question stringlengths 3 301 | answer stringlengths 9 26.1k | context list |
|---|---|---|
why do products that have a yearly title use the next year instead of the current one (e.g. ncaa football 2013, ford 2013 models)? | They're designed for the next year. | [
"In the United States, for regulation purposes (such as VIN numbering and EPA emissions certification), government authorities allow cars of a given model year to be sold starting on January 1 of the previous calendar year. For example, this means that a 2019 model year vehicle can legally go on sale on January 1, ... |
what does it mean when energy drinks say 300% vitamin b6? | It contains 300% of you daily recommended intake of vitamin B6. | [
"vitaminenergy is an energy drink which consists of many of the same ingredients as vitaminwater, such as crystalline fructose, electrolytes, natural flavors, and vitamins (Vitamin B3, B5, B6, B12, and C) along with natural caffeine and ribose. Specific ingredients are added according to the flavor of the drink. Ei... |
how does half sodium salt work? | It's something that is trying to approximate the taste of salt, but has less sodium chloride in it.
The LoSalt product uses potassium chloride. Potassium is right below sodium on the periodic table of elements, so it will bond to chlorine in the same way. It has a salt like taste, but no sodium. | [
"Sodium permanganate behaves similarly to potassium permanganate. It dissolves readily in water to give deep purple solutions, evaporation of which gives prismatic purple-black glistening crystals of the monohydrate NaMnO·HO. The potassium salt does not form a hydrate. Because of its hygroscopic nature, it is less ... |
Will I still be able to taste if my tongue is numb? | Depending on what specifically is causing the numbness, there is a possibility you will still be able to taste. The tongue is innervated by a variety of cranial nerves. The anterior 2/3rds uses the facial nerve (CN VII) for taste while sensation is from the trigeminal nerve (CN V). The posterior 1/3rd uses the glossopharyngeal nerve (CN IX) for both taste and sensation. So in short, yes you can still have some aspect of taste despite numbness depending on what cranial nerves are being impacted. | [
"Excessive absorption of benzonatate (a local anesthetic) in the oral mucosa will result in the rapid development of numbness of the mouth and throat. In extreme cases, the mouth and pharynx may become so numb that pulmonary aspiration may occur.\n",
"When symptoms are present, topical anesthetics can be used to ... |
Did the people in the front lines of ancient armies basically know they are going to die? | I replied briefly to this earlier but reading the thread now I think it deserves some more detailed attention. Here goes:
**On the Matter of Battle in Movies**
There's two ways Hollywood battles can go down. The first is what you see in Troy, with massive armies smashing into each other and men literally tumbling over the enemy front line, carried by their own momentum. The second is what you see in stuff like Gladiator, where individual men are scattered about the battlefield engaging Our Hero one at a time and getting their shit ruined.
While obviously spectacular, neither of these depictions are correct in any way for any period. The first method is obviously suicidal, and no warrior in his right mind would desire to fight that way; it is also ineffectual, as all the men get in each other's way and the chances of people getting hurt by their own and their allies' weapons is frighteningly high. The second method, meanwhile, would require a battlefield the size of Mongolia for everyone to have room to play his part; it ignores such fancy things as formations, shieldwalls, and unit manoeuvre, and is basically just chaos. Again, the odds of people getting accidentally shanked by their own side is very high, this time because it's impossible to tell who is on which side when everyone's mingled together.
While the second type, the open melee, obviously exists just to give movie protagonists a chance to shine, the first type at least has a claim to being based on one interpretation of Classical Greek battle, which is what /u/NeilWiltshire is referring to. However, this is a controversial interpretation, as noted by the ever astute /u/Iguana_on_a_stick. To be precise:
**On the Matter of Hoplite Battle as a Shoving Match**
A number of Greek battle descriptions include some form of the verb *otheo* (to push). Some 20th-century scholars have suggested that this should be read literally: that Greek infantry battle was decided by a mass shoving match (*othismos*, "the pushing"), in which the opposing phalanxes pushed with all their might in order to literally bowl over and trample the enemy. In this theory, the rear ranks of the phalanx served to aid in pushing, and the deeper the phalanx, the stronger the push. Back in 1911, G.B. Grundy described *othismos* as being like "a scrummage in the Rugby game of football", and this analogy stuck (see Neil Wiltshire's post).
However, as early as 1942, A.D. Fraser pioneered criticism of this idea on all levels. In the practical sense, it seemed hard to organise, dangerous to the point of being suicidal, and ineffective compared to the actual use of the hoplite's offensive weapons. In the literary sense, it is difficult to argue that the Greeks meant *othismos* literally when they also use the term to describe, for instance, a debate (*othismos logon*, "push of words"). Would it not be plausible to assume that "the push" in their battle accounts is used in the same metaphorical sense that we use it nowadays? And if not, when Thucydides describes combat as *othismos aspidon*, "push of shields", and when Xenophon describes the fighting of the hoplites by saying "they pushed, fought, killed and died", doesn't the term "pushing" actually refer to the individual warrior's manipulation of his shield in combat, rather than to any collective effort?
Scholars continue to argue over these questions, and there is still no consensus over what happened when two lines of hoplites met. My thesis has a nine-rank footnote just citing authors who have contributed to the controversy. However, the writings of Cawkwell, Krentz, Goldsworthy (cited by Iguana_on_a_stick, the best article on the *othismos* in my opinion) and Van Wees have not just problematised the notion of a literal *othismos*, but also constructed an alternative model, which seems to me a much more plausible reconstruction of what hoplite combat was like.
**On the Matter of Hoplite Battle and Pulse Theory**
This reconstruction is based on the idea that sustained collective pressure on an enemy formation is impossible. Men do not have the stamina or the death wish to fight in such a way, and there are other ways that allow for a much greater endurance and higher survival rate. Mostly, these ways of fighting are based around intermittent contact; the opposing lines may initially crash into each other, but they eventually draw back to catch their breath and clear the wounded, before - individually, in groups or en masse - heading back into the fray.
This interpretation of hoplite combat allows for all sorts of quirks in existing battle descriptions that the theory of literal *othismos* can't explain, like the ability of hoplite formations to draw closer together, or their ability to move wounded commanders away from the cutting edge. It also explains much better why hoplite training, insofar as it existed, focused on stamina and agility much more than on raw strength. Men were expected to use their weapons and dodge the enemy's blows. In a literal shoving match, this would have been impossible.
However, the theory also explains why some battle descriptions involve a moment called "the push". Rather than picturing the whole battle as a shoving match, we should see it as a prolonged engagement in which different groups or units occasionally decided to push. If a large part of the line decided to surge forward at once, and the enemy failed to mount an effective resistance, the battle may fairly be said to have been decided by *othismos*. If they did resist, but one side eventually crumbled, the word is even more apt. It explains why some battles (like Delion or the Nemea) involved locally extreme casualties where opposing contingents had held out beyond hope.
This brings us back to OP's original question. Yes, close combat in Classical Greece could be extremely bloody. According to Peter Krentz' calculations, the losses on the *winning* side averaged some 5%, meaning that even in victory a large part of the front ranks was killed. How did men react to this cruel fact?
**On the Matter of Facing the Spears**
The sheer terror and bloody toll of close combat meant that Greek battle was all about morale. The willingness of troops to engage in melee was much more important than their skill at doing so. Unsurprisingly, several battles were decided without a blow being struck, because one side lost the game of chicken that was the phalanx charge. The Spartans in particular relied on their scary appearance – long-haired, dressed all in red, with shining bronze-faced shields, marching in step with calm determination – to win battles before they had really begun. Scaring the enemy was the best way to avoid the game of dice with the gods of troop morale (mostly Pan, from whom we get the term ‘panic’) that was phalanx battle.
Loads of different methods were therefore used to make men willing, and ideally eager, to fight. Sacrifices before a campaign and before battle assured the good will of the gods. The general’s speech before battle reminded the men of what they were fighting for, and the ones that we know of often included disparaging comments about the enemy. The general sometimes passed down a watchword such as “Zeus Saviour and Victory” to give the troops a creed to fight by. Before the charge, hoplites would sing – a collective song to get their spirits up and instil a sense of collective destiny. The men in the ranks, usually levies from the same town or region, would encourage each other as peers and as seniors to inexperienced young men. To overcome their fear of imminent death, they charged into battle, screaming a war cry.
Even all this was not considered enough. If any man from the front ranks turned, the rest was likely to follow. The Greeks therefore realised that it was crucial to make sure that the men at the front were the strongest and bravest – and that the men at the rear, the file-closers, were wise and reliable men. It was their purpose to keep the wavering middle ranks in the fight. They were the barrier to flight that was to keep men’s attention focused forward. This exact method was used by the Macedonians in their pike formations: the bravest men at the front, the most reliable men at the rear. When a pike formation needed to change its facing, it could not simply have each man turn in place; it needed to carry out an elaborate countermarch to make sure the men at the front remained the men at the front, and the men at the rear stayed at the rear.
The rear ranks, then, served to keep the front ranks moving forward. This was also why the Greeks often deployed a deep formation. It had nothing to do with pushing; it was all about setting down a ton of men who were far enough from the fighting to remain eager, whose very presence made it impossible for the front ranks to flee. | [
"BULLET::::- This is the first episode to feature multiple warriors on each team in an ancient match, and the only one where a member of the losing team is not known to be killed (Attila and his men were not seen killing one of Alexander's soldiers, so either he escaped or was simply not seen dying).\n",
"BULLET:... |
the impeachment of bill clinton | First of all, I don't believe there needs to be any real reason to impeach the president. To remove from office it requires a serious offense, but he wasn't removed from office.
That being said the impeachment wasn't that he had an affair, it was that he lied under oath, which is kind of a big deal. | [
"The impeachment of Bill Clinton was initiated on October 8, 1998, when the United States House of Representatives voted to commence impeachment proceedings against Bill Clinton, 42nd president of the United States, for \"high crimes and misdemeanors\", which were subsequently detailed in 2 articles of impeachment.... |
Overarching explanations of history | > How do Historians view theories that attempt to explain all of history
Historians are a varied bunch of people, but I'm studying history in the Netherlands and most professors seem to oppose these overarching explanations. It's all about acknowledging different perspectives and relativism nowadays. Knowledge is uncertain. Someone on this subreddit advised me to read the book **The Inheritance of Rome** so I read about it, and this is what a (non-professional) reviewer said...
> Just to be clear: Chris Wickham does not believe that he can explain anything. He repeats this over and over, so you'll not get the wrong idea. Let's be very, very clear: nothing in history is 'inevitable,' everything is 'contingent,' and we'd be fools to write history with our hindsight. Nope, we should see things as they were seen at the time.
> (...)
> A historian friend of mine tells me these are the conventional pieties of professional historiography, and that I should just ignore them. (...) Nothing can be compared to anything else without doing violence to the quidditas of the individual. Local experience is everything. If anyone has suggested the existence of a large scale trend (end of Roman civilization/ various crises/ the coming of feudalism) actually happened, Wickham has fifteen good examples to show why it didn't. This is because he disdains moralism in history
> _URL_5_
That might be too negative, but it resembles what a lot of professional historians seem to aspire to. No big overarching explanations that want to explain everything, but local experiences and we shouldn't write history with out hindsight. "Whig history"...
> Whig history (or Whig Historiography) is the approach to historiography which presents the past as an inevitable progression towards ever greater liberty and enlightenment, culminating in modern forms of liberal democracy and constitutional monarchy. In general, Whig historians emphasize the rise of constitutional government, personal freedoms and scientific progress. The term is often applied generally (and pejoratively) to histories that present the past as the inexorable march of progress toward enlightenment.
> _URL_3_
...is not appreciated, in general.
> Marx's theory
A lot of important historians in the 1960s/70s/80s seem to have been Marxists.
> Do you find some true?
Personally, [I believe a technological Singularity](_URL_1_) is near and I do see history as a steadily accelerating development towards increasing complexity. Development was slow in the past: not much change happened in the first billion years of life on earth. Mammals and primates are relatively new developments. We lived as hunter-gatherers, not much better than other animals, only 10.000 years ago. *From hunter-gatherers to Manhattan in 10.000 years!* And again: not much happened between 10.000 BC and 1000 BC. Not if you compare it to the last 1000 years. We are effectively already living in a Singularity;
* [GDP per capita](_URL_0_)
* [Population](_URL_2_)
* [Energy consumption](_URL_4_) | [
"Commager's biographer Neil Jumonville has argued that this style of influential public history has been lost in the 21st century because political correctness has rejected Commager's open marketplace of tough ideas. Jumonville says history now comprises abstruse deconstruction by experts, with statistics instead o... |
How and why were the Mamluks ruled by Circassians from the late 14th until the early 16th century? | The Mamluks were a class of non-Muslim boys who were taken at a young age and raised as Muslim warriors. Many of these solders excelled as administrators and soon enough grew to the status of governors and such. But as time went on the influence of these Mamluks grew to a point where they did a coup and overthrew the Ayyubids( in Egypt) and formed there own governments. These were first Turkic peoples, but they were quickly overthrown by rivals originating from the caucuses region. During these sultanates political infighting and revolts were common and no dynasty ruled for long with the longest being the Burji dynasty.
The rise of the Mamluks started in 1248 when the crusaders invaded Egypt, the Ayyubid sultan, as-Salih Ayyub led an army to stop the crusaders and eventually defeated them, shortly after he died and his son, al-Mu'azzam Turan-Shah took power. His son started to marginalize the Bahri( Mamluk) generals and soon enough he was assassinated by them. From then on the Ayyubid sultanate split in two with the Bahri mamluks controlling Egypt and an-Nasir Yusuf( an officer under the Ayyubid) in Syria fighting to put the Ayyubid back in power, this continued in a massive power struggle where both sides tried to wrestle power from each other. Soon enough both sides agreed to a cease fire by the caliph where an-Nasir Yusuf would own Sham (Syria and surrounding area) and the Bahri's would own Egypt. This cease fire quickly broke down and both sides were bogged down in fighting again. After a long struggle the Bahri Mamluks(now sultans) defeated an-Nasir Yusuf in a battle around Sinai and thus continued the Stalemate. Soon after Hulagu Khan rampaged around Arabia, razing Baghdad and then soon after Aleppo. then governor after governor surrendered to the Mongols. Nasir Yusuf then fled to Gaza where he was soon captured. Thus ended Nasir's reign in Sham. And when Hulagu Khan went back to Karakorum and left Kitbuqa a Nestorian Christian in power, Kitbaqu was then quickly defeated by the Mamluks at the battle of Ain-Jalut and within 5 days Damascus fell to the Mamluks solidifying Mamluks control over the sultanate. More info on: _URL_0_
For info about the specific dynasties in the Mamluk Sultanate of egypt see:_URL_1_
The rise of the Mamluks into positions of power (sultans, emirs, etc) was not too common but a few more Mamluk dynasties did exist such as the Mamluk dynasty of Delhi of Turkic origin and the Mamluk dynasty of Iraq.
While it was uncommon for Mamluks to be sultans a similar form class of people did appear quite often in the Osmanli ( or Ottoman, I am used to saying Osmanli from childhood) empire where they were the governors of the various provinces were from the deverishime (Turkish system almost identical to the way Mamluks were raised)
(Pure speculation) I beleive that the fact that mamluks from circassian or whatever origin would not be precieved as too different because the mamluks were essentially egyption because they were raised that way.
Also I am not a historian so I might have mistakes pls correct me if I do. | [
"The Mamluk Dynasty (sometimes referred as Slave Dynasty or Ghulam Dynasty) (), () was directed into Northern India by Qutb ud-Din Aibak, a Turkic Mamluk slave general from Central Asia. The Mamluk Dynasty ruled from 1206 to 1290; it was the first of five unrelated dynasties to rule as the Delhi Sultanate till 1526... |
Probably simple/stupid: Does my behavior affect the genes I pass on? | Well, yes, no, and maybe.
Once this gets closer to the front page someone can provide a better answer, but there is a certain influence from epigenetics with your phenotype. Epigenetics has to do with how and when certain genes are activated.
The epigenome is influenced by many environmental factors (stress, starvation, etc.). I believe it has been shown in rats to be passed on through at least one generation. When a female rat is under long term stress, she has more children and cares for them less than a comfortable rat. Her daughters will do the same even when under better conditions and raised separately, indicating heritable change. (This is from memory so I may be wrong. I'm on a phone and can't look it up, but pretty sure that was the experiment.)
With people, as always, it harder to demonstrate that this phenomenon occurs. There was study that showed that if a father smokes when impregnates a woman the children are more prone to weight gain which they attributed to epigenetics, but I'm not sure if they adjusted for the social factors involved with that (the father, even if he quits, is more likely to not be health conscious and come in a poorer economic situation)
That being said, the actions of the child and possibly the pregnant mother have a greater effect on epigenetics than the anything before the pregnancy, and I would say for the most part, your genes are your genes. | [
"From these examples, researchers have seen similar patterns in developmental genetics. It is imperative that many genes are silenced at the right time so that cells can maintain their identity and expressional integrity. Failure to do so often leads to symptoms such as cognitive abnormalities, if not fatality.\n",... |
why south american countries are not and don't want to get involved in world politics? | Some South American countries are very involved in world politics. Brazil for example is a pretty big player, and Venezuela is heavily involved, if not particularly influential, in global politics.
Some of the smaller countries though have made the same decision that small countries all over the world have made. That they are better served focusing on local and regional issues and that getting involved in big international slap-fights can only hurt them. | [
"During the first decade of the 21st century, South American governments have drifted to the political left, with leftist leaders being elected in Chile, Uruguay, Brazil, Argentina, Ecuador, Bolivia, Paraguay, Peru and Venezuela. Most South American countries are making increasing use of protectionist policies, hel... |
what is the difference between renting to own a home and purchasing a home, and what are the requirements for home-buying? | rent-to-own is an agreement between you and the real owner to transfer ownership after certain criteria are met.
If you get a mortgage from the bank, your home is yours (but it is also collateral for the home loan). | [
"Rent-to-own, also known as rental-purchase, is a type of legally documented transaction under which tangible property, such as furniture, consumer electronics, motor vehicles, home appliances, real property, and engagement rings, is leased in exchange for a weekly or monthly payment, with the option to purchase at... |
how does gas compression work? highschool chemistry taught me that various states of matter are the same thing just molecularly tighter. why is a compressed gas not just liquid? | Super compressed gas *does* become a liquid for most gasses (though I think a few gasses like hydrogen get kinda funky there instead). Compressing gasses brings the molecules closer together, but most gasses need to be compressed quite a bit (or cooled down a lot, or some combination of both) before they actually transition to a liquid phase.
Check out "phase diagrams" when you get a chance, they show the combinations of temperature and pressure for a given material where the material is a gas, liquid, or solid and can help you to see where things will switch from one to another. | [
"Compressed gas is currently an experimental method of storing energy. In this case, compressed gas is simply stored in a tank and released when necessary. Like elastics, they have hysteresis losses when gas heats up during compression.\n",
"Based on the assumptions that adiabatic compression is carried out (i.e.... |
What was porn like in the 1960's? | An interesting read on the subject is the article *An Empire of the Obscene* in journalist Eric Schlosser's 2003 book *Reefer Madness*. It focuses on the career of Reuben Sturman, who was the biggest distributor of pornographic materials from the 60's onwards and a very big figure in the business until 1989 when he went to jail for tax evasion. It does tell more of the history of porn in the US. At some point before movie projectors became more common, there were entrepreneur's who provided a projector and material for "stag nights" or bachelor parties. Another thing to find some information on is the appearance of viewing booths in porn shops, although I'm not sure whether this was as late as the 70s. I don't have the book with me, but I recommend it highly, the other two articles on underground economies in the US, the marijuana trade and the illegal immigrant business are very interesting too.
Edit: Had to remove some ambiguities.
_URL_0_ | [
"Before the age of internet pornography and a general acceptance of the production of pornography, porn was an underground phenomenon. Stag films, also known as blue movies, were made by men for men. The projections of such films were itinerant and were secret exhibitions in brothels or smoker houses. Stag films we... |
is it still solicitation for sex if i ask a hooker to make me a sandwich for what ever she charges then we both consent to have sex afterwards? | I am fairly sure this is how a lot of escort services work without getting into too much trouble. You pay for the "date" and if sex happens, well that's between two consenting adults!
I think you may need an actual lawyer to answer this question as it is probably incredibly complex and would vary based on states/countries. | [
"Defence counsel may argue the victim consented to the sexual activity. Determining if the victim consented can be problematic when the victim is intoxicated. A Nova Scotia court found there was no sexual assault because the prosecution could not prove the sexual activity was non-consensual. In that case, the sexua... |
how hushing came to be the sound we use when we want people to be quiet. | I always wondered about the same thing and quite recently I discovered that the hushing sound is the most common sound you can make with your mouth to calm down a newborn baby: they naturally calm down when they hear vibrations and white noises.
I wouldn't be surprised it just came out from this: a lot of pèarents who are used to hush to silence and calm their babies and simply go on doing that when they grow up, and, bang, you create the international conventional sound for silencing.
^there ^is ^nothing ^scientific ^about ^this, ^only ^personal ^observation | [
"By the end of the 20th century the sound of chirping crickets came to represent quietude in literature, theatre and film. From this sentiment arose expressions equating \"crickets\" with silence altogether, particularly when a group of assembled people makes no noise. These expressions have grown from the more des... |
Why is Methionine commonly found first to begin protein coding regions? | The initiator tRNA appears to be one that is uniquely capable of a few things. One is that it can bind directly to the P site of a ribosome (the P site is the second of three chambers within a ribosome. Normally tRNA must first enter at the A site, then move to the P site where the amino acid they carry is added to the protein being synthesized, and then exit at the E site). The second is the initiator tRNA's ability to transmit a sort of "START CODON FOUND" signal to a bunch of other proteins involved in initiation of protein synthesis. The third is that it *does not* interact with proteins involved in the *elongation* phase (the part of protein synthesis that's not initiation or termination).
(To be clear, the tRNA that initiates protein synthesis and carries a methionine is different from the tRNA that adds methionine anywhere else in the protein. Each Met-tRNA is encoded by its own gene.)
The only data I know of that looks at the "why methionine?" question suggests that something about methionine *might* promote interaction with protein initiation machinery. The data is, in my mind, kinda sketchy. If you exchange the methionine with an isoleucine or a glutamine, you block initiation (but only in eukaryotes; bacteria can initiate from a glutamine tRNA. *Shrug*). However, a valine-tRNA can initiate in eukaryotic cells. That kind of data suggests that methionine is doing...something, probably. What it's doing, though, is anyone's guess.
I pulled all of this from [this](_URL_0_) review, which I found helpful. | [
"Methionine is one of only two amino acids encoded by a single codon (AUG) in the standard genetic code (tryptophan, encoded by UGG, is the other). In reflection to the evolutionary origin of its codon, the other AUN codons encode isoleucine, which is also a hydrophobic amino acid. In the mitochondrial genome of se... |
How were Jewish released from concentration camps received in their communities after the Holocaust? Did they return to their homes and jobs? What was their reception? | In Canada, Jewish survivors who immigrated from Europe after the Holocaust were often received cooly - even among the pre-existing Canadian Jewish community. Franklin Bialystok describes this process in his book, *Delayed Impact: The Holocaust and the Canadian Jewish Community.* He argues that Canadian Jewish communities were torn between a great sense of shame for failing to provide additional material / political support to European Jews during the Holocaust, material and cultural inequity between the two groups, and even the sentiment that those who had survived "must have done something" to escape while so many had died. Ultimately, he discusses the 1960s in Canada as a period of reconciliation between the two groups - the rise of Canadian neo-Nazi ideology prompted a united response of the Canadian Jewish community. In this same period, we begin to see a united turn towards Holocaust education and "speaking out."
Bialystok provides an excellent overview of the intersections of ethnicity, religion, and experience that comprised the Canadian Jewish community in the post-war period. His explanation of the many divisions evident in this community is a nuanced and extensive contribution to the literature on identity, ethnicity, and immigration. Historiographically, Bialystok turns a sometimes critical eye upon the Canadian Jewish community and comes away with a far more complex portrait than has been previously available. In terms of public history, this book also provides insight into how different groups understand “history” and the relaying of historical knowledge as an activity that underpins group identity. This is especially clear in an extensive discussion of the Erst Zundel case with an eye upon the reaction of Jewish Canadians and Holocaust survivors. | [
"Jewish survivors of the death camps and various work camps refused to return to their countries of origin, starting instead an extensive [[Berihah|underground movement]] to migrate to the [[Mandatory Palestine|British Mandate of Palestine]]. Jewish Holocaust survivors typically could not return to their former hom... |
Are there any animals that migrate towards colder climate during winter ? | Not that I know of, no. In the event of winter, the most northern animals are observed to begin migrating south first, relative to more southern animals. Animals are motivated to migrate due to a variety of reasons such as spawning or seasonal grazing but for winter migration, it's almost certainly to get away from the increasing cold/food scarcity. I don't know of any animal that would willingly go north during winter as that's in the opposite direction of food.
& #x200B;
I suppose some fish populations might possibly move north to follow ocean currents, but I'm not familiar with the migration patterns of fish. | [
"Normally when colder conditions arrive, animals go into a state of suspended animation called hibernation, when they go into a state of inactivity for long periods of time, which they do not come out of until more suitable conditions for them to survive in arrive. However, when animals live in an environment that ... |
why isn't the universe filled with light... or is it? | You're on to something that puzzled scientists for a long time. It's known as [Olbers' paradox](_URL_0_) or the "dark night sky paradox".
There are two reasons the night sky isn't bright. The first reason is that the (edit: observable) universe isn't infinite. An infinite observable universe would have an infinite number of stars, so the sky would be filled with light. But a finite observable universe has only a certain number of stars, so the sky has some measurable level of brightness, which ends up being not *that* bright.
The second reason is that the universe is expanding. All the stars at great distances are accelerating away from one another. So their light gets red-shifted by the Doppler effect. The farther away, the greater the red shift. Much of this light gets red-shifted so far that it's no longer visible to the human eye. However, we can still see it with instruments like radio telescopes. The universe *is* filled with photons, known as the [cosmic microwave background](_URL_1_). | [
"Nothing which consists of corporeal matter is absolutely light, but that is comparatively lighter which is rarer, either by its own nature, or by accidental heat. And it is not to be thought that light bodies are escaping to the surface of the universe while they are carried upwards, or that they are not attracted... |
aren't "gambler's fallacy" and "the rule of averages" at odds with each other? | Gambler's fallacy: "I flipped tails four times. THE NEXT flip MUST be heads because of this."
Rule of averages: "If I flipped the coin a million times, I would have around 500.000 occurances of heads and tails each. So always betting on the same one (either heads or tails) will have the same outcome - me not getting (much) richer or poorer."
Doesn't seem at odds to me. | [
"\"Even odds\" occur when the probability of an event happening is exactly the same as it not happening. In common parlance, this is a \"50-50 chance\". Guessing heads or tails on a coin toss is the classic example of an event that has even odds. In gambling, it is commonly referred to as \"even money\" or simply \... |
Why does social interaction make me (introverts) tired? | There actually is a psychological difference in introverts' and extroverts' brain sensitivity to external stimuli.
Extroverts are less sensitive to arousing environments than introverts are so being in a stimulating environment can become physically exhausting for introverts. | [
"Some online behaviors can cause stress and anxiety, due to the permanence of online posts, the fear of being hacked, or of universities and employers exploring social media pages. Turkle also speculates that people are beginning to prefer texting to face-to-face communication, which can contribute to feelings of l... |
When you heat an unstable isotope, does it decrease its half-life time and does the opposite happen when you cool it? | Heating and cooling doesn't really affect the nucleus, unless you get to temperatures comparable with the typical excitation energies of nuclei (on the order of MeV, corresponding to temperatures on the order of 10^(10) Kelvin).
The only exceptions are types of decay which involve the electron cloud. If you have a nucleus which can only decay by electron capture, and you heat it up such that it has no more electrons, electron capture cannot happen. | [
"This relationship between the half-life and the decay constant shows that highly radioactive substances are quickly spent, while those that radiate weakly endure longer. Half-lives of known radionuclides vary widely, from more than 10 years, such as for the very nearly stable nuclide Bi, to 10 seconds for highly u... |
what causes the giant noise that airplanes make when going over you? | It takes very powerful engines to lift and propel tons of metal and people and luggage through open air. Powerful engines tend to be loud, and this is why most people prefer not to live near a major airport. | [
"Aerodynamic noise arises from the airflow around the aircraft fuselage and control surfaces. This type of noise increases with aircraft speed and also at low altitudes due to the density of the air. Jet-powered aircraft create intense noise from aerodynamics. Low-flying, high-speed military aircraft produce especi... |
why do we bother with antihistamines that make us drowsy when non-drowsy ones exist? | Newer antihistamines tend to cause less drowsiness than older ones, though drowsiness is no indicator of effectiveness. My guess for why there are still drowsy and non-drowsy varieties is that some people find it easier to sleep with assistance when they're sick. | [
"Antihistamine drugs can have undesirable side-effects, the most notable one being drowsiness in the case of oral antihistamine tablets. First-generation antihistamine drugs such as diphenhydramine cause drowsiness, while second- and third-generation antihistamines such as cetirizine and loratadine are less likely ... |
Clarification on Native American tribal distinctions | For the benefit of those who don't check /r/AskAnthropology, I'll post my answer here as well:
There's a mix of synonyms and subdivisions here. Sioux is derived from the Ojibwe name for the Dakota-Lakota alliance they were fighting, the Očhéthi Šakówiŋ--the Seven Council Fires / Great Sioux Nation. So the breakdown looks like this. Bolded names are the seven constituent parts of the Očhéthi Šakówiŋ.
## **OČHÉTHI ŜAKOWIŊ**
(Oceti Sakowin / Seven Council Fires / Great Sioux Nation)
#Isáŋyathi (Santee / Eastern Dakota)
* **Bdewékhaŋthuŋwaŋ** (Mdewakantonwan)
* **Sisíthuŋwaŋ** (Sisseton)
* **Waȟpékhute** (Wahpekute)
* **Waȟpéthuŋwaŋ** (Wahpetonwan)
#Wičhíyena (Western Dakota)
* **Iháŋkthuŋwaŋ** (Yankton)
* **Iháŋkthuŋwaŋna** (Yanktonai)
#Lakota
* **Thítȟuŋwaŋ** (Teton)
1. Sičháŋǧu (Brulé)
2. Oglála (Oglala)
3. Itázipčho (Sans Arc)
4. Huŋkpapȟa (Hunkpapa)
5. Mnikȟówožu (Miniconjou)
6. Sihásapa (Blackfoot / Black Feet, not to be confused with the Blackfoot Confederacy)
7. Oóhenuŋpa (Two Kettles)
The Lakota *oyáte* (the name for the lowest tier of subdivision on this list) can be subdivided further, but since you aren't concerned with a subdivision below Hunkpapa, I didn't bother going into that. Likewise, the Dakota groups can be subdivided, but I didn't go into that for the same reason. | [
"Native American politics remain divided over different issues such as assimilation, education, healthcare, and economic factors that affect reservations. As a nation living within the United States of America, the Native American people face conflicting opinions within their tribes, essentially those living on fed... |
how do both eyes move in the exact same way? and why does it cause strain when they don’t (e.g crossing your eyes for too long) | When the nerve going to one eye is stimulated, somewhere along the way that same nerve stimulates the nerve of the opposite eye. So essentially both nerves for each eye are stimulated at the same time when your brain decides to look a certain way. | [
"The great importance of intorsion and extorsion produced by the two oblique muscles can only be understood when it is considered with regards to the other muscle actions present. The two obliques prevent the eye from rotating about its long axis (retina to pupil) when the superior and inferior rectus muscles contr... |
why do some spam email subjects look so obviously fake? | For efficiency. To weed out all the smart people that won't fall for the scam so that personnel efforts are only spent on the few that are likely to fall for it. | [
"Spam is also a medium for fraudsters to scam users into entering personal information on fake Web sites using emails forged to look like they are from banks or other organizations, such as PayPal. This is known as \"phishing\". Targeted phishing, where known information about the recipient is used to create forged... |
how can a musician be sure that what he wrote is not similar to something that already exists? | You can't be sure. Paul McCartney composed "Yesterday" in a dream, and spent a month playing it for anyone he could, to see if they recognized it. But there is no sure way to tell, other than to put the song out and see if anyone complains. | [
"\"“It appears that you personally wish to have some information regarding the thought which predominates in my symphony. Alas, I am going to scandalize you! I had no literary thought in the sense that you mean. When I write a composition to words, I become a slave to what convention terms the verities of musical e... |
why is flashing headlights to warn others on the road about a speed trap illegal? | ex-cop here.
In Alabama it would be "improper lights" charge because of the high beam or flashing them off. I always thought this was bullshit. I actually wanted people to flash their lights and warn others. The whole purpose of the "speed trap", as it were, was to get people to slow the fuck down....not to write tickets.
So, if others flashed their lights and got people to slow down...then I say mission accomplished. | [
"Though not all of its rules represent law, the Highway Code states \"Only flash your headlights to let other road users know that you are there. Do not flash your headlights in an attempt to intimidate other road users\". Drivers warning others about speed traps have been fined in the past for \"misuse of headligh... |
If hieroglyphics were split into word-symbols and sound-symbols, and each word-symbol was NOT composed of sound-symbols, how did people know how to pronounce them? | First off, it's important to distinguish partial writing from true writing. Partial writing is things like pictographs, where an abstract representation is supposed to serve as a reminder for what's there, rather than an actual abstract representation of some idea or sound. These systems are not "primitive" or at least not limited to things like [petroglyphs in Hawaii](_URL_0_), but also include many of our modern road signs, like [the yield sign](_URL_1_). Their expressive capability is limited--they stand for one thing and can't really be composed into something bigger. It seems that full writing, which has no expressive limitations, evolved in part out of these sorts of things.
The "oldest" and "most basic" graphs in a system like this (I'll be referring to Chinese, because it's more familiar to me) are simple pictographs--essentially partial writing. For instance, 犬 means 'dog', and [its oldest form looks quite different](_URL_2_)--essentially a picture of a dog.
What the people who developed writing (as it pretty clearly developed separately several times) did that was truly genius is something many of us have done as a game as a child: rebuses. A rebus is where you use a picture of something that sounds like the word you mean without spelling it out. For instance, in English you can use an eye to not only mean an eye, but also the homophonous word 'I'.
Once you start with rebuses, it's very easy to start having your symbols represent not just whole words, but just sounds. Many Chinese characters were formed on the principle of having one part to represent a general meaning, and another part to represent the sound of the word. The character 腹 *fù* 'stomach', for instance, is composed of the semantic portion 肉, which is used in characters which are parts of the body^(1), and the phonetic portion 复 *fù*^(2).
Eventually, you'll get to the point where you need to write somebody else's language in your own script. This is where we find characters completely divorced of meaning (and some characters have no other meaning than as someone's name). For instance, 浮屠, one of the words for 'Buddha' is simply composed of characters which sound like the Sanskrit word (in Baxter & Sagart's reconstruction of Old Chinese, 浮屠 would be \*m.bu dˤa). When used for their meaning, rather than just for their sounds, 浮 means 'to float' and 屠 'to butcher'. To finally answer your question, you learn to do this by context, and although Egyptian writing was a bit more complex in some aspects, you essentially work the same way.
______
1. When it's put on the left-hand side of characters like this, 肉 becomes ⺼, which is written the same as 月 'moon' in most peoples' handwriting and almost all typefaces. But it's clear this relates to bodily things, as its found in many bodily organs, like 肺 'lung', 膽 'gall bladder', and 腸 'intestines'.
1. On it's own, 复 means 'again', but the meaning is ignored here. | [
"As no bilingual texts were available, any such symbolic 'translation' could be proposed without the possibility of verification. It wasn't until Athanasius Kircher in the mid 17th century that scholars began to think the hieroglyphs might also represent sounds. Kircher was familiar with Coptic, and thought that it... |
why can't i see millions of stars from the airplane window? | The internal sources of light inside the cabin are interfering and also perhaps your perspective, as you are panning mostly horizontally out the window and not vertically. It would probably work better if it was pitch black in the cabin, and the top of the aircraft was translucent. | [
"Due to skyglow, people who live in or near urban areas see thousands fewer stars than in an unpolluted sky, and commonly cannot see the Milky Way. Fainter sights like the zodiacal light and Andromeda Galaxy are nearly impossible to discern even with telescopes.\n",
"Many celestial objects of interest are too fai... |
how do you know when someone is gaslighting vs. when the person is just stupid/has a selective memory? | This is basically asking how you know when someone is doing something wrong maliciously and purposefully vs. accidentally and innocently. The truth of the matter exists only within their own mind, which no one else can ever really know.
For such actions, we can only go off of their actions and responses. Look at the consistency of the errors, how they respond when faced with evidence of their mistakes. Look for things not dependent on simply their memory. Look for deliberate actions they may be taking to maintain the deception or illusion. | [
"Gaslighting is a form of psychological manipulation in which a person seeks to sow seeds of doubt in a targeted individual or in members of a targeted group, making them question their own memory, perception, and sanity. Using persistent denial, misdirection, contradiction, and lying, gaslighting involves attempts... |
How does our body tolerance to a certain compounds work? | (Nearly?) All drugs work by interacting with receptors. This is almost a truism, in the sense that a pharmacologist (one who studies the behaviour of drugs) calls anywhere a drug binds it's receptor, though in general, these binding sites are on specific proteins, and the whole protein gets referred to as the receptor (e.g. the Mu-opioid receptor is a large protein, that has a binding site for morphine). If you're struggling to picture this, imagine a big blob, with a keyhole in it. The binding site is the keyhole, and the receptor is the whole blob. (We had to change our terminology because a single protein can have multiple binding sites.)
So drugs come along, and they bind to the receptor (fit in the keyhole). And the changes the behaviour of the receptor. Some drugs make the receptor work (which usually means it causes some biochemical reaction to begin inside the cell that the receptor lives on) but other drugs STOP the receptor from working. Some drugs just prevent other drugs from activating the receptor. Respectively, these are referred to as "agonists" "inverse agonists" and "antagonists".
Generally speaking, it's what happens after the drug interacts with the receptor that decides whether you get tolerance. Some drugs, particularly agonists (activators) cause the receptor to get less sensitive. The two main ways this can happen is by the strength of which the agonist binds to the receptor decreasing (the cell modifies the receptor slightly) or It can happen by the cell literally removing receptors off its surface. Whether this happens, how fast it happens and how strongly it happens depends on the receptor AND the drug. Some drug-receptors interactions cause this to happen very strongly. Others don't.
GENERALLY speaking, agonists (activators) of a receptor cause it to happen, and antagonists don't. Drugs which block enzymes generally don't cause it either. Morphine is as agonist while aspirin blocks enzymes. We don't really know how paracetamol/acetaminophen works. Caffeine is an odd one. Caffeine is not an agonist of much. BUT some it's effects are likely to be caused by certain blocking one receptor (adenosine 2A) which in turn causes more noradrenaline to be released, which then activates adrenoreceptors. So there could be a source of tolerance there.
Honestly, I don't know any research (off the top of my head) that shows the degree of caffeine tolerance, nor how it occurs. I'm willing to bet it's not anywhere near as strong as opioid tolerance though, because it doesn't matter how much coffee you drink, you will feel one good espresso (and no, I don't believe you if you say "I drink 20 coffees a day I don't feel it").
Hopefully that sorts it out for you. If it doesn't, reply away. | [
"Pharmacokinetic tolerance (dispositional tolerance) occurs because of a decreased quantity of the substance reaching the site it affects. This may be caused by an increase in induction of the enzymes required for degradation of the drug e.g. CYP450 enzymes. This is most commonly seen with substances such as ethano... |
why do people not realize how dependent their life is on oil? | Many people know, but want it to change, and believe that an abundance of oil will lead to complacency in terms of finding a replacement, at the expense of the environment, whereas lowered supply and the associated costs will encourage research and development of something much more nature friendly. | [
"Our world is seriously dependent on oil, but humans are using it up so quickly to the point that it may eventually run out one day, and the Earth will not have enough time to replenish it. It will happen within a timescale between twenty years to a century, but what if all the oil ran out today?\n",
"Because pet... |
how come an alarm wont wake me up, but someone walking around outside my room will? | To me it’s familiarity. I get accustomed to the sound of the alarm so I tune it out. Someone walking however is not familiar so it wakes me up. For that reason I change the tune on my alarm about once a week | [
"In one common alarm sequence, the light in a window will flash and a bell or horn will sound to attract the operator's attention when the alarm condition is detected. The operator can silence the alarm with a button, and the window will remain lit as long as the process is in the alarm state. When the alarm clears... |
what's the difference between 'ebitda' and just 'profit' that a business makes? | EBITDA is earnings before income tax depreciation and amortization. Basically the difference is EBITDA doesn't take into consideration what happened in the past. It looks at how you would have done this year if you didn't have the burden or benefit of what you did in the past. | [
"EBITDA stands for earnings before interest, taxes, depreciation and amortization. It is one of the best measures of a company's cash flow and is used for valuing both public and private companies. To compute EBITDA, use a company's income statement, take the net income and then add back interest, taxes, depreciati... |
How "much" red, green, and blue light are there in sunlight? | [Here you go](_URL_0_) | [
"The particular color of a white light source can be simplified into a correlated color temperature (CCT). The higher the CCT, the bluer the light appears. Sunlight at 5600K, for example, appears much bluer than tungsten light at 3200K. Unlike a chromaticity diagram, the Kelvin scale reduces the light source's colo... |
I think I figured out how to send information faster than the speed of light using the Quantum Eraser experiment, can someone please debunk me? | If you take a look at the [interference patterns you would get](_URL_0_) (about halfway down the pate) after running the experiment, you can see that you have to separate the "went left" and "went right" events after the fact before you can see their respective interference patterns. Otherwise, it your data just looks like a superposition of the two. That superposition doesn't look different from the "particle" pattern.
In effect, you wouldn't be able to process the signal until another messenger told you when the choice to go left or right was made. | [
"The total pattern of signal photons at the primary detector never shows interference (see Fig. 5), so \"it is not possible to deduce what will happen to the idler photons by observing the signal photons alone\". The delayed-choice quantum eraser does not communicate information in a retro-causal manner because it ... |
why are all computers used by clerks in the service industry (retail, airline, car rental, etc.) extremely outdated? | Because they work!
It's not worth the cost of updating something that works, if it's not going to actually allow the company to make more money.
In fact, in many cases, introducing new technology creates risks of things going wrong, so the company would view it even more severely than simply the expense of the upgrade. They view it as a possibility of everything going horribly wrong with the upgrade, with a benefit of pretty much nothing at all if everything goes right. | [
"An accounting machine, or bookkeeping machine or recording-adder, was generally a calculator and printer combination tailored for a specific commercial activity such as billing, payroll, or ledger. Accounting machines were widespread from the early 1900s to 1980s, but were rendered obsolete by the availability of ... |
what prevents people from ripping cash and having the bank give them back a whole bill for the half? | Well the note has serial numbers and other identifying markers on it.
There's nothing stopping you except that you could be prosecuted for fraud. | [
"Cashless payments eliminate several risks, including counterfeit money (though stolen cards are still a risk), theft of cash by employees, and burglary or robbery of cash. The costs of physical security, physically processing cash (withdrawing from the bank, transporting, counting) are also reduced once a business... |
How does a broken bone know how to exactly replicate how it was before it was broken? Position, thickness, ect? | They don't. Often bones will heal misaligned or improperly before they are properly medically treated and have to be re broken.
This is the function of a cast/sling. It immobilizes the damaged arm whilst maintaining it's correct position so when it heals, the arm is as normal as can be.
As for the actual repair, it is never as strong as the original unbroken bone and so people who have experienced breaks in places before are more susceptible to having a break there again. | [
"When a bone is fractured as a result of an injury, the two fragments may be displaced relative to each other. If they are not, usually no treatment is required other than immobilisation in an appropriate cast. If displacement does occur, then the space separating the fragments fills with blood shed by the damaged ... |
if annual inflation in the united states has averaged 3.3% over the past 100 years, how is it possible to have low prices today? | First of all, this may only makes a tiny difference in the answer, but until 1857 there was a [half penny](_URL_0_) coin.
Have you ever been to a Farmer's market? While there are exceptions, most of the merchant at my local market try to sell everything in whole dollars to keep things simple. A basket of strawberries in the summer is $3, etc. - when things are by the pound, they just round - so if peaches are $2/pound and I end up with 3.2 pounds of peaches, they just ask for $6. The profit margin is built in, they can afford to round in the customer's favor. So that's part of the answer: some things did just cost one penny or a couple of pennies, and without calculators or computers, that was a simple way to handle it.
Another part of the answer is that even though one cent 250 years ago is the equivalent of $32 today, that doesn't mean that something that costs only a dollar today would have cost much less than a penny back then. Without machinery, nearly everything was made by hand and things took more labor. Today you can buy a loaf of bread for a dollar because a single baker can bake dozens of loaves of bread an hour, so it's still profitable. 250 years ago, a baker wouldn't have been nearly as efficient, so the baker would have charged a lot more.
| [
"Official consumer price inflation in January–August 2008 reached 14.8%. By the end of November, food price inflation for an 11-month period reached 15.3%. Overall price inflation, taking into account consumer and industrial prices, reached 12.5% compared to 10.6% for the same period of 2007. Decline in short-term ... |
If we lived in a colony on one of Jupiter's moon, how big would Jupiter appear in our sky? | If we lived on Ganymede, it would appear about 16 times as wide as the moon and the sun do from Earth. | [
"Jupiter has 79 known natural satellites. Of these, 63 are less than 10 kilometres in diameter and have only been discovered since 1975. The four largest moons, visible from Earth with binoculars on a clear night, known as the \"Galilean moons\", are Io, Europa, Ganymede, and Callisto.\n",
"Aside from the Sun, th... |
Why has Fidel Castro's Cuba prevailed as a communist state for so long? | One that has tried have a certain level of success to keep the social contract that communist states work on, that of we will ensure your standards of living does not decrease as long as you do not question the state. The failure of this contract was one of the underlying caused of the collapse of communism is Russia and Eastern Europe. China due to its economy growth as been able to keep the contract (at least on the coast). North Korea failed the contract in 1990's but has been able to hold on due to a mix of social reengineering (moving people to the countryside) and brutal repression.
Cuba was able to keep the contract well until 1991 due to the USSR buying its sugar export at a lucrative rate (before the revolution they had been forced to sell to the USA below the global market rate). However that all disappeared when the USSR collapsed and agreements were cancelled.
After that Cuba became very rocky but seemed to pull thought partly with an allotment drive to encourage people to grow their own food due to food rationing (as not to break the exchequer because of imports) and a strong welfare state. Cuba also benefitted from tourism giving it an influx of foreign capital.
| [
"Fidel Castro's staunch belief in a communist ideology and his criticisms of other international figures elevated the prominence of his rule. He launched a wide range of economic and social changes. Castro's Cuba became a key element within the Cold War struggle between the United States and its allies versus the S... |
how is it possible for the hadron collider to reach a temperature of close to 1 trillion degrees without burning a hole through our planet? | Well the particles that reach that temperature are extraordinarily small, and only exist for the tiniest fraction of a second. Not only that there are extremely strong magnetic fields set up within the collider to prevent such things from happening. | [
"Until August 2008, the highest energy collider in the world was the Tevatron, at the Fermi National Accelerator Laboratory, in the United States. It accelerated protons and antiprotons to slightly less than 1 TeV of kinetic energy and collided them together. The Large Hadron Collider (LHC), which has been built at... |
Was there a unifying way to specify years or days in the contemporary ancient world? Did people in ancient Greece, Persia, Egypt and Mesopotamia (for example) have a singular calendar they used so they could agree on dates? | Well, I'm not entirely certain if you're asking whether they could agree on these things between civilizations, so that the Egyptians and Mesopotamians (for instance) could agree on what year it was, or whether within any of these cultural groups there was a commonly agreed calendar. In either case, though, the answer is broadly speaking "no".
Let's start from years. I'm most familiar with Mesopotamia, where the common practice was to give years names, based on some important event that took place that year, so you'd have a ["year in which Shulgi, the strong man, the king of Ur, the king of the four quarters, smashed the heads of Urbilum, Simurrum, Lullubum and Karhar in a single campaign."](_URL_1_) These were then compiled into lists for reference, which to the historian's delight also serve to an extent as chronicles. In my understanding Egypt had a similar practice.
Of course, this system requires a year to be specifically named through, essentially, a royal decree, which means that a unified system of year names would only be in use in a single empire, if that. So even in Mesopotamia different states had their own lists that are not readily compatible, and of course the collapse of empires would cause havoc to these systems. Already ancient Mesopotamian scholars produced the [Sumerian King List](_URL_0_) as a kind of composite that lists the regnal years of the dominant dynasty, though it starts from mythical rulers reigning thousands of years and, when dealing with historical rulers, occasionally appears to place contemporareous rulers erroneously in sequence. Essentially, keeping track of years accurately even within a single society was tricky, let alone aligning them with other empires.
I have no real expertise on calendars, but generally speaking the same issues apply. Most of the Near Eastern and Mediterranean cultures had lunisolar calendars, which require leap months to be added to align the years with seasons, and this was again done by decree, though presumably under scholarly recommendation. There was also no consensus on when a year started or what months were named, so again calendars would be local affairs unless the ruler of an empire was able to impose his own system of measurement on his subjects.
In closing I should add that all of this makes it quite difficult to accurately assign years, let alone dates, for ancient historical events. Though certain chains of years have been adequately established, there are very few ways (mainly astronomical phenomena mentioned in ancient sources) that would allow us to connect them to our calendar, and these allow for multiple interpretations, leading to multiple competing chronologies for the earliest historical periods. | [
"Historically, units of time in many civilizations are duodecimal. There are twelve signs of the zodiac, twelve months in a year, and the Babylonians had twelve hours in a day (although at some point this was changed to 24.) Traditional Chinese calendars, clocks, and compasses are based on the twelve Earthly Branch... |
why do we like the taste of cola so much? | Yeah, yeah, we get it, cuz of the sugar.
But why COLA?? -- vs. any of dozens of other sweek drinks out there?? What is it about the taste of COLA that makes it the most popular flavor of drink (or soda/pop type drink)?? | [
"The primary taste of Coca-Cola is thought to come from vanilla and cinnamon, with trace amounts of essential oils, and spices such as nutmeg. A 2015 study identified and measured 58 aroma compounds in common colas, confirming significant amounts of compounds corresponding to cinnamon, vanilla, nutmeg, orange and l... |
I'm very interested in early Canada (and North America), including mythology. Any recommendations? | Due to their prolonged exposure as equals, the Mi'kmaq of Eastern Canada also have an interesting history (Chief Membertou) and mythology (Glooscap).
I am a fan the Mi'kmaq story of creating the Moose and Beaver. Initially both were too large and proved destructive to the land. So they were each radically reduced so as to be able to live harmoniously within their environment.
Demonstrates a keen cultural/religious value of balance in lifestyles. | [
"There is no single mythology of the Indigenous North American peoples, but numerous different canons of traditional narratives associated with religion, ethics and beliefs. Such stories are deeply based in Nature and are rich with the symbolism of seasons, weather, plants, animals, earth, water, fire, sky and the ... |
why do people still die of lack of food & water? are there not the super rich and down to 1st world folks who even throw away tons of food? no way to solve it? | One major issue is logistics.
Sure, rich people might be throwing away plenty of completely edible food... But how are you going to get that food over to Africa or another part of the world before it actually does spoil? And who is paying for that transport and distribution? | [
"The United Nations indicates that about 850 million people are malnourished or starving, and 1.1 billion people do not have access to safe drinking water. Since 1980, the global economy has grown by 380 percent, but the number of people living on less than 5 US dollars a day increased by more than 1.1 billion.\n",... |
How are anti-cancer/life saving drugs tested? | This website answers your question about the use of placebo: _URL_0_
In short, placebo trials are use sparingly and must not cause undue risk of death to the patient taking the placebo. For example, if an effective treatment already exists the patient is unlikely to be allowed to participate in a placebo only control group. | [
"An adaptive trial design enabled two experimental breast cancer drugs to deliver promising results after just six months of testing, far shorter than usual. Researchers assessed the results while the trial was in process and found that cancer had been eradicated in more than half of one group of patients. The tria... |
Where did the Sumerians "come from"? | The Sumerians didn't come from elsewhere, nor did they go anywhere. They were the native inhabitants of lower Mesopotamia, and that's where their descendants remained long after Sumerian died out as a spoken language. I wrote more about this in [Mesopotamians and Sumerians.](_URL_0_) Pay particular attention to the bit about the debunked "Proto-Euphratean" language substrate, as that was the primary piece of evidence for the theory that the Sumerians came from elsewhere.
You may want to read my response to [What are the Assyrians and the Babylonians connection to the Akkadians?](_URL_1_) as well.
For general works on the Sumerians, see the [Sumerians section of the r/askhistorians reading list](_URL_2_).
| [
"Sumer (or \"Šumer\") was one of the early civilizations of the Ancient Near East, located in the southern part of Mesopotamia (modern-day Iraq) from the time of the earliest records in the mid 4th millennium BC until the rise of Babylonia in the late 3rd millennium BC. The term \"Sumerian\" applies to all speakers... |
How were the properties of yeast discovered? | So, I took a medieval bread class once upon a time. There's a couple of things going on here. To understand yeast bread, you have to go back to beer. Beer was kinda and accident, and from my limited understanding can cultivate wild yeasts for fermentation.
Anyway, people had beer for centuries before they decided to get to bread. Most bread in the middle ages, especially for poor people (read most people), is nothing like we know of bread now. It was not leavened (read no yeast) except for some cases of steam or vinegar leavening. Mostly bread was a flatish, dense substance. Most similar modern mirror is a bannock, but most people wouldn't have wasted the milk, egg, or butter on bread. They were too poor for that. Bread also was not wheat for most people. Pea flour, oat, rye, spelt, and occasionally when were used (that I know of for northern Europe from about the 6th century to the 14th. After that I'm not sure).
However, yeast breads did exist. Only wealthy people had the means to make it though. Notwithstanding the yeast, you need an oven to make it, which is an expensive and time consuming thing to make and use. Maybe a whole village might share one, but most often only wealthy people have one. Then, you need glutenous flour. Wheat, rye, etc was really only available to wealthy people.
Once you have all these components though, the yeast is rather simple. Beer. Most yeast breads start with a starter, like sourdough. To make this starter, you skim the beer, mix it with flour, and wait. It will start to bubble. Then, you use most of it for your bread, feed the leftover more flour, and set it aside for the next day. Over time, the starter will collect more wild yeast from the environment around it, and keep a nice little culture going. If you get a good colony of yeast going and keep feeding it and using it, mold generally isn't a problem. This also wouldn't have tasted like a sourdough that we know today. Unless you let the starter actually ferment and start to produce alcohol, it will taste like normal-ish bread. Quite good actually.
As to how someone thought to put beer in bread, no one is quite sure (that I'm aware of) why they tried it. I chalk it up to a good old human "hold my beer" moment. But the end result was a fluffy bread that became a symbol of wealth.
Edit: sorry, for clarification, the active dry yeast we know was not a thing. People also didn't know what yeast was. They just knew that if you left beer long enough it would bubble and make alcohol, and similarly a bread starter would do the same. The beer foam was often called "a gift from God". | [
"Scientists before Pasteur had studied fermentation. In the 1830s, Charles Cagniard-Latour, Friedrich Traugott Kützing and Theodor Schwann used microscopes to study yeasts and concluded that yeasts were living organisms. In 1839, Justus von Liebig, Friedrich Wöhler and Jöns Jacob Berzelius stated that yeast was not... |
during ww2 how was post made possible between the uk and germany? | You go through a neutral 3rd country.
For Europe popular choices were Switzerland (usually involving the International Red Cross for sending mail to POWs and civilian internees) and Portugal (for everything else).
The British Mail service, in order to avoid appearing to colaborate with the enemy, enlisted the help of Thomas Cook & Son. You would send your letter to a Thomas Cook & Son office in Amsterdam (or later when Amsterdam was occupied Lisbon, Portugal). They would then forward your letter into occupied territories. Strict limits were placed on what could be discussed in the letters (for example, if your mail was going through Lisbon no location other than Lisbon could be mentioned) the length of the letters (two pages), and the way the letters were written ("clearly written", no erasing, only topics of "personal interest", etc.). | [
"In 1940 further changes were introduced followed through the rapid conquest of Europe. Eventually a series of postal agreements were set up between Germany and the occupied countries providing an extended usage of Feldpost service. Countries such as the Netherlands had close to 50,000 pro-Nazi volunteers that duri... |
how do clicky pens work, and what is the mechanism called?! | Here is a great animation: _URL_0_
As you can see from the animation, the inner surface of the pen is grooved. The button has a "holder", which holds the pen shaft in place and slides back and forth on the grooves. The shaft has a complementary part that fits into the holder. The holder is designed such that the shaft's part always wants to be one section over (it's hard to explain, but if you take apart one of the clicky pens you must have, you can infer from there). The shape of the holder, however, is such that the shaft has to fit in one of the spots in the holder. The spring forces the shaft into these spots. Once you push the button, however, you lift the shaft out of the spot, allowing it to go one spot over. These spots are elevated differently so that the pen has two modes: out and in. The difference in elevation is also why you have to push the button further to open the pen than to close it.
As for what it's called, I have no idea. | [
"Pen clicking is repeated pressing of the button of a retractable pen which produces a clicking sound. In its normal use, the button is only pressed when someone wants the nib of the pen to be exposed so they can write with it. This makes a noise, which varies in tone, dynamic and timbre depending on the size and m... |
what is hawking's radiation, what exactly are these pairs of "virtual" particles? and how exactly are they formed? | According to quantum mechanics, particle-antiparticle pairs can spontaneously come into existence. Since their combined energy is zero, the universe allows such particle pairs. Usually, they annihilate each other after a short time; however, if they form near a black hole one part of the pair can fall into the black hole. To someone observing the black hole, it will look as if a particle has been emitted. Since the emitted particle has energy, the particle that fell into the black hole must have exactly negative energy of the emitted particle. Thus, the black hole loses a bit of energy, and particles appear to be radiating from the black hole (Hawking Radiation).
To understand what these "virtual" particles are, you must think of them as not particles at all. Normal everyday particles are ripples in a field. For example, an electron is an excitation of the electron field. These "real" particles can travel through space, and we can interact with them. In contrast, virtual particles are a disturbance in a field, this disturbance is caused the presence of other particles, often in other fields. The disturbance is usually short lived because as soon as the cause of the disturbance cease to exist, the disturbance goes with it. An example of a disturbance is having two electrons pass close to each other, due to their electric charge, they will create a disturbance in the electromagnetic field. | [
"In the coordinate system of a distant stationary observer, Hawking radiation tends to be described as a quantum-mechanical particle-pair production effect (involving virtual particles), but for stationary observers hovering nearer to the hole, the effect is supposed to look like a purely conventional radiation eff... |
What was the international view of the U.S. Civil Rights Movement as it was happening? | BackStory (an awesome US history podcast) addressed this in their show about the Civil Rights Act of 1964. LBJ's work on the Civil Rights Act was very much shaped by the Cold War, as segregation was some seriously bad PR for the US, especially when diplomats from African countries in the process of aligning with the US or the USSR were forbidden from eating at lunch counters on their way to DC. This was certainly an embarrassment for the US, but on the bright side this embarrassment sped up the process of reform.
Source:_URL_0_ | [
"The civil rights movement (1896–1954) was a long, primarily nonviolent series of events to bring full civil rights and equality under the law to all Americans. The era has had a lasting impact on United States society, in its tactics, the increased social and legal acceptance of civil rights, and in its exposure o... |
how do my cats understand when i'm calling them? | Most cat owners put on a different voice than normal when calling their pets.
Think about animals, they make different sounds based on the general point they're trying to put across. A cat for example makes different types of sounds depending on when they want something from you (food, need to go inside/outside/inside/outside/inside again...) or if they're squaring up to another cat or if they're generally in a foul mood.
You don't know exactly what your cat is trying to put across but you get the general idea.
Same situation in the cat's case, if you talk to other people it's generally a normal talking tone; the cat will probably ignore this and go to sleep. But if you stub your toe and scream bloody nora the cat will probably bolt away thinking you're being aggressive. However if you call the cat it doesn't matter what you say, as long as the tone is the same as normal they will get the general idea of what you're trying to say: which is to summon them.
Also on a side note, some animals do know their name, but only take into account the last 1-2 syllables, so you could call them without any tone of voice and they may still arrive. | [
"The most familiar vocalisation of adult cats is a \"meow\" or \"miaow\" sound (pronounced ). The meow can be assertive, plaintive, friendly, bold, welcoming, attention-soliciting, demanding, or complaining. It can even be silent, where the cat opens its mouth but does not vocalize. Just like humans who talk a lot ... |
do massive fires contribute to climate change like emissions and pollution? | a small percentage of overall pollution, but it is only a very small fraction of the overall scale of pollution. In contrast Human pollution is much much larger.
EDIT: This guy below sounds smarter than me, listen to him my answer isnt as detailed (/u/Tokyojokeyo)
| [
"Climate change poses a challenge to the management of conventional air pollutants in the United States due to warmer, dryer summer conditions that can lead to increased air stagnation episodes. Prolonged droughts that may contribute to wildfires would also result in regionally high levels of air particles.\n",
"... |
Was wondering what parts of an autistic brain develop slower than others, and at what rate? | I don't think it's been figured out completely yet, but one of the most popular theories is improper development of the [amygdala](_URL_0_) in autistic people. This theory explains only *some* of the observations of autism. For example, avoiding eye contact may be because it stresses them out. Since autism seems to affect a lot of higher-order functions like social interactions, I think it's gonna take a while to really understand all of autism. | [
"His neuromorphology research, conducted in collaboration with other researchers from around the globe, has found there are drastic differences in the brains of autistic individuals. The studies that he conducted show that minicolumns (or 'brain strands') of autism spectrum individuals have more cells, but they are... |
Did Russia impose grammatical changes on East Germans? | There really was not that much of an imposed change on the German language in the GDR. Most of the differences between the two Germanies were lexical. Some of this was partly the fault of division. For example, in the GDR *Kaufhalle*/*Konsum* were used for grocery stores while in the FRG *Supermarkt* became more common. Other relatively unique GDR words were a byproduct of the state ownership of various goods and services and their state-given names became part of the everyday vocabulary. The GDR's restriction of movement and its housing crisis also helped to entrench linguistic dialects as GDR as people could not move around easily. German wikipedia has a [list of words](_URL_3_) used in the GDR lexicon.
One of the exceptions to this trend was the use of the du-form. The ruling SED party did encourage the use of the informal *du* (you) over the more formal *Sie*(you). In traditional German language convention, the informal tends to be reserved for personal settings while the formal is often used in workplace settings or ones other social situations where one party is superior, such as pupil/student or employee/boss (note this is a generalization and can be observed as much in breach in some areas- DW has a good explanation of the [du/Sie dilemma](_URL_1_) ). The cultural authorities in the GDR portrayed this formal/informal division as a relic of Germany's inequitable society and did not represent the new worker's state created by the SED. In the workshops and in SED functions, the state encouraged the use of the informal to stress that all the citizens of the state were social equals. GDR state media often emphasized the term *Genosse* (comrade) and it evolved into a quasi-title for SED officials in print (such as "Rede des Genossen Walter Ulbricht," and so on). The SED privileged *Genossen* over the term *Kameraden* because the latter was more frequently associated with comradeship in an organizational context, often martial, exemplified by such the songs like ["Ich hatt' einen Kameraden](_URL_0_) or ["Alte Kameraden"](_URL_2_).
Ironically, this social leveling by language had something of an opposite effect upon the GDR public. Some East Germans associated excessive use of the informal with the various state functions and in private conversation the threshold for breaching the formal/informal divide was higher. Surveys after 1993 about the use of the informal noted that Germans from the GDR tended to use the informal more reluctantly than their Western counterparts. | [
"Joseph Stalin mostly reversed the implementation of Korenizatsiya in the 1930s, not so much by changing the letter of the law but by reducing its practical effects and by introducing \"de facto\" Russification. The Soviet system heavily promoted the Russian language as the \"language of inter-ethnic communication\... |
is it bad to sleep with wet hair? i been hearing from everyone that it is bad. if so why? | As someone who sleeps with wet hair almost every night and has been doing so for decades I can debunk this is a old wives tale. Wet hair does not make you prone to bacterial or fungal infection. Its just allowing your hair to air dry while you're laying down. Air drying hair does not require "additional blood" to the scalp, unless you are in some kind of extreme weather.
The idea that it's bad comes from the antiquated notion that you can "catch cold" or become more cold from wet hair. Which of course can happen if you live in a place without proper heating during the winter. However, for a modern home with proper air/heating/ventilation there's nothing bad or wrong about falling asleep with wet hair.
In fact, allowing hair to air dry is much better for hair. Blow drying is very harsh, causes dullness, split ends and overall damage.
| [
"There are a range of possible reasons for the objection to hair in food, ranging from cultural taboos to the simple fact that it is difficult to digest and unpleasant to eat. It may also be interpreted as a sign of more widespread problems with hygiene. The introduction of complete-capture hairnets is believed to ... |
do caterpillars turn into liquid and then reform into a butterfly in the cocoon? or do they keep some of the same parts? | Here's an interesting podcast about that very thing:
_URL_0_
The upshot is that yes, they turn into goo. But also, it's been proven that memories persist through the goo stage. So somehow, something carries through the chrysalis. It seems like there may be more to memory than we currently understand. | [
"To begin the pupal or chrysalis stage, the caterpillar attaches itself with a silk pad and hangs upside down on a leaf. About 24 hours later, its skin splits, exposing a dull, bronze-coloured case known as the pupa or chrysalis. The pupa hangs for about a week without movement. Within the pupa, the caterpillar is ... |
Is the Battle of Midway movie historically accurate? | Hi there! More can always be said, but you might also be interested in this [megathread on the battle](_URL_0_). It's still somewhat active, so feel free to post follow up questions there. | [
"The Battle of Midway is a 1942 American documentary film short directed by John Ford. It is a montage of color footage of the Battle of Midway with voice overs of various narrators, including Johnny Governali, Donald Crisp, Henry Fonda, and Jane Darwell.\n",
"Midway, released in the United Kingdom as Battle of M... |
Why was the Provisional Government of Russia in 1917 so short lived? | In the most simple terms, they didn't really do much. There was an insistence from the PG that people were going to have to wait for changes like constituent assemblies or land redistribution until after the war had ended. The original leader of the PG, Milyukov was also forced to resign after he promised the allies that he would continue fighting in the war, so the leadership of the PG was weak.
Further revolutionary actions such as an attempted revolt during the 'July Days' and also an attempt to seize power by general Kornilov led to the provisional government looking weak. What made this worse is that the Bolsheviks helped to defend Petrograd from Kornilov and his troops, the Bolsheviks were beginning to gain favour over a 'weak' provisional government.
Along with these weaknesses of the PG there were also the strengths of the other groups. The Petrograd Soviet had strong members (Trotsky and Dzerzhinsky) who set up the Military Revolutionary Committee which led to them supposedly being in control of the defence of Petrograd. This committee then gained control of the Bolshevik red guard and by the time the new PG leader, Kerensky, could do anything about it the city had already been seized.
Sources: Sally Waller 'Tsarist Russia 1855-1917' and Martin Sixsmith 'Russia: a 1,000 year chronicle of the wild east'. | [
"The Russian Provisional Government () was a provisional government of Russia established immediately following the abdication of Tsar Nicholas II of the Russian Empire on 2 March [15 March, New Style] 1917. The intention of the provisional government was the organization of elections to the Russian Constituent Ass... |
how can bad moonshine cause blindness? | "Alcohol" is a fairly broad family of chemicals. Some alcohols you are probably familiar with include isopropyl alcohol (i.e. rubbing alcohol) and ethyl alcohol ("drinking alcohol").
When you are making moonshine you get a mixture of several different types of alcohol. Ethyl alcohol is there, obviously, since that's the whole point--you want the ethyl alcohol so you can get drunk. However, another alcohol is also present: methyl alcohol, or "wood alcohol." When consumed wood alcohol starts out behaving pretty similarly to drinking alcohol--it goes to your stomach, can make you puke if you drink too much too fast, and gets absorbed into the blood stream. In fact, it has a lot of the same effects as drinking alcohol--wood alcohol would get you drunk.
However, once the body starts trying to process the wood alcohol everything goes down hill fast. Your body doesn't directly remove methanol with the kidneys very fast, so it breaks it down into other things with the liver. One of these things is methanoic acid (looks just like Methanol except two of the hydrogen atoms are popped off in favor of one oxygen). Methanoic acid is also known as "formic acid" and is the substance in a fire ant bite that makes it hurt so much. This chemical is *incredibly* toxic and is responsible for causing the blindness.
The classic treatment for this is actually kind of cool: you just liquor up the patient (carefully). When you pump enough drinking alcohol into the system it distracts the liver long enough for the kidneys to remove the methanol.
Methanol is dangerous in un-carefully-made moonshine because it's a challenge to separate methanol from ethanol. The process involves distillation--you hold the initial liquid at a given temperature and evaporate it, then condense the gas. However, ethanol and methanol boil at similar temperatures--if the process is done wrong or in a not-careful manner then you can wind up completely failing to remove the methanol from the mixture. | [
"Improperly produced moonshine can contain impurities (methanol) or adulterants that can be hazardous to public health. Illness and deaths caused by moonshine in the United States are exceedingly rare, though underreporting is likely to be present in the statistics. In December 2011 it was reported that 168 people ... |
I heard that Nazi SS soldiers would have sex with deployed regular soldiers wives often and were ordered to, is that true? | After the begin of the war, when the first casualties reports of the Poland campaign came in, Himmler issued an internal order to the SS and Police. (Although being an "order" it was more like a memo) The order explained that due the nature of war men will die, this was nothing bad as they died for a "higher cause". Yet it was a grievance if they did not have childeren before they fall, leaving without a successor and not spreading his "good blood". As the SS saw themself as the elite, not passing on of the superb gens of the members, was a terrible los. So Himmler issued this order to the SS and Police allowing them to have (multiple) relationships (outside marriage) to breed childeren. Futhermore the order looses women and girls of "good blood" from bourgeois morals, allowing relationships outside of marriages for the purpose of having childeren. The last part of the order aimed at soldiers that dont plan to have childeren till war end to not burden thier brides when they fall. Himmler ensures that every child, legitimate or illegitimate, of a fallen german soldier will be cared for and finacially supported and of the duration of the war the pregnant women and thier childeren will be support if help is needed. The order was a carte blanche for the SS-men and was also used by some, Himmler himself used it to justify his affiar with his secretary. However the order came under large criticism, from inside and outside of the SS. Many people saw it as immoral and for his peers in the Nazi elite it was evidence of Himmler being crazy or ridiculed for expanding his hobby as chickenbreeder on the SS, even Hitler himself was displeased by it. In the SS, especially the officer corps, was very unpopular. There was not so much problem with immorality as many of unmarried lower ranks made use of it. The problem was more that also the wives of the SS-men/soldiers were "free game" now. No soldier is happy about the idea that another man, that has the luck to stay home, can start a state sanctioned affair with thier wifes while he is fighting and dying at the fronline. Futhermore it showed the SS the "insaneness" of thier (unpopular) leader and made out them a laughing stock. So answering the question, Yes and No, SS soldiers would have sex with deployed regular soldiers wives. Often, depends how you see it, Affiars are common in peace and even more in times of war. Men and women dont see thier partners for long time and have thier "needs" or in climate of fear try to enjoy life as death maybe around the corner. However what see with SS order that the affairs, that might have been tolerated when not publicly exposed, were now state sanctioned and propagated. Although ordered or as guidelines installed, by many (often the married) in the SS the order was unpopular and ignored.
_URL_1_
_URL_0_ | [
"Although far from the scale of those committed by the Wehrmacht or Red Army, rapes of local women and girls were committed by British troops during the last months of WWII in Germany. Even elderly women were targeted. Though a high-profile issue for the Royal Military Police, some officers treated the behaviour of... |
did the Minoans speak an Indo-European language? | Normally, we would want to keep the issues of language and culture completely separate. But with Crete in this period, we are still struggling to find the linguistic and cultural connections of Crete to the rest of the Mediterranean.
One thing I would say is that we cannot speak of the identities present in Crete in this period, so we can't honestly say that 'Minoan' refers to a single identity, culture, or even language. So I will be a little guarded with using the term 'Minoan'.
Many different theories have been proposed about the cultural and linguistic heritage of Crete in the Minoan periods.
An older theory that I still occasionally see trotted out is that the Cretans of this period were a precursor to later Ancient Greek, both culturally and linguistically. This theory has no direct evidence, and in addition reflects a tendency to present direct precursors to ancient Greek culture being present in locations that would later be considered culturally Greek. If this theory was to be proven correct, somehow, it would definitely place the Minoans as Indo-European speakers.
A theory that I've heard more than a few times now is that Crete's culture in the Minoan periods was an offshoot of the Luwian cultures/languages. This was a branch of the Anatolian languages, themselves a branch of Indo-European. Indeed, this is connected to general theories of an Anatolian-Minoan connection. Part of the reason this theory gained traction was because certain archaeologists felt that there was a distinct resemblance in Minoan and Anatolian material culture.
However, another major theory regarding Minoan culture and language is that they were what the Ancient Greeks called 'Pelasgians'. This Greek term referred to pre-Greek peoples who lived in what became Greek inhabited areas. There are big issues with regards to reconstructing pre-Indo-European cultures and language groups in the Aegean, so a lot of the specifics of this theory are up in the air. The common element of all of this branch of theories is the idea that the Cretans in this period were speaking a pre-Indo-European language and that their culture predates the expansion of Indo-Europeans from whichever reconstructed homeland you personally ascribe to.
There are almost certainly other theories, but these are the ones that either are or *were* popular and had academic support. There's almost certainly a lot of fringe theories on the subject, Minoan Crete is practically your standard canvas for crackpot ancient historical theories because so little is known about it.
As for my opinion on the subject, much rides on deciphering Linear A, the script associated with Minoan Crete. But it's a chicken and egg scenario; we can't read the script because we aren't sure what language is being represented, and we can't be sure what language is being represented because we can't read the script. I have seen a few attempts at deciphering Linear A, none of them have convinced me so far. It's only once we're able to read it that I think your question will be answered. I am a little hopeful given the number of scripts that have been deciphered across the 20th century. | [
"According to the most widely held hypothesis of the origin of the Indo-European languages, the Kurgan hypothesis, their common ancestor is thought to have originated on the Pontic-Caspian steppe. The Tocharians were an early Indo-European branch in the Tarim Basin. At the beginning of written history the entire st... |
how are vpns legal with things like the patriot act in place? | VPNs are perfectly legal ways of segregating data from a public network. There is no law that says that using a VPN is illegal for general use.
Virtual Private Networks are essentially small "pocket internet" sites, containing special logins that prevent outside access. Many companies use VPN networks to transmit data securely from location to location across the world and their worksites. Without a VPN, this data would be free for the taking and also corruption.
What has to be worried about is not the existence of VPNs, but the existence of the information contained on that VPN. if you know how to use them, VPNs are very difficult tot rack, and hard to trace ways of deciminating information from a classified or protected source, to prvent someone from knowing where it came from or who sent it. | [
"In June 2015 legislation to force ISP's to block access to websites that link to copyrighted material was passed through the Senate. The new legislation will allow rights holders to obtain court orders to block overseas content that are found to contain copyrighted material. The legislation does not however extend... |
how does the ocean go through two tide cycles in a day, where the moon only passes 'overhead' once every 24 hours? | The moon has a stronger pull on objects close to it and a weaker pull on objects farther from it.
* The water between the earth and moon is closest to the moon
* The Earth's body is at a moderate distance from the moon
* And the water on the opposite side is farthest from the moon.
The moon pulls these three parts at different strengths and cause them to separate from each other.
The moon pulls the body of water close to it, causing high tide where the moon is. The moon also pulls the earth toward it, but not as much. And since the earth is being pulled towards the moon, it leaves behind a body of water on the opposite side where the moons pull is weakest.
So there is a high tide on the area close to the moon and another high tide on the opposite side of the earth. As the moon orbits the earth we experience these two high tides.
---
**Edit:** Help me improve this answer by discussing below and upvoting good explanations! There are a few issues with this answer and there are several excellent details in the comments below that I'd like to give visibility to
* Is there a good illustration of this explanation?
* What about moon phases? is there a difference in tide height when there's a full moon vs a new moon? (hint: Syzygy)
* Is the moon being pulled by the earth? Or is the earth being pulled by the moon? Upvote the best explanation below.
* The two high tides on each end of the earth are not the same height - why?
* There are some areas where the tides barely rise and fall. What are these areas and why? (hint: tilt, geography)
* Other than water, are there other stuff that is affected by the moon's gravity? (hint: fluids other than water)
* Sometimes there's only one high tide in a day - why?
* If tides are caused by gravity, what about other stuff that has gravity? Do they affect the tides at all?
* My answer implies that the earth is moving towards the moon which is not the case. Can someone help me clarify this?
Comment your clarification and additional information below and upvote those that you like! Have a nice day everyone!
Edit2: added more hints | [
"The cycle of tides is dependent on the phase of the moon, with the highest tides (spring tides) occurring near full moon and new moon. As the lunar cycle is about 29.5 days, successive tides are approximately 24/29th of an hour later each day or about 50 minutes but many other observations and considerations are r... |
Why does the month precede the day in American calendar system and when did it originate? | Even historically Europeans used both, as did a lot of other people. [Records show that in Europe the y/m/d and m/d/y formats were both used](_URL_0_). And it differs - traditionally the Times in the UK have written it the American way, I think, as did the Guardian until pretty recently. The Encyclopedia Britannica also used the American format well before its ownership switched to American. The European format is sometimes used in America as well - I think airports are a major place where you see the other format, but also in common parlance like the 4th of July.
In Asia, the year always came first, then month then year. Ultimately though I think it falls into language first (Chinese pretty much goes xxxx年x月x号 YMD exclusively in its grammar, it makes very little sense in any other order and would require conjunctions which wound sound terribly unnatural). As for French though, six janvier works better and the D/M/Y format wins out. I've never heard anyone say anything otherwise. English can go both ways (January 5th or the 5th of January), so I suspect it's a matter of custom and fashion that catches on in different places, probably influenced by a host of different places that only became standardized recently, but like I said, even in the UK there are places that use the "American" way and even in the US there are places that uses the "UK" way, so yeah.
| [
"The year used in dates during the Roman Republic and the Roman Empire was the consular year, which began on the day when consuls first entered office—probably 1 May before 222 BC, 15 March from 222 BC and 1 January from 153 BC. The Julian calendar, which began in 45 BC, continued to use 1 January as the first day ... |
cookies...and that's not the kind you eat | Billy, pretend you own a deli. You make some pretty sweet sandwiches and lots of people in town come to your place for lunch. Over time, there's a ton of people coming to your deli! So many that you can't even keep track of them any more. What are you gonna do Billy? What are you gonna do! The line is going out the door!
Johnny comes in for lunch one day. He goes to the counter and says, "Turkey on rye, extra mayo." The next day he comes in, he says, "Turkey on rye, extra mayo." The third day, he says the same thing. This ordering process is what is taking so long! You decide to get smart about it ...
Sally comes in and says, "Ham sandwich on a bun, no tomatoes." So you write that down on a blue index card and staple it to her forehead. You make her sandwich, she eats it, and she leaves. The next day she comes in, you can see quite plainly what you stapled to her forehead: "Ham sandwich on a bun, no tomatoes" on a blue index card. She walks in, you see the index card, you make her sandwich and then chuck her sandwich at her. She eats and leaves.
Over time, you keep doing this for everyone who comes into your deli. Clyde has a blue index card stapled to his forehead that says, "Grilled cheese on sourdough." and Pam has a blue index card stapled to her forehead that says, "Roast beef on pumpernickel." Everyone comes into your deli with blue index cards stapled to their head and as long as they've ordered their sandwich once ... they can waltz right in and you'll know exactly how to serve them quickly and easily.
The next day, Sally comes into your deli. She has an orange index card stapled to her shoulder. It's in a language you can't understand. She must have gone to a different deli for lunch yesterday! But you can still read your blue index card you put on her that says "Ham sandwich on a bun, no tomatoes." so it's all good.
Over time, you notice that people keep walking into your deli with tons of different colored index cards stapled to them. Your blue one, the oranges ones, plaid ones, green ones, silver ones, ... all different kinds of colors. They are the index cards that other restaurants have placed on their customer to help them make their ordering process quick and easy.
But Sally goes home one day and says, "What the hell! I don't want all these index cards on me any more!" She clears all the cards from herself and feels new and refreshed. The problem with that is that when she comes into your deli the next day, she doesn't have her index card on her, so you say, "I'm sorry, who are you? You look familiar, but I need your name and choice of sandwich again." You write that on your blue index card and restaple it to her forehead, as long as she lets you do it this time.
****
In more specific terms, let's say your deli was Facebook. You go to _URL_0_ and the facebook servers will say, "I'm sorry, who are you?" and then you type in your email and password. Facebook will drop a cookie onto your computer that says
EMAIL: ChasingKhaos@email.com
PASSWORD: 1234wxyz
so that the next time you go to _URL_0_, you don't have to sign in anymore. Facebook just sees the cookie it stored on your computer and says, "Oh yeah! You're ChasingKhaos, come right in, I already know your password is good!"
They can store other things like site preferences and the like on their cookie as well. And "Clearing your cookies" (or ripping off all the index cards, in the story above) is when you delete all those little bits of information that all those websites have on your computer, at the cost of you having to go through and re-enter all your information all over again.
****
Now Billy, stop going to all those shady delis. You're covered in index cards and you're going to get food poisoning, no doubt about it. | [
"In the United States and Canada a cookie is a small, flat, baked treat, usually containing flour, eggs, sugar, and either butter or cooking oil, and often including ingredients such as raisins, oats, or chocolate chips.\n",
"A cookie is a baked or cooked food that is typically small, flat and sweet. It usually c... |
: why is my computer downloading 36 mb/s, but my game is only downloading at a 4 mb/s speed ? | Your computer is reporting the transmission speed in Mbps (megabits per second). Steam, or whatever you're using to download your game is reporting the transmission speed in MBps (megabytes per second). One megabyte is eight megabits. That doesn't account for it exactly, but I'd wager you've done some rounding. | [
"The MS-DOS port of the game was very loyal to the arcade game in terms of graphics and speed. However, it was notoriously difficult to run because of the high amount of conventional memory needed to run (580K out of 640K) and would usually need either a boot disk or memory tweaking (or both) in order to load.\n",
... |
how to work out percentages (help!) | What do you mean by work them out?
Like if 68 people out of 212 tested positive, how to figure out what percent that is? | [
"The PUE metric has several important benefits. First, the calculation can be repeated over time, allowing a company to view their efficiency changes historically, or during time-limited events like seasonal changes. Second, companies can gauge how more efficient practices (such as powering down idle hardware) affe... |
how do animals actually get put down at the vet? what happens biologically? | Typically, they are given 2 intraveinous shots: the first is a deep sedative which puts them into a deep unconscious state, similar to the first step of anesthesia. The second step is to give them an overdose of anesthetic, similar to the second step of anesthesia.
The long and short of it is that it's typically the same procedure as anesthesia, except with a significantly higher dose. This, usually, causes the actual cause of death to be cardiac arrest: the animal's heart simply stops, but it's way under anesthesia at the time, so there's no pain or suffering.
As you might suspect, dose does matter: it's an overdose of (the type of) fairly normal drugs used in veterinary practice.
Source: Father was a veterinarian, have had pets, and did some quick research like [this](_URL_0_). | [
"Some veterinarians perform a two-stage process: an initial injection that simply renders the pet unconscious and a second shot that causes death. This allows the owner the chance to say goodbye to a live pet without their emotions stressing the pet. It also greatly mitigates any tendency toward spasm and other inv... |
Before VHS, were people completely unaware of previous decades' movies? | Certainly not. It was more common for theaters to play classic movies back then. Additionally, classic movies were excellent material for television stations to play and were one of the big draws of early cable television. Indeed, the television broadcast rights for motion films became a major source of revenue for production studios. In some respects, prior to the modern age of content on demand it was much more likely for people to be exposed to popular movies on television.
Some examples. NBC had "Saturday Night at the Movies" which ran from 1961, and CBS had the "CBS Thursday Night Movie" which ran from 1965 through 1975. And, of course, you have cable television channels like HBO starting in 1972 and Showtime starting in 1976, before VCRs were widespread. And you have various local channels.
Interestingly, because "top tier" films could still earn money at the box office years after release and their broadcast rights were very expensive the movies that tended to get the most airtime were often "lower tier" films. Which ironically meant that many of those lower tier films ended up being watched by far more people than saw some of the best and biggest films of the day or of the recent past. Though many films that were very popular in the theater were also very popular on television. For example, in 1976 NBC paid $5 million ($22 million in today's dollars) to air Gone With the Wind just once, but doing so broke ratings records. To pick another film, The Wizard of Oz was typically broadcast only once a year until the late '90s (by different broadcasters but mostly by CBS). It became something of a national event that many families would come together to watch.
How each film from the past fared after its initial release varied wildly. Some movies, like Casablanca (incidentally the most heavily shown film on television prior to the VHS age) or The Wizard of Oz, deepened their initial popularity through later showings in theaters and on broadcast television, becoming well worn parts of popular culture. Other films gained what might be fairly said to be a degree of "unearned" popularity due to the needs of television stations to fill their schedules with material. While other films suffered an unwarranted diminution of attention as they faded from the box office but weren't sufficiently broadcast television friendly to live on as an irregular companion of everyone's lives right in their home. | [
"BULLET::::- March 14 - The film \"A History of Violence\" becomes the last major Hollywood film released to VHS. After this point, all VHS releases are either rental-only, available only as screeners or through special programs (such as the Disney Movie Club), or are from indie companies.\n",
"By 1980, VHS video... |
why dogs never seem to get dizzy? | Maybe because your a pussy...but try spinning a dog in an office chair or something of that sort and you will see a dizzy dog. | [
"Symptoms are not necessarily distinguishable from other kinds of distress. A dog might stand uncomfortably and seem to be in extreme discomfort for no apparent reason. Other possible symptoms include firm distension of the abdomen, weakness, depression, difficulty breathing, hypersalivation, and retching without p... |
How much did drinks at a saloon cost in the Old West? | Most communities differentiated between one-bit and two-bit saloons. Really sleazy places would charge just a nickel for a beer, a whiskey, or a cigar, but they were relatively rare. Most saloons were one-bit places (with a range of quality in establishments charging these prices). Communities could only support a few two-bit saloons because the price - twice as much as most saloon- meant that these establishments were exclusively for those who didn't want to rub elbows with the average customer.
To pay at a one-bit saloon (i.e. 12 1/2 cents for a beer, a whiskey, or a cigar), one would pay with a quarter and then receive a "short bit" or a dime, which could then be used for the next drink. So if you ever get a chance to go back in time in a time machine, take a lot of dimes and always pay with short bits. That way you get 10 drinks to the dollar rather than just 8. Because it tended to be a "bit" or nickel-based economy, pennies are rare in the archaeological record.
For sources see Kelly Dixon, Boomtown Saloons (an excellent book on the archaeology of saloons) or Ronald M. James, Virginia City: Secrets of Western Past, dealing with material culture in general. | [
"Imported beer had been very expensive during the initial gold rush, costing around $100 a barrel, or approximately $1 a bottle. The Dawson City Brewery had been established in the city by a businessman called T. Krozner in 1898 to manufacture a local alternative, but this had closed by 1902 as the city's populatio... |
Is immunosuppression required in organ transplantation between monozygotic twins ? | In contrast to solid organ transplantation, in hematopoietic stem cell transplantation recipients receive immunosuppression for prevention or treatment of graft-versus-host disease (reverse rejection, if you will). [This](_URL_0_) pretty large (but now dated) case series of syngeneic stem cell transplants found that most recipients (~85%) did not receive immunosuppressive graft-versus-host disease prophylaxis but still experienced a far lower rate of the complication than what is observed in non-syngeneic settings. It appears that immunosuppression *may* not be required in this setting. | [
"An Isograft is a graft of tissue between two individuals who are genetically identical (i.e. monozygotic twins). Transplant rejection between two such individuals virtually never occurs, making isografts particularly relevant to organ transplanations; patients with organs from their identical twins are incredibly ... |
why does adding white vinegar to the laundry take care of bad smells and why don't laundry detergents already contain these properties? | General rule of thumb, most of the stains you're trying to remove require a high pH(more basic/alkaline). Vinegar, being an acid, actually lowers the pH making commercial laundry detergents less effective. The smell is likely coming from your washer itself, which the vinegar helps to remove odors from.
Source: I work for company that supplies raw materials for making Laundry Detergents.
Edit: Whoa, my first silver! Thanks Anonymous Redditors! Finally putting my chemistry degree to good use.
Second Edit: Platinum! You guys are too kind! | [
"White vinegar is often used as a household cleaning agent. For most uses, dilution with water is recommended for safety and to avoid damaging the surfaces being cleaned. Because it is acidic, it can dissolve mineral deposits from glass, coffee makers, and other smooth surfaces. Vinegar is known as an effective cle... |
karat markings on gold | There are other ways to test the purity, mostly used by jewelers. You can submerge the item to get a measure of its volume and compare to its weight, thus getting the density; golds of different purities will have different densities. You can also test the metal against known-purity samples in a jeweler's shop, how they scratch or rub off for example. Or you can melt down the object and really see what's inside, but that's not always useful, of course.
Basically the karat numbers are just a quick reference; any piece you are buying or selling will be verified by the jeweler. Thieves aren't going to scam reputable shops with lesser quality gold just by forging (if you'll pardon the pun) the karat markings. | [
"The karat (US spelling, symbol K or kt) or carat (UK spelling, symbol C or ct) is a fractional measure of purity for gold alloys, in parts fine per 24 parts whole. The karat system is a standard adopted by US federal law.\n",
"Karat weight (K or kt) is a traditional fraction-based system used to denote the finen... |
Can faecal particles in bathroom spread bacteria and viruses? | hepatitis is not an airborne disease, but im assuming this means in typical scenarios, but in general, about 50%!! of fecal matter is bacteria, so you can get other infections from not wiping properly (ie. UTI), or not washing you hands. Heres some more info on your risk tho: "The greatest aerosol dispersal occurs not during the initial moments of the flush, but rather once most of the water has already left the bowl," according to Philip Tierno, MD, director of clinical microbiology and diagnostic immunology at New York University Medical Center and Mt. Sinai Medical Center. He therefore advises leaving immediately after flushing to not have the microscopic, airborne mist land on you. Worse still is the possibility of getting these airborne particles in the lungs by inhaling them, from which one could easily contract a cough or cold. . . .streptococcus, staphylococcus, E. coli and shigella bacteria, hepatitis A virus and the common cold virus are all common inhabitants of public bathrooms | [
"Preliminary research has shown the fungus is 100% effective in eliminating bed bugs exposed to cotton fabric sprayed with fungus spores. It is also effective against bed bug colonies due to \"B. bassiana\" carried by infected bugs back to their harborages. All subjects died within 5 days of exposure.\n",
"More r... |
what is nash equilibrium? | The Nash Equilibrium is a point where neither player can unilaterally improve their position by changing strategy (if their opponent stays the same). This is not the same as the best outcome.
In the prisoner's dilemma, both confess is the Nash Equilibrium - neither player benefits by changing from confession to silence if their opponent stays on confession.
Both staying silent is NOT a Nash Equilibrium, because one player can confess (with his opponent staying silent) and get a better deal for himself.
It is possible to have multiple (or no) Nash Equilibrium in a given situation, depending on the parameters.
I can't display your ASCII picture to explain it, however. | [
"The Nash equilibrium is the traditional solution concept in game theory. It depends on the cognitive abilities of the players. It is assumed that players are aware of the structure of the game and consciously try to predict the moves of their opponents and to maximize their own payoffs. In addition, it is presumed... |
why is texting and driving not illegal? | It's illegal in a huge number of jurisdictions already. Where do you live? | [
"The Government of Sweden, as of 22 December 2012, has stated that texting while driving is not an offence that can lead to a ban, but that it is looking to clarify the \"Highway Code\" to include it under reckless driving. In 2013, Sweden outlawed mobile telephone activities if it affects driving in a negative way... |
Why do we see hydrogen's spectral lines in absorption in the sun's spectrum? | These light bands are missing because the light is passing through that gas, and that gas absorbs some colors of light.
Stars run on hydrogen, so there's lots of it around, at all levels, including between the bright photosphere and you. That hydrogen absorbs some colors of light, leaving those absorption bands. | [
"The observed spectra consist of neutral hydrogen Lyman alpha absorption lines which are broadened by radiation damping. These systems can be observed in quantity at relatively high redshifts of 2-4, when they contained most of the neutral hydrogen in the universe.\n",
"The visible spectrum of light from hydrogen... |
why do women develop stretch marks on their breasts when gaining weight, but not when getting breast implants? | I have implants. Went from a small B to a DD...I have stretch marks from it. Only a few small ones, but they are there. It just depends on your body. | [
"Many women, such as beauty pageant participants and transgender people, create cleavage by using tape underneath and across their breast, bending forward, tightly pulling them together and up. Types of tape used include surgical micropore tape and athletic tape. Some also use a strip of moleskin under the breasts ... |
Why doesn't dark matter give off blackbody radiation? | It is currently thought that dark matter does not interact through the electromagnetic force, and so cannot emit or absorb light in any form (which also makes it really rather hard to find), and instead only interacts via gravity and the weak force, the particle for which is imaginatively named the [Weakly Interacting Massive Particle](_URL_0_). A similar example of a particle that does this is the [neutrino](_URL_1_), which is generally accepted to have too low a mass to be considered as a dark matter candidate, although it previously did have some promise as one.
This doesn't mean that dark matter doesn't have a temperature - in fact, temperature is one of the main reasons that neutrinos were ruled out! It just means that it can't reduce its temperature by emitting dark matter. | [
"As \"dark matter\", baryonic dark matter is undetectable by its emitted radiation, but its presence can be inferred from gravitational effects on visible matter. This form of dark matter is composed of \"baryons\", heavy subatomic particles such as protons and neutrons and combinations of these, including non-emit... |
A perspective/scale question: In a hydrogen atom, if the proton was the size of a tennis ball, (say 6.5 cm), on average how far away from the proton would the electron be orbiting? | A hydrogen atom is 1.1 angstroms in diameter, a proton 1.7 x 10-5. so the atom is 64706 times bigger than the proton. That means your scaled up atom would be 4206 meters across, or about 2.1 km from center to "orbit". | [
"The internationally accepted value of the proton's charge radius is based on a suitable average of results from older measurements of effects caused by the nonzero size of the proton on scattering of electrons by nuclei and the light spectrum (photon energies) from excited atomic hydrogen. The official value updat... |
how do scientists know what a person's face looks like when reconstructing it form a skull? | Your skull helps define your facial structure. Then layer on things such a muscle, fat, et cetera as appropriate until it looks right. There's a level of guesswork associated with it, but it's still more accurate than not. | [
"Like the face, the skull and teeth can also indicate a person's life history and origin. Forensic scientists and archaeologists use metric and nonmetric traits to estimate what the bearer of the skull looked like. When a significant amount of bones are found, such as at Spitalfields in the UK and Jōmon shell mound... |
How is CERN able to produce the highest man made temperature without completely destroying their collider? | It is a very tiny high-temperature system contained in a vacuum. Two lead nuclei collide and for a brief instant, a very high temperature medium is created. This medium expands and cools, "freezing" back out into a spray of particles within the vacuum.
So this high-temperature medium created in the collisions is never directly observed. It is too small and short lived. To know that such a high-temperature medium was created, one must look at how many particles are emitted in each collision on average, and the patterns in their momentum and direction. From this information, the temperature of the system can be estimated.
Over time, the particles coming from the collision will damage the detector electronics. Maintenance and replacements occur every few years when the LHC shuts down for a long period, such as the current shutdown that will end next year. | [
"BULLET::::- Physicists collide gold ions together to produce a quark–gluon plasma, similar to that which existed in the first instant after the Big Bang. In doing so, they momentarily produce what Guinness World Records reports is the highest man-made temperature ever: 4 trillion degrees Celsius (7.2 trillion degr... |
how difficult would it be to intentionally build an immunity to a lethal poison, a la the princess bride? | There isn't a blanket answer to this. Some poisons you simply cannot develop an immunity to, and they will end you no matter how hard you try. If you were curious, the practice itself is named Mithridatism. | [
"The third case, \"The Poisoned Bride\", addresses the poisoning of a local scholar's daughter, who marries the son of the former administrator of the district and dies mysteriously on her wedding night. This case contains a surprising twist in its solution.\n",
"The princess does not wish to marry a common ex-so... |
how does the naming of marijuana strains work? | somebody makes a strain...and then names it, hence the sometimes rather silly names. theres no organized "Marijuana Naming Committee" | [
"Varieties are developed to intensify specific characteristics of the plant, or to differentiate the strain for the purposes of marketing or to make it more effective as a drug. Variety names are typically chosen by their growers, and often reflect properties of the plant such as taste, color, smell, or the origin ... |
why does dinner usually cost so much more than other meals i.e: breakfast | The general response is that patrons have a higher tolerance to paying more at dinner time. Culturally, dinner is often seen as the most important meal. Because of this, you can add in more expensive ingredients, different flavors and go way beyond for dinner. Breakfast, however, this isn't a whole lot of wiggle room...most breakfasts are going to have some variation and use eggs, bacon, sausage, fruit and pancake or crepe....none of these are incredibly expensive ingredients or requires a disproportionate level of cooking skill to create meals for.
That said, it can be easy to get an expensive breakfast, either in a brunch setting and with alcohol like mimosas and bloody Mary's | [
"Dinner usually refers to the most significant and important meal of the day, which can be the noon or the evening meal. However, the term \"dinner\" can have many different meanings depending on the culture; it may mean a meal of any size eaten at any time of the day. Historically, it referred to the first large m... |
A question for historians about research and methods. | Would you feel comfortable revealing at least the general time period and place? That would be helpful for putting you in the right direction without having to say anything specific.
If there's a university library near you, you could try that out. Some have departmental research librarians who can help you find relevant material.
Also, while intelligent/skeptical friends are good, someone who is an expert in the field is much better. Yes, there are some shady academics out there who might maybe steal material, but that is overwhelmingly not my experience - especially not with historians. It's not like we're going to cure cancer and stand to make bank. | [
"His 1897 work \"Introduction aux études historiques\", written with Charles Seignobos, is considered one of the first comprehensive manuals discussing the use of scientific techniques in historical research. The \"Introduction to the Study of History\" takes a very detailed view at finding a way to make history as... |
Why are certain elements more common in certain parts of the earth's crust? | Each element has a different "geochemical affinity" or flavor. We break them down into 4 groups: **atmophile** elements like to hang out in the gas phase so they're concentrated in our atmosphere (e.g., noble gases, N); **siderophile** elements behave similarly to Fe so they're concentrated in our planet's core because liquid Fe is really dense so it sank in the first few million years of Earth's history (e.g. platinum group elements, Ni); **chalcophile** elements like to bond with sulfur so you'll usually find them wherever you find sulfur (e.g., Sn, Cu, Ag, Zn); and finally **lithophile** elements bond with O (which is the most common element in the Earth's crust) and there are a ton of these elements (e.g., Ca, Al, Si, REE).
You can also further break things down into compatible and incompatible elements: **incompatible elements** like magmas, so when the mantle melts to form a magma, they move into the magma and get carried up to the crust (e.g., K, Na, Rb). Thus these elements are concentrated in the crust relative to the mantle. **Compatible elements** (e.g., Mg, Ni, Cr) like mantle rock, so when the mantle melts they don't melt along with the incompatible elements.
As the Earth has evolved over the last 4.5 billion years, these elements have been more or less clumped together based on this classification. Siderophile elements are *mostly* concentrated in the core. Atmophile elements are *mostly* in the atmosphere. An element that is incompatible and lithophile will be heavily concentrated in the crust.
Tin (for example) can behave as a chalcophile or lithophile element. We're still not totally sure how compatible it is (this is actually something I research), but we can generally call it incompatible. So when part of the mantle melts, Sn will jump into the magma and get carried up into the crust. As the magma starts to cool, it will precipitate out minerals. One of those minerals is sulfide - since Sn is chalcophile, it will probably jump into those sulfide minerals.
Magmas are dynamic so it could drop sulfides off somewhere in the lower crust and then continue on to the upper crust without Sn and the other chalcophile elements. Alternatively, when magmas cool they often release fluids that are saturated in S and the chalcophile elements. Those fluids will be released into the surrounding rock and may precipitate sulfides there, along with Sn and the other chalcophile elements. Both of these mechanisms are how many ore deposits are formed.
| [
"The abundance of the chemical elements on Earth varies from air to crust to ocean, and in various types of life. The abundance of elements in Earth's crust differs from that in the Solar system (as seen in the Sun and heavy planets like Jupiter) mainly in selective loss of the very lightest elements (hydrogen and ... |
I have a question pertaining to dental hygiene. | There could be a few different explanations. We all have a ton of different bacteria (normal flora) in our mouths but not all of us have the same types of bacteria. Cavities(caries) are actually an acquired, contagious disease, as the bacteria that produce the acid to form the cavities are not with us when we are born. They are passed on to us from our caregivers, siblings, etc.
Some people, thanks to their genetic makeup, may be less susceptible to these bacteria.
Your diet also plays a large role in the caries process. If you avoid sugary, sticky food and drink, and eat more fibrous foods or dairy products, you will be less likely to develop cavities. This is because the cavity causing bacteria thrive on simple sugars, while fibrous foods act as a natural cleanser and the calcium you receive from dairy products helps to remineralize any demineralized tooth surfaces (The spots where cavities have started to form). Fluoride also aids in the remineralization process, so if you drink fluoridated water or use fluoridated toothpaste it helps.
A very common area to develop cavities is in the pits and fissures on the occlusal (top) surfaces of your teeth. This is especially true if you have deep grooves and haven't had sealant put in. If the grooves are shallow, they are easier to keep clean. Cavities that develop in between teeth can be much trickier to spot.
Also, caries are not always brown. When demineralization first starts, it appears as a very chalky white lesion and will change color as the cavity progresses. Yellow coloration may be due to staining foods, smoke, etc. However some peoples teeth are naturally more yellow due to a thinner enamel surface allowing the yellow color of the underlying dentin to show through.
As a side note, you should definitely start brushing your teeth, at least at night. Just because you haven't had a cavity in 3+ years doesn't mean that you are not susceptible to them OR to the periodontal diseases. | [
"Oral hygiene is important as dental biofilms may become acidic causing demineralization of the teeth (also known as dental caries) or harden into dental calculus (also known as tartar). Calculus cannot be removed through tooth brushing or with interdental aids, but only through professional cleaning.\n",
"Oral h... |
how saudi arabia, venezuela and other oil export depending countries are dealing so differently with low oil prices. | Imagine you have several households, and all of them have one family member with a pretty decent income as salesmen (oil revenue in this metaphor). However, some of them have to commute further than others, and have other expenses that mean they get to keep less of their total pay. If sales drop low enough, it actually costs them more to sell their goods than to do nothing.
Some families deal with the problem by taking out payday loans, or second mortgages on their house. A bad long term strategy, but so long as sales eventually recover, they will probably be ok.
Some of these families have been throwing extra money into savings for years, so when sales go down, they can tap into their savings (Saudi Arabia for example). Additionally, some of these countries have been using their extra money to diversify their income sources (such as paying for other members of the family to attend college), so they are not as dependent on the sales revenue (Such as the United Arab Emirates). They can also look into selling off assets, like a second car (Saudi is looking into this option).
On the other hand, some countries spent nearly every dime as they earned it so they have no savings, and failed to perform maintenance on the car they use for their sales job, so it doesn't travel as fast anymore, which impacts their sales (Venezuela). Also, they defaulted on the loan for the car and have terrible credit, so no one wants to loan them anymore money. | [
"Both countries are major oil and gas exporters and have clashed over energy policy. Saudi Arabia, with its large oil reserves and smaller population, has a greater interest in taking a long-term view of the global oil market and incentive to moderate prices. In contrast, Iran is compelled to focus on high prices i... |
How are inorganic bones in our organic bodies? How did they ever evolve? | ~~I'm marking this to respond later. It's an interesting discussion.~~
OK, so bone as a tissue. Bone is a living, organic tissue. It receives 25% of the resting cardiac output and helps regulate calcium and phosphate metabolism as well as provide structure to the body. There are 4 main cells types in bone: osteoclasts, osteoblasts, osteocytes, and osteo-progenitor cells.
- osteclasts are from the hematopoetic cell lineage and function to resorb bone via powerful enzymes.
- osteoblasts are from the mesenchymal stem cell lineage and function to excrete and mineralize the extracellular matrix (ECM) of bone.
- osteocytes are long-lived stellate shaped cells that are trapped within the ECM they created.
- osteoprogenitor cells are partially-differentiated cells that require an inductive stimulus to divide and terminally differentiate into osteoblasts.
Bone can be formed from 2 different pathways: intramembranous ossification or endochondral ossification.
- Intramembranous ossification occurs in the flat bones, like the skull. The osteoblasts secrete a substance called osteoid, which they then mineralize. This process is mildly disorganized.
- Endochondral ossification occurs in the long bones, like the femur. The bone architecture is first laid down in a cartilaginous form, and then replaced and mineralized. This process is highly organized.
The major component of the ECM in bone is type 1 collagen. Also present are hydroxyapatite (HA) and tricalcuim phosphate (TCP). All are considered organic compounds secreted from cells.
Endochondral ossification gives us a model of how bone possibly evolved. Animals (like the shark) can have entire skeletons made of cartilage. However, cartilage is soft and difficult to regenerate (at least in humans, someone who is an expert on Chondrichthyes can help me here). The transition from cartilage skeletons to ossified skeletons improved the ability to bear weight (important for the water to land transition), as well as allowed for greater protection and healing capabilities. We traded off in the sense that bone is expensive (metabolically) to produce and maintain, but the benefits outweighed the expense.
The truth is, bone is very organic and highly organized. It is a very active tissue, that responds to and helps regulate hormonal changes, mineral balance, blood production, and load bearing. It just happens to have insoluble compounds (TCP etc) in the ECM, which help give it structural integrity. Obviously, I'm a huge nerd when it comes to the subject, so if you have any more questions, feel free to message me.
Hope this helps. | [
"Several hypotheses have been proposed for how bone evolved as a structural element in vertebrates. One hypothesis is that bone developed from tissues that evolved to store minerals. Specifically, calcium-based minerals were stored in cartilage and bone was an exaptation development from this calcified cartilage. H... |
why do we gag when we push ourselves too hard when exercising? | Well there could be many possible reasons as to why you would gag.
For your situation, exercising hard for an extended period of time will draw blood away from the stomach, which is why you feel nauseous. This nausea can induce a reflex depending on how your brain interprets the stimuli as a threat or not which is different for everyone (ex. "weak"stomached people). If your brain interprets the nausea as a threat you will gag.
Also if you are dehydrated and have a dry throat, dust particles in you throat can induce the reflex involuntarily.
Another possibility is when you are exercising and have too much mucous build up in your throat. This will also induce the reaction to try to clear up the throat. | [
"A gag is designed to prevent speech or the subject making noise. This may be by blocking the mouth partially or completely to preventing the tongue, lips, or jaw from moving. Gags may cause suffocation, so a gagged person should never be left alone.\n",
"The gag reflex involves a brisk and brief elevation of the... |
How do electromagnetic waves "look" likr in 3D? How do waves really work? | Great Question! The answer is quite simple but also kind of boring: depends on the wave.
Here is a picture of a running electromagnetic wave which is the standard picture physics students see when they are told to imagine a light beam as a wave. However, waves don't need to be just sin or cos. Usually they are described as many, or even infinite, amounts of sin/cos added together which can give any kinds of shape or form.[_URL_0_](_URL_0_) | [
"Waves are up to four-dimensional arrays that can carry not only numbers, but also characters (text), or date-and-time entries. Waves can carry meta-information, for example, the physical units of each dimension. Igor offers a wide choice of methods to work with these waves. It is possible to do image-processing wi... |
why do we censor things like nudity and swears to children when eventually, they'll be predisposed to it and consider it "normal"? | > ELI5: Why do we censor things like nudity and swears to children when eventually, they'll be predisposed to it and consider it "normal"?
This is sort of an open-ended question, but I'll give it a shot.
People are certainly not *predisposed* to swearing, and in many circles it is not considered "normal". And while you could argue that people aren't *predisposed* to nudity (with others, which is what I presume you meant) it certainly is considered normal to some extent during certain periods of a human's life. I don't think however you meant to use the word "predisposed", but rather "subject to".
The issue isn't whether or not a person will be subject to these things at some point in their lives, but rather that being exposed to these things *too early* in a person's development could cause them to internalize or interpret the place of these things in our society incorrectly, thereby causing children to develop in a way that harms their ability to integrate in to our society effectively. | [
"In censorship debates, the term means cultural works (including art, literature, films, television and music) that are considered by most people to be generally appropriate for children while at the same time palatable to adults. Frequently, the term \"Think of the children\" is used during a moral panic to censor... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.