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How does memory store? does your brain remove old memory to make space for new ones? | This question has been asked several times before. Here are some related posts/answers:
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Because of the high volume, lots of really great questions and answers get buried. One excellent way to explore /r/askscience is via the search bar. | [
"Memory has the ability to encode, store and recall information. Memories give an organism the capability to learn and adapt from previous experiences as well as build relationships. Encoding allows the perceived item of use or interest to be converted into a construct that can be stored within the brain and recall... |
Why is it impossible for Mercury be the core of a gas giant with its atmosphere blown off? | Mercury is too far from the Sun for stripping by the solar wind ('sputtering') to have eroded the atmosphere of a Jupiter-scale planet that much. It's a common misconception to attribute a huge amount of atmospheric loss to stripping by the solar wind. [This PDF](_URL_0_) gives a good overview of various atmosphere escape processes.
Also, a gas giant being formed at Mercury's distance would be a major challenge for planet formation scenarios. Why would Mercury have acquired a huge gas-giant-scale atmosphere during formation, but Venus (and Earth, and Mars) did not? | [
"Mercury has an observed magnetic field, which is believed to be generated within its metallic core. Mercury's core occupies 85% of the planet's radius, making it the largest core relative to the size of the planet in the Solar System; this indicates that much of Mercury's surface may have been lost early in the So... |
can someone eli5 how a kettle works? | When the water is boiling, the pressure in the kettle increases. This causes air to be forced out of the spout, which is designed to produce a noise when air goes through. | [
"A kettle, sometimes called a tea kettle or teakettle, is a type of pot, specialized for boiling water, with a lid, spout, and handle, or a small kitchen appliance of similar shape that functions in a self-contained manner. Kettles can be heated either by placing on a stove, or by their own internal electric heatin... |
How does a homozygous mutation of MTHFR A1298C (GG) affect the human body? | The long version can be found in the OMIM database (online mendelian inheritance in man) by searching for [MTHFR](_URL_2_) and selecting "table of contents" on the right hand side and selecting "allelic variants - [Table View](_URL_0_)." You can see that variant .0004 has the 1298A-C mutation, clicking on it will give you [this section](_URL_1_) of the original entry. I guess technical terms can be found here - learning how to use OMIM (and the NCBI databases as a whole) is a *very* useful skill.
TL;DR - In homozygous individuals, the mutant MTHFR has reduced activity (reduced even further from the heterozygus mutants). You can see in the header of the section that the phenotype associated with the mutant is increased susceptibility to schizophrenia. There is also increase in spontaneous abortion when the fetus' need for folate is required (due to the reduced MTHFR activity). There are also increased levels of homocysteine correlated with MTHFR 1298CC genotype.
TL;DR in laymans terms - Correlated with increased levels of homocysteine, increased suceptability to schizophrenia, and increased frequency of spontaneous abortion of fetus. This is more prevalent in homozygous mutants (1298CC) than heterozygous (1298AC) | [
"At nucleotide 1298 of the MTHFR, there are two possibilities: A or C. 1298A (leading to a Glu at amino acid 429) is the most common while 1298C (leading to an Ala substitution at amino acid 429) is less common. 1298AA is the \"normal\" homozygous, 1298AC the heterozygous, and 1298CC the homozygous for the \"varian... |
Does cracking your windows actually help them from being blown out during a hurricane? | Not scientific at all, but somewhat relevant personal experience.
I was in a tornado 4 or 5 years ago where water was seeping in sealed emergency exits. I know the pressure is worse in a tornado, but I'm guessing that if you had windows cracked you would have massive amounts of water in your house. Board up your windows. | [
"Hurricane coverings, commonly known as shutters, are used in hurricane mitigation to protect houses and other structures from damage caused by storms. Hurricane shutters are used to prevent windows from being broken by flying objects during a storm. Although the negative pressure caused by high velocity wind flowi... |
what is a po (purchase order) and how do they work? | Purchase orders are really just authorizations from the company to purchase a specific set of products. It is an assurance to your vendor that you have permission to place the order, so the vendor can bill you later for the purchase.
How your company does that is not something we can answer - you should talk to your Accounts Payable team. | [
"A purchase order (PO) is a commercial document and first official offer issued by a buyer to a seller indicating types, quantities, and agreed prices for products or services. It is used to control the purchasing of products and services from external suppliers. Purchase orders can be an essential part of enterpri... |
why do certain accents sound different in real life than how they're portrayed in movies? | Because actors are fallible and don't always spend weeks with a dialect/accent coach to get it right? | [
"In film, English-language accents can be part of acting performances. Actors use dialect coaches to speak in an accent other than their own. Accents can vary by locality, socioeconomic status, ethnicity, and other factors. In film, accents are scrutinized by film critics and film audiences alike. Throughout film h... |
why is it so much easier to converse with people, strangers or friends, online than in real life? | On the computer you have time to come up with and think about all your responses. In real life you don’t have that luxury. You’re also probably more nervous in real life which shows | [
"Viewing peoples' personal websites or \"online profiles\" (as on MySpace, Facebook, or a dating website) can make people as knowledgeable about their conscientiousness and open-mindedness as their long-term friends. The question of whether social-networking sites lead to accurate first-impressions has inspired Sam... |
how do djs get the individual song component tracks (synths, beats, melody, etc) to make unofficial remixes that modify all of these? | Most of the time, DJs get access to the original tracks. Keep in mind most studios *want* remixes - it ultimately makes their song more popular and they get more money.
No, there isn't any software that can split music into all of its separate tracks.
There are some special cases that sometimes work. Sometimes vocals are mixed perfectly in the center channel, so you can subtract the left channel from the right channel and remove the lead vocals. That works maybe 25% of the time. There are also some plug-ins that can isolate the bass and drums. The end result sounds odd since most of the energy from middle frequencies has been removed, but it's one starting point. If you hear a remix that mostly seems to pull from the original song and occasionally just isolates some parts like that, it could have been done this way.
But yeah, if you hear a piece that seems to take all of the different tracks (guitar, synth, drums, vocals, etc.) and rearranges them in totally different ways, there's no way it was done automatically - it means the DJ got access to the original tracks.
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"DJs use audio equipment that can play at least two sources of recorded music simultaneously and mix them together to create seamless transitions between recordings and develop unique mixes of songs. Often, this involves aligning the beats of the music sources so their rhythms do not clash when played together or t... |
If I let soda water sit in a perfectly smooth glass cup that has no imperfections or uneven surfaces on which bubbles could form, will the soda water still go flat? | Yes. Diffusion will still occur according to Fick's laws which will deplete the CO2 eventually, it's the same way bubbles grow once formed. The only difference will be that the process isn't "accelerated" by the thermodynamic favoring of a dramatically changing surface energy. | [
"The adherence of suspended solids to bubbles is easier and more intensive, the smaller the bubbles are. Because of the improved adherence capacity of small microbubbles, the saturation of the introduced air as well as the reduction capability of particles lead to an improved suspended solids reduction, a higher so... |
Why did Japan abolish slavery in 1590? | They did? That's news to me.
Toyotomi Hideyoshi banned the buying and selling of Japanese people by Portuguese merchants in 1587. He seemed to have had no problem with his soldiers abducting Koreans as slaves to be shipped back to Japan. Didn't stop Japanese taking each other as slaves in the aftermath of the fall of Ōsaka castle in 1615 either.
There were orders outlawing the buying and selling of people, both before and after Hideyoshi, but they often came with exceptions. For instance, in 1604, the Uesugi clan ordered that:
> You should detain anyone who arrives with attendants and no proof of their legal possession. This applies both to people with whom you are privately acquaited as well as people you do not know. You must then immediately report the matter to the local official responsible. The selling of people to other provinces, whether they are men or women, will cease. **Sales within the domain are allowed if registered with the local official responsible.**
So...yeah.
The Edo Bakufu outlawed straight-up kidnapping and buying and selling of people...only to turn a blind eye to debt slavery and indentured servitude, especially of prostitutes. Which means slavery wasn't really abolished either. | [
"Slavery in Japan was, for most of its history, indigenous, since the export and import of slaves was restricted by Japan being a group of islands. In late-16th-century Japan, slavery was officially banned; but forms of contract and indentured labor persisted alongside the period penal codes' forced labor. During t... |
Why do microwaves have hot spots? | A [standing wave](_URL_1_) is setup in the microwave cavity because the microwaves reflect inside the cavity and interfere. Where they interfere constructively, you get anti-nodes, the hotspots, and where they interfere destructively, you get nodes, cold spots. Here's an [animation of a standing wave](_URL_0_).
You can use this effect to measure the speed of light - the distance between nodes/antinodes is half the wavelength (λ/2), your microwave oven operates at f=~2.45 GHz and c = f * λ. A heat sensitive sheet or slab of chocolate or something will give you the nodal distance. | [
"Microwave ovens produce heat directly within the food, but despite the common misconception that microwaved food cooks from the inside out, 2.45 GHz microwaves can only penetrate approximately into most foods. The inside portions of thicker foods are mainly heated by heat conducted from the outer .\n",
"Uneven h... |
why can't neutron stars collapse just because they're made of degenerate matter? | I'm not sure what you're asking -- why don't they collapse into black holes, or why don't they collapse into nothing?
For black holes, a star has to start out with a certain mass within a certain size (technically, a certain radius). If the mass is greater than the limit for that size, then it will collapse into a black hole once it stops making energy through fusion -- when the fusion stops, there's nothing to hold the star "up" against its own gravity.
A neutron star forms when there isn't enough mass to keep it squishing until it's a black hole after fusion stops. The star stops collapsing when all of the neutrons in the original star bump together, so to speak, and they can't get any closer because their own gravity isn't strong enough to make it happen.
Imagine it like water in a bottle with a cork in it. Turn the bottle upside down. If it has two or more gallons of water in it, that's enough weight to pop the cork and the water runs out -- voila, black hole. But if it's less than two gallons of water, the cork doesn't pop. Instead, all the water collects in the space at the bottom (well, upside-down top) and takes up as little space as possible, but there's nowhere for it to escape to after that. Hello, neutron star. | [
"In a neutron star less massive than the limit, the weight of the star is balanced by short-range repulsive neutron–neutron interactions mediated by the strong force and also by the quantum degeneracy pressure of neutrons, preventing collapse. If its mass is above the limit, the star will collapse to some denser fo... |
why can't we 'store up' sleep? | No expert here, but I can give this a shot.
Because the body doesn't just immediately go into a good nights sleep. Your body goes through different cycles of sleep, and it takes time to get to them.
This explains the sleep cycles fairly decently-
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Imagine if your phone took about to an hour from the time you plugged it in, until the time it started charging. Charging it for 2 hours and then unplugging it would result in only 1 hour of charging. Plugging it in again for 2 hours would give you only 1 more hour of charge, a total of 2 hours of charging. If, however, you charged it for 4 hours straight you'd have 3 hours of charge. Think of it similarly for sleep.
Although to be fair- The sleep schedule you described would probably be okay for a lot of people. | [
"BULLET::::- Researchers have shown that a fundamental reason for sleep is to clean the brain of toxins. This is achieved by brain cells shrinking to create gaps between neurons, allowing fluid to wash through.\n",
"The need and function of sleep are among the least clearly understood areas in sleep research. Whe... |
Can different types of alcoholic beverage get you 'more' drunk? | It is definitely the case that different drinks are more or less likely to give you a hangover. Spirits which have been distilled with less care often have a higher methanol content, and that can contribute to a worse hangover.
With respect to getting drunk, I suspect any effect there is results from a user-preference. If someone prefers rum to tequila, they will probably drink more and in so doing they will get more drunk. It may also be that because you typically consume different spirits in different ways, your absolute rate of alcohol consumption could vary a lot. For example, if you tend to do one as shots, but the other with mixers, you might expect the drink you do as shots to get you 'more drunk' purely because a shot doesn't last as long, so people will consume more units per hour that way.
As a caveat, this is entirely speculative, and I have no idea if this has been rigorously tested, although I would happily apply to be in the test cohort if needed! | [
"Wine, beer, distilled spirits and other alcoholic drinks contain ethyl alcohol and alcohol consumption has short-term psychological and physiological effects on the user. Different concentrations of alcohol in the human body have different effects on a person. The effects of alcohol depend on the amount an individ... |
do genetics affect our intelligence, personality or habits/hobbies? if so, how much? | Apparently yes, in a lot of aspects.
Currently my gradeschool project is to study the link between genetic and PTSD.
While it's not clearly shown in human yet, studies on rodents make us think that stuff like a traumatizing event can impact your DNA and impact future generations.
In rodents, they found out that male exposed to a extremely stressfull environement in their young age would experience some DNA modification on some genes related to stress...and so would their offpsring.
But those DNA modifications are not mutations, it's epigenetic modifications (epigenetic is basically what affects the expression of some genes but don't affect the gene itself,it's very very linked to the environement. )
EDIT : Forgot to add, the offspring of the male would be more resilient to stressfull situation next to normal rodents, and that without ever being exposed to a traumatic situation themselves. | [
"While both genetic and environmental variables were involved in the manifestation of intelligence, the role of genetics had been shown to increase in importance with age. In particular, the effect of the family environment shared by all children in a family, while important in early childhood, became quite small (... |
how does ice freeze upwards? | It would be best explained in drawings representing steps of the process, but I'll try do without:
It is known fact that ice is lighter than water - icebergs float only partially sunk.
It is also known fact, that if you put the water in a container (here, a single pit in a tray, a single cube) into the freezer, it will not get colder in an uniform way. The middle will maintain initial, room, temperature the longest, and the surface (and sides and bottom) will freeze first because they will cool down below zero first.
Yeeeet... Freezing is also a complicated process. Very complicated, with lots of extra clauses. Two I will mention here are supercooling and ice nuclei. It is possible to lower the temperature of liquid below it's freezing point (in given atmospheric pressure) and yet it will remain liquid until it gets physically shaken - and the process of freezing (crystallization) will begin around the ice nuclei in the instance. Try googling some videos about beer instantly freezing.
Whatever happened in your freezer, was a process breaking the basic path of ice cube forming. The process went along some less common route and either already frozen "surface plate" broke off the forming cube, or water got partially supercooled and formed mini-iceberg floating around the not yet frozen cube. Whatever way, the ice was free to float - meaning some of it stuck out of the surface. And being an already existing nuclei for further freezing, it grew fast, sticking out even further.
If it stuck out diagonally, the plate scenario is more likely.
Or something else happened, I just posit a possible scenario :) | [
"Eventually, the ice will be surging fast enough that it begins to thin, as accumulation cannot keep up with the transport. This thinning will increase the conductive heat loss, slowing the glacier and causing freezing. This freezing will slow the glacier further, often until it is stationary, whence the cycle can ... |
Would helium in your ears make everything sound high pitched? | While the other posters are correct that the frequencies that you hear wouldn't change, a few effects would occur if your ears were filled with helium.
First off, things would get quieter because the difference in the air outside and the helium in your ears would create an impedance transition for waves traveling to your eardrums. At an impedance transition, some energy is reflected, and the amount that is reflected increases with the difference in acoustic impedance (density times sound speed).
Second, your ear canal has a slight resonance around 3 kHz which amplifies the sound in the region most important for speech intelligibility. It's a very slight increase (~3 dB, less than a doubling of perceived loudness), but it would still make things a little harder to listen to.
As to why the frequency wouldn't shift, this can be easily understood as "frequency in = frequency out." Suppose I tapped on a table once every second, and it took 5 seconds for the sound to reach you. If I tapped at times "0, 1, 2, 3" you would receive it at "5, 6, 7, 8" but the time between the taps would still be consistent at 1 second. If the speed that it traveled was faster, like 3 seconds, you would receive "3, 4, 5, 6" and the time between taps is *still* 1 second. Frequency is basically the time between peaks in a sound wave, and as demonstrated, that isn't changed by the time it takes the group of peaks to travel.
As to why your voice goes up when you breathe in helium, that's because your vocal tract acts like a resonator that filters the sounds from your vocal cords. The frequencies of that resonator are determined by the length of your vocal tract (which doesn't change) and the speed of sound in the resonating air column (which does). When you breathe in helium, then, the resonant frequencies of the vocal tract increase, causing a different set of frequencies to be emphasized, creating that weird chipmunky sound. Note that the sound of speech with helium is different than if you just recorded the sound and sped it up, this is because the vocal cords are still flapping at a low speed with helium, so the fundamental frequency of your voice doesn't change, just the filter that's applied.
I hope that answers your question, and feel free to let me know if you have any follow-ups! | [
"The speed of sound in helium is nearly three times the speed of sound in air. Because the fundamental frequency of a gas-filled cavity is proportional to the speed of sound in the gas, when helium is inhaled there is a corresponding increase in the resonant frequencies of the vocal tract. The fundamental frequency... |
why do we "smile" when we cry? isn't smiling a way to show happiness? | Whenever this happens to me, it's usually because I'm feeling a mixture of things all at once and it can be quite overwhelming. Things like happiness, reward, relief, sadness, excitement, and maybe even a little anger or frustration all come at me and then the smile cracks and the tears flow.
This has happened to me during very happy events or experiences like getting accepted into college after *months* of trying to get in, getting straight As in all my classes this semester, learning I do not have HIV after fearing I had been exposed to the virus, learning I do not have breast cancer after a couple lumps were found, and even sometimes after experiencing an amazing yet intense orgasm.
I heard the theory in one of my Psychology classes a long time ago that when we are experiencing an immense positive emotion, our bodies may release a "negative" emotion or tears to sort of *balance* us out again. Pretty neat!
Edit: spelling | [
"Among humans, smiling is an expression denoting pleasure, sociability, happiness, joy or amusement. It is distinct from a similar but usually involuntary expression of anxiety known as a grimace. Although cross-cultural studies have shown that smiling is a means of communication throughout the world, there are lar... |
how does swallowing ssris or any medication get the chemicals into your brain or other body part where it's required? | It is the same way food is processed. It is broken down and absorbed by the digestive tract, then distributed throughout your body via your bloodstream. Medications do not target a specific region. | [
"Many drugs as tablets, capsules, or drops are taken orally. Administration methods directly into the stomach include those by gastric feeding tube or gastrostomy. Substances may also be placed into the small intestines, as with a duodenal feeding tube and enteral nutrition. Enteric coated tablets are designed to d... |
What makes sulfur smell so bad? | Its a biological mechanism to protect living things from consuming rotting material, which is toxic, if not unhygienic, and often hides pathogens. One thing is that as organic material decomposes, it often releases hydrogen sulfide or sulfur containing compounds as bacteria dissolve away bonds between proteins and fat.
The body understands this slowly, and adapts, over the eons, to increase its sensitivity of smell towards sulfur, in order to keep you away from rotting steak that may cause you food poisoning if it didn't. | [
"Sulfur is generally nontoxic and is even a vital nutrient for humans. However, in its elemental form it can cause redness in the eyes and skin, a burning sensation and a cough if inhaled, a burning sensation and diarrhoea and/or catharsis if ingested, and can irritate the mucous membranes. An excess of sulfur can ... |
I learned as a kid, as soon as you see lightning, you count Mississippi's and whatever number you get up to when you heard the thunder, that's supposedly how many miles away the lightning struck. Is this scientifically accurate? | Unless you count very slowly, you probably have to divide the number by 4 or 5 first. In the end, the accuracy of the estimate depends on how fast you count, but the general principle of counting the time between lightning and thunder to determine the distance is sound.
The light from the lightning flash travels with the speed of light, 300,000,000 m/s. That's so fast that in this context, you can assume that you see the flash instantly, without any travel time. Thunder, on the other hand, consists of sound waves which travel at about 340 m/s in air (depends on atmospheric conditions), or about 256,000 miles/fortnight in funny units.
That means that if you counted 5 seconds between flash and the start of the thunder, then the lightning strike was 5 * 340 = 1700 meters (1.06 miles) away. | [
"Lightning at a sufficient distance may be seen and not heard; there is data that a lightning storm can be seen at over 100 miles whereas the thunder travels about 20 miles. Anecdotally, there are many examples of people saying 'the storm was directly overhead or all-around and yet there was no thunder'. There is n... |
what does it mean to plea “no contest?” | Basically it means, "I'm not pleading guilty, but I can't or won't fight the charges." Functionally, the court operates as if the defendant plead guilty, but the plea can not be used against them in any future proceedings; for example, if you plead guilty to a traffic violation that caused an accident, that guilty plea can be used against you in civil court as an admission of fault, while a no contest plea can not. | [
"A no contest plea prevents the court from eliciting a defendant's admission of guilt, but the result of the defendant's plea not to contest the charges against him or her is the same as if the defendant had admitted guilt. If a defendant pleads no contest to a charged offense, with the exception of questioning the... |
how does a brain aneurysm kill you? | Oxygen is like food for cells. They start dying really quickly when there's no oxygen. See how long you can hold your breath for. Now, we are our cells, if they start dying so do we.
Blood transports oxygen to your cells. If your blood supply is cut off, you die. An aneurysm is what happens when a portion of the vessels that cary blood begin to expand. Just as inflating a balloon thins the walls, so does our vessels.
I know the name sounds alarming but most of the time aneurysm don't cause any health problems. Many people live their whole lives without even realizing they have one. The danger is in the fact that it could burst. The exact risk is in the size and extent of the aneurysm. Keep your heart rate low and your blood flowing smoothly and you won't need to worry about aneurysms. | [
"In nearly all cases, hypoglycemia that is severe enough to cause seizures or unconsciousness can be reversed without obvious harm to the brain. Cases of death or permanent neurological damage occurring with a single episode have usually involved prolonged, untreated unconsciousness, interference with breathing, se... |
what events led up to the tiananmen square massacre | The Soviet Union collapsed without triggering a bloody revolution. Despite the efforts of the communist party in China, word spread about the Soviet collapse and it became common knowledge. In China, the idea that the communist party could be removed "peacefully" fired the imaginations of a lot of people (especially young people with no direct experience of the Cultural Revolution, the great famines, or WWII).
Students organized in Beijing, and eventually at many large cities across the country, calling for the replacement of the communist system with a western-style democratic process. Those students were joined by increasingly large numbers of the emerging Chinese middle class.
The communist leadership tried to defuse the crisis and was split between those who wanted to try to find an accommodation with the protestors and those who wanted to put the protests down with violence. Eventually the momentum of the protests grew so powerful that the leadership elected to go with forceful repression. They considered it an existential moment (as in, if they didn't act, the communist party would cease to exist in the same way it had in Russia). The hardliners believed that the Soviets had made a grave error by not cracking down on dissent and protest and that was the reason the USSR had dissolved. They were determined not to see a repeat in China.
The military was ordered to go into the protest zones and break up the protests and arrest the protest leaders. Some units refused - a shocking development in a communist-run military and an indication of how right the hardliners were about the close-run nature of the thing. If they'd waited a bit longer it might have been too late to stop a revolution. Eventually enough forces were assembled willing to follow the leadership's orders, and they moved into the protest zones all over the country but especially and notably in Tienanmen Square, and shot and killed people until the protest effort collapsed. | [
"The Tiananmen Square protests, commonly known in mainland China as the June Fourth Incident (Chinese: , \"liùsì shìjiàn\"), were student-led demonstrations held in Tiananmen Square in Beijing during 1989. The popular national movement inspired by the Beijing protests is sometimes called the '89 Democracy Movement ... |
if you saw a picture of a waveform, could you recreate the audio? | This is actually how a projector reads the sounds of the film.The sound is recorded next to the image on the film, and the projector shines light though the waveform as the film is moving by.
Different amounts of lights gets though as the waveform gets wider and narrower. on the other side there is a light sensor, converting the amount of light in to an electric signal that is then sent to a speaker.
_URL_0_ | [
"Given a 3D audio \"picture\" of the scene, a specialised algorithm generates secondary sound waves necessary to recreate it in the particular room and then instructs a large number of speakers (300-400) to generate the \"audio hologram\". While traditional surround sound systems can only recreate the original 3D s... |
why do microscopic images always look cartoonish? | Depending on the type of microscope, they are often false color, or use a contrast dye. The shallow depth of field tends to make borders stand out looking more like outlines. There's also just not that much stuff in the field of view compared to what were used to in the chaos of the macro world. So simple lines and high contrast look cartoony. | [
"Image macros often feature a \"witty message\" or \"catchphrase\". Although, not all image macros are necessarily humorous. LOLCats, which are images of expressive cats coupled with texts, are considered to be the first notable occurrence of image macros. Advice animal image macros, also referred to as stock-chara... |
Do each of our nerves have separate connections to the brain or do signals travel up a common pathway? | There is a ton of wiring going on up there!
A touch fiber contacts multiple second order touch fibers in the dorsal column nuclei. Those, in turn, contact multiple third order neurons in the thalamus, which then project to sensory cortex.
Temperature and pain are carried by different fibers, on different pathways once the spinal cord is reached. But, again, they contact third order fibers in the thalamus. And those are different third order fibers from the touch neurons. And the temperature and pain neurons are not contacting the same thalamus fibers (even indirectly).
So, yes, the neurons do follow one of several major pathways, but the signals are MOSTLY segregated by the time they reach sensory cortex.
| [
"BULLET::::- Many neurons connect to the brain on one end, with the other end connected to another neuron, with the outside (the brain) junction located within the spinal column. Other neurons bundles which are labeled cranial nerves, connect to the brain on one end, and to locations outside the brain on the other,... |
If heavier elements 'sink' towards the core of a star, why does fusion still occur there? | The core of the star is the only place with enough pressure and heat for fusion, it doesn’t happen in the outer layers because it isn’t hot enough there.
In stars that fuse hydrogen like our Sun there isn’t enough helium yet to prevent hydrogen from fusing, and there won’t be for billions of years. Eventually there will be enough helium to prevent hydrogen from fusing though. Fusion creates an outward force which prevents stars from collapsing in on themselves, so when that happens the Sun will collapse a bit causing it’s core pressure and temperature to go up until the conditions are right to fuse helium into even heavier elements like carbon. When this happens the star enters it’s red giant phase, and if it’s a smaller one like our Sun it will cause powerful solar wind which effectively blows the star apart into a planetary nebula.
In larger stars though the gravity overcomes this powerful solar wind and once the helium is depleted it fuses carbon and the cycle continues with each phase lasting less time than the last. This creates many layers of different elements in older larger stars. This will happen until iron is produced in the core, any atoms the mass of iron larger are special because they take more energy to fuse than they produce, so that drains the star of a lot of energy and quickly causes a collapse resulting in a supernova. | [
"The core of a star is kept from collapsing by the heat generated by the fusion of nuclei of lighter elements into heavier ones. At various stages of stellar evolution, the nuclei required for this process are exhausted, and the core collapses, causing it to become denser and hotter. A critical situation arises whe... |
Did Emperor Ashoka really exist? | Great to see a question about an interesting time and figure! I’ve been doing a lot of research on Ashoka and the Maurya Empire lately, and I currently have an article on the collapse of its currency system under review by a journal.
Our written evidence for the Maurya is limited. That’s at least in part due to the massive upheavel during following centuries, which led to the loss of many sources. Its existence is still corroborated by several Greek writers and surviving texts like the *Arthashastra*. While problematic in a variety of ways (*Arthashastra* has probably been interloped by later writers, and the Greek writers often repeat third hand information), it’s enough to verify broad swathes of the Mauryan history detailed in Buddhist and Jain texts, minus the more religious claims. Certainly Chandragupta Maurya, the founder of the dynasty, existed and led a revolt which toppled the existing Nanda Dynasty in Pataliputra. He then began a conquest which took much of the subcontinent. His sucessors followed this model and continued to expand. Their creation of infrastructure like roads, a uniform currency, encouragement of long distance trade, maintenance of a central army, and governance of a large, multi-lingual and multi-ethnic territory are what makes them an ‘empire,’ although the rulers referred to themselves as *raja*, usually translated as king.
The Maurya Empire is further attested by archaeology. While not attributable to specific rulers, we can see the expansion of a uniform silver currency across their territory. We can also see the growth of a unique art styles, such as the “Mauryan polish” that makes the lion capitals so shiny. Many stupas and Buddhist sites do show notable expansion around the time of Ashoka, such as those excavated by John Marshall at Taxila.
The Ashoka inscriptions are actually multi-lingual, and were sort of like a Rosetta Some for scholars deciphering some no longer used Indian languages. In Prakrit, the main language of the Mauryan court, Ashoka refers to himself as *Devanampiya Piyadasi Asokaraja*, which is translated as “Humane King Ashoka, Beloved of the Gods.” They certainly paint him in an idealistic light and are subject to debate, but that’s true of any ancient document. Most modern scholars accept them as genuine, but there is certainly some debate. There’s really nothing else on the Kalinga War, but we do see the Mauryan currency and some architectural evidence of their rule or influence there.
Lastly, it may be helpful to view Ashoka and the Maurya as one dynasty within the history of a wider empire. Chandragupta Maurya, the founder of the dynasty, largely usurped the existing Pataliputra-based Magadha Empire after overthrowing the Nanda Dynasty, keeping and expanding much of their governmental structure, such as their uniform currency. They may have ruled relatively loosely, relying on satraps and subservient petty kings to govern distant territories. Ashoka’s successors, even less well understood than him, probably split the empore into multiple states. The Pataliputra-based rulers were overthrown by Pushyamitra Sunga, a Mauryan general. The subsequent Sunga Dynasty kept much of the Mauryan government model within a much reduced territory. There’s a marked period of decline and disintegration of central power (especially visible by the collapse of the uniform currency, a major indicator of long distance trade), but the Sungas were eventually overthrown by the Kanva Dynasty in another coup. By now a very small kingdom, they were swallowed up by the Deccan-based Satavahana Empire.
As far as further reading goes, most of the latest scholarship is very specialized and specific, and the broader syntheses are a little outdated. Still, *Aśoka and the Decline of the Mauryas* by Romila Thapar is probably the best. For an outline of the debates of Mauryan historiography, “Main Trends in the Historiography of the Early Maurya Empire Since Independence” by Shankar Goyal (*Annals of the Bhandarkar Oriental Research Institute*, Vol. 76, No. 1/4 (1995)) is pretty solid. | [
"Ashoka was the third monarch of the Maurya Empire in India, reigning from around 269 BCE. Ashoka famously converted to Buddhism and renounced violence soon after being victorious in a gruesome Kalinga War, yet filled with deep remorse for the bloodshed of the war. Although he was a major historical figure, little ... |
why does being upset mentally cause physical symptoms of sickness? | Mental upset causes your body to release stress hormone. Prolonged presence of stress hormone triggers shut down of digestive functions which causes the diarrhoea, loss of appetite, inappropriate reaction to certain foods, ect. It also alters brain functions which can cause headaches, brain fog, ect. The immune system also has reduced functioning making you prone to infection, which may result in additional symptoms later on. There's also the effect it has on the heart and muscles, changes in blood pressure, ect. These can cause you to feel dizzy, light headed, chest pain, muscle tightening, muscle soreness, ect.
| [
"If a person is ill with a medical disease such as diabetes or arthritis, there will often be psychological consequences, such as depression. Some even report being suicidal. In the same way, someone with psychological issues such as depression or anxiety will sometimes experience physical manifestations of these a... |
why is inflation not tied to population? | This is a pretty complex question, as inflation is a pretty in depth topic. I'll try to address it the best I can in a Reddit post.
At a high level, some inflation is _good_ for an economy, regardless of population. You want goods to slowly get more expensive because that encourages spending and investing over straight saving as well as serves as a buffer against deflation (which is really, really bad). Inflation is also necessary for population growth, as you need an ever increasing monetary supply to support growing populations, else we run into that deflation problem again.
That all said, inflation levels that are too high are also very bad for the economy, regardless of population growth. You want the number to hover right around 3%ish, as that seems to be the sweet spot where the benefits are greatest and penalties the lowest.
Inflation doesn't have much of an impact on inequality, so long as wages increase along with inflation. Even if they don't, the inflation targets are still good for lower income people, as inflation reduces the value of any debts they may have. | [
"There is widespread consensus among economists that inflation is caused by increases in the supply of money available for use in a nation's economy. Inflation can also occur when the economy 'overheats' because of excess aggregate demand (this is called demand-pull inflation). The causes of disinflation are the op... |
The idea of "beauty" has changed drastically over the centuries. What underlying reasons are there for this shift of what it means to be "beautiful"? | This is a wonderful question, and one for which I can't offer much of a response. I'd like to suggest that anyone considering answering this question focus on his/her own area of knowledge rather than tackling the changes of aesthetic ideals over the entire modern era.
Do you know something about what was considered beautiful in the height of the Ottoman empire? In Qing Dynasty China? In pre-Columbian America? I'd love to hear your perspective, maybe alongside some speculation about how these aesthetic ideals relate to Western ideals today. | [
"BULLET::::5. \"Beauty\": The collective knowledge of philosophers and mathematicians of the past, as well as modern day artists, scientists, models and musicians form the basis for considering what people find beautiful and why.\n",
"In England, in 1757, the important aesthetician Edmund Burke denied that perfec... |
why have global oil prices tanked so dramatically? | The main reason is a massive increase in oil production. In America, oil production had been decreasing for years. Oil prices had been going up and up. Then in 2013-4, a new technology, called hydraulic fracturing, for extracting oil suddenly took off. It was expensive, but the new high oil price made it worth it.
Huge amounts of money started flooding into setting up hydraulic fracturing oil production in the US. As a result, a huge amount of new oil production came online and flooded the market. US oil demand has been going up for the last couple of years, but the increased production has more than made up for it.
The market flood has been made worse by countries like Saudi Arabia who depends on high oil prices for income. The government needs the oil money badly, and as the price drops, they need to sell more to make up for the lower price. They have pumping oil at maximum speed in order to try to get as much money in as possible.
Finally, it had been expected that oil consumption in China would be increasing at a lightning speed, and even though more supply of oil came, it would only be a few months or a year before China started using it. However, recent figures from China suggest that their oil consumption is increasing much more slowly, so it will take many years before demand catches up with supply. | [
"The price of oil nearly tripled from $50 to $147 from early 2007 to 2008, before plunging as the financial crisis began to take hold in late 2008. Experts debate the causes, which include the flow of money from housing and other investments into commodities to speculation and monetary policy or the increasing feel... |
when people thought that the earth was the center of the solar system, how did they explain planets moving behind the sun? | If I am remembering correctly, the understanding was that the order went something like this:
Earth - > Moon - > Sun - > "Stars" (including planets with everything else that's just a bright dot).
So to the extent they observed the planets moving behind the sun, it made sense since they were behind the sun. | [
"A more conventional picture was that supported by Hicetas, Heraclides and Ecphantus in the fourth century BCE who assumed that Earth rotated but did not suggest that Earth revolved about the Sun. In the third century BCE, Aristarchus of Samos suggested the Sun's central place.\n",
"In the 17th century, Johannes ... |
Why is it so difficult to solve the Schrodinger Equation for multi-electron species? | Let's clairfy some stuff here: There's no _known_ analytical solution. But you can't equate "analytical" with "exact". What you're thinking of is a _closed-form solution_, which is a sub-set of analytical solutions. The classical three-body problem has an analytical solution, but not any known closed-form one.
A numerical solution is not necessarily "inexact" because it can converge to the correct solution. In practice, it may do so more rapidly than an analytical solution.
In short, even if there was an analytical solution, it's not necessarily of any practical use whatsoever. We already have exact-in-principle methods, and it's probably the case that any analytical solution would converge more slowly than they do.
Also, the Schrödinger equation is non-relativistic. For electrons in atoms, it's only physically meaningful to about 5-6 digits, any accuracy above that is actually overkill anyway.
| [
"Due to complex interactions which arise from electron-electron repulsion, algebraic solutions of the Schrödinger equation are only possible for systems with one electron such as the hydrogen atom, H, H, etc.; however, from these simple models arise all the familiar atomic (s,p,d,f) and bonding (σ,π) orbitals. In s... |
why do planes need a billion buttons and switches in the cockpit? | When you're in a flying box with upwards of a hundred people as your responsibility, the last thing you want to do is rely on a computer having 100% control over ANYTHING.
The cockpit has manual controls for damn near (if not all) subsystem onboard. Most switches/buttons probably never need to be flipped, but you want to have absolute control over everything for any sort of "just in case" moment, because at 30,000 ft. you don't have any other options if something goes wrong. | [
"In the design of the cockpit in a military fast jet, the traditional \"knobs and dials\" associated with the cockpit are mainly absent. Instrument panels are now almost wholly replaced by electronic displays, which are themselves often re-configurable to save space. While some hard-wired dedicated switches must st... |
how do illegal immigrants apply for welfare if they dont have any social security card or formal identification? | Under circumstances where you are eligible for such a program, there are usually alternatives to a Social Security Number. For example, illegal aliens can legally receive the child tax credit for their dependents, and can file their tax returns using an IRS-provided International Taxpayer Identification Number instead of an SSN. If you are otherwise eligible for a program, most agencies do not require you to provide an SSN or similar documentation if you can prove you do not have them and cannot obtain them.
As for welfare fraud, illegal aliens who participate in that do it the same way as other people, by making false statements and using false documents. There's a lively market in Social Security cards and birth certificates, which illegal aliens often use without knowing they belong to a real person.
Your driver's license is not a welfare program. Many states try to make it easy to apply for welfare (though others make it hard), because they feel it is important for the poor to have access to these programs, but they make it hard to apply for a driver's license for the first time, because they want to apply extra scrutiny before providing an identification document. | [
"Although in a recent case, an immigrant was charged with \"criminal impersonation\" for using another person's social security number when signing up for a job, some courts have ruled that this is not an actual crime. The ruling hinges on whether there was harm to the other person.\n",
"No person shall receive a... |
The areas controlled by the Russian Empire and the Soviet Union composed many different ethnicities aside from Russians. During war, did all ethnicities serve in the same units, or was there segregation? What attempts were made to integrate all these various peoples into a single military force? | (1/2)
The short answer is no, neither Imperial Russia, nor USSR adopted segregation, due to distrust of non-Russians.
Longer answer: History of the Russian Imperial army can be divided in to the two major periods 1699-1874 and 1874-1917.
**Peterian period (1699-1874)**
Naturally a lot, changed in the period of 270 years, but foundational principles of Peter the Great were fallowed. During the Peterian period, force was raised mostly from Russians (that including Ukrainians and Belorussians) due to recruitment system being tied to serfdom: landholder were tasked to provide number of *rekruts*, from the serfs owned (the ratio fluctuated during the period, but in general we speak about 5-6 *rekruts*, from 1000 *souls*), hence the territories were manorial system did not dominated were outside of the recruitment system.
That by no means was some loophole that accidentally let minorities of the hook: it was intent Peters to have a Russian-majority army and system was designed around that, with no intent to draft non-Russian population. Often cited Imperial Decree of May 17,1798 (stating that recruits must be native born Russians) simply gave legal basis for long standing practice. Still, connecting recruitment with the manorial serfdom had unintended consequence of non-Russian serfs being drafted. In the first paper I linked bellow authors make assumption (page 4) that Mordvinians and Cheremisov Tartars fell under compulsory draft due to being considered more loyal and easier to integrate. Hardly the case, considering that these are the people that were eventual subjugated to serfdom and hence fell under *rekrut* system. Another-and better- example would be Lithuanian population, that also was subject of this system since the Third Partition, despite active participation in revolts against Russians, simply because serfdom was well established in Lithuania.
These non-Russian *rekruts* came from relative small ethnicities, easy absorbed and diluted in much larger body of the Russian servicemen, so no one raised much fuss that some of the serfs given to army were not proper Russians.Somewhat paradoxically, the officer corp was much more ethnically diverse due to inclusion of the nobility of the subjugated nations- Baltic German and Georgian nobility even made themselves a name by are providing a officers to the Imperial Army.
Also I should mention Cossacks- a rather interesting ethno-social group of the Russian Empire. Generally Cossacks were considered Russians, but large number of Tartars were absorbed in to the Hosts, and for all matter and purposes were considered Cossacks.
Aside from this "in the army by technicality", the only use of non-Russian troops was a relatively small auxiliary light cavalry force raised predominately from Muslim populations (Tartars, Bashkirs and such). As this force made only few percents of the overall standing army and were fighting in traditional manner (meaning that Russian empire was the only European power to field horse archers during Napoleonic wars), they never were of much importance.
**Milyutin's Army (1874-1917)**
As much as it matters to the topic we discussing, Milyutin's reform of the 1874 was targeted to update Russian military to the European model of mass levy army. The two major goals was to expand draft pool and establish mobilization reserve. To achieve that compulsory service for all males was introduced, while service time was cut from 12 to 6 years. That was on paper. In practice, the system had a lot of exceptions and fine print attached.
Most of Siberia (especially Siberian natives), Central Asia and Caucasus region were left exempt from the levy.Again, Curran and Ponomareff put all they attention on political reliability of the minorities, and that certainly was a large issue, but there is also some other practical considerations.
Take for example Siberia. While Russians lived here in permanent settlements, most natives like Mansi or Nenets were supporting themselves by hunting and elk-herding and continued to live semi-nomadic lives, interacting with outside word only by occasional visit of the market town. Given extremely low population of such tribal societies, drafting from Siberian tundra or isolated villages in Caucasus mountains would be simply a lot of effort for little to no gain.
Another problem was, in Milyutin own words "low level of civic development". Curran and Ponomareff quotes this to support statement that limited recruitment was adopted due to "distrust of some non- Slavic ethnic minorities" (page 5-6), but again, I would see here simple recognition of reality: if you grab someone from the ancestral yurt or aul and drop him in the modern town (or barracks) there will be some acclimatisation problems. Again- a lot of work for little profit.
Anyway, with large portions of the empire being politically unreliable or simply to hard to draft, disband of native auxiliary units was probably the largest change in the military as far as ethnic policy goes: just as before Army was still mostly raised in European part of the empire and still predominately Russian with other ethnicities being dispersed and diluted.
**World War One and Revolution**
Then war broke out, Empire found it self in want of more cannon-meat and began to weaponize national feelings of the various ethnic groups. Among the most notable examples are Armenians, eager to liberate historical Armenia from the Ottomans and Latvians, known (at the time) for long standing animosity towards Germans. Peterian- style Muslim cavalry auxilia also made return as the *Savage Divisions*.
However, that still remained rather the exception, a propaganda effort to get additional batch of volunteers. For the most part army remained uniform and Russian-dominated. Some units here and there had a larger group of non-Russians but more by accident rather than intent. For example [Gen. S. Raštikis](_URL_0_) (he served in Caucasus Front during WWI) mentions few units with larger number of Lithuanians serving there.
That all began to change after the February revolution, then birds of feather began to flock together like no-ones business. Most prominent- and initially successful- were Ukrainians, by merit of establishing a government- Central Rada- as early as March. Not only new volunteer units (like Bohdan Khmelnytsky Regiment) were raised, but also a significant effort was made to assemble already serving Ukrainians in to national units. Pavlo Skoropadsky put himself on the political map by successfully reorganizing his 34th Army Corps into 1st Ukrainian Corps.
Polish officers in Petrograd formed a Chief Polish Military Committee (Naczelny Polski Komitet Wojskowy), who initiated formations of three Polish corpses ( *Korpus Polski w Rosji* )- one in Belurus, Second in Bessarabia and Third in Ukraine.
Other nationalities, without central institutions acted more from the local initiative and results vere mostly small lived small units. For example Lithuanian efforts amounted to separate battalion within the 1st Polish Corps, reserve battalion in Minsk, Separate Vytautas the Great battalion in Chelyabinsk , field hospital in Romanian front and dragoon detachment in Valka.
As Imperial army effectively ceased to exist in 1918 all these national units fell apart, were disbanded,became nucleus of national armies (like Ukrainians) or were simply dragged- sometimes against they own will- in to one or the other side of the Civil War.
To sum up Empire period it would correct to say that being composed mostly of uneducated peasantry (despite Milyutin's attempt to educate recruits) and dominated by single ethnic group, Imperial Army was capable to ignore dreaded "national question" altogether. | [
"In Russia proper, ethnic Russians were allowed to govern the Lokot Republic, an autonomous sector in Nazi-occupied Russia. Military groups under Nazi command were formed, such as the notorious S.S. Sturmbrigade R.O.N.A., infamous because of its involvement in atrocities in Belarus and Poland, and the 30th Waffen G... |
what is the point of throwaways? | No. If you say something like "I intentionally ruined my best friend's life", and then later (or at an earlier time) posted your personal information, people will know. The point of a throwaway is to use ONLY for telling how you ruined your best friend's life, nothing else. That way, you action can't be associated with you. | [
"In comedy, a throwaway line (also: throwaway joke or throwaway gag) is a joke delivered \"in passing\" without being the punch line to a comedy routine, part of the build up to another joke, or (in the context of drama) there to advance a story or develop a character. Throwaway lines are often one-liners, or in-jo... |
with evolution, if human beings are always evolving from one generation to the next, at what point in the future are people no longer human beings? | By definition they will no longer be homo sapiens when they cannot successful procreate with homo sapiens.
| [
"As a result of the extinction of \"Homo sapiens\", these humans can no longer be genetically tweaked and altered in labs and instead they begin to evolve through natural selection and other natural evolutionary processes, resulting in many new and diverse forms over the course of several millions of years. These n... |
What is this WWII Document? | Here is a transcription of the handwritten portion, which refers to the message above it. Left page:
> This shows a message as we receive them to make our write-ups from and lets you know what some of the letters numbers and words mean & nbsp; here goes. - The NAA \#2 means it was the second message sent from the Washington DC radio station that day. Z RAFT V ANON ~P~ GR 16 is the heading. The portion after the Z is who the message is sent to for action and the part after the V is the originator. In this case acting Sec. of the Navy originated the message and was sent to all naval ships and stations. The -P- designates its precedence which happens to be priority and only gives us 10 min. to be delivered to …
Right page:
> [GR 16 is the number of groups.]
... an officer after we receive it off the air. In the body of the message 3401 means two things. The 34 tells what officer sent or released the message and 01 is the date. The 0340 is the time sent. Just below the message is 0045TA8470/1 Sept. 0045 is time of receipt here in our offices. TA is the radiomans initials that copied the message. 8470 means frequency he was tuned in at and 1 sept is the date. The other scratches just show we received the message and it is all taken care of. Quite a bit of work in each write up but its interesting and isn’t hard after getting used to it. - Note that time this dispatch was sent is 0340 and we received it at 0045. Difference in time belts [aka zones] is the reason.
It appears that your great-uncle was a radioman, and he sent a copy of two significant telegrams (referring to the German invasion of Poland and the Japanese attack on Pearl Harbor) along with an explanation of what all the weird symbols mean. Interesting stuff. | [
"The document also outlined the destruction of thousands of documents that were deemed \"essential\" to the Nazi war machine, this including documents pertaining to military and civilian logistics and installations, medical research, and other technological research.\n",
"BULLET::::- Online WWII references Online... |
what are the differences between different types of missiles/rockets? | The guided vs unguided rule is mostly true, however - a little more information for you:
[Rockets](_URL_14_): Such as the [Mk66m6 Hydra 70](_URL_19_) are 'cheap', high volume, rapid-fire projectiles for causing general chaos. Modern variants can, indeed, be guided and can be fused to explode on impact, in the air above the target or when it detects that it is near a target. You may also have heard of the [RPG-7](_URL_5_) or the classic [Bazooka](_URL_22_) - both man-portable.
[Air to Ground/Air to Surface Missiles](_URL_7_): Such as the [Brimstone II](_URL_18_) are generally assigned a target - like a position on the surface, a specific heat signature on the ground, a laser-designated target, etc. and then fired from an aircraft. That could be an attack helo, a CAS Aircraft like the [A-10 Thunderbolt II](_URL_31_), or most other strike aircraft. These are also the kind of missiles you will hear about when people say 'Drone Strike'. The [MQ-9 Reaper](_URL_2_) carries 4 [AGM-114 Hellfire](_URL_25_) air to ground missiles. It also carries a bunch of guided bombs (we'll get to those) and has been tested with the Brimstone missile system.
[Air to Air Missile](_URL_37_): Such as the well known [AIM-9 Sidewinder](_URL_0_). These do what they say on the tin - how they do it, however, varies massively. Generally, you somehow target or cause to be targeted a (hopefully) enemy aircraft then set your missile loose. Due to the rapid pace of anti-missile technology (beyond our scope here), there is a rapid turn-over of AIM (Air Intercept Missile) variants. Some use heat (IR guided), other onboard radar (active), some ground or aircraft-based radar (semi-active) or passively detect enemy radar and radar jamming signals (passive, or home-on-jam). Yet more, such as the [Python 5](_URL_8_) can use target visual identification to track their target, and can acquire and attack their target *after launch*. Anti-aircraft missiles typically make their kills by firing a cone of shrapnel at the target, shredding vital equipment, control surfaces and possibly people like a giant rocket-propelled, guided shotgun shell.
[Surface to Air/Ground to Air Missiles](_URL_29_): Such as the short range (8km), man-portable [Stinger](_URL_6_) or the huge (5.8m, 700kg), long range (160km) ([Patriot missile system](_URL_36_). These are very much the same as the air-to-air variety but come with a collection of ways to get the missiles into the fight. Without the benefit of the aircraft doing the donkey work of getting the missile up to altitude, they often have booster motors or are generally much larger than their aircraft mounted counterparts. Some, such as the Patriot (again) can be used to protect against ballistic and cruise missiles.
['Cruise' Missiles](_URL_38_): Such as the well known [BGM-109 Tomahawk](_URL_20_), not so well known [Storm Shadow](_URL_23_) or the often forgotten [V1 Flying Bomb](_URL_27_) from WWII. These fellows are basically small (or not so small), incredibly fast aircraft consisting of an airframe, a guidance computer, all the stuff you need to make it fly and generally a pretty hefty payload - in some cases, even nuclear (the Tomahawk TLAM-N for example). Starting with the V1, which was pretty dumb by modern standards (but astonishing by the standards of the day, eventually hitting a target area 7 miles in diameter with a calculated, powered dive) and moving on to modern stealth cruise missiles, which skim inches above the terrain, and even down city streets to sneak up on their targets. Typically GPS/GLOSNASS guided, and sometimes able to make decisions about the final attack vector on approach, because of the big plus that cruise missiles bring - *range*. Ranges can be 190 miles, up to well over 1000 miles. This stand-off capability lets you launch low-risk strikes from far, far away - often on or under the sea. Yes, they can also be launched [from submarines](_URL_9_).
['Ballistic' Missiles](_URL_30_): These are often called 'nuclear missiles', though they don't have to be. Examples are the US/UK nuclear armed [UGM-133 Trident II](_URL_33_) submarine-launched ballistic missile (SLBM), the short range but still scary Soviet-era [SCUD](_URL_12_) which can have anything from a standard high explosive tip to chemical and nuclear warheads. They are called 'ballistic' missiles because they are (generally - there are always exceptions) only powered during their ascent. Once they reach the apex of their trajectory, the motors are spent and the rest of the trip is done under gravity. Control surfaces such as fins are used to target the missile, but essentially its reaches the top and turns into a dangerous sling stone. The technical aspects of the warheads vary, with some very clever ways to deliver maximum death to maximum people - we won't go into it, it's all very depressing. It must be noted that *ballistic missiles are in use in the world today* in Syria, for example. Modern defence systems are getting much better at shooting them down, but those clever ways to deliver death I just mentioned... well, they're always working to make the place a [little worse](_URL_1_).
[Unguided/Dumb/Gravity Bombs](_URL_28_): These are the various unguided, unpowered, low precision explosives dropped from aircraft since we realised [we could](_URL_32_). 'Modern' variants, such as the [Mark 82](_URL_35_) are usually upgraded to be 'smart weapons' by strapping a seeker on the front and some control fins on the back. This significantly increases the effectiveness of the weapons.
[Guided/Smart Bombs](_URL_21_): Around since the end of World War II, guided bombs allow smaller explosive charges to do more precision damage. These are still unpowered, relying on the height and speed of their launching aircraft to impart momentum for their flight systems. Modern examples include the [GBU-39 Small Diameter Bomb](_URL_11_) and the [JDAM](_URL_16_) (a Mark 82 unguided bomb with fancy bits stuck on). Some weapons also cheekily cross the divide, such as the [AGM-123 Skipper II](_URL_4_) which was an unguided bomb platform with two rocket motors taped to its ass to give it a little extra range and earning it the AGM designator - they call it 'rocket assisted'.
[Artillery](_URL_24_): This is your classic 'big gun' and covers everything from the cannon on a tank, through to a cannon on a pirate ship in days gone buy. The general principle is - load a shell that will do the thing you want (blow up, fragment, make smoke, lay a mine, seek its target, etc.), stick a known quantity of explosive behind it, seal it in a tube and light the lot on fire. With a bit of trigonometry (ok, a lot of trigonometry when you consider these things can fire upwards of 40km such that the rotation of the earth becomes a factor). Your current fancy shells can be satellite-guided like the [M982 Excalibur](_URL_34_), laser guided like the [M712 Copperhead](_URL_26_), or classically unguided like [most other shells](_URL_17_).
[Mortars](_URL_13_): A subset of artillery, often man-portable to provide rapidly moving offensives with indirect fire support, or to cover a withdrawal with a staggered fire-move-fire. They can drop everything from your common or garden explosive round, to flares, smoke screens and IR Illuminators (invisible flares). From the wiki article - "*A mortar is a device that fires projectiles at low velocities and short ranges. The mortar has traditionally been used as a weapon to propel explosive mortar bombs in high-arcing ballistic trajectories.*" What that means is, you drop a bomb down a short, angled tube and it detonates a propulsion charge of known strength when it hits the bottom (other launching methodologies are available, see arms suppliers for details). This lets you accurately calculate the landing point of the mortar bomb, given environmental conditions such as wind, humidity, temperature, etc. Once the bomb leaves the mortar, there usually isn't any further propulsion - again, modern weapons are complex beasts and super fancy mortar shells exist, like the [XM395 PGMM](_URL_3_).
There is more to see, from [FAE](_URL_15_) to [HVMs](_URL_10_). It is a fascinating journey into engineering in an extreme environment and man's creativity when it comes to harming his or her fellow man.
TL;DR: **boom** | [
"Some military weapons use rockets to propel warheads to their targets. A rocket and its payload together are generally referred to as a \"missile\" when the weapon has a guidance system (not all missiles use rocket engines, some use other engines such as jets) or as a \"rocket\" if it is unguided. Anti-tank and an... |
how would the billionaires of the world "end poverty" ? | I think allot of the money would go towards building infrastructure so that people can support themselves, it definitely wouldn't be a over the night type of thing and a good amount of work will end up in failure but with enough money and time it would surely reduce poverty and hunger world wide but not without consequences. Charities or individuals who do donate a good percentage of the money and resources are stolen especially in third world countries I think what would help end hunger is using the money to expand control over unstable regions so that people can live relatively safely and begin to build a functioning society | [
"Poverty can also be reduced as an improved economic policy is developed by the governing authorities to facilitate a more equitable distribution of the nation's wealth. Oxfam has called for an international movement to end extreme wealth concentration as a significant step towards ameliorating global poverty. The ... |
Why were Wisdom, Judith, and twelve other books removed from the Protestant Bible? What was the rationale? Was it a controversial decision, and what was the justification given? | The very, very short answer is that the Protestant Reformation was deeply concerned with the original, unfiltered meaning of the Biblical texts. While *sola fideles*, faith alone (rather than works) leading to salvation, is perhaps the famous of the Reformation’s slogans, *sola scriptura*, Biblical text alone, was another. They wanted to recreate, really to rediscover, the original Biblical commadments, unfettered by Church doctrine.
To do this (in Western Europe), of course, meant putting the texts out of Latin into the vernacular. Myriad translations predate the Reformation. Wycliffe's Bible is perhaps the most famous pre-Reformation translation. But translation in the Reformation took on new significance.
The Reformation translators were standing on the shoulders of giants. Most importantly, one of the movements which laid some of the intellectual groundwork for the Reformation was the Humanist movement, which was very concerned with what today we call “lower criticism” and comparing the various versions of Biblical text in their original languages (the greatest Humanist, Erasmus of Rotterdam, despite many pleas from Reformers, never left the Catholic Church).
When the Reformers picked up the Humanists’ work and set about translating new, vernacular (rather than Vulgate Latin) versions of the Bible, they found many Hebrew Bible (“Old Testament”) books either lacked Hebrew originals or weren’t in use in among the Jews. These books were, I believe, without exception found in the pre-Christian Greek translation of the Hebrew Bible known as the Septuagint, but they are not included in the Masoretic text that Jews use today.
I believe Luther was the first to call them “Apocrypha” and said they
“are books which are not considered equal to the Holy Scriptures, but are useful and good to read.” I believe they were included in Luther’s original German translation, in a separate section, and only Calvinist and Radical Reformation Bibles eliminated the, entirely.
Essentially, these are books in the pre-Christian Septuagint translation but not in the Masoretic Text used by Jewish communities in Luther’s time (and today). This discrepancy was known in the Middle Ages but, as far as I know, Luther was the first to move the Apocrypha to its own section, though he didn’t delete it entirely. It was only much later that Bibles were printed without Apocrypha, at least in English (I’m less sure of other languages). The lack of clear Hebrew original made the texts seem of dubious authorship (I believe, thought I’d have to look up further, that Medieval Hebrew versions of some of these texts today are known from places like the [Cairo Geniza](_URL_0_)—version of Ben Sira or the Wisdom of Sirach, for examples, were definitely found there indicating pious Jewish use for the text even as it wasn’t being included in the formal canon). | [
"Newton concludes: \"If the ancient churches in debating and deciding the greatest mysteries of religion, knew nothing of these two texts, I understand not, why we should be so fond of them now the debates are over.\" With minor exceptions, it was only in the nineteenth century that Bible translations appeared chan... |
Who came up with the idea of pricing items a cent under the dollar ($9.99 instead of $10), and how did it become so universal? | In Made In America, Bill Bryson points out that the first cash register, Ritty's Incorruptible Cashier, patented 1883, rang a bell every time the cash drawer was opened. Bryson claims that store owners changed prices to end in an odd number, forcing the cashier to open the register every time. It was only later, he says, that store owners noticed "the odd psychological effect" (his words) that made 99 cents seem markedly cheaper than $1.00
Unfortunately, Bryson offers no source for this idea.
I know of no competing theories as to why or how business owners first started pricing using odd numbers.
Interestingly, the Wikipedia page for the history of the cash register repeats Bryson's theory, citing… Bryson.
_URL_0_ | [
"The price of an item is also called the \"price point\", especially where it refers to stores that set a limited number of price points. For example, Dollar General is a general store or \"five and dime\" store that sets price points only at even amounts, such as exactly one, two, three, five, or ten dollars (amon... |
regular expressions in programming | Regular expressions are patterns that a computer can understand and compare with a given piece of text or numbers.
They are helpful when you want to make sure a text matches a specific pattern. For example to validate email address or credit card number and things like that.
They can also be used in the same way, to extract some parts of a text. For example, maybe you have a paragraph and you want to extract all the words in that paragraph that start with 'A'.
Computers can process regular expressions very fast.
In regular expressions there are different patterns and each one means a specific thing that the computer knows in advance.
So let's have a real example.
So imagine I have a list of thousands of reddit users, and I want to find those usernames that start with 'G' and end in 'o'.
In this case I would write a regular expression like this,
> G.*o
look at that pattern, it starts with G, then a dot, then an asterisk, and ends with o.
To the computer the dot means 'any character' and the asterisk sign means to 'it may or may not be there, or there may be many'.
Now the computer reads the pattern once and turns it (or 'compiles' it) into something that it can run repeatedly and very fast. So it doesn't need to read and understand that pattern many times.
Now if you test 'Great' against that regular expression, the computer says, oh there's a 'G', after 'G' I might see more characters, or there may be an 'o'.
Oh there is 'r', 'e', 'a', and 't'. Ok, but I know it should end in 'o'. So this doesn't match.
If you try it with 'GFandango', it says ok, there's a 'G' and 'F', 'a', 'n', 'd', 'a', 'n', 'g' and finally 'o'. This matches the pattern I was expecting. | [
"Regular expressions are used in search engines, search and replace dialogs of word processors and text editors, in text processing utilities such as sed and AWK and in lexical analysis. Many programming languages provide regex capabilities either built-in or via libraries.\n",
"In \"static typing\", all expressi... |
If the virtual particles exchanged to create forces don't really exist, then what are forces made of? | The "forces" -- in the sense that there are any -- are, like everything else, made of quantum fields. Strictly speaking, there aren't any forces in the sense of instantaneous interactions à la Newton; there are only fields, interacting locally (i.e. where and only where they overlap with each other).
The sense in which virtual particles are fictitious is that they correspond to just one way to decompose the global state of the fields into an orthonormal basis -- and that basis is especially inapt when interactions are turned on. They are just one route to grasping the quantum fields, which are the "real things". | [
"In perturbation theory, forces are generated by the exchange of virtual particles. The mechanics of virtual-particle exchange is best described with the path integral formulation of quantum mechanics. There are insights that can be obtained, however, without going into the machinery of path integrals, such as why ... |
How well received was the Aaron Burr biography "Fallen Founder"? | Nancy Isenberg is a perfectly legitimate historian. And most biographies are sympathetic. It's hard to write a biography without at least exposing a "villain"'s humanity. It wouldn't be a good biography if it didn't do that, I think.
I read that book several years ago, and don't remember anything glaringly wrong with it (not that I was looking for anything, and I haven't heard much about it since) so I say try to enjoy it. | [
"\"Burr\" is the first book of the seven-novel series, \"Narratives of Empire\", with which Gore Vidal examined, explored, and explained the imperial history of the United States; chronologically, the six other historical novels of the series are \"Lincoln\" (1984), \"1876\" (1976), \"Empire\" (1987), \"Hollywood\"... |
What's up with Comet ISON? Can you guys help explain these three distinct pieces? | I don't think those two bars are real, I think they're just pointers to locate the comet which for some reason have been included in that image. Although I'm quite puzzled as to why they were put into the .fits image, that doesn't really make much sense.
Here's a [Hubble image](_URL_3_) that is the same as the picture in question. The bars are clearly not present, and it's not a contrast issue, they just aren't there.
The bottom bar points due southeast and the top bar points due west, for what it's worth, which reinforces the idea that they're pointers put on the image artificially.
Plus, if those were real, someone would have published it by now. Being the first one to identify such an utterly bizarre structure would be a gigantic boost to anyone's career.
More images:
_URL_2_
[Video of its motion over a 43-minute period](_URL_1_) (that's a relatively hi res quicktime, other formats [can be found here](_URL_0_)). Note that the tail points *away from the sun*, rather than away from the comet's direction of motion, which is a common misunderstanding. The tail is blown away by solar wind particles which is why it points away from the sun. | [
"Comet is a web application model in which a long-held HTTPS request allows a web server to push data to a browser, without the browser explicitly requesting it. \"Comet\" is an umbrella term, encompassing multiple techniques for achieving this interaction. All these methods rely on features included by default in ... |
Does nicotine have any merit as a pharmaceutical drug? | **Development of nicotinic drug therapy for cognitive disorders**:
> Nicotine, as well as other nicotinic drugs, may provide useful therapeutic treatment for a variety of cognitive impairments including those found in Alzheimer’s disease, schizophrenia and attention deficit hyperactivity disorder ADHD . We have found that nicotine skin
patches significantly improve attentional performance in people with these disease states as well as normal nonsmoking adults. Animal
models are critical for determining the neurobehavioral bases for nicotinic effects on cognitive function. We have found in lesion and
local infusion studies with rats that the hippocampus is an important substrate for nicotinic effects on working memory function. Both a7 and
a4b2 nicotinic receptors in the hippocampus are involved. Further work has investigated the relationship of nicotinic systems with
dopaminergic and glutaminergic systems in the basis of cognitive function. Nicotine has proven to be a useful prototypic compound for
the family of nicotinic compounds. It produces cognitive improvements in both animal models and clinical populations. Recent work with
more selective nicotinic receptor agonists and antagonists in animal models is providing important information concerning the neural
mechanisms for nicotinic involvement in cognitive function and opening avenues for development of safe and effective nicotinic
treatments for clinical use.
_URL_0_ | [
"There are eight major evidence-based medications for treating nicotine dependence: bupropion, cytisine (not approved for use in some countries, including the US), nicotine gum, nicotine inhaler, nicotine lozenge/mini-lozenge, nicotine nasal spray, nicotine patch, and varenicline. These medications have been shown ... |
What did medieval Christians think about the idea of an apocalypse? | Yes, apocalypticism in general starts to take root in western Europe in the eleventh century (although you can find some interesting earlier sprouts--the Pseudo-Methodius text that really kickstarts Antichrist mythology was translated into Latin in the 7th century; in the 9th century, Agobard of Lyons tried to get someone *else* (I guess he was lazy?) to write a treatise on the coming of the Antichrist; the monk known as Adso finally wrote that treatise at the end of the tenth century.
The Crusades play an interesting role in the development and entrenchment of apocalyptic attitudes. Christianity was always *eschatological*, always looking towards the Day of Judgment. But for Augustine and theologians following him, the "millennium" or eschatological age promised in the Bible ran *alongside* the rest of human history, rather than subsequent to it. The Crusades, which turned Jerusalem from the eschatological allegory for heaven into a historic, concrete reality for western Christendom, paved the theological way for 12th century thinkers and prophets to bring eschatology into the human historical timeline.
Some prophets, like Hildegard of Bingen, preached and wrote *relentlessly* about the coming of the Antichrist--but stressed that day was still far, far in the future (hence the need to reform the Church *now*, because there's still plenty of time for it to be strong and fight heresy). Others, like Joachim of Fiore and especially his followers, predicted the onslaught of the forerunners of Antichrist, Antichrist, and then the dawning of a new age (for the Joachites, the "Age of the Holy Spirit") within a century or so. (So reform the Church *now*, because you don't have much time.)
These two perspectives--apocalypse SOON, apocalypse EVENTUALLY--fight for supremacy throughout the later Middle Ages, but in an ever-mounting feverish atmosphere. By the fifteenth century, prophetic pamphlets forecasting disaster through Bible, bits of Hildegard and Joachim, natural disasters, signs in the heavens are THE hot seller of the new printing press. The early Reformation absolutely takes place under both sides' assumption that the other side is harboring the Antichrist who will cleave the Church (remember, Luther did not "leave the Church"; Luther believed the now-Catholic Church was no longer the real Church) and bring about the End of Days through war, famine, catastrophe.
A lot of the scholarship on medieval apocalypticism is unfortunately hyper-focused and kind of esoteric ("the Book of Revelation versus the 'little apocalypse' of Matthew in the *sermones de tempore* of Johannes Nider"). Bernard McGinn, one of the leading scholars of apocalypticism, has a couple of translated primary source anthologies that might interest you: *Visions of the End in the Middle Ages* and *Apocalyptic Spirituality* (for the excellent Classics of Western Spirituality series). He's also the author of a multivolume encyclopedia of apocalypticism, but unfortunately those books are print-on-demand so they are cost-prohibitive outside an academic library. | [
"The \"Apocalypse\", however, adds a new element to Christian eschatology: the rise of a messianic Roman emperor. This element would remain in Christian apocalyptic literature until the end of the medieval period. Translations into Greek, Latin, Slavonic, Arabic, and other languages from the early eighth century on... |
Did pirates wear eye patches for better vision in the dark? | **If you're new to the thread, please don't post the Mythbusters episode again. Mythbusters is entertaining but it's not history (or more specifically, it's not historical proof of anything.)**
The short answer is no, not that we know of. /u/davidaop, our pirate expert, and I have both answered [questions about this](_URL_0_) in the past. Unfortunately, because it's not a thing people did, there's not a canonical source saying that people didn't do it (if that makes sense); there's just an absence of evidence, into which void people throw half-baked conjecture. And Mythbusters. | [
"Rahmah ibn Jabir al-Jalahimah, once the most popular pirate in the Persian Gulf, was also the first to wear an eyepatch after losing an eye in battle. Although eyepatches have since become stereotypically associated with pirates, the source is unclear, and there is no historical evidence to suggest that their use ... |
how do programmers incentivize ais | Incentive is a misleading word. It's just a weight.
Let's say it can do action A, or action B 50/50. If it picks right, you up the score +5, if wrong, -5.
So if an answer should be A, and the AI picks A, it becomes 55/45, with a stronger weight towards A being the way to do things.
It's not an actual consciousness, so it's not incentivizing like a person. it's just math that reweighs things if it gives the correct output.
Here's some previous posts on the topic:
_URL_0_ | [
"The AI works by keeping track of all players' suggestions. It even keeps track of information which most human players ignore. For example, if Player A suggests that Mr. Green did it with the rope in the lounge and Player B could not disprove it, most players would ignore this fact. But the computer records that P... |
what are the rules for craps? (the dice game) | The basic rules are this:
The player rolls the dice - on the first roll if he or she gets a 7 or 11, it's a winner. 2, 3 or 12, it's a loser. Anything else becomes the "point". If the game goes beyond the first roll (that means if a point value is set), the player's goal is to roll the point again before rolling a 7 (and no longer needs to worry about 2, 3, or 12).
Gamblers around the table can either bet with the player ("Pass") or bet against the player ("Don't Pass"), as well a number of side bets (such as betting a 6 will be rolled before a 7). | [
"Craps is a dice game in which the players make wagers on the outcome of the roll, or a series of rolls, of a pair of dice. Players may wager money against each other (playing \"street craps\") or a bank (playing \"casino craps\", also known as \"table craps\", or often just \"craps\"). Because it requires little e... |
How close were the Nazis to developing 'wonder' weapons? | It really depends by what you mean by 'Wonder' weapons.
If you're referring to atomic weapons, rocket based weaponry, or jet aircraft, all three have been well documented so it's easier to give an answer on those specific weapons programs. I'll go ahead and give you some info on the atomic weapons program and if I have time later (or if someone else well versed gets the chance), I'll go into jet aircraft and rocketry.
In regards to the **German Nuclear Program**. It wasn't anywhere close to having a bomb ready for combat use or testing for a variety of reasons, but I'll just go over a few of the big reasons that I feel were the most vital in stopping the program from achieving success.
For one, Germany experienced a significant brain drain prior to the outbreak of war mostly due to politicization against the academic fields of quantum mechanics, mathematics, and physics. As well as Anti-Jewish employment policies and crackdowns on scientists with political sympathies that didn't extend towards the Third Reich, which in turn led to mass emigration to other European countries and the United States. For obvious reasons, this limited their research capabilities greatly.
Another issue was that while the U.S. and the U.K. both realized early on the usefulness and capabilities of an atomic program (and even then, the fruits of their labor were not even realized until the European Conflict had ended), the Germans forestalled any serious progress on their program until 1942 or so. Even then, the majority of scientists assigned to work on the program were also expected to contribute to many other programs as well, which obviously impeded any kind of steady progress towards their final goal.
One other event that cause the program to ultimately fail was the British SOE and the Norwegian Resistance's operations against the Norwegian Hydro Plant at Vemork. When the Germans occupied Norway in 1940, they were quite determined to make use of the Hydrogen plant at Vemork's production of Heavy Water towards their efforts to build a reactor. Despite having close to four years to produce the quantities they needed, the Germans faced constant setbacks in producing enough supplies, either by sabotage or other problems, usually technical limitations. In February of 1944, the Germans finally had enough Heavy Water to send back to Germany so that they could perhaps finally begin construction an adequate reactor to produce plutonium for a bomb. Again, the British SOE impeded the progress by having a team of operatives sink the ferry carrying the heavy water as it was crossing lake Tinnsjø.
There were many other causes towards why the Nazi's were unable to produce an atomic weapon, but as I stated in the beginning, I usually point to these three as the main underlying reasons why they were ultimately unsuccessful.
Sources:
Evans, Richard (2005) *The Third Reich in Power* p.291-320 _URL_1_
Walter E. Grunden, Mark Walker and Masakatsu Yamazaki
Osiris
*2nd Series, Vol. 20, Politics and Science in Wartime: Comparative International Perspectives on the Kaiser Wilhelm Institute* (2005), pp. 107-130 _URL_2_
Gallagher, Thomas (1975)*Assault in Norway: Sabotaging the Nazi Nuclear Program*
_URL_0_
| [
"Wunderwaffe () is German for \"Miracle Weapon\" and was a term assigned during World War II by the Nazi Germany propaganda ministry to some revolutionary \"superweapons\". Most of these weapons however remained prototypes, which either never reached the combat theater, or if they did, were too late or in too insig... |
How does sunlight break down objects that are exposed to it for too long? | This has been discussed before on here, but to make a long story short - UV degradation. The UV rays have enough energy to cause photochemical damage to certain chemical bonds in materials. This can change both its material properties as well as spectral (color) properties. | [
" Similarly to how sunlight could damage the human eye, direct sunlight is harmful to artifacts too. Light makes colors fade and breaks down organic materials quickly. It is generally best not to place any artifact in a collection in direct light, whether it is natural or artificial. “Light damage is a commonly ide... |
what exactly happens when (in movies) the police trace a call and why can't they do it if the call is less than a minute long? | It's just a movie plot device. The phone carrier knows immediately where the call originated from. The police would get a warrant and the phone company would hand over the information.
With cell phones, they would triangulate the call using 3 or more cell towers. Again, it is immediately available as soon as the phone makes contact with the towers. | [
"For abandoned calls, if the caller requests the police and the call is routed to police and then the line is dropped, either while waiting for connection or on the line with police, they are checked by police and a call back will be done. If there is no answer, the police service are likely to attend and if the li... |
Are we going to get to a point in genetics were scientists can change the composition of genes? | Yes we certainly can, and have, engineered and installed genes in living organisms. Genetically modified crops are commonplace and a bit controversial. Gene therapy had an explosion of popularity in the 90s, but has lost much steam because it is difficult to control and therefore somewhat unsafe for now. There are a couple genetic retina diseases where a person was born blind and spent their whole life that way until doctors managed to insert a fixed gene into their retinas and restored sight.
Human genetic engineering _is_ controversial and quite risky and has not been done to my knowledge. It is certainly possible. Pick up most scientific journals and you'll find that you can buy custom genes made to order with any sequence you design.
We're still at the very beginning of genetic engineering. There is much to understand in how proteins fold and details of many of the molecular machines in a cell. More and more understanding will lead to better ability to design, modify, fix, and control. | [
"Molecular genetics and genomics research have revolutionized biomedical sciences. In the 1980s and 1990s, researchers performed the first trial of gene therapy in humans and are now able to locate, identify, and describe the function of many genes in the human genome.\n",
"While such early biochemical techniques... |
what is supposed to happen astronomically on december 21,2012? | NOTHING
The Mayans were going to introduce a new calendar. Full stop. However, they did not survive long enough to need one, so their current calendar just sort of. . . stops. So then white people interpreted this as meaning that the world will stop. | [
"As September 23 passed, however, Meade again revised the apocalypse to October, making new predictions for that month, such as Nibiru eclipsing the sun on October 5 and that several people would levitate into the sky (including current U.S. President Donald Trump and Vice President Mike Pence) followed by a nuclea... |
What did people think of the horrors that went on when cities were sacked in the ancient world? | So, I'll start by linking [this thread](_URL_0_), which includes both u/Iphikrates talking about the military side in the Greek context and me talking about the civilian side in the Hebrew context. Both of those responses are more about the psychological and less about the ethical side of your question.
On the ethical side, there is a decidedly mixed historical record. Frequently what you find in these discussions is a kind of melancholy. The rape and murder of civilians is treated as basically inevitable, but still tragic. Greek sources are very interested in this kind of pondering, paradigmatically in the story of the sack of Troy. Euripides' *Trojan Women* is a good source for a sympathetic take on the tragedy of the destruction of cities.
Here's Hecuba in that work ([not my translation](_URL_1_)):
> Ah, woe is me! This surely is the last, the utmost limit this, of all my sorrows; forth from my land I go; my city is ablaze with flame. Yet, thou aged foot, make one painful struggle to hasten, that I may say a farewell to this wretched town. O Troy, that erst hadst such a grand career amongst barbarian towns, soon wilt thou be reft of that splendid name. Lo! they are burning thee, and leading us e'en now from our land to slavery. Great gods! Yet why call on the gods? They did not hearken e'en aforetime to our call. Come, let us rush into the flames, for to die with my country in its blazing ruin were a noble death for me.
Hecuba is brave, and admirable in a way. But she's also been destroyed in every way that matters, dishonored in the way the ancients reckoned these things. Note the Roman attitude towards Hannibal or Vercingetorix et al.
I'll leave with a quote from the Iliad. Hector, prince of Troy, has just removed his helmet to reveal his face to his son. (When looking on his father's helmeted head, the child cried in terror.) Hector stands on the city gates and raises his son high while blessing him:
[My own somewhat on-the-fly translation]
> Zeus and the other gods, may my child show himself, like me, greatest among the Trojans, great in power, and rule over Ilium. Some day, let someone say of him as he returns from way, "He is far better than his father" and may he bear the gore-dripping spoil of the enemies he has killed, and may his mother's heart be glad.
In other stories, the child is later thrown from that very wall for fear that he might indeed grow up to be a great warrior and avenge his father. | [
"Entire cities have also been ruined, and some occasionally lost completely, to natural disasters. The ancient city of Pompeii was completely lost during a volcanic eruption in the 1st century AD, its uncovered ruins now preserved as a World Heritage Site. The city of Lisbon was totally destroyed in 1755 by a massi... |
hiv, aids and how are they related to each other? | HIV is a bug that causes AIDS. AIDS is a sickness where the bits of your blood that hunt down other sicknesses stop working. Those bits are your T cells. HIV can sneak into T-cells and take them over, so instead of hunting down sickness, they make more HIV. When there is enough HIV, then many sicknesses can attack you all at once, and that is what kills you. | [
"AIDS is caused by a human immunodeficiency virus (HIV), which originated in non-human primates in Central and West Africa. While various sub-groups of the virus acquired human infectivity at different times, the global pandemic had its origins in the emergence of one specific strain – HIV-1 subgroup M – in Léopold... |
Is there any validity at all in the concept of 'sweating out' an illness? | The reason you get a fever is as a defense against invading pathogens. While harmful to your body the fever is also harmful to the pathogen, and hopefully your body can take the punishment while it cannot. It is a "shotgun" approach.
So increasing your body temperature might be helpful of a sort, but it can also be harmful and dangerous. Your body is already turning the thermometer up to the "danger zone" so you could easily overdo it. Threading the needle between a helpful fever and a deadly fever is only the difference of a degree or two (F); better to let your body take the lead and rein it in if things get out of hand.
And of course the "sickness" isn't going to be literally sweated out your glands, the body and diseases don't work that way. | [
"Hypohidrosis is a disorder in which a person exhibits diminished sweating in response to appropriate stimuli. In contrast with hyp\"er\"hidrosis, which is a socially troubling yet often benign condition, the consequences of untreated hypohidrosis include hyperthermia, heat stroke and death. An extreme case of hypo... |
tesla released all its patent on their car in 2014 so that anyone can use them. why isn't there any other car co. using them atm? | There is no way to know they aren't. There are a lot of patents and licensing that you would have no way to check on who is using what and How.
Also using a Patent doesn't mean it will look like Tesla, that is a different thing. | [
"Tesla Motors has rejected the dealership sales model based on the idea that dealerships do not properly explain the advantages of their cars, and they could not rely on third party dealerships to handle their sales. However, in the United States, direct manufacturer auto sales are prohibited in almost every state ... |
What happens if water vapor is compressed while kept at a temperature greater than 100 degrees Celsius? Can it turn into liquid form? | Yes, it can. The boiling point of water is only 100 deg. C at a pressure of 1 atmosphere. At lower pressures the boiling temperature is lower and at higher pressures the boiling point is higher. You may have experienced this if you've ever gone camping at high elevations. You often have to put salt in the water to raise the boiling point so you can cook your food in a reasonable amount of time.
The relationship of temperature and pressure in regards to phase shifts is described in phase diagrams. [Here](_URL_0_) is the phase diagram for water. It can tell you what phase water will be in for a given temperature and pressure, and at what conditions phase transitions occur.
There are two interesting points on a phase diagram: the triple point and the critical point. The triple point describes the temperature and pressure at which all three phases can occur simultaneously. At temperatures and pressures below the triple point, the liquid phase does not occur, and the phase transitions directly from solid to gas, or vice versa.
The critical point describes the temperature and pressure above which phase boundaries disappear. To describe the concept, envision that beyond the critical point, the liquid phase is so energetic that it becomes similar to a gas while the gaseous phase is so dense that it becomes similar to a liquid. This is called a supercritical fluid. | [
"If the pressure in a system remains constant (isobaric), a vapor at saturation temperature will begin to condense into its liquid phase as thermal energy (heat) is removed. Similarly, a liquid at saturation temperature and pressure will boil into its vapor phase as additional thermal energy is applied.\n",
"The ... |
what do we know about the original purpose of the rise of tax-paid, compulsory schooling that became widespread? | One of the things we know for sure is that every place that has created a tax-payer funded, compulsory system of education has followed its own timeline and had its own purpose. That purpose differed between countries, states, and towns and in many cases, it's more accurate to say there were multiple purposes.
A common sentiment is that tax-payer funded, compulsory schools were created to train a docile and compliance workforce (or army - more on Prussia [here](_URL_1_)). I get into the problem with that narrative in a [response](_URL_0_) to an older question but what's compelling is that the "factory model" origin story is often accompanied by the idea "summer break is because of the agrarian calendar." And yet, neither is supported by the historical record and fall apart under scrutiny. For example, there are instances of schools inside, or next to factories, in large urban areas around the turn of 19th century. Students who attended the school often worked in the factory itself. Which raises the question as to why a system needed to be created to train children to do jobs they already had. In addition, tax payers were funding public education in places without any large factories to speak of, such as North Dakota and Colorado. Meanwhile, nothing usual happened on a farm in the summer that would require a nation's children; most of the work is done in the spring and fall. And it wouldn't make sense to create a system that trained children for factory work but was organized around farming calendars. More to the point, before the American and Canadian school calendar evened out in the modern era, schools often held summer (and Saturday) sessions.
If forced, though, we can bring all systems back to one purpose: large societies have found that a designated place to bring children together under the guidance of a trained adult is an effective and efficient way to transmit knowledge from one generation to the next. In some cases, that knowledge originally had a spiritual or religious focus (i.e. Massachusetts, Quebec, Finland) but has evolved into a secular curriculum. In other cases, it was secular from the beginning (i.e. the Netherlands.) Some countries, such as Saudi Arabia, have maintained a religious focus. The modern British government school system is built on and around charity and private schools, which often, but not always, had a religious focus. Several Asian countries can trace their education systems back to the 5th and 6th centuries, including government funded schools for village children.
The notion of "compulsory" education has likewise shifted over time. In the modern era, "compulsory" education is generally more about a government's responsibility to children than a child's obligation to attend a government-funded school. The United Nations Convention on the Rights of the Child, signed in 1989, says:
> Article 28
> 1. States Parties recognize the right of the child to education, and with a view to achieving this right progressively and on the basis of equal opportunity, they shall, in particular:
> (a) Make primary education compulsory and available free to all;
In effect, this means that governments cannot pay for education for boys and not their sisters, for non-disabled children and not for children with disabilities. While most countries have had some form of education for children with disabilities, it would have been inconceivable for those government officials who argued for funding public education that children with physical, cognitive, or emotional disabilities would be in the same schools as their own children. Basic literacy was illegal for most enslaved people in the American South until the end of the Civil War, which meant schools were off limits to them. So while there were compulsory education laws on the books in Massachusetts and NY, Black children in Alabama could be beaten if they were discovered to be literate. In many cases, once school was an option for Black or African-American children, white taxpayers would refuse to pay school taxes without assurances their money wasn't going to fund Black schools. Likewise, some schools in the Southwest were off-limits to children of Mexican origin while an entire system of schools across the country were attended only by Indigenous or Native children, often taken from their family by those who ran the schools. To make it clear: the purpose of school for those children was vastly different than the purpose of school for white children in Boston.
There is one last concept to discuss and that's the idea of the "grammar of schooling." Tyack and Cuban, two educational historians wrote about how, despite a variety of starting points, reasons, funding sources, and populations, school around the world in the modern area has developed a sort of language. This grammar includes things like desks in rows, colorful wall decorations, separate bathrooms for boys and girls, and calling teachers by a gender identifier (Ms., Mrs., Mr.) and their last name. This grammar has spread, not so much because of a school's origins, but because the idea of "schooling" in the modern era is represented by certain touchstones. Not all schools embody all of the grammar and sometimes, the things that make school recognizable as a place called "school" stick around not because they're helpful for teaching and learning but because they're familiar. So, it's not uncommon for us to look back from 2019, see examples of the "grammar of school" and reasonably conclude they all come from the same place.
| [
"Child labour was also encouraged by new tax laws. British and French colonial empires introduced new taxes to help pay for the local colonial government expenses. One of these, called the Head Tax, imposed a tax payable by every person, in some cases as young as 8 year old. Regional populations rebelled against su... |
Could there be any evidence of life on a planet after 4 billion years? | There are fossils on earth over 3 billion years old, and that is with numerous activities on our planet that can disturb them such as the actions of water, plate tectonics, and life itself.
It does not strike me as unreasonable that fossils on Mars, in the absence of those disturbances for most of their history, could persist at least as long, if not longer, assuming there was ever a situation in which fossilization was possible. | [
"In May 2017, evidence of the earliest known life on land may have been found in 3.48-billion-year-old geyserite, a mineral deposit often found around hot springs and geysers, uncovered in the Pilbara Craton of Western Australia. These findings may be helpful in deciding where best to search for early signs of life... |
what changes in how the engine works when switching between different driving modes like eco, sport, etc.? | Nothing much really, between normal and sport(+) the only difference is that your car will shift later up open the exhaust valve to make more noise(if you have a sport exhaust) stiffen up the suspension. You don’t habe over all more power or something and everyone who says that is an idiot, you just get the power sooner and the car feels mire aggressive. | [
"Mode selection allows the driver to choose between preset shifting programs. For example, Economy mode saves fuel by upshifting at lower engine speeds, while Sport mode (aka \"Power\" or \"Performance\") delays upshifting for maximum acceleration. Some transmission units also have Winter mode, where higher gear ra... |
why is fusion considered the holy grail of energy? | > So, that being said, what is the use in creating a reactor that - albeit will generate a net positive power - will only output such a piddling small amount?
The fusion output of the sun per given volume doesn't really apply to how it would be performed in a reactor as our designs aren't reliant on what will naturally occur. Consider the difference between a fission bomb and a fusion bomb, the fusion bomb has a far greater output. A practical reactor will be generating far more energy per cubic meter than the Sun does.
While fission of uranium releases about 17 times the energy of deuterium and tritium fusion, the key difference is the availability of the fuel. There is enough deuterium in a gallon of sea water to produce an equivalent energy output of about 300 gallons of gasoline. Instead of refining trace isotopes of an already rare mineral into fuel we can just essentially dump water into such a reactor and create huge amounts of energy; that we need 17 times more water than uranium isn't really a problem.
Edit: Consider that U-235 has a natural abundance of 0.72% and there is about 40 trillion tons of uranium on Earth. That means there is conceptually about 288 billion tons of U-235 on Earth.
On the other hand deuterium has a natural abundance of about 0.015% and there is about 1.36 million trillion tons of water on Earth. That means there is conceptually 204 trillion tons of deuterium on Earth.
This means fusion fuel is approximately 708.3 times more commonly available than fission fuel. Oh, and the waste products are far less hazardous. | [
"Fusion power is the process driving the sun and other stars. It generates large quantities of heat by fusing the nuclei of hydrogen or helium isotopes, which may be derived from seawater. The heat can theoretically be harnessed to generate electricity. The temperatures and pressures needed to sustain fusion make i... |
why does the backslash key have a special position on the keyboard? | Mostly for writing code. Even though it's used differently in various coding languages, it's used very often in most of them. (Such as in C an example would be \n to start a new line)
For the same reason that the straight line (**|**) is right above it, and is used for things like || which means OR (as a Boolean expression) | [
"Although the term \"backspace\" is the traditional name of the key which deletes the character to the left of the cursor, the actual key may be labeled in a variety of ways, for example \"delete\", \"Erase\" (for example in One Laptop Per Child), or with a left pointing arrow. A dedicated symbol for \"backspace\" ... |
If electrons surround a nucleus in a cloud, can they collide, and if they can, what happens? | Electrons "colliding" is difficult to quantify in this scenario. Suppose you have a helium atom and you measure the position of one of the electrons, then quickly measure the position of the other electron. (Also note that "one" and "the other" just denote the order of measurement - [electrons are indistinguishable particles](_URL_1_).) In the general case, it's unlikely but possible that the two electron positions are arbitrarily close to each other. The reason a collision is hard to quantify is because electrons don't have well-defined positions until you measure them; at what measured distance between the particles would you call this a collision?
A similar, but more likely scenario is [electron capture](_URL_0_), where the electron "collides" with the nucleus of the atom, turning a proton into a neutron. This actually happens primarily via quantum tunneling - a small portion of the electron's positional wavefunction overlaps with the nucleus of the atom, so with repeated measurement, the electron can be found to be inside the nucleus. The reason this is more likely than an electron-electron "collision" is because the nucleus is oppositely charged, so it acts as a potential well rather than a potential barrier to the electron wavefunction. | [
"In real molecules protons are surrounded by a cloud of charge due to adjacent bonds and atoms. In an applied magnetic field () electrons circulate and produce an induced field () which opposes the applied field. The effective field at the nucleus will be . The nucleus is said to be experiencing a diamagnetic shiel... |
What is the energy average density in the universe/a galaxy and its composition? | So yours is at the level above that of the typical askscience question, so I've got to know, what's your level of background in cosmology and general relativity? What's your comfort level with Lambda-CDM and GR? | [
"Estimates put the average energy density of the present day Universe at the equivalent of 5.9 protons per cubic meter, including dark energy, dark matter, and baryonic matter (ordinary matter composed of atoms). The atoms account for only 4.6% of the total energy density, or a density of one proton per four cubic ... |
how did stores work before barcodes and computers? | The grocer would literally tag every single item (and/or keep a ledger on a nearby desk) that would have the prices of everything for sale. When someone brought it up, the grocer would input the prices it into a till that would give the total.
The till was a giant, mechanical calculator that actually had a bell ("ding!") that would ring when the sound when the sum was calculated and the drawer popped out - it's why the mechanical tills nowadays sometimes still have the bell sound | [
"In the early 1980s, personal computers began to be popular. This further pushed down the cost of barcodes and readers. It also allowed the first versions of inventory management software to be put into place. One of the biggest hurdles in selling readers and barcodes to retailers was the fact that they didn't have... |
artificial rain or cloud seeding | Water needs a surface that isn't gas on which to condense. The technique of cloud seeding is to provide small particles to make this surface, to allow water vapor in the air to condense, which can result in suspended liquid water or ice particles. If these particles becomes heavy enough, they will fall as rain.
That being said, note that it is not putting water into the atmosphere, it uses water that is already there. It's giving it a reason to coalesce. | [
"In the UAE, cloud seeding is being conducted by the weather authorities to create artificial rain. The project, which began in July 2010 and cost US$11 million, has been successful in creating rain storms in the Dubai and Abu Dhabi deserts.\n",
"Cloud seeding is a type of weather modification that aims to change... |
how does the digestion of whey protein differ from protein in various meat sources? | All of what follows is nonsense if you're talking about hydrolyzed or otherwise pre-digested whey protein. If you're digesting it on your own, one way they differ is allergenicity and ease of digestion:
Meat is not meant to be given to any other organism and animals typically defend themselves physically, not chemically. That is, if you bite a bull, it will gore you - it's typically not poisonous or allergenic. There are some cases in which people can be allergic to meats (e.g. alphagal allergies after Lone Star tick bites), but animal muscle is typically like your muscle and it's usually not problematic. From the cow's point of view, its meat is never intended to end up in another organism.
Milk proteins are more problematic. Milk is meant to convey a large number of species-specific proteins from cow to calf. As an example, cow milk contains beta-lactoglobulin, which is present in most mammals but not humans and is one of the main reasons people can be allergic to milk proteins. You've gotten rid of casein, but that's not the only problematic protein.
The human body expects to eat meat. It does not expect to eat anything but human milk. We don't have the same rennet as calves do, so we're not specialized to break down the proteins present in cow milk as efficiently as calves do. We do eventually digest these proteins, but while they're in there they're highly allergenic because they look foreign. They _are_ foreign.
Milk also contains cow antibodies and albumins, which are meant to kick-start the calf's immune system, but humans don't necessarily need to be allergic to what cows are allergic to. | [
"Protein digestion occurs in the stomach and duodenum in which 3 main enzymes, pepsin secreted by the stomach and trypsin and chymotrypsin secreted by the pancreas, break down food proteins into polypeptides that are then broken down by various exopeptidases and dipeptidases into amino acids. The digestive enzymes ... |
how do you tell the difference between being depressed, unmotivated, and lazy? | You don't.
You go to a professional and explain the situation, follow their instructions, and with a bit of luck they'll be able to determine which it is. | [
"One way depression increases the individual's focus on a problem is by inducing rumination. Depression activates the left ventrolateral prefrontal cortex, which increases attention control and maintains problem-related information in an \"active, accessible state\" referred to as \"working memory\", or WM. As a re... |
Assuming I am on the same spot on earth. How far is my current position away from my position 365.256363 days ago? | Relativity says that there is no such thing as "the same place" at different times, anymore than there is "the same time" at different places. We can choose a coordinate system that gives the answer zero, but we can choose coordinate systems that give *any* answer we want, though the "reasonable" ones with nice properties will have answers under one light-year. But there is fundamentally no "right" way to ~~do~~ pick coordinate systems, merely more or less *convenient* ones. | [
"A position on the Earth is given by the UTM zone number and the easting and northing planar coordinate pair in that zone. The point of origin of each UTM zone is the intersection of the equator and the zone's central meridian. To avoid dealing with negative numbers, the central meridian of each zone is defined to ... |
How was Germany able to finance the war machine during WWII? How come they were able to stay strong against multiple military powers (in terms of industrial and manpower resources). How did they provide the fuel needed for the wehrmacht etc? | While it doesn't necessarily cover the entirety of your questions, /u/vonadler wrote [a great post](_URL_0_) about how the Germans financed their war effort. | [
"The proportion of military spending in the German economy began growing rapidly after 1942, as the Nazi government was forced to dedicate more of the country's economic resources to fight a losing war. Civilian factories were converted to military use and placed under military administration. From mid 1943 on, Ger... |
What causes the warm and cold spots in lakes? | I am not a physical oceanographer, but my broad understanding is that the two mechanisms that would cause temperature differences between areas in any given lake are the formation of a [thermocline](_URL_0_) and redistribution of water between the upper warm layer and colder bottom later by currents. Currents may or may not be stable from day to day, but in smaller lakes they're going to be driven by the wind or rivers/groundwater flowing in or out and in larger lakes by mechanisms like the [Coriolis force](_URL_1_) or (possibly) salinity gradients. | [
"Formation of a mixed layer in a lake is similar to that in the ocean, but mixing is more likely to occur in lakes solely due to the molecular properties of water. Water changes density as it changes temperature. In lakes, temperature structure is complicated by the fact that fresh water is heaviest at 3.98 °C (deg... |
how can fizzy drinks go flat if shaken before opening despite having probably been shipped in from overseas and/or jostled around in the back of a truck for days?? | Shaking doesn't make go flat unless you open them in the shaken state. It you let them sit, all the bubbles of pressurized gas consolidate into the top of the can, and the pressure forces a larger amount of CO2 into solution with the liquid (making it "not flat"). | [
"One end of the coiled tube in the box is fitted to the external supply of the beverage to be served (often moved from the supply container by gas pressure, as in the case of beer in kegs, and the other end is attached to taps for serving the beverage, which are often integrated into the box itself. Filling the joc... |
there's always allegations about sportsmen 'doping' before an event. why not allow doping so everyone has the same advantage? | Well, the whole idea of a sport is "how well can humans do a thing under an arbitrary set of rules." There's fundamentally nothing different from asking "why not allow doping?" and asking "why not allow soccer players to use their hands?" The answer to your question, on the face of things, is basically that we've decided the game is better with those rules than without them.
As for why we made that decision (at least for doping), it's likely because of our tendency to view sport as an area of human achievement through hard work and the outsize role professional athletes have in our society as role models. That's more my opinion than a fact though. | [
"Over the years, different sporting bodies have evolved differently in the struggle against doping. Some, such as athletics and cycling, are becoming increasingly vigilant against doping. However, there has been criticism that sports such as football (soccer) and baseball are doing nothing about the issue, and lett... |
why does champagne fizz up so much more when poured into an empty glass than when it's poured into a glass with champagne already in it? | The carbon dioxide, the bubbles, is a gas at RT. Pouring it into an empty glass means the liquid falls from a higher distance, when it hits the bottom of the glass the impact provides enough energy for the gas to escape. Not only does the liquid in there reduce the distance but also softens the impact.
If you were to tilt the glass on a 45 degree angle to compare, you'd see less fizz as the liquid is slowed by the side of the glass before reaching the bottom. | [
"Pouring sparkling wine while tilting the glass at an angle and gently sliding in the liquid along the side will preserve the most bubbles, as opposed to pouring directly down to create a head of \"mousse\", according to a study, \"On the Losses of Dissolved CO during Champagne serving\", by scientists from the Uni... |
dictators and why people see to blindly believe in them? | The simple answer is that by the time someone can be called a dictator, they've taken over the media, silence dissidents, censored the internet, murdered/jailed the opposition party and control information to the point that an alternative to the narrative doesn't really exist. Especially when so many people are just busy and tired. If you work 2 stressful jobs and have a spouse and 3 kids to support/raise, you don't have the mental or physical energy to deeply research whatever's in the newspaper/tv/radio. | [
"Some dictators have been masters of crowd manipulation, such as Mussolini and Hitler. Others were more prosaic speakers, such as Stalin and Franco. Typically the dictator's people seize control of all media, censor or destroy the opposition, and give strong doses of propaganda daily, often built around a cult of p... |
why did the us storm heavily defensed normandy why not somewhere else? | If you're thinking the USA did it alone need to have a talk with your history teacher. The UK and Canada were also there in force. | [
"Bombing of Normandy began around midnight with more than 2,200 British, Canadian, and US bombers attacking targets along the coast and further inland. The coastal bombing attack was largely ineffective at Omaha, because low cloud cover made the assigned targets difficult to see. Concerned about inflicting casualti... |
explain to me, like i'm five, why some economists believe the current of chinese economic growth is dangerous and unsustainable | China has been following the Asian model of growth; Japan did it, Taiwan did it, and Korea did it. Now China's doing it. Basically what that model does is produce tons of goods cheaply. But because there's insufficient domestic demand to snap up all of those goods, they're shipped overseas to mature markets like the US and EU. A trade surplus is basically a certainty.
That ties into the prices and stability of our bonds (because, with a huge trade surplus of dollars, the safest place to sock it away would be US Treasury Bonds), but that's not the subject of this thread.
China's been growing its own domestic market, but still heavily relies on exports as the main driver of its economy. Because US and EU demand is soft, that increases pressure to promote domestic demand. To really stoke domestic demand, China would have to allow the RMB to appreciate. They've been hesitant to do so, because it would kill a lot of industries, so that's one very delicate balancing act, but still only one issue.
Some articles from The Economist and other sources (along with China bears like Jim Chanos) also cite the proportion of their GDP that is based on construction -- it's a staggering 50% or more, depending on whose estimates you are viewing. Basically half or more of their GDP is based on building infrastructure that no one is using, and they are still increasing capacity. On top of that, anecdotal evidence in the Tier 1 cities show new luxury condominiums going up all the time, with mainly speculators snapping up all of the empty lots because real estate prices have been heating up like crazy. That's generally the surest sign of a bubble, but, like all market issues, it's impossible to pin down the exact moment when everything will turn over on itself.
The third issue is simply debt. China's central government recently had to write off a ton of debt from local governments. It has the bankroll to do so, but it's a bad sign for the economy as a whole. Local governments wield tremendous power in developing their respective areas, and until recently when the new guidance from Beijing for determining local governments' efficacy was changed, the only barometer of success was GDP growth. Those debts come from unneeded bloat like construction projects whose sole purpose was for the local official to skim parts of the funding off, and, when that was achieved, the building would be left in its half-finished state.
For all of the wonders of China, their central government is still staffed with people, and their government still has its own political concerns. They are not master planners, even if they're mostly engineers and not lawyers.
Read: everything at _URL_0_ | [
"Conventional belief today is that China dominates the 21st century. Rapid growth in China threatens the entire world with economic bubble and financial bubble. The fundamental problem with China is that it lacks reliable information about the nation's economic situation. However, a huge amount of foreign capital h... |
How far away, in terms of knowledge and technology, are we from keeping a brain fully functioning outside of a human body? | I think the reigning futurist consensus is that, yes, some day we'd be able to do something akin to this if we really wanted.
---
But we are a long, long way off from that. Let me consider the "We can already tap into our neural pathways and control external devices like artificial limbs through pure thought." angle first.
While it's true that we've had some minor engineering successes at precise control of robotic limbs and computer mice and the like using brain-computer interfacing, they are all a far cry from the sort of thing you're looking at. Examples that come to mind include
1. tapping the nerve endings in the chest for victims without arms, which is something of cheat since the brain is already "wired" to send arm movement signals out that direction and we're just hijacking that;
2. implanted electrodes in moneys who are able to learn to feed themselves with the articulated arm, but honestly we do it in monkeys because we're not sure if it destroys brain tissue (or rather, we are but we don't know the extent) and it's very poor articulation since we can only read a very local part of the brain (though it can be targeted to be near the motor cortex);
3. and gross scanning methods like EEG/ECG/MRI/PET which are sort of like trying try to figure out the present your parents got you for christmas by shaking the box, except it's actually a book and you're hoping you can read chapter 1 before Christmas Eve.
In short, our current technologies are very, very crude.
---
I don't follow all the speculation in your question, but I want to stress that while it's easy for us to think of the brain as a symbolic/psychological entity that can just be "decoded" by a computer, our current art is as of yet incapable of looking at it at such a level.
Imagine you were an alien who had built a grand civilization powered by computers that were built using lava lamps. Your comrades spent their lifetimes studying the fluid dynamics of lava lamp wax and created more and more clever and powerful computational schemes from the strict and repeatable results they found. Then one day, you're faced with a silicon CPU. It is clearly well-ordered in your primitive study, though the microfluidic machines you've built your lava lamps with are poor tools for studying the CPU since they keep spilling hot water and wax all over it. Furthermore, you've seen it compute and realize there must be a process in there somewhere that's Lavalamp Complete. Presumably with enough work you could decode and translate instructions being executed on it into a large lavalamp cluster running a simulation of the silicon structure, but, honestly, it's difficult to really make sense of such a complex system.
And we're even worse off since there's less of a guarantee of consistency in the brain.
---
Still, it's fundamentally possible if difficult to see on the horizon just yet. We already emulate some very basic neural circuits we've discovered in fish in machine learning algorithms (multilayer perceptron models) and hope to expand this to more complex ones which exhibit potentially more-brainlike behavior.
Furthermore, since the brain's "circuitry" is inherently "analog", there's some interest in using analog equivalents to FPGAs in order to model brain function, but I don't know much about that besides some guys in my department are doing it. I should talk with them sometime. | [
"Developments in technology and medicine mean that doctors and scientists can examine our brains in more ways and more detail than ever before, all without having to open up the body. In this issue, we explore how imaging research has changed the way we can look inside the human brain.\n",
"The book's main scenar... |
Do historians know if James Buchannan was gay? | It can never really be known with certainty - Buchanan never married, the only president so far to remain a bachelor. He courted one woman named Anne Coleman and was briefly engaged to her before she died. Afterwards he didn't do this or show any interest in it again.
The main base of information for this theory is that he lived with another man named William R. King, who became Vice President under Franklin Pierce and died in 1853. He lived with Buchanan for several years and they became quite close. Their correspondence however doesn't show any hard evidence of Buchanan being undoubtedly gay. | [
"Rich's findings also included documentation that Raymond was bisexual and her marriage was rocky from the start, with Raymond physically and emotionally abusing MacDonald, and having affairs as early as their honeymoon when MacDonald discovered Raymond in bed with Buddy Rogers. Raymond was arrested three times, th... |
how does creating new money stop people from just creating fakes of the old ones | It becomes much harder to get people to believe that your crisp, newly made dollar bills aren't counterfeit when there are no more being made in that style. | [
"Or did it give them free hand to try to take over the name and make money off it as long as they're alive and we're alive? When you start making money rather than to try to complete the project, that's when, to me, it's going off in the wrong direction.\n",
"Although many art forgers reproduce works solely for m... |
how will the recent vote on isp's right to sell data affect the rest of the world's internet users? | It will not change anything.
Here is the thing no one is saying about this entire thing. What actually just happened was Congress prevented an FCC regulation from *going into* affect that would prevent ISP's from selling certain data.
The FCC made this regulation last year and it was about to go into affect. Which means at no point was there a law or regulation preventing ISB's from selling your data.
All this vote did was prevent a new regulation from coming into affect. | [
"In 2017, Moran voted to repeal FCC Internet privacy rules that blocked internet providers from sharing or selling data on customers' private data (such as browsing history) without the customer's permission.\n",
"In early 2017, Blackburn introduced to the House a measure to dismantle an Obama-administration onli... |
what are the point of tokens? | Because once you've bought the fake money you're more likely to spend it on an impulse (and if you don't they sold you a service you never used). | [
"Tokens must be used as reinforcers to be effective. A token is an object or symbol that can be exchanged for material reinforcers, services, or privileges (back-up reinforcers). In applied settings, a wide range of tokens have been used: coins, checkmarks, images of small suns, points on a counter. These symbols a... |
how in the world can the flu make me feel so freezing cold? | infections/viruses thrive at our body temp, but are significantly weaker at slightly higher temperatures. a fever is your body adjusting its internal thermostat to fight infections by bringing up your internal temp. think if you were adjusting the thermostat at your house - your brain is cranking up the 'set-to' temp by a couple of degrees. you feel cold because your body is actually colder than this new desired temp. your muscles contract and relax to generate heat to bring you up to speed (thus, the shivers). | [
"Well over 200 virus strains are implicated in causing the common cold, with rhinoviruses being the most common. They spread through the air during close contact with infected people or indirectly through contact with objects in the environment, followed by transfer to the mouth or nose. Risk factors include going ... |
can someone please explain how ratios work | Let's take a single molecule of water for an example. That's two hydrogens and one oxygen. So you have a 2:1 ratio. Well if you have two molecules of water, you have a 4:2 ratio which can be reduced to a 2:1 ratio. No matter how many water molecules you have, you'll always have two hydrogens for one oxygen.
EDIT: Poor grammar. | [
"Ratios can be expressed as a decimal value, such as 0.10, or given as an equivalent percent value, such as 10%. Some ratios are usually quoted as percentages, especially ratios that are usually or always less than 1, such as earnings yield, while others are usually quoted as decimal numbers, especially ratios that... |
What's the best, free method for researching family history on the internet? | hi! while you may get some answers here, this question might attract more responses in /r/Genealogy | [
"The company uses a wide range of technologies to assist family history research, including face detection, semantic analysis, and DNA testing. MyHeritage's database of more than 9 billion records continues to grow and increase public awareness of genealogy. MyHeritage offers free tools for creating family trees, t... |
why do online news articles have typos or grammatical mistakes, even from notable publications? | The answer is quite simple: they fired the copy editors while simultaneously demanding more output from their journalists. Copy editors don’t produce any content so they’re strictly a cost center. When revenues started falling, they got the axe. Online-only publications mostly never had them to start with. Even experienced journalists can’t be expected to turn it perfectly-edited articles all the time. | [
"Apart from internet slang, grammatical errors and typographical errors are features of writing on the Internet and other CMC channels. As users of the Internet gets accustomed to these errors, it progressively infiltrates into everyday language use, in both written and spoken forms. It is also common to witness su... |
How much did the ancient Egyptian language change through millennia? | ## Answer to your first question
The short answer is no. An early Egyptian (say a native speaker of Old Egyptian around say 2200 BCE) would not almost certainly not understand the speech of the later dynasties (say 332 BCE).
## How to answer this question?
There are a couple of sources of evidence that we might bring to bear on a question like this.
The most obvious source is linguistic. How similar were these languages themselves? If we can read the languages of both time periods, then we can easily form a sense of how different those two languages are. Similarly, a modern English speaker might listen to [Chaucer](_URL_3_) or [Beowulf](_URL_7_) to get a sense of how intelligible those things would be without deliberate study. The answer is clearly "not very". Even if you do understand the older language, it's pretty obvious that it's not at similar to the language that you speak everyday. I doubt anyone would claim that Beowulf (or even Chaucer) is immediately comprehensible to a modern English speaker. If we can't understand them automatically, it's likely that they wouldn't be able to understand us either.
The second source is direct witnesses by ancient scribes. For comparison, it's pretty common to find editions of [Beowulf with parallel modern translation](_URL_1_). The existence of such texts is a pretty dead giveaway that modern people can't read the text without help, because they don't understand the language.
## Linguistic Evidence for Changes in Egyptian
This is a very big topic, but I'm going to try to summarize. For a slightly longer summary, I recommend [Allen's *The Egyptian Language*](_URL_6_). For a more in depth study of how Egyptian changed over time, you'll need to study the various phases separately and combine the information. That's a long bibliography, but we are working to get those sorts of resources in place at r/AncientEgyptian. Some of the weekly reading groups include texts from various times, and we have resources for studying Egyptian in different phases. There are also resources for the study of Coptic etymology, which are the terms in which questions of linguistic change in Egyptian are often framed.
For the sake of illustration here I'll use a quick example. From the [*Autobiography of Harkhuf*](_URL_4_), I've selected a simple sentence:
"I came from my town today"
| 𓇍 | 𓈖 | | 𓏇𓈖 | 𓅓 | 𓊖𓏏𓏤 | |
|------|-------|-----|-------|------|------|-----|
| ỉỉ | n | [ỉ] | mỉn | m | nỉwt | [i] |
| come | perf. | I | today | from | town | my |
The same sentence, in my own (invented) Saidic Coptic:
| ⲁ | ⲓ | ⲉⲓ | ⲙ | ⲡ | ⲁ | ⲧⲓⲙⲉ | ⲙ | ⲡ | ⲟⲟⲩ |
|-------|---|------|------|-----|----|------|----|-----|-----|
| a | i | i | m̩ | p | a | timɛ | m̩ | p | ɔʷ |
| pret. | I | come | from | the | my | town | in | the | day |
If you only compare the literal English translations in the bottom row, it should be pretty obvious that they are quite different. There's a lot going on with both syntax and word choice that make them different. The word order is different, the way of marking aspect/tense is different, and many of the words have changed completely. The old word for town now means "Thebes" and the new word comes from an older word that once meant "harbor". It's hard to imagine that a native speaker of one could do much more than pick out the occasional word, just as we do when reading old English, and even then they would hear the word with a different intended meaning.
The key shift is the boundary between two major linguistic phases, which Allen calls Egyptian I and Egyptian II. Before Late Egyptian, there is a great deal of consistency in syntax among Middle and Old Egyptian. Late Egyptian looks very different from those, but quite similar to all later stages of the language up to and including Coptic. In short, there's a significant watershed at the beginning of Late Egyptian, which is why I can so confidently say that two people on either side of that boundary would not have understood one another.
## Scribal Witnesses
Egyptian texts that were written for long periods of time show evidence of later scribes reforming them to make them more legible. A great example is the [*Story of Sinuhe*](_URL_8_). There's a book with various versions of the story arranged in parallel, [Koch's *Die Erzählung des Sinuhe*](_URL_2_). Looking at [one short passage](_URL_0_), you can see how the various later editions show orthographic changes. The "AOS" version is the Ashmolean Ostracon of Sinuhe, and it was written much later. Fittingly, it shows the most orthographic variation. Some passages have even been modified slightly, presumably because the earlier language was no longer understood.
In just about every case where an ancient text was copied later, we see a similar phenomenon. For instance, the [Maxims of Ptahhotep](_URL_5_) was also recopied over time, and we see the same struggle to understand the original in later copies.
## Conclusion
From two lines of reasoning, the conclusion is the same. The language of Egyptian changed too much to remain intelligible over the entire course of its very long (4000 year) history. If you want a better sense of how it changed, and if you want join us in our etymology-nerd dream project of exploring this language, come hang out with the good people at r/AncientEgyptian. Learn some languages and ask questions.
## Answer to your second question
I have no idea. I hear good things about Icelandic though.
Edit: Omitted a reference. | [
"One of the earliest examples was that of Middle Egyptian, the language in everyday use in Ancient Egypt during the Middle Kingdom (2000 - 1650 BC). By 1350 BC, in the New Kingdom (1550 -1050 BC), the Egyptian language had evolved into Late Egyptian, which itself later evolved into Demotic (700 BC - AD 400). These ... |
can someone please explain to me how best in show dog shows work. how does the judge pick the best? is there personal preference thrown in? | It is essentially nothing but personal preference. Essentially there is an ideal perfect prototype of each bread of dog and each dog is judged based on how close it is to this "prototype". (Simplification)
The judge is doing nothing but making personal judgements on how good the dog represents the ideal state of his breed. | [
"A dog show judge, sometimes dog judge, is a person that is qualified to evaluate dogs at a conformation show. At small shows, there might be only one judge for all breeds and classes. At larger shows, there might be several judges, with each responsible for only certain breeds or classes.\n",
"Even judging that ... |
Why do only certain materials glow under UV light? | It’s the principle of Fluorescence. Only certain molecular structures which make up the material of interest will absorb the light of shorter wavelength like UV or X-ray and produce light of a longer wavelength say in the visible spectrum.
The study of these things is in the realm of photochemistry. | [
"The ultra-violet light to produce these effects may be obtained from an arc lamp, or by burning magnesium, or by sparking with an induction coil between zinc or cadmium terminals, the light from which is very rich in ultra-violet rays. Sunlight is not rich in ultra-violet rays, as these have been absorbed by the a... |
How can an electron be a a "point particle" meaning it takes up zero space and is zero dimensional, yet have a radius of 2.82x10^-15 meters? | It's very simple; the "[classical electron radius](_URL_0_)" is simply not the radius of an electron. The wiki article makes that clear as well: "the classical electron radius is no longer regarded as the actual size of an electron"
| [
"The issue of the radius of the electron is a challenging problem of the modern theoretical physics. The admission of the hypothesis of a finite radius of the electron is incompatible to the premises of the theory of relativity. On the other hand, a point-like electron (zero radius) generates serious mathematical d... |
what makes a person sound old/ young? | I'm assuming you're referring to vocal elements which make age distinguishable.
1. Pitch. It's one of the big ones, and it's the reason why millions of teenage boys across the world answer the phone and get called "ma'am" (or their culture's equivalent). Often, this is the only thing voice-based, and we make the rest of our guess based on other information.
2. Roughness. This is most relevant to distinguishing older people from less-old people. That's why people with lung issues will sound "old". All that phlegm or throat-tearing mucking with the passage of air is perceived as originating from age in absence of other evidence.
3. Word formation. Speech development in children is an ongoing process. While there's a wide range of pitch available to children (all of it high, of course), you can tell a bit about a child's age from how good they are at speaking. Sometime between the ages of 8 and 10, they reach sufficient proficiency in language that they at least pronounce words like an adult, although they certainly don't have the word choice of an adult.
4. Accent. There are always mild changes in word pronunciation over the years. It's not terribly reliable, but sometimes a little word change will trip off an "old person" or "young person" sensor.
Also it turns out we're not too good at this. Working at a call center, a good portion of my work-mates are addressed as the incorrect gender or age, and we end up addressing people by the wrong thing too (I'm never a victim of this, since I have a deep-but-clear voice and modern dialect that pretty much screams "mid-20s male", but that's easy mode for voice-based demographic assessment). We're better than a computer, but our eyes are so much better at this sort of information than our ears. | [
"Age-related hearing loss gradually occurs in many people as they get older, typically affecting those over the age of 65. This type of hearing loss can lead to feelings of embarrassment and isolation due to the fact that those affected may no longer be able to hear family, friends, or simple everyday sounds. Those... |
why does pain, atleast in some cases, throb rather than being a consistent stream? | Pretty sure it throbs because it's your heartbeat. You're area where the damaged nerves are receives blood each throb, and sends that signal of pain even stronger to your brain.
This is just my guess. | [
"Because of their higher conduction velocity, Aδ fibers are responsible for the sensation of a quick shallow pain that is specific on one area, termed as first pain. They respond to a weaker intensity of stimulus. C fibers respond to stimuli which have stronger intensities and are the ones to account for the slow, ... |
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