high school

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.

Radar, Hula Hoops, and Playful Pigs: 67 Digestible commentaries on the fascinating chemistry of ordinary life

Joe Schwarcz is Director of McGill University's Office for Chemistry and Society. He hosts a weekly radio call-in radio show in Montreal and also writes a column about chemistry in everyday life for the Washington Post. The essays in this book are collected largely from his radio show, and they are exactly in the spirit of "Hal's Picks".

The Measure of All Things: The Seven-Year Odyssey and Hidden Error That Transformed the World

In 1792, the French Academy of Sciences appointed two respected scientists to survey a north-south meridian from Dunkirk to Barcelona, for the purpose of determining the size (and shape) of the earth. Why is this important? Because it would establish an international basis for the meter, foundation of the metric system.

DNA as Destiny

We all know that, with the deciphering of the human genome as well as those of other animals, and of plants, that the future will bring a new level of understanding and control of our own heredity. But what can the present level of genetic testing provide? In this story, writer David Duncan has as much determined about his future as you can learn with current technology.