SOLVING THE NEUTRINO MYSTERY • RECOGNIZING ANCIENT LIFE APRIL 2003 WWW.SCIAM.COM $4.95 James D.Watson discusses DNA, the brain, designer babies and more as he reflects on Grid Computing’s Unbounded Potential Ginkgo Biloba and Memory Will Mount Etna Explode Tomorrow? Delivering Drugs with Implanted Chips COPYRIGHT 2003 SCIENTIFIC AMERICAN, INC. contents april 2003 SCIENTIFIC AMERICAN Volume 288 Number 4 features ASTROPHYSICS 40 Solving the Solar Neutrino Problem BY ARTHUR B. M C DONALD, JOSHUA R. KLEIN AND DAVID L. WARK After 30 years, physicists fathom the mystery of the missing neutrinos: the phantom particles change en route from the sun. BIOTECHNOLOGY 50 Where a Pill Won’t Reach BY ROBERT LANGER Implanted microchips, embedded polymers and ultrasonic blasts of proteins will deliver next-generation medicines. 66 James D. Watson VOLCANOLOGY 58 Mount Etna’s Ferocious Future BY TOM PFEIFFER Europe’s most active volcano grows more dangerous, but slowly. CELEBRATING THE GENETIC JUBILEE 66 A Conversation with James D. Watson The co-discoverer of DNA’s double helix reflects on the molecular model that changed both science and society. LIFE SCIENCE 70 Questioning the Oldest Signs of Life BY SARAH SIMPSON Researchers are reevaluating how they identify traces left by life in ancient rocks on earth— and elsewhere in the solar system. INFORMATION TECHNOLOGY 78 The Grid: Computing without Bounds BY IAN FOSTER Powerful global networks of processors and storage may end the era of self-contained computing. MEDICINE 86 The Lowdown on Ginkgo Biloba BY PAUL E. GOLD, LARRY CAHILL AND GARY L. WENK This herbal supplement may slightly improve your memory— but so can eating a candy bar. Also: Mark A. McDaniel, Steven F. Maier and Gilles O. Einstein discuss other “brain boosters.” www.sciam.com SCIENTIFIC AMERICAN COPYRIGHT 2003 SCIENTIFIC AMERICAN, INC. 7 SCIENTIFIC AMERICAN Volume 288 Number 4 departments 10 SA Perspectives Get real about abstract worries. 12 12 16 20 22 How to Contact Us On the Web Letters 50, 100 & 150 Years Ago News Scan ■ ■ ■ ■ ■ ■ ■ ■ 28 100 34 Innovations Manned spaceflight after Columbia. Spilled oil off Spain’s coast proves too slippery to predict. Bacteria thawed an ancient earth. Suspicions about the speed of gravity. Do gray wolves still need protection? More proof that “clone” doesn’t mean “copy.” By the Numbers: Poverty in the U.S. Data Points: Invasive species. Metanomics develops a way to peek into plant metabolism. 37 Staking Claims The case for restricting patents that hinder basic biomedical research. 92 Working Knowledge Patches that deliver drugs. 94 Technicalities Tablet PCs are high-tech tools for scribblers. 97 Reviews Faster Than the Speed of Light looks provocatively at the new cosmology. 94 columns 38 Skeptic BY MICHAEL SHERMER The Three Laws of Cloning. 100 Puzzling Adventures BY DENNIS E. SHASHA Graphing the origins of species. 102 Anti Gravity BY STEVE MIRSKY Burgers and joints. 103 Ask the Experts What is the importance of the new discovery? 104 Fuzzy Logic BY ROZ CHAST Cover image by Mike Medicine Horse, Hybrid Medical Animation Scientific American (ISSN 0036-8733), published monthly by Scientific American, Inc., 415 Madison Avenue, New York, N.Y. 10017-1111. Copyright © 2003 by Scientific American, Inc. All rights reserved. No part of this issue may be reproduced by any m