EXCLUSIVE: WARP DRIVE UNDERWATER ■ ARCTIC OIL VS. WILDLIFE MAY 2001 $4.95 WWW.SCIAM.COM (TOMORROW’S WEB WILL) PLUS: Antibiotics’ Dim Future Rorschach: A Waste of Ink The Oldest Stars Copyright 2001 Scientific American, Inc. may 2001 contentsVolume 284 Number 5 features COMPUTING 34 The Semantic Web BY TIM BERNERS-LEE, JAMES HENDLER AND ORA LASSILA Computers navigating tomorrow’s Web will understand more of what’s going on—making it more likely that you’ll get what you really want. ASTRONOMY 44 Rip Van Twinkle BY BRIAN C. CHABOYER The oldest known stars aren’t really older than the universe after all. BIOTECH 54 Behind Enemy Lines BY K. C. NICOLAOU AND CHRISTOPHER N. C. BODDY Microbes can defeat all current antibiotics, but studies offer hope for new drugs. ENVIRONMENT 62 The Arctic Oil & Wildlife Refuge BY W. WAYT GIBBS How great are the risks and benefits of drilling for oil in Alaska’s largest pristine ecosystem? WEAPONRY 70 Warp Drive Underwater BY STEVEN ASHLEY Exclusive: Top-secret torpedoes and other weapons that move hundreds of miles per hour may transform submarine warfare. PSYCHOLOGY 80 What’s Wrong with This Picture? BY SCOTT O. LILIENFELD, JAMES M. WOOD AND HOWARD N. GARB Rorschach inkblots and similar tests are often less informative than psychologists have supposed. 70 The Shkval torpedo www.sciam.com SCIENTIFIC AMERICAN 3 Copyright 2001 Scientific American, Inc. departments 6 SA Perspectives The case for embryonic stem cell research. 7 How to Contact Us 8 Letters 25 24 9 On the Web 10 50, 100 & 150 Years Ago 12 News Scan 30 Staking Claims ■ What will be the human toll of mad cow disease? A protein fights the killer hamburger. ■ Lightning and air pollution. 32 Profile: Paul W. Ewald ■ Meteors chalk up another extinction. If his theory is right, cancer, heart disease and other ■ Floss to prevent heart attacks. chronic illnesses may have a hidden infectious cause. ■ Nature preserves attract poachers. ■ Plastics that remember their shape. 88 Working Knowledge ■ By the Numbers: Economic revisionism. Bar-code readers. ■ Data Points: The not so sheltering sky. 90 Reviews 28 Innovations The Little Ice Age: How Climate Made History Lord Corp.’s magnetic material that solidifies on cue holds lessons for a warmer world. may be the key to the ultimate shock absorbers. 92 Voyages Sex on the beach: the elephant seals of Año Nuevo. 92 columns 31 Skeptic BY MICHAEL SHERMER Conflict among the “erotic-fierce people.” 96 Puzzling Adventures BY DENNIS E. SHASHA Retracing a villain’s steps. 98 Anti Gravity BY STEVE MIRSKY Sour grapes and vintage humor. 100 Endpoints Cover photoillustration by Miguel Salmeron; preceding page: Philip Howe; this page (clockwise from top left): Jet Propulsion Laboratory; Steve Allen/The Image Bank; Frank S. Balthis MAY 2001 Copyright 2001 Scientific American, Inc. SA Perspectives Save Embryonic Stem Cell Research We know that embryonic stem cells can differentiate in- Polls have suggested that most of the American pub- to any tissue of the human body; might they therefore lic, too, thinks that embryonic cell research should con- also be able to treat diseases like Parkinson’s, Alz- tinue, which means that the government must decide heimer’s and diabetes? In principle, this ability to dif- how to balance ethical objections from a minority ferentiate into blood, muscle or neural tissue may against the wishes of the majority. It would be a mis- make embryonic stem cells the gold standard for re- take to think that the pro-life side has undisputed claim placing bad tissue with good. But some antiabortion to the moral high ground. Many people question advocates, rankled that these cellular chameleons whether it is right to ignore research that offers the best come from embryos, call for a categorical ban on hope for treating or curing so many cruel illnesses. funding this research. Opponents of the research might retort, Why not In 1996 Congress forbade the use of federal funds continue using only adult stem cells? Some stem cells for research that would involve destroying human can be found in adult tissue as well, after all. The sci- embryos. Last year, however, the National Institutes entific answer is that we don’t yet know whether the of Health issued guidelines, sup- adult cells necessarily retain the ported by the Clinton administra- full plasticity of the embryonic tion, that would allow embryonic ones. Research should and will stem cell research to continue as continue on the adult stem cells, long as the harvesting step was not and if they ultimately prove as ca- conducted with federal monies. pable as or better than embryonic In vitro fertilization clinics have ones, it might then be wise to for- been a source of the cells because sake the embryonic cells in defer- such clinics regularly discard ence to the moral debate over frozen embryos left over after whether an embryo is really a hu- conception attempts. man being. Until then, however, Opponents insist that the NIH EMBRYONIC STEM CELLS adult stem cell work can only be is dodging its moral responsibility an adjunct to the embryonic work. by letting private clinics do the dirty work. And the No one should too readily dismiss the objections Bush administration may be swayed by this argument that using embryos in this way is an insult to human as it decides whether to overturn the NIH guidelines. dignity. But these were embryos already abandoned Health and Human Services Secretary Tommy Thomp- by their parents as by-products of other conception son has said that a recommendation on the issue will attempts. Currently these embryos have exactly zero be announced by late spring or early summer. Eighty chance of ever maturing into human beings. Stem cell Nobel laureates and a variety of research institutions research offers the cells more opportunity for life than have petitioned the president not to stand in the way they would otherwise see. It offers many afflicted peo- of the research. They maintain that a ban will hinder ple an opportunity for healthier, longer lives. Saving all progress on stem cells and that the U.S. in particu- embryonic stem cell research may not be an easy lar would stand to lose competitiveness in biotech. choice, but it is the right and moral one. THE EDITORS [email protected] SPL/Photo Researchers, Inc. YORGOS NIKAS 6 SCIENTIFIC AMERICAN MAY 2001 Copyright 2001 Scientific American, Inc. ® Letters EDITORS@ SCIAM.COM Established 1845 EDITOR IN CHIEF: John Rennie JANUARY’S SPECIAL REPORT sent some readers into orbit. MANAGING EDITOR: Michelle Press “I have always considered science a phenomenon that can be cre- ASSISTANT MANAGING EDITOR: Ricki L. Rusting NEWS EDITOR: Philip M. Yam ated, measured, re-created and potentially disproved,” writes SPECIAL PROJECTS EDITOR: Gary Stix Owen W. Dykema of Roseburg, Ore. “ ‘Brave New Cosmos’ is filled SENIOR WRITER: W. Wayt Gibbs with stuff that satisfies none of those criteria. Isn’t it time that EDITORS: Mark Alpert, Steve Ashley, Graham P. Collins, Carol Ezzell, someone, anyone, reminded us that this is all hypothetical—the Steve Mirsky, George Musser, Sarah Simpson hopeful dreams of a few overly optimistic mathematicians?” CONTRIBUTING EDITORS: Mark Fischetti, Marguerite Holloway, Madhusree Mukerjee, Others, though, were practically starry-eyed. Cosmologist Mau- Paul Wallich rice T. Raiford believes “that ‘dark energy’ will become far more im- EDITORIAL DIRECTOR, ONLINE: Kristin Leutwyler portant in the long run than the concept of dark matter. As with atom- ASSOCIATE EDITORS, ONLINE: Kate Wong, Harald Franzen ic physics at the beginning of the past century, in the 21st century, WEB DESIGN MANAGER: Ryan Reid with the application of quantum theory to galactic motion as well as ART DIRECTOR: Edward Bell to the universe as a whole, we are already starting to witness a revolution in cosmology.” SENIOR ASSOCIATE ART DIRECTOR: Jana Brenning The shining lights from our in-box are here, in this selection of topics from January 2001. ASSISTANT ART DIRECTORS: Johnny Johnson, Mark Clemens PHOTOGRAPHY EDITOR: Bridget Gerety PRODUCTION EDITOR: Richard Hunt GETTING TO OMEGA the curvature and the current expansion rate COPY DIRECTOR: Maria-Christina Keller COPY CHIEF: Molly K. Frances In “The Quintessential Universe,” Jeremiah depend on the total energy density: the sum of COPY AND RESEARCH: Daniel C. Schlenoff, P. Ostriker and Paul J. Steinhardt refer to matter and dark energy (quintessence or cos- Rina Bander, Sherri A. Liberman, Shea Dean measurements of the mass density of mological constant). If the sum is equal to the EDITORIAL ADMINISTRATOR: Jacob Lasky the universe, omega, which determines critical density, the universe is indeed flat. SENIOR SECRETARY: Maya Harty whether the universe is open, closed or The second equation, which resembles ASSOCIATE PUBLISHER, PRODUCTION: William Sherman MANUFACTURING MANAGER: Janet Cermak flat. The omega in matter is perhaps 0.3, Newton’s second law of motion, describes ADVERTISING PRODUCTION MANAGER: Carl Cherebin and the cosmological constant is perhaps whether the expansion rate is accelerating or PREPRESS AND QUALITY MANAGER: Silvia Di Placido PRINT PRODUCTION MANAGER: Georgina Franco 0.7. This would give a total omega of 1.0, decelerating. That depends not only on the en- PRODUCTION MANAGER: Christina Hippeli meaning that we live in a flat universe. ergy density but also on the rate at which the ASSISTANT PROJECT MANAGER: Norma Jones I was under the impression, however, energy density changes as the universe ex- CUSTOM PUBLISHING MANAGER: Madelyn Keyes that if the universe is flat, it is so because pands. For any gas, the change in energy den- ASSOCIATE PUBLISHER/VICE PRESIDENT, CIRCULATION: Lorraine Leib Terlecki of the resultant gravita- sity when the volume expands CIRCULATION MANAGER: Katherine Robold tional force.