question stringlengths 3 301 | answer stringlengths 9 26.1k | context list |
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why can you "taste" certain foods after burping, even when it is hours later and you have eaten or drank several other types of food and beverages after eating the initial food? | Smell is a major component of how you"taste" foods. Food can stay in your stomach a long while, especially if you're having a hard time digesting it.
Gases from your stomach carry with it the smells of the food in your stomach when you burp. You smell it again, so recall the tasting of the food. | [
"When ingested, the fruit is reportedly \"pleasantly sweet\" at first, with a subsequent \"strange peppery feeling ... gradually progress[ing] to a burning, tearing sensation and tightness of the throat\". Symptoms continue to worsen until the patient can \"barely swallow solid food because of the excruciating pain... |
the genetics of blood types including the rh factor (positive or negative) | Without your SO's blood type the baby's blood type could be any of the blood types.
_URL_0_
This video should help explain everything easily. As for the Rh factor, being + is considered dominate so the baby be positive. | [
"According to a comprehensive study, the worldwide frequency of Rh-positive and Rh-negative blood types is approximately 94% and 6%, respectively. The same study concluded that the share of the population with Rh-negative blood type is set to fall further in the future primarily due to low population growth in Euro... |
De Broglie wavelength depends on momentum, how does this translate to frames where the momentum is zero? | A quantitative treatment would be really awful to do, but in principle, yes. Instead of worrying about the wavelength of the electrons as they pass through a crystal lattice of atoms with well-defined positions, the crystal atoms would instead have to be described in terms of their own de Broglie wavelengths, in which case they no longer have well-defined positions. The interaction between the resulting "smear" of crystal atoms and the stationary electrons would result in the same behavior. | [
"Louis de Broglie postulated that all particles with a specific value of momentum \"p\" have a wavelength \"λ = h/p\", where \"h\" is Planck's constant. This hypothesis was at the basis of quantum mechanics. Nowadays, this wavelength is called the de Broglie wavelength. For example, the electrons in a CRT display h... |
were the nazis aware of how evil they were? | I believe some of them were. There was an experiment done by Stanley Milgram where one was ordered to test a "participant" then give "electric shocks" to them if they got a question wrong. They were more likely to do it if there was someone in the room with them, and even gave "lethal" amount of shocks. The "participant" was acting, of course. This helped to explain why some people do extreme acts when given orders even if they know it's wrong. Really fascinating. Here's the wikipedia on it: _URL_0_ | [
"Despite exploration into the nature of evil in philosophical and fantasy terms, Carmody's depiction of evil as an authoritarian dictatorship society is very realistic and socially significant and more than one or two parallels can be drawn with such societies as Nazi Germany. Comparisons such as these are even spe... |
what is compartmentalization in psychology? | Pretend your brain is a library-
You dont want all of the work problem books mixed in with the childhood memory books!
So, you make sure to organize your library and keep all the books where they belong- that way they dont cause a mess or problem and you can keep enjoying your library.
Basically you keep your emotions and feelings in certain areas, that are usually less "well traveled " so that they dont interfere with your daily life stuff. | [
"\"Compartmentalization\" refers to the separation of spaces in the living system that allow for separate environments for necessary chemical processes. Compartmentalization is necessary to protect the concentration of the ingredients for a reaction from outside environments.\n",
"When referring to engineering, c... |
A friend of mine got some official papers from his grandfather in Ottoman turkish and can't translate them by himself. Is there a historian that knows what they are about? | It looks like the top picture is an official document in Arabic script, and the bottom one is its translation or transliteration.
If this guess is correct, the document is a title for a piece of land according to the words in the top left corner. At the bottom there is a date, of which I can only make out the year: 1287 in the Islamic calendar (1870 CE).
| [
"It was published by William Nosworthy Churchill, an Englishman who moved to Turkey aged 19 and was familiar with the Turkish language and the Ottoman Turkish script having worked as a translator at the American Consulate in Constantinople. \"Ceride-i Havadis\" published foreign news items translated by Churchill a... |
what is the difference between $5 department store headphones and $500 headphones? do they fundamentally have the same components inside or made with different materials? | The size, weight, shape, material, and electrical properties of the transducer inside the headphones make a big difference in the quality of the sound. Better made headphones will sound much closer to the actual recording than cheap department store headphones.
Professional headphones that faithfully reproduce music and also won't fall apart can be had for between $75-$100 USD.
Source: Part of my day job is to record video and audio of large conference sessions. I need headphones that are very durable and also very accurate. | [
"As a consequence all intervals of any given type have the same size (e.g., all major thirds have the same size, all fifths have the same size, etc.). The price paid, in this case, is that none of them is justly tuned and perfectly consonant, except, of course, for the unison and the octave.\n",
"As a consequence... |
Health questions about bacon |
A risk factor for heart disease is something that increases your chance of getting it. You cannot change some risk factors for heart disease, but others you can change.
The risk factors for heart disease that you CANNOT change are:
* Your age. The risk of heart disease increases with age.
* Your gender. Men have a higher risk of getting heart disease than women who are still getting their menstrual period. After menopause, the risk for women is closer to the risk for men. See: Heart disease and women
* Your genes. If your parents or other close relatives had heart disease, you are at higher risk.
* Your race. African Americans, Mexican Americans, American Indians, Hawaiians, and some Asian Americans also have a higher risk for heart problems.
Many things increase your risk for heart disease:
* Diabetes is a strong risk factor for heart disease.
* High blood pressure increases your risks of heart disease and heart failure.
* Extra cholesterol in your blood builds up inside the walls of your heart's arteries (blood vessels).
* Smokers have a much higher risk of heart disease.
* Chronic kidney disease can increase your risk.
* People with narrowed arteries in another part of the body (examples are stroke and poor blood flow to the legs) are more likely to have heart disease.
* Substance abuse (such as cocaine)
* Being overweight
* Not getting enough exercise, and feeling depressed or having excess stress are other risk factors.
The above information is from Pub Med Health of NIH.
You probably have elevated blood cholesterol from animal fat and higher blood pressure because of increased sodium intake (Bacon is very salty, so are many cheeses). At the same time you probably aren't overweight and get exercise, at least if you follow the keto lifestyle and not just the diet. I don't know your substance usage nor whether or not you have diabetes or chronic kidney disease but I'm guessing you don't. So given all of this I would say that even though you exercise and are not overweight you have a pretty good chance of developing heart disease latter on in your life if you continue to fry your eggs in bacon grease and eat cheese and cream all day. That is not the same as clogging your arteries at an early age. It is more likely to happen later given your interest in maintaining a healthy lifestyle through exercise.
Your body makes all the cholesterol it needs *de novo.* That means from scratch and without the contribution of animal fats.
Try to stick to plant oils, not corn or canola but olive, walnut, peanut oils. [These oils](_URL_0_) are not already available to your body. It has to do with unsaturation, double bonds, in the fatty acid chains and the fact that humans cannot introduce double bonds past the 10th carbon. I can describe it in more detail if you would like.
There is enormous evidence for the benefits of reducing both animal meat/fat **and** complex carbohydrates in your diet. Eat mostly fruits, nuts, vegetables and meat only occasionally... This isn't as lame as it sounds. There are many recipes that can be satisfying and easy to cook. You just have to learn how to make them.
I think TinusDeEerste nailed all of this in one word though.
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"Various different opinions circulate about the health risks associated with the consumption of bacon. The World Cancer Research Fund, a non profit organisation focused on cancer research and cancer prevention, carried out research on just this. They conducted an investigation on 51 million people. The results obta... |
East Berlin and East Germany had the Stazi secret police. Did West Germany, particularly West Berlin have a similar organization to protect against spies or terrorists? | From an [earlier answer of mine](_URL_1_)
There were really four different organizations in the FRG tasked with spying during the Cold War and in theory, each worked their own territory. The main German intelligence agency, *Bundesnachrichtendienst* (BND/Federal Intelligence Agency) was focused on conventional spywork, especially with maintaining contacts throughout Europe and was directly subordinate to the Chancellor's office. Domestic intelligence was the task of two agencies, the *Bundesamt für Verfassungsschutz* (BfV/Federal Office for the Protection of the Constitution) and its *Land* counterpart, *Landesämter für Verfassungsschutz* (LfV/ State Office for the Protection of the Constitution). In some ways the BfV operated in the mold of the FBI, investigating overarching domestic crimes, conducting counterintelligence work, and conducting surveillance and analysis of domestic problems. But there are major differences between the two organizations. Neither the BfV not LfV could legally make arrests or conduct interrogations, so they had to operate in a complex web of arrangements with *Land* police. Finally, the *Bundeswehr* maintained its own intelligence service, *Militärischer Abschirmdienst* (MAD/Military Counterintelligence Service) tasked with preventing sabotage and conducting counterintelligence, but also preventing anti-constitutional elements from taking root inside the FRG military.
This web of intelligence networks, interrelated, but bureaucratically separate was a byproduct of the experience of the Second World War and the arbitrary police networks of the Third Reich. There was a widespread consensus among the Western Allied governments and intelligence agencies that German intelligence should "be no new Gestapo," which was a sentiment echoed in Bonn among the Adenauer government. Thus FRG intelligence was to be a new agency for the new Germany. The BfV's name, for example, averred to the importance of the Basic Law and its agents were unarmed. The federal bans on both the KPD and the SRP were justified in part by evidence gathered by domestic agencies, showing the agencies were investigating both left- and right-wing antidemocratic elements in fulfillment of its subordination to the constitution. But in practice, FRG intelligence operated less nobly than its stated goals. Even though Basic Law provided broad protections for privacy and strictures against surveillance, the BfV and LfV sometimes flaunted these rules. By the same token, there was a consistent charge that domestic agencies like MAD and the BfV were "blind in the right eye," meaning that they regarded left-wing terrorism as a greater danger than right-wing groups. FRG intelligence agencies maintained a climate of anticommunism in which investigating left-wing groups received a higher priority than grassroots neonazis and other right-wing extremists.
Part of these problems for FRG intelligence can be traced back to the genesis of the BND: the Gehlen Group. Reinhard Gehlen was the chief analyst of the wartime *Fremde Heere Ost* (FHO/Foreign Armies East), a military intelligence organization devoted to analysis of the Soviet's military capabilities. Although not a trained intelligence agent, Gehlen made military intelligence more professional in ethos and the *Abwehr*'s complicity in the 20 July Plot made Gehlen seek a closer relationship with the SS's SD. Gehlen realized that the writing was on the wall in 1945 and actively sought to carve out a niche for him in the postwar period. He ordered FHO archives to be carefully sealed in drums Bad Reichenhall in Upper Bavaria because he knew it was most likely that this region would come under American occupation. Gehlen also anticipated that FHO knowledge of the Red Army would be appreciated among his American captors and also drew up lists of potential postwar German partners for a future intelligence network.
Gehlen's bets were not wrong, as he struck up a positive relationship with his US Army interrogator Captain John Boker, Jr., whose recommendations that the US utilize FHO archives and German intelligence personnel filtered up the chain of command in the summer of 1945. American military intelligence on Soviet armies and capabilities was only rudimentary and both the archives and personnel were two prominent chips Gehlen could use for himself and his compatriots. Although the OSS initially rejected the utility of using German intelligence assets, the Pentagon did not, and under Gehlen's group, codenamed Bolero, started conducting intelligence gathering for the Army in 1946. The emerging Cold War soon allowed the Bolero group to mushroom into Operation Rusty, which would be a wide-ranging German-run intelligence network working for the US. By 1947, the Gehlen Group was operating out of the former Reichssiedlung-Bormann, which was an NSDAP retreat outside of Munich and it drew in an ever-increasing swath of personnel. This not only included intelligence personnel, but also key military and SS figures. As an October 1948 CIA report by James Critchfield on Rusty noted, the organization was not merely an auxiliary to the US by this time:
> Another important consideration is that RUSTY has closest ties with ex-German General Staff officers throughout Germany. If, in the future, Germany is to play any role in a Western European alliance, this is an important factor. The issue than appears to be whether from a national viewpoint it is desirable for the U.S. [to] completely relinquish control of the resurgent Abwehr and nucleus of a future German General Staff which has been nurtured for three years by the U.S. Occupation Forces.
As with the Amt Blank maintained by elements of the military, the Gehlen Group maintained a shadow bureaucratic presence that would allow it to fully emerge as a separate organization rather quickly once the FRG had its sovereignty restored.
The semi-autonomy of the Gehlen group, something which their alleged American superiors often griped about, allowed for Gehlen to recruit members from a wide range of sources, including the SD, RSHA, and other NSDAP stalwarts. Critchfield noted that "no attention was paid to the character of the recruits, security, political leanings, or quality with the result that many of the agents were blown almost immediately." But the Gehlen organization had positioned itself as the de facto intelligence agency for the FRG, and as a result, it was able to shape the contours of both its personnel and operations, which at times worked against the spirit that underlay the structural division of the FRG intelligence system.
Although GDR's MfS has rightly earned a reputation as a successor to the Third Reich's network of police state terror and surveillance, it was actually the FRG's intelligence services that had the most former Nazis. Despite the reputation of the MfS as a "Red Gestapo", both the SED and Soviet military government paid a good deal of attention to the screening process. When the Soviet Military Occupation Government (SVAG) created K-5, a department of the Eastern zone's German police charged with monitoring internal politics and a precursor of the MfS, SVAG explicitly ruled out anyone with prior membership in either the RSHA or SD from membership in K-5. The MfS continued many of SVAG's restrictions and recruited among youth as a means to get people without a compromised past, even if it meant sacrificing professional experience over the short term. This type of caution was not really present in the Gehlen group, nor in its various successor organizations. The BfV and BND were allowed to employ "freelancers" as assets, and many of the veterans of the Third Reich turned to existing networks of wartime connections. Some of this freelance soon morphed into official membership in the intelligence agencies. Erich Wenger, a RSHA officer involved in counterintelligence as well as security in France, exemplified this career path. According to a [1963 CIA report](_URL_0_) on BfV personnel in light of an impending visit of BfV delegates to the US, the BfV contracted Wenger as an asset in 1950/51 under a pseudonym. Wenger soon became one of the BfV's chief officers for counterintelligence and when his SS background became known, he threatened to leave the agency for MAD, thus depriving the BfV of one of its most experienced counter-intelligence officers. The CIA memo noted that despite this problematic background, Wenger was a firm anticommunist, but Wenger's past soon caught up with him with a *Spiegel* expose about his involvement in anti-partisan atrocities in France, and his trip to the US was cancelled.
Despite the significant continuities in personnel between the Third Reich and the FRG intelligence system there really was not an attempt to recreate National Socialism inside these agencies. Participation in the FRG intelligence bureaucracy instead became a type of occupational *Persilscheine* for those men who were active in the former regime in which their wartime actions acquired an anticommunist gloss devoid of problematic politics. Gehlen's self-serving memoirs, translated by a then young David Irving, played up his wartime activities as an apolitical professional whom Hitler sneered at, but Adenauer did not. The presence of so many former Nazis inside German intelligence contributed to biases in investigation and a more casual disregard of existing laws, but such abuses were nowhere near as rampant as they had been under the Third Reich; nor were they as extensive as the MfS's methods of domestic surveillance, most of which were nominally illegal under the GDR constitution.
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"In Nazi Germany, the \"Geheimstaatspolizei\" (Secret State Police, Gestapo) (1933–1945) was used to eliminate opposition; as part of the Reich Main Security Office, it also was a vital organizer of the Holocaust. Although the Gestapo had a relatively small number membership (32,000 in 1944), \"it maximized these s... |
How do these new robotic prothetic arms work? | I don't study this specifically, but I have followed Nicolelis' work in the past, who focuses on neuroprothesis- or brain-computer interfaces. One thing to understand is that for every movement- let's say lateral movement of the arm- isn't coded by only one neuron. There are populations of cells that can engage a single motor command. In fact there are clusters which code for different directions. Now when you move your arm, each cell cluster that codes for every direction is activated, and a vector analysis is calculated in the brain to determine the overall magnitude to assess the output direction. Researchers have implanted electrodes into the motor cortices, that when connected to a computational program, has been shown to mimic this vector analysis of the brain.
Consequently, researchers have used a robot arm, that when connected to a computer that is analyzing these motor neuron cluster in real-time, can result in relatively accurate prothetic movement. This is just one example mind you, of a invasive prothetic technique. | [
"Rather than designing Domo's arms for absolute precision, Edsinger and Weber designed the arms to work more closely to that of a human. Human arms are adept at sensing and controlling the forces at every joint, giving up precision in position for compliance. Translating this to a humanoid robot required the design... |
Was Newton aware that interplanetary space is a vacuum? If so, how? | He wrote a bit about that in [Opticks](_URL_0_). But in short: yes, he was. Because he was aware that air pressure dropped with altitude. And because the planets moved without friction through it:
> to make way for the regular and lasting Motions of the Planets and Comets, it's necessary to empty the Heavens of all Matter, except perhaps some very thin Vapours, Steams, or Effluvia, arising from the Atmospheres of the Earth, Planets, and Comets, and from such an exceedingly rare Æthereal Medium as we described above.
So basically he considered it a vacuum in its commonly-understood sense of zero pressure (or near it), but still left the door open to some sort of frictionless aether, which could explain how forces propagate through it, as well as heat (he believed light consisted of tiny particles that moved through empty space in straight lines, and he knew heat moved through vacuum, but he didn't know that heat did so the same way light did)
| [
"In 1898, American astronomer Charles Augustus Young wrote: \"Inter-planetary space is a vacuum, far more perfect than anything we can produce by artificial means...\" (\"The Elements of Astronomy\", Charles Augustus Young, 1898).\n",
"Outer space is the closest known approximation to a perfect vacuum. It has eff... |
Before the European honeybee was introduced to the Americas, how was farming and pollination different? | It wasn't much different. Bumblebees are excellent pollinators and native bees (or solitary bees) can carry out a pollination role in a very similar ways to bees. Hang around a flowerbed for a few minutes, and you'll notice all kinds of tiny, little bees flying around. These little native bees are seldom studied, and it's not well known if the conditions that are affecting honey bee are affecting native bees as well.
Ants are also good insect pollinators. Wind pollinates to a certain extent. | [
"Western honey bees are not native to the Americas. American colonists imported honey bees from Europe for their honey and wax. Their value as pollinators began to be appreciated by the end of the nineteenth century. The first honey bee subspecies imported were likely European dark bees. Later Italian bees, Carniol... |
What is the current state of the field for the History of Space Exploration? | Not an answer, but may I suggest you send a message to David S.F. Portree?
He was the official Historian for NASA for quite some time. I would trust his word on most anything here.
[his WIRED profile](_URL_1_)
[He also tweets a lot](_URL_0_)
This is one of the few men to be a Spaceflight historian, he would be a great resource. | [
"While the observation of objects in space, known as astronomy, predates reliable recorded history, it was the development of large and relatively efficient rockets during the mid-twentieth century that allowed physical space exploration to become a reality. Common rationales for exploring space include advancing s... |
What do we know about those who lie in the Tomb of the Unknown Soldier? | Taking a chance based on Reddit Demographics, but can you clarify that you mean the Tomb of the Unknowns in the US at Arlington?
While obviously the most well known for US citizens, it's far from the only one of its kind. | [
"The Tomb of the Known Soldier is the grave of Private Charles W. Graves (1893–1918). Private Graves was an infantryman in the American Expeditionary Force who fought in World War I. On October 5, 1918, Private Graves was killed by German artillery shrapnel on the Hindenburg Line. His mother received the telegram f... |
can anything be 100% silent? | Sound is dependent on a medium. In outer space sound doesn't transmit since there is nothing to propagate the sound wave. Most of the movies have it incorrect... So you can be above absolute zero and still have no sound. But it you are in a medium that will, yes, everything has a sound | [
"Silent describes the state of silence (the absence of ambient audible sound, the emission of sounds of such low intensity that they do not draw attention to themselves, or the state of having ceased to produce sounds; this latter sense can be extended to apply to the cessation or absence of any form of communicati... |
if all cells are made of lipid walls, what stops two cells from blobing into one when they collide? | It's because cell membranes aren't just made of lipids, they're made of **phospho**lipids. Phospholipids have the typical hydrophobic fatty acid tails that other fats have, but at their head, they have a very hydrophilic phosphate group. Stick a bunch of these phospholipids in water, and they'll naturally group the fatty acid tails together (to limit their exposure to water) and face the phosphate end outward like [this](_URL_0_) to form a bilayer with phosphate groups pointing both toward the exterior and interior of the cell. When two cells are next to one another, the phosphate heads of their cell membranes are what come into contact, and they tend to repel each other and not bond.
Let me know if this was clear. | [
"2. Cohesion, causing cells to aggregate into clumps of various sizes instead of a homogeneous suspension of individual cells undergoing binary fission. Cohesion can cause imprecision and fluctuations in T. Cohesive clumps may also be adhesive, leading to both imprecision due to cohesion and inaccuracy (increased T... |
why and how is it an accepted notion that in quantum physics, particles exhibit different properties when observed as compared to not being observed? | As strange as it sounds, that's what we see when we do experiments. Sometimes particles behave like waves and sometimes like particles. One of the simplest experiments that shows this is [the double slit experiment](_URL_0_). Basically:
You take electrons and shoot them at a piece of metal with one small slit in it. Behind the slit you put photographic film. The electrons to create dots on the film, so they act like particles). There are more of these dots near the slit, but some are to the side, since the electrons can bounce off the edge of the metal slit.
Then you make two slits. If you cover either one, you see the pattern above behind either slit. But if you leave both uncovered, you see an interference pattern, which is what you'd expect if the electrons were waves. Where the path through one slit to the film and the path through the other slit are the same length, then you see more electrons, but when the path through one slit and the other are slightly different, the two cancel each other out and you see no electrons -- since when high and low part of a wave meet you get no wave. Based on this the electrons act like waves.
You fire the electrons one at a time and you see the same effect. The electron is interfering with itself.
Then you create a detector to tell which slit the electrons go through. You can do this by shining light past the slits and the light will scatter off an electron and create a flash. When you do this you see the flashes, but the interference patter goes away. Observing the electron has made it act like a particle.
Then you try dimming the light and sending fewer photons. Now sometimes an electron sneaks past without being detected, and you see an interference patter from only these electrons.
Then you try using lower energy (and therefor longer wavelength) photons. This has no effect until the wavelength gets so long that it can no longer detect and electron, and suddenly the interference pattern returns.
It isn't common logic, but it's the way the world works. In science experimental results win out over what makes sense. | [
"Because of the relativistic unification of the particle and wave pictures into the single expression of Eq. (1), there appears an illusion of co-existence of these two pictures. However, a little reflection shows that this view of the quantum theory of light detection is very far from the truth indeed. Let us say,... |
Why do babies say double-syllable words like "mama" and "dada" when one syllable would seemingly be easier? | It depends on what stage of language development the kid is at.
As children age, they go through distinct stages of learning, and they acquire the ability to recognize, and later produce, words of increasing phonetic complexity.
For example, it's easier for a child to say a 'd' sound than it is to say a 'th' sound. It's easier for a child to say something like 'see' than it is for a child to say 'spree', or 'seat' or 'street'. Often, a child can easily HEAR the difference between a word like 'see' and 'seat' but the child can only say 'see' for both cases.
Invariably, the ability to comprehend words of a given complexity exceeds the ability to pronounce them. Repeating a syllable 'like mama' is often a way for the child to approximate a word that has more than one syllable, like 'mother'-- They can get the first part down pat, but saying the whole thing is often a bit too tricky, so they say the first part twice-- this is called 'reduplication', and it shows that the child has awareness of the syllable structure of a word, but doesn't yet have the ability to properly articulate it yet. (it's also easier to say 'mama' than it is to say 'mommy' (two different vowel sounds in the second word))
Kids can also reduplicate because adults find it cute and give them attention when they do it. Search for 'child language acquisition' for more info!.
Hope this helps! Back to thesis writing.
EDIT: a bit late on this one, but it seems some people are getting hung up on the example 'mama' for 'mother'-- It's kind of a bad example, 'mother' isn't a common form in infants' input. A better example would be something like 'wawa' for 'water'. | [
"Infants begin to understand words such as \"Mommy\", \"Daddy\", \"hands\" and \"feet\" when they are approximately 6 months old. Initially, these words refer to their own mother or father or hands or feet. Infants begin to produce their first words when they are approximately one year old. Infants' first words are... |
Where does the energy go when two apposing wavelengths of light cancel each other out? | Deconstructive interference at one place requires the constructive interference of the wave somewhere else—so you don't lose the energy, the books only don't balance when you include absorption and emission, but then something is going to get hotter or colder, so you're still conserving energy. To bring quantum mechanics into this, photon-photon interaction doesn't occur at first order, so two regular laser beams pointed at each other won't do anything special. | [
"where \"formula_7\" is the resonant wavelength and \"m\" is the mode number of the ring resonator. This equation means that in order for light to interfere constructively inside the ring resonator, the circumference of the ring must be an integer multiple of the wavelength of the light. As such, the mode number mu... |
If I shone a very bright infrared or UV (non-visible EM waves) flashlight into my eyes, would I notice it? And could my eyes be damaged by it? | Yes, your eyes can be damaged by high-intensity light exposure, whether visible, UV, or IR. For example [snow blindness](_URL_0_) is an example of UV damage to the eye.
-
Whether you would notice any immediate effects would depend on the dose of radiation (intensity and exposure time) received. In the snow blindness example, damage would typically be delayed (just like a sunburn), but if you took a high-power IR laser to your eyeball, I'm sure you would realize pretty soon that this was not a good idea. | [
"The infrared light used in telecommunications cannot be seen, so there is a potential laser safety hazard to technicians. The eye's natural defense against sudden exposure to bright light is the blink reflex, which is not triggered by infrared sources. In some cases the power levels are high enough to damage eyes,... |
Does climate science predict we've warmed the earth in the first place? | Those aren't standard deviations, they are 90% confidence intervals. The graph indicates that the available data suggests the total anthropogenic forcing is somewhere between +0.6 and +2.4 W/m^2, with a 10% chance that they lie outside of those values (either above or below). | [
"In 2008, the \"Almanac\" stated that the earth had entered a global cooling period that would probably last decades. The journal based its prediction on sunspot cycles. Said contributing meteorologist Joseph D'Aleo, \"Studying these and other factor suggests that cold, not warm, climate may be our future.\"\n",
... |
What is the consensus among historians regarding the origins of the "second serfdom" in Tsarist Russia? | I'm not sure that a consensus of the sort you are looking for actually exists. But you might find informative [Enrico Dal Lago's 2009 article "Second Slavery, Second Serfdom, and Beyond: The Atlantic Plantation System and the Eastern and Southern European Landed Estate System in Comparative Perspective, 1800–60".](_URL_0_ )
Dal Lago cites most of the major figures of Early Modern Slavic Studies and provides some useful comparisons of the similaries and differences between New World Slavery (called the Atlantic Plantation System) and the "second serfdom" in Russia/Ukraine/Poland (called the European Landed Estate System), particularly in the early-to-middle 19th century.
Dal Lago frames the "European Landed Estate System" as a set of similar by not neccesarily related instituions that existed on large landed estates (sometimes called *latifundia*, confusingly), in the "peripheral" areas of Southern and Eastern Europe. To put it bluntly, I personally think Dal Lago overstates the similarities between widely divergent systems of unfree labor and debt used in places as different as Sicily and Slovakia.
Nevertheless, Dal Lago notices a key insight: that a large part of the incentive for the "second serfdom" was to tie peasants to the land so that large landowners could produce grain and other cash crops for export to global markets in Germany, Britain, the United States, and elsewhere. In this way, the "second serfdom" was part of global economic system of commodities whose production was made possible through the massive use of unfree labor.
**The thesis stated above is not entirely uncontroversial.** Some Marxist historians still insist that the "second serfdom" was essentially a "re-feudalization", with the rise of autocratic governments and large magnates dominating rural political and economic affairs snuffing out an emerging urban proto-industrializtion. The notion of "re-feudalization" was best-developed by Polish historians in the 1960s and 1970s. Probably the best synthesis of this school of thought is Witold Kula's *An Economic Theory of the Feudal System: Towards a Model of the Polish Economy, 1500–1800*. This "re-feudalization" model tends to assume local-oriented forms of economic activity that are not entirely compatible with the "unfree global commodities production" model explained above.
This re-feudaliztion model has not held up very well under newer historiography regarding the idea of "feudalism", but it does have some important points that make the comparative model of Wallerstein somewhat problematic. One key problem with the "unfree commodities production" thesis above is that many of the political, legal, and social changes that enable a re-expansion of serfdom in Eastern Europe appear a good century or two before we see early modern commodities markets develop. Additionally, we see these legal and social changes even in areas like Royal Hungary that don't appreciably participate in large-scale commodities production until well into the 19th century.
One interpretation of this contradiction is that there never was a "second" serfdom, only a continuation of Late Medieval forms of serfdom in Eastern Europe beyond the 14th century, by which point those forms of land-labor relations had gradually become defunct in Northern and Western Europe. Under this "one serfdom" model, the persistence of serfdom in Eastern Europe into the sixteenth century enabled the creation of large estates producing commodities (chiefly grains like wheat, rye, and barley) for export to markets in Germany and the Low Countries. This model is most popular with modern Central European scholars, and there isn't a single comprehensive work of synthesis in English the discusses it in detail, although Wandycz's *The Price of Freedom: A History of East Central Europe from the Middle Ages to the Present*, comes pretty darn close.
~~Wow, that turned out to be more comprehensive than I expected. I guess I learned something in college after all. I'll fix the typos later, but~~ I hope this provides a half-way decent introduction to the last few decades of historiography on the economic and political development of Eastern Europe.
EDIT: Typos, spelling(!), confusing historians with movie directors, etc. | [
"The origins of serfdom in Russia (, ) may be traced to the 12th century, when the exploitation of the so-called zakups on arable lands (, ) and corvée smerds (Russian term for corvée is , ) was the closest to what is now known as serfdom. According to the \"Russkaya Pravda\", a princely smerd had limited property ... |
How did you kill an armoured knight? | /u/Tass237 is correct, but I'll expand a little.
The development of plate armour triggered the development of weapons designed to defeat plate armour. Basic cuts and blows from existing weapons were ineffective, thus poleaxes, halberds, maces, war hammers and the like were developed with the sole purpose of defeating armoured knights.
In order to defend against these weapons, fluted plate armour was then developed, as it reinforced the armour against these blunt forces. This resulted in the development of more sophisticated polearms to increasingly concentrate the strength of blows in a small area.
Additionally, one approach towards fighting these heavily armoured opponents was specifically attacking the weak points of the armours (the joints) with long, tapered daggers and swords. Swordsmanship schools at the time explicitly taught these techniques. As a result, knights began wearing mail shirts underneath their armour (and later mail patches attached to the armour itself). | [
"A frontal charge by the English Knights was stopped by Bruce's spearmen militia, who effectively slaughtered the English Knights as they were on unfavorable ground. The militia soon defeated the knights. As Bruce's spearmen pressed downhill on the disorganised English knights they fought with such vigour that the ... |
if i delete some files on flash storage (e.g a pen drive), how is the data still (partly) recoverable? | Most OS's don't really delete files when you "delete" them. They merely mark the space as usable again if some other data needs to get written. Until the data is overwritten, there may be enough of it around to figure out what was deleted if someone can get a low enough level look at it. | [
"A flash memory storage system with \"no wear leveling\" will not last very long if data is written to the flash. Without wear leveling, the underlying flash controller must permanently assign the logical addresses from the operating system (OS) to the physical addresses of the flash memory. This means that every w... |
why do towels get rough when dried outside on a line? | Hard water deposits not being rubbed/softened by tumble dry action. | [
"Paper towel is absorbent towel made from paper in both British and North American English. In Britain, paper towel for kitchen use is also known as kitchen roll, kitchen paper, and kitchen towel. For home use, it usually sold in a roll of perforated sheets, but some are sold in stacks of pre-cut and pre-folded lay... |
Could beneficial bacteria from probiotics form antibiotic resistance too? | Yes, they can and do. The problem is that you then have those genetics in your gut which can easily be transferred horizontally to pathogens when they arrive allowing them to develop resistance far more quickly then they otherwise would have. | [
"One of the proposed mechanisms of how probiotics protect from AAD is by regulating the composition of organisms in the intestines. Studies involving \"L. acidophilus\" and \"Bifidobacterium\" suggest that these microbes inhibit the growth of facultative anaerobic bacteria, which tends to increase during antibiotic... |
what is madness? | Its kinda like asking “what is sickness?” It is not being well, with specific emphasis on mental state. “Madness” covers an enormous number of conditions with a huge variety of symptoms, and is not at all a strict of protect term.
You could look into different forms of mental illness, which may help narrow things down for you. | [
"Divine madness, also known as theia mania and crazy wisdom, refers to unconventional, outrageous, unexpected, or unpredictable behavior linked to religious or spiritual pursuits. Examples of \"divine madness\" can be found in Hellenism, Christianity, Hinduism, Buddhism, Sufism, and Shamanism.\n",
"Amenomania (co... |
If the gene that codes for six digits is dominant, why do so few people have six digits? | You're confusing dominance with frequency. Dominance refers to the phenotype of heterozygotes. If a gene, like the one for achondroplasial dwarfism is simple mendelian dominant it means that heterozygotes (those people with one copy of the A.D. allele and one copy of the wildtype/normal allele) have the same phenotype (in this case short stature etc) as those with two copies of the A.D. allele. Allele frequency is how common an allele is in the population. Dominant traits will be expressed somewhat more often than recessive traits *at the same allele frequency* but whether an allele is dominant or not says nothing about what that frequency is. In a two allele system, the frequency of the phenotype of a dominant trait is the number of homozygotes for the dominant allele + the number of heterozygotes. For the recessive phenotype, the frequency is the number of homozygotes for the recessive allele. If an allele is dominant but rare ... well then, it's rare. | [
"Because digits are encoded by pairs, only an even number of digits can be encoded. Typically an odd number of digits is encoded by adding a \"0\" as first digit, but sometimes an odd number of digits is encoded by using five narrow spaces in the last digit.\n",
"The main source of problems was confusion between ... |
A question for historians versed in the Japanese occupation of Manchuria and Unit 731 | Firstly, Unit 731 wasn't that big. There were a lot of collaborators who had nothing to do with Unit 731. Policemen, regular doctors, civil servants, etc. The Japanese ruled, if you wanted to be successful you had to go along with them. If he was friends with the Japanese, went to medical school in Nagasaki, then it's very unlikely he was an anti-Japanese resistance fighter... but that does not mean he was working with Unit 731. There were hundreds of thousands of people who accepted Japanese rule and did the best they could, without committing human vivisections, injecting people with diseases to see what would happen, exposing prisoners in the snow to see how long they'd live, and 731's other atrocities.
Do you know what city in China your Grandfather lived in? Unit 731 was based in Harbin, a regional capital.
Secondly, do you know the ethnicity of your Grandfather? Was he a Han, Manchu, or something else?
China was ruled, under the Qing dynasty, by an ethnicity known as the Manchus (whose homeland of course, was Manchuria). The Qing Emperors all came from this ethnic group, and Manchu had special privileges. When the Japanese invaded, they continued to use Manchu as civil servants, etc, in Manchuria, with the Qing Emperor as a puppet ruler. Besides the terror of Japanese soldiers, many Manchu (and other Chinese) obeyed the Japanese-controlled puppet government because it was still the government of their Emperor, while the rest of China was ruled by Nationalists who'd overthrown the Emperor.
What I'm saying is that even if your Grandfather worked with the Japanese occupiers, this does not mean he committed atrocities. He could equally not want to talk about the period because he saw atrocities (either by the Japanese or the Communists when they invaded Manchuko and took it back from the Chinese).
Or it could be that he is ashamed of being a collaborator, but not because he did such bad atrocities. I have a friend who has 3 uncles who were Manchu policemen under the Japanese (they all changed their names to Han names after the Communists took control). Yes, they were collaborators, but that's not the same as taking people to be experimented on.
It should also be said that, while locals were needed for brute labour, the scientists of Unit 731 were Japanese, not Chinese.
I'd also say that the Nationalists were not okay with Japanese atrocities. They fought the Japanese for years, and it was the Nationalists who controlled Nanjing when it was invaded by the Japanese who carried out such brutal massacres. So, while it's quite possible that a Chinese collaborator could hide their crimes from the KMT, I wouldn't say the KMT would be okay with it if they did know. | [
"The Japanese invasion of Manchuria began on 18 September 1931, when the Kwantung Army of the Empire of Japan invaded Manchuria immediately following the Mukden Incident. After the war, the Japanese established the puppet state of Manchukuo. Their occupation lasted until the Soviet Union and Mongolia launched the M... |
why is shooting a deer in the head a bad shot? | It is the same reason attempting to shoot a person in the head is a bad shot. (Assuming you are the general public, and not a navy seal).
Whenever you are trying to kill anything, be it human or animal, with a gun or bow and arrow. There are 4 ways to kill that target in what is considered a humane fashion.
1. Take away the targets ability to breath - puncture the lungs
2. Take away the targets ability to pump blood - puncture the heart
3. Take away the targets blood itself - puncture a main artery
4. Disable the central nervous system or CNS for short.- This is a head shot, breaking of the neck, or spinal cord up high above the shoulders.
If you only have 1 shot to take. The central nervous system is the smallest target to hit. If you miss it, but still hit the animal, you can cripple it, but not kill it. (Look at gabby giffords, she lived through a head shot. She is all sorts of fucked up, but she is alive)
If you aim for the center of mass, that same one shot has the potential ability to hit the heart, lungs or an artery, or all 3 or any combination of the 3. Any 1 of the 3 will put down the animal in short order. And if actually happen to pull off a perfect broadside shot, you will hit the lungs, heart and an artery all in 1 shot.
> Modern power rifles would have no problem getting a kill when hitting a headshot
That is simply not true. As a 17th century musket can do the same thing in the hands of a marksman. It always comes down to shot placement. Center of mass is a larger target than a brain. And technically speaking, you are not just trying to hit the brain, but a specific part of it. Hitting the medulla oblongata is the ultimate "lights out" sniper style shot that will disable the CNS as quick as you can snap your fingers. But with any head shot, If your shot placement is not dead on, all you will do is scalp a deer, but it will otherwise live. (or die slowly in pain and agony). But if your aim is center of mass, you can still have a good hit which equals a clean kill even if your aim is off, or the target moves.
Next is training. When you are first taught to shoot firearms (if you are lucky) you are taught techniques that are reliable, and more importantly, repeatable. Center of mass is a larger target than the CNS. At any kind of distance, you are much more likely to be able to repeatedly hit that center of mass simply because it is a larger target. If you were trained to hit the smallest target possible, under stress, unless you are in the military and shooting tens of thousands of rounds a year, it simply isn't going to happen. Ones marksmanship would not be repeatable.
And lastly there is what is tried, and what is proven. When taking game the whole idea is to cause the least amount of suffering to the animal. If you are a hunter, and your practices/techniques are shown to cause great pain or agony to an animal, then you are just a bad hunter. Over the course of the last few hundred years in regards to both firearm and hunting development. It has been proven that over the course of those hundreds of years that on average a center of mass shot is the most reliable and repeatable way to take game quickly and cleanly without causing any undue pain or agony to that animal.
Last point. If an animal, like a deer, is dying a slow agonizing death. The body will secrete enzymes that do get into the meat, which can do anything from taint to destroy the flavor of the meat. | [
"Deerstalkers have the humane despatch of the deer at the forefront of their mind (right behind safe shooting practice), and there are many scenarios which prevent a shot from being taken, such as no safe backstop, no clear shot, the deer doesn't stop, there are other deer behind the chosen deer, the deer which is ... |
why can you see the dot of a laser when you shine it in the sky at night | The dot? Or the line? Because if you're pointing at the night sky, you shouldn't be able to see the dot unless I'm missing something. As for the line, well that can be a lot of things, but yes, I'd go with dust. | [
"Most people are able to see this phenomenon in the sky, although it is rather weak, and many people do not notice it until asked to pay attention. The dots are highly conspicuous against a monochromatic blue background (~430 nm) instead of the sky.\n",
"The Purple Crow Lidar is considered to be a powerful laser ... |
Were there actually any soilders that could kill dozens of people in battle? | According to the Anglo-Saxon Chronicle, at Stamford a giant Norseman armed with an axe held the bridge alone, buying time for the rest of Harald's army to form a shield-wall. The Chronicle claims that he killed 40 men, although "forty" is presumably chronicler-speak for "a large number, I don't know exactly". The bridge being narrow, the English would have had to come at him one by one, so it wouldn't be "surrounded by people". And, of course, it's not clear whether this is really a lot more reliable than your average movie battle scene. :) | [
"During World War I, no man's land was often hundreds of yards across. The area was usually devastated by the warfare and riddled with craters from artillery and mortar shells, and sometimes contaminated by chemical weapons. Heavily defended by machine guns, mortars, artillery and riflemen on both sides, it was oft... |
Does nicotine addiction permanently change the brain? | There is a reason many drugs have such high relapse rates with some, like methamphetamine, having over 90% relapse rates. The memory of the drug is very powerful. Not only do you have the reward associated with the drug itself, and its effects on dopamine, but you also have a myriad of "cues" that act as part of the reinforcement of the memory. For instance, drinking alcohol in the bar with your friends can create a reinforcing cue that means watching a TV show (like "How I met your mother" where basically the whole show takes place in a bar) can flood the brain with cues that trigger craving. This phenomenon is consistent across drugs (e.g. cocaine, opiates, nicotine...) and is known to be mediated by interactions between two specific brain regions (the ventral hippocampus and the nucleus accumbens). In animals cue-induced reinstatement of drug seeking behavior can be manipulated by stimulating or blocking these specific regions. There are many other brain regions involved, but this is a simple breakdown. Further, there is good evidence for relatively long-term changes in many brain regions using techniques like functional connectivity analysis with fMRI. There is also evidence for permanent changes in brain volumes with some drugs like cocaine. In short, there is quite a bit of evidence for long-term changes in brain structures and networks. Some of these changes may abate with time but this aspect (i.e. how long it might take) is not as well studied, but in the case of smoking anecdotal evidence suggests that the urge for cigarettes does abate over time. | [
"Various causes have been proposed to explain the causes of nicotine withdrawal. Nicotine binds to nicotinic receptors in the brain that, in turn, cause an increase in dopamine. Dopamine is the major chemical that stimulates reward centers in the brain. The brain recruits an opposing force to dampen the effects of ... |
why forward slash is two words but backslash is one word. | Because its real name is "solidus" but that didn't catch on.
"Backslash" as much of a descriptive term as it is a name. It's one whole word because we use "back" as a prefix a lot, in words like backdraft, backgammon, or backward itself. We don't use "forward" as a prefix too often; it's usually 'fore' in prefix terms (forecast, forewarn).
So because backslash is more common than solidus in use, and its logical opposite is forwardslash except that makes for a clumsy prefix, we use a space in there. | [
"A backsword is a type of sword characterised by having a single-edged blade and a hilt with a single-handed grip. It is so called because the triangular cross section gives a flat back edge opposite the cutting edge. Later examples often have a \"false edge\" on the back near the tip, which was in many cases sharp... |
Did the Scandinavian vikings influence the British culture in a major way as a result of their conquests. | Absolutely. Iona Abbey, perhaps the most important Christian site in all of Britain was attacked several times, eventually causing some of the monks to flee south towards Ireland, where they'd go on to write (or influence) several key annals which offer us great insight on the history of Ireland and its language.
For Scotland proper, the cultural significance is perhaps greater still. The Vikings would, between the sixth and tenth century settle almost all of the Western Isles, Shetland, Orkney (both of whom still use a Nordic Cross in their respective flags) and the Isle of Man. Scotland wouldn't regain control of those areas until about the 14th century.
As Scotland has in recent years started to look very seriously at the prospects of independence from the rest of the United Kingdom, the Nordic nations are seen by many Scots as kindred spirits and the blueprint to how an independent Scotland would be set up and run. Interestingly, several members of the [Nordic Council] (_URL_1_) have stated or implied that Scotland would be welcome in their ranks.
England would of course bring about the (symbolic) end of the Viking Age at the Battle of Stamford Bridge in 1066, when, under the command of the King of England, Harold Godwinson they killed Harald Hardrada. The king himself would die less than a month later at the Battle of Hastings, the start of Norman Britain. It's worth noting that there wouldn't even have been a Kingdom of England had the Vikings not repeatedly invaded southern England from their holdings in the north. The raids forced the [Heptarchy](_URL_0_) (Northumbria, Mercia, East Anglia, Essex, Kent, Sussex and Wessex) to unite in the face of Viking aggression creating a Kingdom which would dominate the region well past the Middle Ages, eventually uniting with Scotland to create modern Britain. | [
"During the Viking Age, Scandinavian men and women travelled to many parts of Europe and beyond, in a cultural diaspora that left its traces from Newfoundland to Byzantium. This period of energetic activity also had a pronounced effect in the Scandinavian homelands, which were subject to a variety of new influences... |
Why were pre-firearms european armies so small? Why was there no exception to this, which might have conquered all of Europe with troop numbers that were more common in ancient times? Why are there generally so few or no great conquerors in Europe post Rome? | 'Pre-firearms' would appear to be a rather difficult periodization to make. There is evidence of gunpowder weaponry such as handgonnes being used as early as the late 14th century. But, assuming you mean the 16th century with the so-called 'military revolution,' armies before that time and after Rome (which presents another problem, but that's another story) could be quite large. Charlemagne was able to raise multiple armies numbering at least 40 000 in total for his campaigns of conquest, and the total number of his forces could easily have topped out at 100 000. The armies involved in the crusades, in particular the first crusade, numbered in the tens of thousands, with at least 70-80 000 answering Pope Urban's call for the First Crusade. Edward I invaded Scotland in 1298 with almost 30 000, and Edward III fought the French with a similar number. Ferdinand of Aragon could amass 30-50 000 men to conquer Granada, and combined with Isabella's Castillan forces it was probably greater. I think this also suggests that, contrary to your question as to why there were so few or no 'great conquerors' post Rome, that there were indeed conquerors after Rome. Charlemagne, Frederick Barbarossa, Otto the Great and Henry I of the Holy Roman Empire, Charles the Bold, Duke of Burgundy, Edward III, Robert Guiscard, Philip Augustus, were all great conquerors and commanders. I've left out eastern Europe and the Middle East but Basil 'The Bulgar-Slayer', Heraclius, and many leaders of the Muslim Caliphates were no pushovers either!
That none of these figures were able to raise armies capable of equalling Rome is a result of the fact that, unlike Rome, they couldn't exactly marshal all the resources of the Mediterranean at their disposal. That said, a centralized or fairly centralized government/leadership, with the aid of bureaucrats and other nobles could raise large armies in the Middle Ages, particularly if their population and economy was sufficient to support one.
Sources:
* "Catapults are not Atomic Bombs: Towards a Redefinition of 'Effectiveness' in Premodern Military Technology," by Kelly Devries
* "Charlemagne's Expeditionary Forces: An Essay in Historical Demography" and "The Siege of Antioch: A Study in Military Demography," by Bernard S. Bachrach | [
"These variables impacted the development of military systems. Low population densities for example meant that large forces could not be raised and maintained in being for a long time. The Zulu as one instance, could field an estimated 50,000 warriors, impressive by regional standards. But this was the nation's ent... |
why do water bottles have 2% calcium? | Calcium is one of the minerals added to the water to improve its flavor. They add enough of it that it shows up on the nutritional information. | [
"Elemental calcium is a term used on dietary supplement labels to refer to the amount of calcium in a product. Calcium pills contain calcium in a variety of molecules, such as calcium carbonate, calcium citrate, calcium citrate-maleate, etc. Each pill supplies a different amount of elemental calcium. For example, c... |
what determines what limbs will stop working after a spinal inury? | It depends where along the spine the injury to the spinal cord occurs. If the cord is damaged low down, then signals can still make their way from the brain to the arms, abdomen, and so on, but the leg function and other muscles below the damage may be impaired.
Total tetraplegia is usually a result of damage to the spinal cord in the neck or upper thoracic region. | [
"The injured spinal cord is an “altered” spinal cord. After a SCI, supraspinal and spinal sources of control of movement differ substantially from that which existed prior to the injury, thus resulting in an altered spinal cord. The automaticity of posture and locomotion emerge from the interactions between periphe... |
For a guy with a generally benign reputation in office long ago, Woodrow Wilson provokes fierce criticism, including charges (promoted spying on your neighbors, was relatively pro-kkk, and was eager to jump into the Great War, unnecessarily) that sound very un-American. How fair are his critics? | This question has popped up before, there's a pretty good discussion of it [here](_URL_0_)
Maybe someone else will post their thoughts. I would suggest that humans tend to like all our heroes totally heroic, all our villains totally villainous, and really love surprise: therefore all the variations in print on "Things you Thought You Knew About History That Aren't Really True".
Lots has been said for and against Wilson. Wilson was a Progressive when that was a very new, cool thing , presiding over a US that was quite pleased with itself and optimistic, and a scholarly man with vision of how to achieve world peace. At the end of WWII, when the UN had been created and hopes were high, Wilson got quite high marks for being prescient- his League of Nations was deprived of US support and it was convenient to assume that if it had gotten it, WWII might have been avoided. This is the man of whom Arthur Link would write several volumes of glowing biography - and not finish. Move ahead some decades, and some people would like to say Progressive governments work against the magic of the marketplace, that WWII would have happened with or without the US at the League. And the strong racism that was considered a slight foible in 1900 ( and an expected one from a blue-blood Virginian) is now taboo. | [
"Notwithstanding his accomplishments in office, Wilson has received criticism for his record on race relations and civil liberties, for his interventions in Latin America, and for his failure to win ratification of the Treaty of Versailles. Many conservatives have attacked Wilson for his role in expanding the feder... |
Perhaps it is time to entertain a discussion of the top military leaders of all time? | Subutai, Ghengis Khan's general. I think only Alexander conquered more of the world. | [
"By some historians he is considered the most effective general of his generation as well as one of the greatest in military history. Although a tough leader, he was respected by his troops. He touched their sentiments e.g. by addressing them in his speeches as \"gentlemen soldiers\" (señores soldados), but was als... |
[SOURCE REQUEST] Where can I find diaries kept by people during historical time periods? | Ooh you've actually got a tricky one here. The Troubles are a few decades too young for you to start getting diaries etc. available to the public. Many of the people in that event are still alive, and archives generally don't open sensitive records (like diaries and letters) while people they effect are still living. There was a big dustup at the start of the year [over oral histories on The Troubles](_URL_0_) being used to prosecute people for example. This stuff's just too hot yet.
[You might like this site where people share their oral histories](_URL_1_) though? For diaries and letters you're unfortunately just going to have to wait a decade or two for people to pass away. :/ | [
"Many diaries were retained by the soldier or their family, however some of the surviving diaries are held in the collections of Australian cultural institutions including the Australian War Memorial, National Archives of Australia, State Library of New South Wales, State Library of Queensland, State Library of Sou... |
if media attributes a source anonymously, how does anyone know if that source is true and not just fabricated by whoever wrote/reported it? | Credibility. Does the publication/journalist have a track record of reporting accurate information? This also comes down to the ethics of the journalist as well. Do they have a good track record of their sources reporting factual stories?
If it's fabricated, and it can be proved to be malicious fabrication, that's libel. If it's not malicious (they believed the wrong source), it's just bad journalism, and that person should lose their credibility. | [
"Anonymous sources are double-edged—they often provide especially newsworthy information, such as classified or confidential information about current events, information about a previously unreported scandal, or the perspective of a particular group that may fear retribution for expressing certain opinions in the ... |
how do stars and planets emit radio frequencies without a radio tower - like what's the source and how's that different from our 'manmade' radio towers? | Radio waves are just a frequency of electromagnetic radiation, far below the infrared.
Many things are natural sources of radio waves. Think of them as either glowing or reflecting "the color radio" as opposed to "the color green" or whatever.
It's just that we didn't really notice all the stars and planets emitting these waves because we never aimed our receivers at them - we used the receivers and radio towers for the purposes of *radio*, which is why you think of it as *just* for radio. But it's more that the waves and the radio device were named for the same thing: radiometry.
> The term "radio" is derived from the Latin word "radius", meaning "spoke of a wheel, beam of light, ray". It was first applied to communications in 1881 when, at the suggestion of French scientist Ernest Mercadier, Alexander Graham Bell adopted "radiophone" (meaning "radiated sound") as an alternate name for his photophone optical transmission system.
So basically, radio is just a word meaning "ray". As in of light. | [
"At VLF, LF and MF the radio mast or tower is often used directly as an antenna. Its height determines the vertical radiation pattern. Masts and towers with heights around a quarter wave or shorter, radiate considerable power towards the sky. This allows only a small area of fade-free reception at night, because th... |
Looking for a (great) layperson's book about Babylon....or perhaps just a fantastic look at Babylon that isn't dry. | You could try *Babylon* by Paul Kriwaczek. | [
"There are five principal writers whose descriptions of Babylon exist in some form today. These writers concern themselves with the size of the Hanging Gardens, their overall design and means of irrigation, and why they were built.\n",
"The main sources of information about Babylon—excavation of the site itself, ... |
how does exhaust affect engine performance? | I'm guessing you mean how can changing the exhaust system on a car increase performance?
When combustion happens in an engine, fuel and air is burnt in the combustion chamber, this causes an expansion which pushes the piston down. This is what generates the power in a normal car engine. However this combustion of course results in leftover gas, which is the exhaust gases which have to be pushed out of the chamber so that new air and fuel can be sucked in. The power generated from the expansion is however also used for pushing the gases out and sucking in more fuel and air. In short, the output power is the generated power minus the work the engine has to do, this includes pushing exhaust out.
A sportier exhaust system has less flow restrictions than a stock one, more flow in the pipes makes pushing exhaust gases out easier and therefore subtracts less power from the expansion. More airflow in the exhaust can be achieved by having straighter, bigger pipes and no muffler for example. Sorry for the novel but I hope it was easy to understand | [
"A tuned exhaust system is an exhaust system for an internal combustion engine which improves its efficiency by using precise geometry to reflect the pressure waves from the exhaust valve or port back to the valve or port at a particular time in the cycle. \n",
"The design and orientation of the intake manifold i... |
What does a bruise look like underneath the skin? | Bruises are indeed caused by blood, however, if the bruise is visible it is inside the skin and not underneath it. The skin consists out of various layers and these various layers consist out of different cell-types and tissues. The shape and colour of the bruise on the outside varies depending on how deep inside the skin the bruise is, how big the hemmoraging and how old the bruise. As such, how they look if you were to make a mental image of them would differ wildly from bruise to bruise.
Generally though, bruises are a collection of many small burst capillaries (the smallest type of bloodvessel) which each lose a very small amount of blood which then pushes slightly into the surrounding tissues and coagulates. As such, it is rather difficult to picture how they would look.
It is also possible to have 'bruises' under the skin (for example in fatty tissue or inside muscles) but these are generally invisible from the outside. After all, if we could really look that deep into our bodies we should also be able to see the colour of the underlying muscles, which are actually a very deep red. For that reason, these are more often referred to as hemmorages rather than actual bruises. | [
"A bruise, also known as a contusion, is a type of hematoma of tissue, the most common cause being capillaries damaged by trauma, causing localized bleeding that extravasate into the surrounding interstitial tissues. Most bruises are not very deep under the skin so that the bleeding causes a visible discoloration. ... |
How well can personality traits currently be predicted using neurological measures? | We know that changes in certain brain areas can be associated with certain personality characteristics. This doesn’t mean we can look at someone’s brain and guess their personality, we are still very far from that.
Reduced volume and interconnectedness of the frontal lobes is often seen in people who commit suicide, criminals and sociopaths. This area is associated with ‘executive function’. This includes deterimining ‘good’ and ‘bad’, anticipating future consequences of your actions, working towards a goal and social ‘control’ (the ability to suppress urges that are considered socially unacceptable). | [
"The predictive effects of the Big Five personality traits relate mostly to social functioning and rules-driven behavior and are not very specific for prediction of particular aspects of behavior. For example, it was noted that high neuroticism precedes the development of all common mental disorders and is not attr... |
Chemistry:How do you figure out what something is? | Step 1) Use a separations technique such as HPLC, solid phase extraction, or liquid liquid extraction to fractionate the asparagus
Step 2) Repeat the fractionation with urine
Step 3) Use high resolution LC/MS to analyze all of the fractions, looking for chemicals that are common to the asparagus and urine
Step 4) Using the accurately measured masses and isotope ratios, compute the elemental formula of the compound
Step 5) Search the elemental formula at a site such as [_URL_0_](http://_URL_0_)
Step 6) If a match is found, order an authentic reference standard and confirm the identity.
If no match is found or the identity doesn't confirm, isolate and purify the compound,then obtain NMR and IR data and use classical structure elucidation
Also, search the web for bioassay guided fractionation, Metabolomics, and structure elucidation for more background. | [
"Chemistry focuses on how substances interact with each other and with energy (for example heat and light). The study of change of matter (chemical reactions) and synthesis lies at the heart of chemistry, and gives rise to concepts such as organic functional groups and rate laws for chemical reactions. Chemistry al... |
How did so many Japanese businesses end up involved in so many different industries? | I recommend you to read more about the zaibatsu. The answer to your question lies all in the zaibatsu. Especially Mitsui and Mitsubishi group. Those companies were so dominant that it just made sense to produce "everything".
Actually I am senior management of a "group" company now and I have worked 7 years for Hitachi. You have to imagine that if a company becomes big, it makes economical sense to produce your stuff by yourself.
For example, Hitachi started in 1920 by producing motors. In order to produce a motor you have to buy chemicals such as resins. First you buy it from another chemical company, then you start to think "hey, I could make that stuff by myself and it would be much cheaper because I don't have to pay any commission" and so it goes on.
Finally you start to think: "Hey why pay the bank such a high interest rate, when I could have my own bank" "Why pay insurance companies for my daughter companies insurances when I just can insure them myself through the mother companies money?" | [
"During the Meiji period, Japan underwent a rapid transition towards an industrial economy. Both the Japanese government and private entrepreneurs adopted Western technology and knowledge to create factories capable of producing a wide range of goods. By the end of the period, the majority of Japan's exports were m... |
how long does the earth have left before it becomes uninhabitable? | Check out this Wikipedia [Future timeline of Earth](_URL_0_)
* In about 600 million years the Sun's increasing luminosity begins to disrupt the carbonate-silicate cycle; Carbon dioxide levels begin to fall. Photosynthesis is no longer possible for the most part. ~99 percent of present-day species will die.
* In about 800 million years, all photosynthesis becomes impossible. All multicellular life will die out.
* In about 1 billion years, the oceans will boil away, leaving only single-celled life at the poles.
* 2.8 billion years: The Earth reaches an average temperature of 147°C. All remaining single-celled life will die out.
* 7.9 billion years: The Earth will be destroyed by the expanding sun (now a red giant).
| [
"\"This end of the world will occur without noise, without revolution, without cataclysm. Just as a tree loses leaves in the autumn wind, so the earth will see in succession the falling and perishing all its children, and in this eternal winter, which will envelop it from then on, she can no longer hope for either ... |
why rockets are sometimes launched at night? | Rockets launch whenever is necessary to make sure their payload ends up in the proper orbit. Sometimes that's at night, and so they launch at night.
Rockets are actually a lot easier to spot at night, because they're spewing a giant stream of flaming exhaust out the back. A night launch is really a sight to see, you can continue to tell where it is when it's thousands of miles downrange. There's no need to see any of the details of the rocket's exterior while it's launching (and it quickly starts moving fast enough that it's not practical to do that from the ground), so that's not a concern. | [
"The launch, which occurred in pre-dawn darkness, was the first American night launch since Apollo 17, and was watched by several thousand spectators. The unusual launching time was due to tracking requirements for the primary payload, INSAT-1B; the program would not have another night launch until STS-61-B in 1985... |
why do some osx programs have to be dragged and dropped into the applications folder, while some have installer packages? | Same reason why some windows programs are just simple exes and others require an installer
The ones that need an installer usually have some other dependencies or modify the system in some way. | [
"On Mac devices it requires root privileges; the same is also true for older versions of the installer for Windows in that it requires administrator privileges to install. Newer Windows versions install using normal user privileges and only in the user account that invokes the installer. Once installed it becomes a... |
why humans can walk up and down stairs without having to look down at them. | Also, stairs are required to be a standard step height and minimum tread width. When you find non standard stairs you will look down, guaranteed. | [
"Masses of people walking up and down stairs at once, or great numbers of people stomping in unison, can cause serious problems in large structures like stadiums if those structures lack damping measures.\n",
"The two concentric processions on the stairs use enough people to emphasise the lack of vertical rise an... |
Is the wheel a mandatory invention/discovery for the advancement of a civilization? | There are civilizations that have no wheels.
Canals are an excellent alternative. Dragging things on skids is a passable alternative. | [
"The wheel is one of the most important inventions, but its inventor and exact date of invention are not yet known. The oldest known wheel was excavated from Mesopotamia, believed to be 5500 years old. This earliest wheel was a potter's wheel, used in the city of Ur in Mesopotamia (present-day Iraq), invented by Me... |
What was going on in Austria during the Cold War? | From 1945-1955, Austria was under military occupation by the four Allied powers, much like Germany. Unlike its Germany, the geography of Austria and Vienna did not lend itself well to an easy partition. The military administration and occupation of Vienna was particularly cumbersome, with the Allies forming unified patrols (four men in a jeep) which was clumsy and did not lend itself well amidst the increasing suspicions of the early Cold War.
Much of this confused situation was the result of the Allies' muddled strategic planning with regards to Austria. Although the Moscow Declaration of 1943 had avowed that Austria was a separate nation that was the first victim of Hitler's aggression, the Allies behind the scenes held significant doubts about the viability of Austria as an independent state. Austria's seeming inability to resist Hitler in 1938 validated the opinion that the post-Versailles Treaty Austrian state was too small to keep out aggressors, but whose strategic location invited interlopers to interfere in Austrian politics. While Soviet foreign policy with regards to Austria was to keep their options open in the postwar order, the British floated various solutions such as a Danubian confederacy or a political union with Bavaria that would strengthen postwar Austria and prevent a resurgence of Prussian-German militarism. These plans proved stillborn, but the problem of Austria still remained. The British Deputy Undersecretary of State Oliver Harvey encapsulated how the British saw this dilemma:
> Were it not for the strategic importance of keeping Austria separate from Germany, we could let this flabby country stew. It is clear that Austria is doing next to nothing for herself and we shall have the greatest difficulty in infusing life into her after the war. There are no political leaders inside or outside the country who command any following. Austria will fall into the first arms which are opened to her.
The Americans were reluctant to commit to a full-scale occupation of Austria and were content to push only for an occupation of Vienna. Both the Soviets and the British pushed for a full American commitment to Austria in order to relieve them of burdensome occupation costs. It was this pressure from their Allies coupled with the fear of a supposed "national redoubt " in the Alps that made the Americans switch course and commit to an occupation.
The first years of the occupation made Austria into one of the important sites for the early Cold War. The Americans' close proximity to Soviet troops and the unsettled nature of the occupation made it an epicenter for intelligence gathering operations. Although the Roosevelt State Department looked askance at the British plans for an Austrian-South German confederation. the Truman administration reversed course and proposed an East-West division of Austria in 1947, but the Soviets balked at this idea. The communist's electoral defeats in November 1945 Austrian elections had underscored to the Soviets the generally unfavorable attitude many Austrians held towards the Soviets. The fear in Moscow was that settling the Austrian question on terms proposed by the West would only benefit the West and undercut Soviet security. The result was stasis in Austria until the negotiations for the State Treaty began after Stalin's death.
After Stalin's death in 1953 and the resulting Thaw, the Soviets saw a renegotiation of the occupation as an opportunity to signal a new direction in the Soviet relationship in Europe. By negotiating an end to the Austrian occupation, the hope in Moscow was that the Soviets' position on a neutral Germany would gain traction in the FRG. On a more practical level, the ending of the occupation would end what was becoming a costly occupation for the Soviets. As negotiations for the Austrian State Treaty began, the Soviets staked out a basic position that Austria was to not seek a military alliance with an outside power and explicitly forbid any unification with Germany. A neutral Austria had an additional benefit to the Soviets by creating a gap in NATO's German and Italian front line, which would complicate NATO's existing military plans.
Many in the US State Department saw the Austrian State Treaty as Austria undertaking a voluntary decision to become another Switzerland. The Soviet's insistence on Austria's military neutrality was a marked change from other Soviet peace treaties. There was little concern of "Finlandization" in which a peace treaty with the Soviets also carried certain defense obligations that favored the Soviets. The Americans gambled that although neutral, Austria would politically and culturally align itself with the West. This gamble did pay off as the emerging political consensus in Austria was largely pro-Western.
The Western influence of the Cold War upon Austria was largely cultural. Austria's borders to the West were open, those to the Eastern bloc were, for the most part, not. American cultural missions flooded Austria with programs and materials as a part of the US's strategy of cultural diplomacy. Western products, tourists, and other connections further integrated Austria into the West, even if it could not join the various Western defensive alliance systems. Therefore, Austria emerged as something of an anomaly during the Cold War, culturally and economically connected to the West, but politically restrained by the Treaty from joining either Superpower bloc.
*Sources*
Steininger, Rolf. *Austria, Germany, and the Cold War: From the Anschluss to the State Treaty 1938-1955*. New York: Berghahn Books, 2008.
Wagnleitner, Reinhold. *Coca-Colonization and the Cold War The Cultural Mission of the United States in Austria After the Second World War*. Chapel Hill: University of North Carolina Press, 1994. | [
"After the war Austria was occupied by the allied armies, separated from Germany, and divided into four zones of occupation. The Soviets did not create a separate socialist government in their zone as they did in East Germany. Instead, Austria was required to sign the Austrian State Treaty of 1955 under which it pl... |
how are the us and chinese economies linked? | How are they linked?
Well quite simply trade, the USA imports around $400 billion worth of goods every year from China while it only exports around $111 billion. So every year the USA is on the bad end of a $300 billion deficit, which is not a good position to be in. To offset the trade deficit China purchases large amounts of American debt in order to keep the American economy relatively strong and the exchange rate where it is(the current exchange rates favors China). So what China is doing is sacrificing wealth now, in order to build it's economy on a much stronger footing for the future.
What would happen if one would fall?
Either country could survive a fall by the other but you must remember the fall of any major economy isn't going to be beneficial, hence one of the reasons China is investing so much in slowly waning the USA out of their number 1 position. China will be able to export to other markets around the world, and an American collapse will hurt but won't be devastating. and due to their centrally planned economy they have enough power to invest strategically. While on the other hand a collapse of China would cause significantly more damage to the American economy, America is not in a position to capitalize on Chinese manufacturing closing down while China can capitalize on the closure of US factories. Also a loss of Chinese investment would cause American borrowing rates to rise.
But all in all, neither economy will crash, the USA will get significantly poorer over the next 50 years but it won't be a set crash, while China along with Russia etc will continue to boom.
Source: [WTO figures ](_URL_0_), double major in Finance and Economics, current position as a trader within a bulge bracket firm.
| [
"Chinese dependency on the US dollar became prevalent after the purchase of shares of the United States debt during the Great Recession. Due to this purchase, the two nations share a deeply rooted economic relationship. US depends on China for holding their debt and, in turn, China cannot sell their debt without de... |
if all the ants in the world came together to lift one two month old baby, would they be able to? | Pretty sure if all ants in the world came together they'd be able to lift way more than just a baby | [
"A study of a nest in Romania found that 10 species of ant were fed to the chicks. During the first 10 days, the young received an average of 15 g each, from days 10–20, 39.5 g, and from day 20, 49.3 g. The seven chicks consumed an estimated 1.5 million ants and pupae before leaving the nest.\n",
"Like every ant,... |
Is it really necessary to read the Cambridge Chinese history? | The Cambridge Illustrated History of China, also published by Cambridge University Press, is a less dense text that covers the basic outline of Chinese history (plus it has pictures!). Amazon is selling it for a little over $40 (£24 I believe).
However, if you're looking for books as detailed as the Cambridge series, there really are no equivalents now. The Cambridge series deserves its reputation for being one of the most comprehensive and highly regarded books on Chinese History. Harvard University Press is planning to release its own six volume series on Chinese history, but only the first in the series, *The Early Chinese Empires: Qin and Han*, has been published just recently in 2007. ~~You'll have to wait a few decades if you want the entire Harvard series.~~ Even the Cambridge series, which started over 30 years ago, still had two volumes and a half volume of the 15 that are unpublished.
| [
"The Cambridge History of China is an ongoing series of books published by the Cambridge University Press (CUP) covering the history of China from the founding of the Qin dynasty in 221 BC to 1982 AD. Chinese history before the Qin dynasty is covered in an independent volume, The Cambridge History of Ancient China ... |
why is it easier to see weak light, when not looking directly at it? | Your peripheral vision is designed to see changes in dark/light while your central vision is designed to see color and detail. You can see dim lights better with your peripheral because that is what it’s designed to do. | [
"Functional hypotheses propose that although multiple muscles may be affected, a deficit may be more readily apparent in the eyes for several reasons. Slight weakness in a limb may be tolerated, but slight weakness in the extraocular muscles would lead to misalignment of the two eyes, even a small degree of which c... |
why is it that whenever i am not suppose to or cant touch my face, it always starts to itch? | I don't have an answer for you, but can you imagine being an astronaut with one of those fishbowls on your head for hours at a time? Fuck, I get itchy just thinking about it. | [
"Itch is induced by mechanical, chemical, thermal, or electrical stimuli of sensory receptors in the peripheral nervous system, or by psychological prompts. The receptors that are responsible for the sensation of itch caused by environmental stimuli are found within the upper layers of the skin. Once stimulated, us... |
Ottoman-Bulgarian relations during the First World War | Besides the short fighting in Romania, i don’t believe ottoman/Bulgarian Troops ever worked in tandem, and even then, they where kept separate, Bulgaria had to manage and help oversee Romania and Serbia whilst the ottomans had to focus on things like Gallipoli, the Palestinian front, and the British advance out of Kuwait. | [
"An Ottoman–Bulgarian (or Turco-Bulgarian) alliance was signed in Sofia on 19 August 1914 during the opening month of the First World War, although at the time both the signatories were neutral. The Minister of the Interior, Talaat Pasha, and President Halil Bey of the Chamber of Deputies signed the treaty on behal... |
what prevents people with server access at a bank or payment processor to "spawn" themselves in money? | Auditing. Lots and lots of auditing.
It may surprise you to learn that banks are super serious about money and keeping track of money. So if some money just randomly appears they get pretty suspicious. | [
"When payment transactions are stored in servers, it increases the risks of unauthorized breaches by hackers. Financial cyber attacks and digital crime also form a greater risks when going cashless. Many companies already suffer data breaches, including of payment systems. Electronic accounts are vulnerable to unau... |
Is there a positive correlation between age at which mating occurs and length of life in humans? | > what "significantly longer" means, especially in terms of proportionality
I don't know the paper you're referring to, but significance in this context almost certainly means statistical significance (i.e., p-values) and does not necessarily mean that the effect was large in magnitude; for instance if the sample size is sufficiently large, even very weak effects can be highly significant. You should read the paper to answer this question, as they probably report effect sizes somewhere.
| [
"The age when sexual maturity is gained has been given differently by different studies. Wilson observed that females become mature before 13 months, and the minimum age was found to be eight months. He noted that males take longer to mature, nearly 11 to 14 months. The species is monogamous, with pairs remaining t... |
what the fuck happened/is happening at charlottesville ? | Group A protests for their more extreme conservative views.
Group B protests Group A.
Both Group A and Group B exchange inflammatory statements.
Both Group A and Group B might've engaged in physical altercations.
Person O accelerates vehicle into subset of Group B.
Edit: spelling | [
"Occupy Charlottesville is a social movement in Charlottesville, Virginia that began on October 15, 2011, in solidarity with Occupy Wall Street and the rest of the Occupy movement. The downtown Lee Park encampment was taken down on November 30, 2011 when 18 members of the movement were arrested and charged with tre... |
quantum darwinism | In Layman's terms, this is what the wiki sais:
In QM, the components of the universe exist in an unknown quantum state. Something causes these probability functions to leak information into our universe. This is information we can measure by using "classical" means (like a ruler, a balance, a volt-meter etc.).
The things we measure are relatively limited compared to the humongous amount of solutions (and thus variations of information) our probability equations produce.
Conclusion: something somewhere is on sorting-duty.
This specific theory sais that this "sorting" is the result of some variations being better than others. Like classical darwinsm it is like survival of the fittest, but then on a quantum level. As we see in nature, the possible outcomes, although large, are limited. Also we see these outcomes repeated over and over around us. | [
"Quantum Darwinism is a theory claiming to explain the emergence of the classical world from the quantum world as due to a process of Darwinian natural selection induced by the environment interacting with the quantum system; where the many possible quantum states are selected against in favor of a stable pointer s... |
what technological advances would be needed to make a pharmaceutical cure for obesity/prevention of fat gain possible, and why isn't it possible? | The problem is, if you binge eat and your body doesn't process it, you have to shit it out. If your body is just sending it on through you are going to shit RIGHT after you eat (or even before you're done), and it won't even look like shit but rather look a lot like what you ate.
Now take a look at a big cheeseburger and tell me that can pass through your anus. Sounds uncomfortable at the least, also extremely unsafe.
| [
"Regarding drug therapies, it has been stated that: \"\"An emerging concept is that the development of anti-obesity agents must not only reduce fat mass (adiposity) but must also correct fat dysfunction (adiposopathy).\"\" This is in recognition that the use of weight loss therapies and drugs in overweight patients... |
Will spiders use already formed webs that they have found (whether the web is from the same species or not) or do spiders only use webs that they themselves have made? | I did a bit of research, and I want to offer an expanded and more in depth answer.
As I mentioned in my first post, web building spiders tend to build and rebuild there webs. This is true, but not all web building spiders; some spiders, once the web is built, tend to just repair the web where it's damaged.
To answer your question, the answer is yes; several genuses of spiders, like that of Portia, will invade other spider's webs. Usually, these spiders are of the jumping spider variety, and don't usually build webs of their own. They also tend to eat the spider who made the web.
Other species display 'kleptoparasitic' behaviour, which describes the spider stealing food from other spiders, living on their webs and so forth. The spider family Theridiidae's subfamily, Argyrodinae, has a well documented history of doing such. And they're not the only spiders to practice this.
I hope this answers your question more fully. | [
"There is no consistent relationship between the classification of spiders and the types of web they build: species in the same genus may build very similar or significantly different webs. Nor is there much correspondence between spiders' classification and the chemical composition of their silks. Convergent evolu... |
Would combining isopropyl alcohol with hydrogen peroxide create a more effective antiseptic? | I am speaking from a biology background, so I can't comment much on the chemical implications of mixing isopyopyl alcohol and peroxide. Note, however, that hydrogen peroxide is fairly reactive.
That said, swabs of multiple antiseptics are used when preparing an area for surgery and injection. In my biological research, we utilize a triple regimen of betadine, isopropyl or ethyl alchol, and povidone-iodine before any procedure.
What is important to remember is that different antiseptic chemicals work by damaging bacteria or viruses in different ways. Chlorhexidine, for instance, disrupts bacterial membranes. Alcohols break cells apart and denature (mess up) proteins, Iodine is thought to also denature proteins or damage bacteria, and Hydrogen Peroxide is highly reactive and damages or breaks apart critical cell structures. It is certainly true that some of these methods work better for certain microbes than others. For example, *Norovirus*, infamous on cruise ships and college campuses for causing severe nausea is generally resistant to ammonia or alcohol based cleaners but is quickly deactivated by bleach. Different approaches can be used depending on the target microbes as well as how clean the surface needs to be. From experience, I have used a Chlorhexidine/Alcohol based hand wash deemed suitable by the FDA for pre-surgical scrub, so compounded methods can be very useful.
EDIT: If you are interested, the CDC has a guide to different disinfecting and sterilizing agents with their effectiveness and methods of action.
_URL_0_ | [
"Practitioners of alternative medicine have advocated the use of hydrogen peroxide for various conditions, including emphysema, influenza, AIDS and cancer, although there is no evidence of effectiveness and in some cases it may even be fatal.\n",
"Historically hydrogen peroxide was used for disinfecting wounds, p... |
if quantum physics was created to deal with light, how can it be used with other waves/particles? | One of the key understandings of quantum physics is that light doesn't just act like a wave, it also acts like a particle. **It isn't really either one**, it just sometimes acts like them. It is something that we have a hard time understanding, because it doesn't act like things in the macroscopic world do.
Turns out, it's not just light that is weird like this. The same is true of other subatomic particles. All of them. For example, the electron isn't really just a tiny little ball. It also acts like a wave sometimes, similar to how light does. Electrons can even interfere with each other. | [
"The quantum particle of light is called a photon. Light has both a wave-like and a particle-like nature. In other words, light can appear to be made of photons (particles) in some experiments and light can act like waves in other experiments. The dynamics of classical electromagnetic waves are completely described... |
How could the practice of performing excorcisms in the Catholic church survive for so many centuries? Are there credible cases where it worked? | When you're asking "where it worked" do you mean where someone had an ailment that was actually found to have been caused by demons or demonic possession who were actually, literally expelled by exorcism, or where someone just felt better after an exorcism? | [
"The Canon did not put an end to Puritan belief in the efficacy of exorcism. On the other hand, it stamped out the public use of exorcism by clergy of the church, until the period of the English Civil War. Nonconformists continued to use exorcism.\n",
"The first official guidelines for exorcism were established i... |
how does a smartphone keep track of a timer set when you restart or reset your device? | Two basic ways (phones, computers, etc.)
1. a battery! there is a little clock with a dedicated battery.
2. the network (cell network, internet, etc.) provides the time (time servers, domain controllers etc, for computers and the cell system for phones).
that gives you the current time. Then...the details of the timer you've set are stored on the device's memory. (e.g. started at 1pm finishes at 3pm.) | [
"The products have built-in security codes for controlled activation. Once the code has been input into the device, it is activated for a time period of 8, 12, or 24 hours. Upon expiration of the time clock, the device shuts off and cannot be used again until the code is re-entered. This prevents unauthorized use i... |
Can someone help me find records of a pilot who died during WWII? | Do you know what state they were from? The lists are broken down here at the archives .gov website by state and service branch :
_URL_0_
I linked you the Navy/Marines/Coast Guard database because the Battle of the Coral Sea wad a naval battle, notable as the first time two fleets fought one another without ever seeing each other physically. He was likely a Navy pilot | [
"MIA Hunters was a Minnesota-based volunteer nonprofit organization dedicated to finding and recovering the remains of lost American pilots air crew members missing in action from World War II. MIA Hunters organized at least 34 missions to China, Papua New Guinea, Vietnam, the Philippines, and elsewhere to locate t... |
when radio stations say they have 12 million listeners, how do they know? | [_URL_1_](_URL_0_)
There are basically two methods:
* Surveys. The company asks a representative sample of people "which radio shows did you hear last week"? A similar method is diaries, where each person in the survey keeps a list of every show they hear.
* People meters. Each person in the survey has a special machine that tracks which channel they tune to. This was usually done for TV, not radio. A new method has a machine listening the whole time, and it recognises which show, song or advertisement is heard. | [
"Included is a list of the 20 most-listened-to radio shows in the United States according to weekly cumulative listenership, followed by a selection of shows of various formats that are most-listened-to within their category. (Unless otherwise noted, the \"Talkers\" \"non-scientific\" estimate is the source.)\n",
... |
what makes something microwaveable or non-microwaveable? is all food microwaveable? | Yeah, all food is microwaveable (well, unless it has gold or silver leaf in it as some pastries may).
Non-microwaveable cookware absorbs microwave radiation and so it'll get hot, and also prevent the food from getting hot. That's all.
Microwaveable cookware generally does not absorb much microwave radiation. | [
"Whether polystyrene can be microwaved with food is controversial. Some containers may be safely used in a microwave, but only if labelled as such. Some sources suggest that foods containing carotene (vitamin A) or cooking oils must be avoided.\n",
"Microwave ovens produce heat directly within the food, but despi... |
Why did the victors of WW1 give Danzig to Poland and cut off part of Germany? | I tackled this question [with an answer back in December.](_URL_0_) | [
"Between the two world wars, many in Germany claimed that the territory ceded to Poland in 1919–1922 should be returned to Germany. This claim was one of the justifications for the German invasion of Poland in 1939, heralding the start of the Second World War. The Third Reich annexed the former German lands, compri... |
How does a historic researcher go about finding a topic to work on? | Find journals from your area of expertise. Read the most recent editions. Find out what the prominent questions and debates are. Select a relevant subject.
Edit: I found [this](_URL_0_). | [
"BULLET::::12. Historical research allows one to discuss past and present events in the context of the present condition, and allows one to reflect and provide possible answers to current issues and problems. Historical research helps us in answering questions such as: Where have we come from, where are we, who are... |
Is psychopathy advantageous from an evolutionary perspective? | Reid Malloy submitted a paper in 2011 suggesting just that. Predators in the wild must be able to identify the weakest and easiest target or they will not eat. Malloy argues that psychopaths share that trait and that they can read the facial emotion from people better than non-psychopaths. Wheeler, Book and Costello in *Criminal Justice & Behavior* (2009) confirm that psychopaths can identify women with a history of victimization just by watching videos of women walking.
This research suggests that there is an evolutionary advantage to the psychopathic predator, and back in the evolution of modern humans, this may have been a selective advantage to find a female who won't fight off your advances. In modern man, it only serves to make psychopaths better hunters. | [
"Psychopathy is associated with several adverse life outcomes as well as increased risk of disability and death due to factors such as violence, accidents, homicides, and suicides. This, in combination with the evidence for genetic influences, is evolutionarily puzzling and may suggest that there are compensating e... |
how do cuts on the inside of your mouth, on your cheek, tongue and lip not get super infected by all of our nasty mouth germs? | A big fraction of the germs that live in our mouths are commensal bacteria, which means we share common interest, we offer them the right temperature, nutriments and convenient humidity to live while they stop any infection from arising by other microorgnisms, this of course, is in case of a healthy body. If the commensal barrier is broken (for a general cause or local such as high and prolonged acidity) then we will see all sorts of chaos in that ecosystem. I guess we are on very fragile terms with the friendly bacteria. | [
"Mouth infections spread from the root of the infected tooth through the jaw bones and into potential spaces between the fascial planes of surrounding soft tissue, eventually forming an abscess. These potential spaces are usually empty, but can expand and form a pocket of pus when an infection drains into them. The... |
antenna theory | Think of an antenna like a piece of water pipe. We can send a pressure wave into one end of the pipe, and it will flow through the pipe, hit the cap on the other end, and bounce back.
Now, instead of doing that once, we can do it over and over, rhythmically. If the pipe length and the frequency of our cadence have the right relationship, we will create a [standing wave](_URL_0_), as the system essentially resonates. This creates a much stronger signal, as the waves going back and forth essentially reinforce each other instead of fighting against each other. It turns out that the length of the pipe needs to be 1/4 of the wavelength of the wave pulses, or certain multiples of that, to create a good standing wave.
Now, forget the water. We're really doing this with electricity, and the oscillation of the electric field creates an emanating set of electric and magnetic fields...an electromagnetic wave. (That's what visible light is, when it is a frequency our eyes can detect. Radio waves are much longer wavelengths....more "red".) With a straight antenna, the wave emanates pretty much equally in all directions perpendicular to the straight antenna.
If the antenna has a funny shape, then the wave will interfere with itself, causing various areas of constructive and destructive interference, changing the radiation pattern away from a nice circular pattern. If we focus the wave by bouncing it off a dish, or use multiple antennas, we can also get different wave patterns.
The same thing happens in reverse. As an EM wave hits our antenna, it creates the same kind of oscillation in it. But if those oscillations are too far from a resonant frequency (wavelength), they will be very weak and difficult to pick up as the oscillations they induce interfere with themselves. We can also increase their strength by first bouncing them off a collection dish that focuses more of the incoming wave onto the antenna.
We can even do very fancy things for transmission with multi-antenna waves. By carefully adjusting the relationships between the different waves in the different antennas, we can make the radiation shape different, such as making it a lot like a straight beam aiming in a certain direction. By manipulating those relative "phases", we can re-aim the beam electronically, without physically changing anything! | [
"Antenna theory is based on classical electromagnetic theory as described by Maxwell's equations. Physically, an antenna is an arrangement of one or more conductors, usually called elements. An alternating current is created in the elements by applying a voltage at the antenna terminals, causing the elements to rad... |
When I have a hangover, why do the symptoms come in 'waves'? | Dehydration.
It's your body's way of saying it hates you for being awesome last night. | [
"Symptoms can sometimes come and go with wave-like re-occurrences or fluctuations in severity of symptoms. Common symptoms include impaired cognition, irritability, depressed mood, and anxiety; all of which may reach severe levels which can lead to relapse.\n",
"Common symptoms most frequently reported include a ... |
the purpose of a $1 salary | It's a tradition among the tech giants in silicon valley to have a $1 a year salary.
They own such a big share of the company they are worth billions so putting them on a $200k/year salary is stupid because it's in their best intentions to make the company work. | [
"A number of top executives in large businesses and governments have worked for a one-dollar salary. One-dollar salaries are used in situations where an executive wishes to work without direct compensation, but for legal reasons must receive a payment above zero, so as to distinguish him or her from a volunteer. Th... |
what was the appendix used for before it became obsolete? | The current best theory is that it isn't entirely obsolete. It functions as a place where various microorganisms that live in your gut can survive even if you have diarrhea, or if you eat something that has antibiotic properties. Those microorganisms can be pretty important to proper digestion and good health (you don't want to have just any old random bunch living inside you), so having an internal refuge for them is useful. | [
"An appendix includes supplementary data or information to give more in-depth analysis or clarification. Some items included in an appendix are time tables, work plans, schedules, activities, methodologies, legal paperwork, and letters of support or endorsements from the community.\n",
"Scholars are almost unanim... |
what factors contribute to whether you need to have a/some limbs amputated? is it damage to bones? muscles? nerves? | Med student here. Most of it has to do with the viability of the limb which is determined by the quality of the blood flow to the limb/extremity.
Muscle, bone and nerve damage are like cutting leaves and flowers off a plant. Blood flow is like removing water. Without consistent flow the thing dies and/or cannot repair. | [
"Treatment of tissue defects caused after a trauma present major surgical challenges especially those of the upper and lower limb, due to the fact that they often not only cause damage to the skin but also to bones, muscles/tendons, vessels and/or nerves.\n",
"Injuries to the spinal cord interfere with electrical... |
What are the consequences of vacuums being created within an atmosphere? | > In a river so that water was forced to run around it?
Not sure what you mean by this; "nature abhors a vacuum" and will not flow around it.
> Around a plant and left there for a few minutes?
I'm not sure about the biology, but in a hard vacuum water will vaporize. I suspect the structure of a plant/animal can resist this, but that's a question for a biologist.
> In some arbitrary spot and then released? Would this cause a breeze when the air rushed to fill the void?
It'd cause more than a breeze; a cubic meter of vacuum collapsing suddenly will cause a hell of a loud explosion. | [
"Many have said that a vacuum does not exist, others that it does exist in spite of the repugnance of nature and with difficulty; I know of no one who has said that it exists without difficulty and without a resistance from nature. I argued thus: If there can be found a manifest cause from which the resistance can ... |
What is known about the golden 'cap(s)' that adorned the tops of the Great Pyramids? | A fragmented inscription found near the pyramid of Udjebten mentions a gilded capstone (bnbn.t).
No known pyramidions from the old and middle kingdom exist that have a mechanism for a metal coating. So it is more likely that the inscription refers to the tip of an obelisk that once stood in or near the pyramid temple of the queen.
All found granite or basalt capstones that have a contraption for fixating a metal coating from the old kingdom are for obelisks and originate from royal disticts.
-------------------------
^G. ^Jequier, ^Oudjebten, ^4 ^f., ^16 ^und ^18, ^Fih. ^15, ^Urk. ^I,272
^Edwards, ^Pyramids, ^262
^Preliminary ^Report ^on ^Czechoslovak ^Excavations ^in ^the ^Mastaba ^of ^Ptahshepses ^at ^Abusir, ^1976, ^35 | [
"A pyramidion is a capstone at the top of a pyramid. Called benbenet in ancient Egyptian language, it associated the pyramid as a whole with the sacred benben stone. Pyramidions may have been covered in gold leaf to reflect the rays of the sun; in the Middle Kingdom, they were often inscribed with royal titles and ... |
Slugs. Where are they? | They are probably outside dispersed under rocks and things. Check places that are damp. And there's always a bunch in the hosta :(
Butterflies shelter from rain under leaves and in other little nooks and crannies I believe. | [
"Slugs are parasitised by several organisms, including acari and a wide variety of nematodes. The slug mite, \"Riccardoella limacum\", is known to parasitise several dozen species of mollusks, including many slugs, such as \"Agriolimax agrestis\", \"Arianta arbustrum\", \"Arion ater\", \"Arion hortensis\", \"Limax ... |
when and how did greek/roman mythology slowly shift from a religion to mythology | It happened as the people of those regions converted to other religions, primarily when they converted to Christianity. | [
"In Ancient Roman times, a new Roman mythology was born through syncretization of numerous Greek and other foreign gods. This occurred because the Romans had little mythology of their own, and inheritance of the Greek mythological tradition caused the major Roman gods to adopt characteristics of their Greek equival... |
why do phones have enough battery to show you the picture saying that they're out of battery? | Because most cellphone batteries are Lithium Ion, and it will [hurt the battery's capacity to hold electricity](_URL_0_!) if you let it empty all the way. | [
"A battery indicator is a feature of many electronic devices. In mobile phones, the battery indicator usually takes the form of a bar graph - the more bars that are showing, the better the battery's state of charge.\n",
"An easy fix for this is to put an eraser on the cover and use it to slide the cover open. Fur... |
Do items floating loosly in the ISS (such as astronauts when they aren't touching anything) add to its overall weight? | In orbital mechanics, the mass of a spacecraft (like the ISS) makes no difference in the way It orbits a body (like the Earth). This means that the total mass (Which is proportional to weight) of the ISS makes no difference in the orbital properties of the ISS. You could fill up the ISS with lead and it would still follow the same orbit it follows now.
Mass does become important when you need to accelerate the ship. When you want to change the orbit of the ship, you need to accelerate it by burning fuel. The amount of fuel you have to burn for a given speed change has an exponential relationship with the mass of the spacecraft. When you accelerate the spacecraft, you need to accelerate the people and things inside the craft along with it. These people and objects contribute to the mass of the spacecraft, and result in a need for more fuel. This is where filling the ISS with lead becomes a terrible idea.
In short, yes, people and objects *do* change the mass of the spacecraft. However, mass is only important while the spacecraft is performing a maneuver. While it is in a stable orbit, the mass of the craft makes no major difference. | [
"While the weight of an object is dependent on the strength of the local gravitational field, the mass of an object is independent of gravity, as mass is a measure of the quantity of matter. Accordingly, for astronauts in microgravity, no effort is required to hold objects off the cabin floor; they are \"weightless... |
Does a photon "leaving" the sun (yet close to it) move slower because it's affected by its gravity? | As near as we can tell, photons are massless particles (which makes more sense if you consider light as an EM wave instead of a particle). Gravity does not change the speed at which light propagates, but it can change its frequency ([gravitational redshift](_URL_1_)). Gravity can also change the direction light travels (here is a [previous comment](_URL_0_) where I explained why gravity changes the direction light travels). | [
"BULLET::::- Extra energetic photons: Photons travelling through galaxy clusters should gain energy and then lose it again on the way out. The accelerating expansion of the Universe should stop the photons returning all the energy, but even taking this into account photons from the cosmic microwave background radia... |
how do mobile devices charge while they are in use? | Most fundamentally it's just that the source (informally a wall wart) is providing more power than is being consumed by the device, so the battery charges. | [
"BULLET::::- Inconvenience – When a mobile device is connected to a cable, it can be moved around (albeit in a limited range) and operated while charging. In most implementations of inductive charging, the mobile device must be left on a pad to charge, and thus can't be moved around or easily operated while chargin... |
My uncle gave this to me when he died.. What is it? | Itzamna is the name of the Mayan sky god. In Google images, there is an image of Itzamna from the Dresden codex that looks just like the image on your object. | [
"Great Uncle Bruce is a deceased character who is mentioned in \"Cabin Fever\" and \"The Third Wheel.\" Greg is presented with a rather luxurious blanket as a Christmas gift, only to be repelled by it upon learning that it had formerly belonged to Great Uncle Bruce before his death. This leads him to give it to an ... |
how pepe the frog went from "feels good man" to a conservative political symbol | He didn't. Pepe is still just a frog meme. He's no more conservative political symbol than any other meme. He's more popular on 4chan than Reddit, and 4Chan is more alt-right than Reddit, so that could be why he got mixed up in this. Leave pepe alone! | [
"Pepe the Frog was created in 2005 as part of an online comic. As culture took hold, Pepe the Frog became an established meme, often shared online by celebrities. As its population grew, the designated community morphed from fans of the author and comic to include members of the alt-right and Donald Trump supporter... |
PTSD in the American War of Independence | I recently picked up the audio book of Atkinson's *The British Are Coming*. It is the first part of a trilogy on the military history of the revolution. There are a number of officers and enlisted accounts that he includes from the Canadian campaign, Breed's Hill, Charleston, and others that discuss the horrors of the war. I would mine those sources and see if you can find where the originals are. Some of the accounts are from diaries immediately after, but I seem to remember that a few appeared to be accounts written years after. It was still a fresh memory for many of them. | [
"The development of the diagnosis of post traumatic stress disorder (PTSD) for American veterans of the Vietnam War can be understood as a political act which labeled the collective distress of a defeated USA as individual psychopathology. Proponents of this view, point to the de-politicization of the distress of t... |
What was the first status automobile that a well to do American would have bought when they started to be popular with the rich and famous? | /u/theshowisnottheshow gave a good background. The early automobile market was so flooded with different marques and manufacturers (Over 5,000 marques are listed between 1895 and 1942 in the *Standard Catalogue of American Cars* - most of them never produced a single automobile or ever advanced beyond a single prototype) that it's difficult to single out a single marque as the "go-to" car for the Rich and Famous. I'd roughly describe the period when cars "started to be popular" as 1895-1914(the year that the Model T began to be produced in immense volume - that year more Model Ts were made than any other car), although one could easily make the case that the automobile was already "popular" as early as 1905.
* **Early years:** The first marque that really became popular with wealthy American was the [Winton Motor Carriage Company](_URL_4_), although again "popular" is a relative term - Winton only made 22 automobiles in 1898, and slightly more than 100 in 1899, making it the largest manufacturer in the United States. At this time, France was at the forefront of the industry, and marques like [de Dion Buiton](_URL_0_) and [Panhard et Levasor](_URL_6_) began importing to the US around 1900. It should be noted, however, that at this point the automobile was not quite a "status symbol" - although it was certainly only affordable for the well-off, it was seen more as a novelty (albeit one with great potential).
* **The 1900s** The mid 1900s saw the automobile transition from a novelty into an appliance of great practical value - although the process wouldn't be complete until the 1910s. The [Curved Dash Olds](_URL_5_) introduced in 1901 was modestly-priced and mass-produced, although not particularly technologically advanced. As the automobile became a status symbol, certain marques became more valued. Frequently this was tied with success in racing or endurance events - F.I.A.T., Mercedes, Darracq, Locomobile, Bugatti, and many others achieved success this way.
* **The Brass Era** By 1908 or so, the auto market resembled today's, with different marques offering cars at different price points. Packard, Pierce-Arrow, Rolls-Royce and Cadillac were among the the most successful luxury marques, but there were hundreds of luxury firms of various sizes. ALCO and Pullman (famous manufacturers of locomotives and passenger cars, respectively) each had stints in the luxury auto market; Locomobile and Peerless were other well-known marques. For more performance-oriented customers, there were the powerful [Simplex](_URL_7_) and [American Underslung](_URL_3_), while the [Mercer Raceabout](_URL_1_) and [Stutz Bearcat](_URL_2_) basically invented the sports car.
Hope that answers your question! | [
"BULLET::::- 24 March – Robert Allison of Port Carbon, Pennsylvania becomes the first person to buy an American-built automobile when he buys a Winton automobile that had been advertised in \"Scientific American\".\n",
"BULLET::::- March 24 – Robert Allison of Port Carbon, Pennsylvania becomes the first person to... |
how the "helicopter effect" happens in a car when you have a window open. | It is called [Helmholtz Resonance](_URL_0_). This is basically where there is a low pressure area outside your car because the air is moving relative to the car which, according to [Bernoulli's Principle](_URL_1_), lowers fluid pressure. The air in your car wants to equalize with the lower pressure outside your car, so it gets pushed out. By the time the pressures have equalized, the air is still moving out due to its inertia, so extra air gets out. This creates a low pressure zone in your car and the reverse happens. It flows into the car, but too much flows in, leaving another high pressure zone in the car, and the cycle repeats. This oscillating high and low pressure happens tens of times per second, which we perceive as sound.
Side note: u/fyrillin could be on to something with the bluff body vortex shedding. However, the reason I think he could be wrong is that I get this effect when only my sun roof is open. How could there be a winning side and a losing side if there is only one hole? It is similar to blowing on a bottle and making a noise, which is confirmed to use Helmholtz Resonance.
Edit: I mixed up where the high and low pressure zones start. Fixed. | [
"BULLET::::- Some of the helicopter crashes are caused by resonance too. The eyeballs of the pilot resonate because of excessive pressure in the upper air, making the pilot unable to see overhead power lines. As a result, the helicopter is out of control.\n",
"This phenomenon has been observed during helicopter f... |
Why does the standard deviation formula have an (n-1) instead of n? | Essentially, you want to try and find the population standard deviation from a smaller sample. If the population is finite and you know all the relevant information (eg, you know everyone's age in the US), then you can compute the exact population standard deviation, and this has an 'N' in the bottom rather than 'N-1'. But this works because if we know absolutely everything about a population, then we can compute the actual mean of the population. If we only have a sample of the population, then the mean itself is an estimation. So every time you use the mean of the sample, you're introducing error. In fact, using the sample mean and dividing by 'N', you will always underestimate the actual standard deviation you would get if you knew and computed with the actual mean. [Wikipedia](_URL_0_) has a pretty good explanation of why this happens.
So computing the standard deviation using the sample mean (and dividing by N) will always give you a smaller standard deviation than you should get. Luckily, we can compare this computed standard deviation to the standard deviation you would get using the population mean instead, and the way to correct for the error that you get for using the sample mean is to multiply your result by N/(N-1), which is the same as just dividing by N-1 at the get-go. | [
"The value is assumed to conform acceptably to a normal distribution, so the mean can be assumed to be 1.15 in the reference group. The standard deviation, if not given already, can be inversely calculated by knowing that the absolute value of the difference between the mean and, for example, the upper limit of the... |
After recently watching a Kurzgesagt video about bringing a piece of the sun to Earth: Are fusion reactors truly safe when they fail? | > a piece of the sun, each the size of a house
Note that the core of a star is very dense, so dense it can fuse elements at much lower temperatures because of the extreme pressure. In fusion reactors they have to compensate for the lack in pressure with higher temperatures, however, the amount of stuff being heated is much, much smaller and less dense. Take ITER's chamber, it will be a vacuum housing only a couple of grams of material in gas form and then heated to a plasma. If confinement is lost, there is so little mass that it will cool down immediately and stop the fusion process.
Edit: if my calculations are right, the 500 MW ITER reactor would release about this much energy in case of a breach (around 120 kg of TNT equivalent).
_URL_0_
I wouldn't want to be near the chamber if it implodes and the heat is released, but it's hardly a world ending event. | [
"The design called for the reactor to be positioned in the tip of the spacecraft behind a strong radiation shield protecting sensitive spacecraft equipment. The reactor would only be powered up once the probe was well out of Earth orbit, so that the amount of radionuclides that must be launched into orbit is minimi... |
How can I navigate the dark so easily after just getting a momentary glimpse of my surroundings? | It's not surprising that you are able to create a mental map of areas that you traverse often, but it may be surprising to you that it is constantly utilizing and rewriting this map every time you revisit that area. Let's take your room, for example. Objects with permanency, like your desk or bed, are reinforced in that map every time you walk through the room, because they are in the same place every time. When you walk through your room, you don't consciously try to navigate through it without bumping into your bed, because you generally know where everything is. Less permanent objects, such as the cell phone on your dresser, do not have a great representation in this map. This is why you might occasionally trip on the towel you threw on the floor that you forgot about -- it's not usually there, so you haven't placed it in your mental map yet.
Let's say you went on vacation and left your phone on your table. You come back a week later, at night, and the power is out. You go to your room, effortlessly walk through the room around your bed, but have to search for the phone on your table because, unless you leave it there every day, it is something that moves regularly.
These types of maps are created and rewritten constantly, but important ones may stick with you for years or decades. This might be why you can remember the layout of your childhood home, but not the layout of your friend's home around the same time period. | [
"Under conditions in which there is no visual stimulation (in total darkness), we can still perform smooth pursuit eye movements with the help of a proprioceptive motion signal (e.g. your moving finger).\n",
"If you looked out from a source of light, all of the objects you can see would appear in light. Anything ... |
why aren't there more bruce lee/ninja fighters in us mma? | Basically the best martial artist in the world in a confined space is susceptible to a bull rush or equivalent. Without the space to manoeuvre they are vulnerable to very close quarter fighting. | [
"American Ninja Warrior (sometimes abbreviated as ANW) is an American sports entertainment competition, which is a spin-off of the Japanese television series \"Sasuke\". It features hundreds of competitors attempting to complete series of obstacle courses of increasing difficulty in various cities across the United... |
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