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how is it that i remember hundreds of lyrics when i sing along to songs, but i mix them up or forget parts when i try to sing a capella or to instrumental song versions? | Because you are actually singing with a very very small delay to the actual lyrics, at least the beginning of each line or so, because you can probably finish the lyrics if you have he beginning. | [
"I try not to get too specific so that people can apply the lyrics to their own lives. When I was growing up and listening to the radio and I would hear a song that reminded me of a certain person or a situation or whatever, I would want to be able to completely connect it to that moment. And then if I heard someon... |
Why exactly do migrating birds move from north to south or vice versa in one long event, rather than gradually moving around throughout the year? | Well, first of all, there are several types of migration, and there are some forms that are more similar to your description. Those are usually called Irruptive Migrations. But basically, most Migration depends on food amounts. Birds typically migrate when there is no more food in their current environment and decide to move to a new one. They need to get to the environment with food as quickly as possible, as birds have EXTREMELY fast metabolisms and can die without food in a day or two. That's why ducks, geese and waterfowl can appear out of no where, there home lakes and rivers freeze over stopping them from reaching food so they leave and find liquid water asap.
But most birds do have rates of travel (_URL_0_) with different birds of the same species reaching home at different times, breeding birds getting home first to breed and take territories and older and younger birds getting home later. So, the birds that have the strength can fly very long distances with Anseriformes (ducks), Falconiformes, etc and some larger migratory songbirds moving upwards of 50 miles a day. Some birds do move more slowly, Hummingbirds for example, need to migrate timing flower blooms and nectar productions. If they get somewhere to early they starve, if they get there too late they starve, same with many insect eating species. Funny fact, many Ruby-Throated Hummingbirds (which are the only Hummingbird species east of the Mississippi river, and have one of the fastest metabolisms on earth), coming together in large flocks, decide to cross to Brazil by flying from Miami. But if they take a route that doesn't cross any islands then they will starve and die. There are reports of people on boats in the Caribbean watching groups of Hummingbirds die and fall into the water.
| [
"Most migrations begin with the birds starting off in a broad front. Often, this front narrows into one or more preferred routes termed flyways. These routes typically follow mountain ranges or coastlines, sometimes rivers, and may take advantage of updrafts and other wind patterns or avoid geographical barriers su... |
If I were to strike a tuning fork in space(without dampening from air), would the metal vibrate indefinitely? Would this be an effective way to store energy? | No, the attenuation caused by the vibrating material would eat up the energy. You might heat up the object a bit as a result, or cause some plastic deformation. | [
"BULLET::::- Reduction of resonance: Essentially any piece of metal or glass has certain frequencies to which it is susceptible to resonate. A machine that resonates would make a tremendous noise. Resonance also occurs in enclosures, such as when echoes reverberate in an ocarina or the pipe of a pipe organ.\n",
"... |
Who is our evolutionary "common ancestor"? | > the prevailing theory is that we have not evolved from chimpanzees
No, but we do share a common ancestor with them that lived 6 million years ago. This ancestor was not a chimpanzee and it was not a human. it was it's own unique species that would split into two lineages, one which would evolve into the Homo lineage and the other into the Chimpanzee/Bonobo lineage.
> do we have fossils or even a name for our most recent common ancestor
This is extremely difficult to know because:
1. Fossils represent at best 5% of the living species fossilized at that time.
2. We have to find and dig up those fossils
3. We have to correctly place those fossils within our family tree.
So that very likely do not have a full representation of all the species that were living between 6 mya - 200,000 years ago. Of those that we have found (about a dozen species or so) we have been able to place them with more or less accuracy within our family tree.
> The organism we most recently (or directly) evolved from.
First, this depends on what you define a "human" or *homo sapiens* to be. We will go with the most commonly accepted hypothesis in that humans evolved about 200,000 years ago in Africa. Other fossil finds in Africa that predate this time include *Homo ergaster* and *Homo heidelbergensis*. Again, it depends on how you define these species but one of the more popular hypotheses is that our direct ancestor is *Homo heidelbergensis* who in turn evovled from *H. ergaster* in Africa. In contrast, Neanderthals evolved in *Europe* from either *Homo erectus* or *Homo heidelbergensis*
**More detailed version**
But before humans evolved there were several other species that came before us in our lineage. Here is an overview of the major fossil categories in our lineage, starting from oldest to youngest:
1. Last common ancestor with chimps (it was neither a chimp, nor a human): ~ 6mya
2. The earliest fossil we have in our lineage is [Sahel](_URL_1_) ~5-6 mya. Found in Africa.
2. One of the earliest complete groups that we have the best fossils for are the [australopithecines](_URL_3_): ~ 4 mya All found in Africa.
3. The genus *Homo* diverges from some australopithecine species: ~ 2-3 mya. The first homo species is [H habilis](_URL_0_) although the placement of this fossil is debated. All found in Africa.
4. Evolution of the Homo lineage - our genus. The exact placement of these species is debated but here is one hypothesis that is a strong contender.
* *H habilis* evolves into *[H. ergaster](_URL_2_)* in Africa.
* *H. ergaster* (Africa) migrated out of Africa and became *H. erectus* in Asia. Some place these two in the same species category (H. erectus) others like to maintain the geographical distinction (Africa vs. Asia) when referring to the two populations.
* *[H. heidelbergensis](_URL_4_)* evolved from either H. ergaster or H. erectus in Africa and Europe.
* *H. neaderthalensis* evolved from European *H. heidelbergensis* in Europe
* Humans evolved in Africa from a small population of *H. heidelbergensis*. Then we migrated out of Africa where we encountered: Neanderthals, and *H. erectus*. These two species went extinct and we lived. Anatomically modern humans (*Homo sapiens*) appear in the fossil record about ~200,000 years ago.
**ELI5 Version**
* Humans and Neanderthals are sisters and we come from the same mom (H. heidelbergensis). Neanderthals were "born" first in one place (Europe) and we were "born" second (in Africa). Our mom continued to live even after we were born. Our mom "died" first then our older sister "died" next, but not too long ago.
* To take this further our mom had a mom herself, our grandmother (H. erectus). Our grandmother had other children besides our mom (our aunts - like H. floresiensis). H. floresiensis did not directly contribute to us being here but they are still part of our "family tree". Our aunt died before she had children.
* The further we go back the more our records become muddled. Was Sahel our great-great-great grandmother or just some random great-great-great aunt who died without children? In our giant family tree we are the only ones left alive.
If you would like to know more about how we define a human versus other species please let me know and I will respond.
| [
"In biology and genealogy, the most recent common ancestor (MRCA, also last common ancestor (LCA), or concestor) of any set of organisms is the most recent individual from which all the organisms from such set are directly descended. The term is also used in reference to the ancestry of groups of genes (haplotypes)... |
why do humans get headaches? is there a sole reason or is it a combination of factors? and does the factor(s) also cause migraines? | The exact mechanism that causes headaches isn't/aren't yet fully understood. All we know is that there are many known factors that can trigger it. Like blood vessel constriction/dilation, and a change in hormone levels. (And that's also why more women suffer headaches than men.)
Certain patterns of brain activity have been found to trigger blood vessel constrictions, which will reduce the oxygen supplied to the brain. Consequently, the blood vessels dilate and some chemicals that cause inflammation are released. The nerves nearby have pain sensitive endings and these can be triggered by that, activating the pain centres in return.
As for migraines, we are less familiar wih how they work but apparently have something to do with the constriction and dilation of blood vessels too. | [
"Migraines are currently thought to be caused by dysfunction of the nerves in the brain. Previously, migraines were thought to be caused by a primary problem with the blood vessels in the brain. This vascular theory, which was developed in the 20th century by Wolff, suggested that the aura in migraines is caused by... |
Looking for WW1 combat reports from units issued body armor | You'd have to dig in the archives for actual military documents, but you might take a look at Bashford Dean's [Helmets and Body Armor in Modern Warfare](_URL_0_) (1920), which covers many types of body armor used by different nations in WWI, including some data from empirical testing, reports from the field, etc. | [
"The medal was originally designed for presentation to combat engineers, as well as members of the artillery, anti-aircraft and anti-tank who supported infantry units in combat. It could also be awarded to medical personnel attending to battlefield casualties in \"close combat conditions\". Prior to the introductio... |
Is it possible for humans, in the far future, to colonize a planet moving at such a speed that time moves 50% slower than at Earth? | Well, that means it's moving at 86% the speed of light relative to some frame (let's say, the CMB anisotropy frame). That's really fast. The fastest known orbital system is the star S2 which orbits the supermassive black hole in the center of our galaxy, and it moves about 2% the speed of light. So to answer your question, no I don't think there are any planets that move that fast. | [
"The above concepts which appear limited to high, but still sub-relativistic speeds, due to fundamental energy and reaction mass considerations, and all would entail trip times which might be enabled by space colonization technology, permitting self-contained habitats with lifetimes of decades to centuries. Yet hum... |
the assad regime | Heads up, there are serious conspiracy theorists on both sides of this issue right now from T_D and Trump/Putin truthers.
If you want to learn about geopolitics, this NOT the place. If you want an ELI5 you WILL get garbage. Even if it is a long explanation or seems to make a lot of sense, you need to understand geopolitics is extremely messy. If you actually want to understand situation,
you need to put in the effort. Read from news sources on all sides, Europe, US, Russia. Take note of which actors they use for information, every media outlet has a bias to support their countries interests.
Remember, this isn't rocket science. Rocket science can deliver concrete answers using provable theorems.
This is History in the making. Nobody agrees on history until it is long gone. | [
"The U.S. imposed limited sanctions against the Assad government in April 2011, followed by Barack Obama's executive order as of 18 May 2011 targeting Bashar Assad specifically and six other senior officials. On 23 May 2011, the EU foreign ministers agreed at a meeting in Brussels to add Assad and nine other offici... |
How realistic was Churchills plans to invade Russia in WW2? Could it have succeeded? | Which plan of Churchill are you asking about? Both the planned [Operation Pike](_URL_0_) and [Operation Unthinkable](_URL_1_) would have involved offensive operations against the Soviet Union. There were also [Franco-British plans to intervene in the Winter War](_URL_2_) against the Soviet Union. | [
"Overseen by Brigadier General Dwight D. Eisenhower, the plan was developed in 1942 and reflected American enthusiasm for an early entry into Europe. Senior British commanders and politicians were reluctant to commit themselves to the invasion plan; mindful of the painful losses during the Battle of the Somme (on t... |
How old is the oldest DNA/RNA that has been extracted? Is it the same as the molecules all living organisms have in their cells now? Did nucleic acids evolve or are they the same as they were when life began 4 billion years ago. | DNA will break down over time. The oldest DNA ever reliably recovered was a couple hundred thousand years old, so fantasies of recovering 100 million year old dinosaur DNA are not realistic.
Even in creatures that have stayed relatively unchanged over time (like crocodiles) their DNA continues to mutate and change slightly over time.
It is hypothesized that the primitive life-like cells used RNA. Thus quickly evolved to use DNA and has remained so for probably billions of years. It is really all just speculation, but the general idea is that primordial goop had RNA that started self replicating. This quickly led to variants that recruited or made proteins to make replication more efficient. This then recruited using DNA to stabilize the required information. Thus led to complexes that were able to protect themselves using a lipid and protein membrane...these would be considered the first real cells. DNA took over the role of encoding the plans for future cells while RNA controlled the actual construction of cells and proteins became the structure of cells inside a membrane. | [
"DNA contains the genetic information that allows all forms of life to function, grow and reproduce. However, it is unclear how long in the 4-billion-year history of life DNA has performed this function, as it has been proposed that the earliest forms of life may have used RNA as their genetic material. RNA may hav... |
what this tesla model s thing is about? | 1. A New York Times reviewer wrote up a description of a trip he took in a Tesla car. He described instances where the car didn't get as much mileage as Tesla claimed, and that at one point the car ran out of power and he had to have the car towed.
2. The head of Tesla called him a god damn liar (I'm paraphrasing here)
3. The reviewer published a blog post and stood by his claims
4. The head of Tesla published the log data from the reviewers trip. In it, they were able to demostrate clear discrepancies with what the reporter said (e.g. "I never drove the car over 65 MPH") and what actually happened (e.g. "he drove the car at 80MPH for at least 10 minutes). They produced data that appears to indicate that the reviewer may have intentionally tried to drain the battery, and may have removed the car from the charging station before the car was ready to travel the distance he intended.
5. The Reviewer has responded again, but so far he's blamed the Tesla PR group for giving him false information about what he could/couldn't do with the car.
6. Someone from CNN drove the same car on the same trip as the NYT Reviewer without any significant issues. | [
"\"Road and Track\"s Bob Sorokanich said the \"Model 3 proves that Tesla is thinking far beyond the edges of the Model S and X. Stepping out of the 3, you realize that, as far as the S and X pushed the envelope, they were always meant as intermediaries, stepping stones designed to draw people away from comfortable ... |
if the french helped us with the american revolution, gifted us the statue of liberty, and we liberated them from the nazi's, why is there a mutual dislike of eachother? | I'm not exactly a representative sample, but I'm French and I can give you my two cents on the subject.
I don't think Americans and French people hate each other, at least not the individuals. I don't know many people in France who hate Americans, and I've been to Minnesota twice and have always been very well received. I've also met quite a few Americans from other states and they have always shown a lot of interest for my country.
However, it seems French people dislike Americans politics as they are very different from theirs and the same is true from an American point of view. So each country seems to loath the other's leaders and general population behavior, but appreciate the individuals.
What do you think? | [
"Édouard René Lefèbvre de Laboulaye () (18 January 1811 – 25 May 1883) was a French jurist, poet, author and anti-slavery activist. In 1865 he originated the idea of a monument presented by the French people to the United States that resulted in the Statue of Liberty in New York Harbor. He got the idea thinking tha... |
can somebody please explain what /r/galacticpeacekeepers and all the associated subreddits are? | Red, Green, and Blue took over The Seventh World and enslaved its inhabitants. The Galactic Peacekeepers are trying to free them. | [
"BULLET::::- The Watchdogs (various voices) – The Watchdogs are small eyeball-headed creatures that serve as Hater's minions and the bulk of his army. They are loyal to their master, but are frequently distracted by Wander's interference, particularly as their \"enemy\" treats them better than their ruler. Many epi... |
what property in substances cause light to speed up or slow down | Light is an electromagnetic wave. The atoms in a substance act as barriers to the propagation of the wave. At each barrier, the wave bends and interferes with other parts of the wave. All-in-all the wave will interfere with itself in such a way as to bend AND slow down the resulting wave crests, even though each part of the wave propagates at *c* (300,000 km/s). It's similar to the "bouncing around between atoms" explanation, but fundamentally has to do with *wave propagation and interference* rather than particle behavior. | [
"When light propagates through a material, it travels slower than the vacuum speed, . This is a change in the phase velocity of the light and is manifested in physical effects such as refraction. This reduction in speed is quantified by the ratio between and the phase velocity. This ratio is called the refractive i... |
Why was Vietnam able to transition to capitalism from a failing socialist state when the USSR collapsed attempting to do so? | You're conflating economic reform with changes to political structures. The Soviet Union "collapsed" because it gained a leader that was no longer willing to enforce the party's monopoly on power, not because it attempted to reform its economics. Yes, the economic aspects of perestroika (a communist-based reform intended to revitalize the traditional command economy, rather than an attempt to introduce wholesale capitalism) were not particularly successful and hurt the already lagging Soviet economy, but many states have gone through rough economic periods and not collapsed. There was nothing necessary or inevitable about the specific reforms Gorbachev passed: they were on his initiative. In a classic contrast between the Brezhnev Doctrine (seen in action just 20 years prior, in Czechoslovakia) and the "Sinatra Doctrine", Gorbachev refused to forcibly intervene to assist the wavering Eastern Bloc. This in turn raised hopes that he would have a similar laissez faire approach to internal Soviet matters, which he did. The 1989 elections saw many separatist candidates win over CPSU candidates, but it is more significant that they were allowed to stand for office in the first place: this was due to Gorbachev's new political policies. This new generation of separatist leaders then declared sovereignty for their various republics, and again Gorbachev chose not to intervene with force.
To stick to the very recent past prior to these decisions, Chernenko, Andropov, or Brezhnev never behaved in the same fashion, with Brezhnev being responsible for the end of the Prague Spring, and Andropov being one of that invasion's strongest supporters, with a notoriously hardline opposition to expressions of dissent in general. | [
"The fall of communism in the Eastern Bloc and the dissolution of the Soviet Union in 1991 led the Vietnamese leadership to distinguish between economic and political reform – believing the former led to the fall of communism in Eastern Europe. Despite vague references to \"imperialist and reactionary forces\", the... |
What was Gettysburg all about? | Lee was coming off an absolutely devastating victory over the Union army under Hooker at the Battle of Chancellorsville. His decision to invade the north was based on a few things:
* He avidly read antiwar ("Copperhead") newspapers from the North, which led him to believe that the Union population was war-weary and ready to force Lincoln from office in the 1864 election and elect a president that would sue for peace.
* His army kept winning, but was chronically short of supplies, and he hoped to capture a bunch.
* Lee's later nemesis Grant was besieging Vicksburg, an important fortress on the Mississippi, and Lee hoped that if he raised enough havoc in the North's heartlands, Grant's army would have to lift the siege and send troops to stop him.
* Most of the war in the East up to that point had been fought in Virginia, which meant that Virginia homes were burned and Virginia food was eaten and so on, and fighting it elsewhere for a while was attractive to Lee.
Lee didn't know exactly where the Union army was because his cavalry had gone off raiding. Lee had no particular desire to fight at Gettysburg. His subordinate, division commander Harry Heth, claimed in his memoirs that he sent troops into the town because he had heard there was a shoe factory there, and many of his troops badly needed shoes, but some historians dispute this. But whatever the reason, the troops headed toward the town. Before they quite got there, they bumped into some Union cavalry and got tangled up fighting them. From that point, both sides (with poor coordination and without really understanding what was going on) started feeding more and more troops into the battle. Gradually, more and more senior commanders arrived at the battle and more and more troops got involved, until the thing kind of took on a life of its own. All through the battle, Lee and various other Confederate commanders considered breaking it off at various points and continuing their strategic maneuvering elsewhere. In the end, Lee decided to fight it out, and the rest you know.
Sources: On Lee's thinking:
Coddington, Edwin B. *The Gettysburg Campaign; a study in command*. New York: Scribner's, 1968. ISBN 0-684-84569-5.
See James M. McPherson, "To Conquer a Peace? Lee's Goals in the Gettysburg Campaign." *Civil War Times* (2007) 46(2): 26-33.
For the controversy surrounding Heth and the Shoes, see:
Eicher, David J. *The Longest Night: A Military History of the Civil War*. New York: Simon & Schuster, 2001. ISBN 0-684-84944-5 | [
"BULLET::::- Gettysburg Address helped redefine two war goals of the Union in the Civil War and the nature of U.S. nationalism. It is considered one of the masterpieces of English literature, and generally follows the form of Pericles' Oration. 1948 Issue.\n",
"The Gettysburg Address is an unreleased American doc... |
What's up with this postcard? | Was it common for Japanese soldiers to carry postcards into battle? What does the postcard say? For some context, this was taken off of a Japanese soldier during WW2 by a friend of mine's grandfather during his time in the Pacific theatre. | [
"Another form of collecting regards postcards, a document written on a single robust sheet of paper, usually decorated with photographic pictures or artistic drawings on one of the sides, and short messages on a small part of the other side, that also contained the space for the address. In strict philatelic usage,... |
How were ancient oral epics like the Iliad, the Odyssey, the Gilgamesh epic, etc. recited? | Your guesses are spot on. These epics are broken into pretty discrete episodes, and you'll see scholars referring to "The Song of Diomedes" as a unit of the Iliad (that being the section where Diomededs leads the Greeks and wounds Venus). The rhapsodes who performed these pieces would choose an episode, or perform an episode on request.
During the Odyssey, we have scenes where Odysseus is playing a rhapsode. He tells his own story to the Phaeacians (the Odyssey begins 10 years into O's journey when he washes up in Phaeacian territory where he tells his story beginning with the fall of Troy). His story takes place over a few nights, telling one book each night. So for Homer, it was realistic to portray a rhapsode performing up to 1000 lines of a poem in one night.
For more info check *The World of Odysseus* by M.I. Finley. He bases his information on rhapsodes from anthropological studies of Slavic bards, but I cannot for the life of me remember the author of those. Its a pretty influential study. | [
"It has been shown from comparative study of orality that the \"Iliad\" and \"Odyssey\" (as well as the works of Hesiod) come from a tradition of oral epics. In oral narrative traditions there is no exact transmission of texts; rather, stories are transmitted from one generation to another by bards, who make use of... |
how cloud storage systems (email, google drive, onedrive) don't run out of storage | The very simple answer is that they can always add mode storage as usage grows. Same way you can add storage to your home system. | [
"The introduction of cloud based storage, means portable operating systems are free of the need to store data locally. The unbundling of the office application data and other user data from the drives containing the operating systems has been a key factor in making BYOOS possible.\n",
"The operating system automa... |
How strong is the force that repels electrons? | Strong enough to keep you from falling through whatever you're sitting on right now. | [
"The effective range of the weak force is limited to subatomic distances, and is less than the diameter of a proton. It is one of the four known force-related fundamental interactions of nature, alongside the strong interaction, electromagnetism, and gravitation.\n",
"Being the weakest of the weakest chemical for... |
Why/how do fish demonstrate vigor at temperatures that render reptiles and amphibians immobile? | I am admittedly not a physiologist so my answer is a bit limited in scope, but I can get us started.
On average, water is much colder than the air temperatures of areas that reptiles and amphibians inhabit. Because of this, the fish’s enzymes and metabolism have evolved to operate at these low temperatures, while the reptiles ect. function optimally at a higher range. All of these chemical processes have a range that they work well at and the peak is going to be at the temperatures the animal spends most of its time at. Dropping a coral reef fish into cold water will render it similarly lethargic. | [
"In some fish, a rete mirabile allows for an increase in muscle temperature in regions where this network of vein and arteries is found. The fish is able to thermoregulate certain areas of their body. Additionally, this increase in temperature leads to an increase in basal metabolic temperature. The fish is now abl... |
the two dollar bill. | I'm going to assume you're from the US.
Two dollar bills make up a small amount of the notes in circulation, but they are still being produced so they aren't "rare" like old prints and other collectable currency.
If you consider the other denominations they seem like a sensible fit: $1, $2, $5, $10, $20, $50, and $100. They're obviously useful for buying small items or making up change, it means you can carry less $1 bills and have a low chance of needing note change (as opposed to the $5 and up).
There's no real practical reason why they don't print more to drive up circulation, but in general people are used to just using the one dollar bill. According to Wikipedia some people consider two dollar bills unlucky, and because some store owners don't actually know they're a real thing some people have had trouble trying to spend them. | [
"The United States two-dollar bill ($2) is a current denomination of U.S. currency. The portrait of Thomas Jefferson, the third President of the United States (1801–09), is featured on the obverse of the note. The reverse features an engraving of the painting \"Declaration of Independence\" by John Trumbull. \n",
... |
why do american corporations have the same constitutional rights as citizens? isn't this the reason they are able to become so corrupt and able to get all their power and control? | First, as pointed out below, corporations do not have the same rights as people, but they do have a certain legal personhood, which includes some rights.
Why? Well, it's sort of the point of a corporation. The while idea, since they first came into existence, was that the corporation existed as a distinct legal entity from the people that owned or ran it.
And, in some ways, it's a benefit in the legal field. That a corporation is a person means it can be sued, that it can own and have responsibility for property, that it can be taxed, etc...
The controversies have less to do with the idea of corporations bring people than with the extention of particular legal rights to corporations, like free speech rights or religious rights, where there's less clearly a historical basis. | [
"In addition, from the perspective of business ethics it might be argued that chief executives are not inherently more evil than anyone else and so are no more likely to attempt unethical or illegal activity than the general population. Large multi-national corporations do continue to attempt to erode governmental ... |
why don't web pages refresh automatically after failing to load the first time? | A browser doesn't necessarily know what's slowing down the network. All it knows is that the server has told it more data is coming, but has not yet been provided.
A few reasons that the data isn't there yet:
* It hasn't been generated yet
* It is stuck on a slow transit (satellite)
* The pre-routed network path has broken, and the network is "repairing" itself
* Your firewall has stopped something
* The server has crashed, but in a way that didn't pass on that information
* Network packets have arrived out-of-order, so your computer is trying to figure it out.
* The server thinks your connection is spam, and is deliberately giving you a slow connection.
How can the browser determine which of these is causing the slowdown? | [
"After the first page load, all subsequent page and content changes are handled internally by the application, which should simply call a function to update the analytics package. Failing to call said function, the browser never triggers a new page load, nothing gets added to the browser history, and the analytics ... |
does being under anesthesia "count" as sleep to your body? | There is a small amount of similarity in terms of electrical activity, but the two processes are chemically distinct.
The real difference however comes from the surgical procedure you are likely receiving, the stress, cortisol, sympathetic activation produce a vastly different physiological state to natural sleep. | [
"In this level called \"moderate sedation/analgesia\" or \"conscious sedation\", a drug induced depression of consciousness during which the patient responds purposefully to verbal commands, either alone or accompanied with light physical stimulation. Breathing tubes are not required for this type of anesthesia. Th... |
why is it so difficult to delete online accounts? | With some technical background I can say it is very hard to truly delete data, and I don't mean restoring something delete from a hard drive. Lots of information is stored in databases, these databases have different tables, in a reddit world there is likely a table with user names, one with upvotes and one with comments. All these tables are referencing each other (by your user id or something).
Now, when you delete your account, what do you do? You could just change the name to "deleted user". What about all your upvotes, do we need to remove them and recalculate totals from years ago? Your comments, should they be deleted as well? Most of the time what happens is that the user gets marked as "deleted" and all references stay there, the comments might not be shown anymore, but they are still there hidden.
Then there a backups, when you delete your account today, what about the backups from last week? Nobody has the resources to clean them up.
Where am I going here...? It is just such a nightmare to truly delete an account, and that's maybe the reason why there is no delete account function, or if there is it might be more like a "hide my account" feature. That's the reason why my "website" has no delete account feature... I just couldn't do it, and I don't feel like lying to you about it :) | [
"In Jun 2018 email from fotki.com to one of the members stated \"In order to keep quality of our service we remove old unused accounts. We've noticed that you didn't use your account at fotki.com for a year. That's why your account is queued to be deleted in 2 days\". There is no option to reactivate account withou... |
what a "non-member observer state" is? | State = The UN recognizes Palestine as a country
Observer = Palestine can send a representative to listen to UN meetings
Non-member = Palestine's representative can't vote on UN issues | [
"Observer status may be granted by a United Nations General Assembly resolution. The status of a permanent observer is based purely on practice of the General Assembly, and there are no provisions for it in the United Nations Charter. A distinction has been made between state and non-state observers. Non-member sta... |
What is the most realistic answer to the question of how earlier humans consistently (or inconsistently) made fire without proper fire making tools? | Hi there -- while this question may garner some answers here, you may also want to crosspost it to r/askanthropology. | [
"The use of flint in particular became the most common method of producing flames in pre-industrial societies (see also fire striker). Travelers up to the late 19th century would often use self-contained kits known as tinderboxes to start fires.\n",
"The discovery and utilization of fire, a simple energy source w... |
Cooling without fridge? | There are many different refrigerator designs. Some of them can be used without electricity.
The simplest wayto cool a liquid is by evaporation and this is still used in some places by putting water in earthenware pots. The pot is porous and the liquid will go thought the pores and evaporate, taking away heat from the pot. This is an ancient technique and can also be used to preserve foods:
_URL_3_
I even read in a some places that ancient peoples could make ice using evaporation, though I'm not very sure that this is actually true. Though it seems perfectly possible to make some ice by evaporating lots of water, I don't know if this could be done in scale.
There are also the gas absorption refrigerators that can be run with no electricity:
* _URL_0_
* _URL_1_
* _URL_2_
This is a much more complex technical development and I don't think it could have been invented before the principles of thermodynamics were understood, but it is possible to make them work without electricity and without depending a lot on modern technology. They can even run on solar power.
The basic principle is to have a refrigerant in liquid form (ex.: water) that can evaporate in a low pressure environment, taking heat from whatever you want to cool. Than the refrigerant is diluted (absorbed) in another liquid (ex.: salted water) and then some heat source is used to remove the refrigerant and put it back in the refrigerant storage.
| [
"A refrigerator (colloquially fridge) consists of a thermally insulated compartment and a heat pump (mechanical, electronic or chemical) that transfers heat from the inside of the fridge to its external environment so that the inside of the fridge is cooled to a temperature below the ambient temperature of the room... |
What did Medieval people think about elves? | This question is *extremely* difficult to answer for two reasons:
1) the evidence for how people conceived of elves is very, very thin and 2) the evidence we do have suggests a wide range of beliefs that vary dramatically between places and across the centuries. Still, your question deals with pre-Norman England, so let's focus there.
Did people believe in elves? almost certainly yes, and this belief survives the conversion to Christianity in the 7th and 8th centuries. The most influential work on the subject for England is by Karen Jolly, who analyzes how the evidence for them suggests a form of popular religion that blends pre-Christian and Christian elements (and I am always amused that there is an elf-scholar named Jolly)
What did those elves look like? Basically identical to humans. The idea of long pointy ears is something that develops in the early modern period via influence from Roman fauns, according to Dr Francis Young ([_URL_0_](_URL_0_))
Were they friendly? Sometimes. As the name Alfred would suggest, along side Md. English Elwin (Aelfwine, "elf-friend"), if you could befriend then, they were a really powerful ally. However, *Beowulf* lists them alongside "eotenas" and "orcneas" as the offspring of Cain, and therefore definitely wicked things. This may be a result of Christian influence, but certainly the farther into the Middle Ages we get, the more closely aligned elves and other fairies get association with the demonic. Another example of how they could be enemies is the phenomenon known as "elf-shot", which is a form of sudden pain that could be lethal. Alaric Hall argues that this is largely a metaphorical term, though, not a literal one.
Alaric mostly argues that elves were originally more often friendly to humans than not in early English belief, but he has to rely on linguistic parallels to Scandinavian languages to do so, looking at instances of the word *ælfsīden* (elf-magic). This makes it hard, in my opinion, to reliably get into the specific cultural mindset of pre-Norman England to answer your question directly, though it is undeniably valuable for more generalized analysis.
(I would go into more detail, but the library is closed for Christmas, so I don't have access to these books right now to give you more information)
Reading:
Hall, Alaric (2007). *Elves in Anglo‐Saxon England: Matters of Belief, Health, Gender and Identity.*
Jolly, Karen Louise (1996). *Popular Religion in Late Saxon England: Elf Charms in Context**.* | [
"Beliefs about elves have their origins before the conversion to Christianity and associated Christianization of north-west Europe. For this reason, belief in elves has, from the Middle Ages through into recent scholarship, often been labelled \"pagan\" and a \"superstition\". However, almost all surviving textual ... |
From an engineering perspective, why don't recreational boats have a transmission? | For the same reason you don't have to use a clutch to get a boat going. The propeller can "slip" against the water and essentially acts as a CV transmission, delivering the torque of the engine directly as a force against the water. There is no need for gears because there is no reason for the propeller speed to exactly match the ground speed, or whatever is used in boats. | [
"Traditional sailboat transmissions consist of a simple horizontal output shaft extended rearward from the engine, through the stern via a stuffing box. The saildrive has several advantages over the traditional sailboat transmission: smaller horizontal size, no stuffing box to maintain, and the propeller is mounted... |
How did the Sassanid Empire deal with Huns? Why were they able to resist them while the Romans weren't ? | There were several waves of Hunnic people the Sasanians faced beginning with those known in the Latin sources as the Chionites but including the Kidarites and Hephthalites as well. The short story is that they did not resist them very well. From the limited sources we know of many campaigns in the east against the Huns and massive outlays for defensive infrastructures such as the Great Wall of Gorgan. The Hephthalite king Akhshunwar defeated Peroz I on three occasions. The last time, the Shahanshah was killed along with most of his army who fell into a ditch that had been set as a trap and the Hephthalites rampaged the empire until they were granted a massive tribute that almost bankrupted the empire and inspired Khosrau's financial reforms. The Hephthalites played kingmaker for much of the fifth century. They helped Peroz reach the throne initially as well as his son Kavadh (on two occasions). Some have suggested that some of the Parthian noble families under the Sasanians had actually entered alliances with the Hephthalites as well.
The sources for the eastern Sasanian Empire are a bit of a mess and so is the scholarship, mostly focused on really nitpicky numismatics and archaeological material. A new book covers the history of the eastern empire very well and I would recommend checking it out. Khodadad Rezakhani, ReOrienting the Sasanians (2017) | [
"Until the Sassanids came to power, the Romans were mostly the aggressors. However, the Sassanids, being Persians, were determined to reconquer lands that the Achaemenid dynasty had once held and now lost. Their nationalistic zeal made them much more aggressive foes of the Romans than the Parthians ever were. For m... |
What civilisations spent their entire history as Nomadic or semi-nomadic? | What do you consider a civilization? Consider all the people who lived in and around the Central Asian steppes -- Scythians, Sarmatians, Mongols, etc. Also some of the Plains Indians in the Americas. | [
"The nomadic way of life has become increasingly rare. Many governments dislike nomads because it is difficult to control their movement and to obtain taxes from them. Nomadic migration across international boundaries confuses capital-city bureaucrats. Many countries have converted pastures into cropland and forced... |
why do low-resolution videos viewed in full-screen look blurry and not pixelated? | Because the program you're using decided that it would handle stretching videos by blending colors together instead of pixelating it. | [
"Because the human eye is much more sensitive to small changes in brightness (the Y component) than in color (the Cr and Cb components), chroma subsampling is a very effective way to reduce the amount of video data that needs to be compressed. On videos with fine detail (high spatial complexity) this can manifest a... |
what is group velocity and how can it be faster than the speed of light? | Physics Grad Student here.
So what is important is the assumption that "nothing can move faster than light". This is something you always hear which, however is not actually true. The speed of light as a maximum limit of speed is only restricted to the transmission of *information*. The correct phrasing would thus be:
*Information cannot move faster than the speed of light.*
And by information I also mean energy, matter etc.
But what does that mean?
EXAMPLE:
Imagine a car is draggin a metal rod like [this](_URL_0_). Now the rod is dragged over a finish line (green). While the car moves forward, the intersection between rod and finish line (red) will move both along the rod and the finish line (to the left). If the angle between the rod and the finish line is really small and the car moves really fast, the red dot could move faster than the speed of light.
However, by this no information would be transferred.
This is the same principle that is mentioned in your given article. It says "However, special relativity is not violated in these experiments because they do not involve the transfer of information, matter or energy." at the end of the third paragraph. I don't really know *what* is moving faster than light but the important fact is that it is just the idea of something and not ctual information/energy/matter etc.
EDIT: Information added. | [
"The group velocity is often thought of as the velocity at which energy or information is conveyed along a wave. In most cases this is accurate, and the group velocity can be thought of as the signal velocity of the waveform. However, if the wave is travelling through an absorptive or gainful medium, this does not ... |
What, besides the ship skin, protects cosmonauts from solar radiation during the long stay in space? | It is probably the case that some elevated level of radiation exposure is going to be necessary for interplanetary travel. The primary defense against radiation-induced harm is to track individual astronauts' radiation exposure over their entire lifetime and design missions that are short enough so that everybody accumulates the minimum dose possible while still achieving mission objectives. There are fairly well understood thresholds of exposure as to what constitutes a significant threat to human health.
The reason we have to accept some level of radiation exposure is that the basic defense against energetic particles is mass: the mass of the ship, the mass of food and water supplies, the mass of the fuel, etc. all absorb some incoming radiation. Different materials interact with energetic particles differently, but any dense material provides some significant shielding versus the vacuum of space. The problem here is that mass is the one thing that space missions aren't good at. Space vehicles need to be as light as possible because there are significant weight restrictions on what can be sent to space, so we're probably not going to be able to shield astronauts entirely from radiation- just minimize their exposure.
That said, there are some good strategies mission designers can use to try to minimize radiation exposure. There are some materials that are particularly good at blocking radiation for their weight: materials that have lots of hydrogen atoms. Two such materials that find their way into space missions in abundance are water and plastics such as polyethylene. One theory is that these materials could be densely concentrated around crew living quarters to provide as much protection as possible, or even stowed in a configuration to create radiation shelters. Another theory is that we develop and identify materials that are hydrogen-rich and build as much as the spacecraft as possible out of these (including structural components).
Because the first line of defense against radiation is minimizing exposure, this makes efforts to understand and forecast space weather (like solar flares) very important.
Other maybe more speculative methods exist too. One suggestion says you should make a localized magnetic (electric) field around the spacecraft to deflect energetic particles (so astronauts would be protected by real-life force fields). Another suggestion says that we could collect heavy radiation shielding material from the moon and incorporate it into a spacecraft where the mass problem is less of a problem due to less gravity.
Also, astronauts will still have to deal with this problem on Mars. Mars doesn't have a magnetic field like Earth's, so much more radiation actually makes it down to the surface. | [
"Although the spacecraft itself somewhat reduces radiation exposure, it does not completely shield astronauts from galactic cosmic rays, which are highly energetic heavy ions, or from solar energetic particles, which primarily are energetic protons. By one NASA estimate, for each year that astronauts spend in deep ... |
why is salmon the only fish that is smoked? | It's not. My favorite is smoked haddock aka finnan haddie. Smoked whitefish is a standard at Jewish delis. Smoked trout, smoked herring (kippers)...and of course smoked oysters. | [
"Smoked salmon is a preparation of salmon, typically a fillet that has been cured and hot or cold smoked. Due to its moderately high price, smoked salmon is considered a delicacy. Although the term lox is sometimes applied to smoked salmon, they are different products.\n",
"A common name for cold-smoked salmon is... |
why society shelters children from knowing about sexuality | Because Jesus doesn't like it. And if you ask me again God's gonna punish you. Now go to your room. | [
"Adolescent children are usually segregated in school by sex, because they want this to be a place for education and not entertainment or romance. Thinking that sex education would lead to desire and trouble. The main exception to this occurs during festivals, especially the New Year Festival, when boys and girls t... |
how do the toasters at subway get a crispy toast so fast | Used to work at Subway, those ovens are always around 500°. Like melt your glove to your hand hot. That's why we used a paddle to insert/remove subs. | [
"Toaster Strudel is a toaster pastry convenience food, prepared simply and quickly by heating them in a toaster and then spreading the included icing packet on top. The brand is historically notable for being stored frozen, due to innovations in 1980s food manufacturing processes.\n",
"Conveyor toasters are desig... |
why is the earth elliptical? | When stuff is in space, there's nothing to keep it flat. If something is small, big things make them go nearer - it's like when you jump, you go back to the ground because it's so much bigger than you. When you get a lot of things together with nothing else around, they stay together. And the more things you have, the more it turns into a ball, because that's the shape things make when they're closest to all the other things. So that's why the Earth is mostly like a ball.
But the Earth isn't still. It's actually spinning round and round. You know how when you're on a roundabout, and it's going really really fast, it makes you feel like you're going to get thrown off? That's what happens to the Earth as well. Look at this ball here. When I spin it, the bits at the top and the bottom don't move much, do they? But the bit in the middle moves a lot. Because the Earth is moving so fast around the middle, it gets a bit bulgy there - not so much as you'd notice, but a bit.
Does that help? | [
"The \"T and O\" shape does not imply that its creators believed in a flat Earth. The spherical shape of the Earth was already known to the ancient Greeks and Romans and the idea was never entirely forgotten even in the Middle Ages, and thus the circular representation may well be considered a conventional attempt ... |
why do some games have a problem with cheaters(cs:go) and some don't(rocket league)? | For one, you need a good easy way to cheat. You can do this by either giving you an unfair advantage, (Like giving you more info than the opponent) or by letting the computer do stuff for you its very good at, that humans are bad at.
So in Counter Strike, you can have the computer give you an unfair advantage by giving you information in the form of maphacking. this doesn't work in Rocket League as there aren't any walls or other things that obscure information.
The other thing is letting computers do stuff that humans suck at, like aiming. In CS:Go this is really easy, just point the cursor at the enemy, and give the fire command. In rocket league, the computer would have to drive the entire car. and it isn't aiming at a point and click target, its aiming at a goal with goal keepers.
So to answer your question, in the case of your two examples, its because of the type of game they are. Not by virtue of better security or anything. | [
"There are many facets of cheating in online games which make the creation of a system to stop cheating very difficult; however, game developers and third party software developers have created or are developing technologies that attempt to prevent cheating. Such countermeasures are commonly used in video games, wi... |
What happened to Russian citizens after the purchase of Alaska? | Howdy!
When the United States purchased Alaska from the Russian Empire there was a treaty signed by both governments. The treaty was known as the Treaty of Cession. It was signed by the Emperor of All the Russias, Alexander II and was ratified by the United States Congress. Within the Treaty lies the answer to your question.
> The inhabitants of the ceded territory, according to their choice, reserving their natural allegiance, may return to Russia within three years; but if they prefer to remain in the ceded territory, they, with the exception of uncivilized native tribes, shall be admitted to the enjoyment of all the rights, advantages, and immunities of citizens of the United States and shall be maintained and protected in the free enjoyment of their liberty, property, and religion. The uncivilized tribes will be subject to such laws and regulations as the United States may, from time to time, adopt in regard to aboriginal tribes of that country
This was signed and ratified in 1867. Majority of the Russians in Alaska moved back to Russia, provided with from funding from the Russian American Company (The Crown Charter Company that managed Alaska). The only exceptions in the treaty were for the Orthodox Church, which was allowed to keep their lands and their priests remained in Alaska.
Keep in mind also that the population of Russians in Alaska was very small. It was a trading district, not so much seen as a colony for Russian population expansion. | [
"In the present-day Russian Federation and its predecessor the Soviet Union (USSR) there are periodic mass media stories that Alaska was not sold to the United States in the 1867 Alaska Purchase, but only leased for 99 years (= to 1966), or 150 years (= to 2017)—and will be returned to Russia. However, the Alaska P... |
why isn't catherine, dutchess of cambridge called princess catherine? | I believe because she does not have royal blood - she married into royalty. | [
"Catherine was of a very fair complexion, had blue eyes, and had a hair colour that was between reddish-blonde and auburn. In her youth she was described as \"the most beautiful creature in the world\" and that there was \"nothing lacking in her that the most beautiful girl should have\". Thomas More and Lord Herbe... |
Are there horror stories that come from the middle ages? | Thank you for the interesting question! I'll preface this by stating that I focus on the 12th Century in England and France.
Lots of chroniclers included anecdotes that contain supernatural elements, some of which are similar to stories we tell now. However, these were largely reported as prophetical or symbolic rather than for entertainment or to scare the audience for fun. Largely, we are not told the motives by individual authors for including this kind of content in their work. Some include this type of material under the assumption that these things definitely could have happened, while others merely report these stories as a story that is told by others. I don't want to be misleading by saying that Medieval writers had a specific "horror" genre with the specific intent of creating fiction that was meant to thrill or scare the audience, but there are definitely elements that would be familiar today. That being said, there is a great deal we don't know about oral culture, and it would be interesting to know what kind of 'campfire stories' there were.
The most common, which you see across a wide variety of texts, are weather or environment-related events. I.E. eclipses, comets, famines, plagues, unusual/extreme weather (my personal favourite being rains of blood). These were most commonly interpreted as being signs of God's displeasure with a certain region/group/person, or a warning of forthcoming doom. Astronomical events are a particular favourite, for example:
> "For on that very day the sun, at the sixth hour, covered its shining head with gloomy rust, as the poets are wont to say, agitating men's minds by its eclipse; and on the following Friday at dawn the earth quaked so terribly that it seemed to sink to the depths, and a dreadful noise was heard under the earth before this. In the eclipse I myself saw stars round the sun, and in the earthquake the wall of the house in which I sat I saw lifted up by two shocks and settling down at a third."
>
> \- *Historia Novella*, William of Malmesbury.
The eclipse is later interpreted, and interpreted by other writers (in the 1130's - 1140's) as an omen that King Henry I was going to die, leading to the conflict between King Stephen and Empress Matilda, known as The Anarchy. (This particular eclipse occurred on 2 August 1133 and is one of the best-documented historical eclipses, fun fact).
Another common feature of medieval 'horror' is monster stories. There are endless books written about medieval monsters, from dragons to cow-stag hybrids. These appear in a variety of primary sources as well. There are the stories we are more familiar with today, such as St. George and the Dragon, and similar feats of knights slaying beasts, but there are more heroic literature.
There are examples of monsters that are familiar in our 'classic' horror genre. While the vampire as we know it really developed in the 18th and 19th centuries, there are similar stories in medieval sources. An example of 'vampire' literature can be found [HERE](_URL_0_). There is some debate over exactly how these people are meant to be interpreted (vampires, revenants or witches), and I should point out that there is no explicit reference to drinking blood. This same entry in William of Newburgh's *History of English Affairs* also includes two stories about unusual findings in quarries. The preceding entry is also about an occurrence in which two green-coloured children were found and taken in by a local family. This is not horror per-se, but is in a similar vein of unexplained and supernatural events, so may be of interest. I generally highly recommend William of Newburgh, as in addition to his accounts of supernatural occurrences, he has a lot of interesting, often-funny commentary about the times he lived in.
Werewolves, or men whose form shifted between a man and a wolf or man-wolf hybrid, were more common. Gerald of Wales wrote about werewolves in his *History and Topography of Ireland.* Gerald relates that a priest came upon a talking wolf while travelling, and that the wolf said that he and a companion were compelled to live in exile as wolves on account of a particular Saints wishes for a span of seven years, at the end of which, two others from their community take their place. The wolf then tells the priest that his companion is dying and in need of absolution. The priest prays with the dying wolf, and gives her communion, at which point he is able to help her transform into an old woman, which is described by Gerald as peeling the skin of her wolf-form off. The priest then spends the night talking with the he-wolf before resuming his travels.
A werewolf is also the title character of Marie de France's lay *Bisclavret.* Marie claims that most of her tales are common folktales from Brittany, and in some cases this can be verified. A later version of Bisclavret appears as one of King Arthur's knights. The story itself is about a baron who is compelled to spend part of his days as a wolf. He initially keeps this a secret from his wife, but later admits it to her. He tells her that once he serves his time as a wolf, he can turn back into a man by finding his human clothing. However, she rejects him, and while he is in wolf-form, has a knight steal her husbands clothing, so he is cursed to remain as a wolf. The wife marries the knight. Later, the King is hunting in the forest and happens upon Bisclavret. The King and his court are amused to see such a tame wolf, and the King takes him as a pet. At the King's court, the wolf sees the Knight who is married to his wife and attacks him, leading the King to become suspicious. The King takes Bisclavret back to his old home to see his wife, at which point Bisclavret attacks his former wife, tearing off her nose. This prompts the wife to reveal what she has done, and return the clothes to Bisclavret, returning him to human form. Modern interpretation of this story is that this is meant as a moralistic story about the nature of mankind, and ones ability to rise above baser, animalistic natures. Again, I highly recommend Marie de France as an example of High Medieval literature. Her stories are often funny, and her social commentary often still holds up.
I hope this helps. I know most of these are not scary or horrifying the way the horror genre is today, but there are some parallels at least in content. It's difficult to look through this type of literature to determine whether a contemporary audience would have seen it as scary or frightening, or if that was the intent of the author. However, at least in terms of content, we do see some similarities.
I'm still waiting to read a chronicle about a group of teens out at a lakehouse though. "This messenger came from inside the house."
Sorry for the long post! | [
"The setting is shown to be in the Medieval era, with other elements thrown in, often bizarre ones (e.g., yellow-painted taxicabs pulled by rhinoceroses). Stories have included standard Medieval fare, such as armored knights, and some science fiction elements, such as flying saucers.\n",
"Horror Stories was an Am... |
what makes dog years different from human years+ | There's really no such thing as "dog years". It's just a way to give a rough estimate of how old a dog is compared to a human lifespan. Humans live roughly seven times a long as dogs (though it varies widely based on breed), so a dog that is 5 years old has lived roughly the same percentage of its expected lifespan as a human who is 35 years old.
That's all "dog years" really are. | [
"There are two diametrically opposed definitions of the \"dog year\", primarily used to approximate the equivalent age of dogs and other animals with similar life spans. Both are based upon a popular myth regarding the aging of dogs that states that a dog ages seven years in the time it takes a human to age one yea... |
At a cellular level, is there a difference between mammals, birds, fish, amphibians, and reptiles? | If you are talking the contents of a cell, they roughly have the same features \(i.e. organelles, cytoskeleton\). All will have a nucleus with DNA. All will have mitochondria. You would have a hard time distinguishing cells as mentioned by kernco. In fact, an untrained eye would have a difficult time distinguishing between very young embryos from all five, including humans.
If you are talking what cells comprise the bodies, it will also be very similar. One exception being immune cells and red blood cells. Some species have nucleated red blood cells, adult mammals don't. Fish typically have more ancient/simple immune systems in terms of cell types and proteins. Some very specific functionality of bird immune systems is quite different, like chickens. But on a gross level all five will have pretty much the same tissue compositions. | [
"Birds generally have lower EQ than mammals, but parrots and particularly the corvids show remarkable complex behaviour and high learning ability. Their brains are at the high end of the bird spectrum, but low compared to mammals. Bird cell size is on the other hand generally smaller than that of mammals, which may... |
What was the extent of the Known world in ancient Egypt? | This is my first post, so I hope that I'm doing this correctly :)
I'm going to assume that you are asking from Egypt's point of view as opposed to the entire world.
Due to the fact that my interests primarily lie in New Kingdom Egypt, I'll just answer when it comes to that time period. (Circa mid 1500's BC-1069 BC)
Using Eric H Cline's "1177 B.C the Year Civilization Collapsed" (2014), Minoan artifacts from Crete have been found in Mesopotamia as early as the 18th century BC. The documentation for the trade was written on tablets in ancient Akkadian, the lingua franca of the age.
He goes on to discuss how there was a form of "Globalization" in the near east leading up to what some call the "Bronze Age Collapse". That included trade between Hittites, Egypt, Mittani, Babylon, and the Bronze Age Greeks.
As elaborated on in the book, In the time of Hatshepsut and Thutmose III's reign, many Egyptian nobles and the Pharoah him/herself were using Minoan artisans to create frescoes.
In about 1477 BC, Thutmose ordered construction of a palace in the city of Peru-Nefer that contained these elaborate frescoes.
These were "in", so to speak, and so can be found in palaces up and down the coastal territories of Egypt's client states in Canaan.
Hatshepsut's adviser, Senenmut, included an image of an embassy from the Aegean in his tomb. And he wasn't the only noble of the time to include these details.
Rekhmire, Thutmose III's Vizier, also has images of these people in his tomb. Note that many accept "Keftiu" as the Egyptian given name for the peoples from Crete.
To hear more about this, here is a link to a presentation that Prof Cline gave at the Oriental Institute in Chicago: _URL_1_
When it comes to Southern contacts, Egypt was constantly in contact with the ancient Kingdom of Nubia. Their relationship was everything from trading partners to overlords to servants.
However, deeper into Africa they had contacts with the semi-fabled land of Punt. This land has been placed by some in modern day Somalia (Essay in "Ancient Egypt in Africa" by A. Meeks 2003) , by others in Arabia on the other side of the Red Sea ("Orientalia" by K.A.Kitchen 1973, and by some others in Eritrea ("Mysterious Lands" by David O'Connor and S. Quirke 2003).
For more discussion on its' location, and thus the possible extant of New Kingdom Egypt's contacts in Africa, see the book "Ancient Egypt in Africa" Edited by David O'Connor and Andrew Reid (2003). It includes the essays of 12 Professors in various fields that discuss what Egypt's role on the continent might have been.
Also note that Punt had been visited by other Dynasties before the New Kingdom including Sahure of Dynasty 5, Pepy I of Dynasty 6, and others. ("The Woman Who Would be King" by Kara Cooney 2014- NOTE: Prof Cooney uses A LOT of speculation in her treatment on the thoughts and desires of a millenia old female king, thus take care to use her sources at the back of the book to see what is and what is not a concrete fact)
The first recorded contact that we have of New Kingdom Egypt with the Kingdoms of the Hittites in Anatolia is through Thutmose III. He and his ancestor, Thutmose I, conquered much of the Ancient Near East in a series of "Razzias" which led the both of them to cross the river Euphrates. ("Thutmose III: A New Biography" Edited by Eric H. Cline and David O'Connor 2006 & "The Wars in Syria & Palestine of Thutmose III" by Donald B Redford 2003)
So from the evidence, it would seem that their contact included much of the Ancient Near East, parts of Europe, and parts of Africa. Here is a picture of a map that I hope puts the area into context: _URL_0_ (I HOPE IT'S NOT AGAINST THE RULES!!!!)
And if anyone's got better stuff, I know they'll share.
PS: I LOOOOOOOOOOOOOVE this site. | [
"From 1560 to 1080 BCE, the Egyptian Empire reached its zenith as the dominant power in the Middle East. When Rome was still a marsh and the Acropolis was an empty rock, Egypt was already one thousand years old. Although the period of the pyramid-builders was long over, Egypt lay on the threshold of its greatest ag... |
why cars don't have built in breathalyzers to prevent drunk driving. | Because it'd be weirdly invasive to try and force people to buy cars with what amounts to a monitoring system and it wouldn't be effective; you can't police everybody full time and make sure nobody tampers with it to deactivate it or give false readings. | [
"Additionally, MADD has proposed that breath alcohol ignition interlock devices should be installed in all new cars. Tom Incantalupo wrote: \"Ultimately, the group said yesterday, it wants so-called alcohol interlock devices factory-installed in all new cars. \"The main reason why people continue to drive drunk tod... |
Was Lenin that bad? | I'd have to be really frustrating and say this isn't really an answerable question. If we were to simplify it and just compare Lenin to Stalin, the thing is that Lenin and Stalin were operating in very different times, under different constraints. We don't know what Lenin would have done if faced with the threat posed by Hitler after he wrote Mein Kampf. Lenin approved the use of terror as a policy. And the biggest thing I would take away from NEP is that Lenin was capable of bending his ideological principles in light of immediate circumstantial constraints.
I don't think this tells us whether he's "better" or "worse" than Stalin -- rather, it says we can't possibly use his known ideological positions to predict what he would have done if faced with, say, Hitler's invasion. And as far as I know it's not sufficiently clear what he would have done about the famous industry vs. agriculture debate as time went on.
As personalities, I see many troubling red flags in Stalin's biography that are....not necessarily absent in Lenin's, but different. But I wouldn't feel comfortable judging one as "better" or maybe more sane than the other. I don't think those kinds of diagnoses are possible. Lenin's writings show a level of education, intelligence, and discernment that Stalin's arguably don't, but Stalin had his own form of -- for lack of a better word -- genius that helped him achieve his goals (albeit to the detriment of everyone else). In any case, I see little evidence for moral restraint in Lenin's views, sufficient to posit that he would have stopped short of doing the kinds of things Stalin did out of any moral compunction (that Stalin obviously lacked). Whether he might have come up with policies that might have met his goals with less loss of life is just unanswerable because it's contingent on so many unknowns.
You might be interested in the new biography of Stalin by Stephen Kotkin, and the biography of Bukharin by Steve Cohen, which argues that Bukharin was actually the "better" alternative that was missed. | [
"Service stated that Lenin could be \"moody and volatile\", and Pipes deemed him to be \"a thoroughgoing misanthrope\", a view rejected by Read, who highlighted many instances in which Lenin displayed kindness, particularly toward children. According to several biographers, Lenin was intolerant of opposition and of... |
What is the efficacy of these alarm clocks which use some sort of head-band scanner (I assume EEG) to select the time to wake you? (example linked to in comments) | The method has been [validated](_URL_1_), however the efficacy of the device to improve sleep [has not been](_URL_0_).
| [
"Many alarm clocks have radio receivers that can be set to start playing at specified times, and are known as \"clock radios\". Some alarm clocks can set multiple alarms. A \"progressive alarm clock\", can have different alarms for different times (see Next-Generation Alarms) and even play music of your choice. Mos... |
Why is blue light the first to get absorbed into the atmosphere through rayleigh scattering, but it penetrates water deeper than other colors? | Really good question!
In terms of scattering, yes, blue light is scattered more easily in water and in air. However, absorption is very different for water and even water vapor.
In water, there is a strong preference for absorption at the lower energy red end of the visible spectrum. The reason for this can be derived from quantum chemistry. Uniquely, water gets its blue color (of course a small amount of water is colorless, but if you have a large body of water, even without the reflection of the sky, there is a blue hue as OP discovered) due to the vibrational transitions of water molecules, unlike most media which get their color from electron-based interactions such as standard absorption/emission lines, Rayleigh scattering, etc.
This is because water is unique in its interaction with light being primarily determined by its OH bonds, whose symmetric and antisymmetrical vibrational stretching modes are at a very unusually high energy (spatial frequency). All of this means that an overtone transition happens at (symmetric spatial freq)+3*(antisymmetric spatial freq) = 14300 cm^-1 . This corresponds to a red 698nm peak of absorption, whereas many common materials will peak in the infrared.
In water vapor, on the other hand, this red peak is shifted to lower energy, out of the visible range. This is again due to quantum chemistry; the relevant difference in structure between liquid and gaseous water is that hydrogen bonding is very strong in liquid water. This is why water vapor is colorless. I haven't look at what happens with air (nitrogen and oxygen), but I'm guessing they are colorless too.
So, basically, water is slightly blue because, unlike almost all other molecules, its strongest absorption peak is due to vibrational transitions. And these occur at 698nm - red.
Edit: misspoke by getting ahead of myself. thanks /u/richardmnixon42 | [
"The strong wavelength dependence of the scattering (~\"λ\") means that shorter (blue) wavelengths are scattered more strongly than longer (red) wavelengths. This results in the indirect blue light coming from all regions of the sky. Rayleigh scattering is a good approximation of the manner in which light scatterin... |
why does radiation spike and roam | What is radiating are tiny radioactive particles. Like dust, they can accumulate in certain places because of natural forces such as wind or rain. In your house or flat, dust usually accumulates in certain places, yes? That happens to radioactive particles too. Sometimes spikes emerge from such spots. What also causes spikes are bigger clumps of radioactive material (imagine a piece of the reactor shell that was blown away by an explosion). | [
"Broadcast radiation is the accumulation of broadcast and multicast traffic on a computer network. Extreme amounts of broadcast traffic constitute a broadcast storm. A broadcast storm can consume sufficient network resources so as to render the network unable to transport normal traffic. A packet that induces such ... |
How would high medieval spearmen handle other infantry armed with swords and shields? | Hey, I know your larp!
First, let's establish some historical baselines. Spear and shield was common in the early middle ages, especially in the 5th and 6th centuries. After that, swords gained ground steadily as metallurgy improved and economic ties across Europe + the emergence of more and more professionalized fighters made it easier to get good blades. So let's compare 6th century spears and swords with the boffer versions people use in your game.
In Dagorhir, most people use spears that are on the heavy side compared to the sixth century. In early medieval England, the people who fought with spear and shield used 6' long spears that weighed between 1-1.5lb, and which were balanced to be used in a single hand for loose skirmishing. Compare that to a bandshoppe fiberglass flag pole, the standard spear shaft in Dagorhir--the fiberglass alone weighs near 2lb, and the completed 8' long weapon is nothing like its 6th century counterpart in weight, balance, or length.
In contrast, the swords people use in your game are all far lighter and better balanced than the swords that were used in the early middle ages (when spear and shield was still common). 6th century swords weighed in the neighborhood of 2lb, and they had little distal taper or couterweight. I've held some of the best recreations in the world, and they cut like monsters but are slow to get moving--nothing like a 12oz Dagorhir sword that's counterweighted to swing quick and lively.
So in your game, swords have an advantage over spears that they didn't in the 6th century. Now, as swords became more popular over the centuries, they also got more nimble. Spears, in contrast, got longer and heavier -- think two-handed pikes instead of fencing weapons. The weapons changed to fill different niches. Used for the right purpose, heavy spears work well -- I'm sure you've noticed how devastating spears are in your game when they're used as pikes as part of a massed group of fighters.
So basically, spear and shield worked because the weapons were different when it was popular. That doesn't mean it can't still work in your game, however. If you want to excel with spear and shield in your larp, you need to build a lighter spear, and you need to optimize its balance to make it nimble enough to keep up with the swordsmen. It's possible to do well with this. | [
"The main offensive weapon used was a long and in diameter spear called a \"doru\", or \"dory\". It was held with the right hand, with the left hand holding the hoplite's shield. Soldiers usually held their spears in an underhand position when approaching but once they came into close contact with their opponents, ... |
Why do most insulins advise strongly against mixing with other insulins? What would happen if a mixed injection was taken? | Some insulins can be mixed. Examples are Regular and NPH or an ultra short like Lispro and NPH, which get mixed all the time in hospitals, and even come premixed (Novolin 70/30, Novolog 70/30). The ultra longs are the only ones that I'm aware of that you don't mix (glargine aka Lantus), but as to why I don't know. [This study](_URL_0_) actually says that you can mix glargine with shorter acting insulins without any problems in the short term, though they noted that the solution turned cloudy (precipitates?) and the study did not examine long term use of mixed glargine preparations. | [
"Several groups of drugs, mostly given by mouth, are effective in type 2, often in combination. The therapeutic combination in type 2 may include insulin, not necessarily because oral agents have failed completely, but in search of a desired combination of effects. The great advantage of injected insulin in type 2 ... |
why can your body stop the bleeding from a small cut over the course of a few minutes, but bruises can continue to develop and worsen over the course of a few days? | A bruise is from thousands of capillaries in the area breaking and releasing a little bit of blood into the surrounding tissue. The breaks in the vessels will clot of just as fast, if not faster than those from a cut. The reason it changes color/intensity over time is that the blood will pool in areas that may be easier to see through your skin, and the hemoglobin breaks down into different molecules over time that have different colors | [
"When a normal wound heals, the body produces new collagen fibres at a rate which balances the breakdown of old collagen. Hypertrophic scars are red and thick and may be itchy or painful. They do not extend beyond the boundary of the original wound, but may continue to thicken for up to six months. They usually imp... |
why does covid-19 hurt the market? | If China makes a product for the US and the factory shuts down Because of the virus then there are no products being made. Which means people lose money since they can't sell their product. With the stock market you are investing into companies and such. When the company you're investing into halts production their value goes down.
Edit: so when their value goes down so does their stock price now causing you to lose money. | [
"MiR-19 also takes part in inflammatory responses enhancing or repressing pro-inflammatory mediators expression. It positively regulates Toll-like receptor signaling with Dicer1 deletion and miRNA depletion. MiR-19b is an important protagonist in this phenomenon, regulating positively NF-kB activity.\n",
"miR-129... |
the difference between paraphilia and fetish | A paraphilia is something that is harmful to oneself or others and is needed to achieve orgasm. Paraphilias and fetishes are similar, but not every fetish is harmful, and all paraphilias are in some way. These disorders can cause distress or impairment (and those are the only kind recognized in the DSM), and are harmful overall for the individual and/or society.
Some paraphilias are criminal, such as pedophilia and necrophelia, while others are just weird. There isn't any known working treatment or cure. It's kind of a mystery how these things form. | [
"Separate from fetishes as a paraphilia are garments worn to enhance appearance, such as tight jeans or other eye-catching clothing. The difference is whether, for the person concerned, the clothing is the focus of a sexual fetish, or is merely appreciated and found pleasing.\n",
"In common parlance, the word \"f... |
why would a working class person want to vote for a candidate who favors tax breaks for the wealthy? | As John Steinbeck puts it: « Socialism never took root in America because the poor see themselves not as an exploited proletariat but as temporarily embarrassed millionaires. » | [
"\"We know that elections cannot overcome the massive problems we face. Only our struggles and mobilizations can do that. Nonetheless, by keeping Working Class Party on the ballot, we can give working people a way to express their desire to have a party that represents their own class. And this could lay the ground... |
why are possible gravitational waves at ligo significant? | Stunning confirmation of Einstein's theory of general relativity. Not that other things haven't already been measured, but is another confirmation of a specific prediction, which helps confirm that his theory is correct. Its another stepping stone in the search for understanding gravity and the big bang.
While nowhere near yet, it may lead to another way to observe the universe, in much the same way radio telescopes and what they discovered changed the understanding of space and the universe | [
"In 2015, the LIGO project was the first to directly observe gravitational waves using laser interferometers. The LIGO detectors observed gravitational waves from the merger of two stellar-mass black holes, matching predictions of general relativity. These observations demonstrated the existence of binary stellar-m... |
Martin Meredith's "The Fortunes of Africa": A good source on the subject? | It's a decent introduction to the subject of African history, though if you're looking for detail on certain specific civilizations or events, I'd suggest looking elsewhere. It's a legitimately good broad overview of the history of the continent and providing sources for further reading. It does feel a bit Eurocentric and Angocentric in its focus, but only in that the focus tends to be more on aspects traditionally more accessible to the English-speaking community. It lacks the patronizing or overtly racist attitudes that a lot of older histories have towards African subjects, and it's overall an excellent introduction to African history for someone who doesn't really have any background in it. | [
"African Sources for African History is a book series published by Brill that aims to make available critical editions of indigenous African narrative sources from sub-Saharan Africa. The series aims to expand the sources available to historians of Africa, and to rectify bias that may have been introduced into the ... |
Why is g constant regardless of the mass of an object on a planet, but the mass of the planet does matter? | From Newton's universal law of gravity, we have
F=GMm/r^2
where we can say M is the Earth's mass, and m is the object's mass.
Newton's 2nd law is:
a = F/mass
For the acceleration of the object by the Earth, we set mass=m and F=GMm/r^(2), which gives us a=GM/r^(2) - it depends on the Earth's mass, but not on the object. *But* for the acceleration of the *Earth* by the object, we set mass=M and F=GMm/r^(2), which gives us a=Gm/r^(2) - and that depends on the mass of the object and not the Earth! So it's symmetric.
Putting that all together: the *force* between two objects depends on both masses, but the acceleration of one object only depends on the mass of the other object.
This comes out so tidily that it seemed a bit suspicious, and pondering *why* the masses cancel out is what lead Einstein to invent General Relativity. | [
"The value of \"G\" is difficult to measure and is only known with limited accuracy in SI units (\"see\" Cavendish experiment). The value of \"G\" times the mass of an object, called the standard gravitational parameter, is known for the Sun and several planets to much higher accuracy than \"G\" alone. As a result,... |
How do you know the limit of something as x approaches infinity? | > To take the derivative, it seems as if you would need to have infinte precision? It's seems as if though the whole of calculus is based around this infinite precision thing. Integrals use rectangles to approximate the area under a function right? And then you increase the numbers of rectangles all the way to infinity to get the exact area under the function, how do you do it?
You hit the nail on the head. Calculus *is* all about this "infinite precision thing". And another name for that "infinite precision thing" is a "Limit". A limit formally makes sense of approximating something to "infinite precision", and to understand how this works, you *need* to understand the rigorous definition of a limit. This is a huge failure of the typical calculus curriculum. The formal definition of a limit is not only extremely important to in understanding the concepts of calculus, but it is one of the most practical/applicable things that you could learn in calculus! Limits give you an explicit roadmap to approximating values, but only if you know the rigorous definition of them. The half-assed approach in calc courses that relies on analogies and "it's kinda likes" does just enough for students to compute a couple derivatives in the next chapter, and then promptly forget everything, it's bad for education. And it's bad for calculus applications.
Okay, rant over, let's look at your particular questions.
1.) **How can we calculate e?** While there are many definitions of e, some more computational friendly than others, let's stick with the definition that it is the limit of (1+1/n)^(n) at n=infinity. To see how this is a helpful definition, we need to know how limits at infinity actually work. If a*_n_* is a sequence (like a*_n_*=(1+1/n)^(n)), then the limit of a*_n_* at n=infinity is equal to L if the values of a*_n_* approximate L to arbitrarily small error, for large enough n. Explicitly, the limit of a*_n_* at n=infinity is equal to L if, for any error E > 0, no matter how small, there exists an N so that for all n > N we have
* |a*_n_*-L| < E
This means that the distance from a*_n_* to L is less than the error E. If we can do this for *any* error, then this intuitively means that the values of a*_n_* eventually approximate L to arbitrarily good precision. In the case of e=lim*_n- > infinity_*(1+1/n)^(n), this means that we can set the error to E=0.000000000001, and then for large enough N the distance between (1+1/N)^(N) and e will be less than 0.000000000001. This will mean that (1+1/N)^(N) will share the first ten-or-so digits. If we want to get more digits, then we can just make E smaller. We never actually compute e, we just approximate it well enough to get the number of digits that we want, and the limit formula for e is an explicit guide to approximating e to any precision we could want. The fact that e is this limit means that we *can* just plug in very large values of N and be guaranteed that we'll get e to thousands of digits.
2.) **How can 1+1/2+1/3+1/4+1/5+... be equal to infinity?** Infinite series are examples of limits at infinity. We *define* the infinite sum b*_1_*+b*_2_*+b*_3_*+... to be the limit of the sequence
* a*_1_* = b*_1_*
a*_2_* = b*_1_* + b*_2_*
a*_3_* = b*_1_* + b*_2_* + b*_3_*
a*_4_* = b*_1_* + b*_2_* + b*_3_* + b*_4_*
...
Each of the values a*_n_* is well defined, is called the "Partial Sum", and we say that the infinite sum is whatever the limit of these a*_n_* is. Sometimes, sequences like these converge. For instance, 1+1/2+1/4+1/8+1/16+...=2, because the nth partial sum is equal to a*_n_*=2\*(1-2^(-n)). If E > 0 is any error, then the distance between 2 and a*_n_* eventually becomes less than this error. This is because |a*_n_*-2|=1/2^(n), and this will be less than E for any n > log*_2_*(1/E). So no matter how small the error gets, a*_n_* approximates "2" within that error, so the limit is 2, and so (by definition, 1+1/2+1/4+1/8+1/16+...=2. Note that we did not *compute* this infinite series to be 2, rather we *proved* that this sequence sums to 2 using the definition of a limit. This is a particular case of a [Geometric Series](_URL_0_).
A similar thing happens for 1+1/2+1/3+1/4+...=infinity. We don't compute it, we prove that this happens. In this case, we need to prove that the sequence diverges. If a*_n_* is a sequence and if for any integer M, no matter how large, we find that a*_n_* is eventually larger than M, then the limit of a*_n_* at infinity is infinity. Explicitly, the limit of a*_n_* is infinity if for any positive number M, there exists an integer N so that for all n > N we have a*_n_* > M. Since we can make M arbitrarily large, this pushed the sequence out towards infinity. In the case of 1+1/2+1/3+1/4+..., we need to work with the sequence
* a*_1_* = 1
a*_2_* = 1 + 1/2
a*_3_* = 1 + 1/2 + 1/3
a*_4_* = 1 + 1/2 + 1/3 + 1/4
...
To prove this, we can compare it to the integral of dx/x for x=1 to x=n+1. This shows that a*_n_* > log(n+1). So if M is any large number, and n > e^(M), then this will mean that
* a*_n_* > log(n+1) > log(e^(M)+1) > M
So a*_n_* gets arbitrarily large, so its limit diverges, so the infinite series 1+1/2+1/3+...=infinity. Again, there was no actual computing going on, we *proved* that the limit has to be infinity.
3.) **WTF about derivatives?** Derivatives are also about approximation. We can draw lines between any two points, so it doesn't make too much sense to talk about the slope of a curve at a single point. But we can look at points that get arbitrarily close to each other using derivatives. If f(x) is a function on the real line and x=a is a point and h > 0 is some positive number (representing distance), then the cartesian points (a,f(a)) and (a+h,f(a+h)) are two different points, so we can talk about the line between these two points. The slope of this line will be (f(a+h)-f(a))/h. Obviously, plugging in h=0 is undefined, as you get 0/0, but that doesn't mean the limit at h=0 isn't undefined. What we're going to do is approximate again.
This time the limit is at h=0, so it's worded a little differently. If m(h) is a function (defined around h=0, not necessarily at h=0), then the limit of m(h) at h=0 is equal to L if for any error E > 0, the value of m(h) approximates L for small enough h. Explicitly, the limit is L if for all E > 0 there is some D > 0 so that if 0 < |h| < D then |m(h)-L| < E (ie, if h is small enough, then the distance from m(h) to L is within the error).
For the derivative, this means that we're finding the limit of (f(a+h)-f(a))/h at h=0, we're not *actually* finding the slope between two arbitrarily small points, we're looking at what happens to the slope when points get arbitrarily close together. If this approximates a single value to infinite precision, then we say that that value is the derivative at x=a.
As an example, consider f(x)=x^(2) at x=2. In this case,
* f(2+h)-f(2) = (2+h)^(2) - 4 = 4+4h+h^(2) - 4 = 4h + h^(2)
So the slope on f(x) between the points (2,4) and (2+h, (2+h)^(2)) is equal to m(h)=(4h+h^(2))/h = 4+h. It's important to know that we still have to take the limit of this, we can't just plug in h=0 (without justifying it at least). But the limit of m(h)=4+h at h=0 is 4, and we can prove this as follows: If E > 0 is some error, then whenever 0 < |h| < E we find that |m(h)-4| = |4+h-4| = |h| < E. So, by the definition of a limit, the limit is 4, so the derivative is 4. Again, we *proved* this using out formalization of the intuitive concept of "infinite precision", we didn't "compute" it.
---------------------------------------------------------------------------------
The overall moral should be that math is *not* about computations. Math is about proofs, and sometimes we can use proofs to help us compute and approximate things. These calculus concepts use the formal notion of a limit to mathematical capture the intuitive idea of "infinite precision", but this is only apparent and useful when you know and understand the formal definition of a limit. It's the formality that allows you to understand what is happening and allows you to compute and approximate value based on the proofs of the limits. | [
"which is either 0, if \"d\" = 0, or gets arbitrarily small, when \"n\" tends to infinity. According to the definition of a limit, \"x\" is the limit of [\"x\"] when \"n\" tends to infinity. This is written as formula_7 or\n",
"That is, the limit as \"x\" goes to 8 from above is a sideways 8 or the infinity sign,... |
Animals, e.g. (wild) cats, have loads of anonymous sex and know nothing about protection or medicine. Why aren't they decimated by cat aids? | FIV is much less deadly than HIV.
Cats have been dealing with FIV for a long time, somewhere in the 10's of millions of years. Overtime they have built up some resistance; you see the same thing happening in human populations that are under intense selection from HIV. CCR5 delta 32 is a famous mutation that provides some resistance in humans, and there are others that have started to manifest in Africa. Under intense selection pressure, these will increase in frequency until the whole population is more immune to the disease.
| [
"Cats can be infected or infested with viruses, bacteria, fungus, protozoans, arthropods or worms that can transmit diseases to humans. In some cases, the cat exhibits no symptoms of the disease, However, the same disease can then become evident in a human. The likelihood that a person will become diseased depends ... |
why aren't animals like gorillas who are very strong released back to the wild? | That isn't why.
Sure, some of them might be half tame and too comfortable being around humans, making it easier to kill them or just make them a pest.
But they lack the upbringing thier parents would give them. They dont know how to act around their wild relatives. And they havent been passed down the knowledge of what is good to eat and when.. much less where it is.
There are those that try in various ways to ease animals into the wild. Partly by keeping them on an island first, where they have to get used to not being fed by humans and they can figure out how to fend for themselves.
But there is more culture involved than you might think.. And thats why it would be hard for some species to be integrated back into the wild.
Im sure there are other considerations.. Im not a zooologist.
Also there is the matter of finding a place for them. Lack of habitat can be the biggest problem. | [
"A study published in 2007 in the \"American Journal of Primatology\" announced the discovery of the subspecies fighting back against possible threats from humans. They \"found several instances of gorillas throwing sticks and clumps of grass\". This is unusual. When encountered by humans, gorillas usually flee and... |
why do we have to cook things with a low flame for a long time. why not a high flame for a short amount of time? | Large flame means high temperature. High temperature means the outer layer of food might burn before the inside has been heated up.
Low temperature takes more time, but gives you much more even cooking. | [
"The low temperature of slow-cooking makes it almost impossible to burn even food that has been cooked too long. However, some meats and most vegetables become nearly tasteless or \"raggy\" if over-cooked.\n",
"Because of the longer cooking time, there is greater danger with slow cookers of having an extended pow... |
why does the mixing of alcoholic beverages seemingly get you drunker quicker/why is it seen as such a bad thing? | It doesn't really, it's just easy to physically drink more when you are mixing it up. It seems weird to drink your 5th vodka but if you have drank a bunch of different stuff you don't notice you have drank so much. Food is the same way, People will notice they are eating a ton if there is just one food out, but if there is a selection they will eat one of each and not notice how much they have eaten. Like people will realize eating 5 hamburgers is excessive but if you go to a cookout with hamburgers and hotdogs and steak and chicken and kebobs and stuff people will eat em all. | [
"Mixing alcohol with normal soft drinks, rather than diet drinks delays the dizzying effects of alcohol because the sugary mixture slows the emptying of the stomach, so that drunkenness occurs less rapidly.\n",
"The effect is a consequence of the fact that alcohol has a lower surface tension than water. If alcoho... |
- why do public restrooms have automatic soap dispensers if you will wash your hands directly after applying the soap? | Perceived convince and portion control.
A huge problem for businesses is users who take way more of bathroom goods that they actually would need, wasting goods and leading to more frequent empty situations.
Automatic dispensers usually have some delay between dispensing portions of a product, making it more difficult to take a ridiculous amount of soap or towels.
Users may also percive automatic dispensers as cleaner even if it isn't necessarily true | [
"Automatic soap dispensers (also known as touchless or no-touch soap dispensers) dispense a controlled amount of soap solution (or a similar liquid such as a hand sanitizer). They are often used in conjunction with automatic faucets in public restrooms. They function to conserve the amount of soap used and stem inf... |
why two unrelated movies, songs or books can have the same title but video game titles are vigorously protected? | Because in most cases, a game's title is the strongest and most valuable part of its brand, which is often not true for books and especially music.
In books and music, it is the artist/author which is the stronger part of the brand. For example, the album name "Midnight Love" may not mean much to you, but "Midnight Love *by Marvin Gaye*" will definitely spark some recognition (if you were familiar with it). The album name is almost unimportant. And you'll notice that no-one can go around calling themselves "Marvin Gaye" without incurring huge legal problems.
And even then, if a title of a book or album has a powerful-enough brand, the brand will be vigorously protected. Try releasing a book titled "Harry Potter" without permission. Or an album called "Thriller".
With movies and games, it depends a lot more on the power of the title's brand in isolation. Yeah, there are plenty of movies with similar or identical names, but that's because the name itself is not a valuable brand to anyone. In many cases, the movies brand has more to do with its genre and acting/directing talent. Or one movie has Hollywood promotion and budget, while the other one is a small indie-flick.
For games, the title is usually the strongest brand the game has, so game companies will zealously protect it.
It's all about the value of a brand. | [
"Some games could not be included due to licensing (e.g. \"Tron, Lock 'N' Chase, BurgerTime, Loco-Motion, Mission-X, Masters of the Universe, Pac-Man, Dig Dug, Diner, Pole Position, Commando\"). Others such as \" and \" are working prototype versions to avoid trademarked names. Licenses such as Major League Basebal... |
why do so many books have two to three blank pages at the start? | Imagine I took a standard piece of paper. I could fold it into 4 pieces, then cut the top and bottom a bit, staple it, and have a small book.
This is called a signature. They can be as small as 4 pages, or much larger. A book is typically made up of several signatures.
The result is, I can take two 4 page signatures and make an 8 page book, but I have no way to make a 9 page book. If I add one page, I have no way to attach it. You can imagine if I stick the page in and just glue the end, it will easily fall out. I might be forced to make it fit in a 7 page book, or maybe print a 12 page book with some blank pages (some print methods can use 2 page signatures).
The short answer is that when making books its usually easiest to make them a certain way, and blank pages may be the result. A children's book might be 30 pages, but the publisher finds that one 32 page signature is the cheapest method of production. So they might add something to the pages, or maybe they leave them blank. | [
"The book is laid out in twelve columns from right to left, each one representing a \"page\". Much of the first three columns are missing, and it is not known where the book begins. Closer to the end of the book the text is almost complete (there is a strip missing that runs the entire length of the book). By the e... |
how do tv commercials that mention “amazon alexa” prevent the activation of devices? | I don't have an Alexa, but I literally JUST watched [this video](_URL_0_) before coming to this sub, which mentioned that Alexa doesn't differentiate between your voice and anyone else's. So it can be activated by your kid, someone on the TV, or even a pet parrot (there are youtube vids of parrots activating Alexas, and even some Alexas that have recorded "shopping lists" dictated to them by parrots). So, TV commercials most likely can indeed activate an Alexa. IIRC there was a fast food commercial (Burger King? I only saw it once, on youtube) that did this, although that might have been a different device. | [
"In July 2018, Google banned additional categories of apps, including those that perform cryptocurrency mining on-device, apps that \"facilitate the sale of explosives, firearms, ammunition, or certain firearms accessories\", are only used to present ads, contain adult content but are aimed towards children, \"mult... |
does the black hole at the center of the milky way have a diameter? | It's the singularity that has no diameter. Yes, black holes have event horizons accretion disks which can be measured up to the singularity. | [
"Donald Lynden-Bell and Martin Rees hypothesized in 1971 that the center of the Milky Way galaxy would contain a massive black hole. Sagittarius A* was discovered and named on February 13 and 15, 1974, by astronomers Bruce Balick and Robert Brown using the Green Bank Interferometer of the National Radio Astronomy O... |
Was the United States the first country to have money called "dollar"? Where did the name come from? Why was it chosen? Why have so many countries adopted the name? | No, the word "dollar" is quite a bit older than the US government's unit of currency. It is an anglicised form of "thaler", which was the name given to coins first minted in 1519 from silver mined in Joachimsthal in Bohemia. Thaler is a shortened form of the term by which the coin was originally known: Joachimsthaler.
Eventually, "dollar" came to apply to lots of very similar coins, not only ones minted in central Europe but also the Spanish peso and the Portuguese eight-real piece. Both these large silver coins were practically identical in weight and fineness. This is the origin of phrase pieces of eight.
The word was in general use in England well before the creation of the US (actually when the English colonisation of North America had scarcely begun) and can even be found in two of Shakespeare's plays: the Tempest and Macbeth.
In Macbeth, Rosse says:
That now
Sweno, the Norway's King, craves composition;
Nor would we deign him burial of his men
Till he disbursed at Saint Colme's Inch
Ten thousand dollars to our general use.
Source: *A History of Money from Ancient Times to the Present Day*, Glyn Davies. | [
"The history of the United States Dollar refers to more than 240 years since the Continental Congress of the United States authorized the issuance of Continental Currency in 1775. On April 2, 1792, the United States Congress created the United States dollar as the country's standard unit of money. The term \"dollar... |
what is fcc rules part 15, and why must my devices "accept all interference including interference that may cause undesired operation"? | electricity is just magnetism seen from a different point of view, and magnetism travels through the air. So any electric device creates (induces) electric current in other nearby electric devices.
These FCC rules say that a product can't break because of other devices' electro-magnetic field ("must accept...") and shouldn't break other devices due to emitting a too-strong electro-magnetic field ("may not cause harmful interference").
The FCC is a government agency that regulates electronic devices, and the electro-magnetic spectrum. | [
"The FCC is also responsible for permitting transmitters, to prevent interference between stations from obscuring each other's signals. Denial of the right to transmit could be considered censorship. Restrictions on low-power broadcasting stations have been particularly controversial, and the subject of legislation... |
How does the cold war 'communism' scare compare to today's 'war on terror'? | *Nothing is so irretrievably lost to a society as the sense of fear it felt about a grave danger that was subsequently coped with.* -- George Will.
Reddit's demographic skews young, and people here don't often have the experience to be able to compare the modern "war on terror" to the "war on communism." The truth of the matter is that the war on terror is largely a peripheral concern in the United States, to a degree that Americans between, say, 1950 and 1989 would have loved to have. (As an aside, this is not to say that terrorism wasn't happening during the exact same period -- airplane hijackings in particular were relatively common during this forty-year period, and the thought process that developed on how to handle them played its own sad role on 9/11 -- just that it didn't filter to American cultural consciousness in a way that the "Soviet threat" did.) Yes, you see it on the nightly news, and yes, comedians make jokes about it and it informs both public and foreign policy -- but not to anywhere near the extent that communism did.
**What the Americans saw:** The USSR was, for at least a portion of its history, an aggressively expansionist and often foul-tempered entity with a largely opaque political process, a history of "disappearing" dissidents, and a united cadre of communist nations to back it up. Or at least, *that was the American political establishment's experience with it.* With the opening of the Soviet archives, we know a lot more now about the disagreements and infighting behind the scenes, and that what we thought of as being an unstoppable and belligerent empire was anything but. The Soviets didn't really want to go to war any more than we did (of course, exceptions existed on both sides), and each nation thought of the other as having all its ducks in a row and a united set of allies. Nope. Disagreements between the Soviets and Chinese over what to do about North Korea are pretty representative of stuff the Americans didn't know. It turns out the Soviets were no fools about what Kim il-Sung was up to and that they spent a lot of time trying to rein the crazy in. It didn't work and they sorely regretted having put him (and others around the world) in power, in much the same way that the Americans came to regret having supported their own batch of crazies in the interests of countering communism.
**Not as crazy as it looks:** This all looks insane with the benefit of 20+ years' worth of hindsight, but -- the more you study the era and how politicians on both side acted and why they did, the more you start to understand that, given the insanity of the time itself, just about all parties involved were actually behaving pretty rationally. The Soviets and Americans both behaved in a manner that made perfect sense for how their nations saw the world and their place in it. Or, to put it another way, look at the game theory governing [mutual assured destruction](_URL_2_). The idea of mass war with nuclear weapons is insane, but how people thought through it, and in essence, designed a system to prevent it, was actually pretty smart. Also smart was how quickly people on both sides recognized that the world was changing. I love to cite [this article](_URL_0_) from 1989 as an example of the almost creepy prescience with which the U.S. military accurately predicted what it'd be doing today.
**The Cold War's effect on the American perspective:**
- Think about a forty year national nightmare with Soviet spies in the American nuclear program, nuclear weapons being moved to Cuba and within easy range of the continental United States (probably the closest the two countries came to all-out war before Khrushchev blinked), the "space race," and dick-swinging contests over Olympic athletes and scientific and cultural accomplishments.
- Think about [Dead Hand](_URL_1_) and the rivers of ink spilled by commenters, academics, and polemicists for forty years about the potential for a Soviet-American War and what it would look like.
- Think about the German army's bald admission that it existed largely for the purpose of slowing the Soviet tank advance in the event of an invasion of western Europe.
It was something rather more all-consuming than the current "war on terror." The modern CIA owes its existence to the USSR, as do generations of American politicians and policymakers. Condoleeza Rice, for example, is fluent in Russian, as are many in the State Department around her age. There's been a mass scramble to reorient the CIA around Chinese, Dari, Pashto, and Arabic lately. Hint, hint.
The world as a whole is safer and less violent than it's ever been, to a degree I think very few people truly appreciate. And if you want my honest opinion, future historians will see the modern "war on terror" as an inevitable development of the post-colonial world. They, too, will be writing in a period where that threat has passed and people are largely insensible to why it informed politics and culture the way it did. We are already starting to forget why the Cold War was as scary as it was. | [
"The end of the Cold War and the fall of the Soviet Union have been credited with leading to a marked decrease in this form of terrorism. Brian Crozier, founder and director of the Institute for the Study of Conflict, has said that communism was the primary source of both state-sponsored and non-state terrorism.\n"... |
Do frozen methane clouds on Titan retain a static shape? | The is a big difference between a solid chunk of methane versus a thin accumulation of crystalline droplets. On Earth, some clouds are made of water droplets and others are made of ice. On Titan, the ice methane clouds would behave similarly to the ice clouds on Earth or Mars. Here's some more info:
_URL_0_
The ice clouds in Interstellar are a complete work of fiction and while imaginative have no basis in reality. | [
"Titan's clouds, probably composed of methane, ethane or other simple organics, are scattered and variable, punctuating the overall haze. The findings of the \"Huygens\" probe indicate that Titan's atmosphere periodically rains liquid methane and other organic compounds onto its surface.\n",
"In September 2006, \... |
Did the illuminati have a role in the french revolution? (yes, this is serious) | The Illuminati, as Augustin Barruel describes it, is fictional. He ties together branches of enlightenment philosophy with various secret societies and claims that it's all one big group. [This link](_URL_0_) has excerpts from an essay that debunks specific claims.
Most of the supposed Illuminati connections are the influences of Freemasonry on the Revolution. A lot of pre-Revolutionary masons became revolutionaries, and some lodges turned into clubs. Couthon, Philippe Egalité, Camille Desmoulins, Danton, La Fayette, Brissot, Lazare Carnot, Mirabeau, Jacques-Louis David, and several other influential actors were masons. Masonic lodges were a safe place to spread and develop egalitarian ideas, so it's not surprising that many who were attracted to it would later join the Revolution. The lodges also influenced the creation and function of networks of clubs across France.
That hardly points to a hidden masonic hand controlling events, though. At least not a very competent one. Of the names listed above, Couthon, Philippe Egalité, Camille Desmoulins, Danton and Brissot were executed, along with many other masons. A lot of the time they were trying to take each other out. The number of lodges after the Revolution was a fraction of what it had been before. Support for the Revolution was also far from universal. | [
"In the late 18th century, reactionary conspiracy theorists, such as Scottish physicist John Robison and French Jesuit priest Augustin Barruel, began speculating that the Illuminati had survived their suppression and become the masterminds behind the French Revolution and the Reign of Terror. The Illuminati were ac... |
What keeps Jupiter, a gas giant, from collapsing under its own gravity and becoming a dense solid? | Hydrostatic equilibrium is what you want to look into. It's what keeps big round things round, from planets to stars.
In Jupiter's case, the gas at the center is hot from the extreme pressure exerted by gravity. The heat and pressure causes the gas to rise, so there's an equilibrium between gravity pulling down and the heat and pressure pushing out. | [
"A cold hydrogen-rich gas giant more massive than Jupiter but less than about () will only be slightly larger in volume than Jupiter. For masses above , gravity will cause the planet to shrink (see degenerate matter).\n",
"Jupiter is primarily composed of hydrogen with a quarter of its mass being helium, though h... |
When I look at a projector image on a wall and move my eyes from one end of the image to the other fast, I can see individual RGB lines (a few cm wide). Why? | not really a science based question, but your projector is DLP (digital light processor) based, meaning it has a chip where each pixel is a microscopic little mirror on a tiny hinge, the projector reflects off the chip,
each mirror switches on/off by tilting off axis (a tilted mirror cant reflect the pixel) these mirrors switch on / off many times per frame (faster to represent "brighter" pixels)
this of course only lets the projector show black and white images.... so how does it show color?
the light changes color 3 times per frame (usually via a spinning color wheel with red / green / blue filters)
when your eyes move quickly you are actually seeing the red/green/blue light separating because the projector CANT show all 3 colors at once and as your eyes move, the "streak" left by the light is separated into the component colors.
this also works for dimmable LED lights (car lights) in a way, because they switch on / off quickly, when you move your eyes, you will see the streak left by those lights is not solid but instead just a series of dots. (which annoys the crap out of me in night traffic)
edit:
_URL_0_ | [
"The entire scene, including the window, can be moved backwards or forwards in depth, by horizontally sliding the left and right eye views relative to each other. Moving either or both images away from the center will bring the whole scene away from the viewer, whereas moving either or both images toward the center... |
Red-shift, Blue Shift and Cosmic Expansion. If the universe has been expanding since the Big Bang, and if the further we look out into space the further back in time we are seeing, shouldn't objects appear to be moving closer to each other and to us and thus be blue shifted, NOT red-shifted? | The reason we're "looking back in time" is that light just reaching us from the objects at which we're looking left them a long, long time ago. In the meantime, this light has been traversing expanding space, which has acted to increase it's wavelength—i.e., to redshift it. | [
"Around 1930, Edwin Hubble discovered that light from remote galaxies was redshifted; the more remote, the more shifted. This was quickly interpreted as meaning galaxies were receding from earth. If earth is not in some special, privileged, central position in the universe, then it would mean all galaxies are movin... |
why can't we feel our bodies gaining weight, growing taller, etc.? | It happens really slowly. REALLLLLY SLOWLY. | [
"In regard to adipose tissue increases, a person generally gains weight by increasing food consumption, becoming physically inactive, or both. When energy intake exceeds energy expenditure (when the body is in positive energy balance), the body can store the excess energy as fat. However, the physiology of weight g... |
how do people afford to live in venezuela if a monthly salary is 3$? | It's worth pointing out that Venezuelans can*not* afford to live, if by "live" you mean "afford to pay for food and necessities". As of last year, [Venezuelans lost an average of 19 pounds and 93% said they did not have enough money to pay for food](_URL_0_). Unfortunately the situation has worsened since then. I can't find any hard statistics on the food situation, but it seems almost everyone is now living in poverty, child malnutrition is rampant, and eating 1 meal per day is common. This sometimes means cutting out other things that we might consider "necessities" such as electricity or clean water.
If by "live" you mean literally avoid death, the human body is pretty resilient. POWs have survived several months and sometimes even years of near-starvation. If you cut out almost everything else in your life, and don't care about the quality of your food, it is possible to avoid dying on very little money. | [
"Venezuelans and activists harassed government officials and their families who enjoyed luxurious lifestyles compared to Venezuelan citizens. The top income of a Venezuelan official would be approximately $700 per year. Despite this, families of Bolivarian officials live abroad and even attend foreign universities.... |
how astronomers can find a galaxy 30 billion light-years away, twice as far as the universe is old. | Space is expanding. The galaxy in question was actually much closer when the photons we're now receiving left it. | [
"BULLET::::- Astronomers report that the most distant known galaxy, UDFj-39546284, is now estimated to be even further away than previously believed. The galaxy, which is estimated to have formed around \"380 million years\" after the Big Bang (about 13.75 billion years ago), is approximately 13.37 billion light ye... |
How many Germans actually supported Hitler in his endeavors? | Define support.
Actively endorsing Nazi ideology and joining the party or security forces? Chanting slogans along with everyone else at rallies? Don't really care but works at a government ran munition plan anyway? Don't like the Nazis but never protected any Jews that he was friends with? | [
"Haffner argues that on gaining office in 1933, Hitler achieved many 'miracles' in economic and military policy.. 90% of Germans approved. Had he died in 1938, he would have been remembered as 'one of the greatest Germans ever'. Few people noticed that he had dismantled the state and concealed the resultant chaos. ... |
do photons age? | Photons do not experience time, so they do not age as we understand it. They do 'die' whenever they are absorbed. Every photon emitted by your monitor 'dies' in your retina (converted to electrical impulses) so you can read this answer. | [
"Recent evidence suggests that aging is also related to the loss of myelinated nerve fiber length and the mass of white matter, with individuals losing approximately 45% of total nerve fiber length as they age.\n",
"Age plays a role in brightness, as a contributing factor is the observer's pupil. With age the pup... |
if gravity has a quantum manifestation of itself (gravitons), how does anti-matter relate to it? would there be some kind of anti-graviton particle? | The expectation is that gravitons are their own antiparticle, similar to how photons are their own antiparticle. So no, there probably isn't another such particle unless we have things very wrong. | [
"The first non-classical, non-quantum physical principles underlying a matter-antimatter gravitational repulsion have been published by Marcoen Cabbolet. He introduces the Elementary Process Theory, which uses a new language for physics, i.e. a new mathematical formalism and new physical concepts, and which is inco... |
How does Aloe Vera help with sunburns? | Aloin Suppresses Lipopolysaccharide-Induced Inflammatory Response and Apoptosis by Inhibiting the Activation of NF-κB
_URL_0_
NF-kB is the major inflammatory pathway in humans and signals immune response that inhibit healing in an attempt to kill off what is perceived by the immune system as pathogenic invasion. By suppressing that activity and increasing solvation and oxygenation of the damaged areas healing can be processed. | [
"Home treatments that may help the discomfort include using cool and wet cloths on the sunburned areas. Applying soothing lotions that contain aloe vera to the sunburn areas was supported by multiple studies, though others have found aloe vera to have no effect. Aloe vera has no ability to protect people from sunbu... |
why do businesses build skyscrapers in cities when it would be much cheaper to build their offices further out where land is cheaper? | There are a lot of advantages to having an office in a central downtown area like this.
1) Free advertising
2) Good public transit/ease of access for employees
3) You can rent out unused floors and are likely to fill them as the space is in higher demand
4) Skyscrapers can be more efficient/more compact than wider, shorter buildings
5) It acts a "status" symbol for the company in a sort of industry dick measuring contest
EDIT: Formatting | [
"[not] because [the skyscrapers] are desirable, healthy, beautiful, and reasonable from the perspective of urban planning but because they are theatrical, romantic, unreasonable, and generally harmful, and because it is part of the money-making activities of a metropolis, in what is literally the world's most inter... |
how can you know when you've had enough sleep? if you can fall back asleep, are you not done? | *Enough* sleep is different for everyone. The common number is 8 hours of sleep a night - however this is based on statistical data. Other studies show that many people can function on less sleep with no side effects. You can know when you've had enough sleep when you do not have general sleep deprivation symptioms such as lethargy, depression, decreases in short term memory, concentration, etc. ( however other factors such as caffeine, alcohol, drug use, and medication can affect this ) | [
"The Maintenance of Wakefulness Test (MWT) measures a person’s ability to stay awake for a certain period of time, essentially measuring the time one can stay awake during the day. The test isolates a person from factors that can influence sleep such as temperature, light, and noise. Furthermore, the patient is als... |
why are crossfitters looked down upon by the bodybuilding community? | Crossfit gets a bad rap because of a few different reasons
1) Their teachers only require a weekend certification course, and as such oftentimes give their students subpar lessons on form. This leads to a high rate of injury, which increases exponentially with the WOD being such a variable, with often strange biomechanics. A strength coach for an olympic weightlifting athlete, a professional powerlifter, or a professional bodybuilder usually has either a long history of training champions, or at the very least degree in kinesiology, biomechanics or some other applicable degree.
2) The workouts are timed and are often using ramping up weights. Most bodybuilders or powerlifters want to get strong. The reason that the crossfit workout scheme doesn't necessarily facilitate that wish is because in weightlifting high reps =/= more strength. [Rep Chart](_URL_0_) Here is a chart that shows the relationship between reps and strength. As you can see, 1-5 reps of heavy weight usually facilitates the greatest gains in strength or myofibilur hypertrophy, 5-10 reps of moderate weight increases muscle size, but not as much strength, called sarcoplasmic hypertrophy, and higher reps don't really increase mass or strength much, but instead work out our slow twitch muscle fibers, which are used for endurance training.
When you work out with high reps and low weight, you can increase your endurance quite well. The problem is the hardcore mindset of a crossfitter, combined with weights that are too heavy with no rep scheme, and bad form. As you continue lifting, any lifter will tell you your form has the greatest chance of breaking down in the last reps. This becomes a problem when there is no predisposed last rep, so your form continually breaks down over time. This is a good way to cause an injury.
3) The way crossfit people are portrayed, and the way bodybuilders and weightlifters act. Both are very testosterone fueled events, and as such this causes a lot of competition. One of the reasons the average crossfitter experiences negative feelings from a weightlifter is just the way that crossfit advertises itself. Phrases like 'My warm up is your workout' and the 'hardcore, most elite athletes' mentality really rustles peoples jimmies. That mentality, combined wth crossfits business dynamic which pumps out countless gyms, sweatshirts with logos made to look tough, and consistent facebook updates garners a lot of contempt over time. That isn't to say bodybuilders don't have their own set of personality defects, but there has been a much longer time for society to get used to the idea of the meathead than the idea of the crossfitter.
at the end of it all though, as people tend to do, we stereotype every group into one idea. The truth is there is a spectrum of different people with different mindsets that participate in every kind of lifting sport. Some of them give their sport a bad rap, some of them are shining examples of doing it right. It all depends on how it was exposed to you, and how you feel about it. I'm sure this list could be miles long, but there could also be a long list of things that are bad about powerlifting, or bodybuilding, or gymnastics, or whatever sport you want to criticize. | [
"CrossFit is promoted as both a physical exercise philosophy and a competitive fitness sport, incorporating elements from high-intensity interval training, Olympic weightlifting, plyometrics, powerlifting, gymnastics, girevoy sport, calisthenics, strongman, and other exercises. It is practiced by members of over 13... |
why do we ask for autographs when we meet famous people? | To remember the encounter and to prove to people that we really met them. And to an extent, because the autograph might be worth something one day. | [
"Some celebrities still enjoy signing autographs for free for fans. Many people who stand outside premieres, asking for autographs are actually professional autograph traders, who make their living or supplement their income by selling them for full profit, rather than keeping them as a personal souvenir. This is o... |
why was the concept of the month developed/accepted? why don't we count the date as "day 275" of the year, for example? | The concept of the month was based on the cycles of the moon, which last about 29 days. The English word "month" comes from the word "moon". | [
"During the period between 1582, when the first countries adopted the Gregorian calendar, and 1923, when the last European country adopted it, it was often necessary to indicate the date of some event in both the Julian calendar and in the Gregorian calendar, for example, \"10/21 February 1750/51\", where the dual ... |
In a constant environment at 0 degrees Celsius, will water molecules freeze or melt? | In a water/ice mixture, molecules are both 'sticking' to the ice if they have too little energy to overcome the attraction of the water molecules in the ice, and liberating themselves from it if they have enough energy to break free.
At 0 C both those things occurs at the same rate, so whichever amount of water/ice you start with, the total amount of each will stay the same.
| [
"There are phenomena like supercooling, in which the water is cooled below its freezing point, but the water remains liquid, if there are too few defects to seed crystallization. One can therefore observe a delay until the water adjusts to the new, below-freezing temperature. Supercooled liquid water must become ic... |
Is there evidence that the founders included cannons and bombs in defending the 2nd Amendment? | The 2nd Amendement is not terribly concerned with individual ownership of weaponry, it's concerned with civilian oversight of the military. It is impossible to separate the writing of the 2nd Amendment from the militia laws, and the political beliefs that surrounded them.
In brief: the framers by and large (with major difference of opinion here) that armies were breeding grounds of corruption, moral decay, and served only as a stepladder to tyranny. The militia system was intended to address these concerns by, essentially, empowering and obligating every citizen to bear arms and to serve to defend the nation. Occasionally this would also include ad-hoc, temporary companies or battalions to form in order to *project* force, but generally this was meant to be approved by congress and was further curtailed by the need to raise or motivate the troops that would fight in the expedition.
This system necessarily meant that, yes, civilians could own things like cannons. But the difference was that a *militia* - that is, the armed embodiment of the community - would own the cannon, not an individual. It was no more Bob's cannon than it was Frank's, and it would be inconceivable for Bob to store it personally, it would likely either be emplaced when in use or stored in a public magazine, and served by a trained crew of local militia.
The specifics of each polity's militia are far too complex to go into here, but to TL;DR your question - it was implied that "arms" included functional *military* weapons but was subservient to a system that mandated (to some extent) community-facing training and organization that acted as a bulwark against a tyrannical army. Yes and no, then.
________________________
I always recommend Lawrence Cress and Richard Kohn: *Citizens in Arms* and *Eagle and Sword* respectively for more information on the political battle over standing armies and the political theory that encouraged militias instead.
Saul Cornell's *A Well Regulated Militia* is also good reading on this question. | [
"Modern scholars Thomas B. McAffee and Michael J. Quinlan have stated that James Madison \"did not invent the right to keep and bear arms when he drafted the Second Amendment; the right was pre-existing at both common law and in the early state constitutions.\" In contrast, historian Jack Rakove suggests that Madis... |
If DNA stores information of how to make proteins, where is the information for what to do with the proteins stored? | its horribly complicated and we dont know completely yet. I'll keep to the basics. also have to be careful by what you think of as information
first off, DNA codes for more than just proteins, it also has regulatory sequences in it (promoters, inhibitors, protein binding regions).
moreover, there is another layer of information above this called the epigenome, at its most basic theres DNA methylation, which in higher organisms can lead to histone modification, chromatin status, and chromosome positioning. I'm not going into this because thats a whole other subject, and would need a huge amount of writing. but essentially, its another layer of control, and fundamentally is what makes skin cells different from brain cells etc.
so going back to DNA, in prokaryotes (think bacteria and similar) the DNA is directly transcribed to RNA and then translated into protein. bacteria control gene expression using operons, which comprises of a regulatory gene, and one or more genes after it. one of the classic examples is the LAC operon, which allows the metabolism of lactose where the initial gene codes for a repressor protein that binds to the DNA stopping the transcription of the other genes behind it needed for lactose metabolism, when exposed to lactose the repressor protein unbinds and the bacteria make the enzymes required.
see this link for more explanation
_URL_0_
in eukaryotes its a lot more complicated, there are systems similar to the operons, however there is also, alternative splicing, RNAi and whole bunch of other regulatory methods.
in brief, alternative splicing leads to different characteristics in proteins, (e.g. changes to activity, changes to turnover etc), RNAi is a method of controlling the mRNA transcript, as cells dont like double stranded RNA (looks like a virus) RNAi utilises the same machinery to degrade mRNA. by producing an anti-sense strand (reverse sequence to the one its targeting) the mRNA gets degraded resulting in a silencing of that transcript reducing amount of protein created.
this is horribly simplified, as theres complexities to gene regulation that I really dont want to start typing about now.
going to the second part of your question. in eukaryotes, on of the things that can be encoded in a protein are localisation sequences. there are specific sequences that say a protein is mitochondrial, or nuclear, or to be secreted. these sequences are recognized by pores in the respective organelles. what also happens is that the golgi apparatus modifies the proteins (things like the addition of sugars) before exporting it to its intended destination.
protein levels are regulated by turnover, with them being recycled and replaced. as proteins accumulate a small protein called ubiquitin they are transported to proteosome where its broken up.
finally, as I said at the beginning, you have to be careful with what you think of with regard calling it information. an enzyme doesn't know what to do, where to be, etc. rather it exists and "bumps" into substrates, if its the correct one, and it hits the active site then the enzyme performs its task (breaking it down, or adding stuff, or changing its shape etc) it might be enriched in certain compartments through the use of the afore mentioned localisation sequences. | [
"In order to make a protein, genetic information in DNA is copied (transcribed) into messenger RNA (mRNA) in the nucleus and then exported into the cytoplasm, where it is translated into a protein. Much of Izaurralde's early career focused on elucidating how this export occurs at a molecular level.\n",
"If the ge... |
If heavy elements are formed due to supernovae, how come we have so much of them on Earth if supernovae are relatively rare events? | The elements which only can be formed by supernovae, elements heavier than Nickel, together account for about 0.05 ppm (parts per million) of the matter in the universe - for every ton (1000 kg) of matter, there is 0.05 g of heavy elements. That is not a lot.
However, there's more of them here on Earth. How much more? Actually about 0.16% of the mass in Earth's crust is heavy elements, so that is a ~30,000-fold enrichment compared to the composition of the universe. Where do all those heavy elements come from?
One reason for this is that many of the heavy elements easily form alloys with lighter elements such as rock or iron, and these componds are lighter than the iron core that makes up most of Earth. Thus, when the Earth was still molten, they floated up towards what is now the crust.
Another important point is that while 98% of the mass in the Universe (and a similar amount in the Solar System) consists of the two lightest elements hydrogen and helium, these two elements are comparably rare on Earth (only 0.14% of the crust is hydrogen, and there is barely any helium there). These elements are instead concentrated towards our Sun and the massive gas giants. Why? Well, we will have go back to when the Solar System was formed:
The Solar System was formed in a giant cloud of gas and dust. The gas is mostly hydrogen gas (H2), but also traces of other molecules, but no heavy elements - all the heavy elements were in the dust (which was mostly composed of silicates, which are not heavy). Planets then formed by these dust fragments colliding and clumping together to form larger and larger clumps. Once the giant planets were large enough they could easily hold on to the light molecules with their gravity, and thus ended up as gas giants around solid cores. Further inside the Solar System, the Earth-like planets formed. These were too light to hold on to hydrogen and helium - given time, such light elements would escape the planets' gravity fields and leave the atmosphere. Most of the hydrogen and helium in this part of the solar system therefore sooner or later ended up inside the Sun.
There are other processes that play in, but I think these covers the most important ones. | [
"Supernovae can result from the death of an extremely massive star, many times heavier than the Sun. At the end of the life of this massive star, a non-fusible iron core is formed from fusion ashes. This iron core is pushed towards the Chandrasekhar limit till it surpasses it and therefore collapses.\n",
"Theoret... |
Was China trying to kill the 14th Dalai Lama in 1959? Or were they just generally going for Tibet? | Hi there, sorry I'm late.
Your question seems to imply a misunderstanding of the timeline.
The People's Liberation Army launched their invasion/liberation of Tibet in October 1950. Tibet was then led under the name of Tenzin Gyatso, the Dalai Lama, who was only fourteen years old at the time. A Regency council functionally led Tibet in his name. After the PLA decimated the Tibetan army at the Battle of Chamdo, the Dalai Lama fled to Gyantse Dzong in the small Phari panhandle between Bhutan and Nepal (just in case). The surrender in Lhasa was called "The Seventeenpoint Agreement" and reportedly distressed His Holiness to hear that his country - without his input - had given in to the enemy.
Thus began just under a decade of *attempts* (the operative word) of Sino-Tibetan cooperation. For lots of detailed information on exactly how that cooperation worked out, I recommend Tsering Shakya's *Dragon in the Land of Snows,* the authoritative book on Tibetan history post-1950.^1
Rewinding just a bit, it serves to think about three things:
1. Dalai Lamas have left Tibet before, and bad things frequently happened. Lobsang Gyatso, the Fifth Dalai Lama, was the first to politically control all of Tibet. He left the country early in 1652 to meet the Shunzhi Emperor in China. It went pretty well, all things considered. But his successor, Tsangyang Gyatso, the Sixth Dalai Lama, was captured and taken prisoner across northeast Tibet (Amdo) to China (presumably for execution) and died en route.^2 The Panchen Lama left Tibet to visit the Qianlong Emperor in the late 1700s^3 and the contemporary fears of smallpox in China were well founded... the Panchen Lama died in China. Finally, the Thirteenth Dalai Lama, Thubten Gyatso, predecessor to the current Dalai Lama, fled to Mongolia during the British invasion of Tibet in 1904, and then (somewhat ironically) to India in 1910 when China invaded Tibet. So basically, the Dalai Lama only leaves Tibet if there's something very wrong and he's taking the last resort to set it aright.
2. Tibet is hardly a homogenous entity today, and was far less so in the past. In the '50s, when our story takes place, Lhasa had finished its state-building exercise, managing to coalesce a strong base of power in south-central Tibet, U-Tsang (Tib: dbus gtsang), and this, like most monarchies, was centered around the Dalai Lama as a uniting force. The Gelukpa school was large and powerful, but Tibet had five plus schools of Buddhism. The Dalai Lama was conveniently a multi-religious institution. The regions that had trouble being convinced that Lhasa was vested in their interests, Amdo and Kham, now had an Amdopa Dalai Lama to look up to. In short, the Dalai Lama was a symbol of the nation. If the Dalai Lama fled Tibet, Tibet flees with him.
3. The Chinese, as much as they promoted the "Five Races One Nation" idea, knew all of this. They knew that their position in Tibet would be fractious at best if the Dalai Lama fled, so they did everything (they thought) they could to keep him... short of giving him actual power.
To answer your question, the Chinese *absolutely did not* want anything bad to happen to the Dalai Lama. Beijing dreamed and aspired to show the Dalai Lama of the glories of socialism, hoping to even convert him to Atheism^4 by bringing him to Beijing in 1955, showing him the wonders of the modern world and the prosperity of socialist civilization. There in Beijing, Mao told the Dalai Lama that Tibet would be allowed to transition slowly to socialist paradise, while the rest of China (including Kham and Amdo which Beijing had separated from Tibet proper) would be accelerated into socialist paradise. The Dalai Lama reportedly returned to Lhasa excited with the idea that Mao understood him and wanted to work with Tibet and the Buddhists.
Well, 1956 happened. That year was the 2500th anniversary of the Buddha's Paranirvana and the Dalai Lama was invited to Bodh Gaya to celebrate. The Chinese were scared out of their mind that the Dalai Lama was going to use this opportunity to defect, though no source anywhere indicates it was on his mind. Also in 1956 the Khampas out in Eastern Tibet finally had enough of their land being redistributed and collectivized, and then being forced into collectives where inefficient farming was being led by Beijing bureaucrats who had no idea how agriculture, nevermind local agriculture, worked. Before the PLA could take away everything - including their very valuable guns - the Khampas took what they had left and launched a massive rebellion. Monks often gave refuge to the warriors, and the Chinese attacks on Buddhist monasteries now proved to the Tibetans that the Chinese were not here for liberation, they were here to destroy them and destroy the Dharma.
Things continued to unravel. The Dalai Lama returned to Lhasa and was put in charge of a series of committees that had no real power (or were dominated by Chinese former military, not Tibetan locals). Remember, he was the symbol of Tibet and Tibetan legitimacy, but his ability to help his people was continuously undermined, misportrayed, and ultimately destroyed. He found himself in the position where all he could really do would be to denounce the Khampa rebellion, or the Chinese. Either would ultimately speed the destruction of his nation. I discuss a [here](_URL_0_) from a bit of a different perspective that he was working on his PhD at the time. Well, the Tibetan Buddhist equivalent of a PhD. He passed his final examinations with flying colors and the celebrations were marked for 10 March 1959.
con't | [
"On April 18, in an interview to Canadian journalists, it was reported that the Dalai Lama said that since the beginning of the demonstrations in Tibet at least 400 people had been killed and thousands of others arrested.\n",
"Upon his return to Tibet, the Dalai Lama learns of more horrors perpetrated against his... |
if plants produce oxygen, then is breathing in a garden "easier" or better for you than breathing inside a building? | You don't use a lot of the oxygen you inhale in either case. We generally inhale about 21% oxygen from the atmosphere. The air we exhale is about 16% oxygen. | [
"As aerobic respiration decreases, the plants become oxygen deficient, since the roots are unable to produce enough oxygen in the reduced soil conditions. Decreased oxygen uptake can also decrease plant productivity.\n",
"Clean air supplies oxygen which is an excellent purifier for plants and the aeroponic enviro... |
what exactly is a "double-blind" study? | The tester and the subject are both 'blind'. If you're doing a cola taste test double blind then the person presenting the drinks and recording the data doesn't know which is Pepsi and which is Coke, and neither does the person being tested. | [
"A double-blind study with only objective measures is less likely to be biased to support a given conclusion. However, the researchers or the sponsors still have opportunities to skew the results by discarding or ignoring undesirable data, qualitatively characterizing the results, and ultimately deciding whether to... |
Is water pressure the same regardless of the volume of water? | Liquid pressure (P) is dependent upon three things:
1) density (p)
2) gravity (g)
3) height aka depth (h)
Represent by the equation P = pgh.
So the pressures would be the exact same in your scenario.
Although if you're talking about TOTAL pressure you have to include the pressure if the atmosphere as well, which would potentially change if you are moving locations.
Atmosphere is gases so you would have to calculate the partial pressure of the elements in air (mostly nitrogen, oxygen, carbon dioxide) and sum them to discover what it was. Ideally you would you the PV=nRT law. I believe the atmospheric pressure at sea level is 1 atm. | [
"It is important to recognize that the pressure does not depend on the \"amount\" of liquid present. Volume is not the important factor – depth is. The average water pressure acting against a dam depends on the average depth of the water and not on the volume of water held back. For example, a wide but shallow lake... |
Is there a limit to the amount of languages a person can learn? | The trivial answer is "yes," because we know that there must be a limit: We have finite brainpower, finite time, and there are a finite number of languages.
Giving a more meaningful answer - one giving a number or range - is unfortunately impossible, for at couple of reasons.
The first is that it's very hard to quantify when someone has "learned" a language, because it's a continuum. The opposite ends of the continuum are clear: I'm sure I know "English," as it's my native language, and I'm fluent in it, and have never had trouble expressing my thoughts due to lack of English skill; I'm sure I *haven't* learned Tamil, because I can't even say "hello" in the language. Almost all multilingual people have at least some languages for which they have a level of knowledge between these two extremes, however. Have I learned French? I can live in a French-speaking country and have conversations with people, but my French doesn't even begin to approach my English. I also work with multilingual people often, and saying that they "know" five languages (or whatever number) is a gross oversimplification.
One solution to quantifying how many languages they know would be to adopt a standard -- for example, can they pass a certain language test. The standard would be arbitrary to some extent but would at least provide some sort of answer: we could say "the largest number of languages that anyone has passed this test for is x." To my knowledge, this hasn't been done in an academically rigorous fashion, because how many people can pass a certain test isn't a particularly interesting question.
Let's say we did this, though. Then we would run into a second issue. The question is about how many languages are *possible* to learn; is there a limit or not. However, the number of languages we learn is determined by factors like our social situation and personal motivation. I could learn Tamil, but I haven't, because it's not useful enough for me. The fact that I haven't learned Tamil doesn't say anything about whether or not it's possible to do.
There are few, if any people, who have completely devoted every waking moment of their life to learning the largest number of languages in the most efficient manner possible. Even the most extremely devoted polyglots have other interests. (Maybe they go to the movies every now and then.) Essentially, we are limited by social and personal factors before we ever reach the absolute limit of languages we can learn.
This isn't the type of question that can be answered by an experiment, by putting people in a concrete room and making them learn languages nonstop until they can't anymore.
I'm sure that someone will come along offering information on famous polyglots and how many languages they can speak, and these cases can be interesting. But bear in mind when reading about how many languages that they speak that this can mean a range of different abilities, from full native-like fluency, to "can order a beer", to "can't say a word but can read it." (And also, some polyglots like to err on the side or more languages because it sounds better ...) | [
"BULLET::::3. \"The rules of language make up only a small portion of our language competence\": Acquisition does not provide 100% language competence. There is often a small portion of grammar, punctuation, and spelling that even the most proficient native speakers may not acquire. While it is important to learn t... |
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