Enantiomeric Excesses in Meteoritic Amino Acids
Hal Harris | Sat, 02/01/1997 - 00:00
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The origin of the molecular "handedness" that pervades earth's biology has been an evolutionary puzzle. Given that right and left-handed amino acids have equal energies, why do only the left-handed ones participate in biosynthesis? One hypothesis is that life started from templates that arose from extraterrestrial sources, such as meteors.
Plastic: The Making of a Synthetic Century
Hal Harris | Sun, 12/01/1996 - 00:00
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The dustcover for this book promises it to be an anti-chemistry diatribe, but I found the book itself, with the exception of a chapter near the end ("The Seat of the Plague") to be relatively even-handed in its treatment of the subject. It is full of interesting anecdotes about the history of polymers and their overwhelming impact on mankind.
Search for Past Life on Mars: Possible Relic Biogenic Activity in Martian Meteorite ALH84001
Hal Harris | Thu, 08/01/1996 - 01:00
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How can little green men from Mars not be a "Pick of the Month"? This article has received a huge amount of notice in the popular press, and you've almost certainly heard about it by now. If you click on the highlighted word "Science" above, and you have a personal or institutional subscription to Science, you can read the complete text of the paper for yourself, online.
The Enigmatic 'Battery of Baghdad'
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Did ancient Parthians know how to make electricity with batteries? An object discovered in 1936, during excavation of Khuyut Rabbou'a, near modern Baghdad, has raised speculation that they might indeed have.
Maintaining Diversity in Science - Women and Minorities '96
Hal Harris | Tue, 04/02/1996 - 01:00
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In the social sciences, 1995 may turn out to be (the figures aren't available yet) the year in which as many women earned Ph.D. degrees as men did. But in the physical sciences, the ratio is still about four to one.
Digital Diffraction
Hal Harris | Mon, 04/01/1996 - 00:00
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I've always thought that optical transforms were a great model for the determination of crystal structures using X-ray diffraction, and I've used the ICE (Institute for Chemical Education) kit for this exercise many times.
James Dewar, His Flask and Other Achievements
Hal Harris | Fri, 03/01/1996 - 00:00
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The Dewar flasks that we use for storage of cryogenic fluids such as liquid nitrogen, oxygen, and helium, and which known outside the laboratory as "thermos bottles" were invented by James Dewar, who was the first person to liquefy hydrogen, and was nearly first in the nineteenth century races to liquefy all of the other gases.
The National Science Education Standards
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Well, the final version of the National Science Education Standards has finally arrived. If you are involved in curriculum planning for your school or district, or if you want to study the document in detail, you can buy a copy for $19.95 + 4.00 shipping from the National Academy Press, 2101 Constitution Avenue, NW, Lockbox 285, Washington DC 20055 [1-800-624-6242].
Silent Sperm
Hal Harris | Wed, 01/03/1996 - 02:00
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In the novel "The Children of Men" by P. D. James, set in the year 2021, mankind is faced with extinction due to the worldwide sterility of human males. Is there a basis for fear that this is actually happening? Or is the reported decline in sperm counts, over the past half-century, even a fact?