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PLANKTON VS. GLOBAL WARMING • SAVING DYING LANGUAGES
Asynchronous Microchips: Fast Computing without a Clock AUGUST 2002 $4.95 WWW.SCIAM.COM
IS 95% OF THE UNIVERSE REALLY MISSING? AN ALTERNATIVE TO
Taking the Terror Out of Terrorism The Search for an Anti-Aging Pill
COPYRIGHT 2002 SCIENTIFIC AMERICAN, INC.
contents august 2002
features
SCIENTIFIC AMERICAN Volume 287 Number 2 BIOTECHNOLOGY
36
The Serious Search for an Anti-Aging Pill BY MARK A. LANE, DONALD K. INGRAM AND GEORGE S. ROTH
Research on caloric restriction points the way toward a drug for prolonging life and youthful vigor. COSMOLOGY
42 Does Dark Matter Really Exist? BY MORDEHAI MILGROM
Cosmologists have looked in vain for sources of mass that might make up 95 percent of the universe. Maybe it’s time to stop looking. ENVIRONMENT
54
The Ocean’s Invisible Forest BY PAUL G. FALKOWSKI
Marine phytoplankton play a critical role in regulating the earth’s climate. Could they also help stop global warming? INFORMATION TECHNOLOGY
62
Computers without Clocks BY IVAN E. SUTHERLAND AND JO EBERGEN
Asynchronous chips improve computer performance by letting each circuit run as fast as it can. PSYCHOLOGY
70
Combating the Terror of Terrorism BY EZRA S. SUSSER, DANIEL B. HERMAN AND BARBARA AARON
Protecting the public’s mental health must become part of a national antiterrorism defense strategy. LINGUISTICS
78
Saving Dying Languages BY W. WAYT GIBBS
Thousands of the world’s languages face extinction. Linguists are racing to preserve at least some of them.
42 The puzzle of dark matter
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COPYRIGHT 2002 SCIENTIFIC AMERICAN, INC.
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