (Right or Left handed)\n\nThe minus sign only appeared earlier, because you \"mixed and matched.\""
]
}
|
[] |
[] |
[
[]
] |
|
1s4u3e
|
is there any real difference between the fruit drawer and the vegetable drawer in my refrigerator?
|
My refrigerator has two drawers, labeled "Vegetables" and "Fruits". However, there aren't any knobs or special vents for either of them, as far as I can tell. In fact, I can remove them without any trouble for cleaning.
Perhaps my specific refrigerator model simply creates separate storage areas for fruits and vegetables. However, I'm pretty sure I've seen cases where there ARE knobs, albeit no discernible function...
Could somebody please enlighten me?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1s4u3e/eli5_is_there_any_real_difference_between_the/
|
{
"a_id": [
"cdtx4ob",
"cdtxvgw",
"cdu2c5q"
],
"score": [
3,
5,
5
],
"text": [
"In general, I think the fruits drawer will be vented more than the veg drawer - the idea being to keep fruits from rotting by letting them stay drier, but keeping veg crisper in a higher-humidity environment.",
"The rule of thumb is to put things that rot in a drawer with low humidity (fruit drawer). \n\nAnd to put things that wilt in a drawer with high humidity (veggie drawer).\n\nThe difference is the amount of air/moisture that can leave the drawers though gaps in the assembly. The fruit drawer will have bigger gaps (and therefore more dry air circulation) than the veggie drawer.\n",
"Depends on how nice your refrigerator is. If it's a cheap one, like you'd likely find provided in a typical apartment complex, it's probably just two drawers with labels to help you organize your fridge space. If it's a nicer model then the drawers will actually be climate controlled, with the fruit drawer at a lower humidity, and the veggie drawer at a higher humidity. \n"
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
95l6b7
|
What effects would the most commonly used antipsychotics have on someone not suffering from Psychosis?
|
This is in relation to a personal writing project, so I don't know if this question goes against the sub Reddit's rules. This might count as a hypothetical question, or maybe to specific of a scenario. But assuming a person wouldn't have their misdiagnosis corrected for a long time (which can realistically happen sometimes), what results would long term psychosis treatment have on the person?
|
askscience
|
https://www.reddit.com/r/askscience/comments/95l6b7/what_effects_would_the_most_commonly_used/
|
{
"a_id": [
"e3tzk7b",
"e5t7ti2"
],
"score": [
8,
2
],
"text": [
"One effect that is well documented even in people with psychosis is drug induced Parkinson's disease. For example, Abilify is a partial agonist for the dopamine receptor 2, so it blocks normal activation of that receptor by normal levels of dopamine in the brain. In Parkinson's disease, the dopaminergic neurons are gradually lost, so you have less dopamine and less activation of dopamine receptors, leading to muscle tremors and rigid motor control. A normal person taking Abilify could get parkinson's like symptoms. \n\nOther long term effects would probably involve increased expression of dopamine receptors and synapse remodeling, so when they stopped taking the drugs, they could potentially be more sensitive to the effects of endorphins.",
"There is good evidence that antipsychotics cause irreversible brain shrinkage -- that is, brain damage. They are also associated with significant weight gain, increased risk of diabetes, sedation, apathy, anhedonia, tardive dyskinesia, and sexual dysfunction. In short, they would make a healthy person unhealthy and unhappy.\n\n[_URL_0_](_URL_0_)"
]
}
|
[] |
[] |
[
[],
[
"https://www.madinamerica.com/2013/06/antipsychotics-and-brain-shrinkage-an-update/"
]
] |
|
3mqjp9
|
what's the difference between centrifical and centrifugal force? which is the "fake" one?
|
Every time I attend a science class and we bring up physics someone brings up one of these two and half the time someone gets shot down and told that it doesn't exist. And every time we move on too fast for me to ask.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/3mqjp9/eli5_whats_the_difference_between_centrifical_and/
|
{
"a_id": [
"cvh7tp2"
],
"score": [
10
],
"text": [
"Neither one is \"fake\" however one is \"*fictitious*\". But fictitious doesn't mean \"not real.\"\n\nThe centrifugal force is the fictitious one.\n\nWhen you have circular motion, there must be a force pointing inwards, since the object is always accelerating towards the center of the circle. That is the centri**petal** force, and that's the on that exists no matter what.\n\nThe centri**fugal** force is \"fictitious\" in that it only exists in a non-inertial reference frame.\n\nIn a reference frame that is rotating with the spinning object, there must be a force to counteract the centripetal force, since the object is stationary in this reference frame. That force is the centrifugal force. It's called a \"fictitious\" force because it's really just there to correct for the acceleration of the reference frame itself."
]
}
|
[] |
[] |
[
[]
] |
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