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Why is the domestication of dogs not considered the beginning of the agricultural revolution? | Hi, this question would be worth x-posting to our sister sub, r/AskAnthropology: while there are some specialists in pre-history here, there is a greater focus on early time periods over there. | [
"Since the domestication of dogs, they have evolved alongside humans due to pressure from humans and the environment. This began by humans and wolves sharing the same area, with a pressure to coexist eventually leading to their domestication. Evolutionary pressure from humans led to many different breeds that paral... |
What's the earliest evidence we have of jokes? What is the oldest one we know? were there jokes as we known them today back when Ancient civilizations stood? | Apparently a joke dating back to 1900 BCE was found in Sumeria: "Something which has never occurred since time immemorial; a young woman did not fart in her husband's lap." This Egyptian joke dates back to 1600 BCE: "How do you entertain a bored pharaoh? You sail a boatload of young women dressed only in fishing nets down the Nile and urge the pharaoh to go catch a fish" ([Reuters](_URL_0_)) | [
"Various kinds of jokes have been identified in ancient pre-classical texts. The oldest identified joke is an ancient Sumerian proverb from 1900 BC containing toilet humour: \"Something which has never occurred since time immemorial; a young woman did not fart in her husband’s lap.\" Its records were dated to the O... |
Civil War literature suggestions? | Depends on how committed you are, but Shelby Foote's *The Civil War: A Narrative* is pretty much the gold standard in Civil War history. It's a three volume work, very long and thorough. | [
"The Civil War Book was the fourth book made by William Quigley. Originally it was intended to be a sketch pad for ideas and information about the American Civil War, yet, it later became an elaborate compliment to the Civil War Paintings and was shown at the Lawrence Gallery in 1996. The book's gritty design incor... |
To what extent was local law allowed in the Roman Empire. | Local law was very much allowed in the Roman Empire, as a holdover from Republican days, whether the matter was civil or generally criminal. Governors of provinces generally allowed local courts to handle legal matters, only stepping in when cases were referred to them; at this point, generally the local law would apply to provincials, while Roman law declared by the urban praetor applied to Roman citizens living there (John Richardson's summary article on Roman law in the provinces from the *Cambridge Companion to Roman Law* is a relatively readable summary for an academic text). As Richardson states, local law was eroded as the Empire continued.
However, the issue becomes thornier because you're specifically asking about criminal sentencing to death. This power - known as the *ius gladii* - was one reserved for the provincial governor (although this was not widespread in the first years of the Empire, instead remaining with the Emperor himself). However, this is not a totally clear-cut situation, as can be seen in a well known example - the sentencing of Jesus Christ.
John 18 states that the Sanhedrin - the Jewish court - go to Pontius Pilate and tell him that they do not have the power to sentence him to death despite him breaking a law that demands it (Leviticus 24 states that blasphemy is a capital offence, punishable by stoning to death). So far, so consistent. However, Pilate tells them to "take him (yourselves) and crucify him" and the Jewish historian Josephus recounts other instances of the Sanhedrin issuing and carrying out death sentences at the time. Smallwood's *The Jews Under Roman Rule* hypothesises that an exemption may have been made allowing the Sanhedrin the power of execution in matters of religion, but offers no proof of this, only the examples given above. | [
"In the West, law had been administered on a highly localized or tribal basis, and private property rights may have been a novelty of the Roman era, particularly among Celtic peoples. Roman law facilitated the acquisition of wealth by a pro-Roman elite who found their new privileges as citizens to be advantageous. ... |
why betting the same amount on two boxers to win will not always give a payout due to differing odds. | Any real-world bookie is going to adjust the odds and payouts so that they get a cut for themselves (the vig). They're not working for charity. | [
"Because of the huge number of betting interests involved, bettors will often try to increase their chances of winning by selecting multiple combinations. This can be costly — a bettor who wants to cover two horses in each race must bet on 2 × 2 × 2 × 2 × 2 × 2 combinations, or 64 combinations, times $2 for each fo... |
I'm diabetic and I want to know about the industrially production of insulin | [Wiki](_URL_0_) says this:
> Recombinant human insulin. Thanks to study introduced by Ivan Garelli PhD, recombinant insulin has almost completely replaced insulin obtained from animal sources (e.g. pigs and cattle) for the treatment of insulin-dependent diabetes. A variety of different recombinant insulin preparations are in widespread use.[11] Recombinant insulin is synthesized by inserting the human insulin gene into E. coli, which then produces insulin for human use.
It also appears they've managed to create [plant produced insulin](_URL_1_) as well.
[This](_URL_2_) article also talks about the yeast-derived insulin, as well as some history if you're interested. | [
"In 1980, U.S. biotech company Genentech developed biosynthetic human insulin. The insulin was isolated from genetically altered bacteria (the bacteria contain the human gene for synthesizing synthetic human insulin), which produce large quantities of insulin. The purified insulin is distributed to pharmacies for u... |
Is their a theoretical limit to how much a pound of muscle can do? Is it possible to calculate, knowing a single persons muscle mass, how much they would be able to lift? (this is factoring in a healthy person, with full tanks of energy and no injuries.) | This is pretty hackneyed, but I'll post it anyway:
konstantin konstantinovs is a super strong Latvian powerlifter. He weights around 268lbs and has maxed out his deadlift at 938lbs. He's pretty lean for a powerlifter, so I'll guess that he's around 10% (26lbs) body fat and take that off his total weight, this leaves 242lbs. Next I'll guess that his bones and organs weigh around 80lbs, so I'll subtract that from his total weight as well, leaving 162lbs of pure muscle. Divide that by his max deadlift and I we can estimate that 1lb of Konstantin's muscle has the ability to lift 5.7lbs. | [
"Dr. Weber worked out that 1 cm cross section surface area of any masticatory muscle can produce approximately 10 kg force. The following average surfaces were found: temporalis - 8 cm, masseter - 7.5 cm, and medial pterygoid - 4 cm which makes a total of 19.5cm. However, this force in some people is measured up to... |
how the fuck is spreading jelly (i.e.vapo rub) on my chest supposed to help congestion? | You put it on your chest because you're going to be drawing air in to your lungs from that area. The vapors from the jelly mix with the air you breathe. | [
"ChestEze (or Do-Do ChestEze) is a British over-the-counter pharmaceutical product manufactured by Novartis for \"relief of bronchial cough, wheezing, breathlessness and other symptoms of asthmatic bronchitis and to clear the chest of mucus following upper respiratory tract infection.\" It contains 30 mg caffeine, ... |
Would World War I be classified as a "World War" if the US never got involved? | The first known use of the proper name "World War" (as opposed to "Great War" or "European War") was in 1919, if the *OED* is to be believed. It was used as a general descriptor ("a world-war" or the German *Weltkrieg*) for the conflict as early as 1914 so the idea existed well before US entry. So it might--it involved Canada and Japan at the outset, after all--but as with all counterfactuals, we can't say with certainty. The other choice, the Great War, persisted for a longer time especially in Europe, so the US may have been a crucial driver for its general adoption. But usage varied and turned heavily on political perceptions and motivations, so just as we can't say what a Second World War would have looked like without US involvement in 1917-1918, we also can't say what the contours of its naming would have been. But it was *possible*.
For a discussion of the naming issue in historical context, see David Reynolds, ["The Origins of the Two 'World Wars': Historical Discourse and International Politics," *Journal of Contemporary History* 38, no. 1 (2003): 29-44.](_URL_0_) | [
"Outside of North America, other differences between our timeline and this one exist. World War II (known as the \"European War\" in this universe) is still being fought into the late 1940s, without Japanese or American involvement. The United Kingdom has allied with Nazi Germany, with King Edward VIII becoming a p... |
why do people look slimmer in certain colors? | [Here's](_URL_0_) an article about how wearing black (or other dark colors) can make you look slimmer:
> If you have a very light T-shirt on, your shape will be noticeable within the fabric. Any curves, bulges, or flat areas will be noticeable beneath the white fabric. If the T-shirt is black however, that will not be the case. All that will be easily noticeable is that there is a field of black. This field will not have bulges or areas that look large unless the T-shirt is very tight. That creates a field that is slimmer and smaller looking than it would be otherwise. | [
"BULLET::::- Girls who see thinness as important to their peers or who try to look like the women they see in TV, movies, and magazines are significantly more likely to exhibit bulimic tendencies (using laxatives or vomiting to control their weight).\n",
"Unfortunately thin-idealized bodies are attributed with se... |
why does hand sanitizer feel so cold? | The alcohol quickly evaporates from your skin. Faster than water would. As it does, it grabs a bit of heat from your hand. It’s the same as why water evaporating from your skin cools it off including sweat. Alcohol does it faster so it cools your skin quicker. | [
"A hand sanitizer or hand antiseptic is a non-water-based hand hygiene agent. In the late 1990s and early part of the 21st century, alcohol rub non-water-based hand hygiene agents (also known as alcohol-based hand rubs, antiseptic hand rubs, or hand sanitizers) began to gain popularity. Most are based on isopropyl ... |
Does lightening ever travel up, above the clouds to interact with planes etc.? | Well, lightning doesn't care about direction, only about the electric potential. There are plenty of strikes [between or inside clouds](_URL_1_).
[Planes also get struck by lightning all the time](_URL_0_), which is generally harmless since they act as Faraday cages.
The specific thing you seem to be asking about is whether planes can also get struck by lightning when they're much higher than the clouds. [This seems to say the answer is no](_URL_2_), because the plane isn't an effective ground by itself, and has to be between, inside or below clouds to get hit. | [
"When flying over clouds illuminated by sunlight the region seen around the aircraft's shadow will appear brighter, and a similar effect may be seen from dew on grass. This partial retro-reflection is created by the refractive properties of the curved droplet's surface and reflective properties at the backside of t... |
the meaning/significance of all the nazi stuff in pink floyd's the wall. | It's about shutting out things that are not like ourselves and withdrawing by being unpleasant to people around us. Pink has been so hurt by all of the things that have happened in his life that he is pushing people away so that they won't hurt him any more.
_URL_0_ | [
"In 1993 Haacke shared, with Nam June Paik, the Golden Lion for the German Pavilion at the Venice Biennale. Haacke's installation \"Germania\" made explicit reference to the pavilion's roots in the politics of Nazi Germany. Haacke tore up the floor of the German pavilion as Hitler once had done. In 1993, looking th... |
[Medicine] Do flu shots really contain only one strain of influenza? If so, how is that one particular strain chosen every year? What are the reasons we cannot inoculate with multiple strains? | I did my grad work in one of the labs that develops the annual flu vaccine, and my thesis was on improving viral yield.
It contains three strains, two of Influenza A, and one of B. Every year in the North Hemisphere spring, the strains that are circulating elsewhere in the world are studied, and the committee chooses the three that are predicted to be most dangerous when the winter flu season comes around next. Samples of these strains are grown in pure culture and sent to labs for development.
The flu vaccine is grown by inoculating embryonated chicken eggs with the virus, and then harvesting the allantoic fluid several days later, and purifying the amplified virus from that, killing it with formalin, and formulating the vaccine.
The difficulty lies in that the strain needed for the vaccine might not grow well in eggs, or might kill the embryo quickly. Therefore, the strain containing the surface antigens (hemagglutinin and neuraminidase) are crossed with strains maintained in eggs for decades, and well adapted to high yield in eggs. This is possible because influenza has an 8-segmented genome, and two strains can infect the same cell simultaneously. What we did was inject both strains (vaccine and lab) into the egg, and harvest the progeny. These will contain a mixture of every combination of the genomes from both strains. These are diluted out a great deal, to the point where we are trying to inject < 1 virus per egg, on average, to get pure cultures of the progeny we want. The goal would be to inject ten eggs with the same dilution, and get one with virus in it. This is repeated several times and the progeny are tested to find the ones with the same H and N surface antigens of the wild-type vaccine strain, and the internal genes (Matrix, Nuclear protein, etc..) of the lab strain. These will grow with high yield in eggs, allowing for a faster and more cost effective vaccine production run, and be indistinguishable from the wild-type strain to the immune system.
Edit, Stupid typos from multitasking | [
"Due to the high mutation rate of the virus, a particular influenza vaccine usually confers protection for no more than a few years. Each year, the World Health Organization predicts which strains of the virus are most likely to be circulating in the next year (see Historical annual reformulations of the influenza ... |
when a stock market crashes and everyone is desperately 'selling', who is actually willing to 'buy'? | The fact that not many people are willing to buy is what *causes* the crash. If as many people were buying as selling, the price would stay about the same. The fact people are desperate to sell means there are more sellers than buyers, so the price drops.
The few people who are buying are either ignorant of the crisis, or buying speculatively thinking that he stocks will rebound at a later date. Shares that crash to near zero will either rebound, or become completely worthless if the company involved goes bankrupt and has no positive assets. | [
"A common \"stock market\" transaction is a \"short sale\" where, for example, an investor who believes a publicly traded stock is over-priced will borrow that stock from an owner, sell the borrowed stock, and repurchase the stock later at a lower price to repay the loan, thereby making money if the price has falle... |
Is it possible for things we consider to be waves to exhibit particle like behaviours at a quantum level? | It works both ways: Quantum objects exhibit the characteristics of both particles and of waves, but are they themselves neither. | [
"The concept of wave–particle duality says that neither the classical concept of \"particle\" nor of \"wave\" can fully describe the behavior of quantum-scale objects, either photons or matter. Wave–particle duality is an example of the [[complementarity (physics)|principle of complementarity]] in quantum physics. ... |
why is it that lobsters have the possibility to be born with so many rare colorations? | Short answer:
Each lobster has color pigments (red, blue, yellow), that determine the color of the shell.
Specific mutations change the amount of pigment and thus the color.
Some mutations that influence (for example) blue pigment naturally appear more often than others, that is why blue lobsters appear more often than yellow ones.
Source & cool additional info and more accurate than my short description is here:
_URL_0_ | [
"Typically, lobsters are dark colored, either bluish green or greenish brown as to blend in with the ocean floor, but they can be found in a multitude of colors. Lobsters with atypical coloring are extremely rare, accounting for only a few of the millions caught every year, and due to their rarity, they usually are... |
why doesn't water help with dry skin? | its not water that makes skin stay moist - its oils in the skin. ^edit to be completely clear, the water is still important - the oil just acts to prevent that water from evaporating.
If you have dry skin, its because your skin's natural oil production is for whatever reason lower than it should be.
Edit: I'm not a dermatologist, just a lumpy potato that resembles a [scrotum](_URL_4_), so any questions are going to get some less-than-stellar answers. try /r/Dermatology or /r/AskADoctor
Double edit: Dermatologists/Doctors are there for a reason, if you have a serious skin condition or are worried about your skin, talk to them and see what your options are.
Triple edit: There's got to be a few dermatologists out there somewhere who can help verify answers or answer questions throughout this thread! If anyone viewing knows someone, see if you can ask them and see whats up.
Final edit; Figures one of my most well-voted comments on ELI5 involves a scrotum joke. Cheers all!
---------------
Useful Links:
/u/ieatbugs posted [here](_URL_1_) a link to /r/SkincareAddiction on the types off Moisturizers out there that might be of some use to people
/u/steve-s posted [here](_URL_3_) a link to an _URL_2_ article that has some information on natural skin oils
By request from /u/LgNBullseye , a [selfie](_URL_0_). That is really a potato, I promise :p | [
"Dry skin results from lack of water in the outer layer of skin cells (the stratum corneum). When this layer becomes dehydrated it loses its flexibility and becomes cracked, scaly and sometimes itchy. The stratum corneum contains natural water-holding substances that retain water seeping up from the deeper layers o... |
what a "trust fund baby" is and exactly how a "trust fund" works. | A trust is a specific legal entity that allows someone to separate themselves from an amount of their money. Money placed in the trust is "safe" and can not usually be touched except for the express purposes that are outlined in the formation of the trust. A trust fund baby most likely has a trust set up for them that is for the express purpose of funding their well-being, i.e. the baby is the trust's beneficiary.
Trusts typically have executives that are in charge of ensuring that funds taken out of the trust are in accordance with the trust's objective or stated purpose. For example if I made a trust for my son and decided I wanted to take out a few hundred grand to get myself a car, the executor would tell me to buzz off since that is completely unrelated to the purpose of the trust.
A trust can be ordered liquidated by the court in the event that it appears to be illusory, e.g. I make a trust, make myself the executive as well the beneficiary, in that case I am simply trying to hide funds. I would imagine that unless there is abuse of the funds by the parents or executive a trust fund established for a child would be very hard to prove as illusory, I was just including this for completeness.
That's my understanding of trusts but a lawyer would be able to explain it more thoroughly. In a nutshell, think of it as a special savings account with special protections that can only be used for very specific purposes.
Source: My father is an attorney and has given me a high level summary on how these work in layman's terms. I am not an actual lawyer so I may have some of the minutia wrong, I am pretty confident in the high level functionality though. | [
"A trust may be used as an estate planning tool, to direct the distribution of assets after the person who creates the trust passes away. Trusts may be used to provide for the distribution of funds for the benefit of minor children or developmentally disabled children. For example, a spendthrift trust may be used t... |
it is said that children are (almost) immune to motion sickness up to the age of 2. why? | The main reason for motion sickness is our body has trouble reconciling the visual cues for no movement with the physical sensation of movement. The difference causes our bod to freak out, and we throw up to expel whatever apparent poison we've consumed.
Children don't have the history to realize there is a discrepancy yet. | [
"Children differ from adolescents and adults in their interpretation and ability to express their experience. Like adults, children experience physical symptoms including accelerated heart rate, sweating, trembling or shaking, shortness of breath, nausea or stomach pain, dizziness or light-headedness. In addition, ... |
court mandated community service is like forced labour? | Yes, it is. Punishments by courts almost always involve someone doing something they'd rather not do.
If you think the community service is bad, prison is worse. | [
"Convict or prison labour is another classic form of unfree labour. The forced labour of convicts has often been regarded with lack of sympathy, because of the social stigma attached to people regarded as \"common criminals\". In some countries and historical periods, however, prison labour has been forced upon peo... |
if the reason most mammals have testicles outside their bodies, what about sea-mammals (seals, whales etc)? how do they get around the issue of high body temperature affecting sperm? | Sea mammals keep their testicles in internal pouches surrounded by thick tendon-like tissues that keep the temperature lower than the surrounding muscles. | [
"Boreoeutherian land mammals, the large group of mammals that includes humans, have externalized testes. Their testes function best at temperatures lower than their core body temperature. Their testes are located outside of the body, suspended by the spermatic cord within the scrotum.\n",
"The early mammals had l... |
why are musicians/composers like mozart regarded so highly? if something almost just like it came along now, would it be regarded as highly? | W.A. Mozart is considered by most musicians to be one of the most influential composers for a variety of reasons:
(WALL OF TEXT WARNING, I'm on mobile, sorry)
-Prolific composer: He composed over 600 works throughout his lifetime, for a large variety of mediums (symphony, string quartets, trips, duos, woodwind ensembles, solo instruments, etc...). Many of those works are considered pillars of the repertoire.
-Stylistic innovation: During Mozart's early life, the "stile galant" was the dominant compositional language. This style was characterized by its overly simple harmonic and rhythmic structures, as well as its apparent superficiality. Composers of galant style were primarily concerned with doing away with the intellectual complexity of the Baroque period (most notably J.S. Bach). Mozart gradually did away with this style, incorporating Baroque style complexity into his compositions while maintaining utmost clarity and expressiveness. He also incorporated the "sturm und drang" style (storm and stress) later in life, paving the way, along with Haydn, for the Romantic period, and composers like Ludwig van Beethoven and the such.
A quote by pianist Charles Rosen puts it real nicely:
"It is only through recognizing the violence and sensuality at the center of Mozart's work that we can make a start towards a comprehension of his structures and an insight into his magnificence. In a paradoxical way, Schumann's superficial characterization of the G minor Symphony can help us to see Mozart's daemon more steadily. In all of Mozart's supreme expressions of suffering and terror, there is something shockingly voluptuous."
TL;DR: Mozart changed the musical landscape by bringing back true depth of emotion in music, writing a ton of music, and being a role model for just about all composers after him. And he had the hots for his cousin. And he liked poop and fart jokes. Go figure. | [
"There is little doubt that successive generations of scholars have been sincere in their views of the composer, each claiming to be more 'objective' than the last, stripping away the veneer of speculation to arrive at 'the real man'. It is sobering to realize that these different opinions about Mozart as a person ... |
why can some women be in labor for more than a day and some give birth in less than an hour? | That’s just the way it goes. There will always be a range of time periods. Some babies, especially the second and third births, are more ready and able to make their escape. | [
"The phase of labor that extends into multiple hours (at least 14). The cervix usually dilates to over 14 cm before active labor occurs. When it first begins, it is encouraged that women stand up, walk around, and eat or drink. If failure to progress extends beyond this point, preventative measures need to be taken... |
how do colony based insects, such as ants, decide who to make the queen (or king) and how does that one get so much bigger/different in appearance? | The queen ant mates with a male and his sperm is used by her to produce eggs. The fertilized eggs develop into females and the unfertilized eggs develop into males(haplo-diploid sex determination). The workers feed the larvae and on the basis of each ones diet they develop either into workers or queens. The queens then leave the colony to find males and to start new colonies. | [
"The term \"queen\" is not particularly apt, as the queen ant has very little control over the colony as a whole. She has no known authority or decision-making control; instead, her sole function is to reproduce. Therefore, the queen is best understood as the reproductive element of a colony rather than a leader. O... |
how is it that some drugs are metabolised through the kidneys and others through the liver? | Great question!
Different drugs display a variety of metabolic pathways. Some are metabolized by the liver, while others are metabolized in the bloodstream or other tissues. Others are never metabolized at all. The **main factors that determine how a drug is metabolized (and eliminated from the body) are (1) the intrinsic chemical properties of the drug, (2) which enzymes the drug interacts with, and (3) where the drug actually goes**.
With respect to chemical properties: in broad terms, a drug that is too large, too negatively charged, or too fat-soluble (that is, hydrophobic or with a greater affinity for fatty or nonpolar substances) is difficult for the kidneys to get rid of in the urine. This is because the drug molecule cannot be filtered by the kidney (usually because it's too big or repelled electrostatically by the negatively charged filtering cells in the kidney)—or because, after the drug is filtered by the kidney from the blood, it can simply slip back into the bloodstream by crossing the membranes that line the tubules of the kidney.
How does the body remedy this? The answer is, in most circumstances, by allowing the drug to be metabolized—which can often make the drug molecule smaller, less fat-soluble, or simply more likely to be eliminated through the bile or the urine. Metabolism also allows certain drugs to become activated or deactivated.
Drugs that are metabolized in the liver are therefore usually too fat-soluble, large, or negatively charged to be eliminated by the kidney. They are also typically drugs that are taken in through the gut (that is, in most cases, you swallow the drug) or otherwise end up circulating in the bloodstream. The liver has specialized enzymes that oxidize (take negatively charged electrons away from), hydrolyze (break down), and conjugate (bind other molecules together with) the drug in the body—and only certain drugs can interact with these enzymes.
Other drugs have a higher affinity for enzymes that are present either in the blood or in other tissues around the body (like nerve or muscle). For example, the commonly used paralytic drug succinylcholine is broken down by the enzyme pseudocholinesterase, which circulates in the bloodstream.
Still other drugs break down by themselves or don't need any metabolism at all. Lithium, which is most commonly used today to stabilize the mood in patients with subtypes of bipolar disorder, enters the body as a lithium salt (which becomes simple ionized lithium after getting dissolved in the blood) and exits the body in the urine as a lithium salt. No metabolism necessary!
As a final note, remember that many drugs that we use don't (or, rather, shouldn't) fully enter the bloodstream at all. Most creams or ointments applied to the skin, for instance, are not meant to be used in amounts that can actually make it to the rest of the body. | [
"Factors responsible for the liver's contribution to drug metabolism include that it is a large organ, that it is the first organ perfused by chemicals absorbed in the gut, and that there are very high concentrations of most drug-metabolizing enzyme systems relative to other organs.\n",
"The liver derives its blo... |
How does the revised galaxy count effect Dark Matter? | No the gaaxy count does not matter at all for the dark matter hypothesis. In order to be able to explain the scalar power spectrum of the cosmic microwave background you already need to assume something like dark matter. Since the CMB stems from a time before galaxies even formed, the galaxy number must be irrelevant for the necessity of something like dark matter. | [
"In 2008 a study was published showing that M94 had very little or no dark matter present. The study analyzed the rotation curves of the galaxy's stars and the density of hydrogen gas and found that ordinary luminous matter appeared to account for all of the galaxy's mass. This result was unusual and somewhat contr... |
Are octopuses equally skilled with each arm or do they prefer one or more arms over the others like humans? | [This abstract](_URL_0_) of an article from the *Journal of Comparative Psychology* (J Comp Psychol. 2006 Aug;120(3):198-204.) indicates that researchers did find evidence for octopuses favoring particular limbs.
Full abstract:
> Previous behavioral studies in Octopus vulgaris revealed lateralization of eye use. In this study, the authors expanded the scope to investigate arm preferences. The octopus's generalist hunting lifestyle and the structure of their arms suggest that these animals have no need to designate specific arms for specific tasks. However, octopuses also show behaviors, like exploration, in which only single or small groups of arms are involved. Here the authors show that octopuses had a strong preference for anterior arm use to reach for and explore objects, which points toward a task division between anterior and posterior arms. Four out of 8 subjects also showed a lateral bias. In addition, octopuses had a preference for a specific arm to reach into a T maze to retrieve a food reward. These findings give evidence for limb-specialization in an animal whose 8 arms were believed to be equipotential. | [
"The highly sensitive suction cups and prehensile arms of octopuses, squid, and cuttlefish allow them to hold and manipulate objects. However, unlike vertebrates, the motor skills of octopuses do not seem to depend upon mapping their body within their brains, as the ability to organize complex movements is not thou... |
How do stimulants affect your heart rate? | Stimulants increase the activity of the sympathetic nervous system. They increase or mimic the action of adrenaline. Basically, there are 3 types of stimulants:
- Releasing agents (like cocaine) release more adrenaline.
- Reuptake inhibitors (like amphetamine) prevent the removal of adrenaline.
- Direct agonists (like ephedrine) directly bind to adrenaline receptors.
The receptor in the heart muscle in called B1 (beta-1). When adrenaline binds to this receptor, it increases the heart inotropy (contraction force) and chronotropy (contraction speed). Beta-blockers have the opposite effect, since they block the B1-receptor. | [
"The use of stimulants in humans causes rapid weight loss, cardiovascular effects such as an increase in heart rate, respirations and blood pressure, emotional or mental side effects such as paranoia, anxiety, and aggression, as well as a change in the survival pathway known as the reward/reinforcement pathway in o... |
i'm a casual sports watcher. what's the difference between the level of skill/play between the nfl/nba and their ncaa counterparts? | There is a skill gap, although the top college players are going to be better than the worst pros.
The biggest difference is skill consistency. Every NFL starter is one of the top 100 players in the **world** at their position. The difference between the best and the worst isn't that great. But in college, a starter the in the top 1000 of people who happened to have been born in a certain 4-5 range, a lot less exclusive. That means every college team is going to have holes in it, and the #1 RB is going to look pretty good running over the #1000 linebacker. The same player is going to face a learning curve facing even #100 in the pros.
> My question is WHY and HOW.
Besides the numbers game:
* physical maturity - males can continue to grow into their early 20's...a 28-year-old is not only done growing, but they have had a few years to get used to their final form
* physical conditioning - it can take a few years for even a fully mature adult to work their way up to top physical condition
* mental and emotional maturity - college coaches have to waste a lot of time babysitting teen age boy when the could be making them better football players
* experience - many college players only see the field of a few years of their eligibility, pros can have many years of experience on top of what they learned in college
* pracitce - college player are more limited in the amount of time they can be required to practice and study
* resources - pros make a lot of money, and can afford a home gym and a nutritionist and just about anything else they need to make themselves better | [
"In sports that require a player to play on offense and defense, such as basketball and ice hockey, a two-way player refers to a player who excels at both. In sports where a player typically specializes on offense or defense, like American football, or on pitching or batting, like baseball, it refers to a player wh... |
why people see 'waves' of color in the dark. | Because there's light, and your visual centers are doing their thing, but without enough information to make sense of it.
You might enjoy this article: _URL_0_ | [
"The wholly empirical approach holds that this experience is the sole determinant of perceptual qualities. The reason percipients see an object as dark or light, the argument goes, is that in both our own past and the past of the species it paid off to see it that particular way. Returning to the bucket analogy, im... |
How are gasses commercially produced? | There are quite a few ways to make gasses, though once a gas is made and purified it is usually compressed using some type of mechanical pump.
Lets look at oxygen for example. You could use a cryogenic distillation process or [pressure swing adsorption](_URL_0_) to extract oxygen from the air. There are also selectively permeable membranes that can separate oxygen and nitrogen. Alternatively, you could start with water and produce oxygen (and hydrogen) through electrolysis. The method you use will depend on the desired purity and the cost, which can vary wildly depending on the technique and if the gas is a byproduct of another process.
Different gasses will require different methods. Nitrogen could be obtained using most of those air extraction methods above, while we generally make hydrogen through reformation of natural gas. Small hydrocarbons like propane come from oil distillation and natural gas sources, and some others like ethylene might need to use specific cracking processes.
Once you have the gas in the purity you want you either transfer it to a tank if it already has the desired pressure or you can pass it through a pump to get it to the pressure you need. The type and size of the pump would depend on gas species, input and output pressures and flow capacity. Temperature manipulation can also work to move certain species between liquid and gas phases and deal with them that way, or pressure could be used for the same if applicable. | [
"The production process is distinct, both physically and chemically, from that used to create a range of gaseous fuels known variously as manufactured gas, syngas, hygas, Dowson gas, and producer gas. These gases are made by partial combustion of a wide variety of feed stocks in some mixture of air, oxygen, or stea... |
why is the amazon being deforested? is it just for the wood or are there other reasons? | Its to provide grazing land for cattle. And also for palm oil farms.
They cut down the rainforest then plant either grass or lots of just one type of tree.
Its not really for the wood that much at all. | [
"Before the 1960s, much of the forest remained intact due to restrictions on access to the Amazon beyond partial clearing along the river banks. The poor soil made plantation-based agriculture unprofitable. The key point in deforestation of the Amazon came when colonists established farms in the forest in the 1960s... |
At what point could you escape a planet's gravity by jumping? | Jump. Measure how high you jump in meters. Call this height "h". sqroot(2\*h\*9.81) should be your initial velocity. We want this to be equal to escape velocity, which is sqroot(2gr), where g is the surface gravity and r is the radius of the object. Simplify everything, and you get g=9.81(h/r) | [
"In the video game \"Dead Space\", artificial gravity plates are used to simulate an Earth-like environment in outer space. In several levels, gravity plating is off and the player has to navigate in weightlessness using 'Zero-Gravity Boots', similar to magnetic boots. Defective gravity plates are also encountered ... |
how does the weather get reported by each town to the weather app on my phone? | There are organizations (large groups of people) who have satellites (giant cameras and sensors in outer space) which send the information they find to weather apps.
The satellites along with local meteorologists (weather analysts) provide information to weather apps, which show you the information they have and their predictions. | [
"The app allows the user to see the weather of a number of selected cities. Locations can be added by pressing the list icon and the plus icon which allows the user to type in the city's name, ZIP Code or postal code or airport code. Locations can be removed by tapping the list icon and swiping left on the location... |
if we keep raising the minimum wage then won't it just decrease the value of a dollar and cause to prices to rise because of inflation? | It does cause inflation, but minimum wage proponents don't see it that way. Yet uf you look at countries where minimum wage is high, the price of goods is higher as well.
The reason people want to raise minimum wage is because they feel better about earning more. But usually they just circle back to where they were before.
There are much better solutions to improving people's welfare, and happiness, where there isn't an adverse effect on purchasing power. A universal healthcare system for example, or public transportation, caps on real estate prices, government run educational institutes, etc. But these are harder to plan, and implement, so politicians tend to just do the easiest thing to placate people, which is not raise wages, but outlaw wages below a certain amount, which is what minimum wage really is. It doesn't mean you make more moeny, it just means that employers can't pay you below that specific amount.
| [
"The dollar value of the minimum wage loses purchasing power over time due to inflation. Minimum wage laws, for instance proposals to index the minimum wage to average wages, have the potential to keep the dollar value of the minimum wage relevant and predictable.\n",
"In 2014, over 600 economists signed a letter... |
is there a laser color stronger than the others? if so, why? | Blue is the strongest colour that we can see because it has the highest frequency of visible light. That means that there is more energy per second being delivered by a blue laser than a red laser. A UV laser would be stronger, and an X-ray laser stronger still. | [
"The apparent brightness of a spot from a laser beam depends on the optical power of the laser, the reflectivity of the surface, and the chromatic response of the human eye. For the same optical power, green laser light will seem brighter than other colors because the human eye is most sensitive at low light levels... |
Altitude Sickness? How sudden can it take effect, what can happen? | The cabin altitude of most airliners when in the cruise is about 8000ft. For most healthy people being suddenly raised to 8000ft pressure altitude and spending many hours there is a complete non-issue. There are plenty of long haul flights over twelve hours and 17 hours is the longest scheduled service I’m aware of - I’m not hearing of any cases of altitude sickness amongst healthy people. | [
"The most serious symptoms of altitude sickness arise from edema (fluid accumulation in the tissues of the body). At very high altitude, humans can get either high altitude pulmonary edema (HAPE), or high altitude cerebral edema (HACE). The physiological cause of altitude-induced edema is not conclusively establish... |
octonions - what exactly are they? | The complex numbers are a sort of two-dimensional extension of the real number line, with an imaginary axis (i, 2i, 3i, ...) along with the ordinary real axis (1, 2, 3, ...). It turns out that you can extend this idea even farther to have four distinct axes ("quaternions"), or eight ("octonions"), or sixteen ("sedenions"), and so on for any power of 2. While a real number might just look like 3, and a complex number might look like 3+2i, a quaternion could look like 3+2i+4j+6k, where i, j, and k are distinct values with the property that i^2 = j^2 = k^2 = -1. Octonions would then have eight distinct components, one "real" component and seven distinct "imaginary" components.
The farther you go with this, the more nice properties about numbers you lose. When you go from the real numbers to the complex numbers, you lose the fact that numbers have a neat linear ordering. When you move from the complex numbers to the quaternions, you lose the fact that multiplication is commutative: for quaternions, it need not be the case that x\*y = y\*x. When you move from the quaternions to the octonions, you lose the fact that multiplication is associative: for octonions you aren't even guaranteed to have x\*(y\*z) = (x\*y)\*z.
Despite the fact that the octonions are both rather abstract and lack many of the properties we expect number systems to have, they show up occasionally in theoretical physics. | [
"In mathematics, the octonions are a normed division algebra over the real numbers, meaning it is a hypercomplex number system; Octonions are usually represented by the capital letter O, using boldface O or blackboard bold formula_1. Octonions have eight dimensions; twice the number of dimensions of the quaternions... |
why does yeast in bread-making not produce alcohol like yeast in brewing? | It does, a little. But the amount produced is very small - bread rises for a matter of a day or two, brewing can take weeks or months. | [
"Several different yeasts are used in brewing beer, where they ferment the sugars present in malted barley to produce alcohol. One of the most common is \"S. cerevisiae\". The same strain of \"S. cerevisiae\" which can also be used in breadmaking is used to make ale-type beers. It is known as a top-fermenting yeast... |
it is a famous brag that England was never successfully invaded after 1066. So why doesn't the Dutch Army lead by William of Orange count? | This isn't my area of expertise, so someone else might be able to provide a better answer or more references, but as I understand it there are two issues here, one to do with the particular circumstances of William's 'invasion,' and one to do with British conceptions of our own 'history'.
The simple/traditional answer - ie. the argument that allows one to maintain that England has never been invaded, is that William and Mary were 'invited' to depose the Catholic James II/VII by a group of English peers on behalf of a population which was 'dissatisfied with the present conduct of the government in relation to their religion, liberties and properties.' On this basis, the Dutch army can be seen as only part of what was mainly a civil conflict, and thus it doesn't really 'count' as an invasion.
However, to an extent you have already answered the question yourself - the idea that England has never been successfully invaded is a brag, and isn't actually based in much fact; there are plenty of further examples of successful foreign invasions of England, unless one uses an extremely strict definition of invasion. Throughout the middle ages, for example, numerous Scottish armies successfully fought campaigns in England with control over border regions changing hands repeatedly until around 1482, when the English last conquered Berwick-upon-Tweed. Even if we insist on an invasion requiring a change of government, there are further obvious examples. The future Henry IV, for example, took the throne from his cousin Richard II after being exiled to France and making an alliance with the Duke of Orléans, who controlled the French court. Similarly, Henry Tudor had barely even visited England before he left France with a fleet of English exiles and French and Scottish soldiers to take the throne and end the wars of the roses.
The Tudor example in particular once led my venerable old medieval history tutor to use some less than elegant words to describe the 'little Englanders who maintain that our fair isle has never been sullied by foreign boots'. At the time, I mostly found this amusing because lol teachers swearing, but actually the fact that this myth has developed is interesting in itself. Alas, I have no idea where it came from, so would be interested to hear if anyone else knows.
*Sources*
The 1688 letter of invasion to William of Orange is in Browning, *English Historical Documents, 1660-1714*
*Oxford Dictionary of National Biography* entries on Henry IV and Henry VII are very good for basic info on their rise to the throne
| [
"The next year, William sent his sons William, the Prince of Orange, and Prince Frederick to invade the new state. Although initially victorious in this Ten Days' Campaign, the Dutch army was forced to retreat after the threat of French intervention. Some support for the Orange dynasty (chiefly among Flemings) pers... |
what is the ultimate luminosity? how many photons can we fit in a unit of 3d space? | Interesting question. My first response is an infinite number. Quantum field theory puts no limit on the number of photons that can be in the same place. But quantum field theory doesn't account for the gravity of the photons.
At some point, you'll have so many photons in one place and so much energy in one place, they'll collapse to form a black hole. The number of photons required for this will depend on their energy and how spread out they are, but it will be an absurdly huge number.
This would never happen in nature. | [
"Holograms can theoretically store one bit per cubic block the size of the wavelength of light in writing. For example, light from a helium–neon laser is red, 632.8 nm wavelength light. Using light of this wavelength, perfect holographic storage could store 500 megabytes per cubic millimeter. At the extreme end of ... |
after a natural disaster, what is the benefit of declaring state of emergency? | Not sure about insurance. But declaring a state of emergency will activate funds that have been set aside for clean up, repairs, and other needed things for after a disaster. | [
"In regards to Emergency Management, regions (usually on a local government area basis) that have been affected by a natural disaster are the responsibility of the state, until that state declares a State of Emergency where access to the Federal Emergency Fund becomes available to help respond to and recover from n... |
When was the ironclad warship firs proposed? | It's hard to say when the first ironclad warship was proposed, as many people came up with the idea of putting iron plating on warships at many different times. For example, the "atakebune" warships of the 16th century Japanese warlord Oda Nobunaga allegedly had some form of iron plating on their superstructure. During the early 19th century different people talked about the idea of iron-plated warships, but there was little impetus put into their creation until the Crimean War showed the strength of a type of naval artillery called the Paixhans gun.
Developed by French artillery officer Henri-Joseph Paixhans, the Paixhans gun was the first naval cannon to utilize explosive shells. Shells had been used by land artillery for quite some time, but due to the inherently dangerous nature of shells (they are essentially bombs, after all), they had been limited to use in howitzers and mortars. Howitzers and mortars are designed to lob their shots or shells at a high trajectory, and don't need to fire at as high of a velocity as the sort of low-trajectory cannons that were used in ships at the time. Using shells in high velocity cannons was rather risky. Paixhans was able to develop a new fuse mechanism and cannon that made it safe to use explosive shells on naval ships.
The Paixhans gun was developed in the 1820s and installed on French ships by the 30s, but its first use against enemy ships occurred during the Crimean War. At the naval Battle of Sinop during November 1853, which was the engagement that properly started the war, Russian ships with Paixhans were able to destroy their Ottoman counterparts with ease. Sinop made it clear that wood vessels had no real way to counter these shells, which would lodge themselves in their targets before exploding.
France and Britain declared war on Russia after the Battle of Sinop. The French Emperor Napoleon III, who did not want to risk seeing his ships go the way of those Ottoman ships when attacking Russian coastal fortifications (witch also had Paixhans), ordered the construction of armoured floating batteries, assigning the task to the inspector general of naval construction Garnier, a naval engineer named Guieysse, and Commander Favé, an artillery officer. A floating battery is a vessel with very limited mobility (they might be able to move at a few knots in calm seas and were often towed by other ships) but heavy armament. Floating batteries had been used before, but Napoleon III specified that these were to be designed to be able to deal with enemy shell-fire. He proposed that they use chests full of shot (the solid round projectiles fired out of muskets or cannons), but experiments conducted proved that iron plates backed by wood to be superior to cases of shot when dealing with both shells and shot. The French shared their plans with the British admiralty, and in 1855 the ironclad coastal batteries *Lave*, *Tonnante*, and *Dévastation* helped destroy Russian forts at the Battle of Kinburn with minimal causalities. Britain's ironclad batteries arrived too late to see any action.
During the 1850s the French sought to build up their navy with the construction of many steamships of all classes, but due to improvements in naval guns and the lessons of the Crimean War, the naval commission tasked with this naval construction decided to halt work on wooden ships-of-the-line and instead try to design ironclad seagoing warships (a process that would require lots and lots of men and experimentation). This culminated in the *Glorie*, designed by the naval architect Henri Dupuy de Lôme and his staff.
Rather than crediting one individual, I'd say that the main driving force behind the ironclad was the French Navy as a whole. Given his heavy involvement in the process, though, I suppose one could say that Emperor Napoleon III deserves a fair bit of the credit.
I can't say that I know much about the history of ironclads in the Royal Navy or other navies besides that of the French. If someone does, feel free to elaborate.
Source:
[Baxster, James P. *The Introduction of the Ironclad Warship.* Naval Institute Press, 1933.](_URL_0_) | [
"This is a list of ironclads of the Royal Navy of the United Kingdom. An ironclad was a steam-propelled warship in the early part of the second half of the 19th century, protected by iron or steel armour plates.\n",
"The \"Forester\"-class gunboat was a class of 4-gun composite gunboats built for the Royal Navy b... |
what holds fingernails in place? how far under the skin do they go? | Your fingernails and toenails are made up of cells that form into a hard surface called keratin. Keratin is also what makes up your hair and other parts of animals, like horse hooves and rhino horns. Underneath your fingernail is a soft surface called the nail bed. This is what produces the cells that harden and turn into keratin. The nail grows because it works kind of like the plates that make up the Earth’s crust: The nail bed forms new cells, which push on the older ones and make them grow outward. The whole structure inside your finger doesn’t extend much past the bottom of your visible fingernail. | [
"In human anatomy, the eponychium, or cuticle, is the thickened layer of skin surrounding fingernails and toenails. It can also be called the medial or proximal nail fold. Its function is to protect the area between the nail and epidermis from exposure to bacteria. The vascularization pattern is similar to that of ... |
Why wasn't LVT's used at D-day beach landings? | At the time, there was not enough LVTs for use in both the European and Pacific theaters. The initial stages of Operation Forager (the invasion of the Mariana and Palau islands) underwent preparation and execution at about the same time as D-Day, and few of the vehicles could be spared. Redeployment and retraining of amphibian tractor and amphibian tank battalions from the Pacific to European Theaters would have been another issue; drawing these units away could reduce the potential of troops in the Pacific to conduct landings. If LVTs were used on D-Day, it is presumed that only Army units would have been involved. In the first half of 1944, only a single Army amphibian tank battalion existed, the 708th. Activation and training of new units would also take time, up to a year.
The vast majority of LVT types were not armored at all, having only a thin steel hull.
Version|Armor|Notes
:--|:--|:--
LVT-1|None (9 mm plates added to some vehicles' cabs before Tarawa)|No rear ramp: capacity 18 passengers
LVT-2|None|No rear ramp; capacity 24 passengers
LVT(A)-2|6.5 mm on hull, 12.7 mm on cab|Armored version of the LVT-2; no rear ramp; capacity 24 passengers
LVT(A)-3|Presumably 6.5 mm on hull, 12.7 mm on cab|Proposed armored version of the LVT-4; not produced
LVT-4|None|Rear ramp; capacity 30 passengers
LVT(A)-1|6.5 mm on hull, 12.7 mm on cab, turret with armor characteristics of M3A1 light tank|Crew: 6
LVT(A)-4|6.5 mm on hull, 12.7 mm on cab, turret with armor characteristic of M8 Howitzer Motor Carriage|Crew: 6
Another consideration is their personnel capacity; early LVTs (LVT-1, LVT-2, LVT(A)-2) could carry only 18 to 24 troops, and they had to jump over the side owing to the fact that there was no rear ramp, slowing their exit from the vehicle. Using these vehicles would have forced a reorganization of the agreed-upon assault infantry battalion structure (6 assault boats per rifle company and 5 support boats for the heavy weapons company, plus a command boat, each of 30 men) More waves of smaller-capacity vehicles slows the execution of the landing
The LVT-4, capable of carrying 30 men and having a rear ramp, only began production in December 1943. It is doubtful that the logistical priority for the new vehicle would have been given to the European Theater, as LVT-type vehicles were needed and had proved themselves for the frequent invasions of Japanese-held islands in the Pacific Theater.
The following is purely conjecture, since we do not have any idea how the LVT would have performed in the choppy, currented seas of Normandy. Landings in the Pacific were undertaken only in calm(er) conditions, in which the LVT performed fine. The LVT had quite low freeboard, in comparison to the LCVP and LCM, which were purely boats.
In combat, the LVT probably would have struggled against heavy German antitank and artillery fire. They probably would have performed a role similar to the LCVP or LCM, dropping off troops at the water's edge and retreating to pick up more. Transport versions of the LVT used this tactic in the Pacific, and generally did not advance beyond the beach, except to move cargo or retrieve wounded when combat had already moved inland. Advancing up the beach with a full load of troops in the rear compartment would have been suicidal; there was no overhead protection, and the installation of an armored roof was only theoretically possible on the (new) LVT-4. In places, they also would have been unable to progress beyond the "shingle", a slope of small slippery stones some distance up the beach, that was impossible for tracked vehicles to climb.
Sources:
*Amtracs: US Amphibious Assault Vehicles*, by Steven J. Zaloga
[LVT(A)-1](_URL_1_)
[LVT(A)-4](_URL_0_)
| [
"LVTs were used in the Normandy landings, but their use by the United States was limited as the US Army doctrine in Europe viewed the Sherman DD as the answer to assault on heavily defended beaches. LVT-2s were used to help unload supplies after the landings on Utah Beach, from the cargo ships off the coast to the ... |
from newborn onesies to blouses, shirts and pants... why do men's and women's clothing fasten in opposite directions? | Men's jackets were made to be unbuttoned with their right hand so they could take it off with a cane in one hand. Women were dressed by other people so it's made to be easy for right-handed maids to button them up. Then the tradition stuck | [
"The men's garment was worn loose and was not tucked into the trousers, but instead belted either with a conventional belt, a rope, or a rope-like tie. The tails of the garment hung over the trousers. Women's shirts were tucked into the skirt or worn under the sarafan, and the button line of women's shirts tended t... |
how do these child sex allegations get proven 30+ years later if there is no pictures/videos? e.g cliff richards atm | Rape cases are very difficult to prove especially with no physical evidence.
Not sure who Cliff Richards is, but like when Sandusky got convicted. There were so many people that all told similar stories. It's a he said she said thing, but when so many people are all telling the same story the jury tends to believe the majority of people. | [
"In the 33rd petition, the problem was a video clip showing a man having continuous sex with his seven-year-old daughter. Min Kap-ryong said the video was a pornographic piece produced, and promised a swift investigation, although it is difficult to relate to sexual abuse of children. He apologized for the delay in... |
Why were the Swedish armies in the 17th and early 18th century so effective/had high morale? | There is a great previous answer here that should answer your question:
[How Carolean army was set up and what made it work](_URL_0_) | [
"The Swedish military had a unique position in Northern Europe at the time of the new system, being the only army that did not rely only on enlisted soldiers, mercenaries or conscripted soldiers. In relation to population size, the Swedish army was also the largest in Europe. Because of the allotment system, mobili... |
Is Earth losing oxygen? | Sort of. Most oxygen production on earth happens in the oceans (algae), so loss of forests, while impactful in many ways, isnt going to cause us to suffocate. Increase in CO2 does remove oxygen from the atmosphere through combustion, and we have increase CO2 concentrations substantially, but its still a negligble loss. The Earths atmosphere is ~21% oxygen, and 400 ppm (thats 0.04% of the atmosphere) of CO2. This is up from about 280 ppm pre-industrialization. Even if it got up to 1000 ppm (climate change to the point of palm trees at the poles) it would still not hugely impact the amount of oxygen in the atmosphere as this would reduce it from 21% to 20.99%. | [
"With all photosynthetic organisms gone, atmospheric oxygen can no longer be replenished, and is eventually removed by chemical reactions in the atmosphere, perhaps from volcanic eruptions. Eventually the loss of oxygen will cause all remaining aerobic life to die out via asphyxiation, leaving behind only simple an... |
normal "system" memory versus graphics memory | Graphics memory is designed for ludicrous throughput and custom applications. Graphics cards need access to massive memory bandwidth to do their job, a single 4K frame is ~25 MB and the GPU will be expected to generate at least 60 of them per second requiring a minimum of 12 Gbps of memory bandwidth to achieve 60 FPS at 4k. If you want to run 8x FSAA(full scene anti-aliasing) then you need to generate each frame at 8x the resolution or 32K equivalent and then down sample it. This gives you 1.6 GB **per frame** and 768 Gbps of required memory bandwidth. The Graphics RAM on a GPU serves as its input buffer storing textures that it needs to reference during rendering and storing the finally rendered scene.
Because of this insane bandwidth requirement, GPUs often talk to several chips in parallel so they can have up to 512 bit wide memory buses so each clock edge can give them 512 bits of data and then they run at quite high frequencies. An nVidia 2080 TI has a memory bandwidth of 4,928 Gbps.
Standard memory is designed to be compatible with every system, as such it has an agreed upon bus width (64 bits) and frequency set. While it will sometimes have lower latency than graphics ram and is generally significantly cheaper per GB, even the fastest stick of DDR4 can only give you 200 Gbps, but this is more than enough because your CPU isn't handling huge quantities of data generally. Its restricted on doing math on what it can fit in its L1 and L2 cache, everything else is a longggg wait for a CPU. | [
"In computer architecture, shared graphics memory refers to a design where the graphics chip does not have its own dedicated memory, and instead shares the main system RAM with the CPU and other components. \n",
"Video Memory is built in RAM installed on the video card that provides the graphics card with its own... |
Why did exotic exploration seem quite popular around the turn of the century? | [1/2]
Unlike the so-called "Age of Exploration," this period doesn’t have a codified name, in part because I don’t think that it has as large a place in our popular narrative of "history of Western civilization" the way that earlier explorers like Columbus, Magellan, and others do. However, that doesn’t make that we can’t talk about it. My answer here is going to focus on Britain and the British Empire specifically, both because that’s where my area of expertise lies and because they were all over the globe and had an intense interest in exploration and the "adventures" of these explorers and the knowledge they gained permeated British popular culture. However, the British weren’t alone in this endeavor, and French, Americans, and other nationalities took part. This topic is just too broad for me to go into detail in all times and in all places, so I’m going to try and zero in on a few specific examples that I think are illuminating and also talk some about the popular culture aspect.
As you hinted at when you said that India was at the height of colonial rule, all of this exploration was a facet of imperialism. While the British and other Europeans set out to conquer the globe, they wanted information about the places they were colonizing—clear definition of borders, knowledge of the local geography, and a catalogue of potentially-exploitable resources.
However, this white European incursion (particularly into the African interior) wasn’t just driven by practical considerations that would assist the running of empires. The Victorians in particular had a huge appetite for knowledge and a desire to describe and classify the world.
I’m going to pause here with a disclaimer because this answer is going to be discussing "knowledge" and "science" a lot, and I want to be clear that I’m talking about white European knowledge and ways of knowing. Obviously, the indigenous people who lived in the places being systematically explored for the first time by white Europeans knew their own landscapes and environments, and European exploration pretty much always relied on local guides and porters.
That said, this drive to increase European knowledge was an outgrowth of what the Victorians believed to be a rational, scientific mindset that would add to the huge knowledge-base of British civilization. I’m going to quote a passage from Joseph Conrad's 1899 novella *Heart of Darkness*, both because it’s exactly the time period you’re asking about and because I think it’s instructive:
> Now when I was a little chap I had a passion for maps. I would look for hours at South America, or Africa, or Australia, and lose myself in all the glories of exploration. At that time there were many blank spaces on the earth, and when I saw one that looked particularly inviting on a map (but they all look that) I would put my finger on it and say, 'When I grow up I will go there.' The North Pole was one of these places, I remember. Well, I haven't been there yet, and shall not try now. The glamour's off. Other places were scattered about the hemispheres. I have been in some of them, and... well, we won't talk about that. But there was one yet—the biggest, the most blank, so to speak—that I had a hankering after.
The speaker, Marlow, then goes on to describe the Congo River and eventually goes there, where most of the book is set. We can see in this passage that as a young boy, Marlow wanted to fill in all the blank spaces on the map. Marlow is, of course, a fictional character created by Conrad, but Marlow wasn’t a weird child but rather emblematic of his culture in nineteenth century British—part of the British imperial project was indeed filling in the maps (preferably with red or pink, the color used to denote British imperial holdings). This is all to say that geography, scientific knowledge, and empire are all enmeshed with each other such that you can’t really untangle them. Added onto this was an ideology of "civilization," in which imperialists also believed they were spreading their superior civilization by making contact with indigenous peoples (and in some cases converting them to Christianity).
The case of Dr. David Livingstone seems instructive here. The phrase "Dr. Livingstone, I presume?" is still famous, but most people don’t know why. Livingstone was a Scottish doctor and Congregationalist missionary who spent extensive time in Africa. Livingstone represents the complicated admixture of imperialism, humanitarianism, and science that often underpinned these explorations. Livingstone began his career as a missionary intending to convert Africans to Christianity and eventually led scientific expeditions mapping the African interior. He was the first known European to see Victoria Falls and did much work mapping the Zambezi River (through much of what is today Zambia) with the backing of the British government.
These expeditions made Livingstone a hero in the eyes of the British public. He represented, to them, the best of Victorian society, a missionary with a sharp scientific mind making discoveries for the good of the nation. Livingstone used his fame to oppose the Arab slave trade in East Africa.
In 1866, Livingstone returned to Africa with the intention of locating the source of the Nile River. Keeping in mind that this was before technology like satellites and GPS that aid in mapping and that much of the interior of the African continent was still unknown to Europeans, this was a topic of debate amongst explorers and geographers. The source of the Nile had been identified by John Hanning Speke and Richard Francis Burton (other explorers who both could be subjects of their own posts entirely) as Lake Victoria, but Livingstone disagreed and set out to prove them wrong. (Speke and Burton were more or less correct, by the way, but even a quick perusal of the Wikipedia page on the source of the Nile will give you an idea of why there was so much confusion; several other rivers feed into Lake Victoria itself.) Livingstone was soon in the African interior without contact with the British, and as the years wore on without his return, the public began to worry about him.
Enter Henry Morton Stanley, a Welsh-American whom the *New York Herald* paid to look for Livingstone while sending dispatches about his journey. Stanley's dispatches were a sensation in the press, and he eventually found Livingstone in the town of Ujiji on Lake Tanganyika, hence "Dr. Livingstone, I presume?" (Since Livingstone was the only white guy around, it wasn’t hard to figure out who he was.) Livingstone chose to stay in Africa, continuing to search for the source of the Nile, and eventually died there. Stanley returned to tell his story and became an explorer in his own right, though his reputation is considerably darker than Livingstone's, despite some attempts to rehabilitate him by biographers such as Tim Jeal. When you help King Leopold of Belgium establish the Belgian Congo, one of the most brutal of imperial regimes, history doesn’t look kindly on you. He also had something of a reputation for personal cruelty to his African workers, which doesn’t help. | [
"The era of European and American voyages of scientific exploration followed the Age of Discovery and were inspired by a new confidence in science and reason that arose in the Age of Enlightenment. Maritime expeditions in the Age of Discovery were a means of expanding colonial empires, establishing new trade routes... |
If photons are Massless bundles of concentrated electromagnetic energy, why is there an interaction with electrons and light? Why don't photons just pass straight through objects instead of reflecting off of them? | What holds human-size objects together is electromagnetic forces (electric, mostly) and quantum effects. It's not mass. Solid objects are solid due to molecular forces, which are electric in nature (built on a quantum scaffolding).
So photons have plenty of stuff to interact with.
Also, about that "massless" thing - photons only lack *rest* mass. They do have energy just like any other particle, and "energy" is just another way of saying "mass".
The rest mass is just a number. Any particle has variable amounts of energy (mass), depending on how quickly it moves relative to you. They move faster - they have more energy (or mass). They move slower, they have less. When particles are sitting still relative to you, their energy (or mass) is at a minimum, and it's called rest mass (or rest energy).
Photons can't sit still. They can only move. Therefore, the rest mass concept does not apply here. That's all.
_URL_0_ | [
"Electromagnetic radiation can be viewed in terms of particles rather than waves; these particles are known as photons. Photons do not have a rest-mass; however, photons are never at rest (they move at the speed of light) and acquire a momentum nonetheless which is given by:\n",
"The photon, the particle of light... |
if you're not supposed to eat or drink before midnight before a surgery, what about emergency surgeries? | In a regular surgery, the idea is to make the procedure as uncomplicated as possible, hence the restrictions.
In emergency surgery, the concern is keeping people alive. As such, there may be extra complications in the surgery that may be due to something they have drank/eaten, but it usually pales in comparison to the complications that require you to have emergency surgery. | [
"Before the surgery begins, the surgeon will take multiple blood test, physically examine the patient, and the surgeon will also check the past medical records of the patient to make sure it is safe to conduct the surgical procedure. On top of that, the surgeon doctor will ask about the types of medications that ha... |
Do black holes have "layers" of light around them? | Yes. It is called the [photon sphere](_URL_0_) (two of them actually...see link). Basically this is an area where light orbits the black hole instead of falling in or flying away.
However, it is a very precarious balance to get a photon to do that so they will rarely make more than a few orbits before either falling in to the black hole or flying away.
| [
"which is traditionally assumed to be a supermassive black hole. Such black holes by definition can not be observed directly (light cannot escape them), but various pieces of evidence suggest their existence, both in the bulges of spiral galaxies and in the centers of ellipticals. The masses of the black holes corr... |
Why is nitrogen fixation evolutionarily beneficial? | It's beneficial because it allows the organisms to survive in the absence of oxygen. In that case, they use nitrogen as the final electron acceptor (instead of O2). Keep in mind that the enzymes regulating nitrogen fixation are O2 sensitive, and genes that produce those enzymes are inhibited in the presence of oxygen. So when it is present, they will use it as the electron acceptor, if not, then the nitrogen fixation genes are turned on and allow the usage of nitrogen as the electron acceptor. | [
"Nitrogen fixation is essential to life because fixed inorganic nitrogen compounds are required for the biosynthesis of all nitrogen-containing organic compounds, such as amino acids and proteins, nucleoside triphosphates and nucleic acids. As part of the nitrogen cycle, it is essential for agriculture and the manu... |
Has there been a higher peak than Mt. Everest on Earth throughout its history? | This is one of the most asked questions in the Earth Sciences category on this sub, for example, here are a variety of answers to this question (or flavors of this question): [1](_URL_13_), [2](_URL_14_), [3](_URL_6_), [4](_URL_12_), [5](_URL_15_), [6](_URL_9_), [7](_URL_1_), [8](_URL_8_), [9](_URL_2_), [10](_URL_16_), [11](_URL_7_), [12](_URL_0_), [13](_URL_3_), [14](_URL_10_), [15](_URL_11_), and more that I got tired of linking.
In short (and without rehashing all of these answers or parsing out the spurious ones), there are a variety of mechanisms / properties that impose limits on the height of mountain ranges on average and the height of individual peaks within those ranges. These limits are not precise (despite what some comments in the various links above suggest) and depend a lot on the details, many of which are hard to estimate for extant mountain ranges let alone past mountain ranges. With that uncertainty in mind, we generally think that the Himalaya represent something near the limit of the absolute height mountain ranges can reach. In terms of quantitatively estimating the height of past mountain ranges, there are techniques that allow us to make rough estimates (e.g. [paleoaltimetry](_URL_4_), [geothermobarometry](_URL_5_), etc), but in general these would only tell us about the average elevation of a range (and with pretty large uncertainties again), not the height of individual peaks. Thus, **the question isn't really answerable**. | [
"Mount Everest was climbed the following year. On 26 May, three days before the successful attempt, Tom Bourdillon and Charles Evans reached the South Summit before turning back due to malfunctioning oxygen apparatus. Their height of 8,760 m (28,750 ft) represented a new, short lived, altitude record, and can be se... |
Why and when did we start bombing civilians in World War II? | The first year of the war saw what Richard Overy puts rather well as "the slow erosion of any relative moral constraints that might have acted to limit the damage to civilian targets" (*The Bombing War: Europe, 1939-1945*, very well worth picking up on both Allied and German bombing offensives and the military and civil defence responses).
In September 1939 there was great caution in the use of British bombers. Leo Amery, an early proponent of bombing Germany, recorded in his diary that: "... our Air Force are still not allowed to bomb Essen or even set fire to German forests. In the coffee room I tackled Kinglsey Wood [Secretary of State for Air] on this. He was very stuffy and evidently has been responsible for all this". A later, possibly apocryphal, account has Wood responding to the question of why the Black Forest wasn't being bombed with "Are you aware that it is private property?" Bomber Command was restricted to German naval targets, but still not even permitted to bomb ships in dock for fear of missing and hitting civilians.
May 1940 saw Chamberlain, who had always opposed bombing urban targets, replaced with Churchill, historically a supporter of independent strategic bombing; Churchill's deputy Clement Attlee was also strongly in favour of raids on Germany. On 15th May the Cabinet approved strategic bombing of German targets where civilians *might* be casualties as long as the objective was military.
The early employment of the Luftwaffe was fundamentally operational, against targets in connection with land forces, but there were heavy civilian casualties in Warsaw and Rotterdam in 1939 and 1940, both bombed while under siege. There is debate over whether civilians were intentionally targeted to affect morale, or if civilian casualties were an inadvertent but inevitable result of the inaccuracy of bombing at the time (see, for example, Bas von Benda-Beckmann's *A German Catastrophe? German historians and the Allied bombings, 1945-2010* that includes accounts of historians arguing the legality of Luftwaffe operations compared to the RAF). Likewise the Blitz of 1940-41 against London and other industrial cities was primarily aimed at military and economic targets, but with large volumes of incendiary bombs and proximity of workers housing to docks and factories heavy civilian casualties were again inevitable, easily perceived as the objective of the attacks.
Bomber Command, meanwhile, had much greater problems with accuracy; never mind distinguishing between factories and nearby housing, with much longer ranges to cover and fewer navigational aids just getting within five miles of a target was a rarity (a famous report of 1941 found that, over Germany, three out of four bombers failed to find their targets; on moonless or hazy nights fourteen out of fifteen). Although, in theory, they were aiming at military and industrial targets, from the German perspective they were indeed indiscriminate attacks on "residential quarters and farms and villages" (or more often open countryside); the first attack on Berlin on the night of 25th/26th August destroyed a wooden summer house in a suburban garden and slightly injured two people, more bombs fell in surrounding farms leading Berliners to joke "Now they are trying to starve us out."
Both sides framed their own efforts as precision attacks on purely military targets and enemy action as indiscriminate terror bombing of civilians, backed up by historical precedent (in Britain the long-range bomber and Zeppelin attacks of the First World War, the actions of the Condor Legion in the Spanish Civil War, and Warsaw and Rotterdam; in Germany the naval blockade of the First World War and seemingly random bomber attacks). Bomber Command steadily widened the definition of military and military-economic targets; in September 1940 they suspended the policy of returning to base or jettisoning bombs if a primary target could not be hit in favour of bombing any target of opportunity, finally in October with the Blitz in full swing Bomber Command were authorised to attack, in addition to military-industrial targets, "enemy morale" through "heavy material destruction in large towns", though they were scarcely in a position to undertake such an effort until 1942 as they learned from Luftwaffe attacks and started to use heavy concentrations of aircraft, large high explosive bombs and substantial quantities of incendiaries. German efforts against Britain almost completely tailed off after the Blitz, later attacks were more efforts at retaliation for the ever-heavier Allied attacks (tip-and-run fighter-bomber attacks on the south coast, the 'Baedeker Blitz' of 1942, V-weapons from 1944).
March 1941 saw Bomber Command diverted to focus on naval targets, with the Battle of the Atlantic at a crucial period, until July when they were were allowed to return to what they saw as their main task, attacking the German transportation system and the morale of the civil population. *The Bomber Command War Diaries* has the target of the 14th/15th Hanover mission as "a rubber factory and the city centre". The 30th/31st mission to Cologne was in bad weather, thunderstorms and icing were encountered, Cologne was "believed hit"; German records show 6 buildings were damaged, no casualties.
It's a little lightweight (and entirely neglects other aircraft in favour of the Lancaster) but the BBC did a documentary a few years back, *[Bomber Boys] (_URL_0_)*, with the McGregor brothers where (as I recall) Ewan acted as a navigator, if that might be of interest, it might be available on YouTube.
| [
"During World War II, it was believed by many military strategists of air power that major victories could be won by attacking industrial and political infrastructure, rather than purely military targets. Strategic bombing often involved bombing areas inhabited by civilians and some campaigns were deliberately desi... |
Was Ho Chi Minh Really A Tyrant? | Ho Chi Minh is a difficult figure to analyze because he deliberately cultivated at least two different personalities. The first was of the kindly, elder nationalist and father to the nation. But he also was a committed communist internationalist. He was both. Not one or the either. But, this is precisely why the Indochinese Communist Party chose him as their leader. Men like [Tran Phu](_URL_2_) and [Truong Chinh](_URL_0_), (‘Long March') were committed internationalists that would alienate potential non-communist allies.
The debate about Ho Chi Minh is tied up in the politics of the war. In the late 1960s-70s scholars opposed to the Vietnam War, consciously and subconsciously, used their scholarship on Vietnam as a means to oppose American policies in Indochina. Following the orientalist work of a French scholar Paul Mus, Frances Fitzgerald wrote *Fire in the Lake*. This became the ‘Orthodox' view of the war. Ho Chi Minh represented the only authentic nationalism in Vietnam, combining nationalism with Confucian values. He and other Vietnamese had adopted communism only as a means to liberate their country. But they were *not really* communists. All Vietnamese understood this, and therefore the artificial South Vietnamese regime and US were fighting against the course of history. At the same time, there were writers like Douglas Pike producing much more critical studies of Vietnamese communism that supported US policies. More recently, a ‘Revisionist’ group of writers, most well known in Mark Moyar’s *Triumph Forsaken*, that argues that Washington had it right all along. Their policies in Vietnam were wrong, only in that they gave up too soon. Ho was just a brutal autocrat.
Both views are inadequate. Frances Fitzgerald and the Orthodox view is orientalist and simplistic. It’s rather insulting to Ho and other Vietnamese. They were intelligent, rational, and believed in socialist modernity -- to say they chose communism because it was their only choice is false and insulting. And the Revisionist view of Ho as communist Asian despot is just as simplistic and problematic.
Before I get to Ho’s actions, I want to note that during the period you reference in your question, the American period of Vietnam’s civil war from ~1965-1972, Ho Chi Minh was only a figurehead. He held no real power. It was a man from southern Vietnam named Le Duan who held control. Le Duan was transparently aggressive both in escalating the Vietnam war, and domestically against opponents in the communist Vietnamese Workers Party that opposed his war in South Vietnam. Ho at this time was limited to making public trips to visit allies like Mao, Kim Il-Sung, etc, serving as the regime’s kind public face, and little else. But he chose to continue on as the figure head.
However, Ho was never all powerful, not even in the 1940s. He faced strong domestic pressure from the Indochinese Communist Party (ICP) members who wanted a more communist regime from the start. Ho’s ambassador to France, Tran Ngoc Danh, even defected to the Soviet bloc and wrote scathing reports to the USSR citing Ho’s lack of commitment to communism. There were factions inside Vietnam opposed to Ho’s attempts to form a united front that could attract non-communists as well.
This would soon change after 1949. But first, I want to note that the Viet Minh front group, run by the ICP, was indeed brutal towards its opponents. From the moment the Vietnamese civil war began in 1945, before the French returned, the ICP was killing Vietnamese rivals (and some of their rivals were killing ICP and Viet Minh). Many were executed in the first weeks, and fighting between the Viet Minh and rival religious and political groups persisted. Ho was complicit in this, but certainly was not deeply involved, and in some cases would have opposed it. Local ICP leaders were often running their own show. While Ho was in Paris negotiating in 1946, Vo Nguyen Giap attacked the armed forces of non-communist revolutionary groups (with the complicity of the French army). After that point, there was no real opposition to the ICP within the revolutionary Democratic Republic of Vietnam (DRV) government.
The other main charge against Ho comes from the bloody land reform that took place in 1953-54. After 1949, China began supplying the DRV with weapons and advisors. Not long after China and the USSR formally recognized Ho’s government. No longer needing the support of the non-communists in the countryside, the ICP came back into the open as the Vietnam Workers Party (VWP) and began instituting communist policies. Much control was ceded to the Chinese ‘experts', who guided the VWP’s policies and held ultimate control. But the VWP was also an enthusiastic participant, eager to embark on its path to modernization.
The land reform was a vicious affair. Based on the Chinese land reform model, a set percentage of the Vietnamese population was determined to be exploitative landowners. Cadres went into the countryside and met this quota. They incited the population to denounce landowners, coached their opinions. After this a [staged trial](_URL_1_
) took place under portraits of Stalin, Mao, and Ho. The cadres then carried out a death sentence on behalf of the people. The method varied, sometimes employing a sword or gun, in some cases people were burned alive. Even revolutionary figures who had owned land were targeted. A woman named Nguyen Thi Nam was one of the first executions — the intended message that even if you supported the revolution, it would not absolve your class crimes. The toll of this is unknown. Based on research in Vietnamese archives, it’s likely at least 20,000 were killed. It could be higher toward 50,000. We won’t know unless the current regime falls and we have access to all the records.
Where is Ho in all of this? Well we know very little about decision-making in the government. For ‘Orthodox' writers favorable to Ho in their critiques of US policy, the tendency is to downplay these abuses, eliminate their ideological character, and and say that Ho was powerless at this time. I should note that these are often Americanists who do not know much about Vietnam and haven’t researched there. Perhaps representative, in his Pulitzer winning book *Embers of War*, Fredrik Logevall writes that land reform was to end food shortages, and Ho was powerless, overtaken by extreme elements (no mention of the Chinese advisors), and opposed Nguyen Thi Nam’s execution. Yet another historian Alex-Thai Vo, has shown that Ho Chi Minh published a vicious denunciation of Nguyen Thi Nam that approved of her execution. He may have even attended the trial.
Did Ho full-hearted approve of this, or was he simply falling in line? Much like the assassinations of non-communist rivals, perhaps he was not enthusiastic about these things. But nevertheless he participated and lent his support. The same can be said of the DRV/North Vietnam’s suppression of academic freedom. In an infamous incident called the Nhan Van Giai Pham affair, the regime arrested or ostracized some of the country’s most prominent writers and intellectuals because they had called for freedom of expression or mild reforms in 1955-56.
Was the DRV an oppressive police state? Yes. It remained so after the war, though much less so than the 1940s-80s. Was American involvement driven by that rationale? No. It had much more to do with geopolitics. And while the government of South Vietnam was a freer society than its northern counterpart, it still committed its fair share of abuses and arrested opponents for nothing more than speaking against it. That however did not dissuade the US from supporting South Vietnam. | [
"Minh remained a senior figure in the Party, albeit largely operating from Hanoi in North Vietnam, until 1972, when at the request of Ieng Sary he was sent to hospital in Beijing to be treated for high blood pressure. Minh died in Beijing on 22 December. His death further lessened the influence of the Hanoi-trained... |
Why is the factorial of 1/2 equal to sqrt(Pi)/2 but the factorial of both 1 and 0 is equal to 1? | The way to extend a function from a smaller domain to a larger one is to find some kind of formula that has the function in it that, in some way, suggests what the function should be at values outside of it's original domain.
Let's say that we want to know what x^(-n) has to be, assuming we only know that x^(n)=x multiplied by itself n times and that x^(0)=1. We know that that x^(a+b)=x^(a)x^(b). This suggests that x^(n)x^(-n)=x^(0)=1. So we have the formula x^(n)x^(-n)=1 and the only thing that is not defined in this is x^(-n). So we can solve for it and arrive at the formula x^(-n)=1/x^(n) and we have successfully defined negative powers in a natural way by using an extension formula. This happens all the time in math.
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So if we want to extend the factorial function to include positive half-integers, then we can do so without imposing any Gamma Function magic. This is done by relating the volume of n-dimensional sphere to factorials. Let's have V(n)=Volume of the n-dimensional sphere of radius 1. So V(1)=2 (this is just the interval [-1,1]) and V(2)=pi, V(3)=4pi/3 etc. Can we find a general formula for this in terms of just n?
It turns out that [we can show that](_URL_1_)
* V(2k) = pi^(k)/k!
* V(2k+1) = 2(k!)(4pi)^(k)/(2k+1)!
The formula for the even-dimension case is really nice, but the dimension for the odd dimensional case is really ugly, and the fact that they are split like this kinda sucks. Is there a better way that we can write this that doesn't distinguish between these cases so that I can just write "V(n)=..."?
If n is even, then I can rewrite the even case as V(n)=pi^(n/2)/(n/2)! and this is okay because n/2 is still an integer. This formula is nice. I want it to work for all cases. Since (n/2)! is not defined when n is odd, I'm free to assign to it whatever number I want. So I'm going to define (n/2)! to be whatever number it needs to be so that V(n)=pi^(n/2)/(n/2)! for *any* n.
This means that when n is odd, I need
2((n-1)/2)!(4pi)^([n-1]/2)/n! = pi^(n/2)/(n/2)!
The fact that n is odd means that everything on the left side of this equation is defined. In fact, the only thing that is *not* defined in this equation is (n/2)!, so we can solve for it to see what it has to equal. Doing this gives
(n/2)! = sqrt(pi)n!/(2^(n)((n-1)/2)!)
This formula for half-integer factorials is made so that V(n)=pi^(n/2)/(n/2)! for all integers n. Plugging in various odd n gives
* (1/2)! = sqrt(pi)/2
* (3/2)! = 3sqrt(pi)/4
* (5/2)! = 15sqrt(pi)/8
Obviously, the values of (n/2)! do not tell us how sets of size n/2 can be ordered, because no such sets exist. But the appearance of factorials in the formulas for the volume are connected to orderings of sets, so we're essentially finding a formula for how many ways a set of size n/2 *would* be ordered if it did exist. Generally, anytime you see a factorial, you're counting permutations of sets somehow, for instance [Here's why they are in Taylor Series](_URL_3_). Similarly, whenever you see pi in a formula then you're doing something with circles. Through this method, it's clear why there has to be a pi in the formula for (n/2)!, because we're using the formulas for volumes of sphere to do it!
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This method of extending the factorials is obviously limited to only half-integer factorials. But it's more naturally motivated than just pasting the expression for the Gamma Function and just saying "Plug in x=3/2" and it tells us how pi naturally gets involved. The resulting formula is something that is motivated, and not just handed down from Euler, our Lord and Savior.
But we *can* use the Gamma Function to extend all of this even further, it gives us a factorial for every complex number except the negative integers. In fact, there is a theorem saying that the Gamma Function is the only way to extend the factorial to the complex plane in a "nice enough way". But many of these kinds of results, values of familiar functions at unfamiliar values having unintuitive values, can be done without appealing to modern tools. Our modern tools are super powerful and were developed to find answers to very hard questions, like the [Prime Number Theorem](_URL_0_) or the [Riemann Hypothesis](_URL_2_). They weren't invented to evaluate the factorial function at non-integer values, they just need to be consistent with other, easier methods that do this, but they offer no cool math-tricks or insights. Just plug-and-chug.
I also find it weird that people are okay with the formula (1/2)!=sqrt(pi)/2 and not okay with the formula 1+2+3+4+...=-1/12. To me there's no philosophical difference, both are extending previous notions to where they are undefined by finding some extension relation, yet people get antagonistic about 1+2+3+4+.. and not (1/2)!. | [
"For any base, 0.1 (or \"1/10\") is always equivalent to one divided by the representation of that base value in its own number system. Thus, whether dividing one by two for binary or dividing one by sixteen for hexadecimal, both of these fractions are written as codice_49. Because the radix 16 is a perfect square ... |
Why does food lose some vitamins when baking or frying, compared to steaming or boiling? | When you expose things to heat, things change in them. You have seen this before--imagine you have a pumpkin. It's pretty hard--if you put it in boiling water for a while, it will get softer, will change color, and will change flavor. This is because when exposed to heat, many of the components change into other chemicals. The same thing happens with the nutritional elements in food--you put them in heat too long, and they break down and are no longer so nutritious.
Boiling is a little worse than other methods, though. You see, much of the nutritional substances can dissolve into the water--when you pour the water out, you pour them out too. | [
"Any form of cooking will destroy some nutrients in food, but the key variables are how much water is used in the cooking, how long the food is cooked, and at what temperature. Nutrients are primarily lost by leaching into cooking water, which tends to make microwave cooking healthier, given the shorter cooking tim... |
what is happening in the brain when you are not paying attention to someone saying something and you hear what they said inside your head some minutes after they've said it? | There are different levels of consciousness layered on top of each other that make up your reality. Some you are very aware of/in control of, others are kind of like "auto pilots" that let you do stuff like drive a car without really thinking about it, or wake up on time even though your alarm didn't go off, or hear someone say your name even though you weren't consciously listening to their conversation.
What I think is happening here, is basically your "subconscious" is paying attention even when your "primary conscious" is not, and when your conscious mind is no longer focusing on a thing at hand, sometimes your subconscious is nice enough to be like "hey a thing happened while you weren't paying attention, here it is". I don't really experience the thing you're talking about, but I get a thing a lot where I will just be looking around not focusing on anything in particular, and all of a sudden word pops up in my head as if I had just read it, although I didn't consciously read it. If I examine my environment again, I often find that word somewhere, and obviously my brain read it extremely quickly while I wasn't even trying to read, then helpfully handed me the information moments later. | [
"It is found that when the brain of an individual is activated by a piece of information of an event in which he/she has taken part, the brain of the individual will respond differently from that of a person who has received the same information from secondary sources (non-experiential).\n",
"Mind-wandering (some... |
Why didn't Abrahmic religions gain as much ground in Japan as in Korea did during the 1900s? | Short answer: Buddhism was indigenized in Japan by the 1900s, with a history extending back *centuries* and so was only a "foreign" religion by a technicality, but not in any practical term. That said, Buddhism in Japanese society had a very *very* high place, oftentimes intertwined with government, politics, and daily ritual. Korean Buddhism, since 1392, by design, was removed from society, and was a political pawn (emphasis on the *pawn* part). When Korea was annexed into the Japanese Empire in 1910, Japanese Buddhism was rich, diverse, and influential. Korean Buddhism was poor, decrepit, and seen as a corrupt and ultimately traitorous organization. Buddhism became more or less discredited in Korean society, and was seen as a backwards and ultra-traditionalist perspective that bore little relation to the modern Capitalist economy, of which Christianity seemed to be a part. In Japan, where Christianity did not accompany the modernity of the Meiji Resoration, it was proved that a nation could be developed, modern, and capitalist without mass conversion to Christianity.
Long answer: There was a similar question asked a few months ago which you can read my answer to [here](_URL_0_) | [
"During the absorption of Korea into the Japanese Empire (1910–1945) the already formed link of Christianity with Korean nationalism was strengthened, as the Japanese tried to impose State Shinto and Christians refused to take part in Shinto rituals. At the same time, numerous religious movements that since the 19t... |
What did it really mean to be released from a Gulag? Where would one be "dropped off" after serving their time in a camp? | The gulag was a massive system over a large period of time, so it's difficult to talk about it just as one thing. In fact, it was incredibly variable - that might have been its most defining feature in the end. So let's look at one particularly instructive moment - the 1945 amnesty. There is an absolutely fantastic article on this topic that I will mention at the outset, from which much of the following comes. I'll just throw the citation up here at the beginning so people can go find it if they want:
Golfo Alexopoulos. "Amnesty 1945: The Revolving Door of Stalin's Gulag." *Slavic Review* Vol. 64, No. 2. (Summer 2005), 274-306.
Indeed, the very premise of Alexopoulos article is as follows:
> Stalin's labor camps and colonies formed a dynamic , variable, and unstable system in which a majority of prisoners came and went, and the 1945 amnesty reveals the movement and tension of this revolving door. (275)
So it is not that the 1945 amnesty was typical, but rather than it was such a massive moment when it came to people departing the Gulag that it reveals that variation and dynamism.
So, in 1945 you about one million gulag prisoners either released or having their sentences reduced more or less all at once. It was a very controlled and measured process.
Alexopoulos explains:
> No only did they *[Officials in the labor camps -TMH]* manage the issuance of passports, provide transportation from the camp or colony to the prisoner's new location, and issue (or not) material goods and food for the journey, but more importantly, Gulag authorities decided the destination of each ex-prisoner. According to the Gulag leadership, the issue of where to settle amnestied prisoners 'had to be approached with care' in order to provide maximum assurance that the former inmates would 'return to an honest life.' (292)
One specific treatment an inmate received was largely dependent on who they were, what the crime had been, and what the leadership thought was their best chance at avoiding the person returning to a criminal life. Leaving aside for the moment the "true" criminality of various things - the Gulag did, after all, hold many political prisoners - there were still many different kinds of people who had to be integrated back into Soviet society. Destinations could include ones family or place or origins in the best case scenario, or communities designed explicitly for the rehabilitation of prisoners that were nonetheless distinct from the Gulag system and where they might be working in heavy industry. Others faced exile that meant they weren't imprisoned, but were neither free to return to many parts of the Soviet Union that were likely more desirable. (293-294) Keep in mind that the freedom of movement throughout the Soviet Union was in many cases highly restricted, so simply being out of the Gulag didn't mean you could go just anywhere even after you arrived at your destination. In some extreme scenarios, prisoners were technically released from their prison term and marked in the system as having served their time, but were nonetheless required by law to continue working the same job they had worked in the labor camp as 'civilian laborers'.
Assuming the best case scenario, you still had to integrate yourself back into the society and economy with a criminal record, which was no easy task. Alexopoulous cites 100s of documents he found in GARF (the largest archive in Russia), of former prisoners appealing to be given a clean record after release to help them integrate back into the economy more easily. Remember that when the economy is state run, that criminal record is going to follow you literally everywhere and a lot of jobs simply won't be available to you.
Although the amnesty in 1945 provides us with a major data point, for lack of a better term it actually quite a bit to expose the extent to which the system was incredibly variable. The Gulag wasn't just a place you got thrown in and rotted, although that did happen. People were constantly entering and leaving the system. Still, the experience could be arbitrary. Sentences were extended without warning. The conditions were terrible, and even if and when you did get out, your life wasn't necessarily just going to go back to normal. The high turnover in the Gulag also exposes another feature though - that it permeated Soviet society. With so many people coming and going, many ordinary Soviet people would have had contact with people who had some experience of the Gulag, which meant that it was a very present system in the minds of Soviet people. It wasn't some far away place, but paradoxically close to home despite the often remote locations of the camps. This kind of thinking, thanks in large part to Alexopoulos' article is becoming more the norm in studies of the Gulag.
| [
"After the in 1953, partial amnesty was granted for some labor camp inmates on 27 March 1953 with the end of the Gulag system, then extended it on 17 September 1955. Some specific political crimes were omitted from amnesty: people convicted under Section 58.1(c) of the Criminal Code, stipulating that in the event o... |
Did Protestants, after the Reformation, use large-scale violence to convert differing groups in a manner similar to The Crusades? | A reply to /u/teaandabook
I'm not sure the context of your question. Are you aware of the religious wars in France and Germany, also known as the Thirty Years' War, that saw widespread destruction and violence by all sides of the conflict? Or the Dutch rebellion, known as the Eighty Years' War? | [
"Once a particular Christian sect or creed gained state backing religious violence increased. This took the form of persecuting adherents to rival Christian beliefs and other religions. In Europe during the Middle Ages Christian antisemitism increased and both the Reformation and Counter-Reformation led to an incre... |
the difference between a thc pill and smoking marijuana for medicinal purposes. | There IS a drug on the market (Dronabinol) that contains the main THC in marijuana. However marijuana has a lot more cannabinoids (the class of substances that THC belongs to) and when smoked have a much quicker effect than ingesting a pill. | [
"In an article in \"The Nation\", the author notes that Berenson seems to fail to understand or admit that marijuana contains both THC and CBD (which has been approved by the FDA in the form of Epidiolex to treat some kinds of epilepsy), and that medical marijuana products generally contain low THC and high CBD.\n"... |
Is it possible to know what color a material will be without actually seeing it? | Yes. Color is determined by the band gap of materials. Band gaps between 3-5 eV correspond to visible light (color). We can roughly calculate these electronic levels for a given material computationally (though imprecisely), but know it easily through experiment. Thus, if you have information on these band gaps, you could determine the color the material will be (since energy corresponds exactly to frequency regardless of media).
More laymen discussion easily found at _URL_0_ | [
"It may be difficult to determine whether a given property is a material property or not. Color, for example, can be seen and measured; however, what one perceives as color is really an interpretation of the reflective properties of a surface and the light used to illuminate it. In this sense, many ostensibly physi... |
How "French" were the Franks? (plus some bonus questions) | I can't answer your question because I don't know enough about the time period, but I did want to address your use of names as evidence. Charlemagne was actually called "Carolus Magnus," it was just 'french-ified' to Charlemagne. Germans call him Karl. In the same manner, Louis is called Ludwig by Germans. It isn't really fair to say that they have French names given that they also have German names. | [
"The Franks emerged in the southern Netherlands (Salian Franks) and central Germany (Ripuarian Franks), and later descended into Gaul. The name of their kingdom survives in that of France. Although they ruled the Gallo-Romans for nearly 300 years, their language, Frankish, became extinct in most of France and was r... |
how are broken bones in non-castable areas fixed? | Well, if you break the neck of the femur, they drill a hole and install a screw bracket through the femur and into the head of the femur to hold it in place while it fuses back together. You can't put weight on that leg for 6-8 weeks. Then you get to learn how to walk again, as the muscles have all atrophied. If all that sounds incredibly painful, it is. | [
"When a bone is fractured as a result of an injury, the two fragments may be displaced relative to each other. If they are not, usually no treatment is required other than immobilisation in an appropriate cast. If displacement does occur, then the space separating the fragments fills with blood shed by the damaged ... |
Why is Cyprus not part of Greece? | Greece was under Ottoman control and revolted in the 1830s while Cyprus was under British control and gained independence from them in the 1960s. Cyprus maintained its independence but there were those that wanted it to be apart of Greece, both in Athens and on the island. A Greek sponsored coup in 1974 ousting President Makarios III led to Turkey invading and controlling a third of the island. Now the island is divided between Turkish and Greek halves.
Does that help? | [
"Another concern of the Greeks is the incorporation of Cyprus which was ceded by the Ottomans to the British. As a result of the Cyprus Emergency the island gained independence as the Republic of Cyprus in 1960. The failed incorporation by Greece through coup d'état and the Turkish invasion of Cyprus in 1974 led to... |
why your feet tingle after you almost slip or sometimes when something slips from your hand | It's a small spike of adrenaline. When you're about to slip or drop something, your adrenal glands start pumping in case you need to respond quickly with power, strength, or heightened reflexes. | [
"When touched upon the soles of the feet, for example, it feels in addition to the common sensation of touch a sensation on which we have imposed a special name, \"tickling.\" This sensation belongs to us and not to the hand... A piece of paper or a feather drawn lightly over any part of our bodies performs intrins... |
most americans i've met are very smart, sensible people who generally seem to have been educated far better than i; how is it that there's such a prevalent cultural stereotype of the dumb american? | In the same vain that "the squeaky wheel gets the grease", our dumbest are generally are our loudest. | [
"Walter Russell Mead wrote about the book, Kohut and Stokes create enduring problems as long as the most individualistic people are against most American people. Most American tend to be more effective than most people about their ability to shape their own lives and like to using government action to solve social ... |
how the hell do deep fakes work? | Honestly, I know it's probably against the rules of ELI5, but I would recommend Corridor's Crew video on their Keanu Reeves deepfake to fully understand everything that's behind this.
In short, you basically have to get an actor to play the body of the subject of deepfake, and train an algorithm to match the face of that celebrity you want in the scene to the body of the duble, you need to track the face of the celebrity trough interviews and movies though | [
"Deepfake (a portmanteau of \"deep learning\" and \"fake\") is a technique for human image synthesis based on artificial intelligence. It is used to combine and superimpose existing images and videos onto source images or videos using a machine learning technique known as generative adversarial network. The phrase ... |
why do people say we aren't recovering from the recession? | I don't think anybody says the economy *isn't recovering.* At least, I don't think anybody *seriously* says that.
What some people say is that the economy isn't recovering *as fast as it could.* Everybody agrees that the economy is gradually climbing back out of the hole it dug for itself in the mid-late 2000s, but not everybody agrees that that recovering is going well, or that it's being brought about in the right way. | [
"Economists usually teach that to some degree recession is unavoidable, and its causes are not well understood. Consequently, modern government administrations attempt to take steps, also not agreed upon, to soften a recession.\n",
"When a recession occurs, many people, especially those who have lost their jobs, ... |
Is the reach of gravity infinite? | I just wanted to drop by with some numbers. If you had an empty and infinite universe and placed two hydrogen atoms one million light years apart, a nonrelativistic calculation says that they will collide in 7*10^43 years. That's a 7 followed by 43 zeroes. To give some perspective, the accepted age of the universe is around 10^10 years. That's 0.0000000000000000000000000000000001% of our number.
If instead of hydrogen atoms you put two people, the time would go down to about 7*10^29 years. Now it's just 100000000000000000000 times the age of the universe.
Note: the nonrelativistic approximation breaks down when the distance between the atoms is about 1% of the original 1 million light years, but the bulk of the time is spent going slow so it shouldn't matter a whole lot. | [
"This episode documents how gravity has a profound effect across the universe, and Cox seeks out a non-space zero-gravity experience to highlight his point. From the formation of galaxies and stars to the patterns of uplift and erosion seen on Earth, gravity is centrally important. Examples are given, such as the t... |
A question about optics.... | If this indeed happened then the only reasonable explanation I can think of is that it was a semi-transparent skirt to begin with and looked more opaque due to [ polarized specular reflections. ](_URL_0_) When his glasses partially filtered out the reflected light, the skirt appeared more transparent. Or he was messing with you. | [
"Optics is the study of light, and the instruments created to use or detect it (i.e. telescopes, spectrometers, etc.). Atomic physics, molecular physics, and optical physics are each individual sub-fields of AMO that study the physical properties of the atom, molecules, and light, respectively.\n",
"Two major the... |
Why are significant figures so stressed in chemistry, yet unimportant in physics? | I'm not sure where you've heard that significant figures are not important in physics, but that's absolutely not true. Significant figures are important in every field of science that works with measurements and experimental data.
Many mathematical operations cause the outcome to have more digits than the inputs. If you give the unmodified outcome, you make it appear as though your outcome is more precise than it actually is.
For example, if you measure a distance of 52 meters and a time of 17 seconds, you can calculate the velocity and end up with 3.0588235... (etc...) meters per second. If you then state that the outcome of the experiment is a velocity of 3.0588235 m/s, you're making it appear as though your experiment was extremely accurate, while in reality you only measured distance and time to 2 significant figures.
In reality, the distance might've been close to 52.38271 meters and the time closer to 16.6891 seconds, but the limited accuracy of your measurement system is unable to catch that level of detail.
So in order to accurately represent the precision of your measurements, you should give the final outcome with just 2 significant figures (when dividing, use the lowest number of significant figures of the two input values, which is 2 in this case as both numbers have 2 significant figures). And that's 3.1 m/s.
It doesn't really matter which field of science you're in, you can't "gain accuracy" by taking measurements with limited precision and applying mathematical operations to them. Therefore, you should be aware of the precision of your original measurements and what that means for the precision of your final answer. | [
"Importance: Influence, as described in the presentation speech for the Nobel Prize in Chemistry 1995: “The findings presented by this year's laureates in chemistry have had an enormous political and industrial impact. This was because they clearly identified unacceptable environmental hazards in a large, economica... |
my co-pay is $20, but without insurance it's thousands of dollars. how does the insurance company make any money? | In part, because the insurance company doesn't actually pay that "uninsured rate": because they are a huge customer, they negotiate much better rates for the drugs/services. You will never see what they pay: they get an invoice for the face amount, and then get a discount off that.
It's somewhat the same for car dealers. There's an "invoice" with a price, but they don't actually pay that price. The manufacturer gives them all kinds of discounts and credits based on complex rules, like if they meet an overall sales goal they get an extra 5% off.
| [
"BULLET::::- Coinsurance: Instead of, or in addition to, paying a fixed amount up front (a co-payment), the co-insurance is a percentage of the total cost that insured person may also pay. For example, the member might have to pay 20% of the cost of a surgery over and above a co-payment, while the insurance company... |
why do we sweat and tear up when we vomit? | When you vomit you are emptying your stomach. It is surrounded by large and strong muscle fibers that are responsible for "chewing" the food using your stomach walls as "teeth". Vomiting implies those muscle fibers to suddenly contract: the food goes up and exits using your mouth. Also, there is a lot of blood going in and out near your stomach. This process is similar to a sprint run: if you run for ten seconds at full throttle you will end very tired. | [
"Repeated or profuse vomiting may cause erosions to the esophagus or small tears in the esophageal mucosa (Mallory–Weiss tear). This may become apparent if fresh red blood is mixed with vomit after several episodes.\n",
"While the vomit response is commonly assumed to be a chemical reaction between the two foods,... |
What has to happen to grapes(or any fruit for that matter) for them to become seedless? | I'm a horticulturist that specializes in food, but I'm only on my phone and many of my sources are books that I have. However, I hope someone can help me verify what I'm about to talk about and tell me if I have something wrong.
The answer to your question is pretty long though, although a short form would be, "It varies."
There are many ways seedless fruits are produced, and I'd like to start with talking about what a seed is and how it affects the fruit. A seed is a a method of sexual reproduction, which means that male and female gametes, each with half of the genetic data of their parents, fuse together to create a new organism. It is a way for plants to exchange genetic material to create new combinations of genes that hopefully have a better chance of surviving to maturity and reproducing. For this reason, there are often many consequences to disrupting the seed production, with the most common being fruit abortion, because most plants' final goal is to produce a seed. For example, seedless watermelons are always personal sized for a reason, and it's because the production of the seed triggers the synthesis of gibberelins, which are a class of plant hormone associated with many plant physiology, including the elongation and dormancy of plants. In some cases, plants can also be treated with gibberelins to induce fruit formation and seed abortion, which is how some seedless fruits are made. However, the disruption of seed formation can be a result of human manipulation or mother nature, and in some cases, the seed is simply aborted as a mutation, which would have been the end of the road for most plants. However, someone was fortunate enough to have noticed this and propagate the plant vegetatively to retain the genetic traits.
In some cases, like bananas, the seeds are sterile due to genetic incompatability. I mentioned earlier that gametes carry half of the genetic material of the parents. However, in some cases, plants can gain extra sets of genetic data, and as a result, one gamete might have some extra DNA, then the two gametes cannot fuse because they need to have the same amount of genetic data to match up and fuse. The explanation for this occurence has to do with ploidy number and meiosis, which I'm sure a wiki article or someone else can explain in better way than me.
There are other types too, and I'll continue to add more information as I peruse through my hort books. | [
"The disease affects grapes worldwide, leaving all agricultural grape businesses at risk of \"Uncinula necator\". Powdery mildew of grape affects the size of the vines, the total yield of fruit, as well as affecting the taste of wine produced from infected grapes. The disease can also cause the blossoms to fall and... |
Why is the Byzantine Empire purple? | The real question, in my eyes, is "Why did the Romans like purple so much?"
Just ctrl+F this article for "purple"
_URL_0_
Purple had a "regal" [sic] context to it even in times of the republic. The Byzantines piggybacked on that to some degree. Everyone likes to relive the "former glory" of Rome, such as the Axis of WWII adopting the Roman military salute and the "Third Reich" moniker.
Why? Because it was expensive. Purple is darker than other colors, and looks cheap if it is not dark. As such, it's tough to make a good puple dye. Because of that, it was rare. Like gold, purple dye is valued because of its rarity. Because it was valued, it was used as a status symbol.
Edit: See also- this article on expensive purple dye.
_URL_1_
"The production of Tyrian purple was tightly controlled in Byzantium and was subsidized by the imperial court, which restricted its use for the colouring of imperial silks,[2] so that a child born to a reigning emperor was porphyrogenitos, "born in the purple", although this term may also refer to the fact that the imperial birthing apartment was walled in the purple-red rock known as porphyry."
| [
"Through the early Christian era, the rulers of the Byzantine Empire continued the use of purple as the imperial color, for diplomatic gifts, and even for imperial documents and the pages of the Bible. Gospel manuscripts were written in gold lettering on parchment that was colored Tyrian purple.\n",
"Imperial pur... |
how can there be updates on disc games? | They store the updates on the hard drive. All files have to be loaded into RAM before they're used anyway. When the game goes to load a file, it checks the hard drive to see if there's an updated version. It doesn't actually update the disk. | [
"Several game discs, both first-party and third-party games, have included system software updates so that players who are not connected to the Internet can still update their system. Additionally this can force an upgrade by requiring the player to perform the update, without which the new game cannot be played. S... |
Were any of the U.S. founding fathers alive during The American Civil War? If so what did they think about it? Or did they speak/write publicly about it at all? | None were alive. By greatly stretching the definition of founding father, you can get to 1848 with JQA. But Generally Madison, Marshall and one other guy who can't recall at the moment are considered the last living founders, and they died well before the start of the war.
Edit: Of course Madison was alive to see the Nullification Crisis, and the rise of sectionalism he spoke on both of these points multiple times. Judging by comments I am nearly 100% sure he would have looked at the Civil War with abject horror. | [
"For four decades leading up to the American Civil War, American historians and Revolutionary Era popularizers agonized over whether their generation was worthy of the founders’ sacrifices. While their sectional divisiveness tore the fragile nation apart, Northerners and Southerners competed to assert possession of... |
why do polar bears live at the northern pole and penguins at the southern? | I'd assume they could survive in either places. But neither animal would travel the length of the globe without human assistance. And they exist in those places for the same reasons that gorillas live in Africa and kangaroos live in Australia. They evolved there, they're specially adapted to that particular environment and have had no reason to migrate to other places of the world | [
"The polar bear is found in the Arctic Circle and adjacent land masses as far south as Newfoundland. Due to the absence of human development in its remote habitat, it retains more of its original range than any other extant carnivore. While they are rare north of 88°, there is evidence that they range all the way a... |
what are they doing in those numbered free mason lodges? | Networking, it's mostly small business owners being part of a fraternity. They help each other out and also do a lot of charity work. They are secretive, but that's just part of being a brotherhood. There is nothing sinister about Masonic Lodges. | [
"In some countries, notably the United States of America, there are also organizations affiliated with Freemasonry which admit both Master Masons and non-Masons who have some relation to a Master Mason, such as the Order of the Eastern Star, International Order of Job's Daughters (Job's Daughters International) and... |
king solomon and his temple | According to the Bible, Solomon was the son of King David, and the third ruler of the Kingdom of Israel. He is supposed to have been the one who commissioned the construction of the Holy Temple in Jerusalem, which became the place of worship for what is now the Jewish religion. In the year 586 BCE, the Temple was destroyed by the Babylonian empire. Later on, a second Temple was built on the same spot (the spot currently occupied by the Dome of the Rock), which was renovated by King Herod, and then destroyed during the Roman siege of Jerusalem in 70 CE. As an aside, both Temples were destroyed on the same date of the Hebrew calendar, which is coming up next Tuesday. Anyway, a lot of the conspiracy theories surrounding Solomon's Temple have to do with two groups. First, the Knights Templar, who, during the Crusades, set up their base on the site of the Temple. They went on to be the subject of approximately a metric fuckton of rumors, legends, and theories, including what they may have found on the Temple Mount. The second group is the Freemasons. Masons trace their traditions back to the artisans employed by Solomon to build the Temple, and they are very popular targets for conspiracy theories. To further complicate things, there is very little in the way of written extra-bibilical records of the time period in which Solomon would have lived (not to mention the fact that archaeologists are not in agreement as to when exactly that time period was) *and* the fact that the site of the two Temples is unavailable for excavation, and so much of the archaeological record has already been destroyed during construction and repair work on the two Muslim holy sites currently located there. | [
"King Solomon is one of the central biblical figures in Jewish heritage that have lasting religious, national and political aspects. As the builder of the First Temple in Jerusalem and last ruler of the united Kingdom of Israel before its division into the northern Kingdom of Israel and the southern Kingdom of Juda... |
I have heard plenty of times that the communist system in the Soviet Union is not what Karl Marx intended. | It was quite far away, for a multitude of reasons. There are many different factors, but this is a very broad summary of why the Soviet Union was never “real” communism.
First off, the communism Marx intended for was mainly for advanced industrialized western European countries such as England, France, Germany. This is because the more advanced and industrialized the country, the more distinct class distinction was, with more worker manipulation taking place by the owners of the means of production. This is because with industrialization, the need for a lot of workers decreases, so there was more and more competition for the jobs remaining. This leads to worsening conditions and wages because the workers fighting for jobs left are willing to work for cheaper and longer because they’ll do anything really just to have a job. Marx thought that as this progressed, the workers, or the proletariat, could reach a class consciousness of what was going on and could take the means of production from the bourgeoisie (ruling class) in a revolution. Marx thought that the conditions of the workers in relation to the owners would be so bad that they would reach class consciousness inevitably, and all it would take is for someone like Marx himself to point out the worker manipulation taking place.
What Marx envisioned happening was that once the workers took the means of production, there would be a TEMPORARY socialist government which helped the transition to a communist society. Engels created the term “withering of the state”, which was Marx’s idea of socialism in which the temporary socialist government would slowly wither away as the workers would eventually be able to self govern without the need for a state, which would lead to a communist society. Essentially, a communist society would have 0 government or state, with the people collectively owning the means of production to produce the needs of the society. Each person would contribute what they can in terms of work and skills, but ultimately be free to hunt, fish, write, partake in the arts, as they please, without anyone in particular owning any private property, because private property is what leads to state formation, capitalistic society, manipulation of workers, etc. To get rid of private property, there has to be means of production available where any need by the people such as food and shelter can be met collectively.
But, eastern Europe and its regimes were nowhere close to being an advanced industrialized society, and class divisions were nowhere nearly as prominent. The means of production were quite weak due to the lack of industrialization. Most of the USSR (Tsarist Russia before) was essentially peasants, with a very small ruling class, but not to the degree as western Europe. So, Lenin, inspired by Marx, decided that an elite revolutionary class must bring revolution to the region despite the lack of industrialization, along with class consciousness not being reached by the working class, because the working class itself was not as clear as it was in more advanced countries. His justification for speeding up the process and bringing revolution to a place in Marx’s eyes not ready was because he believed there was no time to wait for industrialization, and that basically it would take too long. Many argue his primary motivation was mainly egotistical, and his opportunistic attitude altered what Marx was after. So, when the bolsheviks took over and the previous Tsar left, the ideally socialist transitionary government took power, but because of unclear class divisions, there was a lot of different groups aiming for power. Along with that, World war 1 was going on at the time with Russia fighting both other countries and internal fighting between the previous regime and the many different factions within Tsarist Russia, such as the Bolsheviks, which essentially destroyed the countries economy. When the Bolshevicks and Lenin took power, the country was in such shambles that it was very evident they weren’t even close to being able to self govern because of the lack of means of production of food, etc. Once Lenin died, Stalin took over the party, and the civil unrest of starvation and poor living conditions led to both the strengthening of Stalin’s regime, along with the millions of deaths as a result of the totalitarianism and need to maintain power.
So, to sum up your question, the brutal dictatorship that arose in the Soviet Union was completely different then Marx’s communism because in Marx’s vision a communist society had no government. The socialism described by Marx and Engles was meant to be very temporary and help ease the transition post revolution to a self governing society, but in the soviet union that transition phase never withered away and the political party in power stayed in power. Essentially, the USSR never reached communism, and no country ever has reached communism. Every country gets stuck when opportunistic people or political parties take power post revolution and never leave. Yet, many modern day marxists say that because the Soviet Union, or any “communist” country was not and hasn’t yet reached the “end stage” capitalism, had very little clear cut class divisions, and essentially no wide spread working population had real class consciousness about their manipulation by the ruling class, that it may still be possible for a communist society to form. They claim that as capitalism continues to advance in today’s society, with the wealth gap between the owners of the means of production and the working class continuing to rise, wages continually lowering, and competition within the working class rising to the tipping point that a revolution of the working class will be inevitable, as Marx predicted. But, a counter argument to modern day Marxism would be that capitalism always seems to find a way to adapt, and things like union formation, universal basic income, are all adaptations to keep workers from reaching any form of unified class consciousness. A good argument regarding modern day marxism could be whether or not this adaptation has an end point. And of course, one can easily play the human nature card if they wanted to, as a strong argument can be made that humans may very well be incapable of such an endeavor even in proper conditions, because we simply are too dangerous to self govern. Many argue power to be extremely easily corrupt-able, so any attempt at communism will fall short due to the difficulty of the transition state ever actually withering away as Marx and Engels had idealized. | [
"Among those who argued for separating Marx into two distinct thinkers - one young and idealistic and the other mature and scientific - were Soviet theoreticians. Dunayevskaya believed the Communist state turned Marxism into its opposite - the totalitarian theory and practice of the Stalinist and post-Stalin USSR -... |
with all of our technological advancements, why haven't we been able to recover the titanic yet? | It is possible, but to what ends and who would finance it. It would be outrageously expensive and they would be bringing up nothing but nearly rotten metal. But it can be done, check this [link](_URL_0_)
*edit for spelling | [
"Since its initial discovery, the wreck of \"Titanic\" has been revisited on numerous occasions by explorers, scientists, filmmakers, tourists and salvagers, who have recovered thousands of items from the debris field for conservation and public display. The ship's condition has deteriorated significantly over the ... |
is it possible to convert ocean (salt) water into drinking water? or is there some inherent property preventing this? | Yes it is possible. The inherent property that makes it difficult is salt.
There are two basic ways to convert it.
1) Distill the water by boiling it and catching the steam. This takes a massive amount of energy and cannot really be done at a high enough volume to supply a community with water.
2) Filter water. The filter plants are complex and hard to build so they are cost prohibitive, take years to build, and they do take a fair bit of energy to run, but several plants can provide water for a town or even a small city. Those however are not likely to be able to afford to pay for its construction or operation and the technology is not sufficient to provide for large cities yet.
The US, Australia, and a few other countries are putting significant effort in developing better technology that is cheaper and can filter higher volumes but that tech is years or decades out. | [
"Saltwater is desalinated to produce water suitable for human consumption or irrigation. One by-product of desalination is salt. Desalination is used on many seagoing ships and submarines. Most of the modern interest in desalination is focused on cost-effective provision of fresh water for human use. Along with rec... |
Has there ever been an event similar to the Arab spring? | Yes. One of the best examples of such a thing was the [European Revolutions of 1848](_URL_1_). This was a period of numerous revolutions which sprouted from nationalistic sentiment and agitation.
It largely spawned from the rapidly changing nature of society in the 1800s. Industrialisation was changing the role of the working class from n agrarian to manufacturing society, particularly in western European cities. This resulted in greater social collections of people within manufacturing districts. Technological advances that happened along side this promoted a popular press amongst the working masses, and allowed them to become increasingly politically aware. As Benedict Anderson (briefly) mentions in his work 'Imagined Communities', this happened at a time when socialist and nationalist goals were becoming far more prevalent, and being exchanged amongst the masses.
It has been argued (though contentiously, I might add) the feelings of the developing middle class largely fell in line with these nationalist goals that were being thrown around. I would argue that it was less that their interests were the same, and more that both working and middle classes were anti-aristocracy, especially after the experiences of [Enlightened Absolutism](_URL_0_) in the 1700s, and of course the overthrow of monarchical authority during the French Revolution.
The spark was provided in Italy, with a small scale revolt in Sicily. The real wave of revolutionary fervour was started by the 1848 French Revolution, with numerous other western nations riding the wave of revolutionary fervour, much as like happened with the Northern African and Arab countries in 2011. Revolution reached as far as Western Ukraine, and arguably reached a global scale in South America, though I again see this as a tenuous link to draw. Even the peace in Britain during this period was broken (albeit peacefully) by Chartist agitation, which resulted in mass rallies calling for the repeal of the Corn Laws, which effectively prohibited foreign trade of corn. Its original intention 30 years earlier was to help struggling farmers in a time of high wages and prices, but in a rapidly expanding and increasingly commercialised world, this became ineffective. | [
"The Arab Spring was a wave of uprisings and protests in North Africa and the Middle East. The first disturbances were in December 2010 in Tunisia. However, in March 2011, when the Arab Spring reached Syria, the Syrian Civil war broke out. This led to tensions with its northern neighbor of Turkey. The Turkish gover... |
why do people still vouch for supply-side economics? | This is an answer I gave this in r/asksocialscience about a month ago _URL_0_ | [
"Supply-side economics is a school of macroeconomic thought that argues that overall economic well-being is maximized by lowering the barriers to producing goods and services (the \"Supply Side\" of the economy). By lowering such barriers, consumers are thought to benefit from a greater supply of goods and services... |
Do satellites maintain the same velocity forever? | I'm going to answer your question, but just because somebody will "correct" me if I don't touch on it first: in an elliptical orbit, the velocity does change, because the speed and direction of the satellite's motion is changing throughout the orbit. But of course I understand what you mean - whether an orbit loses energy, or whether it can keep on going on forever.
In practical terms, yes, orbits can and do lose energy. In particular, this happens in low Earth orbit, because there's still a very thin amount of atmosphere up there. This produces a weak drag force, which has to be countered. The International Space Station actually has to have little boosts now and again, or else it will start to slow down and fall to the Earth.
Satellites and the Earth are also not perfect spheres, and there are also other gravitating bodies in the solar system. These effects can produce mild torques on satellite orbits that can cause their orbits to precess. If things are aligned right, this can sometimes add up to quite a significant effect.
But even in an idealised universe where you can ignore all of those effects, the system will still radiate gravitational waves, which means that the system is *extremely* slowly losing energy, and the satellite could theoretically slow down and plummet to Earth. But in reality, for anything but the most massive objects, this is absurdly slow. Real satellites would be affected more by space gas or the Moon or Jupiter than by gravitational waves. | [
"As the orbital period of a satellite increases, approaching the rotational period of the Earth (in other words, as its average orbital speed slows towards the rotational speed of the Earth), its sinusoidal ground track will become compressed longitudinally, meaning that the \"nodes\" (the points at which it crosse... |
What is the trick to making a Rupert's drop? | When I did it in my materials science lab as an undergrad we used a bunsen burner to melt glass stirring rods and let it drop into a bucket of ice water. How are you doing it? | [
"Prince Rupert's drops are produced by dropping molten glass drops into cold water. The water rapidly cools and solidifies the glass from the outside inward. This thermal quenching may be described using a simplified model of a rapidly cooled sphere. Prince Rupert's drops have remained a scientific curiosity for ne... |
how do all these different fruit and plant seeds form? | There wasn't an identifiable first apple or orange seed. They would have evolved from some preceding plant species slowly over time. So over thousands of generations the preceding plant becomes more and more like an apple or orange tree until eventually it matches what we would recognize as an apple or orange tree but there wasn't a single point where you could say one generation wasn't an apple or orange tree and the next was. Think of it like a person aging. Any given day they won't look any different than the day before but look at two pictures taken 20 years apart and you will see how they aged. | [
"Many structures commonly referred to as \"seeds\" are actually dry fruits. Plants producing berries are called baccate. Sunflower seeds are sometimes sold commercially while still enclosed within the hard wall of the fruit, which must be split open to reach the seed. Different groups of plants have other modificat... |
What significance did the shape of the bomb dropped in Nagasaki have? | The "active" part of the Nagasaki bomb was an immensely heavy egg-shaped collection of high explosives, uranium metal, a plutonium core, and a lot of complicated electronics. The casing was developed to hold all that together and keep it from rolling violently (which could damage the electronics) and more or less have predictable aerodynamic properties (it was not ideal, but it worked).
If you could see it in an X-ray it [would look like this](_URL_0_) — a very snug fit. (This is taken from a declassified manual regarding the electronics system maintenance of these kinds of bombs.) [This visualization](_URL_1_) gives you an indication of the different parts on display there.
It is entirely functional — there is not really any "aesthetics" or "symbolism" to it, just aerodynamics. | [
"The atomic bomb cloud over Nagasaki, Japan was described in \"The Times\" of London of 13 August 1945 as a \"huge mushroom of smoke and dust\". On 9 September 1945, \"The New York Times\" published an eyewitness account of the Nagasaki bombing, written by William L. Laurence, the official newspaper correspondent o... |
how is that alcohol 70% is better than alcohol 90% as disinfectant ? | 70% alcohol has 30% water, and that water is necessary for the alcohol to interact at all with the cells it’s killing.
It’s like cooking pancakes. You know how when your pan is really hot and you put in pancake batter, it cooks the outside really fast? And then you can flip it, but it does the same thing to the other side and the middle doesn’t cook very well? 90% alcohol is like that. It doesn’t penetrate well into cells or clumps of microbes because it just fries everything it touches on the outside. The 70% alcohol is like cooking on medium heat with a moderately hot pan. It contacts the outside, too, but the water helps it penetrate to cook the inside (denature proteins deeper) as well.
From _URL_2_
> The presence of water is a crucial factor in destroying or inhibiting the growth of pathogenic microorganisms with isopropyl alcohol. Water acts as a catalyst and plays a key role in denaturing the proteins of vegetative cell membranes. 70% IPA solutions penetrate the cell wall more completely which permeates the entire cell, coagulates all proteins, and therefore the microorganism dies. Extra water content slows evaporation, therefore increasing surface contact time and enhancing effectiveness. Isopropyl alcohol concentrations over 91% coagulate proteins instantly. Consequently, a protective layer is created which protects other proteins from further coagulation.
> Solutions > 91% IPA may kill some bacteria, but require longer contact times for disinfection, and enable spores to lie in a dormant state without being killed. A 50% isopropyl alcohol solution kills Staphylococcus Aureus in less than 10 seconds (pg. 238), yet a 90% solution with a contact time of over two hours is ineffective.
Edit: Because there’s been some confusion, I’d like to add two points. First, higher concentrations of alcohol solutions (specifically isopropyl) may still be superior as solvents, for use on things like electronics for cleaning, because water is generally bad for electronics. Second, what we’re talking about above you should think of as referring only to ethanol and isopropyl alcohol (which is not safe to consume). There are other alcohols but we’re just sticking to the ones commonly used.
Edit 2: Some people have questioned the source, which is good and part of science. The source offered a decent write-up of what numerous PhD mentors have taught me, and it’s consistent with the science. At the risk of making this too long, here’s what the CDC has to say, from _URL_0_
Adding water enhances effectiveness of isopropyl and ethyl alcohols:
> The most feasible explanation for the antimicrobial action of alcohol is denaturation of proteins. This mechanism is supported by the observation that absolute ethyl alcohol, a dehydrating agent, is less bactericidal than mixtures of alcohol and water because proteins are denatured more quickly in the presence of water
Isopropanol and ethanol effective bactericides
> The bactericidal activity of various concentrations of ethyl alcohol (ethanol) was examined against a variety of microorganisms in exposure periods ranging from 10 seconds to 1 hour 483. Pseudomonas aeruginosa was killed in 10 seconds by all concentrations of ethanol from 30% to 100% (v/v), and Serratia marcescens, E, coli and Salmonella typhosa were killed in 10 seconds by all concentrations of ethanol from 40% to 100%. The gram-positive organisms Staphylococcus aureus and Streptococcus pyogenes were slightly more resistant, being killed in 10 seconds by ethyl alcohol concentrations of 60%–95%. Isopropyl alcohol (isopropanol) was slightly more bactericidal than ethyl alcohol for E. coli and S. aureus 489.
Kills viruses at these concentrations
> Ethyl alcohol, at concentrations of 60%–80%, is a potent virucidal agent inactivating all of the lipophilic viruses (e.g., herpes, vaccinia, and influenza virus) and many hydrophilic viruses (e.g., adenovirus, enterovirus, rhinovirus, and rotaviruses but not hepatitis A virus (HAV) 58 or poliovirus) 49.
Isopropanol similar to chlorhexidine
_URL_1_ | [
"Alcohol and alcohol plus Quaternary ammonium cation based compounds comprise a class of proven surface sanitizers and disinfectants approved by the EPA and the Centers for Disease Control for use as a hospital grade disinfectant. Alcohols are most effective when combined with distilled water to facilitate diffusio... |
Why is mathematics so applicable to all the phenomena we can observe and describe in the universe? | Why is painting so good at reproducing the way the universe looks? Because we invented painting in order to be good at reproducing the way the universe works. Why is math so good at describing the things we observe in the universe? Because we invented math to be good at describing the things that we observe in the universe.
Evolutionary it seems to be advantageous to create patterns. Patterns are things we see and then use to infer what will happen to things that we can't see. Patterns are not of the universe, but are created by us (see optical illusions for some clearly artificial patterns). At some time in the past, we needed to be able to communicate patterns between ourselves and so language was created. But as our patterns became more sophisticated, we needed a more exact way to communicate them, and numbers were invented. Since numbers were invented to communicate sophisticated patterns, they're really good at helping us create new patterns. Eventually, people enjoyed it so much that it evolved from being a language into being an art for it's own sake.
It is totally reasonable and expected that math would be effective in the physical sciences. We invented it to be really good at making patterns, so we shouldn't worship it or ascribe any nontrivial metaphysical properties to it when it does what it was created to do. Math is very sophisticated and most people who use it in practice, applied to the real world, are not trained in it's sophistication. They know enough to do their job. Because they haven't studied it in detail or at the level of abstraction it was meant to be at, they don't understand how it can be so good at finding patterns and some infer that it must be mystical. But, as has been seen many times in the past, a lack of understanding does not justify metaphysical conclusions.
Math doesn't explain everything, it's just that the things that can be explained by math are patterns and math does patterns really well.
It should be noted that this is philosophical question with no actual answer, this is my interpretation and arguments. I also have a bigger spiel about it, you can find more [here](_URL_0_). | [
"BULLET::::- Mathematics describes the real world: many areas of mathematics originated with attempts to describe and solve real world phenomena - from measuring farms (geometry) to falling apples (calculus) to gambling (probability). Mathematics is widely used in modern physics and engineering, and has been hugely... |
please explain how the current wage gap in america works. | There is no wage gap. At least not in how you likely think.
The 75% number often thrown around for women is based on all jobs for women averaged and compared to all jobs for men averaged. That gives you false information. Men hold a larger percentage of the top paying jobs. This is often because they work more overtime, take fewer sick days, and do not take time off to have/raise children often. This means that they will get promotions more often because they have done more work. It is also due to the fact that women tend to gravitate toward lower paying jobs such as Nurse, teacher, and lots of jobs in the humanities. | [
"Wage gaps have been identified for many races within the United States; however, research has found that the size and causes of the wage gap differs by race. For instance, the median black male worker earns 74 percent as much as the median white male worker, while the median Hispanic male worker earns only 63 perc... |
I heard that diamonds do not show up on x-rays. Is this true and if so, why? | All matter absorbs X-rays depending on the atomic density: the higher the density, and the heavier the element, the more X-rays are absorbed. Since carbon is about as lightweight an element as you can get, X-rays can pass through diamonds without being absorbed (meaning they "don't show up" in a conventional radiography). | [
"Most inclusions present in gem-quality diamonds do not affect the diamonds' performance or structural integrity and are not visible to the naked eyes. However, large clouds can affect a diamond's ability to transmit and scatter light. Large cracks close to or breaking the surface may reduce a diamond's resistance ... |
Did Napoleon and Wellington ever meet face-to-face? | No they never met face to face. Though they faced each across the battlefield at Waterloo Napoleon fled for Paris after his defeat and eventually surrendered to the British at Rochefort. At no time despite his captivity in British custody did he and Wellington ever meet face to face. | [
"Napoleon was losing and winning battles on the ground in 1813 and early 1814, but his western flank was weak, and Wellington's army had crossed Portugal and Spain, in April taken Toulouse on its way to Paris. Napoleon agreed to exile on the isle of Elba in April 1814, as its emperor. He slipped off the island abou... |
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