Wikipedia articles of interest

1. Economy of the Han Dynasty. I’ve read about this elsewhere as well, but it turns out that wikipedia has some good stuff on the subject (‘Han Dynasty’ is one of Wikipedia’s featured topics).

2. Effect of psychoactive drugs on animals. It’s not a long article, but I had to link to it because of these awesome images:

If you’d rather read about the caffeine that’s having such a huge effect on spiders, here’s the article. Here’s one bit that I found interesting:

“Extreme overdose can result in death.[48][49] The median lethal dose (LD50) given orally, is 192 milligrams per kilogram in rats. The LD50 of caffeine in humans is dependent on individual sensitivity, but is estimated to be about 150 to 200 milligrams per kilogram of body mass or roughly 80 to 100 cups of coffee for an average adult.[4] Though achieving lethal dose with caffeine would be exceptionally difficult with regular coffee, there have been reported deaths from overdosing on caffeine pills, with serious symptoms of overdose requiring hospitalization occurring from as little as 2 grams of caffeine. An exception to this would be taking a drug such as fluvoxamine or levofloxacin, which blocks the liver enzyme responsible for the metabolism of caffeine, thus increasing the central effects and blood concentrations of caffeine five-fold.[47][48][49][50] Death typically occurs due to ventricular fibrillation brought about by effects of caffeine on the cardiovascular system.”

3. Schwarzschild radius.

“The Schwarzschild radius (sometimes historically referred to as the gravitational radius) is the distance from the center of an object such that, if all the mass of the object were compressed within that sphere, the escape speed from the surface would equal the speed of light.” (The article has much more.)

4. Peasants’ Revolt.

“The Peasants’ Revolt, Wat Tyler’s Rebellion, or the Great Rising of 1381 was one of a number of popular revolts in late medieval Europe and is a major event in the history of England. Tyler’s Rebellion was not only the most extreme and widespread insurrection in English history but also the best-documented popular rebellion to have occurred during medieval times. The names of some of its leaders, John Ball, Wat Tyler and Jack Straw, are still familiar in popular culture, although little is known of them.

The revolt later came to be seen as a mark of the beginning of the end of serfdom in medieval England, although the revolt itself was a failure. It increased awareness in the upper classes of the need for the reform of feudalism in England and the appalling misery felt by the lower classes as a result of their enforced near-slavery.”

5. Przewalski’s horse.

I found the information about the conservation efforts fascinating – this species was saved even though it was about as close to extinction as a species could possibly get. And not only did they survive, some have even been succesfully reintroduced into the wild:

“Przewalski’s horse […] or Dzungarian horse, is a rare and endangered subspecies of wild horse (Equus ferus) native to the steppes of central Asia, specifically China and Mongolia.[3] At one time extinct in the wild, it has been reintroduced to its native habitat in Mongolia at the Khustain Nuruu National Park, Takhin Tal Nature Reserve and Khomiin Tal. […]

The world population of these horses are all descended from 9 of the 31 horses in captivity in 1945.[9] These nine horses were mostly descended from approximately 15 captured around 1900. A cooperative venture between the Zoological Society of London and Mongolian scientists has resulted in successful reintroduction of these horses from zoos into their natural habitat in Mongolia; and as of 2011 there is an estimated free-ranging population of over 300 in the wild.[10] The total number of these horses according to a 2005 census was about 1,500.”

Here are some related links.

6. Strategic dominance (game theory).

7. Collatz conjecture.

“Take any natural number n. If n is even, divide it by 2 to get n / 2. If n is odd, multiply it by 3 and add 1 to obtain 3n + 1. Repeat the process (which has been called “Half Or Triple Plus One”, or HOTPO[4]) indefinitely. The conjecture is that no matter what number you start with, you will always eventually reach 1. The property has also been called oneness.[5]” (long article, lots of stuff including several examples.)

February 9, 2012 - Posted by | astronomy, biology, economic history, economics, Game theory, history, mathematics, Physics, wikipedia

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