question stringlengths 3 301 | answer stringlengths 9 26.1k | context list |
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In a hot desert how should a canteen of water be rationed? | I'd say that pouring it over your head is just stupid if dehydration is a fear. Also, I found this:
> The current rule for water use is “Ration sweat, not water.” Water rationing is an antiquated method for land travel that probably has its origins back to sailors lost at sea. While floating about on a lifeboat with ... | [
"A typical person will lose minimally two to maximally four liters of water per day under ordinary conditions, and more in hot, dry, or cold weather. Four to six liters of water or other liquids are generally required each day in the wilderness to avoid dehydration and to keep the body functioning properly. The U.S... |
Why is the Arab slave trade left out of textbooks and not thought in American schools? | I don't think much Arab history is taught in American schools period. Not even the rise of Mohamed. Not even the Islamic reign in Spain, even though the Middle Ages is usually roughly covered.
Although important, the Arab slave trade is relatively obscure compared to the vast arena of topics that could be but aren't ... | [
"In textbooks for state-run schools, there was an effort to remove stereotypes and educate towards tolerance. In some textbooks for the Orthodox Jewish community, the researchers found derogatory adjectives, prejudices, patronizing expressions and disrespect toward Arabs. The Arab leadership was portrayed as motiva... |
If light is affected by gravity then would the stars position in the nights sky be different from what we perceive? | Oh, yes! _URL_0_ | [
"In the case of annual aberration of starlight, the direction of incoming starlight as seen in the Earth's moving frame is tilted relative to the angle observed in the Sun's frame. Since the direction of motion of the Earth changes during its orbit, the direction of this tilting changes during the course of the yea... |
when i stand far away from one person clapping i can't hear it, at the same distance i can hear 100 people clapping. why? | There are a couple concepts you need to understand to make this a bit easier.
1. Like you said, sound is basically particles vibrating. However, sound is a wave - that is, it's energy that effectively radiates out from a source as ripples radiate from a thrown rock. As the energy passes particles, it causes them to vi... | [
"To place this problem in more common terms, imagine you are talking to someone 6 meters away. If the two of you are in a quiet, empty room then a conversation is quite easy to hold at normal voice levels. In a loud, crowded bar, it would be impossible to hear the same voice level, and the only solution (for that d... |
How is louder sound different from soft sound? | Sound is a wave, specifically peaks and valleys of alternating pressure. The waves travel at the same speed regardless of volume, that instead depends on the medium. Higher volume means those peaks have a higher pressure. | [
"Loudness is perceived as how \"loud\" or \"soft\" a sound is and relates to the totalled number of auditory nerve stimulations over short cyclic time periods, most likely over the duration of theta wave cycles. This means that at short durations, a very short sound can sound softer than a longer sound even though ... |
why everybody hates
hipsters? | "Hipster" is one of the most overused and poorly defined terms on the internet today. I think the hatred towards them stems from a certain attitude of snobbery (the "oh you like mainstream stuff?" hipster archetype), which is of course an intolerable attitude for a person to have, but the hatred has spread to ANYONE th... | [
"Elise Thompson, an editor for the LA blog \"LAist\" argues that \"people who came of age in the 70s and 80s punk rock movement seem to universally hate 'hipsters'\", which she defines as people wearing \"expensive 'alternative' fashion[s]\", going to the \"latest, coolest, hippest bar...[and] listen[ing] to the la... |
why do analysts claim the stock market is tanking because of the glut of oil? (more in comment) | Lower oil prices are good for most American companies, and therefore good for the stock market. They mean lower energy and shipping costs for companies, and put more money in American consumers' pockets to buy more stuff. The main exceptions are companies involved in the energy industry somehow, or that depend on con... | [
"The 2010s oil glut is a considerable surplus of crude oil that started in 2014–2015 and accelerated in 2016, with multiple causes. They include general oversupply as US and Canadian tight oil (shale oil) production reached critical volumes, geopolitical rivalries amongst oil-producing nations, falling demand acros... |
How did the power vacuum created by the fall of the western roman empire influence the events of the middle ages? | Hello! As Roman Imperial authority collapsed, the vacuum it left was more often than not filled by those in the best place to do so: local and regional leaders who in many cases were already *de facto* if not necessarily *de jure* authority figures. Indeed, in some cases the 'fall of Rome' could be equally described a... | [
"A power vacuum was created in the Western Empire after the events of 454 and 455, which saw the consecutive murders of Aetius and of the Western Emperor Valentinian III, who had been responsible for the \"magister militum's\" assassination. After the assassinations, the Roman Senator Petronius Maximus proclaimed h... |
How can the phase speed of a wave of light exceed C? What does this mean? | An analogy would be if you imagine a spinning barber pole moving in space. The information, energy, etc. propagates in the wave packet (the pole), yet the speed of phase fronts (the spirals on the pole, which seem to move faster than the pole is moving) in the wave packet move faster than the packet itself.
Light wav... | [
"The phase speed gives you the speed at which a point of constant phase of the wave will travel for a discrete frequency. The angular frequency \"ω\" cannot be chosen independently from the wavenumber \"k\", but both are related through the dispersion relationship:\n",
"The phase velocity of an electromagnetic wa... |
Is it true that Kosovo became Albanian majority because Tito let them in? | According to the 1921 Census of Yugoslavia (i.e. before the War, before Communism, before Tito), there was a clear Muslim and Albanian majority in Kosovo. We also see this in the 1931 census and, as far as I know, all subsequent censuses except for 1991, where many Muslim boycotted (in the 2011, many Serbs boycotted--t... | [
"On 17 February 2008, Kosovo Albanians unilaterally declared independence from Serbia in the Assembly of Kosovo. In a meeting attended by 109 of the total 120 MPs, the assembly unanimously declared Kosovo's independence, while all 11 representatives of the Kosovo Serbs minority boycotted the proceedings.\n",
"The... |
can police pursue you beyond their jurisdiction? city lines, county lines or state lines....any difference? | Police from one jurisdiction do have the legal authority to follow you into another jurisdiction. However, this is relatively uncommon, since they typically would have alerted that jurisdiction when approaching the boundary and that jurisdiction would have their own police waiting. Also, just because they CAN pursue,... | [
"In very simple terms, this power allows constables of one jurisdiction to travel to another jurisdiction and arrest a person they suspect of committing an offence in their home jurisdiction. For example, constables from Cumbria Police investigating an offence of assault that occurred in their police area could tra... |
how much money do jewelers make knowing they have to stock their entire store with gold and diamonds? | The rule in the jewelry business is "triple key", meaning if the wholesale price is $1000 the jeweler will usually start the price at $3000. This helps deal with the extra costs of running a jewelry store, which are quite high. This may sound like a large markup, but consider most retail markups are 5x or higher compar... | [
"Retail jewelers, especially the prestigious Fifth Avenue stores, prefer not to buy back diamonds from customers, because the offer they would make would most likely be considered ridiculously low ... Most jewelers would prefer not to make a customer an offer that might be deemed insulting and also might undercut t... |
Can plants feel pain? | > I understand that plants have to be sentient to at least a small degree,
What...planet are you on? Plants do not have sentience. They do not have nerve systems.
They do have the ability to react to changes in their environment, through stimulation of hormone production leading to morphological changes. But... | [
"The Animal Liberation Front argues that there is no evidence that plants can experience pain, and that to the extent they respond to stimuli, it is like a device such as a thermostat responding to sensors.\n",
"Contact with a wounded plant causes itch, rashes or blistering on contact with the skin or mucosa. Ing... |
do we really need to spend 8 hours a day for sleep? can we found a way to not sleep and still be healthy? | You don't really need 8 hours of sleep. There are ways to get the rest you need, but to sleep less. You can read about it in this article:
[Alternate Sleep Cycles](_URL_0_) | [
"A 2010 review of published scientific research suggested that exercise generally improves sleep for most people, and helps sleep disorders such as insomnia. The optimum time to exercise \"may\" be 4 to 8 hours before bedtime, though exercise at any time of day is beneficial, with the exception of heavy exercise ta... |
Examples of civilizations which have died out due to poor management of natural resources. | Have you read "Collapse" by Jared Diamond? I think you would like it. | [
"In his analysis of the four cases of fallen civilizations, he notes that two (Easter Island and Sumer) failed due to depletion of natural resources—\"their ecologies were unable to regenerate.\" The other two failed in their heartlands, \"where ecological demand was highest,\" but left remnant populations that sur... |
why does drip coffee make me much more jittery than espresso, even when using the same amount of coffee beans for each? | Caffeine is water soluble, in general the more water and the longer it stays in contact with the ground beans the more caffeine is extracted from the beans. BTW, French press has something like 3x the caffeine of regular coffee owing to the long time the beans are left in contact with the water. | [
"Espresso has more caffeine per unit volume than most coffee beverages, but because the usual serving size is much smaller, the total caffeine content is less than a mug of standard brewed coffee, contrary to a common belief. Although the actual caffeine content of any coffee drink varies by size, bean origin, roas... |
How were the calendar and days of the week followed over 500+ years ago? | [Relevant previous discussion](_URL_0_)
[Slightly less relevant previous discussion, though it may lead you down different paths](_URL_1_)
| [
"This calendar was proposed during the French Revolution, and used by the French government for about twelve years from late 1793. There were twelve months of 30 days each, grouped into three ten-day weeks called \"décades\". The five or six extra days needed to approximate the tropical year were placed after the m... |
Who laid the barbed wire in No Man's Land in WWI? | **TL;DR:** Both sides!
This post of mine may be of interest to you:
_URL_0_ | [
"Groups of soldiers known as wiring parties went out at night into no man's land to position these supports. They later strung the barbed wire through the loops to form a defensive wire obstacle as a protection for their trench line. The British called this type of stake a 'corkscrew' picket because it was screwed ... |
can you develop diabetes from just drinking a lot of alcohol (separate from eating loads of sweets)? | I am a dietitian and work in a county hospital of a large city- So first off, eating a ton of sweets is not going to cause diabetes.
Type 1 diabetes is caused by a lack of insulin- your pancreas stops making it. You have to take insulin or else you'll die.
Type 2 diabetes is caused when your body becomes resistant t... | [
"BULLET::::- Diabetes mellitus – People with diabetes have difficulty regulating their blood sugar levels, and need to limit their sugar intake. Many artificial sweeteners allow sweet-tasting food without increasing blood glucose. Others do release energy but are metabolized more slowly, preventing spikes in blood ... |
What is the oldest mythic creature we have a record of? | Can this include artistic depictions? | [
"Depictions of mythological creatures clearly ancestral to the modern set of four creatures have been found throughout China. Currently, the oldest known depiction was found in 1987 in a tomb in Xishuipo (西水坡) in Puyang, Henan, which has been dated to approximately 5300 BC. In the tomb, labeled M45, immediately adj... |
why do we have to "wait" for our eyes to adjust? | Eyes adjust by deforming the [lens](_URL_0_) in your eyes. The shape of a lens change the path of the light that goes through it. By changing the shape our eyes makes so that the light has a path that makes the image of what you are seeing form exactly on the back of you eye, thus making it good (otherwise it would be... | [
"When concentrating on a visually intense task, such as continuously focusing on a book or computer monitor, the ciliary muscle tightens. This can cause the eyes to get irritated and uncomfortable. Giving the eyes a chance to focus on a distant object at least once an hour usually alleviates the problem.\n",
"As ... |
How did exacly John II emperor of Byzantium ended up hiring Harald Hardrada with the rest of his fellow vikings? | Hello, can I ask at first a bit of clarification?
* Is 'John II emperor of Byzantium' you mentioned correct person in question? AFAIK Emperor John II is John II Komnenos (r. 1118-43), son of famous Emperor Alexios I Komnenos, thus born more than ca. 20 years after the fall of Harald Hardråde of Norway in 1066.
* Ha... | [
"The well-known Harald Hardrada would also serve the Byzantine emperor in Palestine as well as raiding North Africa, the Middle East as far east as Armenia, and the island of Sicily in the 11th century, as recounted in his saga in Snorri Sturluson's \"Heimskringla\".\n",
"Upon conquering Fjordane, Harald demanded... |
why do certain things smell nice, even when they're not edible? | Like jet fuel or 100LL? I love those smells. | [
"Some odors are sought after, such as from perfumes and flowers, some of which command high prices. Whole industries have developed around products to remove unpleasant odors (see deodorant). The perception of odors is also very much dependent upon circumstance and culture. Cooking smells may be pleasant while one ... |
In the Middle Ages and Renaissance, did armies ignore borders? | The answer depends where and when. Various Italian states denied (or attempted to deny) France and the Holy Roman Emperor access to their territory, typically if they disagreed with the war but did not want to get involved. This mandate was ignored at the risk of opening an additional theater of war; a strong enough ar... | [
"As the 5th century progressed, many of the Empire's original borders had been either wholly or partially denuded of troops to support the central field army. In 395, the Western Roman Empire had several regional field armies in Italy, Illyricum, Gallia, Britannia and Africa, and about twelve border armies. By abou... |
What was the typical medical aftermath for someone who has been tarred and feathered? | fyi, you may find these related posts of interest
* [Was "tarring and feathering" fatal? And where in the world was it most often done?](_URL_0_) featuring /u/Goethite
* [How common was tarring and feathering in the American revolutionary period? Also, was this practice supported by revolutionary leadership?](_URL_3_... | [
"The victim would be stripped naked, or stripped to the waist. Hot wood tar was then either poured or painted onto the person while they were immobilized. Then the victim either had feathers thrown on them or was rolled around on a pile of feathers so that they stuck to the tar.\n",
"The Sandakan Death Marches we... |
What was the USA's objective when using atomic bombs on Hiroshima and Nagasaki? Did they expect this to speed up a surrender more than Soviet invasion? | In short, they hoped to force Japan to surrender before the Soviets could help us, if at all possible, to avoiding having to clash with them over post-war Japan, in addition to post-war Europe.
At the Yalta conference, the Soviets agreed to join us in subduing Japan, "two or three months" after the Germans surrendered... | [
"As the first combat use of nuclear weapons, the bombings of Hiroshima and Nagasaki represent to some the crossing of a crucial barrier. Peter Kuznick, director of the Nuclear Studies Institute at American University, wrote of President Truman: \"He knew he was beginning the process of annihilation of the species.\... |
We have superhydrophobic surfaces (ex. neverwet) Are there superoxygenphobic/superairphobic surfaces? What would that even be like? | Superhydrophobic surfaces utilize the entropic benefit from hydrogen bonding in water (the polarity of the partially positive hydrogen and the partially negative of the oxygen can interact to hold different molecules together). The surfaces use a combination of a non-polar surface and special topography to create the h... | [
"Surfaces that are superhydrophobic are desirable for non-fouling behavior because an affinity for water correlates to an affinity for contaminants. Superhydrophobic xerogels made from silica colloids have been shown to reduce bacterial adhesion, specifically \"S. aureus\" and \"P. aeruginosa\". The non-fouling app... |
With the Roman Empire being such a popular topic here, was a typical Roman citizen at all interested in or impressed with previous empires? | This is interested topic. Both Romans and Greeks were very well impressed by the remains of ancient Egypt Empire. There are several "visitors graffiti" in the Egypt and historians of that period talking with much respect about Egyptians and specially their architectonical achievements. | [
"BULLET::::- Excerpt: \"The ancient Roman boasted, with reason, of the growth of Rome from humble beginnings to the greatest magnitude which the world had then ever witnessed. But the citizen of the United States is still more justly entitled to claim this praise.\"\n",
"The Roman Empire was among the most powerf... |
Why are alligators endemic to the US and China, but nowhere else? | This is an extremely interesting question. Fossil alligators in North America predate those in Asia, so as far as we can tell, the genus originated there and dispersed to Asia. The thing is, we don't know exactly how they did that. Neither species can tolerate salt water for very long, so it wasn't an oceanic dispersal... | [
"The Chinese alligator currently is found in only the Yangtze River valley and parts of adjacent provinces and is extremely endangered, with only a few dozen believed to be left in the wild. Indeed, far more Chinese alligators live in zoos around the world than can be found in the wild. Rockefeller Wildlife Refuge ... |
Why don't large organisms with many cells develop cancer more often? | What you described is called [Peto's Paradox](_URL_1_): why do we not see a correlation between animal size and cancer rates.
There are lots of different mechanisms of cancer suppression/avoidance in larger animals. For example, the best studied cancer gene is called p53. Humans (and other animals) only have one copy ... | [
"Multicellular organisms, especially long-living animals, face the challenge of cancer, which occurs when cells fail to regulate their growth within the normal program of development. Changes in tissue morphology can be observed during this process. Cancer in animals (metazoans) has often been described as a loss o... |
what would happen if charging interest on loans were to be made illegal? | If a lender could not charge interest on a loan, they would have no incentive to ever give out loans because they would be essentially throwing away their money. Even though they would get back the exact amount they lent out, the present value of it in a few years would most likely be less than it was when it was first... | [
"If a lender charges above the lawful interest rate, a court will not allow the lender to sue to recover the unlawfully high interest, and some states will apply all payments made on the debt to the principal balance. In some states, such as New York, usurious loans are voided \"ab initio\".\n",
"BULLET::::- Unde... |
Why do people have different reactions than others to drugs? Why do some get side effects while others don't? What differences in biology could account for this? | There's a lot of reasons. One of the major ones is variations in metabolic pathways or in the targets of drugs due to genetic variation. There's a whole field of science, [pharmacogenetics](_URL_0_) that studies this.
Basically, we are all different, usually by small changes in genes. This could be what levels certain... | [
"In medicine, a side effect is an effect, whether therapeutic or adverse, that is secondary to the one intended; although the term is predominantly employed to describe adverse effects, it can also apply to beneficial, but unintended, consequences of the use of a drug. Developing drugs is a complicated process, bec... |
how do dry cleaners avoid spreading lice and bed bugs? | Dry cleaners use perchloroethylene to clean your clothes, it's a pretty aggressively anti-bug chemical. Now those new "environmental cleaners" might be a problem. Similarly, they launder shirts and dry them at super high temperatures (because it's faster) and bugs can't stand those temps.
This is not excuse not to t... | [
"Clothes dryers can be used for killing bed bugs in clothing and blankets. Infested clothes and bedding are first washed in hot water with laundry detergent then placed in the dryer, and then after the items are completely dry, continue drying for at least 20 minutes longer at high heat. However, this does not elim... |
what makes someone professionally good at fishing? | Probably experience and perception. I'm sure a good fisherman can tell where the fish will likely be in the lake, or how deep to go to get certain fish and what patterns they follow | [
"Recreational fishing is fishing done for sport or competition, whereas commercial fishing is catching seafood, often in mass quantities, for profit. Both can have different environmental impacts when it comes to fishing.\n",
"It is difficult to estimate how many recreational fishing boats there are, although the... |
Why is digital preffered over analog when digital is limited to just on and off? | Analog signals also have a [data limit](_URL_1_)! Noise (which is unavoidable) will limit the accuracy that you can get from an analog recording. On the other hand, as soon as you record the ones and zeroes of a digital recording, you can reproduce it perfectly from then on. The fact that digital signals are definite s... | [
"If a proper (no clipping/saturation) analog signal is converted to digital via A/D with sufficient samples, and then reconverted to analog via D/A then Nyquist theorem guarantees that there will be no problem in the analog domain due to \"peak\" issues because the restored analog signal will be an exact copy of th... |
What do we know about related history between Bulgarians and Macedonians? | I assume with ‘Macedonians’ you mean Slavic Macedonians living in the Former Yugoslav Republic of Macedonia (FYROM), who are distinct from the Greek Macedonians that live in the Greek province of Macedonia. This distinction lies at the heart of the naming conflict between the FYROM and Greece I wrote a paper about a ye... | [
"Bulgarians are considered most closely related to the neighbouring Macedonians. The ethnic Macedonians were considered Bulgarians by most ethnographers until the early 20th century and beyond with a big portion of them evidently self-identifying as such. The Slavic-speakers of Greek Macedonia and most among the To... |
If motion is relative, why is it (theoretically) possible for one massive object to move in 0.5c in one direction and for another to move at the same speed in the opposite direction? | It's perfectly possible for the relative velocity of two objects, as perceived by an external observer, to be greater than the speed of light. This is not a contradiction of the fact that nothing can travel faster than the speed of light because relative velocities are not the same in different reference frames in spec... | [
"Al-Baghdaadi also suggested that motion is relative, writing that \"there is motion only if the relative positions of the bodies in question change.\" He also stated that \"each type of body has a characteristic velocity that reaches its maximum when its motion encounters no resistance.\"\n",
"The motion of two ... |
When the Byzantine Empire fell in 1453, did people at the time know that they were witnessing the fall of the Roman Empire? | The continuation of Monstrelet's chronicle (which consists of almost everything in said chronicle after 1444; Monstrelet himself died in 1453), written by Mathieu d'Escouchy, which is in large part cribbing from the *Grandes Chronique's de France* as well as Jean Chartier has this to say:
> ". . . the grand Tur... | [
"The event also marked the end of the Byzantines—the final remnants of the Roman Empire—and the transfer of the control of the Bosporus into Ottoman hands, who made Constantinople their new capital, and from where they expanded their empire in the centuries that followed.\n",
"Eventually, following their repeated... |
how do certain drugs cause you to see things in high detail that aren't actually there? | _URL_0_
Hallucinogens work by shutting down neurons that have the effect of calming other cells in the visual cortex (the bit of the brain that works out what you are seeing). So these cells start firing as if they are really dealing with real visual information.
Human eyes are actually not that great and the brain ... | [
"The drugs are also difficult to detect. Because of the very small amounts of drugs typically administered to achieve these effects, it is difficult to test for the presence of these drugs since they are quickly eliminated from the body. The lack of confirmation through toxicology cannot necessarily be equated bein... |
On brain activity and perception: Can we slow down how we perceive time? | [This](_URL_0_) Wikipedia article talks about time perception, and it's field of study. It probably doesn't answer all of your questions, but it goes over a lot of what's in your post. | [
"In the popular essay \"Brain Time\", David Eagleman explains that different types of sensory information (auditory, tactile, visual, etc.) are processed at different speeds by different neural architectures. The brain must learn how to overcome these speed disparities if it is to create a temporally unified repres... |
Why does banging 2 objects together produce sound? e.g. knocking on a door | Take a look at how [this drum head moves when it gets hit](_URL_0_).
The door does almost the exact same thing from your fist, but to a much smaller degree. As it shakes back and forth, it creates waves in the air that create sound.
Most doors probably are partially hollow as well--in that case, the air in the midd... | [
"BULLET::::- In Brazil, (\"knock on wood\") is something actually done physically, three knocks are required after giving an example of a bad thing eventually happening. No verbalization is required, just the three knocks on the closest piece or object of wood. In the absence of wood, someone can say , to prevent t... |
Are we physically affected by reading left to right? | I'm also interested to know how it affects other parts of our lives, such as when crossing the road, do LR reading people look left first? Or is that more dependent on what side of the road people drive on? When looking at a tapestry or large 'busy' painting, do RL readers start from the right? | [
"Normal reading is typically a function of a left hemisphere-based system. The right hemisphere plays a minimal role in reading. One hypothesis, the \"left hemisphere hypothesis\", supports the idea of a damaged left hemisphere-based reading system associated with deep dyslexia. Deep dyslexics may be attempting to ... |
why is it in the west hiv infections are still primarily related with homosexual activity and drug use but in africa where the vast majority of worldwide cases is it primarily spread through heterosexual transmission? |
Better access to contraceptives in the West. Less contraceptives are used in homosexual activities because no risk of pregnancy, drug use because sharing needles. | [
"Because reported AIDS cases in Africa and other parts of the developing world include a larger proportion of people who do not belong to Duesberg's preferred risk groups of drug addicts and male homosexuals, Duesberg writes on his website that \"There are no risk groups in Africa, like drug addicts and homosexuals... |
how can median household incomes in an area be ~$50k but average home price be $5m? | If you read that page, you will see that the $5M home price was for a specific *part* of that area, and the average income was for the city.
So, basically, that area is a very upscale part of town that also has other, less affluent neighborhoods. | [
"In 2018, the median household income was $70,824; most people spend more than 30% of their income on housing costs. In August of that year, the median home price was $583,000; this is lower than the median home price in Los Angeles, and Orange, counties.\n",
"The median household income was $40,358, with the per... |
Why was the USMC such a small military branch before 1941? | Well, I think your question would be better phrased as "Why did the USMC get so *large* after 1941?"
It should be noted that the USMC is totally unique worldwide in terms of size. Every other marine corps in history has been quite small, and this is simply because of the traditional mission of marine corps.
Marine... | [
"Beginning in World War I, with the U.S. Marine Corps' participation with the U.S. Army in the American Expeditionary Force, in which the 5th and 6th Marines (along with the 6th Machine Gun Battalion) formed the 4th Marine Brigade of the U.S. Army 2nd Infantry Division (United States), the Corps began organizing la... |
Fire in zero oxygen | Yes, you can definitely have a fire without oxygen. However you would need a different oxidizing agent. For instance fluorine gas reacts with hydrogen gas in [such a fashion](_URL_0_). There would be a number of differences such as the maximum temperature of the flame, how fast the fire would burn, what color the fire ... | [
"The limiting oxygen index (LOI) is the minimum concentration of oxygen, expressed as a percentage, that will support combustion of a polymer. It is measured by passing a mixture of oxygen and nitrogen over a burning specimen, and reducing the oxygen level until a critical level is reached.\n",
"Without sufficien... |
Did Britain plan an invasion of Norway during WWI? | There were no such plans that I'm aware of. From 1917, the Allies, mainly as a result of American pressure, began laying a mine barrage across the northern exits to the North Sea. In response to this, the Germans began diverting U-boats through Norwegian waters. These waters were not initially mined, and could not be d... | [
"In March and April 1940, British plans for an invasion of Norway were prepared, mainly in order to reach and destroy the Swedish iron ore mines in Gällivare. It was hoped that this would divert German forces away from France, and open a war front in south Sweden.\n",
"On 1 March 1940, Adolf Hitler ordered the in... |
what is the difference between being depressed and being bored? | Depression is a sort of relentless apathy. If you're just bored you can dispel the boredom through some form of entertainment easily enough. It's not a constant base state of your existence. Depression on the other hand saps away pleasure as well, leaving just emotional numbness. | [
"In conventional usage, boredom is an emotional and occasionally psychological state experienced when an individual is left without anything in particular to do, is not interested in his or her surroundings, or feels that a day or period is dull or tedious. It is also understood by scholars as a modern phenomenon w... |
why do people still use yelp, even though they manipulate reviews? | This post is not asking for a layman-friendly explanation to something complicated or technical, so it doesn't belong here and it's been removed. Entirely subjective questions generally belong in /r/askreddit. | [
"As Yelp became more influential, the phenomenon of business owners and competitors writing fake reviews, known as \"astroturfing\", became more prevalent. A study from Harvard professor Michael Luca analyzed 316,415 reviews in Boston and found that fake reviews rose from 6% of the site's reviews in 2006 to 20% in ... |
How different are mitochondria and other organelles between eukaryotic species? | In case of most organelles (Golgi apparatur, ER, peroxisomes, etc.) the main difference is in proteins so if organisms are relativelly close (in evoilutionary terms) there should be no problem in "transplanting" say ER of a rat into a dog cells but there MIGHT be a problem if you wanted to transplant ER from a fruit fl... | [
"Not all eukaryotic cells have each of the organelles listed below. Exceptional organisms have cells that do not include some organelles that might otherwise be considered universal to eukaryotes (such as mitochondria). There are also occasional exceptions to the number of membranes surrounding organelles, listed i... |
what makes oil, natural gas, and coal sources of energy when other materials aren't? | Hundreds of millions of years ago, because our atmosphere had less oxygen in it, things did not break down as quickly as they do now. You see, nowadays, pretty much anything that is 'organic' is food for something or another. The coal, oils, and gases is the result of all this past uneaten "food" being collected and tr... | [
"Petroleum is used mostly, by volume, for refining into fuel oil and gasoline, both important \"\"primary energy\"\" sources. 84 percent by volume of the hydrocarbons present in petroleum is converted into energy-rich fuels (petroleum-based fuels), including gasoline, diesel, jet, heating, and other fuel oils, and ... |
How do aquatic plants in places like the Chesapeake bay resist algae buildup on themselves? | Marine biologist here. Submerged aquatic vegetation (SAV) actually has a very hard time dealing with epiphytic algae growing on them, as they are outcompeted for light. This is actually one of the major causes of the loss of SAV beds in many areas, as eutrophication increases the prevalence and growth rate of said al... | [
"An algae scrubber filters water by moving water rapidly over a rough, highly illuminated surface, which causes algae to start growing in large amounts. As the algae grow, they consume nutrients such as nitrate, phosphate, nitrite, ammonia, ammonium and even metals such as copper from the water. These nutrients are... |
What evidence is there that women trained in combat sports in Ancient Sparta or other civilizations? | Evidence for women participating in sport and games is significant, however, women were expressly barred from participating or viewing the Olympic Games. The Heraean Games were a single sex series of events in which women competed against each other, divided by age. Greek society as a rule was repressive towards women... | [
"Descriptions of women’s sport during Archaic Period mainly come from literary sources, and there are a few examples of female sporting events. One of the most popular forms of physical activity for ancient Greek women is running. The bronze statuettes of athletic Spartan girl, which depicts Spartan young women inv... |
Other than submitting yourself to Hitler and hating on the Jews, what did the Nazi political party "stand" for? Did they believe in low taxes? Or social welfare? Communism? | Well here is the 25-point party platform published in 1920. And I believe as late of as 1933 it was unchanged. I'm not sure if Hitler had it changed after that time. But by and large this was representative of the party stances.
Edit: I've been asked by the mods to add a lot more commentary to bring this up to the sta... | [
"In Germany during the Nazi era, a 1933 decree stated that \"No National Socialist may suffer detriment... on the ground that he does not make any religious profession at all\". However, the regime strongly opposed \"godless communism\", and all of Germany's atheist and largely left-wing freethought organizations s... |
when people read text, do they "hear" it in their minds? | Yes. It's called [subvocalization](_URL_0_). Some people "hear" words as they are reading them, while others don't. I know I am a subvocalizer because if I try to listen to music with words and read a book at the same time, I can't understand what I'm reading because I'm "hearing" two things at once. | [
"When reading aloud, people must decode written language to decipher its pronunciation. This processing takes place in Broca's area. The reader might use previous knowledge of a word in order to correctly vocalize it, or the reader might use knowledge of systematic letter combinations, which represent corresponding... |
How are generics of high-end medications created when pharmaceutical companies can patent their chemical formulas? | They aren't sold until the patent expires. There is a whole business in slightly altering pharmaceuticals to keep renewing the patent. | [
"The pharmaceutical formulation, an oily resin in capsules, is available by prescription in the US, Canada, Germany, Australia and New Zealand. Possible exceptions for off label use may be in US states passing laws reserving the right to differ from particular FDA regulations.\n",
"When a pharmaceutical company f... |
the nonsense behind the hip-hop illuminati conspiracy theory | In a nutshell rappers keep mentioning it to make them seem more important than they are. I'm a huge Hip Hop fan, and you can see a lot of rappers are desperate for people to think they are successful (see: huge gaudy chains etc). When you see these images in videos, it's often rappers trying to show they are so powerfu... | [
"Conspiracy theories have been referenced in hip hop lyrics for some time. Elements of the Five-Percenter philosophy that has fundamentally influenced hip hop culture revolve around conspiracy theories. Artists such as Professor Griff, Jedi Mind Tricks, and Hopsin have become infamous for their support of New World... |
What happens to the gravitational potential energy of mass lost in nuclear fusion? | Nothing, since gravitation is based on energy density rather than mass. As long as the energy quanta don't leave the star, its gravitation will remain the same from the outside. When particles leave the star, its gravitation gradually decreases. | [
"In nuclear fusion, two low mass nuclei come into very close contact with each other, so that the strong force fuses them. It requires a large amount of energy for the strong or nuclear forces to overcome the electrical repulsion between the nuclei in order to fuse them; therefore nuclear fusion can only take place... |
why does cat food and dog food smell repulsive while the meat i eat smells delicious. | Speak for yourself, I love the smell of the soft, canned cat treats! But 10 year old me found out that I do not enjoy the taste of soft, canned cat treats. | [
"Dogs, as with all mammals, have natural odors. Natural dog odor can be unpleasant to dog owners especially when dogs are kept inside the home, as some people are not used to being exposed to the natural odor of a non-human species living in proximity to them. Dogs may also develop unnatural odors as a result of sk... |
how do scopes work? (firearms) | The scopes reticle/crosshairs arnt parrell with the barrel, it aim downwards slightly and meet the travel of the bullet at certain distances. So if you zero your scope for 200 meters. The bullet will travel lower than the point your aiming at untill it hits 200 meters, then it will travel higher untill it drops back be... | [
"Any sights, telescopic or metallic may be used. Scopes may not be more than 2 inches above the rifle as measured from the top of the receiver to the underside of the scope tube, nor may the scope be offset from the top center line of the receiver. Any sighting device programmed to activate the firing mechanisms is... |
how come you can "spot increase" muscle (by doing isolation movements) but you can't "spot decrease" fat? | As your question implies, if a muscle is isolated then that is the one that will grow. There is no analogous way to isolate fat for consumption. Fat loss occurs throughout the body at equal rates. | [
"Spot reduction refers to the claim that fat in a certain area of the body can be targeted for reduction through exercise of specific muscles in that desired area. For example, exercising the abdominal muscles in an effort to lose weight in or around one's midsection. \n",
"The word tone or toning can be misleadi... |
why are some plates and cutlery not dishwasher safe? | Pots and pans are usually excluded because they are made of materials that react with the harsher chemicals used in a dishwasher (Just like a human hand would be damaged). As a result, they will be damaged.
Other things, like some glassware, are so fine that rattling in the dishwasher is enough to make them bump again... | [
"Most dishwasher detergents are incompatible for use with silver, brass, cast iron, bronze, pewter, and goldleaf. They can also harm disposable plastic, anything wood, knives with hollow handles, and fine glassware.\n",
"Hand dishwashing is generally performed in the absence of a dishwashing machine, when large \... |
after giving blood, is it harder to gain and/or maintain an erection? | No, our bodies very quickly compensate to keep blood pressure the same despite a loss of volume. One way is to just increase the fluid content of the blood, thinning it out until more blood cells can be made. Another is to constrict the blood vessels, decreasing the total volume of the circulatory system.
But ultimate... | [
"Physiologically, erection is triggered by the parasympathetic division of the autonomic nervous system, causing nitric oxide (a vasodilator) levels to rise in the trabecular arteries and smooth muscle of the penis. The arteries dilate causing the corpora cavernosa of the penis (and to a lesser extent the corpus sp... |
silly math regarding supermassive black holes and average density. | > Now, this conflicts with things I've heard, that the average densities of supermassive black holes are in fact very light, some even lower than water.
I thought this was totally wrong at first, but then I [ran the numbers myself in wolfram alpha](_URL_0_) and got a density drastically lower than water. Things I nev... | [
"The first quantitative estimates of the mass density in supermassive black holes were 5-10 times higher than Sołtan's estimate. This discrepancy was resolved in 2000 via the discovery of the M-sigma relation, which showed that most of the previously-published black hole masses were in error.\n",
"Supermassive bl... |
why am i "innocent until proven guilty in a court of law", but only found "not guilty" and not "innocent"? | You (and your lawyer) are under no obligation to prove your innocence, nor your "not-guilty mess." The onus (burden) is on the prosecution to prove that you are guilty, and your job is to refute their accusations and show, if possible, that they can't be true.
That's what presumption of innocence means. If nobody sh... | [
"Another common notion is that guilt is assigned by social processes, such as a jury trial (i. e., that it is a strictly legal concept). Thus, the ruling of a jury that O. J. Simpson or Julius Rosenberg was \"guilty\" or \"not innocent\" is taken as an actual judgment by the whole society that they must act as if t... |
growing up my mother always told me to never start a pot of boiling water from hot tap water only cold. what's the logic behind that if any? | In the past, hot water was stored in a separate holding tank where it was kept heated. This water was not necessarily "safe" for drinking as the same water could be sitting for days at a time.
I've also heard that old lead pipes leach lead into hot water, but not into cold water. This explains why hot water would be ... | [
"BULLET::::1. Boiling: Bringing water to its boiling point (about 100 °C or 212 F at sea level), is the oldest and most effective way since it eliminates most microbes causing intestine related diseases, but it cannot remove chemical toxins or impurities. For human health, complete sterilization of water is not req... |
how the eurozone is facing economic crisis yet the euro remains stronger than the dollar. | When an economy is doing badly, governments have two common answers: make their money worth less, so people from other countries start buying their stuff, and borrow money to spend, to make sure people in their own country have jobs. Governments can afford to borrow this money, *because* they are also devaluating their... | [
"Despite initial fears by speculators in early 2009 that the stress of such a large recession could lead to the break-up of the eurozone, the euro's position actually strengthened as the year progressed. Far from the poorer performing economies moving further away and becoming a default risk, bond yield spreads bet... |
as seen in movies, can you actually run and jump on top of and across moving train cars? | _URL_0_
of course you can. Its just hilariously dangerous and theres never a reason to actually do it | [
"Like its counterpart at Disneyland, it was not a thrill ride, but it was not slow and quiet like most dark rides. It made sudden turns and often the vehicle would move at full speed towards an obstacle, which would move out of the way at the last second. At one point the vehicles on different tracks would head dir... |
today in britain, the sky went really orange for a few hours - why? | I've found out what it was - orange-ish dust has been picked up by Hurricane Ophelia and spread across the atmosphere. | [
"A red sky – in the morning or evening, is a result of high pressure air in the atmosphere trapping particles of dust or soot. Air molecules scatter the shorter blue wavelengths of sunlight, but particles of dust, soot and other aerosols scatter the longer red wavelength of sunlight in a process called Rayleigh sca... |
How accurate is the portrayal of a sadistic slave owner whom would whip and beat his slaves for seemingly trivial stuff? | There is abundant evidence that maltreatment ([whipping](_URL_1_), and [worse](_URL_0_)) of slaves was not uncommon, [NSFW](_URL_3_). However, whenever you see a movie like *Django Unchained* for example, you have to realize that whatever their historical motivations, the movie makers have to tell a story in 2 hours,... | [
"Besides slaves' being vastly overworked, they suffered brandings, shootings, \"floggings,\" and even worse punishments. Flogging was a term often used to describe the average lashing or whipping a slave would receive for misbehaving. Many times a slave would also simply be put through \"wanton cruelties\" or unpro... |
I have heard that H. P. Lovecraft came to regret his racist views later in his life. Is this true? | It's hard to answer the question of how someone felt inside, but to the extent we can judge a man's feelings and thoughts based on his words, the answer is no, he didn't. Or, at least, he didn't state in a public way that he did.
S.T. Joshi, certainly one of Lovecraft's most devoted historians, biographers, and, it mu... | [
"Also noted is Houellebecq's exegesis of Lovecraft's racial preoccupations, which he traces to a 24-month period during which Lovecraft lived in the comparatively racially mixed New York City of the 1920s, where, Houellebecq says, Lovecraft learned to take \"racism back to its essential and most profound core: fear... |
how do antibiotic pills work? if there's an infection say in the mouth, how does the body know to send the medication back through the bloodstream to fight the infection? how does the body know that the medication is made to fight infection? | The others are correct, though I'll expand a bit. Antibiotics are absorbed (generally) through the small intestine where they enter the blood stream. As they permeate the blood, they are dispersed to all tissues in the body (except those that cannot cross the blood-brain barrier). So, if you have an infection in the mo... | [
"There are many different routes of administration for antibiotic treatment. Antibiotics are usually taken by mouth. In more severe cases, particularly deep-seated systemic infections, antibiotics can be given intravenously or by injection. Where the site of infection is easily accessed, antibiotics may be given to... |
why is compulsive hoarding so common among baby boomers? | Baby Boomers are the children of those who went through the Great Depression where all supplies and food were hard to get and you had to save every scrap of everything that could potentially be useful. They were raised by people who developed these habits as a matter of survival and many passed on the tendencies to the... | [
"Economic instability is the primary justification for this phenomenon, as articulated in Kimberly Palmer's 2007 \"U.S. News & World Report\" article \"The New Parent Trap: More Boomers Help Adult Kids out Financially\". In particular, the term Boomeranger has been used to draw reference to those Gen-Xers and Gen-Y... |
how can the government involve itself with sports-related issues? | > What is illegal (by national laws that fall under FBI jurisdiction) about a company giving individuals money?
Bribery of a government official is illegal. You will note that state universities are controlled by the government and the employees are state employees. If you bribe a state employee that is a crime.
>... | [
"Political responsibility for sport is a devolved matter. As England has no parliament of her own, the United Kingdom Department of Culture, Media and Sport which is headed by a cabinet minister -though the Minister for Sport and Tourism is not in the cabinet- deals with English sport in addition to United Kingdom-... |
the differences between a nation, a state, and a nation-state. | A nation is a group of people with several factors in common like land inhabited, religion, ethnicity, language, or culture.
A state is the government over an area of land
A nation-state is a state that governs an area that primarily consists of one nation. | [
"A nation state (or nation-state) is a state in which the great majority shares the same culture and is conscious of it. The nation state is an ideal in which cultural boundaries match up with political ones. According to one definition, \"a nation state is a sovereign state of which most of its subjects are united... |
Where in the universe does time run faster than what we currently experience here on Earth? | Anywhere the gravitational field is weaker than on Earth will see time running faster. Empty space far from any objects will see the fastest time flow. | [
"Time flows more rapidly the higher one ascends in the worlds; Able spends short times in Aelfrice and Muspel and returns to Mythgarthr to discover weeks or months have passed; similarly, he spends decades in Skai and returns to find only a week has passed. It is implied that time stops completely in Niflheim and i... |
why are semi-trailer trucks so deadly in crashes? | The weight difference is the biggest factor. Cars, SUVs, and pickups weigh less than 10,000 pounds. The average loaded semi weighs 80,000 pounds. Cars are also built to transport their own weight and the weight of their passengers, meaning that their frames, bodies, and suspension parts are designed for lightweight ... | [
"According to the Federal Motor Carrier Safety Administration, National Highway Traffic Safety Administration, Large Truck Crash Causation Study 7% of U.S. trucking accidents are caused by improper cargo securement or cargo shifts. Shifting cargo can cause the truck to destabilize or the load can fall off completel... |
In 223BCE how different would the different versions of Greek spoken across the Eurasia, have been from each other? Were they all mutually intelligible? | Koine Greek (from the Greek word for "common") was a variety of Greek spoken throughout the Greek world, including at the least the Greek Islands, Asia Minor, Egypt, and the Levant. The term "koine language" today refers to a lingua Franca used amongst speakers of related languages.
Koine Greek was based mostly on th... | [
"Although Greek was in common use around the Mediterranean and into Asia Minor even beyond Imperial borders, linguistic distribution in the eastern part of the Empire was complex. Now-extinct languages in Anatolia included Galatian (the form of Celtic introduced by invading Gauls in the 3rd century BC), Phrygian, P... |
Does people that have lost limbs have higher blood pressure? | Baroreceptors are specialized neurons which line the walls of mammalian blood vessels. As pressure in the vessels change, they expand and shrink. The baroreceptors are sensitive to that change and fire action potentials (thats science for nerve impulses) back to the hypothalamus (the part of your brain that regulates ... | [
"Observational studies demonstrate that people who maintain arterial pressures at the low end of these pressure ranges have much better long-term cardiovascular health. There is an ongoing medical debate over what is the optimal level of blood pressure to target when using drugs to lower blood pressure with hyperte... |
Dry erase on wood? | As wood is very porous I don't think it's possible. Depending of course on the type of wood you work with. Most woods would need to be lacquered or heavily polished to work with a dry erase marker. | [
"Wood restoration can be an invasive process: to repair warping, for example, shallow cuts are often made in the surface of the wood to allow it to be pulled back into its original position and secured in place. Cracks can be filled with adhesive to both disguise them and prevent them from expanding, while holes or... |
Can dogs observe and recognize aging in adult humans? Do they differentiate between young adult, middle-aged and elderly humans? | I’m not sure about this specifically, but the most common way people find out whether animals and babies can differentiate between things is by using a habituation test.
A habituation test is an experimental procedure where you show images or objects to the subject over and over until they get habituated to it (like... | [
"As with humans, advanced years often bring changes in a dog's ability to hear, see and move about easily. Skin condition, appetite and energy levels often degrade with geriatric age, and medical conditions such as cancer, renal failure, arthritis, dementia, and joint conditions, and other signs of old age may appe... |
When did it become common for Europeans outside Britain/Ireland to learn English? | Of interest would also be when the Irish started learning English... | [
"Before the arrival of the British, the official language for hundreds of years, and one of the educated elite had been Italian, but this was downgraded by the increased use of English. In 1934, English and Maltese were declared the sole official languages. That year only about 15% of the population could speak Ita... |
where did all the cereal prizes go? | Down some toddler's throat. Now we have stickers and website codes which are much more difficult to choke on and far less expensive to package. | [
"W.K. Kellogg was the first to introduce prizes in boxes of cereal beginning in 1906. The marketing strategy that he established has produced thousands of different cereal box prizes that have been distributed by the tens of billions. The first breakfast cereal prize was \"The Funny Jungleland Moving Pictures Book\... |
why do we have to pasteurize cow milk but not breast milk? | Milk is sterile when it comes out of the cow or human. But as soon as it touches anything it becomes contaminated with bacteria. Milk is also an amazing growth medium for bacteria, its impossible to keep the milk totally sterile and even a small amount of bacteria will very rapidly multiply.
What matters for the con... | [
"Proponents of raw milk (in the U.S.) advance two basic arguments for unpasteurized milk. They state that pasteurization destroys or damages some of the milk's nutrients, and that while pasteurization may kill dangerous bacteria, it also kills off good bacteria that raw milk supporters have stated to have health be... |
why is "district attorney" in the us often an elected and political position? | How do you suggest they get appointed, if not by election? Who decides what the test looks like? Who administers it for? Who decides what crimes will be focused on? Who decides what crimes won't be focused on?
Electing a person seems like the only reasonable way to answer all of these questions. | [
"\"District attorney\" and \"assistant district attorney\" are the most common titles for state prosecutors, and are used by several major jurisdictions within the United States, such as California, Delaware, Georgia, Massachusetts, Nevada, New York, North Carolina, Oklahoma, Oregon, Pennsylvania, Texas, and Wiscon... |
Without ready access to sugar, what were popular desserts in early Colonial America? | Settlers in the area lacked traditional cane sugar, but they were not without sugar. The Northeast is full of many sugar maple trees that were used to create maple syrup, used by natives long before Europeans settled the area. Sap is harvested, boiled into syrup, and if you boil it some more you get a crystalline sugar... | [
"The first candy came to America in the early 18th century from Britain and France. Only a few of the early colonists were proficient in sugar work and sugary treats were generally only enjoyed by the very wealthy. Even the simplest form of candy – rock candy, made from crystallized sugar – was considered a luxury.... |
Are there any mammals with the same or similar vocal range/abilities as humans? | Dogs actually have pretty similar ranges as humans, from a deep bark to a high pitched wimper.
More interesting is vocal ability question... Both birds and (some) whales are known to be able to imitate human speech.
| [
"Human beings, along with Apes, are the only mammals that do not have high frequency (32 kHz) hearing. Humans have long cochleae, but the space devoted to each frequency range is quite large (2.5mm per octave), resulting in a comparatively reduced upper frequency limit. The human cochlea has approximately 2.5 turns... |
Does History only pertain to humans? | If considered with its technical and narrow definition, "history" refers to that part of the past that is documented with written records. One can have a history of volcanic eruptions - and not even consider their effect on people - but the use of the term "history" would technically imply "volcanic eruptions" that app... | [
"ii) Human history is a single unique event. Knowledge of the past therefore does not necessarily help one to know the future. \"“The evolution of life on earth, or of human society, is a unique historical process… Its description, however, is not a law, but only a singular historical statement.”\" \n",
"Mandel o... |
why did some animals in the same family become hyper aggressive like geese, whereas ducks are relatively benign? | I'm going to try an ELI15:
Sometimes a lot of behaviour is evolutionary. It's a bit of a generalization to say that geese are hyper aggressive and ducks are meek (although anyone who's been in Canada can tell you Canada geese have no fear). Realistically, there's no exact answer (as far as I know), but I can talk a bi... | [
"Once they reach adulthood, due to their large size and often aggressive behavior, Canada geese are rarely preyed on, although prior injury may make them more vulnerable to natural predators. Beyond humans, adults can be taken by coyotes and grey wolves (\"Canis lupus\"). Avian predators that are known to kill adul... |
How much explosive would be needed to destroy the moon, and if we used the debris to make rings à la Saturn, how would this affect the tides? | The gravitational binding energy of a spherical object is close to (3/5) GM^2 /R - that's the energy you need to completely overcome gravity and blow the object apart. Plugging in the numbers for the moon gives you about 10^29 J. That's the equivalent to 2 x 10^19 tonnes of TNT. The largest nuclear bomb ever detonated ... | [
"The carbonaceous boulder that would have been captured by the mission (maximum 6 meter diameter, 20 tons) is too small to harm the Earth because it would burn up in the atmosphere. Redirecting the asteroid mass to a distant retrograde orbit around the Moon would ensure it could not hit Earth and also leave it in a... |
how does math describe nature so well ? | I disagree with most of the other posters. Math was NOT made to understand or represent nature. It is entirely separate. Mathematics is pure logic. There is nothing in nature we could find to contradict any mathematics, nor is there any possible universe where math could be different. Mathematics is the study of imp... | [
"Geometry (from the ; \"geo-\" \"earth\", \"-metron\" \"measurement\") is a branch of mathematics concerned with questions of shape, size, relative position of figures, and the properties of space. A mathematician who works in the field of geometry is called a geometer.\n",
"It seems to be one of the fundamental ... |
"At near-light speed, we could travel to other star systems within a human lifetime, but when we arrived, everyone on earth would be long dead." At what speed does this scenario start to be a problem? How fast can we travel through space before years in the ship start to look like decades on earth? | It follow the formula for the Lorentz factor, which is 1/sqrt(1-v^(2)/c^(2)). At 86% the speed of light, you age one year for every two years on Earth, at 99% the speed of light you age one year for every seven years on Earth.
edit: I have to go now so stop asking me about warp drives! | [
"Since one might not travel faster than light, one might conclude that a human can never travel further from the Earth than 40 light-years if the traveler is active between the age of 20 and 60. A traveler would then never be able to reach more than the very few star systems which exist within the limit of 20–40 li... |
Whether a woman is fertilized after sex or not, where does the semen go? | Since sperm cells don't last very long at warm temperatures, the cell will undergo apoptosis (cell suicide.) | [
"The human reproductive system usually involves internal fertilization by sexual intercourse. In this process, the male inserts his penis into the female's vagina and ejaculates semen, which contains sperm. A small proportion of the sperm pass through the cervix into the uterus, and then into the Fallopian tubes fo... |
How could Lewis and Clark travel all the way out to Oregon when Louisiana Purchase only included as far as Montana? | One of the greatest hopes of the period was that it would be possible to find a waterway that was navigable from the Atlantic (or at least from the Gulf of Mexico) to the Pacific. [Lewis and Clark](_URL_0_) followed the Missouri through the Louisiana Purchase and then hoped that they could find the nearest navigable ri... | [
"Once across the sand bars and turbulent water at the entrance to the river (later called the Columbia Bar) they sailed up the Columbia River several miles while exploring the river. Gray's find was a significant claim (besides the Lewis and Clark Expedition) put forth by the United States to claim possession of th... |
the situation in israël and palestina. | Please remember to search before posting. | [
"Morten Levin, who is Jewish, is also a critic of Israel, and was one of the initiators of a petition that NTNU boycott Israel because he meant that \"since 1948 the state of Israel has occupied Palestinian land and denied the Palestinians basic human rights\". Together with Ann Rudinow Sætnan (an American-born Jew... |
how do residential solar panels 'give back' to the grid? | > How much power could you actually be contributing?
Depends on a lot of factors: Where in the world is the house? Is it summer or winter (summers have more hours of sunshine)? Are there a lot of clouds?
A very good soar panel has a power of 16.22 W/ft^2 (175 W/m^2) *peak*. This means if *a lot* of sun shines on the... | [
"Under the CEC community solar plan, an individual or entity can buy one or more solar panels, thereby becoming the owner of the solar panel(s). The solar panels need not be physically located on the owner's property but can be installed somewhere else. The electricity each panel generates is fed into the electric ... |
How does H.265 compress video better than H.264? | The most simplistic explanation is that video encoding is always a trade-off between processing power versus file size. The more processing power you can throw at encoding/decoding, the smaller you can get the file size. As computers become more powerful, that can be leveraged to reduce the bandwidth of the file.
T... | [
"High Efficiency Video Coding (HEVC), also known as H.265 and MPEG-H Part 2, is a video compression standard, designed as a successor to the widely used AVC (H.264 or MPEG-4 Part 10). In comparison to AVC, HEVC offers from 25% to 50% better data compression at the same level of video quality, or substantially impro... |
Can a two dimensional object have mass? | Well, electrons and other elementary particles have no dimensions and have mass.
But yes, these are all in fact just mathematical constructs in attempt to describe what is happening. | [
"In dimension \"d\" = 3, this reduces to Newton's theorem that the potential energy of a small mass outside a much larger spherically symmetric mass distribution is the same as if all of the mass of the larger object were concentrated at its center.\n",
"The minimal number of static equilibria of homogeneous, con... |
What is the simplest venom used by an organism? | Im going to answer based on the assumption that you specifically want formation about venom, and not generally poisons.
Off hand most venoms I can think of are mixtures of agents. The primary agent is usually a short protein, more accurately described as a polypeptide of around 20-40 amino acids like iberiotoxin, or c... | [
"Venomous arthropods include spiders, which use fangs — part of their chelicerae — to inject venom; and centipedes, which use forcipules — modified legs — to deliver venom; along with scorpions and stinging insects, which inject venom with a sting.\n",
"The definition of venom by Fry et al. (see Definitions) rega... |
Was Hitler in any way, at any point, a Zionist? | Hi. This question was answered [here](_URL_0_).
The answer is totally and unequivocally no. Being Zionist means supporting the creation of a Jewish state, and Hitler never supported it. The Nazis at one point signed an agreement that deported Jews to Mandatory Palestine, signing the agreement with Zionist groups, but ... | [
"In 1941 and 1943, Bloch was interviewed by the Office of Strategic Services (a predecessor of the Central Intelligence Agency) to get information about Hitler's childhood. He said that Hitler's most striking feature was his love for his mother: While Hitler was not a mother's boy in the usual sense, I never witnes... |
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