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when you cancel a download where does the data already downloaded go ?

The space allocated for the entire program, it just becomes unmarked and available for rewriting.

Does Space-time have an elastic modulus?

The relationship between the bending of space-time and mass-energy, as you say, is that the Ricci tensor minus its trace times the metric (where the metric is a 4x4 matrix that describes the pythagorean theorem through spacetime and the Ricci tensor is a differential function of the metric) is equal to a constant (8 pi G/c^4 ) times the stress energy tensor, which is an extension of the stress tensor from mechanics. Spacetime does have elastic (and viscous) properties, which are manifested as gravitational radiation. I'm not sure you can easily ascribe a modulus to it, but the shear induced by a change in the distribution of mass is proportional to the second time derivative of the moment of inertia.

- what is the method for calculating how much sand you need in an hour glass of various sizes and times?

Though that is needed what’s more important first is the size of the tight canal they have to travel through, and the size of the grain. Then the volume of sand can be calculated

Is gravity the only force that can produce a black hole? Could an extremely strong electomagnetic field create one? Also, is there a way to vary the strength of the weak and strong force in the lab? Could these forces be adjusted in a confined area?

According to the theory of General Relativity, it is mass-energy which warps spacetime, and if that energy comes in the form of photons, it can form an event horizon just like with matter, forming a [kugelblitz](_URL_0_).

How does blubber keep mammals warm despite nerves in the skin that sense the extreme cold?

There is a tolerance system involved. Whales don't dive from land to water so their receptor have time to adjust when they enter cold water(they enter gradually). For seals, bears and other "furry" mammals there is an extra thin layer of air/water that gets trapped in the fur and acts as an insulating layer. Even if they jump into cold water the receptors "get used" to the temperature and their signals get blocked after a while and only get reactivated when their signal changes(water temperature changes).

what does it imply when i read that "patents will expire"?

I'm sure some people with patents would like that, but patents are first and foremost a way for *the public to buy inventions*, or rather information about the way inventions work. To get a patent, you have to tell the world how your invention works, and in exchange you get a limited time to be the only one who can market it (or you can license others to use it). After that time, the patented invention is in the public domain, free for anyone to make, use and sell.

Why do car horns sound like they do and which car was the first to make the sound we hear today??

Most modern cars use a dual tone car horn that actually produces two different notes. The interaction of these two frequencies creates harmonics and are easier for humans to distinguish from general noise. Because of historic manufacturing legacies, most car manufacturers have the same tones in all their cars, and depending on the era, most cars of a single country of origin would have tones in the same key. These common horn keys (F, G & C) are all in the middle octaves, probably because it's easy for humans to hear (we've evolved acoustic and mental sensitivities to noises that are similar in tone to our voice). Most modern horns use a vibrating plate of metal to generate its tone, but trains and semi-trucks take advantage of their onboard air compressors to make really loud sounds.

is it possible to freeze fire?

As fire is hot gas, freezing it would just give you frozen CO2 and maybe some soot.

What are we to make of the story of the Israelites' slavery in Egypt and subsequent Exodus and its reflection on Ancient Israelite society?

As for the consensus, yes. I think this is generally the case that most believe that the Exodus was almost entirely fabricated on the basis of oral tradition. Personally, I’m disinclined from saying it was made up entirely whole cloth. The reason for this sets up the reasons for why I think it was written in the first place. As you’re already aware, the Exodus narrative is central—and has been central—to Israelite and Jewish identity. In the early stages of state formation, hopeful leaders need narratives they can use to rally support as they approach national identity. (E.g., as stupid as it was, “And who has a better story than Bran” would have worked at the beginning of rallying public support for the creation of Westeros—similar to how Aegon the Conqueror did, but I guess D & D kind of forgot how such things work. But I digress.) So, why was it written? Ultimately it’s a difficult question to answer, as any honest archaeological work will tell you there’s no proof for the event and so reconstructing such history is nearly impossible beyond being conjectural. So, my theory: there were traditional social memories of *some* kind of relationship between Egypt and what would become Israel. This shouldn’t be surprising, because we do have record of Egyptian involvement in the Levant thanks to the Merneptah Stela (usually cited as 1204 BCE) and the Tale of Wenamun. Merneptah is difficult because we don’t quite fully understand the determinative used with the name Israel. It means “people group,” but it appears in a larger list of cities destroyed by Pharaoh Merneptah. ¯\\\_(ツ)_/¯ It’s possible there was a very small, Proto-Israelite presence in Egypt at some point that would have served as the source of such memories, but we can’t be too certain. These memories were obviously derivative of multiple sources (hence the presence of what we call doublets—two slightly different accounts of the same story; e.g., did Moses receive the Law at Sinai or Horeb? Was his father in law’s name Jethro, Ruel, or Hobab?). These traditions were eventually put into writing, expanded, edited, and redacted to eventually come into their final form as we have it (read: them, there’s no singular source for us for these texts). These exodus traditions were used as a form of social identity construction—an integral part of state formation and preservation. The use of national literature would become far more important in later periods—especially for the Deuteronomist, who ***loved*** to use the Exodus as a central theme for explaining his perspective throughout the Deuteronomistic History (Joshua, Judges, Samuel, Kings). I don’t think it’s necessarily commentary on Israel’s relationship with Egypt as Egypt kind of falls off pretty significantly after the Iron I. I think it’s national literature, intended to construct social identity by constructing a literary Other. The othering process creates an in/out relationship that early Israelites could identify with—especially in light of the nearby Philistine threat during the Iron I–IIA, eventual Assyrian involvement in the southern Levant in the Iron IIB and later, Babylonian incursions and deportations in the 6th c. BCE, etc. A couple of sources that might help: I. Finkelstein, *The Bible Unearthed* — he’s a little over the top with the low chronology, but deals with a lot of important stuff in a very accessible way. W. Propp’s Exodus commentary is top notch in the Anchor Bible series. E: fixed a couple of typos.

I often hear people say that the Irish Potato Famine was more a genocide than a true famine. How accurate is this claim?

I had a chuckle to see another North Korea flair in this topic of all places. Cheers, /u/koliano! This isn't my area of expertise, so a really detailed answer is beyond me. However, the Irish famine is a pretty common topic while you're studying periods of mass hunger, and it was something I saw pop up occasionally while reading about the mechanics behind North Korea's famine (1994-1998). There's something that I think might provide some helpful context for your question -- namely, how we study and think about famine has changed a lot over the last 40 years, and the line between "genocide" and "famine" has gotten blurrier as we recognize that famine is not really an accident. So -- was the Irish "potato famine" a genocide against the Irish? **Short answer:** The English didn't commit genocide by the strictest definition of the term, but they did create the circumstances that led to the famine. **Long answer:** As others have pointed out, there's a troublesome and often politically-charged distinction to be made between genocide and famine: - **Genocide implies intent.** It's not enough for millions of people to die: Somebody has to *want them dead* and engineer a way to do it, or capitalize on a situation likely to result in mass death. Nobody wants to be told they were responsible for genocide; it's a severe blow to the moral and political authority of the country involved. The Turks resist efforts to characterize [what the Armenians call the "Great Crime"](_URL_1_) as genocide. Russia will tell you to fuck off when you raise the issue of the [Holodomor](_URL_3_) and Stalin's being a huge asshole to the Ukrainians. The Chinese government [only recently stopped censoring public discussion of the famine](_URL_6_) related to the Great Leap Forward. Nobody wants to admit to having committed genocide or -- if it's not genocide by the technical definition of the term -- anything that looks like it. - By contrast, **famine is seen as a tragedy that nobody could have prevented.** Crops fail. Drought happens. Diseases, predators, and wildfires kill livestock. Earthquakes and floods destroy your ability to move food around. Something bad happens that interferes with your society's ability to grow, store, or transport food, and lots of people die despite your best efforts. Famine is the second horseman of the apocalypse, perennial as the grass, cold and grimly present as its brothers pestilence, war, and death. It is ubiquitous in human history and the immutable lesson is that it can happen to anyone. Except it doesn't. Certain human societies have been strangely resistant to famine despite weathering the same shocks that caused mass starvation in similar circumstances elsewhere. Historians and economists had a collective "Eureka!" moment in the late 20th century when we realized that famine DOESN'T just happen, and that it probably never has. Hunger can happen despite your best efforts to prevent it, but *famine is the result of politics*. **Before we go any farther, we need to talk about a guy named Amartya Sen.** He's an Indian economist and historian who's written a lot of really famous and influential pieces about a variety of topics, and he was awarded the 1999 Nobel Prize for his work on welfare economics. In terms of popular reach, he's probably best-known for [a 1990 essay on "More Than 100 Million Women Are Missing,"](_URL_0_) which addressed the result of sex-selective abortions in Asia. However, in the academic world he's arguably most famous for [his work on famine in human history](_URL_2_), and in particular a theory that sounds bananas when you first hear it, and then more and more frighteningly plausible. I'll break it into two parts: - **Sen argued that no famine over the last 1,000 years can be attributed to anything other than primarily man-made causes.** This took a while to get traction; we're used to saying that X famine was caused by a flood, or Y famine happened because of a drought, etc. Sen pointed out that natural disasters and crop failures are actually pretty common, but famines aren't usually the result. Left to their own devices, humans are pretty good at finding and storing food as proof against unpredictable shortages. In order to create a famine, you have to have a bad, unstable, and/or corrupt political/economic system that can't weather a sudden shock and is thrown into crisis. We've gotten used to blaming the shock (e.g., the flood, the drought), when in reality it's just a convenient excuse. The real cause is the shitty and inflexible system that existed before it. - **Sen further argued that no famine has occurred in a democracy with a free press.** The basic idea is that government that isn't accountable to its people is notoriously unresponsive to its needs, and a free press is good at noticing and publicizing problems that government needs to address. There have been some quibbles over this, mostly related to pockets of continuing hunger in India, but for the most part this is a pretty uncontroversial theory. Sen published [his first work on famine in 1981](_URL_4_) and has studied the issue on and off since. His work has heavily colored subsequent discussions of hunger and the political systems that create/d it, and it's a big part of the reason we're disposed to evaluate past famines differently these days. Interestingly, the 1981 piece is primarily about [another famine that the British had a hand in](_URL_5_) (the 1943 Bengal famine) due to rice and transport ship confiscations setting off a price panic. **So let's consider the Irish potato famine :** Again, I have to leave the nitty-gritty details to someone with a better command of this period than I've got, but I can tell you about the commentary that the Irish famine attracts when historians and statisticians are discussing the mechanics of hunger in modern works. The potato blight has been commonly cited as the reason that the famine happened, and it's entirely true that it played a role. The lack of genetic diversity among the strain of potatoes being grown in Ireland at the time made the island incredibly susceptible to the blight. However, it was a classic example of a "shock" that revealed the underlying corruption in the economic system that surrounded it. The blight may have started the famine, but it didn't actually cause it (if that distinction makes any sense). **So what did cause it?** Britain's Corn Laws were an aggressively protectionist series of tariffs enacted with the intent to keep grain prices high for the benefit of domestic producers. (TL:DR: Landowners didn't want to compete against cheap grain from abroad and also had to pay their farm laborers a living wage, so Parliament levied high taxes on foreign grain and tweaked them as necessary to try to bump domestic grain to what they considered ideal prices.) The Irish poor (of whom there were many, for a variety of very complicated historical and socioeconomic reasons) were largely unable to afford grain as a result of the Corn Laws, and on the generally-small holdings they farmed (for which they paid punitive rents to largely absentee English landlords) could only grow potatoes in sufficient quantity to feed their families. The potato was thus the staple food, and the blight an utter catastrophe. When potatoes were no longer available, the poor burned through their meager savings quickly to buy grain, and when that ran out, they starved en masse. Parliament repealed the Corn Laws two years into the famine, but it was too little and too late, and also didn't address the other systemic issues (principally landlord exploitation) that contributed to the famine. So it's pretty apparent why the genocide/famine distinction is a touchy one here: - **Did the English commit genocide against the Irish?** Not as such. - **Did they create the circumstances that led to the famine?** Yes, and most historians judge the government's response to the famine as woefully inadequate, to compound the issue.

why do all drives or partitions defragment all files, but the system one (c: or other) is always fragmented, even if i just defragmented it?

Yes, there are some system files that can't be moved while the system is running. Also, the system partition is used all the time - programs always create and delete temporary files, which usually reside on the system drive. The same defragmentation software you used has a [boot time defrag](_URL_0_) option.

How much does color affect temperature? Details in post.

Color (or more specifically, frequency and wavelength) are supremely important when it comes to radiation heat transfer. Any time light strikes an object, three things can happen to the light. * The energy of the light can get absorbed by the surface. * It can be reflected off of the surface. * It can be transmitted through the surface. Any time radiation strikes an object, all three of those effects must add up to the amount of energy the light initially had ([First Law of Thermodynamics](_URL_0_) - Conservation of energy). Now, where it gets interesting is that a material's absorptivity, reflectivity, and transmissivity are unique to each material, but are also specific to the wavelength of the light. For an example, let's say that you're looking at a small piece of blue glass in a stained glass window. The blue glass is reflecting some of the light back out (the glistening of the sun off the outer surface.) Another portion of the light is getting absorbed by the glass. The portion of light that gets absorbed gets converted to heat (and a portion of this heat gets radiated back out of the material.) Whatever remaining light gets transmitted through the glass. This is the light you'll be seeing on the inside. The fact that the light transmitted through the glass was blue means that of all the light shone at the glass, the blue frequencies of light are allowed to pass through, while the portion of the light that was everything **BUT** blue was the component that was reflected and absorbed. For this reason, if you wear a black shirt in the sun, the shirt will absorb more light and will reach a higher temperature. While a white shirt will reflect more light than a black shirt would, white shirts have a tendency to become transparent when wet so if you're sweating, your skin will actually be exposed to more radiation in a white shirt than a black shirt even though the temperature of the white shirt will be lower.

Why do plants have longer lifespans than animals?

Differences in life spans across species, or even Kingdom, boundaries is a pretty fascinating topic of research. I've had some exposure to a researcher whose done some work with animals, but I'm not very up to date with the current state of the research. But I can talk about plants. One of the big differences between plant and animal cells is totipotency. Plant cells are totipotent, meaning that an individual cell, if isolated and grown on a suitable culture medium, can grow into a plant that is genetically identical to the mother plant. You can't really do that with animal cells. Granted, plant cells in the wild aren't necessarily exposed to some of those same conditions, so perennial plants retain stem-cell like meristematic tissue (e.g. dormant buds) that can be activated in case of damage to the rest of the tree. The ramifications of this for longevity is that any damage done to a plant can be fixed relatively easily. It's not like limb regeneration in some reptiles or other animals, it's like limb substitution. You can see the results after a big storm that removes a lot of limbs from a tree, where the tree then starts to grow very bushy with lots of new stems. The animal equivalent would be like cutting off your arm and having a new one grow out your chest. So damages done to a perennial plant aren't necessarily "fixed", but circumvented through creation of new structure. The other important thing about how plants respond to damage is that they have a sectored vascular system so that part of a tree (or other type of perennial) can survive even if the whole plant can't. If a human's peripheral limbs can't survive, we can amputate and the person will survive, but if any organs can't survive, the human dies. The other issue for some plants is the ability for clonal growth. A good example is aspen forests, where you might be looking at an entire forest of trees that originated from the same mother tree. If the original tree dies, the same genetic material from that tree persists in genetically identical clones. Some of my genes persist in my daughter, but not all of them, so she's not identical to me in a genetic (or even physical) sense. Of course, there's other factors that play major roles in determining life span that have to do with metabolism, resistance to factors that affect senescence, etc. I'm not sure if you can access [this article](_URL_0_), but it describes in pretty basic terms why trees can live so long relative to other organisms

why is it so hard to rip open a package with wet hands (even if it has a notch for ripping)?

When your hands are wet they are lubricated by the wetness. This reduces friction, which reduces your ability to grab and rip a package open.

At what point in history were women knowledgeable enough about their cycles to understand when they might be ovulating?

Well, of course many of them would not have known before my collection of all the knowledge in the Empire of our beloved emperor Vespasianus, long may he reign, in my well known encyclopaideia, the history of the natural world. In fact, I have gathered many strange and interesting phenomena about the female menstruation! Did you know that menstrual blood can reportedly have the most peculiar effects? It turns new wine sour, it can make crops barren, fruits fall of the trees when touched by it, and even whole hives of bees have been known to die! (see book VII, 15) I should probably warn you also, if you didn't know this already, that intercourse with a menstruating woman during a solar or lunar eclipse, or when moon and sun are in conjunction, can and probably will kill you (see book XXVIII, 23). Now, where was I? Ah, yes, conception! Well, it has long been understood that blood is necessary for the generation of new life. Aristotle informs us how the female blood quickened by the male sperm (which is the highest form of blood, cooked to its very essence - which women can't do, owing to their lower body temperature) will bring forth new life. You can read about this in particular in his *Generation of Animals*. Thus, when menstruation stops in their 40th or 50th year, they are no longer fertile. In any case, almost all my contemporaries agree with me^1 in that the chances for conception are the highest shortly after the beginning and towards the end of the menstrual cycle (book VII, 67). * 1 This was the state of the ancient medical knowledge on the subject - the real reason was unknown, since the mechanics of conception were viewed from a very idiosyncratic point, with blood and it's derivate sperm at the centre. Views differed about the nature of the female part in this, Aristotles view is of course very passive, while Galenos attributed sperm to the woman as well, having an equal part and thus accounting for the transmission of the mother's characteristics in the following generation. In any case, the circular reoccurence of menstruation and it's connection to fertility was well known at least to the educated circles.

Could constant cough lead to emphysema?

I am not aware of any studies that show cough alone can cause damage to the alveoli. I wouldn't expect to see a lot of alveolar damage due to chronic cough alone (in the absence of any kind of obstruction), anyway. The physical act of coughing is the result of compression of the lungs while holding the only opening (the glottis) shut, and then opening the glottis fast, releasing a blast of air. This will cause a backpressure in the lungs, but because the source of the compression is outside the lungs, each alveolus will experience pretty much the same pressure. Because neighboring alveoli will have the same pressure, there is no differential, you aren't going to get any tearing. Also, the violent movement in cough is an exhalation; a shrinking of the lungs. This means that the violent portion of the cough isn't stretching the alveolar walls. If anything, it's compressing them. HOWEVER...most of the time, chronic cough is just a symptom of something else; typically some kind of chronic obstruction, inflammation, or infection. And those will cause both alveolar damage *and* cough. Also, if there is an obstruction, you may get places where neighboring alveoli *do* have a pressure differential, and the wall can be stressed or rupture. So although chronic cough is often associated with emphysema, chronic cough is not known to be a cause of emphysema.

why do nearly all space photographs seem 2d?

Pictures create the illusion of depth using one or more of several methods, such as linear perspective, aerial perspective, etc., all of which are pretty impossible in astrophotography. Another issue is that the image is taken of an object millions of miles away, and the only background are the stars which are also millions of miles away. This makes it very difficult for your brain to even perceive depth or size. The lack of anything in the foreground and the lack of much of a background add to the "flatness" of the image.

Wouldn't large scale mining on the moon have a negative impact on Earth? Assuming large deposits of valuable minerals are found in it

No. The moon is simply way too big that mining operations as we know it could have any noticable impact on tides. The total amount of all mining humans have done on earth since ever is smaller than the margin of error we have on the our estimation on mass of the moon.

What will happen to a piece of wood, placed in a "pot"with no oxygen and then placed over a fire?

That's basically a way to make charcoal. By starving the wood of oxygen you allow the moisture and volatile compounds to be burned off leaving you with a mostly pure carbon. It's important that it has some kind of vent though because the steam and volatile compounds will pressurize the container.

Gravitational time dilation for solar systems relative to distance from galactic centre.

Well, the truth is that once you get far enough from an object's Schwarzschild radius, the effect isn't very significant. The equation for gravitational time dilation is: t_0 = t_f*sqrt(1-r_0/r) where t_0 is the observed time, t_f is "proper time" (time when you're far enough from the source that you're not affected by its gravity, but also at rest relative to the source), r_0 is the Schwarzschild radius, and r is the distance you are from the center. The Sun's Schwarzschild radius is 3 km, which is to say that if the sun's mass were compressed to a single point, that point would create a black hole whose event horizon would have a radius of 3 km. The sun currently has a radius of about 7\*10^5 km, which means that a second on the surface of the sun would be about sqrt(1-3/7*10^(-5)) = 1.000002 times as long as a "proper" second. I don't exactly know how far the most inner stars are from the galactic centre, but I know that they have to be far enough that the gravity gradient (the difference between the force of gravity at two points different distances from the source) would be low enough that stars could maintain a fusion cycle. I haven't done the math here, but intuitively I'd assume that if they're far enough away that they can hold a shape on the order of 10^5 km, they're far enough that the gravitational time dilation wouldn't affect them too much. EDIT: Accidentally a caret.

Would quantum computing make it easier to simulate molecular systems?

In principle, the answer is yes. Since a quantum computer is itself a quantum mechanical system, it inherently is able to deal with quantum mechanical features. This is what Feynman had in mind when he proposed quantum computing in the 1980s, though this proposal has little to do with what we now mean by "(universal) quantum computer". Instead of running a full-blown algorithm on a generic quantum computer, it can be easier to build a quantum system one can "easily" control which mimics the system you want to simulate. (In more precise terms: You map the Hamiltonian of the system you want to simulate to the Hamiltonian of a system you can experimentally control.) This is actually done quite a bit for solid state systems already, you can find more information here: _URL_0_

If I am seeing a full moon, does someone a few timezones away see a full moon too?

Yes the moon will be full (or close enough to it) for everyone on earth. The full moon happens with the sun and the moon are on opposite sides of the earth, so that the side of the moon facing the earth is illuminated by the sun. Fun fact: the side of the moon facing earth is always the same side, since the moon rotates at just the right speed so that as it orbits the same side is always facing us. This is caused by a phenomenon called tidal locking.

how does the accelerator pedal in cars work?

In most cars, pushing the accellerator (or gas ) pedal increases the flow of fuel to the engine. This means the engine will output more power, causing the car to accellerate. However, this accelleration doesn't continue forever. Mainly because as a car's speed increases, the amount of wind resistance increases as well, that's like a force pushing against the car forcing it to slow down. So when you press the accellerator, the engine will push the car harder, and as it speeds up, the air will push harder against it. Once they reach an equilibrium, the car stops accellerating and instead maintains a constant speed.

what would happen if i threw a plugged in toaster into the bathtub with me?

With current building codes, probably not much. Any outlet near a tub is a GFCI outlet, which means it has extra protection against exactly this sort of thing. The most likely thing will be that it will short out and trip its breaker before anything happens to you. If you used an extension cord and ran it from an outlet further away, you'd have a slightly larger chance of something bad happening. If the electrical current happens to go through you on the way to the ground (probably via the drain), and it hits your heart, it could disrupt it and kill you.

how does a new computer know the date when you turn it on, even if not connected to the internet?

There is a small battery on the motherboard which runs a variety of things including a clock. If your computer forgets the time when it turns off this battery is likely dead. They typically last 3 to 5 years.

Is it true that sniffing markers/petrol kills brain cells?

_URL_0_ It's not that it's odour particles in your nose, it's often that you're inhaling asphyxiants. They bind to receptors in your lungs which keep you from getting actual oxygen. This causes hypoxia, which can lead to cell death. Your brain needs a constant source of oxygen and you can't regrow brain cells easily if they do die. People do this intentionally because the lack of oxygen leads to delirium and hallucinations and other problems just caused by your brain not being able to function properly. There's other chemicals in various inhalants that are going to be absorbed into your blood and have an effect, but the main reason people use them is that they prevent you from properly delivering oxygen to your brain and make you feel funny, and that's also the main mechanism that causes brain cells to die.

Would people in the middle ages agree that the Barbarians won?

While the Western Roman Empire collapsed in the 5th century, the Eastern Half existed in one form or another until the 15th century. Regarding the Barbarians defeating the Roman Empire, it would be fair to say that what the Barbarians did and the Franks in particular is adopt and absorb Rome into their political and religious structure and eventually shifted away from the still existing Roman (Byzantine) Empire in Constantinople. The event that best highlights this was the crowing of Charlemagne as Emperor of the Romans on Christmas 800. What this did was de jure reestablish the Western Empire much to the anger of the Byzantines, who both viewed themselves as the true Roman Empire and that no Barbarian had the right to proclaim themselves as a Roman Emperor. One book I'd recommend looking at regarding late antiquity and the Barbarians' relationship with Rome/Byzantium is Christopher Wickham's Inheritance of Rome. In short, the Byzantine Empire throughout its history called itself the Roman Empire and its people as Romans while the Franks at the least viewed themselves as the continuation of the Western Empire.

Were the Picts Celtic or non-Indo-European people according to modern historians?

Perhaps an expert will come along and answer this for you, but in the meantime I had a quick look and got what appears to me to be a general consensus towards the Picts being of mainly Celtic origin. Cunliffe summarises the issue as follows: > "The Irish, Attocotti, and Picts were probably Celtic peoples, althought some linguists claim to be able to detect a pre-Indo-European element in the Pictish language." (263). Of course, this quote demonstrates (at least in 1997) that nothing is 'known' on this matter, but we do have probability. A few more recent articles I have found seem to support the assertion that the Picts were of Celtic origin (Keys 41, Snow 46), but Teutonic influences later mixed in amongst the population of Scotland and became somewhat dominant, yet the modern 'Scottish' identity betrays a mix of linguistic influences including "Gaelic, English, Welsh, Norse, French, Flemish and Latin" (Hammond 6-8, 26-7). Celtic and non-Indo-European languages could also have co-existed: > "Though it is fashionable for scholars to ignore it, a non-Indo-European language does seem to be visible in the inscriptions of Pictland, which have never convincingly been interpreted as Celtic. The presence of such a language is supported by the ancient river names, so long as they are not emended. When Isaac analysed Ptolemy’s river names in Britain, he found between thirty-four and forty-one Celtic ones and six non-Indo-European ones, and five of those six rivers turned out to be in north-east Scotland. This is indeed what one might expect on the far edge of an island on the far edge of Europe" (Sims-Williams 431-2). I've only collected some bits and pieces here and I'm a total layman on this matter so I may have horrible embarrased myself. But the summary of Cunliffe seems reasonable on the matter: that is, that the Picts were predominantly Celtic and perhaps had a smaller non-Indo-European aspect. Sources: Cunliffe, Barry, The Ancient Celts, London: Penguin Books, 1999 (1997). Hammond, Matthew H., "Ethnicity and the Writing of Medieval Scottish History", *The Scottish Historical Review*, 85, 219, 2006, 1-27. Keys, David, "Rethinking the Picts," *Archaeology*, 57, 5, 2004, 40-4. Sims-Williams, Dean, "Bronze and Iron Age Celtic Speakers: What we don't know, what we can't know, and what could we know? Language, Genetics and Archaeology in the 21st Century", *The Antiquaries Journal*, 92, 2012, 427-49. Snow, Dean R., "Scotland's Irish Origins", *Archaeology*, 54, 4, 2001, 46-51.

What did the Russians do the German 6th army after they were captured?

The captured members of the German 6th Army were by in large sent to Siberia, or at least to the east of the country to get them as far from the battle lines as possible. They were basically used for forced labor, suffered from ill clothing and malnutrition and general poor treatment. Out of the roughly 100K+ prisoners of the 6th, only @6,000 survived the war to be repatriated, some were not released until the early 1950s. (Christina Morina, *Legacies of Stalingrad: Remembering the Eastern Front in Germany since 1945*)

Is there a situation where crossing two beams of light could interfere with the way the beams look/act after they cross paths?

The short answer is yes, it is indeed possible for light to interact with light, though it happens only at very high intensity, around 10^24 W/cm^2 for ~1 micron wavelength light (not far from realization in the laboratory given the present state and trajectory of high intensity laser technology). This is about two orders of magnitude higher in intensity than we can make in the laboratory today and will probably be reached in a decade or so, allowing for direct probing of quantum electrodynamics in the laboratory using high-intensity lasers. [This article](_URL_0_) describes one such experiment. The essential physics is that at high enough laser intensity, one starts to "polarize" the vacuum, creating virtual electron-positron pairs that interact with the incident light as a nonlinear dielectric. Such dielectric behavior of the vacuum allows for the creation of a "matterless double-slit" in the article. The physics of this process is described well by quantum electrodynamics. Your projectors are many, many orders of magnitude lower in intensity, so this bit of exotica is not occurring in your classroom. [Edit: fixed some awkward wording.]

The Roman Emperor Claudius I is popularly depicted as either a bumbling fool, or a secret genius pretending to be a bumbling fool. What is the historical evidence for either view?

Since I've already been talking about Claudius quite a bit this weekend, I might as well field this question too... Our understanding of Claudius' talents has been shaped by the nature and biases of the literary sources. There are only four that provide (more or less) independent accounts of his reign: Josephus' *Jewish Antiquities*, Tacitus' *Annals*, Suetonius' *Life of Claudius*, and the *Roman History* of Cassius Dio. Each author had a literary and political agenda, and shaped his portrait of Claudius accordingly. Josephus, a Jewish protege of the Flavians, was motivated to present Claudius in a generally positive light. Claudius, after all, had been poisoned (or so it was assumed) to make room for Nero; and since the Flavians wanted to blacken the memory of Nero, Claudius was ripe for rehabilitation. Tacitus, whose great themes were the rise of imperial tyranny and the decadence of the Senate, found ample material in the reign of Claudius, and presented the emperor as an indecisive man driven to tyranny by the machinations of his wives and freedmen. Suetonius was a biographer, not an historian. In keeping with ancient ideas on the relative functions of those genres, he emphasized the moral qualities and failings of his subject, and accentuated the paradoxical rise of a court fool to the imperial seat. Cassius Dio, writing in the early third century, presents a basically positive but rather cursory portrait of Claudius, in which the emperor's achievements are his own, and his failings those of this scheming courtiers. Modern "popular" conceptions of Claudius tend to be dominated by Robert Graves' *I, Claudius* and *Claudius the God* and the BBC series based on them. Graves drew heavily on Suetonius, who provides a fascinating wealth of detail about the emperor's odd personal mannerisms. The idea that Claudius was a secret genius really grows out of Graves' novels, which show a highly intelligent but awkward man trying to survive in a vicious imperial household. So where does the truth lie? It is clear that Claudius was a competent administrator - his recorded measures are reasonable, and occasionally even far-sighted. It is equally clear that he was a bumbling politician, prone to being used and conspired against. One of our very few unvarnished views of Claudius comes from the so-called Lyon Tablet, a bronze panel that records verbatim a speech the emperor made in the Senate to advocate citizenship. This is our one real glimpse into how Claudius always spoke - and it is fascinating. The emperor rambles on about historical minutiae, and has to be reminded repeatedly (by senators shouting from the benches) to get to the point. We see, in other words, an obviously intelligent and learned man, but also one awkward in manner and speech. The Lyon Tablet seems to more or less confirm Suetonius' comments on Claudius' behavior as emperor. Claudius was definitely smart - but we should not imagine him as a secret mastermind.

why does it not matter to climate change that the earth was hotter during certain periods of the past?

Even if we totally accept the argument that climate change has occurred on this scale and with this rapidity before, there's nothing to suggest that it won't be extremely disruptive to our way of life. Regions that are fertile today may become barren, regions that may be farmed in the future may be remote or poorly suited to growing crops. The majority of the human population lives on the edge of the ocean. So we have to shift all our food production around, we have to move our cities. These things don't turn on a dime, and we have a huge population to move and feed. Think of the difficulties right now with Syrian refugees, feeding and housing them. That's < 10 million displaced people. Imagine billions, right when the food infrastructure is suddenly needing massive changes.

shorting the dow

The two main reasons you would short the Dow would be: [1] If you think the DOW will go down. [2] To hedge against some other position. Hedging is another matter and I won't go into it here. Seeing as it is ELI5 I will use an example that is easier to understand (gold as it is traded in dollars not an index like the DOW). Assume there is a gold dealer that you know that will let you borrow any amount of gold you like at current market prices at any time, and will also buy it back off you at current market prices at any time. This is what many financial institutions offer. Say gold is currently worth $1700 and you think it is going to go down in price. A method of speculating that it will go down would be to 'go short' on gold. Going short is where you profit on downward movements in prices. Going long is where you profit of upward movements in prices. Going short: Firstly, you would borrow an amount of gold. Let's say you borrow 100 ounces at $1700. You have borrowed $1700 x 100 = $170,000 worth of gold. The dealer essentially has given you $170,000 and has said "now you owe me 100 ounces of gold". Say in a weeks time gold is now worth $1600. You still owe the dealer 100 ounces. You decide to take your profit. To pay off your debts you will have to give the dealer back his 100 ounces. To settle your debts you will have to buy 100 ounces of gold and then ship them to the dealer. This will cost you $1600 x 100 = $160,000. So in summary you borrowed $170,000 from the dealer, a week later you cleared your debts with a $160,000 payment. You have profited the difference of $10,000 from the price of gold going down. Notes: [1] I have ignored transactions costs and interest payments. [2] The DOW is exactly the same sort of situation except it is an index that you are trading on the movement of. [3] Hope this helps!

[Experiment] Which method would get the boiled water to lower temperature within the same amount of time?

Do the experiment and report back, it's really easy. Any kitchen thermometer will do. To avoid having an effect from fresh tap water being cooler than room temperature, while the other case has 5 minutes to warm up the tap water I suggest using water that has been left at room temperature for 20 minutes. To get good readings I suggest you note down the temperature in both cases at 10-20 s intervals and draw the graphs. There are two main mechanisms at work, heat loss through generation of steam (you need energy for the phase transition) and heat loss to the surroundings, which is proportional to the difference in temperature. My gut feeling is that the second mechanism will end up at a lower temperature, but I'd do the experiment and then I'd know with certainty. **----------------------------------------------------------** Edit: OK, I've done it for you, we got talking about it and I just needed to see what happens. See here for a picture of the [setup](_URL_0_) and the [results](_URL_1_). After finding two thermometers it only took 20 minutes or so - perfect for a coffee break. The black cups were used for mixing and measuring the temperatures, the red ones held equal amounts of room temperature (20 C) cold water, the green ones were used to measure equal amounts of freshly boiled water before pouring them into the black cups. As I'm using two equal fresh cups, the second batch does not get an advantage by coming into contact with a preheated cup. Cup A got the hot and cold water at T=0 (with a little stirring from the thermometer), Cup B got the hot water only, with cold added after 5 minutes. As expected Cup B cooled quickest while it was hottest, and this larger early loss of heat proved decisive. After equilibration of the mixed fluids Cup B had an advantage of 2 C, which it kept nearly constant during the next 5 minutes. After 10 minutes the final temperatures were: Cup A: 47.5 C and Cup B 45 C. So in conclusion, if you want the lowest mixing temperature after 10 minutes, add the cold water after taking advantage of the rapid initial cooling due to the large temperature difference.

[li5] a lake in northern canada freezes solid over the winter. what happens to the fish? would fish even live there?

The surface freezes, but the water below remains liquid. The lake remains in equilibrium, such that there is an equal amount of water freezing, as there is ice melting underneath the surface. The part that makes *me* wonder, is how fish can survive those temperatures.

Adding salt to a supercooled liquid?

It would depend on how deeply supercooled the liquid is. Deeply supercooled solutions (say, beer below -20 & deg;C) would be extremely sensitive to agitation and vibration, so even the act of stirring in the salt would probably trigger a nucleation event. The salt itself would not serve as a "seed crystal", because its lattice is not matched to the crystalline structure of ice, but the process of adding the salt could create a sufficient perturbation to initiate nucleation in the supercooled liquid. - If the degree of supercooling is low or moderate (e.g., beer above -10 & deg;C) , then adding the salt would lower the equilibrium freezing temperature (and also lower the nucleation temperature), thus reducing the supercooling (if temperature is held constant).

how do choloroplasts have their own dna but 95% of the proteins in chloroplasts are encoded by nuclear genes?

Essentially Chloroplasts (and mitochondria) were originally free bacteria. Chloroplasts descend from cyano-bacteria, which means they can photosynthesise. You get things like [lichen](_URL_0_) today, which are a mixture of fungal cells, and cyanobacteria living together. At some point in the past, the ancestor of all plants was something like this. A cyanobacteria was engulfed into a "plant" cell, which resulted in the double-membrane structure. This would confer the plant cell a survival advantage, as it could now get energy directly form the sugars produced by the internal cyanobateria. However, if the cyanobacteria reproduced out of control, it would kill it's host cell. Sometimes bacterial chromosomes (the circular loops) will lose a chunk, which drifts off. If this DNA migrates to the nucleus, it can be integrated into the plant cell itself. Now, the proteins are produced by the DNA encoded in the nucleus, but originally they came from the bacteria! Over time many genes have migrated to the nucleus, which domesticates the chloroplasts, since they cannot reproduce without the nucleus making proteins for them. Proteins which are made at a large rate have stayed inside the chloroplasts themselves. Now the chloroplasts are part of the plant, but originally they were free living bacteria who gradually become tamed.

how exactly does a transformator transform energy to a lower voltage?

Do you mean a transformer? The EMF induced in the secondary coil is proportional to the rate of change of magnetic flux through the coil. More loops means a higher magnetic field (and therefore flux) inside the secondary coil. Less coils means less flux and therefore less induced EMF. So in a step-down transformer, the primary coil has more loops than the secondary coil.

how do people with a hearing impairment think words? i think the way words sound to me - how does it work for others?

You know that thing you do when you're thinking to yourself and your move your mouth as if you were speaking, but without actually speaking? That's called [subvocalization](_URL_0_), and you do it even when you don't want to. Whenever you read, whenever you think to yourself, you're subvocalizing subconsciously. When your brain is recalling language, it activates every part associated with that, including the parts required to actually speak it, even if you aren't speaking it. Deaf people do the same thing with the muscles in their arms, hands, and fingers. They "subvocalize" whatever sign language they use (also, as an aside, there is no single universal sign language: there is American Sign Language [ASL], British Sign Language [BSL], Australian Sign Language [Auslan], French Sign Language [which for historical reasons is the basis of American Sign Language], etc.). Their muscles twitch slightly, imitating the nerve signals that would normally be required for signing, just not fully activating the muscles to sign in the same way that you don't fully activate the muscles in your mouth and larynx. Mind, that is for those who are *Deaf* (capital D Deaf). Meaning, those who are part of the Deaf community and most likely know a sign language as their first and primary language. If someone is lower case d deaf (someone who cannot hear but isn't part of the community), or hard-of-hearing (but still capable of understanding spoken language, even if it's with a cochlear implant) they probably still think in whatever spoken language they learned before they lost their hearing. If you could magically hear their thoughts, it probably wouldn't sound very familiar, but then again, someone from the [American Southeast](_URL_2_) listening in on the thoughts of someone from [certain parts of England](_URL_1_) would probably be very confused.

if the worst nfl teams always get the first (or early) round draft picks, why do the same teams continue to suck year after year?

The overall "best" player isn't necessarily the best fit for a team and its needs. Consistently getting high draft picks and not much improvement is a sign of poor management, simple as that.

what happens when im thinking of nothing?

Honestly you probably just get lost in studying the visual aspects of the thing you're looking at. I don't believe you can ever be truly without a thought.

How does the history of Nazi Germany and the Holocaust affect modern Germany?

How the past is interpreted and processed is perhaps the most important question for an historian, so I think the question is very relevant. Germany has tried to find ways to come to terms with the past. The English language has actually used German terms for struggle, mainly [Vergangenheitsbewältigung](_URL_1_) and Geschichtsaufarbeitung. Both concepts refer to the attempt to understand what has happened and to learn from it. That's obviously a very generalized answer. What actually happened is, as always, way more complex. It starts with the Four Ds of the allied occupation forces. Denazification, Demilitarization, Democratization, Decentralization (sometimes also Deindustrialization and Decartellization). The Allies tried from the beginning to instill a general feeling of guilt and shame to the German people. Visits to the Camps, screenings of videos of war crimes, the whole Nuremberg-thing. On the other hand, there was an obvious continuity of personnel. Germany was a highly industrialized and bureaucratic nation... replacing all officials and elites that had already worked under the NS regime was just impossible. What impact this had on the German people is actually very hard to say. To a certain degree, it just wasn't important. Many people had lost their homes, everybody was mourning over some lost family member, some had lost everything. They were sick of ideology and more occupied with the task of finding a new place to live and enough coal to make it through the winter. The 1950s are usually seen as a very unpolitical time in Germany... there was so much to do, so much to worry about that after the initial shock of losing the war, bigger problems took the scene. This changes with the 1960s and especially with movement of the new left. This new generation, who were in their late teens or early twenties in 1967 and couldn't remember Hitler, started to ask questions about the past of their parents and grandparents. This is where deep and hidden conflicts between the generations break open. (See, for example, Heinrich Bölls novel "Das Vermächtnis" about a Nazi-officer who manages to easily find his way back in the post-war society. Böll wrote it in 1948, but couldn't find a publisher.) This struggle and the inability of the older generations to properly "answer" these questions lead to the belief of the radicalized elements of the left that fascism was always lurking behind the boring lives of boring people in a capitalistic society. Anyway... to wrap this whole thing up a bit: On an academic level, this whole question leads to the [Historikerstreit](_URL_0_) For that, I recommend an article by Götz Aly: The logic of horror, which tries to summarize the whole dispute: > > Twenty years ago the "Historikerstreit", or "historians' dispute", flared up, a decisive conflict on the historical interpretation of the Holocaust and the Germans' understanding of themselves. In the article "Vergangenheit, die nicht vergehen will" (the past that does not want to pass) in the Frankfurter Allgemeine Zeitung on June 6, 1986, historian Ernst Nolte maintained the Holocaust should be viewed in the light of the entirety of 20th century European history. Nolte further explained the murder of the Jews as a reaction to the mechanism of extermination in Soviet Russia: "Was not the 'Gulag Archipelago' prior to 'Auschwitz'?" In an answer in Die Zeit, philosopher Jürgen Habermas accused Nolte of playing down German guilt, and insisted on the singular nature of the Holocaust. The ensuing debate on German guilt and its historical interpretation involved all major German historians. _URL_2_

What pieces of medieval/Renaissance garb still exist?

A room in an Austrian castle, sealed off in the 15th century, was recently opened. It contained many textiles, including undergarments and shoes. [Check out this write-up](_URL_0_)--at this point, the publicly available information seems quite scant, but I'm eager for the publication of an article on the finds!

Why do things bounce?

Solid object deform when you apply forces to them. If an object has elasticity, it will tend to return to its original shape. Now imagine the case of a ball dropped. The ball gains some kinetic energy in its descent, and this energy, at impact serves to deform the both the ball as well as the ground. If the ground or the ball (or both) hold some elasticity, they will attempt to return to their original shape, which will apply a force opposite in direction to the initial force applied. If an object bounces in a collision, the collision is elastic to some extent and energy is conserved in the system as it is transferred from the motion of the object into the compression of the object, into the internal restoring forces of the object, and back out into the object as kinetic energy, giving it motion in the direction opposite the initial direction EDIT: To comment on elasticity, when an elastic object is deformed, the structure as a whole is disturbed from its minimal energy state, and will subsequently to return to this minimal energy state from the higher energy state (provided the object is not permanently deformed and a new minimal energy state created).

Why did Charles Cornwallis not face Washington directly after surrendering at Yorktown? Was this an attempt to slight Washington, and, if so, was it seen as dishonorable or childish?

Gen. Charles Cornwallis, 1st Marquess and 2nd Earl Cornwallis, [surrendered to American forces on October 19th, 1781](_URL_0_) after two days of a ceasefire. It came after a week of fighting where British troops failed to advance or make any dent in the American and French forces who had surrounded them and were well\-fortified. The loss was quite shocking, with over 8,000 British troops being captured by the Americans. The negotations for the surrender were held by Cornwallis' subordinates, which was not unsusual for 18th century warefare. What was unusual is that Gen. Cornwallis did not attend the surrender ceremony, claiming an illness prevented him from coming. Brigadier General Charles O'Hara was the office in charge and led the British army onto the field. Reports say that Gen. O'Hara attempted to surrender to French General Jean\-Baptiste Donatien de Vimeur, comte de Rochambeau , who refused to address O'Hara, and and pointed to Washington instead. O'Hara offered his sword in a ceremonial position of surrender, but Washington refused and had Major Gen. Benjamin Lincoln accept it, thus initiating the formal surrender of the British Army at Yorktown. While it might seem dishonorable to us that Cornwallis did not take to the field, neither his loss of Yorktown nor his refusal to take to the field was largely seen as dishonorable in the eyes of his countrymen. Having just suffered the arguably most embarrasing defeat in 18th century British history \(in the eyes of the British\), Cornwallis may have very\-well been ill and unable to attend. As some historians have noted, "[Although the Yorktown capitulation decided the war in favour of the colonists, Cornwallis remained in high esteem at home.](_URL_1_)" Cornwallis went on to become governor of Indian just four years after his defeat at Yorktown. He went on to have an impressive career, including a promotion to marquess in 1792. It appears that his loss at Yorktown did not hold back his future successes.

what is the difference between fruits and flowers?

A flower is the reproductive structure in flowering plants (called angiosperms). The purpose of a flower is to offer up & receive pollen from other flowers. Flowers are often brightly coloured & scented to attract animals, & offer up substances like nectar to lure insects/birds into the flower, where they can pick up pollen from the flower, that they will carry to the next flower they visit. Pollen is the equivalent to sperm in animals. If it reaches a flower of the same type & it gets transmitted to the female part of the flower, it will fertilise it. The pollinated flower will then develop seeds that will potentially grow into another plant if it is in the right conditions. To get to the right conditions though, the seed often needs to be protected & transported. Some plants have again encouraged animals to help transport the seeds by providing them with another incentive to collect their seeds: by encasing them inside a tasty fruit. The flower will develop into the fleshy body of the fruit surrounding the seeds, which animals will pick & carry or eat. Most seeds in edible fruit are strong enough to pass through through an animal's digestive tract, so they will be pooped out some distance from the parent plant, where it will be able to grow without having to compete with its parent for nutrients. Other, inedible, fruits are just there to protect the seed from being crushed or otherwise destroyed, eg. to deter them from being eaten, because the seeds wouldn't be able to survive the digestive process. **TL;DR**: Some plants have structures called flowers to receive pollen from other plants so they can become fertilised & produce seeds. These flowers then develop into fruits that protect the seeds & help them be transported.

How did Napoleon III's reforms affect the later development of France's economy?

Napoleon III's probably most lasting economic reforms took place in the education and financial sectors. While in the short-term the lowering of tariffs across the board spurred productivity growth and encouraged foreign trade, in the long-term the true determinants of economic growth are threefold: population growth, human capital (i.e. education), and increased liquidity of capital. Modernizing the French agricultural industry helped to mitigate the famines that routinely decimated early-modern France and the new public education system (which competed with the existing Catholic school based system) further served to improve literacy and otherwise prepared children for the "real world." That being said, the legacy of Napoleon III persists mostly in the form of the large number of banks that he encouraged or supported. BNP Paribas (a combination of Banque Nationale de Paris and Paris Bank), Societe-Generale, Credit Lyonnais (which merged with Credit Agricole), are all banks that were created during the Second French Empire. They quickly grew to be some of the world's largest banks and persist even to this day as some of the largest and most sophisticated financial institutions. Without the financial bedrock that they were able to provide (in tandem with a surplus of gold into global markets that increased the currency supply), it is unlikely that Napoleon III could have been able to finance any of the fiscal and infrastructure reforms that he needed to modernize France. The now-defunct Credit Mobiliere, for instance, was a major contributor to the finance of French railways, French public transit, and even the French intervention into the Crimean War. The rise of the French banking sector also worked well with the increased savings of French workers, which provided a sufficient capital base for investment and further growth.

Why was Theodore Roosevelt known as the "Trust Buster" when Taft broke up more trusts?

I'm confused by this question. Roosevelt gained his reputation as a trust buster during his presidency. Taft had not served as president yet. How would people know not to declare Roosevelt a trust buster because his successor would use the Sherman Act more aggressively?

"unincorporated" small town

Some people see unincorporated as a positive. In a city, there's essentially four levels of government that people live under: city, county, state and federal. In an unincorporated region, it's just county, state and federal. Less government is a plus to some.

How is the historical argument of David Graeber's "Debt: The First 5000 Years" viewed?

I always find it hilarious when non-lawyers discuss legal topics (e.g. money and contracts). So, without giving this gentleman from Yale too much credit, and taking into account that only so much can be expected from him as long as he is speaking outside of his area of speciality, I present to you the first error: "The story goes back at least to Adam Smith and in its own way it’s the founding myth of economics." Right. If he had even done cursory research he would have discovered that the Roman jurists also regarded "purchase and sale for cash" (emptio venditio) as a sub-category of the barter transaction (permutatio). The Romans also referred to the creation of currency as being something which happened temporally later than the barter economy. "Now, I’m an anthropologist and we anthropologists have long known this is a myth simply because if there were places where everyday transactions took the form of: “I’ll give you twenty chickens for that cow,” we’d have found one or two by now." There are such places. I often barter with other people, even in my own town. For me, this takes the form of me offering some service in exchange for another service (e.g., my neighbor and I each receive each other's packages free of charge). Every now and then I engage in item-for-item barter as well. However, the point is: barter and trade for money co-exist and are readily observable in many contexts today. (Although perhaps not in Yale classrooms.) "[...]how does that broad sense of ‘I owe you one’ turn into a precise system of measurement[...]" More importantly, when does it become legally necessary to enforce the "I owe you one" if the other person refuses to comply. When do social sanctions no longer work? When is an organized system of contract enforcement necessary? All of this goes well beyond anthropology. "You say that by the time historical records start to be written in the Mesopotamia around 3200 BC a complex financial architecture is already in place." This is the narrator, not the author. But the Mesopotamian financial system is not excessively complex. Money lending and credit did exist but no banks or fractional reserve banking existed. Also, to say the least, there were no stocks, bonds or currency fluctuations. "This was the great social evil of antiquity – families would have to start pawning off their flocks, fields and before long, their wives and children would be taken off into debt peonage." Debt-peonage is under-rated. Happy to expand on this if anyone asks. And calling slavery on account of debt a "social evil" is the worst presentism. "Once you recognize that money is just a social construct, a credit, an IOU, then first of all what is to stop people from generating it endlessly?" It's not, it's a mode of exchange, and that is how it functions. If you generate it endlessly it ceases to be meaningful as a mode of exchange. That stops people from generating it endlessly, as presumably those people have an interest in maintaining the mode of exchange's function. The rest of the interview is all present-day bullshitting about the EU debt crisis. I'll spare everybody my opinions on that kerfuffle.

what exactly happens to person when they're only awake during the night?

You get really fucked up. Shift work is worse as my body can attest. But straight nights causes your body to go all haywire. Basically your body doesn't work well, not receiving Vitamin D, Metabolism diminishes, you're more likely to have heart conditions, blue like also messes you up on nights. I can't recall the article but it was State side where they studied a neighbourhood with new installed LED street lights (blue light spectrum) vs without and there were higher domestic disturbance police calls then the neighbourhoods with regular condescent or halogen street lighting same income range for households and such. _URL_2_ _URL_1_ _URL_0_ That's just the first page of Google,

is there a correlation between how hard you blow and the size of a bubble? if not what defines the size of a bubble?

It's liquid tension - the harder you blow the more force is pushed against the inside of the bubble which has more potential to pop it. A slow smooth bubble will allow more surface area without breaking liquid tension

why is snot green.

When your body first makes it, it's clear. But it's like fly paper. It's there to catch debris going into your nose. So stuff gets mixed in, and if you do have an infection, your white blood cells can turn it green (something in them is oxidizing in the atmosphere)

why did the special effects industry move from bluescreen to greenscreen?

_URL_0_ This portion: Processing a green backdrop[edit source | editbeta] Green is currently used as a backdrop more than any other color because image sensors in digital video cameras are most sensitive to green, due to the bayer pattern allocating more pixels to the green channel, mimicking the human eye's increased sensitivity to green light.[6] Therefore, the green camera channel contains the least "noise" and can produce the cleanest key/matte/mask. Additionally, less light is needed to illuminate green, again because of the higher sensitivity to green in image sensors.[7] Bright green has also become favored since a blue background may match a subject's eye color or common items of clothing, such as jeans, or a dark-navy suit.

citizens united v. federal election commission

It used to be that corporations were allowed to run things called **Issue Ads**, but were not allowed to support actual candidates. So they could run an ad saying, "Support Solar Energy" but not "Support Candidate 'A.'" Citizens United decided that this was an unreasonable restraint on a corporation's and union's rights and that they should be able to spend money in support of candidates. This has angered a lot of people who feel that the decision opened yet another door by which corporations can influence elections and buy favor with candidates. An influence that individuals can't match. However, direct contributions from Corporations and Unions direct to candidates' campaigns were not in question and are still banned under current law.

How did the US Marines and National Guard come to have their own air arms?

Let me correct a few misconceptions. The US Marine Corps is NOT a part of the US Navy. It falls under the Department of the Navy for administrative purposes but is a separate arm in its own right for operational purposes. Furthermore, Marine Aviation did not come about in World War 2. It dates back, for all intents and purposes, to this man: _URL_0_ This is Lieutenant Colonel Alfred Austell Cunningham, and the photo was taken in 1912. As this is not directly related to your question, if you want follow-up on this, go to Wikipedia: _URL_1_ (it's a nice article with references). Marine Aviation was created Feb 26 in Philadelphia, Pennsylvania, when Cunningham was instructed to organize an Aviation Company for the Advanced Base Force. In 1919, Major Cunningham was assigned to command the new Aviation Section, Headquarters Marine Corps. So, by 1941 the air arm of the USMC was already well established, even if not very powerful (they were flying goddamn Brewster Buffaloes as their main fighter aircraft). And now to answer your question: why did the USMC (I know I'm skipping the National Guard, sorry) get its own air arm? Because it needed one. The USMC utilizes Navy ships, but it's an independent force, and thus has to rely mainly on itself in conducting operations, especially once the marines get further away from the coast. Probably if the USMC brass in 1917 hadn't thought of creating its own air arm, some provisions would have been made eventually for the Navy to provide all types of air support. Source & further reading: *The United States Marine Corps: A Chronology, 1775 to the Present*, by John C. Fredriksen. ABC-Clio, Santa Barbara, CA, 2011.

Would we know if another animal on our planet reached a state of sentience/sapience to the level of reason?

It all depends on how you define sentience: * Elephants are known to [grieve and bury their dead.](_URL_6_) * Apes are known to [wage war on each other,](_URL_0_) (I've seen actual footage of an attack in a forest but can't find it now) [make tools,](_URL_5_) and even [weapons](_URL_1_) * Chimps are commonly used for studying behavior relating to humans and exhibit [jealousy and a sense of fairness](_URL_2_). I've read elsewhere that in a similar experiment, grapes were traded as currency [in one case with Capuchins in exchange for sex.](_URL_3_) * Dolphins are known to [kill for sport/fun](_URL_4_)

what's up with the "num lk" on keyboards and what possible scenario would i want the number pad to not work?

Num lock turns the numpad into arrows. _URL_0_

do birds stop migrating? i mean, do i have birds in my city that consider this home base, or is every bird i see just pit stopping on their way to somewhere else?

Some birds stay all winter long. Robins and crows are 2 that I can think of. Bald eagles too.

Why are some planets / moons in our solar system so uniformly colored?

I might not be the best person to answer this question, but I'll take a stab at it. Disregarding life, vegetation, atmosphere, and the ocean (none of which are present in the moon), the Earth would actually look quite a bit more homogeneous than it does now. Much of the variation that would be present would be sure to the fact that the earth is geologically active. The Grand Canyon is red because it is made of sandstone, Mauna Kea is black because it is made of basalt, etc. By contrast, the moon is largely geologically inactive. It has neither liquid water nor atmosphere, so there are no sedimentary rocks. It is not as massive as earth, so there wouldn't be much metamorphization (if that's a word). Those metamorphic rocks that did form would never be brought to the surface because the moon doesn't have tectonic activity. In short, the moon looks homogeneous because there are not any processes that would make it heterogeneous.

do people who speak "faster" languages think faster?

No, Spanish has more consonant clusters and news reporters etc will always talk really fast but they're producing the same amount of information. Another example would be written Chinese where each character has a whole meaning which is different to english which depends on an alphabet to build words. Even though a few Chinese characters can say what a lot of English words do, it takes about the same amount of time to extract the same amount of information. This is because, in reading, you skip most of the letters, ie you recognise whole words without recognising individual letters. You can train your brain to think and react faster, just keep using it productively. Don't be stuck in the same routines all the time, read and learn more things, exercise more, challenge yourself with new ideas.

How does movement on a quantum scale work?

> they have to be somewhere? A tidal wave has to be somewhere, but you can't determine its location more precisely that a few meters. For a ship, you could define it's center of mass and find that location very precisely, but something like a wave doesn't even have a well-defined shape.

When batteries run out in a Gameboy then you turn it back on, it can run for a short while. Why?

While the device is on it is consuming power. Placing an electrical load on the battery causes the voltage to "sag" a little. Once the voltage sags below a certain point, the device detects it as a dead battery. Turning off the device relieves the batteries of the load and the chemical reaction inside the cells quickly recovers the voltage to a point above what the device considers "dead." As soon as you turn the device on again it consumes what little power was generated in the down time and reverts to "dead" status.

why is turning your computer off at the powerpoint, rather than shutting it down properly, bad?

When you're done brushing your teeth, you can carefully wash your toothbrush and put it in its little holder. You can also just throw it down onto the countertop and walk away. Doing it that way will *usually* work, but there's a chance that someone will knock it onto the floor or get some hair on it. Turning off a computer is the same way.

the legalization of marijuana in colorado.

According to [this article](_URL_0_) people 21 years of age can purchase it from specially regulated retail stores, and adults can grow up to 6 plants for personal use. Public use and driving under the influence is still illegal.

why does mankind need a higher power like god to explain our existence?

Long story short? Fear. Fear of what we can't understand, fear of the unknown, fear of what comes next. They take comfort in having answers, even if they are completely bullshit.

how to plants that react to touch like the venus flytrap of the sensitive mimosa work?

If I remember correctly, for the Venus flytrap, there’s sensitive hairs on at the ‘clamping’ area. It takes lots of energy though, so when one hair is triggered, there’s a timing mechanism that’s set off. Only if multiple hairs are ‘moved’ within a set timeframe does the plant exert substantial energy to close the trap. Not an explanation on the cellular scale though, hope someone can explain further too!

If mesons carry the force that binds protons and neutrons together, do other composite bosons (like helium nuclei, for example) carry their own forces as well?

The answer is kind of yes and no. The mesons that bind nucleons together (via what's often called the residual strong force) act as gauge bosons (much like the fundamental force carriers) associated with emergent broken symmetries of QCD, so they actually play something of a special role. But in a more general sense, the mesons aren't actually 'carrying the force' independently of the gluon (the gauge bosons of the strong force). [Here](_URL_1_) is a Feynman diagram showing the interaction between a proton and a neutron via a pion, where the pion is clearly behaving as a force-carrying particle (the proton and neutron are interacting through it). However, if you look deeper, you would see [this](_URL_0_). In a direct strong force interaction, two color-charge carrying particles would exchange a gluon. In this pion exchange, something more complicated is going on. The individual quarks that compose the nucleons are only ever interacting directly via gluons, but the end result is analogous to trading a pion. I suppose something similar could in principle happen with any composite particle, but the likelihood of such an interaction will vanish astonishingly quickly as the complexity of the particle increases. For example if you wanted to draw an interaction between two particles via the exchange of a helium nucleus, you would have to add *a lot* of extra quarks and gluons to that second diagram, and in general, every vertex (a point where multiple particle lines meet) in a Feynman diagram will reduce the likelihood of that interaction actually occurring, and therefore would correspond to a very weak interaction.

Is it possible that the dark matter is actually stars with Dyson spheres around them so we can't see them?

Nice idea, but it won't work. There are a few reasons: (1) We know dark matter does not feel the electromagnetic force. If the dark matter were Dyson spheres, from absorbing the energy of the stars they surround, they would radiate in the infrared, and so we'd detect this. In fact, people have looked, and [no Dyson spheres](_URL_0_) have been found. (2) Dyson spheres would be an example of MACHOs (massive compact halo objects), which more conventionally includes things like brown dwarves (stars that didn't quite ignite). Searches for MACHOs show that the vast majority of dark matter cannot be in MACHO form. (3) Studies of the cosmic microwave background radiation give us the ratio of ordinary to non-ordinary matter in the universe (there has to be a certain amount of matter that interacts with ordinary matter via gravitation but does not interact with photons). Without dark matter, this doesn't work.

why aren't aol-style chat rooms still a thing?

They are. Most proprietary formats have died out, but many people still user IRC. The Freenode network is the most popular, and many communities have channels there. You might have better luck just logging onto Freenode or looking for IRC directories. There are more ad-hoc sites like Tinychat, or group conversations hosted on services like Discord, that are similar as well.

How do chemists produce a weakened state of a disease to create vaccines? How can they confidently determine the disease is ready to be used as a vaccination?

It depends on the vaccine. The simplest to imagine are whole-cell vaccines against bacterial diseases: simply kill off the bacteria. Since they are dead they can no longer infect anyone - but they will still contain all the antigens (structures that antibodies can bind to) that will make the immune system recognize them, which will teach the body to fight them. Other ones are more interesting. For example, the tetanus vaccine is an inactivated form of the toxin (tetanospasmin) produced by the bacteria that cause tetanus (*Clostridium tetani*) instead of the bacteria themselves. The toxin is a protein that can be inactivated by e.g. formaldehyde: this denatures the protein (imagine cooking an egg - heat denatures the egg white and turns it solid) enough to make it essentially harmless while still being recognizable by the immune system. Many vaccines against viruses use another process, by first growing the viruses in the human cells that are their original hosts and then [passing them through cell cultures that they are not adapted to, like e.g. chicken cells](_URL_0_). Viruses are finely tuned, so as they adapt to those other cells, they start to lose the capacity to effectively infect the original human cells - but again, they will still contain all the bits that will make the body recognize them. Then there are modern methods like recombinant vaccines, where you use modern gene editing techniques to create the specific antigens you are after. As for how they can "confidently determine the disease is ready to be used as a vaccination": testing, testing, testing and more testing. Testing in cell cultures. Testing in animals. Testing in people: clinical trials upon clinical trials to determine if the vaccine is safe, if it produces the desired antibodies, and then finally to see if it actually works in practice - and works better than any alternatives already out there. And then there is constant quality control testing of the product itself, to make sure that the plant is still making exactly what they think they are making.

why are / were there flag bearers in armies

It's to accomplish the same thing as radios and computers in today's modern armies. Communication. Imagine a battlefield filled with thousands of people, many wearing the same uniform. But each small unit with a different mission. The flag or more precisely guidon is a point of rally for those in the small unit as well as asifthatwouldhappen mentioned commanders to I'd their troops. Fun fact the guidon bearer is a place of honor only for the most ferocious warrior, if the guidon was seized by enemy forces all communication between commander and unit would cease so the guidon bearer must be able to defend all attacks. This tradition is carried in today in the us marine corps as place of honor for the most worthy marine for all other marines to follow.

sports eli5: why are sports playoffs like hockey and baseball best out of 7 but american football is single elimination?

football is *way* too demanding physically to be played multiple times a week. this in addition to if they did have a series and it was played out once a week the playoffs would last months.

I'm an innkeeper during the High Middle Ages in Europe. What is my life like?

As far as customers at your inn are concerned, you would most often see the traveling lords and vassals, members of the church, and possibly a small number of the artisan/merchant class. Serfs themselves were forbidden from leaving their fiefs without explicit permission and instruction from their local lord, and in some respects, were thought of as property much like the land itself. The result of this restricting ownership is that the "riff-raff" is kept out of your inn (so long as its primarily not a tavern). Merchants and artisans, aside from nobles and clergymen, were the only ones that could potentially have the funds and impetus to travel.

They say as babies our bones are mostly cartilage. How does this change occur as we grow older and why is it advantageous to do so?

Bone growth can occur by one of two processes: endochondral ossification and intramembranous ossification. But to understand those in detail you have to understand exactly what bone is. Bone is a highly active tissue, with important hormonal, structural, hematological, and immunological functions. Your skeleton receives 25% of the cardiac output at rest, one of the highest of any organ. The majority of bone is composed of extracellular matrix, there are in fact very few cells in bone tissue. Additionally, there are several types of cells that make up the cells within bone tissue. The 4 major bone-cell types are osteocytes, osteoblasts, osteoclasts, and osteoprogenitor cells. Osteoprogenitor cells are like bone-stem cells. They can differentiate into different cell lines depending on the needs of the tissue. These are generally mesenchymal stem cells (MSCs). MSCs can become osteoblasts or osteocytes (among a host of other cell lines including muscle and cartilage) but cannot become osteoclasts. Osteoblasts are the work horses of bone tissue, and actively secrete extracellular matrix (ECM) made up of collagen, hydroxyapatite (HA) and calcium phosphate (CaP). Osteoclasts function as a foil to osteoblasts, and actively destroy the ECM. These cells are derived from the hematapoetic cell linage (white blood cells, specifically macrophages). Osteocytes are long lived stellate-shaped cells that have become trapped within the ECM they secreted (as osteoblasts) and have terminally differentiated (essentially gone into retirement). Osteocytes have a role in hormonal regulation in bone. All these cells work in concert to actively remodel and maintain mature bone tissue. In endochondral ossification, the ECM of bone is laid down in a sort of 'trial structure' where the collagen is laid down but the ECM is not ossified (mineralized). This occurs in the long bones such as the femur, tibia, humerus, radius, ulna, and facial bones. This first allows the general shape of the bone to come to form without wasting valuable mineral resources (collagen is a protein, and essentially ubiquitous in the body). During gestation, the collagenous structure is resorbed and then partially ossified except at the ends, the epiphyseal plate. This is the 'growth plate' visible in pediatric x-rays as a non-ossified line across the bone. It's not that the bone is discontinuous, but rather the ECM is not yet ossified. This allows the bone to grow in length by simply depositing mineralized ECM along the epiphyseal line, displacing the growth plate. At puberty, hormonal changes cause phenotypic changes in the cells at the growth plate and the growth line ossifies, or closes. In intramenbranous ossification, there is no 'trial phase' where the collagen is resorbed but instead the ossification occurs directly. this occurs in the flat bones of the skull, sternum, vertebrae, pelvis, and ribs. While these bones do grow during life, they are much more important as protective entities and therefore their ossification is prioritized. In all bone growth, osteoclasts help break bone down so that osteoblasts can lay more, new bone down. Essentially, you have to destroy what is already there to grow bigger. This is a very brief overview so if you have further questions feel free to reply or message me. Hope this helps.

Why is physics so goddamn confusing? An acceleration question.

I don't understand what problem you're asking about. It's very possible for a mathematical function to go from zero to nonzero without its derivative jumping to infinity, so if you're modeling velocity as a mathematical function there's no problem here. In addition, there's nothing special about zero velocity; if you do claim that an object has to go through discontinuous acceleration to get from zero to nonzero velocity, then you're also claiming it has to go through discontinuous acceleration to get between *any* two velocities. Now, if space and time do happen to be discrete, then it's true that velocity and acceleration functions won't actually be continuous. But except on very small scales, they will LOOK continuous, which is all you need for newtonian physics to make sense.

My mom inherited a photo album which once belonged to a WW2 German soldier. Can anyone recognize any of these faces? (imgur link)

Ok! I think I have something Hitler receives a briefing on the tactical situation in Poland from General List (with glasses). Behind Hitler are General Keitel and General Yodl (with forage cap) both of the Supreme Armed Forces HQ. Sept 1939. _URL_0_ List? _URL_3_ _URL_4_ Keitel (back) and List? _URL_2_ Keitel 2nd from right? _URL_1_ Edit: Keitel? _URL_4_

How much social mobility was there in the Late Roman Republic? What could a city dwelling plebeian do to improve his station?

The "average" urban inhabitant was an impoverished day laborer who live on the edge of starvation and was semi-homeless. In all likelihood he would die in the same condition he lived, probably relatively early due to the disease rampant in the more crowded parts of the city. He had no education, although he might have some functional literacy. He had next to no connections. If he was lucky enough to know a trade he might be decently well-off, but only a minority of the urban poor were skilled laborers of any kind. He owned no property of his own and he and his family (which might be quite large, given mortality in the city) lived essentially a hand-to-mouth existence daily--in short, it kind of sucked. The older view of the urban poor as a parasitic "idler population" living on state largess has been thoroughly torn to shreds by this point. The urban plebs had to work to survive, and work quite hard. Day-laborers in the city either found work or did not--a day without work might be a day without food. State-subsidized grain, initially with a reduced price following the Gracchi and then for free following Clodius, maintained limits on the amount that could be collected per family, and though it might have been barely enough to feed an individual it wasn't close to sufficient for a family. The more regulated grain prices of the Augustan Period helped the urban poor to purchase additional grain on the market, but in the late Republic the price of grain was notorious for fluctuation, both by natural famine and artificial manipulation and market speculation. Further, free grain was only available during a brief period between Clodius' tribunate and Pompey's assumption of the *cura annonae*--under Augustus a further requirement, a hereditary token, was added and the state-subsidized grain became the hereditary privilege of a relative few. Besides grain (most day laborers could probably afford little else to eat on a regular basis) and the need to buy clothes, rents in the city were notoriously high. They were often paid daily, which might have been somewhat accommodating given the need to migrate through the city looking for work, but their high cost probably meant that for many laborers a day without work might have been a day without food or shelter. To pay for all this were wages, paid daily according to the ability to find work, at staggeringly low values. Cicero's comment of a denarius a day for even an unskilled slave is almost certainly inflated, but even if we take it for the norm it's depressingly low given what we know about the cost of food and rent--for a family, which might have multiple members unable to work but consuming resources, it might be devastating. If this new opinion of the urban poor is rehabilitating in comparison to the "idler population" of the past, it also has serious repercussions when speaking of the involvement of the urban poor in politics and their social mobility. There's something of a debate about how "democratic" the Republic was, and central to it is how much the urban population, the vast majority of which was horribly poor, actually was involved and kept up. There's a great deal of evidence that suggests that no matter how much the urban poor might have *wanted* to be involved (a question which itself is debatable) a good chunk of it simply could not. A day listening to a *contio* might be a day's work missed, and with it an empty stomach. Those who missed work, we can be sure, might have found themselves able to participate--there are lots of propositions regarding what the work-less did on their off days. But ideally this didn't happen, at least not often or by choice. Besides this the urban poor was a rather impermanent population. Disease swept through the slums of the city, and *insulae* caught fire or collapsed constantly due to shoddy building techniques, more concerned with saving construction money than good workmanship. Seasonal laborers entered the city during the slow part of the agricultural year to make a quick buck or two at the monumental building projects or down at the Tiber warehouses--with them they brought new diseases and caught some that they had never been exposed to before. Even the "real" urban population was semi-migratory, since their constant search for work and daily rents probably forced many of them to move around periodically. The case has been plausibly made that those most capable of regular political participation were the so-called *plebs media*, those members of the urban poor who had skilled trades and possibly owned a little shop or business of their own. They were hardly well-off, but they were not so wretchedly poor as to be unable to leave their shop for a day for fear of starvation. We hear of fabulously wealthy freedmen like Trimalchio, mostly people who inherited some wealth from their former masters. Most freedmen were part of this *plebs media*, however--in fact, they may have dominated it. Our epigraphical evidence is problematic, but something like 60% of goldsmiths, to take a common example of city workmen present in inscriptions, are freedmen--of the other 40% nearly all are slaves. There are problems with assuming this is strictly representative, but it is certainly telling--the number of skilled freeborn laborers in our inscriptions is incredibly small, even given the general trend for freedmen to be more prevalent in epigraphic material than poor freeborns. "Social mobility," no matter how we're defining it, was probably out of reach for most of the urban poor, barring a colonization project or the like. Contrary to what you suggest, military enlistment was rare in the city, most soldiers were country boys. For an unskilled laborer the chances of getting out of abject poverty were slim--with a skilled trade this was more likely. It's probably not *that* surprising that freedmen appear more common in skilled trades, since many freed slaves would have been trained in a trade while slaves, and had close ties with patrons that they could take advantage of to help start businesses--for most freeborn day-laborers, many of whom were coming into the city for the first time, such connections did not exist. Skilled workers, and therefore freedmen, were more likely to rise to minor or local magistracies--a Hadrianic inscription set up by nearly 300 *magistri vici* (the minor elected magistrates who oversaw the *vici*, or neighborhoods--their duties and power in the late Republic are uncertain, but under Augustus they were more or less just there to maintain local cults and little else) lists only 13% of its members as clearly freeborn. In the Augustan Period membership in the *vigiles* or other minor associations might be a good way to start moving up, although this was probably a dead end. More promising might be work as one of the attendants of a magistrate, the *apparitores*. The most famous of these were the lictors--this office was often held by ex-centurions, but *apparitores* included scribes and messengers and so forth, which were frequently freedmen but could also be of course freeborn, usually members of the *plebs media*. A patron's influence was often crucial--one famous inscription set up for a deceased freedman notes that this freedman's son was able to secure a military tribunate thanks to the help of their patron and his former master. Patrons generally had much closer ties to their former slaves, however, than to just any poor shit, and of the poor shits that weren't their slaves familiar faces like the butcher and other skilled laborers were more likely to receive help--who the hell remembers the poor day-laborer, a face in a sea of faces, who might not even be alive a week from now? From there there might be ways forward, although it might take years or generations--your children were more likely to get somewhere than you were

how will the james webb space telescope look for alien life? where will astronomers look first and what type of life might it detect?

So there are 2 ways we can observe planets: 1) When a planet passes between us and a distant star, the light dims. It also changes the color of the star's light. The difference in color and the amount of dimness tell us about the size of the planet and the chemical composition of it's light reflecting atmosphere (if it has on) and its surface. 2) Put a light shield between the telescope and the star. The point is to block out the star's light so it doesn't saturate the camera, even if it's a very distant star, and a mere point of light. This will allow the camera to resolve the light reflecting off the planets in its orbit. We can see these planets this way without them being directly between us and the star, and we should be able to see more light from them. There's also a way to detect planets without seeing them, and that's to measure the wobble in a star's orbit, but this only really works with planets large enough to make a detectable wobble, so, gas giants. If I were an astrophysicist looking for life - I'd look for atmospheric chemicals that are signs of life. There are organic compounds built from amino acids, methane, that comes from organic processes, but these might not be totally reliable. We have one example of life, and that's here on Earth. Life here is aerobic, it relies on oxygen, and plants produce it as a byproduct (life began here before we had an oxygen atmosphere as well). But the dead ringer about an oxygen atmosphere is that oxygen is chemically very reactive, so it would not exist in abundance in an atmosphere on its own, and would inevitably all react with its environment to make other compounds. If we find an oxygen rich atmosphere, the only way we know how that could happen is from life. And that's it, our search for life is searching for life as we understand it. There may be other forms of life, like on our early Earth, but not likely. Life here is made of hydrogen, oxygen, nitrogen, and carbon. These also happen to be the 4 most abundant elements in the universe, aside from helium, which is chemically inert. They're also the 4 most chemically reactive - you can make more molecules out of carbon alone than you can make out of all the other elements combined. If life is going to form, it's likely going to do so using the most abundant, reactive materials around. Exotic forms of life formed out of rarer and more exotic elements aren't necessarily impossible, but unlikely. So we're looking for what we know. And if we spot something really weird, and we can't explain it any other way, maybe we just might consider the possibility of exotic life.

What attempts have there been throughout recent history (most likely during genocides) to specifically erase the culture of a group?

Raphael Lemkin, the man who coined the term "genocide", defined it this way: > Generally speaking, genocide does not necessarily mean the immediate destruction of a nation, except when accomplished by mass killings of all members of a nation. It is intended rather to signify a coordinated plan of different actions aiming at the destruction of essential foundations of the life of national groups, with the aim of annihilating the groups themselves. The objectives of such a plan would be the disintegration of the political and social institutions, of culture, language, national feelings, religion, and the economic existence of national groups, and the destruction of the personal security, liberty, health, dignity, and even the lives of the individuals belonging to such groups. From this perspective, mass killings are an *instrument* of genocide, not the definition of it. In any case, a case can be made that the treatment of native american groups by the US government qualifies. For the last several hundred years, one of the prevailing attitudes held by officials towards natives was the "kill the indian, save the man" ethos. In other words, initiatives focused on assimilating natives into mainstream US society, usually by abandoning previous cultural traditions. The Dawes Act of 1887, for example, granted the President the authority to divide reservation land into individually owned plots, trying to make native americans private citizens of contemporary US society rather than members of tribal organizations. For some groups, this disrupted traditions of communal living that had wide-ranging impacts on their way of life. This was one of a number of attempts to compel large, semi-sedentary native groups to become sedentary farmers and property owners. Besides this, the Bureau of Indian Affairs regularly adopted policies to encourage the use of English and conversion to Christianity at the expense of indigenous traditions.

if everybody has dynamic ip addresses now, how do websites ban people?

Many people don't have dynamic IP's, and there are other ways to determine someone's identity, especially the average child who gets banned and wants back. Having said that, as you can see from the endless parade of "young" accounts in places like T_D, Politics, and anything with "New" in it... there are limits. A dedicated, informed, and slightly careful person who doesn't actually care about any one identity is essentially impossible to ban. Most people don't want to make an endless stream of new accounts though, all while pretending to be different people. If they don't do that, then over time they're busted again and banned. In short, it can be hard for the average user to get what they want out of a site *and* be banned... even if they dodge that ban. The problem is that if your only goal is spread a message by whatever means, spam ads, or just troll... then you don't care about any of that, do you? If that's your game, then bans are just the cost of doing business, you switch your IP (with a paid service) and roll a new account. You see a *lot* of that in any sub where politics is at play. The thing is... *most* people using Reddit aren't just trolls (even tif they think they are) or shills... they want to interact with people, they want to be known, they want to express themselves. You can't do that under a ban on Reddit, and on a smaller site it's *much* easier to spot that NewGuy0001 sounds exactly like OldGuy1000, has the same views, etc.

Why was there no invasion by sea of the north of Germany?

While more can be said, I've previously discussed British plans for amphibious assaults during WWI in the following threads: * [ I was listening to the podcast on the Battle of Jutland, and "..Land a million Russians north of Berlin, and boom..The War's over in a few weeks" caught my ear.](_URL_2_) * [Why didn't the triple entente stage a naval invasion behind the western front in WW1?](_URL_3_) * [Had the North Sea theatre been secured by the British, could the Entente have landed in Northern Germany in WW1?](_URL_0_) * [Was landing soldiers behind enemy trench lines ever considered by either side on the Western Front during WWI?](_URL_1_)

what was the quiet revolution in quebec?

"The Quiet Revolution, which is a term applied to the changes that took place in Quebec from the late 1950's to the late 60's, was a time of great change in the province. The politics and social life of Quebec had been dictated by the Provincial Premier Maurice Duplessis since the 1930's and in a sense it was a throw back to the conservative movement in Quebec when Laurier was trying to break the church, business, nationalistic hold on the province in the 1890's. Quebec had developed slowly under Duplessis and the Union Nationale and at the cost of personal freedom and real progress. A pent up demand for change was released when Duplessis died in 1959 and this was signified by the election of a Liberal government in 1960. Suddenly government action seemed to be the answer to everything. Taking control of the hydro-electric power in the province, nationalising industry and services, legislating rights for the French Canadians, many of who were beginning to describe themselves as Quebecois rather then any type of Canadian. The sixties were a period of increased government involvement in social affairs in many western countries and Canada was no exception but in Quebec the restless energy of change incorporated a revived feeling of nationalism which Duplessis had suppressed for a generation. Young French Canadiens were looking at who ran their province and the English Canadian control over business and decision making. The general revolutionary tendencies in other countries and societies during that era took on a nationalistic twist in Quebec and a new feeling of independence and empowerment developed. As the Liberals pushed through their dynamic changes provincially, the Federal Government plugged along under Diefenbaker and then Pearson with no real dynamic emphasis on change. Some who joined the Liberal revolution such as Rene Leveque pushed hard for the taking control of events by the government and hence, in his mind, the Quebecois, but as he came o recognize the limitations of the power of the provincial government, his believes evolved towards new frontiers and the choice between additional change through the powers of the Federal Government or re-establishing the rules and division of powers between the feds and the provinces. This was the first step towards sovereignty association or separatism. Most Quebecers and Canadians felt that something was happening in Quebec, changes that were hard to identify, shifts in attitudes and objectives and an arising new option for French Canadians to consider. The young were ultimately influenced by the quickening pace of social change around the world and, for some, their sharp turn to the left also included the option of violence. The term quiet really refers to change that occurred that was not announced, not broadcast, not displayed or described. It referred to the acceptance by many Quebecers that there might be another way, one that challenged the status quo, demanded equal rights for the French language, recognition of the Quebecois as a unique nationality with unique needs and aspirations and above all one in which the French Canadians were true masters in their own province. The progression of this political change would ultimately lead to violence as objectives were not meet, aspirations unfulfilled and demands no caved into. This would lead to one of the most tumultuous and fierce confrontations in Canada over the place of the French Canadians in Canada and ironically the two leading protagonists would both be French Canadian with Pierre Trudeau defending Canadian Federalism and Rene Levesque fighting for an independent Quebec." Source: _URL_0_

so, murdering is pretty illegal. in times of war, why is it not illegal to kill an enemy soldier and why aren't there ramifications for it? is there a special set of laws in place when nations are at war?

Yes, there are certain international 'laws' and treaties that we use to regulate a war. The two most famous ones are the Hague Conventions of 1889 and 1907. In these treaties the participating nations outlined what is wrong (a war crime) during a war, and what is considered to be acceptable. They also tried to distinguish between combatants and noncombatants, i.e. soldiers and civilians. According to those treaties it is legal for combatants of either side to kill the other sides combatants. It is generally prohibited to harm/attack/kill civilians/noncombatans, even though we know that in recent times those rules were not followed. Feel free to ask anything more.

Why is veiling a practice done today and in history almost entirely by women? Why isn't veiling done among men?

I'm not sure the premise of the question here is accurate for two reasons. 1) Veiling suggests a covering of the *face*. There is - to my knowledge anyway - no religion that mandates a full face covering. Even the examples you cite are not veils covering the face, but various forms of hair coverings (so hijab, "Christian veils", habits, etc.). While the niqab and the burqa both cover the face in some Islamic traditions, they are not a majority by any means, even among Muslims. But I'm going to assume that this is just an issue with terminology, which brings me to my second point: 2) There are several religions in which men are instructed to cover their heads for religious purposes. Two of the most famous would be Judaism (*Yarmulke* a.k.a. *kippah*) and Sikhism (*Dastar* a.ka. Turban). In both cases the wearing of a head covering is mandated by the religion itself for various reasons, but mostly as a sign of devotion to God. In fact, the term *yarmulke* even means "reverence to God" in ~~Hebrew~~ Yiddish, and the requirement is not limited to Jews alone. If you've ever been inside a synagogue - especially a conservative or orthodox one - you were very likely given a paper or simple cloth *kippah* to cover your head while inside the grounds/building. As for Sikhs, I know less about that religion, but as I understand it, baptized Sikhs are forbidden from cutting their hair, again as a sign of devotion to God, and are required to wear the Dastar as a sign of piety and devotion. I should note, as well, that among Catholic and some Orthodox clergy (so among men), a form of skullcap called a *Zucchetto* is also quite common, although whether its mandated or not, I couldn't say. edit: words edit 2: thanks for the correction u/alice-in-canada-land

hi, i'm not smart but i know how to read, can someone tell me why rockets/spaceships don't go straight up into space but instead curve ? and are they controlling that or does it happen naturally?

An orbit requires a large sideways velocity in order to avoid falling back to Earth. But air gets in the way of going that fast so they first get high then turn to the side to accelerate. They certainly control every aspect of that curved launch path.

Has anyone in the CIA faced legal consequences for MKUltra, or for covering up MKUltra?

Project MK-ULTRA was first exposed in 1975 by the Church Committee and Gerald Ford's Rockefeller Commission. It got a lot of bad press, coming on the heels of Watergate at a time when outrage over the executive branch and distrust of gov't officials was already widespread ([you can see the WashPo article for it here.](_URL_1_)) A guy named John Marks read this in the Rockefeller Commission report: “The drug program was part of a much larger CIA program to study possible means for controlling human behavior. Other studies explored the effects of radiation, electric-shock, psychology, psychiatry, sociology, and harassment substances." Marks filed a FOIA request for all the information the CIA had on behavior control but it turned out that post-1963/Watergate, then-CIA director Richard Helms ordered all MK-ULTRA evidence to be burned. Marks' FOIA request turned up the only documents that were spared from the purge- some retired records of the Budget and Fiscal Section of the CIA. These documents were overlooked when the Church Committee and the Rockefeller Commission asked for the documents previously. [Source.](_URL_3_) So following Marks' FOIA requests there's [a spate of Congressional hearings](_URL_0_). Senator Edward Kennedy spearheaded these and they weren't more than a slap on the wrist for the CIA. Plus, it had already been over a decade since MK-ULTRA had ended, and most of the employees directly involved in it had either retired or moved on to other jobs. No employees involved with MK-ULTRA ever faced repercussions for the project. Every CIA official testifying before Congress in 1977 emphasized how they were merely there to provide helpful information about the actions of the generation of agency officials before their time. Even the senators conducting the questioning stated "It should be clear we are focusing on events that happened over 12 or as long as 25 years ago." So even in these hearings, there was a distinct sense that the testing had been finished, the agents responsible all shuttled off to different projects or different jobs altogether, and the climate had entirely changed. Some people who had been unwitting experimentation subjects did sue the U.S. government, including Wayne Ritchie, who had a breakdown after a Christmas party back in 1957. MK-ULTRA agent Ike Feldman, in a sworn deposition, called Ritchie "a nitwit" who "had been given a full head and deserved to suffer". But even then, the court found [insufficient evidence that Ritchie was an unwitting subject at all](_URL_2_) (this goes to the difficulty of litigating cases in which you were never supposed to have known you were being experimented on in the first place.) It's also important to note that MK-ULTRA researchers specifically targeted vulnerable populations like criminals with drug abuse backgrounds (including people in prison) or johns spending a night with prostitutes (the CIA set up [safe houses](_URL_4_) with two-way mirrors to watch prostitutes engaging with these men, with the full knowledge that the men would already be in too compromising a situation to press charges). The only Supreme Court case related to this, CIA v. Sims, grew out of Marks' FOIA requests. The case was about whether or not the CIA should release the names of university/hospital researchers funded through MK-ULTRA outreach-type programs (there were university researchers doing work on sleep deprivation and interrogation methods and isolation's effect on self-image). The Supreme Court ruled in favor of the CIA, saying that it wouldn't be able to uphold national security if it couldn't guarantee confidentiality of intelligence sources. [Or as Chief Justice Burger wrote it](_URL_5_), "We seriously doubt whether a potential intelligence source will rest assured knowing that judges, who had little or no background in the delicate business of intelligence gathering, will order his identity revealed only after examining the facts of the case." So if anything the only major case to grow out of the entire debacle of a project only reinforced the CIA's discretionary powers. TL;DR: Yes, it was illegal, but it was super hard to hold anyone accountable. Mostly due to a deliberate efforts by the CIA. They failed in the MK-ULTRA experiments to figure out a way to productively induce amnesia in people, but they did a great job erasing their own records and effectively employing institutional amnesia.

why do automotive engines idle around the same rpm regardless of number of cylinder count?

So the alternator can charge the battery. And you will have enough torque to move effectively.

why are there no huge animals?

Oxygen percentage in the atmosphere. When it was about twice as much as it is now, we had dinosaurs and insects as large as dogs. Give it a little higher percentage and who knows what could have roamed the earth

how to companies benefit from letting you file your taxes for free

E-filing your taxes costs them basically nothing. So while you're doing your 1040EZ for free they can advertise their other services to you. It's a good way to get your eyeballs on their site for a guaranteed 20-30 minutes.

why do farts sometines feel like bubbles popping when they come out?

The gases that were initially roaming free and occupying the wider breadths of your intestines now have to squeeze into the narrow constriction of your sphincter. This pressurizes them akin to packing into a bubble, and as the sphincter relaxes and contracts that gives you your pop.

since we're all moving at very high speed in space caused by the 1.rotation and 2.revolution of our a.planet, b.solar system, c.galaxy, etc.. how do we know that our measurements of distance are accurate?

That's the basis of one of Einsteins biggest theories. The gist of it goes that all observations around you are based off of the Frame of reference you are in. For example. Two astronauts are next to each other and use a jetpack to move away in opposite directions. To one astronaut it would seem that he is standing still and the other guy is moving away. To the other it would be the same thing but he would be standing still. For a third guy looking at both astronauts, the two would be moving away from eachother. It's literally all relative. With time it gets a little trickier. Because as you go faster time begins to slow down. But it's the same general idea. If your moving fast enough, time would seem to go normally to you. But if someone was staying still relative to you, they would see you slowing down more and more the faster you go. So for every human being on earth going basically the same speed. It really doesn't matter because most measurements are going to be the same. We actually have to consider this with satellites in space. They are moving much faster compared to us. So we have to compensate for their clocks going a tiny bit slower than us.

What did Eva Perón actually do for Argentina?

To some extent, I agree with your assessment. The praise lavished on her, going so far as to call her a saint, goes beyond the scope of her accomplishments. She didn’t end poverty in Argentina. She didn’t destroy inequality. She didn’t create an worker-centered economy that withstood the shocks of modernity. And she didn’t somehow prevent the period of state terror that rocked Argentina in the coming decades (how could she after all?). However, I think the accomplishments you mentioned are still worthy of significant praise. First, one cannot understand Eva without contextualizing her position within the Peronist system. The recent historiography on the Peróns demonstrates that their system offered tangible financial and workplace benefits for the average person. The working classes were not manipulated by eloquent demagogues saying whatever the people wanted to hear; their followers had a lot more agency in this movement than is often acknowledged. The working classes adored Juan and Eva because they offered viable change for people that had previously been excluded from Argentine political discourses. As a central figure of this movement, she gained a massive following who regarded her in many ways as “one of them.” Her speeches captivated audiences and rocketed her to fame because the message of the Peróns was one that people wanted to hear. She died at the peak of her popularity, which in some ways allowed Juan to use her image as a symbol that transcended her legitimate legacy. But when we examine her accomplishments from a historical perspective, Eva contributed some important changes beyond worker involvement that resonated throughout twentieth century Argentine society. Though not the only woman involved, she played a significant role in the women’s suffrage movement, helping to break down a culture heavily influenced by machismo. She was also one of the first Argentine women to take center stage in the political arena for which she was initially ridiculed. She formed the Partido Peronista Femenino, which eventually helped more women serve in Argentina’s congress than at any other time in Argentina’s history. She championed anti-discrimination laws that guaranteed equality of the sexes before the law and within marriages. Though women’s rights struggled following Perón’s downfall, these changes were adopted by later Argentine governments. She also worked to protect the rights of the elderly, who had largely been ignored by previous governments; this included writing equality into the Argentine constitution. In terms of welfare, her foundation constructed dozens of hospitals, retirement homes, shelters, and schools around Argentina, distributed millions of charitable items each year to needy families, and found jobs for hundreds of thousands of unemployed workers in the provinces. Her foundation also provided free medical check-ups for over 300,000 needy children. According to Tomás Eloy Martínez in *Santa Evita*, “in the first six months of 1951, Evita gave away twenty-five thousand houses and almost three million packages containing medicine, furniture, clothing, and toys.” All of this in less than a decade before she passed away. The effects of this state welfare resonated in Argentine political culture throughout the twentieth century as the government struggled to strike an appropriate balance between free market economics and the welfare culture that Eva helped establish. It would be wrong to say that Eva was the sole contributor to this phenomenon, but she certainly contributed to a period whose effects still reverberate both positively and negatively. In this light, it is hard to ignore her influence, especially in the area of women’s rights and political culture. And perhaps this illuminates a little bit the place of women’s history in our imaginations. How much should we value personal and political accomplishments in the historical narrative? What is the place of individuals and their complicated legacies when they don’t fit as well in our traditional definitions success and failure?

In the High Middle Ages, what sort of unarmed combat training did knights receive?

I actually do some of this!* It's a lot of grappling and what is best compared to judo. You train mostly out of armor, but most of it translates very well to armored combat too. The only differences between armored and unarmored are the places you can hit and your center gravity. Punching someone in plate isn't going to accomplish much, the most you can hope for is to put them off balance (which very important actually.) That, in armor you need almost squat, since you'll be wearing so much more weight up high. It's 2am thanksgiving where I am, but I'll try and edit in some links later. [Grappling]( _URL_0_ ) [Illustrations from Talhoffer's second treatise]( _URL_1_) *not very well, but still.

what is the difference between casualty and property insurance?

Casualty is for people and property is for items?

can fighter aircraft detect when they’ve been “locked on” like in the movies, if they can, how do they know?

Yes, it's absolutely possible for a fighter craft to know it's been locked onto. In order to home in on something, you have to know where it is, and one way to know where things are is to use *radar* -- that is, send out a beam of radio waves that bounces off of objects and comes back to the transmitter, painting a picture of what's around it. A radar system has to scan the entire sky, so the number of times the radar track hits a target aircraft in a minute is relatively low. When a radar system sees something it wants, it turns on a different radar that scans much more quickly to provide more accurate tracking data to the missile. Aircraft can determine how quickly they're being painted by radar; if they're being painted very rapidly, that probably means a radar-tracking missile has acquired them. There are other types of missile guidance that are harder to detect; heat-seeking missiles, for example, don't rely on signals bounced off the target, so an aircraft can't know one's on its tail.

Did flightless birds like ostriches evolve from surviving Dromaesaurs or flying birds?

There was a great article in National Geographic from May of this year that explains this. [Here it is.](_URL_0_) Here is the basic answer though: all flightless birds likely trace their ancestry back to a flying relative. They likely began in the southern section of Pangea and when that broke up they were dispersed and each land-locked group evolved in place.

After decolonization in Africa why did so many nations keep the native language of their colonizers as their official language rather than returning to their historic, local languages?

The borders you see today are not necessarily drawn based off which group of people live where. But more remnants of colonial administrative districts. Two different peoples speaking two different languages will fall back on the common one, regardless of its origins. Therefore the use of ex-colonial languages. _URL_1_ Notice the similarities? Ethiopia, Somalia, Cameroon, Angola, The Congo, Sudan and a number of coastal west african nations are basically the same as they were drawn by the colonists. Here specifically the 1914 partitions. Here is a very detailed ethno-linguistic map with which you can zoom in on, compare it with the borders drawn in 1914, and those present on the map, or a modern one. _URL_0_ Even the "uniform" Green section denoting Guinean languages is fractured as each colour represents a language group, rather than a language. There is no guarantee of decent intelligibility between two languages. People speak english, French, etc because it the administrative language before independence and it was the only one with which they could seriously communicate between ethnic groups that spoke different languages. This is somewhat of a generalization however because recent changes in borders are changing the trend. For example, in this old map, the Sudan is a single country. The country split into two in 2011. As you can see, the southern part of Sudan which split was dominated by a different ethno-linguistic group than the North. EDIT: Added a map, elaborated a little.

how do cinemagraphs work?

They are .gifs someone takes a video or a segment of a video and they cut and play with it until it's seamless. The start of the .gif has to match the end as best the editor can perceive.

in gay marriage ban challenges, why is there never a reference to the full faith and credit clause?

Because they are not arguing for their marriages in one state to be recognized in another state (most of the time), they are arguing for the right to be married in that state. Different point on the timeline. For the Full Faith and Credit clause to be in effect, the couple would have to be married already, which is largely not the case.