question stringlengths 3 301 | answer stringlengths 9 26.1k | context list |
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Is there any scientific truth to the idea that you shouldn't sit too close to the TV? | No. However focusing on one spot for a long period of time can cause eyestrain, however that is only temporary.
You may find this interesting.
_URL_0_ | [
"The work of several researchers support the concept of television reality as a consequence of heavy viewing. According to Wyer and Budesheim's research, television messages or information, even when they are not necessarily considered truthful, can still be used in the process of constructing social judgments. Fur... |
how is it that a vehicle can be good at towing but shit at carrying heavy loads? | A vehicle can have a strong engine, trans and drive train to pull a heavy tow.
It needs a strong suspension system to carry a heavy load.
| [
"The military also deploys tow trucks for recovery of stranded vehicles. In the US Army, a variant of the HEMTT truck is used for this purpose, the M984 wrecker. For recovery in combat situations while under fire, many armies with large vehicle fleets also deploy armoured recovery vehicles. These vehicles fulfill a... |
What is the chemical reaction that occurs when you put ice cream into soft drink? | No chemical reaction... the fat and sugars from the ice cream increases the surface tension on the bubbles, which means they don't burst. You see a bunch of bubbles because you've just introduced something with a bunch of nucleation sites. | [
"Ice cream (derived from earlier iced cream or cream ice) is a sweetened frozen food typically eaten as a snack or dessert. It may be made from dairy milk or cream, or soy, cashew, coconut or almond milk, and is flavored with a sweetener, either sugar or an alternative, and any spice, such as cocoa or vanilla. Colo... |
Besieging castles (pre cannons) | I'm not an expert on sieges, but here's what I can offer:
1. It would depend entirely on the technology available to both besiegers and besieged, as well as what was besieged. The First Siege of Rome during the Gothic war lasted a little over a year. When the Mongols under Batu Khan besieged Kiev in 1240 it took about a week. Another factor would be how much help the people inside the castle had on the outside, the size of both forces, morale, etc. I don't think there can be an average.
2. If you're hitting a wall with a trebuchet, then you are most likely aiming it wrong. These were designed to launch objects over walls, not into them. The projectile had a very high arc and could easily clear walls several stories high. For the other two, it would depend on the wall thickness/build, the number of siege weapons attacking a section, and the objects being used. Again, I wouldn't say there is a set time to penetrate a wall. Too many variables.
3. Again, a lot of variables make this hard to quantify. I'm sure there are treatises available in which people set a science to determining this, but those would just be theories based on exhaustible circumstances. Nothing could cover every siege. A main factor would be the technology available. If the attackers could easily create several points of entry into a fortification, then they might not strive for as large of a numerical advantage then if the defenders could easily turn away the siege engines. Another could be morale. A large defending force that has been out of food for weeks could perform much worse than a smaller force with plenty of provisions. In addition, a group of people that have been trapped in poor conditions for over a year might not have that same spirit as men who have only been there for a week.
5. Fire was a pretty nifty thing to use. Siege weapons were built of wood and other flammable materials, so unless they were protected very thoroughly (covered with animal hides, for instance) they could easily go up in smoke. Using fire would be easiest against towers and rams, since they actually came up to the walls and gates. In order to reach the ranged siege weapons, however, the defenders would most likely have to launch a sally. Some men from inside would exit the fortification under favorable circumstances (night time, through a gate people weren't watching very well, etc) and try to cause damage amongst the siege lines. They could burn tents and siege weapons, kill men who weren't aware, and in general make a lot of chaos arrive in already tense conditions. This of course did not always work, and could easily end with the death or capture of all defenders involved.
I'm sure more people could expand on this, or correct me where I'm wrong. I'm just drawing from some general knowledge of the subject, so if you need specific sources I can't help you there. | [
"Siege castles are only evident from the period of the Late Middle Ages onwards. They were usually built as a temporary fortifications using wood and earth above the castle to be captured and within sight and the range of their guns. From this location the target would be bombarded.\n",
"In 1632 Swedish soldiers ... |
Why do we discuss Ancient Greece in terms of city-states? | Many Greek city-states had slightly different setups, but their basic structure was the same: a single *astu* (city-center) with administrative control over a *chora* (territory). Athens controlled a large *chora* (Attica) as the result of *synoekismos,* or synoecism as the Brits would say. This is the process by which, usually early on in the Iron Age, various smaller population centers came together (literally "housed" together) to form a larger political unit: a *polis*, comprised of *astu* and *chora.* Why one center became the *astu* vs another was usually dependent on population, military might, religious importance, or the like. In Attica, the smaller population centers were organized into districts ("demes"). Some examples are the Piraeus (the harbor), or Sunion (a temple center in the south of Attica). These were not "cities" in that they had no independent authority in the business of Athens the polis. You should think of them as neighborhoods within a modern city, with some localized civic or religious structures. | [
"Athens was chosen as the Greek capital for historical and sentimental reasons, not because it was a large city. At the time, it was a town consisting of only 400 houses at the foot of the Acropolis. A modern city plan was laid out, and public buildings erected. The finest legacy of this period are the buildings of... |
How did Multi-track sound recording come to be and subsequently widely used? | During World War II, some technically-minded people listening to German radio were puzzled: was Hitler really demanding that the Berlin Symphony Orchestra play Beethoven symphonies at 3am in the morning? It was a puzzle, because the sound was pristine, without the clicks and pops you get from a vinyl disc - at that time, the only option for playing pre-recorded material that the Americans and English knew about. They couldn't figure out how the Germans were doing it until, after the war had been essentially won, and the Allies gained access to the premises of Radio Frankfurt in Bad Neuheim, which had been broadcasting the Beethoven symphonies. One American Major who was a classical music fan and curious about German radio, Jack Mullin, decided to head to Bad Neuheim, and discovered that they had a new method of recording to Magnetophon - to magnetic tape - which crucially had an AC bias that enabled almost pristine recording quality.
Previous to this, recording had essentially been straight to vinyl disc, which was more limited in a variety of ways - once the groove had been laid down by the transcription needle, it was that way forever. However, magnetic tape could be altered - you could tape over it.
After the war, Mullin worked with the company Ampex to replicate the technology they'd seen in Frankfurt. Initially using reels of tape taken from Bad Neuheim, and on prototype technology, they pre-recorded radio shows for Bing Crosby, a major star at the time; after Crosby gave the company $50,000 with no strings attached to perfect the technology, they released the first commercially available American tape recording devices in 1948, which basically instantly became the standard.
Crosby gave an Ampex tape machine to his friend Les Paul, a jazz guitarist (and inveterate tinkerer who worked with the Gibson guitar company on the guitar brand that bears his name). Paul, like Mullin, had noticed the German broadcasts at 3am; he was working at Armed Forces Radio in Europe during the war, and he couldn't figure out how the Germans were doing it. So upon getting an Ampex tape machine, Paul was very keen to play with the technology, and discovered that 'overdubbing' was possible; you could record yourself playing along with a previous recording - as a singer you could harmonise with yourself. So you get recordings like Les Paul's recordings with Mary Ford (e.g., ['How High The Moon' from 1951](_URL_0_)), which were exceptionally popular, and which showed Paul playing several guitar parts at once, and Ford harmonising with herself.
This was effectively multi-track recording in one sense - there are multiple tracks of music recorded one after another - but it's not multi-track recording in the modern-sense, because there weren't multiple separate tracks of tape for each instrument - there was just one tape, with different performances literally dubbed over pre-existing performances.
An Ampex employee, Ross Snyder, heard these Les Paul and Mary Ford records and thought that the overdubbing method they used lead to a decline in sound quality, and so he aimed at developing a tape machine that had multiple tape heads that were in sync with each other; this was a complicated project with a lot of technological constraints - getting different tracks to line up with each other and making sure that the tape was at the right speed etc was something of a problem. But in 1956, the Ampex Sel-Sync was put on the market, an eight-track recording device. The Sel-Sync itself was generally seen as impractical for recording studios (it was enormous and heavy and glitchy), but other multi-track recording devices came into vogue in the late 1950s.
In England, someone at EMI who had seen the Magnetophons at Bad Neuheim had also had the same idea as Mullin, and they had unveiled the EMI BTR1 in 1947, a single track tape machine. After some improvements to the design (the BTR2 in 1952), and due to the coming demand for stereo recording, EMI put together a BTR3 in 1956 which had two tracks; however, these were not used for multi-track recording, per se, until just before the arrival of the Beatles in 1962, when a modified BTR3 at Abbey Road dubbed the 'Twin-Track' was used in order to do rudimentary multi-tracking. However, in late 1963 the Beatles began using a Telefunken M1 four-track recording machine made in Germany (which had been on the market since 1957, but which EMI experimented with extensively before allowing its use (Telefunken had also built the Magnetophons in WWII). In 1965 the Beatles started using a Studer J37 four-tape track recorder which was more suited to studio multi-tracking experimentation, and (a modified version of which) was used on *Revolver* and *Sgt Peppers* - the albums where multi-track recording most obviously became an artform in itself, with musicians creating sounds using the studio and the multi-track recorder as an instrument in itself.
Edit: To deal with your second question - for a sound engineer it would have depended on what kind of music they were recording. Firstly, in the mid-to-late 1950s, Frank Sinatra was still recording basically on a single microphone, with the orchestra simply softer than him in the background. In contrast, in more or less the same time period, there was a maze of cables on the floor of the Motown studio at Hitsville USA (thus why the studio was dubbed the 'snakepit') indicating that there were leads and microphones going to different instruments set at different volumes - recording desks that mixed the volume and frequency of different instruments with each other already existed and were more common in pop rather than in orchestral contexts (especially because the levels of rock instruments could vary so much, and needed further control). Basically, once multi-track recording became a thing, it enabled engineers to record as pristine and perfect a sound of an individual instrument as they could, and multi-track recording multiplied the time it took for a band to record a song in the studio, with each part being looked over in detail to try and perfect it; often, when a band was playing together before the era of multi-tracking (or in the early years of multi-tracking), the band recording was basically it, perhaps with overdubs. But as things progressed, musicians would first lay down a basic track and then elaborate on it later, or record instruments one by one. So this meant that the original basic track didn't have to be as perfectly balanced and mixed as it had to be in the pre-multi-track days, as it was likely going to be elaborated on, and that musicians and producers could think more carefully about how the music sounded on record in context, and arrange the music accordingly. Geoff Emerick, who was the engineer on much of the Beatles' records, speaks of his disillusionment on working on the Beatles' stuff in the later era when multi-tracking was a thing in his book *Here, There And Everywhere* - he thought that the broad array of possible options and the pursuit of perfection led to a sort of paralysis, and made working in the studio with the Beatles much more difficult.
Sources:
* *Recording The Beatles* by Brian Kehew and Kevin Ryan
* *Perfecting Sound Forever: The Story Of Recorded Music* by Greg Milner
* *Here There And Everywhere* by Geoff Emerick | [
"Multitrack recording (MTR)—also known as multitracking, double tracking, or tracking—is a method of sound recording developed in 1955 that allows for the separate recording of multiple sound sources or of sound sources recorded at different times to create a cohesive whole. Multitracking became possible in the mid... |
what would happen if there was a second big bang somewhere else outside of our own expanding universe? | If it was outside of our universe it would also be beyond everything that we are capable of observing or understanding, so we would have no way of knowing that it even happened. | [
"The Big Bang itself had been proposed in 1931, long before this period, by Georges Lemaître, a Belgian physicist, who suggested that the evident expansion of the Universe in time required that the Universe, if contracted backwards in time, would continue to do so until it could contract no further. This would brin... |
the four tigers of asia | You could post this question in /r/AskSocialScience if it hasn't been asked there already. | [
"\"Widely known as one of the largest predators, tigers are ranged both in Russia and China, where this species is even considered sacred. Moreover, the form of Chinese character 王, which means “a king”, reminds us of stripe pattern on the tiger’s forehead. White tigers, in particular, adapt easily to any environme... |
why is there so much nudity in classical paintings? | So with the spread of humanism ushered in by the beginning of the renaissance, people started to take a keen interest in humanity. They started thinking that people were incredible and the individual was exceptionally important. As a result, we start seeing changes in a number of artistic modes of expression. To answer your question though, painters and sculptors wanted to idealize the human form which took on a whole new significance in renaissance art. The natural human figure presented an expression of beauty, perfection, and humanity.
TL;DR - Round about 1400 or so, people started thinking of humans as hot shit. As a result they celebrated the ideal human form - a nude figure. | [
"In comparison in the material aspect nudity is considered an art. This view is supported by Sri Aurobindo in his book \"The Renaissance in India\". He says about Hinduism in the book – \"Its spiritual extremism could not prevent it from fathoming through a long era the life of the senses and its enjoyments, and th... |
why do people pass out/feel like they're about to, if the suddenly go from very warm water to very cold water or vice versa? | It's because of the mammalian diving reflex. We experience bradycardia (slow heart rate) and vasoconstriction. Essentially all of our oxygenated blood is shunted to vital areas (Brain, heart, and lungs)only. This conserves oxygen allowing us to endure the cold water for a longer period of time for the best possible chance at survival. Unfortunately in non life threatening situations it can make is feel like we're going to pass out. This "hack" is actually used as a first line treatment by physicians when a patient has a rapid heart rate. | [
"Cold shock response is the physiological response of organisms to sudden cold, especially cold water, and is a common cause of death from immersion in very cold water, such as by falling through thin ice. The immediate shock of the cold causes involuntary inhalation, which if underwater can result in drowning. The... |
Were people in the old west (1865-1890) able to listen to classical music? would the average joe be familiar with composers such as Mozart, Beethoven, Chopin etc...? | Depends on who that "average joe" was. People played much more music for their own pleasure than we do today; small towns did have "opera houses" -- which while they didn't often play Verdi, did have aspirations to European culture. So, for example, we have records that in 1877, an opera by Balfe, *The Bohemian Girl,* was performed at the Belvidere Theatre in Central City, Colorado. This today little known light opera seems to have been a favorite in the old West opera houses, along with *The Mikado.*
Consider the piano player-- he might be self taught, or he might be an Eastern swell who'd come out west, doing his Teddy Roosevelt. A remarkably diverse range of men and women sought adventure and fortune on the American frontier-- the French nobleman, the Marquis de Morès, a graduate of St Cyr (the French military academy-- he was a classmate of Petain)- came to the Dakotas to make a bundle in cattle ranching. He and his wealthy American wife would have been familiar with the "greatest hits" of contemporary European culture; you can say "he's not an 'average Joe", but . . .
What I'd say is: revisit your idea of who "average Joe" is in the "old West". He might be a former Confederate soldier. He might be a former slave. He might be a Chinese railroad worker. He might be British with a fancy title. He might be a Methodist who'd know all the verses of popular hymns but have no idea of Mozart. He might be a Mexican or South American working on ranches (essentially all of the ranching technology and terminology that we think of as "western" is Spanish in origin, that "buckaroo" is actually a *vaquero)* and playing guitar for himself and his friends.
Some of these people couldn't read . . . some of them could play Chopin. It's a very diverse crew, much more so than legend would have it.
& #x200B;
sources:
[Marquis De Mores: Dakota Capitalist, French Nationalist](_URL_4_)
[Chateau de Mores State Historic Site](_URL_3_)
Prairie Fever: [British Aristocrats in the American West, 1830–1890](_URL_2_)
[Kwangtung to Big Sky: The Chinese in Montana, 1864-1900](_URL_5_)
[Colorado's Historic Opera Houses](_URL_1_)
[Spanish Influence in the United States: Economic Aspects](_URL_6_)
[The History of the Vaquero](_URL_0_)
& #x200B;
& #x200B; | [
"Old-time music has been adopted by a few Native American musicians; Walker Calhoun (1918-2012) of Big Cove, in the Qualla Boundary (home to the Eastern Band of Cherokee Indians, just outside the Great Smoky Mountains National Park in western North Carolina) played three-finger-style banjo, to which he sang in the ... |
with woman's equality in military combat roles being normalized, why is it still absurd that woman play with men in the nfl and other major league sports? | Because physically a woman in the NFL would not be able to stop most of the males.
Now, if you have some sort of 6'4 275 she-hulk that would work. | [
"Finally, there is the argument that by not incorporating women into combat, the American government is failing to tap into another source of soldiers for military combat operations. This argument claims that the government is creating a military that treats women as second-class citizens and not equals of men.\n",... |
what is the body trying to accomplish when we dry heave? | Your body is attempting to vomit but not succeeding. That's pretty much it. | [
"Other than treating, curing or remedying the underlying cause of emaciation, it as a symptom is treated by regaining the weight and restoring the tissues. This is done through renourishment, or reintroducing nourishing liquids and foods to the body while increasing the intake of food energy. The process, usually b... |
Why were there only two American Aces in the Vietnam War? | Remember that becoming an ace requires downing five enemy aircraft, and to down enemy aircraft the enemy needs to have some in the first place.
& #x200B;
The VPAF had only started to receive jet fighters in 1964, and their aircraft were generally less numerous and less capable than what the Americans were fielding. Because the aims of the VPAF were exclusively defensive in nature and their supply of both manpower and materiel was very limited, they would deploy their aircraft very conservatively. They generally would only sortie their fighters when the situation was very much in their favor, and tactics were designed around ambushing strike formations, with forcing the attackers to drop their ordnance early and abort the mission being just as effective as downing an American aircraft. A more typical tactic involved having fighters appear away from a strike package to draw away escorts and then having another group pop in under the radar and make a pass on the strike aircraft themselves. While the typical strike aircraft (F-105) was nominally faster than the MiG-17, it could only outrun the MiG-17 once it had jettisoned its payload and thus ruined the mission. The MiGs, on the other hand, didn't exactly stay around to fight - all they had to do was ruin the mission, so a typical "attack" could consist of one pass on the strike aircraft followed by a rapid withdrawal by both the attacking and decoy aircraft.
Because of that, opportunities for American fighters to actually engage the VPAF were few and far between. Making this worse, particularly early on, was the tendency of American forces to rotate pilots through the theater to spread experience and the generally poor air-to-air combat training provided early in the war. So while encountering an enemy fighter was already a rare thing for American pilots in Vietnam, the rotation of aircrews meant that it would be rare to stay in the theater long enough to encounter enough VPAF fighters to even have the potential to make ace, and poor air-to-air combat training meant that you were less likely to be successful at downing an enemy fighter before it was able to disengage and escape. | [
"The Vietnam War saw a move away from cannon fire to air-to-air missiles. Although US forces maintained air supremacy throughout the war, there were still occasional dogfights and US and North Vietnamese aces. The North Vietnamese side claimed the Vietnam People's Air Force had 17 aces throughout the war, including... |
Why did the brain of most animals evolve in the head and not in the torso? | It would be more protected, yes, but we keep our seeing, hearing, smelling, and tasting organs in our heads. If our brains were in our torsos, our senses of sight, smell, and hearing would be much less efficient (because the nerve signals would have to travel farther along pathways), and this would make us less able to survive. It's better to see a predator and run away before being attacked than it is to be attacked at all, even if your brain is better protected. | [
"Human brain – central organ of the nervous system located in the head of a human being, protected by the skull. It has the same general structure as the brains of other mammals, but with a more developed cerebral cortex than any other, leading to the evolutionary success of widespread dominance of the human specie... |
why can some animals give birth without help when humans can't? | The only true assets of humanity are its intelligence and its social/communication skills. Those two assets require one big ass brain, proportionally. That giant brain is what makes our birth so difficult and also why we have such high mortality rates surrounding it.
The other factor that makes birth so dangerous is that humans evolved to walk bipedally, for reasons of vision and locomotion. Bipedal stature makes the hips a lot more narrow, and in turn, gives the baby less room to escape the birth canal. Evolution decided that risk was worth it.
The things that make humans have difficult births were the exact same things that allow us to help each other with them. So we traded safety for knowledge, and we assist each other because we're smart enough to do so.
TL;DR- Your cat can have 4 kittens on her own just fine because the cost of that is cat-intelligence. The cost of human intelligence is a difficult birth and a long childhood. Reproduction and evolution think that this is a reasonable price. | [
"Human infants are also almost always born with assistance from other humans because of the way that the pelvis is shaped. Since the pelvis and opening of birth canal face backwards, humans have difficulty giving birth themselves because they cannot guide the baby out of the canal. Non-human primates seek seclusion... |
The brain is remarkable energy efficient. Is there any limit to the efficiency in which information is computed? | Information is a very important concept in physics (particularly in thermodynamics). At the most basic level information in physics is quantified as [entropy](_URL_2_), and the relationship between energy, temperature, and entropy can be understood in part through viewing [Boltzmann's constant](_URL_3_) as a (temperature dependent) conversion factor between energy and information.
Once you understand that energy and information are closely related and that relationship depends on temperature, you can go a step further and look at [Landauer's principle](_URL_0_) which describes how to apply this conversion factor to finding a lower limit of the energy required to erase 1 bit of information - E=k\*T ln 2 (where E is energy, k is boltzmann's constant and T is temperature). That means there is a minimum energy cost associated with every "lossy" logical operation (AND, OR, XOR, etc.- any operation where the number of output bits is fewer than the number of input bits) a computer performs, at a given temperature.
The universe as a whole is permeated by the [cosmic microwave background radiation](_URL_6_), which is low-frequency microwave radiation at around 2.7 K. That's probably the most energy-efficient temperature for your computer to be at, because you can cool down to that temperature for free (just have your computer sit in deep space), and going colder than that would require you to use active heat pumps (which would almost certainly take more energy than you'd save on the more efficient computations).
So, [plugging and chugging](_URL_1_), that comes out to about 2.58×10^-23 Joules per bit deletion. Just for brevity let's assume that each processor clock is equivalent to one bit deletion (not true but close enough for an order-of-magnitude estimate), and assume your processor was running at 4GHz (why bother running a super-efficient computer if it's not fast enough to run Crysis?) That implies a minimum required power of about [0.1 picoWatts](_URL_4_). By contrast, an i7-4790K consumes about [150 Watts](_URL_7_) - about 15 orders of magnitude more. So while there are indeed physical limits on the efficiency of processing information, current engineering is not even remotely close to those limits. There are much higher and more relevant limits that relate specifically to how information is processed with current technology (moving electrons around).
If you're interested in how physics and information relate, and specifically how those concepts impact computing, [this](_URL_5_) is a good entry point page for learning more. If you liked the topics I wrote about above (which are pretty much just the third 'physical limits' bullet spelled out a bit more verbosely), you'd probably also really enjoy the other links on that page. | [
"Some research suggests that aside from the integrity of white matter, also its organizational efficiency is related to intelligence. The hypothesis that brain efficiency has a role in intelligence is supported by functional MRI research showing that more intelligent people generally process information more effici... |
why do some acne medications cause an "initial breakout," making your skin worse, before making it better? | Hi, it’s because your cells are turning over rapidly and pushing acne that is below the surafce to the top. This is quite normal. Now if at any point your acne become severe and it seems that the breakout is not normal for YOU, go to a derm just to make sure you are not allergic to the product. It is a good idea to start slow and if the side effects are too much, cut back | [
"Acne usually flares up 2–3 weeks into the treatment and is usually mild and tolerable. Occasionally this flare-up is severe, necessitating oral antiobiotics such as erythromycin. A short course of oral prednisolone may be required. Some dermatologists favour a few weeks of pre-treatment with oral antibiotics befor... |
why do professional swimmers wear 2 caps when competing? | So I was actually wondering this out loud the other day while I was watching the Olympics with my wife, and not 10 seconds later the commentator on the TV actually explained it. He said occasionally you will see some swimmers wear their goggles with the strap on the outside of their swimming cap, but most wear them with the strap on the inside. Some swimmers wear their goggles with the strap in contact with their hair, and then a single swim cap over top, but other swimmers may feel that their hair is too slippery for the goggles' strap to stay in place, so they wear a swim cap, then the goggles with the strap over top of the first swim cap, and then a second swim cap to make sure their goggles can't slip off. He seemed to know what he was talking about, so I trust his explanation. | [
"Unlike triathlons, which allow swimmers to wear wetsuits when the water is below a certain temperature (the standard is at the surface or up to for unofficial events.), most open water swim races either do not permit the use of wetsuits (usually defined as anything covering the body above the waist or below the kn... |
What should one look out for when selecting historical works to read, especially ones on controversial matters? | Brilliant question.
So it can often be very hard to know quite what to look out for with works of history, particularly when you are new to the field and can’t spot the problems.
Academic qualification is perhaps a good starting place, yet, as you note, many books are written by journalists without formal training in academic history. This is not in itself an indicator of bad history as many such writers do produce very high quality work (Max Hastings for example). Instead I would look more broadly for what I suppose you could call the competency and dependability of the writer.
There are a number of ways you can check this. Firstly, reviews are brilliant. I would recommend checking feedback a particular book has received since publication, academic journals, and some websites newspapers will run review sections which can often prove helpful. Often books will also feature appraisals on the front/rear cover of the text itself, however I would approach these with caution - remember this is advertising, and I would be sceptical of such appraisals unless you are familiar with the quality of work of the individual writing it.
Next, it is worth considering various matters, publisher, format, style, quality of print, etc. These are all often overlooked but can indicate the quality of a work of history. It has become increasingly easy to self publish bad history in recent years, either online or in print, so it helps to be wary. If something looks off, be wary.
In a similar vein, read the synopsis of a book, this will usually give you a condensed view into the book, its themes and central arguments. Do these seem plausible? Well presented?
Try reading the introduction. This is of course not always possible, especially if not buying a book within a physical bookshop, but is very handy. The introduction, like the synopsis, will offer a glimpse into the soul of the book. Here you should be able to see the quality of the writing which will be displayed throughout, and this can be a brilliant test of character.
At the end of the day, these tips can help, but are not full proof. There is always going to be bad history out there which is not that credible. Often it can sneak through undetected, and can appear entirely legitimate to the untrained eye. In fact, even ‘good history’ is not without its flaws sometimes, and often a brilliant work may be betrayed by its style. It is often hard to tell, and if you are to spend much time reading history, you will certainly come across some questionable, however, there are some general rules which you should consider when reading which may help when you do come across such things.
Always engage critically when you read history. Remember that the author is constructing an argument when they write, and has a point of view they want to convince you of. When writing history, the historians can choose which facts to select, and how to present them, all history is biased and subjective in some way. However, this does not mean all history is created equal, some is better than others. Some writers will make their subjectivity clear, and acknowledge their role in constructing the narrative you will be reading, while others will not, they may present as objective undeniable fact that which they have subjectively interpreted. Keep this in mind while reading. Ask questions of the author, does a claim make sense? Is it backed up convincingly? Does the evidence they cite actually support their claims? Why have they portrayed something in a certain light? Personally I make notes in the margins of history books I am reading through to aid in this process. These issues can at first be tough, but as your wealth of knowledge grows, it does become easier. If something sticks out, pick at it much like a loose thread, and see where it leads.
With this in mind I would like to note that having a particular stance when history is not necessarily a bad thing, it depends upon how this manifests itself. Objectivity relates more to being “fair to the evidence” than being neutral to the topic, if you catch my meaning. To be fair to a figure like Lenin does not mean to be without judgement, but rather to have an opinion predicated upon the evidence. However, evidence is often complicated and vast, and can support many conclusions. One could be positive, or negative, about Lenin, and while neither can be considered undeniably true, both can ‘objective’.
As I hope to have pointed out, it can all be rather complicated, and it’s something we all struggle with. Good luck! | [
"This series provides vital references for students, architects, town planners, historians and philosophers as well as for readers interested in gardens, garden-makers and collectors. By publishing fundamental works of the past – forgotten, unknown or un-translated – along with French and foreign, historic and cont... |
Were number systems written down before words and language? | Sumerian cuneiform has its origin in accounting systems, particularly those used by temples to keep track of goods like cattle and grain. A sign could represent a type of good, and the number with a system of tick marks next to it. Cuneiform symbols originated as mnemonics/pictograms, which were subsequently abstracted, and the representational/mnemonic function of the symbols became more sophisticated over time, developing into a more complete system. [This website](_URL_0_) has a more detailed explanation of how the system developed.
Some kind of abstract numerical representation system does seem to predate what we think of as written language, but the development of written language was very gradual--it wouldn't be accurate to mark a strict cutoff before which proto-writing could be considered merely a mnemonic system and after which it could be considered "fully-fledged writing". John Hayes, in the *Manual of Sumerian Grammar and Texts*, points out that written Sumerian in all likelihood is an incomplete representation of the language as it was spoken, especially phonologically.
Writing may have developed quite differently when it arose in other places--the earliest Chinese writing is from inscriptions on bones used in pyromancy, not accounting. The exact relationship of Egyptian hieroglyphics to cuneiform is still debated, and I don't know if anything is known about the development of Mayan writing, so it's hard to say if the method of development of writing in Mesopotamia out of an accounting system represents a general tendency or a peculiarity.
And, of course, the written accounting tools used by the ancient Mesopotamians were still pretty basic--mathematical notation and double-entry bookkeeping are both much more recent inventions. What they had were pretty much just counting systems.
Hope some of that helps. | [
"Traditionally, certain letters were rendered differently according to a set of rules. In particular, those letters that began sentences or nouns were made larger and often written in a distinct script. There was no fixed capitalisation system until the early 18th century. The English language eventually dropped th... |
what defines a religion from mythology? | A mythology is a set of traditional stories. The Jewish mythology is the Old Testament, the Christian mythology is the Old and New Testaments, the Greek mythology is... well, Greek mythology. Mythology doesn't have anything to do with whether the stories are true or not, it's an agnostic term. It simply says "these are stories that people tell each other."
A religion is a set of beliefs that is accepted on faith by its followers. Religions often incorporate mythologies as part of their belief set, though it's not totally necessary. The point here is that "religion" and "mythology" are not interchangeable terms. One is a set of stories, one is a set of beliefs.
It's confusing because the colloquial usage for "mythology" (and "myth" especially) often *implies* that it's something that's untrue, so many religious people avoid calling the stories from their faith "myths." They are, though, by the strictest technical definition. | [
"Mythology is the main component of Religion. It refers to systems of concepts that are of high importance to a certain community, making statements concerning the supernatural or sacred. Religion is the broader term, besides mythological system, it includes ritual. A given mythology is almost always associated wit... |
how did they predict existence of subatomic particles, black holes, multiple universes using maths and equations? | > subatomic particles
They didn't predict those with math. They were largely experimentally discovered. Thomson's cathode ray experiment found that there were negatively charged subatomic particles we now call electrons, for example.
> black holes
These were first thought of from Newtonian mechanics by Laplace (and others?), but it was really just an idea. After Einstein produced the general relativity theory, Schwarzschild predicted the limit at which a black hole could form.
> multiple universes
Those aren't mathematically predicted either, they're really outside the realm of science. | [
"Improved understanding of the world of particles prompted physicists to make bold predictions, such as Dirac's positron in 1928 (founded on the Dirac Sea model) and Pauli's neutrino in 1930 (founded on conservation of energy and angular momentum in beta decay). Both were later confirmed.\n",
"The Standard Model ... |
if your car gets stolen and your insurance covers it, what happens if the stolen car gets found after you have already gotten a new one? | Usually, it belongs to your insurance company now. They'll take full ownership of the stolen vehicle. This should be stated in your insurance policy. | [
"Some drivers believe that a new car is in greater danger than a used car of getting into an accident or having a collision. Some drivers will leave change under their seats. Others use one coin to scratch the car, based on the (false) belief that since the car is new and nothing has happened to it yet, the chances... |
what is the difference between normal steel and galvanized steel? | Galvanizing is a process of adding a zinc coat to the steel. It should make the nuts last longer and prevents rust.
The actual process is slightly more complicated but this is essentially it. | [
"Electrical steel is one material that uses decarburization in its production. To prevent the atmospheric gases from reacting with the metal itself, electrical steel is annealed in an atmosphere of nitrogen, hydrogen, and water vapor, where oxidation of the iron is specifically prevented by the proportions of hydro... |
how are the "dark triad" traits in psychology different from each other? | Psychopathy is a lack of empathy & understanding of how people feel.
Narcissism is placing your own needs & wants over others.
Machiavellianism is lying & manipulating people to achieve your goals.
They're called the "dark triad" because they do so often overlap & feed into each other. It's easy to be narcissistic if you don't care about how people feel. It's easy to manipulate people if you feel your needs are more important than theirs. | [
"There is a good deal of conceptual and empirical overlap between the dark triad traits. For example, researchers have noted that all three traits share characteristics such as a lack of empathy, interpersonal hostility, and interpersonal offensiveness. Likely due in part to this overlap, a number of measures have ... |
Why don't we launch spacecraft using magnets? | To get into low earth orbit with a rail gun would require an exit velocity so high that whatever you are launching would burn up immediately. It has been suggested as an efficient way to launch things from bodies without an atmosphere. | [
"The main disadvantage of magnetorquers is that very high magnetic flux densities are needed if large craft have to be turned very fast. This either necessitates a very high current in the coils, or much higher ambient flux densities than are available in Earth orbit. Consequently, the torques provided are very lim... |
how does winrar/7-zip just make my files smaller? | Just about any set of information contains some repeating information. My paragraph contains the word contains several times. One means to reduce the size would be to put a short unique identifier in place of each word "contains" and a reference that the identifier means contains.
So a very simple compression scheme for the above paragraph might look like:
Just about any set of ! @ some repeating !. My paragraph @ the word @ several times. One means to reduce the size would be to put a short unique # in place of each word "@" and a reference that the # means @.
!=information
@=contains
\#=identifier
That's a quick 15% reduction in the characters (counting the replacement information we added). If we did the same with parts of words, or shorter binary strings, we could further reduce the space. It's easy to automatically replace the characters with the original words when you want the original file back.
Compression schemes do something similar with the binary data that makes up all computer files.
That's why compression works better on data with lots of repeating information (like text or a bitmap image) rather than data with little repeating information (like a jpg). | [
"7-Zip comes with a file manager along with the standard archiver tools. The file manager has a toolbar with options to create an archive, extract an archive, test an archive to detect errors, copy, move, and delete files, and open a file properties menu exclusive to 7-Zip. The file manager, by default, displays hi... |
model-view-controller pattern | MVC isn't that hard. You have the view (or views). This is everything you see. It's a lot of rules about how to show the info.
Then you have the model, which is the data.
Then you have the controller. The controller takes the data and moves it into the view. If something changes, you tell the controller and he updates the correct places.
Example:
View:
TextBox age: Position left
Slider ageSlider: position right
%%could have separated them into two views if I wanted to
onSliderUpdate(
NotifyControler(newAge)
)
Model:
Person{
int age.
}
Controller:
OnNotify(int age)
model.age = age
for each view
updateView
| [
"Model–View–Controller (usually known as MVC) is an architectural pattern commonly used for developing user interfaces that divides an application into three interconnected parts. This is done to separate internal representations of information from the ways information is presented to and accepted from the user. T... |
why do people like to believe in god | I imagine you'll get a lot of responses along the lines of "they need easy comfort" or "they were brainwashed as children".
I don't think these are untrue. But they're too simplified, even for ELI5.
As far as comfort goes, it's not just comfort people are looking for. It's order. Humans love patterns and we really love authority. We're still very tribal in nature and that concept of a central authority for us isn't just appealing, it's a desire that is a base part of out nature. This is why you often see religions in which gods or a god promise a specific group of people that they are special. This god was part of a tribe. The leader of that tribe.
Gods are a powerful explanation and a powerful authority. As history shows, our commitment to that authority and the sense of community is so strong that many of us simply can't let go of. This is the part where the brainwashing children comes in. I wouldn't say it's intentional, at least not in any kind of malicious way (fundamentalists and extremists notwithstanding, they're a totally different story). It's more that we develop our connection to tribe/community very very strongly as children. And if your tribe follows a god as a leader, you will as well. | [
"My faith is based on a constant search but I don't search frantically. It's no use to rush out into space to search for some gods there, if they want to have anything to do with me, they will come. I have often become aware of them, but I don't rush after them or shout at them. I have gotten to know them a bit in ... |
Why was Iran/Persia never colonized? | While the area that is modern day Iran was indeed never colonized the way that India was, the country was picked apart bit by bit in the 1800s and what was left was more or less defacto colonized by Russia and Great Britain. Although there were resources to be had, nothing was quite so valuable as to engage a Great Power in a series of costly and strategically risky colonization efforts.
As a starting point, a huge area of the middle east, centered in Persia, was controlled by the Safavid Empire through much of the early modern era. Similar to the Ottomans or the Mughals, they had a strong government, a standing army made of slaves similar to the effective Ottoman Janissary system, and in the later years a modern gunpowder based musketeer force.
During the early to mid 1700s, Persia was on a decline. Indian silk was booming in Europe (and drawing some uncomfortable looks from colonizing powers), causing disruption to the economy. Huge swaths of Safavid territory were lost to the Ottomans and to Russia, in a series of wars launched by Peter the Great. A brief resurgence in the mid century would actually see the territory reconquered, but the country subsequently declined again after their ruler was assassinated, their economic woes continued, and the Safavid dynasty ended. By the turn of the century, as the colonizing powers strengthened their hold on India and the East, what would become modern day Iran was much diminished compared to it's past Imperial self.
The 1800s weren't all that great for Iranian empires either. More wars with the Russians would lose them most of the Caucasus, Amernia, and some northern cities. A series of wars with Great Britain would lose Herat and eastern territories which were heavily populated and filled with useful agricultural products like saffron. At this point Iran could more or less see the writing on the wall.
In response to Iran's growing losses and the obvious influence of Britain and Russia, the new Qajar Dynasty ended up more or less acting as puppets to the great powers. Colonization was costly and intensive, and intervention by any power in Iran could have drawn a response from one of the other powers. With this knowledge, and with new diplomatic ties to the west, successive Qajar monarchs sought to modernize Iran, and play western powers off each other, to varying degrees of success. Iran would remain nominally independent, but more or less entirely existing because it lay in both Russian and British spheres of influence. Neither Power willing to commit to an invasion, but both with significant influence in the region.
Iran's situation was precarious, but hadn't changed for generations of Qajar rulers. Just to make things interesting, as the world rapidly approached the end of "classical" colonization coming after World War II, oil was found in the Middle East in the early 1900s (again drawing those uncomfortable looks from hungry Western powers). Almost concurrently, several terrible famines struck the region and millions of Iranians died. The hundred years of more or less "stable" rule quickly crumbled in a rapid-fire series of events.
Iran found itself under (mostly neutral) occupation by British, Russian and Ottoman forces during WWI. The Russians suffered their own revolution, the Ottomans collapsed, and the British unsuccessfully tried to setup a protectorate. The resultant interwar years were filled with several internal revolutions and coups, a brief constitutional monarchy, a military dictatorship, but ultimately independent, Iranian rule. After several hundred years of conflict with western powers, Iran was finally occupied in WWII by a joint invasion of the Soviet Union and Great Britain. I do find it somewhat telling that the only time an occupation like this happened was with the agreement of both British and Russian forces.
However, this wasn't an occupation with the intent to colonize. Iran had just made it just under the bar for that particular form of control. Instead, Iran got to be the very first theater in a different kind of geopolitical power game, the Cold War. The resultant Iran Crisis of 1946 over the withdrawal of the Soviet forces would end up with the eventual relinquishing of Soviet control in the area, and (with some words from the USA) the Iranians would even get to keep their oil.
I would tend to frame what happened to Iran, not as "avoiding" colonization, but merely getting by until colonization wasn't the preferred method for influence in a country. Iran suffered a CIA lead Coup in 1953. To this day, even after the Revolution of 1979, Iran continues to walk a line between spheres of power. It's not "free" from them, no country is really, but it maintains independence by being costly to invade, and being willing to push and pull a little to play the major powers off each other. I don't find it hard to think of some topical examples where this continues right into modern day. | [
"More importantly, the Dutch East India Company and later the English/British used their superior means of maritime power to control trade routes in the western Indian Ocean. As a result, Iran was cut off from overseas links to East Africa, the Arabian peninsula, and South Asia. Overland trade grew notably however,... |
why do people go to the bathroom on a pretty regular schedule? | Because generally your food/drink intake is fairly regular as well. You have coffee every day at 8am. Lunch at noon, dinner at 7 etc. | [
"BULLET::::- Too many people using a toilet: This is especially true in case of shared or public toilets. If too many people want to use a toilet at the same time, then some people may go outside to defecate instead of waiting. In some cases, people might not be able to wait due to diarrhea (or result of an Irritab... |
why do prepaid visa cards ask for social security numbers? | Its a bank account. Just like a bank. You can't open an account at a brick and mortar bank without using a SSN. Same applies to a non-traditional account. | [
"Social Security numbers and cards are issued by the US Social Security Administration for tracking of Social Security taxes and benefits. They have become the \"de facto\" national identification number for federal and state taxation, private financial services, and identification with various companies. SSNs do n... |
How often are planets found? | Planets in our Solar System, or planets in general?
In our Solar System, only two planets still considered planets have been found in recorded history, Uranus in 1781, and Neptune in 1864. If Planet Nine is real, odds are we'll find that within the next 10 years or so.
Outside of our solar system, planets are found on a virtually daily basis, although usually only announced in batches of a few planets, a few dozen planets, or rarely a few hundred planets. For some planets just announced recently, a bunch of planets around nearby stars were announced only a week ago: [_URL_0_](_URL_0_) | [
"BULLET::::- 30 planets: On October 19, it was announced that 30 new planets were discovered, all were detected by radial velocity method. It is the most planets ever announced in a single day during the exoplanet era. October 2009 now holds the most planets discovered in a month, breaking the record set in June 20... |
whats happening when a sneeze ‘gets stuck’ then just burns your nose and makes your eyes water. | Sneezes are a protective response to alert you to less than ideal breathing conditions and remove irritants/allergens from your nose. They’re triggered by the presence of irritants, but only a certain concentration, which is mediated by multiple nerve endings that generate “spikes” when they’re irritated. Once the number of spikes passes a certain threshold, you sneeze.
Sometimes your nose will be irritated to the point of feeling like you have to sneeze, but there isn’t quite enough to push you over the threshold. So you “get stuck.” | [
"Sneezing typically occurs when foreign particles or sufficient external stimulants pass through the nasal hairs to reach the nasal mucosa. This triggers the release of histamines, which irritate the nerve cells in the nose, resulting in signals being sent to the brain to initiate the sneeze through the trigeminal ... |
What was Moscow's relationship with Ceausescu before the Romanian revolution? What role, if any, did they play in the revolution? | Ceausescu was something of a maverick in the Eastern Bloc, which is why your friend probably thinks that. Relations between Brezhnev/Andropov and Ceausescu were cool at best and outright frigid at worst, although they never reached the point of de facto breaking off relations, unlike in Beijing. He denounced the 1968 Soviet invasion of Czechoslovakia. He kept relations with both Israel and the PLO and helped push for peace between Israel and Egypt. He kept up cordial relations with the Chinese, much to the extreme irritation of the Kremlin-Ceausescu personally modeled his personality cult off of Mao Zedong and Kim Il Sung. He openly recognized West Germany and was the first Warsaw Pact country to independently invite a US President to visit. (Nixon would later use Ceaucescu as a conduit for backdoor negotiations with the Vietnamese and while in Bucharest, consulted with him on his desire to open relations with China.) He refused to endorse the invasion of Afghanistan, and participated in the 1984 Olympics in Los Angeles, which the Soviet Union boycotted.
With that being said, however, I don't find it quite plausible. To be sure, if there is one intelligence service in the world which **nothing** should be put beyond, it's Russia's, no matter who rules in the Kremlin. Westerners often have a hard time grasping just how tactically skilled and utterly amoral they are. But Moscow wasn't able to react in places with a much larger KGB presence and more strategic value, like East Germany, in 1989, as none other than Vladimir Putin points out quite vividly. ("Moscow was silent.") I don't think they could have orchestrated a coup in a place like Romania where the security service in practice watched out for the KGB as much as anybody else. Moreover, the 1989 Romanian Revolution wasn't a reaction against just Ceausescu, in contrast to previous coup attempts such as that in 1984(I think), but against Communism as a whole. No matter how many Communists joined the opposition, the ideology was strongly discredited all over the Warsaw Pact by 1989. Gorbachev thought he could keep the genie in the bottle. But the Romanian Communists who joined the Revolution didn't, as seen by their subsequent economic and social liberalization policies. | [
"Satisfied with this appointment, the Soviet authorities were more conciliatory with Romania. On 13 March 1945 Moscow transferred the administration of Transylvania to Bucharest. A few months later, on 19 July 1945, Michael I was decorated with the Order of Victory, one of the most prestigious Soviet military order... |
why do roosters "cock-a-doodle-doo" in the morning? | They actually crow all day. Not just mornings. | [
"A rooster's crowing is a loud and sometimes shrill call and sends a territorial signal to other roosters. However, roosters may also crow in response to sudden disturbances within their surroundings. Hens cluck loudly after laying an egg, and also to call their chicks. Chickens also give different warning calls wh... |
How Accurate/Bias was "Century of the Self"? | Not commenting directly on "Century of the Self", but Adam Curtis:
Most all of his documentaries start with "This is a story about..."
Keep that in mind. It's a story. It's a particular account of events too complex to explain otherwise. It may be compelling, even undeniable. It may be well researched, he may have universal consensus backing his thesis or smoking gun evidence to back it up.
But it's just a story.
I like Adam Curtis, I think he illuminates interesting aspects of our culture and recent history. I agree with him on a lot of his views. But I'd still endorse some healthy scepticism when watching his work. There's often a lot he overlooks or neglects (because if he included it, his "story" wouldn't run).
(I really wanna make a documentary about Adam Curtis that starts with "This is a story about a documentary maker who believed the chaos of historical events could be explained in a simple way, and the key to doing so lay in understanding the ideologies of those involved...") | [
"The term of present bias was coined in the second half of the 20th century. In the 1930’s economic research started investigating time preferences. The findings led to the model of exponential discounting, thus time consistent discounting. However, later research led to the conclusion that time preferences were in... |
how does my (i)phone know which sounds to let through in a phone call / face time? | There are several microphones. 1 intended to pick up your voice, the other(s) to pick up all the rest of the noise around you (lets call them noise microphones). The cell phone subtracts the sounds from the noise microphones from the sounds picked up by the voice microphone. The sounds that are left are just the voice. | [
"A typical phone call using a traditional phone is placed by picking the phone handset up off the base and holding the handset so that the hearing end is next to the user's ear and the speaking end is within range of the mouth. The caller then rotary dials or presses buttons for the phone number needed to complete ... |
In the post red giant stage of a star, why do the outer layers drift into space and not collapse onto the white dwarf? | Two reasons. One is that as the star expands the surface gravity decreases and so it's easier for those outer layers to escape. Two is that it's not actually a "drifting" away in many cases but is in fact forceful; [stellar winds](_URL_0_) are generated which are blowing surface material away. We see this observationally but the physical processes that are all intertwined are quite complex. | [
"A third option is that a giant star passes close enough to the central massive black hole for the outer layers to be stripped away by tidal forces, after which the remaining core may become an EMRI. However, it is uncertain if the coupling between the core and outer layers of giant stars is strong enough for strip... |
why can't facebook, twitter and instagram just shut down bot accounts? | The problem is how do you actually figure out that a twitter user is a bot. You can use Machine Learning with certain features (like tweet sentiment) to analyze the data, but there's the possibility of false positives. Also, it's an arms race. Once they figure out what you're looking for all the bot creator needs to do is to change the bot themselves. You can take a look at [this pdf](_URL_0_) if you're interested in the details of figuring out whether a twitter user is a bot or a human. My ML professor participated in the DARPA Twitter Bot challenge and he said there were a lot of arguments on his team because of it, and at times he felt that it was going to rip the team apart. | [
"Using social bots is against the terms of service of many platforms, especially Twitter and Instagram. However, a certain degree of automation is of course intended by making social media APIs available. Many users, especially businesses still automate their Instagram activity in order to gain real followers rathe... |
why do higher impedance speakers yield better sound quality? | The amplifier has an output impedance and the speakers have an input impedance. The signal itself is a time-varying voltage which is divided between the two impedances according to their ratio. To maximize the amount of power in the speakers, you want as low an output impedance on the amplifier and as high an input impedance on the speakers as possible.
Note that this is the same for *any* sort of amplification process. You want high impedance on the load because that's where you want most of the signal to be dissipated. If you have a low impedance on the load, most of the signal will be dissipated (uselessly) elsewhere. | [
"Speaker sensitivity is measured and rated on the assumption of a fixed amplifier output voltage because audio amplifiers tend to behave like voltage sources. Sensitivity can be a misleading metric due to differences in speaker impedance between differently designed speakers. A speaker with a higher impedance may h... |
why did teachers always tell us to remove hats/caps when we enter inside a building? what does this signify? | It goes back to olden times when a knight would remove his face gear. It's simply a sign of respect to remove head pieces when in someone else's "home", and as well as during the Pledge of Allegiance. | [
"Wearing coats, boots or other outer garments inside someone’s home is often frowned upon as well. Sitting down to eat at table wearing a hat or coat etc. is even worse. Also one should remove one's hat when showing deference. Removing one's hat is also a form of respectful greeting: the origin of this is that knig... |
Would having a more efficient/ faster brain affect our perception of time? | I am by no means an expert, but I know (both firsthand and from [documented sources](_URL_0_) ) that your perception of time can be affected by life-threatening situations. These situations *probably (and I'm guessing here)* do something like speeding up your neuronal activity and cause your neural "clock speed" to increase. This causes things around you to move slowly from your point of view.
Perhaps someone in this field can expand further on this, but it's an interesting subject and I wish I knew more about it to properly answer your question. | [
"The neural efficiency hypothesis postulates that more intelligent individuals display less activation in the brain during cognitive tasks, as measured by Glucose metabolism. A small sample of participants (N=8) displayed negative correlations between intelligence and absolute regional metabolic rates ranging from ... |
Are you born allergic to things or do you get it later on? | No. You are not born allergic to anything. You need to be sensitized to the allergen first, and you aren't really fully capable of that until several months after birth.
You can, however, be born with a predisposition to becoming allergic to things (not specific things, just "things" in general). | [
"An allergic reaction can be caused by any form of direct contact with the allergen—consuming food or drink one is sensitive to (ingestion), breathing in pollen, perfume or pet dander (inhalation), or brushing a body part against an allergy-causing plant (direct contact). Other common causes of serious allergy are ... |
Will the other side of the moon ever be facing earth? | The Moon is [tidally locked](_URL_0_), meaning it's orbital period equals its rotational period. Thus, the answer to your question is that the same side of the Moon will *always* face the Earth. Viewing the Moon from Earth, we will never see the other side. Something very dramatic would have to happen to change that. | [
"As a result of the Moon's synchronous rotation, one side of the Moon (the \"near side\") is permanently turned towards Earth, and the other side, the \"far side\", mostly cannot be seen from Earth. This means, conversely, that Earth can be seen only from the near side of the Moon and would always be invisible from... |
Question about image scaling | It's a bit more complicated than that. [Here's a very good explanation of how it's done.](_URL_0_) | [
"Image scaling can be interpreted as a form of image resampling or image reconstruction from the view of the Nyquist sampling theorem. According to the theorem, downsampling to a smaller image from a higher-resolution original can only be carried out after applying a suitable 2D anti-aliasing filter to prevent alia... |
how exactly do organisms evolve and adapt to their environment? | They don't.
There's a bit of variation between individuals of a generation, and traits that prove beneficial have a better chance of passing on than traits that don't.
If 95% of frogs of a species are green and 5% are red, so long as green is the preferred camouflage color, the green frogs will reproduce more on account of the red ones getting eaten.
If, say, an environmental event occurs that causes red to be a better form of camouflage, you'll see more and more red frogs surviving to breed every generation, as the green frogs try to hide, fail, and get eaten.
It might take generations upon generations, but eventually you might see a day where most of the frogs are red. | [
"Habitats and biota do frequently change. Therefore, it follows that the process of adaptation is never finally complete. Over time, it may happen that the environment changes little, and the species comes to fit its surroundings better and better. On the other hand, it may happen that changes in the environment oc... |
Why are galaxies the colour they are? | The colors gives insight in the composition of the star population of the galaxy.
Blue regions are composed mostly of young hot stars, while red regions are older, cooler stars.
You will often also see smaller, pink spots. These are huge clouds of hydrogen, the color stems from the characteristic emission of hydrogen gas, which you can see in the [balmer series](_URL_0_). The HII line is the bright red emission on the right side of the spectrum.
When you look at galaxies in other wavelengths than the visible light, you can get a lot mor information about the galaxies composition, like radio or gamma emission. But those do not contribute to the visible appearance of the galaxy.
It should also be noted, that most galaxies are not visible to the naked eye at all. They are so far away, that the expansion of the universe stretched their light into and beyond the infrared spectrum, and can only be seen by specialized equipment. Images of galaxies are then "converted" to what a human might see if he were close enough. But it's always an artists impression. | [
"In astronomy, a blue compact dwarf galaxy (BCD galaxy) is a small galaxy which contains large clusters of young, hot, massive stars. These stars, the brightest of which are blue, cause the galaxy itself to appear blue in colour. Most BCD galaxies are also classified as dwarf irregular galaxies or as dwarf lenticul... |
- why wouldn't it be possible to set up a solar heated steam pipeline that also removes salt, to get water to rural parts of africa? | I guess because they can't afford it. | [
"Solar evaporation is the oldest and most energy-efficient method of mineral production. At the Great Salt Lake near Ogden, Utah, Compass Minerals draws naturally occurring brine out of the lake into shallow ponds and allows solar evaporation to produce salt, sulfate of potash (SOP) and magnesium chloride. Its SOP ... |
how fresh water fish populations spread from one river network to another without going through (presumably deadly) seawater? | I wondered that about fresh water mussels. So I asked. They have a free living form which basically hitches a ride in the gills of fish. This means the same species can be in one river system even though they are mussels.
Similar events can occur for other species. Egrets and other fish eating birds will fly from one river system to another. Over geological time species can be transferred. All watersheds border each other so it is not travel over hundreds of miles but perhaps ten miles. Larva can remain in a bird's mouth during such a flight. | [
"A second potential mechanism for accidental movement of infected fish is the international trade in ornamental or aquarium fishes, which includes the global trade of approximately 5000 freshwater and 1450 saltwater fishes. Each year over 1 billion individual fish are shipped among more than 100 nations, creating a... |
Do we experience atmosphere tides? Do the molecules in the air get dragged according to the moons gravity causing “deeper” periods of time? | The moon does indeed effect the atmosphere, but orders of magnitude less than it does the ocean. Tidal effects form pressure waves of about 100 microbars, or about 0.01% the atmospheric pressure at sea level. That's only perceptible to scientific instruments, and practically background noise compared to the regular variations in atmospheric pressure that occur due to weather and the effects of the sun.
_URL_0_
_URL_1_ | [
"Atmospheric tides are global-scale waves excited by regular solar differential heating (thermal tides) or by the gravitational tidal force of the moon (gravitational tides). The atmosphere behaves like a huge waveguide closed at the bottom (the Earth's surface) and open to space at the top. In such a waveguide an ... |
what is the difference between losing weight because i am not eating any food vs losing weight while maintaining a healthy diet and working out to lose more calories? | Losing weight is easy by not eating. But you will feel weak from lack of nutrition and you may still not have a good body composition. Working out and eating well you will feel energised and strong and will end up with a healthy body composition.
Body composition is how much fat and muscle you have in your body. You may maintain the same weight your whole life but if you never workout your body composition will change as your muscle atrophy with age. Working out will help maintain your body, your mind and strength so you will still be able to tie your own shoes when you're 80. | [
"Some popular beliefs attached to weight loss have been shown to either have less effect on weight loss than commonly believed or are actively unhealthy. According to Harvard Health, the idea of metabolism being the \"key to weight\" is \"part truth and part myth\" as while metabolism does affect weight loss, exter... |
why are blood stains on fabric so difficult to remove compared to other types of stains? | Mostly because it's a complex substance, containing liquid, suspended solids, cells, fats, oils, and a plethora of other compounds. Most other stains are caused by small portions of these types of compounds.
Wine is mostly aqueous (water based), grease is lipid (fat) based, etc. Most solvents are good at cleaning up one type of stain because they designed to pick up one type.
Blood, being a mixture of most or all of these types, means many solvents won't work on all of blood's components. | [
"For tissues that are not directly acidic or basic, it can be difficult to use only one stain to reveal the necessary structures of interest. A combination of the three different stains in precise amounts applied in the correct order reveals the details selectively. This is the result of more than just electrostati... |
How long does it take to boot up a supercomputer? | The only 'supercomputer' I have access to is a network of 128 computers, each with some xeon processors and lots of ram. These can be booted simultaneously, and boot into a minimally configured Linux environment, which is very quick. The master node then needs to start the cluster management software and register all the compute nodes and you're more or less good to go. | [
"This process took a total of 0.337 seconds of CPU time, out of which 0.327 seconds was spent in user space, and the final 0.010 seconds in kernel mode on behalf of the process. Elapsed real time was 1.15 seconds.\n",
"To give some perspective to this, using Virginia Tech's System X with a maximum performance of ... |
Does potential energy "count" as energy? | I somehow miss your sub-question, and I gave an answer. I will keep some of what I wrote there, maybe you will like it.
Maybe you didn't realize it, but gravitational energy is also consider/named potential energy. Why? because it has the potential to generate a force (gravitational force in this case) if you put an object in a gravitational field, it will be attracted to the effective force generated from all the gravitational potential in there.
Why is it so intriguing?, well it has point out that if you count this potential energy into the evolution of the universe, we could reach a total amount of 0 energy at the beginning. And that is outstanding. Because it means that the Universe was created from nothing.
Edit: Read DocSmile answer | [
"Common types of potential energy include the gravitational potential energy of an object that depends on its mass and its distance from the center of mass of another object, the elastic potential energy of an extended spring, and the electric potential energy of an electric charge in an electric field. The unit fo... |
prism and the nsa scandal | A low level contractor working for the NSA named Snowden leaked a document describing a classified program that collects data from the largest internet communities in the world, including microsoft, facebook, yahoo, google, etc. The internet companies themselves claim to be unaware of this.
It's a big deal because the government is throwing a wide net and capturing *all* data rather than targeting who, what or when. The part of the law that deals with this would normally require a warrant (of sorts) before digging into your information. Instead they decided they'd search you first then ask for permission. Especially troubling is that the program searches citizens as well, which is illegal and not sactioned under FISA.
The government, under pressure, eventually admitted to the program existing. So it isn't a question or conspiracy, it's very real.
Here is a great start / quick reading to explain : _URL_0_ | [
"Documents indicate that PRISM is \"the number one source of raw intelligence used for NSA analytic reports\", and it accounts for 91% of the NSA's Internet traffic acquired under FISA section 702 authority.\" The leaked information came to light one day after the revelation that the FISA Court had been ordering a ... |
why does rubbing alcohol, vinegar, etc have expiry dates? how can they go bad? | The FDA requires expiry dates on nearly everything aside from alcohol and cosmetics. The manufacturers have to put something, so they generally choose a date a few years out, that they are willing to guarantee the product will meet or exceed that date.
_URL_0_ | [
"Currently there is no practical way of halting or reversing the course of degradation. Many film collectors use camphor tablets but it is not known what the long term effects on the film would be. While there has been significant research regarding various methods of slowing degradation, such as storage in molecul... |
In the 60s, was japan's economy expected to overtake the usa's by now? | One minor note: Realistically, China will probably become the world's largest economy much sooner than 2050. The OECD thinks it could be [within the next 4-5 years](_URL_0_), although that's almost certainly jumping the gun. The U.S. National Intelligence Council [thinks it'll be around 2030](_URL_1_) if present trends hold.
They're by no means guaranteed to -- there are a lot of problems in China's economy that are currently being hidden by their growth rate, and the U.S. is likely entering a natural resources boom -- but either way, 2050 is probably unrealistic. All other things being equal, China and India *should* be the largest economies on the planet if for no reason other than the size of their internal markets. I feel like India gets lost in this debate a lot.
And all of this might turn out to be yet another prediction that never comes true. Macroeconomic tea-reading has never been humanity's strong suit.
Echoing the others here, [predictions about Japan's overtaking the U.S.](_URL_2_) were more a feature of the late 1970s and 1980s. The Harvard professor Ezra Vogel's [*Japan as Number One: Lessons for America*](_URL_3_) was published in 1979, for example, and is a somewhat entertaining read in hindsight. Not because Vogel got everything wrong -- a lot of his analysis is spot-on -- but because it's a decent warning against academic overconfidence. | [
"The high economic growth and political tranquillity of the mid-to-late 1960s were tempered by the quadrupling of oil prices by the Organization of the Petroleum Exporting Countries (OPEC) in 1973. Almost completely dependent on imports for petroleum, Japan experienced its first recession since World War II.\n",
... |
if one were to strike a billiards ball with the cue ball, and we disregard the deceleration as the target ball hits each bumper as well as other balls on the table, would the ball eventually, but always sink into a pocket regardless of where on the table it went? | No, it won't always sink. It's easy to think of a situation in which it won't happen.
If you hit the ball parallel to any side of the table, it would bounce back and forth forever, never entering any of the pockets (unless it was right in front of the pocket already. | [
"BULLET::::- Knocking any ball off the table; opponent receives ball-in-hand plus 2 points (the ball is spotted in its starting position, or as close to this position as possible, unless it was the now-incoming opponent's cue ball, which as noted is in-hand).\n",
"Making the ball: You score a point by making the ... |
germany just made all universities free, how do other countries do this? | Economist here. There is no such thing as free. They are just making college payments compulsory for everyone regardless of whether they use it or not.
The system used by the US was fine until universities realized the government would subsidize them raising tuition to ridiculous rates by lending to students. | [
"In Germany, most institutions of higher education are subsidised by German states and are therefore also referred to as \"staatliche Hochschulen.\" (public universities) In most German states, admission to public universities is still cheap, about two hundred Euro per semester. In 2005, many states introduced addi... |
why apple released ios 6 maps when it obviously wasn't ready for release. | Because google refused to license turn by turn, which was a HUGE feature. Apple had been trying to get turn by turn built in for years but they could never come to an agreement. Also, google changed it's pricing from wholesale licensing to pay-per-use, which would make the maps more expensive. On top of that, google started adding ads to their search results.
Apple was also getting nervous that google was collecting user info, so they made their own.
Basically they had 2 options:
1. Go another year without turn by turn, potentially losing users to android. Pay more for maps in the meantime as google advertised to their users.
2. Buy a bunch of mapping services, develop their own maps using third party data like tomtom or osm. Wait for the kinks to work themselves out through user reports.
They chose option 2. It's really not that hard to grasp. | [
"In iOS 6, Apple replaced Google Maps with its own Apple Maps as the default mapping service for the operating system, and immediately faced criticism for inaccurate or incomplete data, including a museum in a river, missing towns, satellite images obscured by clouds, missing local places, and more.\n",
"In June ... |
How is light that is as old as the universe travelling to us from 13 billion light years away? | The universe was opaque until ~300,000 years after its formation. So the light from the CMB is around that age.
Now, imagine an infinitely long ruler. Pick any marking on that ruler and place yourself there. When the universe became transparent, a photon from 10cm from you gets sent in your direction, but due to the universe expanding, the space between markings keep increasing.
You and the light source are both still at the original markings, but the expansion has caused that 10cm to become billions of light years. When the photon eventually reaches you, it must appear to originate from that marking which is now far away.
P.S. There is no center of the universe. | [
"The light took much longer than 4 billion years to reach us though it was emitted from only 4 billion light years away, and, in fact, the light emitted towards the Earth was actually moving \"away\" from the Earth when it was first emitted, in the sense that the metric distance to the Earth increased with cosmolog... |
why is the minimum age for ‘adult’ medicines usually 12? not 18 or 21? | Because a lot of pharmaceuticals are dosed by patient weight. At 12 years old you are nearly full size. | [
"The most frequently reported drugs that have been associated with the development of AGEP include penicillin, aminopenicillins, macrolides, quinolones, sulfonamides, hydroxychloroquine, terbinafine, and diltiazem. A more complete list of drugs sorted by their intended actions are:\n",
"The initiation of drug and... |
How long after sperm enters the egg does it take to create the DNA for the baby? | The term you're looking for is the "zygote"; this is the first cell that properly has all 46 chromosomes. In general, this takes about 12 hours to form after the sperm cell has entered the ovum.
As to whether it's the "start of a life", I guess you'd have to define what life is. Both the sperm and oocyte prior to fertilization are "alive", and the zygote that's made is also "alive". Perhaps you mean "human life"? Well then you'd need to define a human. | [
"In contrast to oogenesis, the production of sperm cells is a lifelong process. Each year after puberty, spermatogonia (precursors of the spermatozoa) divide meiotically about 23 times. By the age of 40, the spermatogonia will have undergone about 660 such divisions, compared to 200 at age 20. Copying errors might ... |
What connection is there between the esophageal sphincter and your ears? | Are you referring to the upper esophageal sphincter or the lower? | [
"The external ear openings are covered with fur and do not have a pinnae. The nostrils are small vertical slits right below the shield-like rostrum. Although the brain has been regarded as very primitive and represents the \"lowliest marsupial brain\", the olfactory bulbs and the rubercula olfactoria are very well ... |
farting and its relation to poop. | > what purpose does farting serve?
Farting serves the purpose of releasing excess gas in your digestive system. These gases are generally produced by (beneficial to you) bacteria that live within your digestive system
> Why do they smell identical to the shit that I would imminently blast out?
A human perceives smell by directly having relevant particles enter the nose. When you smell poop, you're detecting poop-particles entering your nose. When you smell farts, you're detecting those same poop-particles entering your nose. | [
"Originally, the various Mandarin Chinese words for \"excrement\" were less commonly used as expletives, but that is changing. Perhaps because farting results in something that is useless even for fertilizer: \"fàng pì\" (; lit. \"to fart\") is an expletive in Mandarin. The word \"pì\" (; lit. \"fart\") or the phra... |
Why did none of the southern states have ballots for Lincoln in the 1860 election? | Something to keep in mind is that printed, government-supplied ballots happened relatively late in our political process. In 1860, one would vote by writing out a ballot for a candidate or slate of candidates, or alternatively by using a ballot that was printed in a newspaper or similar publication or handed out by a candidate's supporters at the polls. So Lincoln not appearing on ballots in the South is fairly normal; he was so unpopular there that few people would have dared to write him in or publish a ballot for him. | [
"Among the slave states, the three states with the highest voter turnouts voted the most one-sided. Texas, with five percent of the total wartime South's population, voted 75 percent Breckinridge. Kentucky and Missouri, with one-fourth the total population, voted 73 percent pro-union Bell, Douglas and Lincoln. In c... |
Can somebody explain possible reasons why "Super Luminous Supernova" differ from the garden variety supernova? | I mean... the best source is probably [the paper](_URL_0_) itself.
But, **TL;DR** we don't really know yet. It seems too energetic for most models, so the theorists will need some time to adjust.
> Only within the past two decades has the most luminous class of supernovae (super-luminous supernovae, SLSNe) been identified. Compared with the most commonly discovered SNe (Type Ia), SLSNe are more luminous by over two magnitudes at peak and rarer by at least 3 orders of magnitude.
> The power source for ASASSN-15lh is unknown. Traditional mechanisms invoked for normal SNe likely cannot explain SLSNe-I. The lack of hydrogen or helium suggests that shock interactions with hydrogen-rich circumstellar material, invoked to interpret some SLSNe, cannot explain SLSNe-I or ASASSN-15lh.
> Another possibility is that the spindown of a rapidly rotating, highly magnetic neutron star (a magnetar) powers the extraordinary emission. The total observed energy radiated so far (1.1 ± 0.2 × 10^(52) ergs) strains a magnetar interpretation because, for P ≲ 1 ms, gravitational wave radiation should limit the total rotational energy available | [
"Theoretical studies indicate that most supernovae are triggered by one of two basic mechanisms: the sudden re-ignition of nuclear fusion in a degenerate star or the sudden gravitational collapse of a massive star's core. In the first class of events, the object's temperature is raised enough to trigger runaway nuc... |
if earth's orbit is elliptical, how is it that summer occurs when earth is furthest from the sun, and spring and fall, when earth is closest to the sun, is cooler than summer? | The change in orbit is more or less negligible. You're talking 3 million miles out of about 91 million miles, about a 3% change.
The tilt of the Earth 23.4 degrees. Now think about shining a flash light directly at the wall. It makes a spot right? If you tilt the angle around 30 degrees what happens? The spot stretches out, it covers twice as much ground as it did when you were pointing straight.
But the flash light didn't change its power level, the 'spot' is still delivering x energy to the wall, over twice as much area. So any individual 'unit' of that spot is receiving half the energy it was before.
While not the only factor, that's a big one. Any given spot on the surface in winter is receiving far less energy than it does in summer. | [
"The Earth's orbit is elliptical, with the Sun at one focus; lines drawn through the summer and winter solstice; and the spring and autumn equinox; intersect with the sun at right angles. The Earth is closest to the Sun (perihelion) near the northern hemisphere winter solstice. The earth moves faster through its or... |
-why is that if you get distracted, your muscles become weaker? | Grip strength is a voluntary muscle movement, therefore by distracting them you are taking their mind off that action and so the signal to it will be decreased. | [
"When concentrating on a visually intense task, such as continuously focusing on a book or computer monitor, the ciliary muscle tightens. This can cause the eyes to get irritated and uncomfortable. Giving the eyes a chance to focus on a distant object at least once an hour usually alleviates the problem.\n",
"Ear... |
What unified the Austrian-Hungary Empire - Religion, Culture, etc.? | It was conquest! Always conquest.
The Austrian Empire, or the Austro-Hungarian Empire, had its roots with the Habsburgs, and the Duchy of Austria. Austria and Vienna lay on trade roots coming east out of Italy, North out of the Balkans, and South and East out of the Baltics/Ukrainian steppe. Throughout the Renaissance and Early Modern period, this made Austria wealthy and powerful. The Habsburgs, Austria's ruling family, also gained tremendous political power across most of Germany, they became the Emperor of all of Germany. Austria used this power and prestige to spread their rule across southern and eastern Germany. They joined the thrones of Bohemia and Hungary to the Austrian one, giving Austria de facto rule over the area, while northern Italy was drug into Austria through a series of wars, and an advantageous marriage in Spain, which for a time unified the Austrian and Spanish thrones.
But all this power, wealth, and prestige also made Austria a target. It waged several notable campaigns against the Ottoman Turks, who after toppling the Byzantines continued to push north through the Balkans. Austria continued to strengthen its southern border, as well as Hungary's southern border, to prevent [serious Turkish invasions](_URL_0_). Thus Austria began to see itself as the traditional defender of Christianity in the Balkans, as well as the defender of Europe against the Islamic Turks.
So really, Austria, and later Austro-Hungary, was a polyglot empire because Austria expanded in such a haphazard and seemingly random way. The most important connecting thread was always "what is best for the Habsburgs?" who sat at the top of the whole pyramid. In the Renaissance, it made Austria a dynamic political and military power, which hung a curtain across southern Germany. But following the Thirty Years Wars, and especially after the Napoleonic Wars, the multitude of nationalities, religions, political and social ideas, and ethnic alignments all made Austria a strange and unhealthy nation. The Habsburgs continued to rule as if the Austrian Empire were still the "Habsburg Lands", which you sometimes see printed on older maps of the Renaissance. This led to the breakdown of Austria, which really culminated in the July Crisis of 1914, which directly caused the conflict which would destroy the Austrian (at that point Austro-Hungarian) Empire in 1918. | [
"The \"Austro-Hungarian Compromise of 1867\" created the personal union of the independent states of Hungary and Austria, linked under a common monarch also having joint institutions. The Hungarian majority asserted more of their identity within the Kingdom of Hungary, and it came to conflict with some of her own m... |
why is it so much easier to spend money than to earn it? | Because most employment will only pay you a set amount for an hour's work, limiting you in how much money you can make in a span of time, but you can never exhaust the human race's output of purchasable goods. | [
"It has been argued that money cannot effectively \"buy\" much happiness unless it is used in certain ways, and that \"Beyond the point at which people have enough to comfortably feed, clothe, and house themselves, having more money – even a lot more money – makes them only a little bit happier.\" In his book \"Stu... |
What is the process for a new atom or element to form, specifically from the beginning when there was only hydrogen and helium? | > If all matter began from hydrogen and helium, how did we end up with 120+ elements?
There are 118 known elements, and some of them don't occur in significant amounts in nature.
> Is it possible to create a specific element by mashing x amount of protons, neutrons, and electrons together?
Yes, although there are typically easier ways of producing a given element. We have many different kinds of nuclear reactions in our arsenal, and many stable (or nearly-stable) nuclides that we can use as a starting point.
> Obviously I know this is not how it works AT ALL but how could other elements form from just 2 elements?
[Here](_URL_0_) is a chart of most of the currently-known elements, with the primary production mechanisms shown. In these astrophysical sites, like neutron star mergers and supernovae, there are complicated networks of many nuclear reactions and decays happening. They produce many different isotopes of many different elements. | [
"Since there had been no previous star formation to create other elements, protogalaxies would have been made up almost entirely of hydrogen and helium. The hydrogen would bond to form H molecules, with some exceptions. This would change as star formation began and produced more elements through the process of nucl... |
why do we try to keep people in vegetative states alive, who are not going to recover? | There's several reasons. It's the medical team's ethical and professional duty to maintain the person's life; they have a duty of care to the patient. It could be considered medical negligent or even murder/manslaughter if they ended the person's life. Also, they can't say for sure whether the person will recover or not. | [
"3. Most people want to be kept \"alive\" by machines. Most people don't want to drain their family's funds to keep them alive especially when they are in a persistent vegetative state with no possible chance for recovery. In these cases, it is often weighing the risks and benefits of keeping the patient breathing,... |
why is it in the ingredients section, producers use ingredient a and/or b? do they know what they are putting in the food? | They either have multiple facilities with different suppliers or they alternate as the market price fluctuates.
They do know internally what went into what batch for traceability purposes, but they don't want to print different labels. | [
"An ingredient is a substance that forms part of a mixture (in a general sense). For example, in cooking, recipes specify which ingredients are used to prepare a specific dish. Many commercial products contain secret ingredients that are purported to make them better than competing products. In the pharmaceutical i... |
how having a good lawyer can get you out of serious charges. | The system has a lot of red tape that requires a lot of hands to do things. Someone forgot to sign off on a custody chain document, a tried police offer mistypes a report or something is left out when it should have been locked. The more money you have the more resources you have.
High price lawyers have investigators, (typically ex-L.E.O.s) and teams of people that review every detail of the process and go the extra length. All this is billable hours and as long as the client can afford it they will throw man power till something comes up. Most people who are guilty get off on these types of technicalities because a public defender or middle to low class citizen can not afford to go to these lengths.
| [
"However, most jurisdictions have exceptions for situations where the lawyer has reason to believe that the client may kill or seriously injure someone, may cause substantial injury to the financial interest or property of another, or is using (or seeking to use) the lawyer's services to perpetrate a crime or fraud... |
the interstellar medium is hot? 54,000 degrees f? how is this possible? | Key phrase: **near**-vacuum. The interstellar medium is so thin that it can be treated as a vacuum for all practical purposes, but it’s not a perfect vacuum. It contains the occasional particle, and such particles can be measured to derive a temperature. | [
"In all phases, the interstellar medium is extremely tenuous by terrestrial standards. In cool, dense regions of the ISM, matter is primarily in molecular form, and reaches number densities of 10 molecules per cm (1 million molecules per cm). In hot, diffuse regions of the ISM, matter is primarily ionized, and the ... |
what would it take to change an atom? | Yes, bombarding with neutrons is one of the ways, but it's really slow.
The same process happens when iron is created in the star's core. It starts collapsing so quick that the elementary particles are being crammed inside the atoms, changing iron to heavier metals like gold and uranium. | [
"Electrons can also be completely removed from a chemical species such as an atom, molecule, or ion. Complete removal of an electron from an atom can be a form of ionization, which is effectively moving the electron out to an orbital with an infinite principal quantum number, in effect so far away so as to have pra... |
what's so great about kevin bacon? | I'm not so familiar with him myself, but just by the sheer volume and variety of films he has done, it's easy to pick something you like. Try typing "bacon number [name of another actor]" into Google, it will quickly became apparent just how well connected and involved he is. | [
"Bacon is a commentator on e-health and patient feedback. In June 2012, he formed part of a UK delegation invited to Washington for the Health Datapalooza, a US health data forum attended by UK health secretary Andrew Lansley, US President Barack Obama and Jon Bon Jovi. The discussion centred on how the two countri... |
why does a standing bike fall down but a moving bike does not? | It's not just gyroscopes that others have mentioned. In fact, this actually plays a very small role, and it is still easy to ride a bike where there is a counter rotating wheel designed to eliminate all gyroscopic effects.
It does play a role in a normal bike, but only when you're going very fast. The main advantage the gyroscopic effect gives is making it easier to control the steering.
There are several mechanisms in play. Indeed you'll sometimes hear that scientists don't know how bicycles work, but that isn't really true.
The reality is the maths just gets quite complex.
[minute physics has a great video which answers your question](_URL_0_)
Essentially, bikes are designed so that the front wheel will automatically turn into the direction it is leaning, pushing the bike into an upright position again if it is moving forward.
If it is not moving forward, it will fall over. | [
"Even when staying relatively motionless, a rider can balance a bike by the same principle. While performing a track stand, the rider can keep the line between the two contact patches under the combined center of mass by steering the front wheel to one side or the other and then moving forward and backward slightly... |
Do we know why there is nothing left of the Circus Maximus in Rome when compared to many other structures from the area? | Contrary to popular belief, more of the Circus Maximus survives than one might think. The "floor" level of the race track is now about 10 meters below ground level, and has never been systematically excavated. The *spina* (the central median of the track) was partially dug in 1587 on the orders of Pope Sixtus V. They were looking for the great Egyptian obelisks which had once adorned it, and found two of them: the bronze age granite obelisk taken by Augustus from Heliopolis, which now stands in the Piazza del Populo; and the massive, 522-ton obelisk originally quarried under Thutmosis III (1500-1450 BCE) for the temple of Amon at Karnak, and now standing in the Piazza S. Giovanni in Laterano. In modern times, the starting gates at the west end were briefly excavated (1908) and then reburied.
There have been two major excavations of the still-extant seating on the east end (1930 and again 1979-88), which revealed a confusing series of Trajanic and later rebuildings. It was, apparently, a structure which underwent frequent renovation. From those excavations it also seems apparent that the vast majority of the highest banks of seats, which remained above ground level, were robbed out in the early Medieval period and taken elsewhere, probably for building material. Seats for 250,000 spectators' backsides is a lot of marble, after all.
The last races were held in 549 CE by the Ostrogoth Totila. Thereafter, the structure seems to have fallen quickly into disuse. In the early Medieval period, the area was used as grazing and farmland, and the seating structures were converted into a variety of industrial works. The whole area was cleared out and put in its present, relatively cleared state in the early 20th century.
Why hasn't Italy excavated more of the Circus? First, there is not much new to discover there which is easily accessible. Second, money, which Italy does not have much of these days, especially for archaeology. Third, the space is popular and frequently used (I saw Sting perform there in 2004).
Why do [some structures](_URL_0_) survive so well, while others virtually disappear? The christian church played a big role in the preservation or destruction of many ancient monuments. If it became sacred to the christians, it generally survived and was maintained; if not, then most places lacked the will or the funds to upkeep large and useless old pagan edifices. The local attitude towards preservation, for whatever reason, also played a role, as well as their access to sufficient building materials.
Unfortunately, two of the best and most recent sources are not in English. One is Marcattili, *Circo Massimo : architetture, funzioni, culti, ideologia* (Roma : L'Erma di Bretschneider, 2009); the other is Polt, *Circus Maximus : das gesammelte Werk ; Geschichten, Stücke, Monologe und Dialoge* (Zürich : Kein & Aber, 2002). | [
"Given the size of the Circus, as it happened in almost all Hispanic-Roman cities, it was located on the outskirts of the walled enclosure. It is certain that from the city there was a causeway to the circus, which has not been found.\n",
"Mérida's circus remains very well preserved. As is true with the Circus Ma... |
Did Vikings prefer sword and shield or two handed in the battlefield | The favorite weapon set would be spear and shield, usually with some sort of knife or - if you could afford it - sword in case you needed to get more up-and-personal.
Fighting in the Viking Age relied heavily on shield walls - tight lines of men standing close together and protecting each other with their shields, much like the earlier Greek hoplite phalanx. And just like a hoplite phalanx, the most useful weapon was a spear - it gave you reach, was ideally suited for quick hard stabs, and could (depending on the size of the spearhead) be lighter and quicker than a sword (Viking Age swords tended to be about 2.5lb / 1.1kg; a spear with a moderately sized head and a light ash or hazel shaft could weigh less and be balanced more ideally for a thrust). Most importantly, spears gave each fighter the reach to support the person on either side, and to reach gaps between shields to the right and left instead of being forced to try to get around the shield immediately in front of him. Swords are much less useful in this style of fighting.
The goal of a shieldwall, however, was to push through the other side's formation and get them broken into smaller groups (and hopefully terrify them into running away), at which point swords and long knives (seaxes) might become more useful (though I've seen a fair number of early medieval wounds in the back from spears, so even then they continued to be useful).
And of course, spears can also be thrown. Some were designed specifically to be javelins, but many more appear to have been rather versatile (so you could use it either way). And we have textual accounts of warriors starting off a battle by throwing spears, but keeping one back to use when the fighting became hand-to-hand (the [Battle of Maldon](_URL_0_) is particularly worth a look, if you want to read a great war poem with good descriptions of Viking Age fighting).
Spears were so common that viking age stories like Beowulf refer to especially reliable soldiers as aeswiga ('spear warrior'), and whole people groups as the 'Spear Danes.'
There were other options besides spear and shield - we have people buried with axes that were pretty clearly designed to work better as weapons than tools (some made for use in two hands, toward the end of the Viking Age), and there's a Pictish stone carving showing a warrior with a spear in two hands instead of the more typical one. You don't really see 2-handed swords in this period, however, perhaps because the metallurgy required to make such a long and strong piece of steel was still in its infancy in western Europe, but likely also because the shield remained such an important point of a warrior's social status, enabling him to fight in the shieldwall and, in some early medieval law courts, a required proof of his good social standing. | [
"The Viking Age sword was for single-handed use to be combined with a shield, with a double edged blade length of up to 90 cm. Its shape was still very much based on the Roman spatha with a tight grip, long deep fuller and no pronounced cross-guard. It was not exclusive to the Vikings, but rather was used throughou... |
in the 1960s did most normal Russians still claim to believe in communism's superiority? | When talking about Russian perceptions of Communism you have to be careful who you're talking about. I think at no point besides perhaps late 1917 would peasants have positive opinions of Communists, and that was simply because they weren't the Provisional Government. The Peasants, like most of the Russian Empire, did not get along very well with the Bolsheviks during their rise to power and the 1921-1922 peasant revolts against Lenin were particularly brutal affairs. The status of workers is more controversial, they by and large believed in Communism but not Bolshevism and this brought the Workers Soviets into a series of brutal confrontations with Lenin's forces during and after the Civil War. What the former ruling elite, nobility, clergy, and conservatives thought of Communism is rather obvious.
Stalinism and its measures such as forced collectivization and the great terror undoubtedly contributed to mass resentment against Communists, particularly among those ethnic minorities that suffered the worst under Stalin (Ukrainians, Baltics, Belorussians). These regions became hotbeds of anti-Communist activity, so much so that they initially welcomed the Germans as liberators (though life under German occupation was soon discovered to be hardly preferable).
I think the heyday of Communism among the Soviet Empires various populations would have been the Khrushchev era in any regard, particularly the early 60s. De-stalinization, economic improvement, a spirit of national unity (not achieved among all obviously) following their victory in WW2, and relaxing repression. I wouldn't say this meant the majority of the population "believed" in Communism, past experiences with Communism always made the Soviet people weary of Marxists. However there was certainly a spirit of "things are getting better", which unfortunately was undone with Brezhnev and the era of stagnation.
Though it needs to be said Khrushchev was hardly a messiah or a liberal-democratic ruler. He was a Stalinist who renounced Stalinism mostly because of his own personal trauma/disdain for Stalin and never lost the thuggishly banal ruling policies of Stalins inner circle. He did however make a number of wise decisions (along with other unwise ones, such as the invasion of Hungary and Cuban Missile Crisis) which probably helped him rule during the Soviet Unions peak.
| [
"Finally, there is a human capital dimension to the failure of post-Soviet reforms in Russia. The former Soviet population was not necessarily uneducated. Literacy was nearly universal, and the educational level of the Soviet population was among the highest in the world with respect to science, engineering, and so... |
why does hot chocolate mix/powder stay dry even when milk or water is poured on top of it? | Water likes to stick to itself. That's why the surface of water and water droplets is smooth.
Powder are full of little tiny holes. For water to go into the holes it would have to make a little spike of water. The water would rather stick to itself then make the spike. | [
"Alternatively, the milk can be dried by drum drying. Milk is applied as a thin film to the surface of a heated drum, and the dried milk solids are then scraped off. However, powdered milk made this way tends to have a cooked flavour, due to caramelization caused by greater heat exposure.\n",
"A second type of ca... |
at what point does the flow of air on an object go from cooling it down to heating it up due to friction? | Never, it isn't friction but [air compression](_URL_0_) that heats the object.
As for at what point it out-factors the effect of the air whisking heat away, it depends on the shape. Basically a 'bad' aerodynamic shape will squish a lot more air than a 'good' aerodynamic shape, which will allow the air to flow around it without getting too squished. | [
"A surface loses heat through conduction, evaporation, convection, and radiation. The rate of convection depends on both the difference in temperature between the surface and the fluid surrounding it and the velocity of that fluid with respect to the surface. As convection from a warm surface heats the air around i... |
the cause of the geometric patterns formed in sand with a tone generator | [Standing waves](_URL_2_)
If you shake a string at right frequency "knot" points will form that stay stationary.
This is due to the wave created by the shaking and the wave reflected from the other end interfering with each other.
Video: Standing waves on a string _URL_1_
Objects that are more complex than a string will have different kind of standing waves on them. They too will form knot points that are stationary (or move only very little).
Examples for a circular surface: _URL_0_
The sand will move away from the areas that move alot and accumulate on the stationary areas. | [
"From the physical-mathematical standpoint, the form of the nodal patterns is predetermined by the shape of the body set in vibration or, in the case of acoustic waves in a gas, the shape of the cavity in which the gas is contained. The sound wave, therefore, does not influence at all the shape of the vibrating bod... |
Commercial kitty litter was invented in 1947. Where did house cats pee and poop before then? | If your cat was an indoor cat, you would likely provide them some sort of absorbent material. In the 1922 *Feeding and Care of the Domestic and Long-Haired Cat*, the following advice is offered:
> Each room should also contain a fair sized granite pan, partly filled with sand or sawdust. I prefer saw dust as it does not hold moisture as long as sand and is free from fleas.
Similar advice was offered in the 1921 *Your Dog and Your Cat, How to Care for Them: A Treatise on the Care of the Dog and Cat in the Home*, with the author writing that:
> A pan of sawdust, sand, or torn bits of paper should be kept in some convenient place for their use in attending to their functions. They must have free access to this if they are to be clean with their habits.
Likewise, the 1889 *Our Cats and All About Them* reminds readers that:
> Always have a box with dry earth near the cat's sleeping place, unless there is an opening for egress near.
I do find amusing how much the authors of these old manuals strive to *avoid* directly stating what these are for. It is clear enough, of course, but the language is still euphemistic, speaking of 'their functions' and 'moisture'. Vague allusions to the 'cleanliness' of the cat are common too, such as the 1895 guide which notes:
> The cat is an excessively cleanly animal, and when housed should be provided with means for remaining so. A small box, or -- what is better, as it can be well washed -- a galvanized flat pan such as used for roasting meat, should be placed in some well-ventilated corner out of sight, and kept filled about an inch deep with sand, clean earth, or sawdust. Perhaps the latter is preferable, as it can be burned. The litter should be changed frequently.
Also going on to note that for kittens, a bed of peat-moss litter has the "desired effect" of teaching them cleanliness, when changed at least once a day.
While hardly a scientific survey of the literature, I found in only a single book, 1887's *The Cat* , reference to actual product in noting that the creature is "*guided by a peculiar instinct to scratch up earth for the purpose of hiding their excrements*" and that indoors even will do their best to avoid the carpet, "resort[ing] to cinders or coal-dust"*. They go on to note similar ways to accomodate this as others did, writing that:
> It is a good plan to have a large flower-pot saucer - the larger the better, but not less than fifteen inches in diameter - kept in some suitable corner, with a little clean garden-earth or sand in it. It need not contain much earth and it can be changed at will; but should not be allowed to become foul as to offend the cat.
Writing advice for owners of "catteries", that is, breeders with large collections of cats, the most practical advice in 1901 *Domestic and Fancy Cats* is simply that:
> Sanitary arrangements in these catteries are not so difficult, for the free access to the outside runs, if cats have been trained to habits of cleanliness, will be readily sought for and discovered by them.
But recognizing this isn't always possible, the author continues:
> Still it may be desirable to provide receptacles, and I know of no better than the large stoneware pans supplied by Spratts Patent, or zinc trays can be mate whatever size and shape is desired. Opinion varies as to what these are to be filled with. I have from the earliest period, and down to date, been an advocate of dry earth; some however consider sawdust as far and away the best, and only a few years ago I was informed by a large breeder that if earth and sawdust be placed in separate receptacles, sawdust will be selected by the cat. Be this as it may, I am still open to conviction of is efficacy, over Nature's deodorizer. An efficient deodorizer or disinfectant should always be kept at hand, such as Izal, Sanitas, Jeyes', or Lawes', which rank above most others.
Going back further into the 19th century, there is even stronger emphasis on the *cleanliness* of the cat, with an author in the 1870s writing that:
> Cats of the right sort never fail to bring their kittens up in the way they should go, and soon succeed in teaching them all they know themselves. They will bring in living mice for them, and always take more pride in the best warrior-kitten than in the others. They will also inculcate the doctrine of cleanliness in their kits, so that the carpet shall never be wet. I have often been amused at seeing my own cat bringing kitten after kitten to the sand-box, and showing it how to use it, in action explaining to them what it was there for. When a little older, she entices them out to the garden.
Of course, they later go on too note that a cat will *literally die* if they get too dirty, writing:
> I have known cats take ill and die from having their coats accidentally soiled beyond remedy.
This might be a bit excessive, but this emphasis on the 'instinctive cleanliness', as countless guides in the late 19th to early 20th century noted, was the "natural virtue which renders pussy so generally a favoured intimate of the household".
So the sum of it is that there was no one solution offered, but there was certainly a general consensus on the necessity of providing an indoor place for relief, and while the advice varied as to the specific material, be it sawdust, earth, or otherwise, it ought be something absorbent and changed frequently.
**Sources**
*Feeding and Care of the Domestic and Long-Haired Cat* by Ellen V. Celty and Anna Ray
*Your Dog and Your Cat, How to Care for Them: A Treatise on the Care of the Dog and Cat in the Home* by Roy Henry Spaulding
*The Cat, A Guide to the Classification and Varieties of Cats and a Short Treaties Upon Their Care, Diseases, and Treatment* by Rush Shippen Huidekoper
*Domestic and Fancy Cats: A Practical Treatise on Their Varieties, Breeding, Management and Diseases* by John Jennings
*Cats: Their Points and Characteristics, with Curiosities of Cat Life, and a Chapter on Feline Ailments*
*Our Cats and All About Them: Their Varieties, Habits, and Management, and for Show, the Standard of Excellence and Beauty* by Harrison Weir
*The Cat: Its Natural History; Domestic Varieties; Management and Treatment* by Philip M. Rule
This is just a sampling of texts out there, but you can find them and more on _URL_0_, HathiTrust, and Project Gutenberg.
Afterward: Looking through a lot of old books about cats and trying to find more references, I had to share one false positive hit for "sawdust" which ended up being about a ship's cat:
> Tuesday was flogging day; and to add, if possible, to the terror of the condemned wretch, after the gratings were rigged and the man stripped and lashed thereto, sawdust was sprinkled on the deck all round, to soak up the blood. But at every flogging match
> > “There sat auld Nick in shape o’ beast,”
> at least in the shape of Tom the cat, who would not have missed the fun for all the world. There on the bulwark he would sit, his eyes gleaming with satisfaction, his mouth squared, and his beard all a-bristle. He seemed to count every dull thud of his nine-tailed namesake, and emitted short sharp mews of joy when, towards the middle of the third dozen, the blood began to trickle and get sprinkled about on sheet and shroud. Though I never disliked Tom, still, at times such as these, I really believed he was the devil himself as reputed, and would have given two months’ pay for a chance to brain him. When the flogging was over, Tom used to jump down and, purring loudly, rub his head against his master’s leg.
Tom seems like *kind of a dick*. | [
"BULLET::::- Cat litter is one of any of a number of materials used in litter boxes to absorb moisture from cat feces and urine, which reduces foul odors such as ammonia and renders them more tolerable within the home. The first commercially available cat litter was Kitty Litter, available in 1948 and invented by E... |
why were there tons of super giant creatures like dinosaurs a few million years ago, but there aren't now? why did everything shrink in scale? even a lot of bugs were much bigger then. did earth's gravity change? | The prevailing theory is that our atmosphere had a lot more oxygen in it at the time (right now it's just over 20%). This let animals grow larger, especially with the scale of insects. Since most of them don't have a true respiratory system, they take in oxygen through their skin/exoskeletons. By having more O2 in the atmosphere, that made it easier to sustain larger size. | [
"Recent theories propose that theropod body size shrank continuously over a period of 50 million years, from an average of down to , eventually evolving into modern birds. This was based on evidence that theropods were the only dinosaurs to get continuously smaller, and that their skeletons changed four times as fa... |
Are the any dinosaur hybrids ie (like the mule is a hybrid of a male donkey and a female horse)? | animals in the wild hybridizing naturally is pretty rare, and a terrestrial animal becoming a fossil is also (in the scheme of things) pretty rare
it's certainly possible but i've not heard of such a thing - which makes sense, as finding any evidence would be incredibly unlikely | [
"Equine species can crossbreed with each other. The most common hybrid is the mule, a cross between a male donkey and a female horse. With rare exceptions, these hybrids are sterile and cannot reproduce. A related hybrid, a hinny, is a cross between a male horse and a female donkey. Other hybrids include the zorse,... |
the united states' corporate taxes, and why ours are the highest in the world. | The American tax code is like swiss cheese. There are so many loop holes that in order to actually **make** money off of it, you need to raise the overall tax rate so high that it outweighs the loop holes. | [
"Some argue that the U.S. corporate tax rate at 35% is the \"highest in the industrialized world\", while others argue it isn't. The rate varies from sector to sector, and can be as low as 21% in the manufacturing industry. A high tax rate would place the U.S. at a \"competitive disadvantage in the global marketpla... |
Thoughts on "The Forge of Christendom" by Tom Holland? | I'm working through Tom Hollands 'Persian Fire' and he is very honest in the forward about the amount of embellishment and speculation in the work.
I'm reading this with a few other people, and while they find it significantly more enjoyable to read, we all feel that we're reading exactly what he said, speculation and embellishment. I don't know if that helps here at all.
Hopefully a historian will hop in. | [
"His life work was the establishment of the catechism course in his church of \"Unsere liebe Frau\" (Our Lady), whereby he has merited a place in the history of catechism. The origin and growth of this foundation is described in his large work \"Die gesamte christliche Lehre in ihrem Zusammenhang\" 'the whole Chris... |
what exactly is the bridge of the song? | There are two ways to define the "bridge." A little music theory 101:
Think of how your favorite songs are built. There are choruses (which sound the same each time) and verses (which sound a little different each time). They might be put together like this: ABABA, with A being the chorus and B being a verse.
However, to spice things up, sometimes songs throw in another element - a "bridge." This is a section different from the chorus or verse to make things a little more interesting. So if I wanted to add a little variety to my song, it might go ABACABA, with C being the bridge.
Let's look at an example - Weezer - If You're Wondering If I Want You To. This is a good example of simple song structure. It goes BABACA, with A being the chorus, B is the verse, and C is the bridge.
That's how the term "bridge" is usually used in modern music, at least. There's another meaning for this term. It can also mean a part of a song that leads up to the chorus. Example: Michael Jackson - Billie Jean. When the verse changes noticeably and he says, "People always told me / be careful what you do..." that's the bridge. It's getting you ready for the chorus.
Also, with this other definition of the "bridge," in the Weezer song, when he starts saying, "When the conversation stops..." that part is the bridge. | [
"\"Anyone Seen the Bridge?\" (abbreviated as \"ASTB\") is an instrumental by the Dave Matthews Band, usually played as segue between two songs during a concert. It is an instrumental jam played by the entire band, with scat singing by Dave Matthews. Performances of the tune today typically are heard between \"So Mu... |
how does a temp agency make money? | Company pays temp agency $15/hour-head. Agency pays worker $8/hr | [
"The role of a temp agency is as a third party between client employer and client employee. This third party handles remuneration, work scheduling, complaints, taxes, etc. created by the relationship between a client employer and a client employee. Client firms request the type of job that is to be done, and the sk... |
how does using a debit/credit card work when used internationally? | It displays in the currency of the ATM. So in the US its Dollars, in England its the Pound, in the Eurozone its the Euro and so on. | [
"In Canada, the debit card is sometimes referred to as a \"bank card\". It is a client card issued by a bank that provides access to funds and other bank account transactions, such as transferring funds, checking balances, paying bills, etc., as well as point of purchase transactions connected on the Interac networ... |
how does the volkswagen emission software work? | VW and Audi included software that could sense when the engine was being emission tested. Once a testing situation was detected, the engine was electronically governed to operate in a manner that would pass emissions testing - this would come at the expense of performance.
When the software detected normal operating behavior (daily driving), the safeguards were removed and the vehicle was allowed to pollute at 40x the allowed limit. The final result was increased MPG's and performance at the expense of reduced air quality.
A comprehensive FAQ can be found on [Jalopnik](_URL_0_). | [
"The business strategy of Volkswagen is to standardize platforms, components, and technologies, thus improving the firm's profitability and growth. For example, Audi uses components from their more pedestrian counterparts, sold as Volkswagen Group's mass-market brands. As an effort to place Audi as a \"premium\" ma... |
what is bio chemistry, and what do bio chemists do? | Biochemistry is, simply put, the study of the chemical reactions that underlie biological systems. Think of the way proteins are formed, or how glucose is broken down into ATP. Besides academic study and aid of related fields like pharmacology, biochemistry has a lot of industrial applications nowadays, such as the development of compostable plastics or biological remediation of pollution. | [
"Bioresource Chemistry and Bioenvironmental Science focuses on essential knowledge and application of various chemical substances with biological functions, and on developing a solid foundation in the chemistry and biology of various ecosystems (from the terrestrial land to the seas).\n",
"Biochemical engineering... |
why are astronomers now using radio telescopes more than optical ones? | Light and radio waves are the same thing, photons.
Optical telescopes were used in the past because they were easy to make, and you don't have to process the image, you just take the photo and then look at it.
Radio telescopes pick up light in the 'radio' range of the light spectrum, the data needs to be processed and interpreted for us to 'see' what they are looking at.
We use Radio telescopes over Optical telescopes for certain things, because radio frequencies have a longer wavelength, and have less chance of interacting with things, or getting blocked. It's basically easier to pick up a radio signal than visible light. (Think of how radio can pass through the walls in your house to reach your stereo, but your tv remote doesn't work if someone walks in the way)
There are many types of Telescopes, including Infrared, Ultraviolet, xray, etc. | [
"Because radio telescopes have low resolution, they were the first instruments to use interferometry allowing two or more widely separated instruments to simultaneously observe the same source. Very long baseline interferometry extended the technique over thousands of kilometers and allowed resolutions down to a fe... |
how do recoilless rifles work? | When the round is launched, it blows expanding gas out of the back of the tube. This balances the expanding gas that blows out of the front, along with the round.
It can't be used in tanks and the like because the back of the tube is literally where the crew sits. It would kill everyone inside.
It's also just not necessary. The weight of the tank takes the brunt of the recoil, along with other systems designed to minimize it. | [
"A recoilless rifle (RR) or recoilless gun is a type of lightweight artillery system or man-portable launcher that is designed to eject some form of countermass, such as propellant gas, from the rear of the weapon at the moment of firing, creating forward thrust that counteracts most of the weapon's recoil. Technic... |
why do night vision cameras cast a shadow? | Many night vision cameras use an infrared lamp to illuminate the scene being recorded. You can't see that light, but the camera can. Hth. | [
"Sometimes a shadow can be used to create a visual effect. Areas of the bluescreen or greenscreen with a shadow on them can be replaced with a darker version of the desired background video image, making it look like the person is casting a shadow on them. Any spill of the chroma key color will make the result look... |
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