Science

Lake Vostok: The Most Isolated Lake in the World

The freshwater Lake Vostok is about 160 miles long by 30 miles wide, and has an average depth of 1,417 feet, making it one of the largest twenty lakes in the world by size, depth, and volume. (Within the top 5 by depth and volume). It also just so happens to be buried beneath 13,100 feet of the East Antarctic Ice Sheet. It’s named after Vostok Station (itself named after the Russian vessel that discovered Antarctica), which directly overhead it at the Southern Pole of Cold, the coldest place on Earth.

Due to its location underneath a the ice sheet, the “surface” of Lake Vostok is actually 1,600 feet below sea level. It’s the largest subglacial lake on the continent, of which there are almost 400 known to exist. Nearby lies the Gamburtsev Mountain Range, which is entirely subglacial, and about the size of the Alps. In 2005, an “island” was discovered in the central part of the lake. Its exact size and morphology are uncertain.

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The Perils of Playing God: The Dangers of Geoengineering

People have talked about transforming deserts into friendlier ecosystems for a long time. The Sahara is by far the most popular desert used as an example. Pump enough desalinated water from the ocean, you’ve got a new garden-like environment. It’s a cool idea in theory, but in practice it’s an extraordinarily bad idea.

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Book Review: The Great Transition, by Bruce M.S. Campbell

“Sweeping claims which assert the primacy of one agency or set of relationships over all others will never wash with historians, who are acutely aware that the devil is always in the details.”
-The Great Transition, by Bruce M.S. Campbell (not the actor)

I think Campbell is a little optimistic here- there are definitely plenty of historians who fail this test. (Nationalist historians, most often.) Nonetheless, when dealing with not just history, but with any social science, it is important to weigh any claims against this standard. There are, simply speaking, so few times when we can trace the causes of an event or situation back to a single origin. It’s always far more complex than that.

The Great Transition is an in depth analysis of the later Medieval period centered on the 1300s- that period of massive change that included the Great Famine, the Black Death, the collapse of the Mongolian Empire and its associated land trade routes, the collapse of the European Truce of God that had been reducing warfare in Europe, the end of the Medieval Climate Anomaly (centuries of pleasant, kindly climate) and the beginning of the Wolf Solar minimum and the Little Ice Age, etc, etc. Basically, this time period was one of the most eventful, and important, in human history.

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An idle facebook discussion, wherein I discuss eating thousands of liters of toothpaste.

A Facebook friend posted a meme discussing the dangers of fluoride toothpaste, so I did a little math:

“It takes 5-10 grams of sodium fluoride to kill a full grown human. Fluoride drinking water contains less than a single part per million. (about 0.5 ppm, usually.) The average person consumes a bit more than a swimming pool worth of water in their lifetime. (Around 87,000 liters). The amount of fluoridated water that would be required to reach 5 grams of sodium fluoride? 10 million liters. Humans are literally incapable of drinking enough fluoridated water to kill themselves, or even enough to cause tooth color mottling, the first effect of fluoride buildup to appear. (Other fluoride salts than sodium fluoride can be used, but similar math applies.)
 
What about toothpaste, though? Well, sodium fluoride in toothpaste (or in fluoridated water) reacts with apatite (the mineral your teeth are made of- I’m fairly sure the pun was intended) to to form fluorapatite, which occurs naturally in enamel. (There’s a lot of fluoride on Earth- as the lowest atomic weight halogen, there’s a ton of it around.) The levels of fluoride in toothpaste are pretty carefully calculated so that most of it is used in the reaction that forms fluorapatite, and the rest gets spat out. In order to actually get fluoride poisoning from toothpaste, which has around 1,000 ppm of fluoride, you’d have to eat several thousand liters of toothpaste. Again, rather impractical. You’ll never put enough toothpaste in your mouth to cause even the most minor of symptoms, even if you retained 100% of the fluoride (which your body slowly flushes out over time) and none of it reacts with the apatite in your teeth.
 
Fluoride poisoning does occur, but not from toothpaste or fluoridated drinking water. More often, it’s from industrial waste or wells built in regions with certain types of high-fluoride granite.”
Moral of the story? Don’t eat thousands of liters of toothpaste.