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If a nerve in your body is severed, can it grow back
together? | The axon of a nerve cell—the long part that travels through nerves and conveys signals—can indeed regrow. There are some caveats. (Boy are there caveats.)
* The axon gets all its cellular nutrients from the cell body.
* The part of the broken axon no longer connected to the cell body lacks nutrients and gets disintegrated.
* The axon has to regrow from the point of injury.
* The new axon sprout has to find its way through the same pathway of Schwann cells to get to its original target.
* The further it is from the target, the less likely it is to make it there.
* Also, regeneration occurs at about 1mm/day.
* Without the guidance of the old nerve structures like Schwann cells and whatnot, the axon ain't gonna make it.
* Plus, slicing through a nerve disrupts those supporting structures, too.
* And, when talking about a whole nerve, you need _all_ the axons to sprout and regrow into the proper places through the right maze of supporting nerve tissue (which has also been damaged).
* So in the case of having a peripheral nerve actually severed, regrowth is basically impossible; a little less unlikely if the nerve is "reattached" surgically. | [
"The nerve begins the process by destroying the nerve distal to the site of injury allowing Schwann cells, basal lamina, and the neurilemma near the injury to begin producing a regeneration tube. Nerve growth factors are produced causing many nerve sprouts to bud. When one of the growth processes finds the regenera... |
Did John the Baptist have a philosophy and how did it differ from contemporary mainstream Judaism? | He was most likely influenced at least to some degree by the Essene sect. These were Jews who were dissatisfied or disenfranchised by the Sanhedrin in Jerusalem. Mainstream Judaism would have been the theology of the sanhedrin. Johns theology would have been much more austere, and severe. He denounced them for their corrupt practices and lifestyle. You could simply say that his philosophy was a strict adherence to jewish law. Although he participated in the practice of baptism, which was something alien to mainstream judaism. So close to the Essenes, but not exactly. Though essenes were a little too political and no more about the spirit of the law than the Pharisees and Sadducees. | [
"Judaism, originated in Ancient Israel, is the foundation of Western morality. It impacted the West in a multitude of ways, from its ethics to its practices to monotheism; all of its benefits largely impacted the world through Christianity. The Hebrew Bible, authored by Jews in the Land of Israel from the 8th to th... |
if chihuahuas descended from wolves, would it be possible to reverse breed back to wolf? assuming you're starting with only chihuahuas and their new offspring? | Unfortunately, this is not possible.
Reason: Certain traits from wolves were not seen as desirable so they were not selected for. Thus they were eventually removed from the gene pool of breeding adults.
As time goes on and the pups get further from wolf with each generation, those traits become effectively unrecoverable without a mutation bringing them back or breeding with a dog type that does have the missing traits.
In the end, it's effectively a 0% chance due to how the traits have been selected for over the hundreds of thousands of generations we've had domesticated dogs. | [
"Apart from different types of Chihuahuas, breeders across the world started cross-breeding Chihuahuas with other dog breeds in order to create breeds of mixed traits. The result of cross-breeding Chihuahuas with other dog breeds such as Pomeranian dogs, Pembroke Welsh Corgis, Boston Terriers, Pugs and so on, usual... |
When did playgrounds first appear? | In landscape architecture circles, the Children's Playground in Golden Gate Park is widely referenced as the United States' first 'playground'. Built in 1888. | [
"In the 19th century, developmental psychologists such as Friedrich Fröbel proposed playgrounds as a developmental aid, or to imbue children with a sense of fair play and good manners. In Germany, a few playgrounds were erected in connection to schools, and the first purpose-built public-access playground was opene... |
how do personnel on submarines connect to the internet? | they wait till the sub comes to the surface or periscope depth and all the remaining data is transmitted. When submerged there is no internet access. You do without. | [
"A surfaced submarine can use ordinary radio communications. Submarines may use naval frequencies in the HF, VHF and UHF ranges (i.e. bands), and transmit information via both voice and teleprinter modulation techniques. Where available, dedicated military communications satellite systems are preferred for long dis... |
Why does squinting make my vision clearer? | First of all, realize that this only works for people who have vision problems due to incorrect focusing of the light. For our eyes to work properly, incoming light must be focused down to the retina. When this does not happen, either because light is focused in front of the retina (a condition called myopia or nearsightedness), or behind the retina (hyperopia or long-sightedness), objects are various distances will look blurry since the image will be defocused, as shown graphically [here](_URL_0_).
Now squinting can remedy this situation in two ways. One possibility is that the deformation created by squinting can partially offset the natural imperfection in the eye, and can thus bring the focal plane of the eye closer to the retina. This will effectively offset the initial optical aberration and allow you to see an imagine which is better focused and thus sharper.
The second possibility is more general, and results from the increase in depth of field created that results from decreasing the aperture (opening) through which light enters your eye. Because of this even an image that is equally out of focus will appear sharper because the higher depth of field means that the sharpness of the image decreases more slowly as you move away from the correct focus. To better visualize this second effect, take a look at [this series of images](_URL_1_). Notice that as you decrease the opening of the lens, an increasingly large part of the field of view appears clear. This exact same effect is at play when you reduce the size of the opening into your eye (you can get a similar effect from looking at objects through an index card with only a small opening allowing light through). | [
"Squinting is most often practiced by people who suffer from refractive errors of the eye who either do not have or are not using their glasses. Squinting helps momentarily improve their eyesight by slightly changing the shape of the eye to make it more round, which helps light properly reach the fovea. Squinting a... |
How do other baryons behave inside atomic nuclei? | > I've found quite a few interesting papers on hypernuclei which I am working through, but very little more easily digested material.
Yes, this is what you're looking for. It's a relatively young area of research, and obviously a lot of it is theoretical rather than experimental. We understand QCD very well, but it's hard to calculate the properties of many-body systems directly from QCD. That's why when you look in the literature, only very light hypernuclei have been studied so far. Instead of starting from QCD, one can use an effective nucleon-lambda interaction to do "ab initio" calculations of light hypernuclei, but then that requires an understanding of how nucleons interact with lambda baryons.
As for how other baryons behave in nuclei, they do basically the same thing that nucleons do. They undergo short-ranged interactions with nearby particles via the residual strong force. They occupy some set of orbitals, just like nucleons do. Although other baryons are not identical to nucleons, so there is no Pauli exclusion principle between nucleons and hyperons. The simplest observables that a theorist would try to calculate about some nucleus (hyper or otherwise) are binding energies, charge radii, etc. That's why you see theory papers calculating binding energies for hypernuclei. It may seem like a "boring" observable, but it's the first step for a nuclear structure theory to be able to calculate the binding energy. | [
"All the bound protons and neutrons in an atom make up a tiny atomic nucleus, and are collectively called nucleons. The radius of a nucleus is approximately equal to 1.07 fm, where \"A\" is the total number of nucleons. This is much smaller than the radius of the atom, which is on the order of 10 fm. The nucleons ... |
how come digital videos take up less memory than the sum of their individual frames. | Videos aren't stored as a series of images. It's closer to being stored as a series of **changes** in frames. Since most pixels on most frames are the same as the previous one, this saves an enormous amount of space. It doesn't work exactly like that, but that's an easy way to imagine how it could be much smaller. | [
"Video data may be represented as a series of still image frames. Such data usually contains abundant amounts of spatial and temporal redundancy. Video compression algorithms attempt to reduce redundancy and store information more compactly.\n",
"Digital video comprises a series of digital images displayed in rap... |
channel 3/4 and vcrs | Most older TVs didn't have video signal inputs like today. To send something to the TV, it had to be a modulated RF signal, just like an over-the-air broadcast.
Due to channel frequency spacing, most cities could only have a broadcaster on channel 3 *or* 4, but not both. So one of those channels was usually available for the VCR to 'broadcast' on. | [
"A \"channel 3/4 output\" was a common output selection for consumer audiovisual devices sold in North America that were intended to be connected to a TV using a radio frequency (RF) signal. This channel option was provided because it was rare to have broadcast channels 3 and 4 used in the same market, or even just... |
Is it possible to create heavier hydrogen isotopes? | The hydrogen isotopes all the way up to hydrogen-7 have been studied. You never hear about the unbound ones (4, 5, 6, and 7) because they're only really relevant to some niche areas of nuclear physics. They decay on timescales of 10^(-22) seconds. | [
"The most abundant isotope, hydrogen-1, protium, or light hydrogen, contains no neutrons and is simply a proton and an electron. Protium is stable and makes up 99.985% of naturally occurring hydrogen atoms.\n",
"The lightest isotopes were synthesized by direct fusion between two lighter nuclei and as decay produc... |
Which had a more significant effect on human history and society - Tea/coffee or alcohol? | Very brief answer:
If we're talking about these things as *commodities* rather than *substances*, by far coffee and tea.
Here's why. Starting in the mid seventeenth century, trade in coffee, tea, and sugar EDIT: and tobacco (the non-perishable fruits of Empire) revolutionized the English/British economy and created the wealth (and mercantile interests) upon which the Empire was built. | [
"In the late 17th century, alcohol was a vital part of colonial life as a beverage, medicine, and commodity for men, women, and children. Drinking was widely accepted and completely integrated into society; but drunkenness was not. However, most supporters of the movement were heavy drinkers themselves, according t... |
What is the significance of 232 degrees Celsius? | It may be due to the practical limitations of precipitation-hardened aluminum alloys. That temperature (or 450 °F) is commonly used as a reference point above which the precipitates become unstable and can redissolve. That creates an intrinsically weaker microstrucure, reducing the alloy's hardness and tensile strength. There is some discussion of this in the introduction to basic aluminum-silicon alloy technology in [this 2003 Conference paper](_URL_0_). (pdf) | [
"Absolute temperatures are stated in units of kelvin in his honour. While the existence of a lower limit to temperature (absolute zero) was known prior to his work, Lord Kelvin is known for determining its correct value as approximately −273.15 degree Celsius or −459.67 degree Fahrenheit.\n",
"The zero of the Cel... |
Why are there tight groupings of locations where meteorites were found? | Many meteorites are found in areas of Antarctica because the glaciers act like a conveyor belt: meteorites fall there at the same rate as elsewhere on earth, but the glaciers move them all into the same areas (typically up against a mountain range). The ice is then ablated away by wind, leaving the meteorites sitting on the surface. Because it's otherwise all ice in these locations, any rock you find on the surface of the ice *must* be a meteorite. It's as easy as driving around in a Skidoo and picking them up.
| [
"Meteorites are usually named after the village nearest their place of discovery. Those found in the deserts of Northwest Africa have mostly been called NWA (for Northwest Africa) followed by a serial number.\n",
"The different types of meteorites that originate from the asteroid belt cover almost all parts of th... |
Potato Batteries | Fact: Zinc is very poisonous.
Conjecture: I think the zinc ions end up in the potato electrolyte.
EDIT: Zinc is an essential part of our diet, in very small quantities. | [
"According to legend, the creation of the potato chip is associated with Saratoga Springs. The legend holds that a diner visiting the restaurant Moon's Lake House in Saratoga Springs in 1853 was unsatisfied with the texture of the fried potatoes he had ordered and sent them back to the kitchen multiple times in pro... |
why do a lot of professional gymnasts look underdeveloped/childlike? | Smaller frames (people) are more successful at performing physical feats that gymnasts practice. Larger people just don't make the cut because it gets extremely more difficult the taller and larger you get, to control your body in such extreme precise motions, balance, conditioning, etc. | [
"Top rhythmic gymnasts must have many qualities; balance, flexibility, coordination, and strength are some of the most important. They also must possess psychological attributes such as the ability to compete under intense pressure, in which one mistake can cost them the title, and the discipline and work ethic to ... |
why are the wages for certain occupations so lopsided relative to the benefit a person in such an occupation provides society? | Workforce supply and demand, multiplied by the ability for the person to make money for the company.
Those speculators have to make money based on knowledge to stay employed. If they are successful at this, they make a ton of money for the company, they in turn get paid pretty well.
High end sports work the same way.
| [
"Because workers are paid more than the equilibrium wage, there may be unemployment. Efficiency wages offer, therefore, a market failure explanation of unemployment, in contrast to theories that emphasize government intervention (such as minimum wages). However, efficiency wages do not necessarily imply unemploymen... |
what method have we used to accurately measure the distance to far away objects, for example, the andromeda galaxy and how sure are we of our method's margin of error? | [A standard candle is a class of astrophysical objects, such as supernovae or variable stars, which have known luminosity due to some characteristic quality possessed by the entire class of objects. Thus, if an extremely distant object can be identified as a standard candle then the absolute magnitude M (luminosity) of that object is known. Knowing the absolute magnitude, the distance D (in cm) can be calculated from the apparent magnitude m as shown in the formula below.](_URL_0_) | [
"By combining a galaxy's central velocity dispersion with measurements of its central surface brightness and radius parameter, it is possible to improve the estimate of the galaxy's distance even more. This standard yardstick, or \"reduced galaxian radius-parameter\", formula_30, devised by Gudehus in 1991, can yie... |
How was the mass of the neutrino discovered and confirmed? | There are three kinds of neutrinos (we call them 3 *flavors*). We now have clear evidence that there are neutrino oscillations -- that is, a neutrino of one flavor can turn into a neutrino of another flavor. This can only happen if there are different kinds of neutrinos with different masses. Therefore, based on the existence of neutrino oscillations, we can conclude that there are non-zero neutrino masses.
There are a couple of ways to see neutrino oscillations. The first indication of neutrino oscillations is that there were fewer electron neutrinos seen on Earth than we expected the Sun to produce, although initially, it wasn't clear if this was an oscillation effect or because we needed to understand the Sun better. But now we have a series of experiments -- both using neutrinos coming to the Earth from space and neutrino beams generated on Earth -- that show that a beam that starts out with one kind of neutrino can later have other varieties of neutrinos mixed in.
You might enjoy looking around [this site](_URL_0_). | [
"The supernova 1987A indicated that neutrinos might have mass because of the difference in time of arrival of the neutrinos detected at Kamiokande and IMB. However, because very few neutrino events were detected, it was difficult to draw any conclusions with certainty. If Kamiokande and IMB had high-precision timer... |
how does the pirate bay get away with all the copyright? | They don't, at all. The people behind TPB are currently serving sentences and got fined millions.
The reason the site is still live is that someone else is hosting it and the founders claim they don't know who. As it just contains the information needed to connect to somebody else with the file you want, it's actually a very small site to host. | [
"The Pirate Bay allows users to search for Magnet links. These are used to reference resources available for download via peer-to-peer networks which, when opened in a BitTorrent client, begin downloading the desired content. (Originally, The Pirate Bay allowed users to download BitTorrent files (torrents), small f... |
why is it a crime to attempt suicide? doesn't punishing a depressed person make them even more depressed? | Suicide is legal in almost all western countries.
However, law enforcement is generally compelled to prevent a suicidal person from killing themselves by any means necessary. | [
"Suicide is often seen as a means to escape from solitary confinement, especially amongst those who deal with deeper mental illnesses like depression. Depression is one of the most common reasons why inmates often kill themselves. Solitary confinement has been said to increase symptoms of those with mental health i... |
riot games had a walkout today because of the company's stance on "forced arbitration". what is forced arbitration? | In cases where it's an employer and workers, forced arbitration means that if the workers think the employer did something wrong, they have to let a paid decision maker say who's right and who's wrong. Then that's the end. They can't get a second opinion, they have to take it and keep working or go away for good.
The problem is that people have seen that these decision makers most always say the employer is right. It doesn't look fair, or it really isn't fair. This could be that decision makers get most of their business from employers and if the word gets around that they will tell the employer they're wrong, other employers won't hire them.
Employers know that they will likely win and tell workers that if they have a problem, they must handle it their way or they can't have a job. | [
"The Gamechangers is a British docudrama produced by the BBC. The programme depicts the story of the controversy caused by \"Grand Theft Auto\", a video game series by Rockstar Games, as various attempts were made to halt the production of the games. Directed by Owen Harris and written by James Wood, the film centr... |
What is the history of egalitarian thought? | Your post reminded me of [an article I found](_URL_0_) recently about equality in hunter-gatherer societies. It addresses why some hunter-gatherer societies were more equal than others in similar circumstances. This doesn't necessarily concern the history of egalitarian thought but does offer a perspective on prehistoric disparities. | [
"Modern egalitarianism is a theory that rejects the classic definition of egalitarianism as a possible achievement economically, politically and socially. Modern egalitarianism theory, or new egalitarianism, outlines that if everyone had the same opportunity cost, then there would be no comparative advances and no ... |
why is america so much more homicidal than most other industrialized nations? (like canada, the uk, germany, france, etc) | There are numerous factors, and it could be any one of the following, or some combination of them, or some other factor I forgot to mention (not these are not my personal opinions, these are proposed factors. I am just listing them, I am not saying I disagree or agree with them):
Gun culture
Racial, social, and monetary inequality creating social disparity
Inconsistent and under-prioritized education system
for-profit prisons and other corporate interests causing skyrocketing incarceration rates, taking minor offenders and "[prisonizing](_URL_0_)" them- creating more violent people. | [
"According to Peter Knight, throughout most of the 18th and 19th centuries, the United States rarely experienced antisemitic action comparable to the sort that was endemic in Europe during the same period.\n",
"International reaction was largely unfavorable against the United States. The British and French, who h... |
are mental health issues more prevalent in modern times or did people in the past just not get diagnosed? | There are arguments for both sides but we do have a lot more distractions and focuses than ever before in history. Anything you could possible want to know is at your fingertips, obviously excluding things which haven't been discovered yet. | [
"In America, half of people with severe symptoms of a mental health condition were found to have received no treatment in the prior 12 months. Fear of disclosure, rejection by friends, and ultimately discrimination are a few reasons why people with mental health conditions often don't seek help.\n",
"\"\"Parity o... |
Do we know of any historical Native American martial arts? | In the Puget Sound, wrestling is mentioned in Puyallup-Nisqually by Marian Smith along with a brief account of a contest between a White strongman from a circus, and a Puyallup in which their techniques are vaguely contrasted.
Wrestlers weren't allowed to change holds during the match and only appeared to use one hold.
> "The men faced each other, the right arm of each passed over the left shoulder of the other, the left arm encircled the right side of the opponent's body at the waist and the hands were clasped together at the back. Before beginning, there was often argument about the exact position of the shoulders and arms. This hold was maintained until the opponent was downed or, if it was broken during the struggle, a new start was made. The wrestlers shifted ground constantly, since foot-work played an important part in maintaining equilibrium. One man tried to lift the other straight in the air of bend his opponent forward across his hip. A man thrown or taken off his feet was conquered. Wrestling was called 'skwádgwıs'*."
The account of the wrestling match is quite straightforward: A prominent Indian wrestler had wrestled a wrestler from a circus and both had managed to flip the other using holds the other wasn't familiar with, and the match ended amicably. No other detail is provided.
There are the occasional references to martial arts in terms of warfare and weapons, where techniques for specific weapons are given. However, they are unfortunately far and few in between, and mostly refer to a coup de grâce.
*Modern Xʷəlšucid would be "skʷadgʷis". | [
"Filipino martial arts (FMA) () refer to ancient Indianized and newer fighting methods devised in the Philippines. It incorporates elements from both Western and Eastern Martial Arts, the most popular forms of which are known as Arnis, Eskrima, and Kali. The intrinsic need for self-preservation was the genesis of t... |
If I donate blood consistently, and always at the safest time since the last donation, will my body increase its ability to produce blood to adapt to the environment? | Blood cell production is called [Erythropoiesis](_URL_0_) and is triggered by O2 levels in the kidneys. When you give blood your body signals for more to be made. As soon as it has made enough to get your O2 levels back up, the process slows back down to maintenance levels.
Giving blood has no impact on your ability to produce blood. It only triggers production for the immediate need. How your body functioned the first time you gave blood is the same as how it does now. | [
"Research published in 2012 demonstrated that repeated blood donation is effective in reducing blood pressure, blood glucose, HbA1c, low-density lipoprotein/high-density lipoprotein ratio, and heart rate in patients with metabolic syndrome.\n",
"In patients prone to iron overload, blood donation prevents the accu... |
massive earthquake coming in the nw | There's a history of large earthquakes in the region that can be explained by tectonic plate movements. It's been so long since the last one (1700 CE) that, as time goes by, it becomes more likely that it will happen again.
The mechanism is called "subduction": one plate is sliding under another. In the [Cascadia Subduction Zone] (_URL_0_), The Juan de Fuca Plate under the Pacific is sliding under the North America Plate. The latter is being bent down due to friction, and there will come a time when the force resisting the bending will overcome the friction, and the plate will spring back up, releasing a enormous amounts of energy.
As with many such things, it's *probabilistic*: energy is being stored in the plate over time, so the longer without an earthquake, the likelier it becomes, and the expected magnitude will be higher. The latest predictions I can find for the next 50 years are roughly 37% chance of Mag. 8.0 or higher and 10-12% of Mag. 9.0 or higher. | [
"The 1993 Scotts Mills earthquake, also known as the \"Spring break quake\", occurred in the U.S. state of Oregon on March 25 at 5:34 AM Pacific Standard Time. With a moment magnitude of 5.6 and a maximum perceived intensity of VII (\"Very strong\") on the Mercalli intensity scale, it was the largest earthquake in ... |
Is it possible for the lens of a camera to capture a photo with more precision than perfect vision in a human eye? | Interesting article [here.](_URL_0_)
The main point is that maximum human visual acuity in the eye is a rather small area in the center of vision (the size of a coin held at an arm's distance away), as we move further away towards the peripheral vision it gets progressively worse, but because of brain processing (making eyesight work like a video camera) it feels like our eyesight is better than it actually is. | [
"Its in-lens image stabilisation can be combined with in-camera-body image stabilisation in order to allow shots without a tripod, despite the very small field of view (between 12° and 3.1°). Even at maximum focal length it is possible to get sharp images taken free-hand with exposure times down to a tenth of a sec... |
how does a human body never get short of sperms and cells needed for reproduction? | Well the human body does, in effect, get short on both as we get older. Rather the production slows down. Biologically, we are more likely to mate in younger years. So when we are younger, and of course we have came to mating age, our body ramps up production of hormones need to produce the "seeds" of life (sperm/eggs). That said, the hormones sent to the testicals or overies tells them to produce sperm/eggs. When you get turned on, your body is sending signals that matting is going to happen, hence the need to orgasm increasing. Your body knows it's mating time and starts to prepare for it. The human body (for the most part) wants to procreate. It's a matter of thousands of years of survival kicking in. No offspring, no furtherance of the species.
As we age, that drive decreases as our body knows the likely hood of mating slims down. Evolution has programmed the body to not waste those chances, has it knows the likely hood of product of offspring has decreased vastly. | [
"Sperm cells are carried out of the male body in a fluid known as semen. Human sperm cells can survive within the female reproductive tract for more than 5 days post coitus. Semen is produced in the seminal vesicles, prostate gland and urethral glands.\n",
"Sperm undergoes a process of natural selection when mill... |
what makes pepsi max bad, if it contains no fats, sugars or salts? | Even without sugar, Pepsi Max contains fairly significant amounts of phosphoric acid. While there's far too little of it for it to be actively poisonous, drinking any acidic liquid erodes the teeth over time. In this manner, Pepsi Max is better than normal Pepsi (which combines the acid with sugar, itself bad for dental health) but still not great to drink large amounts of.
It also contains artificial sweeteners, specifically aspartame. You could literally spend years reading studies on the health implications of these - none of them are in any way conclusive, but it's been *very* heavily studied. Studies have, at various times, found links to everything from Alzheimer's disease, to brain tumours, to depression - but in many cases the studies were small, overhyped, and haven't been reliably reproduced. If there was a strong scientific consensus that it was bad for you, it would have been banned by now - but it hasn't, because the main body of research seems to suggest it's very safe in anything even resembling normal amounts. This is likely what you've been told about, but there's a lot more internet hysteria about it than there is actual evidence.
It's not a perfect thing - it can still stain your teeth, and it can still erode them by its acidity. But drunk in moderation, it's definitely a better option than full-sugar soda. | [
"Pepsi Zero Sugar competes in the energy drink market, as is implied by it being marketed as an 'Invigorating Cola.' Compared with other common energy drinks, Pepsi Zero Sugar gives the consumer a relatively low dose of caffeine. Pepsi Zero Sugar provides 5.75 mg caffeine per 30ml, while Red Bull provides 9.64 mg/3... |
Could photons be unstable? | Based on the experimental limit on the mass of the photon (about 10^-45 grams) and the fact that the cosmic microwave background spectrum looks thermal, **if** photons are unstable and can decay into the lightest neutrino, they must have a lifetime of longer than three years in their reference frame, extended to longer than the current age of the universe because of relativistic effects.
_URL_0_ | [
"Much research has been devoted to applications of photons in the field of quantum optics. Photons seem well-suited to be elements of an extremely fast quantum computer, and the quantum entanglement of photons is a focus of research. Nonlinear optical processes are another active research area, with topics such as ... |
why are all of uber and lyft's commercials aimed at getting people to work for them instead of use their ride sharing apps? | From what I've heard they've had a hard time keeping drivers. No insurance or benefits and the pay isn't that great. So they advertise to get new drivers because the ones they have don't do it for that long or consistently. Basically they have more people requesting rides or wanting to request a ride than there are drivers. So they are missing out on a bunch of money.
It's like if a store only has 10 gallons of milk but 50 people that want to buy the milk, the store is gonna go get more milk before they tell people to buy more milk | [
"BULLET::::- Regulations that cover traditional taxi companies but not transportation network companies can put taxis at a competitive disadvantage. Uber has faced criticism from taxi drivers worldwide due to the increased competition. Uber has also been banned from several jurisdictions due to failure to comply wi... |
hologram concerts. what's that about? | A holographic projection is done to to create the illusion of a person being there when they are not (for example when they are dead)
_URL_0_ | [
"In Korea, a huge hologram performance was held in 2014, involving Psy, Big Bang and 2NE1, which was possible because \"Klive,\" a hologram concert hall funded by the Ministry of Science, ICT and Information and Communication and KT, was created. Their performance at the 1,653-square-meter hologram concert hall was... |
Can someone explain why some atoms form metallic bonds? | That's kind of a difficult question to answer. Not because we don't know, but because we _do_ know quite a lot. So you can give a lot of answers at different 'depths', and also explain it in very different terms using different models. Because this is on the boundary between solid-state physics and inorganic chemistry, and they look at things differently and use different models, even if they involve the same physics and principles.
To give the simplest explanation I can, metallic bonding isn't really different from any other chemical bonding. One of the ways you can view it (a chemical viewpoint) is that the d-orbitals (in the transition-metals) overlap and form bonds, and so the electrons become shared. Since all these bonds are identical or near-identical the bonding electrons are shared between _all_ the atoms. So the electrons can move through the material, which explains a lot of their properties, like how they conduct electricity. Basically any substance (doesn't actually need to be a metal) starts acting 'metallic' if its electrons become "delocalized" throughout it.
You might turn the question around and wonder why _everything_ isn't metallic (most elements are). That's because the electrons in those elements/compounds are localized to their specific bonds. The reason for that, is that there's a large energy difference between the energy levels of the orbitals that make up the bonds, and the vacant orbitals to which the electrons have to move to be able to get around. In chemistry terms, there's a large difference in HOMO/LUMO (highest occupied molecular orbital and lowest unoccupied) , in solid-state physics terms, there's a "band-gap". If you have a band-gap, it's not a conductor, and the electrons stay around 'their' atoms.
This all gets a bit complicated since the energy of the orbitals also depends on the neighboring molecules or environment. (in chemistry there's a whole theoretical model called ligand-field theory to deal with how that works with transition metal atoms) So the distinction between metal and non-metal is more about whether it's metallic under 'ordinary' conditions. For instance, hydrogen isn't a metal, but is believed to become metallic under extreme pressures. Tin has two forms, one of which is metallic (white tin) and one of which is not (grey tin), depending on how its crystal structure.
So a 'metallic bond' doesn't really qualitatively describe a distinct kind of chemical bond. (actually, the more you go into detail, the distinctions between all kinds of bonds becomes blurred) It generally refers to the bonds formed between d-orbitals in transition metals, which typically have vacant orbitals with the same energy, and thus delocalized electrons and metallic behavior. Whereas compounds between metals and non-metals, such as metal oxides, aren't metallic, because the s or p orbitals of the non-metal are doing the bonding on their part, which means you usually have a band gap. So those aren't "metallic bonds" even though they're bonds to metal atoms. On the other hand, a conducting polymer like polyacetylene (which has delocalized bonds between p-orbitals), _is_ metallic even though it's not a metal, nor has metallic bonds in the usual sense, nor the material properties we associate with metals.
| [
"The forces between the atoms in a solid can take a variety of forms. For example, a crystal of sodium chloride (common salt) is made up of ionic sodium and chlorine, which are held together by ionic bonds. In diamond or silicon, the atoms share electrons and form covalent bonds. In metals, electrons are shared in ... |
radioactive fallout | In addition to releasing enormous amounts of energy, a nuclear blast will spread radioactive elements from the bomb throughout the nearby area, and cause some local materials to become radioactive.
Some of these radioactive elements will have very short half lives and disappear quickly. Some will have very long half lives, and not release much radiation over time.
But some are like strontium-90. It has a half life of 29 years, so it sticks around for a long time, but it is radioactive enough to be dangerous. What's worse, strontium accumulates in your bones and teeth, so if it is in the environment, people wind up ingesting it and carrying it around for the rest of their lives. | [
"This radioactive dust, usually consisting of fission products mixed with bystanding atoms that are neutron activated by exposure, is a highly dangerous kind of radioactive contamination. The main radiation hazard from fallout is due to short-lived radionuclides external to the body. While most of the particles car... |
could a mother and baby ever survive an ectopic pregnancy? | Yes, it's possible. It's not common, but there have been cases. I think it depends largely on where the embryo attaches. Most ectopic pregnancies are in the fallopian tubes, which don't stretch and basically can't support a pregnancy. As the baby starts growing, you start bleeding and if it's not treated, it can be fatal.
Some ectopic pregnancies have been carried to term if they attach somewhere in your abdomen. It still doesn't have a great success rate, but it has happened. Obviously they have to be delivered surgically as there is no way out otherwise. But there are living children who were ectopic.
Now, I also have a memory of my nursing professor telling me one woman somewhere in Europe carried a baby to term in her fallopian tube and it was a medical marvel and yada yada, but I can't find anything online about it, so who knows if my memory (or my teacher's memory) was correct. | [
"When ectopic pregnancies are treated, the prognosis for the mother is very good in Western countries; maternal death is rare, but most fetuses die or are aborted. For instance, in the UK, between 2003 and 2005 there were 32,100 ectopic pregnancies resulting in 10 maternal deaths (meaning that 1 in 3,210 women with... |
Do people who are constipated absorb more nutrition from the food they eat because it spends more time in their digestive tract? | Almost all of the nutrients in food have already been absorbed before it reaches the lower intestines/colon, etc. So no. | [
"The absorption also largely depends on gastric pH. People have varying gastric pHs on empty stomachs, and thus absorption from one person to another can vary wildly when taken without food. Generally, the absorption in the GI tract is poor due to albendazole's low solubility in water. It is, however, better absorb... |
Is there evidence that mankind has already polluted the deepest parts of the ocean? | Polluted in what way? Oceanic acidification has the potential to significantly change the chemical make-up of our oceans. And because our oceans act as a buffer for atmospheric CO2 levels, it will not only be our oceans that are affected. It's a problem and is most definitely being facilitated by humankind.
| [
"BULLET::::- 15 November – A study led by Newcastle University finds that sea life in some of the deepest parts of the Pacific Ocean – as far down as 11 km (7 miles) – is contaminated with plastic pollution.\n",
"A recent survey of global ocean health concluded that all parts of the ocean have been impacted by hu... |
anxious arousal | That is a psychological use of the term "arousal", not a sexual use of the term. In discussing mood, arousal is general physical and psychological activity, as contrasted with a depressed mood.
Take the example of a person with fear of public speaking. This person can go from a calm state to a highly aroused one when they hear that instead of listening to their boss give a presentation to the whole company, they are giving the speech in her place. Their heart will beat fast, their skin might flush, as though a lion was about to eat them even through there is no lion. They have an anxious arousal response to public speaking.
It's confusing to reuse arousal for this, though many of the symptoms of sexual arousal are similar, but in the psychology community the terms are more narrowly defined than in English overall. Nobody would confuse being eaten by a lion and sex, so there's no grammatical confusion. | [
"The excitement phase (also known as the arousal phase or initial excitement phase) is the first stage of the human sexual response cycle, which occurs as a result of physical or mental erotic stimuli, such as kissing, making out, or viewing erotic images, that leads to sexual arousal. During this stage, the body p... |
why do i see weird, brown, kaledescope-like shapes when i close my eyes and push on my eyelids? does everyone else see the same thing when they do this? also, does this cause any damage to one's vision? | The thing you're seeing is a phenomenon called 'Phosphene' - which is when you see light without light actually entering your eye. When you put pressure on your eyes, it stimulates the retina which causes the weird colour patches you see. So yeah - everyone sees them, and no, they're not damaging.
_URL_0_ | [
"Eyelid fluttering artifacts of a characteristic type were previously called Kappa rhythm (or Kappa waves). It is usually seen in the prefrontal leads, that is, just over the eyes. Sometimes they are seen with mental activity. They are usually in the Theta (4–7 Hz) or Alpha (7–14 Hz) range. They were named because ... |
how does taste work? why does a person a like spinach, but person b does not? | There could be a million reasons why someone doesn't like a food; maybe they ate it while feeling sick one time, and learned to associate the sickness with the taste. Perhaps they were made to eat something all the time as a kid so they're just totally opposed to eating it as an adult. The reasons could be either mental or physical (conditions such as [anosmia](_URL_2_) affect a person's ability to smell, and therefore taste, and cigarette smoking has a similar but much less severe effect), and there are too many potential options to explain them all in detail.
One relevant issue here, however, is that several aspects of taste are actually determined genetically. Some [bitter foods](_URL_0_), such as grapefruit, only taste bitter to people who have the correct genes to taste such a flavour. So what you like, or don't, might have been determined for you at birth.
A relevant side-note: there is a fruit, known as [miracle fruit](_URL_1_), which temporarily blocks the sour receptors on the tongue, which basically completely changes the way you taste food. Lemons are sweet, beer tastes like chocolate milk, and so on. You should try to acquire some, and see how it affects you; it essentially allows you to taste things as if you were a different person and it wears off after a short time. | [
"Conditioned taste aversion occurs when an animal associates the taste of a certain food with symptoms caused by a toxic, spoiled, or poisonous substance. Generally, taste aversion is developed after ingestion of food that causes nausea, sickness, or vomiting. The ability to develop a taste aversion is considered a... |
nelson tv ratings - how do they work? | Nielsen originally started as a radio ratings company. When they started doing television ratings, they had people keep journals of what they watched. They would record what they watched, when, and who watched it (what members of the household). The journals had a TV guide like format. Many smaller cities still use these journals and Nielsen spends tons of resources extracting data from them. Now, many Nielsen homes have boxes which keep track of viewing habits. Most of them you can enter from a menu the people in the house who are watching the show. There's also "guest" options. Nielsen is currently developing technology that can recognize the faces in a room to see who is watching.
So that's how they record ratings. But who are the recorders? Nielsen spends a great deal of time picking their reporters. They are trying to compose a mixed demographic that represents the variety of people in the United States. For example, if 5% of the United States is elderly Hispanic people, 5% of their recorders will be elderly Hispanic people. They spend a good deal of time keeping these ratios appropriate as they can be challenged and they want their data to be as accurate as possible.
Once they collect the viewing habits of all these people, they aggregate the data and produce detailed reports which are used to develop ratings. By extrapolating the data you can get a good estimate of how many people in the United States tune in to watch a show. These reports are then sold to companies, typically advertising companies or TV networks, and ultimately help determine what sort of advertising will be done on what channels during what shows and how much those advertisements cost. For example, both the company airing the super bowl and a company with a product buy the report concerning the super bowl. The company with the product notices that 30 million 30-40 year old white men watch the super bowl. This is the target demographic of their product. They decide they wish to advertise during this event. However, at the same time, the company who is showing the Super Bowl knows how many people watch it and know that they can charge ridiculous rates for advertisements during the Super Bowl because of demand.
Fun fact: the reports DO include data on shows that aren't watched live. If you use a journal you'd record you watched something on Tivo. I'm trying not to reveal too much about what I know about their products, but they even report on how many days after the live date you watch something.
While I'm not sure about the other sources for shows you mentioned, I feel quite sure Nielsen reports on them as well. They report on just about anything that could have advertising. They even report on how many people they estimate look at billboards.
Source: My senior project in college was for Nielsen. We visited their Tampa facility and got a tour and learned about the company. We were helping them with a new reporting tool they were releasing. It was explained to us where the report data comes from.
teal deer: kylenolforkids explains how Nielsen ratings work at a [5] | [
"In the following summary, \"Rating\" is the estimated percentage of all televisions tuned to the show, and \"Share\" is the percentage of all televisions \"in use\" that are tuned in, \"viewers\" is the estimated number of actual people watching, in millions, while \"ranking\" is the approximate ranking of the sho... |
When the Soviet Union dissolved, did Russia try to claim more of the area near the Black Sea? | Russia never made any official attempt to claim back any land from any of the Soviet Republics as or after they became independent, even in areas dominated by Russophones, such as Narva in Estonia, Transdniestr in Moldova, or Donetsk in the Ukraine.
What they did do was encourage the creation of super-autonomous areas in these regions, with varying success levels. The attempted autonomous area in Narva as D.O.A, while the one Transdniestr succeeded in setting up an independent (although not internationally recognised) state. This also happened in areas containing minorities that were not ethnically Russian but were historically pro-Russian (such as Ossetia and Abkhazia in Georgia).
I've heard that Russian nationalist groups often advocate Russia annexing some such areas, notably the Crimea, which is mostly Russian, already has considerable autonomy within Ukraine, and is home to major Russian military assets such as the Black Sea fleet. The Russian government, though, has never made any concrete or even symbolic moves in this direction.
Source: The politics of security in modern Russia, Mark Galeoti
Also I believe Lara Ryazanova is about to publish a book on the subject of Russians in the 'near abroad'. | [
"With the Treaty of Brest-Litovsk, Soviet Russia had given up Estonia, Latvia, Lithuania, Poland, Belarus and Ukraine, enabling those territories to develop independently from Russian influence. Germany's intention was to turn these territories into political and territorial satellites, but this plan collapsed with... |
what is the piece of equipment that's always suspended from the crane at an inactive construction site (ie, during nighttime)? why does it have to be suspended? | Thinking this might be a portable generator or welding unit. Usually moved from a tow hitch, would be pretty easy to drive up pop the lock and drive off with it. | [
"This is most common type of overhead crane, found in many factories. These cranes are electrically operated by a control pendant, radio/IR remote pendant, or from an operator cabin attached to the crane.\n",
"The building also contains a manually operated overhead crane. Transverse movement of the crane is achie... |
Freezing Water in a Cup | Water is a much better conductor. Much like how you can get hypothermia in warm water fairly quickly while in the same temperature of air you would fair much better. The water you added was above freezing. This conducted warmer temperatures into the existing ice faster then the air could conduct colder temperatures into the water/ice combo. | [
"Chipped ice in water is the standard for the freezing point of water, 0 °C (32 °F). Ice made from water can be 0 °C, or a much lower temperature. The agitation of the machines is partially to keep the water from freezing solid. Some of the drinks have additives to make the freezing temperature of the mix lower, so... |
the seemingly high inflated price of aud versus other currencies for goods and services. | I think many of you are not understanding his question.
A good example of this is on Steam, a digital copy of a video game might cost 40 USD in American, but 80 AUD in Australia, which translates to ~60 USD.
Another recent example for me was purchasing an Oculus Rift (Virtual Reality Headset), it cost 600 USD for Americans, and 650 USD (in USD, not even in AUD) for Australians. Shipping/taxes/import fees/etc was added on top.
I believe its just because our average income is higher, and they think we can afford it, and want more money. | [
"The G10 currencies are ten of the most heavily traded currencies in the world, which are also ten of the world's most liquid currencies. Traders regularly buy and sell them in an open market with minimal impact on their own international exchange rates.\n",
"According to data from EvaluatePharma and published in... |
what do the focal length numbers mean for camera lenses? | You've used a zoom lens before, yes? If you have, you would notice that the lens moves as you adjust the focal length; as shown in [this diagram](_URL_0_), the distance from the lens to the camera's sensor determines the focal length. | [
"As with other types of camera lenses, the focal length is usually expressed in a millimeter value written on the lens, for example: a 500 mm lens. The most common type of long-focus lens is the telephoto lens, which incorporate a special lens group known as a \"telephoto group\" to make the physical length of the ... |
why under certain lights do my hands and feet look like they're moving in "slow motion"? | Yer not alone in askin', and kind strangers have explained:
1. [ELI5: Why does really fast flashing lights make you see slow motion ](_URL_0_) ^(_17 comments_)
1. [ELI5: Why do strobe lights make the world seem like it's in slow motion? ](_URL_1_) ^(_4 comments_)
1. [When strobe lights flash, why does everything appear to move in slow motion? ](_URL_2_) ^(_1 comment_)
| [
"When a scene includes both stationary and moving subjects (for example, a fixed street and moving cars or a camera within a car showing a fixed dashboard and moving scenery), a slow shutter speed can cause interesting effects, such as light trails.\n",
"In some cases, it is possible to see flicker at rates beyon... |
if i pirate something i've legitimately bought, and still have (somewhere), am i breaking the law? why or why not? | There are lots of people giving opinions on this here. You must absolutely make a distinction between opinions and the law. Your not disapproving of an action does not actually make it legal. There are plenty of things that some - most - people do not necessarily think are immoral, that some - most - people don't believe cause harm, and yet are still illegal.
Creating copies of someone else's work is illegal, unless the creator has permitted you to do so - explicitly with a license, or implicitly by putting it into the public domain - or unless the creation of the copy falls under one of the fair dealing / fair use exemptions. These vary from country to country, but generally include things like copies/adaptations for the purposes of parody, the copy your DVD player briefly has to make in its memory while playing the DVD (yes, that is the kind of detail the law [has to explicitly allow](_URL_1_) ) etc. They may also differ by the kind of thing it is (the UK's CDP 1988 has lots of fair use clauses for musical/literary/artistic works that explicitly do not apply to computer programs, for instance).
So your question comes down to whether, in your territory, the creation, by downloading, of a copy of the particular material you are pirating is permitted in the case where you own it in another format / on other media - whether it falls under a fair dealing clause. (Seeding is a separate question - you're creating more copies, for distribution to others!)
This matter of law is entirely separate from whether it is moral, whether we approve, whether the copyright holder minds (provided they do not say publically that they permit you to do that) or whether the download harms anyone (except, in some jurisdictions, if you do get sued, the damages will depend on actual harm the copyright holder can show you've done them, so if you've done them no harm all they can do is tell you to cease and desist).
So you'll have to give more details about your situation to get a definitive answer.
-
EDIT: NorthernerWuwu correctly points out [below](_URL_2_) that my use of "illegal" throughout this thread is wrong - copyright infringement, at least in most places when not performed on a [commercial scale](_URL_0_), is **actionable** not illegal; you'll get sued but not arrested. Small comfort, natch, and I stand by the statement that the law has something to say about it. | [
"The US had originally planned to charge the terrorists with piracy under its Criminal Code of 1909 \"whoever, on the high seas, commits the crime of piracy as defined by the law of nations, and is afterwards brought into or found in the United States, shall be imprisoned for life.\" But this would have been proble... |
As Carbon Dioxide is odorless and tasteless, why then does mineral water taste bitter? | When carbon dioxide is dissolved in water, it forms [carbonic acid](_URL_0_). The more carbon dioxide dissolved, the more carbonic acid forms (via what's called an equilibrium relationship). Our taste buds interpret acids as a sour flavor.
That said, real mineral water (from a true spring) can have a variety of other gases and minerals dissolved in it that might be responsible for other flavors. | [
"By itself, carbonated water appears to have little impact on health. While carbonated water is somewhat acidic, this acidity can be partially neutralized by saliva. A study found that sparkling mineral water is slightly more erosive to teeth than non-carbonated water but is about 100 times less erosive to teeth th... |
pros and cons of a single member llc. | Lawyer here! The Limited Liability Company (LLC) has been the go-to entity for small businesses for the last couple of decades, and for good reason. It provides a lot of the same benefits as a corporation, while remaining very flexible and easy to manage.
**What is an LLC?**
An LLC is a legal entity just like a corporation or a partnership. It can sue and be sued, it can own property, it can conduct business, etc. It is owned and (usually) managed by "members." (I'm not being cute here, "member" is a term of art. A "member" of an LLC is analogous to a shareholder of a corporation.)
**Pros/Cons**
The pros are similar to those of a regular ol' corporation. LLC's offer:
* *Limited liability.* If the LLC is sued, liability is limited to whatever assets the LLC itself owns. The assets of the members aren't at risk (beyond whatever they've invested into the LLC). (There's an exception to this called *piercing the corporate veil,* which I'll discuss below.)
* *Pass-through tax status.* For *single-member* LLC's, the company's income "passes through" to you for tax purposes, *i.e.* it's just treated as your income. It's not taxed separately. That makes it easy to deal with come tax season, and in some cases, it's cheaper.
* *Indefinite existence.* The LLC will continue to exist until it dissolves for some reason.
* *Easy to establish and manage.* To start an LLC, you just have to fill out a handful of documents and file them with your state's Department of State/Division of Corporations. The filing fee is usually $50-150. LLC's are managed by private contract, which is usually called an "operating agreement."
For small businesses, the cons are pretty limited for small businesses. That said:
* *Transferability of interests* can be harder to accomplish in an LLC. If someone wants to buy in or cash out their stake in an LLC, that usually has to be done by a meeting and vote and/or a modification of the operating agreement. That can be an onerous process. To transfer interest in a corporation, on the other hand, you can generally just buy and sell stock without having to bug every other shareholder in the business.
**The Operating Agreement**
The operating agreement is more or less the bylaws of how the company is governed. You don't actually need one to register or run an LLC, but that said, *you should certainly have one.* Why?
* Banks will want to see your operating agreement before they'll do business with you. Loans, checking accounts, credit cards—they generally won't give you these things unless you show them an operating agreement.
* Having *and observing* your operating agreement will help you avoid "veil piercing," as discussed below.
**Piercing the Veil**
LLC's offer their members a shield from personal liability. But in court, that shield can be destroyed (and your personal assets will be at stake) under a doctrine called "piercing the corporate veil." Essentially, that doctrine provides that if the managers are just using the LLC as an alter ego of themselves to help limit their liability (as opposed to running a legitimate business), then they're not entitled to the benefits of the LLC. To determine whether the veil should be pierced, a court will consider a lot of facts, such as:
* Whether the LLC is sufficiently capitalized.
* Whether the LLC is sufficiently insured.
* Whether the LLC was actually conducting some kind of real, legitimate business.
* Whether corporate formalities of the LLC were observed (e.g., annual meetings held, minutes recorded, financial records kept).
Of these, I've seen a lot of litigation over the last factor lately, so it's something that's getting more and more attention. Having an operating agreement and actually sticking to it will go a long way in protecting you when it comes to this issue. It'll be hard to convince a court that you were operating an actual standalone business without some kind of written records. | [
"A limited liability company (LLC) is the US-specific form of a private limited company. It is a business structure that can combine the pass-through taxation of a partnership or sole proprietorship with the limited liability of a corporation. An LLC is not a corporation under state law; it is a legal form of a com... |
Are sesamoid bones present at birth? | Sesamoids develop independently within the tendons in areas of mechanical stress, meaning they are not fragments of other bones. They develop from cartilaginous nodules. I believe they ossify completely during childhood and thus are not present at birth as bone.
References: [One](_URL_1_) and [two](_URL_0_). | [
"The sphenoid bone is an unpaired bone of the neurocranium. It is situated in the middle of the skull towards the front, in front of the temporal bone and the basilar part of the occipital bone. The sphenoid bone is one of the seven bones that articulate to form the orbit. Its shape somewhat resembles that of a but... |
what are the scientific reasons why consanguineous marriage causes disabilities, malformations and congenital anomalies in the offspring? | They don't, always. The degree to which it happens is typically overstated. However, inbreeding tends to result in homozygosity. Basically, more people sharing the same copies of genes. Since you get them from your parents, and your SO is closely related and also got them from their parents, your kid has a greater chance of getting one from either/both parents, and so on.
If these genes happen to be ordinarily recessive, harmfully messed up genes, this ups the chance that you get two copies of the bad thing, in which case, even though it's recessive, now you're stuck with the associated condition.
If grandpa has a bad gene, and passes it on to dad, at least you've got a chance to get a good gene from mom. If grandpa has a bad gene, and passed it on to both mom and dad, well, that's more risk. | [
"Clues to the first two questions come from studies that have shown that at least 30% of individuals with autism have spontaneous \"de novo\" mutations that occurred in the father's sperm or mother's egg and disrupt genes important for brain development, these spontaneous mutations likely cause autism in families w... |
Spain's Franco negotiated to join the Axis Powers on condition to take some British and French colonies and territory. Why didn't Hitler agree? | Hitler wanted Franco to participate more, but Franco managed to decline in a polite fashion. When Hitler was winning, Franco started to make promises of military support and even contributed the "Blue" Division to fight on the Soviet front. However, when the proverbial writing on the wall of Hitler's loss was evident, Franco knew his country was in no position, after a devastating civil war, to fight the Allied powers and feared losing his own position he had so recently won.
And he was right. Franco ruled up until his death in like 1973. We all know Hitler didn't do so hot in the Spring of '45. | [
"Raeder's insistence that Germany either needed bases in or needed to annex the Canary Islands cost Germany the chance of bringing Spain into the war. In June 1940, the Spanish dictator General Francisco Franco decided to take advantage of the defeat of France and the widely expected defeat of Britain by entering t... |
bayesian method of logic? | Bayesian statistics basically says that you can't just look at outcomes in isolation, you have to look at so-called "prior probability" - how likely something is to happen at all. XKCD has a [silly example](_URL_0_). I'll modify the XKCD example slightly to make the numbers a little nicer - let's say it has a 1-in-100 (.01) chance of saying the sun exploded even if it did not.
Clearly, even with a low chance of error, it is much more likely that the detector is malfunctioning than that the sun exploded. There's a statistical law, called [Bayes' Rule](_URL_1_), that allows us to calculate it given some knowledge about the background probability of the sun exploding.
We write P(the sun exploded | the detector says the sun exploded) to mean "the probability that the sun exploded if the detector said it did", read the bar as "given that". Bayes' rule states:
P(the sun exploded | the detector says it exploded) = P(the detector says it did | it actually did) \* P(the sun exploded) / P(the detector reads yes).
If, for instance, we estimate a 1-in-a-million background chance that the sun did actually explode, we can calculate the probability that the sun actually did explode given that the detector says it did at .000099. This is very unlikely, and we can feel safe in the knowledge that Planet Earth will survive another day.
-------------------------
A less mathematical take might be this: you think most politicians are liars, and you meet someone who is a liar. You can't immediately conclude that they're likely to be a politician: you have to consider that politicians are rather rare. | [
"The Bayesian approach is superior to use in decision making when there is a high level of uncertainty or limited information in which to base decisions on and where expert opinion or historical knowledge is available. Bayes is also useful when explaining the findings in a probability sense to people who are less f... |
how do they make the machines in factories? is there a factory for factory machines? | Yes, machines are made in factories that use metalworking machines, often called [*machine tools.*](_URL_0_) Sample tools they use (which you can google) include:
- Metal lathe
- Plasma cutter
- Press brake
- Punch press
- Five-axis (or six-axis) milling machine
Check out the YouTube videos from How It's Made to see many examples. | [
"The machine tools often make interchangeable parts, which are assembled into subassemblies or finished assemblies, ending up sold to consumers, either directly or through other businesses at intermediate links of a value-adding chain. Alternatively, the machine tools may help make molds or dies, which then make th... |
What would the atmospheric composition have to be to scatter red light instead of blue? Green Light? Purple? | We actually have two examples - Mars and Earth - with different colored skies. The difference comes down to Rayleigh scattering vs. Mie scattering.
There are two variables to keep in mind with scattering that can be wavelength dependent - the cross section and the scattered angles of the light. Rayleigh scattering is a good approximation for particles or molecules much smaller than the wavelength of light. Rayleigh scattering spreads the light at all angles, but the cross section is higher for blue light than red. This gives us blue skies and red sunsets.
Mie scattering describes what happens when particles are about the same size as the wavelength of light. Mie scattering has a flatter wavelength dependence for the cross section, so it doesn't produce very vibrant colors. However, red light scatters broadly while the blue light scatters in a more limited cone. Mars has dust in its atmosphere that is the right size for Mie scattering. That makes the sky on Mars red and the sunsets blue. You can get the same effect on Earth if a volcano puts up ash that is the right size. This can give a visibly blue moon. | [
"In 1859, while attempting to determine whether any contaminants remained in the purified air he used for infrared experiments, John Tyndall discovered that bright light scattering off nanoscopic particulates was faintly blue-tinted. He conjectured that a similar scattering of sunlight gave the sky its blue hue, bu... |
rally racing co-driver corner call outs and how to understand them | There was a segment in the first episode of season 19 of Top Gear last week where James May had this explained to him. It's actually not that hard. | [
"A co-driver is the navigator of a rally car in the sport of rallying, who sits in the front passenger seat. The co-driver's job is to navigate, commonly by reading off a set of pacenotes to the driver, but other competitions require map interpretation. In stage rallying communication is often over a radio headset,... |
why are credit ratings agencies private for-profit institutions? | credit ratings aren't related to the government. it's a for-profit institution that benefits other for-profit institutions (lending banks). credit bureaus don't work for you the individual, they sell your rating to the banks. | [
"Credit rating agencies also play an important role in the laws and regulations of the United States and several other countries, such as those of the European Union. In the United States their credit ratings are used in regulation by the U.S. Securities and Exchange Commission as Nationally Recognized Statistical ... |
How did the Soviet Union recruit spies within the Western Bloc? | The acronym 'MICE' is often used as a summary of four factors which can drive someone to commit espionage:
* **M**oney: pay for information. There are plenty of spies who simply recognised that the Soviet Union would pay for what they knew: [Robert Hanssen](_URL_3_) or [Aldrich Ames](_URL_2_), for example.
* **I**deology: some spies genuinely hold strong political beliefs, and view espionage as a political act. Prime example here is the [Cambridge Five](_URL_1_), who were spotted and recruited by the NKVD/KGB at university because they were known or suspected communists.
* **C**oercion: simple blackmail. Many people will go to great lengths to avoid having their dirty laundry aired in public. The KGB was known to set up its own snare operations for this purpose: look at [John Vassall](_URL_0_), a homosexual British civil servant who was lured into a KGB honeytrap, photographed and then blackmailed into providing information.
* **E**go: the hardest to interpret, but essentially the sense of doing something 'big' can appeal to the self-importance, especially of low-level functionaries.
Soviet intelligence officers — like the intelligence officers of any country – used all of the above, and more, to manipulate people into providing information. As /u/abt137 pointed out below, many of their recruits were 'walk-ins' (ie. direct inbound approaches to the KGB).
I'd also second the suggestion that you look at Christopher Andrew & Vasili Mitrokhin's *The Sword and the Shield* for a great history of Soviet intelligence operations — it's my go-to source for any question about Soviet espionage. Andrew has had unparalleled access to a couple of major Soviet defectors (Mitrokhin and Oleg Gordievsky) so his work on the history and practice of Soviet intelligence operations is unbeaten, to my knowledge. | [
"The KGB classified its spies as \"agents\" (intelligence providers) and \"controllers\" (intelligence relayers). The false-identity or \"legend\" assumed by a USSR-born illegal spy was elaborate, using the life of either a \"live double\" (participant to the fabrications) or a \"dead double\" (whose identity is ta... |
who decided that women must keep their breasts covered at all times in public, when men can walk around shirtless? | Actually, at one point in time, men couldn't go topless. Remember those one piece bathing suits men wore in old television any thing? That's what they were for. Eventually someone got fed up with it and there was a whole (ever insignificant) movement that remedied the issue. Now someone just needs to do it for women. | [
"In her 2009 book \"Law's Dream of a Common Knowledge\", Mariana Valverde criticized this ruling by arguing that it ensured that \"the women who have the best 'lawful excuse,' as law puts it, to go around topless are expressly forbidden from doing so.\" Elaborating on this, Valverde states that a \"new line has bee... |
why does satellite radio work with small antennas that don't have to be pointed at anything, but satellite tv and other satellite communications require a large dish that needs direct line of sight to a satellite? | Consider the amount of information that is transferred in either case. Video signal requires orders of magnitude more bandwidth than mere audio, and then you still need to send the audio. Therefore, you have to use a larger, directional, high-gain antenna in order to improve signal fidelity enough to get good bandwidth.
I have a historical anecdote. The *Galileo* was a very costly NASA mission to Jupiter and its moons. It was supposed to transfer its data at real-time at 134 **kbits**/second using a fancy high-gain dish. However, because the spacecraft had to be carted around one too many times, the antenna's mechanism broke down, which was discovered way too late for anything to be done about it. So it had to do with a secondary 16 **bit**/second low-gain omnidirectional antenna, forcing NASA to get creative and invest huge money into upgrading their groundside receiver tech. | [
"Due to the relatively high gain of the antennas contained within handsets, it is necessary to roughly aim the antenna at the satellite. As the handsets contain a GPS receiver it is possible to program the ground position of the satellites as waypoints to assist with aiming. \n",
"Satellite antenna farms are usua... |
Why is Texas pride so strong? | There's always more than can be said, but I answered a [previous](_URL_0_) question related to differences between Northern and Southern states with regards to history education that speaks to some of what you're asking. I use Texas and New York State as examples.
> From the post:
> Northern states - through a combination of tradition, guardrails around course expectations, and cultural norms - expect(ed) districts to provide students with a comprehensive history education that focuses on America's shared history, which includes the Civil War.
>
> Southern states - through a combination of tradition, textbook adoption, and cultural norms expect(ed) teachers to provide students a history education that focuses on a comprehensive understanding of what it means to be a Southerner, an identity framed around the Civil War.
| [
"Texas pride the sense of demographic pride felt by people who currently or formerly lived in the state of Texas. Texas is a state with a unique cultural history and complex story of development. This individuality has shaped a state-wide construct of indomitable demographic pride. \n",
"Portrayals of Texas pride... |
why do baking recipes always call for the oven to be set in 25°f increments? | When ovens were first invented, there were only a few temperatures that anyone used; Slow, moderate, and hot. As technology got better, more marks were added to the dial, but numbered temperatures weren't measured or used. Eventually someone measured the temperatures that were actually being produced by the oven at the different marks and sold their oven with those markings to make it seem like the oven was more accurate. Since oven temps didn't need to be very accurate, and most recipes only had to be someone near the old Slow, Medium, or Hot setting, a rough estimate was close enough. 25 degree increments were close enough to be fairly accurate but still easy to remember and eventually became standard. | [
"Common oven temperatures (such as terms: cool oven, very slow oven, slow oven, moderate oven, hot oven, fast oven, etc.) are set to control the effects of baking in an oven, for various lengths of time.\n",
"High humidity in the oven, represented by an elevated wet-bulb temperature, increases the thermal conduct... |
what biological function does grief serve? it doesn't seem necessary for survival yet is a firm part of the human (and animal) condition. | Let's say grief wasn't a thing. You're some proto-human and your mate dies. Oh well, time to find a new mate.
You've removed a very strong motivator to keep your mate safe and cared for. As a result you've negatively impacted your ability to produce additional offspring.
Same can be applied for close social connections if you think of them as people with which you can safely exchange goods necessary for security and survival. | [
"Grief is “a multifaceted response to loss, particularly to the loss of someone or something that has died, to which a bond or affection was formed”. A common emotion amongst humans, grief is also apparent in other animals, known as animal grief. In the late 19th century, research started to show grief in chimpanze... |
What makes a heart attack more or less severe? | First, to clarify some terms. Chest pain by itself does not necessarily signify a heart attack. We refer to chest pain related to the heart as 'angina', which further subdivides into 'stable angina' and 'unstable angina'. The former is caused by gradual, progressive narrowing of the coronary arteries that supply the heart muscle, and is typically characterized by pain with exertion that is relieved with rest. On the other hand, unstable angina is related to plaque instability that causes an acute blockage, and can occur at rest. Unstable angina is much more severe because it represents a dramatic change from the baseline perfusion of the heart, whereas stable angina has a better prognosis because the coronary vessels have so much reserve (typically we don't even get symptoms until they're 70% occluded). A heart attack (myocardial infarction) occurs when there is insufficient perfusion of part of the heart muscle. Note that 'sufficient' perfusion means different things depending on what the heart muscle is being asked to do. MIs are subdivided into ST elevation MIs and non-ST elevation MIs. A STEMI represents an infarction that extends across the entire width of the myocardium, while a NSTEMI represents an infarction that is primarily in the endocardial region (because heart muscle is supplied from the outside inwards, the inside gets damaged first when there's a blockage).
So what determines the 'severity' of a heart attack? The biggest factor is location. If you look at the distribution of [the coronary arteries](_URL_0_), you can see that the location of the affected vessel can have major implications on the location and area of affected muscle. For example, occlusion of the left main coronary artery is potentially much more serious because it supplies much of the left ventricle and intraventricular structures. A blockage here would quickly impair the heart's ability to pump at all. In contrast, a smaller, more distal infarct in a branch of the left circumflex artery would be better tolerated. If the blockage affects vessels supplying the right side of the heart, the treatment actually differs because right sided ventricular failure leads to different hemodynamic changes than left sided ones. Because of the vital importance of location, you'll see cardiologists using tools like EKGs or angiography to help quickly localize where the lesion is. | [
"There is a weak relationship between severity of pain and degree of oxygen deprivation in the heart muscle (i.e., there can be severe pain with little or no risk of a myocardial infarction (heart attack) and a heart attack can occur without pain). In some cases, angina can be quite severe, and in the early 20th ce... |
why does body temperature rise after a meal? | It is because your metabolic rate is increasing to digest the food. Think of it like an engine. When it's on, it is warm however when you give it gas (food) it revs up and the engine heats up. Same thing happens with the body. | [
"After a meal, when the blood concentration of fatty acids rises, there is an increase in uptake of fatty acids in different cells of the body, mainly liver cells, adipocytes and muscle cells. This uptake is stimulated by insulin from the pancreas. As a result, the blood concentration of fatty acid stabilizes again... |
If the gas giants are so much colder than Earth, why are primarily composed of gasses, and not liquids or solids? | > If the gas giants are so much colder than Earth, why are primarily composed of gasses, and not liquids or solids?
They are in some sense, but not because of the cold. Like the other planets, the gas giants become hotter the deeper you go. The reason why liquid substances still occur in them is, that pressure increases as well.
To be more exact, Jupiters and Saturns hydrogen becomes supercritical at one point. Supercritical describes a pahse, in which you can't clearly point out whther it is gas or liquid, because the are actually the same. Even further inside, you get metallic hydrogen, which is a completely different phase, but probably somewhat comparable to a liquid. The transition from gas to supercritical phase is steadily. There is no sharp edge.
Uranus and Neptune have a gaseous atmosphere, under which there is an icy mantle. Although being called ice, the mantle resembles a dense and hot liquid made of water, ammonia and methane. We don't know yet whther or not the ice giants have supercritical hydrogen.
All giant planets have a dense solid core, made of rock, metals and perhaps hot forms of ice. | [
"Gas giants also have cores, though the composition of these are still a matter of debate and range in possible composition from traditional stony/iron, to ice or to fluid metallic hydrogen. Gas giant cores are proportionally much smaller than those of terrestrial planets, though theirs can be considerably larger t... |
What was the process of homosexuality moving from categorization as a mental illness to its normalization? | There’s definitely more to be said, especially on the social history of why LGBT advocates came to protest the DSM, but I (somewhat briefly) discuss the removal of homosexuality from the DSM in context of an answer on the rise to prominence of the DSM and backlashes against it [here](_URL_0_). | [
"The gay rights movement continued to challenge the classification of homosexuality as a mental illness and in 1974, in a climate of controversy and activism, the American Psychiatric Association membership (following a unanimous vote by the trustees in 1973) voted by a small majority (58%) to remove it as an illne... |
what is modernism and other movements? | I can answer most of the -isms that deal with architecture:
**Modernism** with a capital 'M' is the idea that "less is more". This movement was a response to the first world war to answer the calamity that society suffered in Europe. This movement would travel to America and be dubbed "International Style" to the chagrin of its European founders, Ludwig Mies Van Der Rohe and Le Corbusier. The Modernists sought to strike down historical context and tradition in favor of new technology (concrete, glass, steel) and rid the building of "unnecessary ornament".
**Post-Modernism** is the counter-movement to Modernism that began in the late 60s during the many counter-culture movements that were happening. See Robert Venturi and Denise Scott Brown. There was no distinct "style" associated with Po-Mo architecture like Modernism.
**Neoclassicism** is the movement that takes roots in Classical theory. It's typically depicted by ancient Greek and Roman styles of Classicism with particular attention to proportion and geometric principles to define solid and void. | [
"The term Modernism describes the modernist movement in the arts, its set of cultural tendencies and associated cultural movements, originally arising from wide-scale and far-reaching changes to Western society in the late 19th and early 20th centuries. In particular the development of modern industrial societies a... |
Could this be Atlantis? | u/Iphikrates just posted an answer to a [similar question](_URL_0_) | [
"Atlantis is a fictional location appearing in American comic books published by Marvel Comics. It is based on the mythical island of Atlantis first mentioned in Plato's initial dialogue the \"Timaeus\", written c. 360 BC. In the Marvel Universe, Atlantis was a small continent (about the same size as modern Austral... |
How many non-German (Austrian) officers were in Habsburg (Imperial Austrian/Austro-Hungarian) armies and how hard would be for example to Croat, Czech, Pole etc... to advance and acquire high rank? | The Austro-Hungarian Army, the K.u.K (national combined army, not the second line national reserves) was technically ethnically blind in the officer corp. An officers service file contained no data on the soldier's ethic nationality. So on this, there would have been no barrier to advancement for any ethnicity. In fact, the professional officer corp was proudly stateless and expressions of nationalism were viewed as social stumbles.
This also causes some difficulty in determining the ethnic composition of the officer corp, as mostly what we have to go on is the "primary language" data, which is not necessarily a perfect proxy for ethnic nationality. While 79% of KuK officers claimed German as their primary language, that does not mean that 79% of KuK officers were, in fact, German.
First is the education status. On the whole, Germans and Czechs were the most likely to be literate of all ethnic groups in the Empire. Before the war only 3% of the Vienna area population was illiterate, while over 60% of Ruthenes in Galicia and Croats and Serbs in Dalmatia could not read. Obviously the eliminates many males from the potential pool of officers to begin with.
Second, higher education was a requirement to become and officer. This would eliminate an even higher percentage of the population in the outlying areas (Ruthenes and Dalmatians in particular, but also Romanians) where economic conditions were generally significantly poorer and more agricultural.
Third, many officer candidates came from military families as sons of officers or career NCOs. They would have grown up in a military life, which meant a German speaking world. Regardless of genetic background, these people would have been very likely to list German as their primary language. This may partly explain why the regular officer corp identified as 79% German speaking, 9% Magyar, and 5% Czech (v overall army composition of 25 German, 23 Magyar, 13 Czech, 9 Serbo-Croat (inc Bosnians), 8 Pole, 8 Ruthene, 7 Romanian, 4 Slovak, 2 Slovene, and 1 Italian). It may be interesting to note that in 1906 among reserve officers the split was only 59 German to 26 Magyar, and 10 Czech, much closer to the overall make up, and the non German/non-Magyar numbers would have continued to rise in the years before the war. Even at the prestigious Theresian officer academy, the 1914 class was 63% German speaking and 16% Magyar, meaning 21% of the class listed a primary language outside the top two (v only 7% in the KuK officer corp). While the German % is again outsized relative to population, we still have to consider that sons of military families are likely to over-represent in the academy, and those sons will have grown up in a German language dominated environment and list German as their primary language regardless of their heritage.
We do know that off 9 Field Marshals appointed during the War, 3 were Royals, 2 were Austrian Germans, 2 were non-Austrians of mixed German background, 1 was Czech (Krobatin) and 1 was Croation (Boroevic).
I believe that ultimately, the Austro-Hungarian army did not create barriers specifically targeted to non German ethnic groups, and that hard work, some luck, and/or good patronage could see an officer from any background rise to the top. However, it is also evident that various structural issues in the underlying society regarding education and economic power caused a general imbalance in the intake origins of officers from the start that would lead to skewed representation %s down the line.
I relied heavily on John R Schindler's "Fall of the Double Eagle" for my figures on this reply, although relevant information can also be found in Rothenberg's "Army of Francis Joseph" and Deak's "Beyond Nationalism" (and indeed Schindler cotes both in his footnotes). | [
"Antonio von Caraffa (1646 – 6 March 1693) was a General Commissary (Generalkriegskommissär) of the Imperial-Habsburg Army—the highest rank in the Austrian military hierarchy at the time. He also held various other high-ranking offices, including military governor of Upper Hungary and later royal commissioner of Tr... |
Historians, what's the most bizarre aspect of the period and/or culture in which you specialize? | The most bizarre aspect of the culture that I study is that very few people actually knew what happened in the past, and refuse to learn for fear of coming to the conclusion that they are wrong about many things. When I announced to my family that I was doing a degree in Irish History and Politics many looked at me as if to say 'Why on earth would you study the Irish?' (my family are mainly Ulster-Scots) my Grandmother called it a 'Catholic Degree' whatever the hell that means and my cousin said 'Ok as long as you come back with a protestant mindset'. Upon achieving a first my mother exclaimed 'You beat them at their own history?' (She was joking though)
That's only the experience with my family, but I've met many people who are similar, on both sides of the divide and it infuriates me when they refuse to learn just so they can justify killing each other. I've heard sneers from Protestants asking why would I do a useless degree (surely the history of your own land is more relevant, especially for a nation such as Northern Ireland than studying Nazi Germany) I've also received jeers from Catholics who laugh, exclaiming that its funny seeing a 'Prod' trying to learn 'their history' that I will 'never understand'. Why is this all important? Because the theme of generational ignorance is a constant theme in Irish History that never seems to stop.
Yeah history in Northern Ireland/ Republic of Ireland is bizarre | [
"The cultural critic Mark Dery traces the origins of culture jamming to medieval carnival, which Mikhail Bakhtin interpreted, in \"Rabelais and his World,\" as an officially sanctioned subversion of the social hierarchy. Modern precursors might include: the media-savvy agit-prop of the anti-Nazi photomonteur John H... |
What was the casualty rate of the U.S. Army Air Corps during WWII in Europe? | I'm not sure about the entire Army Air Corps, but the Eighth Air Force definitely was hit the hardest.
> These missions, however, carried a high price. Half of the U.S. Army Air Force's casualties in World War II were suffered by Eighth Air Force (more than 47,000 casualties, with more than 26,000 dead).
_URL_0_ | [
"BULLET::::- During World War II, the U.S. Army Air Forces have lost more than 6,500 B-17 Flying Fortress and B-24 Liberator bombers over Europe. In the European Theater, they have lost 23,805 airmen killed in action, 9,299 wounded, and 26,064 captured. In the European, Mediterranean, and North African theaters com... |
when a big corp buys a company, does the company get a lump sum? and does the big corp get financing through a bank? | It varies based on the terms of the deal.
1. you can buy a company by swapping stock, and absolutely no cash would exchange hands.
2. you can buy a company with cash, and it could be paid out over time, all at once etc. These things are negotiable, especially if it's a private company (if it's public, it can also be negotiated so long as the shareholders find it in their interest...but..more typically it would be through acquisition of stock at an agreed to rate). If bought with cash, that cash can come from wherever the buyer can get it - investors, banks, reserves etc.
| [
"Becoming a bank holding company makes it easier for the firm to raise capital than as a traditional bank. The holding company can assume debt of shareholders on a tax free basis, borrow money, acquire other banks and non-bank entities more easily, and issue stock with greater regulatory ease. It also has a greater... |
how related is high school algebra to knowing how to code and do web development? | For coding, you need a very logical mind.
For high school algebra, you also need a very logical mind. For that reason, if you're good at one, there's a high chance you'll be good at the other, and vice versa.
However, you won't actually need algebra skills to be able to code in most business environments (although there are certainly some specialist types of coding that *do* use these skills). | [
"Students involved in the computer science program learn how to write html, videogames, and general computer programming. This is a branch off the Math program and took the place of the Business program in 2009. \n",
"BULLET::::- Gamoran, A., and Hannigan, E. (2000). Algebra for everyone? Benefits of college prep... |
how are services like uber or lyft cheaper than a typical taxi service and more profitable for the driver? | Lack of regulation.
Taxi driver have to be licensed by the local municipalities, who set caps and charge a whole lot (a NYC taxi medallion can auction for over $1 million).
Uber and Lyft drivers are technically limos, which aren't nearly as restricted. And since there is no validation and Uber and Lyft are just matching services, it is easy for people without any sort of special (or even any) license to participate. | [
"The company is trying to grow in a sound way by forging relationships with local businesses, hiring both traditional taxis and regular consumers as Cabify drivers, and placing heavy emphasis on repeat customers, for example by steering its cars in peak hours towards habitual users rather than those that offer the ... |
how does self-confidence work? | Knowing when you've done enough. There is a reason why they say you can deceive everyone else but not yourself. If you did enough you'll know. If you didn't, your reptile part of your brain will let you know. That fucker is never wrong. You can bet on it. Just think of it as 250 million years old sage who has seen it all and made it through to you in the current day. Listen to that and you'll be golden | [
"The concept of self-confidence is commonly used as self-assurance in one's personal judgment, ability, power, etc. One's self confidence increases from experiences of having mastered particular activities. It is a positive belief that in the future one can generally accomplish what one wishes to do. Self-confidenc... |
Before arriving in Scotland, where did the picts come from? | The short answer is simply; we don't know. Also, apologies for the following formatting, because I'm on mobile.
The Picts only really first show up towards late antiquity, when a confederation of Picts was formed, possibly in response to the Roman Empire on their southern borders. The first use of "Pict" as a name for these people occurs in a panegyric from the very late 3rd century, and is usually held to mean "the painted people".
The Pictish Chronicle, a pseudo-historical account of the Pictish kings dated to around the 10th century, presents the Picts as conquerors from Scythia, as does the Anglo-Saxon Chronicle, Bede's *Ecclesiastical History*, and Geoffrey of Monmouth's *History of the Kings of Britain*, though considering how much these sources would have borrowed from one another this view isn't generally regarded as accurate by most historians of the era. If, however, the Picts were indeed descended from Scythia, that would put them around central Asia, near Kazakhstan or thereabouts.
It's generally assumed that the Picts were simply descendants of the Caledonians, or some of the other tribes that occupied Alba in earlier centuries that are mentioned by numerous Roman geographers as well as on Ptolemy's world map. The Caledonians were themselves Celtic, with likely origins being in western or central Europe, and are first attested iirc by Tacitus in his *Agricola*. As we don't really know what the Picts called themselves, it's entirely possible that they even called themselves Caledonians or continued the use of another Iron Age Celtic tribal name; it's been suggested that they called themselves the Albidosi, based on the name found in the Chronicle of the Kings of Alba during the reign of Malcolm I, but even that's disputed by some historians. Really we just don't know much for certain.
There's very little in the way of surviving Pictish writing to tell us much about their language or history in their own words, so we have to rely on what we know of them from folks like Bede and the Irish annals, as well as the scant archaeology that we have that's "distinctly" Pictish.
Sources:
Bede, *Ecclesiastical History of the English People*.
Geoffrey of Monmouth, *History of the Kings of Britain*.
Broun, D. 2005, 'Alba: Pictish Homeland or Irish Offshoot?', in P. O'Neill ed., *Exile and Homecoming: Papers from the Fifth Australian Conference of Celtic Studies, University of Sydney, July 2004*. Sydney: University of Sydney Press, 234-275.
Fraser, J. E. 2011, 'From Ancient Scythia to *The Problem of the Picts*: Thoughts on the Quest for Pictish Origins', in S. T. Driscoll *et al* eds., *Pictish Progress: New Studies on Northern Britain in the Early Middle Ages*. Leiden: Brill, 15-44.
Woolf, A. 2007, *From Pictland to Alba 789 - 1070*. Edinburgh: Edinburgh University Press. | [
"Although an earlier, prehistoric Gaelic presence in Scotland has long been noted by scholars, two early Kings of the Picts suggested to be from the Dál Riata, and who may have been instrumental in the (further) Gaelicisation of Pictland, were Bridei IV of the Picts and his brother Nechtan mac Der-Ilei.\n",
"Ther... |
why hasn't aviation moved beyond jet technology yet? | There was a recent question about why aircraft haven't got any faster over the last few decades, and I explained in that thread that the sound barrier is a huge problem, which simply isn't worth trying to break, from a financial point of view - passengers are not interested in paying enough extra to cover the cost of breaking the sound barrier.
So we have a situation where aircraft can't go faster than they currently - and the current engine technology gets them there perfectly adequately. Why would we need something new?
The invention of the jet engine enabled aircraft to fly faster and higher than propellers would allow. It was being higher and faster that meant that jets became the norm. But without any possibility of faster, I can't see any reason why jets would be replaced now in the way that propellers were replaced by the jet.
However, there have been huge advances in engine technology. Engines are massively more fuel-efficient and quieter than ever before. Just about every new jet aircraft has FADEC which has reduced the number of crew required to fly an aircraft, made the aircraft safer than ever, and easier to operate than ever. Engineers are making advances all the time... but the jet engine still rules. | [
"The development of the jet engine represented a quantum leap in aviation, and revolutionised commercial aviation. Although first developed for fighter aircraft, this engineering triumph changed the world and led to the development of the jet airliner - especially the one which would set the pace for long distance ... |
What is the cosmic background radiation in lay-mans terms? | When the universe was young, about 300,000 years old or so, it was very very hot. There were free particles and there were photons and everything was bouncing around and at the same temperature.
Then, as the universe continued to expand, the particles of matter started to thin out. As they did so, the photons (light) were essentially freed (we say "decoupled") and no longer trapped by the density of matter around them.
But this light (which was EVERYWHERE in the universe) was at a VERY specific temperature. Since this decoupling, that light (of a very specific temperature) has been free to travel in straight lines.
So, for the last 13-14 billion years, this light has been traveling, gradually cooling as its wavelength expands along with the expansion of the rest of the universe. Now, when we look into the universe we see this 13 billion year old light and it is all the remnant of that light from the young universe that was trapped by the density of matter around it.
EDIT: more info!
It's worth noting that the "power spectrum" of this light, which is just a measure of how much light we see at each wavelength, EXACTLY matches with the power spectrum predicted by an ideal "blackbody" at a temperature of about 2.7 Kelvin. This is due to the fact that when the universe was young the thermal equilibrium was nearly perfect--everything was really at the same temperature. | [
"The cosmic microwave background radiation is an emission of uniform, black body thermal energy coming from all parts of the sky. The radiation is isotropic to roughly one part in 100,000: the root mean square variations are only 18 µK, after subtracting out a dipole anisotropy from the Doppler shift of the backgro... |
if eye contact is considered a challenge in the animal kingdom, why do we have to make eye contact with each other to be polite? | Eye contact is not universally a challenge in the animal kingdom, and for that matter it's not universally polite in human societies. We often use it as an important form of nonverbal communication, along with other gestures that are sometimes quite different in animals. For instance, smiling is often a threatening gesture for some apes and monkeys. Conversely, in some bird species eye contact can be a part of positive interaction. | [
"But different cultures have different rules for eye contact. Certain Asian cultures can perceive direct eye contact as a way to signal competitiveness, which in many situations may prove to be inappropriate. Others lower their eyes to signal respect, and similarly eye contact is avoided in Nigeria; however, in wes... |
were famine and water scarcity always such huge problems in africa? how has it come to such conditions? | Not always. In some places, colonists brought non-native plants and agricultural methods that were not sustainable to the area, and cut down large areas of jungle and forest. This damaged the ecosystem and made it hard to grow sustainable crops. Wangari Maathai’s memoir “Unbowed” talks more about this. | [
"Since the start of the 21st century, more effective early warning and humanitarian response actions have reduced the number of deaths by famine markedly. That said, many African countries are not self-sufficient in food production, relying on income from cash crops to import food. Agriculture in Africa is suscepti... |
how do tl;dr bots work? | There are [a bunch of ways this can work](_URL_0_), but I'm going to explain one of the simpler ones.
You know how Google originally got their great search results? They had a clever algorithm called PageRank that looked at which web pages link to each other. Web sites that got linked to a lot by sites that had high PageRank scores were given higher PageRank scores, and vice versa. Like, if everybody was linking to Wikipedia pages, Google figured that Wikipedia was probably a big deal. They could figure this out just by looking at what links to what.
Imagine that each distinct word or short phrase in a news article got its own "web page", and it links to every word that appears close to it. If you ran PageRank on this imaginary collection of web pages, it would notice some words and phrases that seemed to be really central and important. If there's a news article talking about a dog who ate Brexit, or whatever, then "dog" and "ate" and "Brexit" would stand out as really key parts of the article.
Once you've figured out which bits of the article matter the most, you can try picking out the top 10 most important sentences and, boom, suddenly you've got a ten-sentence excerpt. It works better than you'd expect!
(And maybe add on a boost for sentences early in the article, or words in the title of the article, or phrases that are really uncommon. There are a bunch of tricks you can use to make this work a little better.) | [
"In order to find other infected machines, the bot discreetly probes random IP addresses until it contacts another infected machine. The contacted bot replies with information such as its software version and list of known bots. If one of the bots' version is lower than the other, they will initiate a file transfer... |
the invasion of afghanistan and iraq | Soviet comrades invade Afghanistan.
We invade to fight Soviets.
Afghans are like wtf.jpeg
Taliban fights Soviets too; funded by us.
Taliban decide they don't like us there either.
We overstay our welcome.
Then Bush did 9/11. (Obviously)
We invade Iraq because wmd's.
Surprise surprise no wmd's.
Mfw Vietnam flashbacks start.
We increase presence in Afghanistan too.
And now attempt to win an unwinnable war against an enemy whose identity can change at the drop of a shell casing. | [
"The invasion of Afghanistan is seen to have been the first action of this war, and initially involved forces from the United States, the United Kingdom, and the Afghan Northern Alliance. Since the initial invasion period, these forces were augmented by troops and aircraft from Australia, Canada, Denmark, France, I... |
how do "sanctuary cities" benefit from hosting illegal immigrants? | In a lot of cases, "not being a sanctuary city" means any interaction between police and potential immigrants has to involve a citizenship check. This is to happen whether the interaction is with a perpetrator or a victim.
As-is, even in sanctuary cities, if a person is arrested or a crime their citizenship is checked. If it turns out they're not a citizen, what happens to them depends on whatever the law says, I'm not an expert on that. No one's working to keep felons on the streets.
The problems arise in the interactions with victims. If someone is raped, they should be able to call the police. If someone is murdered, their family should be able to ask for justice. If calling the police *always* involves a citizenship check, they won't call the police. That creates a very large population vulnerable to crime. Some people say "Good, then they won't move here." Now imagine how that applies to human trafficking.
Further: ICE is asking that cities and counties spend their tax funding on these checks because the federal agency doesn't have a large enough budget to manage the entire country. This is, in effect, funding ICE with local dollars. Many, MANY parts of the country are vehemently opposed to the federal government controlling what state and local agencies do. This is a big factor in why many cities choose to be sanctuary cities: they don't believe their city taxes, city jails, and city officials should be doing the work that ICE is supposedly using federal funds to do.
It turns out it's expensive and complicated to deport someone. They have to sit in jail while lots of paperwork and negotiation happens. That means feeding them, housing them, paying guards for them, etc. Many jails are already crowded, and many local police forces are already overtaxed. And ICE sure isn't offering funds to build bigger ones.
People who support sanctuary cities believe:
* The Constitution protects all individuals in the country no matter what, and no fundamental rights can be revoked.
* There is no strong evidence showing immigrants commit more violent crimes than any other citizen group.
* Proposed regulations create opportunities for organized crime to flourish by creating victims who can't be protected.
* It is not good for the federal government to dictate the activities of state or local law enforcement to this degree.
* Maybe we should ask why we're paying for ICE at all if it needs city governments to do the job for it. | [
"There has been controversy around sanctuary cities, one response from the state and local governments. Many American cities have designated themselves as sanctuary cities and many other state and municipal governments discourage the reporting of illegal immigrants to U.S. immigration and Customs Enforcement. A san... |
why do boys and girls sound different? | Physiologically, boys and girls have different types of throats. Testosterone will cause the angle of your thyroid cartilage to become sharper, the cartilage thickens and enlargens and the vocal cords thicken as well. This gives boys a deeper and a 'darker' timbre (flavour) of their voice. In contrast, girls have a shallower thyroid cartilage angle, it's not as large and their vocal cords aren't as thick. So they have a higher and brighter timbre of their voice.
Every person develops a little differently so these are generalisations. Apart from this, which is called resonance and pitch, boys and girls are socialised differently. Even from a young age, boys are taught to act like other boys and girls are taught to act like other girls. As such, they learn speaking patterns from men and women respectively, and from other boys and girls respectively. These speaking patterns are intonation, inflection and expression. Like boys will be louder when they want to emphasise a point, while girls tend to raise their pitch.
Of these two types of things that contribute to voice, neither of them are set in stone. A boy can sound like a girl and a girl can sound like a boy. Whether it's by changing intonation, inflection and expression, or manipulating their throat positions to change their pitch and resonance, these factors only contribute to how a person 'naturally' sounds at a neutral state. | [
"Girls are more likely to wait their turn to speak, agree with others, and acknowledge the contributions of others. Boys, on the other hand, build larger group relationships based on shared interests and activities. Boys are more likely to threaten, boast, and call names, suggesting the importance of dominance and ... |
Why did Israel, India, Pakistan and S. Sudan never sign 'The Treaty on the Non-Proliferation of Nuclear Weapons'? | South Sudan came into existence as a country in 2011 and has had internal conflicts and civil war since then. Aside from being outside of our guidelines here, I don't think we can say very clearly whether they will or won't sign it at some point. They have a lot of other things on their docket before this. There is no danger of them becoming a nuclear state in the near future.
India made it clear it would not sign the treaty because it divided the world into "nuclear haves" and "nuclear have-nots" — they thought this was inherently unfair, that some powers got to keep their nuclear weapons while nobody else was allowed to do anything.
Pakistan didn't sign because India didn't sign — they are bitter rivals.
Israel publicly didn't sign because it judged the NPT as infringing on its sovereignty as a state. Also because they had a secret nuclear weapons program.
Today these states are outliers but it should be kept in mind that many states were non-signatories until the 1990s. Non-nuclear states of note which did not sign for a very long time included Brazil and Argentina (who were nuclear aspirants). Nuclear states that were not signatories for a very long time include China and France.
You can see [when various nations signed/ratified/acceded to the treaty here](_URL_1_). It was not all at once.
As for why nobody brings up Israel — they do, sometimes. But the general way of talking about it is that Iran _did_ sign the treaty (under the Shah regime), so it is bound by it unless it withdraws. The place where Israel gets problematic is that by being a non-signatory there should be sanctions attached, esp. since we do know that they do have nuclear weapons (which should make the [Symington Amendment](_URL_0_) kick into action re: US arms exports). But the US's very obvious lack of acknowledgement of the Israeli nuclear program has been going on for so long that it is not really news, and everybody sorts of gets what it is about, and everybody sort of acknowledges the hypocrisy (and sometimes it is explicitly justified). | [
"Four states—India, Israel, Pakistan, and South Sudan—have never signed the treaty. India and Pakistan have publicly disclosed their nuclear weapon programs, and Israel has a long-standing policy of deliberate ambiguity with regards to its nuclear program (see List of states with nuclear weapons).\n",
"However, I... |
Why didn't Greece become a satellite state of the Soviet Union after World War II? | The short version is that Greece did not become of the Soviet bloc because Stalin kept his agreements with the Western Allies.
According to legend spread by Churchill, at the Moscow conference in 1944, he and Stalin divided up Europe by percentage. According to him, Stalin and he did that on a paper napkin. Churchill even went so far as to publish [his secret "percentage agreement"](_URL_0_) after the war.
While it is a good story, a lot of it is the stuff of legend. The day after this happened, Stalin got a memorandum of the meeting and was careful to remove all references to spheres of influences and percentages. While the percentage thing was probably the stuff of legend, there was nonetheless an agreement between the USSR and the West that Greece would be in the Western sphere of influence while the USSR would get free political passages in other countries.
That Stalin kept to this agreement and that it was to him and the regime of the USSR politically unfeasible to integrate Greece in their sphere of influence is obvious from the post-war situation in Greece. Greece during the Axis occupation presents a picture similar to that in Yugoslavia, most notably by being a civil war inside a war of liberation.
With the Greek government in exile from the Axis invasion 1941 onward, a variety of political liberation movements formed in Greece during the war, most prominent the National Liberation Front (EAM), and its military branch the Greek People's Liberation Army (ELAS); both being communists and effectively run by the Greek Communist Party (KKE). Another, though smaller, non-communist resistance organization was the National Republican Greek League (EDES).
In 1943, with the Axis encountering major problems and with Italy dropping out of the war, a rift between EAM/ELAS and the other resistance organizations erupted, mainly concering the political future of Greece (Socialist Republic vs. Republic vs. Kingdom), over accusations of collaboration leveled by EAM at EDES and because of British support for virtually all resistance organizations except the biggest one, EAM/ELAS. As mark Mazower wrote in *Inside Hitler's Greece*:
> As potential allies for the British in an anti-communist crusade the Germans and the Security Battalions were obviously less politically palatable than ELAS's resistance rivals, even though these incresingly powerless and confirmed to the area of Athens. As well as contacting the GFP [Geheime Feldpolizei – the Wehrmacht's political police], Stott [the British Secret Service representative in Greece] had alos met representatives of all the Greek resistance organizations except EAM/ELAS to discuss how British arms could be supplied to them. These contacts, unlike those with the Germans were carefully maintained, chiefly through the Greek governemnt in exile, in the months leading up to Liberation, by which time the non-communist resistance was being seen as an essential buffer against the Left.
>
> By 1944, hostility to EAM/ELAS had pushed several of these right-wing "resistance" groups closer to the Security Battalions and their German sponsors. Here we find ourselves in the murky atmospehere of underground "nationalist" politics, a highly duplicitous and dangerous world, where resistance did not rule out collaboration, and where service alongside the Wehrmacht was justified on the grounds that it was necessary to save Greece from the Left. In Athens, for example, members of EDES enlisted in the Battalions, while several prominent leading EDES officals cultivated close ties with the [collaborationist] Rallis government.
The hostility between EAM/ELAS and the British supported other resistance organizations as well as collaborationist police agencies was not over when Liberation came but actually got worse. Take the happenings of December 3, 1944, two months after the Germans had retreated from Greece. On that day, Greek government gendarmes opened fire on an unarmed EAM demonstration with British troops watching on. Similarly, in the streets of Athens EAM/ELAS troops actually fought with British troops over control of the city when the British army came to drive the Germans back.
In 1946 civil war erupted openly. Unlike Yugoslavia where the resistance was strong enough to quickly establish supremacy and also did not face rivals supported by the Western Allies, in Greece that was not the case. Additionally, the Soviet Government denied the EAM/ELAS and the KKE all support, practically as well as politically. In the following three years of Civil War, the only force supporting the EAM/ELAS was actually Yugoslavia, explicitly against Stalin's wishes.When Yugoslavia ceased its support under Soviet pressure in 1949, the KKE and its troops lost the war and left Greek society deeply divided for years on – so much so that in the late 1960s the military orchestrated a coup d'etat against a moderate left-wing government for fear of communism returning.
That the Soviet Union was opposed to support for the Greek communists can be gleaned from a meeting they had with the Yugoslavs in the Kremlin in 1948 where Stalin explained that the situation in Greece has always been different from the one in Yugoslavia because the US and Britain would "never permit [Greece] to break off their lines of communication in the Mediterranean".
So, in short, the reason Greece did not become socialist was the the Soviet Union didn't regard support for the quite large and popular communist movement as politically feasible while the Western Allies, including the US and Britain massively backed former collaborators and political rivals of EAM/ELAS to prevent the communists from gaining power either by violence or democratic means. | [
"Other states were converted into Soviet Satellite states, such as East Germany, the People's Republic of Poland, the People's Republic of Hungary, the Czechoslovak Socialist Republic, the People's Republic of Romania and the People's Republic of Albania, which aligned itself in the 1960s away from the Soviet Union... |
What were the political structures used by medieval Muslim states? Was any of them similar to European feudalism? | I think it would be useful to briefly chart the development of Dar-al-Islam, or the Islamic states, as you say.
Two things to keep in mind:
1) The Roman Empire and Sassanid Empire possessed highly developed political structures with centuries if not millennia of political theory, philosophy, and culture upholding them. These did not disappear. And in most cases, the original Bedouin or Hejazi Arab Muslims were not the majority of the population in the early Islamic period. They certainly spread and migrated and many tribes came to settle in Mesopotamia or Syria or Iran or Egypt but assimilation always goes both ways.
2) The Early Muslims were not as organized as we may think. There have been some arguments that the yearly tribal raid (Ghuz) became impossible when most tribes converted to Islam, because they were all in the same 'tribe' or family of Islam and one could not raid one's tribe members. So they raided the only people they could, the ones to the north.
The early caliphate (first 4 caliphs) was essentially a big tribal organization. Arab leadership was based on senior tribal leader democracy, so the chiefs (or luminaries) chose among themselves by voting. Governors and other administrators were appointed. The government was highly centralized. The caliph would send someone he trusted to govern and after a period of certain years, might appoint someone else, etc.
When the Abu Umayya clan took over the caliphate following the civil war with Ali, the government became centralized along Roman lines. The capital was in Damascus and the chief bureaucrats and administrators were mainly Romans who had converted to Islam. This was a government based on the Umayya and organized along Byzantine/Roman lines. So the tax collection, etc, were all given to certain governors who were responsible for getting so much back to the central treasury. Things worked out fine enough until they didn't.
The Abu Abbas took over in 9th century. Their model was based on persian administration. Here things get interesting. From the 9th century onwards, the Persian practice of appointing sub-kings , if you will, takes root. The caliph gives out land to certain dynasties and they rule it on his behalf. This leads rise to a sort of feudalism but I am hesitant to call it that. This is also the great rise of Islamic science and humanities as all of these little provincial courts try to distinguish themselves by sponsoring the next big thinker.
European Feudalism is a unique phenomenon. I would not say that the Islamic states were similar to Feudalism, but that certain ways of ruling seem to be more or less efficient given certain circumstances, and both shared some similarities, especially in the 10th and 11th century. The centrifugal forces in Islamic governance arose from a need to accommodate local reality with state ideals and it did so by using a commonplace tactic that had been developed in Persia thousands of years ago and had probably also been developed in many places, namely, having someone rule on your behalf. European Feudalism is a whole different thing though on a superficial basis, it did incorporate this. | [
"Proto-states proliferated in Western Europe during the Middle Ages, likely as a result of a trend towards political decentralisation following the collapse of the Western Roman Empire and the adoption of feudalism. While theoretically owing allegiance to a single monarch under the feudal system, many lesser nobles... |
could two planets orbit a star on the same plane, yet lay opposite of one another? would they stay at the same distance or eventually catch up and collide? | It's a possible orbit (it would more or less be the [L3 point](_URL_0_)), but it's not stable against perturbations. So eventually one would catch up to the other, and they'd probably fling each other into different orbits.
It's called "Anti-Earth" or "Counter-Earth" in fiction, mythology, and pseudoscience, so you might be able to find info on the orbit's (non-)stability under those terms. | [
"Just as planets can be gravitationally bound to stars, pairs of stars can orbit each other. Some binary stars are visual binaries, meaning they can be observed orbiting each other through a telescope. Some binary stars, however, are too close together to be resolved. These two stars, when viewed through a spectrom... |
why roman soldiers wore open toed footwear? | Roman Caligae weren't really "open toed," the toes were covered more or less. They'd also add socks for colder climates.
Open shoes keep the feet dry (boots hold moisture) during long marches so they don't get trench foot. | [
"The Romans, who eventually conquered the Greeks and adopted many aspects of their culture, did not adopt the Greek perception of footwear and clothing. Roman clothing was seen as a sign of power, and footwear was seen as a necessity of living in a civilized world, although the slaves and paupers usually went baref... |
how serious is our national debt (u.s.)? are other countries so far in the hole? is it even possible to get out of debt? who do we owe and why haven't they broken our kneecaps?! | > How serious is our national debt (U.S.)?
Bad, but not terrible. It's higher than most people would like, but not so high that we're going to have serious problems because of it.
> Is it even possible to get out of debt?
Yes, but not desirable. Bill Clinton ran a study on what would happen if we paid off the debt (it was a possibility if the budget had stayed how it was under him), and the conclusion was that the US shouldn't go out of debt. The US debt interest rate is the way that interest rates all over the world are measured. It's considered the safest investment in the world.
What most economists talk about isn't paying the debt back but lowering how big it is in proportion to the GDP. The best way to do that is to grow the GDP, which is why that ratio is actually falling right now.
> Who do we owe and why haven't they broken our kneecaps?
What happens is the treasury auctions off the debt when they need more money. People bid by offering to take a lower interest rate. After a specific amount of time, the treasury pays what was owed. The people who buy the debt can't just call the loan due, and they generally buy the debt because it's very safe.
> It's a cartoonish number that is gaining a comical amount of interest every second.
You could say that about everything about the US economy. However, the debt is growing more slowly than the economy as a whole, so the debt to GDP ratio is actually getting better. | [
"The total national debt of the United States in the United States was $18.527 trillion (106% of the GDP) in 2014. The United States has the largest external debt in the world and the 14th largest government debt as a % of GDP in the world.\n",
"Some observers such as Professor Steve Keen of University of Western... |
why do colors disappear when you zoom in with a microscope? | In order to see something with a light microscope, you need to have a very, very thin cross-section. It has to be thin enough for light to be able to pass through it (for the most part). Otherwise, the image under the microscope would appear opaque or black.
But a small cross section means that there's not really that much material and/or pigment to add color to the light.
Look at a drop of water or a very shallow puddle of water on a white background. Not very much color is there? But look at the ocean from space. All that water is a rich, deep blue.
It's the same with a microscope. A carrot may look deep orange with the naked eye, but when you slice a thin enough piece off to see it under a microscope, it's a very pale orange if any color can be [seen at all](_URL_0_).
If you're talking about images from an electron microscope, then an EM doesn't really see color. An EM uses electron beams and their reflection off of things for a computer to render a 3D image of what something looks like. It's like a blind person examining an object with his hands. Sure he can tell you precisely what shape and texture the object is, but he has no clue what color it is. An EM is the same way. | [
"When an isotropic crystal is viewed, it appears dark because it does not change the polarization of the light. However, when it is immersed in a calibrated liquid with a lower index of refraction and the microscope is thrown out of focus, a bright line called a \"Becke line\" appears around the perimeter of the cr... |
what is the easiest way to accrue credit with a credit card? | The successful way to build credit using a card is to use it for everything. I use my awards earning cards that have no annual fee to purchase everything. I utilize it to pay bills that do not charge a surcharge for using a CC, groceries, gas, clothing, etc. At the end of the month when the CC bill is due I remit the total amount due. In this manner I earn, on average, $35 a month in cash rewards and accrue no interest. The rewards are paid out annually. So once a year I am sent a check averaging anywhere between $400 and $500 and build my credit. I’ve done this for about 15 years and my credit score hovers around 750. | [
"Some consumers prefer \"credit\" transactions because of the lack of a fee charged to the consumer/purchaser. A few debit cards in the U.S. offer rewards for using \"credit\". However, since \"credit\" transactions cost more for merchants, many terminals at PIN-accepting merchant locations now make the \"credit\" ... |
united states primary canidates | not a US citizen and have some very big political biases so don't know how valuable my word will be but whatever.
I'll give you what I know about 2 big Democrat candidates that reddit don't shut up about.
Hilary Clinton you've hopefully heard of. She's a woman if you didn't notice, so she tries to play the feminist appeal and hopes she can get support from feminist groups, however she hasn't really done much for female empowerment and represents privileged elitism which kind of contradicts the whole thing, as you may have noticed I'm a bit anti-Clinton. She was a former secretary of state and people have differing opinions on how good she was. Her main legacy while holding office was supporting Israel during a time the middle east was deteriorating, making extremism and terrorism more anti-US than it already was. Other than being a woman, Clinton really isn't that different from any other candidate, she has strong liberal values and supports ideas like government spending on things like social security and other typical Democrat stuff.
Bernie Sanders is interesting. Let me be clear on this, Bernie Sanders is not a socialist, he is not a marxist, he is not a communist. Sanders is what you would call a welfare capitalist or a social democrat. He does not support a prolateriat revolution, he does not support the dismantling of capitalism and he does not support the workers should have control over the means of production, so he is not a socialist. He does have many left leaning ideas. He believes strongly in workers rights, that the US government is corrupt and that the free market has a lot of problems. He is one of the most left leaning candidates since...well probably before the Cold War. But despite what people will say, he is not a socialist, a lot of America does not understand what that means. No US president will ever be a socialist.
The Republicans I can't talk about in any detail, all I know is Trump is an idiot and he thinks Mexicans are out to get his rug he wears to keep his head warm. | [
"The American College of Pediatricians (ACPeds) is a socially conservative advocacy group of pediatricians and other healthcare professionals in the United States. The group was founded in 2002 and claims to have over 500 members, although independent sources report that group has between 60 and 200 members and one... |
When did the conventional view in western culture of Germans as cold/severe/harsh people arise? | It did not arise until after Germany was united and seen as a power in Europe. [This comment](_URL_0_) by u/white_light-king in a thread comparing the rise of Germany to that of modern China discusses how Germans were portrayed prior to 1870. Excerpt below:
> In the 1850s-1870s the German states began to industrialize. Industrialization was a trend that was happening Europe wide, and the major powers at the time were more interested in each other's strengths and weaknesses than the progress of small, nonthreatening German principalities. Cartoons of Germans in the 1850 and 1860s portray Germans as sleepy and dimwitted small town hicks. Tolstoy in War and Peace (1869) depicts Russian aristocrats sneering at Napoleon because he only beat Germans (meaning both Austrians and Prussians)
> This view of Germany was dramatically upended in 1870. Prussia's victory over Austria in 1866 was seen as a comfortable sign of Austrian weakness. France in 1869 was widely viewed as the largest and best organized army in Europe backed by the second largest industrial power. Prussia's ability to defeat and humiliate France was a shock. It instantly catapulted Germany from a marginal power to a nearly hegemonic force. This happened over less than a decade. | [
"With the start of the Cold War a curse on the Anti-Westernization was proclaimed, mirroring the American Second Red Scare to some extent. For instance, in the 1950 edition of \"The Ordeal of Sevastopol\", censors made over three hundred cuts, screening the book's references to Frenchmen as \"a people of very livel... |
why are there random super cold spots when you are swimming in a lake or river? | Sometimes there are convection currents that keep water in one spot and bring water up from the bottom. Because the sun can only heat the top, those areas tend to be colder. If you feel the current in these cold spots, there is usually a flow of water going up from the floor
| [
"Winter swimming can be dangerous to people who are not used to swimming in very cold water. After submersion in cold water the cold shock response will occur, causing an uncontrollable gasp for air. This is followed by hyperventilation, a longer period of more rapid breathing. The gasp for air can cause a person t... |
in ice hockey, why can't i just plug the goal with the fattest guy i can find. | The pads are limited in size.
A normal fat guy is much too slow to be a goalie and will get beat badly (as we all learned in high school). Typically the goalie is the fastest guy on the ice, you just rarely see it.
An astonishingly obese man might physically obstruct most of the goal, but a lot of his body will not be protected by pads. A few NHL slapshots later and your backup goalie is in while the fat guy is getting stitches. | [
"While a team is short-handed, they are permitted to ice the puck as they wish, without having the icing infraction called against them. This allows short-handed teams to relieve pressure more easily when defending with fewer skaters than their opponents. This exemption does not apply to teams whose opponents have ... |
how do those bank tokens work? | That's *Two Factor Authentication*.
The idea is that there's a *huge secret number* that both the bank and the token know **and** they both know they time. By doing some tricky math, the token can generate a smaller number that proves it knows the secret number *without* giving away the whole number. The bank can then do the same math & check the results.
Just to come up with a trivial example, let's say you've got a 10 digit secret number with the following digits in order:
1. 4
2. 3
3. 8
4. 5
5. 2
6. 6
7. 7
8. 9
9. 7
10. 2
If somebody tries to authenticate at 2:45pm (14:45 in 24 hour time), you just take the 1st, 4th, 4th and 5th digits and add them together and then give the digit in the result's 1s place, giving 4+8+8+2 = 22 and send the "2" back.
This allows you to quickly see if they know the right number but if a hacker is listening in on the conversation, they *won't* know the number & can't use the same verification code in the future (like they could with a stolen password).
Obviously, real-world implementations use bigger numbers and more specific times (ie - date + time) and more complex functions but the idea is the same. | [
"In some modern automated teller machines, currency counters allow for cash deposits without envelopes, since they can identify which bills have been inserted instead of just how many. The user is given the chance to review the automatic counter's idea of the quantity and kinds of the inserted banknotes before the ... |
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