question stringlengths 3 301 | answer stringlengths 9 26.1k | context list |
|---|---|---|
Good place to find scholarly sources | Not to be snarky, but if you had read the sidebar, you'd have seen the handy [list of sources](_URL_0_) there that was recently put together for precisely questions like this. | [
"These resources are available at many leading research universities throughout the world (usually universities with reputable Japanese studies programs). One will need to check each individual library's collection for information about the availability of these sources. WorldCat is a good starting point.\n",
"St... |
why aren't we more concentrated on space exploration and colonization? | The cost-benefit ratio is too high. Anything you want to do in space, you've got to spend an assload of energy--which isn't cheap these days, to get it out of our gravity well. Also, what we've found so far is that human beings have evolved for Earth and are really not suited to space. | [
"Space programs have generated a wide range of hardware, software and processes that have made their way into a myriad of applications. The benefits of these applications are directly attributable to the original investments made by the space agencies and the private sector. Space exploration alone has provided a s... |
If the Moon had the same terrain as the earth, would it still light up the night? | It would in fact be much brighter if its surface was similar to Earth! With its current surface, the moon has an albedo of approximately [0.11](_URL_2_) compared to Earth's ~0.3-0.35. This means the moon reflects only about 11% of incoming radiation while the Earth reflects over 30%. In fact almost all natural terrains have [higher albedos](_URL_1_) than the moon- especially ice caps and clouds!
This makes a big difference- from the moon, our earth appears as roughly [100x](_URL_0_) brighter than the moon is here (a combination of the larger size and greater albedo). As to what exactly the relationship between albedo and brightness is I'm not sure, you'd need to confirm with a proper astrophysicist, but if it's directly proportional you'd expect the moon to be ~3x brighter if it had a surface like the Earth. | [
"Since the Moon's axial tilt relative to its orbit around the Sun is nearly zero, the Sun traces out almost exactly the same path through the Moon's sky over the course of a year. As a result, there are craters and valleys near the Moon's poles that never receive direct sunlight, and there may exist mountains and h... |
How does Platelet-Rich Fibrin cause increased healing if its just our own blood? | The short explanation is that these things circulate in an inactivated form. When an injury happens, tissue plasminogen activator and other substances start activating a bunch of reactions that causes the fibrin to cross link. And recruit fibroblasts to the area. | [
"In inflammatory conditions in which fibrin is deposited in tissues, PAI-1 appears to play a significant role in the progression to fibrosis (pathological formation of connective tissue). Presumably, lower PAI levels would lead to less suppression of fibrinolysis and conversely a more rapid degradation of the fibri... |
What is an aspect of everyday life in early or late medieval life that is either very interesting and unknown or often overlooked? | Here is one.. The 'typical' Medieval European serf ate:
Lard
Butter
Beer -- The reason for this is not simply they wanted to be drunk all day, but that the alcohol killed the bacteria in the water.
And probably a few other things, but those were the staples. | [
"On the other hand, many historians now point out that most of the negative social factors popularly associated with the medieval period—poverty, warfare, religious and political persecution, for example—seem to have worsened in this era, which saw the rise of Machiavellian politics, the Wars of Religion, the corru... |
Did any Native American cultures practice map making or route recording? | While I love talking about this topic, I unfortunately don't have the time for it now. [Hopefully my past self and company from a little over a year ago can handle it for me](_URL_0_). Also, you'd probably be interested in [this section](_URL_1_) of the FAQs. | [
"He found the Handbook of North American Indians to be very helpful in constructing his maps. He cross-referenced the book with other sources such as missionary records and army records to determine where a European trader reported that he met a particular tribe. This allowed him to narrow down the locations of tri... |
if the universe were like google earth, and we zoomed out to the maximum, what would we see? | We don't know 100%. The observable universe is huge with billions of planets, but we are only just now really starting to look at the nearest ones outside of our solar system. | [
"Cosmic Eye is a short film and iOS app, developed by astrophysicist Danail Obreschkow. It shows the largest and smallest known scales of the universe by gradually zooming out from and then back into the face of a young lady called \"Louise\". According to the developer, the film and app were inspired by the essay ... |
Were there ever any snake-worshipping cults such as the one in Conan the Barbarian? | This one is not very Conan-ish, but Alan Moore has talked a bit about the [cult of Glycon, the snake puppet](_URL_5_).
There's a better profile about how it worked - why a charismatic puppeteer could attract followers to worship a wig-wearing snake puppet for more than a century - [in a *Fortean Times* profile of Alexander of Abonoteichus](_URL_3_).
A couple of snips from that article:
> We only have one source for his life story, an extremely hostile attack by the satirist Lucian (c.120–180), who came from Samosata in Syria and may have met Alexander in person, probably about 162.
...
> Alexander is described as tall, long-haired and good-looking, and Lucian accuses him of prostitution as a youth, through which he became apprenticed to a doctor and magician, apparently taught by the Pythagorean philosopher and wonder-worker Apollonius of Tyana (early 1st century–c. AD 98). After the doctor died, Alexander travelled with a chorus-writer from Byzantium nicknamed Cocconas, making a living as quacks, magicians and conmen. Latching on to a rich widow, they headed for Pella in Macedonia, noted for its huge, tame snakes, and bought one for a few coppers. Then, ditching the widow, they decided to set up in the oracle business.
>
> Heading for Chalcedon, they buried bronze tablets in the temple of Apollo, announcing that the god and his son, the healing deity Asclepius, would soon be moving to Abonoteichus. When these were ‘discovered’ the news spread like wildfire, particularly to Abonoteichus, where the townsfolk began to build a new temple in readiness. ....
>
> His status as a prophet and healer foretold by similar oracles, Alexander arrived claiming descent on his mother’s side from the hero Perseus (he said his father was Podaleirius, son of Asclepius), and chewing soapwort so he foamed at the mouth, an obvious sign of the ‘sacred disease’ epilepsy. Inserting a live baby snake in a blown goose egg, he hid it in a puddle in the foundations of the new temple. Next morning, he ‘miraculously’ discovered the egg, broke it, and revealed his new deity: snakes being particularly sacred to Asclepius.
>
> A few days later, Alexander presented his serpentine god to the astounded population, miraculously fully-grown, with a somewhat human-looking head and now called Glycon (‘Sweetie’). This, we’re told, was the gigantic snake Alexander had bought in Pella, which he held wrapped round his body with its head tucked under his armpit, while holding a false head supposedly made of linen, with horse-hairs inside that could be pulled to make the mouth open and the tongue shoot out.
Basically, people would come into the sacred space, write down important questions about their lives on scrolls, Alexander would take them overnight and, without unsealing them (ostensibly), come up with answers from Glycon. Or, in personal audiences, Alexander would whisper questions into the snake-puppet's ear, and Glycon would deliver a kind of mystical answer through what Lucian described as a pretty complicated ventriloquist arrangement:
> Lucian says this effect was achieved by making a long tube of crane’s windpipes, which ran from the linen head of Glycon to an assistant in another room, who then provided the answer.
The showmanship worked, and Alexander soon became enormously influential.
> Lucian imputes one more act of hubris to Alexander, which was persuading the emperor to change the name of Abonoteichus to Ionopolis, and to issue coins bearing Glycon’s image.
We know these things happened - some of the coins are still around.
But there are some doubts as to the accuracy of Lucian's account overall - he doesn't describe Glycon's iconography that well - and there may have been a more allegorical or metaphorical element to the whole transaction that Lucian glosses over. (That's Moore's contention, basically, although he also likes the idea of worshipping a deity who's an obvious fraud.)
----
Beyond Glycon, further north, Jörmungandr would be seen as a figure not unlike Rahab or Leviathan in the Old Testament - a reptilian beast that somehow is binding together or identified with the ocean (especially the ocean as a malevolent, destructive force). I doubt there were any shrines to the Midgard Serpent, though.
Further south, the West African deity who traveled to the New World as the lwa Damballah is strongly identified with snakes, appears as a snake, has snakes around his veves (icons, essentially). Like [so](_URL_4_) or [so](_URL_6_). (He's generally seen as part of a pair with [Ayida Wedo](_URL_1_), his consort, also snaky.)
The Kongo name for a closely related deity, *Nzambi*, is usually included in etymologies of the word "zombie" but really refers to a creator god or goddess who is sometimes associated with snakes - the "[rainbow serpent](_URL_2_)" is the typical motif there, and [elsewhere in Africa](_URL_0_).
And then, even further south, you'll find Python appearing in many Bantu folk tales - not really as an object of worship, but as someone who can be bargained with to get wisdom, or knowledge how to do something, or new sources of food (or, rainbow-serpent-style, to get it to rain).
| [
"Ancient Egyptians worshipped snakes, especially the cobra. The cobra was not only associated with the sun god Ra, but also many other deities such as Wadjet, Renenutet, Nehebkau, and Meretseger. Serpents could also be evil and harmful such as the case of Apep and Set. They were also referenced in the Book of the D... |
What was courtship/dating like in 1920s America? | There is more that can be said, but I have a few answers on the development of dating culture in the early 20th century:
[What did guys do to express interest in women before telephones became widespread in the 1900s?](_URL_1_)
[Did Flappers use birth control?](_URL_0_) | [
"The primary change in courtship rituals during this time was a shift from marriage to social status as the desired result. Before the 1920s, the primary reason for courting someone was to begin the path to marriage. It functioned as a way for each party's family to gauge the social status of the other. This was do... |
someone asked in askreddit and i thought eli5 would have good answers. if puerto rico became a state, could someone born there before they achieved statehood become president? | Puerto Ricans are US citizens by birth. Puerto Rico is not a state, but its US soil the same as Alabama or New York City. | [
"Former chief of the Puerto Rico Supreme Court José Trías Monge insists that statehood was never intended for the island and that, unlike Alaska and Hawaii, which Congress deemed incorporated territories and slated for annexation to the Union from the start, Puerto Rico was kept \"unincorporated\" specifically to a... |
What is the earliest philosophical text or oral history that we know of? | There is a reasonable amount of surviving Sumerian literature older than 2300 BCE. In particular the Enheduanna hymns are generally considered to be older than 2700 BCE. These are religious and theological texts so I'm not sure if they meet your criteria.
The Sumerian "Instructions of Shuruppak" is dated to around 2600 BCE, and is a collection of wisdom both practical (guidance on where to build roads) and moral (don't sleep with married women).
There are Egyptian writings from around 2400 BCE (the Pyramid Texts). These are also religious texts, but have some historic elements.
| [
"In China, the earliest history was recorded in oracle bone script which was deciphered and may date back to around late 2nd millennium B.C.. The \"Zuo zhuan\", attributed to Zuo Qiuming in the , is the earliest written of narrative history in the world and covers the period from . The Book of Documents is one of t... |
how does oil lubricate an engine without combusting or contaminating the fuel? | The fuel is sprayed into the cylinders, where it mixes with air, is compressed, combusted and then evacuated out.
Engine oil is not put directly into the cylinders. It gets pumped and directed to just about all of the other internal components though.
What separates the inside of the cylinder from the rest of the inside of the engine, is a set of piston rings. And actually, a tiny bit of the engine oil gets in between the piston rings and the walls of the cylinders and lubricates that movement.
As I understand it, a tiny bit of the oil does get caught up with the combustion of the fuel.
An engine has an oil consumption rate. So even if you don't have any leaks, you eventually do have to add oil. It's usually pretty low and most people simply get to an oil change interval before actually having to add oil. But some (likely older) engines can go though oil much faster and will need to be topped up regularly. | [
"Fuel oil in the crankcase lube oil can cause the oil to chemically degrade. This means that the oil loses viscosity and is less effective when lubricating. The loss of viscosity of the lube oil causes the oil to not fully connect and lubricate the moving parts of the engine. This lack of lubrication can cause the ... |
Were many scientific discoveries we think were made by men actually made by women they worked with? | Pickering's Harem comes to mind. I'm not an expert by any means, so I would love to see someone with more knowledge jump into this.
The basic outline:
Pickering was the head astronomer at the Harvard Observatory from 1877-1919. His male assistants were subpar for the work he needed (computations, filing, organizing) so he hired women at half the pay to do the same work. None of his discoveries would have been possible without their work.
Some of the women rose through the ranks to produce their own work. E.g. Annie Jump Cannon produced a system for classifying stars that is still in use today.
Questions for someone who actually knows about this:
* How much would these women have understood the science behind what they were doing?
* What was the social backlash for this at the time? The name "Pickering's Harem" has negative connotations now. I imagine it did then as well.
* How "progressive' was Pickering for the time? Was he interested in women's rights or cheap labor?
* Just how much does Pickering's reputation rest on the shoulders of these women? | [
"The men of the Academy expressed deep skepticism against the invention of a woman, and it took twelve years of testing, during which she had to fight among others the attempts of Reinhold von Anrep, General of the Artillery, to take credit for her invention, before the ministry of war approved it, recognized her a... |
Portugese Colonial War | Often lost in the discussion of Portuguese counterinsurgency is that it was not one but three conflicts centered around the major colonial holdings: modern-day Guinea-Bissau and Cape Verde, Mozambique, and Angola. While Angola was certainly a success militarily and Mozambique was going decently, the conflict in Guinea did not go particularly well and, arguably, was not much more effective than Vietnam. Below I'll discuss the Portuguese strategy and then go into some particulars about why some of the conflicts went better than others.
Portugal had been worried about a colonial war for some time. The Portuguese leadership was anxious about the spread of communism and the decolonization process by the other european powers resulting in a loss of their prized colonial holdings. This anxiety the creation of a formal counterinsurgency doctrine in 1960 called *O Exército na Guerra Subversiva.* Much like other counterinsurgency doctrines it emphasized population-centric action, a separation of insurgents from the general population via relocation and community self-defense. The doctrine is important to shaping Portuguese action during the subsequent conflicts because it incorporated lessons from the French and British experiences in colonial counterinsurgency and was completed the year before the colonial wars began in 1961.
In a somewhat ironic twist, Portugal's meagre resources relative to the US, UK, and France actually helped their strategy on the ground. The logic underpinning Portuguese action was to keep costs low enough to sustain the wars as long as necessary. A focus on affordability lead to some interesting efforts, such as the creation of cavalry units to patrol vast distances on the cheap and extensive recruitment of indigenous soldiers and auxiliaries to lower the costs of transporting troops from Portugal itself. The Portuguese also maintained a decent intelligence network that successfully infiltrated a number of rebel groups to spur internal strife and defections.
The Portuguese were also pretty successful in some instances of winning - or at least not *losing* - the hearts and minds of the local population. The Portuguese built more schools and medical facilities than they ever had during earlier colonial times. Often army manpower would be used on these projects, and Portuguese soldiers would be instructed to work as teachers, doctors, or construction workers during their off-time. Portugal also could not cause as much collateral damage as the united states did in vietnam because they did not have the airforce or the munitions to fight that way.
All that said, lets move into the individual cases, where we can look at specific factors instead of making generalizations.
**Angola**
Angola was the most successful example of Portuguese doctrine in action, but there were also favorable external conditions that helped the Portuguese do as well as they did. For starters, the opposition was disjointed. While it was the UPA/FNLA rebel group that had started the conflict, there was also the communist MPLA and the FNLA-breakaway group UNITA. These groups did not get along with each other and had a ton of internal divisions, which made them susceptible to infiltration and exploitation by the Portuguese intelligence services.
Additionally, the Angolan rebel groups were in a bad neighborhood to wage a counterinsurgency. Portugal successfully used its economic leverage to pressure neighboring Zaire and Zambia to not overtly support the rebel groups, although they were often used as shelter by the rebels. Additionally, South Africa was also waging a counterinsurgency and worked with the Portuguese by using its air power to help patrol southern and eastern sections of Angola.
These factors all came together in favor of the Portuguese and resulted in them more-or-less having the situation contained by the late 1960s.
**Mozambique**
Mozambique was less successful than Angola but is generally considered to have been salvageable. Mozambique also had a disunited opposition that struggled to win over the local population, and neighboring Rhodesia and South Africa actively resisted the rebels using their countries as rear bases.
One of the main problems with the Mozambique conflict was that some of the leadership was not on board with the low-cost hearts and minds doctrine. While the FRELIMO rebel group had been fairly contained in the north of the country using the established doctrine, in 1970 General Kaulza de Arriaga took command of Portuguese forces and went on a different path entirely. De Arraiga, a giant fan of U.S. general Westmoreland, masterminded operation "Gordian Knot," by far the largest operation by the Portuguese in the Colonial war, which used thousands of troops in an effort to rout FRELIMO and end the conflict. The result was much like Vietnam, tactical success and strategic disaster. FRELIMO didn't do very well but remained intact and many of its fighters were able to slip away and reestablish themselves in central Mozambique. The operation was expensive and displaced a ton of people. By 1974 it was a stalemate, with FRELIMO growing but not exactly beloved by the population, and the Portugese working to get a handle on the situation.
**Guinea-Bissau and Cape Verde**
This conflict was a lost cause for the Portuguese by 1974 and begs the question if their doctrine was actually good or if they enjoyed favorable circumstances in Angola and Mozambique. Unlike Angola and Mozambique, neighboring Guinea and Senegal couldn't care less about Portugal and actively supported the rebels. There was also only one major rebel group, the PAIGC, which was fairly united and pretty well-led, at least relative to the other groups Portugal was fighting.
They also couldn't move the population away from the rebels. In Angola and Mozambique there was enough space that when the rebels occupied an area, the Portuguese could relocate the population away from the rebels to prevent them from spreading their ideology and recruiting. Guinea was too small for this, so the population was more frequently in contact with rebels. Additionally, the terrain was very difficult for the Portuguese, and flooding and other factors undermined their ability to build infrastructure to win over the local population or effectively supply/reinforce their outposts.
Most agree that even if there wasn't a coup in Portugal in 1974, they would probably have lost this one. In 1973 the CIA drafted a memo to US secretary of state Kissinger on the state of Portugal's counterinsurgency, and claim Portuguese officials were privately admitting that the conflict may soon be lost.
**Conclusion**
I think the last thing that needs to be brought up is that the colonial war put enormous pressure on the Portuguese government and society. Portugal completely reshaped and reoriented its military to fight this war and withdrew most of the troops it had committed to NATO on the border with the Warsaw Pact. To fight these wars Portugal needed to implement extensive conscription and ended up losing five times as many men proportionally as the US did in Vietnam. Spending ballooned even while they were trying to keep costs low, and the coup that eventual ended the *Estado Novo* regime and the colonial wars was led by disaffected junior officers who had in some cases served tours of something like eight years at a time. So while some claim that Portugal did a better job in these wars, we need to consider what it cost them financially and socially to do so.
Bibliography:
Cann, John P. *Counterinsurgency in Africa: The Portuguese Way of War 1961-1974.* Solihull:Helion & Company. 2012. **If you want a good overview of the conflicts with more details and you don't speak Portuguese, this is the book to get**
Cann, John P. “The Artful Use of National Power: Portuguese Angola (1961-1974)”, *Small Wars and Insurgencies* 22:1 (2011), 196-225. _URL_5_
Cann, John P. and Jose Manuel Correia. “An Unlikely Alliance: Portuguese and South African Airpower in Angola, 1968-1974.” *Small Wars and Insurgencies* 28:2 (2017): 309-336. _URL_4_
Engelhardt, Michael J. “Democracies, Dictatorships and Counterinsurgency: Does Regime Type Really Matter?” *Conflict Quarterly* 12:1 (1992), 52-63. _URL_3_.
Henriksen, Thomas H. “Lessons from Portugal’s Counter-insurgency Operations in Africa.” *The RUSI Journal*, 123:2 (1978): 31-35. _URL_2_.
Horan, Harold E. “Portugal in Africa.” CIA Reading Room. (1973). _URL_1_
Paul, Christopher, Colin P. Clarke, Beth Grill, and Molly Dunigan. *Paths to Victory: Detailed Insurgency Case Studies*. RAND Corporation, 2013. _URL_0_
Reis, Bruno C. and Pedro A. Oliviera. “Cutting Heads or Winning Hearts: Late Colonial Portuguese Counterinsurgency and the Wiriyanu Massacre of 1972.” *Civil Wars* 14:1 (2012):80-103. _URL_6_.
| [
"In 1478 (during the War of the Castilian Succession), near the coast at Elmina was fought a large battle between a Castilian armada of 35 caravels and a Portuguese fleet for hegemony of the Guinea trade (gold, slaves, ivory and melegueta pepper). The war ended with a Portuguese naval victory followed by the offici... |
WW2: I've heard contradicting reports on how depleted the manpower of the major powers on each side was by the end of the war - How did the manpower situation for each country evolve throughout the war, and what was the situation at the end? | The US Army's manpower shortage was largely, but not completely, a result of their own doing and not the result of an actual shortage of bodies. In the Victory Program of fall 1941, the Army had outlined a force of 213 divisions that it would need to take on Germany. This program had hypothesized that Germany would defeat the Soviet Union and the United States and Great Britain would have to take on Germany alone, which meant a far larger number of German troops would be facing the two countries. Fear of the German *blitzkrieg* (a fear which proved to be unfounded) resulted in a massive expansion of the antiaircraft and tank destroyer arms. This massive initial unit expansion made it difficult to staff them. It was originally planned to have 222 tank destroyer battalions, but this figure was later reduced to 106 in March 1943, and 78 in October 1943. Due to the lack of enemy aircraft in Italy, a provisional infantry regiment (the 473rd) was constituted out of the headquarters of the 2nd Armored Group and the 434th, 435th, 532nd and 900th Antiaircraft Artillery Automatic Weapons battalions.
A major problem which constricted America's manpower during WWII was their industrial and agricultural capacity and its value to the Allies. As a result, in 1942 Army planners shortsightedly estimated the maximum number of men which could be brought into the service of the United States without disrupting these critical areas was about 10.5 million, out of an eligible population of twenty-five million, about 7.8 percent of the US population. In reality, the maximum population of these men which could be brought into service was about fifteen to sixteen million.
On December 5, 1942, President Franklin D. Roosevelt signed an executive order reducing the draft age from 21-37 to 18-38, and eliminating voluntary enlistment in order to avoid straining the war economy and controlling the amount of men the armed forces received at a time. Men aged 17, and those aged 38-45 could still voluntarily enlist if they met the armed forces' qualifications.
By the middle of 1943, the Selective Service was falling behind on its inductions (a planned 200,000 men per month). Back in October 1941, 10 million out of 16 million Selective Service registrants were classified as III-A, "Men with dependents, not engaged in work essential to national defense" and were deferred. A major cause of this induction shortfall was the continued refusal to draft these men who had dependents. The Selective Service estimated a shortfall of nearly 450,000 if it didn't draft these men. On October 1, 1943, the Selective Service administratively eliminated the III-A classification and began to draft those fathers whose children were born before December 7, 1941.
**Number of Fathers Drafted**
Month(s)|Fathers drafted|Percent of monthly inductees
:--|:--|:--
October 1943|13,300|6.8
November 1943|25,700|13.4
December 1943|51,400|26.4
April 1944|114,600|52.8
October 1943-December 1945|944,426|30.3
By V-J Day, of the 6.2 million classified fathers aged 18-37, 20 percent had been inducted. Of those 18-25, 58.2 percent were on active duty.
In late 1943, the maximum size of the Army was reduced from 8.2 million to 7.7 million and 100-125 divisions. This program was further modified by reducing the number of divisions to the already-activated 88, (three more divisions would later be activated, bringing the final Army total to 91) and deleting 15 divisions scheduled for activation in 1943. Meanwhile, divisions were accumulating in the United States due to the uncertain strategic situation in Europe (the proposed *Operation Roundup*, a cross-channel invasion of France in late 1942 had been cancelled) The Army was struggling to fill the 7.7 million quota, being short nearly 200,000 men.
By early 1944, the Army Ground Forces was short between 87,000-97,000 men due to the inadequacy of replacement training programs to produce enough infantrymen to refill divisions which had taken casualties. The initial War Department figure for the percentage of replacements that needed to be trained as infantry was 64.3; by April 1944 this had been raised to 70.3 percent. Fighting in Normandy soon proved that this figure was far too low; estimates were that 90 percent of Army Ground Forces casualties occurred in the Infantry.
Also by early 1944, 100,000 men, mostly service troops, had been "saved" by economizing the organization and activation of units, but the needs of the new B-29 program stripped these men away; the Army Air Forces had asked for 130,000 men to staff it. This resulted in a serious shortage of the potential number of service troops that could be deployed overseas. As a result of this shortage, trained divisions in the US that were ready for deployment were used to perform "housekeeping", running training camps and the like. In February 1944, the laboring Army Specialized Training Program was cut back from 150,000 to 30,000 men, releasing 120,000 men for overseas duty; many of the later divisions to enter combat had a high percentage of former ASTP men. On January 19, 1944, it was authorized to strip divisions still in the United States for replacements, sending nearly 100,000 qualified men from fully-staffed divisions overseas. Note that the figure for infantry replacements had proven far too low.
**Number of Men Stripped From Divisions, April-September 1944 by Division and Branch**
Division|Infantry|Field Artillery|Cavalry|Armored|Airborne Infantry|Total
:--|:--|:--|:--|:--|:--|:--
13th A/B|1,172 Pvt.|--|--|--|580 Pvt.|1,652
8th Armd.|1,150 Pvt.|40 NCO, 420 Pvt.|33 NCO, 207 Pvt.|570 Pvt.|--|2,420
13th|1,800 Pvt.|40 NCO, 460 Pvt.|9 NCO, 260 Pvt.|610 Pvt.|--|3,179
16th|1,597 Pvt.|39 NCO, 475 Pvt.|45 NCO, 235 Pvt.|15 NCO, 541 Pvt.|--|2,947
20th|1,459 Pvt.|49 NCO, 1,450 Pvt.|20 NCO, 208 Pvt.|660 Pvt,|--|2,846
42nd Inf.|372 NCO, 3,564 Pvt.|69 NCO, 771 Pvt.|45 Pvt.|--|--|4,821
63rd|278 NCO, 3,290 Pvt.|579 Pvt|5 NCO, 33 Pvt.|--|--|4,185
65th|5,222 Pvt.|314 Pvt.|45 Pvt.|--|--|5,581
66th|3,999 Pvt.|840 Pvt.|5 NCO, 38 Pvt.|--|--|4,882
69th|102 NCO, 4,312 Pvt.|143 NCO, 697 Pvt.|5 NCO, 40 Pvt.|--|--|5,299
70th|41 NCO, 2,804 Pvt.|6 NCO, 474 Pvt.|5 NCO, 40 Pvt.|--|--|3,370
71st|3,172 Pvt.|36 NCO, 294 Pvt.|--|--|--|3,502
75th|4,459 Pvt.|70 NCO, 710 Pvt.|5 NCO, 40 Pvt.|--|--|5,284
76th|516 NCO, 5,730 Pvt.|69 NCO, 711 Pvt.|5 NCO, 40 Pvt.|--|--|7,071
78th|4,698 Pvt.|50 NCO, 730 Pvt.|1 NCO, 44 Pvt.|--|--|5,523
86th|4,050 Pvt.|50 NCO, 670 Pvt.|40 Pvt.|--|--|4,810
87th|3,850 Pvt.|38 NCO, 680 Pvt.|40 Pvt.|--|--|4,610
89th|2,700 Pvt.|360 Pvt.|--|--|--|3,060
97th|5,064 Pvt.|57 NCO, 279 Pvt.|9 NCO, 21 Pvt.|--|--|5,430
100th|125 NCO, 3,550 Pvt.|--|--|--|--|3,675
103rd|2,550 Pvt.|--|--|--|--|2,550
106th|366 NCO, 3,859 Pvt.|57 NCO, 723 Pvt.|45 Pvt.|--|--|5,050
Another problem bugging the Army from 1942-1944 was the number of 18 year old draftees it was receiving. In May 1943, it was decided that 18 and 19 year old inductees would be assigned to units in training and unlikely to deploy overseas soon only, and inductees 20 or over would mostly be assigned as replacements. As the Italian campaign intensified in late 1943, the need for replacements became acute. On February 26, 1944, the War Department issued a ban on using 18 year olds and "pre-Pearl Harbor" fathers as replacements unless they had at least six months' training; men from any other source were to be taken first. On June 24, 1944, the ban became even more rigid, with no man under 18 years and six months old to be assigned to an infantry or armored replacement center, and no man under nineteen to be assigned as an overseas replacement. More than 37,000 men were affected, unable to be shipped outside the United States. As a result, it was necessary to "store" these men until they became of age by assigning them to units still in the United States and not likely to deploy anytime soon.
By August 1, 1944, the ban had proven very problematic, and was rescinded; 18 year olds began to be shipped as overseas replacements again in December 1944. On December 8, 1944, the US Third Army was short 11,000 infantrymen; this was only four percent of the Third Army's total strength, but actually the rifle strength of nearly two infantry divisions.
Another problem in the Army in the WWII period was segregation. African-Americans made up nearly 10 percent of the US population, and restricting them solely to service units or rejecting them entirely based upon their education or AGCT scores deprived the Army of a large portion of potential combat manpower.
Sources:
[US WWII draft classifications](_URL_1_)
[US Army in World War II](_URL_2_), by Rich Anderson
*"Daddy's Gone To War": The Second World War in the Lives of America's Children*, by William M. Tuttle, Jr.
*The Tank Killers: A History of America's World War II Tank Destroyer Force*, by Harry Yeide
[*The Procurement and Training of Ground Combat Troops*](_URL_3_), by
hy Robert R. Palmer, Bell I. Wiley, and William R. Keast (Historical Section Army Ground Forces)
[*The 90-Division Gamble*](_URL_0_), by Maurice Matloff | [
"The nation went from a surplus manpower pool with high unemployment and relief in 1940 to a severe manpower shortage by 1943. Industry realized that the Army urgently desired production of essential war materials and foodstuffs more than soldiers. (Large numbers of soldiers were not used until the invasion of Euro... |
how did cuba's economy survive the last 50 years? | The country received huge economic subsidies from the Soviet Union, and later from Venezuela. For example, they were able to buy petroleum for far less than normal global prices. | [
"The country achieved a more even distribution of income after the Cuban Revolution of 1953-1959, which was followed by an economic embargo by the United States (1960- ). Following the collapse of the Soviet Union, Cuba's GDP declined by 33% between 1990 and 1993, partially due to loss of Soviet subsidies and to a ... |
Who were the first settlers of Appalachia and how did they live? | Just for clarification, you *do* mean European Americans, right? | [
"The archaeological record reveals that native peoples have been in this area of the coastal plain of Virginia since the Early Archaic period, around 9000 BC. It was thought that due to the steep topography at Crow's Nest the Patawomecks may not have lived in permanent villages adjacent to the surrounding water, th... |
how does stopping the affordable care act /obamacare advance the tea party agenda? | They've convinced a portion of the electorate that the ACA will do everything from allow the government to decide you can't get heart surgery to deciding to effectively killing your parents. Their predictions have been so dire that it has become for them a defining moral issue that can't be ignored without potentially several repercussions. **Not** fighting it is going to be a problem with their base come next year's elections. | [
"Opposition to the Patient Protection and Affordable Care Act (PPACA) has been consistent within the Tea Party movement. The scheme has often been referred to as 'Obamacare' by critics, but was soon adopted as well by many of its advocates, including President Obama. This has been an aspect of an overall anti-gover... |
i was under the impression that war is generally good for the economic health of a nation. what makes the wars in iraq/afghanistan different? | Let's start by explaining *why* wars can be good for economies.
A nation must consume everything it produces. If a nation produces 100 TVs, it must consume 100 TVs. That doesn't seem obvious, does it? Yet it's true.
Suppose we produce 100 TVs, and nobody consumes them. Then they'll go into a warehouse. The storage fees will be expensive, and the TVs will gather dust until they're obsolete. The company that made them will lose money. The company will learn from this mistake, and next year, they won't make as many TVs. So production will *fall* until it equals consumption.
Production EQUALS consumption. If you encourage lower consumption, you're forcing production down as well!
That's not obvious to many people. Sometimes, naive politicians encourage people to tighten their belts, to stop consuming so much. This always has the same consequence: stuff goes into warehouses, and companies slow down production. If this goes on long enough, factories close and people get laid off. The nation will harm its own economy by refusing to consume the stuff it produces.
Individuals aren't to blame for this. A society decides how to channel its money by making policies - it can either channel money to consumers or to investors. If it makes a mistake and channels too much to investors, and not enough to consumers, it will end up with a shortage of consumption.
So this is where war comes in: a war is an enormous consumer. If consumption has been driven down by policies that channel too much money to investors, and away from consumers leading to a consumption shortage, then a war can help compensate for the consumption shortage.
A war is a crappy way to consume the goods a society produces. A better way is to arrange policies that allow people to enjoy the goods the society produces, by ensuring that people have enough money to buy those goods.
As for the wars in Iraq and Afghanistan: they probably are helping, believe it or not. But both wars are pretty much on a low burn these days, they're not huge consumers the way they used to be.
| [
"War usually leads to a shortage in the supply of commodities, which results in higher prices and higher revenues. When it comes to supply and demand in terms of economics, profit is the most important end. During war time, \"war-stuff\" is in high demand, and demands must be met. Prior to the invasion of Iraq in 2... |
hair | It is dead tissue constructed by special cells for the purpose of insulation. Evolution (probably sexually selective) has caused it to not grow on parts of our bodies at least until we have exceeded the normal breeding age.
The pore that hair comes out of is self lubricating, you also have lots of sweat glands. As you go about your day, that evaporates. When you sleep your body does a lot of work rebuilding damaged tissues, killing germs, doing general maintenance. This causes you to sweat a bit more, meanwhile the pillow is rubbing your hair against your scalp to collect more than the usual amount.
It itches because of the way it moves, your body thinks you have something in your hair that needs to be removed.
Hair dye is like any other organic dye. It bonds to the cells to make them a different color. If you wash a cotton shirt a bunch of times, it fades. Shampoo is specifically designed to strip oils from hair. So it will strip color much faster. | [
"Hair is a protein filament that grows from follicles in the dermis, or skin. With the exception of areas of glabrous skin, the human body is covered in follicles which produce thick terminal and fine vellus hair. It is an important biomaterial primarily composed of protein, notably keratin.\n",
"\"Hair\" is a so... |
how can we so sure that a certain species like megalodon in deep sea is extinct when we knew very little about ocean floor? | We dont really, but given what we can infer from their fossils and we can find things like their diet and typical depth and such. Which means if they did still exist they would be either insanely rare or very specific to one part of the ocean.
Most of the creatures we discover down there arent large creatures as the depth is basically squishing their body and so they come up with adaptations to counter this like having no bones and such. Even the giant squid isnt as big as alot of people would assume with its name.
Really comes down to inferring things and a mentality of “until we find it, it doesnt exist” | [
"The most dramatic deterioration has been caused by biological factors. It used to be thought that the depths of the ocean were a lifeless desert, but research carried out since the mid-1980s has found that the ocean floor is teeming with life and may rival the tropical rainforests for biodiversity. During the 1991... |
Was there ever any significant fighting between Muslim factions within the Ottoman empire? | This isn't really my area of specialty, but one example might be the Ottoman-Saudi war (1811-1818). Long story short Egyptian troops were sent, at the Ottoman's request, to fight Wahhabi rebels in an area that now forms part of Saudi Arabia.
This isn't quite an example of Ottoman empire infighting because:
- Egypt's leadership at this point was trying to chart a separate course from the Ottoman empire. It wouldn't be long before Egypt was defacto independant after this conflict.
- The core of the the Emirate of Diryah (the Wahhabi state) wasn't actually in the Ottoman empire (as I understand it). Instead Ottoman involvement came when the Emirate started messing around on their periphery.
So in a way the war was about two states on the periphery of the Ottoman empire, one of which happened to be a very close ally rather than a feudal property of the Sultan or similar, fighting on the periphery of the empire. Hope that makes sense and I haven't made any major factual errors. | [
"The history of Ottoman–Safavid relations started with the establishment of Safavid dynasty in Persia (Iran) in the early 16th century. The initial Ottoman–Safavid conflict culminated in the Battle of Chaldiran in 1514, and was followed by a century of border confrontation. In 1639, Safavid Persia and Ottoman Empir... |
How Eurocentric is the word "medieval"? | **Short answer:**
The most literal definition of "medieval" is "between two ages". Taken that way, the term might be considered "Roman centric" ,"Mediterranean-centric", and perhaps even "Asia \[Minor\] centric" -- it refers to the time between the fall of Western European Empire and the fall of the Eastern Roman Empire -- most of which was in Asia, not Europe. But the reason the term continues to be used is because it describes historical dynamics found in many places.
**Discussion:**
François-Xavier Fauvelle, an historian and archaeologist of Africa, entitled a recent book "*The Golden Rhinoceros: Histories of the African Middle Ages"*. Why did he refer to an "African Middle Ages"? Does the fall of Rome or the fall of Constantinople have anything much to do with African history? Not really.
In his introduction, he explains his choice of the term:
> \[L\]et us admit that there can be many reasons to use the term “Middle Ages” or the adjective “medieval” that are not particularly related to the way medieval Europe is medieval. There’s also a good reason not to use it; for if its usefulness resides only in designating a period of almost a millennium roughly coeval with the European Middle Ages, one could rightfully ask why we should import a label that conveys unwanted associations with medieval Europe: Christianity, feudalism, the crusades against Islam. True. But despite all this, I think that applying the term “Middle Ages” to Africa is justified.
>
> The justification concerns the scale at which we observe the Middle Ages {snip}
>
> \[T\]he physical centrality of the Islamic civilization within this global world, the role of specialized long-distance merchants (mostly Muslims and Jews) as connecting agents between different provinces, or the related significance of a few chosen commodities (such as slaves, gold, china, glass beads, ambergris) \[is\] evidence of an interconnectedness of a kind limited to what met the needs and tastes of the elites. In that sense, the broad picture that this book wants to draw, its fragmentary nature notwithstanding, is that Africa also deserves to be considered a province of the medieval world. Not out of a will to “provincialize” Africa in the sense of making it marginalized or peripheral, but, on the contrary, to make it part of a world made up of other such provinces.
Fauvelle thus claims a case for the generality of the term "medieval", if we discard its literality.
Literally, "medieval" means "between two ages". No one who lived at the time could have made sense of that. They might have known -- and indeed lamented-- the fall of Rome. Christians might have thought of themselves as being "between" the appearances of Christ on Earth, but no one could have understood the periodization that the later Italian humanists like Petrarch applied, between the loss of Rome, and the rediscovery of Rome.
So we leave aside the Merriam Webster definition; its literal, but can't explain why anyone would use the term today. Why does Fauvelle speak of an African "Middle Ages"? Why did Gustav von Gruenebaum speak of "Medieval Islam"?
Fauvelle gives us a clue as to one reason-- it's an age when earlier trade relations have largely collapsed, and knowledge and goods move through the world transported by new agents, Jews and Muslims for example. In the Africa he's describing, the historical record is almost entirely recorded by Muslim traders, soldiers, missionaries and explorers. Sub-Saharan Africans leave us very little written material from the period; but the institutions of travel in Islam - particularly the *hajj* \-- mean that not only do we have records of Muslim trade with Mali, we have the pilgrimage of the King of Mali, Mansa Musa, to Mecca.
Seen in this light, the "Middle Ages" is a period after antiquity in which the religions we know in the modern world assume roughly their current geographic distribution, and this isn't Eurocentric. Indeed while Christianity may be thought of as a "European" religion-- it is in fact an Asian religion which "conquers" Europe. Similarly Islam is an Arabian religion which explodes into Africa, Asia, Europe. And Buddhism, which had begun it spread a bit earlier, comes to dominate China, Japan and Korea . . . The Tang Dynasty is often characterized as the age of "classical Buddhism" in China.
Considered as a practical matter, the period "medieval" tells you something about the languages you might need to know to study history. A "medieval historian" of almost anyplace in the Mediterranean world will often need to read Arabic, Latin and probably Greek in addition to other languages. If you're an historian of 17th century Spain-- you don't particularly need to read Arabic or Hebrew; if you're an historian of 12th century Spain, you do. Similarly a student of medieval Islam may well want to read Greek or Latin, Hebrew, Coptic or Italian, in addition to Arabic, Turkish and Persian. In the same vein, if you're a scholar of "medieval" Indonesia-- you're often going to want to read some Arabic to understand the history of the spread of Islam.
So this is a period where parallel dynamics of religious and political spread can be seen around the world. The arrival of Islam in what is now Pakistan, the arrival of Christianity in Scandinavia-- there are commonalities here. This is a period in which peoples adhere to a world civilization, which shares ideas across thousands of miles. Scholars in Cordoba and Damascus read the same documents and argue fine points of theology and jurisprudence; scholars in Ireland and Constantinople do the same.
Seen in this light, the "middle ages" gets another meaning-- its the time of the spread of world religions, the time in which a previously largely polytheistic world is adopting monotheism, and religions that are heavily based on sacred texts, which require literacy and exegesis to apply. Greeks and Romans argued about "what is a good life" -- sometimes with a reference to "the Gods", but never with a deeply textual codified scholarship. What we see in the "Middle Ages" is the rise of a new scholarship, scholars who engage the scripture to derive rules for living that apply to tens of millions of people-- and which still do today, in the Americas, Africa, Europe and Asia. Jews in particular had developed this style of exegesis and and application to daily life earlier-- but "the Middle Ages" is the period where what had been a kind of analysis and scripture driven policy moves from the practice of a minority religion, geographically quite limited, to the practice of much of the literate world.
Finally, it's a common characteristic of this period that religious doctrine becomes intertwined with political interests in a new way. Looking back to the world of antiquity, we don't have much evidence for religious doctrine as a twin to political interest. Athena was the tutelary deity of the Athenians, but we don't get any sense that they fought the Peloponnesian War to get others to erect statues of Athena; when they put the boot in on Melos, that's not one of their demands. But Christians and Muslims alike -- as they spread their faiths, they have a demand "tear down your temples to your old Gods, ours isn't interested in company". | [
"Medievalism is a system of belief and practice inspired by the Middle Ages, or by devotion to elements of that period, which have been expressed in areas such as architecture, literature, music, art, philosophy, scholarship, and various vehicles of popular culture. Since the 18th century, a variety of movements ha... |
How many non-Spartans participated in the Spartan agoge? | I can't speak for instances of other Greeks participating in the agoge, but I can at least give you a partial answer. Your post made me think of the mothakes (Doric Greek for "stepbrothers"). Essentially they were male members of Spartan society who participated in the agoge and existed outside the privileged homoioi class. They were permitted to fight, however, I'm not quite sure of the extent of their social limitations. There were different individual circumstances, but generally they were the children of poor/disgraced families or the bastards of Spartan father's and Helot mothers. Some Spartan commanders (most notably Lysander who defeated the Athenian fleet) even came from this underclass of the Spartan hierarchy and rose to prominence. | [
"The Spartan hoplite followed a strict laconic code of honor. No soldier was considered superior to another. Suicidal recklesness, berserkery, and rage were prohibited in a Spartan army, as these behaviors endangered the phalanx. Recklessness could lead to dishonor, as in the case of Aristodemus. Spartans regarded ... |
Why is the average atomic mass compared to the carbon-12 isotope? | So there's kind of an amusing story there. The definition of a mole using carbon-12 only started in 1961. Prior to that, the standard was based on oxygen-16. But physicists and chemists could not quite agree on how to regard oxygen-16, because the physicists defined it (using spectrographic data) based on pure oxygen-16, whereas chemists preferred to use naturally occurring oxygen which is a blend of isotopes (16, 17, 18). They apparently could not see eye to eye on oxygen at all, resulting a "bitter controversy" as _Science News_ put it in 1961. The resolution was to scrap oxygen as the standard and just go with carbon-12 instead, which apparently was less problematic for both camps.
I haven't seen any strong historical scholarship on the subject — it would be interesting to me to know if there was more behind-the-scenes maneuvering or not. But the answer appears to be: it is just a standard, you pick something and run with it; plus a dash of "it was the only thing the physicists and chemists could agree on." | [
"In the example above the standard atomic weight of carbon is 12.011 g/mol, not 12.00 g/mol. This is because naturally occurring carbon is a mixture of the isotopes C, C and C which have masses of 12 u, 13.003355 u and 14.003242 u respectively. Moreover, the proportion of the isotopes varies between samples, so 12.... |
what parts of the spectrum does a mirror reflect? can a mirror be melted by any part of the spectrum? | It depend on the mirror. Each material have different reflectivity for each wavelenght.
_URL_1_
Visible light go from 0.4 um to 0.7 um. So you see in the image that Silver is pretty good to reflect most of visible light. That's why most mirror we use are made of silver. It can also reflect infrared as you can see in the chart and in that video.
_URL_0_
So if you could have a Ultraviolet laser, that would destroy a silver mirror pretty fast since it doesn't reflect those wavelength. But you can also see that at best a mirror will reflect about 98%. So if have a laser strong enough, it could melt through any mirror even if most of the energy is reflected.
| [
"A chirped mirror is made to reflect a wider range of frequencies. This is done by creating layers with different depths. There may be 10 layers with a depth designed to reflect a certain wavelength of light, another 10 layers with slightly greater depth to reflect a slightly longer wavelength of light, and so on f... |
How does the speed of the movement of the milky way, in which the planet earth is immersed, affect our perception of time? | Two points!
One thing is that these are all quite slow speeds. You really need to be going close to the speed of light for time dilation to matter significantly. There aren't many things in space that move faster than thousands of km/s relative to each other, and that's just not fast enough to time dilation to be very strong. So we can mostly just say that everybody experiences time at about the same rate.
The other thing is that it's important to keep in mind that *velocity is relative*. There's no difference between a supercluster approaching us at 1000 km/s and us approaching a supercluster at 1000 km/s. So you can't just say that whoever is going faster gets more time dilation, because there's no universal agreement about who's going faster. What actually happens is both of you end up observing *each other* as experiencing time slower than yourself. This also tells us that it's meaningless to talk about the absolute speed of the Milky Way - you can't just add up the Earth's motion to the Sun's motion to the Milky Way's motion and get the total motion. All of these are just different frames of reference, and all of these are just as correct as each other. | [
"This planetary order, in which the Sun stands at the center of the continuum, with the planets between the Sun and the Earth on one side and the outer planets on the other side, reflected the perception of the speed of each planet's motion as seen from the Earth.\n",
"This planetary order, in which the Sun stand... |
Does the probability in deal or no deal work similarly to The Monty Hall Problem? [Please see inside for details] | > The big question is: does switching the case at the end increase the probability of me winning the $1M from 1/26 to 25/26 (in other words it works like the Monty Hall Problem) or is it 50/50 chance at the end.
50/50. (Anyone saying otherwise do not understand the MontyHall problem ...)
You can sum up the Deal or no Deal situation like that :
* choose 1 box randomly.
* open 24 boxes randomly
* The 1M$ box is still in play.
It is easy to convince yourself that it doesn't change anything if you do the first two steps in reverse order. In other words, when you start the game you have 26 doors in front of you, it is completely equivalent (from the point of view of probability) if you first open the 24 boxes before choosing your box.
Now if you understand that, then the problem becomes trivial. If you open first the 24 boxes. There are two boxes left. From your point of view they are undistinguishable. There is no reason to choose one over the other. You have a 50/50 chance for each box.
NOTE : What is different in the Monty Hall problem is that the two steps :
* I pick a door.
* Monty reveals a door.
can not be done in reverse order ! I mean it can but it changes everything ! If the host reveals a door with a goat before you get to choose your door, then you have 50/50 chance of winning. If the host reveals after you choose the door, then you have a 2/3 chance of winning (if you switch) | [
"\"Odds\" (as in gambling) are expressed as a ratio. For example, odds of \"7 to 3 against\" (7:3) mean that there are seven chances that the event will not happen to every three chances that it will happen. The probability of success is 30%. In every ten trials, there are expected to be three wins and seven losses... |
Why are there no fireflies on the West Coast? | There are fireflies on the West Coast, such as [*Ellychnia californica.*](_URL_0_) The problem is that many are either diurnal (out during the day) or have relatively weak bioluminescent capabilities as adults. | [
"The sea-firefly is a small crustacean living in sediment. At rest it emits a dull glow but when disturbed it darts away leaving a cloud of shimmering blue light to confuse the predator. During World War II it was gathered and dried for use by the Japanese military as a source of light during clandestine operations... |
why weren't army uniforms using camo earlier? | In the 1700's, getting shot by other people on your "team" was a big problem, and color coding uniforms helps with that. You had to be quite close to shoot someone, because the firearms of the period were not excellent. By WWI and WWII, firearms were excellent. Also, at that time, armies had radios. This allowed more complex communication that the bugle calls of earlier periods. This led to better maneuver, and less "friendly fire". | [
"The development of modern camouflage patterns and the rising desire of the various U.S. military branches to differentiate themselves from each other has resulted in new patterns for uniforms. The U.S. Marine Corps was the first branch to replace their BDUs. The Marine Corps Combat Utility Uniform (MCCUU) uses the... |
why do we measure liquids by volume when we could just as easily measure them by mass? | Generally speaking scales are more accurate than household volume measuring devices. however, until digital scales were invented, scales were a nuisance for some people to use. Especially for small, high precision measurements. Therefore recipes and such typically used volume, which can be measured with the cheapest of devices.
Liquid fuel is sometimes sold by volume like in gas stations, and sometimes by weight like at airports.
| [
"Litres are most commonly used for items (such as fluids and solids that can be poured), which are measured by the capacity or size of their container, whereas cubic metres (and derived units) are most commonly used for items measured either by their dimensions or their displacements. The litre is often also used i... |
why didn't they use shields made of metal in ww1? | Do the math:
A .303 armor piercing round was able to penetrate 8mm of steel at 100 yards. (8mm/25.4mm/inch = 0.315 inches). So, for shorter distances, if we wanted to build in a safety factor of 50%, we'd need a shield of at least 12mm in thickness to ensure the standard British round couldn't penetrate the shield. (12mm/25.4mm/inch = 0.472 inches).
A shield 3' tall by 2' wide (and 0.472 inches thick) would yield a total volume of steel of (36"x24"x0.472") 408 inches^3.
Steel weighs 0.284 lbs per inch^3.
So your shield would weigh 116 lbs.
So, how combat effective would a soldier be with a 3' x 2' shield weighing 116 lbs?
Answer: Not very effective. | [
"BULLET::::- Gun shields - Not all modern guns have shields. Before World War I, shields were intended to provide gun crews with protection at shorter ranges from the recently-invented repeating rifle and shrapnel shells when they were engaged in direct fire. During the First World War on the Western Front, machine... |
how are news agencies allowed to outright spread lies or misinformation to the public? why is there no system of moderation to license news reporters similar to how engineers/doctors are licensed to design buildings or treat patients? | Who would do the moderation? The government? This is what happens in some countries, such as Russia and the UAE, and the governments in those countries influence the news to suit their own agenda.
The UK had an independent Press Complaints Commission which does try to keep the news sane, even if that means censuring the government. If you wanted to try that in the USA, it would probably require an Act of Congress, and it wouldn't get past your current highly-partisan Congress. | [
"Journalists are often expected to aim for objectivity; reporters claim to try to cover all sides of an issue without bias, as compared to commentators or analysts, who provide opinion or personal points of view. The resulting articles lay out facts in a sterile, noncommittal manner, standing back to \"let the read... |
how exactly does astrology predict one's personality traits? | It doesn't.
Those stars are trillions of miles away and have no bearing on your life. | [
"Astrologers believe that the position of the stars and planets determine an individual's personality and future. Astronomers study the actual stars and planets, but have found no evidence supporting astrological theories. Psychologists study personality, and while there are many theories of personality, no mainstr... |
did the holocaust really happen? | Sorry Ahmadinejad, I thought Reddit was blocked in Iran?
The evidence is the sudden disappearance of six million Jews and six million more "undesirables" between 1938 and 1945.
And the thousands of survivors.
And the thousands of Nazi soldiers who admitted it.
And the millions of corpses. | [
"The Holocaust (which roughly means \"great fire\") was the deliberate, systematic murder of millions of Jews and other minorities during World War II by the Nazi regime in Germany. Several differing views exist regarding whether it was intended to occur from the war's beginning, or if the plans for it came about l... |
Why do scientists hypothesize dark matter and not some non-matter phenomenon that generates gravity? I.e. why consider it "matter" at all? Or is "dark matter" just short for "gravity-producing phenomenon"? | They're marginalized for two main reasons:
1) They don't explain the data better than (cold) dark matter does, and lately have often had a harder time explaining several observations, and
2) They're ugly as sin. The equations governing a theory like TeVeS are just plain gross, and the only reason anyone even dreamed up such gross equations is because they wanted to reproduce MOND.
All of these theories, dark matter and modified gravity, are really "dark matter theories," because all of these introduce new fundamental fields and particles. Dark matter, at least, seems to work with only one type of dark matter particle. Theories like TeVeS and STV add at least three or four new particles into the mix.
A mysterious new particle we can't see may sound ad hoc, but it's at least a very simple hypothesis. And we're pretty sure the [Standard Model](_URL_0_) isn't the last word on particle physics, so the idea that there are more particles out there and that some of them don't interact electromagnetically (i.e., are "dark") is not weird at all. Plenty of theories we've come up with for reasons unrelated to dark matter end up producing a dark matter particle anyway.
These modified gravity theories, on the other hand, have no motivation in fundamental physics - they're dreamed up solely to solve the dark matter problem. *Which is fine!* They're worth looking at. But they're not elegant, they're not well-motivated, they don't do a great job explaining the data, and there's an alternative hypothesis - dark matter - which beats them on all of those counts.
Oh, and nowadays these modified gravity theories need some dark matter to work, anyway. | [
"Dark matter is postulated in order to account for gravitational effects observed in very large-scale structures (the \"flat\" rotation curves of galaxies; the gravitational lensing of light by galaxy clusters; and enhanced clustering of galaxies) that cannot be accounted for by the quantity of observed matter.\n",... |
why are men so disinterested in sex once they've ejaculated? | The rise in dopamine and serotonin post orgasm gives a man feelings of security and contentment.
It also increases the sleep hormone.
Due to all this, they lose interest. | [
"The most common sexual issues in diabetic males are problems with erections and ejaculation: \"With diabetes, blood vessels supplying the penis’s erectile tissue can get hard and narrow, preventing the adequate blood supply needed for a firm erection. The nerve damage caused by poor blood glucose control can also ... |
why are some trials completed with a jury while others are not? | In the US you generally don't get a criminal jury trial if the maximum punishment for your crime is less than 6 months. If its more than 6 months, you have a *choice* to get a jury trial - you can opt out if you want and people typically do when there is a strong emotional component to the trial.
When there is a strong emotional component to a trial - ie, the defendant is accused of raping a child - its normal to opt out of a jury trial because there is a sense that juries are much more likely to convict a person in those circumstances as they're more concerned about letting a guilty predator go than putting an innocent person in jail.
In civil trials - ie you sue someone - you aren't entitled to a jury below a certain dollar value, which varies from state to state. Above that dollar value either side can request a jury, but both sides can agree to opt out of it.
With civil trials you're much more likely to see a jury trial when there is a strong emotional component because Plaintiffs believe that juries give less reasoned, larger verdicts under those circumstances.
Also, most civil "trials" that result from a contract don't get a court trial at all, but instead go to arbitration. Arbitration is a private court system in which the case is heard solely by an arbitrator, who is usually retired judge. However, both sides have to agree to arbitrate.
In most other countries there is no right to a jury, or if there is its substantially more limited than what exists in the US. | [
"Some jurisdictions with jury trials allow the defendant to waive their right to a jury trial, thus leading to a bench trial. Jury trials tend to occur only when a crime is considered serious. In some jurisdictions, such as France and Brazil, jury trials are reserved, and compulsory, for the most severe crimes and ... |
What is cardiac pre-load and after-load? | I wanted to expand on some of the explanations that have been given here, especially because I think the concept of afterload is commonly oversimplified.
As one user mentioned, preload is defined as the end-diastolic volume. In other words, the volume of blood in the ventricle at the end of diastole, right before it begins to contract in systole. It is usually thought of as related to the left ventricle, but as another user mentioned, the concept of preload also exists for the right ventricle, and the two preloads are not equivalent.
The problem with many people's conception of afterload is that it is thought of as the pressure at which the heart has to pump against. This is not necessarily true and it is important that this be realized.
Afterload should be conceptualized as the resistance which the ventricle must overcome to generate blood flow.
Now let's look at how this relates to the left ventricle. In systole the LV contracts and attempts to eject blood into the aorta. There are a couple of things that can make this more difficult for the LV.
The first is high **vascular resistance**. This is a physical property of the arteries, depending primarily on the diameters of the blood vessels. If the arterial system is constricted, the resistance to flow is greatly increased. The classic example is trying to suck fluid through a straw: you know that the skinnier your straw is, the harder it is for fluid to flow through. Other things that may affect vascular resistance are things that deform the arteries, such as a kink in the aorta caused by [coarctation](_URL_0_).
The second is **blood viscosity**. Viscosity of the blood is part of afterload because if you can imagine the heart trying to pump maple syrup vs. water, it’d be much easier to pump water. Also remember that at end-diastole, the blood in the LV is relatively still. The LV must then eject its stroke volume into the aorta, and to do so must overcome the inertia of the blood. The thicker blood is (i.e., the more viscous it is), the more difficult it is to do so. This is relevant in medicine because the amount of hemoglobin in the blood has a significant effect on the blood’s viscosity.
The third factor that is often overlooked is **outflow obstruction**. Outflow obstruction is any lesion that blocks the flow of blood out of the ventricle. For example, if you have a very constricted aortic valve, a disease called [aortic stenosis](_URL_1_), this will impede the flow of blood. Imagine putting a cork on the heart. You could have an aorta you could drive a truck through, but if your aortic valve is severely constricted, the afterload of the heart will be way high and the heart will not be able to eject blood well.
We’ve mostly looked at the left ventricle, but the same concepts apply to the right ventricle. Afterload of the right ventricle can include the pulmonary vascular resistance, viscosity of the blood, and outflow obstructions such as pulmonic valve stenosis.
So while a lot of people like to think of afterload as the “pressure the heart has to pump against,” this is an oversimplification. If someone has “high blood pressure,” it is usually because his arteries are more constricted or less elastic than normal, and it is the increased resistance to flow that defines the high afterload state. High blood pressure is an indication that the afterload is probably high, but it does not in itself define high afterload. | [
"In cardiac physiology, preload is the end diastolic volume that stretches the right or left ventricle of the heart to its greatest dimensions under variable physiologic demand. In other words, it is the initial stretching of the cardiomyocytes prior to contraction; therefore, it is related to the sarcomere length ... |
How accurate is this Gif? | Might be easier if you let the gif run and just screen shot the last segment so the users here can take the time to look at it in more detail | [
"As a noun, the word \"GIF\" is found in the newer editions of many dictionaries. In 2012, the American wing of the Oxford University Press recognized \"GIF\" as a verb as well, meaning \"to create a GIF file\", as in \"GIFing was perfect medium for sharing scenes from the Summer Olympics\". The press's lexicograph... |
why do you have to put certain expensive electronics in your shopping cart in order to see their price? | It actually isn't a gimmick, it is done for legal purposes.
It comes from a supreme court ruling in 2007, without going into too much detail, it limits the ability of a retailer to openly advertise certain products below a certain price that the manufacturer will set as a minimum advertised sale price.
While a physical store can just have a sale and not advertise it, online retailers get kind of screwed by this, as something like an amazon product page is considered to be an advertisement.
Bear in mind the reason this isn't rampant is because not a lot of manufacturers really care if retailers take smaller margins on goods, but some feel it is harmful to the value of their brand.
Supreme court case for more in depth info:
_URL_0_.
| [
"Many shoppers also perceive shopping costs as a barrier to place the order and leave the shopping cart before purchasing. 31.6% of respondents mentioned the latter as a main barrier during the online shopping experience based on Internet Retailer / Bizrate Insight consumer survey conducted in May 2018. \n",
"Whe... |
why are some cancer patients too sick for cancer trial drugs. | A lot of cancer drugs cause harm to the patient. Its unethical to cause harm when the person has no realistic prospect of benefiting from the drug in the long-term.
Its like how in some cases they won't actually operate on very old men with prostate cancer, because its just causing unnecessary harm without a clear benefit. | [
"Drugs and radiotherapy given for cancer can cause unpleasant side effects such as nausea and vomiting, mouth sores, dermatitis, and menopausal symptoms. Around a third of patients with cancer use complementary therapies, including homeopathic medicines, to try to reduce these side effects.\n",
"A common conseque... |
how neutrinos can travel through (it's said) a light-year of lead and not hit anything. how is that even possible? | Neutrinos have no charge, so they don't interact through the electromagnetic field. They are the lightest of the non-massless subatomic particles, so that they have very little interaction through gravity. They do not interact through the strong nuclear force because they are not quarks, gluons or hadrons. That leaves only the weak nuclear force, which is much less strong than the strong nuclear force. (Thanks to physics for some super-explanatory names). | [
"In a analysis of their data, scientists of the OPERA collaboration reported evidence that neutrinos they produced at CERN in Geneva and recorded at the OPERA detector at Gran Sasso, Italy, had traveled faster than light. The neutrinos were calculated to have arrived approximately 60.7 nanoseconds (60.7 billionths ... |
el5 : why the slr cameras are more expensive then compact ones with same mega pixels ? what make them expensive ? | The number of pixels is not the only thing that defines the "goodness" of a camera. The sensor on a DSLR camera is substantially better than the one on a point-and-shoot camera. Also, the lenses on SLR cameras are of much better quality.
The mechanism (the "reflex" part in SLR) that exposes the sensor is also incredibly fast on an SLR camera (my entry-level camera can do 1/4000 second exposures). This type of speed requires precision hardware, which costs money.
Physically speaking, it's difficult to produce high-quality optical lenses when they're very small. Also, the size of the lens is directly related to how much light can be collected in a given amount of time. Generally speaking, more light = better picture. The difference is obvious for night images and other low-light situations. | [
"The price of SLRs in general also tends to be somewhat higher than that of other types of cameras, owing to their internal complexity. This is compounded by the expense of additional components, such as flashes or lenses. The initial investment in equipment can be prohibitive enough to keep some casual photographe... |
Monday Methods: A special episode of our podcast and a discussion post regarding: Post-modernism and history. How do we engage with it? Where do we go from here? What is the history of the future? | The category of postmodernism I spend the most time engaging with (as a historian of science/STS person) is not so much the construction of identity, which I take as sort of a given (it's pretty obvious that national identities are constructed ideas or imagined communities, and it doesn't take much more to go from there to racial identities, gender identities, etc.), but on the broader question of what it means to be a "fact" when you lack a "solid" reference point. As a historian of science this is always tricky because even the things that some other historians might like to occasionally reference as "givens" (like, "atoms are real") are things that we tend to argue are also somewhat constructed (what does "real" mean in this statement?).
The epistemology I find most useful in my day to day work is Bruno Latour's as described in his _We Have Never Been Modern_, which basically articulates facts as nodes in networks that need to be continually reinforced as refreshed in their early days of establishment, but at some point become so enmeshed in the network (and future networks) that they become almost invisible and taken for granted (until something comes along and reinterprets the network relationships).
So for example, one of the examples that Latour discusses is that of Boyle's air pump and the establishment of the idea of a vacuum (which itself is borrowed from Shapin and Schaffer's _Leviathan and the Air-Pump_). Robert Boyle (the 17th century Irish natural philosopher/chemyst) created a new tool (the "air-pump," what we would today call a vacuum pump) that he believed could deploy a kind of mechanical objectivity to create new natural philosophical facts. There was considerable debate in his time as to what exactly was happening when you used it — was it really leaving a vacuum behind in the chamber, or was it doing something else? For Latour, the key thing here is that to establish the idea that the vacuum was real, you needed a whole lot of things to be working together. First you needed Boyle to actually do quite a lot of not only the creation of the device but the writing that disseminated information about it and interpreted it (as Latour puts it, facts always require "spokesmen," as they cannot speak for themselves and certainly do not write themselves). You need the pump itself (for Latour, non-human actors are members of the network) — you need it to behave correctly (a non-trivial difficulty), you need it to actually work as it is supposed to. You need the other people, Boyle's gentleman witnesses, to attest to it doing what Boyle says it does, because replication was largely impossible (there were only five or six air-pumps in all of Europe over that time period, and they were finicky and not easy to access). You needed Boyle's compelling explanations of existing phenomena that other natural philosophers were interested in (e.g. the Torricelli experiment). You need Boyle's access to a printing press and the dissemination of the information. And so on.
In the earliest days of establishing the idea of the vacuum, the network was pretty weak — vulnerable in places. Do you really trust Boyle's gentleman witnesses? How about people who tried to replicate the work but failed, because their pumps didn't work quite like Boyle's? And there were those (like Thomas Hobbes) who attacked Boyle's claims, dissecting nodes in the network (like Boyle's interpretation of the data).
But over time, with more and more refinement of the tools, and more and more incorporation of the ideas into other models of the world, the idea of the vacuum moved from being a very weakly established fact, to a very strongly established one. It never crossed some magic line and went from "non-fact" to "fact," as a more modernist, positivist epistemology might have it. Rather its "factiness" was built up over repeated strengthening of the network, to the degree that to question whether a vacuum exists became completely absurd — to do so, you'd be questioning a fundamental, "easy to demonstrate" matter of the world.
We might contrast this "fact" to the idea of the luminferous aether, which was built up with a very robust network in the 19th century. But in the end, its network collapsed: certain instruments stopped cooperating (e.g., the Michelson-Morley experiment, where Michelson's interferometer stubbornly refused to show aether drift, no matter how much he tried to coax it into cooperation), various theoretical models stopped requiring it, and finally it found itself not so much overthrown as dissipated. Einstein rejected it, sure, but the aether really fell out of favor because no networks kept requiring it — it became superfluous more than it was proven wrong. Without correspondence to a network, it just vanished out of "fact."
What I like about this approach is that while it never really enshrines "truth" as some kind of simple, binary, yes/no status, it also doesn't make it seem like it's totally up for grabs by anyone. It doesn't make it entirely a human process (the non-human actors are very important, and don't always obey!), but it also doesn't pretend like "nature" is some kind of easy category to observe, much less some kind of actor that can speak for itself.
Which is to say, it seems to preserve the best aspects of the postmodern critique, without falling into the pit of sophism or arbitrariness. It allows us to say, for example, that some ideas or facts have more support than others, and have a good, solid definition of "support" (the network). It also helps us understand what undermining a fact means (you are attacking the network) in terms that have better historical and frankly practical use that simple notions of proving something "right" or "wrong."
You can take this model and apply it to the other categories mentioned earlier, like, say, nationality and race. You can identify the actors, the network, the nodes, from which these concepts pop out. And it also emphasizes that while, say, nationality or race are "constructed" (as is everything in the network, including each and every node that makes up a given network), they can still be as "real" in their effects as anything else.
An additional advantage to this epistemology, as a methodology, is that it makes the job of the historian quite clear: show the development, change, dissolution, etc. of the network over time, and you are doing quite interesting history.
Anyway. Just some stray thoughts. I find this kind of approach gets me more "use value" than either the modernist ("facts are real, you just discover them!") and postmodernist ("everything is just stories, man!"*) approaches. It is also incidentally mostly compatible with both: you end up redefining facts in ways that either, I think, could live with, preserving both the "hard" quality of facts that modernists like, yet emphasizing the constructedness that postmodernists like.
\* Actual quote from a colleague who self-describes as a postmodernist. | [
"Postmodern Culture is an electronic academic journal established in 1990. It is the result of an early experiment in electronic content delivery via the Internet. The journal publishes commentary and criticism on a wide range of concerns including literary theory, politics, and contemporary society. Occasionally, ... |
Is sex pleasurable for all species? | as kwoklius said dolphins, human (pigs, chimps and others). It's not clear as to why many animals have sex. For some it's most likely a biological response, as in it is not a choice. In others some speculate that it is indeed involuntary and it could be considered rape.
So why do animals have sex? Because they don't have a choice, the only purpose of life is to be and to be you need to have sex. Now some animals with higher cognitive ability use the euphoric results of sex for stress relief amongst other things. | [
"It is often assumed that animals do not have sex for pleasure, or alternatively that humans, pigs, bonobos (and perhaps dolphins and one or two more species of primates) are the only species that do. This is sometimes stated as \"animals mate only for reproduction\". This view is considered a misconception by some... |
1 tb micro sd cards | There's an observation in technology called "Moore's Law", which states that transistor densities on chips will double approximately every 18 months. Computer chips are just large collections of transistors, and SD cards are just another form of computer chip. So, we can expect flash memory storage densities to nearly double every 18 months. If 1TB is today, then 3 years ago 256 GB would be State of the Art. 3 years before that, 64GB. 3 Years before, 16GB (2010).
On top of that, flash memory had a huge jump in density with the development of 3D NAND, which builds the memory in three dimensions, rather than just a two dimensional plane of transistors. This allowed Flash memory to achieve a higher density of data per square inch than hard drives for the first time. In 2016, companies were reporting lab tests of 2.77 TB/square Inch. | [
"As of August 2017, microSD cards with a capacity up to 400 GB (400 billion bytes) are available. The same year, Samsung combined 3D IC chip stacking with its 3D V-NAND and TLC technologies to manufacture its 512GB KLUFG8R1EM flash memory chip with eight stacked 64-layer V-NAND chips. In 2019, Samsung produced a 1T... |
What (if any) physiological changes do men experience when their partner is pregnant? | **HEY EVERYONE!** Make sure you distinguish between research on father's-to-be vs. fathers. The findings are better understood for fathers, whereas there is far more dispute regarding changes in expecting fathers. | [
"Studies have shown that the male partner cohabitating with a pregnant female will experience hormonal shifts in his prolactin, cortisol, estradiol, and testosterone levels, typically starting at the end of the first trimester and continuing through several weeks post-partum.\n",
"Changes in hormones during a fem... |
why are video games moving from standalone titles to to microtransaction heavy models or free-to-play models? | Money.
It turns out that if you make a free to play game with microtransactions, most players will pay nothing or only a small amount, but some people will get addicted and spend hundreds or even thousands on it.
Because there's no upfront cost to start playing the game, there's the potential to have far more players than a traditional game. So even if most of those barely spend anything on it, there are enough "whales" (actual industry term) who pay more than enough to make up for that.
It doesn't really benefit gamers, it's not meant to. It's meant to make money. | [
"Modular or upgradeable video games were not commonly offered by the major video game companies in the 1970s and 1980s, because it was more profitable to sell an entirely new machine. System 1 and the Japanese JAMMA wiring standard were attempts to move to a modular solution, though there were many smaller companie... |
why are there so many website url extensions (eg; .com, .org, .net) and no universal one ? | TLDs *(Top Level Domains, what you called extensions)* are usually ruled on a nation-wide level. And as we know the world can never agree on something and everybody wants to do their own thing. So there's that. | [
"The essential reason to create new gTLDs is due to the fact that there are not enough domain names available for businesses or individuals to create sensible and logical URLs. A vast amount of .com’s are in use already, and individuals and businesses are having difficulties in creating a fitting and simple domain.... |
What made Frederick II so unique compared to other rulers? Why was he given titles such as "the wonder of the world", or considered by some as the "first modern ruler"? | I don't think I can do the full question justice, but I can give you a minor, albeit somewhat odd, angle on it: Falconry.
**Frederick loved falconry.** He loved collecting the birds themselves, he loved exotic and rare raptor species, he loved flying them at game, he loved arguing with his staff of falconers over the best training methods, and he loved competing with his court members to see who could take the most quarry in a single day. I assume the smartest among them made a habit of losing to him regularly.
**He wasn't alone in this. This was an era in which falconry, and hunting more generally, played an outsized role in the lives of many royals and aristocrats, to the point of having its own little impact on history.** There's a semi-funny story from the siege of Acre in 1191 in which the French king, Philip Augustus, lost an incredibly valuable white-morph gyrfalcon while hunting a few miles away from the city. (He was likely after the *houbara* bustard, which is the traditional quarry for falcons in the region. Sadly, the bustard's modern population on the Arabian peninsula has been almost completely wiped out by Saudi royals who go hawking with Land Rovers and dozens of falcons at a time.) The bird failed to make a kill, flew over Acre's walls and into enemy territory, and was captured and brought to Saladin. Once Philip figured out where the bird had gone, he sent emissaries to negotiate for its return. Saladin was having none of it, and Philip was reduced to begging and offering a small fortune to try to get it back. This is napkin math and shaky at best, but I think he offered the modern equivalent of $180,000-220,000. Saladin decided to hold onto the bird because: a). gyrfalcons, particularly white-morph gyrfalcons, were huge status symbols: b). it was actually a lowball number for the value of the bird, and c). it was a convenient little fuck-you to the guy who was besieging the city.
**This wasn't the last time that birds of prey played an unwitting role in the region's oft-fractious politics.** In 1396, John the Fearless (son of Philip the Bold, then duke of Burgundy) got himself and twenty four of his knights captured by the Turks either during or immediately after the Battle of Nicopolis. The Turks under Bayezid I refused to give them up until negotiators settled on the eye-popping sum of 200,000 Venetian ducats (napkin math gets shakier here but this could easily be hundreds of millions of dollars) and 12 gyrfalcons. They wanted the birds more than the money; because the gyrfalcon is indigenous only to high northern latitudes, people in or around the Middle East didn't have easy access to them.
**Anyway! The difference between Frederick and most of his noble cohorts was an intense intellectual curiosity -- and of course, the means to satisfy it.** Being as familiar with the sport as he was, he couldn't help but notice that many of the existing scientific treatises on birds of prey, even those by the venerated Aristotle, either didn't match what he saw in the field or were woefully incomplete. He hired scholars to translate Greek and Arabic texts on birds for him. He started dissecting dead hawks and taking extensive notes on their anatomy; a significant portion of his resulting book is about nothing but bird organs and their function. He observed the different species' behavior, both in the wild and captivity, critiqued different training techniques, wrote extensively on the use of gear and strategy in different environments in the field, and wrote detailed descriptions of the various species used in falconry and their traditional prey.
**The end result was an enormous book titled *De arte venandi cum avibus,* or "On the Art of Hunting with Birds."** It is arguably the first modern manual on the sport of falconry, which I know is a very strange thing to say about something that was written in the mid-13th century, but a lot of the practices, observations, and suggestions made in *De Arte* are instantly familiar to ornithologists and falconers today. With the exception of satellite tracking for the birds, the growing use of North/South American species, artificial insemination, and the introduction of Aylmeri jesses in the 20th century, falconry really hasn't changed much since antiquity. What *has* changed is our scientific and factual understandings of the birds and their behavior, and Frederick made an unusually early contribution to this.
**Here's an excerpt.** I had to borrow this from the very few pages available on Google Books; my copy of the English translation has apparently disappeared into a black hole somewhere. Anyway, this is from his chapter on migratory patterns:
*We notice also that when a favoring wind springs up, whether by day or night, migrating birds generally hasten to take advantage of it and even neglect food and sleep for this important purpose. We have observed that migrating birds of prey, that have begun to devour food we have thrown to them, will abandon it to fly off if a favorable wind begins to blow. They would rather endure hunger and travel day and night than forego such an advantageous opportunity.*
*The calls of migrating cranes, herons, geese, and ducks may be recognized flying overhead even during the night, and not, as Aristotle claims, as a part of their efforts in flight; they are the call notes of one or more birds talking to their fellows. For example, they understand wind and weather so thoroughly that they know when meteorologic conditions are favorable and are likely to remain so long enough to enable them to reach their intended haven.*
**This was centuries before the scientific method was a thing, but there's a distinctly modern feel to how Frederick researched and wrote the book.** Not only did he spend a lot of time watching birds (and likely assigned underlings to do it for him and report back), but he also experimented to see if their behavior varied in the presence of food or other incentives. Interestingly, his correction of Aristotle here is also the modern ornithological understanding of migrating bird calls, e.g., geese honk to communicate with each other, keeping the flock in formation at a consistent speed.
I'm hesitant to address why Frederick might be considered the "first modern ruler" in a political sense, but you can make a strong argument that his commitment to empirical observation and questioning of scientific orthodoxy in *De Arte* certainly set him apart from most of his contemporaries. However, you can also argue that Frederick's work reflects the huge push in the academic establishment of the 13th century toward logical thought and rigorous observation; he overlaps with such luminaries as Albertus Magnus, Grosseteste, and Roger Bacon.
So was Frederick ahead of his time, or more a reflection of its best sensibilities?
| [
"Frederick II \"the Great\" is best known for his military genius and unique utilisation of the highly organized army to make Prussia one of the great powers in Europe as well as escaping from almost certain national disaster at the last minute. However he was also an artist, author and philosopher, who conceived a... |
Is it possible to recover data from RAM? | Yes!
Modern SDRAM is based on tiny capacitors. They lose their charge fairly rapidly and thus lose the contents of the memory they were storing, this is why the computer needs to constantly refresh the charge in the capacitors (which is why it's called "dynamic ram"). Normally the data will decay in an amount of time that is too small to be useful in an attack, but if you cool the RAM to below freezing then you can significantly extend that time. This is called a [Cold Boot Attack](_URL_0_). The basic premise being that you have physical access to a running computer, then you cool the ram on the computer, turn off the computer, remove the ram and transfer it to a computer or device that you have control over. The charges in the capacitors and thus the data in the RAM will be maintained which you can then read out. By booting to another media (such as a USB stick), this can also be managed on the same computer, assuming the option is available.
Any encryption system that retains keys in plain text in memory is thus extremely vulnerable to such an attack. | [
"A potential technical hurdle with in-memory data storage is the volatility of RAM. Specifically in the event of a power loss, intentional or otherwise, data stored in volatile RAM is lost. With the introduction of non-volatile random access memory technology, in-memory databases will be able to run at full speed a... |
A question about Pavlov's Dog. | My psych teacher sat in front of me and said a bunch of random words, and every time he said "candy" he sprayed me in the face with a water bottle. I knew exactly what he was doing but when he said "candy," i flinched every time, even when he stopped spraying me. | [
"Ivan Pavlov () is a 1949 Soviet biopic directed by Grigori Roshal and starring Aleksandr Borisov, Nina Alisova and Nikolai Plotnikov. The film portrays the life of the Russian scientist Ivan Pavlov (1849-1936), known for his Pavlov's dog experiments. The film was made during the Stalinist era, despite the fact tha... |
does gothic (as in clothing, rock, architecture, fonts etc.) come from the gothic tribes? why/why not? | Very indirectly.
The Goth subculture ultimately derives its name from the Gothic literary movement of the 18th and 19th century, which was a darker offshoot of the Romantic movement (think *Frankenstein*, *The Legend of Sleepy Hollow*, and the works of Edgar Allen Poe).
The literary genre takes its name from Gothic art and architecture from the middle ages, since the stories were stereotypically set in castles and other medieval buildings.
That name itself originated as a pejorative coined during the Renaissance (the style was in its time called "French") and was compared to the Goths, barbarous Germanic invaders who supposedly destroyed Rome and erected their "Gothic" architecture across Northern Europe before the resurgence of classical style during the Renaissance. Basically, it was meant as a synonym for "barbarian." | [
"Gothic is an extinct East Germanic language that was spoken by the Goths. It is known primarily from the \"Codex Argenteus\", a 6th-century copy of a 4th-century Bible translation, and is the only East Germanic language with a sizable text corpus. All others, including Burgundian and Vandalic, are known, if at all... |
How reliable are battle numbers in Chinese antiquity? | It's not an accurate statement to say that one should simply "lop off a zero" of Sima Qian's statements to make them approach accuracy... **it's a fun statement, it gets the point across, and I've done it myself in the past... but it's not really accurate... probably.***
See, there's a couple things anyone looking at that period needs to know about 1) Chinese historiography and 2) Chinese literary conventions o really understand Sima Qian and his numerations...
# 1) Sima Qian's *Records* are pretty much the one-and-only historical text we have after the *Spring and Autumn Annals*
That means there's A) a 3-400 year gap in historiography, and B) we're forced to rely on *a single source*. The problems with that single source are several... First, it's written (as with almost every official Chinese history) with a strong narrative bias *against* the dynastic order that preceded it. In Sima's case, that meant he was writing for the early Han, which had directly ousted the Qin a half-century or so prior. It's unlikely his account was terribly favorable to the Qin wars, or their wartime conduct... better to paint them as monsters... Sima's career and indeed life may well have hinged on an "acceptable" rendition being delivered. But more than that, there's nothing else in the historical records to either corroborate or disprove his particular telling. That's is **not** to say nothing else was written... quite to the contrary, later Chinese histories are smattered with *references* to other works of Sima Qian's time and before... but they either haven't survived the rigors of time, or perhaps (fingers crossed) just haven't been excavated yet... that's not as impossible as it might sound... a [medical text](_URL_0_) long thought lost was recovered in 2013, and major, systemic excavations of historical sites in China have really only being going on in an organized (read: not-tomb-robbing) sense since the late 70's... *it's definitely possible that more will eventually turn up.* But the other thing is...
# 2) Chinese literary tradition tends to use large numbers more for *effect* than accuracy.
The numbers don't even have to be *particularly big.* But if it looks/sounds nicer, that's what writers have tended to go with... the examples are too numerous to really count (*which is itself soft of... ironic? Poetic??*)... but everything from the prayer that a dynasty will endure for 10,000 years (meaning: *forever*), to era names (the 16 Kingdoms was more like 20, the 5 Dynasties & 10 Kingdoms was more like 6.5 and 25 or so...), to the List of "100 Family Surnames" (actually a list of 504 surnames)... numbers are used for their emotional *punch* much more than their mathematical accuracy in such literary devices. This isn't unique to China, by the way... the "300 Spartans at Thermopylae"? (Yeah, maybe 300-ish, but alongside and among some 7k combined Greeks... Herodotus/Zach Snyder lied, I know it's shocking) The "million-man Persian army of Xerxes? What, did someone sit there and count? Numbers that we've been societally forced to actually come to terms within the modern age... simply meant *less* in ancient eras, where the maximum one might be reasonably expected to estimate was in the hundreds, or thousands. Above that, we *still* have terminology analogous to what many of the ancient authors used "hundreds of thousands" or "millions" for... unspecified, hyperbolic words like "zillion", "jillion", and ~~Brazilian~~ "bazillion". *That's* more akin to what numbers like Sima Qian likes to throw around represent: **"there were a crap-ton of soldiers in that fight, no way to count 'em all!"** | [
"Not much is known about this battle since it, along with other events of the era, are clouded by mythology. Thus, the historical accuracy of accounts of this battle is disputed. Chinese historiographical tradition places it in the 26th century BC.\n",
"Although most western historians claimed that there were ove... |
Why is my theory on antimatter wrong? | This is a small complaint, but you don't have a theory about antimatter. You have a conjecture. I don't know enough about the topic to say if it has any possible credence or not, but a theory requires a lot more work than "hmmm, maybe it's this!"
This is not supposed to discourage you wondering or asking, just helping fight the common phrase "well, that's just a theory!" that you hear non-scientists say. | [
"When antimatter was first discovered in 1932, physicists wondered about how it would react to gravity. Initial analysis focused on whether antimatter should react the same as matter or react oppositely. Several theoretical arguments arose which convinced physicists that antimatter would react exactly the same as n... |
how does my touchscreen know between a finger and a non-finger? also, how does it know to respond to a stylus? | TL;DR _URL_0_
Most touchscreens are capacitive. If you know how a capacitor works, it stores charges over time and a voltage drop is noted by the smartphone. Fingers carry charges, and can take some away from the capacitor. This causes a change in the capacitors voltage drop and is registered as a touch. An object that doesn't carry as much charge away from the screen, like a rubber gloved hand, doesn't register as a touch to the touch screen.
Any modern touchscreen stylus simply has a material that conducts those charges from your fingertips to the screen, effectively fooling your phone into thinking a finger is touching it.
Edit: removed an incorrect reference to van der waals interactions. | [
"Touchpads operate in one of several ways, including capacitive sensing and resistive touchscreen. The most common technology used in the 2010s senses the change of capacitance where a finger touches the pad. Capacitance-based touchpads will not sense the tip of a pencil or other similar ungrounded or non-conductin... |
Were Werner Heisenberg's nuclear capabilities overestimated? | Heisenberg was one of the most brilliant quantum theorists of his generation. Nobody doubts that.
But making an atomic bomb requires more than one brilliant scientist. The person at the "top" of an organization (and Heisenberg, as an aside, _was not that_ — he was the head of one of two research groups that was working on fission, and had a boss organizing the whole thing: Walter Gerlach, who ran German defense physics research fro 1944 onward) needs other skills as well. That job is partly organizational (they need to know how to manage large groups of people efficiently), part motivational (they need to know how to lead large groups of people effectively), and part technical (they need to have a head that can accommodate the whole range of potential problems that might come up). Separately, there needs to be someone who knows how to _get things done_ — how to get the materials necessary, how to accelerate the work, how to create factories from scratch.
In the USA, no single person held all of these functions. Oppenheimer did the job as top scientist, and did a great job of it. He could wear many hats and do many things and talk to many people. He had the intellectual as well as the organizational chops, and his personality was one that most of the scientists found inspiring. Groves did some of the other heavy lifting: he was the man who got things _done_. The US project needed _both_ of them, and arguably needed a few other key figures as well: Ernest Lawrence was quite experienced at large-scale physics machine building (necessary for building the facilities that were used to enrich uranium), Enrico Fermi was a once-in-a-generation jack-of-all-trades sort of genius who was as comfortable with the theory as he was with actually building nuclear reactors by hand, and Vannevar Bush had unique access to the President's ear and could coax entire agencies out of him based on conversation alone. (It is something of a nuclear historian parlor game to consider whether you could eliminate one or two of the major scientists and see if the project would still survive — I think if you dropped Lawrence, Fermi, or Bush, it would be much harder; if you drop Oppenheimer but not Lawrence or Fermi, it might still survive if one of them ran it; if you drop Groves, the whole thing fails).
Similar dynamics existed in the Soviet bomb project. Igor Kurchatov played a mixture of the Oppenheimer/Fermi roles — an organizational scientist who also got his hands dirty. Yuli Khariton picked up the theoretical physics slack. And the "get things done" person was none other than the architect of Stalin's reign of terror, Lavrenty Beria.
The roles don't have to be siloed out exactly like this, but making an atomic bomb is _not_ a theoretical physics project. It is a massive industrial-engineering enterprise that in the 1940s tested and pushed beyond the limits of known theoretical and experimental physics, but also required herculean contributions in the areas of chemistry, metallurgy, and numerous types of engineering.
OK, so let's go back to the German case. What did they have? They had two relatively small nuclear physics research groups. They had a few A-list physicists in there, and a few B-listers. You don't need all A-list physicists to make an atomic bomb, but the more you have helps. In the case of the US, the list of A-listers is staggering: Oppenheimer, Bethe, Fermi, Feynman, von Neumann, Lawrence, Compton, Szilard, Kistiakowsky, Rabi, Bacher, Teller, Smyth, Chadwick, Bohr, Seaborg, McMillan, Alvarez — just to name a couple who come to mind easily. Each of these people could easily have been chair of a major national physics department — and some were — and several of them were either present or future Nobel Prize winners. Imagine plucking up one of these A-listers and giving them a staff of a few dozen B-listers. Could they have built an atomic bomb in 2.5 years? Jeez, of course not. Heck, could such a team have gotten a first-generation nuclear reactor working in 4 years? It would have been hard, especially if you didn't end up with Fermi as your A-lister (and Fermi was, again, unique among his contemporaries in his very wide skill-set, a rare bridge of experimental and theoretical knowledge). And woe to you if the one you picked was someone who didn't work well in groups, like Teller or Szilard, both of whom could be quite brilliant but were interpersonally very tricky and prickly, prone to "rage-quitting" whatever organizations they were part of.
Heisenberg was good at theoretical physics, primarily the intersection of mathematical and philosophical aspects that makes up quantum mechanics. No doubt there. Matrix mechanics, his baby, was an intellectual tour de force. But it's not the kind of work that implies he knows much about building _things_. And, indeed, he wasn't great at that. if Heisenberg had been part of Los Alamos, I am sure he could have made some great contributions. But expecting him to carry the burden of an entire program... it's just not his forte.
Separately, we should point out that there was no Groves or Beria figure on the German program. There was no "get things done" person. Gerlach was not that person: he was a physicist-administrator who was not entirely liked and certainly did not have his finger on the pulse of power in the German state. He was no Werner von Braun, to make a German analog — von Braun was both a hands-on guy, focused on one thing (rockets), and he knew how to get things done (even if that meant doing some things he later found unpleasant to admit to, like becoming a member of the SS and using slave labor in his factories). But he knew how to get things done, and knew what he wanted to get done, and the V-2 program as an aside cost more than the Manhattan Project. Gerlach wasn't a von Braun, much less a Groves or a Beria.
The Germans never mustered up much enthusiasm about the ability to make an atomic bomb in time for it to be useful for the war. They were not entirely wrong about this: they correctly saw that the odds were long ones, and the expenditures would be big ones. The US was in retrospect over-optimistic about how hard it would be, and they only pulled it off through incredible expenditure and ridiculous amounts of brainpower. The Manhattan Project employed, over the course of its existence, some 500,000 people, nearly 1 out of 100 Americans in the civilian labor force. The German program employed a few hundred people total.
This was not a "failure" of the German program — by 1942 the German government had decided that it was not worth trying to build a bomb, that they would focus on reactors instead. They didn't even get those working, in part because of the disruptions caused by the war, but also because of fracturing within the organization.
There were also some technical errors. Heisenberg is to blame for a few of them, others are to blame for others. They are relatively minor errors, though, that would not have "sunk" a bigger effort. Because it was a small effort, they bogged it down.
One can argue (as historians have) about _why_ the Germans didn't make more of an effort. There isn't much evidence they did it willingly to stop Hitler from getting nuclear technology. A more plausible view, in my mind, is that they truly did see it as a technology to be developed in the next 10 years, not the next 3 years. This is not anomalous — every other government group of scientists who studied the problem of fission came to the same conclusion _except_ those in the UK, who managed to convince those in the US that it would be easy (the US physicists originally came to the same conclusion as the Germans, prior to 1941). So the "weird" case to be explained is not the Germans' non-enthusiasm but the British and later American enthusiasm.
As for whether Heisenberg was overestimated at the time... his contemporaries knew he was very smart. If you combined his intelligence _with the intelligence of others_ and _a very efficient and well-funded organization_, the Germans might have had a shot at the bomb _if_ it had been as easy as the Americans ended up thinking it would be, when they decided to build a bomb (late 1942). It was actually much harder than that (and cost 5X what they expected it would). Personally I think it would be nigh impossible for the Germans to build a bomb during World War II under almost _any_ circumstances unless they knew _exactly_ what all the "right" ways to do things were (and they very obviously didn't, and neither did the USA, because it had not yet been done).
On the German program, Mark Walker's _Nazi Science: Myth, Truth, and the German Atomic Bomb_ is very good, as is his longer (and more technical) _German National Socialism and the Quest for Nuclear Power, 1939-49_. I would avoid Thomas Powers' popular _Heisenberg's War_, as it spends a lot of time trying to bend the facts to a very discredited thesis (that Heisenberg was actively trying to sabotage the project). I have written [a bit on my blog](_URL_3_) about what we know about the German program, and also about such questions as "[When did the Allies know there wasn't a German bomb?](_URL_1_)" and "[What did the Nazis know about the Manhattan Project?](_URL_2_)" as well as [many posts](_URL_0_) about the size and scope of the Manhattan Project as well. | [
"Heisenberg's comment that he knew about the potential for weaponizing uranium fission, appears to counter the arguments of critics such as Rose and Bernstein that calculation errors in 1940 about feasibility, rather than moral scruples, led Heisenberg not to pursue building nuclear weapons.\n",
"Historians have ... |
Robert E. Lee is lauded as a military genius of his time, but what were his real victories? Most of his 'decisive victories' seemed to have been more of utter failures and poor coordination by Union leadership rather than ingenious use of strategy by confederate leadership. | First, it should be pointed out that historians don't call Lee's victories decisive, even when he won them convincingly, as they didn't decide the war in the Confederacy's favor. Given the debate about whether Confederate victory was even possible, this isn't a terribly strong strike against his generalship; certainly the war would not have lasted four years and ended with 700,000 dead and 3.5 million people freed from slavery without his leadership.
I challenge you to find a battle in history where the losing side made no mistakes; indeed, a battle where the *winners* fought perfectly is a rare thing. Being able to take advantage of an enemy's mistakes, while preventing your own from undoing you, is a key element of military tactics.
Furthermore, it's important to understand the context of the key decisions on the battlefield. Looking back on events that already happened, we know which hills and ridges will prove decisive, which generals will go left and which right, where this or that unit's flank ends; the commanders at the time had to make it up as they went along, because they fought under conditions of heavy uncertainty, with incomplete information and a rapidly changing situation.
Regarding 2nd Bull Run, you have to remember that the battle unfolds across time as well as space. It takes time to find the enemy's flank and then to maneuver thousands of men into a position to attack it, and the enemy are using that time to move as well. John Pope wanted to attack Jackson's right flank, but could not get Porter into position before Longstreet's command arrived to envelop the Union line. He tried to roll up Jackson's left flank, but Jackson beat him back.
Pope had sound military reasons for attacking at 2nd Bull Run; the enemy's main army was temporarily divided, giving him superior numbers at what he thought would be the decisive point. It would be inexplicable incompetence for him to pass up the opportunity; one of the basic principles of war was to mass superior forces against a weaker enemy -to throw rocks against eggs is how Gary Gallagher put it- and Lee enticed him to battle by offering the opportunity. Furthermore Pope had staked his career on giving the administration the vigorous offensive it wanted; given the civilian-run nature of republics at war, it's relevant to note that Lincoln's administration is not commonly convicted by the tribunal of historians for the tactical offensive posture of the Union army at 2nd Bull Run.
Pope did everything he could, but Lee had absolutely outmaneuvered him on the operational level, which I think is something that slips by a lot of newcomers to the ACW. People have a bad habit of looking only on battles to get the measure of a general, when in reality, wars in the modern style typically came down to what Jomini called the skillful arrangement of marches. You'll notice that Bull Run isn't so far outside of Washington, when just a few weeks before, the main Union army had been preparing for the siege of Richmond. Lee had marched circles around Pope, turning him out of his position along the Rapidan River, yanking the leash of his rail lines, so to speak. Because of skillful and rapid marches, Jackson got to deploy first, shaping the battle to come, with Bull Run anchoring his left flank and Longstreet on the right.
If you zoom out even further, though, the greatness of Lee's victory becomes even clearer. He was faced with two Union armies in Virginia, both of which outnumbered his; McClellan was menacing Richmond from the East on the Peninsula, and Pope's was threatening the Virginia Central Railroad to the north. Furthermore, he knew from partisan leader Mosby that Pope's army would soon be reinforced. Lee took advantage of the central position to engage Pope's army while observing McClellan, used a strategic turning movement to bring it to battle on favorable ground, and an operational envelopment to defeat it with the clock ticking. With the main rebel army just across the Potomac from the U.S. capital, and faith in the Peninsula concept dropping, he didn't even need to turn to face McClellan on the Peninsula.
Furthermore, I think you misunderstand the flank march at Chancellorsville. It's important to remember Hooker's concept of operations for the campaign; he wanted to either lever Lee out of his strong position on the Rappahannock or force him to attack an entrenched and more numerous force. In modern terms, he wanted to assume the position of tactical defense within an operational offensive, which military scientists are generally enthusiastic about, given the advantages of both. Furthermore, since his approach was coming out of the west, the battle lines were initially oriented north-south, while Lee's line of retreat was towards the south.
When the greater part of Lee's force started marching south, it would have been a reasonable assumption that he was retreating. After all, his position was being turned and he was outnumbered. Hooker did however consider that Jackson could be undertaking a flank march. He ordered Howard to prepare for such an eventuality, and told Sickles to attack and take possession of the road. His corps, down a division, became hotly engaged with a regiment and two brigades out of the Confederate column; Jackson's corps did not just brazenly march in front of the Union line. They used their cavalry well to find a route around the Union flank and cover their flank march (one of the riskiest tactical maneuvers), and they went all in.
The name of the game here was economy of force. Lee could recognize where the decisive point of the battle would be and where he could afford to merely delay while preparing to deliver the main blow. Lee left just 10,000 men to hold back 40,000 under Sedgewick; they eventually gave way, but it didn't matter. He only had 14,000 men to hold back 70,000 under Hooker, but that was alright, because his main striking force had worked its way around his flank to deliver a terrible hammer blow. If he misidentified the decisive point of the battle, he might have massed his main force against Sedgewick; after all, his was the weaker of the two wings, why not go after it? This approach, though, would not have decided the battle in his favor, because nothing he does to Sedgewick's force matters if Hooker succeeds.
He had previously displayed this capability in the Seven Days Battles, though adapted to different circumstances. Because of his astute tactical understanding of the value of fieldworks, he was able to economize manpower south of the Chickahomminy River to mass superior force on the north side, where an isolated Union corps guarded the Army of the Potomac's rail communications with White House. As a result, McClellan had to abandon that line of operations, and thereafter the campaign, when the administration sought other approaches to the problem. Thus, the greatest danger to the main Confederate army and the capital until Grant's crossing of the James had passed.
This victory also becomes more impressive when viewed in the broader context. Earlier, Lee had detached two divisions under his best fighter, Longstreet, to secure provisions for an offensive in North Carolina. Thus, not only did Lee win a battle gravely outnumbered, but because he was even more outnumbered than he could have been, he was prepared to quickly follow up on an impressive tactical victory with a strategic offensive into the north. While this offensive failed in its main objective of destroying the main Union army, it achieved several secondary objectives. The Shenandoah Valley had been cleared of Union presence, Lee had resupplied his army off of enemy territory, and bled the Union army so badly it was passive enough for him to send two divisions under his best fighter west to win the Army of Tennessee's only victory.
Even campaigns that ended in failure typically featured an extremely strong showing from Lee; Harsh's book on the Maryland campaign concludes that Lee made the right decision at every turn until he attempted to invade through Williamsport again, and achieved the largest surrender in U.S. history until the Philippines in WWII at Harpers Ferry. The Overland campaign is considered very good work from Lee as well, but the thing that strikes me is how quickly the campaign burned through his lieutenants. Jackson had died the year before. Longstreet was shot at the Wilderness; Stuart was killed at Yellow Tavern; AP Hill had a flare up of his prostatitis; Ewell had a nervous breakdown. At the North Anna, with a golden opportunity to strike the divided Union army in the midst of a river crossing before him, Lee fell ill with malaria, and there was no one to strike the blow.
Lee is a bit of an odd duck when it comes to perception. Most people approach the topic knowing only the bottom line that he was a great general; their perception is positive, but shallow. As they continue to study, they find that Lee indeed made mistakes, and that his opponents didn't exactly measure up to the same expectations he's held to. But I've found the more I study military history, the more I appreciate Lee's generalship; it's not quite the infallible marble man you see coming in, but it's far deeper and more profound. | [
"BULLET::::- Confederate generals such as Robert E. Lee, Albert Sidney Johnston, and Thomas \"Stonewall\" Jackson represented the virtues of Southern nobility and fought bravely and fairly. On the other hand, most Northern generals were characterized as possessing low moral standards, because they subjected the Sou... |
why does n. korea have concentration camps and treat its own people in them so poorly? | North Korea is pretty much the last Stalin level regime that still exists. In these regimes, this kind of stuff is necessary to maintaining order. When hard work isn't rewarded, like in any Socialist (Stalin socialist, not Hollande Socialist), you need to motivate them. Stuff like this is a good way to do that. Similarly, you need to stop potential dissidents and others that threaten the regime. These camps take those people, as well as their families. A regime that doesn't govern at the will of the people, doesn't let people leave, and fails to reward hard work essentially has no other option. Stalin didn't want to eliminate his own people, but he still employed similar tactics. | [
"North Korea is known to operate six concentration camps, currently accommodating around 200,000 prisoners. These camps, officially called Kwan-li-so (Korean for \"control and management center\"), are large political penal-labor colonies in secluded mountain valleys of central and northeastern North Korea. Once co... |
how were cartoon sound effects produced such as those from hannah-barbera and 80's-90's anime? | They had people called "foley artists" who would record unique sounds. Some of these sounds would be kept in a library of sounds that could be reused, other sounds would be recorded specifically for individual purposes.
They'd use anything and everything imaginable. People still do it today, and it's not just cartoons.
_URL_0_
Some sounds are really obvious, like walking on concrete. Other things you have to improvise more. Like, the sound of walking on snow might not sound enough like walking on snow- sounds contradictory, but sometimes real sounds aren't as exaggerated as we'd want them to be. So maybe for walking on snow they'll instead walk on crackers, or maybe in molasses, or maybe in bread dough. Whatever sounds right. | [
"American animation studio Hanna-Barbera Productions was noted for their large library of sound effects. Besides cartoon-style sound effects (such as ricochets, slide whistles, etc.), they also had familiar sounds used for transportation, household items and more. When Hanna and Barbera started their studio in 1957... |
how do shooting games like duck hunt (if you're old like me) or buck hunter know if you hit the target or not? | Duck hunt works as follows. The trigger tells the screen to go all black, with the exception of the duck, which shows up as white block. The gun is looking for the white block. If you are pointing at it, the gun sees the light, and registers it as a hit. If you are not aiming correctly, the gun doesn't see any light, and it registers as a miss.
If there are two ducks, then the screen goes black for 2 frames. Frame one, duck one is lit up. Frame 2 duck two is lit up. In that sense, the gun doesn't know where the duck is on the screen. The actual location doesn't matter. The gun only knows if it sees light or doesn't see light. The Nintendo can calculate the timing of the frames, so it knows which duck you are looking at based on when it sees light.
And something to note. The NES gun doesn't work on modern TV's. I believe its because it relies on precise timing between the CRT TV and NES, which is highly predictable. Modern TV's may have some input lag, which is unpredictable (and we are just talking a few milliseconds), but that is enough to throw it off. Don't quote me on that being the exact reason though. | [
"The player is required to successfully shoot a minimum number of targets in order to advance to the next round; failure will result in a game over. The difficulty increases as the player advances to higher rounds; targets will move faster and the minimum number of targets to shoot will increase. The player receive... |
How do Maxwell's equations prove that electromagnetic waves are light? | Initially, Maxwell conjectured that, since Maxwell's Equations predict waves that move at the speed of light, light waves might be electromagnetic waves.
However, once you make that connection, then you can test it, and see if light interacts with charges as it should if it is an electromagnetic wave. In this way, you can indeed verify that light waves are electromagnetic waves. You can study how charges will produce electromagnetic waves and then check that in those situations in which those waves have the right frequencies, you see light. You can see what properties cause electromagnetic waves to be reflected, transmitted, or scattered, and by how much, and then show that light waves reflect, transmit, and scatter in exactly these situations by the right amount. In this way, you can demonstrate that light is, indeed, electromagnetic radiation. | [
"With the addition of the displacement current, Maxwell was able to hypothesize (correctly) that light was a form of electromagnetic wave. See electromagnetic wave equation for a discussion of this important discovery.\n",
"James Clerk Maxwell derived a wave form of the electric and magnetic equations, thus uncov... |
Is there a point where water is under enough pressure that it's boiling point is above it's point of incandescence but remains a liquid? | Beyond a certain temperature and pressure known as the critical point, [the hard boundaries between the gaseous and liquid phases break down and the transition between the two becomes continuous](_URL_0_). For water, this critical point is at temperatures above 374 centigrade, whereas incandescence starts at approx 520 centigrade. At temperatures it would glow, it would act either as a gas or a [supercritical fluid](_URL_1_) depending on the pressure, but would never boil at these temperatures. | [
"Boiling-point elevation describes the phenomenon that the boiling point of a liquid (a solvent) will be higher when another compound is added, meaning that a solution has a higher boiling point than a pure solvent. This happens whenever a non-volatile solute, such as a salt, is added to a pure solvent, such as wat... |
why does my nose run when it's windy? | There are these little cells that make mucus. This does a number of things for the body, but they're not everywhere so there are other cells with wee little "fingers" that push the mucus around. When you breath in cold air (winter, ac, wind) they slow down, like many other things and they can't keep up with the mucus being produced so it starts to run. | [
"Wind has a range of effects, the first being the effect of making the projectile deviate to the side (horizontal deflection). From a scientific perspective, the \"wind pushing on the side of the projectile\" is not what causes horizontal wind drift. What causes wind drift is drag. Drag makes the projectile turn in... |
What exactly is going on when we adjust to something (a smell, temperature, etc)? | When you "feel" something like temperature a series of action potentials are propagating from the receptor to the brain to be interpreted so you feel the hot or the cold. These action potentials are sent when the receptor is stimulated enough to cause an action potential. These receptors are made of proteins which have a certain conformation, which determines their functionality. When a receptor is repeatedly stimulated it will change conformation making it more difficult for it to be stimulated. So in the example of hot water...Originally, the hot receptor is very easy to stimulate so you feel the hot. But as the receptor is repeatedly stimulated by being in the water for a while the hot receptor is less effected by the stimulus so it doesn't feel as hot.
The brain can also filter out signals from sensory receptors when they are redundant as in classic [dot and circle illusion](_URL_0_). So it's really a combination of processes that alter your perception of stimuli. | [
"\"Adaptation\" occurs when one makes a change within oneself in order to better adjust to one's surroundings. For example, when the weather changes and temperatures drop, people adapt by wearing extra layers of clothing to remain warm.\n",
"The plateau effect is also experienced in acclimation, which is the proc... |
what would happen if google became a tier1 isp? | This question really calls for speculation; it would probably be better off in /r/AskReddit. No one can "explain" the answer to this, as any answer is just guesswork. | [
"Other ISP plans apply \"per gigabyte\" excess charges to downloads beyond the monthly download quota. However, since the duopoly on internet access into Australia was broken in 2009 with the coming into service of the PPC-1 cable to Guam, there are many ISPs providing inexpensive unlimited internet plans on par wi... |
Guys, Girls and Sex: A Gender History Panel AMA | There's a blog post floating around recently talking about how mass shootings are higher than they've ever been, are higher in America than anywhere else, are almost entirely perpetrated by men, and speculates that this might be related to something particular in American masculinity.
I apologize in advance for the ickiness I'm about to start, but I had some questions. Answer whatever you can or feel inclined to.
* How has American masculinity changed since, say, the second world war?
* Have there been places/periods where masculinity was markedly more violent than the places/periods around it? Where, when, and what came of it?
* Has there ever been a place/period where *femininity* was marked by aggressive or violent behavior?
* In places/periods where a third gender was recognized, how did gendered segregation work? Were the third genders allowed to move freely between worlds? Was it more or less restrictive? Could people pass between the two (man or woman and third) at will, or was it restricted? | [
"\"Women... Oh, Women!\" is a sex-documentary focusing on the women of Japan, with particular emphasis on participants in the country's night-life. The film is a series of scenes visiting a variety of women such as female wrestlers, strippers, and \"geisha\". Nuns and sea divers are also shown, along with scenes of... |
I've obviously heard of people being born without hearing and sight, and less commonly smell/touch, but can we be born without other senses like proprioception or our sense of time without brain damage being a factor? | All of these can occur. Anosmia is a lack of smell, which can potentially lead to life threatening situations (can't detect when food is bad, gas is leaking, smell of smoke, etc). While I haven't researched in people missing a sense of taste, they would encounter many of the same problems.
Problems with priopreception and nociception (pain) are going to be neurological in nature, and can coincide with other neurological abnormalities. As you can imagine, these two can be exceptionally dangerous as both of these senses are necessary for day to day functioning.
| [
"Children are often taught five basic senses: seeing (i.e., vision), hearing (i.e., audition), tasting (i.e., gustation), smelling (i.e., olfaction), and touching. However, there are actually many more senses including vestibular sense, kinesthetic sense, sense of thirst, sense of hunger, and cutaneous sense.\n",
... |
why does light reflect off of glass and shine through it at the same time? | Every material has 3 factors .. transmission factor, reflection factor and absorption factor .. these three factors depends on the material itself .. and on the frequency of the light which is falling on it.
In the case of glass .. at the visible region (from 390nm to 700nm) .. the glass reflect around 8% of the light falling on it .. and only absorbs leas than 2% ... And transmits the rest. | [
"The glass is coated with, or has encased within, a thin and almost-transparent layer of metal (usually aluminium). The result is a mirrored surface that reflects some light and is penetrated by the rest. Light always passes equally in both directions. However, when one side is brightly lit and the other kept dark,... |
Stars made from elements other than Hydrogen? | At conditions hot enough for fusion molecules don't exist, you get individual atoms instead. So water and carbon monoxide would fall apart to hydrogen, carbon and oxygen.
Stars which don't contain enough hydrogen to start fusion would probably never ignite (remaining a brown dwarf) or collapse directly to a neutron star (if the star is massive enough to overcome electron degeneracy). The heavier elements can fuse together, but this requires very high temperatures. You are unlikely to achieve such temperatures if you don't start with hydrogen fusion. As far as we know all stars contain large amounts of hydrogen (simply because it the most common element in the universe), so this is purely hypothetical | [
"Hydrogen is the chemical element with the symbol H and atomic number 1. With a standard atomic weight of , hydrogen is the lightest element in the periodic table. Hydrogen is the most abundant chemical substance in the Universe, constituting roughly 75% of all baryonic mass. Non-remnant stars are mainly composed o... |
why are concerts a safe haven for open drug use? | They're not, it's just easier to hide in a crowd.
someone smells pot smoke and there's only one person in the area as opposed to someone smells pot smoke and there are hundreds of people all moving and close together | [
"The report titled Keeping People Safe at Music Festivals (PRS) summarises the expert panel's recommendations to how the legislation should be changed to reduce the overall harm of drug-use at festivals. The recommendations are as follows:\n",
"A key initiative for Safe Amp has been establishing a \"permanent, le... |
During the Early Middle Ages, how did one find a husband or wife given how sparsely populated it was, along with their close ties to the land? | When the Church finally got to issuing particular injunctions about marriage, the prohibited it if the parties were within seven degrees of consanguinity. Even in the highly populated thirteenth century, this was probably not possible to avoid in most villages; the nobility certainly couldn't manage it. So, the answer to one of your questions is that the rules weren't yet actually rules, and were in any case more like guidelines.
A more important point is that just because there was relatively few people per square mile, it didn't mean that the people were evenly distributed. Villages were near each other, and near the surviving Roman roads. Also, a lot of the original assumptions we've made about the "horizons" of travel have come under attack. Long distance travel did drop off, but short and medium distance travel continued. Finally, although there were major population collapses, we see signs of recovery shortly thereafter. By 700, population was growing once again.
In short, it wasn't as bad as all that. | [
"The Anglo-Saxon settlement, the \"combe\" or valley of a certain Wifele, was mentioned in the Domesday survey (1086), when it was quite large, consisting of twenty-seven households, with an annual value to the lord, the Bishop of Wells St Andrew, of £25. During the Middle Ages the bishops maintained a residence he... |
why did the arab countries only developed normally until the 70's? | If I remember my history correctly (and in this incredibly brief synopsis):
Up until the 1970s, the world pretty much left the Middle East alone.
Then the US and the USSR got in the ultimate pissing contest: the Cold War.
From there, both superpowers wanted governments in the region to have heads of state that would be loyal to one or the other, especially with the promise of oil availability.
Insurgencies/revolutionaries/freedom fighters were then funded to topple the existing governments, which had *relatively* stable countries with a modern outlook. Those revolutionaries that had been funded then took over those seats of power and instigated their own forms of law, which was often based on harsh/strict interpretations of the Quaraan (the "freedom fighters" were okay with their role of toppling the local government with the common tendency that they didn't agree to the current religious practices).
Then it became a cycle, and with every new "government," things got more and more strict and bizarre, especially for women. | [
"Over the period, the history of the Arab states varies widely. In 1956, the year of the Suez Crisis, only Egypt, Syria, Lebanon, Tunisia, and Sudan, among the Arab states were republics; all, to some degree, subscribed to the Arab nationalist ideology, or at least paid lip-service to it. Jordan and Iraq were both ... |
why is it in the morning/afternoon/evening, but at night? | The difference is when you say "at night", you are speaking of a point or interval in time, similar to how you say "at 3:00" not "*in 3:00". When you say "in the morning/afternoon/evening/night", you are thinking about the quality relating to that time period. And yeah, you do see "in the night" too. Examples:
"things that go bump *in the night*"
"awakened at some point *in the night*"
However, you are good to notice that the usage in constructions like "X o'clock in the morning" and "x o'clock at night" is inconsistent, in which case, there is no really good explanation, that's just the way that the language developed.
Language isn't engineered, it grows naturally, and sometimes the way that it grows is not perfectly logical. For some reason, when talking about times, "at night" became so popular as to be idiomatic, while "in the [ ]" became idiomatic for the rest. | [
"The opposite of night is day (or \"daytime\", to distinguish it from \"day\" referring to a 24-hour period). The start and end points of time for a night vary, based on factors such as season and latitude. Twilight is the period of night after sunset or before sunrise when the Sun still illuminates the sky when it... |
commonlaw "marriage": are you automatically married or do you have to apply? (in canada) | While common law marriage varies by state, and there have been many recent changes, you have to live together for YEARS not 6 months lol. Check your state laws on the matter for accurate information. A quick Google search will do it | [
"The law in England authorizes marriages to be legal if properly carried out and registered in the Church of England and some other religious bodies (e.g. Jewish, Quakers): other men and women who wish to marry can be married by a local official authorized to do so (civil ceremony). Circumstances may result in the ... |
why, historically, do socialist countries often experience economic collapse? | An open market allows consumer needs, wants, and demands to match up with producer supply spontaneously and organically. A top down planning approach fails because leaders and decision makers in overly socialized economies are not capable of actually anticipating and providing for consumer needs and wants.
To bring that down a bit, you cannot build a car that fits everyone, because there is no best car for everyone. There is no diet or housing situation that is ideal for every family. In free trade each spender picks the one that best fits them, and less popular options downsize to fit their lesser needs while in a top down controlled economy that does not happen.
In a socialistic society time, effort, and resources are wasted because they don't have free market signals to drive their production. You end up with things like the Trabant being forced on unwanting citizenry at prices that are very inflated compared to their actual value. | [
"Socialism suffered a setback in some countries in recent years. As a consequence of this, the imperialists and reactionaries are claiming that socialism has ‘come to an end’. This is nothing but a sophistry to beautify and embellish capitalism and patronise the old order.\n",
"Economic collapse is any of a broad... |
what is the martingale system of betting and how does it work? | In principle, it is like doubling your bet after you lose. So bet $1, if you lose bet $2 etc. The idea is that "There is no such thing as an infinitely long losing streak - so eventually you'll win and break even".
Problem is: "It doesn't work"
Most casinos have table limits and minimums. This means you'll rapidly hit the maximum bet size after you double more than a few times. The problem is that when you hit that scenario, you'd have already lost so much money it is hard to recover. So while you can imagine "I'll never lose 10 times in a row (which implies a bet 1024x the size of your initial bet)", once you do, you'd have lost close to 1023x the size of your initial bet. | [
"Originally, \"martingale\" referred to a class of betting strategies that was popular in 18th-century France. The simplest of these strategies was designed for a game in which the gambler wins their stake if a coin comes up heads and loses it if the coin comes up tails. The strategy had the gambler double their be... |
what is a "currency" and what is not? | What you created is something less than a currency. I was going to say it was like scrip (where companies would give their employees coupons that could be used at company-owned stores, instead of cash) but it's not even like scrip.
There are two functions of currency:
- Store of value. Currency has to be able to be traded for almost the same amount of goods tomorrow as today, because if there's a significant change, I'll stop using it (either I will hoard it in anticipation of it going up in value or I will refuse to accept it as payment because it will become useless long term)
- Medium of exchange. Currency has to be widely used, and freely exchangeable, to work. If it's too difficult to use something you try to make into currency, people will find something else.
Your pseudo-currency is not very good as a medium of exchange. It's not freely transferable between people - they can only get what's on offer from the stall owners, rather than being able to buy Magic cards or something from their friends. | [
"This is a list of alternative names for currency. A currency refers to money in any form when in actual use or circulation as a medium of exchange, especially circulating banknotes and coins. A more general definition is that a currency is a \"system of money\" (monetary units) in common use, especially in a natio... |
how is internet speed divided if multiple people are on the network? | first come first serve on a packet by packet basis.
unless there's something on the router to prioritize one device over the other. | [
"According to Akamai Technologies, Indonesia, with 9 connections to undersea cables, had in Q1 2014 an average Internet connection speed of 2.4 Mbit/s, which was an increase of 55 percent from the prior year. Just 6.6 percent of homes had access to 4 Mbit/s or higher speed connections. But in Q4 2014, the average i... |
why do british people address their female superiors as "mum" (mom)? | It's not mom or mum that they're saying. It's actually "Ma'am", which is a contraction of madam. | [
"She can be regarded as a foil for \"Mother,\" a wheelchair-using male British government official who gives orders to the main characters in the last season of the series and in the film. The humorous use of \"Mother\" for a male character is the source of the use of \"Father\" for a female character. In the origi... |
How much extra energy does an amputee have considering they don't have a limb they have to provide energy to? | Ever cell generates energy so they require less energy but are also missing those cells to begin with. So it's pretty much irrelevant. However internal organs, specifically the brain require a greater amount of energy so they likely have a lower overall amount because the internal organs can't siphon off the energy production from the limb | [
"Not only does the patient need to pay for their multiple prosthetic limbs, but they also need to pay for physical and occupational therapy that come along with adapting to living with an artificial limb. Unlike the reoccurring cost of the prosthetic limbs, the patient will typically only pay the $2000 to $5000 for... |
When televisions began selling in the 1930s until 1950, what programs were available? | In 1984, McGraw-Hill published "The TV Schedule Book: Four Decades of Network Programming from Sign-On to Sign-Off," which has charts of the daily schedules of the major U.S. networks (including DuMont) for every season beginning with 1944. The book also contains explanatory text about the history of TV programming. It's out of print but you can probably find it in libraries, and you can buy reasonably priced used copies. | [
"The first television shows were experimental, sporadic broadcasts viewable only within a very short range from the broadcast tower starting in the 1930s. Televised events such as the 1936 Summer Olympics in Germany, the 1937 coronation of King George VI in the UK, and David Sarnoff's famous introduction at the 193... |
pensions | So I want you to come work at my candy store this summer, and not the candy store down the street. Maybe they offered you $500 a week and I can only offer you $400 a week and some free candy. Either I just can't afford to pay you more, or the Candy Store Guild said I'm not allowed to.
So, if you're smart you'll probably work at the other place so you make more money. But wait! I'll make you a deal. If you work for me for $400 a week every summer until you graduate high school, I'll pay you $200 a week for the next five summers--and you don't have to work!
If you're in this for the long haul, we both win. I get a good employee for a long time, you get money even after you stop working here. The money I pay you after you stop working is called a pension.
(Irrelevant fun fact: lots of companies calculate your pension based on a Final Average Pay plan... that's right, a FAP plan.) | [
"There are three \"pillars\" of the UK pension system, which aim to ensure dignity and a fair income in retirement. The first pillar is the [[state pension]], administered by the government, and funded by [[National Insurance]] contributions. The third pillar is private, or \"personal pensions\", which individuals ... |
what stops our body from defecating when we pass gas? how does flatuce exit below a solid? | If you can imagine how air could leak out of a balloon filled with rocks without the rocks falling out, that's pretty much how it works with your butt. And if the solid isn't "solid" enough... well, sometimes your body can't stop both happening at the same time. | [
"If a peptic ulcer perforates, air will leak from the inside of the gastrointestinal tract (which always contains some air) to the peritoneal cavity (which normally never contains air). This leads to \"free gas\" within the peritoneal cavity. If the person stands erect, as when having a chest X-ray, the gas will fl... |
What is the History of the Handshake? | Oldest known instance of a handshake that i could find is in this babylonian tablet. _URL_0_
Its of two different kings (assyrian and babylonian) king hands in public and was to reflect a time of peace. Similar images can be found in other ancient works of art.
In this piece _URL_1_ theseus is being welcomed by posidon and shaking hands. This is of two different cultures and a few thousand years apart. Suggests the idea of the handshake is a sign of goodwill going back to early history. | [
"Various sources have attributed the origin of the handshake, as an ancient sign of bravery and respect, to Lord Baden-Powell's encounter after battle with Prempeh I, or to earlier published works by Ernest Thompson Seton. There exist various versions of the Prempeh story, all centering on African warriors using th... |
whats the difference between 44khz and 48khz when the human ear can only hear up to 20khz ? | You're getting confused by two totally separate things.
First of all you have the frequency of a specific sound, which as you rightly say is limited to about 20kHz for young, healthy people, and generally the upper range decreases as you get older.
However this is nothing to do with the frequency you see for encoded digital music files.
In this case it's referring to how many bits of information get recorded in every second of music. In this case it's generally "more is better" because the more bits of information, the closer the digital file will be to the analogue sound it's trying to represent. You can think of this as like a "frame rate" but for sound. | [
"The human auditory system is sensitive to frequencies from about 20 Hz to a maximum of around 20,000 Hz, although the upper hearing limit decreases with age. Within this range, the human ear is most sensitive between 2 and 5 kHz, largely due to the resonance of the ear canal and the transfer function of the ossicl... |
why are there "terms of service" of websites? what do they do and don't do? what happens if you go to a website with no tos? | TOS are quasi-legal contracts between you and the website. Most of them are filled with legalese that lets the website do anything and takes away any legal rights you might have had (but not always), and these sorts of TOSs are not always legally enforceable in their entirety.
Sometimes TOS spell out how you are to behave in the community, but again these are merely CYA so they can ban virtually anyone for whatever they think is misbehavior.
If you go to a website that does not have a TOS and/or a McDonald's that also does not have a TOS you merely retain all your normal legal rights.
TOS only exist because it's 'easy' to make everyone click the agree button on a website, and because people will do it. You don't see TOS in a lot of business because it's awkward to have everyone who walks into your store sign a waiver - but if the business is sufficiently dangerous they will still have you sign one (which like a TOS is also not always legally enforceable) | [
"Businesses that have an online presence should provide accessibility to disabled users. Not only are there ethical and commercial justifications for implementing the Web Content Accessibility Guidelines, in some countries and jurisdictions, there are also legal reasons. Under UK law, if a business's website is not... |
why do the whites of the eyes become red easily when bloodshot, but the iris never changes color? | The whites (sclera) are full of visible blood vessels called capillaries which can easily burst from overexertion such as eye strain. Since these vessels are much more visible than those within the iris due to contrast, the whites are more susceptible to appear bloodshot whereas the iris won't | [
"A red eye is an eye that appears red due to illness or injury. It is usually injection and prominence of the superficial blood vessels of the conjunctiva, which may be caused by disorders of these or adjacent structures. Conjunctivitis and subconjunctival hemorrhage are two of the less serious but more common caus... |
Does light effect Stalactite formation? | Though I'd only be guessing, I can't immediately think of any significant effect that camera flashes would have on stalactites.
The only minor effect I can think of is the energy from the flash could cause a very tiny heat increase in the droplets which deposit minerals on to the stalactites. This would make minerals dissolved it the fluid very slightly more soluble, meaning they'd be less likely to go out of solution and onto the stalactite.
If this was going on with hundreds of flashes constantly all day long for hundreds of years, it may become a problem (I haven't really done the maths), but to be honest, the best bet is that the cave owners want a monopoly on photographs of the cave for advertising to make it look as good as possible.
Edit: [Here](_URL_0_) is a handy pdf I found that has quite a bit of information about speleothems (Stalagmites, stalactites and flowstone)
| [
"Chatoyant minerals display luminous bands, which appear to move as the specimen is rotated. Such minerals are composed of parallel fibers (or contain fibrous voids or inclusions), which reflect light into a direction perpendicular to their orientation, thus forming narrow bands of light. The most famous examples a... |
If Someone was in space without a space helmet/oxygen supply and tried to inhale what would happen? | When you inhale you are essentially just increasing the volume of your lungs while leaving a pathway open to the outside air. You feel the air flow through your nose or mouth and down your trachea as it seeks to maintain an equal pressure from the outside air to inside your lungs.
In a vacuum that mechanism doesn't really work, since there is no air to flow into your lungs. In fact, if you were to try to hold your breath it would likely cause your lungs to burst (a similar effect is seen if you try to hold your breath when ascending from a very low depth, such as in a downed submarine escape exercise). If you let the air out of your lungs and then tried to breathe then in the few seconds of consciousness you had you would be able to drop your diaphragm and open your chest, but you would feel no air rushing in. | [
"BULLET::::- The environment within the astronauts' pressure suits was not changed. Because of the rapid drop in cabin (and suit) pressures during ascent, decompression sickness was likely unless the nitrogen had been purged from the astronauts' tissues before launch. They would still breathe pure oxygen, starting ... |
What geological evidence do we have to prove that ice ages are cyclical?? | Tree ring data; sediment cores from lakes and oceans; and ice cores. [More info.](_URL_1_)
Paleoclimate from [ice cores](_URL_0_) allows us to determine temperature based on oxygen isotope ratios.
Most oxygen is 16O, but some of it is 18O, meaning the atomic mass is slightly greater. To quote [Wikipedia:](_URL_2_)
> The 18O/16O ratio provides a record of ancient water temperature. Water 10 to 15 °C (50 to 59 °F) cooler than present represents glaciation. As colder temperatures spread toward the equator, water vapor rich in 18O preferentially rains out at lower latitudes. The remaining water vapor that condenses over higher latitudes is subsequently rich in 16O.[2] Precipitation and therefore glacial ice contain water with a low 18O content. Since large amounts of 16O water are being stored as glacial ice, the 18O content of oceanic water is high. Water up to 5 °C (41 °F) warmer than today represents an interglacial, when the 18O content of oceanic water is lower. A plot of ancient water temperature over time indicates that climate has varied cyclically, with large cycles and harmonics, or smaller cycles, superimposed on the large ones. This technique has been especially valuable for identifying glacial maxima and minima in the Pleistocene.
From this, we can get a good idea as to the temperature of "ancient" water vs. time (from ice cores), and therefore determine the periods of glaciation. These data are all combined (tree ring, sediment cores, and ice cores) to determine paleoclimate. | [
"Geological evidence for ice ages comes in various forms, including rock scouring and scratching, glacial moraines, drumlins, valley cutting, and the deposition of till or tillites and glacial erratics. Successive glaciations tend to distort and erase the geological evidence, making it difficult to interpret. Furth... |
how do tesla coil suits work? | Electricity takes the path of least resistance. Metal is low resistance. Humans are medium resistance. Air is high resistance, even with rain in it. If an arc has a choice between human and air, it goes through the human.
However, if there is a low resistance path to ground, then the electricity will not run through the human, even if one is available. Good arc protection suits provide a good path to ground and maximize the resistance from the suit to the human inside. | [
"A T-coil consists of a metal core (or rod) around which ultra-fine wire is coiled. T-coils are also called induction coils because when the coil is placed in a magnetic field, an alternating electric current is induced in the wire (Ross, 2002b; Ross, 2004). The T-coil detects magnetic energy and transduces (conver... |
What happens when a noise gets louder? | Sound travels as slight increases and decreases in air pressure (compressions and rarefactions). The further these increases and decreases are from ambient pressure, the louder the sound. Greater pressure differentials will cause the eardrum to move further. | [
"Another cause of noise is due to the exocytosis of neurotransmitters from the synaptic terminals that provide input to a given neuron. This occurrence happens in the background while a cell is at resting membrane potential. Since it is happening in the background, the release is not due to a signal, but is random.... |
Would a fusion reactor that utilizes only hydrogen, with no need for deuterium or helium3, be feasible? | No, the reaction you're referring to just has too small of a cross section. It would never be favorable for an artificial reactor. | [
"Fusion reactors generally use hydrogen isotopes such as deuterium and tritium, which react more easily than hydrogen. The designs aim to heat their fuel to tens of millions of degrees using a wide variety of methods. The major challenge in realising fusion power is to engineer a system that can confine the plasma ... |
how does my dog understand when i'm pointing at something? is this inherent, or did i teach him this? | It's inherent, and the fact that dogs instinctively understand pointing is actually pretty interesting. Very few animals are able to understand a point, and it's believed that evolution actually selected for pointing identification in early domesticated dogs; a dog that couldn't follow instructions was of no use to early hunters.
| [
"Dogs have shown an ability to understand human communication. In object choice tasks, dogs utilize human communicative gestures such as pointing and direction of gaze in order to locate hidden food and toys. It has also been shown that dogs exhibit a left gaze bias when looking at human faces, indicating that they... |
Shouldn't all multicellular organisms develop some sort of cancer given enough time? | Probably yes for animals. For plants, it depends a little on how we define cancer. For fungi I don't know.
All animals seem to develop cancer. Naively you would expect larger animals to be at a higher risk of developing cancer early on, since they have more cells that could accumulate cancerous mutations by chance. The fact that larger animals do not get cancer more quickly is known as Peto's paradox. The resolution to that paradox seems to be that [larger animals are better at suppressing cancer](_URL_2_) with tumor suppressor genes. Could upregulated tumor suppressor genes cause the chance of developing cancer to go to zero? Probably not, but it might get pretty close. We need more research, and unfortunately studying large animals is slow and costly work. But within the animal kingdom the answer to your question is probably yes.
But animals aren't the only multicellular life out there. Plants [develop tumors](_URL_0_) that are similar to cancer (i.e. uncontrolled cell division). But they seem to be caused by [pathogens rather than genetic mutations](_URL_1_), so it may be possible to prevent plant tumors by shielding them from pathogeneic bacteria, fungi, and viruses. Also, plant tumors don't really metastasize the way animal tumors do, since plants are organized differently from animals. So these tumors are rarely lethal to the plant, and you could argue whether they really are cancer at all.
Fungi are another important form of multicellular life, but I don't know if anyone has observed tumors in fungi. Googling a bit mostly gives (1) a bunch of crank theories that cancer in humans is actually a fungus or (2) links to studies on the health effects of compounds from fungi. Maybe someone with more specific knowledge can chime in here with a useful reference. | [
"Multicellular organisms, especially long-living animals, face the challenge of cancer, which occurs when cells fail to regulate their growth within the normal program of development. Changes in tissue morphology can be observed during this process. Cancer in animals (metazoans) has often been described as a loss o... |
What exactly is the "stuffy" when someone says "it's getting a bit stuffy in here?" How does it happen? | My interpretation is that a room full of mouth breathers has overwhelmed the A/C's ability to evacuate the heat and humidity produced. This causes the room to become uncomfortable.
Another interpretation is that again, the room is poorly ventilated and holds a musty smell. | [
"BULLET::::- Miffle ( – also as a common noun, \"det lilla knyttet/skruttet\", \"the little creep\"; \"skrutt\", a noun with \"various meanings, although with one common feature, that is something small or something weak, rubbish (\"skräp\", \"garbage\"), trash or core, which in turn also suggests something quite i... |
Before "fire" was associated with launching ordinance, what were the common English verbs for shooting arrows? | Hi! I've removed this question because it is attracting a lot of short answers that aren't up to the standards of the sub. Indeed, your question would be perfectly suited for our [Short Answers to Simple Questions](_URL_0_) feature - the link is to the current session at the top of the front page. Please post it there - I'm sure one of the helpful contributors to this thread will be able to find it! | [
"Fire arrows were one of the earliest forms of weaponized gunpowder, being used from the 9th century onward. Not to be confused with earlier incendiary arrow projectiles, the fire arrow was a gunpowder weapon which receives its name from the translated Chinese term \"huǒjiàn\" (火箭), which literally means fire arrow... |
why do cats have to smell everything? why can't they just look at the things? | The cat's response:
Why do humans have to look at everything? Why can't they just smell things?
Each of your senses gives you a wealth of information. Humans are very visually-based creatures, for a variety of reasons (leading evolutionary theories that I've heard have to do with brachiation - swinging through trees, which means we have to SEE the trees to grab them; and avoiding dangerous creatures, specifically being able to SEE snakes and spiders - because they're hard to smell or hear).
Cats, on the other hand, have evolved to fit a different niche. Humans, as relatives of apes, evolved to mostly eat plants and bugs, which don't require a lot of hunting, so we don't need a particularly great sense of smell, since we just kind of look for a plant to eat. Cats are obligate carnivores: they *must* eat meat (even dogs don't *have* to eat meat if you give them the right vegetarian diet). So they have to hunt, and that means tracking down small critters, which relies a lot on smell.
We also evolved a very complex society, and we use sound to communicate mostly. Cats do use sound, but they also use a lot of chemical signals, too. That also requires smell. Using sound was better for us, so again, our noses aren't quite so good.
All of that is to say that there's a lot of information available through smell that isn't available through sight, and vice versa. We don't need the smell information, so our noses aren't as good. But cats do, so they spend a lot of time sniffing around. | [
"Cats are highly territorial, and secretion of odors plays a major role in cat communication. The nose helps cats to identify territories, other cats and mates, to locate food, and has various other uses. A cat's sense of smell is believed to be about fourteen times stronger than that of humans. The rhinarium (the ... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.