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What's the deal with Hugh Everett's "Many Worlds Interpretation"- is this taken seriously? | > is this another one of those "Yes, that's another way of looking at the math, but it has no bearing on reality" things?
Right now it is. It has no bearing on anything testable. | [
"There is a wide range of claims that are considered \"many-worlds\" interpretations. It was often claimed by those who do not believe in MWI that Everett himself was not entirely clear as to what he believed; however, MWI adherents (such as DeWitt, Tegmark, Deutsch and others) believe they fully understand Everett... |
How long can brain cells live for? | Well, neurons (the cells generally being referred to with the term "brain cells) are only replaced by stem cells, so an animal's neurons are generally as old as it is. From [wikipedia](_URL_0_), the longest recorded lifespan of an animal is around 200 years, so that it is a limit on the lifespan of neurons as well. This is by now means an absolute limit, and they could perhaps last even longer.
If you were referring to how long they live for without oxygen (as occurs in stroke, cardiac arrest, asphyxiation etc), then that is on the order of ten minutes; this can vary however, with hypothermic conditions often times extending the time that neurons can survive without oxygen. | [
"Another interesting feature of the hybrot is its longevity. Neurons separated from a living brain usually die after only a couple of months. However, due to a specially designed incubator built around a gas-tight culture chamber selectively permeable to carbon dioxide, but impermeable to water vapor, reduces the r... |
why do so many people wiggle their feet to fall asleep? what exactly's happening there? | I've never heard of this, but I assume it would give your mind something benign to focus on instead of thinking of things that may induce anxiety or other emotions that may keep you awake. Similar to the classic idea of counting sheep. | [
"Rises and falls of the body is a natural phenomenon during casual walking: when feet are apart the body is closer to the ground than when the feet are together. Some dances, e.g., Charleston, exaggerate this natural \"bobbing\", while in many others bobbing at each step is considered to be bad style or lack of pro... |
Why do we hear a difference between good and wrong notes/tones in music? | A musical pitch is just the sound waves resonating at a certain frequency. So for example, middle A is a sound wave with a frequency of 440 Hz.
If you play two notes at once, the ratio between the two frequencies will determine whether you perceive it as consonant or dissonant. Basically, small whole number ratios will sound consonant to us. So an octave (low A to middle A) will have a frequency ratio of 2:1. A fifth (A to E) will have a ratio of 3:2.
On the other hand, a diminished fifth, the interval that is (geometrically) half an octave, will have an irrational ratio of the square root of 2 to 1. This interval sounds very dissonant to us.
(This is a slight oversimplification, because pianos etc are generally tuned evenly to allow us to change keys in a song. This means the actual ratios you hear are a small bit off from the small whole number ratios, but close enough that it is very hard to perceive a difference.)
This explains it pretty well:
_URL_0_ | [
"The highest notes can have a shrill, piercing quality and can be difficult to tune accurately. Different instruments often play differently in this respect due to the sensitivity of the bore and reed measurements. Using alternate fingerings and adjusting the embouchure help correct the pitch of these notes.\n",
... |
why does software like itunes tell me "an unknown error occurred" and then give me an error number which obviously means the error is known? | Did you look up the code? Because there is a code for "Unknown error." It's what you get when none of the other known error codes match. | [
"The error messages has been described as being an example of poor user interface design. For most users, if the message appeared, the only choice was to hit 'R'—which repeated the message—or hit another letter, which caused the program to crash and all work to be lost. One scholar described it this way:\n",
"An ... |
what is instantaneous frequency? | Let's you were playing a trombone, moving the slide to constantly change the frequency of the notes.
The instantaneous frequency would be the note your were playing at any given moment in time. If I grabbed your slide and stopped it from moving, it is the note you would keep on playing. | [
"Instantaneous phase and frequency are important concepts in signal processing that occur in the context of the representation and analysis of time-varying functions. The instantaneous phase (also known as local phase or simply phase) of a \"complex-valued\" function \"s\"(\"t\"), is the real-valued function:\n",
... |
Can anyone help identify the ribbons and branch of service of my South African ancestor? | Thanks to a tip elsewhere, I think the cap badge might be from the 1st Infantry Brigade from the Union of South Africa. If that helps narrow the possibilities, Wikipedia says they served in Egypt and on the Western Front.
Could the third medal then (from the left) be a French Cross/Croix de Guerre? I was looking all through British and South African medals and decorations, and never thought to look for awards from foreign powers.
| [
"Robert H. C. (Bob) Kershaw (died 6 May 1998) was a fighter pilot and later businessman of South Africa, notable as the first South African recipient of the Distinguished Service Order in World War II, for his daring rescue of downed squadron leader John Frost.\n",
"In 1906, King Edward VII gave the HAC the disti... |
Why are Art History departments in colleges usually separate from History departments? | Someone studying art history would need to study history as well because historical context matters in studying works of art. However, it is more about the development of art than purely history. The difference between an art program and an art history program is similar to the split in many English departments--you have a creative writing track and a literature track. One is focused on creating literature, the other is focused on studying the historical development of literature. | [
"The School of Art + Art History + Design is an undergraduate and graduate school in the Arts Division of the College of Arts and Sciences at the University of Washington. Formally known as the University of Washington School of Art, the institution is divided into three major departments, with the design departmen... |
Is it true that Milan was relatively unscathed by the Black Death? How, as a major center of trade, were they able to manage this? Did they take any pro-active steps to spare the city? | You are probably referring to the Black Plague of 1348; this plague outbreak (the first in Europe identified as the Bubonic Plague) is estimated to have killed up to 40% of Europe's population, but only 10% of the population of the Italian city of Milan. I'd first point out that subsequent plague pandemics, notably that of 1629 - 1633 which was immortalized by the 19th century novelist Alessandro Manzoni, did have an enormous and devastating impact on the city of Milan. Indeed, modern examinations reveal that the Black Plague seemed to reappear (with varying severity) in intervals between 6 to 12 years, and the city of Milan was not spared by these reappearances. In fact, plague recurrence was one of the reasons plans for the *Lazzaretto* hospice in Milan, named after both St. Lazarus and its architect (nomen omen), were drawn up in the mid 15th century, and I touched upon the milanese *Lazzaretto* as well as other forms of hospice care in Italy [in this older answer](_URL_0_) which you might be interested in.
The Milanese response to the 1348 plague, managed by the city's monarch Luchino Visconti, was aggressive and, according to apocryphal evidence, less than humanitarian. A possibly apocryphal explanation circulating in some medical histories would have it that Luchino had the sick walled in their homes with their family members. Some accounts would have it that they were left to asphyxiate, while others would have it that some windows were left open, through which they could also be provided food by caring neighbors.
More well-documented are the claims that Luchino Visconti halted outside people and goods from entering Milan in 1348. Luchino fortunately had a few month's head start on the pandemic's arrival to formulate a plan. Indeed, the plague's first appearance on the Italian mainland was in Genoa in 1347, where grain shipments from Crimea had probably brought the plague in the early fall. Luckily for the Milanese, the convoys carrying that summer's grain harvest arrived just as Autumn rains muddied the roads over the Ligurian Apennines.
Milan is very much a city of the Padan Plain (at the time, the city was less than a day's travel from the alpine foothills, but several days from the sea in any direction). Thus Luchino's administration was afforded precious time to devise a plan as the disease erupted in Italy's maritime entrepôts: after Genoa, the disease appeared in Venice and Pisa. A combination of disrupted Milanese relations with the northeastern river-routes (more on that later) as well suspended economic activity thanks to the fall harvest bought the Milanese precious months, as the trickle of travelers who did arrive from Genoa and Pisa brought increasingly dire news of the pandemic.
Lucchino's decision to isolate Milan is actually not as audacious as it might first sound: Lombardy is crossed by waterways, and Milanese territories could be effectively isolated by closing the bridges at Pavia, Piacenza, and Crema, all of which had fallen under the yolk of the Visconti over the course of the past century. River traffic could likewise be stopped at Piacenza, or further upriver at Cremona.
Of course, fords and minor bridges over the Serio and Ticino were more difficult to police, but Luchino was an energetic and merciless ruler who had never let small inconveniences stop him (past inconveniences that had failed to daunt him included foreign armies and aristocratic rebellions). Born into a cadet branch of the plenipotentiary Visconti dynasty, he had initially dedicated himself to military service for the Milanese *comune* and was only elevated to the lordship by the city council (in tandem with his brother, the archbishop Giovanni Visconti) upon the death of his nephew Azzone under somewhat fortuitous circumstances: Azzone, sick with gout, had dispatched Luchino as *condottiero* of Mlan's forces to meet the Veronese at Parabiago in 1339 (at the time, the Scaligeri of Verona at the time were the Visconti's main rivals in northern Italy). The defection of important Lombard aristocrats to the Veronese had made victory somewhat improbable, but following his victorious return to Milan, the city council saw little choice but to elevate Luchino to the city's lordship once disease sent Azzone to an early death.
Luchino's rule was ferocious and tyrannical, dispensing cruel revenge on the aristocratic factions which had defected to the Veronese, in addition to anyone else suspected of opposing his rule (this included three of his own nephews, who barely fled Milan with their lives). Luchino also aggressively secured Milan's borders, seizing Parma from the duchy of Ferrara to the south and seizing terretory as far west as Cuneo. Thus Milanese state was one of the most militarized in Italy (and probably in Europe) under Luchino Visconti, with sycophants placed in town councils all over the north of Italy, and a despotic ruler who had spend the better part of the past decade making himself unassailable.
When, in first months of 1348, Luchino instructed his sergeants to bar bridges and waterways, these measures were not meant to protect the whole of the Viscontean domain, nor were they meant to protect Lombardy. They were studied to protect the city of Milan, the city's aristocracy, and the city's ruling dynasty.
The state, such as medieval Italians understood it to exist, could be simultaneously democratic and despotic. Even under the harshest conditions of military occupation, Italians never outright dismantled local councils and institutions; rather, only those politicians who were recognized as being most unsympathetic were removed from positions of power (in the best of cases). But there was never any question question that what was occurring was a subjugation. This meant that in times of prosperity, agreements of subjugation would have subject communities render taxes and produce to their overlords. In times of war, they might have to provide fighting men, or war materiel like arms and armor. In times of pestilence, they were fundamentally left to their own devices.
Luchino was thus disinterested in the fate of Pavia, Novara, Varese, Lecco, Como, and Monza, even though they were cities which for centuries had entwined their economic, social, and political fate with Milan. Local councils could try to enact quarantine measures analogous to those in Milan, but lack of a fearsome figure like Luchino meant that these efforts were often difficult to enforce.
Thus at strategic bridges, crossroads, and canals, Luchino's goons kept an eye out for foreign goods, foreign foods, and foreign accents.
Luchino's system was far from perfect. Foreigners, possibly asymptomatic carriers of disease, only needed to make it as far as the countryside from which the city was supplied in order to transmit the plague to people who would find their way to the city. By the end of 1348, there were some estimated 15000 victims in Milan, a disaster by any perspective. But seeing that the city had a population of 150000, the Milanese got off much easier than the Genoese or especially the Venetians, which is estimated to have lost as much as 60% of its population.
Another, more modern assessment of the first wave of the black plague would have it that the Milanese were also able to prepare in another significant manner: Much like the characters of Boccaccio's *Decameron*, those Milanese who had means to do so left the city.
No city can exist without its hinterland, that much is certain. But perhaps no other city in Europe, and certainly no other city in Italy, existed in such intimate contact between town and country as Milan did. While in much of the rest of Italy (except maybe in Venice) great urban dynasties could retreat to country estates, Milan also hosted an influx of countless seasonal or temporary workers who travelled to the city from their more permanent homes country. Further, all across the social ladder professional and familial units could stretch across a multitude of towns and cities of the Lombard plain. In short, the slow moving rivers and flat plains of Lombardy had created a web of interpersonal and economic relationships with Milan at its heart. As word spread of the devastation in other parts of Italy, people reversed course across that same web, and the Milanese depopulated their city before the disease crept up the Po and over the Apennines.
So in summary, Milan had a head start. Benefitting from being deep in the Italian mainland, word of the disease arrived before the disease itself. The city's ruler was willing and able to be ruthless in order to take advantage of that head start, while the city's residents also left the city for more isolated communities in the countryside if they could. | [
"The Black Death devastated Venice in 1348, and once again between 1575 and 1577. In three years, the plague killed some 50,000 people. In 1630, the Italian plague of 1629–31 killed a third of Venice's 150,000 citizens. Venice began to lose its position as a center of international trade during the later part of th... |
my iphone is 32 gb. it says i have 22.5 used gb and only 5.2 gb left, why is this. | Apple pre-loads the device with things like the operating system and apps. It has about 32GB storage before they load it. | [
"Since introduction in 2011, each account has 5 GB of free storage for owners of either an iOS device using iOS 5.x or later, or a Mac using OS X Lion 10.7 or later. Users can purchase additional storage for a total of 50 GB, 200GB or 2TB. The amount of storage is shared across all devices per iCloud Apple ID.\n",
... |
why do most helmets have a bunch of gaps? | For ventilation and weight reduction.
Sports helmets don't need to be maximally strong.They're plenty strong enough to do their job, so it's safe to make some holes in them to reduce weight and improve ventilation and comfort. | [
"The main reason for the development of the MICH was due to the protective but heavy PASGT being supplanted by these bump helmets by special forces operators due to them being lighter, more comfortable, closer-fitting, and made of plastic making them easier to mount accessories onto, especially night vision devices... |
what is a stable star? | There is an online game about horses called Star Stable.
Mister Ed was a TV show about a talking horse, so he was a stable star.
There was a groupie in the '70s named Sable Starr.
You're going to have to give some context to that question. | [
"Compact stars are often the endpoints of stellar evolution, and are in this respect also called stellar remnants. The state and type of a stellar remnant depends primarily on the mass of the star that it formed from. The ambiguous term \"compact star\" is often used when the exact nature of the star is not known, ... |
Why are there natural grassy 'fields' with no canopy layer? | There's a lot of conditions that could cause that. In the Ozarks there are places like that called glades. These glades are formed over variable depth soil that can't support the growth of trees. If you don't do anything to these places they do tend to get overgrown by shrubs and other tree species that can handle the conditions. In many cases, these glades are kept open by fires. In a more alpine or mountainous situation, those openings are probably pretty transient and might be the result of big fires that came through and destroyed most of the vegetation, or they're the result of periodic flooding that knocks back many of the shrub or tree species.
In short, glades often result from disturbances such as fires or avalanches or poor soil conditions. | [
"A meadow is an open habitat, or field, vegetated by grass and other non-woody plants. They attract a multitude of wildlife and support flora and fauna that could not thrive in other habitats. They provide areas for courtship displays, nesting, food gathering, pollinating insects, and sometimes sheltering, if the v... |
what is donald trump's platform? | He literally doesn't have one.
I recently read somewhere (can't remember where, sorry) how political reporters covering him are getting frustrated, because they try to find policy statements for background that are standard issue for candidates, and it simply doesn't exist for Trump. He is just making it up as he goes along. | [
"Trump makes his case for why he would be an effective leader of the United States, and reassures Republicans that he upholds conservative values. He criticizes the media's coverage of him while defending his decisions on the campaign trail. \"Crippled America\" stresses that the United States needs to start \"winn... |
In electricity, where does the flow of electrons actually come from? | The electrons were already in the copper, before the turbine started spinning. They were drifting between the atoms of copper. There's no damage, because the electrons just go back and forth. A typical speed might be 0.02 millimeters per cycle, at 50 cycles per second. Even if the current is DC, the electrons go around in a loop, from the turbine out to your house (for example) and back again. The slow drift speed is tiny compared to the average electron speed from its internal energy. | [
"In classical electromagnetism electrons move in the opposite direction of the current (by convention \"current\" describes a theoretical \"hole flow\"). In some semiconductors it \"appears\" \"holes\" are actually flowing because the direction of the voltage is opposite to the derivation below.\n",
"When electro... |
Why are popular depicted byzantine pieces of art less realistic than counterparts from the roman empire? | > Since the byzantines inherited much of the roman culture **one would expect** the art to have sustained the realistic depictions of known ancient artwork.
Why? There are a lot of assumptions packed into your question. Roman portraiture, especially imperial portraits, were not realistic. It was strongly *idealized* to present an Emperor as semi-divine. Now there was a period where hyperrealistic sculpture was popular during Republican times, maybe an art historian can elaborate. And it resulted in images [like this](_URL_3_) with "warts and all" in vogue. But all the depictions of Caesar Augustus we have, who died at 75 after a 40 year reign, look like [this](_URL_4_). He became emperor in his mid 30s, he probably didn't look so youthful even then. And behold [the sainted Constantine](_URL_1_) with his huge doe eyes gazing placidly up to heaven.
It's not like Byzantine artists weren't capable of producing reasonably realistic depictions. Look at this illumination of an [11th century emperor](_URL_0_), this [12th century mosaic of Mary and an imperial couple](_URL_5_), or this [13th century mosaic of Christ](_URL_2_).
Western art *today* hardly puts a premium on realism despite descending from Rome, too. [This](_URL_6_) is the highest-selling piece of western art of all time. The Western movie isn't an accurate historical depiction of the West, it's a highly stylized and stereotyped mythology of what was in reality a nasty colonization campaign. And one of the most universal touchstones of our culture is a story of telekinetic space-knights who defy all the laws of physics and astronomy to fight a star war like World War II dogfighters. | [
"Byzantine art has been compared to contemporary abstraction, in its flatness and highly stylised depictions of figures and landscape. Some periods of Byzantine art, especially the so-called Macedonian art of around the 10th century, are more flexible in approach. Frescos of the Palaeologian Renaissance of the earl... |
How much do you think Alexander the Great's success was due to his father? | I think what we see today regarding the credit given to Philip rather than Alexander is a bit on the revisionist side of the pendulum swing. What I mean by this is for quite a long time we'd all learned what an amazing human being Alexander was, who did all of these incredible things through sheer force of personality and brilliant intelligence. More recently we've seen a batch of people crop up who claim that Alexander wasn't anything special; he was a sub par commander at best who was handed a legacy by his far more skilled father. This truth is likely somewhere in between;
The Greek cities - Yes, by the time Philip was assassinated he had subjugated essentially all of the Greek cities. This made Alexander's job easier, but not a cake walk. Many of the cities considered revolt (Thebes actually did revolt) following Philip's death and it was through Alexander's political and military prowess that he was able to keep this from happening. Philip was also responsible for the Hellenization of the rougher and previously less 'civilized' highland tribes, a trend which Alexander continued.
The troops - This is most certainly where Philip can be almost wholly attributed. Alexander was handed one of the best trained armies in the world which Philip had just spent considerable time reforming. This included the use of a much longer spear used by his phalanx troops and the creation of the companion cavalry (some of the best cavalry the west had ever seen). He also created units of a sort of commando type shield bearers who had the duty of protecting the phalanx's flanks as well as other less specified duties. He skillfully incorporated archer and skirmisher mercenaries into his army and finally introduced something like a proto-ballista into Mediterranean warfare.
The Persian invasion - Yes, Philip had plans to 'liberate' the Greeco-asian cities from Persian rule and likely had concrete ideas of how he was going to accomplish this but even still, the invasion was left in the hands of Alexander and a cabal of skilled generals. Alexander almost certainly wouldn't have followed an exact template set by his father and definitely had to work out his own lines of attack and invasion policies. One interesting example; Alexander is known most famously for having marched his armies to the edges of the world however he was probably better known in his own time as an expert in siege warfare. He managed to deftly conquer some extremely well fortified Persian cities and this was obviously the work of Alexander alone and had little to do with this skills of his father.
I hope this gives you some idea of the relationship between the two. | [
"Alexander the Great (356BC-323BC) was a Greek king of Macedon and the creator of one of the largest empires in ancient history. He was tutored by the philosopher Aristotle and, as ruler, broke the power of Persia, overthrew the Persian king Darius III and conquered the Persian Empire. His Macedonian Empire stretch... |
have we not yet found a scientific proof of homosexuality in humans? | My favorite come-back to "it's a choice" is "let us assume it IS a choice. Why the fuck do YOU care?" | [
"In February 2014, the Indian Psychiatric Society (IPS) issued a statement, in which it stated that there is no evidence to prove that homosexuality is unnatural: \"Based on existing scientific evidence and good practice guidelines from the field of psychiatry, the Indian Psychiatric Society would like to state tha... |
what kind of people are on the committees for major awards like the oscars and how does someone get appointed to the committee? | You can't apply, you have to be invited. If you work in the film industry in some capacity and your work has been critically acclaimed they'll invite you into one of the categories. It's the same categories you win awards for so actors, actresses, directors, set designers, writers, hairstylists- they all have their own group. Lately there's been a bit of a push to diversify because it's so predominately white men over the age of sixty. Unfortunately it's a body made up of thousands and you stay in for life so it's hard to change the demographics until people start dying.
Here are some articles from Variety that have the new members listed:
[2014](_URL_1_)
[2013](_URL_0_)
Edit: It's also important to remember the Oscars are only one thing the Academy does. They also work in film preservation and history, provide scholarships and grants for young filmmakers, work for better women/minority representation in the industry (they do a horrific job of it, but they do), and a more. The official mission is to advance the art and science of film. They started the Oscars in the '30s as a way to legitimize film as an art form and not just an entertainment. The idea was that they could reward films that didn't make a huge amount of money but deserved praise, so people would take it seriously like literature, painting, music, and theater. | [
"In July 2017 the Academy of Motion Picture Arts and Sciences (AMPAS, also known as simply the Academy), invited Kunuk to become a member. The Academy, which has almost 7,000 motion picture professionals as members, is known internationally for their annual Academy Awards, the Oscars. In 2017 they invited 774 new m... |
Why do lightbulbs need so much "free space" between the filament and the glass? | The bulb is filled with an inert gas (usually argon) that does not react with the filament. Throughout the bulb's life time, oxygen slowly seeps into the bulb, and once it passes some threshold, there is enough oxygen for the filament to oxidize and break, which causes the light to go out.
Therefore, with a large bulb volume, you increase the amount of oxygen that must enter the bulb volume (i.e. increase the life time) before there is a high enough fraction of oxygen to react with the filament. | [
"In contrast to radio frequency waves used by Wi-Fi, lights cannot penetrate through walls and doors. This makes it more secure and makes it easier to control access to a network. As long as transparent materials like windows are covered, access to a Li-Fi channel is limited to devices inside the room.\n",
"Becau... |
What was the historical Western response to terrorism prior to the 20th century? | Not an answer just a note that terrorism is a slightly modern term. The example you ask is either piratry (if the ship was working independently) or a act of war (if the ship was state-sponsored in its acts).
You'd have to define to terrorism before we can get a proper argument going.
This is a good question however and the incident that springs to mind is that of the gunpowder plot. Hopefully actual historians chime in as I'm curious as well. | [
"During the Cold War, especially in the 1970s, West Germany experienced severe terrorism, mostly perpetrated by far-left terrorist groups and culminating in the German Autumn of 1977, the country's most serious national crisis in postwar history. Terrorist incidents also took place in the 1980s and 1990s. Some of t... |
why does white look pink after coming inside on a bright day? why does white look blue on a camera? | It's all about white balance. White, unfortunately, isn't white. It's made up of a lot of different colors in combination so that it looks white. But there are lots of ways to subtly change what "white" is - and when you see two different "whites" together, it's easy to see that one may look pink while another looks blue.
So when you're out in the sun, your eyes get used to that particular white balance. Your eyes are really awesome at adjusting to different colors - you can tell what's green and what's red even if it's in daylight, shade, cloudy, etc. But it takes a short while for your eyes to adjust to a new white balance.
Your camera, on the other hand, doesn't know that leaves are supposed to be a particular shade of green - you have to manually input a white balance into your camera. Sunlight, shade, fluorescent lights, and incandescent lights all have different white balances, and there are different settings for each one. | [
"White is the lightest color and is achromatic (having no hue). It is the color of fresh snow, chalk, and milk, and is the opposite of black. White objects fully reflect and scatter all the visible wavelengths of light. White on television and computer screens is created by a mixture of red, blue and green light.\n... |
How can vegetarian animals be so similar to carnivore physically? | Herbivores have the ability to digest more plant matter, and get various nutrients that omnivores and carnivores can't. Herbivores can make certain proteins, while carnivores can't, so the carnivores eat the herbivores to get the proteins that they make.
That's as simple as I can put it. | [
"\"Carnivore\" also may refer to the mammalian order Carnivora, but this is somewhat misleading: many, but not all, Carnivora are meat eaters, and even fewer are true obligate carnivores (see below). For example, while the Arctic polar bear eats meat almost exclusively (more than 90% of its diet is meat), most spec... |
how is it that microscopes can see through an organism? | The microscope focuses on a very thin plane. Everything above and below is blurred out. So as long as light is getting through then you can see an image.
If you think about it, MRI's get their pictures the same way. One layer is in sharp detail. Every thing else is taken out.
I never tried to do anything but sex a fruit fly with with a microscope. It was a dissecting scope which was different.
But most of the time microscope images are transmitted light modified by the organism viewed. Thin slices are used to view bacteria. The slide is generally stained first to enhance detail. You can also view with reflected light. | [
"A microscope (from the , \"mikrós\", \"small\" and , \"skopeîn\", \"to look\" or \"see\") is an instrument used to see objects that are too small to be seen by the naked eye. Microscopy is the science of investigating small objects and structures using such an instrument. Microscopic means invisible to the eye unl... |
what is reactive power and how is it different from active power ? | There are some mathematical definitions of AC power, active power and reactive power - but they mostly require knowledge of complex numbers which i won't go into (unless someone wants me to).
**Definition of power**
Let us start with the definition of power in a component:
Power = Voltage * Current
A positive value of power means that the component draws power out of the circuit while a negative value means that the component adds energy to the circuit.
In AC-circuits both voltage and current can be described by a [sine-wave](_URL_1_) with some frequency, amplitude and phase. As the sine-wave varies over time the power in the circuit won't be constant. The power depends on the component.
**Power in a resistor:**
In a resistor both voltage and current can be described by sine-waves with the same frequency and phase (but not necessarily the same amplitude). If we multiply these two sine-waves with eachother we get [another sine-wave](_URL_2_).
This sine-wave will be positive at all points - meaning that a resistor can only draw energy from the circuit and convert it to heat.
**Power in a capacitor:**
In a capacitor the voltage and current can be described by two sine-waves with the same frequency and a phase offset of 90 degrees. If we multiply these sine-waves with eachother we get [another sine-wave](_URL_0_).
This sine-wave will oscillate between positive and negative energy - meaning that the capacitor alternate between drawing energy from the circuit and delivering it back. It will store the energy in the form of an *electric field*.
**Power in an inductor**
The current and voltage in an inductor can be described very much like in the capacitor (the phase offset is in the other direction this time). This means that the inductor will also alternate between drawing energy and delivering it. In this case the energy will be stored in a *magnetic field*.
**AC-power**
In reality capacitors and inductors will not store 100% of their energy but will convert a small amount of energy to heat. They can therefore be modelled as being in series with a resistor.
The power which is drawn out of the circuit is called the active power while the take-and-deliver-power is called the reactive power.
I hope this shed some light on the subject. | [
"Reactive power is the name given to unusable power. It does no work in the electrical system, but is used to charge capacitors or produce a magnetic field around the field of an inductor. Reactive power needs to be generated and distributed through a circuit to provide sufficient real power to enable processes to ... |
Is there any benefit to being lighter skinned in colder climates? | Usually colder climates have less sun. Even if not, people cover up. Lighter skin helps people make more vitamin D with less light, so it is a survival thing for places where skin is more covered up or there is less sun. | [
"Other important factors of environmental factors include climate and disease. Climate has effects on determining what kinds of human variation are more adaptable to survive without much restrictions and hardships. For example, people who live in a climate where there is a lot of exposure to sunlight have a darker ... |
Why are microphones so much smaller than speakers? | You don't need the full length of a wave to pick it up. The physics behind it can be complicated, but basically there is a piece of metal between magnets and the flux of the metal as it move in the pressure wave creates a voltage in the magnets. This voltage can be very small, as long as it's measurable. Once it's measured you can boost it up much higher so that you get a better signal with more power.
Speakers on the other hand need to expel lots of power, the exact opposite of a microphone. The best size to transmit a wavelength with is (I think) 1/4*wave-length. Speakers which make high frequency noise (tweeters in your car) are usually very small so as to best meet the optimal size or the transmitter. Your mid's are usually a little larger than tweeters. Subwoofers are usually large; the best size for a 30Hz frequency is something like 11m. Since that's HUGE, we up the power going to the subwoofer to overcome the losses.
So speaker size depends on what type of sound you are trying to get out of it due to how they physically operate. Microphones do not really matter on their size, but their sensitivity to pressure waves. Since being very large doesn't make the microphone more sensitive it doesn't matter, while different sizes allows speakers to create more efficient (and hence louder) sounds at different frequencies. | [
"While a large loudspeaker is naturally more directional because of its large size, a source with equivalent directivity can be made by utilizing an array of traditional small loudspeakers, all driven together in-phase. Acoustically equal to a large speaker, this creates a larger source size compared to wavelength,... |
what is the mad cow disease? why can humans get it? | I'm sorry to hear about your friend.
Bovine Spongiform Encephalopathy (mad cow disease) and the version humans get (Creutzfeldt-Jakob disease) are both caused by a "corrupted" or misfolded version of a certain protein that both cow and human cells make, called the prion protein (PrP). The disease doesn't spread as a virus or bacteria, your body puts proteins together by using existing versions as template. If that template is corrupted, the new copies are corrupted too.
In the nervous system, misfolded PrP sticks together and grows into fibrous masses, destroying and displacing cells.
| [
"Bovine spongiform encephalopathy (BSE), also known as \"mad cow disease\", is a fatal brain disease affecting cattle. It is believed by most scientists that the disease may be transmitted to human beings who eat the brain or spinal cord of infected carcasses.ref name=\"FDA/CFSAN\"\n",
"Cattle diseases were in th... |
what causes ‘the zoomies’ in animals? | Children do not get hyperactive from ingesting sugar. If they become more active than before, it's because their blood sugar was LOW, before.
If high blood sugar made people hyperactive, diabetics would be the most physically active people on earth, which is the opposite of what is observed.
If your family members " sometimes lose their marbles and run around wide-eyed and crazy-pants? " then they are, indeed, crazy. | [
"Plumb traveled to over sixty zoos in the US and Europe, filming captive elephants exhibiting what biologists refer to as stereotypy, a behavior only seen in captive animals, which includes rhythmic rocking, head bobbing, stepping back and forth, and pacing. This compulsive movement is a coping mechanism for stress... |
Lobsters have blue blood due to a lack of haemoglobin. How do they transport oxygen around their body without it? | They have proteins called hemocyanins, which do the same thing, in essentially the same way. The active site uses copper instead of iron, so it's blue instead of red. | [
"Lobsters, like snails and spiders, have blue blood due to the presence of hemocyanin, which contains copper. In contrast, vertebrates and many other animals have red blood from iron-rich hemoglobin. Lobsters possess a green hepatopancreas, called the tomalley by chefs, which functions as the animal's liver and pan... |
How do Tesla Coils make sound? | It makes sound in a manner similar to lightning - what a Tesla coil is doing is overcoming the breakdown resistance of the air and ionizing it, allowing the air to briefly become a conductor. This process causes the air to heat up and expand, and, in a single-spark scenario, makes the audible 'crack' you associate with a particularly bad static shock. A Tesla coil does this many, many times per second (it's AC, after all) and, by carefully controlling the frequency of these discharges, you can create a tone in the air via rapid thermal expansion and contraction. Pretty neat, huh? Actually, since the discharges from Tesla coils aren't all that regular, Tesla coils usually don't make great speakers - but there are devices called plasma speakers that use similar principles, namely, using thermal expansion of the air to create sound, and they are prized for their very good linearity at high frequencies. | [
"Tesla coils can also be used to generate sounds, including music, by modulating the system's effective \"break rate\" (i.e., the rate and duration of high power RF bursts) via MIDI data and a control unit. The actual MIDI data is interpreted by a microcontroller which converts the MIDI data into a PWM output which... |
Can plasma only be made out of specific elements? Do the properties of the source elements influence the behavior of the plasma? | Just an educated guess, but since no-one's answered yet...
Plasma is just a more "energized" state than gas.
Heat up a solid, it turns liquid, heat that up, it turns gas and then even more to plasma.
But with the increase of energy, chemical reactions come into serious play.
As the energy of an atom increases, it tends to bump electrons to a higher energy state, ultimately discharging one or some.
This leaves the atom "vulnerable" to bond with other surrounding atoms; this produces heat -not always though- and lowers the now-molecule's energy, not letting it become plasma.
Inert --or noble-- gasses, have the tendency of being quite solitary; they don't bind with other elements. I assume that is the reason they are used as a primary plasma "source".
Now wait for a scientist to come around and rub my face in the mud. | [
"A plasma is any gas in which a significant percentage of the atoms or molecules are ionized. Fractional ionization in plasmas used for deposition and related materials processing varies from about 10 in typical capacitive discharges to as high as 5–10% in high density inductive plasmas. Processing plasmas are typi... |
back in 2005 my speakers would always do a little bark before i got a text message, but not anymore. why did this happen and what changed? | The phone used 2G GSM(or another similar system) in 2005 and today you are likely using 4G
2G GSM Time-division multiple access to share a channel with 8 or 16 other cellphones. That mean that is transmit in short burst and the stopped tramsitting. There was buliple burst per second and it those burst that was picked up by the speaker.
Later standards uses Code-division multiple access among other thing and then the cellphone will send the whole time but how the signal is shaped lets the tower to determine the signal from each cellphone.
The continual transmission will not induce sound in the speakes | [
"Listeners complained when transmission ceased in 2005. In 2008, the transmission was reported in the press as gaining more attention than the spoken-word programming of Oneword, and even of attracting half a million listeners.\n",
"Because the communication over telephone lines did not use any kind of error corr... |
Were there eastern parallels to "Orientalism" at the height of eastern empires' powers? | I'll try to answer your question, sorry if it doesn't satisfy you. I will focus on the Ottoman Empire, though mostly on the 19th century so not really a time of 'height'
We can see the judgement and views of Western Europe from travelogues made by Ottoman men who traveled there. These travelogues contains curiosity, accompanied with occasional religious rancor but with no accompanying sense of inferiority, disdain, or envy. Travelers to Europe from the Ottoman world who wrote travelogues from the 17th to the early 19th century never fail to notice the sexual, social, and gender differences, and seem to be intrigued by them, but no sense of surprise is evident, and no fantasies are evoked by such sights. If such reactions exists, it was mostly on lower emotional scale and only present on very early travelogues. This less fervent appraisal of Europe by Ottoman travelers probably had to do with the fact that inhabitants of most Ottoman urban centers were closer to Europe and had centuries-long commercial and cultural ties with the West. Though more cautious about public displays of unveiled women and mixed company than in Western Europe, inhabitants of the European quarters of Istanbul and similar areas in other commercial cities such as Izmir, Aleppo, Alexandria and Salonika did not always conform to Ottoman Islamic social codes. For the Ottomans the European West was alien, yet far more familiar and ubiquitous. For example, during his travel to France in the early 18th century Yirmisekiz Celebi Mehmet Efendi recorded rather positive observations. He was certainly aware of cultural differences, and he refers to strange eating habits and to the frequent presence of women in the public sphere, yet he remarks on them with a certain humor and detachment, without any connotation to sexual promiscuity or gratification. Although some of the customs he encountered were anathema to an Ottoman member of the elite, he adapted himself to them with relative ease and portrayed himself as a gallant French gentleman.
However, starting in the mid 19th century, this perceptions changed. With the spread of printing press and mass printing of travel literature, Europe was now viewed as a locus of dynamic change and as a powerful rival and little by little an "Occidentalist" counter-discourse evolved, which attempted to unravel the experience of travelers and to demonstrate Europe’s dark side as well as its possible contribution to Ottoman culture. With the printing of European travelogues, Ottoman readers were shocked when looking in the mirror set up for them by the Orientalist tendencies of the genre. At the time there are two Ottoman travelogue genre to counter this European discourse and to present an equally valid Ottoman one. First, is an ottoman travelogue on the empire’s own "Oriental" places like the Caucasus and in Central Asia, essentially reproducing the themes of European voyagers, presenting to themselves the strange otherness, the quaint sexual morality, and the backwardness of their own East. Second is to painstakingly demonstrate the moral decrepitude of European culture in contrast to their own high moral standards. The latter was particularly ubiquitous in the late 19th century. For example, Midhat Pasha in his book persistently shows the gap between European superiority in science, technology, and material achievement, and its moral inferiority. Although his descriptions of European social and sexual morality are often self-contradictory, he focuses on the corruptibility of Western women as ultimate proof of Ottoman Muslim preeminence. For example in Vienna he listens to a coffeeshop owner describe the plight of the numerous young "fallen women". The owner said that they come from respectable families, but their fathers and brothers have gone broke or lost their money in card games. The girls, educated and well mannered, leave their houses devoid of any means of existence. They become musicians and singers and even play in theaters and casinos for a while, only to finally "fall to the street", where their only option is prostitution. To this, Midhat cynically commented on how he now understands why European women move far from their home to places like Izmir, Salonika, and Syria.
A similar description of European moral decrepitude also comes the Lebanese modernist Jurji Zaydin and Ottoman officer Mehmed Enisi. Zaydin was so affected by the sight of pervasive prostitution that he reversed his good opinions on European women. He also mentions about foundlings, babies discarded by their mothers. He claims that there are eighteen thousand such foundlings in Paris alone each year, and it is all the result of an excess of liberty and a disdain for religion. Zaydin then warns about the outcome of European modernity and liberalism and to keep their morally superior values. Mehmed Enisi, an Ottoman officer on a military expedition to France describes his dicsussion with the French officer in his travelogue. Strolling on deck, the two soldiers argue about the status of women in their societies. The Frenchman accuses Muslims of imprisoning their women. "Aren’t they bored behind those bars all day long?" he asks. "We call it concealment, not prison", responds Enisi, and goes to great lengths to explain how important women’s role is in the Islamic household, and how much they contribute to educating the children and looking after the house. Having convinced the French officer, he now countered. "Our women," he says, "are protected from misfortunes that French and other women of the ‘free’ world are exposed to.” He talks of French women leaving their houses and running away with strangers, and about prostitution and fallen women. He also brings up the same problem of foundlings that Zaydi mention. "Let’s leave your customs to you and ours to ourselves" he concludes. "Our women find nothing useful in your customs"
Simultaneously with their condemnation of European morality, Midhat and other travelers defended Islam and Ottoman culture against what they saw as a distorted representation of Islamic culture. A scantily dressed dancer appearing as a Muslim Arab at the Paris exhibition infuriates Midhat. In an conference in Stockholm he then criticizes the images of voluptuous harem odalisques, and attributes them to poetic imagination rather than to serious academic research. Muhammad Amin Fikri, an Egyptian traveler while responded rather positively on the Paris exhibition saying that the buildings and bazaars are splendid and he doesn't take much offense to the dancer, he noted how his fellow Egyptian visitors are disgusted and embarrassed by the exhibition. He also criticizes the Europeans for overreacting to the dancers and the dervish dancer for doing what was called "dancing" in such a place, something not appropriate for his order.
However as the result of such travelogues, the Occidentalist reaction drove home the claim about the superiority of local morality. Readers of Turkish and Arab travelogues were convinced that their sexual and moral conduct was something to be proud of. On the other hand, molding morality to fit the new standard presented as superior, necessitated far-reaching changes in attitudes toward sex and sexuality. In other words, while reassuring themselves that their culture was still superior to that of Europe, the travelers, as well as their readers needed not only to find fault with Europe but also to redefine their own morality to fit these new standards, or to create an ethics of sex that was absent from discourse before
**Sources:**
*Producing Desire: Changing Sexual Discourse in the Ottoman Middle East* by Dror Ze'evi
*An Ottoman Occidentalist in Europe: Ahmed Midhat Meets Madame Gülnar, 1889* by Carter Vaughn Findley
*East Encounters West: France and the Ottoman Empire in the Eighteenth Century* by Fatma Muge Gocek | [
"In \"For Lust of Knowing: The Orientalists and Their Enemies\" (2006), Robert Irwin said that Said's concentrating the scope of \"Orientalism\" to the Middle East, especially Palestine and Egypt, was a mistake, because the Mandate of Palestine (1920–1948) and British Egypt (1882–1956) only were under direct Europe... |
what is the difference between inflation and deflation (in terms of currency) and how are they caused? | Imagine a market with one guy selling apples. All the people in his village want apples, so that there is more money than goods. The price of each apple is now 10$. Now a lot of people notice that selling apples might be lucrative so new apple stands are popping up left and righht and every one of them wants to sell their apples. Since there are so many apples now and the demand for apples stays the same each apple is now worth less money, say 5$.
Inföation starts when a country is printing more money than new goods are generated. For our example that would mean everyone now has 10.000$ and only wants to buy apples. Of course our stands figure that 5$ for an apple seems way underpriced now, so they rais their price to 100$. Thats basically inflation.
Mote money generated while not the equal amoount of goods networth is created.
Deflation happens when prices are dropping rapidly. Our 100$ apple is only 90$ the next day and a week after that 70$. People figure they will still keep dropping in price and therefore they wait in spending their money because they will have way nicer deals next week and so on. That is basically the opposite of inflation. Aount of money stays the same while more goods are created. So every penny is now worth more than a dollar last week. | [
"In economics, deflation is a decrease in the general price level of goods and services. Deflation occurs when the inflation rate falls below 0% (a negative inflation rate). Inflation reduces the value of currency over time, but deflation increases it. This allows more goods and services to be bought than before wi... |
how do brands (e.g. audemars piguet, hermes, etc.) get to where they are today? why does their brand cost so much? at which point did people start going 'it's actually reasonable to pay this price for this brand'? | David Lynch once said that the best thing about being wealthy was buying a book at a bookstore and never having to look at the price.
There is a certain level of wealth where the difference between a $20 and $200 shirt is negligible, and they don't have to worry about it.
There is a certain level of pretention where it is worth $200 to you to make people think you belong to that superior socioeconomic group.
Those two groups are the customer base. | [
"Branded products carried include HARIBO in Germany, Knoppers in Belgium and France, Marmite and Branston Pickle in Great Britain; and Vegemite and Milo in Australia. This is usually very strongly branded items, that in the past they have had difficulty in creating a generic version of the product. In the United St... |
Dark matter finally detected? Can anyone shed some light on this? | As a rule of thumb: if dark matter were definitively detected it would be a big enough deal that you wouldn't have to ask reddit. It would be on the front page of the NYT, all the science blogs would be talking about it, etc. This is a possible indicated of dark matter axions, but I would be highly skeptical at this point that much will come of it. | [
"BULLET::::- NASA scientists report that hints of dark matter may have been detected by the Alpha Magnetic Spectrometer on the International Space Station. According to the scientists, \"the first results from the space-borne Alpha Magnetic Spectrometer confirm an unexplained excess of high-energy positrons in Eart... |
enantiomers and how the differ from one another? | Look at your hands. Your left hand is a mirror copy of your right hand. If you position one on top of another, they do not match exactly - because they arent same, they are mirrored.
This is what Enantiomers are - they are basically "mirrored molecules". They have same atoms, in same positions, connected to each other in similar way - except mirrored.
[Here is example](_URL_0_) | [
"The optical activity of enantiomers is additive. If different enantiomers exist together in one solution, their optical activity adds up. That is why racemates are optically inactive, as they nullify their clockwise and counter clockwise optical activities.\n",
"If there is a pair of enantiomers, each with one s... |
the "spin" classification system of particles and atoms | "Spin" refers to how a particle can have momentum without changing its position. A similar phenomena in the visible world is how a basketball can spin in place. That's not exactly what's happening to the particle, but we use the words "spin" and "angular momentum" for lack of better words in our vocabulary to explain it.
The number that comes after the word "spin" (like "Spin-1/2") indirectly tells you how many possible spins a particle can have. It turns out that there are only certain "quantized" values for particle spin, and every possible value is a multiple of half of a certain physical constant. A Spin-1/2 particle has two possible spin values in on a particular axis: +1/2 and -1/2. A Spin-1 particle has three possible spin values: +1, 0, and -1. A Spin-3/2 particle has four, +3/2, +1/2, -1/2, and -3/2, and you can probably deduce the rest. | [
"In some ways, spin is like a vector quantity; it has a definite magnitude, and it has a \"direction\" (but quantization makes this \"direction\" different from the direction of an ordinary vector). All elementary particles of a given kind have the same magnitude of spin angular momentum, which is indicated by assi... |
how do mods improve a game's graphics? | Well I know in the case of Skyrim a lot of the graphics were downgraded to make the game more readily available so upgrading wasn't hard because its framework was already capable for this, I think a lot of PC games are like this. Not sure how its done though. | [
"For advanced mods such as \"Desert Combat\" that are total conversions, complicated modeling and texturing software is required to make original content. Advanced mods can rival the complexity and work of making the original game content (short of the engine itself), rendering the differences in ease of modding sm... |
basic physics and/or chemistry | What level are you after? And which area(s) of each subject? | [
"Chemical physics is a subdiscipline of chemistry and physics that investigates physicochemical phenomena using techniques from atomic and molecular physics and condensed matter physics; it is the branch of physics that studies chemical processes from the point of view of physics. While at the interface of physics ... |
When did "I'm coming " or "coming" in general, begin to take on a sexual connotation in the English language? | This question might be a better fit at /r/etymology. | [
"English loanwords were common in late (pre-revival) Manx, e.g. \"boy\" (\"boy\"), \"badjer\" (\"badger\"), rather than the more usual Gaelic \"guilley\" and \"brock\". Henry Jenner, on asking someone what he was doing, was told \"Ta mee smokal pipe\" (\"I am smoking a pipe\"), and that \"[he] certainly considered ... |
how do plants mimic each other if they can't see? | Plants don't actively mimic each other. It's a passive process that occurs through natural selection.
For example, lets say you have a random selection of mimic plants, some of which are better at mimicking than the others. In this case, let's say that the mimic plants are weeds, and they are mimicking a legitimate crop. When you go out to pull the weeds from your garden or whatever, you'll pull out all the ones that are obviously weeds. This means that the plants that do a poor job at mimicking will die, usually before they've had time to spread their seeds. The plants that do a better job will last longer, meaning they have a higher chance of spreading seeds, which results in offspring that are more or less the same at mimicking.
Over time, the worst mimics are killed off, while the best ones live on to produce more seeds, resulting in a population of plants that is better at mimicry. Yet, throughout this entire process, none of the plants were aware of what they were doing. They simply continued with their natural functions, e.g. growing and producing seeds. They had no awareness of why certain members of their species would be uprooted and die. | [
"Many plants have evolved to appear like other organisms, most commonly insects. This can have wide-ranging benefits including increasing pollination. In Pouyannian mimicry, flowers mimic a potential female mate visually, but the key stimuli are often chemical and tactile. \n",
"Many species of flowers resemble e... |
does anyone or any nation own antarctica? | Many countries have signed agreements that nobody can own Antarctica. | [
"Antarctica currently has no permanent population and therefore it has no citizenship nor government. All personnel present on Antarctica at any time are citizens or nationals of some sovereignty outside Antarctica, as there is no Antarctic sovereignty. The majority of Antarctica is claimed by one or more countries... |
Are there any sources that describe upward mobility during the medieval era? | I think the social structure is far more fluid than you give it credit for certainly before c.1300. If you are thinking that the 'feudalistic system' in terms of a rigid pyramid structure then this is certainly not the case for inhibiting social mobility. Other, more pragmatic, factors tended to influence social mobility than abstract notions of hierarchy until into the very later parts of the Middle Ages.
At any rate, specifying a period is rather essential for any kind of detailed answer. The social and economic milieu of the eleventh- or twelfth-centuries versus the fourteenth- or fifteenth-centuries are very different. At a certain point in English history it is rather anachronistic to even discuss these things in terms of 'class', I would argue before c.1200, although after the 1350s I believe that there has been a real social stratification (exemplified by the birth of a 'gentry' group).
Baelish reaches his position chiefly through meritocracy and patronage. Like almost any period in history one's social connections and ability to exceed expectations could enable almost anyone to breach *most* 'glass ceilings'. William Marshal rose being the fourth son of an English baron to Regent (or Guardian) of England upon his death. The chief reason for his meteoric rise was his martial prowess which earned him first the attention of Eleanor of Aquitaine, then Henry II (who put him in charge of the martial training of his heir Henry 'the Young King'). The Marshal made a fortune through ransoms at tournaments fighting alongside the Young King. He had acquired extensive lands throughout England, the Marches, Ireland, and even retained his French territories after the French reconquest (he was the only landholder permitted to do homage to both John and Philip Augustus - which rather throws a spanner in the spokes of a 'feudalistic' setup). See Crouch's study or the Anglo-Norman Text Society's modern translation of his biography (written shortly after his death in the 1220s) for more detailed overviews.
At the other end of the scale (in almost every sense: chronological, social, gender) is Joan of Arc, who rose from 'low' (if not quite peasant) social status to being an influential and ennobled member of Charles VII's court in the 1430s. Not that she had much time to enjoy it as she was burned at the stake by the English in 1431. Her family retained the titles and some of the wealth, it seems, but it is another example, if extraordinary, of how patronage and what amounts to merit (ie. she was manifestly helping the French cause against the English) can completely destroy any notion of rigid social structure. [Here is a collection of my posts on Joan on this sub, with bibliographies found in and among them](_URL_0_).
I would recommend reading more widely around the subject, if this is what interests you:
Peter Coss, *The Origins of the English Gentry*, (Cambridge, 2003) | *The Foundations of Gentry Life: The Multons of Frampton and their World, 1270-1380*, (Oxford, 2010).
David Crouch, *William Marshal: Court, Career and Chivalry in the Angevin Empire 1147-1219*, (Harlow, 1990) | *The Image of Aristocracy in Britain, 1000-1300* (Cambridge, 1992) | *The Birth of Nobility: Constructing Aristocracy in England and France, 900-1300* (Harlow, 2005) | *The English Aristocracy, 1070-1272: A Social Transformation*, (London, 2011).
Rodney Hilton, *Bond Men Made Free: Medieval Peasant Movements and the English Rising of 1381*, (2nd Ed., London, 2003).
(eds) Holden, Crouch, and Gregory, *The History of William Marshal*, 3 vol., (London, 2002-2006).
(eds) Rosemary Horrox and Mark Ormrod, *A Social History of England, 1200-1500*, (Cambridge, 2006). An excellent set of essays, see especially Philippa C. Maddern, 'Social Mobility', pp.113-133.
Maurice Keen, *The Origins of the English Gentleman: Heraldry, Chivalry and Gentility in Medieval England, c.1300-c.1500*, (Stroud, 2002).
Phillipp Schofield, *Peasant and Community in Medieval England, 1200-1500*, London, 2002. | [
"In the late Middle Ages social mobility was not generally seen as a good thing, and could be regarded as dangerous to the social order. There had always been social mobility, as the economy expanded continuously, but much of it was in the church, which was more acceptable. In the 15th century the heavy losses from... |
What happened to the Women in the workforce at the conclusion of WW2? Did they mostly remain working, or did they stop working for one reason or another. | There's always more to be said, but you may be interested in my answer to [What happened to female skilled labor, like Rosie the Riveter, after the conclusion of WWII?](_URL_0_) | [
"At the end of the war, most of the munitions-making jobs ended. Many factories were closed; others retooled for civilian production. In some jobs women were replaced by returning veterans who did not lose seniority because they were in service. However the number of women at work in 1946 was 87% of the number in 1... |
essential oils. | They're the extracted/refined "essence" of plants, condensed down to an oil. Some people think they have all sorts of amazing healing properties but there's not a whole lot of science behind that. Currently, it's somewhat of a hot topic because a few big MLM schemes are marketing them fairly aggressively. | [
"Essential oils are volatile and liquid aroma compounds from natural sources, usually plants. They are not oils in a strict sense, but often share with oils a poor solubility in water. Essential oils often have an odor and are therefore used in food flavoring and perfumery. They are usually prepared by fragrance ex... |
Why do we believe recent population growth is due to technological advancements? | I think this is more of a math misunderstanding than a historical question. It is easy to see the rate of growth is higher by looking at the graphs on a logarithmic scale, in which case an exponential function is a straight line while the population growth is curved. | [
"Technological innovation and human population can be similarly considered, and this has been offered as an explanation for the apparent hyperbolic growth of the human population in the past, instead of a simpler exponential growth.\n",
"Before industrialization technological progress resulted in an increase in t... |
What's the proper name for the religion of ancient Greeks, Egyptians, or Norsemen other than just "x mythology" or "ancient x religion?" | This is a really great question, but answers must be framed with a great deal of ambiguity and caveats. The problem with translating foreign and especially ancient terms into modern English is that the vocabulary comes loaded with concepts that don't necessarily apply. To speak of "religion" in many pre-conversion societies implies that the belief system had established theologies/cosmologies/canons as you suggest, and yet this was not always the case. The Egyptian state religion was an early leader in developing a written, state-sponsored version of the indigenous belief system, but how this translated into day-to-day practices among a village of illiterate farmers is another matter. We can see this removal of beliefs from established religion in Emmanuel Le Roy Ladurie's Montaillou: The Promised Land of Error, for example, where the inhabitants of a remote medieval village, suspected by Rome of being heretics, were not consistently very well "plugged in" at being either Roman Christians or heretics. They thought what they thought, which sometimes wandered away from what an established religion or subsequent historians must suggest in general terms.
When it comes to something like pre-conversion Scandinavia, it can be hard to say what exactly was going on since it was a prehistoric society that was documented by Christian contemporaries or later Scandinavian Christians peering through imperfect lenses. But it is safe to say that there was no consensus theology or cosmology and there was certainly no canon. There were people who participated in a belief system that held itself together with oral tradition that was less than rigorous and filled with diverse points of view and opinions - these conclusions based on analogy from ethnographic studies of pre-literate societies and from the work of folklorists in subsequent Scandinavian societies where folk beliefs were seen to meander a great deal from place to place and person to person.
The same was likely of Archaic Greeks; as literacy become more pervasive, things changed, and various philosophies added a new texture to the belief system. But even here, one can imagine a considerable difference in what was believed and practiced in a remote farming village as opposed to a room of students listening to one of the great philosophers.
Regardless of how one might arrive at a way to summarize all these sorts of things, the summary will fall short because we are talking about expanses of time, geography, and relative literacy and education.
In general, it would probably be correct to say that the three cultures you mention would not have used a word for "x" - that person was simply "a priest." But even that term comes loaded with ideas that might not apply. Each of those societies had people whom others regarded as having a special ability to navigate spiritual issues and the spiritual world. Sometimes, these people were professionals, but other times they were only semi-professional (or even less). The Egyptians were particularly good at establishing an institutionalized religious structure with professionals, but even these professional priests may not adequately fit what a remote farming village was doing to address its spiritual and medical needs. One can imagine other practitioners who might mirror, more or less, what the professional temple priests were doing, but that may not have been the case. The same was probably true for the Greeks. For pre-conversion Scandinavia one would be less likely to encounter an institutionalized professions; there is some indication that these may have existed, but documentation is sparse and may reflect the perspective of Christian writers more than what was really going on.
The most important thing in considering how these various groups viewed their own belief systems and religious practices is that early on, people would have likely viewed their own traditions as correct and obvious, and when they encountered others, they would regard them as strange and bizarre, if not troubling. In our modern society, we are constantly confronted with religious diversity, so we need to define what sort of priest, what sort of temple/church that place is, etc. We are constantly framing "our" religion" in the contexts of others. Early on, this would have been less of an issue for the Archaic Greeks, the pre-Viking Scandinavians, and the early dynastic Egyptians. Encountering other belief systems - initially through trade and later as a consequence of a shrinking world - resulted in challenges to how one viewed one's belief system, but for the most part, pre-literate, isolated peoples tended to view their culture as the correct one and those of others as oddities where they just don't seem to get things right. | [
"There are no official naming practices for the Hellenic religion, and the ancient Greeks did not have a word for \"religion\" in the modern sense. Some informal naming conventions have developed since the formation of the first Hellenic religious organizations in the 1990s, based on academically accepted descripti... |
how does one design a cpu? | Are you asking how a CPU works, or process of building one?
I'll try to answer the first question but I think you have to actually
ask a CPU designer the other question...
OK, so imagine that a computer is a small town. The main street is
the **BUS** (this is the only street), and on main street there are
a lot of small shops, but instead of making bread and horse shoes
they do math.
You are the mayor, and therefore live in the mayors house. Your in
charge of telling the town what to do, you are the **PROGRAM MEMORY**.
Because you are the mayor and you are focused on running the city
actual communication between the shops and you is done by the
secretary or **CONTROL UNIT**
The problem is that there can only be one person in the main street
at a time. The way the secretary solves this is by using a telephone,
she tells which shop is allowed to use main street at that moment.
The telephone is the **CONTROL LINE**. And there is a separate
one going to every shop.
Lets also say that there is a billboard where the mayor can write
things onto.
If we assume the mayor wants to write the amount of money left over
that month. First he would tell his secretary to read how much money
they collected from taxes that month. The secretary then places that
number on main street so anybody can get to it. She then phones the
subtraction shop and tells it that she want it to use this number, the
subtraction shop then writes this down on a notepad we'll call a **REGISTRY**.
The secretary then takes the first number off of main street and places
the second one. She then phones the subtraction shop and tells it to
use that number as the second number. The shop writes the number
on another page and does the math. The secretary takes the second
number off of main street and tells the subtraction shop to put the
answer on main street by calling it.
At this point the secretary (before the shop takes the answer off)
tells the output shop to send the amount on main street out to the
billboard.
I am a software person so there is a good chance I missed
something, if so please let me know so I don't continue to lie to people.
EDIT: If you want to learn how to make one, follow a tutorial on mine craft, or download a program like _URL_0_
EDIT v0.2: If you decide to build one using _URL_1_ (feel free to pm me if you get stuck) just learn to read simple schematics, make an ALU, and it'll be easy from there.
EDIT v0.3: Added grammar
EDIT v0.4: Added grammar to edit v0.3 | [
"In more traditional processor architectures, a processor is usually programmed by defining the executed operations and their operands. For example, an addition instruction in a RISC architecture could look like the following.\n",
"Processor design is the design engineering task of creating a processor, a key com... |
What is the cause of the genealogical relationships of US Presidents? Is this common? | Once you get out past second or third cousin, there's a lot less general relationship between the people. I know I have several third and fourth cousins, but I've never once met them.
As stated, a lot of those listed, especially close relatives (Second cousin, etc), are from the same geographical area. Social elite are going to marry social elite. Kind of like why Europe's nobility were all related to one another. | [
"This is a list of children of U.S. presidents, including stepchildren and alleged illegitimate children. All full names with married names are given. Currently there are 31 confirmed, known living presidential children, the oldest Lynda Bird Johnson Robb, the youngest confirmed Barron Trump. Two presidential child... |
How easy/or hard would it be to tell that there is life on earth looking from another planet or galaxy? | The best method from a distance -- barring something like receiving a radio signal -- is to look for gases in the planetary atmosphere that are reactive and thus can only be there if they are constantly being replenished. Oxygen is the prime candidate for such a gas. Methane coexisting with oxygen is an even stronger indication. The Earth has both such signals and they were identified by the [Galileo spacecraft](_URL_2_) from space when it was pointed at the Earth.
Determining atmospheric composition at interstellar distances is obviously much harder. We are beginning to be able to get spectroscopic information from extrasolar planets -- see [this](_URL_1_) and [this](_URL_0_). An alien race would have to do the same in reverse and look at us from afar.
finally, here is a [nice article from 1998](_URL_3_) on how to go about such studies of planets at interstellar distance. | [
"The chemistry of life may have begun shortly after the Big Bang, 13.8 billion years ago, during a habitable epoch when the Universe was only 10–17 million years old. According to the panspermia hypothesis, microscopic life—distributed by meteoroids, asteroids and other small Solar System bodies—may exist throughou... |
why do computer air-dusters get cold? | When gas expands, it cools down. It's sort of because the molecules are a lot less crowded together (you can imagine how hot and stuffy you feel in a crowded subway car, and then you feel a lot cooler once you have some space).
This is actually the premise behind how your refrigerator and air conditioner work. Your air can is actually acting like a personal AC unit! | [
"Dust accumulation caused by static cling is a significant issue for computers and other electronic devices with heat generating components that need to be cooled by airflow. Dust is carried into the computer by the airflow created by case- and component fans. The accumulated dust covers metal surfaces and clogs th... |
where does the money that is given to charity for africa in the last 50 years go if the people there are still in poverty? |
In countries where corruption, bribery and theft are an integral part of daily business. Money, food stuffs, clothing and medicine etc can disappear long before It reaches those in need. | [
"Self Help Africa is a recipient of funding from Irish Aid, the European Commission, US AID, the United Kingdom Department of Foreign and Overseas Development (DFID), of variety of trusts, foundations, other institutional donors, and the general public.\n",
"From 2014 to 2017, ME to WE donated roughly 85 percent ... |
if you can't get sunburnt through windows/glass because it blocks uv, how do greenhouses work for plants which need uv for photosynthesis? | I believe windows and glass have to be treated to block UV, it doesn't do that automatically because it is glass. So the glass for a greenhouse simply does not have that same treatment. | [
"In regions continuously exposed to sunlight, UV rays can cause biochemical damage to plants, and eventually lead to DNA mutations and damages in the long run. When one of the main molecules involved in photosynthesis, photosystem II (PSII) is damaged by UV rays, it induces responses in the plant, leading to the sy... |
Is there a specific depth below Earth's surface where life ceases to exist? | _URL_0_
We've found life pretty deep, but it's generally tricky going extremely deep so it's hard to specify exactly where the cut off point is. Once you get to the mantle with temperatures of 500C any life will die based on what we know of extremophiles, but some bacteria can take a lot of heat and pressure. | [
"Life has been found at depths of 5 km in continents and 10.5 km below the ocean surface. The estimated volume of the deep biosphere is 2–2.3 billion cubic kilometers, about twice the volume of the oceans.\n",
"Under certain test conditions, life forms have been observed to thrive in the near-weightlessness of sp... |
Is there such a thing as "good stress"? | Depends on how stress is defined.
When you jog or run, you are putting stress on your cardio vascular system. Is this good? Most doctors are going to say it is beneficial in moderation. In the long run, it strengthens your heart, lowers blood glucose levels, etc.
Having deadlines for the completion of complicated mental tasks causes mental stress. It also helps strengthen memory.
Excessive mental stress as well as physical stress can be detrimental to our well being just like excessive water can kill a person.
Too little mental or physical stress can also lead to a decreased quality of life.
Moderation seems to be the way to go here. | [
"In psychology, stress is a feeling of strain and pressure. Stress is a type of psychological pain. Small amounts of stress may be desired, beneficial, and even healthy. Positive stress helps improve athletic performance. It also plays a factor in motivation, adaptation, and reaction to the environment. Excessive a... |
Is it true that you are more likely to get hurt during a car crash if you tense up? | To be entirely frank, the force regime that is encountered in a *serious* accident probably moots any effects of tensing up or relaxing. In minor accidents (fenderbenders and such) it might make a difference, but the effect is probably dependent on many uncontrolled variables.
As far as the drunk driver hypothesis: I want to introduce you to a topic that most med students pick up during their trauma/ER rotation. It's called "the law of inverse value." Basically engineers, artists, generally contributing members of science are easy to kill - shoot 'em hit them with a bat, whatever. But your drunk drivers, crackheads, thugs are immune - shoot 'em three times and they'll pull through fine. Essentially, the law of inverse value states that the more valuable you are to society, the more fragile you are. (I know it's not strictly related to your question, but I thought it was funny). | [
"Following collisions, long-lasting psychological trauma may occur. These issues may make those who have been in a crash afraid to drive again. In some cases, the psychological trauma may affect individuals' life can cause difficulty to go to work, attend school, or perform family responsibilities.\n",
"Erichsen ... |
how do apartment buildings that use water towers never run out of water? | The tower is constantly filled with water from the water main. The tower is just there to allow gravity provide constant water pressure regardless of current usage, which is much easier than trying to get pumps to exactly balance supply and demand to maintain a constant pressure. | [
"Architects and builders have taken varied approaches to incorporating water towers into the design of their buildings. On many large commercial buildings, water towers are completely hidden behind an extension of the facade of the building. For cosmetic reasons, apartment buildings often enclose their tanks in roo... |
why do different processor architectures require programs to be rewritten? | The processor architecture (more specifically the instruction set architecture) is sort of like the "language" it speaks.
CPU instructions are 1s and 0s, but different architectures have different meanings assigned to different patterns of 1s and 0s.
Code for a different architecture won't run because the CPU just won't be able to make sense of it. | [
"In some cases short sections of self-modifying code execute more slowly on modern processors. This is because a modern processor will usually try to keep blocks of code in its cache memory. Each time the program rewrites a part of itself, the rewritten part must be loaded into the cache again, which results in a s... |
Civilizations of the pre-Columbian Americas - Massive Panel AMA | These two questions particularly relate to the Mississippian cultures and eastern north America:
* How "Mississippian" was the Mississippian culture? By which I mean, was it heavily dependent on the river itself as an exchange network? Does the material culture indicate that the rivers themselves were central to the diffusion of culture?
* What did the landscape look like in terms of settlement patterns? What sort of settlement did most people of the time live in? And what sort of settlement hierarchy (ie, orders of settlement size that is often used to indicate political consolidation) was there?
One about the southeast US in particular:
* What was the primary subsistence strategy in the southeast? Was it primarily agricultural, or was there a mix of farming and hunting? I ask this because the southeast today is home to a range of tasty critters.
One about the Caribbean:
* My understanding is that sail technology was known along the coast of Mexico during pre-Columbian times. Did this ever lead to a sort of "cultural sphere" encompassing the shores of the Caribbean? I am thinking in comparison to other marginal seas such as the Mediterranean and east China Sea.
And one about the Andes:
* I once heard an argument (from [this lecture series](_URL_0_)) that many of the scenes on Moche pottery have traditionally been interpreted as pornographic or showing human sacrifice, however, they are better interpreted as depicting ritual scenes, particularly of healing. What is the current consensus about the Moche scenes?
EDIT: I remembered one more. This is primarily of interest to those studying state societies, but I'm happy to hear anyone's perspective:
* Do you see frontiers? I am defining a frontier loosely as a zone of uncertain political control that acts as an interface between societies of different social or political organization. | [
"Cuicuilco is the site of the first large-scale ceremonial center in the Mexican Plateau and one of oldest of any size in the Americas, with occupation starting around 1000 BCE. Cuicuilco means “place of hieroglyphics” in Nahuatl. The most important structure of the site is the Gran Basamento Circular or “Great Cir... |
if you are a beekeeper, and your bees fly away, how do you recapture them? | You basically own their house and the only female they have. Of course they are coming back | [
"Beekeepers are sometimes called to capture swarms that are cast by feral honey bees or from the hives of domestic beekeepers. Most beekeepers will remove a honeybee swarm for a small fee or maybe even free if they are nearby. Bee swarms can almost always be collected alive and relocated by a competent beekeeper or... |
Is the "goldilocks zone" or habitable zone of a star different depending on the type of star? | Yes. Also, it varies in size, if I remember correctly. | [
"BULLET::::- In astrobiology, the Goldilocks zone refers to the habitable zone around a star: As Stephen Hawking put it, “like Goldilocks, the development of intelligent life requires that planetary temperatures be ‘just right’”. The Rare Earth Hypothesis uses the Goldilocks principle in the argument that a planet ... |
Why doesn't gravity become infinitely strong at zero distance? | It does. This is what a gravitational singularity is.
Note that this requires an object of zero size.
For an object of finite size and density, gravity decreases as you go from the surface to the centre. | [
"BULLET::::- Because the force of gravity decreases with distance, objects with non-zero size will be subjected to a tidal force, or a differential pull, between the ends of the object nearest and furthest from the Earth. (An extreme version of this effect is spaghettification.) In a spacecraft in low Earth orbit (... |
Why was the "Polish Corridor" created in a way that separated East Prussia from the rest of Germany? | Refer to Point 13 of U.S. President Woodrow Wilson's 1918 "14 Points" peace proposal. This point, which appealed to the large Polish-American community, stated:
> An independent Polish state should be erected which *should include the territories inhabited by indisputably Polish populations, which should be assured a free and secure access to the sea,* and whose political and economic independence and territorial integrity should be guaranteed by international covenant.
I've emphasized the relevant sections of that point. The "Polish Corridor" was the simplest way for the newly independent Poland to get sea access while minimizing the number of Germans within the new country.
Having a seaport was deemed essential if Poland was to be an economically viable state. The question then became where to give Poland that sea access?
Even after WWI, East Prussia remained predominantly German. Danzig itself was almost entirely German, so as a sop to German demands, it was made a free city governed by the League of Nations and not handed over to Poland proper. The corridor was narrow by design: just 20 to 70 miles wide in order to limit the number of Germans in Poland.
This was a compromise that pleased no one. To the Germans, Danzig was under Polish rule. For the Poles, having their only seaport inhabited by an unfriendly majority (at best) and an outright hostile one at worst was intolerable. During the interwar years, Poland constructed a new port at Gdynia next to Danzig but entirely within the Polish Corridor.
This further stressed ties with Danzig, which saw its economy suffer as shipping traffic was diverted to the new port. After considerable acrimony, Poland compromised with Danzig and agreed to split shipping tonnage through each port. | [
"The creation of the territory known as Polish Corridor at the end of World War I separated the German exclave of East Prussia from the German Province of Pomerania. As a result, the German Ministry for Transport established a ferry connection to East Prussia (\"Sea Service East Prussia\" or \"Seedienst Ostpreußen\... |
wjy is it that whenever i'm dirnk, loud music or loud anything is easy on the ears, but whenever i'm by mself, my esars ring like crazy? | if you've listened to a lot of loud music and the ringing becomes constant you might have developed [Tinnitus](_URL_0_).
for temporary ringing... it has something to do with damaging your hearing ability little by little
| [
"It is now thought by professionals that Farr was possibly suffering from hyperacusis, which occurs when the olivocochlear bundle in the inner ear is damaged, causing it to lose its ability to soften and filter sound, making loud noises physically unbearable (auditory efferent dysfunction). \n",
"Hromadske Radio ... |
Is there a theoretical rationale for the common core arithmetic curriculum? | Common Core is great. The issue is not with the curriculum but with 1.) parent/teacher ignorance of what it is and 2.) bad books/resources that corrupt publishing companies, like Pearson, release.
Let me first explain what Common Core is. Common Core is a list of concepts that students should learn. It is *not* a new teaching method or style. The idea of Common Core is that understanding the logic and concepts behind math are vastly more important than memorizing algorithms to get answers. The focus on Common Core is ideas, not answers. The old standards only encourage the thought that math is rigid, complete and is just a means to an end (the answer). The goal of Common Core is to help students figure out that numbers and math are flexible things where creativity is possible, independent thought is encouraged and there is room to grow.
In math, the answer is the least important thing.
This does not sit well with people raised on the old system who only think that math is there to balance your checkbook. Parents and many teachers think that the answer is not only the most important thing about math, but that the answer is the reason math exists. So when they encounter curriculum that is designed to diminish the importance of the answer, and bolster the thinking process and concepts, they react in the way you've seen on the internet. They say things like "This old way works well for me, why does my kid learn differently?" But does it *really* work well for them? Sure they get the answer, but they hate math and have no appreciation for it. They also couldn't tell you why the typical multiplication/addition algorithms work. The only thing that it's good for is the answer, the least important thing in math. They have no "number sense" and are bound to the four algorithms and three formulas they can remember since they stopped taking math in high school. They have very little capability for critical and abstract thinking, which are the things math, and Common Core, encourage the most. If the teacher doesn't understand that they are teaching abstraction and critical thinking, then they will present Common Core as a list or rules to memorize, just like they learned growing up. But Common Core is not a list of rules, it is a list of concepts. It is supposed to teach you how to be creative in your problem solving, not give you some things to memorize (the worst way to learn anything).
People who can only do things the "old way" are nothing more than really shitty calculators and it's these people that wonder why we don't just use calculators all the time. Not using calculators forces you to figure out creative ways to get solutions and to actually think about the numbers you're using, and this abstract creativeness is the goal of math. Almost all math that almost all people learn, even engineers, can be done on a computer if all you want is the answer. The reason we teach math is not so that you're good at getting answers, but so that you're good at thinking critically, creatively and abstractly. The rigid algorithms of the old curriculum do not do this. The Common Core standards do.
Then you have companies like Pearson putting out the resources for Common Core. The one thing that you can be guaranteed to get from Pearson is a shitty product. The Pearson customer is not the students, but the government and the school administrations. So if they have to put out new books that follow the Common Core curriculum, you can bet that they are going to to as little work as possible to put out something that, technically, presents the curriculum. This is why the teaching materials are so poor. They don't care about teaching your kid, they about getting as much as they can for as little work as possible.
So, people don't understand what math is and how Common Core is a closer realization of how we should think about it. Even though many of them are proud of being bad at math, they don't want to face the realization that most of the country is, essentially, math illiterate. If I see someone complain about Common Core, I immediately judge them as an illiterate. This applies to the ones that try to show off their engineer credentials, engineers can get by without learning math, even if they use it every day. Common Core challenges us to raise out literacy levels, but the illiterate don't understand why we need to.
[Here is a video illustration of what it's trying to do](_URL_0_) | [
"The Common Core mathematical standards recognizes both the sequential as well as integrated approach to teaching high-school mathematics, which resulted in increased adoption of integrated math programs for high school. Accordingly, the organizations providing post-secondary education updated their enrollment requ... |
Why is so much of the New Testament written by Paul? | > Another way of looking at this could be: Why wasn't stuff written by the other apostles included? The apostles who spread in basically every direction from Jerusalem, and spread to sub-Saharan Africa, and even into India, surely they wrote stuff worth including?
There's no evidence that the other apostles wrote anything else. *If* there were texts circulating early that had been accepted by the early church as authentic (whether they were or not), they probably would have been included, but there's simply no such texts. And there's no reason to necessarily suggest that they did write.
Why Paul, and why so much?
Consider: Paul appears to have been quite well educated, from the Jewish perspective, and probably of reasonably good background in a hellenistic city and exposed to some hellenistic learning. Paul also works as an itinerant, visiting cities where he establishes local christian communities where he spends some time, up to 3 years in one case, 'kick-starting' those groups. He then engages in letter-writing to these communities while absent, very often to address local issues. This is why Paul wrote so many letters. The other apostles (a) do not appear to have followed such a strategy, (b) if they did 'spread' so far, did so relatively late in life, and (c) do not appear to be prolific Greek-language letter-writers.
Paul's letters, meanwhile, were valued enough that they were circulated and copied among christian communities, gaining currency as valued texts, and eventually inspired and authoritative ones.
| [
"Of the 27 books in the New Testament, 14 have been attributed to Paul; 7 of these are widely considered authentic and Paul's own, while the authorship of the other 7 is disputed. The undisputed letters are considered the most important sources since they contain what everyone agrees to be Paul's own statements abo... |
why did washington, dc develop so that it has residential areas in it rather than just government property? | Because the people working in the government offices need to live nearby. And because they're all there, they need services (shops, barbers, coffee houses), all of which need to employ staff, who need to live nearby. And they need services, whose businesses need to... etc etc. | [
"The streets and highways of Washington, D.C., form the core of the city's surface transportation infrastructure. Given that it is a planned city, streets in the capital of the United States follow a distinctive layout and addressing scheme. There are of public roads in the city, of which are owned and maintained b... |
Were certain gladiators in Ancient Rome as famous as our professional athletes today? | First, I have a BA in history. I'm fairly interested in Rome. But remember that this is just a reddit post and is bound to contain flaws.
In short, yes. Kinda. It's difficult to tell what the average Roman thought of individual gladiators, but the fact that some of them have been preserved by historical accounts shows they were at least widely known at the time they were alive.
You've undoubtedly heard of Spartacus, but he's a unique case. Commodus was well known because he was emperor at the time he competed; notably, pundits at the time were extremely displeased that an emperor sullied himself by entering the games. He fashioned himself as a sort of Hercules. Statues often depict him as wearing/holding a lion's pelt and carrying a club.
Flamma ("Flame" or "Fire") was a Syrian, probably a slave forced into gladiator school. He won the *rudius*, a wooden baton which granted the right to retire from the gladiatoral games, an astonishing four times, but refused to retire each time. Why is anyone's guess. The sources I'm reading differ on how many battles he fought: one says 34, one says 22. He was killed in his last battle, one source says at the age of 30. (Rachael Hanel, *Gladiators*, p. 31: _URL_0_)
Some works allude to familiarity with certain gladiators and their styles of fighting. In one, the author expressed an apparently widespread disapproval with one gladiator, Naevius, for his tendency to aim for the head, thereby ending battles quickly (Cic. Quinct. 7). Cicero may have said this in part to portray Naevius' reputation for legal/strategic reasons I won't go into at the moment.
Martial was crazy about a *bestiarius*, a gladiator who fought animals, named Carpophorus (greek for "fruit-bearer"). The author claims Carpophorus killed 21 wild animals at once. (Martial, *Spectacles*, XVII, XXVI)
There are many other well known examples you can look up yourself: Priscus and Verus, Mavia (a woman), Tetraites. Wikipedia can be a great source because it often gives citations to the original works, and it's very easy to find classical sources online through portals like Tufts' Perseus site. Evidence of these gladiators can be gleaned from poetry, busts, and graffiti. The graffiti is perhaps the best example: if ordinary people are literally writing your name on the wall, it stands to reason you're well known. Graffiti of Tetraites has been discovered as far from Rome as England.
It's important to note that even if they were sometimes well known or well regarded for their abilities, they usually didn't have the kind of social standing or wealth that modern professional athletes would. Remember, most of them were foreigners who were enslaved, brought to Rome, and more or less murdered for the pleasure of the citizens. Moreover, there were many writers through the life of the gladiatoral games (more than half a millennium) who decried the games. You could write a whole thesis about the perception of gladiators and their place in Roman culture. It was complicated, as history always is. Gladiators occupied social roles that simultaneously drew disdain and popular acclaim. | [
"Irrespective of their origin, gladiators offered spectators an example of Rome's martial ethics and, in fighting or dying well, they could inspire admiration and popular acclaim. They were celebrated in high and low art, and their value as entertainers was commemorated in precious and commonplace objects throughou... |
What military technology, if any, where the Japanese more advanced then the other countries during ww2? | You cannot really ignore ships for your question. Ships is one of the places where one of the best Japanese weapons of the war was deployed, the Type 93 "Long Lance" torpedo.
The type 93 had a heavier warhead, better range, and better speed than any other torpedo in the war. It gave Japanese light fleet element devastating punch at nearly twice the reach of their allied counterparts. | [
"In the two decades between the two World Wars, radio technology in Japan made advancements on a par with that in the western nations. There were often impediments, however, in transferring these advancements into the military. For a long time, the Japanese had believed that they had the best fighting capability of... |
how can so many deep sea creatures be so "squishy" when we have to travel down in a thick metal shell due to the high pressure? | Right now, you're under a quite a bit a pressure. You've got miles of air over your head pressing in on you at 1 atmosphere of pressure. At the same time, you and your ancestors have spent virtually all of your time at 1 atmosphere, so you've evolved to press outward at 1 atm.
Likewise, the closed and empty bottle sitting on my desk is pushing out at 1 atm of pressure. If I took the bottle, or you, and sunk you into very deep water, you'd be crushed, because the pressure outside of you would become far greater than the pressure inside.
If I were to slowly sink that water bottle into the water, while simultaneously pumping in more air to increase the internal pressure, there'd be no problem. As long as I balanced the internal and external pressures, all is good. The bottle doesn't really need to be any stronger than it is.
So why do we need a metal shell to go that deep. Well, unlike the bottle, the human body doesn't do great under pressure. We can be placed under some pressure, as long as we ramp up or down that pressure slowly so as to avoid medical complications. So we build a metal shell that can withstand a big difference in pressures. The shell, as long as it's intact, can withstand a difference between it's internal and external pressures so that we can survive within it.
So, back to those deep see critters. Like you, they've evolved to match their environment. Their bodies push out with enough force to match the external pressures at those depth. No strong shell needed because internal pressure equals external pressure.
However, there's a catch. If you are taken up out of the atmosphere, you'll eventually pop (not like the movies though). Your internal pressure of 1 atm will be far higher than the external pressure of 0 atm. Likewise, if you take the deep sea creature out of the deep sea, it'll pop when the external pressure is too low compared to the high internal pressure. | [
"Because pressure in the ocean increases by about 1 atmosphere for every 10 meters of depth, the amount of pressure experienced by many marine organisms is extreme. Until recent years, the scientific community lacked detailed information about the effects of pressure on most deep sea organisms because the specimens... |
who is ayn rand and why does my roommate hate her? | Hatred of Rand doesn't necessarily stem from her philosophy. Some people simply dislike her as an author for various reasons. Some people dislike her because they believe that she writes weak characters that undergo no growth. Others believe that her novels go on for about 800 more pages than necessary - in fact, in Atlas Shrugged, a character goes on a rant about Objectivism for around 90 pages, which for some equates to being hit repeatedly in the face with a hammer marked NOVEL THEME.
However, you could always ask your roommate why he hates Rand. | [
"Advocate of Ayn Rand's philosophy, has references \"Atlas Shrugged\" in interviews. Formerly a baker on a Texaco ship, later a landlord and a day renovator. Opposes any form of rent control. Gained local notoriety in the 1999 provincial election by making two bleating noises during a Rotary meeting. Claimed his in... |
Would moving your body (subtly and imperceptibly) back and forth at 99.99% the speed of light cause you to experience time any slower? Would you live longer than everyone else around you? | > Would moving your body (subtly and imperceptibly) back and forth at 99.99% the speed of light cause you to experience time any slower?
Yes, for a fraction of a nanosecond.
> Would you live longer than everyone else around you?
No, you'd die a second or two earlier than them.
So, you're vibrating with a peak velocity of 99.99% of the speed of light. Assuming your rest mass is 80kg, the energy of your vibration has a mass equivalent of order 70 times that, or 5.6 tonnes, ie, 510 exajoules. (For comparison: the daily energy consumption of New York City is about 0.0005 exajoules)
Now, something is keeping you vibrating - some force, or motor, or engine, or superpowered muscle. I'll assume it's 99.999% efficient.
You will be generating waste heat at ten times the rate New York City does, that is, about 60000 Megawatts. This will boil the water in your body within 3 seconds. it then burns out the machinery maintaining the vibration, the efficiency drops to 0%, and the 5+ tonnes of energy of your vibration is released with the force of a 120 Gigaton nuke. Nobody knows the precise effects of this, but it probably wipes out a good chunk of whatever continent you happen to be on, and plunges the rest of the earth into an unsurviveable nuclear winter.
Please don't try this at home. There are safer ways to achieve longevity. | [
"Einstein showed in his thought experiments that people travelling at different speeds, while agreeing on cause and effect, measure different time separations between events, and can even observe different chronological orderings between non-causally related events. Though these effects are typically minute in the ... |
why does my flatulence sometimes smell similar to what i've recently eaten and other times like hot death? | There are several different species of bacteria in your intestines that produce various gases and compounds when they digest things. The contents of your food (fiber, sugar, proteins) affect the consistency and odor of your stool. Your stool smelling "similar" to what you ate is probably a coincidence. Also, your ability to digest different foods and your sensitivity to those foods affects your regularity. | [
"Flatulence is observed even after years of surgery. Patients may suffer from persisted problems of producing flatus with foul-smell due to the accumulation of gas in the gastrointestinal tract. There can also be problems of abnormal distension of the abdomen after meals.\n",
"The distinctive odor of feces is due... |
what physiologically causes that "lurch" in your gut - when you get scared you've forgotten something or that you've upset someone etc | There is a biochemical signalling path called the 'gut-brain axis'. It connects the gastrointestinal tract with the central nervous system via the vagus nerves. It is why you are able to become nauseous from eating bad food. It is important for the regulation of the immune system, and has a great influence on neurotransmitters. If you do a quick google search on the impact of probiotics on mental health you will come across a great amount of information regarding the incredible influence the 'gut-brain axis' has on a multitude of physiological mechanisms. | [
"More persistent intention tremors are often caused by damage to certain regions of the brain. The most common cause of intention tremors is damage and/or degeneration in the cerebellum. The cerebellum is a part of the brain responsible for motor coordination, posture and balance. It is responsible for fine motor m... |
what exactly happened during the french revolution? (referring to les miserables) | Starting with Louis XIII, France started moving towards absolutism, which is basically total dictatorship (opposite of absolutism is a total democracy). Louis XIV (Louis XIII's son) was even MORE absolutist, and over the course of his reign he got involved in a ton of wars and drove up France's national debt.
Fast forward to Louis XVI. The Enlightenment/Scientific Revolution's in full swing and people are looking for more openness, intellectually, rather than just listening to the same explanations they've heard forever. Louis XVI's wife, Marie Antoinette, was foreign and spent extravagant amounts of money (she had a multimillion dollar budget for her wardrobe while the French people were starving), which incurred the anger of the people.
Also, Louis XVI did nothing to stop the problem. See, the only people being taxed were the Third Estate (First Estate were priests, Second Estate was the nobility, Third Estate was everyone else), and they were taxed ridiculously. Several of Louis XVI's advisors said, "Hey man, tax the rich people or you're going to be fucked" and he persistently refused.
Now, this process goes on for a few years until eventually Louis XVI runs out of money. Important: around this same time, France goes through several years of bad harvests. Everyone is hungry, poor, and pissed off.
Now, Louis XVI, like most monarchs, had one main source of money for when he spent it all on hookers and cocaine: that was the nobility. He calls the Estates General, which was this group of representatives from the three Estates. It was an archaic, outdated, traditional kind of thing, and so calling it sent out a signal that he was in deep shit. Louis XVI calls and begs for money.
Now, the Estates General worked on a one-vote-per-Estate basis. The Third Estate (poor people) had the other two outnumbered by people, but the 1st and 2nd Estate always voted together, so the 3rd Estate couldn't get anything done. The 3rd Estate was fed up and said "fuck this" so they split off and formed the National Assembly.
The National Assembly, fueled by years of being dicked over by everyone in France and being starving for food while Louis XVI lived like, well, a king, swore to keep meeting until Louis XVI was bound by a constitution.
This goes on for a while and several important events happen. For one, a bunch of really angry mothers and wives from Paris marched on the king's palace at Versailles (which was twentyish miles away, relatively close), overpowered the guards and brought him back to Paris.
The National Assembly changed names and forms (National Constituent Assembly, Legislative Assembly, etc) over the next ten or so years. Louis XVI tries to escape Paris and almost makes it, but he and his family get caught and executed by the ravenous crowd. (Louis XVI, after being taken to Paris, was caught corresponding with rulers of other countries. Joseph II of Austria was related to Marie Antoinette, Louis XVI's wife, and he swore that he would invade France if she was harmed. Louis XVI wanted these foreign powers to invade, put down the revolution, and put him back in power).
Now, the king is dead and France has its very own new government. This works out about as well as a bunch of five year olds duct taping their teacher to her chair and trying to teach class (but in this case, it was a really shitty teacher, so we can't blame them). The government is rife with corruption and in constant debt. On top of that, they start wars with half of Europe and have to build up a huge military to try and fund the war effort (this allows for a man named Napoleon Bonaparte to conquer most of Europe a little later on, but that's for another day).
The government goes on to become really, really corrupt, when the Jacobins start to get involved. The Jacobins were a radical left-wing party, and they eventually formed the Committee of Public Safety, which was like the Gestapo. They started executing people without trials for "treason" and were led by a guy named Robespierre, who openly advocated using terrorism on one's own populace. This regime also banned religion from France (regardless of your thoughts on religion, it was a really, really stupid move) and introduced a new calendar. Along with the religion, they established a ten-day workweek with one day off, which REALLY pissed people off. After Robespierre was executed, a new form of government called the Directory took control. They were a group of five leaders who controlled France with about as much efficiency as any five random US Senators, and wound up with a few revolts on their hands. They had to call in superstar officer Napoleon Bonaparte to put down the revolution. Another revolt happened and they called Napoleon back in, to which he replied "Fuck you guys" and he seized control of the Directory, eventually getting himself voted Emperor. Aaaand that's about it.
In short, Louis XVI was a really hesitant, inefficient ruler, who didn't react decisively to problems in his country. The people got angry, formed their own assembly, eventually marched on him, and seized total political power. They eventually grew really corrupt and collapsed, giving way to Napoleon to take over France.
Source: Took AP Euro. However, I don't claim to be flawless, historically, and after a few weeks of winter break I know I probably fudged a few details, so anyone feel free to correct me, I don't want to mislead our dear friend the OP. | [
"\"Les Misérables\" gave the relatively little-discussed rebellion widespread renown. The novel is one of the few works of literature that discusses the June Rebellion and the events leading up to it, though many of those only familiar with its popular musical adaptation wrongly assume that it takes place during th... |
My textbook says electricity is faster than light? | You are right to be dubious of your textbook, because the statements made are false. Not "false but only because we are making an approximation" or "false but it's only an apparent effect and not real", but "egregiously and totally false", to the point that it's rather embarrassing that this paragraph made it into that text.
Let's take a look at each of these statements.
> In a DC circuit, the impulse of electricity...
Just for the record, I have never in my life heard the term "impulse of electricity". An impulse is momentum and the term is typically used for describing the change in momentum due to a force that acts for only a very short time (e.g., the impulse of a tennis racket on an incoming tennis ball). We do have a term "electromotive force" which is abbreviated "emf" since it's not actually a force, but an electric potential. So maybe this author has defined "impulse of electricity" analogously, which would make "impulse of electricity" an electric potential per unit time. Those units strongly suggest that the author means "impulse of electricity" to mean that the dV/dt (where V is the voltage across the battery) is a unit impulse function. Not only is that impossible anyway, the term is still just not used, or used so exceedingly rare for my never to have heard it in my entire academic career.
**edit:** *On further examination, however, it seems the author is using "impulse of electricity" to refer to (what he thinks to be a correct) fact that all electrons start moving at the same time once the switch is closed. So he is probably using "electricity" to mean electric current or the electron speed, and the "impulse" refers to the (incorrect) fact that the electrons begin at 0 speed and then all instantly being moving at some non-zero speed. Again, the term "impulse of electricity" is not used and it is extremely difficult to figure out what he means by it precisely because his entire explanation is wrong.*
> Assume for a moment that a pipe has been filled with table-tennis balls. If a ball is forced into the end of the pipe, the ball at the other end will be forced out. Each time a ball enters one end of the pipe, the ball at the other end will be forced out.
Yes... but it's not instantaneous as the author wants us to infer. In fact, this very consideration is what leads to one of the most commonly asked questions on this sub ("if I push a rod longer than one light-year, doesn't the end move faster than light?" or something similar). When you push on the first ball, you create a pressure wave which propagates through the other balls and eventually pushes the last ball out. The speed of this wave is not infinite: it is finite and equal to the speed of sound in whatever material the balls are made of.
> This principle is also true for electrons in a wire.
No. The tennis balls in the pipe provide only a very rough analogy. In reality, when there is no electric field in the wire, the electrons are still moving. But they move randomly, and so, on average, they are at rest. If there is an electric field, the electrons still move randomly, but with some average drift in the direction of the higher potential. (Brownian motion with non-zero drift is a closer analogy than balls in a pipe.)
> There are billions of electrons in a wire. If an electron enters one end of a wire, another electron is forced out the other end.
Yes... but again, not instantaneously. If the electric field is already present in the wire, the drift velocity of the electrons is, in fact, very slow, literally a snail's pace in many common applications.
> Assume that a wire is long enough to be wound around the earth 10 times. If a power source and switch were connected at one end of the wire and a light at the other end, the light would turn on the moment the switch was closed. But it would take light approximately 1.3 seconds to travel around the earth 10 times.
No. Absolutely not. Period. This is certainly the most egregious error in this entire paragraph. **The light does not turn on instantaneously.** When the switch is closed, the change in the electric field in the wire propagates at a *finite* speed, less than the speed of light. (This signal is analogous to the pressure wave in the tennis balls.) The actual speed of this signal is determined by many factors, including the composition of the wire and its surroundings, and in copper wires in your home is typically on the order of 50-99% the speed of light.
The author of your textbook is demonstrating a very fundamental misunderstanding of physics. I would say that I am horrified, but I have seen worse.
---
**Various followups to some common responses and questions**
---
* The author's first statement is that the electricity *appears* to travel faster than light. The word appear does not necessarily mean "looks as if this happens, but it doesn't". The word can mean "this happens because this is what we see". Regardless, the author very clearly states in at least 3 places ("instantaneously", "instantly", "the same moment") that the propagation of the EM wave in the wire is instantaneous.
* Some have commented that according to the second figure, the light bulb is actually connected via a very short wire to the battery, and the EM wave does not have to travel all around the world to reach it. First of all, I think it's rather odd to think that that specific part of the figure is drawn to scale but not anything else (or else the bulb is as large as Earth). Secondly, and more important, the light would *still* not turn on instantaneously. "Nearly instant", "so quickly as to be imperceptible to humans", "effectively instant", etc. are *not the same as* "instantly", which is what the author claims.
* The text is written for electricians in a high school or community college trade program. It is not written for physicists. The errors are rather egregious, and I do understand that the correctness of this particular paragraph is likely not relevant to most using the book. (There are applications in signal processing where the signal speed in the wire does matter though.) However, I believe that a book that purports to be an educational tool, a textbook no less, should not be incorrect in anything it claims (barring new discoveries that make statements outdated). Yes, electricians probably don't need to know the details of copper wires and electricity to the atomic level, but the claim that common electricity allows for FTL communication is outrageous. I sincerely believe that many students would doubt the veracity of that statement, just as the OP has. Would you not then be cautious in trusting anything else in the book? Regardless, there are other mistakes in the text which are very relevant to the audience.
* For those asking what I have seen that is worse, well, just your standard fare of creationism biology textbooks was what I had in mind. In terms of physics, I have seen new-ish fluid dynamics texts explain airplane lift incorrectly (i.e., that streamlines split and must meet up again at the other edge). I have also seen many incorrect explanations of why light does not travel at *c* in media. But IMO those last two are not as bad as an implication of FTL communication via a long wire and a light bulb.
| [
"The word \"electricity\" refers generally to the movement of electrons (or other charge carriers) through a conductor in the presence of potential and an electric field. The speed of this flow has multiple meanings. In everyday electrical and electronic devices, the signals or energy travel as electromagnetic wave... |
how come drugs are found in urine much longer than in blood, when urine is filtered out of blood? | Imagine you have a pool ful of warter and you throw a special kind of colouring in there which turned the water red.
Suppose you have a filter which removes the colouring from the pool, and jettersons it out. At first the pool would be bright red so you could just look at it and see that someone threw the colouring in.
However as time goes on more and more of the colour gets removed from the pool and you can't tell by looking that the pool ever had dye in it.
However if you look at the filter you can see that the water filtered out has lots of red in it still, because it is extracting it from a very dilute source, but in large volumes.
In the pool if your blood, the drugs are the red colouring and the pump is your kindeys/liver, you can see why urine has a higher concetration of drugs than blood: Because its being deliberatly extracted from the dilute solution (where it can't be tested for) to a concentrated one. | [
"A urine sample is urine that has come from the bladder and can be provided or taken post-mortem. Urine is less likely to be infected with viruses such as HIV or Hepatitis B than blood samples. Many drugs have a higher concentration and can remain for much longer in urine than blood. Collection of urine samples can... |
What sort of populist movements existed in the Middle Ages and/or Renaissance? | First of all, I would contest that the Renaissance is a distinct time period buuuuuuut, there were many populist movements during the Middle Ages.
One could describe many of the heretical movements as populist/anti-establishment as many contested the sacraments, which were at the heart of everyday religious practice and helped to institutionalize the Church in the daily life of many inhabitants of Latin Christendom.
In terms of more explicitly political movements, however, in Italy, you have the Ciompi revolt, which was instigated by the wool carders guild that also represented all low-skill jobs and generally didn't have much power. They rose up and created a fairly radical government.
Cola di Rienzo was a Roman and the son of a tanner who declared the reestablishment of the Roman Republic with him as Tribune of the Plebs and sought to represent the populace of Rome against the machinations of the noble families that dominated the city.
Later medieval Italy is full of "populist" revolts.
The Boccanegra Revolt in 1339 Genoa.
The *popolo* government of Bologna in the 1280s and that of Teddeo Pepoli in the beginning of the 14th century.
There were also a bunch in the Low Countries with which I am less familiar. Pieter de Coninck who led the pro-independence forces in the Franco-Flemish war could be called a populist leader.
You also have the Wat Tyler who rose up in England, accusing the advisers of King Richard II of misadvising their king and turning him away from caring for his people.
Edit: Cohn's *Lust for Liberty* is one of my favorite works of history and it deals with this topic. | [
"Conversely, the historian Barry S. Strauss argued that populism could also be seen in the ancient world, citing the examples of the fifth-century B.C. Athens and Populares, a political faction active in the Roman Republic from the second century BCE. The historian Rachel Foxley argued that the Levellers of sevente... |
Why is Carbon Dioxide a gas while Silicon Dioxide is a solid? | Carbon dioxide is molecular: It exists as individual units of O=C=O Those bonds each have 4 electrons. SiO2 is reduced formula for silicon dioxide. It is not a molecular chemical. Each Silicon is actually bonded to 4 oxygens *via* 2 electron bonds. This means it is a solid because it forms a huge extended network. | [
"Carbon dioxide, like other gases, is soluble in water. However, unlike many other gases (oxygen for instance), it reacts with water and forms a balance of several ionic and non-ionic species (collectively known as dissolved inorganic carbon, or DIC). These are dissolved free carbon dioxide (CO ), carbonic acid (HC... |
Will sunlight that's passing through glass have the same tanning effect on skin as direct sunlight? | Depends on the quality of the glass. If it's just old, plain glass, then yes, you can tan through it, and she should wear whatever sunblock she feels is best. The newer windows have some reflectivity, and reduce the UVA, and possibly the UVB rays. And yes, "effect" is what you were looking for.
If you "affect" an accent for your wife, it may have a startling "effect" on her. | [
"Photochromic lenses filter 100% UVA as well as UVB. UVB light is more energetic and causes sunburn as well as skin damage including cancers, UVA light causes skincancers but not usually sunburn. UVB is blocked by all glass, UVA light is not blocked by ordinary windows or lenses glass.\n",
"The skin is usually mu... |
How does a pregnant body "decide" when it's time to go into labor? | The body doesn't the baby does. When the baby starts to get cramped for space it gets stressed and releases the stress hormone cortisol. The cortisol from the baby then starts a cascade of events in the mother that leads to birth.
EDIT: sorry I'm a veterinary student. This is how a lot of other species initiate parturition and I thought it was the same for humans but I guess not. | [
"Gestation, called \"pregnancy\" in humans, is the period of time during which the fetus develops, dividing via mitosis inside the female. During this time, the fetus receives all of its nutrition and oxygenated blood from the female, filtered through the placenta, which is attached to the fetus' abdomen via an umb... |
why its ok to name a person mohammed, but not an inanimate object, or animal. | Because humans think that other humans are more or better than things or animals. Since Mohammed is really important to Muslims, they thing you should only name "important things" like your son after him. On top of that some things or animals are considered "unclean" in some cultures, so using naming a dog after someone would not be cool even if you really like this dog. | [
"The name \"Muhammad\" () means \"praiseworthy\" and appears four times in the Quran. The Quran also addresses Muhammad in the second person by various appellations; prophet, messenger, servant of God (\"'abd\"), announcer (\"bashir\"), witness (\"shahid\"), bearer of good tidings (\"mubashshir\"), warner (\"nathir... |
How did scientists at the first nuclear explosion test (Trinity 1945) know for sure the bomb wouldn't destroy the planet? | Some people said it would, but the math showed otherwise. More were concerned with how people would use the weapon.
_URL_0_ | [
"BULLET::::- At 8:59 am and 45 seconds local time, Operation Crossroads was carried out as a fleet of 73 retired and unmanned ships were destroyed, sunk or damaged by an atomic bomb. The test took place at the Bikini Atoll in the South Pacific Ocean to observe what a nuclear weapon could do to American warships. It... |
What would happen if you drove a vehicle onto a moving ramp? | They did this on a tv show...i dont remember which one...
Anyway...they had a car driving 65mph drive up a ramp onto a flatbed truck moving 60mph...
As the car hit the ramp they let off the gas and the momentum kept the car moving up the ramp at 5mph (relative to the ramp).
***Edit: it was on mythbusters...testing out knightrider...as michaek would drive kitt onto a moving 18-wheeler at highway speeds via ramp on the show*** | [
"BULLET::::- On \"MythBusters\", Adam and Jamie tested whether KITT could in fact drive up the ramp into the mobile garage or whether upon hitting the ramp he would instantly accelerate into the truck and through the wall.\n",
"There must be some positive movement of the vehicle. Simply rolling it forwards or bac... |
peripheral neuropathy | Peripheral neuropathy is a malfunction of the nerves in the extremities, usually the arms or legs, but sometimes the face. It can cause numbness and tingling, or in some cases a very painful burning sensation or feelings like cold water being poured on the area. | [
"Peripheral neuropathy, often shortened to neuropathy, is a general term describing disease affecting the peripheral nerves, meaning nerves beyond the brain and spinal cord. Damage to peripheral nerves may impair sensation, movement, gland or organ function depending on which nerves are affected; in other words, ne... |
how is there enough oil under the ground to power hundreds of millions of cars, planes, boats..etc. daily? | The earth is BIG, compared to our oil consumption:
We consume 93,250,000 barrels a day of oil (not just gas) world wide.
At 42 gallons per barrels, that's 3,916,500,000 gallons used every day!
But!, the surface of the earth is 5.1 x 10^8 square kilometers. Oil has been found most everywhere, under land and water so lets assume there is oil under the crust everywhere.
If you took all the oil the world burns in a day, and spread it across the world, it would be only 1.1x10^-6 inches thick. Tha'ts 1000 times thinner then a human hair.
If their was only a inch of oil under the crust (which can be up to 50 km thick), it would supply us with oil for 8.75x10^5 days, or 2,400 years. This assumes our oil consumption doesn't increase. | [
"In the United States, oil is primarily consumed as fuel for cars, buses, trucks and airplanes (in the form of gasoline, diesel and jet fuel). Two thirds of US oil consumption is due to the transportation sector. A national strategy designed to shift all transportation to a combined use of alternative fuels and plu... |
Did Pearl Harbour have the same effect on Americans' perception of security as 9/11 did? | Sorta. It certainly put some American citizens of the mind that the Japanese were "the other", just like many Americans did regarding Muslims in the days and months(and until today, really) after 9/11.
Since 9/11 is within the past 20 years or so(which makes it verboten for discussion), I'll simply point out that the US [rounded up residents of Japanese ancestry](_URL_0_) out of fear that they were a 5th Column. The argument could be made that is was a shift of perception of security.
Before the war US aviation assets tended to be on the flightlines [bunched together, the better to keep an eye out for sabotage](_URL_1_). After the attack, the US switched to a dispersion technique so it would be harder for someone to bomb a bunch of them at once. | [
"Pearl Harbor is generally regarded as an extraordinary event in American history, remembered as the first time since the War of 1812 that America was attacked in strength on its territory by foreign people – with only the September 11 attacks almost 60 years later being of a similarly catastrophic scale. It has be... |
Has any serial killer ever been killed by somebody they were attempting to murder? | Not killed, but serial killer [Richard Ramirez](_URL_1_), who terrorized Southern California in the early 1980's as "The Night Stalker", after a failed attempt at a carjacking, was ultimately overpowered by a vengeful public and beaten within an inch of his life before he was taken into police custody.
British serial killer Colin Pitchfork was also engaged in a violent struggle with a prospective victim, who he picked up as a hitchhiker. Rather than submit to his assault or trying to reason with him, this young woman reacted by fighting tooth and nail, causing him to almost crash the car; when he stopped the car, she jumped out and escaped. The woman is unnamed for privacy reasons in author [Joseph Wambaugh's "The Blooding"](_URL_0_) non-fiction work on the first use of forensic DNA analysis to identify a criminal.
In both cases, it's illustrated that these particular killers expected to establish and maintain total control over their victims, who typically reacted as many of us might, by trying to reason and placate the killer; with a victim who reacted with a hysterical violence and put up a crazy amount of fight, the killers realized they could not maintain control of this particular victim and they risked injury themselves that could lead to identification; it's also implied that the sense of dominance and control is part of the gratification the killer receives in the act; take that away, and their motivation is diminished.
| [
"The search for the serial killer, called \"the Atlanta Ripper\" by the press, found six different suspects, but no convictions were ever made, nor was the crime ever solved. By the end of 1911, fifteen women, all black or dark-skinned, all in their early 20s, had been murdered in the same manner. The \"Ripper\" ma... |
Can the human acceleration limit be worked around? | Magnets won't work for this, however the idea of accelerating the whole body evenly is the right solution, though there is no practical way to do that yet.
Right now what can be done is immersing a person in body-density liquid, this will increase the G-tolerance to an estimated 15~20G; if the person's lungs and other body cavities can be filled with liquid, then the G-tolerance can be even higher -- but perfluorocarbon breathing is still at a very experimental stage.
| [
"By riding the decelerator sled, in his 29th and last ride at Holloman Air Force Base in New Mexico, Stapp demonstrated that a human can withstand at least 46.2 g (in the forward position, with adequate harnessing). This is the highest known acceleration voluntarily encountered by a human, set on December 10, 1954.... |
how does the "conscious" part of the brain know to ignore normal bodily functions? | This all has to do with how the brain is divided up with regards to function. All of the actions happening automatically in your body are controlled by their perspective parts of the brain, and those have nothing to do with sensations like pain.
For example, the region of your brain (and corresponding nerves) that make your intestines contract don't deal with pain. When you get a stabbing pain in your bowels, that pain is carried upwards to a different part of the brain by different nerves. If there's nothing to cause you pain, those nerves aren't sending any signals.
Like you guessed, it does vary from organ to organ. The stomach, for example, can send signals up to the brain when it's stretched out, and you feel that. On the other hand, the stomach (and other internal organs) doesn't have fine sensation like your fingers, so you're not constantly aware of every little thing going on down there. In that case it's not that your brain is tuning anything out, there's just no signal of "feeling" being sent to the brain. The only time you have feeling is when specific things like "pain" happen. The other issues like "why am I normally unaware of my nose in my vision" has to do with how your brain simply learns to ignore it, which is totally different.
**TL;DR - Most of your internal organs aren't even capable of sending constant signals of "feeling" to the brain like your skin/tongue/etc can.** | [
"Unconscious processing goes on in the mind of humans, not because we have to filter out threatening stimuli and impulses, but because many cognitive operations go on without conscious participation. The brain operates in this way in order not to flood the conscious part of the mind with impressions. The unconsciou... |
why does food taste different outside than inside? | Not entirely familiar with this feeling, but since smell plays a huge role in the perception of taste (not directly, but taste is very limited and what we're used to when we say "taste" as an experience is actually a combination of taste *and* aroma), that might be the answer. Being outside means air movement can interfere with smells, plus multiple other sources of smells can slightly change the perceived taste of foods. | [
"The basic tastes contribute only partially to the sensation and flavor of food in the mouth—other factors include smell, detected by the olfactory epithelium of the nose; texture, detected through a variety of mechanoreceptors, muscle nerves, etc.; temperature, detected by thermoreceptors; and \"coolness\" (such a... |
the difference between youtube's buffering and loading an image from anywhere else on internet - and why buffering is so much faster | This might not be the complete answer but a part of the answer. Try loading a video in Youtube, and then a video from a website which is not primarily a video-hosting site (Like IMDB). You will notice that the IMDB video takes significantly longer to load for the same quality of video. Google has some amazing compression algorithms, and a great network of servers which ensure you are always getting the best speed possible. | [
"Having a big and constantly full buffer which causes increased transmission delays and reduced interactivity, especially when looking at two or more simultaneous transmissions over the same channel, is called bufferbloat. Available channel bandwidth can also end up being unused, as some fast destinations may not b... |
Blood contains so much salt, how conductive is it? | Approximately 0.7 S/m (siemens per meter) It depends on the hematocrit (the the proportion by volume of the blood that is red blood cells). A rough formula is 1.57/[1+1.91H/(1-H)] S/m where H is the hematocrit.
Source:_URL_0_ | [
"BULLET::::- The brine surrounding the cells has a higher concentration of salt than the fluid within the cells, but the cell fluid has a higher concentration of other solutes. This leads salt ions to diffuse into the cell, while the solutes in the cells cannot diffuse through the cell membranes into the brine. The... |
when we say a person is worth $300 million, how much of that is the person actually entitled to? | Generally what that means is the person has wealth and assets valued at $300m. Which could include things like property, real estate, and stock in companies.
So the person could, if they sold everything they owned at the price it is appraised for, come up with about $300m. | [
"There are multiple approaches to determining a person's status as a millionaire. One of the two most commonly used measurements is net worth, which counts the total value of all property owned by a household minus the household's debts. According to this definition, a household owning an $800k home, $50k of furnis... |
What are some counterintuitive non-quantum level phenomena? | When a human being moves from a low-altitude place to a higher altitude place, their body has to cope with lower oxygen levels. One of the ways a body can adapt is to make more hemoglobin, the protein in red blood cells that carries most of the oxygen we breathe to our tissues. Some athletes will train in a high-altitude environment to gain this adaptation and use it to their advantage when they return to the lower elevation where they normally play. So you'd expect that populations living at the highest possible elevations to have a lot more hemoglobin than people living near sea level.
Wrong. They actually have less. The reason is that more hemoglobin is better only up to a point, and then the blood becomes to viscous to flow properly. Instead, high-altitude populations have acquired mutations that enable their cells to use oxygen more efficiently. | [
"Macroscopic scale quantum coherence leads to novel phenomena, the so-called macroscopic quantum phenomena. For instance, the laser, superconductivity and superfluidity are examples of highly coherent quantum systems whose effects are evident at the macroscopic scale. The macroscopic quantum coherence (Off-Diagonal... |
How common was tarring and feathering in the American revolutionary period? Also, was this practice supported by revolutionary leadership? | Tar and feathering was not as common as you might think. It certainly did occur, and was truly horrific when it did, but we should try to understand the true nature of it, rather than the popular understanding of it.
Revolutionary leadership never came out explicitly in support of tar and feathering. It was a mob action against political opponents (or at least *perceived* political opponents) that resulted in physical harm. This kind of violence, if endorsed by the political leaders of the revolution, would have completely undermined their ability to work toward change in the political realm and would have confirmed the objections of their opponents: that the political leadership of the colonies were nothing more than rabble rousers.
The clip below can give you a pretty good idea of what the act of tar and feather might have been like (though I've read of cases where the tar was applied over the clothing), but you definitely would not have seen John Adams, John Hancock, or Samuel Adams in attendance. That would have been political suicide.
Privately, some leaders (Samuel Adams, perhaps) may have endorsed tar and feathering, but they were smart enough to not publicly state that.
Tar and feathering was very, very painful. I have yet to find a source from the Revolutionary period that presents any case where it was fatal. One man, suspected of being an informer, was tarred and feathered, then forced to lead a mob through Boston. Within a short time he was working as a sailor aboard the *HMS Rose*. As most people are aware, working as a hand before the mast on an eighteenth century warship was a difficult and physically demanding job, which indicates that the tar and feathering did not slow him down as much as you might imagine. A lower level functionary was also tarred and feathered, and sent a strip of his tarred flesh (which had apparently peeled from his body) to Parliament to reinforce his claim for government support.
These two cases seem to indicate that the method of tar and feathering was not uniform (one was well enough to work on a frigate, the other had to send his dead flesh to Parliament to secure compensation for his apparently debilitating ordeal), but neither suffered death.
One of the best secondary sources for mob violence in the Revolutionary period of 1763-1775 is *Cradle of Violence* by [Russell Bourne](_URL_0_), though you can also get a good idea of the legal reprecussions (and lack thereof) for mob violence in [Hiller B. Zobel's](_URL_1_) *Boston Massacre*. | [
"The Sons of Liberty popularized the use of tar and feathering to punish and humiliate offending government officials starting in 1767. This method was also used against British Loyalists during the American Revolution. This punishment had long been used by sailors to punish their mates.\n",
"The practice appeare... |
can someone explain the trade deal that obama is trying to push through? what is it, and why do a lot of democrats not like it? | Trans Pacific Partnership is a large corp sponsored bill. With most of its negotiations and contents being kept secret. If that doesn't already make you feel strange.
Its job on top of Pacific Free Trade is international Copy Right and Piracy Laws. It forces each signer to recognize a lot of international over site when it comes to freedom of expression namely on the internet. The U.N. has gone so far as to call it a violation of Human Rights.
That's why its having issues passing. | [
"Like his predecessor, Obama pursued free trade agreements, in part due to the lack of progress at the Doha negotiations in lowering trade barriers worldwide. In October 2011, the United States entered into free trade agreements with Colombia, Panama, and South Korea. Congressional Republicans overwhelmingly suppor... |
why do stores never charge the full dollar amount for goods, like a video game costs $59.99, not just $60? | We read left to right, so we see:
> $59
before:
> .99
The first thought we have is that it's below $60. While we later realise this to only be the case by a single cent, the first impression makes the price-tag appear cheaper that it really is. It's an illusion that makes us more likely to purchase something. | [
"Some video games have collector's editions available for limited amount of time. It can include additional content such as a comic book or a CD of soundtracks used in the game. The most expensive collector's edition was featured for Saints Row IV, priced at $1,000,000. However, it was never sold. \n",
"The game ... |
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