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Do radioactive elements/molecules decay until they reach the first stable sized element/molecule (such as lead) or do they decay until they are essentially hydrogen or helium? | They decay until they reach the the first stable element. In addition, if you think of the [chart of the nuclides](_URL_0_), they decay in a path of isotopes that tends toward the line of stability.
The chart of the nuclides has total number of protons and nuetrons on the horizontal axis and number of protons on the ... | [
"Unstable isotopes decay to their daughter products (which may sometimes be even more unstable) at a given rate; eventually, often after a series of decays, a stable isotope is reached: there are about 200 stable isotopes in the universe. Stable isotopes have ratios of neutrons to protons in their nucleus which are... |
how is my water, gas and electricity usage counted? | Depends on where in the world you are. There are thousands of people who have been employed as meter readers around the world. Some physically read the meter, others connect a device to the meter and electronically download the usage.
You have a water meter as the water main enters the house, and records the flow of ... | [
"The energy unit used for everyday electricity, particularly for utility bills, is the kilowatt-hour (kWh); one kWh is equivalent to 3.6×10 J (3600 kJ or 3.6 MJ). Electricity usage is often given in units of kilowatt-hours per year (kWh/yr). This is actually a measurement of average power consumption, i.e., the av... |
if digital cameras weren't invented until 1975 then what kind of cameras were on the probes that were sent out into space pre 1975 | Basically the technology used to send TV images over the air. We've had electronic alternatives to film for a long time, and the storage was analog or digital video tape.
For example, the list of instruments of the [Mariner](_URL_0_) program on wikipedia might contextualize it. | [
"The Nikon NASA F4 Electronic Still Camera was one of the first and rarest fully digital cameras with development started in 1987. While Nikon delivered a modified Nikon F4 body, most of the electronics for the digital camera and housings were designed and built by NASA at the Johnson Space Center and other supplie... |
Good introduction books about stone-age (including palaeolithic, Mesolithic, neolithic)? | Heya, you might be interested in the [booklist](_URL_0_) at r/AskAnthropology, especially the Archaeology section. :) | [
"The Lower Paleolithic (or Lower Palaeolithic) is the earliest subdivision of the Paleolithic or Old Stone Age. It spans the time from around 3.3 million years ago when the first evidence for stone tool production and use by hominins appears in the current archaeological record, until around 300,000 years ago, span... |
why are our vocal chords so unique? | Well, often times that depends on your genetics as well as the shape of your throat and mouth. There are a lot more reasons as to why your voice differs from many others. If you're taller you're more likely to have a deeper voice and vice versa. Your vocal cords vibrate to use airflow from your lungs so the shape and s... | [
"On the lower pitches in the modal register, the vocal folds are thick and wedge-shaped. Because of the thickness, large portions of the opposing surfaces of the vocal folds are brought into contact, and the glottis remains closed for a considerable time in each cycle. The glottis opens from the bottom first before... |
why does alcohol make some people amped up to fight and make others really social but makes me want to pass out? | Alcohol is a central nervous system depressant. Which doesn't mean that it makes you depressed. It means that it depresses (i.e. reduces) the functions of the central nervous system. One of the most intensive functions of the central nervous system is behavior inhibition. For instance, maybe you hate someone and re... | [
"A lot of people think drinking alcohol gives them a sense of identity that may help them fit in with social networks. Some also believe it heightens confidence to take part in social situations. Some may oppose the fact that they are being pressured into consuming alcohol, but others look to find social networks w... |
Is there any detailed geological understanding of where all of the soil from the Dust Bowl actually went? | Not to my knowledge. The volume just wasn't enough to produce any geologically significant strata.
[Here](_URL_0_) is a brief report on dust collected in a similar storm from 1954. He extrapolated a 4-ftsuper^2 area to get 100+ pounds of dust per acre of deposition, but this is sitting atop grass and such so you coul... | [
"Farmland is typically very susceptible to wind erosion. Most farmers do not plant cover crops during the seasons when their main crops are not in the fields. They simply leave the ground open and uncovered. When the soil is dry, the top layer becomes similar to powder. When the wind blows, the powdery top layer of... |
nasas conference today | They're discussing recent discoveries about the red planet. Your question is pretty vague. What do you want to know about it? | [
"NASA is working in cooperation with National Renewable Energy Laboratory (NREL). The goal is to produce worldwide solar resource maps with great local detail. NASA was also one of the main participants in the evaluation innovative technologies for the cleanup of the sources for dense non-aqueous phase liquids (DNA... |
What are some inventions through history that although *could* work, weren't practical enough to go mainstream? | Surprisingly, a lot inventions that ultimately became mainstream didn't look like it from the start.
A simple example is the "first" steam engine, the Newcomen engine of 1712, which was invented to help deal with drainage problems in coal mines. Coal was plentiful and cheap at the source - and the engine guzzled it by... | [
"History shows that turning the concept of an invention into a working device is not always swift or direct. Inventions may also become more useful after time passes and other changes occur. For example, the parachute became more useful once powered flight was a reality.\n",
"3) Very often the original patent on ... |
Why are non pneumatic tires not used as often as pneumatic tires? | If the technology can mature into a product that can compete with pneumatic tyres in a *balance* of pricing, reliability, manufacturing simplicity, ease maintenance, etc etc, then you'd see more of it.
It doesn't have to be cheaper, more reliabile, easier to make, easier to maintain all at once. Only that overall it b... | [
"The materials of modern pneumatic tires are synthetic rubber, natural rubber, fabric and wire, along with carbon black and other chemical compounds. They consist of a tread and a body. The tread provides traction while the body provides containment for a quantity of compressed air. Before rubber was developed, the... |
Has there ever been a point after the Anglo-Saxon migration into England that the English didn't identify as a Germanic people? | I dont know if the Anglo Saxons even really knew they were 'Anglo Saxon' in the sense you describe. King Canute called himself King of England, 500 years after Hengist and Horsa came across the channel for an extended holiday, and he was a Dane. If your great great grandparents were a mix of Saxons and/or Angles and/o... | [
"According to Bede in the \"Ecclesiastical History of the English People\", from the late 4th century onwards, Germanic tribes such as the Goths, Vandals, Angles, Saxons, Lombards, Suebi, Frisii and Franks invaded or migrated to the island of Great Britain (Britannia) from continental Europe, the generic term for t... |
Given the scale of World War II, its effects on the environment should have been devastating. Were there any records taken on the environmental damages caused by the war? If so, how much did it actually disrupt ecosystems? | In countless ways, big and small. World War II was by far the biggest ecological impact of any conflict up to that point, a combination of several factors, including technology but also the sheer scope of course. The *space* that a single soldier commanded in World War II was over 10x larger than in World War I, let al... | [
"The environmental impacts of World War II were very drastic, which allowed them to be seen in the Cold War and be seen today. The impacts of conflict, chemical contaminations, and aerial warfare all contribute to reduction in the population of global flora and fauna, as well as a reduction in species diversity.\n"... |
i can't really feel the difference between -20f and 32f as much as i can feel the difference between 70f and 80f. why? | How cold it feels (or how warm it feels; same difference in this context) has less to do with the absolute temperature of the air around you and more to do with *how fast* heat moves out of your body into that air.
See, your sense of temperature is all about something called *thermoregulation.* For reasons of chemistr... | [
"In music, 22 equal temperament, called 22-TET, 22-EDO, or 22-ET, is the tempered scale derived by dividing the octave into 22 equal steps (equal frequency ratios). Each step represents a frequency ratio of , or 54.55 cents ().\n",
"Cooling degree days are also measured by the difference between the average tempe... |
why do extremely hot items glow "red hot" as opposed to other colors, like green, blue, purple, etc.? | Heated objects produce light.
Even room-temperature objects are emitting light. It just isn't *much* light and the wavelength is way too long to see (it is low-energy).
The more an object heats up, then more energy it emits. It also starts to emit more energy of higher frequencies (higher energy levels). So if it get... | [
"It is true that objects at specific temperatures do radiate visible light. Objects whose surface is at a temperature above approximately will glow, emitting light at a color that indicates the temperature of that surface. See the section on red heat for more about this effect. It is a misconception that one can ju... |
why are dead bodies and objects in bogs so well preserved. | bogs have 2 things going for them, there's a general lack of oxygen and the water is acidic. the acidic water basically tans the skin and organs like it would leather and the lack of oxygen means there's no real microbes or other things to eat at the flesh.
*edit* also they're cold which again helps keep the microbes... | [
"Bog Bodies are human remains which have been found in peat bogs in various locations around the world. They have been preserved naturally in varying degrees due to the specific conditions of peat bogs. Despite their natural preservation, these remains are sensitive to deterioration after being removed from their o... |
How did plague doctors not get sick? And also what made the plague different from the flu and how come diseases like it haven’t happened much since then? | Physicians during plague outbreaks certainly _did_ get sick. They lived in the same conditions as those who did get the diseases (which are responsible for exposure to bubonic plague, spread by fleas), and some forms of plague (notably pneumonic plague) can spread from person to person. I don't know of statistics as to... | [
"Plague doctors practiced bloodletting and other remedies such as putting frogs or leeches on the buboes to \"rebalance the humors\" as a normal routine. Plague doctors could not generally interact with the general public because of the nature of their business and the possibility of spreading the disease; they cou... |
is florida really going to be under water in 40 years? | No. Conservative estimates place sea-level rise at 1.5 feet by the end of the century. Assuming a steady increase (not accurate, but good enough as a guesstimate), that's a little over half a foot in 40 years. The mean elevation of Florida is 100 feet.
Mind you, that's going by a conservative estimate, and a half-foo... | [
"According to the Natural Resources Defense Council's recent study, Florida is one of 14 states predicted to face \"high risk\" water shortages by the year 2050. The state's water is primarily drawn from the Floridan Aquifer as well as from the St. Johns River, the Suwannee River, and the Ocklawaha River. Florida's... |
I've seen a lot of pictures of Cuba recently, and many of them have 1950's era cars in them. What is the reason behind all of these classic American cars? | Cuba was an enthusiastic consumer of American vehicles from the teens to the 1950s, but the Cuban Revolution in 1959 changed all that. With the country’s transition to a Communist government under the leadership of Fidel Castro, its relationship with the United States soured, and before long the U.S. government had ban... | [
"Most new vehicles came to Cuba from the United States until the 1960 United States embargo against Cuba ended importation of both cars and their parts. As many as 60,000 American vehicles are in use, nearly all in private hands. Of Cuba's vintage American cars, many have been modified with newer engines, disc brak... |
How were the early American colonists chosen? | It's important to know that colonies were, at their core, business ventures, and their success or failure depended on colonies doing two things: providing raw materials that could be collected and shipped back to the home territories more cheaply or reliably than they could be found locally, and providing the home terr... | [
"Colonists arriving after the first wave found that the early towns did not have room for them. Seeking land of their own, groups of families would petition the government for land on which to establish a new town; the government would typically allow the group's leaders to select the land. These grants were typica... |
Why does the brain easily notice when a poem or song breaks the rhyme scheme? | The short answer: because pattern recognition is one of the most important tasks the brain has evolved to do, and it's remarkably good at it. [This article](_URL_0_) uses face and speech recognition to discuss how much better the human brain is at complex pattern recognition than computers are. It does mention that t... | [
"Many aspects of language and musical melodies are processed by the same brain areas. In 2006, Brown, Martinez and Parsons found that listening to a melody or a sentence resulted in activation of many of the same areas including the primary motor cortex, the supplementary motor area, the Brocas area, anterior insul... |
if the u.s. is a net exporter of oil for the first time since 1949, why is gasoline in my neighborhood $3.94? | We are a net exporter of refined petroleum products (gas, diesel, etc.) We are most certainly not a net exporter of oil.
Huge huge difference. | [
"In 2017, the United States became a net exporter of natural gas on an annual basis for the first time since 1957. Net exports averaged 0.4 billion cubic feet per day. The US Energy Information Administration projected that net exports would grow to 4.6 billion cubic feet per day in 2019. Export growth was driven b... |
I've always been taught that the universe is infinitely expanding, how then does the Second Law of Thermodynamics apply to it? | To clarify some basic thermodynamcis for you:
1st law: There is a property of nature called energy. Energy is always conserved (total amount is always the same). There aren't usable and unusable types of energy. There is just energy whether it is heat, light, chemical, gravitational, magnetic, etc.
2nd law: There is ... | [
"Since a finite universe is an isolated system, the second law of thermodynamics states that its total entropy is continually increasing. It has been speculated, since the 19th century, that the universe is fated to a heat death in which all the energy ends up as a homogeneous distribution of thermal energy so that... |
what are a series of events of the worst case scenario from this ukrainian conflict | Russia goes balls deep and blitzkrieg Ukraine. Poland and Lithuania respond by sending a shit ton of troops with bitch be good sticks to Ukraine. Moscow responds by nuking Poland and Lithuania. Nato goes to war with Russia. China says fuck it and decides to back the Ruskies and immediately attacks Japan. They then figh... | [
"The Battle of Motovilivka was a military engagement fought between forces of the Ukrainian State and the Directorate of Ukraine. The battle took place on 18 November 1918 during the Ukrainian Civil War, and resulted in a major victory for the Directorate. The battle resulted in the eventual collapse of the Ukraini... |
After 1980, wages stagnated, the amount of strikes drastically declined and the amount of prisoners increased enormously. What happened?! | The productivity vs. wages graph is true, but misleading. There's a difference between wages and total compensation - total compensation includes things like matching 401k contributions, medical insurance paid by the company, and so forth.
When you graph productivity vs. total compensation and not wages, [the gap mo... | [
"Six years of intermittent wage freezes, policies adverse to industry and restrictive measures like the Circular 1050 had left GDP per capita at its lowest level since 1968 and real wages lower by around 40%. Given these conditions, the return of some freedoms quickly led to a wave of strikes, including two general... |
networking question - difference between a class a , class b, and class c network? | Yer not alone in askin', and kind strangers have explained:
1. [ELI5: IP adressing and IP classes ](_URL_0_)
1. [Can you ELI5 subnetting of a Class A network? ](_URL_1_)
Post your other question separately. | [
"A classful network is a network addressing architecture used in the Internet from 1981 until the introduction of Classless Inter-Domain Routing in 1993. The method divides the IP address space for Internet Protocol version 4 (IPv4) into five address classes based on the leading four address bits. Classes A, B, and... |
how are a group of people determined to be an "ethnic group" rather than people who look "alike" or share a common nation? | Those three classifications are of Race, not ethnicity. Ethnicity are subgroups to those that also include cultural factors in addition to the genetic ones.
What you are missing is that geographic isolation caused many mutations that happen to favor one group more than others numerous times. For Example: fair skin an... | [
"It is difficult to define the ethnic group a person belongs to, especially in Western societies where ethnic groups are porous and fluid. Individuals often shift from one ethnic identity to another as they transition between life stages. Ethnic group membership is constructed not just on the basis of descent but a... |
why is there one standard for music and movie playback that multiple manufacturers use but not for video games. | Actually they do. Both PS4 games and Xbox One games use Blu-Ray discs.
The reason why you can't play a game for one console on the other however is twofold. First, the encoding done on the disks at the time they're burned which includes code that prevents "unapproved" disks from being used. This is why you can't just... | [
"With the re-popularization of FMV games in the early 1990s following the advent of CD-ROM, higher-end developers usually created their own custom FMV formats to suit their needs. Early FMV titles used game-specific proprietary video renderers optimized for the content of the video (e.g., live-action vs. animated),... |
can someone [eli5] what would happen if the economy collapses. | If the economy completely collapses (which is unlikely) unemployment will rise far above 10%, it could go as high 25% or even 30% if things got *really really* bad. Absolutely everyone but those who had large amounts of money in savings would feel the effects, and even those who felt alright might have difficulty if th... | [
"Economic collapse is any of a broad range of bad economic conditions, ranging from a severe, prolonged depression with high bankruptcy rates and high unemployment (such as the Great Depression of the 1930s), to a breakdown in normal commerce caused by hyperinflation (such as in Weimar Germany in the 1920s), or eve... |
how does excess fertilizer burn the roots of a plant? | The same way that too much of any vitamin will cause you to overdose. Depending on what the fertilizer is composed of and how the plant process and stores it, an excess of a nutrient could overwhelm the plant’s ability to process it. Since plants can’t really get rid of excess nutrients, they have to store them, and wh... | [
"Careful fertilization technologies are important because excess nutrients can be detrimental. Fertilizer burn can occur when too much fertilizer is applied, resulting in damage or even death of the plant. Fertilizers vary in their tendency to burn roughly in accordance with their salt index.\n",
"BULLET::::- Rad... |
How was Chinese styled-communism different from Soviet styled-communism during the era of Mao/Khrushchev and then Brezhnev? | This will be a bit disjointed I think, I'm in a bit of a rush:
I suppose the two big picture things to keep in mind between the Soviet Union and China during those periods are firstly Mao's version of Communism put a lot more emphasis on the peasantry and communes compared to the urban workers and industrialisation th... | [
"From 1956 to the late 1970s, the Communist Party of China and their Maoist or anti-revisionist adherents around the world often described the Soviet Union as state capitalist, essentially using the accepted Marxist definition, albeit on a different basis and in reference to a different span of time from either the... |
Did the introduction of Emperors affect the Roman army? | Octavian was left holding a bag of over 60 legions after Actium, his own and the majority of Antony's legions (which had defected to him). The highly professional, standing army that most people think of when talking of the Roman army is the army of the Principate as reorganized by Augustus, not the army of the Republi... | [
"Arminius was not the only reason for Rome's change of policy towards Germania. Politics also played a factor; emperors could rarely trust a large army to a potential rival, though Augustus had enough family members to wage his wars. Also, Augustus, in his 40-year reign, had annexed many territories still at the be... |
why do we say that spiderwebs are "stronger than steel"? | because strength is measured proportionally to the size of the object in question. In this case, the strength being measured is tensile strength (or how strong it is while being pulled, think of trying to measure how much weight you could hang on one strand of silk before it snapped)
We don't think of spider webs as ... | [
"Spider silk has some amazing natural properties and is one of nature’s strongest materials. Spider’s dragline silk has a tensile strength (force by which it can be stretched without breaking) similar to alloy steel, or about half as strong as Kevlar. Weight for weight it is five times stronger than steel. One appa... |
how does a dog know it's the owner walking up to their door as opposed to a stranger? | Dogs have outstanding hearing. Even a person can often identify another person coming from the sound of how they walk. | [
"While the dog is walking with its owner, a half-silhouette of a person is quickly raised 3 metres from the dog. The dog should totally overcome its fear and return to a calm state, indicated by 'contact' with the cut-out (judged by the observer). If the dog is still uncertain, the step progresses to other phases, ... |
what would it take for a country to actually create a post-scarcity society, and how far are we away from realistically making it happen? | Post-scarcity societies can't really exist, because some things are inherently scarce. There will always be a scarcity of concert tickets, for instance. Even if we use technology to broadcast the concert across the world, there is a scarce amount of *front-row seat* tickets with added value, and the usual market mechan... | [
"...to completely interrupt production in the whole country, and stop communication and consumption for the ruling classes, and that for a time long enough to totally disorganise the capitalistic society; so that after the complete annihilation of the old system, the working people can take possession through its l... |
what is the biological process behind the memoryloss of pot smokers? | Basically, when you smoke pot it causes you to lose focus.
When you're sober, your brain stores information in a pretty complex way, but basicly it is stored in very short term (memory lasting few seconds), then moved to short term (a few moments), and eventually long term if its determained to be important.
When yo... | [
"It is unstable, and slowly decarboxylates into THC during storage, and the THC itself slowly degrades to cannabinol, found with potential immunosuppressive and anti-inflammatory activities. When heated or burned, as when cannabis is smoked or included in baked goods, the decarboxylation is rapid but not complete; ... |
In medieval Europe, would kings' young widows be expected to remarry? | Probably the most famous re-married queen is Eleanor of Aquitaine. After bearing two daughters to Louis VII of France, she got into a bit of a scandal resulting in the annulment of their marriage. She later remarried to the future Henry II of England. Which caused a whole host of problems as it meant that the English k... | [
"In 1535, the King was widowed by Catherine of Saxe-Lauenburg and left with only one legitimate child and heir. A new marriage for the King was deemed necessary, and his decision to choose a spouse from among the nobility has been explained by the need to secure inner support and allies among the nobility for his r... |
how do 2-party governments work? surely one party would always have a majority in the goverment, and therefore win every vote. | Not necessarily, especially in countries like the US. Here in the US, the elections of our executive branch are separate from the elections of our Representatives, which are again separate from the elections of our Senators.
What this means is that you can have a Democratic President, and a Republican controlled House... | [
"A two-party system often develops in a plurality voting system. In this system, voters have a single vote, which they can cast for a single candidate in their district, in which only one legislative seat is available. In plurality voting (also referred to as first past the post), in which the winner of the seat is... |
How does a cell decide between undergoing apoptosis or necrosis? | > It seems there is a lot of overlap between the pathways and mechanisms.
There is some cross over, but you can generally tell the difference between the two by their hallmarks.
* [Apoptosis](_URL_1_) or genetically programmed cell death generally only affects one cell or a small group of cells and is generally a ... | [
"The initiation of apoptosis is tightly regulated by activation mechanisms, because once apoptosis has begun, it inevitably leads to the death of the cell. The two best-understood activation mechanisms are the intrinsic pathway (also called the mitochondrial pathway) and the extrinsic pathway. The \"intrinsic pathw... |
can you change your genetics? | In the great majority of cases, no. Your genetics, at least in terms of what you would pass down to your children, are fixed. Your body does modify gene *expression*: you keep the same genes, but your body can 'turn them off' under certain circumstances. This usually doesn't affect gametes (egg/sperm cells), though, so... | [
"The kind of technology used in genetic engineering is also being developed to treat people with genetic disorders in an experimental medical technique called gene therapy. However, here the new gene is put in after the person has grown up and become ill, so any new gene is not inherited by their children. Gene the... |
Belgian independence and its borders | That's a pretty big question. I tried to write up an answer for this and found myself writing about territorial shifts during the Middle Ages and the Burgundian Netherlands... but that might've been unnecessarily in-depth. I'll just try to stick closer to your questions this time:
As I mentioned, the process of territ... | [
"Belgium, a constitutional monarchy, received its independence in 1830 after a revolution against the Dutch government of the United Kingdom of the Netherlands. By the time Belgian independence was universally recognized in 1839, most European powers already had colonies and protectorates outside Europe and had beg... |
video game edition! why don't all hd ports from past consoles run at 60fps without stuttering? | Because they have to use an emulator that is shitty in order to play on the PS3 at all. It would cost a lot of money to do that. | [
"The Xbox 360 and PlayStation 3 versions do not have a V-Sync feature which later Lego video games have, meaning that there is a possibility of tearing in the image despite the fact that they are running in progressive scan mode, depending on the HDTV's native resolution & refresh rate, due to the simplistic nature... |
How are nutrients/chemicals in food dispersed to where they are needed in the body? | Almost everything is extracted from food in your intestine and directly transferred to blood. There are lots of blood vessels right next to your intestine that make that work.
(The only exception is fat, which is extracted from food in your intestine and transferred to your lymphatic vessels and *then* transferred to ... | [
"These agents work by binding to phosphate in the GI tract, thereby making it unavailable to the body for absorption. Hence, these drugs are usually taken with meals to bind any phosphate that may be present in the ingested food. Phosphate binders may be simple molecular entities (such as magnesium, aluminium, calc... |
if pi is an infinite non-repeating number, then it contains an infinite amount of information. shouldn't this be impossible? | This is a common misconception.
First of all, Pi isn't infinite - it's a finite number that lies somewhere between 3.14 and 3.15. If we try to write Pi as a decimal fraction, we get an infinite, non-repeating sequence of digits. This is because Pi is irrational, and this property is true for every irrational number, w... | [
"The impossibility of answering truly the question whether the 100th (or 10,000th) decimal in the evaluation of Pi is or is not a 9, splendidly illustrates how impossible it is to predicate truth in abstraction from actual knowing and actual purpose. For the question cannot be answered until the decimal is calculat... |
Do tardigrades have bones? How do they move around? | Without going into too much detail, bones and cartilage aren't really the best mechanism at that level; they're heavy and take up too much space. The inside of a tardigrade, like most invertibrates, is goopy soup and gauzy membranes. Figure 2 of [this paper](_URL_0_) has a reasonable diagram of their internals.
The mo... | [
"Tardigrades have barrel-shaped bodies with four pairs of stubby legs. Most range from in length, although the largest species may reach . The body consists of a head, three body segments each with a pair of legs, and a caudal segment with a fourth pair of legs. The legs are without joints, while the feet have four... |
Why is there a ton of heat during reentry into the atmosphere? | In the broadest terms, when something has been in orbit and is reentering the atmosphere, it is in the process of going from moving VERY fast with respect to the air to being at rest with respect to the air.
That means there is a VERY large amount of kinetic energy that has to go somewhere (as well as a comparatively ... | [
"During its reentry into the atmosphere, the ARD's heat shield is exposed to temperatures reaching as high as 2000 °C and a heat flux peaking at 1000 kW/m2, resulting from the ionisation of the atmosphere, which is in turn caused by the vehicle travelling at hypersonic speeds, in excess of 27,000 km/h during parts ... |
On the 1977 Panama Canal handover | President Carter's primary argument in releasing US control of the Canal was that the act would improve relations with Latin America, which viewed American control of the Canal as an imperial act. In return for the dissolution of the Canal Zone, the United States would be shown as being an ally and supporter of the sov... | [
"Ten years after construction was complete, this arrangement was becoming unacceptable to the Panamanians and they insisted that the United States give to Panama all the Canal Zone property they had purchased, ownership and control of the canal, ports, water supply, etc., and to submit the Canal Zone to Panamanian ... |
why sometimes when i open my mouth, very rarely, a stream of liquid flies out for a second | That's called gleeking! I can do it on command. My husband thinks I'm weird, or have raptor spray | [
"In scuba diving, a freeflow occurs when the diving regulator continues to supply air instead of cutting off the supply when the diver stops inhaling, or starts to flow when out of the diver's mouth due to a pressure difference over the diaphragm or a bump to the purge button, and continues to flow due to the \"ven... |
We've all heard of Benedict Arnold and his switching of sides. Was there any British officers or troops that went to the American side? | I am no expert, and as such my post ought to be deleted if it's not helpful or accurate, but I will do my best.
Perhaps one of the more well-known spies for America during the revolution was Nathan Hale, whose famous and somewhat disputed last words at his hanging were said to be "I only regret that I have but one lif... | [
"Arnold's troop movements did not escape British notice. General Thomas Gage in Boston was aware that Arnold's troops were \"gone to Canada and by way of Newburyport\", but he believed the target to be Nova Scotia, which was at the time virtually undefended. Francis Legge, the governor of Nova Scotia declared marti... |
how is electronic banking managed, wherein money can't just appear out of nowhere, considering that it's just a number in a computer? | Banks _are_ permitted to create "new money" in the form of loans. It's just there are very heavy procedures to follow to do so, and by regulation they can't create more new money than solvency rules require. Meaning they have to demonstrate that for every X dollars they lend out in new loans they own Y dollars in act... | [
"Several computers work together in a distributed system. Each of them represents a bank account holding a certain amount of money. The participants can transfer money between their accounts by exchanging messages.\n",
"Each financial institution can determine the types of financial transactions which a customer ... |
Does a stronger shockwave neccessarily mean a louder soundwave? | The actual shock is very short lived and near the explosion. When it has traveled all the way to the observers it has dissipated a lot. I don’t think the soldiers in the movies were standing close to the bomb.
If you look at the videos of the tests done to houses etc you can see how destructive the winds are much clo... | [
"Shock waves are formed when a pressure front moves at supersonic speeds and pushes on the surrounding air. At the region where this occurs, sound waves travelling against the flow reach a point where they cannot travel any further upstream and the pressure progressively builds in that region; a high pressure shock... |
How good is the science behind massage therapy? Muscle knots, scar tissue, fascial adhesions: are any models or causes proven in peer-reviewed journals? | There is some evidence in some conditions. For example this [Cochrane review of the evidence for massage in back pain, published in Spine](_URL_0_). It appears to me that the evidence of benefit is not overwhelming. I think you need to consider each medical condition separately and look for the evidence of benefit for ... | [
"It has been suggested that massage therapy for TMD improves both the subjective and objective health status. \"Friction massage\" uses surface pressure to causes temporary ischemia and subsequent hyperemia in the muscles, and this is hypothesized to inactivate trigger points and disrupt small fibrous adhesions wit... |
how do the doctors/scientists in cdc actually work on cures? where do they even start? | To explain in the simplest way possible, the process for curing a disease starts with carefully studying and analyzing the disease to figure out exactly how it functions. What causes it, what effects it has, etc. For example, is it a bacteria or a protein, what functions and materials from the body does it grow off of,... | [
"The organization accepts almost any type of medical supplies, including catheters, IV lines, and walkers. It also accepts capital equipment such as ultrasound machines and operating tables. It works with a number of hospitals, mainly in the U.S. Northeast, that place recycling bins in operating rooms and other are... |
how did the australians lose the emu war | There were only a few soldiers assigned to eradicate the emu, a small amount of ammunition and their main weapon was a machine gun on a car, they were unsuccessful because an emu can often take more than one shot to kill and even then can run a long way before it does, making it difficult for the soldiers to assess how... | [
"Following the British declaration of war on the Japanese empire, the leadership of the British Phosphate Commission urged the Australian government to assist in the evacuation of BPC employees. The authorities were slow to respond, due to reports speculating that an invasion of the island by Japan was unlikely bec... |
Can we synthesize glucose artificially from basic starting components of CO2, O2, H2O and heat/electricity, without using plants? | Here's the short answer: there are a variety of enzymes that can facilitate "putting together" larger carbon chains from initial sources like CO2 or CO (and switching between CO and CO2 is a matter of using any of a variety of redox catalysts.) (Source: _URL_0_) And yes, we know enough about functional transformations ... | [
"-Glucose does not occur naturally in higher living organisms, but can be synthesized in the laboratory. -Glucose is indistinguishable in taste from -glucose, but cannot be used by living organisms as a source of energy because it cannot be phosphorylated by hexokinase, the first enzyme in the glycolysis pathway. O... |
Does cellular senescence directly impact organismal senescence? | Cells receive and respond to survival/apoptotic signals independently, so the senescence or death of one cell does not directly impact those around it. This is key since [controlled apoptosis is a normal part of embryonic development](_URL_0_) in multicellular organisms. However, a multicellular organism relies on coor... | [
"Cellular senescence was first formally observed cellular in 1965 by Leonard Hayflick, who demonstrated that certain cells have limited ability to proliferate in-vitro. After several replications, certain cells can lose their ability to divide, but still remain functionally viable. These phenomena became known as c... |
Tuesday Trivia | The Scent of History | While I could probably write an entire essay just on the diversity of smells in 18th century trade shops (linseed oil shows up everywhere and is my personal favorite), I'll throw out an old myth/mixup instead. So, in the 18th century and 19th century mercury was commonly used in the felting process to make hat blanks (... | [
"It has been suggested that the legend originated in a sermon given by Caesarius of Heisterbach in which he reflects on the occasion of the translation of the remains of Saint Elizabeth, in 1236. Caesarius speaks of a sweet aroma that emanates from the grave as soon as it is opened (a common theme in hagiography). ... |
How come if something is moving faster than a certain speed in a picture, it turns up as a blur? | In order to take a picture, the shutter of a camera stays open for a short length of time. The amount of time varies, and as a result the speed at which an object has to move in order to show up as a blur varies. If, for example the shutter speed (time) is 1/60 of a second, the object in the frame has 1/60 of a second ... | [
"Motion blur can be used artistically to create the feeling of speed or motion, as with running water. An example of this is the technique of \"panning\", where the camera is moved so it follows the subject, which is usually fast moving, such as a car. Done correctly, this will give an image of a clear subject, but... |
What are some of the most "interesting" books on Cromwell & the English Civil Wars? | A major development has been to see the civil war as a war of the three kingdoms. A few sources on Ireland :
T. C. Barnard, *Cromwellian Ireland* (1975)
Nicholas Canny, *Making Ireland British 1580-1650* (2001)
Jane Ohlmeyer, *Ireland from independence to occupation 1641-60* (1995)
Micheál Ó Siochrú, *God's executi... | [
"Cromwell is an 1820 verse tragedy by Honoré de Balzac. It was Balzac's first work as an author, when he decided to quit his career as a solicitor to become an independent writer. That decision displeased his mother, who agreed to give him the bare minimum of money to live on his own, in order to discourage him to ... |
how is it schools in the united states can teach creationism or intelligent design in their science classes instead of evolution whenever it is clearly specified in nclb (no child left behind) that all teachings must be scientifically based methods? | They can't, legally speaking. Teaching creationism or any of its badly disguised cousins (such as 'intelligent design' or 'creation science') is illegal in public school science classes in the US, as per repeated rulings at [various levels]( _URL_1_ ) of courts all the way up to [the SCOTUS itself]( _URL_0_ ). Every ti... | [
"The school board claims there are \"gaps\" in evolution, which it emphasizes is a theory rather than established fact, and that students have a right to consider other views on the origins of life. The school board claims it does not teach intelligent design but simply makes students aware of its existence as an a... |
why do some things cut better with a serrated knife and others with a straight blade? | It actually depends on a few factors. What you are cutting, the type of knife or blade you are using, and other things like temperature of the knife and the object you are cutting.
The biggest determiner, is the thing you are cutting. Soft, malleable things like loaves of bread, or very loose meat, don't cut well with... | [
"Cuts made with a serrated blade are typically less smooth and precise than cuts made with a smooth blade. Serrated blades can be more difficult to sharpen using a whetstone or rotary sharpener than a non-serrated, however, they can be easily sharpened with a diamond. Serrated blades tend to stay sharper longer tha... |
Is there another way to potentially power hypothetical devices (computers and such) besides electricity | Sure, there are many other ways to power computers besides electricity. There are [chemical computers](_URL_3_), [DNA computers](_URL_4_), and [optical computers](_URL_0_) that exist today, at least in prototype stages. [Mechanical computers](_URL_1_) were used in the past. [Quantum computers](_URL_2_) don't neces... | [
"Electric power systems can be classified in multiple different ways: non-linear, dynamic, discrete, or random. Artificial Neural Networks (ANNs) attempt to solve the most difficult of these problems, the non-linear problems. \n",
"Nominal power is the nameplate capacity of photovoltaic (PV) devices, such as sola... |
Did the Russian population ever experience a feeling of 'Manifest Destiny' towards Siberia and eastern Russia like Americans did with the American West? | Well, the first thing we need to do is define "population". Who precisely would be feeling Manifest Destiny? Serfs certainly did not, but at different points various parts of the Tsarist elite body, or educated intellectuals critiquing that body, suggested an idea of Siberia as the manifest destiny of the Russian Empir... | [
"According to Wilson, negative attitude towards the Russian Empire had no roots in the country itself, but was fueled by attitude of the British Empire, at a time when New Zealand was still a British colony. It was aggravated by lack of information about Russia and contacts with it due to the mutual remoteness. Var... |
why are political parties in america so polarized? | Our news media is very polarized, and most people seem to gravitate to media outlets (formal and social) that their friends use. This reinforces that polarization.
And our leadership, across the board, has learned to stoke these fires for votes. (People who think only the 'other side' is guilty of this simply don't re... | [
"Some scholars argue that diverging parties has been one of the major driving forces of polarization as policy platforms have become more distant. This theory is based on recent trends in the United States Congress, where the majority party prioritizes the positions that are most aligned with its party platform and... |
Can a single celled organism get cancer? | No. "Cancer cells are defined by two heritable properties: they and their progeny (1) proliferate in defiance of the normal constraints and (2) invade and colonize territories normally reserved for other cells." (Essential Cell Biology, Garland Science, 2010)
A single-celled organism thus can't get cancer because they... | [
"In order for a cell to become cancerous it must undergo a significant number of alterations to its DNA sequence. This cell model suggests these mutations could occur to any cell in the body resulting in a cancer. Essentially this theory proposes that all cells have the ability to be tumorigenic making all tumor ce... |
how are submersibles different from submarines and why are submersibles not fully autonomous? | It's a definition problem
If a vessel can submerge and operate autonomously it's a submarine
If it can submerge but can't operate autonomously it's a submersible
Autonomous in this case doesn't mean self driving, but instead by itself without assistance. A submarine will have air processing and food stores that allo... | [
"Apart from size, the main technical difference between a \"submersible\" and a \"submarine\" is that submersibles are not fully autonomous and may rely on a support facility or vessel for replenishment of power and breathing gases. Submersibles typically have shorter range, and operate primarily underwater, as mos... |
what would happen if i shut my car off while driving? | The power steering will be disabled, I almost crashed once when my car died on me in a curve! | [
"If the driver has exited the vehicle with the engine running (to for example retrieve an item, open a gate or close a garage door, etc.), a vehicle in false park can shift into powered reverse from a few seconds to several minutes or longer, after the driver has exited, and then run over the driver or a bystander.... |
why does it smell worse when you fart in water? | There is also another explanation. When you fart in the air due to "diffusion" the fart and the "normal" air mix up, so that you smell less fart gas.
In water (usually in the bath tub, where you are in and your head close to the water surface) the fart gas moves up the water bubble without mixing with the air. When it... | [
"Some time after leaving the body, urine may acquire a strong \"fish-like\" odor because of contamination with bacteria that break down urea into ammonia. This odor is not present in fresh urine of healthy individuals; its presence may be a sign of a urinary tract infection.\n",
"An online study of people's respo... |
why after downloading some applications, do i need to restart but others work straight away? | Because some applications use low-level resources which are already loaded into memory and used continuously by other applications and the operating system as well. Since reloading that particular resource in to memory is way too hard without crashing other applications or the OS itself, the best is to make the user re... | [
"Shortly after the free version of the game comes out, the influx of players starts to affect the online component, which occasionally crashes and disconnects users, causing them to save progress they have made in the game. The company redeploys its resources and tries to mitigate the situation by incrementally imp... |
in academic articles, why are units of area often shown as being multiplied to the power of -1? | The word "per" implies "divided by." For example, miles per hour can be represented as (miles)/(hour). Newtons per square meter (the SI unit of pressure, also known as the Pascal), can be represented as (N)/(m^2 ). m^2 is the SI unit of area.
Also, to directly answer your question, a/b is equivalent to ab^-1. Another ... | [
"There are corresponding units of area and volume, the square yard and cubic yard respectively. These are sometimes referred to simply as \"yards\" when no ambiguity is possible, for example an American or Canadian concrete mixer may be marked with a capacity of \"9 yards\" or \"1.5 yards\", where cubic yards are o... |
Several questions reguarding light and colors- | > What is a blacklight, and how does it work?
A blacklight is a flourescent lamp that emits light in the ultraviolet (UV) range. This wavelength range is too short for the human eye to see efficiently, although usually we do see a modest puple-ish glow from a blacklight. Some of this purple glow may be from our eyes... | [
"A color rendering index (CRI) is a quantitative measure of the ability of a light source to reveal the colors of various objects faithfully in comparison with an ideal or natural light source. Light sources with a high CRI are desirable in color-critical applications such as neonatal care and art restoration. It i... |
how are glaciers (the largest source of water) fresh water but the ocean is made of salt water? | Sea water has gathered dissolved ions in it for billions of years. Thats why its salty. Those ions don't evaporate with the water and the don't fall as snow or rain that later becomes freshwater sources on Earth.
The ice caps may be the largest source of fresh water on Earth at the moment, but the oceans have been ar... | [
"Apart from the conventional surface water sources of freshwater such as rivers and lakes, other resources of freshwater such as groundwater and glaciers have become more developed sources of freshwater, becoming the main source of clean water. Groundwater is water that has pooled below the surface of the Earth and... |
Is the coin toss paradox real? | The 4 tails already happened. You're not betting on a 5-tails streak happening in general, you're betting on having tails next.
Not only that, but the chance of getting a 5-tail streak when you already have a 4-tail streak is, in fact, 50%. Let's look at the set of all possible variations of 5 coin flips. Since we alr... | [
"This does not state if the coin flip is for each question, or each \"session\", that is the entire series of questions. If interpreted as being a single random selection which lasts for the duration of the session, Rabern and Rabern show that the puzzle could be solved in only two questions; this is because the co... |
please eli5: finding the exact value of sin, cos and tan. | I don't think it can be done like you're 5, but [read this section on the Wiki article for them](_URL_0_).
| [
"In the 7th century, Bhaskara I produced a formula for calculating the sine of an acute angle without the use of a table. He also gave the following approximation formula for sin(\"x\"), which had a relative error of less than 1.9%:\n",
"The first measure of original sin (OSIN1) is defined as one minus the ratio ... |
why can’t those liquid meal replacements completely substitute the benefits of eating real solid food? | They can. The problem is that unless they are made specifically for you, then the nutrients in them may be unsuitable or in incorrect amounts related to your requirements. | [
"A clear liquid diet, sometimes called a \"surgical liquid diet\" because of its perioperative uses, consists of a diet containing exclusively transparent liquid foods that do not contain any solid particulates. This includes vegetable broth, bouillon (excepting any particulate dregs), clear fruit juices such as fi... |
Why do Uranus's rings and moons orbit 90 degrees to the sun too? | Let's not forget that the whole planet is tipped (something like 97-98 degrees) and Uranus' poles point towards the sun. The rings and satellites still orbit the equatorial region of the planet (which is the relatively normal). It's believed that some "near miss" with another large object early in the formation of the ... | [
"Because Uranus orbits the Sun almost on its side, and its moons orbit in the planet's equatorial plane, they (including Titania) are subject to an extreme seasonal cycle. Both northern and southern poles spend 42 years in a complete darkness, and another 42 years in continuous sunlight, with the sun rising close t... |
Will the cores of the gas giants ever cool? If they will, what will become of the rest of the planet? | First we need to understand the current structure of Jupiter.
At the top we have the atmosphere, made mostly of cold hydrogen gas. As we dive deeper, the pressure and temperature starts rising. Eventually once hot and dense enough we hit a layer where hydrogen has transitioned to a "supercritical fluid", a state that... | [
"Gas giants also have cores, though the composition of these are still a matter of debate and range in possible composition from traditional stony/iron, to ice or to fluid metallic hydrogen. Gas giant cores are proportionally much smaller than those of terrestrial planets, though theirs can be considerably larger t... |
What's the role of a salt in a buffer solution? Wouldn't using just a weak acid/base be enough? | The purpose of a buffer is to keep the pH of a solution relatively constant, so that [its pH changes very little when a small amount of strong acid or base is added to it.](_URL_0_). If you had only acetic acid in solution, then it **would** neutralize a strong base, like NaOH, if it were added. But if you added a st... | [
"A balanced salt solution (BSS) is a solution made to a physiological pH and isotonic salt concentration. Solutions most commonly include sodium, potassium, calcium, magnesium, and chloride. Balanced salt solutions are used for washing tissues and cells and are usually combined with other agents to treat the tissue... |
why do video games crash and stop working, rather than produce an error and move on? | I'm speaking from a general programming standpoint, not as a game dev, so my information may be inaccurate. That being said:
Programs that crash do so because they try to execute an impossible action. Either dividing by zero, accessing memory that doesn't exist, etc. This causes crashes because, if we didn't, and just... | [
"A similar problem can occur when attempting to accomplish a game goal using a certain combination of actions, locations and objects, which may appear rational and legitimate to the player, and are accepted by the game, only to be incorrectly handled and resulting in a gameplay error or game crash. \n",
"Because ... |
why is it often only possible to focus on one eye when trying to look someone in the eyes | Having two eyes never meant we were able to focus on two things simultaneously. Our sight converges on whatever it is we're focusing on, and the stereoscopy provides us with depth perception. | [
"The brain's ability to see three-dimensional objects depends on proper alignment of the eyes. When both eyes are properly aligned and aimed at the same target, the visual portion of the brain fuses the forms into a single image. When one eye turns inward, outward, upward, or downward, two different pictures are se... |
how the u.k. elects a prime minister and what makes this most recent election so weird? | The UK citizenry does not vote for the Prime Minister at all. They vote for their Member of Parliament (MP) which is roughly the equivalent of the US House of Representative, and then the party that gets control of Parliament (or coalition if on party does not get enough seats) chooses the Prime Minister.
And yes, th... | [
"The Prime Minister is elected from the results of a general election which takes place every five years. The President is required to appoint the leader of the party who in his opinion has the most support of the members of the House of Representatives to this post; this has generally been the leader of the party ... |
Culture in the States Pre WWI | Hooray! Ok, so here's a brief overview of American popular music from roughly the Civil War until World War I. Not a full answer to your question, but hey.
In the area of live music, by far the most popular popular music form in mid-19th century America was blackface minstrelsy, though its popularity steadily declin... | [
"After the Civil War, the music industry of the United States had a rapid development. That time was regarded as the birth of American pop music. America composers create songs depend on America culture at that time. Then, a variety of musical styles have been formed such as Country music and Jazz. And these music ... |
how is sweating good for your health? | It keeps you from overheating and flushes out your sweat glands, keeping them from clogging and getting infected. | [
"Oxybutynin's tendency to reduce sweating can be dangerous. Reduced sweating increases the risk of heat exhaustion and heat stroke in apparently safe situations where normal sweating keeps others safe and comfortable. Adverse effects of elevated body temperature are more likely for the elderly and for those with he... |
Did flying creatures evolve with the flight feature independently, or do they all share a common ancestor? | Within various taxonomic groups, the ability to fly may be inherited from a common ancestor.
Different groups independently developed the ability to fly.
For example, all bats may have inherited flight from a common ancestor.
All pterosaurs may have inherited flight from a common ancestor.
But bats, pterosau... | [
"A number of animals have evolved aerial locomotion, either by powered flight or by gliding. Flying and gliding animals (\"volant\" animals) have evolved separately many times, without any single ancestor. Flight has evolved at least four times, in the insects, pterosaurs, birds, and bats. Gliding has evolved on ma... |
why you get thrown into a corner when you are driving around a bend but don't when you fly in circles? | Because the plane banks, you feel the turn as pushing down on you rather than to the side like in a car. | [
"BULLET::::- Spin: An attacking driver may position their car such that they contact the rear of the car in front from the side causing the car ahead to lose traction and spin. This is a relatively unusual technique partly because of the risk to the attacker of being blocked by the car they have spun but also becau... |
How did introns and exons get their names? | Exons are expressed and introns are intragenic. | [
"An exon is any part of a gene that will encode a part of the final mature RNA produced by that gene after introns have been removed by RNA splicing. The term \"exon\" refers to both the DNA sequence within a gene and to the corresponding sequence in RNA transcripts. In RNA splicing, introns are removed and exons a... |
why did socialism and communism reach mainstream political status in europe & asia, but remained comparatively fringe in the us? | Thank the American Dream.
Your average working Americans don't see themselves as an exploited working class. They're just waiting for their big break to become millionaires. Socialism isn't in the best interest of the people on top, and thanks to the *American Dream* we're all just a hop skip and a jump from being mi... | [
"Socialist and Communist parties around the world saw drops in membership after the Berlin Wall fell and the public felt that free market ideology had won. Libertarian, neoliberal, nationalist and Islamist parties on the other hand benefited from the fall of the Soviet Union. As capitalism had \"won\", as people sa... |
in sound, what is a note? | Music Q's! Love 'em.
Here's the deal with "tone" or "timbre". When I play a single note (let's take your C# and change it a bit to be an A, because I'm a lazy, lazy bastard of a musician) I am not *actually* playing a single note. I am playing a single note that CAUSES a bunch of notes that your brain (and mine) in... | [
"In music, a note is the pitch and duration of a sound, and also its representation in musical notation (♪, ♩). A note can also represent a pitch class. Notes are the building blocks of much written music: discretizations of musical phenomena that facilitate performance, comprehension, and analysis.\n",
"Although... |
How does the ISS prevent shifting when Soyuz or other spacecrafts dock? | This is not an issue.
Imagine you're on board the ISS. It weighs about a million pounds, and cruises around earth at almost 5 miles a second. Soyuz pulls up alongside to dock. The Russian craft weighs about 15 thousand pounds, and as it gets closer to the ISS, it matches velocity with the space station (otherwise, the... | [
"Docking and undocking describe spacecraft using a docking port, without assistance and under their own power. Berthing takes place when a spacecraft or unpowered module cannot use a docking port or requires assistance to use one. This assistance may come from a spacecraft, such as when the Space Shuttle used its r... |
Why are the noble metals so unreactive? | Because we live on a planet covered in water.
The best way to understand this, look at the [electrochemical series](_URL_0_), and scroll down to 0, which corresponds to Hydrogen. Now, observe the metals below that point - Your "noble" metals.
Basically, the "noble" metals stay in their metallic elemental form becaus... | [
"The term noble metal is commonly used in opposition to \"base metal\". Noble metals are resistant to corrosion or oxidation, unlike most base metals. They tend to be precious metals, often due to perceived rarity. Examples include gold, platinum, silver, rhodium, iridium and palladium.\n",
"While the noble metal... |
how can space be constantly growing? what emptiness is it replacing, if any? | It's not thought to be replacing anything. Rather over time, any two very distant points in space are further apart.
Our leading theories of the universe are one that is infinite. There's no point where you reach an edge of "stuff," rather it's voids, galaxies, stars, and planets, in every direction forever. So there... | [
"Even if the overall spatial extent is infinite and thus the universe cannot get any \"larger\", we still say that space is expanding because, locally, the characteristic distance between objects is increasing. As an infinite space grows, it remains infinite.\n",
"Golas posits there is no such thing as empty spac... |
Were ancient scholars and philosophers compensated for their work? | As a bit of a placeholder response before an actual expert comes along with a wall of text, I can give you a rough outline of trends. First of all, there did exist something like the concept of a "court philosopher" in the Hellenistic period (so from the death of Alexander the Great in 323 B.C. to the end of the Roman ... | [
"Many of the Ancients' writings would have been lost had it not been for the efforts of the Christian, Jewish and Persian translators in the House of Wisdom, the House of Knowledge, and other such institutions in the Islamic Golden Age, whose glosses and commentaries were later translated into Latin in the 12th cen... |
why don't americans get medical operations done abroad to avoid the staggering costs at home? | _URL_0_
they do | [
"Critics of the industry suggest that the western patients are taking away medical resources from local residents. But according to the MedSolution website, it is because of international patients that local residents’ treatments can be subsidized. For example, MedSolution’s hospital in India, Krishna Heart Institu... |
Did any of the Allies have their own version of the Enigma machine? | While more can be said, please see my answers [here](_URL_1_), [here](_URL_0_) and [here](_URL_2_), which discuss Allied coding systems and the German attempts to break them. | [
"As with other early rotor machine efforts, Scherbius had limited commercial success. However, the German armed forces, responding in part to revelations that their codes had been broken during World War I, adopted the Enigma to secure their communications. The \"Reichsmarine\" adopted Enigma in 1926, and the Germa... |
v-sync in video games. | Monitors don't paint the whole picture at once. Now with flatscreens it's even more confusing than it used to be so let's assume a CRT. The picture is created by lighting up the picture starting in the upper left corner and then going row by row to the bottom right. Then that starts again really fast.
How often the wh... | [
"The Xbox 360 and PlayStation 3 versions do not have a V-Sync feature which later Lego video games have, meaning that there is a possibility of tearing in the image despite the fact that they are running in progressive scan mode, depending on the HDTV's native resolution & refresh rate, due to the simplistic nature... |
how can the government lower college cost effectively? | Severely restrict Pell Grant's and lending for college. The primary reason that it's so expensive is because the general public has too easy access to those funds and colleges have done a great job of gate keeping the general public by saying "you want to make more than $30k a year? Better get ready for $50k in student... | [
"The Federal government provides a block grant to universities based on student enrolment but unrelated to performance and lacking in accountability. When university education was first introduced, students were given free room and board but, since 2003, there has been cost sharing whereby the student pays full cos... |
How much did the Romans learn about fighting elephants from the war with Pyrrhus? Did that knowledge help them in the Punic wars? | The short answer is that the Romans did not learn very much from the Pyrrhic elephants; they learned much more from a succession of battles with Carthage during the Punic Wars themselves.
Here's the long answer. Pyrrhus brought with him Indian elephants, no doubt obtained from the Seleucids (who had a virtual monopol... | [
"The Roman army had not yet seen elephants in battle, and their inexperience turned the tide in Pyrrhus' favour at the Battle of Heraclea in 280 BC, and again at the Battle of Ausculum in 279 BC. Despite these victories, Pyrrhus found his position in Italy untenable. Rome steadfastly refused to negotiate with Pyrrh... |
why can't computers use storage devices as ram? | They can and do, it's called a swap space(unix)/paging file(windows). It can't be the main RAM source though due to speed limitations. | [
"Most home computers of the 1980s stored a BASIC interpreter or operating system in ROM as other forms of non-volatile storage such as magnetic disk drives were too costly. For example, the Commodore 64 included 64 KB of RAM and 20 KB of ROM contained a BASIC interpreter and the \"KERNAL\" of its operating system. ... |
what's the difference between voice, text, and data on modern cell networks? | Voice requires the necessary bandwidth to be reserved for the call duration, while data services take whatever is available. Messages skip the call setup phase entirely. | [
"Historically, voice and data communications were based on methods of circuit switching, as exemplified in the traditional telephone network, wherein each telephone call is allocated a dedicated, end to end, electronic connection between the two communicating stations. Such stations might be telephones or computers... |
Is there really a section in space that emits zero radiation? | Real photo, but terribly misinformed description (as is common on the internet). Read more here:
_URL_0_
_URL_2_
The nebula itself is only half a light year across. Sizable, but not "a billion light years" as the caption says. And it's only 500 light years distant, close enough that no stars lie between it and us. F... | [
"But of course the radiation belts are within Earth's magnetosphere and do not occur in deep space, while organ dose equivalents on the International Space Station are dominated by GCR not trapped radiation. Microscopic energy deposition in cells and tissues is distinct for GCR compared to X-rays on Earth, leading ... |
is it possible to develop a resistance to motion sickness through constant exposure? | The short answer is maybe. Habituation helps most people, but not all. There are a bunch of coping mechanisms that help me, but there are some combinations of motion that will still get me. [This](_URL_0_) article gives you a pretty good overview. The Scopolamine patches work for me, but only if I put one on before I'm... | [
"Often, adaptation is the single most effective solution to simulator sickness. For most individuals, adaptation can occur within only a few sessions, with only a minority of individuals (3–5 percent) never being able to adapt. This adaptation occurs within the psyche of the individual with repeated, controlled exp... |
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