question stringlengths 3 301 | answer stringlengths 9 26.1k | context list |
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What aspects of a speaker determine it's max volume? | Two things can go wrong with a speaker.
The coil can push the cone too hard and it rips. This happens a lot with older paper speakers.
You can put too much electricity through the coil (a little transformer) and burn it out.
The volume produced is (sort of) the diameter of the cone times the travel in and out. That tells how much air it will move.
Also, some speakers are more efficient than others. If you use a lighter weight Mylar cone, it takes less electrical power to move the cone than a heavy paper one, and you can move more air. | [
"Due to the reactive nature of a speaker's impedance over the audio band frequencies, giving a speaker a single value for 'impedance' rating is in principle impossible, as one may surmise from the impedance vs. frequency curve above. The nominal impedance of a loudspeaker is a convenient, single number reference th... |
what makes elements perform ionic and covalent bonds?(x-post from askscience) | Ionic bonds are a bit easier to visualize I think. You can sort think about it this way: Atoms are composed of a nucleus with protons and a bunch of electrons. Each proton carries a positive charge and each electron carries a negative charge. Like the poles on a magnet, the positively and negatively charged particles attract each other, and if an atom has the same number of protons and electrons, they balance out and the atom has no charge overall.
It turns out that atoms kind of store their electrons in a set of bags, where each bag holds a certain number of electrons. The first bag holds two, the next one holds eight, the next one holds 18, etc.
The atoms on the left hand side of the periodic table have juuusstt too many electrons to fit evenly in their bags. Take sodium, for instance, with 11 protons and electrons. The sodium atom puts its first two electrons in the first bag, the next eight into the second bag, but it only has one electron remaining for the last bag, which is designed to hold 18 electrons. Now sodium doesn't necessarily want to expel that last electron, but if someone else comes along that might want an extra electron, sodium wouldn't feel too bad about giving it away, because then it would only need 2 bags instead of carrying around a whole third bag with only a single electron in it.
Along comes chlorine with 17 protons and electrons. We can do the same kind of analysis and find that it has 2 electrons in its first bag, 8 in next, and 7 in its last bag. Even the though the last bag can hold a total of 18 electrons, it turns out that 8 is also a pretty even number that fits in the last bag, so if chlorine had one more electron, it would be happy. When sodium and chlorine meet, sodium gives its awkward electron to chlorine. After the exchange, sodium becomes positively charged because it lost its electron, and chlorine becomes negatively charged. The oppositely charged sodium and chlorine attract each other and form an ionic bond and become Sodium Chloride (NaCl), or common table salt.
Also, regarding your question about if you'd get water if you massaged oxygen and hydrogen together... Typically, if you have pure hydrogen or oxygen, they exist as hydrogen gas molecules composed of 2 hydrogen atoms, and oxygen gas molecules, also composed of 2 oxygen atoms. Say you mix the two gasses together in a room at room temperature. In this case, not much would happen. This is because the hydrogens are lazily happy on their own bonded to each other, and the oxygen as well. Sure, the hydrogen would _rather_ be bonded to the oxygen, but at such a low temperature, they're too lazy to do anything about it. If there should happen to be a spark though, the hydrogen and oxygen close to the spark might get just enough energy to change from hydrogen and oxygen gas into water vapor. When that happens, it turns out that energy is released by the atoms as they exchange in the form of heat and light. The released heat and light might cause other neighboring hydrogens and oxygens to bond, too, causing a very fast chain reaction throughout the room. The resulting heat and light from the gigantic chain reaction would cause a hindenburg explosion in your room, after which you'd have water vapor. Like this: _URL_0_ | [
"Going down the above table, there is a transition from covalent bonding (with discrete molecules) to ionic bonding; going across the table, there is a transition from ionic bonding to metallic bonding. (Covalent bonding occurs when both elements have similar high electronegativities; ionic bonding occurs when the ... |
What did people do before coffee? | A similar question was asked about a month ago. You will find somewhat relevant answers in the comments.
[Did the Ancient Romans have their own version of a "cup of coffee"? by which I mean a mild stimulant they would have used on a daily basis](_URL_0_) | [
"The history of coffee dates back to the 15th century, and possibly earlier with a number of reports and legends surrounding its first use. The native (undomesticated) origin of coffee is thought to have been Ethiopia.The earliest substantiated evidence of either coffee drinking or knowledge of the coffee tree is f... |
What equipment would ancient Romans use against armoured opponents? ~107BC-395AD | Standard fighting equipment for a post-Marian legionnaire was the gladius, pilum, pugio, scutum, galea, and some sort of body armor, either the lorica squamata, lorica hamata, or, mainly imperial, lorica segmentata. This profile rarely if ever changed in any meaningful way, whether fighting naked Britons or Parthian horse-archers or perfumed Egyptians or other Romans legions. This changes in Late Antiquity, when we start to see specialized units, but in your period specialized forces would always be auxiliaries.
Your focus on [weapon type] effective against [protection type] is mostly a modern construction. The vast majority of casualties in an ancient battle happened after a side broke and fled. Ancient battles were much more about maneuvering, positioning, and maintaining morale rather than inflicting damage to combatants along the line of battle. Casualties were incidental to those three, and killing blows often the consequence of an injury unrelated to body armor (like taking a *tragula* through an exposed thigh at twenty meters, or going down with a sprained ankle in the push).
You should also not discount the gladius. It was a vicious, versatile weapon, and the legionnaire treated it like a tool. Gladius, shovel, wooden stake. Its tapered point made it a sturdy puncturing weapon as much as a slasher, and with the force of a thrust, it was more than enough to push through the weakpoint of a lorica hamata or the joint of a lorica segmentata. The hilt design was intended to help transfer force to a thrust attack in this way. | [
"Siege warfare gave the Roman army significant offensive advantages over their enemies. Though the catapult was developed in ancient Greece, the Romans were able to replace the traditional Greek catapult made of wood making the most stressed components out of iron or bronze. This allowed for a reduction in size and... |
why was black and white photography very high resolution at it's peak, but soon after when color photography was introduced, it was very bad quality? | Black and White film has one emulsion, color film has three emulsions (RGB).
According to [Wikipedia](_URL_0_):
> Photographic emulsion is a fine suspension of insoluble light-sensitive crystals in a colloid sol, usually consisting of gelatin. The light-sensitive component is one or a mixture of silver halides: silver bromide, chloride and iodide. The gelatin is used as a permeable binder, allowing processing agents (e.g., developer, fixer, toners, etc.) in aqueous solution to enter the colloid without dislodging the crystals. Other polymer macromolecules are often blended,[citation needed] but gelatin has not been entirely replaced. The light-exposed crystals are reduced by the developer to black metallic silver particles that form the image. Colour films and papers have multiple layers of emulsion, made sensitive to different parts of the visible spectrum by different colour sensitizers, and incorporating different dye couplers which produce superimposed yellow, magenta and cyan dye images during development. Panchromatic black-and-white film also includes colour sensitizers, but as part of a single emulsion layer.
> Most modern emulsions are "washed" to remove some of the reaction byproducts (potassium nitrate and excess salts). The "washing" or desalting step can be performed by ultrafiltration, dialysis, coagulation (using acylated gelatin), or a classic noodle washing method. Emulsion making also incorporates steps to increase sensitivity by using chemical sensitizing agents and sensitizing dyes.
The number of emulsions affects the quality and the volume of byproducts that had to be removed. | [
"This made photography much more useful to science, allowed a more satisfactory rendering of colored subjects into black-and-white, and brought actual color photography into the realm of the practical.\n",
"However, even if both techniques have inherent noise, it is widely appreciated that for color, digital phot... |
How can a layman tell how reliable a source is? | I tell my students to start with a Google of the author. Is s/he affiliated with a university? With a think tank? NGO? Each of these will have differing goals in publishing, and you need to weigh them when considering a source.
Then read her/his CV, paying attention to what has been published and in which journals. Is the author publishing stuff in the *Journal of American History?* If so, probably reliable. Is the author publishing stuff in the *Journal of Crazy Conspiracy Theories?* If so, maybe not as reliable.
Is the book published by an academic press (University of Somewhere You've Heard Of Press, etc.?) If so, it has most likely gone thru a pretty rigorous peer-review process. That doesn't guarantee a good book, but it does mean that at least a few people think it's probably OK.
Thumb thru the citations. By itself, footnoting doesn't mean anything. Heck, I can cite Phil Foner all day, but that doesn't mean it's a good thing. Are the footnotes citing someone reputable? Are the notes to works that are as describes above (academic presses, solid journals, etc.?) Do the notes include historiographic discussion? (nb: historians, if allowed by a publisher, would probably write a 5000 word article with a 25000 word set of footnotes politely bashing or congratulating their colleagues.)
This list is far from exhaustive, but should give you a fair footing.
Cheers and keep reading. | [
"BULLET::::- Using Primary Sources as Evidence is the ability to locate, choose, understand and provide context for the past using primary sources. This approach to reading a source will be dependent on the kind of source being used and the kind of information the user is trying to find (e.g. reading to a book for ... |
If genetic testing shows Ashkenazi Jewish people have much more relation to the semitic people, where did the Khazar jews end up after the empire collapsed? | This thread has a pretty good compilation of threads on the religion of the khazars
_URL_0_
_URL_1_
By /u/gingerkid1234 | [
"Much awareness of \"Ashkenazi Jews\" as an ethnic group stems from genetic studies of disease. Some regard these studies as exhibiting ascertainment bias which created an impression that Jews are more susceptible to genetic disease than other populations. They cite BRCA1 and BRCA2 mutations becoming identified as ... |
Books on early fascism's relationship to liberalism and socialism? | Emilio Gentile (whose works have the additional quality of being, some times, available in an English translation) has spent a good portion of his career analyzing the early stages of the ambiguous definition of a "fascist ideology" within the environment of what he has defined "national radicalism".
His early works that focus especially on this process - *Le origini dell'ideologia fascista (1918-25)* [1975, 1996] and *Il mito dello stato nuovo dall'antigiolittismo al fascismo* [1982, 1999] - provide a good insight into the context of the transition from the ideas of the Italian liberal state to those advocating for a new, albeit often ill defined, political system. Since both are somewhat technical in their perspective, I would suggest pairing them with a general overview of Italian politics during Giolitti's age and the Great War (for instance Bosworth's), unless one is already familiar with the period.
Still with Gentile, and for additional context, his early work on *La Voce* - *Mussolini e La Voce* [1976], especially for the influence of Prezzolini's newspaper on Mussolini's (tenuous) attempts at developing his own revisionist approach to Marxism - *La Grande Italia* [1997] for the affirmation of a new sentiment of *Italianismo* during the early XX Century - *"La nostra sfida alle stelle", Futuristi in politica* [2009] for the origins and relative impact of Italian Futurism as a political formation - *Mussolini contro Lenin* [2017] for a review of Mussolini's "anti-Bolshevism" during 1917-22, mostly taken from the pages of his *Popolo d'Italia* and for an attempt at a critical examination of how Mussolini's "revolutionarism", or instinct for a national renovation, could adjust to the impact of the Bolshevik revolution.
For a more detailed coverage of Mussolini's relations with the internal currents of early fascism, and for the illustration of the traditional distinction between "party" and "movement", one should check De Felice's *Mussolini*, especially vol. 1-2-3. As well as De Felice's additional works on the relations between Mussolini, De Ambris and D'Annunzio centered around the "Fiume endeavor" (for context on the latter, one should check Alatri, P. *Nitti,D'Annunzio e la questione Adriatica*)
In more recent years, specific works have attempted to cover Mussolini's experience as a more or less prominent figure of Italian socialism and his eventual transition to revolutionary interventionism and then to "national" interventionism.
Di Scala, E. ; Gentile, E. - *Mussolini 1883-1915, Triumph and transformation of a revolutionary socialist* [2016]
For a comprehensive examination of the ongoing social and political landscape across the Great War, I would nonetheless recommend Vivarelli, R. - *Storia delle origini del Fascismo* and his *Il fallimento del liberalismo* - the latter especially more focused on the elements of weakness of the Italian liberal system. In English, but much shorter and with a different (and far more "British") perspective on Italian liberalism, Seton-Watson C. - *Italy, from liberalism to Fascism, 1870-1925* [1967]. | [
"In the book, Goldberg argues that both modern liberalism and fascism descended from progressivism, and that before World War II, \"fascism was widely viewed as a progressive social movement with many liberal and left-wing adherents in Europe and the United States\". Goldberg writes that there was more to fascism t... |
Can a solar system or star get pulled into a different galaxy? | In around four billion years our galaxy will collide with the Andromeda galaxy (Since galaxies are largely empty space with the odd solid bit - it won't be quite as violent as it might seem - probably).
Assuming that the two galaxies subsequently go on their merry ways (imagine a comet having a close pass with the sun) then it is likely that the two galaxies will exchange some mass (solar systems) during the encounter.
There are two parts of the interaction that are likely to be interesting:
1. The action of the centre of masses of the galaxies on solar systems.
2. The specific interaction when two solar system pass near each other.
Both of these types of interaction can/will disturb orbits and could lead to a solar system (or part thereof) to be pulled into a new orbit. | [
"This galaxy is known to contain two counter-rotating populations of stars. That is, one set of stars is rotating in the opposite direction with respect to the other. One means for this to occur is by acquiring gas from an external source, which then undergoes star formation. An alternative is by a merger with a se... |
Is the Higgs field an actual physical field of energy? | First off the Higgs field is as real a field as any other field and was predicted in the 60's. As to whether particles or fields are fundamental or mathematical tools, that is really a philosophical question. | [
"In the Standard Model, the Higgs field is a scalar tachyonic field \"scalar\" meaning it does not transform under Lorentz transformations, and \"tachyonic\" meaning the field (but not the particle) has imaginary mass, and in certain configurations must undergo symmetry breaking. It consists of four components: two... |
Why is the direction of the torque vector significant? | The direction of the torque vector is only significant once an arbitrary convention (i.e. the right hand rule) has been chosen. Really I think it make more sense to think of toques and angular momenta as defined by a plane plus a direction of circulation than it does a vector. However, there's a nice property in three dimensions that each plane has exactly one direction perpendicular to it, and we can define a direction/magnitude of circulation by specifying a given vector along the direction of that normal.
From this point of view the direction (in or out) is just a stand in for the direction of circulation of the plane. In some ways the plane picture is better, however most of the math you would have developed is better at using vectors and since this one to one correspondence between the two exists we can jump back and forth between the two.
that was a bit rushed by I hope its clear.
As for the second question radians are dimensionless so the units of meters/radian are the same as the units of meters. Radians are the ratio between the arclength (distance around the circumference) and the radius. ratios of two things with the same units are dimensionless. | [
"Due to the way the torque vectors are defined, it is a vector that is perpendicular to the plane of the forces that create it. Thus it may be seen that the angular momentum vector will change perpendicular to those forces. Depending on how the forces are created, they will often rotate with the angular momentum ve... |
law of conservation of mass | It's like when you're playing with your legos, buddy. You can take your house apart, make it into a car, move the bricks closer together or further apart. But you can't break the bricks, they're indestructible. Now pretend everything in the world is made of legos which are so tiny that you can't see them, those are called atoms. Atoms work in almost the same way as legos, if you burn, cut or pull something apart then you only break that thing, but not the legos. The legos stay. Do you get it? | [
"The law of conservation of mass can only be formulated in classical mechanics when the energy scales associated to an isolated system are much smaller than formula_1, where formula_2 is the mass of a typical object in the system, measured in the frame of reference where the object is at rest, and formula_3 is the ... |
just seen captain phillips, why are cargo ships sailing around the horn of africa so poorly defended? | International maritime law forbids arming merchant ships. | [
"Several factors combine to make the passage around Cape Horn one of the most hazardous shipping routes in the world: the fierce sailing conditions prevalent in the Southern Ocean generally; the geography of the passage south of the Horn; and the extreme southern latitude of the Horn, at 56° south. (For comparison,... |
why can't robots move exactly like humans yet? what is holding engineers back? | The trouble is software. We have the technology to build the physical machine itself. We could build an artificial skeleton with artificial tendons and muscles and the necessary sensors, but developing the software to control it all simultaneously in a way that duplicates human movement is a daunting task. | [
"Robots able to co-exist and co-operate with people and reach or even surpass their performance require a technology of actuators, responsible for moving and controlling the robot, which can reach the functional performance of the biological muscle and its neuro-mechanical control.\n",
"The tendency to build robo... |
why can't the cellular infrastructure that is in place to provide 3g and lte just be used to create a giant wifi network? | Those networks use different standards to provide their signals. It's not like it's all using the same frequency for all of the various forms of wireless. [Source.](_URL_0_) | [
"3G networks have taken this approach to a higher level, using different underlying technology but the same principles. They routinely provide speeds over 300kbit/s. Due to the now increased internet speed, internet connection sharing via WLAN has become a workable reality. Devices which allow internet connection s... |
why are "bologna" and "lasagna" pronounced so utterly differently? | We've Americanized the pronunciation of *bologna* a lot more than *lasagna*. | [
"\"Knöpfle\" means \"small buttons\" and describes the compact, round form of the pasta. In everyday language usage, the two names refer to the same product made from the same dough and are interchangeable. There is no clear distinction between the way the two names are used and usage varies from one region to anot... |
I'm an extremely deep-sleeper, and have massive troubles waking up on time. Is there a scientific alarm solution? | I read about using sunlight/simulated natural light to help people wake up: _URL_0_
I use a similar thing but I go low-tech when trying to wake up my 5-year-old (not an easy task) and just turn on the light. | [
"Scientific studies on sleep having shown that sleep stage at awakening is an important factor in amplifying sleep inertia. Alarm clocks involving \"sleep stage monitoring\" appeared on the market in 2005. The alarm clocks use sensing technologies such as EEG electrodes and accelerometers to wake people from sleep.... |
how can banks detect if someone else is using your credit/debit card when the amount is small and the location of purchase is near? | What was the store? What was the time? Had you made any other purchases recently?
Fraud detection systems work by finding patterns in your spending and flagging things that don't fit the pattern. If it's in a weird city when you're normally at work & not buying things at all, that's going to flag things. If you're a guy & suddenly you're buying lingerie, it might raise a flag. If a purchase 10 minutes away is made 5 minutes after a purchase you make, it might trigger an alert. If you always shop at Safeway & they see you shopping at Publix, it might raise a flag. If you filled up your gas tank yesterday & you're buying gas today, it might raise a flag. If you always use debit+PIN & they ran the charge as credit, it might raise a flag. If they entered your PIN wrong twice, it might raise a flag. There's probably hundreds of other things they look at - exactly what they look for is kept a secret.
Sometimes, no one thing is enough to trigger a warning - it takes a combination of things, possibly spread over multiple transactions, to really be sure that something might be fraud. | [
"The Senate report identified \"data pass\", or the automatic transfer from the merchant after the transaction of the customer's credit card information. Information provided by the Federal Trade Commission and the National Association of Attorneys General, and information collected from telephone billing has found... |
Why is Napoleon often portrayed with his right hand tucked into his vest? | The pose is quite common in period paintings:
Directly bearing on the "hand-in" posture, and underpinning Nivelon's description of it as "manly boldness tempered with modesty," is Bulwer's "Sixth Canon for Rhetoricians," which claims that "the hand restrained and kept in is an argument of modesty, and frugal pronunciation, a still and quiet action suitable to a mild and remiss declamation."
_URL_0_
| [
"The hand-in-waistcoat (also referred to as hand-inside-vest, hand-in-jacket, hand-held-in, or hidden hand) is a gesture commonly found in portraiture during the 18th and 19th centuries. The pose appeared by the 1750s to indicate leadership in a calm and firm manner. The pose is most often associated with Napoleon ... |
albinism seems like a very disadvantageous mutation. how has it continued in the animal kingdom? | A mutation can appear more than once in time. Albino animals pretty much never have albino parents, it just appears randomly and likely subsides again as the chances of reproduction are lowered. The parents have instead carried an albino gene, without being albino themselves. | [
"Oculocutaneous albinism is generally the result of the biological inheritance of genetically recessive alleles (genes) passed from both parents of an individual such as OCA1 and OCA2. A mutation in the human TRP-1 gene may result in the deregulation of melanocyte tyrosinase enzymes, a change that is hypothesized t... |
what happens when my computer is connecting to/loading a website/? | There's many steps, but here is a simple explanation:
You send an "HTTP request" to the server. HTTP is the protocol commonly used to send/receive data on the internet. Let's just say it's like the format of when you write your address and destination address on an envelope.
This request will look something like this (They don't always look like this, but most contain these common "headers"):
GET /r/explainlikeimfive/ HTTP/1.1
Host www._URL_1_
User-Agent Mozilla/5.0 (Windows NT 6.1; WOW64; rv:29.0) Gecko/20100101 Firefox/29.0
Accept text/html,application/xhtml+xml,application/xml;q=0.9,/;q=0.8
Accept-Language en-us,es;q=0.5
Accept-Encoding gzip, deflate
Referer _URL_0_
That's saying that I want to access "/r/explainlikeimfive" from the host "www._URL_1_". This is how the server know what page I want.
The "user-agent" tells the server I'm using "windows NT 6.1" which just means Windows 7. The "Gecko" and "Firefox" basically just mean I'm using Firefox. (Fun fact, see that "Mozilla" at the very start of the user agent string? All browsers include this, even IE, Chrome, Safari, etc. It's a neat bit of trivia that I won't go into, but you can look it up)
The "Accept-Language" header tells the server my browser preference. Right now it's set to US English, followed by Spanish. If I made Spanish first, and I visited Google, I'd get Google in spanish. That happens purely because Google's server sees my language preference, and changes the response. Most sites would probably ignore it.
The "Referer" tells the server what page I was on when I clicked that link. In this case, it was the Reddit homepage.
So, all these headers and their values get sent to the server whenever you try to access anything on the internet. They tell the server exactly what you're trying to access, and the server responds with it (assuming everything is OK). If everything is good, it'll respond with response code 200. If the file wasn't there, it would give a 404. If the server encountered an error trying to get it, it'll respond with 500.
Keep in mind that this is what happens on the very top level. Networking workis via different protocols and layers, all stacked on each other. Before anything I explained even happens, for example, the TCP/IP protocol is used to get the IP address of _URL_1_, establish connection, etc.
TL;DR: You send some headers that tells the server what content you want, and the server responds with it.
| [
"Each time a user visits a website using Microsoft Internet Explorer, files downloaded with each web page (including HTML and Javascript code) are saved to the Temporary Internet Files folder, creating a web cache of the web page on the local computer's hard disk drive, or other form of digital data storage. The ne... |
Why is the modern nation of Ghana located far southeast of the medieval kingdom of Ghana? | This question comes up from time to time. My answer in [this thread](_URL_0_) gives the specific context for how the Gold Coast colony came to be named Ghana. Also, [this post from last month](_URL_1_) provides additional context about the oral traditions that Danquah was drawing on to justify the connections. | [
"Ghana was inhabited in the Middle Ages and the Age of Discovery by a number of ancient predominantly Akan kingdoms in the Southern and Central territories. This included the Ashanti Empire, the Akwamu, the Bonoman, the Denkyira, and the Mankessim Kingdom.\n",
"Thus, although the Ghana Empire was geographically d... |
Why do old portraits all look so similar? I feel like I have no idea how these people really looked. | I don't think this is universally true; if you look at the portraits by Hans Holbein the Younger for example it starts to become very obvious that these people all look different. Some people have rather large noses, some people have rather wide or round or skinny cheekbones, some people have the most absurd tiny eyes, and so on and so forth. This is most obvious when you look at his male portraits; it's a little less visible in his female portraits but it's present. Bear in mind also that all these people are wearing very similar clothing and formal robes; because we are used to using very visible differences in clothing habits, hairstyles and dress to tell people apart(think about how recognizable some of your friends are simply by their haircut or the way they dress) and strongly expect old portraits to be idealized(not that they weren't; but a greater or lesser degree of idealization is always a intentional choice on the part of the artist) we might also be less sensitive to subtle distinctions in their appearance. Indeed, once we look more closely at the portraits of his wives in sequence, salient differences emerge in the length of their faces, their noses, how deep-set their eyes are, the prominence of their chin and so on and so forth. A useful point of comparison is the rather nasty racist joke that 'all Asians look alike"; in the same way we tend to mentally categorize all people in 16th century paintings as looking alike. This extends to the clothing; the fact is that a typical modern viewer is going to be less sensitive to the vagaries of 16th century fashion and less sensitive(in a world where virtually everyone wears cheap and affordable comfortable cotton or synthetic fabrics on a regular basis) to the different textures and qualities of linen, silk, taffeta, velvet, or brocade is probably going to not recognize subtle differences in dress that would be glaringly visible to a 16th century viewer-look at for example how the portrait of Jane Seymour you probably saw shows a much wider collar than the portrait of Anne of Cleves, or how much more loosely and widely cut and fabric-intensive the clothes of Anne of Cleves look. | [
"Portraits are natural reflection of real people. The ability to achieve a true likeness was greatly valued until the mid-nineteenth century. However, once photographs became common, artists could use their skills to show something about the subject that no camera could match. In addition to showing the person, a g... |
Chinese(?) coins | Based on your drawing the first one is from the period of the Daoguang 道光 Emperor, the 8th Qing emperor who ruled from 1820 to 1850. The second is from the reign of the Shunzhi 順治 Emperor, who was the third Qing emperor, ruling from 1644 to 1661. The side with Chinese characters just says the name of the empepror and that it's money (通寶).
The other side is written in Manchu and says "Ministry of Revenue" on both coins. That's the minting authority, which in this case was in the province of Chihli, which no longer exists today as a modern administrative division. Basically Beijing, though.
Chances are these are not authentic. A lot of these are made as tourist trinkets and you can get them for literal pennies. If they look to be very similar in condition and material, then it's almost certain that they are knock-offs, since if they were authentic you'd expect the 200 years differnce of when they would have been minted (if authentic) to leave different patterns of ware. Even if they are authentic, the Daoguang one isn't going to make you rich. Neither is the Shunzhi though it might arguably be worth more. You'd obviously need them authenticated by a collector to really know, though.
Also your red is pretty darn accurate. Well done! | [
"Chinese coinage during the Spring and Autumn and Warring States periods includes some of the earliest coins produced in the world. However, they were mostly not the typical round shape of modern coins. They included cowrie shells, ant nose money, spade-shaped money and knife-shaped money.\n",
"Chinese coins of t... |
How are artifical sweeteners digested by the body? | It depends on the sweetener. They are very different molecules.
Aspartame, brand name Equal, is basically a tiny protein molecule with an alcohol molecule stuck on the end. It gets broken apart into its component parts and they are digested separately. This generates about 4 calories per gram-- the same as sugar.
The reason aspartame is a "low calorie" sweetener is that it's 200 times sweeter than sugar, so you use much less of it. Instead of two teaspoons of sugar, you use one blue sweetener packet, which contains 0.04 grams of aspartame and some filler.
Sucralose, brand name Splenda, works differently. It's low calorie because the body does not recognize it as a nutrient, so it doesn't get digested at all. It passes through the digestive tract unchanged, and almost entirely unabsorbed. The tiny amount of sucralose that does get absorbed into the bloodstream gets excreted right back out again, still unchanged, in the urine. | [
"BULLET::::- Low-calorie sugars and artificial sweeteners are often made of maltodextrin with added sweeteners. Maltodextrin is an easily digestible synthetic polysaccharide consisting of short chains of glucose molecules and is made by the partial hydrolysis of starch.\n",
"Sweet taste signals the presence of ca... |
I have some hypothetical questions about magnetic spheres. | Based on what I can understand of your question you are horribly misunderstanding magnetism.
Reason: Your spheres are impossible.
Without a path to complete what I generally hear termed the "magnetic circuit" you are effectively looking at some sort of magnetic monopole type structure which is (as far as science understands so far) is impossible.
By "thicker" and "thinner" it sounds like you are thinking of a spherical shell but the same idea of inability to complete the circuit applies even when they are within each other. Does that make sense? (as in, flux lines from the very center cannot loop back out as they want to)
Also, magnets cannot be magnetized spherically like you indicate. It can be approximated with smaller magnets put together but can't just be magnetized that way to begin with. (_URL_0_)
Is there a particular reason you are asking? That will direct how I can address perhaps creating a type of situation like you're thinking of. | [
"The spheres are to in diameter (larger than Geomag), approximately in weight, and are prone to surface corrosion, unlike most other magnetic construction toys. The bars with magnets at each end are long, or , or and flexible, or short rigid curves. Panel shapes include two types of interlocking triangles, interloc... |
Why don't we create a small scale nuclear reactor to power cars individualy? | The cost is far too high for it to be reliable and consistent, and the waste produced would be difficult to manage, depending on the type of fuel used. | [
"Reactors used in nuclear marine propulsion (especially nuclear submarines) often cannot be run at continuous power around the clock in the same way that land-based power reactors are normally run, and in addition often need to have a very long core life without refueling. For this reason many designs use highly en... |
in terms of microeconomics, how does piracy of digital goods affect supply, demand, sale, price, etc.? | Within a narrow context, piracy has two effects. It depresses or increases potential demand for a product at the rate at which the file spreads through a population. There's less than 1 to 1 correlation between the number of people with an illicit copy who drop out of the demand population. The number of people who will potentially purchase a file through sanctioned means can sometimes be greater with a moderate amount of piracy than with none at all, due to marketing and to pirates who pay their respects. In other cases, piracy allows a digital good to be sampled at no cost to the consumer, and the product fails due to lack of appeal or quality. | [
"According to the same study, even though digital piracy inflicts additional costs on the production side of media, it also offers the main access to media goods in developing countries. The strong tradeoffs that favor using digital piracy in developing economies dictate the current neglected law enforcements towar... |
why do emojis show up differently on ios vs android devices? | Well consider it like a different font type. It still conveys the same information, but it is a separate style. | [
"The second problem relates to technology and branding. When an author of a message picks an emoji from a list, it is normally encoded in a non-graphical manner during the transmission, and if the author and the reader do not use the same software or operating system for their devices, the reader's device may visua... |
Did the Romans have some concept of 'standardized spelling'? | I think this depends entirely on what era you're looking at.
So far as I am aware, there wasn't an institution in Rome that said "Ok, everyone, amicus is a second declension noun, not a fourth declension one!" I'm not sure how linguists would approach this issue, so I can't speak to how everyone agreed that it should be "amicus, amici." There doesn't seem to be the same variation of dialects that you get with ancient Greek writings.
However, the educational curriculum was extremely conservative insofar as people studied the same Latin texts regardless of where they were in the empire. By the late antique period, people studied Vergil and Cicero (and a few others), and being able to write like them was considered the gold standard of Latin writing. | [
"In its spelling, it retains medieval Latin orthography, sometimes using \"oe\" rather than \"ae\", and having more proper nouns beginning with \"H\" (e.g., \"Helimelech\" instead of \"Elimelech\"). Unlike the edition of Rome, it standardizes the spelling of proper names rather than attempting to reproduce the idio... |
if someone were to dip a live electrical wire into the ocean, wouldn't everyone swimming in the ocean at that time be electrocuted? | No. Electricity moves from one place to another place, along the path of least resistance. It doesn't spread out and electrocute everything that happens to be in the same body of water.
In the case of an electrical wire in the ocean, it'd likely prove dangerous to things within a few feet of it (maybe even a few dozen feet), but that's about it. | [
"There is no visible warning to electrified water. Swimmers will be able to feel the electricity if the current is substantial. If the swimmers notice any unusual tingling feeling or symptoms of electrical shock, it is highly likely that stray currents exist and everyone needs to get out. Swimmers should always swi... |
why did we domesticate chickens for the use of eggs and not other birds? | Most likely because they tend to be slow, their eggs full of protein and they can't fly. Chickens are probably a lot easier to domesticate over a pigeon, for example. | [
"The domestication of poultry took place several thousand years ago. This may have originally been as a result of people hatching and rearing young birds from eggs collected from the wild, but later involved keeping the birds permanently in captivity. Domesticated chickens may have been used for cockfighting at fir... |
Does the "subconscious" really exist? | As DeathSquid5000 said, it's really just a catch-all term for cognitive processing that you're unaware of, for example, a lot of decision-making processes (most of which seem to occur outside of awareness, although you'll likely be inclined to think otherwise). In terms of the singular, nebulous, primal, almost mystical construct that Freud discussed... evidence is currently not working in his favour.
An interesting unconscious process can actually be seen in the phenomenon of [blindsight](_URL_0_), which is seen in people who lack conscious visual perception due to the destruction of their primary visual cortex (a.k.a. striate cortex, V1, or Brodmann Area 17), or at least part of it. They still retain above-chance ability to react to objects presented in the blinded areas of their visual field, which suggests some unconscious processing in other brain areas (~10% of retinal neurons don't project to V1), or in the lateral geniculate nucleus in the thalamus (which is the step before V1). Some people have suggested that their may be "islands" of intact striate tissue remaining, though, but it's hard to be sure due to the fact that researchers need to use human patients with pre-existing cortical damage, which will pretty much never be uniform from one patient to the next. (Of course, surgical cortical lesions could be done in monkeys, chimpanzees, etc., but I'm not sure of what's happening as far as research into non-human blindsight is concerned.)
Also, the idea of "accessing" the subconscious may be taken to imply that it's a singular entity or cognitive store, which it really isn't. Still, hypnosis and lucid dreaming appear to allow us to tap into some of our unconscious processes, since they can aid in memory recall and, in the case of lucid dreaming, even allow us to analyse our emotional states and aspects of our memories and lives that we normally don't seem to be able to consider. Also, hypnosis patients sometimes report that there is an almost separate subconscious aspect to themselves that is able to perceive things that are happening when their "conscious mind" is hypnotised, although, like with any hypnosis research, you do get a lot of skeptics out there. | [
"The word \"subconscious\" represents an anglicized version of the French \"subconscient\" as coined by the psychologist Pierre Janet (1859–1947), who argued that underneath the layers of critical-thought functions of the conscious mind lay a powerful awareness that he called the subconscious mind.\n",
"Charles R... |
Does tourettes exist in all languages and if so does it manifest itself differently in different cultures? | Verbal tourettes is just a very small part of the disorder at about 12% of the individuals who have it and of those only a small percent expel curse words. Most manifestations occur in physical repetitive motions such as tapping or twitching and can be as grand as siting down repeatedly. So yes it happens in all cultures in many different ways | [
"Tripura has several diverse ethno-linguistic groups, which has given rise to a composite culture. The dominant cultures are Bengali, Manipuri, Tripuris, Jamatia, Reang, Naitong, Koloi, Murasing, Chakma, Halam, Garo, Hajong, Kuki, Mizo, Mogh, Munda, Oraon, Santhal, and Uchoi.\n",
"In South Asia, they are known as... |
How close to the Moon would you have to be before you would fall to the Moon instead of to the Earth? | "Zero velocity" is a little ambiguous in this context, since the earth and the moon are each moving with a different velocity. Let's take that to mean zero velocity with respect to the center of mass of the Earth-Moon system. In that case, we can define r_moon and r_earth to be your height from the center of each body, with the constraint that r_moon+r_earth=400,000 km, the approximate earth-moon distance. This tells you that r_moon/r_earth =sqrt(m_moon/m_earth) =0.11. So something like 90% of the way to the moon is where you would start to fall towards the moon and not the earth.
One problem with this position is that the moon would be zipping sideways from you, and as it gets farther away you would start to fall back towards the earth again. A more useful number is the [L1 Lagrange point](_URL_0_). Here we assume "zero velocity" means that you stay between the earth and the moon. This means you have to add in some centrifugal forces to balance things out, but it turns out that at that point you would hover between the earth and the moon without falling towards either one. Less intuitively, there are four other points that have this property: one behind the moon, one behind the earth, one "ahead" of the moon's orbit, and one "behind" the moon's orbit. They are useful places for [satellites](_URL_1_). | [
"BULLET::::- (~3 meters in diameter) may have passed as close as 0.97 lunar distances (371,000 km) from Earth (0.68 lunar distances (261,000 km) from the Moon on either April 14 or 15th, 2014, but the nominal orbit calculates an approach of 1.29 lunar distances (495,000 km) from Earth (1.23 lunar distances (473,000... |
What would it mean if we proved that P = NP, or P != NP ? | A side remark: polynomial time is usually taken to be a short amount of time, and in the limit of large inputs it is much much *much* smaller than exponential time. However, even if someone proved that P=NP, it could still be the case that the complexity of a problem scales as n^(100000000) or something ridiculous like that. Talking about crypto for example, it means that there could be crypto protocols that although are broken in polynomial time, they take forever and a day to break for all practical purposes. So the possibility that they are secure wouldn't be completely ruled out.
P and NP, and the 'polynomial hierarchy' in general, are really coarse grained gauges of the complexity of a problem. P=NP would mean that we would have to go to 'finer grains' to distinguish the difficulty of problems. | [
"The question of whether P equals NP is one of the most important open questions in theoretical computer science because of the wide implications of a solution. If the answer is yes, many important problems can be shown to have more efficient solutions. These include various types of integer programming problems in... |
Why are mid-air manifestations of electricity jagged? (i.e. sparks, lightning bolts etc.) | This was a really interesting question that I didn't know the answer to so I looked it up. [This Scientific American article](_URL_0_) does a pretty good job of explaining it. | [
"ESD can create spectacular electric sparks (lightning, with the accompanying sound of thunder, is a large-scale ESD event), but also less dramatic forms which may be neither seen nor heard, yet still be large enough to cause damage to sensitive electronic devices. Electric sparks require a field strength above app... |
"Photons" of different EM spectrum? | All electromagnetic waves are made of photons -- visible light, radio waves, X-rays, gamma rays, ultraviolet light, infrared light, you name it. | [
"EM radiation can have various frequencies. The bands of frequency present in a given EM signal may be sharply defined, as is seen in atomic spectra, or may be broad, as in blackbody radiation. In the photon picture, the energy carried by each photon is proportional to its frequency. In the wave picture, the energy... |
why is being deaf or blind much more common than say having no taste, touch, or smell? | Part of it is confirmation bias. Blind people are really obvious, deaf people are fairly obvious. You wouldn't know someone couldn't smell or taste just by looking at them.
Localized loss of touch is not uncommon. But you have so many touch receptors in so many places, there are few conditions that will systemically shut down all of them. | [
"This interplay of various ways of conceiving the world could be compared to the experience of synesthesia, where stimulus of one sense causes a perception by another, seemingly unrelated sense, as in musicians who can taste the intervals between notes they hear (Beeli \"et al\"., 2005), or artists who can smell co... |
how can the un give sanctions for nuclear weapons to some countries and not to others? | The nuclear nonproliferation treaty recognized the then-nuclear states as legit, and called on them to disarm to some degree (which they haven't) and tried to prevent nuclear capability from further spreading. It's called, creatively, The Treaty for the Non-Proliferation of Nuclear Weapons (NPT) of 1970.
Edit: India is not a signatory to the treaty, North Korea un-signed it, I believe. It permits Russia to have their weapons. Russia, France, the U.K., the U.S., and China are all permanent security council members with vetoes - that means that any of them can unconditionally strike down any legislation from the U.N. that they don't like. | [
"According to the Charter of the United Nations, only the UN Security Council has a mandate by the international community to apply sanctions (Article 41) that must be complied with by all UN member states (Article 2,2). They serve as the international community's most powerful peaceful means to prevent threats to ... |
What language/script is this? Where can I have it translated? | This is almost certainly Yiddish(essentially late medieval German in Hebrew script). I do not myself read Yiddish but /r/Judaism and /r/Yiddish would be able to help here. | [
"The text has also been widely translated under different titles into Asian languages such as Burmese, Khmer, Thai, Malay, Persian, Sinhala, as well as into Dutch, English, French, German, Greek, Spanish and Russian. \n",
"It has been translated into at least 17 languages, including Hebrew, Spanish, Dutch, Hungar... |
What oscillates in light? | The thing that oscillates is the electromagnetic field of the photon itself. It is a self-sustaining electromagnetic field. A changing magnetic field induces an electric field, and vice versa. | [
"When discussing the quantum theory of light, it is very common to use an electromagnetic oscillator as a model. An electromagnetic oscillator describes an oscillation of the electric field. Since the magnetic field is proportional to the rate of change of the electric field, this too oscillates. Such oscillations ... |
Medieval French translation help (again!) | Looks like an ancient french version of the actual « cuillère » ("spoon").
Source : french and historian | [
"The Medieval Translator (French \"Traduire au Moyen Age\") is an annual volume of studies dedicated to translation in the Middle Ages and the study of translation of medieval texts. First published in 1991, it has been published since 1996 by Brepols. The volume comprises a collection of papers read at the Cardiff... |
Who were the Desert Fathers? What was their impact on early Christianity? What happened to them and the desert monastic movement? | The desert fathers emerge toward the end of the fourth century as Christianity transitioned from a fringe cult to an accepted community in the pantheon of faiths. While earlier Christian communities had faced persecution and martyrdom, in this new period asceticism became the hallmark of true commitment to the faith. Thus some Christians sought to lead a life marked by exceptional ascetic rigor while pursuing constant prayer and fighting the temptation to return to the world. These figures spent their time alone in caves, atop pillars, or in the ruins of old roman structures now reclaimed by the wilderness and often gained a reputation for sanctity and holiness in their local community, becoming—ironically—something of an attraction and public figure. St. Anthony, whom historians consider to be the first of these "Desert fathers," retreated to the desert sometime in the late third century after giving away a large inheritance he had recieved from his parents. As a hermit living in an old military outpost, his commitment to prayer and the memorization of the bible attracted a number of followers that he organized into a informal monastic community that continued until his death in probably 356.
Some later emulators took Anthony's message of retreating from the world a little too seriously. My favorite example is [Saint Symeon the Stylite](_URL_0_), who, frustrated at the incessant visitors who came to him for prayers, placed himself atop a pillar to escape their pleas.
The communities that formed around these Desert Fathers became the earliest monasteries, ordering themselves around a communal set of principles. These "Rules" by which they lived their life formed the backbone of the monastic movement as it spread across the Late Antique world, although the earliest focused on physical work and communal prayer, not the intellectual work and reading that later monasticism would become known for.
This is merely a cursory sketch of the very large question you have outlined. I might suggest some further reading if you feel interested. [Peter Brown's The Rise and Function of the Holy Man in Late Antiquity (1971)](_URL_1_) remains the fundamental text for understanding the growth and social importance of these figures. For a more general overview, I would still recommend Peter Brown. His World of Late Antiquity is now in its Third Edition, and has an excellent chapter on the desert fathers and the growth of monasticism.
| [
"The Desert Fathers were Christian hermits, and ascetics who had a major influence on the development of Christianity and celibacy. Paul of Thebes is often credited with being the first hermit monk to go to the desert, but it was Anthony the Great who launched the movement that became the Desert Fathers. Sometime a... |
how did my plane yesterday depart late but it was able to reach the destination before it's original scheduled arrival time? | We generally do not fly "as fast as we can go". We fly at a speed that is calculated by our airline to be a nice balance of speed and fuel economy. However, if a flight is behind schedule and could potentially impact the departure times of flights further down the line, then we can be authorized to kick it up a notch, so to speak, and try to make up some time in the air. We can also pester air traffic control for a few extra "shortcuts" along the way if we really feel that we need to catch up a bit with our schedule. | [
"After flying , the aircraft passed the control tower back at Carswell on March 2 at 10:22 am, marking the end of the circumnavigation, and landed there at 10:31 a.m. after having been in the air for 94 hours and one minute, landing two minutes before the estimated time of arrival calculated at take-off.\n",
"BUL... |
How did Taiwan handle the massive influx of Chinese refugees following the Chinese Civil War? How did the Kuomintang "set up shop", so to speak? | In the memoir of Taiwanese author [Chiung Yao](_URL_0_), she said because her father was an intellectual and easily found another professor job, her family received a Japanese style house the size of twenty ["tatami"](_URL_1_) from the university. Her family was still extremely poor despite being better off than most refugees.
Another Taiwanese author named Liu Hsia wrote in her memoir that a family of fellow refugees could barely survive on the father's army pension with five kids. The author's father wanted to help them out so he resorted to forging a letter of recommendation and found a nurse position for the mother.
The less fortunate ones with fewer resources and connection would live in what they call "Military dependents' Village" consists of very poorly built houses similar to slums. They were originally intended to be temporary housing built with organic materials, but eventually the buildings were replaced with more permanent structures. In recent years those communities were demolished and replaced by low cost high rise apartment buildings. | [
"Prior to the 1950s emigration from Taiwan (ROC) (then called Formosa) was negligible. In 1949, the Chinese Communist Party took control of mainland China, and 2 million refugees, predominantly from the Republic of China (ROC) Nationalist government, military, and business community, fled to Taiwan. Since the 1950s... |
Why did the Tlaxcalans allow Cortes to remain in Tenochtitlan/Mexico? | There's two big misconceptions that are commonly held about post-Conquest Mexico: that Hispanicization progressed rapidly and the native population faced discrimination equally. I covered in a [previous post](_URL_2_) how life in Mesoamerica basically continued on with business as usual for almost a generation after the fall of Tenochtitlan. This was doubly true for the Tlaxcalans since they were not only granted great leniency in "New Spain" in maintaining independent governance, but also the end of what was basically an Aztec embargo on trade.
The point made again and again is that, when the Spanish arrived, the Tlaxcalans had neither salt nor cotton, those two items standing in for a whole range of trade for not only luxury, but staple goods that the Aztec encirclement had cut off. Hassig, in *Aztec Warfare* makes the point that the *xochiyaoyotl* (flower wars) which had typified conflicts between the Aztecs and Tlaxcalans had, in the years leading up to the Spanish arrival, been becoming more intense, more bloody, more vicious, and more territorial. The whole idea of the Tlaxcalans manipulating the Spanish into the Cholula Massacre was that it had recently flipped from being sympathetic to the Tlaxcalans to shifting allegiances to the Aztecs. Since Cholula sat on the doorstep of Tlaxcala, this was a major blow to their state security.
Thus, after the Tlaxcalans and Spanish spent a few rounds beating the crap out of each other, they eyed each other up and entered into a mutually beneficial alliance. To suggest that the Tlaxcalans manipulated the Spanish to their own gain is, well, to understand the political landscape of Postclassic central Mexico. To suggest that the Tlaxcalan goal was the conquest of the Aztec states is to misunderstand the restricted role they were in. Fighting the Aztecs was a much a matter of survival for the Tlaxcalans as it was for the Spanish, more so even, since the actual existence of the Tlaxcalan nation was on the line.
There are numerous instances in the Spanish texts and even in the *Historia de Tlaxcala*, written in the 16th Century by a Tlaxcalan-Spanish chronicler, Diego Camargo, supporting the idea that this was a mutual alliance that was highly valued on both sides. For instance, after the deal was struck, Cortés said that they should destroy their "idols," to which the Tlaxcalans basically said, "no thanks."
Gomara's biography of Cortés actually deals directly with this in a chapter titled "The Tlaxcalans Defend Their Idols" wherein the response of the Spanish to the Tlaxcalans rejecting Christianity is thus:
> Cortés answered them, promising that he would send someone to teach and indoctrinate them, when they would see the improvement and the very great profit and pleasure they would have by following his friendly advice; but that at the moment he could not do so because of his haste to get to Mexico.
Yeah, his "haste to get to Mexico."
Cortés, who spent weeks on the Gulf Coast casting down idols and messing with local politics before trekking inland through unknown and hostile lands, is suddenly in a huge rush to get to Tenochtitlan. Just in cast the sarcasm isn't coming through, the modern interpretation of this is that Cortés looked around, saw he had zero chance of forcing conversions without alienating the only friends he had, and opted to table the whole Jesus-thing for a later date.
Other notable events include the famous joint "Tlaxcala! Castile!" cheer and the fact that a powerful noble, the son of one of the Tlaxcalan rulers (like the Aztecs, Tlaxcala was not a singular state but a confederation of *altepetli* tied together by custom and marriage), was put to death for his agitation against the Spanish following their expulsion from the Valley of Mexico after La Noche Triste. Here is Bernal Díaz del Castillo's account of a speech given by Maxixca condemning the noble in question, Xicotencatl the Younger:
> I ask you, do you yourselves think, or have you ever heard others say that such riches or so much prosperity was ever known for the last hundred years in the land of Tlascalla as since the time these teules *[the Spanish]* have appeared among us? Were we ever so much respected by all our neighbours? It is only since their arrival we possess abundance of gold and cotton stuffs; it is since that time only we eat salt again, of which we had been deprived for such a length of time. Wherever our troops have shown themselves with these teules, they have been treated with the utmost respect; and if many of our countrymen have lately perished in Mexico, they certainly fared no worse than the teules themselves. All of you must likewise bear in mind the ancient tradition handed down to us by our forefathers, that, at some period or other, a people would come from where the sun rises, to whom the dominion of these countries was destined. How dare Xicotencatl, taking all this into consideration, contemplate this horrible treachery, from which nothing can flow but war and our destruction? Is this not a crime which ought not to be pardoned? Is it not exactly in accordance with the evil designs with which this man's head always runs full? Now that misfortune has led these teules to us for protection, and that we may assist them with our troops to renew the war with Mexico, are we to act treacherously to these our friends? ([Lockhart trans.](_URL_1_))
You can see the lines about having access to salt and other goods again, but also the idea that "we are in this together," which really does permeate a lot of how the Tlaxcalans and Spanish come off during this period. At the end of the war with the Mexica (in which the Tlaxcalans are noted as engaging in a bit of looting), this paid off in being relatively unbothered by the new Spanish regime. It was a return to normalcy. As Lockhart notes in *Nahuas After the Conquest*, the fact that Tlaxcala was saved from the ravages of war meant that it was also the best organized state in the region, and thus provided a great deal of officials, like traveling judge-governors, throughout central Mexico. Groups of Tlaxcalans also moved north with Spanish/Aztec forces in the pacification of the Gran Chichimeca to establish towns in what are now San Luis Potosí, Coahuila, and Zacatecas. They essentially had an independent state which, while denied tributary domination over the nations in the Valley of Mexico, nonetheless benefited from no longer being under siege and branching outward.
So why didn't the Tlaxcalans end up establishing dominance over the Valley of Mexico. The easy answer is that the Spanish moved very quickly to recognize Mexica nobility and re-establish them in their roles. Descendants of Motecuhzoma II continued to rule Tenochtitlan for decades after the "conquest," and there is in fact a [Spanish ducal title held by his direct descendants](_URL_3_). This lazy ethnocentric answer fails to take into account that, with the surrender of Cuauhtemoc, the Spanish/Tlaxcalans no longer had any cause to press the war further. Despite beating the Mexica back, the idea that Spanish/Tlaxcalan/Etc. forces would completely remove the Mexica from power would have meant a kind of total war that was really outside the discourse. Within the framework of Mesoamerica, the Spanish had made the Mexica a tributary state and the Tlaxcalans had removed the Mexica as a threat. It was win/win.
Let's take a moment, however, and consider another, more speculative reason why the Tlaxcalans did not press for more substantial spoils of war. Well, one reason is that the lands that served as the buffer between Tlaxcala and the Aztecs, Huexotzinco and Cholula, both allied with the Tlaxcalan-Spanish (albeit after the aforementioned massacre at the the latter altepetl). Then there's the fact that the eastern side of the Valley of Mexico and the 2nd most important state in the Aztec Triple Alliance, the Acolhua, flipped to the Spanish early on. Thus, the Tlaxcalans could not exactly demand that land. Other groups in the region, like the Xochimilca, also turned against the Mexica, if not exactly jumping on the Tlaxcalan-Spanish bandwagon. Thus those groups were also not considered to be in conflict with the Tlaxcalan-Spanish forces, which again put them off-limits for punitive measures according to the custom of war in both cultures.
A more speculative view is that, following the 1520 smallpox epidemic, the Tlaxcalan leadership was devastated and unable to effectively press their claims. Accounts generally credit Xicotencatl the Elder and Maxixca as the most important leaders. Xicotencatl most likely died either at the tail end of the conquest or shortly afterwards, while Maxixca is said to have died in the smallpox outbreak leaving some sons which are generally unnamed in the sources as successors, or at least what the Spanish recognized as successors. There's a [passage in Torquemada](_URL_0_) (start at the top of pg. 63) which gives clues to the kind of chaos of succession that followed the death of Maxixca. So one interpretation would be that there was no effective leader to press Tlaxcalans claims post-Conquest, and that by the time there was, the epidemics of 1540s and 1570s would devastate the native population, setting the stage for Spanish control.
| [
"Cortés stayed in the city of Tlaxcala for 20 days and forged an alliance with the Tlaxcalans to bring down Tenochtitlan. Cortes added 6,000 Tlaxcala warriors to his ranks and arrived to Tenochtitlan in November 1519. They were received by Emperor Moctezuma II, who understood the potential danger of a Spanish-Tlaxc... |
moving matter from a neutron star | If you were to bring a chunk of neutron star matter to the Earth, it would expand. Before I can explain this I have to explain what's actually going on in a neutron star.
When a star 'dies' it collapses in on itself and blows off its outer layers of gas. The core that's left is called a stellar remnant. This remnant can become 1 of 3 things, depending on it's mass. If its mass is below 1.44 solar masses (the Chandrasekhar limit) it becomes a white dwarf. If it's above that limit and below 3-4 solar masses(Tolman–Oppenheimer–Volkoff limit,) it becomes a neutron star. If it's above that limit it becomes a black hole. In normal matter, you have electron degeneracy pressure. Under normal conditions, the electrons of a material prevent you from compressing it too much. However, in a neutron star, the energy and pressure is so great that the electrons and protons of the material actually combine to form neutrons. What causes neutron stars from collapsing into a black hole is now neutron degeneracy pressure.
So, if you were to take away some of that material and bring it to Earth, you would no longer have the immense energy compressing it. You'd end up with a large ball of neutrons.
Now free neutrons are quite radioactive so if you were to do this then they'd start decaying and releasing a whole bunch of harmful ionizing radiation. So don't do it :P | [
"When they are formed, neutron stars rotate in space. As they compress and shrink, this spinning speeds up because of the conservation of angular momentum—the same principle that causes a spinning skater to speed up when she pulls in her arms.\n",
"These stars gradually slow down over the eons, but those bodies t... |
we see ordinary city pigeons in most major cities, but never in between (e.g., chicago and denver but not in north dakota). how do they get there? | 1. Pigeons and doves are the same thing. People tend to call them pigeons in cities and doves in the country. They are common in cities and in rural areas. North Dakota has seven types of pigeons/doves.
2. City pigeons are often domesticated pigeons that were released back into the wild (in this case, cities). So humans brought them there.
3. Feral pigeons in cities were domesticated from rock doves that were used to living on cliffs. So hanging out on buildings wasn't that hard of an adjustment.
4. Most birds have to feed their young worms, nuts, seeds, etc. They need access to that type of food. Pigeons can eat pretty much anything, and they can create a special paste that they feed their young. That means they can better survive on the food in cities than other birds, which makes it seem like there are more of them. There is a lot food in cities, and there are fewer birds that can live off of it besides pigeons.
6. There are fewer predators. There are animals like peregrine falcons that eat pigeons in Chicago, but for the most part, there are are more pigeons than animals that eat pigeons. | [
"Several species of local marshland birds and water birds including the little egret, the little green heron and cinnamon bittern, and migratory birds form Northern Hemisphere have been spotted there. Binoculars will come in handy for bird watching. The visitors can also enjoy a leisurely walk, jog or cycle along i... |
it is said that there are more possible games of chess than there are atoms in the observable universe. how is something like this calculated? | I don't think there is an easy way to calculate the exact number of games. One can estimate though and get a ballpark figure. Claude Shannon, father of information theory, was the first one to publish his ballpark estimate. It is based on the assumption that, on average the number of moves available to white, and then black (together) is about a thousand possibilities. Since a chess game lasts about 40 moves or so, the answer is about 1000 to the power 40. That is a one followed by 120 zeros.
The relevant question is not really how many chess games there are, since most of those games are not "good" games. One might wonder how many chess games there are that have good moves in them. This question can be posed more rigorously. Let's define a "good" move as one that does not change the best possible outcome for the side that makes the move. Then one can pose the question, how many chess games are there with only good moves in them. Now, the number is much smaller. But I have no idea how many. | [
"BULLET::::- Chess on an Infinite plane: One type of infinite chess. Seventy-six pieces are played on an unbounded chessboard. The game uses orthodox chess pieces, plus guards, hawks, and chancellors. The absence of borders makes pieces effectively less powerful (as the king and other pieces cannot be trapped in co... |
since a country can print its own currency indefinitely, why can't the us for example just arbitrarily pay off all its debt that way? | Yes. The more money in circulation, the less it's really worth, period. | [
"Another, less used means of maintaining a fixed exchange rate is by simply making it illegal to trade currency at any other rate. This is difficult to enforce and often leads to a black market in foreign currency. Nonetheless, some countries are highly successful at using this method due to government monopolies o... |
How did Egypt become so thoroughly Arabised? | Egypt was under the control of the Arabs directly for six consecutive centuries, and then under the control of people who likely used Arabic for government functions due to the varied origins of the Mamluks themselves. So, in short, for almost a thousand years it was under the control of administrators who spoke Arabic, right in the middle of a large empire where Arabic was the main lingua franca. That is a huge time frame for the language to filter down to the general populace.
As to the second claim, the 'Arabization' of North Africa was mostly a cultural exchange rather than a replacement of peoples. Recent studies suggest that the average Egyptian can likely trace their heritage back thousands of years, and of course, clearly Berbers are a wholely distinct people from the Arabs. The Fertile crescent and Syria is a bit more, but there would have been Arabs and other Semitic peoples there before the Muslim invasions. The truth is that outside of a few isolated points in time, large scale population transfers just weren't that common. While the elites might be replaced, and the language of government and administration might change to reflect that, the change in the general population is generally going to reflect the cultural pressure from above rather than wholesale replacement of populations. This is not to say that some population transfers didn't take place in the Caliphate, but that they are almost certainly a minor component of the over-all Arabization of the Middle-East and North Africa. | [
"During the 20th century, Egypt experienced several waves of revolutions to regain control of their nation from colonial rulers as to create a modern nation-state. Much of Egypt was Muslim at the time although there were significant numbers of Jews and Christians as well, but many of the political revolutions that ... |
Has the U.S. Military ever conducted assassinations of foreign leaders in the past? | Going off that, of the assassinations done by either CIA or military was it widely known who did it or did people think it was different countries? | [
"FAR is most significantly known for having killed the U.S. ambassador to Guatemala, John Gordon Mein, in 1968. Also killed that year were two U.S. military advisers, Colonel John Webber and Ernest Munro, although they might have been killed at the command of PGT leader Leonardo Castillo Johnson.\n",
"In the Unit... |
terryology. | He's just mixing up multiplication and addition. He thinks 1 X 1 is the equivalent of holding up one index finger for each hand and seeing 2 fingers. He also said everyone thinks √4 is 2, so √2 must be 1, but it's not *because we're told it's 2,* which proves that he knows nothing about simple arithmetics. | [
"Occupational therapy—often abbreviated OT—is the \"use of productive or creative activity in the treatment or rehabilitation of physically, cognitively, or emotionally disabled people.\" Most commonly, occupational therapists work with people with disabilities to enable them to maximize their skills and abilities.... |
what is the difference between a bison and a buffalo? | You can find pictures on the internet easily so let me explain why the words got mixed up. We keep them separate because they aren't that closely related.
* ~~In Europe, Asia, and Africa there are only Buffalo. There used to be Bison in Europe but they went extinct thousands of years ago.~~ I read a little more about it and there are Bison in Europe but there weren't very many. They only lived in a small part of Europe because they were hunted a lot, just like the American Bison.
* In The Americas there are only Bison.
When Europeans came to America they saw Bison. They look kind of similar to the buffalo they were knew of so they called them buffalo. They weren't actually Buffalo so we gave them the name Bison, the same name we give to the extinct Bison from Europe.
It's not terrible to call bison buffalo, but it isn't correct. Don't worry about it too much but they are definitely different. | [
"The American bison (\"Bison bison\") is a North American species of bison, also commonly known as the American buffalo. These bison once roamed the grasslands of North America in massive herds; their range roughly formed a triangle between the Great Bear Lake in Canada's far northwest, south to the Mexican states ... |
how to best describe/explain ionization energy and electron affinity? | Ionization energy is the amount of energy that must go into an atom to remove an electron. As you remove more electrons, the amount of energy required becomes larger and larger because of the effective nuclear charge. This pulls the electrons closer and closer to the nucleus, which results in higher energy to pull it off. Once all the valence electrons are removed, the ionization energy increases substantially.
& #x200B;
Electron affinity is basically the opposite. It's the energy that's released when an electron is added to an atom.
& #x200B;
In the context of NaCl, not much energy is required to remove an electron from a sodium atom, and a lot of energy is released when an electron is added to a chlorine atom (in fact, it has the highest electron affinity in the periodic table). | [
"Electron affinity can be defined in two equivalent ways. First, as the energy that is released by adding an electron to an isolated gaseous atom. The second (reverse) definition is that electron affinity is the energy required to remove an electron from a singly charged gaseous negative ion. Either convention can ... |
What happened to the Rockefellers fortune? | This is a complicated question because when people see that the brothers had such a large sum they automatically assume the same thing you did. That wealth typically creates more wealth. The trouble is no one takes into account the time value of money. Which states that money today is more valuable than money tomorrow or a year from now. He was once valued at 336 billion but that was for at that time in history. The value of money decreases over time, plus the brothers were worth that much. Since their deaths it has been split between 200 family members. The fact that they are still able to be wealthy at this day and age is more what we're use to. In that families that are wealthy usually remain wealthy. The Rockefellers actually made some smart investments. They owned Chase Manhattan bank and were large investors in Apple, so their wealth has accrued but the world will never see the same as in the Gilded age. When there was The Rockefellers, JP. Morgan, Carnegie and So on. | [
"At the time of his death, \"Forbes\" estimated Rockefeller's net worth was $3.3 billion. Initially, most of his wealth had come to him via the family trusts that his father had set up, which were administered by Room 5600 and the Chase Bank. In turn, most of these trusts were held as shares in the successor compan... |
what would happen if a massive planet came very close to earth, as in, would our gravity change? | The planets would disrupt each others orbit, draw each other closer together and then shoot apart again, over and over and over like this for years as gravity ripped chunks off of each with every pass, each time getting closer together.
Those chunks would hit both planets turning them into lifeless balls of molten rock before finally slamming together completely, most of which would eventually cool down forming a solid mass, a new planet. The remainder of the materials would orbit around the new planet for a while, most of it raining down in the form of giant meteors, until they too eventually merge together and form a moon.
That's actually how Earth and the Moon were formed. | [
"The absence of close orbiting super-Earths in the Solar System may also be the result of Jupiter's inward migration. As Jupiter migrates inward, planetesimals are captured in its mean-motion resonances, causing their orbits to shrink and their eccentricities to grow. A collisional cascade follows as their relative... |
which one is more environmental friendly - eating with a disposable plate and cutlery to save water; or eating with normal plate and wash them with water and soap? | Washing your dishes is more environmentally friendly. The water is not destroyed in the washing process. | [
"Besides ingredient quality, there are also sanitation requirements. It is important to ensure that the food processing environment is as clean as possible in order to produce the safest possible food for the consumer. A recent example of poor sanitation recently has been the 2006 North American E. coli outbreak in... |
why do animals in a particular ecological niche often look so similar even if they are completely unrelated? | This is a concept called "convergent evolution." Basically, if the pressures on one creature were such that flight was advantageous to survival in a particular environment, those same pressures could easily select for similar variations should they happen to randomly arise in another species.
This is particularly true for those filing the same niche, as the pressures will be particularly similar. | [
"In morphology, analogous traits arise when different species live in similar ways and/or a similar environment, and so face the same environmental factors. When occupying similar ecological niches (that is, a distinctive way of life) similar problems can lead to similar solutions. The British anatomist Richard Owe... |
non-native speaker here, why is "biannually" considered to be twice a year, but "biweekly" only once every two weeks instead of two times per week? | "Biweekly" can refer to either twice a week or two times a week. The same for "bimonthly" (i.e. once a month or two times a month).
The issue stems from the prefix *"bi-"*, which is inherently ambiguous in that it can mean either **occuring twice** or **occuring every two**.
English offers us an alternative with 'annual', as things can either be *"biannual"* (twice a year) or *"biennial"* (every two years). However, using the word "biannual" to mean every two years is also technically correct, and is more often used over "biennial".
*"Bi-"* is one of English's many ambiguities and requires experience with understanding context to decipher its true meaning in a given situation. | [
"Biweekly means either occurring every two weeks, or occurring twice every week. This causes ambiguity when the term is used. As a result, in the United Kingdom, Ireland, Australia and New Zealand, the term fortnightly is more commonly used for an event that occurs every two weeks.\n",
"The custom of \"At Home\" ... |
why are people/businesses moving to the south and not detroit? | A lot fewer unions in the south is a big part. Also rules and regulations setup over decades that are unfriendly to new business in Detroit. | [
"All of these changes in the area's transportation system favored low-density, auto-oriented development rather than high-density urban development, and industry also moved to the suburbs. The metro Detroit area developed as one of the most sprawling job markets in the United States by the 21st century, and combine... |
Would a helium filled balloon float on Mars? | You can solve this with the ideal gas law, pV = nRT. Pressure x Volume = #molecules x ideal-gas-contant x temperature.
Mars' atmosphere is made of carbon dioxide, which has a molar mass of 44g/mol. Air, which is basically an 80-20 mix of nitrogen and oxygen, has a molar mass of 29 g/mol. Helium is 4g/mol. Helium is actually 50% more boyant on Mars than it is on earth. It's looking good, but we haven't factored in the balloon yet.
Balloons equalize pressure between the atmosphere and the gas inside, plus a little tension from the balloon itself. From some random YouTube video, it seem a balloon fully inflated is at 110 kPa. About 10 kPa over earth's atmosphere. On earth this extra pressure due to the balloon's tension is minimal. On Mars, not so much. Mars' atmosphere is at 0.6 kPa, so a fully inflated balloon would be at 10.6 kPa.
The volume of a mol, from the ideal gas law is, V = RT/P. For earth (100kPa, 25C), a mol is about 24L. Which is about a large party balloon, we'll go with that. So the air it is displacing is 29g. The helium is 4g. And the balloon is about 15g. So about 10g of displaced air mass. 10g at 9.81 m/s/s of gravity is 98 mN of lift. About 0.02 pounds for those of you using barbarian units.
The same 24L of martian air is 0.6 kPa(24L) = nR (-55C). So 0.00795 mol. Which at 44g/mol, is 0.35g. Which is way less than the 15g balloon, so even without the helium weight it simply can't be done. The helium at 10.6 kPa is going to be 0.1404 mol. Which will have a mass of 0.56 g. Even the helium itself will weigh more than the displaced martian atmosphere. The displaced 0.35g is replaced by 15.6 g, which at 3.7 m/s/s of gravity is 58mN of force.
98 mN rise on earth, 58 mN sink on Mars, varying obviously with some assumptions and averages I made. Nonetheless, a helium filled party balloon on Mars will definitely not float, but will sink with around the same force one rises at on earth.
As for a balloon on Mars made to be a balloon on Mars, it definitely could be done. After all, helium is actually 50% more boyant on Mars. You'd have to go with a much lighter material, as Martian air doesn't weigh much. Or go with a much bigger latex balloon, as you increase the volume the balloon weight starts becoming a much smaller relative to the volume, by a squared factor. Neither of these will matter though if your helium under pressure still weighs more than your martian atmosphere. You'd have to have much less tension in the balloon to keep the helium at a pressure much closer to the atmospheric pressure. | [
"BULLET::::- Mars has a very thin atmosphere – the pressure is only 1/160th of earth atmospheric pressure – so a huge balloon would be needed even for a tiny lifting effect. Overcoming the weight of such a balloon would be difficult, but several proposals to explore Mars with balloons have been made.\n",
"Fully i... |
Japan and the UK were allies in WW1. What happened to this alliance post WW1 and pre WW2? | Japan's entry into the First World War was a highly measured response. Japan acted against German interests in the Pacific, most notably invading the German concession at Tsingtao. Japan did not put its economy on a wartime footing and only after repeated entreaties by the British did she send some military force into the European theater in 1917, a small destroyer force engaged in ASW operations in the Mediterranean. Japan justified entry into the war on the grounds of the Anglo-Japanese Alliance, an accord that had its origins in the two countries' concerns with defense issues in the Pacific at the turn of the century.
The Anglo-Japanese Alliance had really begun to fracture significantly by the outbreak of the First World War over differing strategic priorities. The initial orientation of the alliance when it was signed in 1902 was as mutual security pact against Russian intervention within the East Asia. The British conceptualized the pact as a means to guarantee imperial defense within India. For their part, the Japanese saw this alliance as a means to gain access to British naval technology and as a means to ensure a friendly Britain in the event of war with Russia. Japan's victory over Russia in the Russo-Japanese War and the latter's subsequent strategic retreat from East Asia because of the Revolution of 1905 changed this strategic calculus. But the ardor for alliance had cooled somewhat even before the Russo-Japanese War. Prior to 1902, London's understanding of the balance of power was that by helping prop up Japan, they would have prevented Russia from capitalizing upon Japan's perceived weakness and expanding into Korea and Manchuria. This strengthened Russia could then pose an even bigger threat to India. In the run-up to the war, Balfour declared of the alliance that:
> If we interpret the Japanese Alliance as one requiring us to help Japan whenever she gets to loggerheads with Russia, it is absurdly one-sided. Japan certainly would not help us to prevent Amsterdam from falling into the hands of the French, or Holland falling into the hands of the Germans. Nor would she involve herself in any quarrel we might have over the northwest frontier of India.
Russia's defeat altered this strategic equation. The negotiations over the alliance's renewal in 1911 illustrated these new strains. Although the Anglo-Japanese diplomatic negotiations were successful and led to a renewal of the alliance for ten years, there was a clear tension between the two nations. Japan had sought British guarantees for support in case Japan went to war with the United States, and London steadfastly refused. Instead, Article IV of the renewed treaty stated:
> Should either High Contracting Party conclude a treaty of general
arbitration with a third Power, it is agreed that nothing in this Agreement shall entail upon such Contracting Party an obligation to go to war with the Power with whom such treaty of arbitration is in force.
Although Article IV does not explicitly mention the US, London had already begun the long process of signing just such an arbitration treaty with the United States that would culminate in the Peace Commissions Treaty of 1914. Renewing the treaty helped forestall any other alliance Japan might make with another power and kept a modicum of security for imperial defense.
For their part, the opinion of the alliance within Japanese elite circles had dimmed considerably by 1911. Katō Takaaki, the Anglophile foreign minister in 1914, was a strong proponent of the alliance and saw fulfilling it as a means to enhance Japanese power and the strength of the foreign ministry. Yet Katō's opinion of the alliance was increasingly a minority one. One of Japan's senior statesmen, Field Marshal Yamagata Aritomo saw Article IV as proof that Japan would have to stand alone in the coming conflict over Asia and the state would have to double its defense burden. The Japanese Navy had already designated the US as Japan's main hypothetical enemy in its budgetary plans by 1907 and had begun a program of naval expansion, the eight-eight fleet.
Within this context, Japan's entry into the war and Britain's reluctance over Japan's belligerence makes more sense. The alliance gave Japan a pretext to enter the war, but on Japan's own terms. Factionalism within the Japanese government and ruling elite meant that Japan's leadership was divided upon what Japan's goals should take. Yamagata Aritomo saw the war as a means to create a rapprochement with Russia and help orient Japan towards an Asian-based land power, undercutting the increasingly expensive naval arms build-up. Katō saw the war as a means to cement Japan's status as an imperial power and take its place with its fellow empire, Britain. Other pan-Asianists within the government saw the power-vacuum created by the war as an opportunity to institute an Asian Monroe Doctrine with Japan as its main enforcer.
Given the Japanese use of the treaty, Britain did not really exert too much effort in renewing it in the aftermath of the First World War. Although Britain initially proposed a tripartite Anglo-Japanese-American pact to keep the Pacific status quo, the US was reluctant to enter into this arrangement. The Washington Conference of 1921 proved the last gasp of the Anglo-Japanese Treaty as British negotiators used the threat of its renewal if the Washington Conference fell apart or was otherwise unfavorable to Britain. The resulting Four-Power Treaty assuring the status quo in the Pacific proved the end of the Anglo-Japanese Alliance, but both the strategic vision of both Japan and Britain had parted ways well before 1921.
*Sources*
Dickinson, Frederick R. *War and National Reinvention: Japan in the Great War, 1914-1919*. Cambridge, Mass: Harvard University Asia Center, 1999.
_. *World War I and the Triumph of a New Japan, 1919-1930*. Cambridge: Cambridge University Press, 2013.
O'Brien, Phillips Payson. *The Anglo-Japanese Alliance, 1902-1922*. London: Routledge, 2004. | [
"The onset of the First World War in Europe eventually showed how far German–Japanese relations had truly deteriorated. On 7 August 1914, only three days after Britain declared war on the German Empire, the Japanese government received an official request from the British government for assistance in destroying the... |
how do glute muscles become weak? | The same way any other muscle gets weaker. Over time and extended periods of low use, they deteriorate and lose mass. | [
"Muscle coactivation allows muscle groups surrounding a joint to become more stable. This is due to both muscles (or sets of muscles) contracting at the same time, which produces compression on the joint. The joint is able to become stiffer and more stable due to this action. For example, when the bicep and the tri... |
why is fertilizer the primary ingredient in many homemade bombs? | It's the nitrogen//nitrogen-based chemicals in the fertilizer. The nitrogen stuff is great for growing crops... but it's also good for explosives.
You can search for "nitrogen explosive compounds", but read here this one example of why:
_URL_0_ | [
"A fertilizer (American English) or fertiliser (British English; see spelling differences) is any material of natural or synthetic origin (other than liming materials) that is applied to soils or to plant tissues to supply one or more plant nutrients essential to the growth of plants. Many sources of fertilizer exi... |
how is it that someone (like myself) is allergic to almost every antibiotic? what makes the body hate them so much? | Essentially an allergy is an immune response to a foreign substance.
For you, the antibiotics has 'proteins' antigens which trigger the white cells of you immune system to attack them. This appears as massive inflammation due to degranulation of mast cells releasing imflammatory proteins etc. Typically presenting as Rashes to full blown anaphylaxis (air way compromise)
& #x200B;
When patients come with multiple drug 'allergies' it important to differentiate what is a true allergy vs what is a side effect of antibiotic such as nausea/diarrhoea. | [
"Aside from these ambient allergens, allergic reactions can result from foods, insect stings, and reactions to medications like aspirin and antibiotics such as penicillin. Symptoms of food allergy include abdominal pain, bloating, vomiting, diarrhea, itchy skin, and swelling of the skin during hives. Food allergies... |
Is cancer a preventable disease? | You addressed it in your post, but I just want to point it out as well : "Prevention" in medicine is like "safety" in engineering. It depends on what you mean by "prevention".
If by prevention you mean complete prevention, as in cancer risk is gone...no. Not going to happen.
But for what you are asking, yes. You can significantly lower your risk (most likely; there is the of a "doom gene" somewhere that means you're getting cancer no matter what you do). However, the degree to which you can lower your risk of a certain cancer is not the same as the degree to which I can lower my risk of the same cancer, largely due to genetics. Personal history, like smoking, sunburn, etc plays a role too, although most people think of these as prevention. I personally don't think of it that way because if you did it in the past, there's not a lot you can do to change that fact now. Your history is just as set as your genes. More so, actually.
Not sure why....just feel like expounding here...
Cancer is a multihit disease. Consider an oversimplified individual cell. This cell is only supposed to grow (divide) in response to very specific signals. It has layers of protection to ensure that happens as dictated and only as dictated, with checkpoints all along the way that slow or halt the pathway to division. These checkpoints must be shut down or circumvented in order for the cell to divide. This can happen in a healthy way (controlled division) or as a pathology (cancer).
It should go without saying, but the checkpoints are all gene products in some way. Some are proteins, some are the products of proteins, some are RNA, etc, but they all work to slow or prevent division of the cell, and they all ultimately come from specific genes or sets of genes.
Say there are 5 of these checkpoints, A, B, C, D, and E. But, unlucky you, you inherited a bad copy of a gene crucial to making C, so you only have 4 of the checkpoints. No worries, though, you still have A, B, D, and E. But suddenly...a wild gamma ray appears, and now the gene that encodes A has mutated into uselessness. OK, it's not great, but you still have B, D, and E.
Until you take your next drag on that cigarette and you mutate D into uselessness. OK...there's still B and E.... but then you get a free radical straying where it's not supposed to and the gene that ecodes the the thing crucial to the processing of E is mutated so it no longer interacts with E. And then a few weeks later, when the cell divides due to a legitimate signal, a replication error takes out something in the pathway that makes B.
And now all bets are off. All the stuff telling the cell "Stop growing!" is gone, and any tiny little push towards "grow!" is heeded and taken on with gusto. Cancer.
Some of those things you had zero control over and were set from the beginning; the inherited gene, for example.
Some you had no real control over and happened through the course of life, like the gamma ray.
Some were strictly your choice, like the cigarette.
But then there are things like that free radical; you get those as a course of metabolism. They are inevitable, but their half-life and frequency can be reduced by diet.
And the replication error? Certain micronutrients may have been able to reduce the frequency of replication errors (another risk factor). Maybe if you hadn't gotten injured in just that way, that division never would have occured. This is an example of another important aspect; there are risk factors that are simply not known or are not really predictable.
Just for the record: It's not really that simple. The checkpoints aren't all just "yes/no" things (some are checkpoints, they just aren't all checkpoints); many work as a balancing act. Once you get an imbalnce, you "tip" towards division.
There are also gene products that work the other way; they initiate division. It's possible to go that way as well, but as it's a gain of function mutation it's much, much more rare than the loss of function mutations you get elsewhere.
| [
"Cancer prevention is defined as active measures to decrease cancer risk. The vast majority of cancer cases are due to environmental risk factors. Many of these environmental factors are controllable lifestyle choices. Thus, cancer is generally preventable. Between 70% and 90% of common cancers are due to environme... |
What is the maximum rate of rainfall possible? | There are some great answers so far, but I think everyone is missing the point. /u/evilmercer is not asking what the maximum observed rate has been historically, but what the maximum *theoretical* rate of rainfall is. Given the wording of his question, I believe he is seeking two separate answers:
* What is the maximum rate of rainfall from an air density perspective?
* Would a storm system be able to create this rate of rainfall, even momentarily? | [
"The maximum annual rainfall ever recorded was 1500 mm for every year. The highest rainfall recorded in a single day was 850 mm. The average total annual rainfall is 1500 mm. The average annual temperature is 32 °C, and the average maximum temperature is 35 °C, while the average minimum temperature is 28 °C. In the... |
Do the Strong and Weak Forces have a field like Gravitation and EM? | Yes, but unlike gravity and EM, their fields have very short interaction lengths. They are mediated by W+-/Z bosons and gluons, respectively. | [
"The strong force is today understood to represent the interactions between quarks and gluons as detailed by the theory of quantum chromodynamics (QCD). The strong force is the fundamental force mediated by gluons, acting upon quarks, antiquarks, and the gluons themselves. The (aptly named) strong interaction is th... |
What are some lesser known epidemics of the past? | The bubonic epidemic no one ever hears about: [The Plague of Justinian](_URL_0_).
It is estimated to have killed over twenty-five million people, only 25% of the casualties caused by the Black Death, but the PoJ was the first recorded instance of a (confirmed) Yersinia pestis epidemic. | [
"It appears that epidemic meningitis is a relatively recent phenomenon. The first recorded major outbreak occurred in Geneva in 1805. Several other epidemics in Europe and the United States were described shortly afterward, and the first report of an epidemic in Africa appeared in 1840. African epidemics became muc... |
why can you only know an electron's position if you give up on knowing its momentum and vice versa? | It's not that you don't *know* the electron's momentum and position at the same time. Electrons don't **have** well-defined momentum and a well-defined position at the same time.
Electrons operate under the rules of quantum mechanics, where they actually exists as a probability wave. And the position and momentum of a subatomic particle share the same relation as position and wavelength for a normal wave: If you drop a stone in a pond, the wave radiates outward, dissipating as it goes. So you can *kind* of define its position, in a fuzzy sort of way (its position is spread out across part of the surface of the pond), and you can *kind* of give an average wavelength (but since the wave dies out as it travels, it's not super accurate either), but you don't have either very accurately.
The more confined you make the position of a ripple like that, the less-defined its wavelength becomes, to the point that a ripple that exists in a single, well-defined spot has no wavelength at all. And if you want a proper wavelength, you have to spread the wave across the entire pond, in which case the wave has no position.
That's the same relation as the one between position and momentum in a subatomic particle. | [
"This principle of uncertainty holds for many other pairs of observables as well. For example, the energy does not commute with the position either, so it is impossible to precisely determine the position and energy of an electron in an atom.\n",
"An elegant illustration of the uncertainty principle is Heisenberg... |
Are thoughts physical objects? | Thoughts are webs of electricity traveling through different sections of your brain. Most are reactionary responses to outside stimuli, and then chained together based on memories that surface during the process...
I try not to think about it really; that our entire lives are just a chain of reactionary electric charges pulsing on a lump of meat...
I'm sad now. | [
"Before asking whether any such objects exist outside me, I ought to consider the ideas of these objects as they exist in my thoughts and see which are clear and which confused. (Descartes, Meditation V: On the Essence of Material Objects and More on God's Existence).\n",
"BULLET::::- \"Brain and Consciousness\" ... |
why on mobile devices can i find nothing except live and cover songs on youtube? | Youtube checks the user-agent header and blocks certain videos from appearing on mobile. Music videos seem to be a popular choice for such filtering. I don't know why it's done, but you can get around it.
You need to change your user agent header so you appear to be coming from a desktop browser. (or strip it altogether - I don't know how YouTube reacts to this but it should work). If your phone/browser is locked down and doesn't allow you to do this, and you don't want to root it, you could set up a proxy server on a Raspberry Pi or similar low-cost device, and have that spoof the user-agent for you. | [
"There are now over 100,000 videos posted on YouTube using “Sa Isang Sulyap”—all in all, these videos have been viewed more than 400 million times. It is also one of the most downloaded songs today by mobile phone users.\n",
"YouTube (owned by Google Inc.) is the premier site for finding music videos for both ind... |
why is the distribution of elements on earth not uniform? | Basically because each element is chemically unique, and therefore behaves differently to other elements in given conditions.
Take for example crystallisation from a magma. As the magma cools, certain elements are able to form stable crystalline structures (minerals). Different minerals can start to crystallise at different temperatures, and different minerals have completely different chemistries. So, for example, pyroxene (which crystallises early) can crystallise out lots of aluminium, whereas quartz (which forms late) mostly only crystallises out silica. This gets even more complicated when you realise some elements can substitue for others in crystal structures, so for example [Europium can be preferentially substituted into plagiclase feldspar](_URL_0_) in place of Calcium.
This kind of chemical differentiation is very common, and there's lots of different processes in which it is important. But there's other differentiation processes too. For example, simple density sorting can be really important. The reason we find large concentrations of gold in many places is because gold-rich rocks have been eroded by rivers, and the gold grains have been deposited by those rivers simply due to density contrast. That leads to a secondary 'placer' deposit of gold which is far more enriched than the rocks from which the gold originally came.
The processes which form oceanic crust are different to those which form continental crust, so again the mineral assemblages (and therefore elemental distributions) of the two systems are very different. | [
"The organization of elements on the periodic table in to horizontal rows and vertical columns makes certain relationships more apparent (periodic law). Moving rightward and descending the periodic table have opposite effects on atomic radii of isolated atoms. Moving rightward across the period decreases the atomic... |
when smoking, why does your throat hurt only when you breathe in air? | You're breathing in hot air and chemicals that get absorbed by your lungs and cooled down by the time they're breathed out.
You should probably look into quitting it's super unhealthy :). | [
"Many compounds of smoke from fires are highly toxic and/or irritating. The most dangerous is carbon monoxide leading to carbon monoxide poisoning, sometimes with the additive effects of hydrogen cyanide and phosgene. Smoke inhalation can therefore quickly lead to incapacitation and loss of consciousness. Sulfur ox... |
Why can Phosphate have five bonds? (More than an octet) | First off, I want to say that d-orbitals are not involved in the bonding of hypervalent main group compounds like PCl5. The central atoms in molecules like PCl5, SF6, etc. still obey the octet rule. Many introductory resources claim otherwise, but there is ample computational evidence that that this is the case. I can provide references if you are interested.
Now that that is out of the way, essentially what happens is that each phosphorous-chlorine bond has less than two electrons. You can have chemical bonds that have fewer than two electrons, a simple example of this is H2^+, which is a stable molecule even though there is only one electron holding the two H nuclei together.
Molecular orbital theory explains this as I explained above: there are four bonding molecular orbitals that bond the phosphorous to the 5 chlorine atoms, each bonding orbital connects the phosphorous to multiple chlorine atoms. The rest of the electrons are in nonbonding orbitals on the chlorine atoms. If you know anything about molecular orbital theory, you know that this isn't strange.
The valence bond theory picture is perhaps more intuitive. You can think of molecules like PCl5 as a set of ionic resonance structures. That is, think of it as the ionic molecule PCl4^+ Cl^- with 5 resonance structures, each with a different Cl atom having the negative charge. The thing to keep in mind about resonance structures is that they do not distinctly exist: The real electronic structure of the molecule is the average of all the resonance structures together. This produces the same result as molecular theory: on average each P-Cl bond is less than two electrons. | [
"The octet rule is a chemical rule of thumb that reflects observation that elements tend to bond in such a way that each atom has eight electrons in its valence shell, giving it the same electronic configuration as a noble gas. The rule is especially applicable to carbon, nitrogen, oxygen, and the halogens, but als... |
The New Testament largely covers the final three years of Jesus's life; is there any more known about the first 30 years of his life? | The simple answer is no.
Apocryphal sources exist but are universally pretty late. Even the length of Jesus' ministry isn't exactly known. We assume it was a three year ministry because of the Gospel of John, but the interesting point there is that the Gospel of John isn't a common source for information concerning the historical Jesus -- it's just too different from the synoptic Gospels (Matthew, Mark, and Luke). But the synoptics do not specify how long Jesus was active. Gospel of John provides a clear time frame while the other Gospels do not.
But even the seem to disagree a lot about Jesus before his ministry. Mark has no infancy narrative, and while Matthew and Luke do both diverge in pretty significant ways. Luke's narrative include a story about Jesus as a child at the Temple while Matthew's infancy narrative is more concerned with Joseph than anything else.
The epistles are directed to communities who we can presume were already told the story of Jesus by whichever evangelist founded the community so those are more concerned with the theological implications of history. In general there's not a whole of history about Jesus there.
Documents like the Infancy Gospel of Thomas or the Protoevangelium of James do exist, but they're all later and, while interesting reads, do not appear to be historical accounts. Outside of Christian texts, when Jesus is mentioned by ancient historians Jesus is not really the focus -- there's more concern for Christians than for Christ. | [
"For a \"century and a half\", then, after Jesus' death, we have no means whatever of substantiating even the existence of the Gospels, as now bound up in the New Testament. There is a perfect blank of 140 years; and a most serious one it is.\n",
"Although Lindsey did not claim to know the dates of future events ... |
how wind can push my car sideways when my wheels are pointed straight forward? | Eh? When does your car move sideways? | [
"Before entry to the bend, the car is turned towards the bend slightly, but quickly, so as to cause a rotating motion that induces the rear of the car to slide outwards. Power is applied which applies further sideways movement. At the same time, opposite lock steering is applied to keep the car on the desired cours... |
why is it that there are plenty of tropical small islands throughout the pacific (guam, us virgin islands, etc) but there are hardly such islands in the atlantic ocean? | The pacific ocean is a hotbed for volcanic activity. Under water volcano explodes, creates an island, plants and animals move in. Pretty neat | [
"The Hawaiian Islands are about from North America and from Asia, and it is because of this isolation that the Hawaiian Islands have extraordinary numbers of unique species. Only a species that could fly or swim immense distances could reach the archipelago. But whereas Polynesians, and later, Europeans, have large... |
how do night contacts work? | My understanding is they reshape the eye. The degree of how concave or convex the lens of the eye causes near sightedness or far sightedness. Sleep contacts temporarily shape your eyes back to neutral. | [
"Hand signals are a form of sign system used by divers to communicate when underwater. Hand signals are useful whenever divers can see each other, and some can also be used in poor visibility if in close proximity, when the recipient can feel the shape of the signaller's hand and thereby identify the signal being g... |
based off of this photo that keeps going around reddit what would actually happen to the moon and this person. | Alot of shrapnel, if not that then the lack of oxygen after a couple of days. | [
"In November 1969, a nude photo of Wilson made a trip to the Moon. As a joke, NASA ground staff hid a small nude photo of her (along with fellow playmates Angela Dorian, Cynthia Myers and Leslie Bianchini) inside the schedule of Apollo 12's mission commander, Pete Conrad. Although it is certain that the photo made ... |
The lack of a strong socialist party in the US linked to the absence of feudalism? | I think the contention that feudalism was a heavy contributor to socialism is a pretty weak one. What is Lipset's evidence for that assertion? I think the rise of socialism is a heck of a lot more complex than "the struggle against feudalism and the ravages of industrialization took on a class conscious character in a relatively homogeneous population".
If we don't accept that as true, we have to look for other reasons that African-Americans didn't turn to socialism as an answer. On the other hand, it must also be remembered that the socialist movement in the United States was heavily involved in the civil rights struggle (and one of the justifications of the heavy handed FBI surveillance and infiltration of those civil rights movements).
| [
"Socialism in the United States has been composed of many tendencies, often in important disagreements with each other as it has included utopian socialists, social democrats, democratic socialists, communists, Trotskyists and anarchists. The socialist movement in the United States has historically been relatively ... |
why do we still take test and learn the same as how people did in the whole of history when technology has advanced so far? | Learning has advanced a great deal since formal education began. There are some things that have become redundant, and some things may seem useless. For instance, why bother learning that there are 4 quarts in a gallon when I can just look it up? But many people, myself included, would argue that a fundamental understanding of the simple elements is necessary for an understanding of the complex. Albert Einstein wouldn't have been able to come up with the things he had if he hadn't been good at math (he didn't actually fail math, that's an urban legend). Facts tend to rest on other facts in our minds, and rote memorization doesn't lead to understanding; a book can contain all the facts in the world, but it doesn't come up with new ideas. | [
"\"Section 1:\" The use of Science has improved tremendously in many ways for humans. The knowledge of science has grown considerably. However, the way we manage knowledge has remained the same for centuries. We are no longer able to access the breadth of scientific breakthroughs. Alternatively, the technology has ... |
why is norway so horrendously expensive? | It is difficult to transport anything to Norway because the land is very difficult to traverse and the sea can be incredibly rough. However though it does have large income from oil it also has an extremely generous social welfare system and that means high taxes and that means expensive goods and services. | [
"BULLET::::- Cost of living. Norway is among the most expensive countries in the world, as reflected in the Big Mac Index and other indices. Historically, transportation costs and barriers to free trade had caused the disparity, but in recent years, Norwegian policy in labor relations, taxation, and other areas hav... |
Prior to the rise of Ataturk, what made someone in the Ottoman Empire a “Turk”? | Short answer: ethnicity and language (both in place well before the 19th century), plus some negative experiences with other nationalities (mostly in the 19th-20th centuries, triggering the rise of Turkish nationalism.) When you read the memoirs of the future political and military leaders of Turkey, at one point almost all of them mention a story like this:
The young X (the future leader) enters an elite Ottoman school/military academy. There he meets others from different parts of the Empire. He witnesses how Albanians, Arabs (insert any other nationality here) create societies and promote their national culture. Yet he does not belong to any of these groups, and often he insists on the shared Ottoman identity. He feels alienated. At some stage, he thinks this does not work anymore (1912 Albanian independence and the Arabic revolt during WW1 being primary turning points for many, apparently) and he becomes more Turkish than Ottoman. This general story is repeated so many times that it is fair to say the Turkish identity resurfaced in the late 19th-early 20th century as a negative reaction to other nationalisms.
What Turkish culture is probably a question too deep for me to delve into here. The native tongues seem to have played a vital role in reinforcing unity among ethnic groups in the Empire, so Turkish as your native tongue (which often even though not always meant you are ethnically Turkish) plus undergoing experiences similar to the story I told made people Turks. A reminder though: it is simply a mistake to suppose that such individuals and modern states created the national identity of Turkishness. There are several much older occasions in which people spoke of themselves as "Turks" and clearly regarded others as non-Turkic/Turkish "others." A 15th century Ottoman chronicle by Mehmed Neşrî Efendi, for example, describes how Murad I of the Ottoman Empire said he ached to showcase “the Turkish manliness” against the Serbian Army, in the 14th century! So what we are talking here about is the Turkishness as understood from the late 19th century onwards but “Turkishness” itself has deeper roots in history.
Finally, I do not think that most ordinary Turks felt failed or ignored by the Ottomans. They did not really think of the Ottomans as someone else either, it seems. There was a time following the foundation of the Republic of Turkey in 1923 when the state sought to instill such a mentality (now largely exaggerated for modern political purposes). Indeed, there are speeches by Mustafa Kemal Atatürk in which he criticizes how the Ottoman conquests were merely for the benefit of the Palace and the Sultan but at the cost of much Turkish blood. The Ottoman past was often used as a yardstick to demonstrate the success of the Republic, one success being the more clear expression of Turkishness in the Republican era. But at the end of the day, I highly doubt even the elites regarded the Ottoman Empire as an enemy per se. The confrontation with the Ottoman past in the Republic of Turkey never reached levels witnessed in the French Revolution or in the Soviet Union. It was never an issue of nationality alone anyway since the Ottoman past was often criticized also for not being secular, modern and independent enough too.
| [
"With the establishment of the Turkish National Movement, the partitioning of the Ottoman Empire, and the abolition of the sultanate, the Ottoman era and the Empire came to an end, and with Atatürk's reforms, the Turks created the modern, secular nation-state of Turkey on the political front. On 3 March 1924, the O... |
I hoped this isn't looked down upon in this subreddit, but I think that it's inevitable. Either way, I'm curious. How accurate are the age of empire games? | Off the top of my head:
Age of Empires 3 is completely made up.
* Specifically, there were no Ottomans in the New World and no Russians except on the Pacific Coast
* The Ottomans did [invade](_URL_1_) Malta in 1565. New Brunswick is a real place.
* The [Sepoy Rebellion](_URL_2_) really did happen, and I remember some of the reasons for it being depicted accurately in the game. The campaign ends before getting to the bloody bad ending, though.
* The China campaign is based on fanciful [speculation](_URL_0_)
Age of Empires 2 used more real history in its campaigns, but took significant liberties as well. I think most of the battles really happened but were nothing like as depicted in the games, such as the [siege of Acre](_URL_3_)
As far as I know the weapons, units, buildings, and nations in the games are mostly real. Though in Age of Empires III most of the national leaders were not alive at the same time.
| [
"On 24 February 2017 Ashen announced a sequel to \"Terrible Old Games You've Probably Never Heard Of\", titled \"Attack of the Flickering Skeletons: More Terrible Old Games You've Probably Never Heard Of\", again through Unbound, was released on 2 November 2017.\n",
"Alessio Cavatore comments: \"Anyone who knows ... |
if trees initially were non-biodegradable, and a fungus adapted to degrade them could the same be done for plastic? | Sure and we are working on it. But its a slow process and we are producing literally thousands of tonnes of plastic every day.
Recycle. | [
"Biodegradable additives have the potential to significantly reduce the accumulation of plastics in the environment. Plastics are ubiquitous in everyday life and are produced and disposed of in huge quantities each year. Many common plastics, such as polyethylene, polypropylene, polystyrene, poly(vinyl chloride), a... |
what is software and how does it all work? | That's a **very** broad question, so rather than go into detail, I'll just give some very high-level answers, and you can ask for clarification as needed.
> how does software work?
Software is simply a set of instructions for a computer to follow. The "how" is fairly complex, but it boils down to setting voltages on billions of tiny circuits inside the computer in a very specific way.
> For that matter hardware too
Hardware is generally composed of billions of transistors, which are like tiny electrical "switches". A signal to one part can switch the transistor on or off, allowing other signals to either be blocked or allowed through.
Using transistors, you can build logic gates: circuits that perform operations like AND (give a high-voltage output only if both of the inputs are high-voltage), OR (give a high-voltage output if *either* of the inputs are high-voltage), NOT (give a high-voltage output for a low-voltage input, and vice versa), etc.
Using logic gates, you can build slightly more complex things, like adder circuits that can add binary numbers.
Using those more complex circuits, you can build even more complex things, like a CPU that can act on certain pre-defined instructions.
> I hear these terms - application, server, middleware.
An application is just a piece of software, and is generally used to describe something that needs an operating system to run (the Operating system itself is just a very complex bit of software, but is generally not referred to as an "application"). Internet Explorer is an application, for instance. So is iTunes. And Steam. And anything else that your computer can run.
A server is a computer that is set up to listen for network requests and respond to them (usually "serving up" webpages, hence the "server" name).
Middleware is a bit abstract. It's specialized software that exists to make it easier for other types of software to communicate with each other.
> When I read something like - "x application was built on top of y server" - what does that mean?
It's hard for me to say without knowing what X and Y are. My guess is that they're using the other definition of "server" that I haven't mentioned. Software that takes requests and sends responses is also referred to as a "server". For instance, when you check your email, your computer contacts the "mail server". In one sense, this describes the computer that is responding with your email. But in the other sense, the "mail server" is the specific application/software running on that computer that does all the mail-related stuff. The same computer might also serve up web pages, and the application that does that would be a "web server". The computer itself can be referred to as either a "mail server" or a "web server" depending on context (though it's pretty standard just to call it "the server").
Also, the opposite of a "server" is a "client". Whatever application/computer consumes messages sent by a server is referred to as a client. So Internet Explorer is a "web client", for instance. If you play online games, the game software itself is a client.
So "x application was built on top of y server" probably means that "x application" is some type of middleware that acts as both a server and a client, taking requests from other programs, modifying them somehow, and passing them on to "y server".
But again, without specifics, it's hard to say for certain. | [
"\"Software\" refers to parts of the computer which do not have a material form, such as programs, data, protocols, etc. Software is that part of a computer system that consists of encoded information or computer instructions, in contrast to the physical hardware from which the system is built. Computer software in... |
why do different regions of usa sell varying octanes of gas? i can buy 85 octane in idaho, but can't find anything less than 87 in arizona. | Elevation.
"Octane" is a description of how much compression the fuel can be put under before it spontaneously ignites. The higher the octane number, the more pressure the fuel can take before it just ignites. An engine wants to take the fuel/air mixture as close to this point as possible (but not past it) before the spark plug sparks and lights the fuel. This (I think) ensures the most power for a given amount of fuel.
When you go to a higher elevation (like the mountains in Idaho), the air is thinner. This means the pistons in the engine can't compress the air as much. Since the pressure in the engine can't go as high, you need to use a fuel designed to ignite at a lower level of compression, a.k.a. a lower octane number. | [
"The octane rating of typical commercially available gasoline varies by country. In Finland, Sweden and Norway, 95 RON is the standard for regular unleaded gasoline and 98 RON is also available as a more expensive option. \n",
"Most states do not mandate certain standard gasoline grade octane ratings. In the Unit... |
what causes laziness? is it a physical condition? | I guess everyone is too lazy to reply, OP. There are some good explanations for this, but my vague, non-scientific understanding is, it is indeed a physical condition, one that we inherited from our ancestors. I'm sure you can find a more technical/accurate/correct explanation of this, but here's the gist of it.
Our brains have a vulnerability that makes it extremely easy to get addicted to things. Watching TV can stimulate you (you are rewarded with dopamine). The more TV you watch, the more you want to watch it. The brain is rewiring itself to crave TV, because it was a source of dopamine release. Why does the brain do this? Because it worked to our ancestors favour. Their brain would be wired to be 'addicted' to gathering food, because it was necessary for survival and even the act of simply gathering the food would be rewarding to them, giving them a higher chance of surviving the next drought. This routine of gathering now becomes ingrained.
So after a while, any moment you are not watching TV, your brain will be agitated, because your primitive brain isn't doing something it thinks is useful (because you're not getting dopamine) so you will crave TV. So basically, you are addicted to a low energy, highly stimulated state, it's as simple as that. Ever notice that you browse reddit for hours, even when you've seen everything, and there's nothing even remotely enjoyable about it? It's your brain telling you "keep looking, you'll find it! (dopamine)". As your brain continues to rewire itself, it also starts to cull the circuits in the brain that it deems 'un-useful', such as the ability to learn. Soon, TV will be the only thing that gives you a dopamine fix, which means everything else in the world will seem boring, and this is the root of laziness.
Our brains are still plastic, however. Abstain from TV for a long enough time and you will no longer be addicted to it. Don't game for a few years, you will never be compelled to game again.
Here's a study that examines the physical changes in the brain when addicted to internet use, and the similarities to drug addiction: _URL_0_
| [
"Laziness is a habit rather than a mental health issue. It may reflect a lack of self-esteem, a lack of positive recognition by others, a lack of discipline stemming from low self-confidence, or a lack of interest in the activity or belief in its efficacy. Laziness may manifest as procrastination or vacillation. St... |
What was the basis of the Nazi war machine? How did the managed economy of the Nazis work? | The Nazis did not nationalize all off industry; now they forced Jews to sell their businesses for peanuts to non-Jewish owners, under the policy of Aryanization/Arisierung - that was in 1938.
However they placed limited on what owners could do with their property, effectively the nazi state managed an increasing part of the economy - this tendency began in 1936 (the Nazi's had a four year plan between 1936-40); from 1939 this the economy switched to war economy and between 1942-45 most of the economy was managed directly by the state.
For instance farmers would be told what they should plant (they also did price fixing), and factories would be told what to produce; however the old manager was still in charge, provided he was not Jewish.
Much of the free market was gradually abolished; by 1936 prices and salaries were fixed; the central bank lost its independence; etc.
Much of the prewar years was based on deficit spending; actually the Bruehning government started this, but because of Versaille/Young plan he was not allowed to finance these measure by inflation. The measures were efficient at stopping unemployment; however the planning body was a mess of different interest and priorities, the office of the four year plan (Goehring) would quarrel with leader of war economy (Schacht) vs. Wehrmacht officials, etc.
Also deficit spending had the result that there were no currency reserves left by 1939.
So it is correct to say that eventually the business plan of the Nazi system was war, also planning went for war in 1939; the second four year plan would have ended early in 1940, the object of the plan was to create a self sufficient economy/decrease dependence on imported raw materials and to prepare for war.
----
"Deutsche Wirtschaft und Wirtschaftspolitik 1914 - 1945" Prof. Dr. Rainer Goemmel
_URL_0_ | [
"Hitler completely reorganized the economic landscape in Germany. The economic chamber of the Third Reich consisted of over two hundred organizations and national councils involved in industry, commercial, and craft lines. Large public works programs, such as the construction of the Autobahn, stimulated the economy... |
how to talk to children | Reading your username makes me question your intentions. | [
"BULLET::::- \"So Much to Say\" (1980), regarding the language of children from birth to age five. It proposes that children are driven to talk because they have \"something to say,\" have private emotions and thoughts to report.\n",
"Children who have delayed speech or other mental illnesses cannot grasp the con... |
did thousands of people die trying 'food' that we now know is poisonous? | Probably. And more than a few avoided food that we know is fine. Many people in Europe in the 1400s thought fruit was slightly poisonous and shouldn't be given to young children. Many people used to think tomatoes were toxic. | [
"There have been cases where people died after eating foods containing palytoxin or poisons similar to it. In the Philippines people died after eating \"Demania reynaudii\", a crab species. After eating bluestripe herring some people died in Madagascar. People who had eaten smoked fish and parrotfish experienced ne... |
When people say some metals are "better" at conducting electricity what does this mean, do they conduct faster or more efficiently? | Both. The conductivity of a material is the constant that relates the current per unit area to the applied electric field. σ = J/E. So using a more conductive material you could design a circuit that moves the same amount of current using a weaker field (more efficient) or moves more current at the same field (faster) or somewhere in between. | [
"Metals (e.g., copper, platinum, gold, etc.) are usually good conductors of thermal energy. This is due to the way that metals bond chemically: metallic bonds (as opposed to covalent or ionic bonds) have free-moving electrons that transfer thermal energy rapidly through the metal. The \"electron fluid\" of a conduc... |
3g/4g. | That's a pretty broad question. I think it's really 3 questions in one, so I'll try to tackle each one individually.
**What's the difference between 2G, 3G, and 4G?**
Imagine there is a deliver service. At the beginning they have a very basic setup of just a few horses that run on small local roads. It can only deliver a small amount of packages a day because of constraints on the delivery center, the amount you can put on your horses, and the 1 lane roads you're stuck using. That's basically 2G or EDGE service.
A few years later after government regulators agree that they're doing a good job and will help widen the roads and everyone thinks it's a good time to update the entire delivery centers and buy some trucks. Now everyone have a much larger facility for moving packages/data from point A to point B. There are also new larger trucks that can fit more per load, and the roads are now bigger for everyone to drive more load through. Great! You've got 3G!
3G operates pretty fast but soon everyone and their mom want to send packages so the government says ok, we'll reserve some highway space, some 16-wheeler trucks, and automated systems in delivery centers to get packages moved as quickly as possible. Now you're at 4G speed, you can now move A LOT of data at once.
In this analogy the delivery centers are the switch centers at the major telecom companies. To move more data through with each new generation of service (2G, 3G, 4G) the equipment need to be updated. The roads in this are basically spectrum frequency. Which are regulated by the government/FCC. The feds have to sell or free up additional spectrum for telecom companies to operate more data on the higher frequency channels. Trucks are basically the underlying internet backbone that can accommodate for more and faster data transmission. Without all 3 upgrading almost at the same speed, it's impossible to move from from one generation to the next. Also, your cell phones have to upgrade to the latest generation of processors too because high data-speeds require faster chips to process it.
----------------
**So how does my cell phone communicate data wirelessly?**
Think of your phone as a just like a mailbox that you leave a request letter in the morning for Youtube. The delivery guy picks up your letter requesting a large order of videos from Youtube and delivers it to them. In the letter you ask "Please send me a video on XYZ to my address." When Youtube gets your request via the delivery service, it will package it all up and send you the video as many large packages. Depending on the speed of the delivery centers, size of the trucks, and width of the road the packages can arrive slowly one by one or really fast almost instantaneously. 2G, 3G, and 4G are just different agreed upon standards the service centers, trucks, and roads that are built. The newer generations are faster at delivering packages.
Think of your phone as almost like a mailbox. With each new generation of technology, it has to be bigger, stronger, and more automated to support all the packages/data that you've ordered. If you have an old phone that's using 2G, it's pretty much like a tiny mailbox that the deliver service just says "Nope, it won't be able to handle the load. If you want to use our 3G service, upgrade it so we can fit these larger boxes in."
------------------
**How does the data go from your phone to the receiving tower and then get moved to Youtube?**
Scatter around the entire world are cell phone towers, hundreds of thousands of them. They're like listening stations that can talk directly with your phone when it's near. When you turn your cell phone one or walk within range of a new tower, the phone will ask "who's the closes cell tower?" A lot of towers will reply by shouting back "Tower XYZ, I'm here!", "Tower ABC, I'm here." Depending on how clear your phone hears the response, your phone will start a conversation with one that has the highest quality connection and sounds the clearest. Each cell phone tower is connected to a landline that's hookup to the internet. It acts as an intermediary that passes on your request from the phone, to the tower, from the tower through the landline, into the internet, and through to Youtube. Youtube then replies, passes the video right back. No magical satellite is needed unless you're somewhere super remote and it's cheaper for the cell tower to talk to the satellite than it is to lay down some land lines to the tower.
If you want to get a bit more technical, 3G and 4G differences are more than just more bandwidth but requires all new equipment by the cell phone carriers to handle all of the new extra load. It takes forever for some places to move to 4G from 3G because of the cost of setting up new infrastructure. Upgrading costs millions of dollars that require faster computers, more expensive connections, and new software to handle everything. None of it is cheap or easy. Which is why it's taking forever for 4G to move forward.
If I made any technical errors, please excuse me, I'm trying to remember as much as I can from college 11 years ago. | [
"4G is the fourth generation of broadband cellular network technology, succeeding 3G. A 4G system must provide capabilities defined by ITU in IMT Advanced. Potential and current applications include amended mobile web access, IP telephony, gaming services, high-definition mobile TV, video conferencing, and 3D telev... |
Does "smell" expand at different rate, due to surrounding temperature? | Absolutely. When you smell something, molecules from whatever source you're smelling are in your nose. But they had get there from the source - they had move. As it happens, temperature is actually a measure of molecular motion; when things get hotter, the molecules are moving faster. And if the molecules are moving faster, they get to your nose faster. | [
"Temperature is a monotonic function of the average molecular kinetic energy of a substance. When a substance is heated, the kinetic energy of its molecules increases. Thus, the molecules begin vibrating/moving more and usually maintain a greater average separation. Materials which contract with increasing temperat... |
Why did American snipers in World War 2 were given the Springfield 1903 when the M1 Garand uses the same type of ammunition and is Semi-Automatic? | Short answer. Because that's what they had on hand.
Short answer number 2. Because nobody had bothered developing the M1 as a sniper platform until late in the war.
Long answer. Well, nobody was bothering with the M1 until late in the war. Seriously, that's about the gist of it. None of this mess about "Semi autos being inherently inaccurate compared to bolt rifles" (The Russians would like to introduce you to the SVT 40, and some of the lovely and lethal ladies who used it to great effect on the Eastern Front) or pinging clips and such.
When the US entered WWII they didn't even have enough M1 Garands to go around yet, famously the Marines started the war with a large quantity of 03 Springfields on hand, as they had yet to fully transition to the M1. The first priority was getting standard M1's out to all the troops, and ramping up production of them to match the needs of the rapidly growing armed forces.
So, when a sniper rifle was needed, it was simpler to use the existing 03 Springfield platform to use as sniper rifles. They had been built in sniper configurations before, the tech was all worked out, there was a ton of civilian knowledge on how to turn them into scoped rifles. It was easy, simple and straightforward. The M1C and D rifles didn't make an appearance until 1944 and beyond, because of the need to first focus on getting standard rifles to the troops, and the fact that an entire program of turning the M1 into a sniper rifle had to be started up.
The M1 C and D were standard sniper rifles during the Korean War, and served quite well there, which should settle the myth of the weakness of a semi auto platform as a sniper rifle. You can also see the Russians have fielded many successful semi auto sniper rifles, such as the SVT 40, and the famous Dragonuv. The M1 was not a standard sniper platform in WWII, because it had not been developed as such yet, nothing more, nothing less.
Are bolt guns more inherently accurate? On off the shelf rack grade units? Probably. But when you start building match grade semi auto and bolt action rifles, I don't think it really matters anymore. Modern out of the box AR 15's get exceptional accuracy, and it's not uncommon to find or build sub MOA units for competition or varmint hunting. It's not the action of the gun, as much as it is the way it is built. | [
"The US entered the war with the M1 Garand as its service rifle. However, due to its size and weight, it was not an ideal weapon for some specialist roles such as engineers, tank crew, radio operators etc. So the lighter and smaller M1 Carbine was introduced in mid-1942. A semi-automatic weapon it used different am... |
why are asians buying real estate all over the world, causing a housing crisis in various cities? | It's not "Asian", it's only Chinese. China is about to implode and the people know it. The Chinese stock market is ludicrously overpriced because everyone in China buys stocks on margin, and when the price blips, everyone is leveraged to ridiculous levels and goes bankrupt overnight, so the blip becomes a catastrophe. People want to get their money out of China and into somewhere safe. If you have money to put somewhere, the options are real estate or offshore investment.
China is so paranoid that they will not allow people to move money out of the country, (the limit is something like $5000/day and only with a foreign passport), so that makes it impossible to *legally* invest in foreign stocks, leaving only real estate. (note that it's at the point now that Chinese companies are suing their own subsidiaries in America, so they have to pay themselves a settlement into their own American account, which *is* legal - sort of)
China is so paranoid that they will not allow people to buy land - if you buy an apartment, you don't own the land it's built on. And looking at Chinese real estate (remember those entire cities for 200,000 apartments, all of which are empty?), Chinese people are too smart to huff what the government is selling, so they need to buy real estate off shore. This is different to buying stocks off shore for legislative/tax reasons (I think the investment property is a business, but there are also people buying properties for their kids to stay in whilst studying as an excuse etc)
As for why it forms a bubble, that's because foreign governments are eyeing building industry bribes/donations/kickbacks along with wages for union members, stamp duties and other land taxes for treasuries and deciding that a bubble is a good thing.
This in turn means the people in Sydney, Auckland, Vancouver etc are buying real estate at greatly inflated prices on mortgages (i.e, buying on margin), so when housing prices here blip, everyone goes broke and the blip becomes a catastrophe. And the cycle repeats. Thanks China!!
edit: For the $0.50 brigade who think China is too strong to fall: We saw exactly this happening in the 1990's with Japan. Everyone was worried that the Japanese were infinitely rich with foreign currency from their exports inflating their markets beyond reasonable levels; we said they were buying too much property, racists/nationalists were saying they were buying what they couldn't conquer in WWII. Reality kicked in, Japanese stocks fell to realistic levels, everyone went broke and the Japanese economy is, even 25 years later, in such a bad shape that interest rates are negative. | [
"Housing in Asia has an important role in economic growth. In the early 1990s large urbanization in Hong Kong, Singapore, Thailand, Philippines and other Southeast Asia countries brought about a large housing price appreciation. Asia attracted global economic interest up until the economic crash of 1997. A decade l... |
why can we tell an airplane is pitched up when looking straight down the aisle. | Cause of your ears. Your ears have, on the inside of your skull, structures in them that are filled with fluid. The insides of these structures are lined with little sensory nerves that "tell you" where the fluid is. Since gravity pulls the fluid downward, these organs tell you which way is down. | [
"After the initial pitch-up, the pilot places the elevators in the neutral position. Failure to do this will cause the aircraft to continue pitching up during the upright part of the maneuver, and downward in the inverted part, resulting in something resembling a barrel roll. The pilot then applies full aileron, ac... |
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