question stringlengths 3 301 | answer stringlengths 9 26.1k | context list |
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why did certain countries like the usa and china experience an immense population boom in the 21st century, while countries like the united kingdom, france and germany barely saw any population increase at all? | It's not really a population boom per se but a gradual increase. Population booms are mostly a thing of the past (outside sub-Saharan Africa). Two factors are immigrants and birth rates.
The US takes on a lot of immigrants, more than any country on earth, both legal and illegal. They take on a million legal immigrants... | [
"Many countries in the developing world have experienced extremely rapid population growth since the early 20th century, due to economic development and improvements in public health. China's population rose from approximately 430 million in 1850 to 580 million in 1953, and now stands at over 1.3 billion. The popul... |
How did the Portugese empire go from once spanning the whole world to it's current state as not even being a G20 country? How did such a drop off from prominence occur? | I covered a lot of reasons of early decline in power in [this post](_URL_1_).
You can also read this very nice and concise [thread](_URL_0_) by /u/nathanial_jones | [
"Starting in the 15th century the Ottoman Empire began to expand at the expense of the Byzantine Empire and other countries friendly to Genoese merchants. The gradual loss of Imperial territory, coupled with the destruction of smaller Christian states such as Trebizond, Cyprus, and Amasra chipped away at Genoese me... |
Czechs in the Austro-Hungarian Army | Since no one answered I'll tell you what I know and give you a few things you can look up.
So, from a cemetery in Prague I know that they fought (and died) in Italy, places like Slovenia and Croatia, anywhere the Austrians fought.
Many also didn't think it right they should be fighting their Slavic brothers under the... | [
"During the First World War, while nearly 1.5 million Czechs fought in the Austro-Hungarian army, exiled Czech politicians backed by the military legions worked on the regaining of the independence of Bohemia in the form of Czech-Slovak union. The Entente powers supported their plans, which did not provide any auto... |
if photons are mass-less and travel forever without friction, if i point my flashlight at the sky, do they travel forever? | Within the atmosphere, the photons are being absorbed by the molecules in the air. Those that are not absorbed are scattered, which is why in dusty air you can see the dust dancing in the air - it's the light bouncing off the dust particles and flying off in different directions. The flashlight also doesn't send all th... | [
"Photons travel at the speed of light, yet have finite momentum and energy. For this to be so, the mass term in \"γmc\" must be zero, meaning that photons are massless particles. Infinity times zero is an ill-defined quantity, but \"E/c\" is well-defined.\n",
"Shengwang Du claims in a peer-reviewed journal to hav... |
what's the difference between veteran's day and memorial day? | My understanding is that Veteran's Day is meant to focus on the living veterans of the armed service, while Memorial Day is meant to focus on the _deceased_ members of the armed service who gave their lives in defense of the country.
Practically, however, there is little difference. | [
"Veterans' Day was created as a permanent extension of Veterans' Awareness Week first held in 2005. Armed Forces Day generally focuses on celebrating living current/ex servicemen & women, whereas Remembrance Day focuses on honouring the dead. Although it used to be called Veterans' Day in the UK, it is not the same... |
Once a European power in the age of exploration, Portugal isn't seen as a mighty or influential nation in the world today. What caused this? | Finally a question I can answer! The reasons for the decline of Portugal from its height as the first colonial power to its situation today as, at best, a middling european power are varied and extend over centuries. First, Portugal had an inherent disadvantage to other colonial powers like England, France, or neighbor... | [
"With the end of Portuguese reconquista and integration in the European Middle Age economy, the Portuguese were at the forefront of maritime exploration of the age of discovery, expanding to become the first global empire. Portugal then became the world's main economic power during the Renaissance, introducing most... |
how computers turn 0's and 1's into text, video, and other programs/applications. | Imagine you're sitting at a desk with three levers in front of you, each one can be "on" or "off." Each lever controls something different in the room you are sitting in. The first switch turns the lights on or off, the second switch turns on or off some music, and the third turns on or off the television.
Now lets sa... | [
"\"Text\" is a built-in routine that outputs a string of characters. The zero (0) tells where to send the string. In this case it is sent to the display screen, but it could just as easily be sent to a printer, a file, or out a serial port by using a different number.\n",
"Most programming languages let the progr... |
If I had a stationary slinky hanging from a mile up, and let go. Would the bottom stay in place until the top falls down to it? | [Explanation](_URL_1_)
[Longer slinky](_URL_0_) | [
"Two early successful \"Veritasium\" videos demonstrate the physics of a falling Slinky toy. The videos explain the following: when a slinky is held dangling vertically and then released, it can be observed in slow motion that the bottom end does not begin to move until the entire slinky has collapsed, making it lo... |
How important are genetics in sports? | Approximately 17% of people are born without the ability to create fast-twitch muscle fibers. They have nonsense genes in place of the gene that allows the creation of fast twitch muscles. [One study](_URL_0_) showed that elite sprinters and power athletes are much less likely to have the nonsense allele, and [another ... | [
"The Sports Gene is a nonfiction book written by David Epstein, at the time a senior writer for \"Sports Illustrated\", on the effects of genetics and sports training on human athleticism. Through investigative journalism, Epstein takes the reader through his experiences regarding what makes the difference between ... |
If you stacked an infinite line of standard dominoes .5 inches apart and pushed one end knocking them over. Would the whole line fall, or would the energy eventually run out? | With dominoes, the energy supplied by the push is negligible. The real source of energy in the sequence of falling dominoes is the potential energy from gravity that each of the dominoes is storing. When you tip one, you allow that energy to be released and the domino settles in a lower-energy state. | [
"Another example is the block-stacking problem: given a collection of identical dominoes, it is clearly possible to stack them at the edge of a table so that they hang over the edge of the table without falling. The counterintuitive result is that one can stack them in such a way as to make the overhang arbitrarily... |
what is it i'm actually smelling as a thunderstorm approaches? | An electrical charge—from lightning or a man-made source such as an electrical generator—splits atmospheric nitrogen and oxygen molecules into separate atoms. Some of these recombine into nitric oxide, and this in turn reacts with other atmospheric chemicals, occasionally producing a molecule made up of three oxygen at... | [
"William Henry Pickering noted that at eight stations in Canada a trembling of the house or ground was felt. In many other places loud, thunder-like sounds were heard, occasionally by people who had not seen the meteors themselves. Pickering used the sound reports to perform a check on the height of the meteors, wh... |
After light slows traveling through a medium, does it accelerate back to c upon reentering a vacuum or does it remain the same velocity as it was the moment it exited the medium? | The idea of "the speed of light in a medium" is really just a helpful trick for simplifying a more complex phenomenon.
What's really going on is that the incident wave, as it propagates through a material, causes charges in the material to oscillate and in turn radiate EM 'wavelets'. The combined effect of these 'wave... | [
"When light propagates through a material, it travels slower than the vacuum speed, . This is a change in the phase velocity of the light and is manifested in physical effects such as refraction. This reduction in speed is quantified by the ratio between and the phase velocity. This ratio is called the refractive i... |
why is mitochondria called "the powerhouse of the cell" and what is its relationship with atp? | Your mum makes you meal so that you can get energy from food to play; mitochondria makes ATP so that cells have the energy to do what they need to do. | [
"The most prominent roles of mitochondria are to produce the energy currency of the cell, ATP (i.e., phosphorylation of ADP), through respiration, and to regulate cellular metabolism. The central set of reactions involved in ATP production are collectively known as the citric acid cycle, or the Krebs cycle. However... |
Did Henry Ford say this quote, and what did he mean by it? | That particular quote first appeared in *The American Mercury* in 1957 in an article [How Internationalists Gain Power](_URL_2_), and it is important to remember that the entire passage is prefaced with "It was Henry Ford, Sr. who said *in substance*" (emphasis mine) - that is, the quote was abridged or paraphrased - t... | [
"\"Lord, Mr. Ford\" is a satire on the social, cultural and economic influence that the automobile has had on the American public. The lyrics bemoan the fact that a seemingly simple invention to assist mankind has instead brought nothing but grief, become increasingly more complex and added to the increasing fast-p... |
how are some munitions designed to detonate before they hit the ground/target? | In addition to the fancy things mentioned by other folks, like lasers/radar/altimeters, some air-burst munitions just use a simple timer. For example, part of calculating the details of an artillery mission is figuring out the round's time of flight to the target. So you just set a timer on the fuze to function a littl... | [
"BULLET::::- Detonation – Emeralds, Starflowers, Rubies and Black Pearls can be detonated on the player's command. The explosion causes some of the adjacent pieces to explode, making it easier to destroy \"locked\" pieces or clear bombs.\n",
"A kinetic projectile can also be dropped from aircraft. This is applied... |
Before Loving v Virginia how common were non white mixed race marriages? | I know that the Siamese twins Chang and Eng Bunker had problems when they moved to North Carolina with attempts to classify their race. Eventually, they must have been considered white as they were married to white people and owned slaves. Their descendants (they managed to have about 23 children) ignored the "one-drop... | [
"In 1918, there was controversy in Arizona when an Indian farmer married the sixteen-year-old daughter of one of his White tenants. California law did not explicitly bar Filipinos and whites from marrying, a fact brought to wide public attention by the 1933 California Supreme Court case \"Roldan v. Los Angeles Coun... |
How does this gyroscope hand exerciser work? | gyroscopes work by angular momentum, basically it creates a force that keeps the spinning disc inside it straight (or at a constant angle) and it 'forces' it's self back to this position, gyroscope are used to keep some large ship upright in heavy storms you know, as far as the exercise involved, what do you do with it... | [
"A gyroscopic exercise tool is a device used to exercise the wrist as part of physical therapy or in order to build palm, forearm and finger strength. It can also be used as a unique demonstration of some aspects of rotational dynamics. The device consists of a tennis ball-sized plastic or metal shell around a free... |
Could there, theoretically, be particles that don't interact with ANYTHING? If so, in what sense would they 'exist'? | > If so, in what sense would they 'exist'?
That's the key question there. If there is something out there, the existence of which won't change _anything_ observable in the world, then it does not exist, as far as science is concerned. Science requires an assertion to be falsifiable. | [
"Identical particles, also called indistinguishable or indiscernible particles, are particles that cannot be distinguished from one another, even in principle. Species of identical particles include, but are not limited to elementary particles such as electrons, composite subatomic particles such as atomic nuclei, ... |
Who are the indigenous people of Europe? | Who are the indigenous people of Europe? It depends how far you want to go back.
& #x200B;
If you go back longer than 40,000 years ago the indigenous people of Europe were Neanderthals who had interbred with Homo Sapiens. About then the Neanderthals went extinct in Europe and were succeeded by the undifferentia... | [
"In Europe, present-day indigenous populations as recognized by the UN are relatively few, mainly confined to its north and far east. Notable minority indigenous populations in Europe include the Basque people of northern Spain and southern France, the Sami people of northern Scandinavia, the Nenets, Samoyedic and ... |
How powerful a magnet would I need to levitate a drop of water due to it's diamagnetic properties? | According to Wikipedia,
"**A substance that is diamagnetic repels a magnetic field**. All materials have diamagnetic properties, but the effect is very weak, and is usually overcome by the object's paramagnetic or ferromagnetic properties, which act in the opposite manner. Any material in which the diamagnetic componen... | [
"Diamagnetic levitation can be used to levitate very light pieces of pyrolytic graphite or bismuth above a moderately strong permanent magnet. As water is predominantly diamagnetic, this technique has been used to levitate water droplets and even live animals, such as a grasshopper, frog and a mouse. However, the m... |
Why are there no tides in non ocean connected waters? | The moon does have a tidal effect on all bodies of water, but it's only the oceans that are big enough that we can see it easily. The Great Lakes do have measurable tides, but they're fairly small and not as important of a regulator of water level as wind speed and direction. The great lakes are big, but still minisc... | [
"Because the oscillation modes of the Mediterranean Sea and the Baltic Sea do not coincide with any significant astronomical forcing period, the largest tides are close to their narrow connections with the Atlantic Ocean. Extremely small tides also occur for the same reason in the Gulf of Mexico and Sea of Japan. E... |
How much text do we have from different ancient languages? | This is going to be a very difficult question to answer, though I've often, as a Classicist, wondered something similar myself. The only way to really quantify in a way you are wanting would be by "word count," which is itself problematic (Greek has articles and particles, for instance, which inflate its word count vs... | [
"The oldest texts since the 11th century are in Glagolitic, and the oldest preserved text written completely in the Latin alphabet is , from 1345. The Arabic alphabet had been used by Bosniaks; Greek writing is out of use there, and Arabic and Glagolitic persisted so far partly in religious liturgies.\n",
"Certai... |
If I were dropped into Jupiter's atmosphere with a spacesuit, would I be pulled in until I reached the core, or would I eventually come into contact with a surface that stops me? | Assuming that your suit is pressurized/rigid, you will eventually reach a point where you're too buoyant to sink any further through the planet since it gets denser and denser as you get closer to the center. We don't really have any materials that would survive at the ridiculous pressures where the metallic hydrogen i... | [
"BULLET::::- 27 August – NASA's \"Juno\" probe makes a close pass of Jupiter, coming within of the cloud tops – the closest any spacecraft has ever approached the gas giant without entering its atmosphere.\n",
"A major problem in sending space probes to Jupiter is that the planet has no solid surface on which to ... |
"Hollywood" is so synonymous with the motion picture industry that the word itself has become shorthand for it; how did this come to be the case? How were they able to establish and maintain (for nearly 100 years) such a dominant hold over the industry? | A very similar question was answered by /u/Strabbo in [this post](_URL_0_). /u/kirbyderwood also provides an answer lower in the thread explaining the Hollywood - Los Angeles dynamic. | [
"By the mid-1920s, the evolution of a handful of American production companies into wealthy motion picture industry conglomerates that owned their own studios, distribution divisions, and theaters, and contracted with performers and other filmmaking personnel, led to the sometimes confusing equation of \"studio\" w... |
if trans fats are truly as dangerous as people say, then why is it still legal to put them in food? | not legal anymore...
_URL_0_
| [
"On 7 November 2013, the FDA issued a preliminary determination that trans fats are not \"generally recognized as safe\", which was widely seen as a precursor to reclassifying trans fats as a \"food additive,\" meaning they could not be used in foods without specific regulatory authorization. This would have the ef... |
how does exercise benefit the body so greatly if it increases oxidative stress, the basis for all known disease? | The oxidative negative effects are negligible compared to the PREVENTION of the negatives of not exercising. Basically, having amazing, "non-oxidated" heart arteries arent worth much if they are clogged with fat. | [
"It has been claimed that this relationship, characterized by positive effects at an intermediate dose of the stressor (exercise), is characteristic of hormesis. However, it is important to point out that there is evidence that the oxidative stress associated with intensive exercise may have long-term health benefi... |
how do companies sell away so many stocks to public, still totally owned and controlled by the same people, if stock are a form of ownership? | Apple has been regularly giving out dividends for 10 years. In 2017 they gave out .57 cents a share in February, and .63 cents a share in May for the first and second quarters respectively. That's your cut of the profits. Apple's market valuation is over 300 billion dollars. Even if Bill gates liquidated his 75 billion... | [
"Stock can be bought and sold privately or on stock exchanges, and such transactions are typically heavily regulated by governments to prevent fraud, protect investors, and benefit the larger economy. As new shares are issued by a company, the ownership and rights of existing shareholders are diluted in return for ... |
why jupiter, saturn, uranus and neptune are considered giant planets and not small planets with big atmospheres? | Even if you ignored their crushing atmospheres as "just atmosphere", you rapidly get down into the quasi-liquid, or maybe solid who knows? cores, which are still many times larger than any of the terrestrial planets.
Seriously, they are giant. | [
"Giant planets are also sometimes called jovian planets, after Jupiter (\"Jove\" being another name for the Roman god \"Jupiter\"). They are also sometimes known as gas giants. However, many astronomers now apply the latter term only to Jupiter and Saturn, classifying Uranus and Neptune, which have different compos... |
would google fiber's phenomenal download/upload speed be useful for people who don't torrent movies or software like your average redditor? why are cable companies wrong in saying that fiber's speed is unnecessary and overkill? | More speed is desirable because, while we cannot predict exactly *what* customers will be doing with that bandwidth, we can predict that they will want and need it. We all use more data than we did 5 years ago and 5 years before that. We will surely use more 5 years from now. Keeping our internet services sufficient... | [
"Google Fiber provides an Internet connection speed of up to one gigabit per second (1,000 Mbit/s) for both download and upload, which is roughly 100 times faster access than what most Americans have. Google Fiber says its service allows for the download of a full movie in less than two minutes.\n",
"AT&T and oth... |
What does science have to say about Free will Vs Determinism? | It doesn't say much about free will, but determinism is pretty much out.
At least, on the quantum level, there's no such thing as determinism. | [
"Some conceive free will to be the capacity to make choices in which the outcome has not been determined by past events. Determinism suggests that only one course of events is possible, which is inconsistent with the existence of free will thus conceived. Ancient Greek philosophy identified this issue, which remain... |
why did video games require memory cards when past games used to be able to save within the game itself? | Cartridge games had the equivalent of memory cards built into the game cartridge. You can't do that with games on a CD. Well, technically you can if you have a CD-burner and a re-writable CD, but that technology was *much* more expensive than read-only CDs at the time, and memory cards were a cheaper alternative. | [
"Many older video game consoles used memory cards to hold saved game data. Cartridge-based systems primarily used battery-backed volatile RAM within each individual cartridge to hold saves for that game. Cartridges without this RAM may have used a password system, or wouldn't save progress at all. The Neo Geo AES, ... |
Would it be possible for a human being to actually walk on water? [Please, bear with me] | Only if it's frozen. Otherwise, you'd have to displace your own weight in water before you started to float. You'd but in up to over your neck in fresh water. A bit less in very salty water, which has a greater density.
| [
"For example, if we were to see a man walking on water, and the man really were walking on water, that would not be possible given the laws of nature \"as we understand them\". (The surface tension of water is not great enough to support a man's weight.) But it is logically possible that our understanding of the la... |
why is hayfever so massively common compared to other allergies? | Hayfever isn't just one allergy, it's dozens, if not hundreds, of different allergies lumped into a single name. Somebody with a peanut allergy is probably just allergic to peanuts. Hayfever covers people allergic to any number of trees, grasses, flowers & weeds - each of them is a *specific* allergen. This is why ... | [
"One concern is that genetic engineering could make an allergy-provoking food more allergic, meaning that smaller portions would suffice to set off a reaction. Of the food currently in widespread GMO use, only soybeans are identified as a common allergen. However, for the soybean proteins known to trigger allergic ... |
memory leaking | "Leaking" is a metaphor. It actually refers to a situation where a program tells the computer "I need to use some memory" and then forgets to say "I'm done using that memory." Over time, the computer allocates more and more of its memory to this program, making it hard for other programs to run. | [
"In computer science, a memory leak is a type of resource leak that occurs when a computer program incorrectly manages memory allocations in such a way that memory which is no longer needed is not released. A memory leak may also happen when an object is stored in memory but cannot be accessed by the running code. ... |
If I drink a pint of water, how much of it is absorbed into my body becoming part of my organs and blood versus being excreted as urine or sweat? | A bit hard to know how to answer this, because the body doesn't consume water - it creates it. Burning sugars to power the body results in carbon dioxide and water as waste products. And that water, along with what you drink and what you eat, ends up in your bloodstream, from where it used for sweat or excreted as urin... | [
"When ingested, only about 0.05% of samarium salts is absorbed into the bloodstream and the remainder is excreted. From the blood, about 45% goes to the liver and 45% is deposited on the surface of the bones where it remains for about 10 years; the balance 10% is excreted.\n",
"The adult male body is about 60% wa... |
difference between 2-stroke and 4-stroke motorcycles (specifically dirt bikes) | [2 strokes](_URL_1_) have a power stroke every rotation. [4 strokes](_URL_0_) have a power stroke every second rotation.
Most 2 strokes use ports that are covered and uncovered by the piston to inject air/gas and remove the exhaust. 4 strokes use valve for those jobs.
2 strokes tend to be less efficient than 4 stroke... | [
"As applied to motorcycles, two-stroke engines have some advantages over equivalent four-strokes: they are lighter, mechanically much simpler, and produce more power when operating at their best. But four-stroke engines are cleaner, more reliable, and deliver power over a much broader range of engine speeds. In dev... |
if you feed a cow with its own milk, will that cow be able to live out its life with no additional food source? | Like, feeding the cow milk taken from that same exact cow? That won't work because cows don't turn 100% of their food into milk. Some of it is lost.
But just feeding cows with cow milk - sure. Milk has all the nutrients necessary for the animal that the milk comes from. The only problem is that some individuals may no... | [
"Cows kept on poor forage (as is typical in subsistence farming) produce a limited amount of milk. A calf left with such a mother all the time can easily drink all the milk, leaving none for human consumption. For dairy production under such circumstances, the calf's access to the cow must be limited, for example b... |
what black light is and how it works to highlight many fluids and make certain colors glow | Black light is ultraviolet light. Ultravolet means it is a wavelength too short for the eyes to see. However, some chemical compound can absorb certain wavelenghts, and emit light at an other, hence the glowing effect | [
"Black light is used extensively in non-destructive testing. Fluorescing fluids are applied to metal structures and illuminated with a black light which allows cracks and other weaknesses in the material to be easily detected. It is also used to illuminate pictures painted with fluorescent colors, particularly on b... |
How can there be "a" human genome? [continued] | Humans are about 99.9% genetically homogenous as determined by studies where groups of people were compared for differences individual base pairs, know as single nucleotide polymorphisms.
A gene codes for a trait like hair color and each person has their own version of that gene like blonde brunette or redhead. These ... | [
"The human genome is the complete set of nucleic acid sequences for humans, encoded as DNA within the 23 chromosome pairs in cell nuclei and in a small DNA molecule found within individual mitochondria. These are usually treated separately as the nuclear genome, and the mitochondrial genome. Human genomes include b... |
why do halogen headlights look white at some angles but blue at others? | HIDs, which I think you're talking about, AKA Xenon, is an electric arc.
They're often used behind a projector lens, which gives a sharp cutoff of the beam, to prevent glare. At the edge of this cutoff, is a [varied color area](_URL_0_)
When your eye is in the area of this blue fringe, they appear blue. | [
"The other attributes of infrared photographs include very dark skies and penetration of atmospheric haze, caused by reduced Rayleigh scattering and Mie scattering, respectively, compared to visible light. The dark skies, in turn, result in less infrared light in shadows and dark reflections of those skies from wat... |
how radiation stays inside the nuclear plants but radiation can go through almost anything? | Well, there are different types of radiation, and they all have different properties, but I'm going to give you a general answer.
There are specific materials that have a high tendency to interact with the radiation coming through it and slow it down. If the "shielding", such as a lead wall for example, is thick enoug... | [
"Emission of radioactivity from a nuclear plant is controlled by regulations. Abnormal operation may result in release of radioactive material on scales ranging from minor to severe, although these scenarios are very rare.\n",
"Nuclear radiation is harmful to the environment over immediate (seconds or fractions t... |
Why does my sweat crystallize into salt when I sweat during exercise? | Your [sweat is salty](_URL_2_). The water evaporates and the salt precipitates out, depositing on you. Some people resorb more than others. This is the basis for the [sweat test](_URL_1_) for [cystic fibrosis](_URL_0_). Don't worry, just because you have more salt stains after running than someone else doesnt' mean you... | [
"In both apocrine and eccrine sweat glands, the sweat is originally produced in the gland's coil, where it is isotonic with the blood plasma there. When the rate of sweating is low, salt is conserved and reabsorbed by the gland's duct; high sweat rates, on the other hand, lead to less salt reabsorption and allow mo... |
What was the Roman tax system like? | usually tax rate would be between 1-3% on your wealth, but higher in wartime. sometimes there would be an income tax in Urban areas.
in Rural areas where organised tax collection was either impossible or poorly executed Rome would put a levy and lump sum tax on the provincial governor, as long as he paid and supplied ... | [
"In the early days of the Roman Republic, public taxes consisted of assessments on owned wealth and property. The tax rate under normal circumstances was 1% of property value, and could sometimes climb as high as 3% in situations such as war. These taxes were levied against land, homes and other real estate, slaves... |
what does a "reset signal" to a cpu do? (computer science) | Well that's depends on what it's designed to do and what architecture. There's a really good book (_URL_0_) that goes through what happens when a computer boots up, this article explains in brief depth.
_URL_1_
The ELI5 version is that there is an address your CPU is programmed to jump to when a reset hardware interr... | [
"The reset vector is the default location a central processing unit will go to find the first instruction it will execute after a reset. The reset vector is a pointer or address, where the CPU should always begin as soon as it is able to execute instructions. The address is in a section of non-volatile memory initi... |
what causes sponges to be as absorbent as they are compared to others? | Assuming by 'others' you mean other materials, it's because they are full of tiny holes and chambers. Liquid is drawn into the chambers by capillary action. | [
"Like many other sessile organisms, sponges are rich of secondary metabolites with toxic properties and most of them, including Latrunculin, have a defense role against predators, competitors and epibionts.\n",
"Sponges do not have distinct circulatory, respiratory, digestive, and excretory systems – instead the ... |
Is it possible for a falling object's terminal velocity in a given atmosphere to exceed the speed of sound within that atmosphere? | Sure. [This guy](_URL_1_) broke the speed of sound in freefall about a week ago. All you need is a large, non-lifting, not too draggy body.
FYI, speed of sound for air at the conditions found anywhere in the atmosphere is a mostly a function of just composition (as in how much water vapor, etc.) and temperature. It is... | [
"In subsonic flight, the plane pushes the air ahead of it out of the way as it moves. When a plane is traveling faster than the speed of sound (i.e. faster than air molecules normally travel) the air ahead of it is not pushed out of the way: the air remains still until the plane has approached to within half an inc... |
Has there ever been a movement to 'unite' the various Caribbean countries like Antigua and Barbuda, or Trinidad and Tobago? | Are you asking why Islands of the Lesser Antilles haven't all banded together in a political union? Because I have no idea about that, sorry :/
But the way I read it, it looks like you're asking if pairs of small, neighboring islands are politically united, and they are!
[Antigua & Barbuda] (_URL_0_)
[Republic of... | [
"On its 1962 independence, Trinidad and Tobago joined the United Nations and Commonwealth of Nations. In 1967, it became the first Commonwealth country to join the Organization of American States (OAS).\n",
"Both nations were colonised by the British Empire; India supported independence of Trinidad and Tobago fro... |
Why does the U.S. have so many aircraft carriers in comparison to the world? | Hello, as you've stated the question, it essentially is violating our 20 Year Rule. You would have better luck with /r/CredibleDefense. But if you are looking for a more general answer about the development of US carrier policy through the Cold War, please feel free to resubmit the question here with some tweaking in t... | [
"In the 21st century, the aircraft carrier is the last remaining capital ship, with capability defined in decks available and aircraft per deck, rather than in guns and calibers. The United States possesses supremacy, in both categories of aircraft carriers, possessing not only 11 active duty supercarriers each cap... |
Does mold automatically indicate spoilage? | Mold *is* (one form of) spoilage. Visible mold in one place usually indicates non-visible trace amounts threaded through the food nearby. Cutting out only the visible bits will leaves these traces, and you don't know how much else to cut off. | [
"Signs of food spoilage may include an appearance different from the food in its fresh form, such as a change in color, a change in texture, an unpleasant odour, or an undesirable taste. The item may become softer than normal. If mold occurs, it is often visible externally on the item.\n",
"Molds cause biodegrada... |
what causes tornadoes to form and why are they so often along the same historical paths? | When warm, moist air mixes with cold air. When they meet the work around each other creating the cyclone. Most tornadoes form during thunderstorms, but that is not a requirement for there to be one.
Same paths have to do with where these warm and cold fronts meet which is typically around “tornado alley.” (cold air f... | [
"Tornadoes may be formed out of season, especially during the months of hurricane season in the Gulf Coast states and Southeastern states. Because these areas are prone to hurricanes, they may be struck with tornadoes that are spawned from hurricanes. Tornadoes are most likely to form in the right-front quadrant of... |
Why did the Beer Hall Putsch fail despite the Nazis superior numbers? | Hitler and the Nazis made a few key mistakes in their handling of the Putsch that led to it being easily defeated (Hitler wouldn't have succeeded in installing himself as leader of Germany even if the initial Putsch had succeeded, but more on that later).
The first mistake was made by SA leader Ernst Rohm. He ordered ... | [
"BULLET::::- 1923: The failed Beer Hall Putsch, from 8 to 9 November, marks an early emergence and provisional downfall of the Nazi Party as an important player on Germany's political landscape. Without sufficient preparation Hitler simply declared himself leader in Munich, Bavaria. Hitler's march through Munich wa... |
Were past cultures attracted to fatter women? | Each culture had an ideal body weight.
In Renaissance & Romantic Era paintings, you'll notice the women are average-'overweight' sized because that was what the nobility looked like; they looked like they could feed themselves, and that's what was desirable.
In the 20's, the flapper look, practically malnourished l... | [
"In the culture of the Cook Islands, particularly before the introduction of Western standards of beauty, being fat was the \"symbol of wealth and beauty\". Upon the onset of puberty, girls had to \"ritual seclusion and feedings to gain weight\".\n",
"Other common factors, besides a sedentary lifestyle and unheal... |
what are exactly elementary particles? | Elementary particles are, simply put, particles that make up, and regulate the behaviour of, all of the matter around us. That is to say that they are discrete particles that cannot be broken down into other parts or particles. These include the various quarks, leptons and bosons.
The bosons are the "force carrier" p... | [
"Elementary particles are particles with no measurable internal structure; that is, it is unknown whether they are composed of other particles. They are the fundamental objects of quantum field theory. Many families and sub-families of elementary particles exist. Elementary particles are classified according to the... |
How was Mark Antony's relationship with Cleopatra viewed by the roman and egyptian general public? | Terribly, at least by Romans--we don't really know what the Egyptians thought (and it's also difficult to figure out what the different social elements within Egyptian society would've thought). But we know that the Romans despised Antony's relationship with Cleopatra, because there's an enormous body of work on it in ... | [
"Mark Antony's alliance with Cleopatra angered Rome even more. Branded a power-hungry enchantress by the Romans, she was accused of seducing Antony to further her conquest of Rome. Further outrage followed at the donations of Alexandria ceremony in autumn of 34 BC in which Tarsus, Cyrene, Crete, Cyprus, and Israel ... |
what do the letter classifications (kroq, wfan, kmox etc.) for radio stations mean and/or how are they assigned? | K and W denote the assignment area, general east (w) and west (k) of the Mississippi, the other 3 letters are either requested by the registering party or randomly by the FCC. | [
"All AM and FM radio stations are assigned unique identifying call letters by the FCC. International agreements determine the initial letters assigned to specific countries, and the ones used by U.S broadcasting stations—currently \"K\" and \"W\"—date back to an agreement made in 1912. (The assignment of the letter... |
why does everyone in the us seem to have an ac system? | It's hot, and they're affordable. | [
"AC became the dominant form of transmission of power with innovations in Europe and the US in electric motor designs and the development of engineered \"universal systems\" allowing the large number of legacy systems to be connected to large AC grids.\n",
"DC was used on earlier systems. These systems were gradu... |
What percent of our dinosaur fossils come from the Cretaceous–Paleogene extinction event? | > What percent of our dinosaur fossils come from the Cretaceous–Paleogene extinction event?
From the event itself? I don't think that I've ever heard of even one fossil being identified as being from the event itself. | [
"Non-avian dinosaur fossils are only found below the Cretaceous–Paleogene boundary and became extinct immediately before or during the event. A very small number of dinosaur fossils have been found above the Cretaceous–Paleogene boundary, but they have been explained as reworked fossils, that is, fossils that have ... |
Question about the movie Kingdom of Heaven | While these organizations may have been nominally part of the same court within the kingdom of Jerusalem they all had their own objectives and motivations, which often put these groups at odds with one another.
For example shortly before the events that take place during this film there was a period of civil disorder ... | [
"Kingdom of Heaven is a 2005 epic historical drama film directed and produced by Ridley Scott and written by William Monahan. It stars Orlando Bloom, Eva Green, Ghassan Massoud, Jeremy Irons, David Thewlis, Brendan Gleeson, Iain Glen, Marton Csokas, Liam Neeson, Edward Norton, Michael Sheen, Velibor Topic and Alexa... |
during a commercial break, what happens to live-audience shows that are not broadcast live? | It's called an intermission. They go for a break to get drinks or food or stuff like that. | [
"However, since many live events became available via social media in the late 2000s, tape delays have become increasingly irrelevant because of live television's resurgence as a broadcast format. Since the mid-2010s, several high-profile entertainment programs with huge live global audiences like the Academy Award... |
odor eliminators | It is kind of like bubbles. You are spraying a kind of chemical which is ring shaped and it traps the odor chemicals inside that ring which stops the odor. This happens at the molecular level.
_URL_0_ | [
"The odorology or science of smells is a technology used mainly in criminology for judicial identification. The technology is based on the analysis of smells by dogs notably to merge the criminals or to identify the smell of objects (explosives, drugs).\n",
"Sachs mentions the earliest reference as old as early n... |
the procedures taken if mid surgery there is an emergency (active shooter, tornado, fire) | It depends, each hospital is different... it wouldn't really affect anything.
Active shooter, you remain in place, stay away from windows. Based on how OR rooms are situated, it's never off a hallway... there's prep rooms, etc. Only certain people get in and out. Not a concern. If the shooter is in the room, you try t... | [
"To examine scheduling challenges, consider three possible surgical scenarios: elective (e.g. cosmetic procedures, stable situations not increasing in severity), imminent (e.g. inflamed gall bladder removal, potential for worsening harm if situations not surgically corrected,) and emergency surgeries (e.g. burst ap... |
When it's stated that "In the year [XXXX], the average lifespan was only [XX] years," is this figure very skewed by infant/child mortality? | Once you cut out infant and childhood mortality figures, people were living what we'd consider to be normal lives, if slightly shorter.
Lancaster's *Expectations of Life* took data from nobility (because it's what we have the most of). Once they got to 21, noble males could expect to live through their 60s or 70s, ... | [
"Note that life expectancies are not the same at different ages. For example, in Paleolithic era, life expectancy at birth was 33 years, but life expectancy at the age of 15 was an additional 39 years (total 54).\n",
"Although, among moderns, \"life expectancy\" tends to mean \"the average number of years lived a... |
Why does Kosovo have so many more people than Montenegro? | Having been to both I would say that Kosovo has larger urban centres and much more agricultural land available. Standing by themselves the geography of Kosovo is more conducive to a larger agrarian and urban population than Montenegro who's landscape is much more mountainous and dry. The mountains of Montenegro have si... | [
"The links between the two nations remain strong, and the fact that for the last two centuries a great number of Montenegrins had emigrated to Serbia further strengthens the ties. The Montenegrin littoral is still the main tourist destination for citizens of Serbia, and a large population of Serbians own property i... |
Did Roman legionaries' families receive compensation if they died in battle? | There are a few previous question you can cobble together to answer most of this. Someone may come in and give you a comprehensive answer, but in the meantime...
[How did the wives of roman soldiers learn of their husbands deaths?](_URL_0_) in which /u/Celebreth explains how Roman soldiers couldn't get married, so for... | [
"All legionary soldiers would also receive a \"praemia\" (veterans' benefits) on completion of their term of service of 25 years or more: a sizeable sum of money (3,000 \"denarii\" from the time of Augustus) and/or a plot of good farmland (good land was in much demand); farmland given to veterans often helped in es... |
how does the brain decide what is funny and what is not? | Humor is literally a shift in the frame of reference. You expect one thing, you get another. (Alternately, you don't know what to expect, and what you get is still unexpected.)
Consider the knock-knock joke:
When you say "who's there?' the expectation is the name of the knocker. Instead you get something else.
Wh... | [
"Cognitive humor processing refers to the neural circuitry and pathways that are involved in detecting incongruities of various situations presented in a humorous manner. Over the past decade, many studies have emerged utilizing fMRI studies to describe the neural correlates associated with how a human processes so... |
How did pouch evolve on marsupials? | There are even marsupials today which don't have pouches. The babies just hang on to the fur next to the teat. If the skin is a bit loose in that area, it's probably easier to grab. A bit looser still, and you have a nice little fold. Expand the fold, and viola, a pouch! | [
"A pouch is present in most, but not all, species. Many marsupials have a permanent bag, whereas in others the pouch develops during gestation, as with the shrew opossum, where the young are hidden only by skin folds or in the fur of the mother. The arrangement of the pouch is variable to allow the offspring to rec... |
what is that clicking sound that nuclear radiation detectors make? | The noise is because of how [Geiger Counters](_URL_0_) function.
The Geiger counter has a chamber filled with an inert gas, like helium, and a high voltage applied to it. If high energy radiation hits the helium gas, it gives enough energy to the Helium atoms to bump electrons off their orbitals, so the atoms become ... | [
"In electronic recording devices, a major type of noise is \"hiss\" created by random electron motion due to thermal agitation at all temperatures above absolute zero. These agitated electrons rapidly add and subtract from the voltage of the output signal and thus create detectable noise.\n",
"Microbaroms are a s... |
Could quantum entanglement be used for communication if the two ends were synchronized? | One of the absolute truths about quantum entanglement is that it can't be used for communication. If you ever think of a scheme (using entanglement) that can communicate, faster than light or otherwise, then it must be flawed.
The reason your plan does not work, even theoretically, is there is no way to control the b... | [
"He also showed that even bound entanglement (when used in conjunction with a single pair of free entangled particles) can lead to quantum teleportation with a fidelity impossible to achieve with only separable states.\n",
"The monogamy of pure entanglement also has a strong analogue within the toy model, as a gr... |
When and why did nations start "declaring war"? | The official international protocol for declaring war was defined in the Hague Convention of 1907 on the Opening of Hostilities. | [
"The United States has formally declared war against foreign nations five separate times, each upon prior request by the President of the United States. Four of those five declarations came after hostilities had begun. James Madison reported that in the Federal Convention of 1787, the phrase \"make war\" was change... |
how do tires on the landing gears of heavy airplanes withstand the speed and weight of the airplane when landing? | They're big tires, so the force is spread out over a larger area, and they use quite a few tires—a Boeing 747 has 18 tires on it—further distributing the load.
They use thick rubber, so they're stronger than your average tire by a pretty wide margin.
Even with these, they don't last particularly long. Any given tir... | [
"The landing gear on aircraft used on aircraft carriers must be stronger than those on land-based aircraft, due to higher approach speeds and sink rates during carrier landings. As early as the 1940s, drop tests were conducted by lifting a carrier-based plane such as the Grumman F6F Hellcat to a height of ten feet ... |
Healthier: high caloric intake + exercise, vs lower caloric intake | Caloric intake isn't specific enough. High saturated fat intake? High cholesterol intake? High carb intake?
You got my point. | [
"Some research has pointed toward hormesis as an explanation for the benefits of caloric restriction, representing beneficial actions linked to a low-intensity biological stressor such as reduced calorie intake. As a potential role for caloric restriction, the diet imposes a low-intensity biological stress on the o... |
Do runaway stars get shot out of the Galaxy? | It takes a lot of time and energy for matter to be ejected completely out of the Galaxy. Most runaway stars that are flung around thanks to close interactions with other objects remain close to the galaxy, but the probability of this actually occurring is very low. In general, stars and clusters in the Galaxy are ver... | [
"A runaway star is one that is moving through space with an abnormally high velocity relative to the surrounding interstellar medium. The proper motion of a runaway star often points exactly away from a stellar association, of which the star was formerly a member, before it was hurled out.\n",
"An example of a re... |
what would happen if the richest people on earth asked their banks to pay them out their fortune in cash? | Bill Gate's bank would tell him to shove off, since he doesn't have $20 billion in cash. He probably has tens of millions in cash, so the bank would probably just ask him to wait a couple weeks so they could assemble the cash and give it to him.
& nbsp;
Similar logic with other rich people. | [
"The Millionaires is a novel written by Brad Meltzer examining the inner workings of private banking. After taking $3,000,000 from an abandoned account, brothers Oliver and Charlie Caruso are forced to escape the Secret Service. According to WorldCat, the book is in 2191 libraries \n",
"It was reported in Februar... |
why do couples that are having trouble getting pregnant want a biological child so much when there are many children in need of adoption? | It is the innate human drive to carry on the individuals own genetic heritage. If you adopt, you and your partners DNA is not passed to future generations. This also plays into an individuals want/need to be genetically immortal via its offspring. | [
"In the Adoption and Children Act 2002 Parliament provided that an application to adopt a child in England and Wales could be made by either a single person or a couple. The previous condition that the couple be married was dropped, thus allowing a same-sex couple to apply. The Lords rejected the proposal on one oc... |
bullet penetration | There are different kinds of bullets. Some bullets (called [full metal jacket bullets](_URL_0_)) are surrounded in a hard metal like steel and have rounded or pointed tips. They usually leave a clean hole.
Other bullets, like the ones in this video, have [soft or hollow points](_URL_1_). They expand inside the target.... | [
"The IWBA's and FBI's penetration guidelines are to ensure that the bullet can reach a vital structure from most angles, while retaining enough velocity to generate a large diameter hole through tissue. An extreme example where penetration would be important is if the bullet first had to enter and then exit an outs... |
why do songs become popular on the radio months after they were released? | There are a few reasons:
1) The song was not expected to be popular. The album comes out and after a little while the internet discovers how cool track 7 is - marketing people pick up on it and jam it on the radio to sell more albums.
2) It is planned to not conflict with another song. If Kanye has a new album he'l... | [
"This change coincided with the greater emphasis on albums as opposed to singles in the rock market. Hugely popular albums such as The Beatles' \"Sgt. Pepper's Lonely Hearts Club Band\" and Arlo Guthrie's \"Alice's Restaurant\" did not contain any singles, so there was clearly a need for a radio format that would e... |
proton cancer treatment | It's very simple once you understand some basic biological concepts.
Cancer is the uncontrolled growth and reproduction of cells.
Cells require DNA to reproduce themselves and when DNA is damaged tremendously cell reproduction will usually just fail.
Radiation destroys DNA as well as cells.
They're going to focus b... | [
"Proton therapy is a type of external beam radiotherapy that uses ionizing radiation. In proton therapy, medical personnel use a particle accelerator to target a tumor with a beam of protons. These charged particles damage the DNA of cells, ultimately killing them by stopping their reproduction. Cancerous cells are... |
why are so many countries aiming for 2% inflation? | Economists generally agree that around 2% inflation is a rate that is desirable for an economy. Basically the reason this number is chosen is that it provides a balance between goals the government hopes to achieve .
The 2% rate of inflation is chosen as:
1. at this amount , inflation is high enough to encourage cons... | [
"In 2017, inflation rates were observed to be in a downward trend in most of the major economies. The reasons are prior exchange rate appreciations and food price deflation. Some countries are even expected to lower their target bands in 2019.\n",
"Other sources have argued that chronic inflation is caused by gov... |
Treaty of Versailles--Trying to recall where I read a discussion on the severity of the treaty. Was the treaty too lenient? | > Was the Treaty of Versailles justified in the form it took?
Expecting the Germans to pay reparations for the Damages they had done; reducing their military (in theory) to ensure that they could not seriously threaten the borders of their neighbours; relinquishing territories, most of which were off majority non-Ge... | [
"The terms of the Treaty of Versailles were written in secret. It was unveiled on 7 May 1919 and was followed by an ultimatum: either ratify the treaty, or the Allies would take whatever measures they deemed necessary to enforce its terms. While Germans of all political shades cursed the treaty as an insult to the ... |
Are suicide fighters a modern development? If not, how long have they been around and where/what regime? | Suicide tactics are not a modern concept but it really comes down to your definition of suicide fighters. Soldiers have, at times, committed to attacks in which they would have known that their odds of coming out alive were next to non-existant. They may not have blown themselves to bits but the end result is still in ... | [
"Hezbollah's attacks in 1983 during the Lebanese Civil War are the first examples of the modern suicide terrorism. Workers Party of Kurdistan (PKK) used its first suicide attack in 1996, and al-Qaeda in the mid-1990s. The number of attacks using suicide tactics has grown from an average of fewer than five per year ... |
how does new information still get uncovered from classified state archives after decades of research and analysis? | There are several reasons.
1. First and most obvious, it's **a huge amount** of information to go through. The people digging through it all are usually academic researchers looking for some specific thing for their research. Nobody is just sitting down to read millions of pages of decades-old government papers just... | [
"BULLET::::- Access to new data: Much historical data has been lost. Even archives have to make decisions based on space and interest on what original material to obtain or keep. At times documents are discovered or publicized that give new views of well established events. Archived material may be sealed by Govern... |
Did Japanese-Americans have any warning that FDR was going to intern them during WWII? How did so many of them lose their savings and their houses? | Expanded from [an earlier answer of mine](_URL_0_)
In terms of notice, FDR signed Executive Order 9066 in 19 February 1942 which authorized exclusion of enemy aliens in what were termed "Military Areas", on 2 March Lieutenant General John L. DeWitt declared the Pacific Coast "Military Area No. 1", and throughout the ... | [
"When the United States entered World War II, President Franklin D. Roosevelt ordered the relocation and internment of Japanese Americans due to fears that some would turn out to be traitors. However, for communities outside the sensitive coastal \"military zone\", this was not mandatory, and local authorities coul... |
Why can we NOT drink seawater to survive? | The problem with seawater is not trace minerals and metals, but rather the > 3% salt content. Your body needs to maintain a certain percentage of electrolytes, and doesn't have a good way to absorb only the water and not the salts from sea water. The result is that you'll need more and more water to offset the increas... | [
"Although humans cannot survive on seawater, some people claim that up to two cups a day, mixed with fresh water in a 2:3 ratio, produces no ill effect. The French physician Alain Bombard survived an ocean crossing in a small Zodiak rubber boat using mainly raw fish meat, which contains about 40 percent water (like... |
Mass of falling objects | Yes, technically speaking, the more massive ball does cause the moon to accelerate towards the ball faster, which means that it hits the moon quicker.
However, this effect is so laughably small that's it's completely unmeasurable. | [
"This particular equivalence often referred to as the \"Galilean equivalence principle\" or the \"weak equivalence principle\" has the most important consequence for freely falling objects. Suppose an object has inertial and gravitational masses \"m\" and \"M\", respectively. If the only force acting on the object ... |
I recently learned that scientiists use zircon crystals to date rocks and, with them, the Earth. How do we know that the zircons weren't created elsewhere in material that then combined to form the Earth? | Well - sometimes they are, and in some instances that fact is the main story the rock can tell. All Zircon-based geochronology studies must begin with a morphological assessment of the material: how many populations are there, do they look fresh, are they corroded, fractured, is their geometry coherent with the setting... | [
"Chemically, zircon is a particularly useful mineral because of its ability to incorporate many trace elements. Many of these elements can be used for radiometric dating to provide an age for the crystal. It is known to exchange uranium, thorium and rare earth elements (REE) such as yttrium, and lutetium. However, ... |
How does the universe decide where an electron is when you observe it? | It is different for cards. The cards are predetermined, we just don't know where they are. The electrons are everywhere and nowhere until measured.
The truth is, we don't know how some electrons get measured over here and some get measured over there. We do know one thing that it's not: Predetermined. The universe isn... | [
"According to the more complete theory of quantum mechanics, the location of an electron is best described as a probability distribution within an electron cloud, i.e. atomic orbital. The energy can be calculated by integrating over this cloud. The cloud's underlying mathematical representation is the wavefunction ... |
Say I had a beaker of water at room temperature and threw in one salt molecule (NaCl). The Salt would separate into Na and Cl ions. What if I was able to separate the water containing the Na ion from the water containing the Cl ion and evaporated them, what would happen to the ions? | If you're asking if ions can exist freely, the answer is yes. In our environment though they quickly become neutralized. | [
"The solubility in water depends on the type of salt. Sodium chloride can be dissolved in cold water to a concentration of 357 g∙l. Not only solubility differs between salts but also the conductivity. When performing a Bresle method test, not only sodium chloride is dissolved but also all other salts present on the... |
why do employers ask you to resign instead of just firing you? | In the U.S., in most places, at least, if you resign then it is harder to get unemployment. If they fire you, it is easier to get unemployment.
Also, for higher end jobs or jobs under contract/with union protections, there are often ways to contest being fired, which can make the process longer and more expensive. ... | [
"A forced resignation is when an employee is required to depart from their position due to some issue caused by their continued employment. A forced resignation may be due to the employer's wishes to dismiss the employee, but the employer may be offering a \"softened firing\", or in a high profile position, the emp... |
What accounts for the French paradox? (Why are French people not as fat as we'd expect, given their diet) | As a chef I can say for two reasons. First are the portion sizes, a lot smaller than American plates. Secondly, a more natural diet. Less processed foods and fewer chemicals in their food. | [
"In his 2009 book \"Cholesterol and The French Paradox\", Frank Cooper argues that the French paradox is due to the lack of hydrogenated and trans fats in the French diet. The French diet is based on natural saturated fats such as butter, cheese and cream that the human body finds easy to metabolize, because they a... |
Sword vs spear combat | The spear, pike, halberd, when not used in a phalanx are typically best suited against cavalry/horse based combatants. The typical Roman foot soldier (legionnaire) would be using either gladius or spatha, in conjunction with a scutum, which was a devestating combination that not only enabled great versatility in melee ... | [
"In the Ilocano fighting arts of Kabaroan learned by Grandmaster Ramiro Estalilla, 2 spears () can be used at the same time, with the second spear held with a grip in the middle and used as a shield. When one spear is thrown, the practitioner can then draw his blade and dual wield with a blade and spear.\n",
"Spe... |
Is there any evidence about why "mood lighting" (dimmer lighting) makes people feel sexy or "in the mood"? | It's all about the dilated pupils.
Your pupils dilate when you are interested in something or someone. This results in us subconsciously interpreting someone else's dilated pupils to indicate interest in us.
You lower the light, the pupils dilate, and your subconscious does the rest.
| [
"BULLET::::- Kuijsters, Andre, et al. “Lighting to Make You Feel Better: Improving the Mood of Elderly People with Affective Ambiences.” PLoS ONE, vol. 10, no. 7, 2015, doi:10.1371/journal.pone.0132732.\n",
"Over illumination has been linked to various negative health effects. While some effects might happen beca... |
what's the difference between the labour party and the liberal democrats in the uk? | The Labour Party's ideological tradition is democratic socialism, i.e. the establishment of state ownership of the means of production and the abolition of capitalism by democratic means, but they have moderated that stand somewhat with "New Labour's" so-called "third way," which was adopted to regain popularity after ... | [
"The Conservative Party, the Labour Party and the Liberal Democrats (formerly as the Liberal Party) have, in modern times, been considered the UK's three major political parties, representing the British traditions of conservatism, socialism and liberalism, respectively. However, in both the 2015 and 2017 general e... |
Are poor people more susceptible to religious conversion? | Hi there - you may have more luck asking this question, as phrased, in /r/asksocialscience - the present tense in the question suggests you are interested in this in general rather than through history, and so that might be a question for sociologists and social psychologists and the like. Alternatively, if you're inte... | [
"Citizens of the world's poorest countries are the most likely to be religious, and researchers suggest this is because of religion's powerful coping abilities. Luke Galen also supports terror management theory as a partial explanation of the above findings. Galen describes evidence (including his own research) tha... |
Could you kill somebody by injecting a large pocket of air into their blood stream? | Yes, though the amount of air required is somewhat questionable. When air gets into the blood stream it's known as a gas embolism, and it's not uncommon for it to happen during surgery. Most of the time it's harmless, however if it's large enough it can disrupt blood flow from the heart which can obviously lead to de... | [
"A blood clot or other solid mass, as well as an air bubble, can be delivered into the circulation through an IV and end up blocking a vessel; this is called embolism. It is nearly impossible to inject air through a peripheral IV at a dangerous rate. The risk is greater with a central IV.\n",
"Air can be injected... |
Why is the body unable to regulate the growth of all cancer cells? | When the body is unable to regulate cancerous cells, that's when cancer occurs. There are several fail-safe cellular devices that are meant to kill/nullify cancerous cells before they go hay-wire. For example, there are a few well known devices in the cell that are meant to trigger cell death in the case of cancerous g... | [
"A disregulation of the cell cycle components may lead to tumor formation. As mentioned above, when some genes like the cell cycle inhibitors, RB, p53 etc. mutate, they may cause the cell to multiply uncontrollably, forming a tumor. Although the duration of cell cycle in tumor cells is equal to or longer than that ... |
how does bell's experiment disprove local hidden variable theory | Indeed, to deal with one particular loophole these tests you need to be able to choose which measurements you're going to do on your particles (for example, what directions you'll be measuring polarization relative to), and you need to do it such that each of your particles can't get information about your measurement ... | [
"Most advocates of the hidden-variables idea believe that experiments have ruled out local hidden variables. They are ready to give up locality, explaining the violation of Bell's inequality by means of a non-local hidden variable theory, in which the particles exchange information about their states. This is the b... |
how do facebook "meme" pages get revenue from 'likes' and 'shares'? | They don't, but if someone buys the page they can then post a status and get something in front of all of those people who liked it, and thats valuable to some people. | [
"The number of \"likes\" on Facebook can serve as a measurement of interest and/or popularity in a particular brand, product or personality, though there have also been reports of the \"overblown importance\" of likes. Due to social media's role as an influential way of shaping reputations, there exists companies s... |
What do we know about the Natives of South Western Pennsylvania pre European settlement? | "Circular Villages of the Monongahela Tradition" by Bernard Means is a 2007 is a good overview of this poorly understood culture. Bernard Means also publishes extensively in specialized archaeology journals, so if you have access to J-STOR, you will find a treasure trove of in... | [
"The earliest settlers in Pennsylvania arrived from Asia between 12000 BCE and 8000 BCE, when the glaciers of the Pleistocene Ice Age were receding. Fluted point spearheads from this era, known as the Paleo-Indian Period, have been found in most parts of the state. Archeological discoveries at the Memorial Park Sit... |
Why are jokes less funny when you've already heard them?
| Part of what makes jokes funny is the element of the unexpected, usually in the punchline. Once you've heard it, it's no longer surprising. /opinion | [
"A particular strength of the theory is that it predicts when things are not funny: a situation can fail to be humorous because it depicts a violation that does not simultaneously seem benign, or because it depicts a benign situation that has no violation. For example, play fighting and tickling cease to elicit lau... |
Why does the spin of a Black Hole affect how it looks? | It is not really appropriate to say density since it is a singularity but yes they should both have the same mass. However I think it has to do with the fact that spinning black holes twist spacetime with it's rotation. In short it creates an area outside the event horizon called the ergosphere which can do work on pas... | [
"A black hole spin-flip occurs when the spin axis of a rotating black hole undergoes a sudden change in orientation due to absorption of a second (smaller) black hole. Spin-flips are believed to be a consequence of galaxy mergers, when two supermassive black holes form a bound pair at the center of the merged galax... |
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