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how much of the "side effects" medicine talks about are actually side effects? | > But how much is actually proven to be a side effect?
All those are "possible side effects", meaning you *might* experience them. Drugs can be difficult to predict and just because someone experienced them in testing doesn't mean you will.
> because companies are too cheap to do extra testing?
Extra testing probably won't help. Suppose 5% of people who take the drug experience anal leakage while others don't. What will more testing reveal about that possible side effect?
> Does that mean that heart attack could actually be a 10% occurrence and not a .01%?
Such a dangerous drug would never pass FDA approval. | [
"The most common adverse effects (occurring in at least 1% of those taking the drug) include agitation, anxiety, confusion, dizziness, irritability, abnormal sensations, like pins and needles, without a physical cause, sleep disturbances (e.g. sleeplessness) and a drop in blood pressure upon standing up. Less frequ... |
why when another person is picked up when they are conscious, they feel lighter than their actually weight, but if they are unconscious or like a rag doll they feel more like their true weight? | Think about it like trying to pick up a hundred pounds of sand. Consciousness is, metaphorically, sand bags. The contain the mass. A conscious person being carried has a desire to not be dropped, and so will assist the carrier by keeping his limbs tucked in, maybe even wrapping arms around the center mass of the carrier and alleviating pressure on the arms by putting more weight on the hips and legs. An unconscious person can't contain their body, their legs and arms will flop and they won't grab on for support, so it's like trying to lift a hundred pounds of sand using a large piece of tarp to carry it instead of a bag. | [
"Weight lifting can effectively demonstrate the effects of post-activation potentiation. For example, if a person lifts a light weight, and then lifts a heavy weight, before lifting the light weight again, the light weight will be relatively easier to lift and feel lighter the second time it has been lifted. Becaus... |
why does orange juice after brushing my teeth with mint tooth paste feel like the gods are punishing me? | Orange juice is very sour and very sweet. Your tooth paste temporarily makes you unable to taste sweetness. Without the sweet there to balance it, the sourness of orange juice becomes kinda overwhelming.
[A similar thing happens with the miracle berry, which blocks sour and salty tastes](_URL_0_) | [
"After using toothpaste, orange juice and other juices have an unpleasant taste. Sodium lauryl sulfate alters taste perception. It can break down phospholipids that inhibit taste receptors for sweetness, giving food a bitter taste. In contrast, apples are known to taste more pleasant after using toothpaste. Disting... |
li5: cuban missle crisis, bay of pigs... | Long ago, in 1823, President Monroe announced the Monroe Doctrine, which essentially said that the United States would view any attempts by European nations to colonize North American countries as threats to US national security. This is important.
Cuba used to be ruled by a US-friendly dictator named Fulgencio Batista. The US liked Batista, the communists in Cuba didn't like him. In 1959 there was a revolution in Cuba and the communists, led by Fidel Castro, took power. Now, the communists in the Soviet Union were generally big fans of any other nation becoming communist, so they immediately tried to become allies with Cuba. The United States was not happy about the Soviet Union getting an ally in their backyard, and remember the ancient Monroe Doctrine allowed them to say that the Soviet Union interfering in Cuba's affairs was a threat to the US. This made sufficiently flimsy justification for the US to attempt to remove Castro and reinstate Batista or another US-friendly ruler.
In 1961, Kennedy authorized the Bay of Pigs invasion. Essentially a bunch of exiled Cubans were trained by the CIA to invade Cuba. The plan hinged on the fact that the communist Cuban army would be weak, the Cuban resistance would want to lend their support to the exiles, and the Cuban people in general would be happy to help overthrow Castro. As you can guess, it backfired. The invasion failed in 3 days, and it was a big foreign policy disaster for Kennedy.
The Cuban Missile Crisis was basically the closest the world ever came to full-scale nuclear war. As I mentioned above, the USSR and Cuba were allies, and the USSR had started stockpiling missiles in Cuba that had the ability to strike most of the continental US. The US had a similar situation with their allies in Turkey allowing them to strike the USSR. In October, 1962, a US surveillance plane took photos of Soviet nuclear bases under construction in Cuba. This kicked off about two weeks of posturing and brinkmanship over the Cuban bases. Hawks in the US wanted Kennedy to invade Cuba, which would have essentially kicked off a nuclear war. Ultimately the crisis was settled by Kennedy and Khrushchev (then head of the USSR) agreeing to get rid of the bases in Turkey and Cuba. | [
"The Bay of Pigs Invasion (known as La Batalla de Girón in Cuba), was an unsuccessful attempt by a U.S.-trained force of Cuban exiles to invade southern Cuba with support from U.S. armed forces to overthrow the Cuban government of Fidel Castro. The plan was launched in April 1961, less than three months after John ... |
how did cavemen maintain their teeth if they didn't have the proper knowledge and tools the same way we do in the modern world? | They did not. Many died of starvation because they could not eat. | [
"The Indus Valley Civilization has yielded evidence of dentistry being practiced as far back as 7000 BC. This earliest form of dentistry involved curing tooth related disorders with bow drills operated, perhaps, by skilled bead craftsmen. The reconstruction of this ancient form of dentistry showed that the methods ... |
Why did stars stop producing new elements? | _URL_0_
Elements up to Iron are formed during the life of stars, heaver during supernovae star deaths.
So, stars *are* producing new elements as they die, if they're massive enough.
Stars that aren't massive enough to die as a supernova just use up all their fuel and become white dwarfs and eventually black dwarfs. The reason is that the fusion of iron atoms does not *produce* energy, it *consumes* energy. So, fusion past Iron doesn't release energy and everything just "runs out of gas" quite literally. | [
"Stars evolve because of changes in their composition (the abundance of their constituent elements) over their lifespans, first by burning hydrogen (main sequence star), then helium (red giant star), and progressively burning higher elements. However, this does not by itself significantly alter the abundances of el... |
how come most people who grew up poor/lower socioeconomic, usually stay that way? | Poverty is known to be perpetual for one pretty huge reason; the available opportunities.
It is repeated time and time again, but basically those born economically struggling area, in a "poor" family, and such forth have less immediately available opportunities to succeed upwards compared to those of the upper 10% and more opportunities for failure downwards than those of the upper 10%.
For example:
A child growing up in a poverty-stricken lifestyle will most likely have easier access the drugs, gangs, and other influences. As well as less access to positive influences such as a good school, a supportive and educated family, great role models for advice, etc.
Meanwhile, a child growing up in a well-off family will have access to better schools, educated individuals, and would most likely know no one in a gang. As for drugs, a well off child's parents will probably have the proper resources to help any problem, however, drugs will not too apparent in his environment to influence him.
That is merely just growing up. In adulthood, many of the same problems exist, however, more are tacked on. The key to success is having an education or marketable skill, those are usually tied. A poor working full time and barely making it will most likely face constant stress and anxiety around just surviving. He most likely will struggle to save enough to get an expensive education or won't have enough time to work on a skill.
On the other side, a very well-off person can afford to pay people to do his/her chores there for freeing up time to work on a skill, or they can have enough money to go get an expensive education. They are not stressed or living check to check, and there for can focus on further their education, bettering them.
The list can go on and on, but pretty much it comes down to opportunities. | [
"Lower-class people experience a wide array of health problems as a result of their economic status. They are unable to use health care as often and when they do it is of lower quality, even though they generally tend to experience a much higher rate of health issues. Lower-class families have higher rates of infan... |
Is there anything special or discerning about "visible light" other then the fact that we can see it? | It's not amazingly special, but there are some good reasons why animals have similar ranges of vision (although some go a little bit into infrared and ultraviolet). I can't talk about evolutionary pressure because that's not my field, but I can talk about the physics of light and why if I was the engineer tasked with designing a biological eye, I would use visible light.
1. While the Sun emits light at all sorts of wavelengths, the peak is in visible light - in green to be specific. So we get the brightest light at visible.
2. The atmosphere is partially opaque at a lot of wavelengths. There are convenient "windows" where the atmosphere is transparent: at radio wavelengths and at visible wavelengths. So it's much easier to transmit and receive information over long distances using radio or visible light.
3. Our eyes detect light with chemical reactions. So the light photons need to have a similar energy to the range of energies used in chemical reactions, and visible light has energies of around 1-10 eV, which is just right. It also means that this light is easily absorbed and reflected by objects we interact with, and that's what allows us to see things: things like gamma rays or radio waves aren't very well absorbed by things like people, trees, or computers, so it's very difficult to get a proper image of those types of object at these wavelengths. | [
"Tyson proceeds to discuss the nature of light as discovered by mankind. Work by Isaac Newton using refraction through prisms demonstrated that light was composed of the visible spectrum, while findings of William Herschel in the 19th century showed that light also consisted of infrared rays. Joseph von Fraunhofer ... |
The golden age of Islam saw the middle east as one , if not the centre of scientific progress during it's time. What happened that today the west overtook the islamic world in scientific progress and innovation? | [A great answer to a similar question here](_URL_0_) by u/profrhodes | [
"The Islamic Golden Age was also an important early stage of globalization, when Jewish and Muslim traders and explorers established a sustained economy across the Old World resulting in a globalization of crops, trade, knowledge and technology. Globally significant crops such as sugar and cotton became widely cult... |
When a fighter jet fires it's machine guns, does it slow down the jet by a considerable amount? | Other answers are generally correct, explaining that the effects are mostly negligible.
However, there is one airplane that stands head and shoulders above other aircraft in terms of amount of gunfire that it can rain down upon a target: the A-10 Thunderbolt II (aka Warthog).
The A-10 has a 30 mm gatling cannon under the cockpit, capable of firing over 4,000 rounds per minute. On the A-10, the firing rate is set to 3,900 rounds per minute. Many rounds can be used, but a favorite is the .69-kg (1.5 lb) depleted uranium ammo. Muzzle velocities are around 1070 m/s (.66 mi/s).
So when the above rounds are fired at the specified rate and velocity, they produce about 48 kN force. This is over half of the force generated by the two GE turbofans in back (40 kN each).
To compensate, pilots would dive when firing (diving is also helpful at hitting targets on the ground).
Additionally, yes, I know there are sites that say this is a myth, but no, it's not. Do the math. The recoil of the gun is greater than the force generated by one engine. | [
"The introduction of jet engines and the subsequent rough doubling of aircraft speeds greatly reduced the effectiveness of the SPAAG against attack aircraft. A typical SPAAG round might have a muzzle velocity on the order of and might take as long as two to three seconds to reach a target at its maximum range. An a... |
What mechanisms support genetic diversity of the whole population of (complex) species? | Most mutations are indeed deleterious/bad, but there are also beneficial/good mutations. A good example is the ability to metabolize lactose as adults - since we've domesticated cows/goats/etc. and milk is a good source of nutrition, there is positive selection on this trait being maintained on a population. That's why this mutation, or trait, is very common among European and African populations.
It's helpful to think of selection as a "force" that pushes a trait to become more or less common in a population. If selection against a trait is strong enough, it will die out (go to 0% incidence in a population), and if it is strong enough, it will "fix" (go to 100%).
In addition to selection, there is genetic "drift." Because of how people pair off to mate and how traits get passed on, there is a degree of randomness that causes the percentage incidence of a trait in a population to fluctuate - like a random walk in physics.
Just from these factors alone, with the introduction of new traits (mostly bad, but some good), there is always going to be diversity within a population. But because we have two copies of each chromosome and each gene, one from mom and one from dad, you can also have interesting situations where having one mutation has a very different outcome than none or two. In some of these cases, you can get a stable percentage of a trait in a population at a value between 0% and 100%. A good example is the mutation that causes sickle cell anemia if you have two copies, but may protect against malaria if you have one copy.
If you want to learn more, Population Genetics by Gillespe is an accessible (and cheap) book on this subject. I think a little bit of calculus helps for the math.
_URL_0_ | [
"It is clear that levels of genetic diversity vary greatly within a species as a function of local recombination rate, due to both genetic hitchhiking and background selection. Most current solutions to the paradox of variation invoke some level of selection at linked sites. For example, one analysis suggests that ... |
Could a Middle English speaker and a Modern English speaker have been able to verbally communicate | Eddie Izzard once tried an experiment similar to this. See _URL_0_ | [
"BULLET::::- Elizabeth I of England (1533–1603) could speak ten languages: English, French, Spanish, Italian, Dutch, Latin, Welsh, Cornish, Scottish and Irish. The Venetian Ambassador once said: \"it is as if she possessed these languages as if they were her mother tongue\".\n",
"...the Norman could not speak any... |
historically, does socialism work long-term? why or why not? | Social policies mixed with capitalism have been proven to work very well together. This includes the United States, Canada, and many European countries. Pure socialism (public ownership of *all* means of production) has never been properly implemented.
Capitalism comes with many inherent flaws, and a "mixed" approach which applies social control over some aspects of the economy seeks to remedy those flaws. | [
"Socialism is the mode of production which Marx considered will succeed capitalism, and which will itself ultimately be succeeded by communism - the words socialism and communism both predate Marx and have many definitions other than those he used, however - once the forces of production outgrew the capitalist fram... |
what are the main differences between sunni and shia islam? | Orthodox vs Roman Catholic is kind of a workable example to a point, but it misses the huge political factor.
To delve into it a bit more, you need to know why they're different. Islam follows on from Judaism and Christianity with a fellow named Muhammad, who around 600AD, proclaimed that he was receiving revelations from God and that he was the next great prophet (Christ being the last one). He gathered followers, eventually raised an army, and conquered the crap out of the Middle East, giving conquered people options between converting to this new religion of Islam, paying tax, or dying (some debate on this in posts below). Then he chilled out for a bit and eventually died.
Now, let's get to the point differences:
1: A large part of Islam has been based around those who knew Muhammad but weren't recorded in the Quran, and what they claim Muhammad said, meant, or did off the record. Called Hadiths, these are Islamic laws or suggestions based around such anecdotes. It could be as simple as a man who once observed Muhammad treat a beggar in a certain way declaring that this way of treating beggars is the one true way all Islam should follow, through to rather complicated arguments of how to interpret Islamic law written in the Quran based on what was implied by something Muhammad was once recorded to have said. Sunni and Shia Muslims believe in and accept different Hadiths, as do various smaller branches within those two factions.
2: The more concrete divide is the matter of a chap named Ali, and the matter of who would succeed Muhammad upon his death. Ali was Muhammad's first cousin and closest living male relative, and also married Muhammad's daughter. Shia Islam believes and accepts that Ali was the rightful heir to Muhammad, stating that only God has the right to choose such leaders, and had appointed Ali caliph and all round #1 guy in Muhammad's wake. The Sunni, by contrast, whilst holding him in high regard still consider him one of FOUR caliphs, rather than the one and only. It's a bit more complex than that, but it'd be stepping out of ELI5 territory and into a major debate (Llama Labia made a post below that does go into those details a bit more. Scroll down and go look!). At the time, there were battles over this.
3: Sunnism puts a LOT of emphasis on Sharia, Islamic law. Shia aren't as strict about taking law solely from the Quran, and have several other ways of defining Sharia law (such as Mantiq, which is argument of traditional logic, or proclaiming a change to the law to be in 'public interest'), for better or for worse.
4: Different beliefs on what will happen at the end of the world. Both believe some kind of redeeming figure will appear as prophecised, but its nature and actions are disputed by both sides. The Sunni view him kind of as another of God's prophets who will arrive to rule the world and re-establish Islamic rule and law. The Shia view is more akin to a Biblical rapture, with a great host of badasses showing up to kick the hell out of everything bad and wicked and wrong.
Clarification by SuitedPair below: "Sunnis also believe in Jesus and the Mahdi returning for the end of days to fight off Dajjal(the antichrist)"
Double-clarification by LlamaLabia below, go read a big long post!
5: Lots of different practices. Praying is done slightly different between branches, how much of a woman should be covered by hijab is debated between branches, those kind of things.
So now we know where they came from and how they differ.
Why they commit acts of violence and hatred against one another? That's where it all gets very political. Traditionally, Sunni has been the more dominant, anti-revolutionary branch, and in the last 30 years this has been challenged. Shia has been on the rise, foreign interests such as America have gotten involved, the Gulf War and the War on Terror have all contributed. Most of these attacks are explicitly Sunni attempting to supress Shia uprising, or Shia attempting to destabilize Sunni rule.
Iraq and Pakistan are the most notable. Much of it stems from the balance of power shifting away from Sunni towards Shia. Sunni proclaim Shia to be rebels, troublemakers attempting to start a civil war. Shia proclaim Sunni to be an unpopular, corrupt dictatorship and lackey of the American government. Iran is a bee in everyone's bonnet as it's the only country (edit: see TheWierdSide below) with a huge majority Shia population (around 90% Shia, most Muslim countries are closer to 80-90% Sunni) which makes Sunnis grumble and point at it as a bad example of what Shia rule is like. People don't like losing power and influence, ostensibly because it stops them being able to enforce their version of Islam in the form of Sharia law, banning of western influence, etc.
Extremists constantly wade into the mix to do whatever they can for a personal power grab. Accusing the opposition of Zionism and collaborating with western forces is a great way to gain support and discredit political opponents, which is largely rooted in Sunni vs Shia political parties. The Taliban for instance explicitly supported anti-Shia groups in Pakistan in order for Sunnis to give political support in return, helping escalate the violence in the region.
Hell, some Al-Qaeda have called for all Shia to be treated as heretics and put to death.
All in all, it's a bit of a mess. The differences between the groups are in the minutae of religious texts. The violence between the groups really stems more from pure politics of who is in control.
Edited to add: Check out the [ELI5 about Syria](_URL_0_) for a good breakdown of such a conflict playing out in detail right now. Though it's between Sunni and a tinier minority called the Alawites rather than Shia.
Also edited to add: I'm not a muslim myself, just have a friend who converted a few years back, and I made a great effort to understand. Also generally fascinated by theology but no formal education in it. So feel free to correct the hell out of my layman's understanding. Double edit: People have! Read the rest of this thread, there are a few practicing muslims correcting me or adding to what I wrote in more detail if you want that.
Final edit: Read the fucking sidebar. ELI5 has not literally meant "something a five year old can understand" for a longass time.
Double-final edit: Thanks for gold! Between that and a couple of PMs saying I've genuinely opened some eyes and educated people, this discussion has made me feel warm and fuzzy inside. | [
"Shia Islam, on the other hand, is separated into three major sects: Twelvers, Ismailis, and Zaydis. The vast majority of Shias are Twelvers (a 2012 estimate puts the figure as 94% of Shias being Twelvers) to the extent that the term \"Shia\" frequently refers to Twelvers by default. The Twelver Shias are also nota... |
How popular was the name Muhammad before the prophet Muhammad was born? | I spent around an hour looking but couldn't find too much. There is an article from 1936 (so methodologies have definitely changed since then) by Edward Jabra Jurji that claims that the name Muhammad has been in use in Arabia since the first-millennium B.C.E.
Jurji cites *Kitāb al-Ishtiqāq* written by Ibn Durayd (~10th century C.E) that the name Muhammad had been used prior to the birth of the prophet Muhammad in ~570C.E. However, it wasn't a customary name of the Quraysh tribe themselves. Muhammad's grandfather allegedly named him Muhammad so that he would "be praised in the heavens and the earth" (the name Muhammad is derived from the Arabic root ḥ-m-d meaning *to praise* and can literally be seen as the passive participle meaning "the one that is praised").
Just to be safe, I checked the Arabic of *Kitāb al-Ishtiqāq* and found the quote attributed to Muhammad's grandfather as well as a list of others who had been named Muhammad before the Prophet himself.
Jujri also said that the name Muhammad had been found in Southern Arabian inscriptions and cited the *Corpus Inscriptionum Semiticarum* (The Collection of Semitic Inscriptions). However, when I tried to find the references inside of it I could not locate them (Volume 2, Tome 1, #353 and Tome 2, #420). This is probably due to my own inexperience with the Corpus though.
So at least according to Jujri and Ibn Durayd, the name Muhammad had indeed at least *existed* before the prophet was born. However, at least among the Quraysh it does not appear to be very popular. This can be backed up by the fact that in lists of early notable *Ṣaḥāba* (companions of the prophet) there are only [1 or 2](_URL_1_) other Muhammads found. However, after a few generations we can find [137](_URL_0_) with the name Muhammad. As you can see on the second list, a lot of them are "Muhammad ibn xxx al-Ansari" meaning that they were the sons of the residents of Medina who converted to Islam when Muhammad made it his home after fleeing Mecca. Thus, much of the popularity of the name can be attributed to the prominence of the Prophet, and not necessarily that it was a popular name before.
**Sources:**
Jurji, E. J. (1936), PRE-ISLAMIC USE OF THE NAME MUHAMMAD. The Muslim World, 26: 389–391. doi:10.1111/j.1478-1913.1936.tb00898.x
Ibn Durayd, Abu Bakr Muhammad, *kitāb al-ashtiqāq*.
| [
"\"Muhammad\" was the most popular baby boys' name in four regions of England and Wales, including in London and the West Midlands, according to 2013 official statistics. It is also sometimes reported that \"Muhammad\" is the most popular boy’s name in all of Britain, however this is based on combining multiple spe... |
how people get graffiti in ridiculous places | However they have to. Ladders, are common, as is standing on your friend's shoulders. They climb, jump, or hang as necessary. Some even bring rope and rappel down to where they need to get.
If you have Netflix, the documentary "DamNation" has a scene where protesters painted a dotted line and scissors on a dam they wanted removed. You can watch them do it, and it's one of the biggest and most ridiculous places I can think of.
Hanging from a rope with a bucket of paint. That's all there is too it. | [
"Graffiti, a form of street art, typically refers to illegal forms of street art. Public response to graffiti is not always favorable and is often negative. Others say that unauthorized art comes from a desire to spread beauty and make cityscapes more interesting by painting over blank or barren walls.\n",
"Graff... |
What is the history of the Western Sahara? Why does Morocco have (no) legitimate sovereignty over this region? | A good resource is the non-binding ICJ advisory opinion issued in 1975. _URL_1_
It essentially holds that there was some contact between certain nomadic Saharawi tribes and Morocco, but not enough to establish sovereignty or have them be considered subjects of the crown. That said, advocates for Morocco either decry the advisory opinion or interpret that limited contact as proof (despite the fact the opinion says otherwise).
Another landmark document in the conflict is the Madrid Accords, when Spain was in a hurry to give up the territory. _URL_0_ | [
"The area of Western Sahara is home to the Saharawi people who became Spanish subjects when Spain colonized the area in 1884. The United Nations (UN) became involved with Western Sahara when the UN asked Spain on December 16, 1965, through a General Assembly resolution, to decolonize the former Spanish territory. K... |
Is it possible to detonate a thermonuclear device without a fission primer? | Yes. Most current fusion experiments use lasers, no they would not work for a weapon systems. It would be possible to use lasers to detonate a thermonuclear device, but it would be a very big system using lots of power. The energy has to come from somewhere. Fission is nice because it is the most energetic reaction we can produce, it is very high efficiency and puts lasers to shame in terms of pressure and heat. Where you'd need a whole modern physics lab to just get sustained fusion, a small, footlocker sized device with a shaped charge around some fissile material around fusion material would be all it takes, with a control system to kick off the charges right, to achieve thermonuclear fusion.
Extreme magnetic fields can also sustain nuclear fusion, but again, it would be a huge amount of energy to push this anywhere near explosive amounts of energy. So much so that you'd probably need a fission reactor generating electricity to power the magnets (or lasers) thereby effectively just moving the fission out of the simple device and into the complex powerplant.
There are no chemical ways of generating the incredible amounts of energy required to fuse a meaningful amount of hydrogen rapidly enough to have it all fuse at once, rather than slowly.
Fusion's trouble is that as it occurs, it heats things up, and makes it harder for further fusion to occur in a sample, so you need more pressure and energy, which just makes it harder and harder. Achieving sustained positive delta energy fusion has been a subject of international research since, like, the 70s. It would be an incredible tool for generating electricity.
I suppose if something was to work. It could be gravity, if you were to. Make something massive enough that the pressure of the fusion material on itself was enough to fuse, you'd be able to sustain it, maybe even explosively, but then the issue is if it is massive enough to do this how is it transported and aren't we just talking about stars at this point.
There's no conceivable way to sustain fusion without fission for the purpose of weapons, if it was possible we'd have it in power plants. | [
"All current thermonuclear weapons use a fission bomb as a first stage to create the high temperatures and pressures necessary to start a fusion reaction between deuterium and tritium in a second stage. For many years, nuclear weapon designers have researched whether it is possible to create high enough temperature... |
why do cribs get recalled all the time? | It's easy to make a safe crib. Take hard, dense wood, shape it to fit snuggly, and use high quality fasteners.
The problem is that this is expensive. Given the choice, most people will buy the cheaper option if the product performs the same function. To chase sales, companies have to find ways to make things cheaper.
So companies try to reduce the cost of their products with cheaper materials and labor so they are barely functional. This generates the most profit (cheaper = more people buy it over expensive options and they make more money per sold piece). Often times, this sacrifices safety because they didn't need to test for it (no regulations) or they didn't want to test for it due to cost. For more unscrupulous companies, recalls cost less than the lost profit if they didn't make the product. | [
"Some older cribs contained a \"drop gate\" (or \"drop side\"), a side which lowers to ease the process of putting the child into the bed, but can be raised again to restore the integrity of the enclosure. However, assembly problems and malfunctioning hardware on drop gates can cause the formation of gaps, which ha... |
why do laptops use fans -loud, annoying fans- while an iphone/ipad can run processor heavy apps for hours with no fan and not get hot? | cause laptop cpu's are more powerful than ipad processors. tablet and smartphone cpu's sacrifice processing power for less heat dissipation. | [
"In contrast to desktop PC, laptop and notebook typically do not have power supply fans or video card fans, generally use physically smaller hard drives and lower power components. However, laptop CPU fans are usually smaller, so may not necessarily be quieter than their desktop counterparts - and limited space, li... |
How were the Romans able to replenish so much of their manpower despite devastating losses in battles such as Cannae? | I take it your question is less about Roman logistics and more about the specific fact that the forces at Cannae were effective crushed as a standing army, and how did Rome recover from something like that?
First thing is first, with Cannae specifically there were very real and very profound consequences. Several city-states defected from Rome and turned to Carthage. Most estimates put Rome's total loss at over 70,000 with almost 40,000 of those being straight up casualties.
The Second Punic War devastated Rome.
So what was their response?
Well, for lack of a better term, conscription.
The Carthaginians attempts to parley after Cannae and it was rejected. Instead, Rome conscripted *everyone* they could get their hands on, including peasants with no ties to land, as well as slaves. Furthermore, Rome flexed its legendary resilience by quickly adapting military doctrine and tactics, developing ways to counter Hannibal's classic flanking technique and changing their strategy to *never put that many people under one command again*, instead relying on much smaller, independent forces to face future foes.
In short, Rome survived because it was never too proud or too stubborn to find a way to make things work. Making the best of what they could gather, and getting mad rather than despairing. They took on totally new tactics and exploited the weakness of Carthage; attacking everywhere Hannibal was not. | [
"Nevertheless, the Hannibalic War stretched Roman military manpower to the limit. Of their 400,000 available manpower, the Romans kept at least 200,000 men in the field, in Italy and overseas, continuously in the period 214–203 (and 240,000 in the peak year). In addition, c. 30,000 were serving in the Roman fleets ... |
if a company has a labor strike, why can't they just fill their positions with temporary workers and let the strikers just continue to strike in perpetuity? | Those temps are called scabs, and it is not an uncommon occurrence. It definitely undermines their relationship with their regular work force, and often times results in violence, especially towards the scabs. | [
"In the U.S., unlike the UK and several other countries, the National Labor Relations Act (NLRA) provides a legally protected right for private sector employees to strike in order to gain better wages, benefits, or working conditions without the threat of termination. However, striking for economic reasons (i.e., p... |
why do the carbons in graphene only have 3 bonds? | Each carbon atom in graphene is sp2 hybridized and bonded to three other carbon atoms via sigma bonds. The remaining p orbital is perpendicular to the plane of the carbon atoms, but it is most certainly not non-bonding; in fact, these p orbitals give graphene its remarkable properties.
The electrons in the aforementioned p orbitals are delocalized due to resonance (or molecular orbitals, according to MO theory), similar to benzene, but on a much greater scale. Thus, there are partial double bonds in addition to the sigma bonds, and overall, each carbon has four bonds. | [
"Carbon is known to have electron configuration of 1s 2s 2p. As the only unpaired electrons it has are the two in the 2p orbitals, carbon is theoretically only capable of forming 2 single bonds. However, this is definitely not true as in reality, each carbon in ethene forms 2 single bonds and 1 double bond whereas ... |
why is it so hard for reddit to keep the site from crashing | Buying gold more often keeps it from crashing. And if you've noticed they don't often meet the daily goal. | [
"Major news sites or corporate websites are typically engineered to serve large numbers of requests and therefore do not normally exhibit this effect. Websites that fall victim may be hosted on home servers, offer large images or movie files or have inefficiently generated dynamic content (e.g. many database hits f... |
How did Polish pilots come to fly in the RAF during the Second World War? | After the German and Soviet invasions, substantial numbers of Polish military personnel escaped to neutral countries, primarily Romania, Hungary, Lithuania and Latvia, where they were interned. Air force personnel mostly evacuated to Romania, from where significant numbers made it to France either overland via Yugoslavia and Italy (still neutral at the time), or by boat; the internment camps weren't very closely guarded, and the Polish government in exile worked hard to assist with transport.
Polish air force units were then formed in both France and Great Britain (around 7,500 personnel in the former, 2,500 in the latter), though neither were particularly enthusiastic about it, the French mostly assigning obsolescent aircraft, the RAF forming two bomber squadrons flying Fairey Battles. Following the fall of France, Polish units were evacuated to the UK from western French ports in Operation Aerial, allowing the RAF to form a further two bomber squadrons and two fighter squadrons. | [
"After being evacuated after the defeat of France, Polish fliers had an important role in the Battle of Britain. At first, the Polish pilots were overlooked, despite their numbers being high (close to 8,500 by mid-1940). Despite having flown for years, most of them were posted either to RAF bomber squadrons or the ... |
what is the core of the earth made of, how does it stay molten, and what would the impact of it cooling be? | It has a solid iron and nickel core surrounded by a liquid outer core mostly of the same metals. It stays molten due to the immense pressure of all the mass above it, generating heat.
The liquid core is believed to be the source of the planet's magnetic field. If you were to magically cool it and harden it, the planet would lose much of its magnetic field which would expose the surface to significantly more solar radiation, likely resulting in the planet becoming much less if at all habitable. | [
"The early formation of the Earth's dense core could have caused superheating and rapid heat loss, and the heat loss rate would slow once the mantle solidified. Heat flow from the core is necessary for maintaining the convecting outer core and the geodynamo and Earth's magnetic field, therefore primordial heat from... |
why do we still laugh at jokes we have heard before? | If I hide behind your dresser and pop out and scare you, why would I be able to repeat that effect? Your mind or body still transmit information, whether it's new or old information is irrelevant. It still triggers those emotions in the same way. Not to mention mediums of entertainment are usually enjoyed with a heavily suspended disbelief - so we allow ourselves to forget we know what will happen the same way we allow ourselves to forget Johnny Depp is an actor and not actually a pirate or a guy with scissors for hands. | [
"Laughter researcher said: \"Laughter is a mechanism everyone has; laughter is part of universal human vocabulary. There are thousands of languages, hundreds of thousands of dialects, but everyone speaks laughter in pretty much the same way.\" Babies have the ability to laugh before they ever speak. Children who ar... |
Are there any moons we know of that rotate the planet at the same rate that the planet spins? | There is no planet like this, but [Pluto](_URL_2_) and its moon [Charon](_URL_1_) have this property. They are mutually [tidally locked](_URL_0_). | [
"The Earth and its Moon are one example of this configuration. Today, the Moon is tidally locked to the Earth; one of its revolutions around the Earth (currently about 29 days) is equal to one of its rotations about its axis, so it always shows one face to the Earth. The Moon will continue to recede from Earth, and... |
how does clicking a pen to the "closed" position prevent it from drying out? | They're put in the "closed" position to prevent them accidentally writing all over you. The ink comes out when the ball (in the ball-point) rolls and exposes it. | [
"Pen clicking is repeated pressing of the button of a retractable pen which produces a clicking sound. In its normal use, the button is only pressed when someone wants the nib of the pen to be exposed so they can write with it. This makes a noise, which varies in tone, dynamic and timbre depending on the size and m... |
what is a "mainframe" and why are people always trying to hack into it in movies? | Mainframes are what we'd think of as big corporate servers or supercomputers.
If you roll the clock back not that many years anything important was stored on a company mainframe - usually they were custom built for big database applications. The same basic role still exists and IBM and HP and Dell and a few others sell equipment for this, but it no longer requires custom hardware to run on, so the terminology has largely fallen out of use. Now we just call them 'servers' because they're just a particular case of 'server', of which there are many varieties.
The IBM zEnterprise series are still occasionally branded as 'mainframes', or called servers, and then run in the 100k - > multiple millions price range.
edit: Big database servers don't *require* custom hardware, but IBM produces custom CPU's and there are things like custom casings and cooling for it. That's generally beneficial, but you can get by using generic server parts too. | [
"The human operator of Mainframe is perceived by its denizens as a distant, impersonal, deity-like figure. Often destructive, it subjects the city to Game Cubes and assumes various avatars to do deadly battle with the unfortunates trapped within them. In layman's terms, the User is a computer owner that enjoys play... |
how do sea creatures manage to live in water that others regularly poop in, without getting sick or dying? | As an analogy how do we manage to not getting sick breathing the air that someone somewhere is sneezing in?
There are creatures in the water who eat that poop and break it down so eventually the poop becomes harmless.
In the short time : there is dilution (even humans swimming in the river that collects poop water ) don't get sick.
And there is biochemistry. Bacteria in human poop isn't as damaging to some sea creatures as it is to humans. | [
"Benthic fish, sometimes called groundfish, are denser than water, so they can rest on the sea floor. They either lie-and-wait as ambush predators, at times covering themselves with sand or otherwise camouflaging themselves, or move actively over the bottom in search for food. Benthic fish which can bury themselves... |
Who did the U.S./Nato support in the Bosnian War? | 1. Why did the US/NATO chose the sides they did?
You had a well equipped army/force (various kinds of armored vehicles, artillery, even a small airforce, etc) on one side, the Army of the Republika Srpska (VRS), which were essentially the units of the previous state force, the Yugoslav Peoples Army (JNA), in which Serbs from Bosnia and Herzegovina served, against lightly armed Bosniaks and Croats, who in the beginning didn't even have real defence forces. Now the VRS was able to conquer about 70% of the whole of Bosnia in the course of several months. The VRS conducted ethnic cleansing, genocide and various other crimes against humanity on their territorry against Croats and Bosniaks. The pressure for the western governments to intervent grew over the course of the war. In 1995 they had finally to do something in Bosnia (in this year there were several big massacres which got a lot of publicity in the western media e. g. Srebrenica with 8000 civilians dead). So they helped the recently formed Army of the Republic of Bosnia and Herzegovina (Bosniak and Croat forces) with a bombing campaign.
2. Why does Kosovo not join Albania?
Well for the moment this is impossible, because Serbia views it still as a rebellious province. And culturally/religiously Kosovo was an important serbian region, with the oldest churches and monasteries. Maybe at some point in the future Kosovo will join Albania, but that's just speculation.
3. Why does not the same happen in the US?
Well the situation is completely different. Yugoslavia was a multinational/ -ethnic/ -religious state that was only held together through the charisma of Tito and nothing else. It was not really a natural construct and every now and then bloody wars were fought in the Balkans between the ethnic groups and the nations (1912, 1913, 1914-1918, 1942-1945 and finally 1991-1999). Now as soon as Tito died in 1980, the problems came to the surface and it started to break apart. | [
"The Bosnian War was an international armed conflict that took place in Bosnia and Herzegovina between April 1992 and December 1995. The North Atlantic Treaty Organization (NATO), after popular pressure, had decided to intervene in the Bosnian War after allegations of war crimes against civilians were made by vario... |
human consumption of other animal's milk. | Milk is pasteurized (heated quickly to kill germs) before being sent out to market. This has nothing to do with lactose intolerance. Lactose is a type of sugar naturally present in milk, and it's that sugar that gives some people stomach problems when they drink it.
For most of history, all mammals became lactose intolerant after being weaned. Several thousand years ago some human developed the ability to keep drinking milk after being weaned, which gave them a new, calorie rich food source that decreased their chances of starving, therefore increasing their chances to reproduce.
So milk isn't bad for you, but it's also not necessarily good, especially whole milk, which is high in fat. If you're eating a balanced diet you don't *need* milk, but if you like it and budget for the calories it's fine. | [
"Humans first learned to consume the milk of other mammals regularly following the domestication of animals during the Neolithic Revolution or the development of agriculture. This development occurred independently in several global locations from as early as 9000–7000 BC in Mesopotamia to 3500–3000 BC in the Ameri... |
how are new "4k" tv's able to plat 4k content with old processors, but my new i5 computer lags with 4k content? | My guess would be graphics performance of the chips. On your computer your GPU rather than your CPU will handle, by and large, the rendering of the images whereas TVs will have chips designed for rendering images and little else. If you set them both to find the billionth prime number your laptop would win hands down. If you had a animators/video editors' PC then the rendering would be no problem.
That's my guess anyway. | [
"In comparison to 4K UHD (38402160), the 16:9 5K resolution of 51202880 offers 1280 extra columns and 720 extra lines of display area, an increase of 33.% in each dimension. This additional display area can allow 4K content to be displayed at native resolution without filling the entire screen, which means that add... |
why can't divers fly after diving? | You're right: the main gas involved is nitrogen. Basically, when we dive very deep, there's more pressure on our entire body, including our blood. More nitrogen dissolves into our blood than it would at a lower pressure (e.g. at sea level). If we come up too quickly from very deep, we can get "the bends," which is a syndrome of pain and potentially organ damage from all that extra nitrogen un-dissolving and forming bubbles in our blood vessels. Blood has trouble flowing past those bubbles.
The problem with flying is that it lowers the pressure much more than just being at sea level (our ears popping is another effect of the pressure drop). This means there's another chance for nitrogen to un-dissolve and create bubbles in our blood vessels and tissues. Basically, you're creating a situation just like if you went from very deep in the water to the surface too quickly. | [
"Divers operate in an environment for which the human body is not well suited. They face special physical and health risks when they go underwater or use high pressure breathing gas. The consequences of diving incidents range from merely annoying to rapidly fatal, and the result often depends on the equipment, skil... |
the revolutionary war; what caused it, and how was it regarded from an english perspective? | It started because King George was taxing the colonies above and beyond reason. The English people thought the colonists were being ungrateful. | [
"In the 1770s, the American Revolutionary War began with the passage of the Intolerable acts, and the battles of Lexington and Concord, and Bunker Hill. von Fersen told Beaumont that in France \"it is the fashion to rhapsodize over the Americans' rebelliousness against England\". France had officially declared war ... |
Were there any economic interactions between the United States and the USSR during the Cold War? | In 1972 the USSR bought 440 million bushels of wheat from the US, with more purchases in following years. Here's a paper from the St Louis Fed -
_URL_0_ . I'll never find the link, but in the late 80s/early 90s The Economist made an editorial comment about Russia being in the grain market again, due to "70 years of worse-than-expected winter weather in the Ukraine." | [
"Although the Union of Soviet Socialist Republics (USSR) and the United States co-operated during World War II, the tensions between the two superpowers over economics (Communism versus capitalism), political authority (totalitarianism versus liberalism) and the fate of Europe (East versus West) escalated into the ... |
how does germany not have a crazy high rate of alcoholism and related crime when it has relaxed liquor laws? | People who are happy and secure generally don't drink to excess, or when they do, don't commit crimes. Germany has a strong economy, a strong social safety net, widely available substance abuse treatment, and a rather effective police and judiciary.
As various attempts at alcohol prohibition worldwide have proved, people will always get alcohol if they want it. It's a simple chemical any idiot can make at home. The way to reduce alcohol-related crime and health problems is to attack the things that cause problem drinking. Namely insecurity, anxiety, and untreated mental/psychological disorders. | [
"The German laws regulating alcohol use and sale are mostly focused on youth protection. In contrast to many other countries, the legislation is not designed to keep young people away from alcohol completely, but rather to teach them an appropriate approach to alcohol consumption. Alcohol consumption of all sorts, ... |
what does it mean to "soft reboot" my android device? | Soft reboot is when you actually go through the OS and choose the "Reboot" or "Restart" option, as opposed to a hard reboot, which is physically(or using the 5 second switch that is standard on most computing devices now) cutting the power and then turning it back on again. | [
"The official Android 2.2 update prevents rooting the device, disallowing loading of custom ROMs. Root access can be restored through a multi-step process that requires the device to be connected to a computer.\n",
"Normally, reconfiguring an FPGA requires it to be held in reset while an external controller reloa... |
tesla’s fascination with the numbers 3 6 9 | I remember from my studies that in middleage the 3 was a link to Catholic God (the trinity) and so 6 because is two times 3 and 9 because is three times 3, You can find this obsession with number in Dante's Divina commedia. | [
"9 is a composite number, its proper divisors being and . It is 3 times 3 and hence the third square number. Nine is a Motzkin number. It is the first composite lucky number, along with the first composite odd number and only single-digit composite odd number.\n",
"Writers/producers Aron Coliete and Joe Pakaski h... |
In what ways were European states forced to reform in order to defeat Napoleonic France? | The biggest change, militarily speaking, was in the size of militaries involved before the Wars of the French Revolution and after. To give you an example, the British army, on the eve of the American Revolution in 1775 was something like 48,000 soldiers over its entire empire. For a sense of comparison, Wellington had about 30,000 British soldiers (Not counting allied soldiers) just for the Battle of Waterloo in 1815. At the [Battle of Leipzig](_URL_1_) in 1813, the French army alone suffered more casualties than soldiers existed in the British army only a few decades prior. The French concept was called the [levee en masse](_URL_0_)
Basically, war on this scale was completely unprecedented in history, and the necessity of raising such large military forces required changes in the states that supported them. In Britain, you see more influence going to the House of Commons along with greater governmental centralization. Soldiers also had to be supplied, so you needed vastly increased industrial output to produce the weapons, ammunition, clothing, and so on that they all required.
All in all, I've always thought that the Napoleonic Wars did away with the last real vestiges of European feudalism, at least in Great Britain, and after 1815, we see something approaching what we could consider the modern centralized state. | [
"The Napoleonic Wars brought radical changes to Europe, but the reactionary forces returned to power and tried to reverse some of them by restoring the Bourbon house on the French throne. Napoleon had succeeded in bringing most of Western Europe under one rule. In most European countries, subjugation in the French ... |
How did nobility/royalty prove who they were while traveling? | Could you specify what time period you're thinking of? It would vary a lot from civilization to civilization, and era.
There were a lot of things that could be used to distinguish people that would not have been easily replicated. Certain insignia like a signet ring, sceptre, or crown. Or official papers bearing the seal of their government, monarch, or whatever. Other times the size of a person's retinue would make it clear that they were a person of note.
Now adays a diplomat presents his credentials to the other country's head of state, who then acknowledges them and accepts that diplomat as an emissary. | [
"Nobles were born into a noble family, adopted by a noble family - this was abolished in 1633 - or achieved noble rank through Ennoblement by a king or Sejm for reasons such as, bravery in combat, services to the state, etc. Yet this proved to be the rarest means of gaining noble status. Many nobles were, in fact, ... |
when did most people in England start thinking of the royal family as their native leaders instead of foreign invaders? | This is a very tricky question because it's not clear which royal family you're discussing. The last time the dynasty changed by foreign invasion was in the Glorious Revolution of 1688, and there was a *very* widespread effort among the elites in England, especially the Whig faction, to invite in the House of Orange and conspire against the Stuarts. Stuart loyalists, or Jacobites, were the main group that thought of the House of Orange and, later, the House of Hanover as foreign, but the Jacobites were deeply limited in their support due to the House of Stuart's association with A. Catholicism and B. Scottish nationalism and C. the French monarchy (the Bourbons were *very* close cousins to the Stuarts and Louis XIV would become the Stuarts' biggest sponsors), which meant that even the English Tories that might have had closet sympathy with them would find the sort of people that backed the Stuarts very difficult to work with. The House of Hanover, which inherited the throne after Queen Anne died childless, was not very popular at first: George I barely spoke English and had little interest in this distant island.
Both France and Spain continued to recognize James II's son "James III" as the rightful king of England, Scotland, and Ireland, and James "The Old Pretender" attempted an invasion of Scotland in 1715 to reclaim the throne, but was swiftly driven off. During the reign of George II, James's son Charles, or "Bonnie Prince Charlie" or "The Young Pretender," attempted his own somewhat more credible invasion in 1745 that attracted support from disaffected Scottish people and Catholics across the United Kingdom, but they were decisively smashed at the Battle of Culloden. After Culloden in 1745 the idea of a Jacobite Stuart restoration became utterly implausible and the House of Hanover was clearly not going anywhere. There were still sympathetic old Jacobites, and there are even a few today, but there hasn't been a serious prospect of a restoration of the Stuart monarchy since 1745 (and, more realistically, since 1689). | [
"Later monarchs who also have carried sobriquets as \"relatives\" of Europe include Queen Victoria of the United Kingdom (\"grandmother of Europe\"), Christian IX of Denmark and Nicholas I of Montenegro (both respectively \"father-in-law of Europe\"). These late 19th and early 20th century sobriquets are however pu... |
why do dogs like tummy rubs but cats tease you with it but then attack you? | A lot of cats (not all - I've got one that rolls on her back and meows at me if I *don't* rub her belly) don't like having their belly rubbed.
Them rolling on the back is a trust thing - they're exposing their most vulnerable parts to you and trusting you not to take advantage of that. | [
"Touching, petting, and stroking a cat can stimulate the release of chemicals called cytokines, which in turn signal the brain to release natural painkilling chemicals called endorphins. Cats may show their pleasure during massage by purring and gently kneading their paws.\n",
"Cats sometimes repeatedly tread the... |
Why did it take semi automatic weapons so long to be developed? | Self loading rifles (firearms callable of firing a round, extracting and loading a new one by itself) are a very complex mechanical enterprise that requires high tolerances and advanced knowledge of metallurgy. There are a few thing you need for a self loader. Firstly you need a method of loading the next round which the nature of muzzle loading muskets made this task impossible, plus powder had to be loaded in separately from the round adding additional complexity to self loading. A magazine with a spring-loaded follower may seem obvious to you but this took time to develop. Many repeater rifles used tubular magazines in the gun which prevented the use of pointed bullets.
Another must is a strong receiver that can withstand high pressures. One shot produces a lot of pressure but automatic or even semi-automatic fire prevents the pressure in the chamber from having time to lower. This is why modern rifles use intermediate cartridges (7.62x39, 5.45x39, 5.56x45) and not the large beefy rifle cartridges of older rifles like the Mosin or Lee-Enfeild (7.62x54, .303); those cartridges produce pressure that too high for controllable, useful automatic fire.
Another reason independent from mechanical problems was the beliefs of most armed forces until The First World War. It was a common belief that soldiers with access to magazine fed bolt action rifles would fire wildly and waste ammunition. Now try to convince them that soldiers with weapons that load rounds by themselves are a good idea. Self loaders may seem like the obvious way to go but their development took a lot more then the simple idea of rapid fire weapons.
Sources
T.L. McNaugher "M-16 Controversy":
Skennerton, Ian "Small Arms Identification Series" | [
"The world's first automatic rifle was the Italian Cei-Rigotti. Introduced in 1900, these 6.5mm Carcano or 7.65×53mm gas-operated, selective-fire, carbines attracted considerable attention at the time. They used 10-, 20- and 50-round box magazines. The Cei-Rigotti had several failings, including frequent jams and e... |
why can cows and other animals constantly produce milk but humans cannot? | All female mammals only produce milk after being pregnant. If you're thinking of dairy cows, they "constantly" produce milk because they are constantly being inseminated, going through pregnancy, giving birth, then having their babies taken away (and killed if male), and being artificially milked for human consumption. Then the cycle repeats until they aren't seen as being productive anymore, then they're killed. The same thing *could* be done to human women, but it would break a whole bunch of different laws (plus, you know, ethics) .... | [
"Although all mammals produce milk to nourish their young, the cow is predominantly used throughout the world to produce milk and milk products for human consumption. Other animals used to a lesser extent for this purpose include sheep, goats, camels, buffaloes, yaks, reindeer, horses and donkeys.\n",
"The female... |
How is action potential measured in a cell? | Hi there, as a biochemist studying ion channels I hope I can provide enough information to satisfy you and your student, or even better, whet your curiosity for more.
As to your question about how we measure membrane potentials. We take a glass electrode and stab a cell with it, then measure the voltage between the electrode (now continuous with the inside of the cell, and a reference electrode outside the cell. There is a lot more sophistication to the technique and many many variations that allow for extremely careful and accurate measurements of cells all the way down to the activity of a single protein in the membrane, but basically that's what we do. This technique is called "Patch Clamp" (technically what I described is a subset that technique called "Whole cell" patch clamp). [ref1](_URL_0_)
The technique was first developed in squid because they had a giant (meaning visible to the naked eye) axon that could be patch clamped using the tools available at the time.
it isn't exactly that there are more ions outside the cell than inside the cell. What is more strictly true, is that for each different type of ion (at least the major ones used to generate action potentials: K+ Na+ Ca2+ and Cl-) the cell uses up some of its energy in the form of ATP to establish an electro-chemical gradient across the membrane.
The gradients established are:
For Sodium (Na+) about 14 mM (millimolar) inside, and about 145 mM outside.
For Potassium (K+) basically the opposite, about 150 mM inside and 4 mM outside
For Calcium (Ca2+) about 70 nM (that's 0.00007 mM) inside, and 2 mM outside.
For Chloride (Cl-) about 10 mM inside and 110 mM outside.
The concept that you need to grasp for action potentials in cells is that it is all controlled by proteins in the cell membrane. The cell membrane itself is made up of lipids and are extremely impermeable to ions. Ions only cross from inside to outside (or vice versa) if there is a protein called an ion channel in the membrane that opens to allow ions through. Additionally these ion channels can be extremely selective, meaning that when they open, only one type of ion can go through them.
So thinking about the system. We have a charged species separated by an impermeable membrane, that sets up an electrical potential, and when an ion channel opens current flows according to that potential.
I'll keep the context to the action potential in a neuron. [ref2](_URL_1_)The rules of electrical impulses in biology follow the same laws as in physics, ohms law (voltage = current x resistance), but with a couple twists to make the units/scale and conditional factors (temperature, gas constant, Faraday constant) to fit the range that works best in biology. Ultimately we use these factors in an equation called the Nernst equation. This give us: Membrane potential of a given ion = -((temperature x gas constant)/(Faraday Constant x Charge on ion)) x natural log((concentration of ions outside the cell)/(concentration of ions inside the cell). [ref3](_URL_2_)
If you take the concentrations of ions I listed above and plug them into the Nernst equation, you'll see that for Na, the membrane potential is about +60 mV (millivolts), for K+ the membrane potential is about -98 mV and for Ca2+ the potential is about 137 mV. Since at "rest" most/all of the Na+ and Ca2+ channels are closed, the resting membrane potential is controlled mostly by K+ channels (which are open), and thus the cell membrane potential is around -60.
Action potentials are triggered when a chemical stimulus (such as presence of a ligand (something that binds to a protein and turns on its activity) or a neurotransmitter (a specific subset of ligands) binds to an ion channel (in this case a Na+ or Ca2+ channel) and triggers it to open. When that happens, lets say for Na+ channels, the Na+ will now be able to cross the membrane and the membrane potential will move towards that of Na (+60 mV). At some threshold, the membrane potential becomes different enough from the resting potential, that other channels which are sensitive to changes in voltage, also activate. Suddenly many many channels (Na+ and Ca2+ type) are open and the the membrane potential rapidly depolarizes in what we refer to as an action potential.
I did skip over a HUGE amount of detail, caveats, and specifics for this background, so please feel free to ask follow up questions, or for clarification (also if I didn't actually answer your question let me know and I'll try again).
*edit, added refs | [
"The course of the action potential is determined by two coupled effects. First, voltage-sensitive ion channels open and close in response to changes in the membrane voltage \"V\". This changes the membrane's permeability to those ions. Second, according to the Goldman equation, this change in permeability changes ... |
what happens when a banana is bruised | When part of the fruit starts to decay it releases a chemical called ethylene which signals other parts of the fruit that it's time to die as in the natural process of nature. Bananas also contain an enzyme called polyphenol oxidase, and the oxygen present in the air readily reacts with the enzyme found in the bananas. This oxidation reaction is seen as a rusting or browning of the banana's surface. | [
"Banana streak was first identified in 1958 in Côte d’Ivoire and is now in many countries in the tropics. The primary symptoms of disease are chlorotic streaks on the banana leaves and splitting of their pseudostem. In later stages of the disease, these streaks may become necrotic, and the heart of the pseudostem m... |
are fabrics like linen really anti-microbial? | An educated guess is that either the fabric has been treated with something, or that the fibers are woven tightly enough together that bacteria and microbes have difficulty passing through it. So while it is "anti-bacterial" it doesn't kill them on contact.
Here is an album of someone showing the difference of a lab coat's weaving and a shirt, with enough magnification that you would be able to see individual skin cells. You can see how bacteria would have difficulty passing through something finely woven.
_URL_0_ | [
"BULLET::::- Anti-microbial finish causes a fabric to inhibit the growth of microbes. The humid and warm environment found in textile fibers encourages the growth of the microbes. Infestation by microbes can cause cross-infection by pathogens and the development of odor where the fabric is worn next to skin. In add... |
If no information can be transmitted via quantum entanglement, how did we discover it in the first place? | Quantum entanglement was first hypothesized in a thought experiment originally thought out as an argument against the Copenhagen Interpretation of quantum mechanics. This thought experiment is now known as the [EPR paradox](_URL_1_) named Albert Einstein, Boris Podolsky and Nathan Rosen after the three people that proposed it. The thought experiment wasn't in direct disagreement with quantum mechanics, but it seemed to defy physical causality with by what Einstein famously referred to as "spooky actions at a distance". This thought experiment ultimately led to the discovery of quantum entanglement and it has later been directly or indirectly confirmed by for example [Bell's Inequality](_URL_0_). | [
"Peres claimed that the resolution to the Einstein–Podolsky–Rosen puzzle of quantum entanglement, often called \"spooky action at a distance\", lies in the fact that quantum states are information. Peres wrote, \"Information is not just an abstract notion. It requires a physical carrier, and the latter is (approxim... |
How high can roller coasters be built? | roller coasters are already being limited in the max Gs they induce
4-6 Gs more than briefly can result in loss of consciousness )
creating a taller one increases the cost a lot for support - with no "real" benefit beyond a "wow" factor (which, admittedly, IS something)
somewhat credible link about max Gs on various coasters
_URL_0_
| [
"Original plans for the ride showed a SLC ride 265 feet (81 metres) in height, which would have made it the tallest Inverted roller coaster in the world and seventh tallest overall. The plans were scrapped due to complaints from local residents, limiting the height to a maximum of 180' (54.60m).\n",
"High Roller ... |
When did people start snorting cocaine? | I don't know when people started snorting cocaine. In the late 19th century, the drug would either be taken orally, or injected intravenously. Think Sherlock Holmes, with this famous scene from the Sign of Four:
> Sherlock Holmes took his bottle from the corner of the mantel\-piece and his hypodermic syringe from its neat morocco case. With his long, white, nervous fingers he adjusted the delicate needle, and rolled back his left shirt\-cuff. For some little time his eyes rested thoughtfully upon the sinewy forearm and wrist all dotted and scarred with innumerable puncture\-marks. Finally he thrust the sharp point home, pressed down the tiny piston, and sank back into the velvet\-lined arm\-chair with a long sigh of satisfaction.
This is the famous "seven percent solution," though a three percent solution became preferred as it was thought to have fewer side effects.
Sigmund Freud was one of cocaine's most ardent popularizers. Freud himself did not snort the drug, but rather drank it in a solution. Freud's famous essay is called Über Coca, and he's very explicit about how he took the drug. From section V \(the Effect of Coca on the Healthy Human Body\):
> The first time I took 0.05cg. of *cocaïnum muriaticum* in a 1 & #37; water solution was when I was feeling slightly out of sorts from fatigue. This solution is rather viscous, somewhat opalescent, and has a strange aromatic smell. At first it has a bitter taste, which yields afterwards to a series of very pleasant aromatic flavors. Dry cocaine salt has the same smell and taste, but to a more concentrated degree.
He notes that later in the essay, higher concentrations cause some stomach upset, so he dissolved his cocaine in soda water.
I should not that experimenting with medications on yourself in this period was not unusual \-\- John Snow would regularly inhale his own anesthetics and mark their effects \(which likely led to his early death\), and to make another Holmes connection, Sir Arthur Conan Doyle's first academic publication was in the BMJ on self\-poisoning with escalating doses of gelsemium.
Cocaine was purified in the 1850s, and in the first half century of its existence, there was considerable excitement about its effects \(and lack of side effects\). It was thought to be particularly useful to treat morphine addiction \(think William Halstead, who basically switched from morphine to cocaine\). Cocaine was found in a number of over\-the\-counter products, most notably coca cola. | [
"At the beginning of the 20th century, cocaine began to be linked to crime. In 1900, the \"Journal of the American Medical Association\" published an editorial stating, \"Negroes in the South are reported as being addicted to a new form of vice – that of 'cocaine sniffing' or the 'coke habit.'\" Some newspapers lat... |
Why are African Americans usually lighter skinned than Africans? | > My thought is that it is a result of interbreeding with light skinned people
Yup.
([ref](_URL_0_)) | [
"Within the African-Americans population, the amount of African admixture is directly correlated with darker skin since less selective pressure against dark skin is applied within the group of \"non-passing\" individuals. Thus, African-Americans may have a much wider range of African admixture (0–100%), whereas Eur... |
I've always heard that in the middle ages, people drank beer/mead instead of water because the water wasn't clean. Is this true, and if so, why wasn't everyone drunk/dehydrated all the time? | Not a historian, but a homebrewer and history enthusiast. The water is boiled in the process of making beer so this is why it was safer to drink than the water as any nasties in the water would be killed during this process. As for being drunk/dehydrated all the time this didn't happen because most of the beer consumed daily would have been small beer which would have been of a much lower alcohol content. It would have been made from the second or possibly third runnings from the grains. The first runnings would extract the largest amount of sugars from the grains and would have been used for making beer for export or special occasions (Belgian Tripel, Imperial Stouts, etc.). The grains would then be mashed again and the runnings from this would contain significantly less sugar. The amount of sugar in your wort is directly proportional to the amount of alcohol in you finished beer as this is what the yeast will eat and produce alcohol and CO2 as waste products. With the lower sugar content you end up with a much lower alcohol content suitable for everyday drinking without becoming too inebriated or dehydrated. | [
"Water as a neutral table beverage did not appear in Europe until well into the Industrial era, when efficient water purification could ensure safe drinking water. All but the poorest drank mildly alcoholic drinks on a daily basis, for every meal; wine in the south, beer in the north, east, and middle Europe. Both ... |
How did Cavendish avoid/account for the gravitational attraction of the Earth affecting his experiment to determine G? | It's rather easy to make the rods perfectly tangential to earths gravity by making them level. Just adjust the setup so that the weights don't rotate at all when left alone. | [
"The Cavendish experiment, performed in 1797–1798 by British scientist Henry Cavendish, was the first experiment to measure the force of gravity between masses in the laboratory and the first to yield accurate values for the gravitational constant. Because of the unit conventions then in use, the gravitational cons... |
Is it possible for an earth-like planet to have a ring around it? | Yes, terrestrial planets can have rings. | [
"A ring system is a disc or ring orbiting an astronomical object that is composed of solid material such as dust and moonlets, and is a common component of satellite systems around giant planets. A ring system around a planet is also known as a planetary ring system.\n",
"BULLET::::- In the Ringworld series by La... |
Did JFK actually say he wanted to "Shatter the CIA into a thousand pieces and scatter it to the winds"? | Vincent Bugliosi (former prosecutor in the Charles Manson trial, author of a careful, skeptical book about the Kennedy assassination), writes:
> Whatever the CIA's short laundry list of dissatisfactions (some merely illusory, some real) with Kennedy, as I discuss later in the anti-Castro Cuban exile section of this book, Kennedy was highly disturbed with the CIA for its incompetence and its having misled him on the probable success of the Bay of Pigs invasion in 1961. Perhaps the most famous alleged quote from Kennedy about his animus toward the CIA after the Bay of Pigs debacle was that he wanted "to splinter the CIA into a thousand pieces and scatter it to the winds." But in the two and a half years after the attempted invasion he never did anything remotely close to this, and it is not known to whom he supposedly said these words. The New York Times only said that Kennedy made this statement "to one of the highest officials of his administration."
Vincent Bugliosi, _Reclaiming History: The Assassination of President John F. Kennedy_, page 1189.
The New York Times article in question is: "[C.I.A.: Maker of Policy, or Tool?](_URL_0_)", New York Times (April 25, 1966). It is on the second page of the article, under the heading of "Kennedy's bitterness," and the specific quote there is "splinter the C.I.A. in a thousand pieces and scatter it to the winds."
This appears to be the original source of the quote in print? In any case, it is an interesting round-about: the article is really about public perceptions of the CIA, and how they get blamed for lots of things there isn't any evidence for. Not entirely ironic that this quote is most used by people trying to establish a CIA motivation for killing JFK.
Which is to say: the quote's origins appear to be an anonymous source in the New York Times in 1966, which credits it (without saying whether it is direct or indirect credit) to a high-level administration official. It's not entirely implausible. But it's got a lot of gauze around it, as far as quotes go. | [
"Plausible Denial: Was the CIA Involved in the Assassination of JFK? is a 1991 book by American attorney, Mark Lane that outlines his theory that former Watergate figure E. Howard Hunt was involved with the Central Intelligence Agency in the assassination of United States President John F. Kennedy. Published by Thu... |
why is it still not commonplace to install antivirus software on on mac computers? | Simple. It's already integrated in the OS.
All versions of OS X since 10.6.7 have been able to detect known Mac malware in downloaded files, and to block insecure web plugins. This feature is transparent to the user. Internally Apple calls it "XProtect."
Read [this](_URL_0_) thread on _URL_1_ for further information. | [
"Some computer security software, such as McAfee's McAfee VirusScan and Symantec's Norton AntiVirus, worked by patching the kernel on x86 systems. Anti-virus software authored by Kaspersky Lab has been known to make extensive use of kernel code patching on x86 editions of Windows. This kind of antivirus software wi... |
How did men study during the Enlightenment? | Disclaimer: I'm a history student, but probably not much more knowledgeable about this subject than a layman. Anyway, I'm not sure whether this answers your question exactly, but hopefully you'll find it interesting.
What differentiates academic study during the enlightenment from the middle ages, is the abandonment of universities in favor of a decentralized community of scholars, often called [the republic of letters.](_URL_0_) The "natural philosophers" found in Stephenson's book lived during the heyday of this intellectual community.
My understanding is that the republic of letters emerged because people became dissatisfied with how things worked at the universities. During the middle ages (from the 12th century or so), universities starting popping up all over Europe. These universities organized subjects into *trivium* and *quadrivium*, terms taken from Roman times. Trivium consisted of grammar, logic and rhetoric, whilst quadrivium consisted of arithmetic, astronomy, geometry and music. These subjects were studied by all students, similarly to how all American university students study liberal arts today. After the introductory studies, students would go on to study either medicine, law or theology. Universities largely became institutions for educating civil servants and the clergy.
In addition, a academic tradition developed at the medieval universities, which is known as scholasticism, with representatives like Thomas Aquinas. They basically studied authors like Aristotle, and tried to fit the texts into an orthodox christian perspective.
As you see, there wasn't much room for actual scientific thought, and this explains why enlightenment scholars established themselves outside of the established universities. In regards to information about the republic of letters, I suggest reading the Wikipedia article I linked, as it seems pretty good.
| [
"The role of women in the Enlightenment is debated. It is acknowledged that women during this era were not considered of equal status to men, and much of their work and effort were suppressed. Even so, salons, coffeehouses, debating societies, academic competitions and print all became avenues for women to socializ... |
Can someone explain the validity of this claim? Using microwaved water vs. purified water to water your plants | To address the first paragraph of the claim, this describes ionizing radiation. Microwaves do not have enough energy to ionize substances.
If any nutrients are destroyed, it is due to heat and cooking time. The interesting thing is that microwaves use less heat than an oven, and have shorter cooking times, so things cooked in microwaves will retain most of their nutrients unlike things fried or sautéed, which will have a good bit of their nutrients destroyed.
Watering plants with microwaved water (which I assume is allowed time to cool) should be no different than non microwaved water. Water is H2O no matter how many times you microwave. And there are no nutrients in water to be denatured even if microwaves could do that.
Another thing. They say radiolytic compounds are formed by radiation. This radiation does not refer to electromagnetic radiation, which is what microwaves emit, but radioactive decay. Microwaves will not produce radiolytic compounds. | [
"Snow's 1849 recommendation that water be \"filtered and boiled before it is used\" is one of the first practical applications of germ theory in the area of public health and is the antecedent to the modern boil-water advisory.\n",
"Microwave disinfection can also be employed for treatment of Biomedical wastes. M... |
what happens to a wasp when i hit it with raid? | You must have hit the wasp with RAID 0, which is why it worked so fast. RAID 1 was still effective on the beetle, it just didn't have the same level of performance (but was safer for you, incidentally).
...I'm so sorry. | [
"The Floater Bug Aliens appear in the 2012 movie \"American Warships\". They are cockroach-like aliens capable of hovering and are armed with a trigger-less flamethrower that launches radioactive fire balls. Using wreckage from sunken ships, they use a stealth ship with an LCD screen for camouflage armed with EMP m... |
why does netflix regularly remove movies instead of increasing the size of their library when adding new titles? | When Netflix buys the rights to distribute certain content they are ALWAYS time limited. Meaning, Netflix has the rights to a show like The Magic School Bus for a certain period of time. Once that time is over, Netflix must renegotiate the contract with whomever owns the rights to The Magic School Bus.
If it were fully Netflix's choice, I'm sure they would never remove content. but it's not. So most of the time this happens it's because the rights holder wanted more money than Netflix was willing to pay for the content. They could not come to an agreement so the old contract was allowed to expire. | [
"In 2014, opinion web blogger Felix Salmon wrote that Netflix couldn't \"afford the content that its subscribers most want to watch.\" He cited as evidence the company's loss of rights to stream several major movies. According to journalist Megan McArdle, the loss of these movies was extremely problematic for the c... |
Zoo animals getting excited before earthquakes? | There are two things at work here. The first is for the events that happen mere seconds to a minute before the Earthquake hits. There are two types of waves that travel through the earth during an earthquake, p-waves and s-waves. P waves travel faster but are hard to detect, s-waves travel slower and are the ones that cause all the damage. Some animals are better at detecting these small p-wave vibrations than humans and they start freaking out because of it.
Now, what about the animals that start freaking out hours before, or even a day before, the earthquake? Selection bias, pure and simple. Any given day in the zoos around the world, animals are going to start freaking out and acting strange for no apparent reason. However, no one really pays it any mind because animals do weird crap all the time. However, when they happen to do weird crap, and then an earthquake comes, people say "oh yeah, I remember. The monkeys were all huddled in a corner yesterday, and they looked scared. And then today an earthquake came" However, if the earthquake hadn't come, no one would have paid it any mind. | [
"Staff at the National Zoo in Washington, D.C., reported that some of the animals in the park appeared to show behavior suggesting that they anticipated the earthquake from seconds to minutes before it was felt in the area. The earthquake was felt at the great ape exhibits during afternoon feeding time. About three... |
When did Christendom forbid slavery? Did the church have anything to do with it? Were there any exceptions to the ban? | What exactly do you mean by Christendom forbidding slavery? Do you mean as in a bible verse, a decree from the Pope, or what?
I'm asking because there are arguably pretty late instances of individual Christians practicing slavery (in the United States for example), and I don't know if they considered it to be forbidden at the time. | [
"Passages in the Bible on the use and regulation of slavery have been used throughout history as justification for the keeping of slaves, and for guidance on how it should be done. Therefore, when abolition was proposed, many Christians spoke vociferously against it, citing the Bible's acceptance of slavery as 'pro... |
How can a person remain "themself" after undergoing a hemispherectomy? | if you need a hemispherectomy, probably because of epilepsy, then that hemisphere is probably already very damaged, and much of its function has probably been taken up by the healthy hemisphere. and this is the real answer to the question; the cerebral cortex is very adaptable, especially early in life. if you lose a hemisphere early in life, you can attain surprisingly close-to-normal function in most domains. but if you lose a hemisphere late in life, and there was no long-term cause for reorganization (e.g. relative unusability of much of the lost hemisphere due to epilepsy), then you will have many, many problems: paralysis or paresis of half the body, blindness in half the visual field, problems with language, memory, attention, etc.
if you're getting at a more philosophical question about the unity of consciousness - the sensation you have of being a thing, a self, with all this simultaneous access to sights and sounds and feelings and memories and volitions - there are good theories of how it works. my favorite is Giulio Tononi's "[information integration theory] (_URL_0_)", which says that consciousness corresponds to the subset of structures in the brain that are all informative about one another in a certain (mathematically-defined) way. two properly connected hemispheres (Tononi and most other researchers think that consciousness mostly subsists in the cerebral cortex, and disagree about which parts precisely are included) constitute a single, highly-complex, integrated structure that corresponds to your subjective consciousness or "self". if you remove a hemisphere, then the size of this structure decreases, but it is still integrated, and so the self remains. interestingly, if you leave both hemispheres alone but *cut* the connections between them, you can have a "split brain" patient, someone who effectively has two parallel consciousnesses, without access to one another but sharing the same body (and same sub-cortical brain structures).
so there is science out there to get at your question, and it's really a hot topic these days, but the short answer boils down to.. we don't know but we have lots of good ideas. | [
"Hemispherectomy is a very rare neurosurgical procedure in which a cerebral hemisphere (half of the brain) is removed, disconnected, or disabled. This procedure is used to treat a variety of seizure disorders where the source of the epilepsy is localized to a broad area of a single hemisphere of the brain, notably ... |
Circumstances surrounding the Death of Ludwig II of Bavaria | His death was quite mysterious and there are many conspiracy theories, but he died in 1886 and the unification was already accomplished in 1871. | [
"Ludwig II, whose passion for building palaces and near-total neglect of his governmental duties were becoming a serious crisis, was declared insane and on 10 June 1886, his uncle, Prince Luitpold, became the regent. Three days later on 13 June, Ludwig II was found dead in Lake Starnberg. The question of whether hi... |
if frozen yogurt comes from cow dairy and ice cream comes from cow dairy, how is frozen yogurt "healthier"? | It's not really. Yogurt is viewed as a healthy snack, so people assume frozen yogurt is healthy, when frozen yogurt is just as full of sugar as regular ice cream. | [
"This is a list of notable frozen yogurt companies. Frozen yogurt is a frozen dessert made with yogurt and sometimes other dairy products including non-dairy products. It varies from slightly to much more tart than ice cream, as well as being lower in fat (due to the use of milk instead of cream). It is different f... |
as people get older, why does it become harder to consume large quantities of food in one sitting? | It's not a hard and fast rule, although *appetite* tends to peak during and shortly after puberty. What can certainly alter your ability to eat a lot in one sitting would be obesity; you have less room for your internal organs, and that includes stomach and intestines. | [
"The elderly usually develop a decrease in appetite, leading to a lower intake of vitamins and minerals. However, many nutrients are recommended at the same amounts as younger people. Another reason why inadequate nutrition levels are more prominent with elders is if their dental status is poor, with missing teeth ... |
Why is 2^1024 the limit of so many web calculators? | A limit has to be chosen, since we only have a certain number of bits at our disposal to represent a number. The choice is somewhat arbitrary.
However, there are a few standard representations that are commonly used and implemented as low-level instructions within the FPU, so it's common to use one of them in order to make the calculations go faster.
a [double](_URL_0_) is the standard way of representing real numbers using 64 bits.
You have 1 bit of sign, 52 bits of "data" and 11 bits of exponent (1 for sign and 10 for value).
Using that representation, a number takes the form:
+/- [0 1] * 2^[-2 ^ 10 2 ^ 10[
Where [0 1] is quantized using 52 bits.
2^10 is 1024, so the maximum representable value is
1 * 2 ^ ( 2 ^ 10 - 1 )
which is 2 ^ 1023
| [
"Enabling PAE (by setting bit 5, codice_4, of the system register codice_5) causes major changes to this scheme. By default, the size of each page remains as 4 KB. Each entry in the page table and page directory becomes 64 bits long (8 bytes), instead of 32 bits, to allow for additional address bits. However, the s... |
how come perfect eyesight is 20/20? | Eye doctors have decided what a "normal" human being should be able to see when standing 20 feet away from an eye chart. If you have 20/20 vision, it means that when you stand 20 feet away from the chart you can see what the "normal" or average human being can see. In other words, your vision is "normal" -- most people can see what you see at 20 feet.
If you have 20/40 vision, it means that when you stand 20 feet away from the chart you can see what a normal human can see when standing 40 feet from the chart. That is, if there is a normal person standing 40 feet away from the chart and you are standing only 20 feet away from it, you and the normal person can see the same detail. 20/100 means that when you stand 20 feet from the chart you can see what a normal person standing 100 feet away can see. 20/200 is the cutoff for legal blindness in the United States.
Source
_URL_0_ | [
"BULLET::::- In some countries, the number 20 is used as an index in measuring visual acuity. 20/20 indicates normal vision at 20 feet, although it is commonly used to mean \"perfect vision\". (Note that this applies only to countries using the Imperial system. The metric equivalent is 6/6.) When someone is able to... |
does earth appear as a bright planet? | A few million light years away? That is an insane distance. Our entire galaxy is only ~100,000 light years in diameter. Even one lightyear away would be too far, not only is our planet not that bright, it is minuscule in comparison to the sun so anyone trying to look for us would just see our big, bright sun. This is a struggle we have in our search for planets outside of our solar system, no telescope is powerful enough to see them, however we are able to detect them by other methods. | [
"The reflected light of a planet contains absorption bands due to minerals in the rocks present for rocky bodies, or due to the elements and molecules present in the atmosphere. To date over 3,500 exoplanets have been discovered. These include so-called Hot Jupiters, as well as Earth-like planets. Using spectroscop... |
thinking about probability, how is it possible that one and only puzzle piece fits in another in a jigsaw puzzle? | That's not probability that's design. Jig saw puzzles arent random. Someone actually sat down and drew out the lines specifically so that they only fit one place. | [
"Many puzzles are termed \"fully interlocking\". This means that adjacent pieces are connected in such a way that if one piece is moved horizontally, the other pieces move with it, preserving the connection. Sometimes the connection is tight enough to pick up a solved part by holding one piece.\n",
"Due to differ... |
How did Mohammed and his followers--and, for that matter, his immediate predecessors and fellow Arab people of the time--come to believe in a bunch of the same stuff as the Jews did? | You may also be interested in reading some of the answers in this fairly recent [AMA on Pre-Islamic Arabia](_URL_0_). | [
"There were Jews, such as Natan'el, who accepted this model of religious pluralism, leading them to view Muhammad as a legitimate prophet, albeit not Jewish, sent to preach to the Arabs, just as the Hebrew prophets had been sent to deliver their messages to Israel.\n",
"The Islamic prophet Muhammad's views on Jew... |
if carbon dioxide is bad for you to inhale, and people provide it when you breath out, wouldn't the carbon dioxide do any damage to the person getting mouth to mouth? | Carbon dioxide doesn't hurt you. A lack of oxygen hurts you, and carbon monoxide hurts you.
You don't convert all the oxygen you inhale into carbon dioxide, so CPR is still effective. However, these days, heartsaver CPR is recommended (unless you have special training and two people). This uses the chest compressions to move some air through the lungs while also working the heart. It doesn't involve breathing into the person's lungs. | [
"Home remedies for throat irritation include gargling with warm water twice a day, sipping honey and lemon mixture or sucking on medicated lozenges. If the cause is dry air, then one should humidify the home. Since smoke irritates the throat, stop smoking and avoid all fumes from chemicals, paints and volatile liqu... |
Theory | > A scientific theory means that it has been tested and *proven* without fail MANY times.
This is incorrect - theories are never *proven*. They can only be accepted or rejected based on an ever-growing (hopefully) pile of evidence. It would be more accurate to say that an accepted theory has been tested and scientists recognize that it has passed all tests so far.
Gravity itself is not a theory but an observed force; our current *understanding* of that force, including the equations we use to describe our observations, is a theory. | [
"A theory is a contemplative and rational type of abstract or generalizing thinking about a phenomenon, or the results of such thinking. The process of contemplative and rational thinking often is associated with such processes like observational study, research. Theories may either be scientific or other than scie... |
Is there any science behind why elderly people often die close to the death of their significant other? It also seems to happen frequently with pets. | increased stress and depression in the immediate period after
here's one showing heart problems associated with bereavement [link](_URL_1_)
Edit: heres a [link](_URL_0_) to the original infamous Finnish study | [
"The large number of individuals within a small area indicate that all of the animals died at around the same time. However, their bones are well preserved and minimally scattered, indicating that the cause of death was not a catastrophic event such as a flood or mudslide. It has been suggested that the group peris... |
What is "chemistry" between two people actually? What is the logical explaination? Why is it so instant? | It was thought for a while that there may be some kind of pheromone exchange responsible for this effect. That idea has been largely dismissed though as no Vomeronasal organ which would be sensative to such pheromones has been identified on adults even though some fetuses have been thought to show the organ. Even in it did appear in adults however there is no evidence that human beings have active sensory neurons like those in working vomeronasal systems of other animals.
The current discussion on the subject generally involves the principles of and the basic physiology behind interpersonal relationships. Most papers I've read on the subject tend to take it to the idea of like attracts like. [According to some evolutionary psychologists](_URL_0_) we select for a mate simply by scanning the environment and quickly filtering out those deemed unworthy, including those that are considered by us to be unattractive. From those not filtered out we select a potential mate. Love in this case is simply a transitory physiological experience caused when the body excretes epinephrine, dopamine, phenylethylamine, and other endorphins into our bloodstream.
In short there is no "chemistry" between you really, but there is a large amount within yourself as a kind of psychological response. | [
"In the context of relationships, chemistry is a simple \"emotion\" that two people get when they share a special connection. It is the impulse making one think \"I need to see this [other] person again\" - that feeling of \"we click\". It is very early in one's relationship that they can intuitively work out wheth... |
what is chemotherapy, and what happens during it? | it's chemical treatment to combat (usually) cancer growth. most are in liquid form and are administered intravenously (through a drip in your arm). a single treatment of chemo may involve receiving several different chemicals in one session, commonly over quite a while (an hour or more). usually you sit on the ward with others while receiving it or there are some you can receive at home. depending on the length of course this may be done weekly or fortnightly for several months. on ward most people chat / read / watch tv while receiving treatment. the combination of chemicals are designed to slow down cell reproduction in your body. others are designed to kill cancer cells or types of cell in your body. there are lots of different kinds of chemo for lots of different kinds of cancer. the side effects usually stem from the slowing cell growth and killing of certain cells : hair loss, nausea/vomiting, constipation, thirst and so on. it's common to have additional courses of medicine that combat the side effects specifically. | [
"Chemotherapy is a treatment that injects a drug into a vein (IV) or that is given via the mouth to prevent the growth of cancer cells by stopping them from dividing. It is often used after surgery or as the first line of treatment. The drug injected flows through the bloodstream and destroys cancer cells.\n",
"C... |
How was honey harvested in ancient times? Were bees kept like they are today or was all honey harvested from the wild? | hi! Could you specify which region/culture you're interested in - e.g. Greece, Nepal, the Maya, etc. That will help the appropriate historian(s) provide a meaningful response. Thanks! | [
"Depictions of humans collecting honey from wild bees date to 10,000 years ago. Beekeeping in pottery vessels began about 9,000 years ago in North Africa. Domestication of bees is shown in Egyptian art from around 4,500 years ago. Simple hives and smoke were used and honey was stored in jars, some of which were fou... |
how can plants turn sun and water (and dirt) into wood, leavies and pretty much anything they need? | You are actually missing out a critical part: air
Yes, most of a mass a plant actually comes from carbon dioxide within the air. They can convert it into plants with the Calvin cycle, which is a cycle made up of several chemical reactions that takes in carbon dioxide and converts it into glucose, which is essentially sugar
The energy to do this comes from the sun, chloroplasts receive solar energy and store it to be used for the Calvin cycle
Lots of molecules of glucose can then be chained together in order to form more complex molecules like cellulose that makes up most plants | [
"The plants prefer gritty well-drained soil in partial sun to shade. Water regularly during the growing season, and rarely if at all during dormancy. Propagate from seed, divisions, or from individual scales which once removed, will eventually form numerous bulbils.\n",
"Climate-friendly gardeners may use deep-ro... |
welfare and food stamps | Welfare is sometimes called TANF or temporary assistance for needy families. Those who fall under federal guidelines for poverty may apply and are given money for rent, bills and other necessities. Typically, there is a work requirement and the recipient must comply to continue to be eligible. Food stamps are similar although the money can only be used for food. There is usually a misconception that people that receive the benefits are lazy but many have jobs and use these programs to stay afloat so to speak. | [
"Government funds provided to poverty stricken individuals by the Supplemental Nutrition Assistance Program are often referred to colloquially as \"food stamps\". The parallels between these \"food stamps\" and ration stamps as used in war time rationing is limited, however, since food can be purchased in the Unite... |
What is a good book to read that will give me a survey history of modern European history? | The trouble is that there are very few survey histories which aren't textbooks. The only one I can think of off the top of my head is [A Concise History of Modern Europe](_URL_1_), but I can't vouch for its quality since I haven't actually read it myself (one of my friends did).
My history classes often use readers from the [Bedford Series of History & Culture](_URL_0_) - they have a lot of selected documents from the period and varying amounts of commentary about the events. You can usually find them on Amazon, and they're really, really cool if you're into primary documents.
If you'd like recommendations for any specific periods in modern Europe, though, I'm happy to help! And also, your username has me intrigued. | [
"The library offers approximately 90,000 printed titles and 900,000 licensed online resources on the history of Europe from the mid-15th century. There is an emphasis on general European history and international history, as well as on church history and the history of theology since the period of Humanism and the ... |
why are some atoms "easier" to become ions than others? | Because of their Electronegativity (hope thats the right translation) and their size. The Electronegativity basically is a force (Noted in the Periodic table) which defines how strong they are able to "suck" other electrons to themselves. | [
"Ions may be larger or smaller than the neutral atom, depending on the ion's electric charge. When an atom loses an electron to form a cation, the other electrons are more attracted to the nucleus, and the radius of the ion gets smaller. Similarly, when an electron is added to an atom, forming an anion, the added e... |
what's the difference between a $10 bottle of wine compared to a $100 bottle? | A person who has developed the palette for it could tell the difference, and appreciate it.
I think the subtleties of the $100 bottle would be lost on me, but I have tasted some $30/bottle wines, and they have been far richer and better-tasting than the $10 ones. | [
"BULLET::::- According to one Bordeaux shipper cited by McCoy, \"the difference between a score of 85 and 95 [for one wine] was 6 to 7 million Euro\", and a \"bottle rated 100 can multiply its price fourfold.\"\n",
"Described by Jancis Robinson as \"one of the ten best wines of the twentieth century\", and consis... |
animal pain, human pain | Other mammals experience pain pretty much as humans do. But they don't have language or facial expressions to describe their suffering. And they need to get up and walk away, if the alternative is to sit around forever and die. No paramedic or doctor is coming. | [
"According to the U.S. National Research Council Committee on Recognition and Alleviation of Pain in Laboratory Animals, pain is experienced by many animal species, including mammals and possibly all vertebrates.\n",
"Pain negatively affects the health and welfare of animals. \"Pain\" is defined by the Internatio... |
Who were the great administrators? | If you're looking into US history I strongly recommend you examine Andrew Jackson's contest with the [Second Bank of the United States](_URL_0_). | [
"The highest officials in the central bureaucracy, who provided advisory, censorial, executive, and judicial roles in governing the empire, consisted of cabinet members known as the Excellencies, heads of large specialized ministries known as the Nine Ministers, and various metropolitan officials of the capital reg... |
Planets can have rings. Can stars have the same sort of rings? | It is definitely possible.
First, a solid celestial body would have to enter the star's sphere of gravitational influence. Then, it would have to pass through the Roche limit. That's the distance where the tidal forces will rip the object apart.
If the object wasn't on a collision trajectory with the star before disentegration, then it will form a ring around the star.
| [
"The most prominent and most famous planetary rings in the Solar System are those around Saturn, but the other three giant planets (Jupiter, Uranus, and Neptune) also have ring systems. Recent evidence suggests that ring systems may also be found around other types of astronomical objects, including minor planets, ... |
why did linux get more popular then unix? | It was free. It had no support guarantee, but the lack of cost made up for it. And because it was open source it could be ported to anything it could be compiled for, and there wasn't a big company making budgeting decisions based on volume sales potential keeping that from happening. | [
"Unix was an early operating system which became popular and very influential, and still exists today. The most popular variant of Unix today is macOS (previously called OS X and Mac OS X), while Linux is closely related to Unix.\n",
"Unix was originally meant to be a convenient platform for programmers developin... |
how come i can remember a certain moment from my childhood, yet i can't remember a maths equation i learned today? | You have two forms of memory - short-term and long-term. The first is far from perfect but can get better with the proper training. So just after you learn it, your math equation is in short term memory.
When you sleep, some of the long-term memories are created from the short-term memory experiences you had during that day, particularly when it really stood out. (For example, an afternoon playing will likely not be as long-term memorable as a trip to Disney). But if you got swamped with new information that day, not everything is permanently written down and so you forget some stuff like your equation.
When you're younger and learning lots, you're pretty good at this conversion process, so many long-term memories exist and can be recalled well into adulthood. But the short-term ones that didn't get transcribed into long-term form are lost, just like that equation. | [
"Pars triangularis has been shown to have a role in cognitive control of memory. There are more ways than one to remember something. When a person remembers, (s)he retrieves information from storage in a memory center of the brain. This information may be the muscle contraction sequence for shoe-tying, the face of ... |
Why are there 3 different names for meteoroids/meteorites/meteors? | Because they are different by definition.
**Meteoroid**: A small body moving in the solar system that would become a meteor if it entered the earth's atmosphere.
**Meteor**: A small body of matter from outer space that enters the earth's atmosphere, becoming incandescent as a result of friction and appearing as a streak of light.
**Meteorite**: A meteor that survives its passage through the earth's atmosphere such that part of it strikes the ground.
| [
"Meteor showers are named after the nearest constellation or bright star with a Greek or Roman letter assigned that is close to the radiant position at the peak of the shower, whereby the grammatical declension of the Latin possessive form is replaced by \"id\" or \"ids\". Hence, meteors radiating from near the sta... |
why do mobile video games have so many commercials on tv all of a sudden? | Mobile games have the best potential to be profitable because they cost far less to develop than traditional PC or console games and everyone has a phone. A few companies have figured it out (including those people at Candy Crush who sue anyone that uses the word "saga." They're the new monster cable of frivolous lawsuits) | [
"Commercials for certain video games include trailers that are essentially CGI short-films - with graphics of a much higher caliber than the actual game. This practice has been used more in recent years and has led to major backlash from video gaming communities.\n",
"In order to make the game successful, Nintend... |
how can a person have 8 pack abs when theres only 6 rectus abdominis? | Actually you just have 1 rectus abdominus muscle, which is split in the middle longitudinally by linea alba (white line). And there are tendinous insertions horizontally that gives the impression that you have 6 different muscles. There are normally 3 of these insertions, hence 6 bulges, but some have 4 of them making a 8-pack. | [
"An \"overbust corset\" encloses the torso, extending from just under the arms toward the hips. An \"underbust corset\" begins just under the breasts and extends down toward the hips. A \"longline corset\" – either overbust or underbust – extends past the iliac crest, or the hip bone. A longline corset is ideal for... |
what are stocks and what is insider trading? how are they related to each other? | This is VERY ELI5
& #x200B;
Stocks are a share of ownership in a company. Insider trading is when someone close to or with connections inside a company know of a large move (either positive or negative) the company is about to do that is going to effect the stock price. They then act on this information to either buy a bunch or sell a bunch of the company's stock before the information becomes public. | [
"Insider trading is the trading of a public company's stock or other securities (such as bonds or stock options) by individuals with access to non-public information about the company. In various countries, trading based on insider information is illegal because it is seen as unfair to other investors who do not ha... |
why does skipping five seconds of a video often take longer due to buffering than just sitting through the five seconds? | The way online video is compressed, you're receiving data that represents incremental updates from the last frame. If you start playing the video at the beginning, it all works as intended.
However, if you start playing in the middle, you need to process incremental updates for some time period prior to the frame you want to see before you can display it. It takes time to download both the incremental data and process it. | [
"In computing, buffer underrun or buffer underflow is a state occurring when a buffer used to communicate between two devices or processes is fed with data at a lower speed than the data is being read from it. (The term is distinct from buffer overflow, a condition where a portion of memory being used as a buffer h... |
Does a radar gun in a moving vehicle function the same as one in a stationary vehicle? | All detectors can only tell you relative speed. So that means that a stationary radar would detect 0 in the first case, 5 in the second and 5 (speed is absolute value of velocity) in the third, 75 in the last. You have the right idea. It's not a mistake. The nature of physics is that the relative value is the absolutely real answer - assuming you've chosen yourself as the frame of reference.
Which doesn't matter if your radar unit includes a detector for your own speed, which can then be added or subtracted from the target. That's what police use. In many well funded places cars have internal systems that have antennas mounted on the rear and front, which can detect accurate speeds of cars moving the same or opposite direction and ballpark speeds of things moving off axis.
In some cases you can also detect multiple objects, including stationary ones that are known, and get an even more certain result. Either way the result is that you can return to a universally agreed frame of reference (the Earth's ground) by a simple transformation.
So they do work differently, but only in the data processing. The radar itself is the same. Your ticket will be the rounded down end of the margin of error, but if you're speeding enough that's still not great.
Similar computerized systems are used on ships, aircraft and anything else that might be moving when you need a reading. Sometimes RADAR units are used to determine your own speed and position as well. They're pretty versatile for being very simple in concept.
_URL_0_
There's an example. Note that it plugs into the car's data port to pull vehicle speed info (VSS). | [
"Traffic radar comes in many models. Hand-held units are mostly battery powered, and for the most part are used as stationary speed enforcement tools. Stationary radar can be mounted in police vehicles and may have one or two antennae. Moving radar is employed, as the name implies, when a police vehicle is in motio... |
how does a gym's business model hold up? the equipment is insanely costly and the memberships cost next to nothing in most cases. how does it pay off the investment and become a stable income source? | It's like planet fitness cheap membership so everyone and their mom signs up, but then they literally never go. So tons of $20. A month payments and if you forget a yearly fee but noone uses it. | [
"The company has approximately 128 gyms and fitness suites across its estate of over 160 centres, which include a variety of equipment, such as cardiovascular and weight-training apparatus. Customers can work out independently, as part of an instructor-led small group, or with a personal trainer of their own.\n",
... |
What happened to the territory gained by Justinian I? | It was lost again.
In Italy the war with the Ostrogoths lasted for decades and devastated the country. Some historians hold this war to be the true end of antiquity. As Goldsworthy puts it, it "probably destroyed many aspects of Roman culture and society that had survived the collapse of the Western Empire."
Although the Byzantines eventually defeated the Ostrogoths and took control of the whole of Italy, the Lombards (Or Longobards, i.e. Longbeards. Another German tribe) invaded Italy very soon after Justinian's death, and took over most of the interior. The Byzantines held on to coastal cities and Sicily, and over the centuries afterwards would sometimes regain parts of Italy, but they never got anywhere close to achieving Justinian's territorial ambitions. They fought over it as late as the reign of Manuel Komnenos, who tried to regain control over the southern ports there in the 12th century.
The Spanish possessions were contested by the Visigoths, and though the Byzantines held on for some decades, and even made some temporary gains by exploiting Visigothic dynastic conflict, they lost all their mainland possessions in the 7th century even before the Muslims invaded. (They held on to the Balearic islands for a bit longer.)
Africa remained a Roman possession for several generations, until it fell to the Arab invasion along with Egypt and Syria later in the 7th century.
The bubonic plague that devastated the empire shortly after the start of the Ostrogothic wars likely had something to do with the empire's inability to hold on to its conquests, but Justinian's projects had also been opportunistic and ended up opening up several new fronts in an empire already struggling to defend its existing possessions from attack. Hardly anybody considers the loss of the new conquests surprising. | [
"Justinian I, who assumed the throne in 527, oversaw a period of Byzantine expansion into former Roman territories. Justinian, the son of an Illyrian peasant, may already have exerted effective control during the reign of his uncle, Justin I (518–527). In 532, attempting to secure his eastern frontier, Justinian si... |
How do we know the orbit of the sun? | Yes, our instruments are actually are that good, but the reason you're looking for is our toolbox has grown significantly since the days of Galileo. We can collect data much more accurately and at a much greater distance than ever before.
To the best of our knowledge, the Milky Way is a [barred-spiral galaxy](_URL_0_) , and most barred-spiral galaxies we observe spin like a giant record on a player. By looking at the distant stars in our local galaxy and observing the [doppler shift in the starlight](_URL_1_) we can get an idea of what direction the galaxy is spinning. Stars moving away from us look more reddish than stars moving toward us. This is due to a change in the light-particle frequency because of the relative motion between us (Earth) and the star we're looking at.
Since our star is part of the galaxy, it's snared in the same rotational movement the rest of the galaxy is locked at, which gives us an idea of which direction the sun will move as the galaxy spins, giving us its orbit and velocity. We can even tell the vector the sun uses to travel through the galaxy. I've read the planets of our solar system orbit the Sun on its Y-axis, not horizontally like charts always show. Supposedly, the solar system stands on its side as it burns around the Milky Way, but I can't find any supporting information about this. | [
" orbits the Sun at a distance of 0.9–1.9 AU once every 19 months (583 days). Its orbit has an eccentricity of 0.38 and an inclination of 9° with respect to the ecliptic. The body's observation arc begins with its official discovery observation, as no precoveries were taken, and no prior identifications were made.\... |
how do the inner leaves of cabbage perform photosynthesis? | The inner leaves may not see the sunshine but the entire plant acts as a "unit". Much like kindergarten, sharing is important for the success of everything involved | [
"Photosynthesis requires plants to take in carbon dioxide gas (). As they do so, they lose water through transpiration. Like other types of succulents, cacti reduce this water loss by the way in which they carry out photosynthesis. \"Normal\" leafy plants use the C mechanism: during daylight hours, is continually d... |
how does applying toothpaste to a cd to help fix scratches work? | The data on a CD, DVD, etc is stored on the label side, on the surface of a thin sheet of metal that can be seen through the plastic. The top of a CD is usually pretty well protected by being a nice hard surface, but the bottom is just a plastic that is prone to being scratched.
If you have scratches on this side of the CD then it can deflect the laser that's trying to read the information. Polish the scratch off of the surface and the data can be read.
Toothpaste just happens to be a pretty good mild abrasive. Off the shelf CD repair kits work similarly and may have a clear compound to fill the scratches. | [
"BULLET::::- It is used to polish CDs, DVDs, screens, and pools to repair scratches. It is a mild solvent and an extremely fine abrasive, so when applied to the reflective surface of the disc and rubbed radially (in straight lines between the edge and centre), it can smooth scratches and reduce their effect.\n",
... |
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