THE SCIENTIFIC A MERICAN 50 FOR 2005 Leaders Shaping the Future of Technology Recycling Nuclear Waste into Energy DECEMBER 2005 WWW.SCIAM.COM What is spacetime? Experimental models hint that it could be a kind of fl uid Wormhole A Crossword Trip through Science COPYRIGHT 2005 SCIENTIFIC AMERICAN, INC. december 2005 contentsSCIENTIFIC AMERICAN Volume 293 Number 6 features TECHNOLOGY LEADERS 47 The Scientific American 50 Flu preparedness, fl exible electronics and stem cells all star in our fourth annual salute to the research, business and policy leaders of technology. PHYSICS 68 A black hole for 68 An Echo of Black Holes sound waves BY THEODORE A. JACOBSON AND RENAUD PARENTANI Does the behavior of sound waves suggest that spacetime is a kind of fl uid? MEDICINE 76 Tackling Malaria BY CLAIRE PANOSIAN DUNAVAN Interventions available today could decisively improve prevention and treatment. ENERGY 84 Smarter Use of Nuclear Waste BY WILLIAM H. HANNUM, GERALD E. MARSH AND GEORGE S. STANFORD New fast-neutron reactors could extract more energy from nuclear fuel and reduce the waste problems without encouraging weapons proliferation. PUBLIC HEALTH 92 Sick of Poverty BY ROBERT SAPOLSKY The stress of being poor has a staggeringly harmful infl uence on health. EVOLUTION 100 Getting a Leg Up on Land BY JENNIFER A. CLACK Recent fossil discoveries cast light on the evolution of four-limbed animals from fi sh. NEUROSCIENCE 108 Inside the Mind of a Savant BY DAROLD A. TREFFERT AND DANIEL D. CHRISTENSEN Anatomical curiosities in the brain of savant Kim Peek, the inspiration for Rain Man, offer hints to how his amazing memory works. CROSSWORD 114 Wormhole BY PATRICK MERRELL Challenge your knowledge of science and the past year’s issues of this magazine. www.sciam.com SCIENTIFIC AMERICAN 3 COPYRIGHT 2005 SCIENTIFIC AMERICAN, INC. SCIENTIFIC AMERICAN Volume 293 Number 6 departments 8 SA Perspectives Defi ning leadership on energy conservation. 10 How to Contact Us 10 On the Web 20 127 12 Letters 16 50, 100 & 150 Years Ago 18 News Scan 42 Insights Mirror-making astronomer Roger Angel fi ghts to ■ Can randomized trials dissect poverty? launch the Giant Magellan Telescope, which might ■ Radiocarbon dating your body. become the fi rst to glimpse Earth-like planets ■ Quantum dots on the cheap. around other stars. ■ Growing beta cells to cure diabetes. ■ Paring away junk DNA. 116 Working Knowledge ■ Written in Martian clay. An inside look at digital x-ray machines. ■ By the Numbers: Personal bankruptcy. 118 Technicalities ■ The Nobel Prizes for 2005. An automatic transmission makes cycling a breeze. 124 Reviews To understand the chaos of modern confl ict, look 42 to the tribal and primate roots of human behavior: a consideration of the books Us and Them and Our Inner Ape. Roger Angel, University of Arizona’s Steward Observatory columns 38 Skeptic BY MICHAEL SHERMER Gullible’s Travels: a skeptic’s sojourn among the credulous. 127 Anti Gravity BY STEVE MIRSKY The unintelligent design of penguins. 128 Ask the Experts How and why do fi refl ies light up? Cover image by Kenn Brown; photograph at left by Jeff Smith. Scientifi c American (ISSN 0036-8733), published monthly by Scientifi c American, Inc., 415 Madison Avenue, New York, N.Y. 10017-1111. Copyright © 2005 by Scientifi c American, Inc. All rights reserved. No part of this issue may be reproduced by any mechanical, photographic or electronic process, or in the form of a phonographic recording, nor may it be stored in a retrieval system, transmitted or otherwise copied for public or private use without written permission of the publisher. Periodicals postage paid at New York, N.Y., and at additional mailing offi ces. Canada Post International Publications Mail (Canadian Distribution) Sales Agreement No. 40012504. Canadian BN No. 127387652RT; QST No. Q1015332537. Publication Mail Agreement #40012504. Return undeliverable mail to Scientifi c American, P.O. Box 819, Stn Main, Markham, ON L3P 8A2. Subscription rates: one year $34.97, Canada $49 USD, International $55 USD. Postmaster: Send address changes to Scientifi c American, Box 3187, Harlan, Iowa 51537. Reprints available: write Reprint Department, Scientifi c American, Inc., 415 Madison Avenue, New York, N.Y. 10017-1111; (212) 451-8877; fax: (212) 355-0408. Subscription inquiries: U.S. and Canada (800) 333-1199; other (515) 248-7684. Send e-mail to [email protected] Printed in U.S.A. 6 SCIENTIFIC AMERICAN DECEMBER 2005 COPYRIGHT 2005 SCIENTIFIC AMERICAN, INC. SA Perspectives Running on Empty It was a remarkable turnabout. In September, after rebuild their facilities. For this reason, some econo- Hurricanes Katrina and Rita pushed gasoline prices mists recommend raising the federal gas tax by 50 to more than $3 a gallon, President George W. Bush cents a gallon. The increase could be gradually im- spoke out for energy conservation. The president, posed as prices at the pump decline, so that the impact who had previously insisted that new oil wells and on consumers is minimized. To offset the dispropor- refi neries were the solution to the nation’s energy tionate burden on working-class drivers, revenues from woes, called on Americans to save gas by driving less. the gas tax could be used to reduce payroll taxes. Listeners with long memories recalled President Jim- Unfortunately, Bush and Congress are adamantly my Carter’s television appear- opposed to any new tax, even one that would protect ances during the oil crisis of the the environment, lessen our dependence on oil from 1970s, when he urged Americans the Middle East and save consumers money in the to turn down their thermostats. long run. Instead the Bush administration has pro- The only thing missing was the posed revising the corporate average fuel economy cozy cardigan that Carter had (CAFE) standards for light trucks, a category that worn when he made his plea. includes SUVs, pickup trucks and minivans. Whereas Environmentalists, though, passenger cars must average 27.5 miles per gallon, the RISING gas prices were less than thrilled by the required average for light trucks is now 21 mpg and prompted conservation. Bush administration’s new strat- scheduled to rise to 22.2 mpg by the 2007 model year. egy, which focused on public- The administration’s proposal divides light trucks service advertisements encouraging conservation. into six subcategories; although small SUVs have to When it comes to transportation, which consumes 70 average 28.4 mpg by 2011, the target for big pickups percent of U.S. oil and generates a third of the nation’s is only 21.3 mpg. The average for all light trucks carbon emissions, voluntary measures may be ineffec- would rise to 24 mpg, just 8 percent more than what tive. Decades of suburban sprawl and neglect of pub- the current CAFE rules would require by then. lic transit have made it harder for Americans to cut Such feeble measures will do little to ease Ameri- back on driving; from 1990 to 2001, the average length ca’s addiction to foreign oil or slow the global warm- of a shopping trip grew from fi ve to seven miles, and ing caused by vehicle exhaust. Lawmakers should the number of shopping trips per household rose from press for more stringent CAFE standards that would 341 to 496 a year. Driving to schools, churches, doc- boost fuel economy for both cars and light trucks by tors and vacation spots also increased signifi cantly. at least 40 percent over the next decade. The goal is A more constructive approach would be to im- technologically feasible—by adopting hybrid engines prove the fuel effi ciency of cars and trucks. The rise in and strong but lightweight auto bodies, manufactur- gas prices has prompted some movement in this direc- ers can make their vehicles more effi cient without Corbis tion: after the hurricanes disrupted the oil industry, compromising passenger safety or infl ating sticker car buyers shunned gas-guzzling SUVs and snapped prices. What we need are political leaders genuinely up more effi cient models. This trend, however, may committed to energy conservation, not just to speech- prove short-lived if gas prices subside as oil companies es and public-service ads. FEANNY NAJLAH THE EDITORS [email protected] 8 SCIENTIFIC AMERICAN DECEMBER 2005 COPYRIGHT 2005 SCIENTIFIC AMERICAN, INC. 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