Scientific American-July 2007
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Must Science and Religion Be Enemies? (see page 88) Warmer Water, SUPER HURRICANES page 44 July 2007 www.SciAm.com The MEMORY CODE Learning to read minds by understanding how brains store experiences Hijacked Cells How Tumors Exploit the Body’s Defenses Wireless Light Beats Radio for Broadband No-Man’s- Land Suppose Humans Just Vanished ... COPYRIGHT 2007 SCIENTIFIC AMERICAN, INC. FEATURES ■ SCIENTIFIC AMERICAN July 2007 ■ Volume 297 Number 1 ENVIRONMENT 76 An Earth without People Interview with Alan Weisman 76 One way to examine humanity’s impact on the environment is to consider how the world would fare if all the people disappeared. CLIMATE CHANGE 44 Warmer Oceans, 44 Stronger Hurricanes 52 By Kevin E. Trenberth Evidence is mounting that global warming enhances a cyclone’s damaging winds and fl ooding rains. COVER STORY: BRAIN SCIENCE 52 The Memory Code 60 By Joe Z. Tsien Researchers are closing in on the rules that the brain uses to lay down memories. Discovery of this memory code could lead to new ways to peer into the mind. 60 68 MEDICINE 60 A Malignant Flame By Gary Stix Understanding chronic infl ammation, which contrib- utes to heart disease, Alzheimer’s and other ailments, may be a key to unlocking the mysteries of cancer. GENETICS 68 The Evolution of Cats ON THE COVER By Stephen J. O’Brien and Warren E. Johnson Artist Jean-Francois Podevin (www.podevin.com) Genomic paw prints in the DNA of the world’s wild fancifully depicts the goal of uncovering a universal cats have clarifi ed the feline family tree and uncovered neural code: the rules the brain uses to identify and several remarkable migrations in their past. make sense of the body’s experiences. www.SciAm.com SCIENTIFIC AMERICAN 3 © 2007 SCIENTIFIC AMERICAN, INC. MORE FEATURES ■ INFORMATION TECHNOLOGY 82 Broadband Room Service by Light 82 88 By Mohsen Kavehrad Encoded light transmissions can provide the wireless devices in a room with multimedia Web services. DEBATE 88 Should Science Speak to Faith? By Lawrence M. Krauss and SCI Richard Dawkins AM The Conversation Continues Two prominent defenders of science discuss Find an extended version of the views of Lawrence M. Krauss how scientists ought to approach believers. and Richard Dawkins at www.SciAm.com/ontheweb WHAT IS IT? SciAm.com Find Out in the Gallery We’re ANTARCTIC URCHIN (below) is one of the astonishing array Number of previously unknown creatures that populate the cold Two depths of the Antarctic. Three expeditions to the Weddell For health care, Sea between Antarctica and the wider South Atlantic Canada is as brought more than 1,000 species, ranging from single-cell good as or better than the U.S. foraminifera to oddly shaped crabs. Catch other breaking A recent study could news, analyses of key issues, photo essays and more at fortify the argument ); that the U.S. should top right www.SciAm.com/ontheweb cease to be the only developed nation without universal health coverage. ); PATRICIA BRENNAN ( BRENNAN PATRICIA ); top left ( Battered Brains Podcast: ) Even when wearing headgear, amateur boxers suffer strokelike insults to the brain. bottom right bottom Blog: Scent of a Man London College University Sniffing around for a human pheromone. News: Scaling Back Greenhouse Gas Emissions While Keeping the Lights On Fact or Fiction? ( ARIZONA NASA/JPL/UNIVERSITY OF ); German Center for Marine Biodiversity Marine for Center German Underwire Bras Cause Cancer left bottom Is your bra killing you? ARMIN ROSE ROSE ARMIN IPHAS NORTHERN GALACTIC PLANE SURVEY/NICK ( WRIGHT BRIESTEIN A. Scientifi c American (ISSN 0036-8733), published monthly by Scientifi c American, Inc., 415 Madison Avenue, New York, N.Y. 10017-1111. Copyright © 2007 by Scientifi c American, Inc. All rights reserved. No part of this issue may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying and recording for public or private use, or by any information storage or retrieval system, without the prior 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. 4 SCIENTIFIC AMERICAN July 2007 © 2007 SCIENTIFIC AMERICAN, INC. DEPARTMENTS ■ 8 From the Editor 10 Letters 92 102 14 50, 100 and 150 Years Ago 16 Updates 18 NEWS SCAN KYLE LISA ■ What EPA regulation of greenhouse gases will mean. ■ Behind the secrecy of lethal injection. ■ Whither New Orleans? ■ Pulsars and gravity waves. ■ Jamming radio tags. ■ Restoring shredded spy documents. ■ Chimerism in twins. ■ Data Points: Tour de France. OPINION 36 ■ SciAm Perspectives By the Editors What’s to be done about lethal injection? 21 ■ 37 Sustainable Developments SCI By Jeffrey D. Sachs AM Featured Q & A The promise of the blue revolution. Latanya Sweeney and our reporter discuss “anonymizing” programs, “deidentifiers” and more 38 ■ Forum at www.SciAm.com/ontheweb By Jose Goldemberg Nuclear energy’s limited appeal. 92 Insights Computer scientist Latanya Sweeney’s ■ 40 Skeptic search for privacy. By Michael Shermer The prospects for Homo economicus. 96 Working Knowledge Hawkeye on the tennis court. 43 ■ Anti Gravity By Steve Mirsky 98 Reviews How to observe by watching. Justifying mistakes. Getting better. Tracking the Anasazi. 102 Ask the Experts Why do ice cubes develop 16 stalagmitelike spikes? Does sleeping after a meal 104 lead to weight gain? 104 Fact or Fiction? Does premium gasoline deliver 96 premium benefi ts for your car? 6 SCIENTIFIC AMERICAN July 2007 © 2007 SCIENTIFIC AMERICAN, INC. Page Intentionally Blank SCIENTIFIC AMERICAN Digital FROM THE EDITOR ■ A Little Revolution Bold and visionary science still has a home in our new design July brings Independence by neurobiologist Joe Z. Tsien on “The Day, a time for celebrating Memory Code” (page 52). Tsien and his freedom. With this July is- co-workers have begun to tease out of the sue, Scientifi c American brain a code for understanding how neu- shakes off the constraints rological activity corresponds to specifi c of its past design and embraces more of thoughts and memories. Some of the the- the opportunities of publishing in the dig- oretical fruits of these studies—such as ital age. The topfl ight content of SciAm is computers that can read human thoughts unchanged: our feature articles continue in detail—are far off in the future, if ever, to be written by leading scientifi c author- but the fact that researchers today can ities and journalists and illustrated by the even speak meaningfully about pursuing finest artists. The layouts and figures, such goals is breathtaking. however, are more modern and approach- A more pressing concern is climate able. Busy readers will also appreciate the change and how it contributes to the se- introductions from the editors that high- verity of cyclones, as Kevin E. Trenberth light the major points of the feature articles. explains in “Warmer Oceans, Stronger Among Our And for readers whose appe- Hurricanes” (page 44). Un- Contributors tites are only whetted by the ar- like rising sea levels that may RICHARD DAWKINS ticles, notes throughout the is- become critical decades from Evolutionary biologist sue point to related content on- now, intensifying storms al- University of Oxford line at www.SciAm.com that ready seem to be a problem. His nine books, ranging from The Selfi sh Gene (1976) to The God Delusion (2006), can further their explorations. The 2007 hurricane season, have made him one of the world’s most At your suggestion, we have unlike that of 2006, will most celebrated essayists both on evolution and on scientifi c critiques of religion. taken our SciAm Perspectives likely be a tough one—which, editorial, bundled it with the as Mark Fischetti reports in LAWRENCE M. KRAUSS voices of our regular colum- our News Scan section (page Physicist Case Western Reserve University nists and added a Forum for 21), is unwelcome news in A prolifi c writer and commentator on guest essayists to create a consolidated New Orleans, where post-Katrina repairs science, he is the author of seven popular books, including The Physics of Star Trek, Opinion section. We have also brought to to the levee system may not be enough to and four articles for Scientifi c American. print our popular online Fact or Fiction? protect the city. column and installed it on the last page. Author Alan Weisman, who discusses STEPHEN J. O’BRIEN Geneticist A widespread weakness of science jour- his new book in “An Earth without People” National Cancer Institute nalism, in my own opinion, has historical- (page 76), is not specifi c about what ca- His DNA-based studies of cat evolution have brought home to him that almost all of the ly been a lack of follow-up. News media lamity might eliminate the human race, 37 feline species are in danger—a trend that routinely tout recent discoveries or an- but that is beside the point. Rather he ar- he hopes science can reverse. nouncements of promising inventions, gues that imagining a world without KEVIN E.