question stringlengths 3 301 | answer stringlengths 9 26.1k | context list |
|---|---|---|
what's the difference between a forest and a wood? | They're used interchangeably a lot. You'll get different answers from different resources, but the general consensus seems to be that woods are smaller than forests.
> A wood is an area covered in trees, larger than a grove or a copse. A forest is also an area covered in trees, but it is larger than a wood
> The U.S. National Vegetation Classification system differentiates them according to their densities: 25 to 60 percent of a a wood is covered by tree canopies, while 60 to 100 percent of a forest is canopied. | [
"Wood is divided, according to its botanical origin, into two kinds: softwoods, from coniferous trees, and hardwoods, from broad-leaved trees. Softwoods are lighter and generally simple in structure, whereas hardwoods are harder and more complex. However, in Australia, \"softwood\" generally describes rain forest t... |
Are there any good source material on the Warsaw Ghetto to be had online? | Many of the relevant primary sources wont contain the those specific details in an aggregated way. There are a few great examples of diaries and reports coming from the Warsaw Ghetto. The statistics you are looking for would likely come from secondary sources.
One great example is the Stroop Report. This is written by a commander (Stroop) and it documents the suppression of the uprising. I've included a link to the National Archive where you can get the the full report [here](_URL_1_). This document was used in the Nuremberg Trials.
I would recommend you check out the [Yad Vashem site](_URL_2_). That is the Holocaust Museum in Israel. They have spent a lot of time collecting primary sources, photos, personal accounts etc, about the Holocaust of the Jews (Shoah). I've linked to the overview of the Warsaw Ghetto, but check out the digital collection at the top.
A last little tip is diaries of the time. I don't know where you're located, or which libraries you have access to but here are a few WorldCat records for some notable ones: [The Warsaw diary of Adam Czerniakow](_URL_0_) and [Scroll of agony, the Warsaw diary of Chaim A. Kaplan](_URL_3_).
Hope this help.
Source: I'm an academic reference librarian and Jewish history specialist | [
"Engelking's book \"The Warsaw Ghetto: A Guide to the Perished City\" (2009), written with Jacek Leociak, provides detailed maps of the ghetto so that readers can locate the streets and former community structures. Michael Marrus described it as \"a stunning work, one of the most important books on the history of t... |
we do we instinctively grab a part of our body after it is hurt? | A) instinct. To protect it from further damage (if the damaging agent is ongoing) or to prevent bleeding and such.
B) pain. Our brain knows that pressure sensation blocks pain sensation from experience. So we reflexively grab the injury site because it alleviates the pain.
Edit: English and clarity | [
"Bring the victim into a sitting position, making sure that both legs are free. Approach him from behind, putting both your arms under his armpits. Both your hands then grab one of the lower arms of the victim with all fingers and the thumbs being placed on top of that lower arm and parallel to each other (so calle... |
Following the passing of the Thirteenth Amendment, were there any cases of slave-owners attempting to continue the practice illegally? | It was less a few dark corners, and more a concerted effort by large swathes of society, who attempted to keep slavery alive in all but name. Here is the Fourth Circuit discussing some of this history:
> The South was far from wholly reconciled to the abandonment of the system of forced labor that contributed significantly to the economic success of its agriculture. *See* [R. Fogel and S. Engerman, *Time on the Cross* (1974)](_URL_1_). Many planters felt strongly that they simply could not work their fields without compulsory service. *A Georgia Leader on Reconstruction and Conversation of Alabama Planters* in *R.N. Current, ed., Reconstruction [1865-1877]*, at 39, 46 (1969). Moreover, the war-torn South had large numbers of homeless uprooted people who today would probably be characterized as refugees but were then commonly seen as roaming, "dangerous" vagrants.
> Some local authorities responded by permitting employers to engage laborers on a basis that essentially bound the worker for life. [C. V. Woodward, *The Strange Career of Jim Crow* 23 (3d Rev.Ed.1974)](_URL_6_). Many states enacted so-called "Black Codes" that severely restricted the freedom of the former slaves and provided tough criminal sanctions for those who violated their "labor contracts" with employers. [J. H. Franklin, *Reconstruction After the Civil War* 48-50 (1961)](_URL_4_); [J. L. Roark, *Masters Without Slaves* 139-40 (1977)](_URL_3_).
> ...
> In [*Bailey v. Alabama*, 219 U.S. 219 (1911)](_URL_7_), the Supreme Court held invalid an Alabama statute that prescribed criminal penalties for laborers who breached their employment contracts without satisfying debts owed their employer. The statute established a presumption of criminal intent to defraud the employer by the fact of the mere breach of the contract. The Court ruled that the statute effectively required compulsory service impermissible under the thirteenth amendment because the compulsion inherent in the threat of criminal sanctions was as strong as that inherent in the use of physical force.
> In [*United States v. McClellan*, 127 F. 971 (_URL_0_.1904)](_URL_2_), the district court refused to quash an indictment that charged several defendants with the sale of a man into forced labor, holding that the [federal statutes] broadly regulated behavior of this type and were neither unconstitutional nor were to be confined to the narrow circumstances of the particular evils which they were intended to redress.
[*United States v. Booker*, 655 F. 2d 562 (4th Cir. 1981)](_URL_5_) (some citations omitted and some spacing added). | [
"Proponents of the 13th Amendment to the Constitution knew that without legislation that codified the 13th Amendment in the form of laws and statutes along with law enforcement agencies to uphold the laws, there would be no true end to slavery, and this is the reason for the inclusion of Section 2 of the 13th Amend... |
In medieval and pre-modern times, political entities made marriage pacts between heirs in order to secure peace. Often times, this didn't last for more than 20 years, if not even less. Why did they even bother? | Twenty years of peace is much better than no peace at all. Twenty years is enough time for a generation of young men to forgo military service, time to build infrastructure, time to consolidate power, and time grow a treasury.
There are also plenty of examples of peaces that last longer than twenty years, or even result in permanent peace and consolidation. The nation of Spain was formed from [the union of the Kingdom of Castile and the Kingdom of Aragon](_URL_0_), a union that was set in motion when Isabella of Castile, the future queen, married Ferdinand the Catholic, a future king of Aragon. Their grandson Charles V and great grandson Phillip II would later become kings of a united Spain. James the VI of Scotland similarly oversaw the personal union of England and Scotland when he inherited the crown of England, becoming James I, in 1603. England and Scotland would later formally join together to become the Kingdom of Great Britain in 1707.
Your question also implies that it is particularly unusual for a peace treaty to last less than twenty years. There are numerous examples of more modern treaties that did not maintain peace for much longer than twenty years. There were only twenty-one years between the World Wars (1918 to 1939) and only twelve years between the Gulf War (ended 1991) and the Iraq War (began 2003).
I can try to include better sources if asked, but I don't think anything I've said here is controversial. | [
"Regionally and across the time span of the Middle Ages, marriage could be formed differently. Marriage could be proclaimed in secret by the mutually consenting couple, or arranged between families as long as the man and woman were not forced and consented freely; but by the 12th century in western canon law, conse... |
What happened to German and Italian volunteers in the International Brigades of the Spanish Civil War after they were disbanded in 1938? | I gave a relatively brief answer to this [here](_URL_0_), focusing more on the Germans (for whom I had a relevant source handy). If I get the chance later today, I'll try and expand on it! | [
"The Yugoslav volunteers in the Spanish Civil War, known as Spanish fighters (, , / \"Španski borci\") and Yugoslav brigadistas (), was a contingent of volunteers from the Kingdom of Yugoslavia that fought beside the Republican side (in support of the Second Spanish Republic) in the Spanish Civil War (1936–39). An ... |
What (if anything) did Native Americans think lay beyond the Pacific and Atlantic oceans? | The desert people of the American Southwest generally understood the concept of oceans as not being fundamentally different from a large lake or stream. Among the [recorded] creation myths of the O'odham peoples, at least two contain gods or demigods turning small rivers into vast oceans, splitting apart the original peoples of the Earth, although the survival of remote peoples is left ambiguous. One of these stories later goes on to discuss the people who survived the flood on the other side of the ocean, who were conveniently white-skinned. Another passage from the same source states that another group of people over the ocean were in fact dark brown. Both of these groups were the result of mistakes in creation, after which the perfectly colored Hohokam groups were created. As prophetic as these may sound, our one source of these tales was recorded from a drunkard by a priest in the 1930s. Given that it is the only semi-complete history of the O'odham remaining today, we have no means to determine how far back the individual elements go.
Among the Hopi and other Puebloan peoples, we have an understanding that the oceans were not the complete end of land. At the very least they understood that people lived in the islands off the Atlantic and Pacific coasts from trade with groups living nearer to the sea.
Both groups had an accurate understanding of the geography of their continent between the oceans and an understanding that humans could live on the water as their neighbors did. It's not impossible that they conceived of other lands similar to their own across the water, which was understood to be similar to a large river or lake. The stories we have hint at this understanding, but the near-complete absence of historical records about the O'odham and Yuman people make that suggestion speculative at best. The situation among the Puebloans is little better. While they clearly understood the concept of sailing quite well, the myths make scarce mention of foreign lands that would not have been visible from shore.
Bahr, Donald M., et al. *The short, swift time of gods on earth: The Hohokam chronicles.* Univ of California Press, 1994.
Courlander, Harold, ed. *The fourth world of the Hopis.* UNM Press, 1971.
| [
"The Pacific recognized: Europeans knew that there was a vast ocean to the west, and the Chinese knew that there was one to the east. Learned Europeans thought that the world was round and that the two oceans were one. In 1492 Columbus sailed west to what he thought was Asia. When Pedro Álvares Cabral, en route to ... |
Is it possible that in the distant future, an organism that exists right now on Earth, will evolve to the point that it can be considered intelligent life? Which animal comes the closest? | > Is it possible that in the distant future, an organism that exists right now on Earth, will evolve to the point that it can be considered intelligent life?
Yes, it's possible, but by no means is it a sure thing. Evolution doesn't have a goal in mind, nor does it have specific end points that are inherently better than others. Evolution adapts to the environment, and what works works, what doesn't dies off.
> Which animal comes the closest?
We have a difficult time defining intelligence *within our own species*. The difficulty goes up astronomically when you look at other species.
Are you talking about technic intelligence? It's unlikely anything in the ocean will ever develop technology (at least, as far as we can tell - without fire lots of tools are going to be difficult to make).
Social intelligence? Well, insects seem to have a big advantage there... but they're probably a ways off on the tool front.
etc, etc, etc.
You see the difficulties? | [
"It is possible that even if complex life is common, intelligence (and consequently civilizations) is not. While there are remote sensing techniques that could perhaps detect life-bearing planets without relying on the signs of technology, none of them has any ability to tell if any detected life is intelligent. Th... |
How much can you learn from someone's genome? | Well this is fun, we literally just covered this kind of stuff in my advanced molecular biology course.
Your genome will contain variation depending on genetics that has been passed down from your parents. You may be homozygous for 11 copies of a short-tandem repeat (STR, 2-3 'letters' repeated over and over again in the sequence) where I will be heterozygous for 13 and 8 copies. Your "DNA fingerprint" that the FBI uses involves these regions, when the areas that contain them are amplified by PCR, they show up as different lengths.
Furthermore, there are single-nucleotide-polymorphisms (SNPs) where you may have an A where I have a C (or C-A or T-G or T-A...you get the point). There are also "indels" - insersions or deletions relative to one genomre or another. These can serve as markers for disease or other traits, especially if they occur in protein coding genes. There are a very very large number of these variations, and I could predict (not even close to 100% certainty, though) some traits about you as well as heritable diseases you may carry. The debate on nature/nurture is how certain could I be given your genotype?
[This database](_URL_0_) is called Online Mendellian Inheritance in Man and catalogs diseases/traits and contains a *wealth* of SNP and indel data about them. Doing some mining, you can find tables like [these](_URL_1_) that will list all known variants for a gene and link to more information about them. This example is the Von Willebrands Factor, mutations of which cause Von Willebrands Disease which is a mild bleeding disorder. I don't know your background, but this site contains a lot of very technical information.
You may have heard of [23andMe](_URL_2_) which is a commercial service that will assay your genome for specific markers as well.
EDIT: If your family has submitted their genomes to a database as well, we could ID them as well | [
"Over the course of the next three years, scientists at the Sanger Institute, BGI Shenzhen and the National Human Genome Research Institute’s Large-Scale Sequencing Network are planning to sequence a minimum of 1,000 human genomes. Due to the large amount of sequence data that need to be generated and analyzed it i... |
why are hispanics included as whites in statistical polls instead of being considered their own independent demographic like blacks or native americans? | Hispanic is not a race. It's an ethnicity. There are white Hispanics, black Hispanics, Native American Hispanics, and even Asian Hispanics.
| [
"In January 2016, CUNY sociologist Richard Alba wrote an article in the American Prospect arguing that the way in which majority-minority calculations are made by the Census are misleading. Anyone with any Hispanic, Asian, or Black ancestry is seen as non-white, even if they also have white ancestry. Alba argues th... |
what causes "flashing lights", or blurry vision after strenuous physical activity? | **NOTE**: I am not a medical doctor, and this is not a diagnosis; just the best attempt I can at explaining it.
It's likely caused by the gel inside of his eyes rubbing on or pulling at the retina. If he stood up after a car ride, it can cause a change in blood pressure as well, which would lead to less oxygen going to the brain and some experience flashes of light along with a narrowing of the field of vision. | [
"In some epileptics, flickering or flashing lights, such as strobe lights, can be responsible for the onset of a tonic clonic, absence, or myoclonic seizure. This condition is known as photosensitive epilepsy and, in some cases, the seizures can be triggered by activities that are harmless to others, such as watchi... |
if an ambulance on its way to a call witnesses an accident, what do they do? | It depends on the severity of the accident compared to the severity of the call they're en route to. If they see a horrible car wreck, and they're on a call for a broken bone, they'll stop for the wreck and radio in to let the dispatcher know to send out a new ambulance for the initial call. However, if they were on their way to a heart attack victim, they'll likely radio in and request a new ambulance for the wreck. | [
"The refusal of medical assistance, or RMA, ensures the continuum of care that ambulance squads have a responsibility towards. In a typical emergency call, the ambulance service will assess and transport the patient to an appropriate facility. The ambulance squad's duty towards the patient begins with patient conta... |
how do i know that i don't have depth perception? | Sure, if you've never experienced true binocularity (brain fusing each eye's image into one that is 3D), you might not realize you don't have it. It's possible to develop that skill so long as both eyes are physically intact and functional and so is your brain. Neuroscience ftw!
A book that discusses this is "Stereo Sue" by Sue Barry about a lady scientist who didn't realize that very thing she was in her 50s and was able to regain it. It's an interesting story! | [
"Depth perception is the visual ability to perceive the world in three dimensions (3D) and the distance of an object. Depth sensation is the corresponding term for animals, since although it is known that animals can sense the distance of an object (because of their ability to move accurately, or to respond consist... |
since oil & water don't mix, how are essential oil soaks helpful? | As far as I know there is no scientific proof that essential oils work anyway, but yes your skin can only absorb so much. | [
"Due to differences in physical properties, oil does not readily mix with water. Many food and non-food systems require stabilization of mixtures of oil and water in order to prevent phase separation. Therefore, additives are used to provide stability. Lactylates are such additives.\n",
"The essential oil is obta... |
if a nuclear bomb is dropped on other nuclear bombs that are idle on the ground, will it create a double explosion or do these weapons need to become 'activated' in order for them to be able to detonate? | Depends on a lot of things.
Nuclear bombs work by changing the critical mass of the nuclear fuel. "Critical mass" is the amount of nuclear material you need to have a sustained nuclear reaction. You can artificially make a smaller-than-critical mass into a critical mass in several ways. One way is to cover it with a material that reflects neutrons (which would cause all the neutrons that would've escaped outwards from the material to reflect back inwards, generally used in nuclear reactors and research), but another way is to change the temperature and pressure of the material (which is done in nuclear weapons by using "explosive lenses" which is a fancy way of saying you surround it with conventional explosives).
Without those explosives going off (and a few other things I'd guess) that nuclear weapon isn't actually fissile (able to undergo fission). A nuclear explosion above the silo where the bombs are stored is just as likely to vaporize the exposive as anything else, not to mention that unless that explosion is able to actually trigger the explosive correctly it's not going to explode. (C4 and TNT for example are completely safe to burn, and only explode with specific stimulii.)
| [
"Many nuclear detonations have taken place using [[aerial bomb]]s. The [[B-29 Superfortress|B-29]] aircraft that delivered the nuclear weapons at [[Hiroshima]] and [[Nagasaki]] did not lose power from electrical damage, because [[electron]]s (ejected from the air by gamma rays) are stopped quickly in normal air for... |
why do bottles of liquid have a dent/semi circle at the bottom of them? | Its to make the plastic stronger. Without it they would have to add much more plastic to make it stable, which is more expensive. The bottle wouldn't explode, but it would cause the thinner areas to sag and deform. That would increase the chance of it bursting apart when force is applied. But with the divot, that sort of outcome is essentially impossible. | [
"Some cans, such as those used for sardines, have a specially scored lid so that the user can break out the metal by the leverage of winding it around a slotted church key. Until the mid-20th century, some sardine tins had solder-attached lids, and the winding key worked by forcing the solder joint apart.\n",
"Th... |
the dow futures is reported to have dropped 700 points already. what does that mean for retirement funds, the market in general, etc...? | What u/Chumkil said but it is unlikely to be a long-lasting drop, the underlying economy is strong and, once the excitement has died down, the markets will return to their original state - i.e. rising.
The BBC were talking about this yesterday, apparently these flash-crashes are more to do with computer algorithm trading more than human sentiment. Their analyst's advice to investors was "play the long game and sit tight, use any significant drop to expand your portfolio." | [
"On October 9, 2007, the Dow Jones Industrial Average closed at a record high of 14,164.53. Two days later on October 11, the Dow traded at an intra-day level high of 14,198.10, a mark which would not be matched until March 2013. In what would normally take many years to accomplish; numerous reasons were cited for ... |
During the Cold War period, was Able Archer and The Cuban Missle Crisis the peak of tensions? | I would see a distinct difference between "peak of tensions" and "closest we came to a nuclear exchange." The Berlin crisis of 1948 was potentially a higher "peak of tensions" than Able Archer 83, but because the nuclear situation was only one-sided, it is not cited as a "close call." I would not consider Able Archer 83 a "peak of tensions," as it was primarily one-sided, though it was definitely one of the top "close calls." (What made it so dangerous was that the USA/NATO was so utterly unaware of how tense the Soviets felt about it.)
Similarly, there were other "close calls" that were not marked by "peaks of tensions" — such as the numerous "false alarm" scares that the US and USSR both suffered from errors in their early warning systems.
I would disentangle these two categories. What makes the Cuban Missile Crisis so remarkable and interesting is that it is the rare confluence of the two — a peak of tension _and_ a close call. There were many other very tense moments that were not close calls, and many close calls that were not actually peaks of tensions. | [
"After the Cuban Missile Crisis had passed, the Cold War situation kept Fort Stewart in an active training role. During the late 1960s, another developing situation would bring about yet another change in Fort Stewart’s mission. With tensions growing in the divided country of Vietnam, the U.S. found itself becoming... |
what's in artificial food coloring that makes it so toxic to consume? | Food coloring is not considered toxic by most people. From Google:
>
>
> While red dye #2 was subsequently banned from products sold in the United States, many health-conscious consumers continue to avoid foods with other artificial colors or dyes — **even though the U.S. Food and Drug Administration (FDA) still considers them safe for human consumption**.
But that doesn't even tell the full story.
Red Dye #2 might have never been particularly unsafe to humans.
>
>
> In 1976, the Food and Drug Administration (FDA) concluded that, in high doses, Red No. 2 could cause cancer in female rats. The FDA declared it an ingredient non grata in the United States because **although it had never been shown to pose health risks to humans, no one had been able to prove it safe, either**.
But the media painted a scary picture of Red Dye #2.
>
>
> In 1971, however, Soviet scientists announced that Red No. 2 caused cancer. Public outcry in the U.S. against the dye quickly gained such fervor that the Mars candy company temporarily stopped producing red M & Ms despite the fact that they had never contained Red No. 2 in the first place.
Red dye #2 was replaced in America by Red Dye #40, but #2 is still available and considered safe in Europe where one last bizarre fact enters the picture:
>
>
> But in a twist of fate, the European Food Safety Authority recently recommended limiting children's intake of Red No. 40. As a result, while Red No. 2 is illegal in the U.S. but flows freely in the EU, the near-opposite is true for Red No. 40.
You can read more about it [here](_URL_0_). | [
"In response to concerns about the safety of certain food additives, the UK FSA commissioned a study by researchers at Southampton University of the effect of a mixture of six food dyes (Tartrazine, Allura Red, Ponceau 4R, Quinoline Yellow WS, Sunset Yellow and Carmoisine (dubbed the \"Southampton 6\")) and sodium ... |
why does it feel like your stomach drops when your adrenaline kicks in? | It's related to the fight-or-flight response. Your body prioritizes your extremities and blood is drawn away from "non-essentials" such as the digestive system. This leads to that uneasy stomach feeling you get. | [
"During states of excitement or stress, the body releases adrenaline. Adrenaline is known to cause physical symptoms that accompany test anxiety, such as increased heart rate, sweating, and rapid breathing. In many cases having adrenaline is a good thing. It is helpful when dealing with stressful situations, ensuri... |
what happens to someone convicted of a felony that is going to die soon? | There are Hospitals/infirmaries in prisons. They'd likely just spend their final time in there.
Or they might just be put in with the general population if they don't need constant medical care. | [
"If a person committing a predicate felony directly contributed to the death of the victim then the person will be charged with murder in the first degree - felony murder which is a capital felony. The only two sentences available for that statute are life in prison and the death penalty. \n",
"If a person commit... |
Why can a person safely receive platelets donated by anyone, but can only receive a particular type of whole blood? | Platelets don't have antigens (the things antibodies recognize) on them. What might be a good way to remember this is that they're not made from red blood cells where the ABO blood group antigens are, they're shed from cells in the bone marrow called megakaryocytes.
That's not to say platelets are JUST floating bits of cytoplasm. They've got glycoproteins on the outside to recognize various signals that, if received, may then induce them to release granules filled with clotting factors.
But why don't people have antibodies to these glycoproteins? People have antibodies against certain glycoproteins on red blood cells, right? Yes, they do. However, basically EVERYONE has the same platelet glycoproteins. Developing an immune reaction against them would almost certainly mean death. Super bad thrombocytopenia (low platelets) AND what's basically a bad transfusion reaction, which can kill a person in minutes.
That being said, there are bleeding disorders where people lack some of these platelet factors (von Willebrand disease, for example). That's different from their bodies actively attacking any cell that has them, and they have problems with clotting and blood vessel damage, for the most part. | [
"Most platelet donations are given to patients who are unable to make enough platelets in their bone marrow. For example, patients with leukaemia or other cancers may have too few platelets as the result of their disease or treatment. Also after major surgery or extensive injury, patients may need platelet transfus... |
why don't people get tolerance from orgasms like they do from drugs? | Well you can. Masturbate everyday, and compare it to not masturbating for a month. You do build up a tolerance if you will. It's less intense. | [
"Some forms of sexual dysfunction such as erectile dysfunction can be treated with drugs. Because of their effects, erectile dysfunction drugs are sometimes used for recreational purposes. Many drugs, both legal and illegal, some sold online, have side effects that affect the user's sexual function. Many drugs can ... |
Is the shield wall fighting depicted on the show "Vikings" historically accurate? | Awesome thank you. I checked the FAQ and totally missed it. | [
"The term dates from at least 1000 AD and derives from Old English roots expressing the idea of a \"shield-troop\". Some researchers have also posited this etymological relation may show the schiltron is directly descended from the Anglo-Saxon shield wall, and still others give evidence \"schiltron\" is a name deri... |
what is the difference between inches, millimeters and caliber when talking about guns? | Caliber is a measure of the internal diameter of a gun barrel. Inches are an SAE unit, and millimeters are a metric unit. Either can be used to describe the caliber, based on the manufacturer's preference. | [
"Modern firearms can be described by their caliber (i.e. their bore diameter; this is given in millimeters or inches e.g. 7.5 mm, .357 in.) or in the case of shotguns by their gauge (e.g. 12 ga.); by the type of action employed (muzzleloader, breechloader, lever, bolt, pump, revolver, semi-automatic, fully automati... |
why is hydrogen so common on earth and helium quite rare? | Hydrogen is highly reactive, it bonds to oxygen, forming water. Water is quite dense, even as a vapor, and is therefore quite durable in the atmosphere.
Helium is a noble gas and nearly perfectly inert. Being unbound to any heavier elements, it quickly rises to the top of the atmosphere and is lost to space by various mechanisms.
Hydrogen is lost over time, but only slowly. | [
"The atmospheric proportions of hydrogen and helium are close to the theoretical composition of the primordial solar nebula. Neon in the upper atmosphere only consists of 20 parts per million by mass, which is about a tenth as abundant as in the Sun. Helium is also depleted to about 80% of the Sun's helium composit... |
Why do the Russian scientists have to wait till December to study the water they took from Lake Vostok? (Lake under Antartica) | Vostok Station is one of the most [inhospitable places for humans to work](_URL_0_). December is the Antarctic summer, so the weather will be better, temperatures warmer, and up to 24 hours of daylight. | [
"By plan, the following summer, the team was to drill down again to take a sample of that ice and analyze it. The Russians resumed drilling into the lake in January 2012 and reached the upper surface of the water on 6 February 2012. The researchers allowed the rushing lake water to freeze within the bore hole and m... |
I hear a lot about rape from the Red Army in Berlin during WWII. Did the German army (and SS) rape women too? If so, why isn't it talked about as much? | This topic is very well covered in two Russian books: [this one](_URL_3_), called "For What the Soviet People Were Fighting" and [this one](_URL_2_), called "Unknown Faces of War". The Nazis invaded the Soviet Union in WWII with the overall mindset of creating Lebensraum and the getting rid of most of the local population (keeping some for slave labour), since Russians, Belorussians, Ukranians and Jews alike were all considered Untermenschen. When the Soviet Army was pushing the Nazis back and liberating captured towns and villages it was very often the case that they were discovered entirely empty. Houses were burnt, wells were filled with bodies and trenches filled with bodies were all over the place.
Rape of the local populace by the advancing Nazis was as commonplace as the fighting itself and in addition to the "unorganised" rape carried out normally, organised brothels were set up to service the officers and soldiers. [Here](_URL_0_) and [here](_URL_1_) are fragments from the respective two books which summarise the extent of what was going on. The sources for the books are Nuremberg trial materials and eyewitness accounts from both sides.
EDIT: The following is a particularly telling excerpt: "We went to the village near the town of Gatchina Rozhdestvenno - told who served on the Seversky airport Private Peter Shuber. - We had a mission: to bring the girls the officers. We have successfully carried out the operation, all cordoned off the house. We collected a truckload of girls. All night the girls kept the officers, but in the morning they gave us - the soldiers. In large cities, organized stationary brothels. It was standard practice Wehrmacht. "There were soldiers' brothels," puffs "were called - remember shturmbannfyurera SS Avenir Bennigsen. - Almost all fronts. Girls from all over Europe, of all nationalities, from all camps collected. By the way, an indispensable accessory of a German soldier and an officer were two condoms, which are regularly issued in the army. " But while in Europe the Wehrmacht brothels staffed with more or less voluntarily, on Soviet soil invaders such delicacy is not going to show. Girls and women for the German soldiers for the most part collected by force - a scene that will forever remember the people trapped under the occupation. In Smolensk, for example, women dragged by the arms and hair, dragged on the pavement - in the officer's brothel, organized in one of the hotels. In case of refusal to stay in a brothel followed the shooting. After the Red Army drove the Germans out of Kerch, views of Red terrible sight presented itself: "In the prison yard was found mutilated shapeless pile of naked girls' bodies, wild and tortured by the Nazis cynically."
The way the advancing Nazi army treated the captured territories was known to the people fighting in the Soviet Army, and after the turning point occurred and the captured territories were liberated, the extent of the brutailty only served to increase the anger felt by the Soviets, resulting in the mass rape that occurred in East Germany when the war came there. The Soviet materials regarding the matter are still classified, but the German director, Helke Sander, states that a million women were raped by the Soviets in [this film](_URL_4_). However, reading the accounts of what the Germans did, it's really no wonder that the Soviets responded in kind, and helps explain why Victory Day (VE Day) is marked on a much larger scale in Russia today than in the Western Allied countries. | [
"As Allied troops entered and occupied German territory during the later stages of World War II, mass rapes of women took place both in connection with combat operations and during the subsequent occupation. Most Western scholars agree that the majority of the rapes were committed by Soviet servicemen, while some R... |
Do different types of wood have different specific heats? | Wood in general is a very complicated material. The specific heat of any particular piece of wood is going to be dominated by the amount of water in that wood. So it can vary significantly not only from species to species but also within species according to what treatment, if any, the wood has undergone. | [
"The energy content of a measure of wood depends on the tree species. For example, it can range from per cord. The higher the moisture content, the more energy that must be used to evaporate (boil) the water in the wood before it will burn. Dry wood delivers more energy for heating than green wood of the same speci... |
why is the greek language used in science so much? | Most of what we consider 'Science' was developed in the European university system post-Renaissance. Since such universities were almost always affiliated with the Church, they created a common course of study that included Latin and Greek.
As a result, while scientists in different nations spoke different native languages, they *all* had familiarity with Latin (and, to a lesser extent, Greek). The Greek *letters* in particularly came to be used for many mathematical formulas because they were distinct from the standard alphabet, but still recognizable. | [
"The discussion on the Greek language question began at the end of the 18th century. Because western Europeans were familiar with, and valued, the ancient Greek language, Eugenios Voulgaris, along with Lambros Photiadis, Stephanos Commitas (1770–1832) and Neophytos Doukas, proposed that the modern Greek language sh... |
Just finished watching "12 Years a Slave": Was life for slaves in the southern U.S. during the 1800's really as bad as these movies depict? What was the average life like for an average slave on an average plantation? | > but people don't beat their horses to within one inch of their life.
Of course they do.
In the 1930s the WPA interviewed more than 2000 slaves, who describe their treatment in detail. These are available [online](_URL_1_). [Here](_URL_0_) is a selection with brief descriptions of their contents. The first link takes you to a master link of narratives. They're quite brutal. It is not pleasant reading in any sense. Of course, Solomon Northrup's own account can also be found online, [here](_URL_1_) for example. | [
"On November 4, 2013, Cohen published a column about the film \"12 Years a Slave\", in which he wrote: \"Instead, beginning with school, I got a gauzy version. I learned that slavery was wrong, yes, that it was evil, no doubt, but really, that many blacks were sort of content. Slave owners were mostly nice people —... |
why does sunset time sometimes decrease or increase by 2 minutes instead of 1? | Daylight time changes vary by latitude; in July the North pole experiences 24 hours of daylight while in December it experiences 0, so there must be a change of at least 24 hours daylight time in 180 days, which turns out to average about 8 minutes a day change. At the equator no change is perceived at all (0 minutes per day).
More than that, the *rate* of change varies through the year. At the winter and summer solstices the changes are relatively slow. At the autumn and spring equinoxes the rates of change are at their highest. This is because during winter and summer the earths pole is pointing directly away or toward the sun (depending on hemisphere and season), while at spring and autumn the earths axis is perpendicular to the sun.
As a result the daily change in daylight hours varies by how North or South you are, as well as the time of year. You can explore the range of impact here: _URL_0_ | [
"The time of sunset varies throughout the year, and is determined by the viewer's position on Earth, specified by longitude and latitude, and elevation. Small daily changes and noticeable semi-annual changes in the timing of sunsets are driven by the axial tilt of Earth, daily rotation of the Earth, the planet's mo... |
why do humans have fetishes and animals appear to do not? | Depends on what you call a fetish.
Male goats have been shown to like pee play and seeing female goats simulate sex. | [
"This may be greatly affected by masculine people being less inhibited by social norms for expressing their desire, being more aware of their sexual desire or succumbing to the expectation of their gender culture. When feminine people employ tactics to show their sexual desire, they are typically more indirect in n... |
Can you transmit the flu through semen? What about sweat? | It is primarily an infection involving the upper respiratory tract. The virus is primarily shed through coughing/sneezing. The likelihood of semen or sweat containing the virus is low and unless those fluids are inhaled it wouldn't cause an infection. | [
"Semen can transmit many sexually transmitted diseases and pathogens, including viruses like HIV and Ebola. Swallowing semen carries no additional risk other than those inherent in fellatio. This includes transmission risk for sexually transmitted diseases such as human papillomavirus (HPV) or herpes, especially fo... |
Why are pipe organs used to play songs or jingles at hockey games? | For the same reason that they're used (or used to be used) at baseball games: volume. Even a small hockey stadium is a huge place, filled with screaming fans, and the pipe organ has the oomph to be heard in that environment.
Nowadays, most use "electronic pipe organs." The one in Chicago's United Center, for example, uses recorded pipe organ sound, and cost something near $150,000.
It's not as fun as the one that was demolished with "The Madhouse on Madison," but it still sounds good. | [
"A pitch pipe is a small device used to provide a pitch reference for musicians without absolute pitch. Although it may be described as a musical instrument, it is not typically used to play music as such. Technically, it is a harmonica; however, it lacks many characteristics of harmonicas.\n",
"It is played by b... |
What was the Roman Empire's opinion of the crusades, and how did they feel about the outcomes? | I'm not well versed on their reaction to all of the Crusades, but their opinion of the First Crusade was initially very positive. Emperor Alexius had extracted oaths of loyalty from the prominent Crusader leaders, and promises to restore reconquered territory in Anatolia to the Romans, and this is what happened initially. Alexius gave the Crusader armies extensive supplies for their journey, as well as knowledgeable guides. He sent his navy along the coasts to help them whenever possible, and eventually sent armies in their wake to protect the conquests of the Crusaders (which, naturally, he wanted to see restored to his empire). Cooperation between the Romans and the Crusaders was effective and relation were relatively positive - both parties had the same objectives; to defeat the Seljuks and restore land to the Christians. However, things took a sharp turn when the Crusaders refused to hand over Antioch to the Romans following its capture in 1098. Alexius was understandably angry, since it was in direct violation of their previous agreements.
Things took a further negative turn when the Crusaders revealed their intention of invading the Fatamid Caliphate and retaking the Holy Land. Alexius was on good terms with the Fatamids, since both of them viewed the Seljuks as a more serious threat than each other, and they agreed that it was in both of their best interests to focus their attention on defending against the Seljuks rather than fighting each other. Alexius warned the Crusaders not to start a war with the Fatamids, but they ignored him and marched down the Levant coast. The Emperor was furious and promptly cut off all aid he was giving them, including supplies and naval assistance. For the rest of the First Crusade (which at that point continued for only a few more months) there was no cooperation between the Romans and Crusaders. Alexius saw the invasion of the Holy Land as pointless from a strategic perspective and in nobody's best interests, and quickly distanced himself from the Crusaders and tried to maintain positive relations with the Fatamids, telling them he had nothing to do with it.
The only Crusader state that the Romans had somewhat positive (or at least not overtly negative) relations with was the Principality of Antioch, since its prince, Bohemund, swore fealty to Alexius as his overlord. This took some of the sting off the Crusaders' refusal to hand over the city, although Roman control of the principality was minimal and tensions were always high, since the princes simultaneously were influenced by the Kingdom of Jerusalem as well.
Source: *God's War: A New History of the Crusades* by Christopher Tyreman | [
"Crusades against Christians in the East by Roman Catholic crusaders were not exclusive to the fourth crusade nor the Mediterranean. The sacking of Constantinople and the Church of Holy Wisdom, the destruction of the Monastery of Stoudios, Library of Constantinople and the establishment of the Latin Empire in Const... |
how are you assigned to classes in college? | You'll talk to an advisor who will give you a schedule based on the program you are enrolling in. | [
"Online courses are typically divided into units of class discussions (ongoing posts of classmate queries and comments), downloadable assignments and quizzes. What students are actually graded on is based on the course and the professor, however, class participation is usually required in the form of threaded discu... |
why does throwing an extremely light object, for example a golf ball, strain the arm as opposed to a baseball that is relative in mass? | The same reason you should never dry fire a bow (shooting a bow without an arrow in place). If there is no arrow to transfer the energy of the pulled bowstring, all of that energy will go into the bow itself and can damage or shatter the bow.
Your arm functions the same way as a bow: transfering energy into the ball (arrow). A lighter or smaller ball doesn't require as much energy to launch. If you perform your normal throw on the lighter ball, the excess energy not transferred to the ball will travel back through your arm and can strain it especially if you don't do a full follow-through to help release the energy. | [
"Further refinements to the motion of the ball can be made by taking into account air resistance (and related effects such as drag and wind), the Magnus effect, and buoyancy. Because lighter balls accelerate more readily, their motion tends to be affected more by such forces.\n",
"The swing weight of a baseball b... |
Why is there so much Carbon-14 in these fossils? | There's a lot of crap on that page.
First, carbon dating doesn't work for things like dinosaur fossils. They're too old.
The number 22,380 has no reference next to it so I'm not sure which reference at the bottom they're referring to.
The premise of the article is that in 2005 a fossil was dated to 20-30k years. None of their references seems to point to this event, nor does Google come up with anything that's not a blog or some anti-evolution web site. Hugh Miller comes up a few times, he's apparently a creationist.
There's nothing on that page that can be responded to without vomiting. | [
"Carbon-14 (C) is a naturally occurring radioisotope, created in the upper atmosphere (lower stratosphere and upper troposphere) by interaction of nitrogen with cosmic rays. It is found in trace amounts on Earth of 1 part per trillion (0.0000000001%) or more, mostly confined to the atmosphere and superficial deposi... |
As the needle approaches the centre of a record, its speed increases, right? Are the grooves cut differently towards the middle of a record to account for this? | The grooves aren't intentionally cut differently, but the wavelength representation is longer near the edge compared to the center because the speed of the track increases from the center to the edge. Since the grooves are cut directly into the recording material, no external adjustment is necessary, since it's always going to be a 1 to 1 correspondence when played back at the same speed it was cut. | [
"Examining a vertically-cut groove along its length reveals a continuous wavy line as the needle cuts at different depths according to the tone and the loudness of the audio being recorded. These grooves show a transition from high to low peak as a smooth curve, giving the characteristic rounded 'hill and dale' eff... |
How was the East India Company able to maintain rule over the massive subcontinent for over 100 years? Was it stable? Was it more than a loose administration? How much indigenous resistance was there? Did this change under direct British rule? | While there were a numerous way in which the English East India company were able to maintain control over their massive Indian territory , I will cover some important ways in which they exerted control :
#**Part 1**
#**Control over the rulers**
One of the important pillars of power of company support were a loyal class of local rulers . These rulers were helpful because
1) They helped maintain an illusion of indigenous rule when in reality they were nothing more than company stooges .
2) They helped in suppression of local rebellions and other minor disputes that were not big enough or important enough to warrant the use of the company army
3) By getting support and loyalty of these indigenous rulers , They hoped to obtain a sense of legitimacy as they often touted themselves as the protector of mughal empire and in later years as successors of the mughal state
But how did the company develop this class of royal rulers?
The Company exerted control over the rules and various kingdoms via mainly the
* Subsidiary Alliance system
* Protection alliance and protective custody
* Picking sides in succession disputes to install a puppet
* Doctrine of Lapse and Adoption
* Using wars between rival Indian kingdoms to their advantage
Let us understand each of the above in a brief manner
***Subsidiary alliance system***
Under the subsidiary alliance system , The ruler agreed to enter an alliance with the company . The terms of these alliance were as follows:
> An Indian ruler entering into a subsidiary alliance with the British would accept British forces within his territory and to pay for their maintenance.
> * The ruler would accept a British official (resident) in his state.
> * The ruler who entered into a subsidiary alliance would not join any alliance with any other power or declare war against any
power without the permission of the British.
> * The ruler would dismiss any Europeans other than the British and avoid employing new ones.
> * The ruler would let the British rule on any conflict any other state.
> * The ruler would acknowledge the East India Company as the paramount power in India.
> * The ruler would have his state be protected by the Company from external dangers and internal disorders.
> * If the rulers failed to make the payments that were required by the alliance, part of their territory would be taken away as a penalty.
> * Indian rulers have to maintain British troops in his state.
As you can see after reading the above terms , Any kingdom which entered / or was forced to enter into a subsidiary alliance was reduced to nothing but a kingdom with a rubber stamp ruler who were official puppets of the company on almost all matters of importance
*Examples of kingdoms which entered the subsidiary alliance system : Awadh , Many maratha princely kingdoms ,Tanjore , Indore etc*
***Protection alliance or protective custody***
Many Indian rulers or royal families who were afraid of being attacked by their rivals or by members of their own house often entered British protective custody . These forms of agreements generally involved the Company defeating/killing/driving off the enemies of the person seeking protection . In return for these , The ruler would become predisposed to the company and do what the company advised them in case they needed the company protection in the future again
***Picking sides in succession disputes to install a puppet***
The company often took advantage of succession disputes to further their own advantage . They would select one of the people involved in the disputes and offer their support , resources and help to get the throne . In return , the ruler would have to promise to be favor and have good relations with the Company when he becomes the ruler
Such actions were also often done when they felt that a ruler soon to come to power in a throne would be bad for the prospects of the company
In most of the cases , Getting the official support of company on your side generally meant that the game was over for the opposing side more or less
Thus , by helping these rulers ascend the throne , they got a loyal group of rulers who they could rely on in times of difficulty
***Doctrine of lapse and adoption***
> Under an ancient Hindu custom, to avoid a disputed succession to the throne, a ruler with no born-to heir could adopt a male of any age from another branch of the ruling family and appoint him heir apparent. This parallels similar customs in ancient Rome and during the Chinese Qing Dynasty.
> When the British Empire came to India in 1757, among the land-grabbing stratagems devised was the Doctrine of Lapse, which abrogated the ancient custom. Under this doctrine the British arrogated to themselves the right to veto the succession of an adopted heir, and instead, to annex the territory concerned, although the adopted successor and his heirs were usually allowed to keep their titles and a substantial annual allowance.
Thus , this one more method to install a puppet regime in many kingdoms . Many big Indian princely thus fell to this policy
~~**# Part 2 to follow soon**~~
# ***Part 2***
# ***Military power of the company***
The army of the East India Company were one of the most feared and powerful in the subcontinent uptil its dissolution in 1857
* Company army had massive superiority over indigenous kingdoms in terms of artillery , firepower and firearms ,military discipline and military tactitcs
* To help the company further , they had a exceptional and experienced class of military commanders and officers who had experience fighting in many terrains and countries in different parts of the world . In many wars , the company won not to due to superior quality of equipment , but rather due to the experienced officers and commanders leading the charge during the war .
* The trademark red coat and bucket coat that the company is now famous for stuck fear in many Indian kingdoms. In order to increase troop morale , many Indian kingdoms introduced a similar looking uniform for their own army
* The payment system of the company was **extremely punctual**. The company placed a great emphasis on ensuring that due salary payments were done to all troops . This ensured that the Company army became a lucrative job for many Indians . The best and smartest of various kingdoms often tried their hands to get a job in the company army
* Any disturbance anywhere in the country that had the potential to weaken company hold over power invited a visit from the Company army . Many regiments in the company evoked special fear such as the Bengal regiment which were the backbone of company power in the country
# Part 3 to follow soon
Meanwhile you can read my answer regarding opinion of various sections of the Indian society towards East India company to understand the flames of discontentment that were rising in the Indian society
[Answer](_URL_0_)
# ***How much indigenous resistance was there?***
Let me quote you a section which will directly answer this part of question
> Among the myths which became current in the wake of the rebellion of
1857-8 was the idea that it was a unique event, something that had to
be explained in terms of the peculiar folly of the revenue policy of the
> With this in mind, several broad types of dissidence can be isolated
from the great range of revolts between 1800 and i860. Most notable
were the periodic revolts of zamindars and other superior landholders
fighting off demands for higher revenue or invasions of their status as
'little kings' in the countryside. Then there were conflicts between
landlords and groups of tenants or under-tenants objecting to the
transformation of customary dues into landlord rights or to some violation of the obligations between agrarian lord and dependant.
Next there was a range of conflicts arising from tension between wandering
or tribal people and settled peasant farmers which usually
centred on the control of forests, grazing grounds or other communally
exploited resources. Finally, there were frequent revolts in cities
and towns. These had many causes: some were riots over market control
and taxation. Some involved bloodshed between religious or caste
groups or the protests of embattled artisan communities. All these
types of conflict were widespread but they surfaced in exaggerated
form in the course of the Mutiny and Rebellion of 1857.
Source for the above quoted text :Indian society and makings of british empire | [
"The East India Company was one of the most powerful and enduring organisations in history and had a long lasting impact on the Indian Subcontinent, with both positive and harmful effects. Although dissolved by the East India Stock Dividend Redemption Act 1873 following the rebellion of 1857, it stimulated the grow... |
In a chemical reaction, if the product has a lower energy than the reactant, why doesn't all reactant convert to product? | Reactions have an [activation energy](_URL_0_) associated that acts as a barrier from all reactants rapidly and spontaneously turning into products. That is, there requires some extra energy put into the reaction before it can proceed. Commonly this is heat energy - hence reactions occurring faster at higher temperatures. | [
"If the products are higher in chemical energy than the reactants then the reaction will require energy to be performed and is therefore an endergonic reaction. Additionally if the product is less stable than a reactant, then Leffler's assumption holds that the transition state will more closely resemble the produc... |
Why is there such a thing as "critical mass" for a radioactive material? Why couldn't the chain reaction sustain itself with less mass than the critical amount? How is this mass calculated? | Fission results in the release of 2 to 3 free neutrons. To sustain a critical chain reaction, on average, one of these neutrons should be captured by a fissile nucleus and cause it to fission.
So what you need to understand is the parameters that affect how likely it is for a free neutron to be captured in this way.
One important parameter is the shape of the material. If a neutron escapes the material it is lost from the system and doesn't contribute to the chain reaction. This is called leakage. A sphere is the most efficient shape as it has the smallest surface area from which leakage will occur for a given volume. We also want to maximise the density of the material as this will also minimise the surface area for a given mass.
The larger the mass of the sphere the less likely it is a neutron will escape i.e. a neutron will on average have to pass by more fissile nuclei before it can escape the edge of the sphere. For each pure fissile material of full density in a vacuum there is an ideal spherical mass where a just critical chain reaction will occur. Any less material and there will be too much leakage and the system will be subcritical.
This critical mass can be reduced by adding a reflector around the fissile material. Beryllium is an excellent reflector, as it has a high neutron scatter cross section and a low neutron capture cross section (I'll come back to these terms in a bit). By adding a thick shell of beryllium around our spherical critical mass we minimise leakage and thus reduce our critical mass.
The next thing to understand is how neutron capture or scatter cross sections vary with neutron energy. Cross sections are measured in barns, a unit of area. The bigger the cross section, the more likely it is that a neutron will be absorbed or scattered when its comes into proximity with a nucleus. After a fission the free neutrons are "fast" and have an energy in the MeV range. By slowing down neutrons to a "thermal" energy in the eV range the cross sections increase significantly and neutrons can more easily captured. So if we reduce the average neutron energy then we need on average fewer interactions between a neutron and fissile nuclei before a capture occurs. In which case the volume needed for a chain reaction reduces further. Slowing down neutrons is achieved by including a "moderator". This is a material with a low atomic mass which reduces the energy of a neutron by elastically scattering it. This is analogous to a pool ball being slowed down by multiple collisions with other balls by transferring some of its energy to them. The best moderator is one with a similar mass to a neutron as momentum transfer is most efficient at equal mass. A secondary factor is that the moderator should not capture too many neutrons. Hydrogen-1 is by far the most effective moderator. The next best, deuterium, is much less efficient at absorbing momentum energy. Again we want to minimise the size of our sphere so we want a material with a high hydrogen density. Water has a good hydrogen density, but polythene is even better.
Side note: Moderation also has a secondary benefit in that thermal fission produces slightly more neutrons per fission than fast fission on average. This further improves our balance of neutrons available for the chain reaction.
The next point to make is that a nucleus can absorb a neutron without contributing to fission. This is called parasitic absorption. This can happen with the fissile nuclei itself, which is unavoidable, with the moderator and the reflector and also with any impurities that may be present. To minimise this we want to exclude any impurities and to use just enough moderator mixed in a ideal way with the fissile material (a homogeneous mix for high enriched uranium and plutonium or a lattice for very low enriched uranium).
Taking all of that into account we can now design our system with a minimum critical mass. Most minimum critical masses reported will be for pure u-233, u-235, pu-239 and pu-241 mixed homogeneously at maximum density with an ideal concentration of polythene, surrounded by beryllium.
The differences between the masses for each fissile isotope are due to there different capture-fission and capture-parasitic absorption cross sections and the differences in the average number of free neutrons produced per fission.
Technically there are some ways we could produce an even smaller minimum critical mass. In theory beryllium hydride is an even better moderator than polythene and could result in a critical mass of as little as 87 grams for pu-239. Additionally some of the higher transuranics are also fissile and have very very small minimum critical masses (a few grams, maybe less). Both of these cases are a bit academic and not really relevant in industrial settings (e.g. Where want want to know the minimum critical mass for safety control purposes).
Edit: How is it calculated? These days we use computer software to very accurately model a system. The most accurate tools are Monte Carlo models that individually model the fate of many postulated neutrons until the statistical error is negligible. These models are validated against a library of test data. The better validated the data, the more accurate the model. There are analytical approaches that can be used, with formulas to estimate the effects of geometry, moderation, etc (try googling geometric and material buckling as an example). These are rarely used outside of a classroom as the software models are more effective and widely available. | [
"A critical mass is the smallest amount of fissile material needed for a sustained nuclear chain reaction. The critical mass of a fissionable material depends upon its nuclear properties (specifically, the nuclear fission cross-section), its density, its shape, its enrichment, its purity, its temperature, and its s... |
how do hackers hack a web cam? | > How do hackers hack a web cam?
Bugs. A lot of software is insecure. Not all. A standalone webcamera is an "Internet of Things" device. Oh god, there are so many poorly secured IoT devices.
> And is it possible for them to record without the indicator light turning on?
Depends. If the light is hardwired to the power of the camera, no. But other devices, like [logitech cameras](_URL_1_) or [macbooks](_URL_0_) don't even need the firmware flashed. So, that's a solid yes.
> specifically a laptop's built-in webcam - if that makes a difference...
As a device that's part of a real laptop, with a real OS, then it's probably more secure. But on the flip side, OS's do a lot more stuff which are more vectors for an attack.
| [
"Camfecting, in the field of computer security, is the process of attempting to hack into a person's webcam and activate it without the webcam owner's permission. The remotely activated webcam can be used to watch anything within the webcam's field of vision, sometimes including the webcam owner themselves. Camfect... |
Do Historians studying Colonial America *need* to be fluent in Native American Languages? | Probably not. Many of the indigenous languages at that point were only spoken languages and were not written, which is why you aren't finding many, if any, sources in an indigenous language. You should be fine if you focus on one of the European languages (French or Spanish if you are studying an area colonized by the Spanish). In the unlikely event that you need an indigenous language for your area of research, your future advisor will tell you and help you find a way to learn it. | [
"Lisa Brooks is an historian, writer, and professor of English and American studies at Amherst College in Massachusetts where she specializes in the history of Native American and European interactions from the American colonial period to the present.\n",
"Alden T. Vaughan (born 1929) is an American historian, ha... |
Will Solar Energy Ever Surpass the Efficiency of Fossil Fuels and Will it be a Viable Source of Energy for the Future? | You're comparing apples to oranges. You can't/shouldn't compare efficiency across different methods of extracting energy. What you should care about is dollar pr watt hour. | [
"BULLET::::- To realistically reduce our reliance on fossil fuels as a source of power, we have to utilize clean sources of energy. Solar energy is a sustainable source of energy with incredible potential for expansion and opportunity to develop on both the individual level and the commercial scale.\n",
"In 2011,... |
why do marathoners and triathletes tend to have small body frames? | Most body frames (skeletons) are very similar, and most "shape" comes from fat or muscle on those bones.
The heavier you are, the more work you have to do. It's easier to move 150 pounds 100 feet than 200 pounds 100 feet.
Running results in injury to heavier people more often. Joints stand up better to 150 pounds coming down on them than 200 pounds. This is a "[squares and cubes](_URL_0_)" problem. Stuff gets heavier basically in a cubic function, stuff gets stronger basically in a square function. n^3 grows much faster than n^2.
Marathoning and training burns a lot of calories. Compared to eating less, running isn't usually as effective for weightloss, but when you start talking 20 miles, you're talking about burning in the area of 2500 calories, which is more calories than the average person should consume per day. | [
"Athletes in this class who good trunk control and mobility have an advantage over athletes in the same class who have less functional trunk control and mobility. This functional difference can cause different performance results within the same class, with discus throwers with more control in a class able to throw... |
How is the primality of extremely large numbers tested/proven? | There are fast primality tests: _URL_0_. These tests aren't easy to understand, and we only proved that they are "fast" (polynomial time in the number of digits) recently. Historically, we used imperfect algorithms that basically just tell you that a number is "not prime" or "almost certainly prime."
If your goal is just to hunt for very large primes, then one way is to use the Lehmer-Lucas test. Given a prime p, it's computationally easy to find out if a number of the form 2^p - 1 is prime. | [
"Although this method is simple to describe, it is impractical for testing the primality of large integers, because the number of tests that it performs grows exponentially as a function of the number of digits of these integers. However, trial division is still used, with a smaller limit than the square root on th... |
Is MDMA really harmless? | One of the problems you'll note when reviewing literature on MDMA is the recent influx of research on MDMA assisted psychotherapy. This research tends to be biased towards showing the safety of the substance, and it's making it harder and harder for unbiased research to make clear conclusions about MDMA. It might be part of the reason why you're getting mixed messages.
With that said, even within the unbiased scientific research, there isn't a clear understanding on what exactly the relationship is between MDMA and permanent neuronal dysfunction. It is well accepted that high dose MDMA use is associated with long-term dysfunction of serotonergic circuitry, and for a long time it was thought that the dysfunction was actually from neuronal death. However, more recently there have been studies that challenge this because with CNS death you should see certain glial cell markers, and those markers aren't seen in high dose MDMA associated serotonergic dysfunction. So with serotonin at least, we know that MDMA disrupts normal functioning, but we don't know the exact mechanisms. Similar findings of acute dysfunction with dopamine and norepineprhine have been reported, but it's generally felt that the monoamines are not disrupted as severely as serotonin or with as much concern for permanence.
The last thing I'll mention is that most of this research is done on primates and occasionally rats, and less is known about the specifics in humans. With all of that said, I certainly wouldn't classify it as "safe" or "harmless" especially when used in high doses, but the exact mechanisms and potential for permanent neural dysfunction are not clear at this point. | [
"MDAI and other similar drugs have been widely used in scientific research, as they are able to replicate many of the effects of MDMA, but without causing the neurotoxicity which may be associated with MDMA and some related drugs. No tests have been performed on cardiovascular toxicity.\n",
"MDMA is illegal in mo... |
what is economic contagion? | Most business and currency is based on confidence and belief.
Belief that things will largely be worth tomorrow, what they are today.
Confidence that the systems and structures that are useful and effective today, will remain so for the indefinite future.
With these ideas, you can plan on a micro-level how to allocate your time and money. On a macro-level, economies do the same thing.
Problems arise when you lose confidence and belief. Should you plant your fields? Can you sell your produce in six months? Should you build a new expansion? Where should you put your money? Stocks? Guns? Gold?
Nothing has actually happened, but you are starting to consider or make choices that don’t follow the usual pattern. I see you doing that and I get spooked and change my behaviour. Now you and I are both acting unusually and spending or saving money in ways that spook our suppliers and customers... Things start spiraling, even though again, nothing has changed except you got a little panic-y. | [
"\"Fundamental causes of contagion include macroeconomic shocks that have repercussions on an international scale and local shocks transmitted through trade links, competitive devaluations, and financial links.\" It can lead to some co-movements in capital flows and asset prices.Common shocks can be similar to the ... |
Why is there such a hard cut-off in the glacial lakes in Canada and northern US? | It has to do with comparing the previously glaciated terrane with areas which were not (or minimally) glaciated. The lake-rich northern terranes are underlain by glacial sediments. These typically include large proportions of poorly sorted material (such as till) as well as glacio-lacustrine clays, both of which give rise to poor drainage. The landforms created by deglaciation also create all sorts of variations in topography (kames, thermokarst, moraine, etc.) where small shallow lakes can form in these relatively impermeable deposits.
You will find that the unglaciated areas are much better drained, and probably generally flatter.
Your state is sort of half and half - the northern part was glaciated while the southern part was not. | [
"As recently as the last glacial maximum about 30,000 years ago, the majority of northern Canada was buried under the enormous continental Laurentide ice sheet. The tremendous erosive powers of the Laurentide and its predecessors, at maximum extent, completely buried what is now the Mackenzie watershed under thousa... |
How can fish swim their entire lives? | How do you breath all your life? Your diaphragm muscles must surely tire of pulling air in all the time, if you spend all your life breathing. Or your heart, which pumps blood nonstop your whole life.
Some muscles don't tire because they can't. They're too important. | [
"Fish live in Fresh or Saltwater habitats and some exceptions are capable of coming on land (Mudskippers). Most fish have a line of muscle blocks, called myomeres, along each side of the body. To swim, they alternately contract one side and relax the other side in a progression which goes from the head to the tail.... |
What role did pike phalanxes play in late 16th and 17th century warfare? | By the time period in question, the pike blocks [(*not* phalanxes)](_URL_0_) have taken further and further secondary roles to shot/firearm troops.
In the early 16th century, the shot troops are there to support friendly pike blocks and harass enemy pike blocks when contact is made. By the 17th century the proportions have changed drastically. A figure from *"Fighting Techniques of the Early Modern World"* shows:
* 1622: 10 deep formation, 3 pikes for every 2 muskets.
* 1630: 8 deep formation, 1 pike vs. 1 muskets.
* 1650: 6 deep, 1 pike vs. 2 muskets.
You can guess where the trend was heading. Swedish infantry in the 30YW deployed about 1-1 pikes-muskets, and this isn't much different from what the Imperial and Spanish troops deployed, even if the Swedish ran smaller squadrons than their adversaries.
By the 1650s period, the pike block was a smaller contingent with muskets on both sides. Or rather, perhaps it is more accurate to say that an infantry squadron was a 6-deep line of muskets with a few pikes concentrated in the center. If that squadron is threatened by horse, the pikes then move forward and muskets back behind them to get protection.
You may want to read through [previous answers](_URL_1_) on pike and shot formations in battle. | [
"The pike square dominated European battlefields and influenced the development of tactics well into the 17th century. Even when muskets became common, their slow rate of fire meant that soldiers armed with them were vulnerable to cavalry; to combat this, some soldiers continued to carry pikes until the improving p... |
how someone like marvel can copyright something like thor and loki? | They can't. What they can do is copyright their portrayal of them, so if you write a story or draw cartoons about one of them which is so close as to be mistaken by the man in the street for their version, then they'll jump on you.
Of course, they might well try anyway, which is enough to put many people off - which is an abuse of the copyright system, but i suspect it happens all the time. | [
"Loki is a fictional character appearing in American comic books published by Marvel Comics. Created by writer Stan Lee, scripter Larry Lieber and penciller Jack Kirby, a version of the character first appeared in \"Venus\" #6 (August 1949). The modern day incarnation of Loki first appeared in \"Journey into Myster... |
appears to be water on the road ahead. | It's a mirage.
_URL_0_ | [
"In April 2007, artist Henk Hofstra painted a road in Drachten blue with white lettering and traffic markings. The road is called Moleneind. The lettering spells \"Water is Leven\" (Water is Life), meant to symbolize a prior waterway that was paved over.\n",
"A road running below the water level of a stream or ri... |
If deaf people put their fingers against the diaphragm on a speaker, could they "feel" the music? | Deaf people actually dance to music. Anyone can feel the music, especially if it is very bass heavy, without touching a speaker.
One of the best concerts I've been to had an amazing sound engineer and you could feel everything. | [
"Articulation disorders may be attributed to a variety of causes. A child with hearing loss may not be able to hear certain phonemes pronounced at certain frequencies, or hear the error in their own production of sounds. Oral-motor problems may also be at fault, such as \"developmental verbal dyspraxia\" (a problem... |
why do only some animals have recreational sex, while other animals only have sex purely with the intent of reproduction? | It has mostly to do with the mating behaviors of specific animals. If we're talking about higher vertebrates (mammals, birds), lots of animals will engage in coitus if given the opportunity, presumably because it feels good and/or they have a strong natural instinct to do so. However, not all animals have the opportunity to engage in recreational sex because they don't form stable pair-bonds like humans. Take rutting animals, like elk for example. Pretty hard to go in for a casual lay if every time you make a move, some bro-elk comes along and tries to smash his antlers into your face to c-block you. | [
"It is often assumed that animals do not have sex for pleasure, or alternatively that humans, pigs, bonobos (and perhaps dolphins and one or two more species of primates) are the only species that do. This is sometimes stated as \"animals mate only for reproduction\". This view is considered a misconception by some... |
Is it really possible to colonize other planets considering the laws of special/general relativity? | It's not as crazy as you imagine. The entirety of human civilization is a small place today, it takes mere hours (or sometimes minutes) to travel to the other side of the planet, and it takes mere milliseconds for messages to travel around the world. But it wasn't always that way. For much of human history it took years for news and trade to make its way from one region to another. And some regions were effectively cut off from each other (such as the Americas and the rest of the world). In comparison, being able to send and receive huge volumes of data at the speed of light is a massive improvement, even if it takes tens, hundreds, or thousands of years for that data to be received. Interstellar colonization is technologically possible, but it'll result in a different sort of civilization than we're used to. | [
"The primary argument calling for space colonization is the long-term survival of human civilization. By developing alternative locations off Earth, the planet's species, including humans, could live on in the event of natural or man-made disasters on our own planet.\n",
"Based on his Copernican principle, J. Ric... |
why don’t all phone services send texts over the internet (like apple’s imessage does)? | The short answer is that they don't because they didn't originally.
*Short Message Service*-messages, as they are called in the GSM standard among other more recent standards, is a technical feature offered in the communication protocol used to communicate to and from the phones.
Internet traffic relies on one or several other technical substandards that are also offered in the communication protocols.
From the phone operators point of view, a SMS is awesome. Because they have full control.
The problem, if you wish, is that since they have full control, they also have pretty pricey business models. Or had, at least.
iMessage, WhatsApp, Line, Facebook Messenger, Google Hangouts, Signal, Telegram and all the others are internet services that happen to be linked to your phone number. SMS is a phone network service that is offered to your phone number. It doesn't necessarily have anything to do with the internet.
The idea is pretty much that if the phone plan has a pretty decent cost for data (and often there is a monthly allowance of sorts in the data plan...) it's cheaper to use the data plan for your messages than to pay for each individual message that you send out.
But. Smartphones too must follow the phone network communication standard. They *must* be able to receive SMS. Which means that they all can. No matter if your grandma has a brand new iPhone 11 (or whatever the newest one is?) or if she runs around with a Motorola from 1996, the terminal has SMS reception capabilities. And probably sending capabilities too.
It's also a pretty dumb thing if you compare an iPhone and an Android phone; Google has their text messaging app. Apple has theirs. They don't work well together. If you want to communicate with others, you have to first agree on which app to use for your communications.
With SMS, you don't. You just have to know the phone number, and that's it. Which is why your phone falls back on SMS every time it tries to communicate with someone who is not on iMessage. Because SMS always works. If you typed in the correct number, the message will be received. | [
"As of 2017, text messages are used by youth and adults for personal, family, business and social purposes. Governmental and non-governmental organizations use text messaging for communication between colleagues. In the 2010s, the sending of short informal messages has become an accepted part of many cultures, as h... |
Did fighting cease at night during the Battle of Stalingrad, or did soldiers fight 24 hours a day? | In reading just now excerts from "Stalingrad: The Fateful Siege: 1942-1943 By Antony Beevor", Its talks of how Chuikov had ordered an emphasis on night raids because the Luftwaffe could not respond and that he was convinced it struck fear into the Germans. It talks about the use of flares to constantly trick soldiers into a belief of an imminent attack.
In addition a comment from a corporal about the "eerie change in sound" of the U-2 bi-planes used for night time bombing as the pilot would turn off the engine on assault until the bomb hit.
So a constant psychological onslaught from the Russians, the author comments as well that the Germans were exhausting ammo as they would fire at anything during the night.
edit: type in: "Stalingrad night raid" the piece i read should be in Google books.
| [
"Most of the fighting occurred at night, under heavy mortar fire, while the daylight hours were usually spent by the UN forces evacuating the dead and wounded, replacing the defending company, sending up resupplies and repairing the fortified positions. The daylight hours were punctuated with artillery, mortar and ... |
Why does water form the shape it does when poured? | The shape is dependent on a lot of things. Some are properties of the water itself like viscosity, density, and surface tension. Some are properties of the environment like gravity, density/viscosity of the air you are pouring into. Some are properties of the way you actually pour the water like the shape of the container and its mouth, the velocity of the water as it crosses the mouth and the distance that it falls.
The shape of the stream of water is dependent on all of things and probably some I didn't mention. The system is complicated enough that you can't say the shape is because of this one thing - they all influence the shape. The best way I could describe it is to say that the stream gets its shape from the edge of the mouth of the container and the amount of fluid flowing over the edge. Once it clears the edge, it's original momentum will be conserved and it will be accelerated by gravity. That will stretch it out as it falls, but surface tension will hold it as a single stream for a certain distance. The sine like shape you see is some combination of all these things. | [
"Surface tension is responsible for the shape of liquid droplets. Although easily deformed, droplets of water tend to be pulled into a spherical shape by the imbalance in cohesive forces of the surface layer. In the absence of other forces, including gravity, drops of virtually all liquids would be approximately sp... |
If island chains like Hawai'i were formed by the continuous movement of a plate over a magma plume in the mantle, why do they take the form of separate islands rather than a continuous ridge? | To form a continuous line, you would have to assume that magma plumbing is continuous; that is that you apply magma at the base of the crust at position x and it comes out at y above, apply at x+1 and it will come out at y+1. That is not the case.
Magma plumbing is highly discontinuous; magma will preferentially propagate along fractures and pre-existing weaknesses in a system. A pool of magma accumulating at the base of the crust will tend to propagate along the same route it first successfully found. That route will be used until the low-level magma suipply is cut off. At this point a new low level accumulation will form, until it too finds itself a new plumbing route.
Consider too that the ocean floor is cut by numerous large faults which cut through pretty much the entire plate - these and their related structures can form preferentially weak loci for magma injection.
The vast majority of magma never even makes it out to the surface - most is simply crystallised at depth in magma chambers which dead-end several kilometres below the surface, or are injected as dykes or sills within the host strata.
It's a bit like considering the population living around a city, and thinking that you should be able to draw a straight line from their house to the centre, and that will be their route in, resulting in a perfectly radial distribution of travel. In reality, they move along main arterial roads because that is the *easiest* route, rather than climbing over fences, walking through other peoples houses, and navigating the *shortest* route. | [
"The volcanic islands that comprise these island arcs are thought to have been formed from the release of volatiles (steam from trapped water, and other gases) being released from the subducted plate, as it reached sufficient depth for the temperature to cause release of these materials. The associated trenches are... |
why do brownie corners taste better than brownie centers? | Brownie center lovers are going to debate you on this, but the reason is because the brownie edges simply taste different due to a process called a [maillard reaction](_URL_0_). | [
"Various types of openings and projections give a square character and variety. Doors, windows, and balconies opening into the square give it character while making it more accessible, thus encouraging its use for recreation. The squares therefore are vibrant places with a wide variety of colours. \n",
"Salty liq... |
what is the difference between gdp and ppp? | GDP is the gross domestic product, the total output of the entire nation's industries and workers. Sometimes they list this as "GDP per capita" which means how much each person would contribute to that total if it were divided equally.
PPP is purchasing power parity, it's a determination of how much one person could buy with their income, by comparing their currency to another country's. This is sometimes different than GDP per capita because of exchange rates, artificial price controls or tariffs, and various subsidies. | [
"GDP comparisons using PPP are arguably more useful than those using nominal GDP when assessing a nation's domestic market because PPP takes into account the relative cost of local goods, services and inflation rates of the country, rather than using international market exchange rates which may distort the real di... |
In curling, how do sweepers influence the path of the rock? | The ice has little bumps on it. Sweeping away the bumps to smooth the ice allows the stone to speed up on the left or right side therefore making essentially different drag on the left or right causing it to turn. | [
"The player can induce a curved path, described as \"curl\", by causing the stone to slowly turn as it slides. The path of the rock may be further influenced by two sweepers with brooms, who accompany it as it slides down the sheet and sweep the ice in front of the stone. \"Sweeping a rock\" decreases the friction,... |
why do stores, businesses, buildings play music? | i don't know about other buildings, but i know that grocery stores will play slow music because you slow down while browsing the aisles with slow music, thus giving you a higher chance to buy something. | [
"In the 2010s, music stores can be \"bricks and mortar\" stores (either individual small businesses or chain stores, which may be a regional or national chain); online musical instrument stores, which consist of a website describing the merchandise, various online payment systems, and shipping or delivery systems; ... |
Homophobic slurs in turn-of-the-century/WWI Britain? | *Sodomite* and its variants were certainly in use at that time in Britain. The Marquis of Queensberry left a calling card at Oscar Wilde's London club in February of 1895 that was addressed "To Mr. Oscar Wilde, posing as a somdomist" (sic). His handwriting was so poor that some have suggested that the card was actually intended to read "ponce and sodomist." Either way, Wilde sued for libel, lost, then was tried and convicted of indecency.
English sexologist Havelock Ellis, in his *Studies on the Psychology of Sex* from 1897, used the word *pervert* to refer to a homosexual; the word definitely had negative connotations at the time, but lacks the level of disdain that you're probably looking for.
*Punk* has evolved through several meanings, but it was at the turn of the century that it took on the meaning of the less dominant of two men that are having sexual relations. It was used most frequently in all-male societies such as hoboes, sailors, and prison inmates. A similar term from the time was *prushun*, referring to a young man who served as traveling companion, beggar, and bedmate for an older hobo (who was known as a jocker in such a relationship). In both cases, there is the inference that the less dominant of the two had been coerced into it.
The word *queen* can be traced back to 1924 in the *OED*, but the use of the word to mean a homosexual man (rather than being a disparaging term for a bold woman) can be traced back to the 1880s, in testimony from London's Cleveland Street Scandal. That testimony also shows us that the word *gay* was used at the time to refer to both homosexual men and female prostitutes. It is believed that because those two groups lived in close association in big cities during the nineteenth century, they used many of the same slang terms, and that was one of the reasons that the use of so many slurs evolved, in that they first referred to one gender, then the other.
*Mary* dates back to the 1890's, and *Nancy*, *nancy-boy*, and *Miss Nancy* to the 1800's. [Andrew Jackson](_URL_1_) even referred to William King, the 13th American Vice President, as "Miss Nancy."
Since you mentioned *cocksucker*, it was included in Farmer & Henley's 1891 dictionary *Slang and Its Analogue*, published in London, with the one-word definition "feliatrix." It was in use there at the time, but was not gender-specific.
As far as the written record goes, *faggot* as a gay slur dates back to 1914; it is generally regarded as an Americanism, and in fact *to faggot* meant 'to have sex with loose women' in nineteenth century Britain, according to Farmer & Henley.
Info from Hugh Rawson's *Wicked Words*, 1989, and [The Straight Dope](_URL_0_) | [
"The earliest recorded occurrence of the slur seems to be in the \"Time\" magazine of 5 January 1942 where \"three Nip pilots\" was mentioned. The American, British, and Australian entry of the Pacific Ocean theatre of World War II heightened the use of racial slurs against the Japanese, such as \"Jap\" and \"Nip\"... |
why does food microwaved in commercial kitchens turn out much better than what someone can do at home? | It actually has nothing to do with the tech. You use normal microwaves in a commercial kitchen - it's entirely up to the quality of the food. Your meal would have been prepared that day (or immediately - not everything is nuked!) by someone who knows what they're doing, with OTHER expensive tech. The reason microwave meals suck so much is because they're cheap. Just like any other cheap food, it's not made very well... I think they're starting to improve now, what with the popularity of 'hipster' food growing... But if you nuke good quality fresh food, it'll taste great. 2 day old lasagna may not be as impressive!! | [
"Microwave ovens are a common kitchen appliance and are popular for reheating previously cooked foods and cooking a variety of foods. They are also useful for rapid heating of otherwise slowly prepared foodstuffs, which can easily burn or turn lumpy when cooked in conventional pans, such as hot butter, fats, chocol... |
with plea bargaining, why is it not acceptable to pressure someone to forego their right to a lawyer for a better sentence, but it is acceptable to pressure someone into foregoing their right to a trial? | Because the lawyer can tell you what are and are not reasonable offers, and not having the lawyer present will never benefit the suspect. Forgoing a trial benefits both the justice system by avoiding a timely, costly, and pointless procedure (assuming there's clear evidence of guilt), while the suspect can benefit by reduced sentences etc. The lawyer ensures that the deal is reasonable and fair (at least theoretically). | [
"Some legal scholars argue that plea bargaining is unconstitutional because it takes away a person's right to a trial by jury. Justice Hugo Black once noted that, in America, the defendant \"has an absolute, unqualified right to compel the State to investigate its own case, find its own witnesses, prove its own fac... |
so i've been wondering, if the ocean water gets affected by the full moon, does human also get affected (maybe just the slightest) since we are consisted of water? | Yes you are, not because you're made of water because you have a mass in general. So if you weight yourself on a super precise scale when the moon is straight up in the sky you will be (slightly) lighter than if you weight yourself when the moon is on the opposite position. But that effect is soooo insignificant that you wont notice it on your scale. | [
"Believers in the lunar theory suggest several different mechanisms by which the behaviour of the Moon could influence the behaviour of human beings. A common suggestion is that, since the Moon affects large bodies of water such as the ocean (a phenomenon known as \"tidal force\"), the Moon should be expected to ha... |
How big were vegetables 2,000 years ago? | I can give only one example and that is of corn and the domestication was much earlier then 2000 years ago. It was first domesticated in Southern mexico by 4000 to 3000 B.C.E.. The ancestor of corn was a mountain grass called teosinte. It does not look like modern corn. Thousands of years of selective adaptation were required to develop a large cob. Teosinte was about the length of two quarters long. | [
"Originally, vegetables were collected from the wild by hunter-gatherers and entered cultivation in several parts of the world, probably during the period 10,000 BC to 7,000 BC, when a new agricultural way of life developed. At first, plants which grew locally would have been cultivated, but as time went on, trade ... |
Was the fear of communists in the US mostly about the military threat, or the fear of the idea and it leading to a revolution from within? | There were many periods of anti-communist sentiment in the United States, each having its own set of domestic and international issues. Many consider the 1930s to be the "heyday" of American Communism (see [Harvey Klehr's book](_URL_0_)) because that's when the US was closest to revolution (due to the 1929 stock market crash and millions of unemployed workers- i.e., Communists' ideas seemed pretty good to the downtrodden). So, in the 1930s, the anti-communist sentiment was very much a fear of a domestic revolution- it seemed that Marx was right (in some regards), and that capitalism couldn't support itself. In 1935, the Party entered the Popular Front era, meaning it was more acceptable for communists to associate with liberals, democrats, moderates, union organizers, etc. to push for rights for the working class. So Party influence was at an all-time high. Many historians note that if the US was ever to have a communist revolution, it would've been then due to the Party's influence on politics and culture (and would have been very different from Maoist China or the Bolshevik revolution). This all fell apart when Stalin signed the Soviet-German non-aggression pact, essentially making nice with the Popular Front's greatest enemy: fascism.
In 1938, the House of Un-American Activities Committee (HUAC established the Dies committee to hunt for Nazi's in the country, which led to suppression of other political groups, like the communists and socialists. From there, there was no real turning back. After the US entered WWII, the threat of attacks on the US gained credence, and political suppression was seen as a legitimate way to preserve domestic and international peace. I have less expertise in the post-war era and communism, so if someone wants to step in on that, that would be great. But in general, after the communist witch-hunt of the 1950s, most Americans no longer feared the communist revolution, but instead feared espionage and Soviet attacks. | [
"As U.S. relations with the Soviet Union rapidly deteriorated following World War II, there were accompanying concerns about government infiltration by communists. As the U.S. fell from being wartime allies to staunch adversaries with the USSR, American obsession with perceived dangers associated with the Soviet Un... |
Did medieval cities have street names?/ How did people in urban areas tell each other where they lived? | hi! feedback on street naming in medieval Europe is welcome, but meanwhile, you might be interested in a couple of posts that discuss other times/places without street names, to get an idea of how it works:
[Did streets in Rome use street numbers during the Republic and/or Empire period?](_URL_1_)
[Why does Tokyo have such unusual street address designations?](_URL_0_) | [
"It was normal practice for medieval street names to reflect their function, or the economic activity taking place within them (especially the commodities available for sale), hence the frequency of names such as The Shambles, Silver Street, Fish Street, and Swinegate (pork butchers) in cities with a medieval histo... |
In Classical-age Europe, how pervasive was the ability to speak Greek? | The flaw in your premise is asking about Europe, when your question is about Judea.
Pretty much west of the Balkans, Latin was the dominant language of the Roman empire, though Greek was very prevalent among educated Romans and among the upper classes diglossia (switching between two languages to talk about different fields/areas of life) appears common. It's extremely likely that Pontius spoke Greek well.
East of the Balkans , Greek was the dominant lingua franca. Even in areas where another local language was spoken, e.g. Aramaic, Greek was in widespread usage. It was not rven necessarily about formal education, widespread usage of Greek meant that many people were bi or trilingual. For this reason it is not at all unlikely that Jesus knew Greek and could speak in it, even though he was probably not educated in it nor spoke it as well, say, as Pilate.
| [
"Popular Western opinion is reflected in the \"Translatio militiae\", whose anonymous Latin author states that the Greeks had lost their courage and their learning, and therefore did not join in the war against the infidels. In another passage, the ancient Greeks are praised for their military skill and their learn... |
when watching shows set in earlier centuries, the "lords" or "estate owners" always seem to be lounging all day or attending balls. where was their wealth coming from that they didn't have to work at all? | First off, don't trust TV. As far as the income of nobles in those days it came from 2 sources. 1)They owned a lot of land and got the profits of the production of that land. 2) They were the government back then, and taxes were paid to them.
As far as what they did all day generally they held court where they heard from people asking them to do things or resolve disputes or mete justice in criminal matters. They also had to deal with management issues for their properties. They also hunted, a lot.
A lot of medieval aristocrats spent 6 months a year hunting. This wasn't modern hunting, going out on weekends ambushing deer from a blind or stand. They hunted actively in packs chasing down prey and killing them in hand to hand combat. Organizing the groups, getting them in the field, locating animals, tracking them, chasing them and killing them were all a form of military training which was the other main job these people had. | [
"Despite popular perception, a small estate owner often led a boring and primitive life. The owner had few pursuits to distract him besides maintaining relationships with neighbors, religious and family obligations, and hunting, all of which made for a dull existence in the interim. Palaces did not feature privies ... |
why does everything seem to be so much smaller than it was millions of years ago? | We do have the blue whale which is the largest animal on record, but yes we are at a low point in terms of huge animals, especially land animals. If you're comparing us to the various giant dinosaurs it's worth remembering that they existed over a period of almost 200 million years and we tend to remember the highlights over that whole time, giving a skewed perspective of the average sizes. It may also be that as mammals are warm-blooded they have less energy to invest in growth than the dinosaurs did but that's a bit hand wavy and the blue whales are an obvious exception.
If we just consider the recent past, as in the past 10 million years or so, we do seem to have lost a lot of the biggest animals. Megatheria, mammoths, aurochs, elephant birds, haast eagles and many more that would be record setters if alive today were all around until very recently. There has been considerable debate as to what brought an end to all these species, the two chief candidates are climate change and human hunting activity. Humans have been confirmed as the guilty party in many cases but there is also evidence for the role of climate. When environments undergo rapid change it tends to be the largest animals that go the fastest as they require larger areas of functioning ecosystem to survive.
Lower oxygen levels is primarily associated with smaller insects as they absorb Oxygen through diffusion. Oxygen levels were around the same as they are now when the dinosaurs were around. | [
"BULLET::::- The largest structures in the universe are larger than expected. Current cosmological models say there should be very little structure on scales larger than a few hundred million light years across, due to the expansion of the universe trumping the effect of gravity. But the Sloan Great Wall is 1.38 bi... |
What would be the critical mass a black hole would need to be to consume our planet? | Here is my first stab at an answer. As I note below I don't think it's the right answer, but it should give you an idea of how we might go about calculating this.
The power a black hole puts out from [Hawking radiation](_URL_0_) is inversely proportional to its mass squared. For my simple calculation, I'll take the rate that mass flows into black hole as the density of the Earth times the surface area of the event horizon, times the speed of light. If I multiply that by c^2 to get the effective "power" of that mass flow, I can set that power equal to the Hawking power and find out what the mass needs to be:
M > (hbar * c^7 / (245760 * pi * density))^(1/4) / G
plugging in 5.5 g/cm^3 for the Earth's density, I get that the limit is **[1.3x10^14 kg](_URL_1_)** (mass of a middling mountain)
I am guessing that the actual answer is lower than this, because it ignores the fact that matter will get compressed as it is pulled into this point, and the evaporation time for this black hole is 6*10^18 years. Any GR people care to comment? | [
"BULLET::::- In \"The Singularity is Near\", Ray Kurzweil cites the calculations of Seth Lloyd that a universal-scale computer is capable of 10 operations per second. The mass of the universe can be estimated at 3 × 10 kilograms. If all matter in the universe was turned into a black hole it would have a lifetime of... |
Weird question. Does a wine drunk have a different effect on your emotions? [neuroscience]? | The different effect of different alcohols have to do with the social situations they are consumed in. I people drank wine at frat parties and spring break they would associate wine with the behavior that is currently associated with tequila. | [
"Wine contains ethyl alcohol, the same chemical that is present in beer and distilled spirits and as such, wine consumption has short-term psychological and physiological effects on the user. Different concentrations of alcohol in the human body have different effects on a person. The effects of alcohol depend on t... |
/r/shitredditsays. i don't get that subreddit. can someone please explain to me what the fuck is going on there? | They read the Wiki for [Poe's Law](_URL_0_), then cranked the retard full blast and created a subreddit to record the progress.
The experiment is ongoing. | [
"The site frequently focuses on trending topics, with the few articles created by users of the site mostly being about sensational topics such as YouTubers, memes, activists, white supremacists, and police shooting victims. The site has been criticized for initially presenting false information in wiki pages on bre... |
I have a few questions regarding colonial-era naval battles. | The image which you attach is of the battle between the USS Wasp and HMS Reindeer in the War of 1812.
Like most naval battles, this was fought near land (in the approaches to the English Channel) rather than in the middle of the sea. It is hard to find enemy ships (or fleets) in the vast reaches of the open sea, so most battles occurred near ports or other strategic locations close to land.
In this case, the Wasp's mission was to raid English commerce in the English Channel (a very strategic location, as a vast number of merchant ships trading in or out of England would have to pass through the Channel). The Reindeer was sent out to attack the Wasp once the British learned that she was there, raiding their commerce.
Though it was risky (and not always strategically wise) for a captain to engage in ship on ship battle, sea captains in this era rarely refused battle. It seems to have been a point of honor.
It could be argued that continuing to destroy British merchant shipping in the Channel approaches was more valuable to the American War effort than destroying one small British warship. (Though the morale and propaganda value of ship to ship victories in the War of 1812 was high). Even though victorious, the Wasp had to put into a French port for repairs, and was out of action as a commerce raider for seven weeks as a result of the battle.
The Wasp and the Reindeer do not seem to have engaged in much of a tactical duel. The two ships sailed towards each other in very light winds. When they were close, they went broadside to broadside and began firing the cannon. After twenty minutes of cannon fire, the two ships were alongside of each other, and the British tried to board the Wasp but were repulsed. The Americans follwed up by boarding the Reindeer (this is the moment shown in your picture).
The Wasp had heavier cannon (22 32 pounder carronades vs 18 24 pounder carronades) and more crew (178 vs 118), so had the advantage in both phases of the battle. The Reindeer was too damaged to sail back to port, so she was burned. Reindeer had 25 men killed and 42 wounded when she surrendered. Wasp had 11 killed and 15 wounded.
There often would be more strategy and maneuvering in a ship on ship battle than there was in this one.
In the Napoleonic wars, the British liked to try to achieve the "weather gauge" (that is to get their ship to windward of the enemy). The ship that had the weather gauge could better control the action and prevent the enemy from escaping. The French often preferred the lee gauge, from which they would try to keep the distance open from the enemy and shoot at sails and rigging, hoping to disable the British ship and gain a maneuverability advantage that might allow them to achieve a raking broadside.
To be able to "rake" the enemy was often a decisive blow. Raking meant to cut across the bow or stern of the enemy ship, so that you could send a broadside down the entire length of the enemy gun deck, while the opponent could not shoot back (having very few guns pointed fore or aft).
Mostly, it was hard to out maneuver the opponent well enough to achieve a raking broadside. The USS Constitution, however, seems to have been able to do this in several of her victorious engagements in the War of 1812. Perhaps because she was unexpectedly faster or more maneuverable than her opponents expected.
Cannon were very effective in naval combat. They rarely sunk wooden ships, but they crippled them and killed the crew until the ship would no longer function as a fighting force. Ships could be defeated by cannon fire alone (and most often were) but it was also not uncommon for the final action of a battle to be boarding the enemy and hand to hand fighting on the decks (as in the battle between the Wasp and the Reindeer).
Sources:
_URL_0_
_URL_1_
| [
"On March 25, 1655, during the English Civil War, (1642-1651), in Europe, the Battle of the Severn, the first naval colonial battle ever fought in America was fought in Anne Arundel County on the Severn River between Puritan forces supporting the Commonwealth of England and forces loyal to the Lord Proprietor, Ceci... |
what's the big deal about the leicester city soccer team? | Leicester City were promoted to the EPL in 2014. They've generally been considered a lesser team, having been relegated several times and rarely have competed with the more established teams of the EPL.
Also, the EPL has traditionally been dominated by the likes of the big spending clubs such as Manchester United, Manchester City, Chelsea and Arsenal.
Leicester City are *not* a rich club, and have a squad without any superstar players (although their striker Jamie Vardy is fast becoming one), yet they currently sit top of the EPL and look to have a *strong* chance of actually winning the title this season.
They are considered massive underdogs and will be one of the only teams to break the EPL dominance without having to have spent a lot of money to do so. | [
"Leicester City qualified for the group stage of the 2016–17 UEFA Champions League by winning the 2015–16 Premier League. It was their first participation in this competition. As champions of England, the club was in Pot 1 for the group stage draw.\n",
"Leicester City (Division One play-off winners in 1994 and 19... |
Can you make electricity from radio waves? | Antennas are devices that turn radio waves into electrical power (or vice versa). It is possible to harvest energy from ambient electromagnetic radiation, but the amount of power you get is fairly low, usually on the order of a few milliwatts, which can be used to power small electrical devices. | [
"Power might also be transmitted by changing electromagnetic fields or by radio waves; microwave energy may be carried efficiently over short distances by a waveguide or in free space via wireless power transfer.\n",
"Thus, the work of many researchers enabled the use of electronics to convert signals into high f... |
How did people "optimise" crops for better yields in ancient civilizations or in the middle ages? | Interestingly enough, this question coincides with “How was the cow domesticated?”
A little bit of context, the cow (aurochs) before domestication was an absolute brute. They were violent beasts much larger than humans and much larger than the modern cow. So how the heck did it get domesticated???
Well humans didn’t choose to domesticate the cow. It was a symbiotic relationship that developed because both sides learned about the benefits of keeping each other around which develops a tolerance between each other and eventual direct interaction. But that still doesn’t go all the way. Why the heck would humans tolerate such a beast??? (Some surviving documents from Rome/Greece reference the aurochs as an untamable beast. I can track those down if you’re interested. But the aurochs survived until the 1600s while cows were already domesticated.)
So! If we need them to hang around each other for long enough to realize that they benefit from each other, then what could bring them together in the same place?? WHEAT!
In Ancient Rome it was punishable by death to let your cows eat from the wheat fields of another farmer... except for certain months of the year. The months of the year where the wheat’s seeds haven’t sprouted yet and we’re just leaves.
Why? Because the cows would eat the leaves, allowing the wheat to reserve their energy for growing seeds (the substance humans were interested in). This was a practice that was developed well before the cows were domesticated (aurochs at the time), and continued through Rome (recorded in agricultural guides which I can also track down if interested) and the medieval world.
So to sum it up/tl;dr: A practice of ancient civilizations through the Middle Ages to optimize wheat yields were to have cows eat the leaves off of wheat before the seeds sprouted. This meant the wheat plant would have energy exclusively for growing the seeds which made more larger yields.
Sorry for grammar mistakes, I’m at work typing frantically. | [
"Columella's \"Husbandry,\" circa 60 CE, advocated the use of lime and that clover and alfalfa (green manure) should be turned under, and was used by 15 generations (450 years) under the Roman Empire until its collapse. From the fall of Rome to the French Revolution, knowledge of soil and agriculture was passed on ... |
Physical interpretation of impedance | Let's consider an RC circuit, with a sinusoidal current. As current flows in one direction, charge will be accumulating on the "front" side of the capacitor, while when current flows in the opposite direction, charge will flow off the "front" and onto the "back" side of the capacitor. Let's call the first direction positive current and the second direction negative current. Let's also take positive voltage for the capacitor to be the case when the "front" side of the capacitor has positive charge.
Consider a sinusoidal current, I(t) = I_0 sin(bt).
For a resistor, the votlage is proportional to the current, so the voltage reaches its maximum when the current does.
For a resistor, the voltage is proportional to the charge on the "front" side of the capacitor. When does this reach a maximum? This charge is increasing as long as I(t) is positive. That means it will be increasing from t=0 right until the point where I(t) reaches 0 again (t=pi/b). Even after I(t) reaches its maximum, the current is positive, so the charge on the "front" plate of the capacitor will keep increasing, as will the capacitor's voltage.
It is only after an additional quarter-cycle after I(t) reaches its maximum that the current reaches 0, and then switches direction, causing the capacitor's voltage to start to decrease. Thus the maximum voltage of the capacitor occurs a quarter-cycle off from when the maximum voltage of the resistor occurs.
A similar effect occurs for inductors, since their voltage goes as dI/dt. | [
"Impedance is the opposition by a system to the flow of energy from a source. For constant signals, this impedance can also be constant. For varying signals, it usually changes with frequency. The energy involved can be electrical, mechanical, acoustic, magnetic, or thermal. The concept of electrical impedance is p... |
how did marijuana suddenly become legal in 3 states? why is there such a sudden change in sentiment? | I wouldn't say that it's been a "sudden" change in sentiment. The legalization movement had been gaining traction for quite a while.
Two big tipping points, however, are probably due to 1) the growing realization that the *War on Drugs* has been one colossal—and expensive—failure, and 2) the nuanced view the Medical establishment has taken on the use of marijuana for medicinal purposes.
EDIT: Several big tipping points! | [
"Some studies show that the increased legalization of cannabis in the United States (beginning in 2012 with Washington Initiative 502 and Colorado Amendment 64) has led Mexican cartels to smuggle less cannabis in exchange for more heroin.\n",
"Cannabis began to attract renewed interest as medicine in the 1970s an... |
how do plants avoid pollinating themselves? | There are multiple techniques to avoid this.
The first one that comes to mind is only activating one gamete at a time. A plant may choose to do it in 6 month cycles, say 6 months of pollen release with stigma closed and then 6 months of stigma open with pollen not being released (in actual fact the time will probably be less than this but you get the point).
Plants also have chemical markers on their pollen and chemical receptors on the stamen. The plant is able to recognize self from non-self and reject the self pollen. There is only a finite amount of chemical markers so plants will often reject foreign pollen because it has an identical marker.
Plants do not have to avoid pollinating themselves all the time. In cases where there is fewer potential 'mates' self pollination is a great idea. There are many plant species that do not mate at all and in effect produce clones of themselves with no real genetic diversity. | [
"Few plants self-pollinate without the aid of pollen vectors (such as wind or insects). The mechanism is seen most often in some legumes such as peanuts. In another legume, soybeans, the flowers open and remain receptive to insect cross pollination during the day. If this is not accomplished, the flowers self-polli... |
how come some liquids(like milk) can be held in paper cartons, and some can not(like toothpaste)? | Toothpaste isn't a liquid. It's a paste. And the easiest way to dispense a thicker substance like that is in a tube you can squeeze. Also, nobody needs a 1L carton of toothpaste. | [
"Cartons for liquids can be fabricated from laminates of liquid packaging board, foil, and polyethylene. Most are based on either Tetra Pak or SIG Combibloc systems. One option is to have the printed laminate supplied on a roll. The carton is cut, scored, and formed at the packager. A second option is to have the p... |
why dont metals compound with each other | I can answer this and I made an account because I really wanted to answer this!
I'm a metallurgists, basically a metals engineer and I work at a steel factory. Metals are unique in that they don't make up what people think of as "normal" compounds. But they do make substances with other metals. A lot of people think this is because of metals only taking electrons, but this is a misconception. Metals, more or less, share electrons, kind of like CO2, but it's a weaker bond.
This is how stronger steels are created. Steel is mostly iron and carbon, but in order to get things like stainless steel, you have to add elements like chrome or nickel. And to make them stronger, you add thing like titanium or aluminum. The way steels get stronger, in this case with nickel and titanium additions, is that the nickel and titanium form a compound known as an intermettalic phase (or compound) that is Ni3Ti. It happens with aluminum Niobium, Cobalt, and other elements too. Some things, like lead solder or even gold, are compounds. Lead solder is actually lead and tin and gold is typically gold and copper (the karats deal with purity I'm gold. So the higher the karats, the purer, and less alloyed, it is). All of these compounds need a lot of energy to form. Which is why it typically only happens during melting or at high temperatures of < 800F°.
TL;DR. Metal does compound with other metals. It just needs the another metal that will be able to form something with it at a high enough temperature. | [
"When it was realized that some metals form two different binary compounds with the same nonmetal, the two compounds were often distinguished by using the ending \"-ic\" for the higher metal oxidation state and the ending \"-ous\" for the lower. For example, FeCl is ferric chloride and FeCl is ferrous chloride. Thi... |
how does face paint, such as that used by quarterbacks, help block the sun? | It doesn't exactly "block" anything.
What it does is it darkens the reflection of light off your own face into your eyes. If you're looking into sunlight, the brightness of your own cheekbones below your eyes causes glare that can be distracting. It sounds absurd, "glare off my own face? Wtf", until you actually try it sometime. You get a noticeable increase in visibility when looking into the sun if you have eyeblack under your eyes. | [
"Mike Silver of NFL.com reported that on the morning of game day, officials discovered the logos at midfield and in the end zones had been painted using paint which was not intended for use on the newly installed FieldTurf. Subsequently, the paint had not fully dried, and officials heated the field to speed up the ... |
Can someone describe with good detail how exactly the sacking of a major city by Roman troops would occur? | This is a pretty broad question and there is no hard and fast rule for every aspect of your question. One of the chief concerns for a Roman soldier was booty, particularly during the Republican when such booty would make up the majority of their pay during their soldierly career. The types of deprivations inflicted upon a city were going to be based on highly complex factors. Sometimes a city was not sacked, other times it was. Sometimes that sack was orderly, often times it was not. In general, if a city was to be sacked, a commander would grant his men leave to basically be scoundrels, and sometimes this played out with horror.
So, let's begin:
> What happened to people inside the city
A quote from Polybius:
> The incidents of the capture of Corinth were melancholy. The soldiers cared nothing for the works of art and the consecrated statues. I saw with my own eyes pictures thrown on the ground and soldiers playing dice on them; among them was a picture of Dionysus by Aristeides---in reference to which they say that the proverbial saying arose, "Nothing to the Dionysus,"---and the Hercules tortured by the shirt of Deianeira. . .
The holy places of even your enemy had power and deserved respect in the ancient world, so to treat them with such disrespect was as sacrilege and brutish as it gets. The fate of the Corinthians was not particularly pleasant either of course. According to Diodorus Siculus
> This was the city that, to the dismay of later ages, was now wiped out by her conquerors. Nor was it only at the time of her downfall that Corinth evoked great compassion from those that saw her; even in later times, when they saw the city leveled to the ground, all who looked upon her were moved to pity. p443No traveller passing by but wept, though he beheld but a few scant relics of her past prosperity and glory. Wherefore in ancient times, nearly a hundred years later, Gaius Iulius Caesar (who for his great deeds was entitled divus), after viewing the site restored the city.
So this city lay in ruins for a century before being rebuilt. For the record, Corinth was basically sacked to the ground, with all women and children carried off into slavery. Those that were not enslaved were slaughtered. The Romans could be quite brutal. You'll note from the writings here that even they were quite shocked by what occurred in Corinth, and it could be called a bit of an over-reaction. It did serve a purpose though, which was to put the Greek (and Mediterranean world) on notice that to challenge Rome wouldn't mean you would be conquered, it meant you would be annihilated. Twenty years earlier during the Third Macedonian War, Epirus had seen a reported 150,000 people enslaved, and was devastated to such a point that centuries later it was noted that what had once been a highly populated state was still barren and empty.
> what happened to soldiers and officers still alive
Generally, common soldiers were slaughtered at worst and enslaved at best. Leaders would be spared for a triumph, which would see them paraded in Rome in chains before being strangled. This is assuming they didn't commit suicide to avoid such shame.
> what happened to commerce, trade and daily routine in the city
We can assume that if a city was destroyed, such commerce would end. However, in many cases, as with Corinth, the city itself occupied a position that was valuable (thus explaining the existence of the city in the first place). Both Corinth and Carthage would be rebuilt and occupied near or on top of their former sites as Roman colonies. If the city remained unsacked and simply surrendered, we can assume trade would continue (as it did for Carthage after the second Punic War).
> How long would the Romans stay in a city, is there a reason to raise the city, or keep the city?
This depended entirely on the period and the situation within the city. During the Republican Period, particularly prior to the integration of the provinces after the sacks of Corinth and Carthage, permanent Roman garrisons were not a common thing. Roman policy was designed not around direct occupation and control during these years, but around force projection and client states/tribes. Tribes were expected to police themselves, and when they didn't, incidents like Corinth would occur to set the rest straight. Sometimes it worked, sometimes it didn't.
| [
"BULLET::::- December 17 – Sack of Rome: After almost a year's siege, the capture of a grain fleet sent by the exiled Pope Vigilius near the mouth of the Tiber, and failure of troops of the Byzantine Empire under Belisarius to relieve the city, the Ostrogoths under King Totila plunder Rome and destroy its fortifica... |
why does it feel good to soak in a hot tub or a hot bath when we are sore? | The heat relaxes your muscles. When you're sore your muscles are cramped, stiff and or sensitive. The heat counteracts those symptoms. Often you don't even realize that some of your muscles are cramped until you take a bath.
I found this really nice article about it; [_URL_0_](_URL_0_) | [
"Showers or compresses using hot (but not scalding) water can relieve itching for up to several hours, though this \"also taxes the skin's integrity, opening pores and generally making it more vulnerable\", and is only useful for secondary treatment (not for cleaning urushiol from the skin, which should be done wit... |
why does the usa allow harmful chemicals, preservatives, and dyes in our food (and health care products) which are otherwise banned in other countries? | It has not been proven that they present a serious risk or serious harm. Other countries have different standards. | [
"Certain product ingredients are prohibited under Chapter IV of EC 1223/2009 based on their threat to human health. Annexes II through VI address what substances are prohibited and restricted, including ingredients such as colorants, preservatives and UV filters.\n",
"As of 2013, the European Union bans nearly 1,... |
Why did Standard Oil continue to drop prices as their monopoly went on? | I didn't know that happened. I do know that Standard Oil took a huge advantage in economies of scale and scope, that allowed it to drastically lower its cost compared to potential competitors. If Standard Oil did drop prices as you claim, then they valued market share over pricing in order to maximize revenue. If they continued to lower their prices, then competitors, who would have naturally higher costs, wouldn't be able to compete and would have to leave the market, allowing Standard Oil to occupy even larger market share. If the amount of petroleum they sold increased faster than the price drop (through increasing market share and generally increasing demand as the market for petroleum grew very quickly as Standard Oil developed), then Standard Oil would see its profits balloon, while competitors would face intractable barriers to entry.
In all, with a naturally growing market in petroleum and lower relative costs compared to competitors, Standard Oil preferred to maximize market share over optimal price setting in order to erect more barriers to entry for potential competitors by setting artificially low prices. | [
"Some economic historians have observed that Standard Oil was in the process of losing its monopoly at the time of its breakup in 1911. Although Standard had 90 percent of American refining capacity in 1880, by 1911 that had shrunk to between 60 and 65 percent, due to the expansion in capacity by competitors. Numer... |
ruby ridge incident. | Do you have a specific question?
If not I would direct you to the overall pretty decent wikipedia article.
_URL_0_
The short version is that the federal government had a sniper shoot people who were not threatening anyone and did not even know the feds were there, including a child and an unarmed woman. The federal government investigation into the incident concluded that the use of deadly force was completely inappropriate.
| [
"Ruby Ridge was the site of an 11-day siege near Naples, Idaho, U.S., beginning on August 21, 1992, when Randy Weaver, members of his immediate family, and family friend Kevin Harris resisted agents of the United States Marshals Service (USMS) and the Hostage Rescue Team of the Federal Bureau of Investigation (FBI ... |
How common is cannibalism among animals? | [Searched](_URL_2_)
Relevant [discussion](_URL_4_)
Original question by [negativefps](_URL_1_)
> What exactly detracts humans and other animals from cannibalism?
Relevant comment courtesy [smalrebelion](_URL_0_)
> This. Members of the same species share almost identical immune systems so a disease that is capable of surviving in the victim is more likely to find the cannibals immune system hospitable than a prey with a dissimilar immune system.
Relevant follow-up courtesy [libertasmens](_URL_3_)
> In addition to what others have said, you can look at it like this:
> It is more beneficial to a community to increase its population than decrease it. More members means more work, more food, and more protection. Cannibalism would decrease population, not to mention it would limit trust, which is generally essential to a community.
> Now, when it comes to humans, we have laws which protect our right to life. Unless some factor such as religion supersedes law, cannibalism is out of the question. | [
"Cannibalism is prevalent in aquatic ecosystems, in which up to approximately 90% of the organisms engage in cannibalistic activity at some point in their life-cycle. Cannibalism is not restricted to carnivorous species: it also occurs in herbivores and in detritivores. Sexual cannibalism normally involves the cons... |
why was jfk assassinated? | To put it simply, we don't know! There are a multitude of theories out there, some with more evidence than others, but there is no definitive answer to that question. | [
"In 1992, the popular but controversial movie \"JFK\" had renewed public interest in the assassination and particularly in the still-classified documents referenced in the film's postscript. Largely in response to the film, Congress passed the JFK Act, or \"President John F. Kennedy Assassination Records Collection... |
What makes Jupiter's giant red spot red? | The spot actually changes color. Ranging from dark red, to white, to blending in with the clouds around it.
The spot is a stable vortex caused by opposing currents of hydrogen and other gases that make up Jupiters atmosphere.
The reason for it's color is not known precisely but has something to do with the chemical composition which differs from that of the surrounding gases due to the nature of the disturbtion of gases caused by the vortex. The color difference could also have to do with the altitude difference between the gases in the vortex and the surrounding area which again would change it's chemical composition altering the wavelength of the subsequent light reflection. | [
" The Great Red Spot on Jupiter is, by far, the largest extraterrestrial anticyclone (or cyclone) known. It is so large that about 2 to 3 Earths could fit inside it. The Great Red Spot has existed on Jupiter for at least 340 years. In the image at the left, the Great Red Spot can be seen near the top center. The Gr... |
Does it take more energy to heat water from 10°C to 20°, than it does to heat water from 80° to 90°? | Very, very close. As others have mentioned, the quantity you're looking for is "(specific) heat capacity". For water, there's a nice table at _URL_0_
For 10°C to 20°C it varies from 4.193 down to 4.184 kJ / (kg K), while for 80°C to 90°C it varies from 4.198 up to 4.208 kJ / (kg K), so it does take a bit more energy, but it's a very small difference. Far more relevant would be it losing heat faster to the outside environment. | [
"All materials change with temperature, but superheated water exhibits greater changes than would be expected from temperature considerations alone. Viscosity and surface tension of water drop and diffusivity increases with increasing temperature.\n",
"As the heat of vaporisation (energy needed to vaporise water)... |
How do the rovers get there directional heading on Mars? | [_URL_0_](_URL_0_) – I don't have an account to read the full article, but the preview suggests that navigation is mainly done by physical landmarks. For coarse positioning and direction, you'd use the angle from the rover to larger hills and craters that you can match to satellite photos of the area. On the scale of one day's drive (a few hundred meters at most), it's also possible to use smaller features that aren't clear in the satellite photos, but that the rover has seen from multiple positions. | [
"Since the rover communicates with the ground controllers via the ExoMars Trace Gas Orbiter (TGO), and the orbiter only passes over the rover approximately twice per sol, the ground controllers will not be able to actively guide the rover across the surface. The \"Rosalind Franklin\" rover is therefore designed to ... |
What would a standard English soldier during the late 1300s be composed of? | Some mail would have been in use. Much would have already shifted to plate harnesses. Since you didn't specify, I'm going to cover basics, using manuscript illustrations for reference, [sourced from here](_URL_1_)
[BL Yates Thompson 35 La chanson de Bertrand du Guesclin, dated 1380-1392](_URL_0_)
Looking at this particular illustration, we see multiple figures, from various social classes. On the side of the defenders, we see first a crossbowman, with a simple kettle hat and what may be mail on his arms and torso. Note that he has no gauntlets nor any indication of plate armor defenses.
Next we see members of a higher class, one holding a shield and spear, the other a boulder. They're wearing more extensive defenses. They have houndskull bascinets, plate arm harnesses, breast plates and mail defenses around the neck. They are also equipped with gauntlets on their hands.
On the side of the attackers, the higher class members are wearing defenses almost identical to that of their class counterparts on the defending side. Take note of their weaponry. The carry weapons such as two handed axes and spears, with swords in reserve.
Next on the attacking side, we see three bowmen. One is wearing a kettle helm, the second an open face bacsinet (with mail defenses at the neck) and the third a closed face bascinet (which is very unusual for this time, it may be a mistake in drawing or in my interpretation). They may be wearing some sort of torso protection underneath an arming garment, but they are certainly not wearing an defenses (past possibly an aketon or gamebson) on their arms.
Behind them, there are foot soldiers, equipped with spears, most likely swords as well, and leg harnesses (and no doubt arm harnesses as well). Though we cannot see to be certain, their helms may have visors. They certainly do have mail protection at the neck. | [
"The English army was estimated to be between 7,000 and 10,000 strong and consisted of both English and Welsh soldiers combined with specialists and officials. It is considered to have been unusually well equipped for a medieval army and included miners, blacksmiths and Welsh to English interpreters. It included se... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.