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Why do quasars emit so much light? | Essentially, because there is a lot of material falling into the black hole. When things fall down a gravity well, they lose gravitational potential energy. Drop something off a cliff, and gravitational energy gets transformed into kinetic energy, which upon hitting the ground will partly turn into thermal energy. Of course, if you drop something off a cliff, then even ignoring air resistance it will probably only be going tens of meters per second. If you drop something into a black hole from very far away, then as it approaches the event horizon, its speed will approach the speed of light. Now, typically things don't just fall in on a single trajectory, it's usually a longer process of orbital decay and tidal forces that eventually usher the particles to their ultimate fate, but nevertheless they gain a tremendous amount of kinetic energy, and much of that gets transformed into radiation. That's why quasars are so bright.
The specifics of how energy gets turned into light (and particle jets) in an Active Galactic Nucleus is more complicated. First of all, you've got a rapidly spinning [accretion disk](_URL_0_) of matter around the black hole. As you get closer to the inner edge of this disk, it gets hotter and denser, so that the inner edge is radiating mainly in the X-ray regime. Since this material is a plasma, you've got magnetohydrodynamical effects that come into play. That's a fancy term for a combination of fluid dynamics and electromagnetism. We don't yet have a precise understanding of the process, but basically the disk creates powerful electromagnetic fields which shoot some of the infalling particles out in jets rather than letting them fall toward the event horizon. | [
"Quasars (/ˈkweɪzɑr/) or quasi-stellar radio sources are the most energetic and distant members of active galactic nuclei. Quasars are extremely luminous and were first identified as being high redshift sources of electromagnetic energy, including radio waves and visible light, that appeared to be similar to stars,... |
why is it that "time flies when you're having fun"? | I think because you focus much harder on the task at hand you stop thinking about the time so much. | [
"\"Funny How Time Flies (When You're Having Fun)\" is the seventh and final single from American R&B singer Janet Jackson's third studio album, \"Control\" (1986). While \"Funny How Time Flies (When You're Having Fun)\" was officially released in the United Kingdom and Australia, it was released solely for airplay ... |
what are the grey areas that we can see in the moon from down here? | They're called mares. It means "sea," but these are actually more like patches of the surface that had melted and re-hardened in the distant past. | [
"The lunar landscape used in the film is Vasquez Rocks, a popular television and feature film shooting location near Los Angeles. A red camera filter was used to make the blue sky photograph very dark on the black-and-white film, but the result is still far from the ideal starry black. Bits of scrubby vegetation ca... |
since blue whales have aortas large enough to swim in, do they have fewer issues with blood clots? | considering they have an extremely active lifestyle (swimming constantly all the time) and a relatively low cholesterol diet (mostly plankton and krill iirc) they are presumably at very low risk for blood clots in the first place. | [
"All squamates and turtles have a three-chambered heart consisting of two atria, one variably partitioned ventricle, and two aortas that lead to the systemic circulation. The degree of mixing of oxygenated and deoxygenated blood in the three-chambered heart varies depending on the species and physiological state. U... |
When heating something to high temperatures it becomes “red hot” and then continues to change color to orange, yellow, and then white; why doesn’t the hot object start to glow green or blue after yellow? | The "red hot" appearance of an object is due to its thermal radiation. This is EM radiation emitted by every object and the spectrum of which is determined by the temperature. Objects at room temperature emit thermal radiation in the infrared part of the spectrum, but once objects get hotter, the spectrum of thermal radiation shifts more towards the visible part.
However, this radiation is a broader spectrum, not a single line. So a red hot object will emit red visible light along with plenty of IR light. Since the red light is the only thing visible to us, we see the object as red. If you heat up the object further, shorter wavelength visible light gets added to the mixture, making the combined color shift towards orange.
If you heat the object enough, the thermal radiation will cover the entire visible light part of the spectrum, making the combined radiation appear white. At no point does the object only emit green or blue light. By the time it's hot enough to emit green or blue, it's also emitting plenty of light in other colors (with longer wavelengths) and what we see is the mixture of all visible light that is emitted. | [
"It is true that objects at specific temperatures do radiate visible light. Objects whose surface is at a temperature above approximately will glow, emitting light at a color that indicates the temperature of that surface. See the section on red heat for more about this effect. It is a misconception that one can ju... |
why does fabric (temporally) change colour when it gets wet? | First of all, you have to look at how colour works. When light hits something, most of the light is absorbed by whatever is there, in your case, the backpack. What you see is only the light that isn't absorbed, it's reflected back at you. So, when you add water (rain) the reflection back is different because the water has changed how the reflection works. When you see something white, you see everything reflected back, when you see something black, thats because no light is reflected back. | [
"Linen fabrics have a high natural luster; their natural color ranges between shades of ivory, ecru, tan, or grey. Pure white linen is created by heavy bleaching. Linen fabric typically varies somewhat in thickness and is crisp and textured, but it can in some cases feel stiff and rough, and in other cases feel sof... |
what will happen if a republican president is elected in 2016 and signs the obamacare repeal bill? | Yes, it could be repealed, and what would happen depends on what exactly is in the bill repealing it.
While the Affordable Care Act is one discrete public law, it is codified by inserting provisions into various titles and sections of the U.S. Code (statutes) that deal with health care and insurance. So whatever act repeals it needs either to show what part of the current code needs to be repealed or it can repeal all of the provisions of the ACA at once and leave [someone else](_URL_0_) to do the dirty work of tracking it all down and updating the Code.
Then I suppose _URL_1_ goes down, no one gets insurance subsidies anymore, you can get jacked out of qualifying for insurance based on health condition, and premiums could be underwritten again. You might have to pay for preventive care, you might have a lifetime maximum benefit again, and there's no guarantee that the plans you do qualify for will offer decent coverage. A lot of poor people would get kicked off Medicaid.
It would be like 2008 again. | [
"In January 2017, at the beginning of the Congress, Collins voted in favor of a bill to begin the repeal of the Affordable Care Act (\"Obamacare\"). However, with four other Republican senators, Collins is leading an effort to slow down the ACA repeal in the Senate. Collins and fellow Republican Senator Bill Cassid... |
why there is no radio function in iphones (not sure about androids) radio was avaliable in almost all old phones | Because you need to add yet another chip which can receive the right wavelength, which adds complexity, costs, and takes away space for things you'd rather put in. | [
"Some previous iPhone models contained a chip capable of receiving radio signals; however, Apple has the FM radio feature switched off because there was no antenna connected to the chip. Later iterations of the iPhone (starting with the iPhone 7), however, do not contain radio chips at all. A campaign called \"Free... |
Did any Native American civilization possibly know that there was land and people beyond the Americas? Did they have any mythological tales about the rest of the world? | I think, from my understanding, you are asking about concepts of aboriginal knowledge- this is " including traditional teachings, empirical observation, and revelation" (1). I caution that I have only an amateur background in the histories, but hope to answer the concept of your question.
Of the concepts mentioned the most relevant, I believe, is that of *traditional knowledge* as it is the preservation of understanding handed down, "more or less intact... And it memorizes battles, boundaries, and treaties and attitudes... Toward neighboring nations" (1).
So where is such contact recorded? First, there is the acknowledging that such information, while flawed, is of value. This is illustrated with the oral preservation of accounts of the Franklin Expedition:
> > The key methodological shift in Franklin expedition scholarship in recent years came with David Woodman’s Unravelling the Franklin Mystery: Inuit Testimony (1991). Woodman went back to Hall’s notes and journals from the 1860s to challenge the traditional account of the disaster and carefully piece together a narrative based on the oral testimony of Inuit. Woodman also emphasized the location of relics, bodies, and other artifacts to paint a picture of multiple abandonments of the ships and multiple groups moving in different directions, some of which returned to the Erebus and piloted it south to where it sank in the Utjulik region. This narrative would account for stories of separate groups of white men encountered by Inuit far from the Great Fish River and stories of survivors still interacting with Inuit well into the 1850s. > > ... Potter believes Inuit testimony about the expedition to be “the single most important body of evidence we have” (2).
In addition, the accuracy and usefulness of Aboriginal Songlines are also respected and well as the impact of "continual cartographic encounters, exchanges, and translations between American Indians and Euro-Americans"(3, 4).
This leads to... Is there evidence within traditional knowledge respecting the existence of external cultures? First, I looked to see if the Native American of the North American Content were aware of the Southern Content or vice versa - but it is important to remember the scope and newness of current geographic boundaries. For this section "pre-contact" is to define the physical presence of sustained non-Native populations.
According to an *Historical Survey of First Nation Market Culture* there evidence to suggest a working from of communication across Continents for there to be the usage of non-local materials. Two notable examples are that of trade between two divisions of Mayans of the
> > Northern Lowlands and the Highlands was well established via water routes on the Gulf of Mexico and the Gulf of Honduras as well as various inland routes. The Northern Lowlands Maya imported corn, fruit, cacao, various manufactured goods, flint, game, cotton, cloth, obsidian, metates, and manos. The Highland Maya imported honey, salt, ceramics, various tools, salted fish, marine shells, dye, incense, jade, and rubber.
Additionally the use of a soft stone (pipestone) found in the current Minnesota region as was important to the creation of objects for religious reasons was found as far as South Dakota, Ohio, and Kansas. After contact and with it the introduction of the horse, the material was found as far as Arizona and Kentucky (5).
All this contact is important as it allows for the development and subsequent preservation of intricate trade agreements. An example of this is that found in the pre-contact legislation of the Great Law of the Iroquois (now commonly referred to as Haudenosaunee). The Iroquois Confederacy had such an extensive documented sytem that it is still very much under legislative analysis. As noted in the brillant thesis *INTERNATIONAL LAW/THE GREAT LAW OF PEACE* by Beverley Jacobs, "European diffusionism will be defined through an elaboration of brief historical accounts and an analysis of law that has affected O:gweho:we. Eurocentric values, ideals, language, laws and institutions are an integral part of diffusionism, which has tried to replace O:gweho:we history, language, religion, laws and philosophy."(6).
Now that we have determined that there was contact, trade, and therefore knowledge across sections of the American Continents, and the risk that there is and will continue to be effects of non-Native interpretations of traditional knowledge, I attempted to source information about ex-Continental knowledge, firstly with that of the natives of Hawai'i. It might almost be cheating, in a sense, as the oral traditions of Hawai'i and New Zealand are quite well preserved compare to other Nations, and were treated with an unusual level of respect and importance to historical research.
> > Some of the data provided by recent stratigraphic excavations in Poly- nesia is pertinent to this problem, however, for it allows some very sound inferences as to certain aspects of Polynesian voyaging. For example, as a result of intensive excavations for the last ten years, Emory believes that the Hawaiian archipelago was settled by a planned, well-equipped expedition of some size (Emory 1959). Pigs and dogs are found in the earliest sites so far discovered there, and it is believed that the domesticated plants must have also been present to support the population. > > In the Marquesas, excavations at site NHaal, the oldest known site in that archipelago to date, (ca 120 B.C.) yielded evidence that pigs and dogs accompanied the settlers. Furthermore, the presence of coconut grating tools and knives of a type generally used for peeling breadfruit and starchy root crops demonstrate that the main Polynesian staples also arrived with the settlers (7).
The trade and communication within the Polynesian region is not just known but documented (8, 9, 10). Referencing non-Polynesian sources was difficult so I plan on providing more later in the day if that is alright.
--added---
While I did not want to deviate from your question, which was strictly about the North American continent, as I was limited to the papers I currently have access to. I have copied a section of a paper to illustrate part of the difficulties of studies into indigenous knowledge:
An important task of an "Indigenous paradigm" would be to challenge these notions according to which the world is divided along lines of Western "high culture" and non-Western ''folkloric'' traditions. Although many contemporary practices of poststructuralism, feminism, postmodern and postcolonial theories have undermined and rejected these assumptions, unfortunately they still guide much of people's everyday thinking and actions. Unlike many Western scholars who can ignore this since it is not as common an academic approach as it used to be, we as Indigenous peoples cannot remain indifferent, since it affects us directly in various ways through dismissive and biased attitudes on our selfhood, our culture and its products (11).
As my studies are in the field of criminology and legal development, I can say that indigenous people the world over are inheritances to some of the most historic and under studied legal systems on the planet with unique concepts of civil and criminal law. Further, the usage and impact of these legislative systems upon the cultures - and the impact this had on colonialism - is, I think, too often ignored.
--added--
To be honest I am hesitant to touch the aspect of mythological tales - it is in no way my forte. In addition, sorry for the formatting and writing style, this was done in my phone on the train. Finally, I'm going to do my best to find more Indigenous sources as I felt there could be more I wasn't able to access on my mobile.
(1) Indigenous Knowledges in Global Contexts: Multiple Readings of Our World edited by Budd L. Hall, George Jerry Sefa Dei, Dorothy Goldin Rosenberg
(2) Finding Franklin: The Untold Story of a 165-Year Search by Russell A. Potter (review) Shane McCorristine
(3) Songlines and navigation in Wardaman and other Australian Aboriginal cultures by RP Norris, BY Harney
(4) Theorizing indigital geographic information networks by Mark Palmer
(5) First Nations Trade, Specialization, and Market Institutions: A Historical Survey of First Nation Market Culture by Andre Le Dressay
(6) INTERNATIONAL LAW/THE GREAT LAW OF PEACEA Thesis Submitted to the College of Graduate Studies and Research in Partial Fulfillment of the Requirement for a Masters Degreein the College of Law, University of Saskatchewan By Beverley Jacobs
(7) Histmical Traditions and Archeology in Polynesia by Robert C. Suggs
(8)Oral Tradition as History By Jan M. Vansina
(9) Myth, Experiment, and the Reinvention of Polynesian Voyaging by Ben Finney
(10) Polynesian settlement and palaeotsunamis by James Goff, Bruce G McFadgen,Catherine Chagué-Goff etc
(11) TOWARDS AN "INDIGENOUS PARADIGM" FROM A SAMI PERSPECTIVE by Rauna Kuokkanen
--added--
Additional Sources:
Tsilhqot’in Nation v. British Columbia (2014)
Harry Daniels, et al v Her Majesty the Queen as represented by The Minister of Indian Affairs and Northern Development, et al (2016)
Edits: Spellings, additional context, more sources. | [
"In his very last years, Knorozov is also known to have pointed to a place in the United States as the likely location of Chicomoztoc, the ancestral land from which—according to ancient documents and accounts considered mythical by a sizable number of scholars—indigenous peoples now living in Mexico are said to hav... |
why are australia's vast empty planes simply not covered in solar panels to help with their power productions crisis? | A couple of reasons:
* it's expensive as fuck
* you lose a lot of the power having to transfer it across lines to where it is useful.
* despite it being fairly inhospitable to people, there's still a great deal of wildlife there that would be impacted by such a huge construction project.
I mean yeah put a solar plant or two as close as you can to civilization, but don't cover the land with them. | [
"Solar Ship Inc. is a company based out of Toronto, Ontario, Canada in order to develop hybrid aircraft to deliver critical cargo to cut-off places. The solarship gains lift from both buoyant gas and aerodynamics and uses power from solar panels. The aircraft is a new concept of transport that does not rely on foss... |
why is it recommended to cook with cold water instead of hot water? | Yo ho ho! Yer not alone in askin', and kind strangers have explained:
1. [ELI5: Why is it better to start with cold water and boil it when making pasta or coffee, rather than starting with hot water? ](_URL_3_) ^(_30 comments_)
1. [ELI5: When I boil water, why am i supposed to use cold water? ](_URL_2_) ^(_29 comments_)
1. [When cooking, why do we not boil hot water from the faucet? Won't it be faster and doesn't the heat kill any bacteria anyway? ](_URL_1_) ^(_4 comments_)
1. [ELI5: Why do packages often say bring cold water to a boil? ](_URL_0_) ^(_11 comments_)
| [
"Since cooking foods at high temperatures in order to kill bacteria and pathogens is required, cautionary measures need to be taken into consideration. One of these precautions is the use of water and other solutions around deep fryers because water or ice that meets hot oils is likely to gurgle, splash, and bubble... |
What properties make an object heat faster in a microwave? | You are observing the dielectric properties of the various materials. Some materials like dry ice are transparent to microwaves and will not heat up in a microwave because it has low dielectric loss. Some ceramic plates and bowls have higher dielectric loss than others meaning they couple with the microwaves and begin to vibrate generating heat.
Metals reflect most of the microwaves but the surface layer can build a considerable charge creating sparks if the voltage is high enough to arc through air. | [
"Different compounds convert microwave radiation to heat by different amounts. This selectivity allows some parts of the object being heated to heat more quickly or more slowly than others (particularly the reaction vessel).\n",
"Microwave heating can cause localized thermal runaways in some materials with low th... |
How much of Real Madrid's early success was because of Francisco Franco? | Sid Lowe's book 'fear and loathing in la liga' goes into great detail on this. Essentially people on both sides will claim lots and nothing.
An important point to note is that real madrid were one of the best teams in the country directly before the civil war and were gutted by the civil war. Real madrid's president was a key part of the republican government and so was exiled upon franco winning the civil war and the vast majority of real's trophy winning team broke up and either left spain or went to other clubs. In particular, their star player Zamora ended up in a prisoner of war camp and was appointed manager of atletico madrid after the war finished, where he won them their first league title despite the fact that atletico had been relegated prior to the civil war and therefore probably shouldn't have been allowed to play in la liga that year.
So as result, the first 15 years of franco's reign were real's worst ever as a club (they won no league titles and only two cups), because while Atletico had the reputation as the establishment's choice and barcelona were assembling their firstly truly great team, Real were doing very little at all.
The tipping point, though it wasn't obvious at the time, was a copa del rey semi final with Barcelona. Barcelona won the first leg 3-0 thanks, in part, to a great support from their fans resulting in the ref being a bit of a homer. Real made a big deal in the papers about this and encouraged their own fans to do the same in the return leg and they won 11-1. Barcelona players have claimed they were basically told before the game by officials not to try and win that game and were threatened into losing.
Now during the civil war, barcelona and madrid were the two main centres of opposition to franco. It was only when first barcelona and then madrid finally fell that the war was won. Franco was advised to not base his capital in madrid after the war but in a loyalist city instead and he choose to move there precisely to conquer his enemy, to make madrid his. Both Real and barca had funded the republican side in the civil war but after the war you started seeing franco's narrative taking from, in which the catalans did that because they were traitors but the madridstas did it because they were victims of the republicans looting their club. But Franco's dream was a united castilian spain, run from the biggest castilian city. He didn't want madrid and barcelona united against him but he also didn't want them fighting among each other. He wanted the catalans and the basques to forget they were catalans and basques and become spanish, which is why he even changed the name of barcelona fc.
And so this squabbling between a catalan club and a castilian club really didn't suit him especially when both clubs were calling upon their fans and thus the spector of regionalism. So he acted by deploring spanish clubs hating each other when they should be united, had the madrid journalist who'd told real fans to make their stadium a cauldron of noise blacklisted and asked for the resignation of the president of both barcelona and real madrid.
The first thing the new presidents did were give a speach in which they talked about a new era of friendship and peace between the two clubs. And both of the new men had served in franco's army during the civil war so this was him taking control of the football clubs. Barca's new man was Colonel Josep Vendrell and real's was their ex player and decorated war veteran Santiago Bernabéu.
Bernabeu's first major act was to build the Santiago Bernabéu Stadium with money raised by local businesses so that real could have the attendences they needed to afford the best players. He then used that money to buy a bunch of players, threw his support behind the new european cup and turned real into the biggest club in the world. He pretty much did that single handedly and he was only in charge of the club because franco had exiled the president who was there in 1939 for treason and then asked his replacement to stand down for beating barcelona 11-1. So in that respect, 100% of their success was because of Franco.
Also Bernabeu, like Vendrell, was trusted by the regime, which probably helped him a lot in terms of being able to fight his corner. Sid Lowe uses the fact that bernabeu banned a major francosist figure from the ground as proof that bernabeu had connections, that an outsider would never be able to do that but someone within the regime could without fear.
And once Real became successful, Franco used them as much as possible. Real being the best club in the world was fantastic pr for Franco. They were essentially his diplomats in an era where he was trying to build bridges with the west, they were a great source of prestige, and even within spain, it suited propoganda that the best team were castillian and from madrid and not catalan or basque. But again, barcelona were also used for propaganda, the great hungarian footballer Kubala who played for barca starred in a francosist propoganda film depicting his flight from communist hungary to the better land of fascist spain.
So in the 1950s you had spanish embasseys welcoming the real madrid team when they were playing away in austria or germany say and giving them dossiers of the opposing team before asking them to do a photoshoot or visit an ambassador. The regime wanted Real to remain dominant because it made the regime look good.
A francoist minister said at the time that di stefano's goals, bull fighting and opera singers were there three best weapons in the fight for the hearts of the west.
Barcelona fans argue that as a result Real got the benefit of the doubt in referee decisions and transfer desputes (in particular that di stefano ended up at real rather than barca) because everyone wanted Real do do well.
There's not much in the way of actual proof of that, though. My own opinion is that it's probably true to an extent.
I do think that if bernabeu had gone to valencia or atletico or seville and made them the best club in europe instead, Franco wouldn't have intervened to help Real at all anymore than he did in the first 15 years of his reign. | [
"With a record of success that exceeds that of any other team in European basketball, Real Madrid has always lived willingly with high expectations. For at least half a century, Madrid has been a standard-bearer in European basketball, accumulating a record ten continental titles, based on its dominance in the 1960... |
how is it possible that we encounter plateaus when losing weight even if we continue to operate at a caloric deficit? | There are a lot of possible explanations. One big thing to keep in mind is water weight.
What are the physical things that make up your weight? Bones... Fat... Muscles... Organ tissues........ and Water! You're actually mostly water, by the way. And the amount of water sitting inside of you can vary DRAMATICALLY.
You ever really, really have to pee? A full bladder can potentially fill multiple bottles of water when emptied. There's a significant weight difference right there, especially since urine is a little bit heavier than plain water.
But when you pee, you're not peeing out all of the water inside of you. Your body actually really wants to keep a certain amount of water most of the time.
We depend on a water-to-salt balance. If you eat A LOT OF SALT one day, your body decides it needs A LOT MORE WATER to compensate. So the water that you drink, or eat in the form of fruit, etc., will just STAY there inside of you.
If you eat HARDLY ANY salt, and especially if you drink A LOT more water than usual, your body says hey! We can dump all this OLD water in place of the NEW water! And you'll pee a lot.
Yes, that's right. The more water you drink, the less water you retain. Putting MORE of something into your body can actually make you LIGHTER (temporarily). Weird.
The difference between a "LOTS OF SALT" day and a "NO SALT, lots of water" day can be HUGE. Many pounds.
But the most important thing to remember is that this is all TEMPORARY. You're NOT gaining and losing fat. It's an ILLUSION.
For example, you can't do the "no salt, lots of water" trick multiple days in a row and expect to lose 5 pounds every day. It doesn't work. Your body only stores so much water. It's best not to think of this as contributing to your "real weight" at all.
It's more like, say, on Tuesday morning Bob steps on the scale, and it reads 205 lbs. Bob has no idea how close this number is to his real weight. His real weight is a total mystery. Bob figures 205 must be pretty close, so that's the number he writes down. (There are actually only 200 pounds of average-day-Bob, but his water stores allow plus-or-minus 5 pounds based on water retention, but Bob doesn't really need to know this.)
Basically, this is the reason it's really kind of silly to record your weight every day. Every week is a little better. But even then, don't take every number for gospel. Come back a month or two later and take a look at the trend line. You'll probably see plateaus, maybe even ups and downs, even if you've been super consistent in caloric intake and exercise. If you eat a lot of salt the day before a weigh-in, you'll "balloon up" - who cares? You're still getting skinnier, and your pants are falling down. You've still lost "real weight". The scale is just guesstimating.
One really common thing is to lose weight REALLY, REALLY QUICKLY at the start of a diet. You're eating less than usual, so you're probably eating less salt than usual, so you lose a lot of that "fake" water weight RIGHT AWAY and feel super good about yourself. In the first month, maybe the scale says you've lost 10 pounds!... Hooray!... but actually no. You've probably lost like 5 pounds. A week later, the scale hasn't moved. A week after that, the scale still hasn't moved. You think you're plateauing....... You're probably not. You're probably still losing like 1 pound a week. Your water levels are just fluctuating and hiding your progress.
**tl;dr - your scale is lying to you, water weight can fluctuate up and down like crazy, don't trust day-to-day numbers, just look at the trend line over a period of multiple months** | [
"A practical application of the plateau principle is that most people have experienced \"plateauing\" during regimens for weight management or training for sports. After a few weeks of progress, one seems unable to continue gaining in ability or losing weight. This outcome results from the same underlying quantitat... |
How does our body keep track of time? And how might this effect space travel? | On your question about the role of the sun and the implications for space travel, there were a series of interesting studies a while back that provides part of the answer. The goal of these studies was to determine if our normal [circadian rhythm](_URL_3_) (as measured by physiological markers like the body temperature) as well the sleep/wake cycle was set by some kind of an internal clock or by external factors such as sunlight and other temporal cues. To answer this question researchers placed a group of individuals in a controlled environment e.g. in bunkers), where at first they gave them temporal cues (by providing access to TV, radio, etc) about the time of day.
During this adaptation period, both the circadian rhythm and the sleep/wake cycle remained matched to the 24 hour cycle. But then, the researchers removed these cues to see how the individuals would adapt.
Interestingly what happened is that the [sleep cycle of many of the individuals gradually lengthened](_URL_4_) ([source](_URL_1_)). In fact further studies have a shown that the sleep/wake cycles can vary significantly among individuals. In contrast, when the circadian rhythm was monitored by measuring physiological markers (such as the core body temperature), [researchers found that individuals maintained a circadian rhythm of about 24 hours (on average 24.18hrs)](_URL_0_), with much less variation. These results suggest that while external cues and stimuli can cause the activity cycle (or sleep/wake cycle) to change dramatically, the internal clock that sets the circadian rhythm is much more stable and in most people is tightly aligned with the 24 hour daily cycle. Nevertheless, this fact does not mean that external stimuli do not matter as far as the circadian rhythm is concerned. In fact over time the circadian rhythm can respond to match external stimuli such as the light/dark cycle in a process called [entrainment](_URL_2_). This fact makes it possible to gradually shift the circadian rhythm (within a certain range) from the normal 24 hour cycle by changing the external conditions.
Edit: Added in the original sources of the studies referenced, and made a key correction as pointed out by /u/whatthefat | [
"Time is discretized into time steps. This discretization in both space and time results in a cellular automaton. One can think of a cell as being a few car lengths long and the maximum velocity as being the speed limit on the road. The time step is then the time taken for a car at the speed limit to travel around ... |
How does graphite bind to paper, and how does an eraser remove it? | [So this is what paper looks like close up](_URL_0_)
[This is what graphite might look like close up](_URL_1_)
When you write, the graphite becomes all dusty and lands on the paper, and into the holes of the paper and all over it. But it isn't bonded to it. This is why, after long periods of time, lots of things like books and papers and letters fade and become harder to read, because this dust that is on the paper flies off.
An eraser rubs right on the paper, and pulls some of the dust off. This is why the eraser leaves little rolled up rubber side-effects, with graphite on them, because they got stuck to the sticky rubber.
There is no bonding, just being stuck in the holes of the paper and all around it, and so on. Also, pressing a pencil on the paper makes nice little indents for the graphite to stick into, so it's not just like you can shake your paper and have the graphite fall off! | [
"The ability to leave marks on paper and other objects gave graphite its name, given in 1789 by German mineralogist Abraham Gottlob Werner. It stems from \"graphein\", meaning \"to write\" or \"draw\" in Ancient Greek.\n",
"An ink eraser is an instrument used to remove ink from a writing surface, more difficult t... |
Royal chefs in Middle Ages | The first German language cookbook was written by a woman named Sabina Welserin in 1553 (you can read it [here](_URL_0_)). Not much is known about her life but she mentioned in one recipe that the cook for Count of Leuchtenberg instructed her to cook fish a certain way hinting she is a professional cook of some kind. From the recipes she wrote (many recipes ask for large quantities of spices and sugar and some recipes were clearly for fancy banquets) it suggests she cooks for a very wealthy (if not downright aristocrat) household. | [
"The most well known French chef of the Middle Ages was Guillaume Tirel, also known as Taillevent. Taillevent worked in numerous royal kitchens during the 14th century. His first position was as a kitchen boy in 1326. He was chef to Philip VI, then the Dauphin who was son of John II. The Dauphin became King Charles... |
why would human poop be white? | White stool is not normal and should be evaluated promptly by a doctor. White stool is caused by a lack of bile, which may indicate a serious underlying problem.
Bile is a digestive fluid produced by the liver and stored in the gallbladder. Stool gets its normal brownish color from bile, which is excreted from the liver into the small intestine during the digestive process. If the liver doesn't produce bile or if bile is obstructed from leaving the liver, stool will be light colored or white.
Liver diseases, such as hepatitis and cirrhosis, can cause white stool. In some cases, the problem lies not in the liver but in the tube (duct) that delivers the bile to the intestines. This tube can be squeezed shut or blocked — for example, by a tumor or a gallstone — which prevents the bile from entering the intestines. Some babies are born with constricted bile ducts.
mayo clinic | [
"Sometimes food may make an appearance in the feces. Common undigested foods found in human feces are seeds, nuts, corn, and beans, mainly because of their high dietary fiber content. Beets may turn feces different hues of red. Artificial food coloring in some processed foods, such as highly colorful packaged break... |
what is actually in contraband (cheap) cigarettes and why are they so cheap and illegal? | Because some states like New York tax cigarettes heavily. Contraband cigarettes are purchased out of state to avoid the taxes and sold at a discounted rate. | [
"The ICC (International Chamber of Commerce) warns counterfeit cigarettes were found to contain unsanitary ingredients (such as human feces, dead flies and mold), as well as a higher dosage of lethal substances in excess of legitimate cigarettes. Illicit cigarettes seized in Canada and the United Kingdom were found... |
Winston Churchill often spoke about his "little black dog" (i.e. depression) that constantly followed him around. Did any Nazi leaders suffer from depression or other clinical mental disorders? | Suicidal tendencies were a sufficient problem in the SS that Himmler made a point of saying that funerals shouldn't be given for officers who committed it for "trivial" reasons. Between July and September of 1942, 30 members of the SS committed it. One particular case was a SS Brigadier named Fritsch who killed himself in 1944 because he cheated on his wife and felt guilty. Himmler ordered the SS insignia removed from his headstone.
Source: Suicide in Nazi Germany
By Christian Goeschel
_URL_0_
| [
"The book revealed that \"Black Dog\" was the name Churchill gave to \"the prolonged fits of depression from which he suffered\", leading many later authors to suggest that throughout his life Churchill was a victim of, or at risk from, clinical depression. Formulated in this way, Churchill's mental health history ... |
If I unraveled the DNA in a human cell, how strong would it be? | What you're looking for is the tensile strength of DNA compared to the tensile strength of something like, say, nylon. It takes about 1 nN to break a strand of DNA, which at around 2nm wide and roughly circular, gives you a tensile strength of about 318 MPa. This is compared to somewhere in the neighborhood of ~100 MPa for nylon and other common polymers used in ropes. If we assume you can weave DNA strands into a cable, they would be quite strong, barring degradation and the thermodynamic nightmare that would be building such a large DNA structure.
Even though DNA is pretty rigid as a double-strand, once you get very long, thermodynamics make it want to curl up on itself, so you've got that working against you.
Source: Materials science researcher with a background in DNA nanotechnology | [
"Ordinarily, cellular transport mechanisms in humans and some other animals limit the amount of chromium(III) that enters a cell. Hypothetically, if an excessive amount was able to enter a cell, free radical damage to DNA might result.\n",
"Each human cell contains around two metres of DNA, which must be tightly ... |
why everyone seems to hate /r/politics. | Reddit as a website skews young, especially on the default subreddits. Reddit also skews liberal (which I am too).
As a result, you get a bunch of 15-18 year olds yelling about politics they have only recently started to be interested in and learn about and which they barely understand. They lack an awareness of context/historical precedents. Further, [/r/politics](/r/politics) has turned into a witchhunt for any sign of conservativism while it derides conservatives' endless debasing of liberals. The whole of the subreddit doesn't seem to grasp the irony that they're as distorted and left wing as Fox news is distorted and right wing. | [
"We were talking about all the bulls— on the Internet and how people just hate on stuff. We were saying, “What if we used that energy to spread positivity? Would it spread as fast as the hate does?” “All the hate and lies around us like an ember in the brush”: It just started writing itself from everything we were ... |
during the cold war, how did the united states (and by extent, the soviet union) know that a nuclear missile was fired at thier respective country early enough so that they could deploy countermeasures? | A combination of huge long range radar stations and satellite early warning systems.
You can't really hide a rocket launch from a satellite. Large rockets like ICBMs have a *massive* thermal signature that is easy to spot. That is why the US and USSR (and now Russia) notify each other of peaceful rocket launches in advance. | [
"Soviet concern about the issue grew with the U.S. development of highly accurate submarine-launched ballistic missile (SLBM) systems in the 1980s. Until then, the United States would have delivered most nuclear weapons by long-range bomber or ICBM. Earlier U.S. sub-launched missiles, such as the 1960s-vintage UGM-... |
Do rainbows also have sections in the infrared and/or ultraviolet spectrum? | Yes, definitely! You can easily see that in [this series of images](_URL_0_) taken in the ultraviolet (UV), visible, and infrared (IR) parts of the spectrum. As you can see there is a UV band below the violet edge and an IR band above the red edge, which you obviously can't see with the naked eye.
This result is exactly what we would expect. The way rainbows work is that when sunlight strikes water droplets suspended in the air, part of the light is reflected at the air/water interface at the back of each droplet, [as shown in this diagram](_URL_1_). Since water is dispersive (meaning that the rerfractive index varies by wavelength), each droplet effectively acts as a small prism spreading the white light into its spectral components. Now our eyes our only sensitive to the visible (by definition), which is why a rainbow looks like a colorful transition from violet to red. However, sunlight also contains [IR and UV components in addition to visible light](_URL_2_). While the water droplets absorb some of this light, much of it ends up reflected, as part of this extended rainbow that you can see from the IR and UV images posted above. | [
"Supernumerary rainbows cannot be explained using classical geometric optics. The alternating faint bands are caused by interference between rays of light following slightly different paths with slightly varying lengths within the raindrops. Some rays are in phase, reinforcing each other through constructive interf... |
how can we identify different instruments playing at the same time if it is the same air that is vibrating? | Vi Hart explains it better than I ever could. Basically, it's what your ear was made to do. _URL_0_ | [
"When each instrument of a symphony orchestra or the jazz band plays the same note, the quality of each sound is different — but the musician perceives each note as having the same pitch. The neurons of the auditory cortex of the brain are able to respond to pitch. Studies in the marmoset monkey have shown that pit... |
what is the reasoning behind above-ground power lines? germany buries them, mostly, but the usa keeps them exposed to the elements. | Germany only buries the low-voltage power lines between transformers and the homes. The power lines between the transformers, switching stations and power plant are above-ground lines most of the time. | [
"In a building with electricity it is normal for safety reasons to connect all metal objects such as pipes together to the mains earth to form an equipotential zone. This is done in the UK because many buildings are supplied with a single phase supply cable where the neutral and earth conductors are combined. Close... |
how do free mobile games make money when all the ads in the game are from other free mobile games? | Free mobile games make money primarily in three different ways:
(1) offering in-app purchases usually used by their ‘whales’ (i.e - 20% of their customers who spend a significant amount of money on the game and keep it alive for the rest of the non paying users).
Edit: Just wanted to clarify that the 20% isn’t supposed to be an exact figure, it’s a reference to the [Pareto principle](_URL_0_) also known as the law of the vital few. I’m aware that the actual amount of users who pay can be significantly fewer.
(2) Is by running ads, usually bought as a advertising package (meaning you don’t have to you choose a specific game to advertise on you can just specify which customers you aim to target and how much your company is willing to spend on it and it is accordingly shown to such users. Alternatively, if your game if quite similar to another one in the App Store, you can specifically target that app as you might find a lot of users with the same interest all conveniently in one place) and shown to you based on your past user data and preferences from the App Store. They always make sure to give you the option to remove ads with a small fee - which appeals to our human need to remove a ‘pain point’ (an inbuilt aspect in many free to play mobile games that slows down the player or tries to push them towards making paid purchases - these include things like in-game wait timers).
(3) That other major way they make money is buy selling your user data to other third parties (businesses) as user data is an extremely powerful tool for companies to have because it allows them to understand you and how to market and target you as a customer. | [
"Many mobile games are distributed free to the end user, but carry paid advertising: examples are \"Flappy Bird\" and \"Doodle Jump\". The latter follows the \"freemium\" model, in which the base game is free but additional items for the game can be purchased separately.\n",
"Typically, commercial mobile games us... |
how do man-made canals work? like the suez, erie, panama canal? | Their purpose is to move boats between places that don't directly connect. This saves a lot of money on shipping things, because then you don't have to steer your boat all the way around Africa or South America if you're shipping stuff from Greece to India or from New York to San Francisco. They are built, as you'd expect, by digging out the dirt between the two bodies of water.
Most canals have locks, which are doors that close and allow the water level to change by pumping, kind of like an airlock but for water. This accounts for the water level differences between bodies of water. The Panama and Erie canals both have locks because of the need for changes in elevation during the crossing. In contrast, the Suez canal has no locks because there is no perceptible change in the elevation of the Red and Mediterranean seas. | [
"A canal basin is (particularly in the United Kingdom) an expanse of waterway alongside or at the end of a canal, and wider than the canal, constructed to allow boats to moor or unload cargo without impeding the progress of other traffic, and to allow room for turning, thus serving as a winding hole. For inland wat... |
why are electoral votes all or nothing(for the most part)? why are they not divvied out representative to popular vote? | Because each state chooses to use all of its electoral votes to elect the person the majority of the electorate in that state voted for. Each state chooses to not divvy up its electoral vote. | [
"The advantages of this system are claimed to be that: there would be only one election campaign to fund, it does not waste votes because votes for minority parties will count in the Upper House and so it should improve voter turnout, and as the upper house has no direct vote it has no separate mandate and so the C... |
Why is the strong force repulsive at small distances? | My favourite [link](_URL_0_) for "why" questions, especially of this nature.
Also the Strong force itself isn't repulsive over short distances, just an effective description of it for use between nucleons is. | [
"The effective range of the weak force is limited to subatomic distances, and is less than the diameter of a proton. It is one of the four known force-related fundamental interactions of nature, alongside the strong interaction, electromagnetism, and gravitation.\n",
"This is because gravitation is an attractive ... |
What are your favorite historical books about great empires and/or historical figures. | Caesar: Life of a Colossus
Adrian Goldsworthy
Fantastic well researched life of quite possibly the worlds most interesting man that is a great approachable read.
American Ceasar
William Manchester
Sometimes a bit heavy but riveting all the same. Makes this complicated controversial man understandable and appreciable on his merits. | [
"BULLET::::- Shadow of Wings (1972). A historical novel set around the rise of the Persian Empire. It starts with the career of Cyrus the Great, founder of the Persian Achaemenid Empire, but mainly deals with the rise to power of King of Kings Darius I (the Great).\n",
"His best known work is a History of the sec... |
What did pre-Columbian indigenous nations do with the dead bodies of people who they fought? Did they just leave them on the field? | I can't speak to the specifics of Aztec battles, but the huge diversity of pre-Columbian nations over thousands of years and across two continents gave rise to a variety of methods of treating fallen combatants. There will be as many answers to this question as there are distinct cultural traditions and skeletal remains with evidence of interpersonal violence.
For example, the Crow Creek Massacre is one of the largest pre-Columbian skeletal assemblages attributed to a violent encounter in North America. Sometime around 900 CE the ancestors of the Mandans built several earthen structures in the south central portion of modern-day South Dakota. Eventually the Caddoan-speaking ancestors of the Arikaras replaced the Mandans (no indication the replacement was by force) and increased the settlement to a decent-sized community of roughly fifty-five earthen lodges.
For unknown reasons, in roughly 1325 CE, at least 486 individuals at Crow Creek were violently killed. Evidence of the massacre was discovered in 1978 when skeletal remains eroded out of a fortification ditch. Analysis of the remains indicated extreme violence during the attack. I will spare the gory details, the destruction was quite complete, and trophies appear to have been taken by the attackers. The state of the remains indicates they were exposed for a period of time and subject to the typical animal scavenging expected on the Northern Plains. Some time later the remains were gathered together, placed in a communal burial, and covered with a thin layer of clay from the nearby river. We don't know if survivors of the attack, their kin, or someone altogether different were responsible for cleaning up the battlefield.
For all the brutality of the treatment of the victims at the Crow Creek Massacre, biological archaeologists can illustrate the care taken with the burial preparations for victims of interpersonal violence across the Americas. As in our modern culture, treatment of the dead varied according to immediate circumstances and local traditions. | [
"In 1847, during the Mexican–American War, the U.S. Army occupied northeastern Mexico. Captain John E. Dusenbury, a white bean survivor, returned to El Rancho Salado and exhumed the remains of his comrades. He traveled with the remains on a ship to Galveston, and by wagon to La Grange in Fayette County, Texas.\n",
... |
why do we get random bouts of euphoria? | Hmm, I've never experienced that. I've known people who had sharp mood swings one way or another, but they usually had issues like hypoglycemia, bipolar disorder, etc.
I've for sure personally moved from down to up, but never very quickly, and never for no apparent reason. | [
"Euphoria () is the experience (or affect) of pleasure or excitement and intense feelings of well-being and happiness. Certain natural rewards and social activities, such as aerobic exercise, laughter, listening to or making music, and dancing, can induce a state of euphoria. Euphoria is also a symptom of certain n... |
why does ssds have a specific number of reads/writes. | The way my boss describes it is like this:
When you write to a cell, you're basically shooting it with a shotgun (electrons). This makes it return a different signal when you apply power (to read it).
When you erase that cell, you take a giant magnet to rip the bullets out. Unfortunately some of the target comes out with the bullets.
Edit: I work in Intel's Non-Volatile Memory Solutions Group | [
"SSDs store data in flash memory cells that are grouped into pages typically of 4 to 16 kB, grouped together into blocks of typically 128 to 512 pages. Example: 512 kB blocks that group 128 pages of 4 kB each. NAND flash memory cells can be directly written to only when they are empty. If they may contain data, the... |
Why do so many aerosol products use things like propane and butane as propellants? Why not air or nitrogen? | Propane and butane are liquids when compressed. This allows a lot of the gas to be stored in a small space. Normal compressed air is still a gas, and has to be compressed at much higher pressures to even approach the compact storage of the usual propellants. | [
"Propane and butane are gases at atmospheric pressure that can be liquefied at fairly low pressures and are commonly known as liquified petroleum gas (LPG). Propane is used in propane gas burners and as a fuel for road vehicles, butane in space heaters and disposable cigarette lighters. Both are used as propellants... |
In WWII, did anyone become an ace as either a pilot or gunner of a bomber? | There are certainly gunners credited with five or more kills. Albert E. Conder's *The Men Behind The Guns: The History of Enlisted Aerial Gunnery 1917 - 1991* has a section, "Some of the Aces"; Conder says "The thousands of enemy fighters downed by Gunners were counted as a "team" effort, rather than crediting individual gunners. The AAF claimed that record keeping was to [sic] difficult." He nevertheless goes on to list a number of "aces", including S/Sgt Donald Crossley with 11 kills, S/Sgt Michael Arooth with nine, S/Sgt Benjamin Warmer with nine (seven in one mission) and several others including S/Sgt John Quinlan, tail gunner of the Memphis Belle who later flew on B-29s, credited with five German and three Japanese fighters.
Air-to-air victories are enormously difficult to verify, though, even at the best of times with a small number of combatants and gun camera footage; with large formations of bombers, each with multiple gunners, the number of aircraft claimed downed by gunners was invariably higher than the number of actual losses suffered. Conder gives the total claims of Eighth Air Force Bombers as 6,259 destroyed, 1,836 probables, 3,210 damaged; those figures are likely out by a factor of eight or nine (see [a previous question] (_URL_3_) for further details). I'm not sure where Conder gets his individual figures from, but they're difficult to corroborate; [The Unknown Aces of the Eighth] (_URL_1_), for example, credits Arooth with "at least 17 enemy planes".
In the RAF [Wallace McIntosh] (_URL_2_) had the most claims as a bomber gunner (eight and one probable, though again it's hard to verify), [Peter Engbrecht] (_URL_4_) of the RCAF claimed five and a half. The highest claiming RAF gunners were those in Defiant turret fighters, particularly those of 264 Squadron; Ted Thorn (pilot) and Fred Barker (gunner) had the highest total, 12. Once again, though, the "confirmed" kills of 264 Squadron are likely too high, not tallying with German losses (for more details on the Defiant, see [another previous question] (_URL_0_)).
I haven't got any details of World War I gunners; *Above the War Fronts: The British Two-Seater Bomber Pilot and Observer Aces, the British Two-Seater Fighter Observer Aces, and the Belgian, Italian, Austro-Hungarian and Russian Fighter Aces 1914-1918* by Norman Franks may be of some help. | [
"A flying ace or fighter ace is a military aviator credited with shooting down five or more enemy aircraft during aerial combat (The Germans traditionally set the threshold at 10 victories.). During World War II, hundreds of German Luftwaffe fighter pilots achieved this feat flying contemporary piston engine fighte... |
why should i bother getting married? | From a secular point of view, a marriage is a contract between (usually two) people. They agree to pool their resources. The general idea is that both partners gain something from this, for instance financial security, a stable home situation and - not unimportant - a partner in procreation.
The government (that is, the other people who live in your country) generally find this pooling of resources an excellent idea and try to promote it by giving married couples all sorts of financial and other benefits that unmarried people (couples, single or otherwise engaged) do not receive.
So, to answer your question: nothing will stop you, and if you choose to not marry, you will miss out on (mainly financial) benefits that you would otherwise be eligible for.
The down side of marriage is that you enter a legally binding contract, and should you at any point in the future wish to disband it and no longer be held to the responsibilities that stem from it, you cannot simply quit operations and leave but have to go through a legal procedure (a *divorce*) which can set you back financially and emotionally. | [
"A marriage of convenience is contracted for reasons other than that of relationship of love. Instead, such a marriage is entered into for personal gain or some other sort of strategic purpose, such as political marriage. Some cases in which those married do not intend to live together as a couple, typically marry ... |
how do mesh networks maintain speed? | Any wireless mesh network will lose speed each hop because of the overhead. Even wired networks you will lose some speed each hop but it is not near as noticeable because there is much less overhead in wired communication. Basically each wireless node takes the data off the wire, encapsulates it in the wireless packet, sends it to the next node which has to process the packet and send it back out for the next node to pick up. So if your PC is 5 nodes away then the wireless packet has to be processed 5 times coming in, and then another 5 times going back out. If there is a lot of traffic then it will be even slower because the radios will have to wait until the air is clear to send each packet. I hope this makes sense. | [
"A mesh refers to rich interconnection among devices or nodes. Wireless mesh networks often consist of mesh clients, mesh routers and gateways. Mobility of nodes is less frequent. If nodes constantly or frequently move, the mesh spends more time updating routes than delivering data. In a wireless mesh network, topo... |
why do i see product placement at big events in the form of only the name of a brand? | When you go to buy, say, a TV, you might see a Sony and a Magnavox. If you see Sony's name over and over again, you'll be more familiar with the brand name and think it more reputable. | [
"Due to the variety of ways in which product placement can be accomplished in any media, and because the category is nascent, this category is not standardized at all, but some examples include branded in-game goods or even in-game quests. For example, in a game where you run a restaurant, you might be asked to col... |
What was the power relationship between USSR "spy agencies" and the Communist Party up until the fall of the Soviet Union? | First off, it's important to remember that the KGB didn't exist until the 1950s. The Cheka, OGPU and NKVD all came before. After NKVD director Lavrenty Beria fell in 1953, intelligence gathering was done by more than one agency, though KGB certainty had the most influence.
The answer to your question varies greatly with the time period being examined. Having the approval of the NKVD was far more important in the Stalin era than being on the KGBs good side during Gorbachev's reign. | [
"All sides in the Cold War engaged in espionage. The Soviet KGB (\"Committee for State Security\"), the bureau responsible for foreign espionage and internal surveillance, was famous for its effectiveness. A massive network of informants throughout the Soviet Union was used to monitor dissent from official Soviet p... |
Could a large object come close enough to Earth to cause people to temporarily float without knocking the planet out of orbit? | For that to happen, the surface gravity of the object would have to be greater than the surface gravity of Earth. Such as object, presumably made of some sort of rocky material, would have to be of comparable mass to the Earth. The only way this object would careen past the Earth at super close range without hitting it is if it was going really, really, really fast. | [
"At a distance relatively close to Earth (less than 3000 km), gravity is only slightly reduced. As an object orbits a body such as the Earth, gravity is still attracting objects towards the Earth and the object is accelerated downward at almost 1g. Because the objects are typically moving laterally with respect to ... |
What was happening along the rest of the eastern front during the Battle of Berlin? | On the Balkans, the Croatians and Heeresgruppe F were retreating under the combined pressure of Titos (by now regular) army, the Soviets and elements of the Bulgarian army. They were mostly attempting to make contact with the British in western Austria to surrender to them in a vain hope to not be turned over to Tito or the Soviets.
The Soviets were pushing westwards from Slovakia into Bohemia and were clearing Hungary of German troops after Budapest finally fell. Towards the end of the Battle of Berlin they were at the outskirts of Vienna.
In Germany, the Soviets had reached the agreed demarcation line, and were fighting the German 12. and 9. Armee, which had fought their way to unite and then through multiple Soviet attacks and defence line to cross the river together with thousands of civilians to surrender to the Americans.
The Soviets were also advancing in Pommerania along the coast of the Baltic sea and keeping check on a small German force on the Hel peninsula (outside Gdansk) and a much larger one in Courland (what remained of Heeresgruppe Nord). | [
"The Battle of Berlin was the final major offensive of the European theatre of World War II and was designated the Berlin Strategic Offensive Operation by the Soviet Union. Starting on 16 April 1945, the Red Army breached the German front as a result of the Vistula–Oder Offensive and rapidly advanced westward throu... |
can someone explain to me what a tax bracket is? | A tax bracket says the percentage of your income that is taken as income tax when you're earning a given amount.
So, for example, it might be (taken from the Australian tax scheme):
* 0 - $6,000: Nil
* $6,001 - $37,000: 15c for each $1 over $6,000
* $37,001 - $80,000: $4,650 plus 30c for each $1 over $37,000
* $80,001 - $180,000: $17,550 plus 37c for each $1 over $80,000
* $180,001 and over: $54,550 plus 45c for each $1 over $180,000
One thing to note here is that each bracket gets applied in turn. If you look at the $80,001 - $180,000 bracket, you'll notice that it says "$17,550 plus 37c for each $1 over $80,000". This is because $17,550 is what you would have owed from the previous tax brackets if you earned $80,000. Generally speaking, you are said to be 'in' your highest tax bracket, as that informs how much of every extra dollar you earn will be taken in tax.
As an example to see how much tax you'd pay in this, assume that you earn $70,000.
From the previous brackets, you'd pay $4650. Then from the current bracket, you'd pay (70,000 - 37,000) * 0.3 = $9900. So your total income tax on $70,000 would be $4650+$9900=$14,550. | [
"Tax brackets are the divisions at which tax rates change in a progressive tax system (or an explicitly regressive tax system, although this is much rarer). Essentially, they are the cutoff values for taxable income—income past a certain point will be taxed at a higher rate.\n",
"Bracket creep is usually defined ... |
Why is there so little known about seizures? | I think we know more about seizures than you'd think, and are learning more and more with the advancement of technology. It's just that this information isn't yet to the point where it is truly helpful to doctors.
> Doctor's cannot even tell us why it happens
Do you mean why seizures happen in general, or why they happen to your specific family members? From a research perspective we are beginning to understand more and more the genetics, heredity, childhood illnesses, previously unknown brain anomalies, etc that are associated with seizures. The problem is that there is a huge gap between where the research is and the clinical side of things. Our treatments (medications) just aren't good enough that it really matters what's causing an idiopathic epilepsy and so there's no reason for the doctors to try to figure it out (though in most cases they likely could with some degree of certainty). If we develop better medications then you might see doctors start to try to determine what is causing the epilepsy.
Using technology (MRI, fMRI, SPECT, Wada, MEG, scalp EEG, intracranial EEG, EEG with depth electrodes, Video EEG monitoring) we are getting really good at identifying exactly where in the brain the seizures originate for a given individual, and often times can surgically remove that area and drastically reduce the frequency and severity of a person's seizure disorder.
> There are no answers or cures
I'd agree that other than surgery there is no clear cure, but I think there are lots of answers. If you have more specific questions I'm happy to try and answer them.
| [
"It has been reported that repeated seizure stimulation can result in spontaneous seizures, but studies have had conflicting findings on this question. In humans, some seizure disorders come to an end by themselves even after large numbers of seizures. However, in both human epilepsy and in some animal models, evid... |
how does billing work for toll roads? | Will be helpful to list the specific system you are talking about
In many cases in the US, tolls may be assessed on certain entry/exit points and certain points along the road. | [
"The toll can be paid by different means. Firstly, a particular route can be pre-booked over the Internet. Secondly, the toll can be paid at terminals (often found in fuel stations). Thirdly, the preferred method is the fully automated billing using On-Board-Units (OBUs) deployed in the trucks, receiving GPS signal... |
You're in a medieval European city and you need to find yourself a place to call home. Who do you talk to? A medieval realtor? | Obligatory "medieval Europe can mean a lot of different times and a lot of different places." You should probably make your question a little more specific. | [
"In Medieval days a destination for such days out would be religious (to a nearby shrine) or commercial, for example to a seasonal fair. Later, in England, visits to stately homes by those who regarded themselves middle class became frequent and it was the tradition to reward the butler or housekeeper with a tip fo... |
why does it hardly rain in southern california, despite being adjacent to the pacific ocean? | Proximity to an ocean is only one of the factors when determining rainfall. There's lost of deserts in the world that are ocean adjacent.
The overall weather patterns play a much more significant role. So air currents, ocean temperature, as well as land features like mountains. There's more important factors than how close you are to the ocean. | [
"The large Westerly winds from the oceans also bring moisture, and the northern parts of the state generally receive higher annual rainfall amounts than the south. California's mountain ranges influence the climate as well: moisture-laden air from the west cools as it ascends the mountains, dropping moisture; some ... |
Mom says you will catch a cold if you go out in the cold weather or rain without a coat. Do these actually contribute to getting you sick? And how? | The 'common cold' is usually caused by a rhinovirus. Cold temperature itself does not cause illness. [However, temperature effects may facilitate viral infection:](_URL_0_)
> Although not all studies agree, most of the available evidence from laboratory and clinical studies suggests that inhaled cold air, cooling of the body surface and cold stress induced by lowering the core body temperature cause pathophysiological responses such as vasoconstriction in the respiratory tract mucosa and suppression of immune responses, which are responsible for increased susceptibility to infections.
This is further confounded by the fact that people may stay indoors during the cold months, further allowing spread of the virus. | [
"In addition to providing warmth for residents, cold weather rules help prevent damage to homes. Wintertime temperatures can freeze Water pipes, potentially causing bursts in the lines as the water inside expands as it turns into ice. Cleaning up after this can lay heavy burdens upon people who are already of limit... |
Instead of a space elevator, how (un) feasible would a railgun /coilgun be to shoot things into orbit? | Because even without drag, nothing could survive the acceleration required. Let's assume no drag, and you're on the surface of the Earth. In fact, we'll put you right on the equator, to get maximum benefit from the Earth's rotation. Now, the ISS is in LEO (low earth orbit) so that takes the least energy to get into place. It is traveling at 17000 mph around the Earth. So you at least need to accelerate to that speed in order to get into orbit (minus the 1000 mph you get from being on the equator). So, assuming you are accelerated over an entire mile, you must be accelerated at [16,244 m/s^2 ](_URL_0_) over the course of that mile, otherwise known as 1657 g's.
The human body can only withstand an instantaneous acceleration of 40 g's, and sustained it is somewhere less than 10. So, let's say it is 10 g's is how fast you want to accelerate this capsule. Since the above calculation was inversely proportional to distance accelerated, that means the tube we accelerate the capsule in would have to be 165 miles long. And of course, this is assuming no drag, and that it takes no energy to get to the height required. So in reality, it would have to be much longer than this. | [
"BULLET::::- In the video game \"Portal\", yet another similar gun to \"Half-Life 2\"'s, which is titled the \"Aperture Science Handheld Portal Device\", can create a weaker zero-point energy field by simply lifting objects and carrying them, but cannot throw or pull in from a distance. These items can also be drop... |
Hypothetically, if someone with a cold ate ice cream out of a tub of ice cream and then the rest of that ice cream tub was put back into the freezer, would all the cold germs "freeze to death" making it safe for someone else to eat that ice cream? | Bacteria are not going to "freeze to death", they are frozen at much lower temperatures on a normal basis (a normal lab freezer is set to -20C). Ice formation in the bacterial cells can lead to them "freezing to death", but this is unlikely in your freezer. I suppose if you waited long enough, the tunneling effect would kill them but this is not going to happen on a realistic time scale.
That said, if you don't want the ice cream send it to me, the immune system is pretty incredible and I'll take my chances. | [
"BULLET::::- Freeze-dried ice cream is ice cream that has had most of the water removed from it by a freeze-drying process; sealed in a pouch, it requires no refrigeration. It achieved fame as a popular food in human spaceflight.\n",
"Some Turks believe that cold foods, such as ice cream, will cause illnesses – s... |
how does an iud work? | Yer not alone in askin', and kind strangers have explained:
1. [ELI5: How does a IUD work? ](_URL_3_) ^(_18 comments_)
1. [ELI5: How do hormonal IUDs release a reliable, steady stream of hormones for years? And do they taper off or just stop releasing hormones? ](_URL_0_) ^(_3 comments_)
1. [How does a copper IUD work? (ParaGard or equivalent) ](_URL_2_) ^(_3 comments_)
1. [ELI5: how do non-hormonal IUD's work? ](_URL_1_) ^(_2 comments_)
1. [ELI5: How can IUDs prevent periods? Where does the uterine lining go? ](_URL_5_) ^(_3 comments_)
1. [ELI5: What are IUDs? ](_URL_4_) ^(_4 comments_)
| [
"IUDs primarily work by preventing fertilization. The progestogen released from hormonal IUDs mainly works by thickening the cervical mucus, preventing sperm from reaching the fallopian tubes. IUDs may also function by preventing ovulation from occurring but this only occurs partially.\n",
"An intrauterine device... |
When I take medicine that supresses symptoms, do I prolong the sickness? | There are basically three classes of symptoms
* caused by the disease "intentionally" to help it survive
* caused by your body to manipulate your behavior
* caused by your body to promote healing
And each symptom is often a mix of the three. There isn't enough research in lots of cases to say surely if a specific symptom is good or bad, and intensity of the symptom is important to consider as well.
In short: it's complicated, and for your specific question, not well understood. | [
"Many pharmacological treatments which are effective for nausea and vomiting in some medical conditions may not be effective for motion sickness. For example, metoclopramide and prochlorperazine, although widely used for nausea, are ineffective for motion-sickness prevention and treatment. This is due to the physio... |
if what we see and hear has happened in the past does that mean that time outside our sphere of awareness is moving faster? | It's all "going at the same speed", so to speak. The brain just takes a fraction of a second to 'boot up', and so it is starting out on the back foot.
A bit like... if you have two identical marathon runners in a race, but one of them is given an 80ms handicap. You wouldn't say that time is now "running slower" for that person. They are running at exactly the same speed as the person in front of them. They're just suffering the effects of a momentary delay to start with. | [
"A proposed explanation for this effect is that the visual system is predictive, accounting for neural delays by extrapolating the trajectory of a moving stimulus into the future. In other words, when light from a moving object hits the retina, a certain amount of time is required before the object is perceived. In... |
Is there any evidence to suggest that the Coliseum was flooded for sport? | Seutonius passes over it quickly in his *Life of Nero*:
> But he compelled four hundred senators and six hundred Roman knights, some of whom were well to do and of unblemished reputation, to fight in the arena. Even those who fought with the wild beasts and performed the various services in the arena were of the same orders. **He also exhibited a naval battle in salt water with sea monsters swimming about in it;** besides pyrrhic dances by some Greek youths, handing each of them certificates of Roman citizenship at the close of his performance.
There are a few accounts of it happening in addition to Seutonius', but the logistics and specifics are debated and not precisely known. | [
"The Coliseum by this time was hailed as a financial success. Besides football games, the facility hosted bicycle races, the Military and Athletic Carnival of the AAU, Buffalo Bill's Wild West Show, horse shows, agricultural exhibitions, and commercial trade shows. But all this would soon come to an end. On Decembe... |
Were there ever any battles that involved artillery units targeting each other? | It's a frequent occurrence known as counter-battery fire. It's one of the more basic artillery strategies there is, employed as far back as there's been artillery. I suggest picking up John Norris' *Artillery: A History*. It's a good introductory primer to the history of big guns. | [
"The firefight included large-scale troop movements and the simulated destruction of major bridges – coal dust and dynamite were used to create explosions. Nine troop formations held three positions each during the tightly scripted invasion sequence; they were directed via telephone (one line per formation) and fla... |
why does adobe publish so much software for free? | By publishing so much free software, they can get their name known to pretty much every computer user in the world.
That way, when someone needs some software which is not free, Adobe's offering is a natural choice, because you've already heard of them. | [
"Adobe's decision to make the subscription service the only sales route for its creative software was met with strong criticism (see Creative Cloud controversy). Several online articles began offering replacements of Photoshop, Illustrator, and other programs, with free software such as GIMP and Inkscape or competi... |
if the europe-central map projection used in most places is inaccurate, why isn't a more accurate created and used instead? | Are you talking about the distortion of certain maps, physically? Or are you talking about the fact that it's centered on Europe, and people think it should be centered elsewhere?
In general, though, there is no "accurate" flat map of the earth. The earth is round, and a map is flat. That will cause every map to be inaccurate in some way. We just get to choose WHICH inaccuracy we want, when we use different maps. | [
"Modern national mapping systems typically employ a transverse Mercator or close variant for large-scale maps in order to preserve conformality and low variation in scale over small areas. For smaller-scale maps, such as those spanning continents or the entire world, many projections are in common use according to ... |
what is the tech bubble burst that everyone keeps talking about will happen soon? | Tech is part of our daily lives now and it's unlikely that will change any time soon so the demand for tech is comfortably high. But what is happening is the nature of that tech is always changing.
Consumers are opting for tablets and smart phones over computers and laptops so the industry has to evolve to meet the new demand, and handle the decreased demand for products which used to be the bread winners.
Ironically in spite of all the money being spent on mobile devices, there was already a pretty big tech bubble that burst a few years back in telecomm with some pretty big names like Nortel and Alcatel. Even Nokia and Avaya.
Right now there is a lot of money being thrown at the internet of things and having many tiny, inexpensive, computers operating together rather than big machines being central to the home. If consumers decided they don't really need smart toasters and refrigerators, then that could be a bust and there will be some shaking up of the job market some more.
| [
"The dot-com bubble (also known as the dot-com boom, the tech bubble, and the Internet bubble) was a historic speculative bubble and period of excessive speculation mainly in the United States that occurred roughly from 1994 to 2000, a period of extreme growth in the use and adoption of the Internet.\n",
"The dec... |
What was the original motivation, intent, and context of the 14th amendment to the US Constitution, specifically in regards to the public debt? | The primary motivation for the section was unquestionably to confirm that the U.S. would neither assume nor even recognize the validity of Confederate debt.
This part of the amendment was not heavily contested, so there is a relative lack of contemporary statements explaining its meaning, but here is Senator Howard giving an adequate explanation of Amend. XIV, Sec. 4:
> I take it for granted that no member of this body would oppose the adoption of this section of the amendment. I do not believe the people of the United States will object to declaring that the whole of the rebel debt shall be eternally repudiated and extinguished — a debt contracted in the prosecution of the most wicked war with which the earth was ever cursed, against a Government that was never felt by them except in the benefits it conferred. Such a debt can never be assumed or paid by the loyal people of the United States, and if suffered to remain in *quasi* existence it can only be left in that condition as a subject of political squabbling and party wrangling.
> The assumption of the rebel debt would be the last and final signal for the destruction of the nation known as the United States of America. Whatever party may succeed in so wicked a scheme, by whatever name it may be called and under whatever false guises or pretenses it may operate, if it succeed in assuming this indebtedness, puts an end first to the credit of the Government, and then, as an unavoidable consequence, to the Government itself. I do not propose to spend time upon this branch of the subject. I simply refer to it as a necessity of such magnitude as in my judgment to demand our action and the action of the States of the Union without delay. It is necessary to act, to extinguish this debt, to put it beyond the pale of party controversy, to put it out of sight, and to bury it so deep that it can never again be raised to life in such manner as to become a theme of party discussion. The amount of that debt is probably not less than five billion dollars. We do not know its exact amount, and I am not sure that it is possible ever to ascertain it; but if there should ever be a fair prospect of its assumption by the United States or by the States it is perfectly certain that the evidences of it would multiply thicker than the leaves in Vallombrosa. Those evidences are a great curiosity in the history of commercial affairs.
[Cong. Globe, Sen., 39th Cong. 1st Sess. 2768 (1866)](_URL_1_)
And here is what the Supreme Court had to say about Amend. XIV, Sec. 4 in the Gold Clause Cases:
> While this provision was undoubtedly inspired by the desire to put beyond question the obligations of the Government issued during the Civil War, its language indicates a broader connotation. We regard it as confirmatory of a fundamental principle, which applies as well to the government bonds in question, and to others duly authorized by the Congress, as to those issued before the Amendment was adopted.
[*Perry v. United States*, 294 U.S. 330, 354 (1935)](_URL_0_).
Indeed, the divided Court in that case appears to be unanimous in holding that the Fourteenth Amendment's injunction on questioning "[t]he validity of the public debt" is merely declaratory or confirmatory of a principle already part of the U.S. Constitution prior to the ratification of the Fourteenth Amendment. And the Justices have the right of it.
Section 4 is a great example of a literary technique the Constitution often employs, which I like to jokingly refer to as "the passive-aggressive tense." The device operates when there are two interacting legal principles, one of which is uncontroversial, and the other of which is either a contested principle and/or a proposed innovation. Instead of stating the *innovation*, the Constitution will reiterate the *uncontested* principle, applied in such a way that it necessarily implies the innovation, while unstated, is now a part of the law.
For instance, the Eleventh Amendment, says that the sections of the Constitution setting out the subject-matter jurisdiction of the judiciary "shall not be construed to" abrogate a State's sovereign immunity. The thing is, everyone already knew that giving jurisdiction over a party doesn't necessarily abrogate immunity; the real debate was whether the States had immunity in the first place. By stating the point about jurisdiction not abrogating immunity, the amendment implies that immunity exists, but it doesn't actually state the principle which grants it.
Similarly, the Fifteenth Amendment states that the "right of citizens of the United States to vote shall not be denied or abridged ... on account of race...." Well, the thing is, the Constitution already prohibited discrimination based on race when it came to rights of the citizen. The contested question was whether voting was even a right of the citizen in the first place, such that a racially-restrictive voting law denied someone the right based on race. By stating the point about discrimination, the amendment implies that voting *is* a right, and that denying it based on race *is* racial discrimination against that right. But, again, it doesn't actually state the operative principle, leaving us to sort out if there any other implications of the principle implicitly being affirmed.
Section 4 of the Fourteenth Amendment is doing a similar thing. The uncontroversial principle at the time was that the grant of power to Congress "[t]o borrow Money on the credit of the United States," Art. 1, Sec. 8, cl. 2, implied that money properly borrowed became an obligation that continued until repaid, and that the obligation could not be cancelled by a subsequent law. (Note that actually *paying* the debt is another matter, which I will explain below.) The controversial matter was how this should apply to the Confederacy:
If the Confederacy were thought of as an independent nation which had been defeated and annexed by the U.S., then the U.S. was the successor state to the Confederacy under international law, and therefore ought to assume its debts. Likewise if the State governments of the Confederacy were legitimate, then the Reconstruction governments were their successors and still owed their debts. But if the Confederacy was thought of as invalid from the start, then there was never a legitimate government there, and the U.S. was not in any sense a successor to the Confederacy or its debts.
This latter interpretation is the one that the Reconstruction-era government consistently takes. And it is this interpretation that Section 4 aims to enforce in the context of sovereign debt. The amendment does not say that "the public debt ... shall not be questioned" because that principle needs stating. It says that the debt shall not be questioned because the correct *application* of that principle needs stating. The amendment gives an authoritative gloss to the principle by asserting that it does not mean that the U.S. has (or even could have) an obligation to pay the Confederate debts.
Now, I should add as an afterthought that affirming the validity of debt is different from actually paying it. An analogy to the States illustrates the difference:
The Constitution also provides that the States cannot invalidate contracts by power of law. ("No State shall ... pass... [a] Law impairing the Obligation of Contracts...." Art, 1, Sec. 10). And this extends to a prohibition on invalidating its debts. Nevertheless, States have permanently defaulted on debts on numerous occasions. The States do this not by questioning the validity of the debt, but by acknowledging the wrong and providing no remedy for it. The States simply deny anyone access to their courts to collect on the debt, and rely on their immunity from suit in federal courts. That leaves only the very rare case where it is possible to sue a State in *another* State's court, and to then seize assets of the first state found within the second state.
Currently the U.S. government grants its permission to be sued on its debts (waiving its sovereign immunity), but conceivably it too could withdraw this permission to be sued on its debts, never questioning the *validity* of its debts while still failing to actually *pay* them. The proposition has never been tested in court, and is the subject of current (if infrequent) debate. | [
"At the time that the Constitution came into effect, the United States had a significant debt, primarily associated with the Revolutionary War. There were differences within and between the major political coalitions over the possible liquidation or increase of this debt. As early as 1798, Thomas Jefferson wrote:I ... |
why do we pronounce the "w" in words like "swore," but not in "sword?" | Because English is a stupid language.
_URL_0_ | [
"Many imported words beginning with \"w\" in English have cognates in French that start with a \"g\" or \"gu\". This is because the English word was not borrowed directly from French or Old French, but from some of the northern langue d'oïl dialects such as Picard and Norman, where the original \"w\" sound was pres... |
how can you get pregnant when not taking the pill every day at the same time/missing a day or when leaving the hormonal ring out for more than 3 hours? doesn't hormonal bc have a longer-term effect on women's bodies? | As I understand it (and I'm not an expert or anything close), hormonal birth control stops you from ovulating, and the part that it stops doesn't take very long. If it gets messed up, that little part will happen, then when whole process starts and you can be fertile. | [
"Progestogen-only contraceptive pills (sometimes called the 'mini pill') are taken continuously without a 7-day span of using placebo pills, and therefore menstrual periods are less likely to occur than with the combined pill with placebo pills. However, disturbance of the menstrual cycle is common with the mini-pi... |
why is it we find walking outside in 90 degree heat unbearable, yet sitting in a 90 degree sauna is so relaxing? | Part of it probably has to do with the sun. The temperature isn't really the unbearable part, the burning from the sun is. In a sauna it is dark and moist. Even so I still hate them. | [
"BULLET::::- Being in cold and humid places such as bathtub, swimming pool, cold tub, and steam sauna is not good for them, while taking intense exercise such as jogging, running, cycling especially under low sun is recommended to them.\n",
"Though known to cause a rise in the stress hormones due to hyperthermic ... |
How did the US become solely a British Colony when originally there were so many different colonial powers in the area? | Remember that the French controlled Louisiana (a territory that does not match the boundaries of the State of Louisiana) until well after the American Revolution. We bought it during the presidency of Thomas Jefferson.
Each area has its own history of turning from non-English controlled areas to either English or American control.
It is also a little misleading to say that the US became a British Colony. The US was an amalgamation of pre-existing colonies that had already revolted from colonial control and gone through one failed attempt at a common government by the time the Constitution finally knitted them together.
By the time the US was created, each of those colonies had already become sovereign states (little s to denote the fact that they were essentially countries) which agreed to give up a portion of their sovereignty in order to become the United States. | [
"Three types of colonies were established in the English overseas possessions in America of the 17th century and continued into the British Empire at the height of its power in the 17th century. These were charter colonies, proprietary colonies, and royal colonies. A group of 13 British American colonies collective... |
Why isn't Juneteenth a national holiday in the United States? | Juneteenth does not commemorate the actual emancipation of slaves; that happened in January 1863 for the states in rebellion, and with the ratification of the Thirteenth Amendment in Dec. 1865.
Juneteenth celebrates when news of the Emancipation Proclamation finally reached Texas in June 1865. Initially a celebration only among Negroes in Texas, the commemoration first spread to a couple of adjacent states, and in the 20th century traveled with African-Americans from Texas as they migrated to industrial cities elsewhere. In particular, it seems to have taken hold among those who moved to the Bay Area during World War II to work in shipyards and defense industries. It seems likely that its enduring popularity owes something to the summer date, suitable for large outdoor gatherings and celebrations. Only in the last 25 years has the celebration become known nationwide.
[The *Handbook of Texas* has a good summary.](_URL_0_) | [
"Commemoration of the American Revolution typifies the patriotic sentiment surrounding the American Revolution and the desire to preserve and honor the \"Spirit of '76\". As the founding story of the United States, it is covered in the schools, memorialized by a national holiday, and commemorated in innumerable mon... |
the expulsions of the germans in european countries during and after ww2. | By the time of the World Wars, German speaking populations existed in many places throughout Europe, including Central Europe and along the Baltic Sea. These maps both show Prussia and other German states [before WWI](_URL_4_) and [before WWII](_URL_0_). Note how the territory is larger than modern Germany, and includes much of modern day Poland.
As WWII drew to a close, many German speaking residents of Eastern Europe/the Baltic migrated west with the retreating front line, fearing dire ramifications from the Soviets. Eventually by the war's end a lot of German speakers (regardless of ethnicity) and German citizens (regardless of language) ended up in Allied-Occupied Germany or Austria.
According to the Potsdam Agreement by Allied leaders on the state of post-war Europe/boundary changes/etc, this population migration continued up until 1950 or so. About 12 million Germans are estimated to have been moved. Up to 500,000 may have died during this migration.
If you look at a map of Europe, you can see notable changes, especially in Russian territory. [Koenigsberg](_URL_3_) for example, the former capital of East Prussia was heavily war-torn and repopulated with Russians. Today, it's called [Kaliningrad](_URL_2_) it's about 0.7% German by ethnicity.
EDIT: For more reading I'd recommend this _URL_1_
| [
"Germans fled, were evacuated, or were expelled as a result of actions of Nazi Germany, the Red Army, civilian militias, and/or the organized efforts of governments of the reconstituted states of Eastern Europe. Between 1944 and 1950, at least 12 million had fled or had been expelled and resettled to post-war Germa... |
Why wasn't Augustus one of the "5 good Roman emperors"? | I think the best explanation in this case is the simplest one: the term “5 Good Emperors” refers specifically to the chronological succession of five emperors (Nerva, Trajan, Hadrian, Antonius Pius, and Marcus Aurelius) who were lauded for their expansion of the empire and the relative stability of their reigns. It’s not simply a list of “the five best Emperors of Rome — number 4 will shock you!” it’s a non-dynastic succession of notable emperors. Augustus is widely regarded as a successful and comparable emperor, but he wasn’t part of the succession that involved the aforementioned 5, he reigned much earlier and as part of the Julio-Claudian dynasty. | [
"Many consider Augustus to be Rome's greatest emperor; his policies certainly extended the Empire's life span and initiated the celebrated \"Pax Romana\" or \"Pax Augusta\". The Roman Senate wished subsequent emperors to \"be more fortunate than Augustus and better than Trajan\". Augustus was intelligent, decisive,... |
How does the fact that heat moves from warmer objects to cooler objects relate to IR emitted from greenhouse gases? | No, that is a entirely unreasonable argument.
As an illustration, which do you think would heat up to higher temperatures? An oven with the door open or an oven with the door closed?
If you consider the surface of the planet to be the IR source in the oven, and greenhouse gasses to be the oven door, you have a fairly reasonable (albeit exaggerated) analogy on your hands.
Now the person you are talking to is onto *something* with the point that you can't increase the heat of an object by trapping smaller amounts of heat around it... but in the real world that really only applies to very specific and simple situations and is totally irrelevant here. The surface of the planet (rocks, soils, buildings, etc) are already in balance between heat gathered from the sun and heat lost to the atmosphere. As the atmosphere increases in temperature, the physical surface of the planet will have a harder time shedding heat, and it can be expected to increase in temperature too. | [
"When greenhouse gas molecules absorb thermal infrared energy, their temperature rises. Those gases then radiate an increased amount of thermal infrared energy in all directions. Heat radiated upward continues to encounter greenhouse gas molecules; those molecules also absorb the heat, and their temperature rises a... |
How did Plato's name become root word for non-sexual friendship? Platonic. | Mainly because of his dialogue the *Symposium*, which is effectively a prose drama showing several people making speeches about the nature of love/desire. All of the speakers are in agreement that physical desire is the "lowest" kind of love, and as the drama progresses there's a kind of escalation of what "higher" kinds of love look like. One speaker casts "higher" love as a relationship between minds, not bodies; another casts love as a cosmic force, representing all forms of attraction; another casts love as the desire for wholeness; Socrates (the hero) casts different kinds of love on an ascending scale that reaches up, at its most philosophical "heights", to the meditation on and contemplation of abstractions that are usually known as [Platonic forms](_URL_0_).
The term "Platonic love" was coined by Ben Jonson in his 1631 play *The New Inn*. Act III scene 2 is essentially a discourse on love, and explicitly summarizes a number of passages in Plato's *Symposium*. At lines 73-6 the character Lovel starts off by defining love as follows:
> For, what else
is *Love*, but the most noble, pure affection
of what is truly beautiful, and faire?
Desire of union with the thing beloved?
This is essentially a paraphrase of an opening section in Socrates' speech. A few lines after that, Beaufort paraphrases Aristophanes' speech in the *Symposium*, and Lovel makes the attribution explicit ("It is a fable of *Plato's*, in his Banquet, / and utter'd, there, by *Aristophanes*"). Lovel goes on to cite ideas from other speeches in the *Symposium*:
> **Beaufort.** I relish not these philosophicall feasts;
give me a banquet o' sense, like that of Ovid...
> **Lovel.** They are the earthly, lower forme of lovers,
are only taken with what strikes the senses!
And so on, until we get to Lovel coining the phrase at line 278, with the twist of simultaneously demanding a kiss as a fee for his time:
> **Lovel.** Most *Socratick* Lady!
Or, if you will *Ironick*! gi'you joy
o'you *Platonick* love here, Mr *Lovel*.
But pay him his first kisse, yet, i'the Court,
which is a debt, and due: for the houre's run.
Plato's/Jonson's philosophization of love, and Jonson's emphasis on the non-sexual nature of "Platonic" love (a view that Plato did not share!), provided a useful way for people to rationalize homosocial relationships and categorize them as non-sexual. A lot of western homosocial culture depends on the existence of that non-sexual category. Platonic love as sexual did get somewhat rehabilitated, largely thanks to the invention of homosexuality and elevation of "Greek love" in the 19th century, but Jonson's phrase has stayed with us. | [
"\"Platonic\" refers to the writings of Plato, an ancient Greek philosopher who wrote on the interesting subject of love. Platonic love and platonic friendships are marked by the absence of physical or sexual desire. Plato did acknowledge physical desire, but thought that if two people truly inspired each other, th... |
how do the "double irish" and "double irish w/ dutch sandwich" tax avoidance techniques work? | The EU operates a free trade regime such that a state can't attempt to tax an entity based in another country selling to its citizens. In the US context its very similar to the way US states behave, if I live in NY and buy something from a company in MA then NY doesn't tax the company in MA for profits they make but instead they are taxed in MA.
In the EU Ireland has the most favorable tax rate so many corporations HQ there in order to pay the lower tax rate. If you buy a Dell computer in France you are not doing business with Dell France but with Dell Ireland. In effect businesses funnel all sales through an Irish office to pay a lower rate of corporation tax.
Ireland has a tax treaty with the Netherlands which massively reduces Irish tax burden for profit transfers there (technically its an entire exemption but some revenue will be subject to taxation due to licensing arrangements). Once in the Netherlands there is a small tax imposed (again licensing arrangements) but then it is transferred back to Ireland to a separate entity (2nd Irish subsidiary, hence the "Double").
A quirk in Irish tax law means that a company that is actually controlled by foreign managers can transfer all profits to that country tax free so the 2nd Irish subsidiary is actually controlled by another subsidiary in another country (outside the EU, Bermuda is popular).
[This](_URL_0_) illustrates the process fairly well.
Some countries (most of the Middle-East, Africa, Australia, Asia) has lax revenue shifting controls so companies also shift earnings from these subsidiaries through Ireland to similarly reduce their tax exposure.
While this is typically mentioned in the context of US corporations it actually has no impact on US tax revenue at all, its impossible to shift US based revenue out of the US and due to IP transfer fees (fees a subsidiary has to pay to its US parent to account for brand, technology etc developed in the US) some of the non-US revenue does make it back in to the US and instead primarily impacts EU income. In the Google example in 2012 they had an EU effective corporate tax rate of 4.4% while a US effective corporate tax rate of 29.1%. | [
"In 2013, Bloomberg reported that lobbying by PriceWaterhouseCoopers Irish Managing Partner Feargal O'Rourke, who Bloomberg labelled \"grand architect\" of the Double Irish, led to the Irish Government to relax the rules for making Irish royalty payments to non-EU companies (i.e. IRL2), without incurring Irish with... |
how do they get water up large skyscrapers | with pumps! the pressure that is supplied by the water main available in most cities is usually only adequate to get water up around 6-8 stories. any building higher than that needs to supplement the water pressure in its system with pumps. | [
"In particular, the problem of bringing and keeping water on the upper floors is an important constraint in the design of skyscrapers. Water is necessary for tenant use, air conditioning, equipment cooling, and basic firefighting through sprinklers (especially important since ground-based firefighting equipment usu... |
how did media control symbols become standard (play, pause, fast forward, etc.)? do other parts of the world use different symbols? | _URL_0_
There is actually an international standard for all forms of icons.
I'm going off of personal knowledge here, so correct me if I'm wrong, but during the 80s when electronics started to become more widespread globally and production switched from the west to the east, many of the manufacturers understood they would need a standardized way of denoting controls on electronics. They held a convention to draft up a list of virtually any kind of control one would need as a symbol that could be understood. There like a huge book of hundreds of symbols.
TL;DR the symbols we used are arbitrary and standardized internationally.
EDIT:removed the extra "d". | [
"In digital electronics, analogue electronics and entertainment, the user interface of media may include media controls or player controls, to enact and change or adjust the process of watching film or listening to audio. These widely known symbols can be found in a multitude of software products, exemplifying what... |
what does 'all property is theft' mean? | It is a saying that implies that anything you can own involves the exploitation and/or abuse of someone or something that is not being compensated, and that you can't separate the property itself from it's origins... That you can't, for examply, own a pair of shoes without separating them from the fact that it likely used child workers to make them, or the rubber in them came from rubber trees planted on land taken generations ago from the indigenous people originally there. | [
"In common usage, theft is the taking of another person's property or services without that person's permission or consent with the intent to deprive the rightful owner of it. The word is also used as an informal shorthand term for some crimes against property, such as burglary, embezzlement, larceny, looting, robb... |
why has the global temperature spiked so dramatically in the last 10-20 years even though that's the timespan we've become aware of global warming and started trying to combat it? | Guess what happened before 20 years ago? Rampant pollution while being oblivious. "Just exhaust it, planet Earth will pick up the slack and balance out" was the mentality back then. | [
"The Intergovernmental Panel on Climate Change stated in its first working group report that “most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations, contribute to climate change.\n",
"\"... |
How do trees grow in such a way as to not fall over? | I think it has more to do with the roots than with the branches. If trees had to balance their branches in order to stay upright, they would get blown over all the time. | [
"Trees that grow adjacent to lakes or other natural forest edges, or in exposed situations such as hill sides, develop greater rooting strength through growth feedback with wind movement, i.e. 'adaptive' or 'acclimative' growth. If a tree does not experience much wind movement during the stem exclusion phase of sta... |
How did the idea of the atom advance beyond a theory? (other questions inside) | Atomic theory came from chemistry, from the realization that there must be little indivisible bits of each element. (Actually atomic theory is often said to go back to antiquity and the Greeks, but that's a bit misleading, because until the 19th century it all amounted to little more than "I bet stuff has bits in.")
So the chemists did their thing for about a hundred years, and came to the conclusion that you can't ever have less than *this much* of any element, and in fact all stuff is made of integer multiples of these little indivisible bits.
*Subatomic* theory didn't come until about a hundred years later, with the discovery of the electron.
I'm not sure where you got the idea that different elements can have the same number of protons. That's the *opposite* of the truth. Elements are *distinguished* by the number of protons in their atoms. That's why the periodic table of the elements has one entry for each number of protons, starting at one — hydrogen — and counting up to 118 or whatever we're up to now.
The number of *neutrons* in an atom, for a given number of protons, distinguishes *isotopes.* Some isotopes are stable, and others are unstable and will decay into more and more stable forms over time. This is the source of radioactivity.
The number of *electrons* in an atom can change essentially any time, through a process called ionization. Chemistry is concerned almost entirely with the way the electrons in different atoms interact.
And no, quarks are not "the smaller version of atoms." They're in fact completely different. *Completely* different. Once you get past "here are some things that are too small to see," you're basically done comparing the atomic model to the quark model. | [
"Atomism is a central part of today's relationship between thermodynamics and statistical mechanics. Ancient thinkers such as Leucippus and Democritus, and later the Epicureans, by advancing atomism, laid the foundations for the later atomic theory. Until experimental proof of atoms was later provided in the 20th c... |
AskScience AMA Series: We're a group of paleontologists here to answer your paleontology questions! Ask us anything! | In your field, what is the biggest unsolved mystery or unexplained fossil that you want answered? | [
"The Paleontological Research Institution, or PRI, is a paleontological organization in Ithaca, New York with a mission including both research and education. PRI is affiliated with Cornell University, houses one of the largest fossil collections in North America, and publishes, among other things, the oldest journ... |
would hiv/aids cancel out leukemia? | Not really, HIV is a virus, AIDS is a deficiency of CD4 white blood cells, and leukemia is a cancer causing elevated abnormal nonfunctioning white blood cells (there are more types than just CD4)
That about as ELI5 as I can get, there is alot more science behind it, between the progenitor cell lines and such. | [
"The AIDS crisis was shadowed by constant politicization which magnified the struggles of HIV/AIDS patients, as well as heavily hindered research and the search for treatment and/or a cure. The HIV virus wasn't discovered to be the cause of AIDS until 1984, and the first treatment, AZT, was not approved until 1987.... |
Why were the Channel Islands not liberated soon after D-day? | There was a plan to liberate them as early as 1943, called Operation Constellation. Drawn up by Lord Louis Mountbatten, based on aerial reconnaissance.
The problem was that, as it stood, the Channel Islands weren't actually much of a strategic advantage. Obviously if the Luftwaffe were to establish a bombing base there, that would change, but until 1945 the Germans hadn't made much of an advantage of the occupied islands. Really, the only purpose they had served for the Germans, was as a slight bloodied nose for the British.
Mountbatten observed that while the islands could be retaken by force, they were also heavily fortified, and it would require a fairly large landing force to retake these strategically unimportant islands.
The other consideration was the civilian population. They hadn't fared too badly under the Germans, there were no reports of abuses or reprisals, but attempting an invasion might put their lives at risk. Certainly their lives would be at risk if a battle broke out.*Mountbatten also noted that either aerial or naval bombardment would be necessary in order to break the islands defences, again at a potentially high civilian loss.
Mountbatten's plan was eventually rejected on the grounds that the cost would likely be far too high, and that the sensible option was to have them peacefully returned as part of Germany's unconditional surrender.
I'm afraid the only source I have for this is Lord Louis Mountbatten's biography, *"The Life and Times of Lord Mountbatten"*, John Terraine, 1968.
There is also a wikipedia entry for Operation Constellation, and most of it seems to back up what I've read in Mountbattens biography, for what it's worth:
_URL_0_
*Edit | [
"Not knowing that on 15 June the British Army commanders had decided the Channel Islands were not defensible, the islanders were surprised to see the resident army units quickly depart on ships, with all of their equipment, the islands were being abandoned. The \"Channel Islands had been demilitarised and declared.... |
how did mining work back in the day? did people just picaxe long tunnels into the rock hoping they’ll find something useful? | Yes and no. Depending on what's being mined.
Typically they'd find a vein and surface level evidence. (Think of gold washed down a creek, it comes from a vein somewhere) | [
"The task of excavating the tunnels began on 25 May 1782, carried out entirely by hand. The miners broke up the limestone rock using a variety of methods, including gunpowder blasting, fire-setting (building a fire against the face of the rock to heat it, then quenching it with cold water to cause it to shatter), q... |
how does someone go from being christian to jewish and vice-versa? | Judaism discourages conversion (but encourages people once they've been accepted for conversion). So you'd first have to convince a Rabbi that you're serious about wanting to convert. Then you'd have to engage in study so that you know enough about what it means to be and live as a Jew (which will vary depending on denomination). When your Rabbi thinks you're ready, you'll appear before a Rabbinic Court, and convince them that you're ready. If they agree, then you can go through the ritual immersion (in a ritual bath called a *mikveh*) and, in the case of men, circumcision. | [
"List of former Jews, or more accurately, people of Jewish ethnicity and adherents of Judaism who have converted to another (or no) religion. According to certain concepts of Jewish being (cf. who is a Jew?), a Jew who converts to another (or no) religion is still \"a Jew,\" by family and heritage alone, if not als... |
Can you recommend any sources (book or journal articles) that summarize issues related to Oral Tradition? | All sources - every bit of evidence about the past - requires source criticism to evaluate what flaws have insinuated themselves into the weave of information presented. The difference between a written primary source and recorded oral testimony that is not first hand can be summed up with the following:
Historians continually find that primary source documents about the past have flaws that need to be identified and isolated from the telling of an accurate history and perception of the past.
Historians (and folklorists) are often surprised to find that a historical legend includes information that is accurate and can be relied upon in the telling of history and perception of the past.
In other words, historical legends are sometimes surprisingly accurate and primary sources are sometimes surprisingly inaccurate. Well, OK, maybe we're actually not that surprised about either, but there is a core assumption that primary sources depict the past (but we find they are flawed) and that historical legends are inaccurate and inflated beyond use (but we sometimes find they are useful).
Of course folklorists don't often look to historical legends to understand the period described. Rather, they look at a historical legend to understand the people who told it - it is a different use of the source. But that aside, there has been ample analysis of historical legends and their surprising value in capturing the nature of past events.
Of particular use here is a collection of essays edited by Reimund Kvideland and Henning K. Sehmsdorf: Nordic Folklore (1989). This includes essays by Lauri Honko, who is one of the great modern theoreticians when it comes to the nature of legend. A particularly good essay for your question is a chapter by Brynjulf Alver, "Historical Legends and Historical Truth."
The bottom line is that oral tradition can be a surprising conveyor of accurate information about the past. As I began - all sources require source criticism. It is simply important to understand that written primary documents require a certain type of analysis while oral tradition requires another species of analysis. The filter for oral tradition must be more intense if it is to be used to understand an historical event, and without the anchor of written documents, it is difficult to use oral tradition, alone, to peer into a remote past. | [
"Oral Tradition is a peer-reviewed academic journal established in 1986 by John Miles Foley covering studies in oral tradition and related fields. As well as essays treating certifiably oral traditions, the journal presents investigations of the relationships between oral and written traditions, as well as brief ac... |
why is feet bone structure much more complex and composed of so many bones, while hands are much more simple? | There are 27 bones in each hand. There are 26 bones in each foot. Can you please explain what you are talking about? | [
"Because of the wide variety in body types, scaling and morphology of the distal limbs of terrestrial vertebrates, there exists a degree of controversy concerning the nature and organization of foot structures. One organizational approach to understanding foot structures makes distinctions regarding their regional ... |
what exactly happens to my body when i get the flu. | For most viruses, all the symptoms are your body's attempt to slow the progression of the virus while it searches for an antibody.
The virus is taking over cells and reprogramming them to produce more of itself. The only way to actually stop it is to produce the right antibody. I don't really know how that whole system works, but your body essentially produces millions of randomly shaped antibodies until the right one is made to stop the virus.
To explain some of the symptoms; a sore throat is acid being produced to kill off infected throat cells, this is a non-direct attack that kills healthy cells too. A fever raises the body temperature hopefully killing off or slowing weaker infected cells, chills make you seek warmth to crank your body temperature up even more, shivering produces more heat.
Vomiting speeds up the expulsion of dead cells. Your lymphatic system deposits them in your stomach, normally you would digest these and they would exit your body through stool and urine. But vomiting can get rid of a lot of stuff quickly, and it reduces strain on your kidneys that are also taking an increased load.
These responses are not perfectly utilized, over reaction of the immune system can make the symptoms way worse than they need to be. You vomit when there is nothing to vomit, and a high fever can kill you etc.
Some viruses directly cause side effects that are not an immune response.
It is a lot more complicated than this and I don't know what I am talking about really, there are a lot more systems and doo-dads doing complex things in your body. | [
"Influenza, commonly known as the flu, is an infectious disease caused by an influenza virus. Symptoms can be mild to severe. The most common symptoms include: high fever, runny nose, sore throat, muscle pains, headache, coughing, sneezing, and feeling tired. These symptoms typically begin two days after exposure t... |
The M60 was the only machine gun authorized by the Army to be used on gun trucks in Vietnam. How did officers react when they saw gun trucks armed with M2s and miniguns? | The officers were the ones leading the development of the Vietnam era gun trucks. Company, Battalion, and Group (Brigade equivalent) level transportation officers in Vietnam were heavily involved in these field modifications, and they also were the ones creating the doctrine to allow their units to use these gun trucks as effectively as possible. Not only that, many of them recorded their experiences to share and preserve the lessons learned and at least one Captain went through the effort to have a gun truck sent to the US Army Transportation Corps Museum to serve as an example for future generations. So this wasn't a dirty little secret the soldiers tried to keep to themselves, it was leadership pushing this as a reaction to the conditions in Vietnam (along with other tactics to protect convoys).
Now when they say "authorized", they're referring to what's listed on the official Army "TO & E" (Table of Organization and Equipment) for that type of unit.
A TO & E is a document that lays out the organization and weapons/vehicles/equipment for a given type of unit according to Army doctrine. Everything from how many soldiers they're supposed to have and how the unit is organized, to what type of weapons each individual soldier is assigned, to the types and numbers of vehicles used, what (if any) weapons are assigned to those vehicles, and so on. If something isn't on the TO & E, the Army isn't going to issue it to your unit, hence the backdoor deals to get added weapons in Vietnam.
While the Army didn't adopt the idea of the gun truck at a higher level (it was never added to the TO & E and mostly forgotten after Vietnam), I'm not aware of anyone getting in trouble for any of these field modifications in Vietnam. While it was not necessarily viewed by everyone as the ideal long term solution to convoy security, it was also not viewed as a problem that needed to be stamped out.
Richard Killblane, a historian for the US Army Transportation Corps (featured in the Smithsonian video you referenced) has written two papers on the history of US Army convoy security.
[Circle the Wagons: The History of US Army Convoy Security](_URL_0_)
[Convoy Ambush Case Studies](_URL_1_) | [
"The M60 later served in the Vietnam War as a squad automatic weapon with many United States units. Every soldier in the rifle squad would carry an additional 200 linked rounds of ammunition for the M60, a spare barrel, or both. The up-gunned M113 armored personnel carrier ACAV added two M60 gunners beside the main... |
air conditioning | [This](_URL_0_) is the basic cycle of the refrigeration cycle. There is a lot of thermodynamics but basically it works on the fact that the liquid inside the air conditioner has a low boiling point and can transfer thermal energy well/ as it it pumped through the cycle the liquid experiences phase changes and these changes cause a transfer in energy causing the heat from the outside to be taken out of the air and this cooler air blown out of the air conditioner
| [
"Air conditioning is the cooling and de-humidification of indoor air for thermal comfort. Using a system of coils as a solution to cool and remove moisture from muggy air in a printing plant that was wrinkling magazine pages, Willis Carrier invented and manufactured the world's first mechanical air conditioning uni... |
is there such a thing as a material that is completely impermeable? For example, can some molecules get though a plastic baggy? | Small molecules such as water may diffuse through most plastics, so even an airtight container is "porous" on a microscopic level. In any case, unless the bag is perfectly sealed by melting the plastic, chances are that the moisture can diffuse through small leaks at the sealing. | [
"Lightweight plastic bags are also blown into trees and other plants and can be mistaken for food. Plastic bags break down by polymer degradation but not by biodegradation. As a result, any toxic additives they contain—including flame retardants, antimicrobials, and plasticizers—will be released into the environmen... |
why is it a mark of quality for a watch to be "swiss-made"? couldn't a swiss company make a crappy watch? | Of course - but like much advertising it trades on beliefs and mystique rather than facts.
Switzerland does produce some truly amazing watches, but it doesn't have a monopoly on it.
Not sure whether they'd bother to produce really poor quality stuff these days simply because anything they could do badly the Far East could do just as badly but cheaper. | [
"The legal standards for the use of \"Swiss made\" on a watch are a very minimum standard, and the Swissness of a watch is largely dependent on the brand and its reputation. The Swiss watch industry has not reached an agreement over the specific definition of Swiss made, as some companies favor stricter regulations... |
Is it possible for an astronomical body to have a molten core, without orbiting a star? | Sure. If a planet forms and then gets ejected from its star system, there's no reason it couldn't have a molten core for a while. The Earth's core isn't molten because of the Sun, it's molten because of residual heat from planet formation plus radioactive heating from decay within the crust. | [
"Solid planets up to thousands of Earth masses may be able to form around massive stars (B-type and O-type stars; 5–120 solar masses), where the protoplanetary disk would contain enough heavy elements. Also, these stars have high UV radiation and winds that could photoevaporate the gas in the disk, leaving just the... |
if working out is just damaging and repairing muscle tissue, couldnt we just mechanically damage the tissue and recouperate saving time and energy? | Finally something I might have insight on! First off, you can use electric pulses to build and repair damages tissue. I have had terrible knees for years, I started physical therapy at around 17. However, the cartilage damage was so bad in my knee, that I couldn't build the muscle in a healthy way to keep my knee in better traction. Long story short I had surgery. I am 22, and recovering. Because of the nerve and tissue damage I cannot build muscle in my leg through exercise alone. Instead, when I go to PT they hook me up to a machine that sends a small electric charge into my knee, making the muscles contract, nerves reactivate, and swelling in my knee go down. Because of this machine I am able to do my exercises after with little pain. So, regular exercise is needed to build muscle quickly and healthy, but you can use electric shock therapy to help your body out! It is really amazing. | [
"Skeletal muscle is able to regenerate far better than cardiac muscle due to satellite cells, which are dormant in all healthy skeletal muscle tissue. There are three phases to the regeneration process. These phases include the inflammatory response, the activation, differentiation, and fusion of satellite cells, a... |
Chemistry - A few questions about pH buffers. | normally the range is roughly the pKa +/- 1. you can extend the range if you really need to, but i wouldn't recommend it. any more than that and it starts to lose effectiveness. to increase the capacity, use a higher concentration.
the way it works is that since the two "versions" of the molecule exist in equilibrium, when you add acid, the base absorbs the hydrogen ions and removes them from the system. the opposite if you add base: the "acid version" becomes protonated. the reason the entire system works is because there are so many more molecules of the weak acid/conjugate base than there are for the acids or bases that you add to the system. | [
"Aqueous buffer solutions will react with strong acids or strong bases by absorbing excess hydrogen ions, or hydroxide ions, replacing the strong acids and bases with weak acids and weak bases. This has the effect of damping the effect of pH changes, or reducing the pH change that would otherwise have occurred. But... |
When fat is burned via exercise, which is burned first: the most recently stored fat or the oldest fat in the body? | Links, and abstracts to three papers pertinent to the question. Its a bit long, but (I think) very interesting. I have **bolded** a few key statements for those who would just like to skim
_URL_1_
"**Fatty acids are the most abundant source of endogenous energy substrate.** They can be mobilized from peripheral adipose tissue and transported via the blood to active muscle. During higher intensity exercise, triglyceride within the muscle can also be hydrolyzed to release fatty acids for subsequent direct oxidation. Control of fatty acid oxidation in exercise can potentially occur via changes in availability, or via changes in the ability of the muscle to oxidize fatty acids. We have performed a series of experiments to distinguish the relative importance of these potential sites of control. The process of lipolysis normally provides free fatty acids (FFA) at a rate in excess of that required to supply resting energy requirements. At the start of low intensity exercise, lipolysis increases further, thereby providing sufficient FFA to provide energy substrates in excess of requirements. However, lipolysis does not increase further as exercise intensity increases, and fatty acid oxidation becomes approximately equal to the total amount of fatty acids available at 65% of VO2 max. When plasma FFA concentration is increased by lipid infusion during exercise at 85% VO2 max, fat oxidation is significantly increased. **Taken together, these observations indicate that fatty acid availability can be a determinant of the rate of their oxidation during exercise. However, even when lipid is infused well in excess of requirements during high-intensity exercise, less than half the energy is derived from fat.** This is because the muscle itself is a major site of control of the rate of fat oxidation during exercise. We have demonstrated that the mechanism of control of fatty acid oxidation in the muscle is the rate of entry into the mitochondria. We hypothesize that the rate of glycolysis is the predominant regulator of the rate of carbohydrate metabolism in muscle, and that a rapid rate of carbohydrate oxidation caused by mobilization of muscle glycogen during high intensity exercise inhibits fatty acid oxidation by limiting transport into the mitochondria. **During low intensity exercise, glycogen breakdown and thus glycolysis is not markedly stimulated, so the increased availability of fatty acids allows their oxidation to serve as the predominant energy source. At higher intensity exercise, stimulation of glycogen breakdown and glycolysis cause increased pyruvate entry into the TCA cycle for oxidation, and as a consequence the inhibition of fatty acid oxidation by limiting their transport into the mitochondria.**"
_URL_0_ **The rate of carbohydrate utilization during prolonged, strenuous exercise is closely geared to the energy needs of the working muscles. In contrast, fat utilization during exercise is not tightly regulated, as there are no mechanisms for closely matching availability and metabolism of fatty acids to the rate of energy expenditure.** As a result, the rate of fat oxidation during exercise is determined by the availability of fatty acids and the rate of carbohydrate utilization. Blood glucose and muscle glycogen are essential for prolonged strenuous exercise, and exhaustion can result either from development of hypoglycemia or depletion of muscle glycogen. Both absolute and relative (i.e. % of maximal O2 uptake) exercise intensities play important roles in the regulation of substrate metabolism. The absolute work rate determines the total quantity of fuel required, while relative exercise intensity plays a major role in determining the proportions of carbohydrate and fat oxidized by the working muscles. **As relative exercise intensity is increased, there is a decrease in the proportion of the energy requirement derived from fat oxidation and an increase in that provided by carbohydrate oxidation. During moderately strenuous exercise of an intensity that can be maintained for 90 minutes or longer ( approximately 55-75% of VO2max), there is a progressive decline in the proportion of energy derived from muscle glycogen and a progressive increase in plasma fatty acid oxidation.** The adaptations induced by endurance exercise training result in a marked sparing of carbohydrate during exercise, with an increased proportion of the energy being provided by fat oxidation. The mechanisms by which training decreases utilization of blood glucose are not well understood. However, the slower rate of glycogenolysis can be explained on the basis of lower concentrations of inorganic phosphate (Pi) in trained, as compared to untrained, muscles during exercise of the same intensity. The lower Pi level is a consequence of the increase in muscle mitochondria induced by endurance exercise training. A large increase in muscle glycogen concentration, far above the level found in the well-fed sedentary state, occurs in response to carbohydrate feeding following glycogen depleting exercise. It was recently found that this muscle "glycogen supercompensation" is markedly enhanced by endurance exercise training that induces an increase in the GLUT4 isoform of the glucose transporter in skeletal muscle.
_URL_2_ **Endogenous triacylglycerols represent an important source of fuel for endurance exercise. Triacylglycerol oxidation increases progressively during exercise; the specific rate is determined by energy requirements of working muscles, fatty acid delivery to muscle mitochondria, and the oxidation of other substrates.** The catecholamine response to exercise increases lipolysis of adipose tissue triacylglycerols and, presumably, intramuscular triacylglycerols. In addition, increases in adipose tissue and muscle blood flow decrease fatty acid reesterification and facilitate the delivery of released fatty acids to skeletal muscle. Alterations in fatty acid mobilization and the relative use of adipose and intramuscular triacylglycerols during exercise depend, in large part, on degree of fitness and exercise intensity. Compared with untrained persons exercising at the same absolute intensity, persons who have undergone endurance training have greater fat oxidation during exercise without increased lipolysis. **Available evidence suggests that the training-induced increase in fat oxidation is due primarily to increased oxidation of non-plasma-derived fatty acids, perhaps from intramuscular triacylglycerol stores. Fat oxidation is lower in high-intensity exercise than in moderate-intensity exercise, in part because of decreased fatty acid delivery to exercising muscles.** Parenteral lipid supplementation during high-intensity exercise increases fat oxidation, but the effect of ingesting long-chain or medium-chain triacylglycerols on substrate metabolism during exercise is less clear. This review discusses the relation between fatty acid mobilization and oxidation during exercise and the effect of endurance training, exercise intensity, and lipid supplementation on these responses. | [
"Diet itself helps to increase calorie burning by boosting metabolism, a process further enhanced while gaining more lean muscle. An aerobic exercise program can burn fat and increase the metabolic rate.\n",
"The distribution of adipose (fat) tissue changes slowly over months and years. HRT causes the body to acc... |
how do composers write music? | It's all a grand formula called music theory. With Hans Zimmer and most other composers the steps go kind of like this: find a theme, build a central melody and build around the melody. Finding a theme is first step of the creative process and a theme can be deliberately sought after by a composer or it can just come to them. Hans Zimmer wrote the score to the Dark Knight because he was paid to write a Dark Knight soundtrack. Beethoven wrote his fifth symphony because he was contemplating his life after going near deaf. Think of this as the overall spirit or personality of the piece. The next step is developing a melody or motif, this step often includes most of the technical structuring of the piece. This can include time signature, playing directives, key signature and tempo. Think about the iconic Dark Knight theme and how it fits the theme of the movie itself. Or perhaps think about the easily recognizable opening of the Fifth Symphony (short short short long) that reappears throughout the piece. This step is probably the most important step in the composition process and is the heart of the piece. The last step is usually to develop a harmony and 'background'. This includes most of minor instrumentation, bass line and beat. This step is important and it's what separates a good composer from a great one, however it isn't as central to the piece as the first two steps. | [
"Although a musical composition often uses musical notation and has a single author, this is not always the case. A work of music can have multiple composers, which often occurs in popular music when a band collaborates to write a song, or in musical theatre, when one person writes the melodies, a second person wri... |
Did Sherman purposely let the Confederate garrison in Savannah escape? | "Sherman, along with Federal forces in Hilton Head, could have prevented Hardee's escape. Sherman was aware that the Confederates were building a pontoon bridge to South Carolina, yet upon his departure for Hilton Head Island on December 19, he left orders for his army not to attack the Savannah works until he had returned. Sherman's subordinates clearly observed the Confederate evacuation on December 20 yet did nothing to interfere with it. Sherman's victory in Savannah was won through default, not brilliant tactical maneuver."
source: [National Park Service](_URL_0_)
The article also argues that he was somewhat nervous about his army being divided by a river, which may have stopped him from attacking earlier.
I have not heard of the theory you mention. Where might I find a discussion of it? There is no conceivable reason for Sherman to allow Hardee's men to escape. | [
"Sherman's 1864 campaign against Atlanta, Georgia, was initially characterized by a series of flanking maneuvers against Johnston, each of which compelled the Confederate army to withdraw from heavily fortified positions with minimal casualties on either side. After two months and of such maneuvering, Sherman's pat... |
Are there more planets or more stars? | Based on what the Kepler space telescope has found, there are almost certainly more planets out there than stars.
Before Kepler it was hypothesized that few enough star systems had planets that there might be more stars than planets, but it turns out there are a lot more planets out there than expected. A few planets have even been found around Neutron stars which to this day has astronomers scratching their heads. | [
"The table below contains information about the coordinates, spectral and physical properties, and number of confirmed planets. The two most important stellar properties are mass and metallicity because they determine how these planetary systems form. Systems with higher mass and metallicity tend to have more plane... |
if atoms have a positive nucleus with electrons that orbit it, why don’t they collapse into themselves? | There are many levels of understanding this.
In the simplest terms, one can think of the electrons as spinning around the nucleus in circles. In the same way as you feel pressed outwards on a carousel, the electrons don’t want to stay on circles but move outwards. This outwards force is cancelled by the attraction between the positive nuclei and negative electrons (opposite charges attract) so the electrons stay on their circular path. In fancy physicist terms, the electric attraction acts as the centripetal force to keep the electrons in their orbits but is not so strong as to make the electrons fall into the nucleus.
Look up the Rutherford model of the atom for more detail.
If we want to be a bit more advanced (don’t worry if you don’t understand everything from here on, this is starting to get into university level physics), there is one problem with that description. We know from other fancy physics that when a charged particle moves in a circle, it loses energy and slows down, which would mean that the electron falls into the nucleus after all! The way we solve this problem is by saying that there are a certain group of distances between electron and nucleus where the electrons don’t lose energy after all, and the electrons are only ever allowed to be at these distances (this doesn’t seem like a good answer but it works well with the experiments - and since this idea we have gained a much better although much more complicated understanding of why some distances are special).
These different distances have different energies, just as an object has a higher energy when we lift it up (which increases the distance between earth and the object). The electrons can jump between those distances (or ‘levels’ as physicists call them) and can emit or absorb light (they emit light when jumping down and need to absorb light when jumping up to higher energy levels - you can’t get more energy out of nothing). This is what happens in neon lights, the electrons in the atoms jump to levels with lower energies and we see the light they emit. Look up the Bohr model of the atom if you want more details or mathematics.
If we want to get even more technical, we need some more hardcore quantum mechanics. Basically, the electrons aren’t really like billard balls but more like a diffuse electron mist, or electron cloud. The reason we often think of them as Billard balls is that when this cloud is very bunched up it looks like a solid ball from far away and it is easier to think and calculate with this image (even if it isn’t technically correct). The shape of this cloud that forms the electron (also called the save function of the electron) is determined by a certain equation, the Schrödinger equation (in fact, all matter and not just electrons work like this!). If we calculate the form of this cloud, we find that only certain energies are possible, for which the cloud has different form. And the distance where most of the cloud is turns out to be the Special distance that is allowed for the electron (nice when things work out). And none of these forms have any cloud right at the nucleus. If this last explanation feels a bit like “the maths says so, so it’s true”, that’s because it is - quantum mechanics is really weird and often the only insight one can get is to do the calculations and see that something must be true. | [
"A classical electron orbiting a nucleus experiences acceleration and should radiate. Consequently, the electron loses energy and the electron should eventually spiral into the nucleus. Atoms, according to classical mechanics, are consequently unstable. This classical prediction is violated by the observation of st... |
Does cold have diminishing returns, e.g. does -40 degrees generally really feel that much colder than zero degrees? | I can tell you first hand from living in North Dakota that base temp is not the end all be all of feeling cold.
The air from these arctic high pressure systems that have had a strangle-hold on us this whole winter is typically very dry and *crisp* if that makes sense. It's a lot different than that damp, wet cold you get on the East Coast in winter.
This weekend it was sunny, calm, and -15F out. Today, it's snowy, windy, and 3F out, and it feels much colder today than it was this weekend even though the base temp was about 20 degrees colder over the weekend. | [
"Temperatures rarely rise above 30 °C (86 °F). The average winter low is −10 degrees Celsius (14 °F) and temperatures rarely drop below −20 degrees Celsius (−4 °F) although strong winter winds can make it seem much colder.\n",
"Cold is the presence of low temperature, especially in the atmosphere. In common usage... |
what makes rent so high in some areas for small apartments, and so low in others for relatively large apartments? | It can be largely based on surrounding areas income but it’s mostly just location. Are you in close proximity to a large employer (like a medical center?), close enough that people wouldn’t *have* to drive? Then it’s gonna be higher, marketed towards medical employees. It’s based on a lot of factors, but for most apartments that aren’t really near any significant employer but are surrounded by general urban sprawl, just check the average income for the surrounding neighborhoods and such. If it’s high, probably in a ‘better’ part of town. Low, ‘worse’ part of town and the rent reflects it | [
"Low-rise apartments sometimes offer more privacy and negotiability of rent and utilities than high-rise apartments, although they may have fewer amenities and less flexibility with leases. It is also easier to put out fires in low-rise buildings.\n",
"Price ceilings can create shortages and reduce quality when t... |
why do bulbs (that glow white) become green and stays illuminated for a while? | I assume you're talking about fluorescent bulbs. They work by having a gas inside which generates intense ultraviolet light when you pass an electric current through it.
The inside of the glass tubes is coated with phosphor, this is a range of chemicals which glow in different colours when they absorb energy, in this case the mix of phosphors has been chosen to generate white light when uv light pumps energy into it.
When you turn off the power the uv generation stops, but the phosphor still has enough energy to glow faintly. The phosphors that glow greenish are most efficient at using the stored energy to glow so they go on longer and the light glows pale green for a while.
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"Incandescent light bulbs have been commonly used in holiday lights until recently. These lights produce a broad-spectrum white light, and are colored by coating the glass envelope with a translucent paint which acts as a color filter. Some early Japanese-made lamps used colored glass.\n",
"Film and TV production... |
can anyone explain if there is any actual valuable take-away from schrödinger's cat? or just an abstract thought experiment? | Firstly, the 'answer' to the Schrödinger's Cat thought experiment is not agreed upon. We simply don't have a universal answer to what actually happens. If you read the Wikipedia page, you get a short list of what the different interpretations on quantum mechanics say. It's not like actual physicists have one opinion and outsiders have another. Actual high level physics professors don't agree.
Okay. When quantum mechanics came around it was realized it said really absurd things about tiny particles. You couldn't know whether a particle was here or there. In fact, it's even worse. It seemed like the universe hadn't decided yet. When you actually looked directly at the particle, it suddenly seemed to be only at one place. Einstein was extremely upset and said that he may not know what God thinks, but God surely doesn't play dice with reality(he was talking metaphorically about God).
It's somewhat okay to accept these weird things about tiny particles. I mean, we can't really see them anyway. But what Schrödinger pointed out was that that's a mistake. He thought, what is true of the small must also be true of the large. And to illustrate this he came up with his cat experiment. If a particle's position can be at different places at the same time, why can't a cat be dead and alive at the same time? His experiment poses exactly that question. What is the physical mechanism that allows weirdness at the small scale, but not the large?
As I said, this is actually unresolved and there are a number of different possible answers. All of them really absurd.
_URL_0_ | [
"A variant of the Schrödinger's cat experiment, known as the quantum suicide machine, has been proposed by cosmologist Max Tegmark. It examines the Schrödinger's cat experiment from the point of view of the cat, and argues that by using this approach, one may be able to distinguish between the Copenhagen interpreta... |
Should the Chinese Emperors' mausoleums be excavated? | That's a very hard question to answer and honestly - I am
Not quite sure if I am qualified for it. Especially not for the imperial tombs in china.
What I can answer is what happens if things get done too fast, without a clear preservation plan and without a clear idea of what you want to achieve.
I am from Vienna and I studied art history there - and my dad was an archeologist at the Vienna city museum.
During his job he oversaw the excavation of Michaeler Platz (Michaeler square) if you have ever been in Vienna you can't really miss it since it's right in front of the Hofburg.
This is what it looks like : _URL_0_
So the square has quite an interesting history , with buildings from roman times , the Middle Ages and the old imperial theater being located there - and when a new subway line was built they excavated part of the square in the course of the construction.
They found some frescos on the medical buildings - the city wanted to have them displayed in Situ - my dad wanted to cover it up completely or at least transfer the Freskos to a safe spot.
Politically the city won - and the result is that the frescos are basically gone and the ruins are falling more and more into ruin every year since they are exposed to the weather year round.
And the can't really cover it up and keep it visible since this would destroy the sight of the Hofburg from
The Kohlmarkt which is a famous view of the Hofburg itself.
So basically even on a very small excavation, in a very rich city, preservation was not done as it should have been done and the buildings are falling apart more and more.
And I think that this is one of the lessons the Chinese learned from a lot of similar projects in Europe - that you need a perfect plan, a perfect idea of what to do and goals and to have the means (both in money and technology) to achieve those goals.
And as long as they are not 100% sure that they can conserve whatever they find in the tomb they won't dig it up - the risk is basically to high for them.
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"The eighteen mausoleums of the Tang Dynasty emperors (唐十八陵) in the valley of the Wei River north of the Qin Mountains(秦岭). Most are natural hills shaped by man, and they are among the biggest Chinese mausoleums, such as Qianling (乾陵), joint tomb of Emperor Gaozong of Tang and of the Empress Wu Zetian. Some mausole... |
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