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why do humans have such small irises compared to other animals? | There are a few ideas, one being the "cooperative eye hypothesis" which suggests that it is easier to follow another's gaze when communicating. We communicate a lot through our eye gaze, and it's easier to distinguish different communicative attempts from one another with the white part (sclera) present. Another idea suggests it's a sign of good health when choosing a partner. | [
"Goats have horizontal, slit-shaped pupils. Because goats' irises are usually pale, their contrasting pupils are much more noticeable than in animals such as cattle, deer, most horses and many sheep, whose similarly horizontal pupils blend into a dark iris and sclera.\n",
"The molluscs have the widest variety of ... |
would it be legal at all for godaddy to be specifically exempt from the sopa legislation? if not... how was that clause worked in? | When you make the law, you can make anything you want legal. GoDaddy will probably just become a branch of the government, the one that controls domain name.
It's not like there was something governing what power the state should have over the citizen or how it should behave.
Maybe we should have something like that and call it the constitution, it would help a lot these days. | [
"It was one of several similar bills in U.S. state legislatures allowing individuals to refuse service based on religion, with some bills specifically protecting religious disapproval of same-sex marriage. It was widely reported as targeting LGBT people, although Arizona law provides no protection against discrimin... |
when software updates say they've optimised it to run faster, what exactly did they do and why didn't they do it before? | Let's say you have an old PC game. The game is written to run on Windows 2000, but it still works on Windows 7. Sort of.
Well that company might re-release the game *Optimized for Windows 7*.
They physically re-work the code of the program so it works better with the current system.
____
Other programs may have already been written for that current system, but those systems can go through updates too that might conflict with the program. This would cause the software to need an update so it can run without issues on the updated software. | [
"Upgrades of software introduce the risk that the new version (or patch) will contain a bug, causing the program to malfunction in some way or not to function at all. For example, in October 2005, a glitch in a software upgrade caused trading on the Tokyo Stock Exchange to shut down for most of the day. Similar hav... |
when a large company (typically oil & tobacco) has "lobbyists in washington" how does that actually affect the passing of legislation? | You know how when you want a family portrait *painted* you go to that person with the little cart in your local shopping mall, who has been there since before you were born, and you give that person a commission fee and they paint you a stunning portrait of your family?
A lobbyist is the same thing. They do something for a fee—in this case—they perform civic duties that all citizens can perform. They petition, meet, rally, network, collaborate and organize to pass something through congress.
So what's with my painting example? Because everyone has the potential to be a painter, but some people are *paid* to paint. A lobbyist is the same thing. A lobbyist is paid to move something through legislation.
As to the very specific *how*: through all the legal channels, but primarily, by establishing relationships. So lobbyists are kinda like high school popular kids in that respect.
But there's another big component: lobbyists are researchers too. They know *everything* they can about the issue and make decisions about how to spin things, sell things, and frame things. It's like a chess match meets a high school science fair meets a ad agency.
Source: some good friends in the lobbying biz. I gladly welcome revisions from anyone with corrections as I could be off. | [
"Lobbying in the US and in the UK is regulated to stop the worst abuses which can develop into corruption. In the United States the Internal Revenue Service makes a clear distinction between lobbying and advocacy. Proposed solutions to the influence of lobbyists within the UK have been discussed by MPs and non-gove... |
Non-American scholars of US History: What inspired you start? | I'm not completely US-oriented since I'm interested in the 19th century in general and not just the US, but I did take a lot of classes on US history and I was always fascinated by how much the US considered themselves special, from the puritans' concept of "city on a hill" to Manifest Destiny.
Also, I like how you can see the US's various historical border changes by looking at your states' borders. It's like living history. | [
"The Glory and the Dream: A Narrative History of America, 1932-1972 is a 1,400-page social history by William Manchester, first published in 1974. Sometimes sold as two volumes, it describes the history of the United States between 1932 and 1972. \"The Glory and the Dream\" was listed as a \"New York Times\" bestse... |
What would happen to a single photon going through a prism? | Describing the statistics of photons passing through a prism, as though a classical electromagnetic wave were passing through it, and where this classical EM wave determines the photon statistics is a perfectly legitimate way to go. The quantum operators for the electric and magnetic field actually obey Maxwell's equations, just like in classical Electromagnetism.
& #x200B;
In quantum optics, describing a single photon passing through a prism would be:
First: Give the initial quantum state of the electromagnetic field
Here, it's a single -photon state with a given frequency spectrum and momentum.
Second: Propagate the initial state of the field to the final state of the field using Maxwell's equations for the operators, or Heisenberg's equations of motion.
Third: Calculate the statistics of the final state of the field
Here it would be a single-photon state whose momentum is now correlated to its frequency spectrum due to the prism. | [
"If a single photon is emitted into the entry port of the apparatus at the lower-left corner, it immediately encounters a beam-splitter. Because of the equal probabilities for transmission or reflection the photon will either continue straight ahead, be reflected by the mirror at the lower-right corner, and be dete... |
why are white paints always bluish in color? | There are lots of colors of white. It sounds like you are looking at "cool whites," but there are also "warm whites" which use yellow or other warm colors as a slight tint. | [
"The appearance of white line indicates that there is an onset of failure of the corresponding material. This phenomenon is known as \"stress whitening\". This is more common in amorphous materials, and also in some brittle polymers like PS, PMMA and Polycarbonate. The white colour is because of the light scatterin... |
why it is hard to think about death deeply? | Imagination doesn’t actually ever create truly new things. It takes bits and pieces of experiences that you’ve had and uses those to construct what you’re imagining.
If you want to test this, try imagining a colour you’ve never seen.
Thinking deeply about death falls into the realm of trying to imagine something you’ve never experienced. You’re alive and as far as your brain is concerned always have been. So to imagine death it has no construct to piece together what it is like. The brain can fritz out while attempting to do this as it’s searching hard through your memories for something related.
This may cause the fear response you feel especially since we are told enough messages that death is something to fear. | [
"On the other hand, death and thoughts of death can serve as a way of empowering the self, not as threats. Researchers, Cooper \"et al.\" (2011) explored TMHM in terms of empowerment, specifically using BSEs under two conditions; when death thoughts were prompted, and when thoughts of death were non-conscious. Acco... |
genome vs. gene expression | Your genome is all the DNA that defines how your body operates. It's the same in all the cells in your body (except for sperm/egg cells - they have half your genome).
Gene expression defines what kind of cell each one is. So a skin cell and a muscle cell have different gene expression patterns.
Gene expression regulation is *incredibly* complicated, but the most basic principle is described by the central dogma of biology. DNA is transcribed to RNA and RNA is translated to proteins. Proteins do most of the work in a cell, including transcription and translation. They also regulate transcription and translation.
To define where a transcription starts and ends, the DNA has specific codes that are recognized by a protein RNA polymerase which starts making an RNA version of the gene. The binding of the RNA polymerase is regulated by other proteins called transcription factors. These can be regulated by chemicals, hormones etc. Transcription factors enhance or decrease the ability of the RNA polymerase to make mRNA.
The way the DNA is structured also determines what genes are expressed. The DNA strands are wound around histones. The histones are grouped in such a way that some DNA is accessible, while other DNA is blocked in. Different types of histones have different configurations, and so they affect which genes are expressed.
Once the mRNA is made, it can be translated into proteins, but again there are mechanisms that affect this. Some non-coding RNA is made by the RNA polymerase, and these can trigger degradation of mRNA to further regulate which proteins are ultimately produced by the cell.
So to summarize, expression is affected by the cell type and signals from inside and outside the cells (chemicals, sugars, hormones etc.). The regulation uses structure (histones etc.), protein signals (transcription factors etc.) and RNA signals to determine which genes are expressed (meaning which proteins are made). | [
"Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product. These products are often proteins, but in non-protein coding genes such as transfer RNA (tRNA) or small nuclear RNA (snRNA) genes, the product is a functional RNA.\n",
"The genome is the entire ... |
Let's just say that the LHC had a place that you could open up and get inside the collider. What would happen if particles were accelerated to maximum speed and you stepped in front of them? | [Nothing good](_URL_0_). A single beam in the LHC is about 100 times as powerful as the beam that Bugorski encountered. Even if the beam struck somewhere other than your head, the local nerves would probably be permanently damaged. | [
"In 2013, the LHC collided protons with lead ions for the LHC's first physics beams of 2013. The experiment was conducted by counter-rotating beams of \"protons\" and \"lead ions\", and begun with centred orbits with different revolution frequencies, and then separately ramped to the accelerator's maximum collision... |
What would be the biggest boat I could build if I was a king or a rich person around 1000 CE in western Europe? | It's hard to say with confidence how big of a boat *could* have been built at that time. A lot depends on the design and the resources said king could have pulled together. At the time a large cog would be about 50 or 60 feet in length, and carry maybe up to 150 tons. Supposedly, there were some legendary viking longships that were up to 150 feet long, though those are not that well documented as far as I know.
Try checking out: Gillian Hutchinson, *Medieval Ships and Shipping*
Disclaimer: I'm not a Medieval naval expert, though I do have some history in Medieval Mediterranean trade. If anyone has better information than I, please correct me. | [
"Examples of clinker-built boats directly descended from those of the early medieval period are seen in the traditional round-bottomed Thames skiffs, and the larger (originally) cargo-carrying Norfolk wherries of England.\n",
"The boat was an important means of transport in the lake regions of prehistoric Finland... |
For how long has October/Halloween/All Hallows' Eve been associated with spooky, mystical forces and the dead? | The simple answer to your second question is yes, the modern Halloween associations with supernatural entities reflects 'a mindset from an earlier age' when these things were 'thought to be real and lurking in the dark corners of the world at any time of the year'. It also appears that the end of October/beginning of November has a long specific association with these 'spooky, mystical forces and the dead'.
The problem with arriving at a definitive answer to your questions is that primary sources are not always precise about these sorts of things, and there needs to be a lot of inferences - a lot of connecting the dots with too few dots. There is a sufficient body of information to indicate that in Britain and Ireland there was a strong association of this time of year with the opening of a door between the natural and the supernatural worlds, allowing for crossing over and contact with powerful forces. In Irish Gaelic, it is called Samhain, and ethnographic/folklore work gives clear evidence to this being an important part of the Irish calendar. In addition, references in primary sources hint at the antiquity of this calendar tradition; it is likely a tradition that predates historical records associated with conversion to Christianity.
A great deal has been written on this; an excellent summary of these calendar traditions appears in James MacKillop, A Dictionary of Celtic Mythology (Oxford: Oxford University Press, 1998). | [
"The live events were based on specific paranormal themes, the two most common themes being Halloween and the summer solstice which are reputedly the two most paranormally active periods of the calendar. Some themes are based on well known historical figures such as Dick Turpin, William Shakespeare, Jack the Ripper... |
why is it that certain weapons, like poisonous gasses, are banned from use in warfare by the geneva convention, yet countries and governments can still use them against their own population, such as tear gas to control riots? | Geneva convention is largely a gentlemen agreement. No one wants their soldiers getting gassed or having to patch up wounds from hollow points. Its easier to just say no one gets chemical weapons and fight with conventional weapons, then it is to say "there are no rules" and everyone have them. Its already illegal for citizens to use tear gas on cops, so there is no objective reason to outlaw it for law enforcement.
The question of its something is humane or not doesnt really tend to stand in the way of most governments. | [
"Syria is a party to the 1925 Geneva Gas protocol, which bans the use in war of asphyxiating, poisonous or other gases, and of all analogous liquids, materials or devices. The use of chemical weapons is also prohibited as a matter of customary international humanitarian law, or the laws of war. The prohibition on t... |
Why do humans make similar facial expressions in response to similar situations? Nature, or nurture? | I would say the basic facial expression are a product of nature and cite the work of [Paul Ekman](_URL_0_).
BTW, the TV show Lie to Me was inspired by his work on facial expressions and lying. However, the early work on basic human emotions and facial expressions pre-dated the lying work.
| [
"People intuitively mimic facial expressions; it is a fundamental part of healthy functioning. Similarities across cultures in regards to nonverbal communication has prompted the debate that it is in fact a universal language. It can be argued that emotional regulation plays a key role in the ability to emit the co... |
whats the difference between christianity and orthodox christianity? | The meaning of "Orthodox" in the Christian teaching is to denote a kind of Christianity that, according to the speaker, is close to the early Christian beliefs. This means that many different branches of Christianity are likely to regard themselves as orthodox, even if they are at odds with each other regarding theological matters.
"Orthodox Christianity" is often used to refer to the Eastern Orthodox Church, which is one of the branches of Christianity, one that is mainly practiced in Eastern Europe, Greece and Russia. In this sense of "Orthodox", the question about the difference between Christianity and Orthodox Christianity is similar to asking "what's the difference between a sandwich and a ham sandwich?". Eastern Orthodox Christianity is one of the branches of Christianity.
Basically, like the Roman Catholic church, it believes it is the kind of Christianity that carries on the original intent and authority of Christ and His apostles. Unlike the Roman Catholic church, it is not united under the authority of a single pope, but rather it is a group of related churches with their own religious leaders. The Roman Catholic Church and the Eastern Orthodox Church (which also calls itself the Catholic Church) were joined together in most matters until 1054, when they split due to disagreements. One of those was the issue of the authority of the Pope. | [
"The Orthodox believe themselves to be the One Holy Catholic and Apostolic Church, that is, the true Church established by Jesus Christ and placed into the care of the apostles. As almost all other Christian groups are in indirect schism with the Orthodox Church, mostly as a result of the Great Schism with the Cath... |
how is it not entrapment when the fbi provides you the means to commit a crime? | FBI > "I hear you're looking for explosives, here you go"
vs
FBI > "Hey, you should blow up this airport. Here are some explosives you could use" | [
"In criminal law, entrapment is a practice whereby a law enforcement agent or agent of the state induces a person to commit a criminal offense that the person would have otherwise been unlikely or unwilling to commit. It \"is the conception and planning of an offense by an officer or agent, and the procurement of i... |
- what does a 3200 rpm stall converter mean, and why do i want it in my modified muscle car? | If you have to ask you don't need one. | [
"The stator element of the torque converter has two blade positions, controlled by the driver via the accelerator pedal to offer a 'passing gear' and extra response at any speed from heavy throttle application. In normal driving the stator blades are arranged at 'cruise' angle which offers improved efficiency and r... |
how did articles in the roman languages come about? | Actually, Ancient Greek did have articles: it had definite articles, but not indefinite articles. This is why some sticklers for correct grammar insist that you cannot say "the hoi polloi", because that translates as "the the people".
Ancient Greek's definite articles were derived from the demonstrative pronouns of an earlier form of Greek, Homeric Greek. Demonstrative pronouns are words like "this", "that" and "yonder".
This is also the derivation of Germanic definite articles. For example, in Old English, the phrase "se dæg" could mean "that day" or "the day", while "þæt ēage" could mean "that eye" or "the eye". The word "se" became our modern "the", and "þæt" is now "that". The reason the word was sometimes "se" and sometimes "þæt" has to do with grammar: Old English, like modern German, had three genders; "se" was used with masculine nouns and "þæt" with neuter nouns. Feminine nouns used the form "sēo", and it's believed that this is where our word "she" comes from.
In modern German, the connection between "the" and "that" is even more obvious: a sentence like "**Das** ist **das** Haus, **das** ich gebaut habe" translates into English as: "**That** is **the** house **that** I built."
A similar thing happened in the Romance languages. In Latin, the word for "that" was "ille" for masculine nouns and "illa" for feminine nouns. From those words we get the modern definite articles in French ("le" and "la"), Spanish ("el" and "la") and Italian ("il" and "la").
As for indefinite articles, they simply evolved from the word for "one". In fact, in most European languages, it's still the same word: "ein Hund" is German for "a dog" or "one dog"; "un chat" is French for "a cat" or "one cat". | [
"Articles are found in many Indo-European languages, Semitic languages (only the definite article), and Polynesian languages, but are formally absent from many of the world's major languages, such as Chinese, Korean, Turkish, Indonesian, Japanese, Hindi, Punjabi, Urdu, Tamil the majority of Slavic (incl. Russian) a... |
the weird lettering and symbols that are meant to “help” us pronounce words. | What else would you use? It is defined in the International Phonetic Alphabet. You need a system that complex to describe how word are pronounced.
I would agree that is is not useful for most people as you need to understand it. But if you study languages and look at it you can start to learn it. A simple usage is to look at words that you know how it is pronounced and see if parts are the same. If it is not the pronunciation is different. | [
"One way to remember the letters is to sound them out phonetically (i.e., \"SOH-CAH-TOA\", which is pronounced 'so-ka-toe-uh' ). Another method is to expand the letters into a sentence, such as \"Some Old Hippie Caught Another Hippie Trippin' On Acid\".\n",
"Some signs are spelled to convey the aura of another la... |
How do plants change the pH of the soil? | The assertion that Microstegium varieties raise soil pH by altering local nitrogen content is asserted by [Ehrenfeld](_URL_1_):
> Soils directly beneath each of the two exotics had higher pH values and higher nitrification rates and often had higher net N mineralization rates than did soils beneath adjacent patches of the most common native understory shrub, Vaccinium pallidum.
The suggested mechanism is specificity of nitrogen absorption:
> Both species evidently favor uptake of nitrate, which may elevate pH.
So we have an invasive grass which prefers nutrient poor, high drainage, shaded soils, and which exhibits an allelopathic effect on other nearby plants by preferential intake of more highly acidified nitrogen compounds, which results in a net raising of soil pH.
Generally, a highly effective solution to this type of invasive plant is soil treatment. Because the plant is competitive with nitrates you cannot rely on nitrogen acidification as a soil treatment. Till soil and treat with acidifying agent, because this invasive grass depends on high drainage soils for tillering growth I would suggest something like a [sphagnum peat moss](_URL_0_[com.lowes.commerce.storelocator.beans.LocatorStoreBean%40fc20fc2] & pl=1 & productId=3319744) which will add weight to sandy soils and lower soil ph. Denser soil will inhibit fast extension beneath the ground, so then you want to seed the area with a stoloniferous competitor species - I do not know your region so I cannot suggest a competitive local grass. The invasive variety has maximum growth efficiency at 25% exposure, so clear the area after tilling in the peat, and seed with a high-light competitor. | [
"Soil pH is considered a master variable in soils as it affects many chemical processes. It specifically affects plant nutrient availability by controlling the chemical forms of the different nutrients and influencing the chemical reactions they undergo. The optimum pH range for most plants is between 5.5 and 7.5; ... |
What decade is this painting portraying? | Based on the automobiles I would say the 20s/30s. | [
"The painting was originally displayed in an exhibit that featured modern and contemporary art. The painting was exhibited at the Miami Art Fair in January 2007, and created a worldwide controversy that was covered by ABC, NBC, CBS, CNN, and Fox television networks, as well as \"The International Herald Tribune\", ... |
Do you expend more energy running on a treadmill or a non-moving flat surface? | If you look at the surfaces providing the normal force to hold the runner up against gravity, they are both moving in a circular fashion. Earth is rotating and the treadmill belt is rotating. If you stand still on either, you will expend no energy and stay in the same position on the surface as that surface rotates. The only difference is that Earth is much larger and more spherical, so you won't fall off it like you will the end of the treadmill.
However, if you run at 5 mph on either surface, you will be expending the same amount of energy and be moving at the same velocity, covering the same linear distance. If the Treadmill had a surface area and rotational period equal to Earth's, there would be no difference in the perception of how much energy you need to expend on either to walk or run at a specific speed (assuming the same gravitational forces, no air resistance, etc).
*edit*: clarification. | [
"In terms of energy efficiency on flat surfaces, wheeled robots are the most efficient. This is because an ideal rolling (but not slipping) wheel loses no energy. A wheel rolling at a given velocity needs no input to maintain its motion. This is in contrast to legged robots which suffer an impact with the ground at... |
if congress passes a bill that has a 'watered down' version of net neutrality, can't obama simply veto it? | Sure, but it goes back to Congress after he vetoes it, and if over two thirds of both the House and Senate (voting separately) vote in favor of the bill, they can override the presidential veto. | [
"Sanders opposes the repeal of net neutrality in the United States, as voted by FCC commissioners in a 3-2 vote on December 14, 2017 — his statement on the issue from his U.S. Senate website on the same day as the vote, partly reads: \"The FCC's vote to end net neutrality is an egregious attack on our democracy. Wi... |
what was the point of ww1? was anything significant achieved? | [Just listen to this - trust me](_URL_0_) | [
"The First World War was a turning point in Western attitudes to war. At the 1919 Peace of Paris—where the leaders of France, Britain, and the United States, led by Georges Clemenceau, David Lloyd George, and Woodrow Wilson respectively, met to decide the future of Europe—Wilson proposed his famous Fourteen Points ... |
Could we workout for longer if we inhaled pure oxygen during the process | Inhaling pure oxygen would theoretically increase the rate at which your body could produce energy. However this is dependant on there not being any metabolic bottlenecks that exist so that the extra oxygen delivered to the muscle tissue is utilised in generating ATP. Your breathing rate will be relatively unaffected as your body has no way of monitoring O2 levels, only CO2 levels which would only change if the metabolic rate changed.
So assuming there are no metabolic bottlenecks (eg. enzymes in glycolysis or beta-oxidation of fatty acids) that are limiting the rate of ATP production then the extra O2 would allow for longer muscle contractions before failing. Whether this translates into a longer workout would be more about efficiency of fat metabolism, phosphocreatine levels and glycogen levels in the muscles and liver, as these will determine how long energy can be synthesised. For reference you only get a few seconds of high intensity muscle contraction before your muscles run out of energy and must make more. | [
"Supplemental oxygen is recommended in those with low oxygen levels at rest (a partial pressure of oxygen less than 50–55 mmHg or oxygen saturations of less than 88%). In this group of people, it decreases the risk of heart failure and death if used 15 hours per day and may improve people's ability to exercise. In ... |
why is the media not referring to the lax shooting suspect as a 'terrorist'? | There is no evidence he was a terrorist, was involved in terrorism, had connections to terrorist organizations, or was doing this act for terror purposes. This was just a crazy/suicidal guy with a gun shooting people, though its currently thought he had "anti-govt" views, but not terrorism. | [
"Speaking on June 19 at a press conference in Baltimore, FBI Director James Comey said, while his agency was investigating the shooting as a \"hate crime\", he did not consider it an \"act of terrorism\", citing the lack of political motivation for the suspect's actions. He said, \"Terrorism is act of violence done... |
Are electricity and magnetism related in a similar way that space and time are related? | > Are electricity and magnetism related in a similar way that space and time are related?
There is at least one relationship that I think it would benefit you to understand. Energy and momentum are related in a similar way that space and time are related, as are electricity and magnetism.
In ordinary three dimensions, we consider energy to be a scalar quantity (a simple number, equivalent to a 1x1 matrix), and momentum to be a three-dimensional vector (i.e. a column matrix -- 1xn where n is 3).
But we can model time as if it were a dimension, like space, which leads us to relativity. It's easy to generalize a scalar quantity to higher dimensions -- it doesn't change, it stays a scalar 1x1 matrix. But to generalize a vector quantity requires an additional degree of freedom. In relativity, momentum is not a 3-dimensional vector; it's a 4-dimensional vector. If each dimension corresponds to a momentum in that respective direction, what corresponds to momentum for the time dimension?
Turns out it's the energy (along a conversion factor of c^(2) or sometimes c based on conventions) -- you can think of energy as a "momentum through time," similar to how ordinary momentum in any direction is a momentum through space. Just like how objects moving through space with momentum can affect other objects in space (but objects with no momentum, relatively, can't), so too do objects with energy affect other objects throughout time -- without energy to drive it, change is non-existent.
That's super cool right, but what about electricity and magnetism? Well, in classical mechanics, the electric potential is a scalar potential (meaning there is a scalar quantity for every point in space -- the electric potential), and the magnetic potential is a vector potential (meaning there is a vector quantity for every point in space). Since space is 3-dimensional, the magnetic potential is a 3-dimensional vector -- a potential corresponding to each direction in space.
(Edits: I was too loose with distinguishing potentials and fields, so I've cleaned this part up a bit to be more accurate -- thanks /u/tagaragawa!)
But in relativity, space and time are related into a 4-dimensional space, and the magnetic potential vector must be 4-dimensional! What should go into the time component for this relativistic 4-vector?
Turns out if you put in the (scalar) electric potential in, you get the [electromagnetic four-vector](_URL_3_) which describes the electric and magnetic potentials as a single potential, from which the (unified) electromagnetic field can be derived.
> Space and time change in some proportional manner, mass and energy both increase (obviously because they are the same thing)
Actually, mass and energy *aren't* the same thing, the same way that a square and a rectangle are not the same thing. A square is a rectangle, but the opposite is not necessarily true. Likewise, mass is a form of energy, but the opposite is not necessarily true -- not all energy is mass.
You *can* sort of consider energy part of a "relativistic mass" -- but really that's a fancy way of saying "energy with a conversion factor of c^(2) so that it's in units of mass." It's not really the same thing, it just can be put into the same units. You *cannot* use relativistic mass in every equation that you can use rest mass in, and still get correct answers.
For example, Einstein's famous equation E=mc^(2), defines "m" as the "rest mass," and it's *not* the full equation. The full equation is E^(2)=(pc)^(2) + (mc^(2))^(2), where "p" is the momentum. If you set p=0, the equation reduces to E=mc^(2) -- so that equation only applies to particles with mass that are at rest (zero momentum). If you instead set m=0, you get the equation for the energy of massless particles, which is E=pc. That's the energy of a photon, which is experimentally measured.
But if instead you try to use the relativistic mass term (M=γm, where "γ" is the Lorentz factor and "m" is the rest mass), and tried to use E=Mc^(2) in every situation, then massless particles would need to have zero energy (since m=0 and anything times zero is zero, including γ). But we know that in reality this is not true, so the relativistic mass M cannot be a fundamental part of Einstein's equation. Instead we have to use the full equation that includes *rest* mass, and an added term from momentum.
> I can't see why electric fields in motion should produce magnetic fields. Is there any way to conceptualize it, or is the answer all in the equations?
It's all in the transformations between reference frames. There are some textbook ways of teaching how to conceptualize it, but you have to be familiar with the [Lorentz transformation](_URL_0_).
Try watching [this video](_URL_2_) if you aren't already familiar with visualizing Lorentz transformations, then [read this explanation](_URL_1_) of how Lorentz contraction demands that a static electric field be transformed into both an electric and magnetic field (or vice versa) because of a Lorentz transformation. But the gist of it is, magnetic fields can be thought of as arising due to differences in Lorentz contraction of space, in order to guarantee that the same phenomena (electromagnetic physics) happen in every reference frame.
Hope all this helps! | [
"As a consequence of Einstein's theory of special relativity, electricity and magnetism are fundamentally interlinked. Both magnetism lacking electricity, and electricity without magnetism, are inconsistent with special relativity, due to such effects as length contraction, time dilation, and the fact that the magn... |
How much, if at all, does the moon's gravity effect satellite's orbits? | Yes, the moon's gravity exerts influence on satellites. This is especially important for geostationary satellites where very small alterations in their orbits could make them no longer geostationary.
> moon's gravity variable
Unfortunately is isn't that simple. The distance between the moon and the satellite is constantly variable as both things are orbiting.
Analyzing deviation from a mathematically ideal orbit is called [orbital perturbation analysis](_URL_0_. This gets incredibly complicated very quickly, as the orbits of the moon and Earth themselves are also irregular.
Satellites have some propellant onboard for station-keeping, which is regularly correcting for irregularities in its orbit. | [
"Lunar mascons alter the local gravity above and around them sufficiently that low and uncorrected satellite orbits around the Moon are unstable on a timescale of months or years. The small perturbations in the orbits accumulate and eventually distort the orbit enough that the satellite impacts the surface.\n",
"... |
why do so many games have a "start" screen where you have to push a button before they decide to start a several minute loading process? (i'm looking at you, battlefield 4) | The primary reason is going to be player input. Let's say you omit that start screen, and just begin loading. All of a sudden, the player is sitting there, as you say, for minutes at a time, before anything happens. Is the game working right? did I do something wrong? is it frozen?
By forcing a player to hit start, it provides feedback that indeed, things are proceeding correctly. If it doesn't work, then you can safely begin troubleshooting reasons it might not be. | [
"The buttons on the game system and controllers are large to accommodate small children's less developed manual dexterity. The default controller consists of an analog stick, four colored buttons, a large enter button, a button (dubbed the \"Learning Zone\" button) that immediately takes the player to a minigame se... |
why is it that most corporate jobs don't have unions? | When I worked for Boeing, there was an attempt by some to unionize the engineers. It was voted down. Most of the engineers preferred having raises based on performance rather than flat increase across the board. | [
"Unlike other political organizations, labor unions do not directly participate in elections, although they may campaign for parties and politicians supporting their positions. Labour unionization is a way for workers to maintain unity and preserve their rights. Often, major corporations antagonize the principle of... |
During WW2, were there any jews who actively collaborated with the Nazis to hunt down other jews? | Ok, first off, it is important to understand that this is an extremely touchy and controversial subject even within academia today.
The short answer is that there were indeed Jews who collaborated with the Nazis though most of it was part of the perfidy with which the Nazis ran their system of genocide, basically actively forcing people to assist in their own murder.
The more nuanced answer must start with how the Nazi system of deportation etc. worked. In Germany in a model they would transfer to most of Western Europe, Jewish communities had their own official infrastructure in place. Meaning they had an official organization with elected officials running stuff like determining who was to be become Rabbi, organizing community life and so on. These community organizations (Gemeinde) were essentially left in place by the Nazis and placed under guardianship and overall control of the Nazis. They determined who was to become Judenältester (Jewish elder) as the guy who was ultimately responsible for running the whole thing. It was part of the Nazi enforced mission of these communities to not only run stuff such as Jewish hospitals and homes but also the transit camps in which Jews awaited deportation and to compile the lists of who was to be deported. In essence the Gestpo ordered the Jewish community of Berlin for example that next week 8000 people were to be deported to the east. And then under the threat of deportation and death, these communities had to compile the lists of who was to be deported.
Often it was not just limited to the lists but also the forced responsibility of these communities to gather then people for deportation. To this end, a Jüdischer Ordnungsdient (Jewish Order Service) was to be established. This was in essence a sort of police force consisting of members of the Jewish community charged with arresting people and bringing them to the detention sites where they awaited deportation.
This system was put in place in much of Western Europe as well as in the Polish Ghettos where the Jews inside the Ghetto were essentially placed under self-managment with only the higher ups receiving orders from the Nazis locally in charge.
The difficult and controversial question comes up around the behavior of the officials of these Jewish communities and of the Ordnungsdienst and revolves around the fact that they essentially collaborated but did so under the threat of deportation and death but also with the - in the end unbeknownst to them imaginary - perspective of being able to at least save some of their people.
The difficulties of these situations are exemplified by Adam Czerniaków, head of the Warsaw Ghetto Judenrat. Czerniaków was made head of the Judenrat in the Warsaw Ghetto and helped draw up lists for "resettlement to the East" as was the Nazi code word for deporting people to their death. When he found out what that meant and when his Nazi superior demanded he send 6000 Jewish orphans to their death in 1942, he committed suicide for he saw no way out. We know of his impossible moral struggle from his dairy which survived the war and has been published, exemplifying the dilemma in which people like himself or members of the Jewish Ordnungsdienst found themselves in.
Several survivors also make mention of Jewish Gestapo collaborators who hoping to avoid their own deportation did indeed help the Gestapo. However, in contradiction to other collaborators, they always operated under the dire threat of their own death by the hands of the Nazis and that would also be their fate ultimately, which is why we don't have any accounts of these people.
Again, I can't stress enough that the issue of Jewish collaboration in the Judenräte, the Ghettos and the camps is incredibly difficult since it always operated with the faint hope of saving oneself, a loved one or larger numbers of the total community and that it always was intended this way by the Nazis as a way to force their victims to a certain degree of complicity in their own murder.
Sources:
* Trunk, Isaiah Judenrat: the Jewish Councils in Eastern Europe under Nazi Occupation, with an introduction by Jacob Robinson. New York: Macmillan, 1972.
* Michael Berenbaum: [Judenrat](_URL_0_)
* Dan Michman: 'On the Historical Interpretation of the Judenräte Issue: Between Intentionalism, Functionalism and the Integrationist Approach of the 1990s', in: Moshe Zimmermann (Hrsg.), On Germans and Jews under the Nazi Regime. Essays by Three Generations of Historians. A Festschrift in Honor of Otto Dov Kulka (Jerusalem: The Hebrew University Magnes Press, 2006), S. 385–397.
* Doron Rabinovici: Instanzen der Ohnmacht. Wien 1938–1945. Der Weg zum Judenrat. Jüdischer Verlag bei Suhrkamp, Frankfurt am Main 2000.
* Aharon Weiss: Jewish Leadership in Occupied Poland. Postures and Attitudes. In: Yad Vashem Studies. 12, 1977, S. 335–365.
* Adam Czerniakow's diary. | [
"Between March and October 1943 the group, led by former auto mechanic and Willem Briedé, was responsible for tracking down Jews in hiding and arresting them. The group arrested and \"delivered\" to the Nazi authorities 8,000-9,000 Jews. Most of them were deported to Westerbork concentration camp and later shipped ... |
lagrange points for a planet with two moons | It would depend a lot on the relative sizes and positions of the bodies. Taking the solar system as an example: Jupiter has fairly large concentrations of asteroids at some it's lagrange points, because it and the sun are much more massive than anything nearby which would disrupt the system. By contrast, Earth doesn't have big concentrations of asteroids at the same solar/Earth lagrange points because Jupiter would tend to disrupt the system.
There's so many things that would change the situation in your moon question - relative masses, orbits, whether the orbits are in any sort of resonance, all might make a difference. But broadly speaking, you'r intuition is right, that more bodies tends to make lagrange points less stable. | [
"The only two stable Lagrange points are and . Langrange points are stable if the mass of the larger body is at least 25 times the mass of the secondary body.. The Earth is over 81 times the mass of the Moon. The L5 Society was founded to promote settlement by building space stations at these points in the Earth Mo... |
why hasn't microsoft word made times new roman the universal font? | Fonts with serifs (the little embellishments on the end) are great in printed materials, but are harder to read on a computer screen. It's why most of the Internet uses sans-serif fonts, like Arial or Helvetica, and why Word switched the default font from Times New Roman (a Serif font) to Calibri (a sans-serif font) in 2007- Microsoft noticed that people had stopped printing out most Word documents and instead were reading them on a laptop or tablet. | [
"\"The Times\" stayed with Times New Roman for 40 years, but new production techniques and the format change from broadsheet to tabloid in 2004 have caused it to switch typeface five times from 1972 to 2007. However, all the new fonts have been variants of the original New Roman typeface. Once released for commerci... |
if calories are the measure of how much energy there is in food - how can things be 0 calorie? | ok, so essentially calories are the value attributed to the amount of simple and complex sugars that a material has inside of it. Wether that's carbohydrates, fats or protein calories are the estimated value of how much energy that food stores in it.
Calorie free, or extremely low-calorie foods use substitute ingredients to provide something that may still have nutritional values, however provides very little in the way of caloric value.
Case in point, Coke Zero. While it helps quench your thirst, and will settle/calm your stomach, it will not provide you any significant boost in energy. This is because Coke Zero is made with many inorganic and processed chemicals that will not provide your body with beneficial nutrition or chemical based energy that it needs. The chemicals pass through your body almost undisturbed until you either pee/poop them out. The only useful thing is whatever water your body can strip chemicals off of to use.
Other foods, such as rice cakes, may have 1-2 calories, however still have other minerals and nutrints, such as sodium or Vitamin A, but still have no fuel to add to the mix.
Its like your body is a car. Do you need brake fluid? not every day. Do you need oil? Yes, but in small amounts every 1-4 months. Do you need Gas? Yes, every 2-5 days depending on how you drive.
In this instance, equate GAS to CALORIES. Oil, transmission fluid, etc... these are going to be other minerals and vitamins you NEED, but arn't actively used to make you GO. They work with the things that make you GO to make sure you keep GOING, but they arn't the fuel your body burns. | [
"The calorie equals the amount of thermal energy necessary to raise the temperature of one gram of water by 1 Celsius degree, from a temperature of 14.5 degrees Celsius, at a pressure of 1 atm. For thermochemistry a calorie of 4.184 J is used, but other calories have also been defined, such as the International Ste... |
How was the production of coins organised in ancient Greece / Rome (or even after)? How did rulers ensure the people who made coins didn't steal them? | The production of coins within Republican Rome was under the direction of the *tresviri monetales*. They are referred to by Pomponius (*Digest*) as the *triumviri monetales aeris argenti auri flatores* which is basically 'the three men for casting and striking of bronze, silver, and gold.' The position of *monetales* was an introductory position into Roman public life. When such position was introduced is unknown, some scholars suggest a date of 290-289 BC based upon the introduction of other similar offices, some scholars suggest 269 BC given the date that a Roman mint began to produce silver coins, and some just believe that we do not know but establish the foundation to the 3rd century BC.
The mint of Rome was a building on the Capitoline Hill located next to the temple of Juno Moneta. The *triumviri monetales* would supervise the production of said coins including the type (design) included on the coin, which would then be struck by the mint workers (*monetarii*). It was under there supervision then that it would be expected to understand how many coins were to be produced. The method of striking coin was simple. The designs for the obverse and reverse of the coins would be engraved into metal known as *dies*. One die would be placed in an anvil and the other in a metal bar, the soon to be coin was placed inbetween and a hammer was then used to make an imprint.
The production of coins was pretty standard between 218 BC - 140 BC. Bronze coinage (*aes grave*) had standard designs for the most part made up of six types: the As (Head of Janus/Prow); the Semis (Head of Saturn/Prow); the Triens (Head of Minerva/Prow); the Quadrans (Head of Hercules/Prow); the Sextans (Head of Mercury/Prow); and the Uncias (Head of Roma/Prow). Likewise, the silver coins (*denarii*) for the most part included designs related to the state such as Roma, Hercules, the Wolf and Romulus and Remus, the Dioscuri and so on.
It was in the 130s BC in which we begin to see the iconography of coins beginning to change annually with the focus being political propaganda. The reasoning behind this change is suggested as being because of an increase in political competition during the period (I myself believe it had been ongoing for decades prior). Another influence may have been the *lex Gabinia Tabellaria* in 139 BC which introduced secret ballloting - the use of coins as propaganda then became more important. From then on the position of *monetale* became important as one could issue coins outlining the achievements of their families and alike (this could have also been simply a way of remembering their family members - something which was important in Republican Rome).
& nbsp;
In terms of stealing within the Roman Republic, I am not aware of any cases of the mint itself being robbed. The mint was provided with the metal they striked by either the state or individual citizens so they would know how much metal they provided and therefore how much coin they should receive. However, there was issues with forgery.
According to Pliny (*Natural History*. 33.13.46), it was Livius Drusus (tribune of the plebs) in 91 BC who produced a silver coin alloyed with one-eight of copper. According to Cicero, the issue became that bad by 85 BC that the tribunes of the people and praetors took action to standardise the value of currency, because (*On Duties*. 3.20.80):
> ...or at that time the value of money was so fluctuating that no one could tell how much he was worth.
Sulla introduced a law in 82 BC as dictator known as the *lex Cornelia de Falsis* which considered forgery as an act of *falsum* (fraud) and a *crimen publicum* (crime against the public) and would result in severe punishment.
If you are interested further in books then really the best place to start is M. Crawford. More recently published books will no doubt reference back to Crawford.
Crawford, M. (1974). *Roman Republican Coinage*, London.
Crawford, M. (1985). *Coinage and Money under the Roman Republican: Italy and the Mediterranean Economy*. London. | [
"The production of coins is accomplished through the use of either a die for minting coins by hammering or, in modern times, milling or, mostly in prehistoric times and also in Asia, a mould for casting the desired object. Artistic medals and plaquettes have mostly been produced by lost wax casting.\n",
"Ancient ... |
why does germany have such a strong influence over the eu? | Germany is the EU's strongest economy and has the largest population. Why wouldn't they have a strong influence? | [
"Germany has played a leading role in the European Union since its inception and has maintained a strong alliance with France since the end of World War II. The alliance was especially close in the late 1980s and early 1990s under the leadership of Christian Democrat Helmut Kohl and Socialist François Mitterrand. G... |
Can anyone explain how someone can be an asymptomatic carrier of disease? | There are actually four ways that you can be asymptomatic:
1. Early in the infection you can start shedding virus before you start showing symptoms. That might be true for everyone. I've heard estimates for perhaps 24 hours before symptom onset.
2. You might have such mild symptoms and not recognise you have COVID-19.
3. You might have rarer symptoms and not recognise you have COVID-19. You might for instance just have a sore throat or diarrhoea—rather than having the more usual high temperature, dry cough and muscle fatigue. It's not clear how many people move from these rarer symptoms to more full blown "standard" symptoms later.
4. You might have no symptoms at all.
I find Number 1 the most scary in some ways as suggests there is no way of avoiding contact with carriers in the early stages of the disease. Numbers 2-4 are also problematic, but at least they suggest the current mortality rates are probably exaggerated which is good news.
From a semantic point of view I only think 1 and 4 are truly asymptomatic, but it's clear that all four uses of the words are going to be mushed together for the foreseeable future. | [
"Asymptomatic carriers can be categorized by their current disease state. When an individual transmits pathogens immediately following infection but prior to developing symptoms, they are known as an incubatory carrier. Humans are also capable of spreading disease following a period of illness. Typically thinking t... |
Why do a lot of little kids have freckles, but not that many adults? | Two theories about the prominence of freckles in children are as follows:
1. Freckles, being triggered by exposure to sunlight, are more common due to more frequent exposure to the sun and outdoors play, coupled with less care for sunscreen.
2. Freckles, being clusters of melanin, are more easily visible through the thinner skin of a child. On adults their presence becomes more subdued.
As for redheads, there is likely a genetic correlation to freckling; the amount of freckles is genetic and is related to the presence of the melanocortin-1 receptor MC1R gene variant. | [
"Freckles are predominantly found on the face, although they may appear on any skin exposed to the sun, such as arms or shoulders. Heavily distributed concentrations of melanin may cause freckles to multiply and cover an entire area of skin, such as the face. Freckles are rare on infants, and more commonly found on... |
what is r/circlejerk? | It is a subreddit where they mock the rest of reddit. The more time you spend on Reddit the funnier /r/circlejerk becomes | [
"A circle jerk is a sexual practice in which a group of men or boys form a circle and masturbate themselves or each other. In the metaphorical sense, the term is used to refer to self-congratulatory behavior or discussion among a group of people, usually in reference to a \"boring or time-wasting meeting or other e... |
How well did the the late Roman(Byzantine) emperors know their history? | The Byzantines were always relatively interested in antiquity, and especially in Rome. They never "forgot" that they were, however theoretically/distantly, part of the Roman empire. I can't say for certain how much Constantine XI was interested in this, since he probably had more pressing concerns than ancient history. But the Palaiologoi *do* seem to have been very interested in their connections to pre-Fourth Crusade Byzantium, and in turn to Late Antique and even ancient Rome.
For example: the Souda is a relatively well-known Byzantine reference book, a kind of encyclopedia containing mostly interesting grammatical and historical trivia, originally compiled around the year 1000. (You can check out a pretty handy translation online [for free](_URL_0_); see the entries for e.g. [Augustus](_URL_1_), [Caesar](_URL_6_), [the Roman Empire](_URL_2_), etc. for what the Byzantines might have been interested in on these subjects.) Now, the Souda is written in Greek, and the Byzantines didn't know much (if any) Latin, but aside from the grammatical component of the entries (mostly, for example, words that appear only once in Homer/Sophocles/etc.) a great deal of the Souda's entries are on Roman history. There's certainly some Greek stuff, but not the kind of classical-interest stuff you'd get in a modern ancient history course: they've got a pretty substantial entry on [Alexander the Great](_URL_5_), but no single entry on "Athens" or "Sparta." When they quote historians like Polybius or Plutarch, it's mostly for what they've got to say about Rome, and almost certainly about imperial Rome (since the Byzantines too recognized the importance of having an emperor).
The tenth century was a remarkable period for this sort of thing, so maybe the Souda is just a fluke. But the Palaiologoi, at least two hundred years after the Souda was compiled, made tons of copies of it: [Pinakes](_URL_4_) lists some 53 manuscripts copied between 1204 and 1500. Some of these are [pretty fine copies](_URL_7_), if not terribly embellished, but even a plain hand-written copy of an encyclopedia represents a tremendous amount of time and work. The manuscript I linked here is dated to 1402, so it's probably not originally meant for a western audience (as some of these, especially after 1453, may have been); this also means it was written when the empire was not necessarily in the best position, diplomatically or financially. Yet even while they're surrounded on all sides they're still copying books about the Roman past. Not all of the information they have about this past is accurate -- but at this point, the same is certainly true of the West.
I'm not terribly knowledgeable about Palaiologan classical reception, but most of the scholarly reading on the Souda that I'm familiar with is a.) in Italian and/or b.) probably difficult to get to outside of an academic library. If you can get to it, I recommend Barry Baldwin, "Aspects of the Souda," *Byzantion: Revue Internationale des Études Byzantines* 76 (2006): 11-31. The [S\(o\)uda On Line](_URL_0_) site also contains some general information about the work, the most relevant of which you can find [here](_URL_0_about.shtml) (under "The Raw Material"). | [
"The \"Historia\", an expansion and extension of Paul the Deacon's eighth-century \"Historia Romana\", contains a list of Byzantine emperors until the then-living Basil II and Constantine VIII (d. 1028) and another of empresses from Fausta to the wife of Michael IV.\n",
"While Byzantine historians were mostly dep... |
Can cancer cells potentially mutate to virulent forms? | [Yes, cancer can become virulent(potential NSFW GORE)](_URL_0_), and it is the main reason Tasmanian devils are endangered. | [
"As with other immortalized cell lines, H1299 cells can divide indefinitely. These cells have a homozygous partial deletion of the TP53 gene and as a result, do not express the tumor suppressor p53 protein which in part accounts for their proliferative propensity. These cells have also been reported to secrete the ... |
why aren't we sexually attracted to our siblings or parents? | [Westermarck effect](_URL_0_) - we're not attracted to thoe we grew up with. | [
"Innate sexual aversion between siblings forms due to close association in childhood, in what is known as the Westermarck effect. Children who grow up together do not normally develop sexual attraction, even if they are unrelated, and conversely, siblings who were separated at a young age may develop sexual attract... |
Did Nazi Germany get any tourism? If so, what countries visited? Were people who would be otherwise gassed (Jews, Blacks, homosexuals, etc) allowed there? Were they allowed to leave? | Having written on the topic of forreign tourism before, I'll reproduce that here as it may be of interest, although more can always be said.
Nazi-era Germany wasn't necessarily destination number one for foreigners looking to travel abroad, but that isn't to say it wasn't seeing any visitors, and during the 1930s, Germany wanted to encourage people to see it as a travel destination for both economic and propagandist reasons. the push came both from private, industry related organizations such as well as government related groups, one of the big ones being the Reichsbahnzentrale für den Deutschen Reiseverkehr (German Railroads Information Office, or RDV), which was one of the biggest initiatives for promotion of Germany as a vacation destination, which took up the vast majority of its advertisement focus. They ran 31 offices in 26 countries by 1938, and coordinated from its headquarters in Berlin. The aim of the RDV in its promotions was to serve state needs, not only bringing in foreign currency from visitors, but also attempting to create more positive images of Hitler's Germany for people, even if they were unable to follow through with the journeys the RDV was selling.
The image that the RDV projected was one heavily laced with propaganda. They billed Germany as a modern, attractive, cultural destination, but heavily played up "*how Germany is going ahead: no unemployment, production at peak levels, social security, gigantic projects for industrial development, economic planning, organized efficiency, a dynamic will of pulling together – a happy, energetic people who gladly share their achievements with you*" to quote one ad. The low cost of Germany as a destination was also a popular draw that the RDV played up, a favorable exchange rate for most foreign visitors allowing for the country to be billed as a good destination for those on a budget.
To focus on the USA, the RDV had an annual budget of 470,000 RM which were spent on initiatives such as newspaper advertisements, promotional films, and informational handouts for travel agencies, highlighting and promoting different destinations of interest in Germany and various events being held through the year that might draw people. They also did 'cultural' promotions with museums and schools. Prospective travelers could reach out to the RDV office and receive sample itineraries to help them plan their trip, as well as informational packets to guide them on various things they would need to be aware of. Although it of course doesn't mean every single person ended up going through with a trip, the RDV was receiving anywhere from 65,000 to 150,000 such inquiries a year during the 1930s, which can help give some idea of the level of interest for travel to Germany from the USA during the decade. The campaign was evidently successful too, and authorities recorded that from 1934 to 1937, numbers of American tourists had doubled. Interestingly, even after war broke out in 1939, the RDV continued to operate in the US, working to signal German confidence in a speedy victory and resumption of travel in the near future, nothing more than thinly veiled propaganda at that point in time - to the ire of many - but it wouldn't be closed down by the US until June of 1941 (offices in neutral and Axis countries would remain open beyond that point).
All in all, the push for foreign tourists seems to have been a successful one. from 1933 to 1935, German authorities claimed that foreign tourism increased 260 percent. Although as with any numbers from the Nazi government, it must be taken with a grain of salt as to its precise accuracy, the numbers certainly were going up. To quote from Semmens' "Seeing Hitler's Germany", from which I've been drawing on here, she provides a brief overview of the numbers for the middle of the decade:
> The Olympic Games marked a banner year in international tourism and Berlin was not the only city to benefit. That summer, 1.2 million foreigners, about 15 per cent of all registered visitors, arrived in Germany, an increase of 55 per cent over the summer of 1935. Thuringia alone witnessed a 61.3 per cent rise in visitors from abroad.77 But the Olympic year merely presaged what was to come. Berlin welcomed almost 56,000 more foreigners in 1937 than it had in 1936.
Looking at the entire initiative, it seems to have been on the whole successful in the goals Germany wanted. While the rising amount of tourist traffic to Germany should be understood as part of the larger international picture which "saw a continual increase in leisure travel after the Great War", the initiatives by the German government specifically played an undoubted part in seeing the country, specifically, chosen as a destination out of other options. And although not every visitor of course was swayed and instead left with sour impressions of the Nazi movement and the changes it had wrought, most visitors seem to have left the country for home with thoroughly positive impressions of what they had seen, extolling the "pleasant normality", a small victory for the propagandist aims of the tourist initiative as a whole, although of course hardly enough to sway international opinion in the end.
All cited from "Seeing Hitler's Germany: Tourism in the Third Reich" by Kristin Semmens. Specifically see Ch. 6 "International Tourism" pp. 129-153 | [
"The history of tourism in Germany goes back to cities and landscapes being visited for education and recreation. From the late 18th century onwards, cities like Dresden, Munich, Weimar and Berlin were major stops on a European Grand tour.\n",
"Life in the Weimar Republic was marked by massive hyperinflation, cri... |
How did some species (i.e, humans) come to require proteins that they could not produce themselves? | I think what you meant to ask is why some species have come to lose the ability to synthesize certain amino acids - not proteins. Amino acids are the building blocks of proteins. In the process of digestion, any protein that you consume are actually decomposed into the amino acid building blocks, which are then absorbed by your body for whatever use.
Now, as for why species have come to lose the ability to produce certain amino acids? Well, that's kind of a tricky question to answer. The really unsatisfactory answer is that at some point in our past, our diet had these amino acids in sufficiently consistent and large enough supply that when our genes that conferred us the ability to synthesize the amino acids were damaged or lost, the impact on our fitness was minor enough that it wasn't really a problem. | [
"Ingested proteins are usually broken up into single amino acids or dipeptides in the small intestine, and then absorbed. They can then be joined to make new proteins. Intermediate products of glycolysis, the citric acid cycle, and the pentose phosphate pathway can be used to make all twenty amino acids, and most b... |
What was the relationship between knight and horse? | I don't have an answer to knights of the medieval period in particular but the training and relationship between horse and trooper in the Napoleonic Wars and beyond is essentially that first and foremost that it was a primary mode of transport and fighting platform. In a sort of quid pro quo scenario, a trooper that looked after his horse and that his horse was attuned to could make your life on the trail/campaign much easier. A horse soldier without his horse is not well equipped and trained for life on the march, although towards the end of the Napoleonic Wars, the Grand Armee had some dismounted dragoon units (distinct from what the British called dragoons, which was every mounted unit in existence). A late as the Australian campaign in the Middle East in WW1, the reports of troopers loving their mounts and the great care and dedication which the men made for them are as common as accounts of general staff aides riding horses to death to bring news and/or messages between generals.
Certainly, a lot of famous generals and marshals had horses which they loved; the Duke of Wellington had a horse which he rode throughout his Peninsular Campaign and Waterloo (a half Arab named Copenhagen) and the Emperor Napoleon had an Arab which he rode from his Egyptian campaigns all the way to Waterloo. Both of these men had a great love of their horse, I guess very much in a way you have a favourite dog but I wouldn't like the speculate what sort of affection they had to their mounts - they certainly loved them, after a fashion. The hunting dogs of Louis XIV of France were greatly loved as well - there are paints and bronzes of these guys all over Fountainbleu.
All in all, the conclusion I would draw is that a knight would love and care for his horse so long as it was able to fulfill his or her obligation as either a war horse or palfrey, for which either were expensive commodities which affected a knight's ability to fight on campaign much more than, say, the quality of his arms and armour but less than his retinue of sergeants and 'staff' for want of a better term.
Sources:
Australians at War (?) - Unknown (pre 1950), Monash University Library Collections **This is not a properly cited source, I'm sorry! It was missing pages and water damaged to boot!**
Captain Coignet - Jean-Roche Coignet (Published Leonare 2007)
Swords around a Throne - J R Elting (1988)
Breaking and Riding: With Military Commentary - James Fillis (2005)
Interesting read: _URL_0_ | [
"Knight was a far more successful, and certainly regular, one-day player for England. In one-day cricket, this backing away in fact helped him score a lot of runs and became something of a hallmark. This same strength/weakness was mirrored in Michael Bevan – one of Knight's contemporaries.\n",
"The elite horseman... |
swift, apple´s new programming language | It was just announced. This is the first that anyone outside of Apple's heard of it. Ask again in a week or a month if you want to get some unbiased opinions on how good it really is.
Ultimately, it can only help so much. Programming complex programs is complex. No matter how much easier it becomes to express the complexities, they won't go away. If you're making a fighting game with 500 different moves, somebody still has to program them and decide how they interact - no language can make that go away. | [
"Swift is an open source programming language with first-class functions for iOS and macOS development, created by Apple and introduced at Apple's developer conference Apple Worldwide Developers Conference (WWDC) 2014.\n",
"Swift is a general-purpose, multi-paradigm, compiled programming language developed by App... |
how are large games abled to be rendered? | Generally there are a few methods:
* Intelligent clipping. You only draw the polygons that might be visible.
* Variable Level of Detail. As objects become more distant, they get drawn more simply. A building might be very intricate up close, but at a distance might be rendered as just a single rectangle.
* Fog. This one is cheesy, but it's been used in a few games. You draw a stack of semitransparent polygons at fixed intervals out from the camera, creating the effect of a uniform fog. Then you just stop rendering stuff at a distance where it would barely be visible anyway. | [
"Rendering games at 4K resolution is achieved through various rendering techniques and hardware features; PlayStation technical chief Mark Cerny explained that Sony could not \"brute force\" 4K without compromising form factor and cost, so the console was designed to support \"streamlined rendering techniques\" usi... |
Why didn't every independent medieval ruler declare himself a king? | One does not just become a king. In almost all circumstances a higher power created kings. In the older kingdoms that trace back to antiquity that 'higher power' is often claimed to be descent from a god or the ancestral founders of a people. Just assuming the title of king back then was the equivalent of an American citizen just declaring themselves President. Even if that person has a lot of power everyone knows its not legitimate.
Most people in the Middle Ages would look to the Bible for the example of how a new king is chosen for a people or area without one. God sent the Prophet Samuel to anoint Saul and only that made him king. They would also note that God and Samuel could also remove the king which they did when they anointed David in Saul's place. In the Middle Ages the Pope would be the equivalent representative from God as a Prophet. The power to be king as opposed to a mere lord of some time flowed from the religious authority ie the Pope. The other possible source was from the Emperor (Roman or Holy Roman as the case may be). Now was it always on the up and up? No. In the case of Sicily there were definite shenanigans. Dukes of Sicily playing Popes against Antipopes and Popes against Emperors until someone was desperate enough to make the Duke a King in return for aid. But the Duke still had to get that outside acknowledgement before crowning himself however forced (and contrived) it might have been or he would have been looked at as illegitimately assuming a title.
The rulers above did not just declare themselves king:
* The King of Naples was previously the King of Sicily who lost Sicily in a rebellion. The Kingdom of Sicily was granted its crown by the Pope in return for its assistance against the HRE.
* Cyprus was created a kingdom after it was conquered by Richard the Lionheart of England. It was given to a former King of Jerusalem who was Richard's vassal as a consolation prize for being ousted from Jerusalem and to rid Richard of a problem territory. It was done with the consent of the Holy Roman Emperor Henry VI. The King of England has long considered itself as a lord over lesser kings, notably Scotland so this was not a case of a king creating an equal but a king creating a lesser king.
* You will have to be more specific on German states but I'm sure if you do the research you will find that in almost all circumstances a higher power (Pope or Emperor) raised a lesser noble with a lot of power to the title of King.
| [
"In the early medieval period, with its many competing kingdoms within the modern boundaries of Scotland, kingship was not inherited in a direct line from the previous king. A candidate for kingship usually needed to be a member of a particular dynasty and to claim descent from a particular ancestor. Kingship could... |
why aren’t more major electronics companies making video game consoles? | The cost is way too high for the profits available. You have to invest huge sums in games and then make profit from selling hardware at very low margins. It's more a question of why anybody is still making consoles. | [
"The differences between consoles create additional challenges and opportunities for game developers, as the console manufacturers (e.g. Nintendo, Microsoft, Sony) may provide extra incentives, support and marketing for console exclusive games. To aid development of games for consoles, manufacturers often create ga... |
why is the ability to ride a bike something you can't lose once you gain it | If you learn to ride a bicycle with reversed steering, you can no longer ride a bike with normal steering until you learn again. The Backwards Brain Bicycle - Smarter Every Day _URL_0_ From /u/MrPennywhistle I believe. | [
"An abstract illustration of human capability is a bicycle. A bicycle itself is a resource—a mode of transportation. If the person who owns a bicycle is unable to ride it (due to a lack of balance or knowledge), the bicycle is useless to her or him as transportation and loses its functioning. If a person owns a bic... |
Was there ever any protest or opposition to mandatory military service in ancient Greece and Rome? | Nothing as dramatic as burning draft cards. Anyway, those people wouldn't have histories that survive. We do get a couple hints though.
I'm assuming you aren't referring to mutinies - these are often not objections to service in general, but rather a way of bullying the state into giving the soldiers a better deal.
The big one is entirely unattested. It's a bit of a hike to get there, so strap in.
The standard narrative of the 2nd century leading up to the crises of the Late Republic is usually framed around the Land Crisis and the Gracchan reforms. All the sources agree on the basics of the story: Ti. Gracchus got concerned with 1) the mass of urban poor, 2) the proliferation of slave labor inside Italy, 3) the lack of men that met the property qualification to serve in the army. Gracchus proposed to solve this by distributing publicly owned property, which Rome rented to wealthy men to farm (with slave labor) as a source of state revenue, to the urban poor, so that they would both reduce the need for slave labor on the big farms (latifundia) AND provide a new body of men of sufficient wealth to participate in the army. I'm going to skip over the the causes of this problem and success or failure of this project and it's long term effects for this question, but lots of us have written about it elsewhere.
That is the traditional narrative. All the sources agree. It seems to be entirely wrong.
Rosenstein recently wrote a book* Rome at War* (here's a [review](_URL_0_)) that argues that there was no land crisis. There is no archaeological evidence of latifundia in Italy, or dissolution small farms, or proliferation of slaves. The sources are entirely wrong. So what did Gracchus think he was doing? He was responding to something, right? He wasn't manufacturing a crisis he died trying to fix out of whole cloth. Rosenstein suggests there WAS a dearth of soldiers, but not because of the property qualification. Rome's major engagement at this time was in Spain, which was a long, messy slog without much by way of loot. People just didn't want to go. They didn't show up when the call for soldiers went out, leaving the army understaffed.
I have a suspicion that this (whether right or wrong) is partly the product of a scholar who lived through the problems with the draft the US experienced in Viet Nam; if nothing else it might have inspired Rosenstein to look for another reason for the dearth of soldiers. We'll see in a generation or so how that works out.
There are a couple of other incidents.
After Punic 2, there was reluctance on the part of some centurions to serve in Macedonian 3. [Livy gives the account at 42.32](_URL_1_). Some people were being enlisted with a lesser rank than they held in P2, and the case was tried in the assembly. This isn't strictly speaking a refusal to serve, but rather service with conditions. Livy says the movement fell apart when they were shamed by another potential centurion.
The move towards paid professional armies might also be seen to follow this general line of protest. Scipio Aemilianus led an army largely of his clients to Spain.
There is somewhere a reference to the veterans of Scipio Africanus' African expedition being exempt from service in one of the wars following P2, but I can't find it at the moment. If I dig it up I'll add it. | [
"At least in the Archaic Period, the fragmentary nature of Ancient Greece, with many competing city-states, increased the frequency of conflict, but conversely limited the scale of warfare. Unable to maintain professional armies, the city-states relied on their own citizens to fight. This inevitably reduced the pot... |
Will the first Quantum computer disrupt worldwide encryption and security? | It's going to be a long slow process from first proof-of-concept prototypes (which we've seen), to prototypes that work reliably, to prototypes that have an actually useful capacity, to demonstrations of breaking weak crypto as another proof-of-concept, then finally something usable in a lab, then the NSA getting one and not able to use it all the time, to finally being commercially available someday.
The point is that there will be plenty of time for cryptographers to watch the technology develop and to respond. When big enough and reliable enough quantum computers become a reality, they will be able to instantly break today's asymmetric ciphers and significantly weaken (but not break) the symmetric ciphers. That may be a cause of concern for anyone worried about recorded communications, but by that time I imagine post-quantum cryptography research will have settled on some usable alternatives that can hold up.
It's an uncomfortable fact of most cryptography algorithms that they are not mathematically proven to be secure, it's just that after pounding on it for a long time they haven't found a way to break them. Probably that will happen again with post-quantum crypto. A cryptographer will say "well I think this holds up against quantum computers, but I'm not sure, can you break it?" And if no one does for a few years they'll say ok, that's good enough to use for now. | [
"Developments in quantum computing over the past decade and the optimistic prospects for real quantum computers within 20 years have begun to threaten the basic cryptography that secures the internet. A relatively small quantum computer capable of processing only ten thousand of bits of information would easily bre... |
why does some scientists/countries still want to go on the moon ? | The moon is the closest large object to earth in space, so going to the moon allows us to develop and test a lot of technology related to landing on and moving around on solid, non-earth objects. Mars would be better to colonize for several reasons (atmosphere, temperature, soil, similar hours in a day, etc.), but we don't have the technology to set up a space colony yet and the moon is a much closer place to do testing. | [
"The National Space Society (NSS), a private nonprofit, regards a return to the Moon as a high priority for the US space program, in order to develop the body of scientific knowledge of the Moon, particularly in regards to its potential for the creation of new industries, in order to provide further funding for fur... |
why do subreddits need mods to control posts? doesn't the voting system show what people actually want, whether it's shitty or not? | If you have someone being abusive and harassing, simply down voting won't remove it from existing. | [
"Ballot design and polling place architecture often denies the disabled the possibility to cast a vote in secret. In many democracies disabled persons may vote by appointing another person who is allowed to join them in the voting booth and fill the ballot in their name. This does not assure secrecy of the ballot.\... |
why do royal families of defunct monarchies still exist? | Even if they came with no money or lands, titles can still give you an edge. | [
"Only legitimate descendants of the reigning monarch and the reigning monarch's siblings and their legitimate descendants can be in line to the throne. The King's elder sister, Princess Astrid and her descendants, along with descendants of the King's deceased eldest sister, Princess Ragnhild, are excluded from the ... |
We saw that bionic eyes can be a success. Could we make them better? | > Could we modify such a bionic eye so that a person could see beyond the visible spectrum (..., radio, IR, UV, X-ray, Gamma, ...)?
Yes. Current high quality CMOS sensors in cameras already do this. They need filters and coatings to keep them seeing the visible spectrum instead of IR and UV.
As far as X-Ray and Gamma that's a bit difficult since you need an emitter source and you also get cancer.
> If yes, what kind of limiting factors would we run into?
The eye is still better than any camera sensor out there but the tech still has room to improve. Hold onto your pants.
> If such a thing is possible, why can't we expand into other types of sensors, such as being able to feel (much more sensitively anyway), the strength of an electromagnetic field rather than it's frequency?
Interfacing directly with the optic nerve especially in the resolution and bandwidth required is not possible yet. | [
"BULLET::::- Scientists at California's Stanford University invent a working bionic eye powered only by focused light. Though currently a prototype, the device could eventually restore the sight of millions of people suffering from eye diseases such as macular degeneration and retinitis pigmentosa. (BBC)\n",
"Var... |
how come space probes that travel to distant planets not collide with the smaller objects in space? | Asteroid belts are nothing like in the movies. They are mostly empty space. Chances of getting hit are incredibly small.
It's like spreading millions of ants across a Sahara desert and stepping on one. | [
"Every planetary probe was placed into its escape trajectory by a multistage rocket, the last stage of which ends up on nearly the same trajectory as the probe it launched. Because these stages cannot be actively guided, their trajectories are now different from the probes they launched (the probes were guided with... |
why can you feel capsaicin irritating your mouth, stomach, and butt but don't seem to feel anything when it's passing through your intestines? | Oh I've felt it. You try some good peppers or other high scovile oily food and you feel it working it's way through. It's not the same sensation, but you know it's there.
As for why you feel it less sit is because capsaicin triggers pain receptors and your main gut just doesn't have many pain receptors. Why would it? Skin, mouth, and anus have way more pain receptors because they are far more likely to come into contact with pain causing things. | [
"Amtolmetin guacil stimulates capsaicin receptors present on gastrointestinal walls, because of presence of vanillic moiety and also releases NO which is gastro protective. It also inhibits prostaglandin synthesis and cyclooxygenase (COX).\n",
"By preventing the drug from dissolving into the stomach, enteric coat... |
Tuesday Trivia | Treasure Hunters | Here is one of my favorite stories.
In the 19th century a man named Heinrich Schliemann (1822-1890) decided to try to use the Iliad, which he had loved since he was a little boy, to find the location of Troy. Until then it was unclear if it was real or purely mythological. Schliemann, however, was convinced it was real and decided to critically study the Iliad for clues. In the 1860s, with Schliemann now in his 40s, he finally found what he had been searching for: The site of Troy.
Unbeknownst to him he actually dug farther than he needed to and began to excavate an even older civilization that lay under the ruins of Troy.
Among his discoveries is the so-called "Mask of Agamemnon", which didn't actually belong to Agamemnon but still retains that name:
_URL_0_
His discoveries helped spark a rush of new investigations into ancient Greek history, including what became known as Minoan (Crete) civilization.
Source:
-Leonard Cotrell: *The Bull of Minos*.
[Yes, I keep citing this book. Yes, I really, really like it] | [
"The Story of the Treasure Seekers is a novel by E. Nesbit. First published in 1899, it tells the story of Dora, Oswald, Dicky, Alice, Noel, and Horace Octavius (H. O.) Bastable, and their attempts to assist their widowed father and recover the fortunes of their family; its sequels are \"The Wouldbegoods\" (1901) a... |
What really was Bushido? | Not to discourage other answers but /u/bigbluepanda and /u/ParallelPain discuss Bushido in these answers from the FAQ
_URL_1_
_URL_0_
| [
"Bushido is a young silent Japanese swordsman, who is made an Honorary Titan by his American counterpart to fend off an incursion by the Brotherhood of Evil, which is preparing to mount an assault on young heroes. In the events of \"Calling All Titans,\" he is defeated and captured, and ultimately flash-frozen by P... |
Why are far away galaxies redshifted, when they aren't actually traveling away from us, there's just more space there than there was before? Does light lose energy traveling through a vacuum? | Yes, the light loses energy by being stretched as the Universe expands while it travels. | [
"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... |
How much, if any, correspondence occurred between opposing leaders during wartime? Is there more correspondence nowadays, or has it decreased over time? | The first thing I thought of when I read your question was the ['Willy-Nicky Telegrams'](_URL_0_), an increasingly desperate series of telegrams exchanged between cousins (hence the familiar way they address each other) Kaiser Wilhelm II and Tsar Nicolas II in the last days of July 1914 as Europe was dragged towards war.
Though the correspondence abruptly ends with the declaration of war on Russia by Germany on August 1st and so doesn't fit within the parameters of your question, you (and anyone else who hasn't seen them) might still find these fascinating.
| [
"The effect of the outbreak of war was immediately felt by Chi-Stelle, in so far as all participating nations began to transmit the majority of their messages in codes and cyphers. Thus the evaluation of the contents of messages was made more difficult, although the organisation of Allied air forces, as such, that ... |
Who was history's first recorded gay right's activist, in times of homophobia? | It depends on what you define as an "activist."
Keep in mind that homosexuality as a category of identification really dates back to the late nineteenth century, when sexologists began to classify and medicalize homosexuality. This is also when the first real "movement" for homosexual rights was launched. The movement really began in Germany. Karl Heinrich Ulrichs is the man credited with launching the movement. He "came out" (before "coming out" was a thing) to his family by letter and called himself a Uranian, the term he coined for homosexual. He then went on to write extensively about homosexuality in a series of essays. This, of course, was almost unthinkable in 1860s Germany, where homosexuality was against the law. By 1867, Ulrichs was fighting for the repeal of the anti-homosexual law.
In 1897, two years after Ulrich's death, Magnus Hirschfield--a sexologist and advocate for homosexual rights--started the Scientific-Humanitarian Committee in Germany, the first major homosexual rights organization. The major focus of the group was to push for the repeal of Paragraph 175, an anti-homosexual law passed in 1871. This is when the "movement" pioneered by Ulrichs became larger and more influential.
The (albeit small) movement in Germany spilled over into the United States in the early part of the twentieth century. Having been in the military, Henry Gerber traveled to Germany and witnessed the movement for homosexual rights in action. He brought the idea home and started the Society for Human Rights in 1924 in Chicago. It did not last long. After one of the members' wives found out about the organization, she reported it to the police, who promptly raided its headquarters and shut it down, arresting those involved. The headline the next day read "Strange Sex Cult Exposed." No gay rights organization would exist again in the United States until Harry Hay founded the Mattachine Society in the 1940s.
Hopefully that answers your question. For more reading about this, I would recommend John Loughery's book The Other Side of Silence: Men's Lives and Gay Identities. It goes into detail about the American side. For more on Germany, Richard Plant's The Pink Triangle: The Nazi War Against Homosexuals gives a pretty good survey of the early German movement. | [
"As a result of the publicity, from 1962 through 1964 Wicker was one of the most visible homosexuals in New York. He spoke to countless church groups and college classes and, in 1964, became the first openly gay person to appear on East Coast television with a January 31 appearance on \"The Les Crane Show\". Wicker... |
how can a distiller like jack daniel's meet doubled demand within one year when their product takes 4 years to age? | Jack Daniels complies with "straight bourbon" classification, which requires a minimum of two years in barrels. It's a blended whiskey, meaning that some of it may be older, and that blend can be varied. The company doesn't go in to exact details about blends and aging. | [
"BULLET::::- In late 2006, Gibraltar lawmakers passed the \"\"Children and Young Persons (Alcohol, Tobacco and Gaming) Act 2006\"\", which raised the minimum purchase age from 16 to 18 years. But the new law made an exception: minors aged 16 or 17 can purchase and consume on premises beer, wine or cider under 15% A... |
What's the longest single cell in the world? | Informal estimates place the dorsal root ganglion of the blue whale at ~25 m on average.
If we include prehistoric animals, though, this figure would not be the largest by a long stretch. The recurrent laryngeal nerve, which does a loop down the length of the neck all the way to the heart (only a fraction of total length, usually), can equal or exceed this figure in length in the longest-necked sauropods. | [
"HAP1 cells are a cell line used for biomedical and genetic research. They are near haploid, having one copy of almost every chromosome and are smaller than the average human cell, growing to about 11 micrometers in diameter. HAP1 cells are derived from a line of cancerous cells, which means they are able to divide... |
why old tech is being shown in new movies | Because most people can't identify models in simple passing.
If someone pays for the rights to feature their latest and greatest, the studio would use it, but otherwise it's just a prop phone with the model being completely unimportant. | [
"New Media Technology. If students prefer to go into filmmaking, this academy offers the best opportunities. The New Media Technology academy helps students build their knowledge of technology. They are afforded hands-on experience with equipment usually found inside a film studio. This academy also provides intern... |
bosons, do they facilitate all matter and how? | > I was under the impression that energy is made matter through Bosons or something at that level.
This is not really a correct statement. It sounds like you're referring to force carrier particles, which are bosons (a boson is anything with integer spin). There are a number of force carrier particles in the Standard Model of particle physics. They mediate interactions between all of the different particles in the Standard Model. For example, the photon is the force carrier particle for the electromagnetic force. | [
"In the conceptual model of fundamental interactions, matter consists of fermions, which carry properties called charges and spin ± (intrinsic angular momentum ±, where ħ is the reduced Planck constant). They attract or repel each other by exchanging bosons.\n",
"BULLET::::- Quarks and leptons (including electron... |
What will happen when we run out of accessible stocks of rare-earth elements? | Earth-bound rare earths will be around for a long time. This is why investing in [Planetary Resources](_URL_1_) might not pay off for a while, for example:
[Japan finds major rare earth deposits](_URL_3_)
> JAPAN has found a large deposit of rare earth minerals in its Pacific seabed, enough to supply its hi-tech industries for more than 200 years, a scientist says.
DR Congo has a [crapload of all kinds of minerals](_URL_2_), as does [Greenland](_URL_0_).
And yes, there may be substitutes for many rare earth properties:
[Substitutes for Rare Earth Minerals Under Development (MCP, AVL, REE, REMX, GM, TM, PHG)](_URL_4_)
> While rare earths miners like Molycorp Inc. (NYSE: MCP), Avalon Rare Metals Inc. (AMEX: AVL), and Rare Element Resources Ltd. (AMEX: REE) race to begin production, other companies like General Motors Corp. (NYSE: GM), Toyota Motor Corp. (NYSE: TM), and Koninklijke Philips Electronics NV (NYSE: PHG) are working on finding substitutes for the rare metals. Toyota announced last January that the company had developed a new motor for its hybrid cars that does not require lanthanum, neodymium, and dysprosium.
| [
"Another recently developed source of rare earths is electronic waste and other wastes that have significant rare-earth components. New advances in recycling technology have made extraction of rare earths from these materials more feasible, and recycling plants are currently operating in Japan, where there is an es... |
do nutrients in food change when heated/frozen, and if so, how? | Yes and no. Freezing won't change anything about the nutritional value of food, but cooking will.
There are many molecules that the human body cannot easily digest, and therefor cannot extract nutrients from. Cooking food can help to break those down into digestible molecules, and allows people to get a greater nutritional benefit from the food. There are also some chemicals our bodies need that can be broken down by high heat, so in those cases cooking can make things less nutritious. | [
"The USDA has conducted extensive studies on the percentage losses of various nutrients from different food types and cooking methods. Some vitamins may become more \"bio-available\" – that is, usable by the body – when foods are cooked. The table below shows whether various vitamins are susceptible to loss from he... |
why do many companies nowadays see tattoos as being "unprofessional"? | Because in much of modern history the people with tattoos have been people very often associated with unsavory organizations, crime, and violence. I think you can understand why companies wishing to present a professional and safe environment would shy away from hiring those with tattoos. That general attitude has been passed down, even though it may not be as applicable nowadays as it was in the past, since many people with tattoos are in no way associated with violence or crime. | [
"Parsons has expressed in articles a strong loathing for tattoos. In the 1990s, he wrote a story called \"The Tattooed Jungle\", suggesting that tattoos were symptomatic of the decline of the working class. In a 2012 article for \"GQ\" magazine, Parsons lamented the fact that in the last 20 years in Britain, tattoo... |
what purpose do continents serve apart from broad classification? | There is not one but a few different models for the continets. Some of them are just for classification. Some are used to differentiate what is one landmass and what is another. I thing the most common models used are the geopolitical and historic political one. These differentiate between what you could roughly call cultures. | [
"To a large extent, major continental regions are mental constructs created by considering an efficient way to define large areas of the continents. For the most part, the images of the world are derived as much from academic studies, the media, or from personal experience of global exploration. They are a matter o... |
Where did energy originate from? | [This video is about pretty much exactly what you are asking for, watch it!](_URL_0_) | [
"The word \"energy\" derives from the , which possibly appears for the first time in the work of Aristotle in the 4th century BC. In contrast to the modern definition, energeia was a qualitative philosophical concept, broad enough to include ideas such as happiness and pleasure.\n",
"In physics, energy is the qua... |
why are united states parents much more strict with the sexual life of their children compared to european parents? | The main reason is because of the religious background of the United States. | [
"In America, not only do U.S. students receive sex education within school or religious programs, but they are also educated by their parents. American parents are less prone to influencing their children's actual sexual experiences than they are simply telling their children what they should \"not\" do. They promo... |
how have beauty standards changed so much throughout the years? wouldn't what humans find attractive be genetically ingrained into our heads and not really allow standards to change over time? | A lot of the things we find attractive are not physical attributes but does have different physical manifestations depending on technology and culture. For instance we are attracted to wealth. Previously wealthy people were fat and sat indoor all day as opposed to poor people who were skinny, fit and dark as they worked outside on the fields all day. But as times have changed poor people started working inside and the current symbol of wealth is to have time to exercise and have a nice golden natural skin color. | [
"Beauty standards are rooted in cultural norms crafted by societies and media over centuries. Globally, it is argued that the predominance of white women featured in movies and advertising leads to a Eurocentric concept of beauty, breeding cultures that assign inferiority to women of color. Thus, societies and cult... |
What happened to the French, Belgian and Dutch colonies when their European owners were conquered by Nazi Germany during WW2? | I can answer in some detail where the Dutch colonies are concerned.
& nbsp;
The Dutch had 3 major overseas holdings: the Antilles, Suriname and Indonesia.
& nbsp;
The Dutch colonies in the West Indies became vulnerable after the Germans occupied the Netherlands in May 1940. The Antilles produced oil and Suriname was a major supplier of bauxite (which was made into the strategically vital aluminium). Especially the United States feared that these vital holdings, in their own backyard no less, would fall prey to the Germans. The Americans cooperated with the British and occupied these territories before the Germans could get to them. This is one good example of how involved the Americans were in World War II before Pearl Harbor. The Dutch government was not too pleased with the US-UK action but pretended to be okay with it. These territories remained peaceful and their resources made a significant contribution to the allied war effort. They were returned to Dutch control after the War ended in 1945.
& nbsp;
Indonesia was an entirely different scenario. The Governor in Jakarta remained in power after May 1940 and still ruled on the orders of the banished Dutch government in London. This would not hold for long however, as in early 1942 the Japanese began their invasion of the Dutch territory. Indonesia was also very rich in natural resources, notably rubber and for that reasons was too great a price for the resources-starved Japanese to let go. Not long after the invasion started did the Japanese occupy the Dutch East Indies. The more nationalist elements in Indonesia were quite happy with this and they were actively encouraged by the Japanese to consolidate their own identity and turn away from their European colonisers. This fit in the broader Japanese strategy to mobilise Asia under Japanese leadership and stop the influence of Western powers there. There was clear collaboration between the Indonesian Nationalists and the Japanese occupation forces. The Japanese occupation was brutal though, partly to the dismay of the Indonesian nationalists.
& nbsp;
The Dutch loss of control over Indonesia proved crucial. Nationalism had taken a hold on Java, the biggest and most populous island of the archipelago. Despite largely successful campaigns by the Dutch military to regain control over Indonesia, broader geopolitical considerations forced the United States to force the Dutch into giving up their colony (this whole process is worthy of a post in itself). Therefore it could be said that in the long term the Japanese occupation did lead to revolution in Indonesia, as the fires of revolt proved impossible to tame without repercussions after it had been boosted by Japanese intervention. | [
"During World War II, Belgium was once again occupied by Germany. The Third Reich enacted laws to protect and encourage the Dutch language in Belgium and, generally, to propagate ill-feelings between Flemings and Francophones, e.g. by setting free only Flemish prisoners-of-war (see Flamenpolitik). The Nazis had no ... |
what is passion and where does it come from? (passion for subjects or jobs.) how can it be created? | This is a good question. Comparable to "how do you knew when you've met the one?" You just know. | [
"Since passion can be a type of motivation in hobbies then assessing intrinsic motivation is appropriate. Intrinsic motivation helps define these types of passion. Passion naturally helps the needs or desires that motivate a person to some particular action or behavior. Certain abilities and hobbies can be develope... |
Why don't dead leaves smell bad like other decaying organic matter? | It actually takes quite a while for leaves to decay - assuming the leaf was detached from the tree in the fall due to 'normal' circumstances. So, think a regular autumn leaf, not a bunch of leaves that fell off when a branch broke.
Deciduous trees will actually begin pulling nutrients out of their leaves during the autumn. This is evolutionarily advantageous, since the nutrients are not then lost when the years leaves fall off. So what's left when the leaf finally falls off? Just a bunch of tough cell components (lots of carbon) with little nutrients in it. So when the bacteria that decompose organic matter go to town on these leaves, there's not much there. It takes a while for the leaves to be broken down! | [
"Dead plants or animals, material derived from animal tissues (such as skin cast off during moulting etc) gradually lose their form, due to both physical processes and the action of decomposers, including grazers, bacteria and fungi. Decomposition, the process through which organic matter is decomposed, takes place... |
are you able to move your hand forward whilest traveling at the speed of light? | You can't travel at the speed of light. So any question asking "what would happen if you could travel at the speed of light" is like asking "what does physics say would happen in a situation that physics says can't possibly happen" | [
"This formula shows that the work expended accelerating an object from rest approaches infinity as the velocity approaches the speed of light. Thus it is impossible to accelerate an object across this boundary.\n",
"In the mid-1980s HKB model experiments, subjects were asked to wave one finger on each hand in two... |
Since the Earth is getting more mass in the neighborhood of 100 tons a day, will the gravitational pull be strong enough to pull the moon into it? | 100 tons compared to the mass of the earth (~6x10^24 kg) is barely a rounding error.
It would take approximately 1.8 x 10^14 years to increase the mass of the earth by 1/1000 of it's current mass at that accumulation rate. The universe is only about 13.75 x 10^9 years old. So the Earth's mass isn't changing much percentage wise.
Also, the moon is moving away due to tidal interaction with the earth transferring energy to it. | [
"The acceleration due to gravity on the surface of the Moon is about 1.625 m/s, about 16.6% that on Earth's surface or 0.166 . Over the entire surface, the variation in gravitational acceleration is about 0.0253 m/s (1.6% of the acceleration due to gravity). Because weight is directly dependent upon gravitational a... |
how vinyl record players can play not only the pitch but also other details of some sound | Different instruments produce different shapes of sound wave. [Here](_URL_0_) are a few examples.
These are stored on vinyl by physically making the edge of the groove into the shape of the sound wave that the instrument makes. | [
"There is a theory that vinyl records can audibly represent higher frequencies than compact discs, though most of this is noise and not relevant to human hearing. According to Red Book specifications, the compact disc has a frequency response of 20 Hz up to 22,050 Hz, and most CD players measure flat within a fract... |
how and by whom are generation groups (x,y,z etc.) determined? | Marketers, mainly. Most of the time, you get a steady drip-drip-drip of people being born every year; there's about as many 7 year olds as 5 year olds or 9 year olds or whatever.
But the World Wars, particularly WWII, fucked that up: All over the world, the young people who would normally be getting married and having their first kids weren't, because the young guys were in the army and times were tough, so even people who were married put off having kids if they could. Then the war ends and all of a sudden you had like 6 years worth of kids being born at once. That changes things up: You have to build bigger schools, bigger toy stores, more cribs and braces and so forth all at once. That forced the people who sell stuff to pay particular attention to what was going on with young people, because they knew that in, say, a couple year's time there was going to be 6x the normal demand for bicycles or prom dresses or whatever. So they started doing more advertising aimed at young people, more TV shows and movies and books specifically aimed at young people and so on, all through the years. Young people are pretty much always rebellious in their late teens early 20s; but when you have six times the normal number of them at once all that rebellious energy can cause much more profound changes in society than it normally does. Viola: The 60s.
So it wasn't until the baby boom came around that people really started paying attention to the idea of generations as an important thing.
By the time the boomer wave was passing into adulthood marketers were used to this idea that people the same age as each other have the same types of ideas and desires, and that those desires are different from those of their parents and so they know they'll have to adapt themselves. (Technological change helps too.) They're the ones whose bottom lines are affected, and they're the ones who pay attention to all this stuff and write most of the BS you see about how generation whatever thinks about the world. | [
"A generation is defined as \"a cohort of people born within a similar span of time (15 years at the upper end) who share a comparable age and life stage and who were shaped by a particular span of time (events, trends, and developments).\" Generational segmentation refers to the process of dividing and analyzing a... |
What originally defined the human size/mass? Why are most of us 1.5-1.9m tall instead of 0.5m or 20m tall? | Evolution is an optimising process, it's always making tradeoffs between competing criteria to find the highest fitness for the environment. There are advantages to being bigger, as well as disadvantages. On the simplest level, if you're bigger you can win more fights, but you need more food. So maybe you want to be as big as you can be for the amount of food available. But htere are more factors than just those two of course. The size an organism ends up approximating the optimal tradeoff between all of those sorts of factors for the environment that organism lives in. Interestingly over the last few thousand years people have become a little bigger, and one of the proposed reasons for this is that we have become better at growing food, so the problem of being too big and needing too much food is less of an issue than it used to be. Also of course even genetically identical people will end up different sizes if you feed one much more.
Regarding being massive, the issue is the [square-cube law](_URL_0_). Basically weight is determined by volume, so it's size cubed, but muscle strength is determined by muscle cross section, which is area so it's size squared. As you get bigger the amount of strength you have goes up by squares, but the amount of weight you have to lift goes up by cubes. So there's a limit to how big you can be and still lift your own weight. This is also a big part of why ants can lift so much relative to their weight. | [
"The sizes with which humans tend to be most familiar are body dimensions (measures of anthropometry), which include measures such as human height, and human body weight. These measures can, in the aggregate, allow the generation of commercially useful distributions of products that accommodate expected body sizes,... |
what is "fair trade" and why should i care that my coffee is labelled as such? | Originally, fair trade was about a group of people that came together and said that they would pay the farmers that grew coffee a "fair" price. They wanted to do this in order to help them make more money, so that we weren't just using (exploiting) them. A lot of coffee comes from the poorest parts of the world, even though it gets used by the richest parts of the world, so the system was designed to help these farmers. The system pays these farmers slightly higher than what the world agrees on, thus being "fair".
Now the problem with Fair Trade. There's delicious coffee, and then there's the crappy coffee you find at Wal Mart. Let's say you're a farmer, and you have two separate batches of coffee to sell. One is delicious, that you could probably sell for more money, and one that's kind of crappy, that would sell for less money. Wouldn't you sell the crappy coffee to the Fair Trade people, in order to make more money than you could have, selling to anyone else? The delicious coffee gets sold at an even higher price than that, so you're still making money. This means "Fair Trade" coffee CAN be less delicious than if you were to buy coffee from the indie cafe down the street, that really cares about quality.
Fair Trade also claims to be a non profit, and takes some money from the people that buy their coffee instead. This money pretty much goes to telling everyone what a nice bunch of people they are (advertising/marketing), instead of going back to help the farmers. Then, the people that buy the coffee from the Fair Trade people, let's say Starbucks, can ALSO say that they're trying to do good. They have good intentions, but they're not really helping us have good coffee WHILE helping the farmers too.
This is where Direct Trade comes in. Before, the Fair Trade people were the only people that could actually PROVE that they were helping farmers. Direct trade means that a bunch of guys are going to the farmers, and telling them how to grow coffee in the best way possible. They give these farmers "coffee tests" to make sure that the coffee will turn out to be absolutely delicious, and if the farmers pass these tests, they get rewarded by being paid more.
==
**Edit** - I'm sorry if this isn't too easily understood by a five year old :/ I tried my best! Feel free to ask me to clarify on anything, though. More reading for non 5 year olds [here](_URL_0_) about the problem with fair trade. | [
"According to the World Fair Trade Organization and the other three major Fair Trade organizations (Fairtrade Labelling Organizations International, Network of European Worldshops and European Fair Trade Association), the definition of fair trade is \"a trading partnership, based on dialogue, transparency and respe... |
how do cpu temperatures drop so rapidly? | The temperature sensor you're reading is most likely part of the silicon die, and inside a particular CPU core(which is very small, so it doesn't have much thermal mass). As the silicon in a CPU has the same atomic structure as diamond, it has a very high thermal conductivity, so when heat stops being generated in this particular core, the core temperature drops to the average die temperature very quickly.
It takes much longer for the average die temperature or the heatsink temperature to change. This is why when you start a stress test the temperature will jump up almost instantly, but then slowly creep up as the heatsink comes up to the new equilibrium temperature.
For an analogy: The CPU core(what you're measuring), is the heating element of a stove, while the heatsink temperature is the pot of water on top of it. If you boil a pot of water, the heating element will heat up much more quickly than the pot of water, and can get hot enough to glow red. When you turn the burner off, it very quickly cools down to not-glowing temperatures, but it will take a long time for the temperature to go all the way back down to room temperature because the pot of water is still holding a lot of heat. | [
"Intel claims that the smaller die of Ivy Bridge and the related increase in thermal density is expected to result in higher temperatures when the CPU is overclocked; Intel also stated that this is as expected and will likely not improve in future revisions.\n",
"In modern processors from manufacturer such as Int... |
Is rain water pure H2O, or does it pick up other elements from the air on the way down? If not, why? | No, rain water is not pure. For starters, it has to have a "cloud condensation neuclei," basically a particle on which water forms. When the cloud becomes dense enough, rain begins to fall. The rain will react with various gasses and particulates on the way down, including hydrogen sulfide and carbon dioxide, creating sulfuric acid and carbonic acid respectively. In addition, rain water may pick up particulates such as pollen and carry them down. So when it reaches the ground, although it is primarily water, it is far from pure. | [
"When SO is emitted as an air pollutant, it forms sulfuric acid through reactions with water in the atmosphere. Once the acid is completely dissociated in water the pH can drop to 4.3 or lower causing damage to both man-made and natural systems. According to the EPA, acid rain is a broad term referring to a mixture... |
paradox? | Don't post just to complain.
Also, you're using "paradox" incorrectly. | [
"A paradox is a statement that, despite apparently valid reasoning from true premises, leads to an apparently-self-contradictory or logically unacceptable conclusion. A paradox involves contradictory-yet-interrelated elements that exist simultaneously and persist over time.\n",
"In literature, the paradox is an a... |
why are so many americans hooked on opiate pain pills? | First of all, most synthetic opiates are extremely addictive. For reasons I cannot explain, doctors in the USA still tend to prescribe these rather than the less addictive kinds of opiates (tramadol for instance). In Europe, prescriptions for these kinds of opiates are very tightly controlled - not many european doctors prescribe oxycodone or morphine outside of a hospital setting, so these pills seldom leave that setting. Hence, addiction is relatively rare due to oversight from hospital personnel.
Then, there's the fact that US pharmacies aren't interconnected most European pharmacies are. I don't know about the UK, but in the NL all pharmacies are connected to a central database where prescriptions are checked. Anyone shopping for pharmacies would be caught quite easily.
Furthermore, most European doctors use digital systems to communicate with pharmacies. This makes faking a prescription next to impossible. In the US, they still use paper prescriptions quite often, which allows for forgeries, theft and illegal transfer.
In the end, it all has to do with the relative ease one can get ones hands onto a substance. Pill-popping is most popular in rural parts of the USA, where illegal drugs are otherwise hard to come by. In Europe, it is more easy to obtain heroin than oxy or other such drugs. Hence, relatively speaking, more people are addicted to prescription pain meds in rural US, and more people are addicted to heroin in Europe. | [
"poemAs we have all seen, opioids are a prime contributor to our addiction and overdose crisis. In 2015, nearly two-thirds of drug overdoses were linked to opioids like Percocet, OxyContin, heroin, and fentanyl. [...] Americans consume more opioids than any other country in the world. In fact, in 2015, the amount o... |
What made the United Nations significantly different from the League of Nations? | One of the larger differences is that the League of Nations had no teeth, it had no military force of its own to physically put down an aggressor. The League of Nations provided that if an aggressor would not stop it could use military force but it having no force if it's own made it an empty threat.
A nation would have to volunteer it's military but that means that nation would be declaring war.
Members of the UN volunteer troops to UN command, that allows the UN to have teeth when needed( like in the Korean War)
_URL_0_ | [
"The principal forerunner of the United Nations was the League of Nations. It was created at the Paris Peace Conference of 1919, and emerged from the advocacy of Woodrow Wilson and other idealists during World War I. The Covenant of the League of Nations was included in the Treaty of Versailles in 1919, and the Lea... |
humanism | See /r/humanism
> Humanism is a democratic and ethical life stance, which affirms that human beings have the right and responsibility to give meaning and shape to their own lives. It stands for the building of a more humane society through an ethic based on human and other natural values in the spirit of reason and free inquiry through human capabilities. It is not theistic, and it does not accept supernatural views of reality
> -- International Humanist and Ethical Union, minimum statement on Humanism.
or
> I am a humanist, which means, in part, that I have tried to behave decently without expectations of rewards or punishments after I am dead.
> -- Kurt Vonnegut | [
"Humanism is a philosophical and ethical stance that emphasizes the value and agency of human beings, individually and collectively, and generally prefers critical thinking and evidence (rationalism and empiricism) over acceptance of dogma or superstition. The meaning of the term \"humanism\" has fluctuated accordi... |
Is it possible to melt snow (or whatever) with sound? | I was the guy who made that comment on the other post. While technically you could input enough energy to melt snow, the amount of energy contained in sound is very small.
Assuming you have 1 g of snow at 0 C, the amount of energy needed to melt that is 334 Joules. The sound from an entire orchestra only amounts to 1 W of energy. If you could somehow focus all of the energy from the symphonies music onto that ice, it would take 334 seconds to melt it, a full 5 minutes. And that's an entire symphony focused directly on a little more than a tablespoon of freshly fallen snow
Hope that answers your question. | [
"BULLET::::- Snowmaking was successfully tested for the first time by inventors Wayne Pierce, Art Hunt and Dave Richey at Milford, Connecticut, operating on the principle of blowing water droplets through freezing air to create snow.\n",
"All of these designs had numerous problems. In cold snow, ice would freeze ... |
Why do plants go "limp" after you pick them? | Plants use turgor pressure to maintain the rigidity of structures. When you pick the plants they lose pressure because they lose water. When they lose turgor pressure, they wilt. | [
"This is due to the ability of the plant's leaves to streamline and flex as the flow passes them thus lowering the resistance to flow. High velocity flows will cause some vegetation (such as grasses and forbs) to lay flat, where a lower velocity of flow through the same vegetation will not.\n",
"Weed pulling in g... |
how is monster energy allowed to claim some of their drinks contain zero calories, yet there's 4g of carbs per can? | The FDA allows numbers on Nutrition Labels to be rounded to the nearest whole number. If those 4g of carbs amount to less than half a calorie per serving, then the manufacturer is going to take advantage of the situation and put 0.
& nbsp;
As for the erythritol, the regulatory definition of what counts for the purposes of ingredients and nutritional labeling doesn't always line up with scientific definitions of the same. The law that talks about what products can make a "zero sugar" claim uses the wording "The food contains no ingredient that is a sugar or that is generally understood by consumers to contain sugars," and I imagine the manufacturer would claim that consumers don't generally understand sugar alcohols to be sugars.
& nbsp;
And for all this seems like the Labeling requirements are filled with loopholes, the FDA does try to press back against some of the more flagrant attempts by the industry to game the system. A few years back they issued a "stop doing that" notice to some manufacturers who were trying to disguise sugar on their ingredients labels by calling it "Evaporated Cane Juice". | [
"The caffeine content of most Monster Energy drinks is approximately 10 mg/oz (33.81 mg/100ml), or 160 mg for a 16 oz can. The packaging usually contains a warning label advising consumers against drinking more than 48 oz per day (16 oz per day in Australia). The drinks are not recommended for pregnant women or peo... |
With the recent horrifying earthquake that hit Japan, I'm curious: With today's technology and know-how, how difficult is it to predict an earthquake? | Prediction of catastrophic failures is basically impossible. Scientists have been making progress in being able to measure tectonic pressures in earthquake hotspots, but it is still just an indicator and not a full blown predictive theory. | [
"Twenty percent of the world's earthquakes are centered on Japan. The Japanese have been developing systems for early warning of earthquakes. For people of the city of Sendai who were testing the new earthquake warning system, they received a warning of the earthquake from the Meteorological Agency 16 seconds befor... |
why does cannabis make people sleepy after the high wears off? | CBN is a degradation product of THC and other cannabinoids. It is highly sedative.
There is also the issue of flooding the endocannabinoid system (which regulates our hormonal functioning and a number of other systems) with exogenous cannabinoids producing a temporary down-regulation.
If you don't want to get tired from smoking pot you can do two things: Smoke less and choose sativa dominant strains. Smoking less is the key really. In moderation cannabis will not produce the burnt out effect that heavy smokers are familiar with. | [
"The feeling of increased appetite following the use of cannabis has been documented for hundreds of years, and is known colloquially as \"the munchies\" in the English-speaking world. Clinical studies and survey data have found that cannabis increases food enjoyment and interest in food. A 2015 study suggests that... |
Are most living organisms today considered to be more complex than those, say, 70 million years ago? | No. First off complexity is a very hard thing to measure. Are ants more complex than non-hive insects? But most importantly most life on Earth (by any measure, number, mass, etc.) is single celled. So most life on Earth is just as complex as it was.
Now there may be a slight increase on some "average complexity" (assuming that term has meaning). There is some minimum complexity to to a living organism but no obvious maximum. Likely this is a bounded random walk and so there will be over time a slight movement from the wall.
| [
"In this hypothesis, the apparent trend towards more complex organisms is an illusion resulting from concentrating on the small number of large, very complex organisms that inhabit the right-hand tail of the complexity distribution and ignoring simpler and much more common organisms. This passive model emphasizes t... |
AskHistorians uses a 20-year rule to consider something to be "history." Is this a common rule among historians, or is it just a pragmatic measure to moderate this community? If so, how do scholars decide when something can be called "history"? | There's not a hard and fast rule among universities or historians in general to consider events beyond a certain number of years "history" vs. "current events." One only has to look at ~~Mao~~ Zhou Enlai's (probably apocryphal) comments on the effects of the French Revolution being too recent to analyze to see an example of this.
That said, we do have a 20-year rule fairly explicitly to avoid discussion of modern politics and modern events ... and as we inch closer to Jan. 1, 2021, we are semi-seriously considering extending the deadline to avoid 9-11 conspiracy theories.
[This rules roundtable](_URL_0_) explains the reasoning behind the 20 year cutoff, both on the pragmatic side of things (we don't want to endlessly analyze every past US administration in the light of the current one) and the philosophical (at what point do we actually feel we have enough remove from a topic to engage with it).
To sum up, 20 years is *arbitrary*, but we don't think it's *capricious* in what can and can't be discussed, and it functions pretty well in keeping modern politics out of the subreddit.
With somewhat more than 900,000 subscribers and slightly less than 40 mods, we can only do so much in the time we're given, and removing modern debates lets us focus on, well, history. | [
"[A]s a student of history I believe that those who govern today must ask ourselves how we will be judged 10, 20 or 50 years from now. Our applications of law must stand the test of time, because, over the passage of time, what we find tolerable today may be condemned in the permanent pages of history tomorrow.\n",... |
why do toddlers prefer to run everywhere instead on walking? it doesn't matter if it's indoor/outdoor or what distance. the first option is to run to get from point a to point b. | They have the energy and impulse control isn't developed in their brains yet. Won't happen til closer to 4. That's why kids have to be taught o walk safely places in preschool and kindergarten. | [
"Backward running is a less natural motion, but can be accomplished with some speed with practice. It is better to start out backward walking (also called retropedaling), which is relatively easy, and speed up. Like normal running, running up and down hills backwards will add an additional degree of difficulty.\n",... |
Why is it that a SSD (Solid State Drive) will eventually decrease in performance after a long period of time, but RAM doesn't? | Two differences that contributes to write speed degradation:
1) DRAM stores data as a charge in a capacitor. NAND flash used SSDs stores the data as a charge in a floating gate. In DRAM, the charges simply flow through the transistor into the capacitor. In NAND flash, writing requires tunneling electrons into the floating gate. This damages the insulation and eventually more time is needed to successfully write the bit.
The effects of NAND wear can manifest as higher error counts and SSD spare area decrease, both which can decrease SSD write performance. On the other hand, the difficulty in getting charges in and out of the floating gate is why SSDs are nonvolatile. DRAM must be refreshed constantly to keep the data which is why it needs a constant electric supply. The charge will leak out of the capacitor in the order of milliseconds.
2) DRAM has a more fine-grained addressing mechanism. Current SSDs can only be erased in "blocks," which is a large chunk of data. So in the course of usage, the SSDs controller will have to read a whole block, change data in a portion of the block in memory, erase the block, and then write. If fresh blocks are available, then it can skip the 'erase' stage and write the block. TRIM will try to minimize the churn involved in writing to a dirty block, but SSDs are always fastest fresh out of a complete wipe.
Flash can be much more compact than DRAM because it lacks the extra circuitry needed for addressing.
Generally speaking, SSD write performance will quickly degrade upon first use after a clean wipe and remain stable until the end of the line. | [
"SSDs based on NAND Flash will slowly leak charge over time if left for long periods without power. This causes worn-out drives (that have exceeded their endurance rating) to start losing data typically after one year (if stored at 30 °C) to two years (at 25 °C) in storage; for new drives it takes longer. Therefore... |
if atoms are over 99% empty space, how is it possible to create structures like spaceships that contain air and are airtight themselves while being surrounded by a vacuum?` | Yer not alone in askin', and kind strangers have explained:
1. [ELI5: I know that even though atoms are mostly empty space, we can't walk through walls because of electric fields, but if they're mostly empty, why isn't everything practically invisible? ](_URL_5_)
1. [ELI5: If atoms are 99% empty space, and everything is made of atoms, what are we actually seeing when we look at something? ](_URL_6_)
1. [ELI5: If atoms are 99% empty space, and if all matter is made up of atoms, why does solid matter appear ...well, solid? ](_URL_7_)
1. [ELI5: How do we see objects if the atoms that make it are 99% empty space? ](_URL_3_)
1. [ELI5:If atoms are 99.99% empty space then why some objects are solid? ](_URL_8_)
1. [ELI5: If atoms are 99.99% empty space, why aren't objects mostly empty space? ](_URL_10_)
1. [ELI5:Why if atoms are mostly empty space, we do not phase through matter. ](_URL_0_)
1. [ELI5: If atoms are mostly empty space, how do we make impervious or waterproof things? Shouldn't atoms be able to get through? ](_URL_11_)
1. [ELI5: If atoms are mostly empty space and don't even touch each other, why dont we just go right through? ](_URL_4_)
1. [ELI5: if atoms are almost completely empty space and I am made up of atoms, then what is stopping me from walking through walls if the empty space lines up right? ](_URL_9_)
1. [ELI5: If an atom is 99.99% empty space, why isn't all matter transparent, irrespective of density? ](_URL_1_)
1. [ELI5: If all matter is primarily made up of empty space, how can a knife cut a tomato? And why can't my hand go through wood? ](_URL_12_)
1. [ELI5: the reason why matter is solid, if the space between nucleus and electrons is so vast ](_URL_2_)
| [
"Although not currently practical, it may be possible to construct a rigid, lighter-than-air structure which, rather than being inflated with air, is at a vacuum relative to the surrounding air. This would allow the object to float above the ground without any heat or special lifting gas, but the structural challen... |
Is there any historical documentation of the Viking Blood Eagle execution? | More could be pried out of someone, but you might like to start with ['What are the chances the Vikings actually used the "Blood Eagle"? (previous highly rated answer has been deleted and other posts just link to the deleted answer)'](_URL_0_) by /u/mikedash .
This is not to discourage discussion. More questions, data, and debate are always welcome.
| [
"The blood-eagle ritual-killing rite appears in just two instances in Norse literature, plus oblique references some have interpreted as referring to the same ritual. The primary versions share certain commonalities: the victims are both noblemen (Halfdan Haaleg or \"Long-leg\" was a prince; Ælla of Northumbria a k... |
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