high school

Special Issue: Water, The Wellspring of Life

"Whiskey is for drinkin', water is for fightin'" goes the old saying. The current (November, 2007) issue of Natural History has nine articles about what we will be fighting over. "A Special Brew", by Christopher Mundy, Shawn Kathmann, and Gregory Schenter is the one that is most "chemical", but the others describe some environmental aspects of water resources.

The Dark Side: What we re missing in the night sky

One of the most memorable experiences of my youth was when I was camping in the Mojave Desert. Having lived all of my life up to that time in Los Angeles, I had never seen a truly dark night. Lying under the stars, I found it very difficult to close my eyes because of the extraordinary beauty of the sky, full of stars and planets - the Milky Way clearly visible.

The Unintended Consequences of Hyperhydration

The folly of spending more per liter to buy water than gasoline has been mentioned in Hal's Picks previously (July 2003). That article, by Michael Schermer, emphasized the waste of money that this boondoggle constitutes. In the New York Times magazine this week is another argument against the practice, and that is its impact on the environment.

An Exact Value for Avogadro's Number

The currently accepted formal definition of a mole is the number of carbon-12 atoms in exactly 12 grams of the pure substace. This is not a good operational definition, however, because it takes too long to find, purify, and count all those atoms. The best experimental value is based on x-ray diffraction experiments on silicon crystals and puts the number within 0.0000010 of 6.0221415 x 10^23.

The Darkening Sea (Annals of Science)

You may remember Elizabeth Kolbert as author of the extensive New Yorker series on climate change that was Hal's Pick in May of 2005. She also wrote about the ways in which ice core samples disclose the history of the atmosphere; that article was Hal's Pick in January of 2002.

Fuels Gold

The search for replacements for oil and natural gas is heating up, as the price of oil rises. No alternative is getting more attention than biofuels - which in the US means ethanol from corn or biodiesel from soybeans. The movement has terrific political momentum because it promises not only to increase the price of corn, but also to enrich those who have invested in distillation facilities.

Department of Food Science - The Search for Sweet: The tricky technology of sugar substitutes

In 2005, the average American consumed about 140 pounds of sugar, which is about 50% more than the average German or Frenchman and nine times as much as the Chinese (see Hal's Pick for December, 2005). We also consumed about twenty four pounds of sugar substitutes per person, which translates to even more sweetness than the natural substance.

The Climate of Man - I, II, and III

It was not that many years ago that one could reasonably defer judgement about global warming. But the evidence that our planet's climate is changing at a pace that can only presage disaster is becoming so compelling that only the US executive branch can't see it. Even the Bush administration now acknowledges that there may be a problem, but not one that would require significant action.