Scientific American July 2010 ■ Volume 303 Number 1

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Plug-In Hybrids Their Dirty Secret War of the Machines Robots Transform Battles DNA Drugs and Vaccines July 2010 $5.99 www.ScientificAmerican.com Potent Therapies to come

The Universe Leisaking

Light seems to lose energy as it crosses the cosmos, apparently breaking the laws of physics. What gives?

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www.diako.ir contents features Scientific American July 2010 ■ Volume 303 Number 1

COSMOLOGY 38 Is the Universe Leaking Energy? By Tamara M. Davis As the cosmos expands, light seems to lose energy, in violation of the laws of physics. What gives?

MEDICINE 48 DNA Drugs Come of Age By Matthew P. Morrow and David B. Weiner New vaccines and medicines in human trials offer hope for fighting HIV, influenza and other maladies.

transportation 54 The Dirty Truth about Plug-in Hybrids By Michael Moyer Cars that draw electricity from the grid may not be as clean as you think. The key factor? Where you live.

ROBOTICS 56 War of the Machines By P. W. Singer 38 Thousands of robots now operate in Iraq and Afghanistan. They mark the most profound 70 transformation of warfare since the atom bomb. ENERGY 64 Clean Energy from Filthy Water By Jane Braxton Little California cities are pumping their treated wastewater underground to create electricity.

EVOLUTION 70 Winged Victory By Gareth Dyke Modern birds, long thought to have arisen after the dinosaurs perished, actually lived alongside them.

PSYCHOLOGY 76 How Babies Think By Alison Gopnik Even the youngest children know, experience and 76 learn far more than scientists ever thought possible. ENVIRONMENT ) On The Cover 82 The Drillers Are Coming baby By some reckoning, the cosmos is leaking energy. By Mark Fischetti Yet, physics tells us, energy is always conserved. The puzzle has an entertaining solution. A process for extracting natural gas is expanding

Photograph by Mark Hooper. despite concern over risks to drinking water. ( archibald timothy

4 SCIENTIFIC AMERICAN July 2010 www.diako.ir© 2010 Scientific American For the first time in history, more than half the world’s population lives in cities. By 2050, that number could rise to 70% — which means cities have to get smarter about how we move around, share resources, keep people safe and healthy and teach our young. See what happens when smart ideas from all over the world come together in one place. Let’s build a smarter planet. Visit TheSmarterCity.com

IBM, the IBM logo, Smarter Planet and the planet icon are trademarks of International Business Machines Corp., registered in many jurisdictions worldwide. A current list of IBM trademarks is available on the Web at www.ibm.com/legal/copytrade.shtml. © International Business Machines Corporation 2010. www.diako.ir

IBM_0710.indd 1 5/24/10 10:57:49 AM contents departments 8 From the Editor 14 1 0 Letters 1 4 50, 100 & 150 Years Ago 1 6 News Scan ENERGY & ENVIRONMENT 28 ■ ■ Gulf oil spill and the environmental consequences. Research & Discovery 16 ■ ■ Why up to 4 percent of your DNA is Neandertal. ■ ■ Under stress, women bond and men withdraw. ■ ■ Water detected on asteroid. ■ ■ Microbial mat the size of Greece discovered. ■ ■ Early images from the Solar Dynamics Observatory. MEDICINE & HEALTH ■ ■ New connections between insomnia and addiction. ■ ■ Risks from overuse of popular acid reflux drug. Technology ■ ■ Manipulating the wisdom of online crowds. 3 6 Critical Mass ■ ■ Green tech wilts under Patent Office scrutiny. By Lawrence M. Krauss Perspectives Whether volcanic or nuclear, disasters anywhere 3 0 in our interconnected world affect us all. By the Editors The prospect of androids that can hunt and kill Recommended on their own should give us all pause. 8 6 Earth sans ice caps. Biomimetics. Immortality. 3 2 Sustainable Developments Anti Gravity By Jeffrey D. Sachs 8 8 By Steve Mirsky Why curbing public debt is so crucial. Cruising with Mac fans. 3 4 Skeptic By Michael Shermer When scientists sin. go to .com 30 Urban Visions: Cities of 2030 34 What will population centers look like in 20 years’ time? Innovations in urban agriculture, distributed energy and mass

transit should make future cities rchitects both more sustainable and more A self-reliant, for starters. More at www.ScientificAmerican.com/jul2010 ourtesy of SOA C

Scientific American (ISSN 0036-8733), Volume 303, Number 1, July 2010, published monthly by Scientific American, a trading name of Nature America, Inc., 75 Varick Street, 9th Floor, New York, N.Y. 10013-1917. Periodicals postage paid at New York, N.Y., and at additional mailing offices. 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 Scientific American, P.O. Box 819, Stn Main, Markham, ON L3P 8A2.Individual Subscription rates: 1 year $39.97 (USD), Canada $49.97 (USD), International $61 (USD). Institutional Subscription rates: Schools and Public Libraries: 1 year $69 (USD), Canada $74 (USD), International $81 (USD). Businesses and Colleges/Universities: 1 year $299 (USD), Canada $304 (USD), International $311 (USD). Postmaster: Send address changes to Scientific A merican, Box 3187, Harlan, Iowa 51537. Reprints available: write Reprint Department, Scientific American, 75 Varick Street, 9th Floor, New York, N.Y. 10013-1917; fax: 646-563-7138; [email protected]. Subscription inquiries: U.S. and Canada (800) 333-1199; other (515) 248-7684. Send e-mail to [email protected]. Printed in U.S.A. Copyright © 2010 by Scientific American, a division of Nature America, Inc. All rights reserved.

6 SCIENTIFIC AMERICAN July 2010 www.diako.ir© 2010 Scientific American U.S. Navy photo by Ensign John Gay. Explore the Physics of the Impossible Traveling through a wormhole. Chasing quantum particles. Re- Impossible: versing the flow of time. These and other astounding adven- tures are staples of science fiction. And yet they also provide Physics beyond the Edge Taught by Professor Benjamin Schumacher, an engaging way to grasp the fundamental laws of nature and Kenyon College discover profound truths about our universe. Lecture Titles Impossible: Physics beyond the Edge uses this ingenious ap- 1. From Principles to 13. A Spinning Universe, proach in 24 lectures that teach you more about physics than you Paradoxes and Back Again Wormholes, and Such ever imagined. Your guide is Professor Benjamin Schumacher, 2. Almost Impossible 14. What Is Symmetry? a pioneer in quantum information who deals everyday with 3. Perpetual Motion 15. Mirror Worlds things once deemed impossible. His richly illustrated course 4. On Sunshine and 16. Invasion of the Giant Insects probes the nature of the impossible from many perspectives Invisible Particles 17. The Curious Quantum World 5. Reflections on the Motive 18. Impossible Exactness and takes you to the frontier of current scientific knowledge— Power of Fire 19. Quantum Tunneling all in pursuit of an answer to the question, “Is it possible?” 6. Maxwell’s Demon 20. Whatever Is Not Forbidden 7. Absolute Zero Is Compulsory This course is one of The Great Courses®, a noncredit, recorded 8. Predicting the Future 21. Entanglement and college lecture series from The Teaching Company®. Award- 9. Visiting the Past Quantum Cloning winning professors of a wide array of subjects in the sciences 10. Thinking in Space-Time 22. Geometry and Conservation and the liberal arts have made more than 300 college-level 11. Faster than Light 23. Symmetry, Information, courses that are available now on our website. 12. Black Holes and Curved and Probability Space-Time 24. The Future of the Impossible Order Today! Offer Expires Friday, August 20, 2010 ACT NOW!

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A Global Affair Board of Advisers Leslie C. Aiello M. Granger Morgan President, Wenner-Gren Professor and Head of Foundation for Engineering and Public Policy, Anthropological Research Carnegie Mellon University Roger Bingham Miguel Nicolelis Professor, Center for Brain Co-director, Center for and Cognition, University Neuroengineering, of California, San Diego Duke University As I type this letter, I am sit- tive. More rarefied still are the scientists G. Steven Burrill Martin Nowak CEO, Burrill & Company ting in a hotel room in Bar- who have achieved the honor of winning Director, Program for Arthur Caplan Evolutionary Dynamics, celona, Spain, having just a Nobel Prize, and 143 Nobelists have Emanuel and Robert Hart Harvard University Professor of Bioethics, completed an important contributed a collective total of 232 pieces University of Pennsylvania Robert Palazzo Sean Carroll Provost and Professor but little-known meeting: to Scientific American,often years before Senior Research Associate, of Biology, Rensselaer Department of Physics, Polytechnic Institute the twice-a-year gathering their work was recognized in Stockholm. Caltech carolyn porco of editors and other members of Scientific Just as those Nobelists have provided George M. Church Leader, Cassini Imaging Science Director, Center for Team, and Director, CICLOPS, American’s international editions. Reflect- their insights in our pages, they have also Computational Genetics, Space Science Institute Harvard Medical School Vilayanur S. ing the scientific enterprise itself, the pro- shared their wisdom and encouragement Rita Colwell Ramachandran ducers of the 14 local-language editions in lectures and conversations with young Distinguished Professor, Director, Center for Brain University of Maryland and Cognition, University are spread around the world. Although we scientists at another important but under- College Park and Johns of California, San Diego are in frequent e-mail and phone contact appreciated assembly, the Nobel Laureate Hopkins Bloomberg School Lisa Randall of Public Health Professor of Physics, throughout the year, we also meet in per- Meetings in Lindau, Germany. This year Drew Endy Harvard University Professor of Bioengineering, son in various cities, the better to learn from marks the event’s 60th anniversary, and it Stanford University Martin Rees Ed Felten Professor of Cosmology one another. will include some 60 laureates and more and Astrophysics, Director, Center for Information Technology Policy, University of Cambridge Around the long table were representa- than 600 young scientists. I will also be Princeton University John Reganold tives from Brazil, China, Japan, Kuwait, there, feeling humble among so many bril- Michael S. Gazzaniga Regents Professor of Soil Director, Sage Center for Science, Washington Russia and essentially every European na- liant minds but eager to listen, learn—and the Study of Mind, University State University of California, Santa Barbara Jeffrey D. Sachs tion. Our collective readership is a diverse then to share with readers. Look for my David Gross Director, The Earth Institute, audience that numbers more than one mil- blog posts about the meeting at the end of Frederick W. Gluck Professor of Columbia University Theoretical Physics, University Eugenie Scott lion, but they all share a passion for science June on www.ScientificAmerican.com; we of California, Santa Barbara Executive Director, National (Nobel Prize in Physics, 2004) and technology. And we, as editors, share will also be posting videos and other cov- Center for Science Education Lene Vestergaard Hau Terry Sejnowski a common mission to comb the globe for erage from the conference during that time Mallinckrodt Professor of Physics and of Applied Physics, Professor and Laboratory the science that matters, the better to serve and in subsequent months. Harvard University Head of Computational Danny Hillis Neurobiology Laboratory, those readers. Members of the editions Last, but certainly not least, I direct Salk Institute for Co-chairman, Applied Minds Biological Studies traded intelligence on best practices and you to the scientific marvels within this is- Daniel M. Kammen Michael Snyder Director, Renewable and also shared new ideas. One initiative, which sue. You can explore the strange apparent Appropriate Energy Laboratory, Professor of Genetics, University of California, Stanford University School I expect to be under way on www.Scienti- “lost” energy of the cosmos, in “Is the Berkeley of Medicine Vinod Khosla Michael E. Webber ficAmerican.com by the time you read this, Universe Leaking Energy?” by Tamara M. Founder, Khosla Ventures Associate Director, Center is to conduct global surveys about science Davis, starting on page 38. Learn the lat- Christof Koch for International Energy Lois and Victor Troendle & Environmental Policy, topics, working together and also in part- est about promising vaccines and medi- Professor of Cognitive and University of Texas at Austin Behavioral Biology, Caltech Steven Weinberg nership with the journal Nature (which is cines in “DNA Drugs Come of Age,” by Lawrence M. Krauss Director, Theory Research in the same Macmillan corporate family). Matthew P. Morrow and David B. Wein- Director, Origins Initiative, Group, Department of Physics, Arizona State University University of Texas at Austin I will report further in the coming months. er, starting on page 48. Watch robots re- Morten L. Kringelbach (Nobel Prize in Physics, 1979) Along with our global reach, we at make the modern battlefield in Director, Hedonia: TrygFonden George M. Whitesides ) Research Group, University of Professor of Chemistry and Scientific American take pride “War of the Machines,” by Oxford and University of Aarhus Chemical Biology, robot Steven Kyle Harvard University in our unique inclusion of P. W. Singer, on page 56. Professor of Applied nathan wolfe Economics and Management, scientist authors, who And delve into that most Director, Global Viral Cornell University Forecasting Initiative collaborate with us on mysterious terrain: the in- Robert S. Langer David H. Koch Institute R. James Woolsey, Jr. many of our feature fant mind. Turn to page 76 Professor, M.I.T. Venture Partner, Lawrence Lessig VantagePoint Venture articles and give us a for “How Babies Think,” by

Partners ); bryan christie design ( Professor, Harvard Law School distinctive perspec- Alison Gopnik. ■ ernest j. moniz Anton Zeilinger Cecil and Ida Green Professor of Quantum Optics, Quantum Nanophysics, Distinguished Professor. M.I.T. DiChristina John P. Moore Quantum Information, BATTLEFIELD ROBOTS Professor of Microbiology University of Vienna are reshaping Mariette DiChristina and Immunology, Weill Medical Jonathan Zittrain

College of Cornell University Professor, Harvard Law School modern warfare. editor in chief ethan hill (

CMY

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® Math Wars ■ Fusion ■ Toxic Gas Established 1845

EDITOR IN CHIEF: Mariette DiChristina executive EDITOR: Fred Guterl MANAGING EDITOR: Ricki L. Rusting CHIEF NEWS EDITOR: Philip M. Yam SEnIor writeR: Gary Stix “Fusion scientists consider EDITORS: Davide Castelvecchi, Mark Fischetti, Steve Mirsky, Michael Moyer, their goal to be more tractable George Musser, Christine Soares, Kate Wong and relevant than ever before.” CONTRIBUTING EDITORS: Mark Alpert, — Steven Ashley, Stuart F. Brown, Graham P. Collins, Richard Hazeltine, Miklos Porkolab, W. Wayt Gibbs, Marguerite Holloway, Stewart Prager and Ronald Stambaugh Christie Nicholson, Michelle Press, John Rennie, Michael Shermer, Sarah Simpson March 2010

ASSOCIATE EDITORS, ONLINE: David Biello, Larry Greenemeier ■■ Reform or Re reform? need for an inquiry-based approach that news Reporter, ONLINE: John Matson - ART DIRECTOR, online: Ryan Reid In “Numbers War” [News Scan], Linda emphasizes conceptual understanding. Baker’s treatment of our inquiry-based Steven Rasmussen Discovering Mathematics series is filled Publisher, Key Curriculum Press design director: Michael Mrak ASSISTANT ART DIRECTOR: Jen Christiansen with errors and naive claims. For instance, Emeryville, Calif. PHOTOGRAPHY EDITOR: Monica Bradley there was no “three-year pilot” of our contributing ART DIRECTOR: Edward Bell texts, contrary to what Baker reported. BAKER REPLIES: For this article, I interviewed pro- The article repeats many unfounded fessional math educators, mathematicians and math COPY DIRECTOR: Maria-Christina Keller criticisms of reform in mathematics educa- teachers, many of whom self-identified as reform tion. For one, Baker describes the National math or traditional math advocates—or somewhere

Editorial Administrator: Avonelle Wing Council of Teachers of Mathematics in between. Some were off the spectrum entirely. SENIOR SECRETARY: Maya Harty (NCTM) document as a volley in the war, The consensus was that reform math had indeed although it is actually an effort to bring reshaped a generation of math instruction but that

COPY and PRODUCTION, nature publishing group: coherence and conceptual clarity to the the pendulum had since swung back toward the Senior COPY editor, npg: Daniel C. Schlenoff most important topics in high school math- center, with many educators now advocating both COPY editor, npg: Michael Battaglia ematics. She claims that NCTM reform conceptual and skill-based strategies. The article editorial assistant, npg: Ann Chin managing pRODUCTION EDITOR, n pg : “reshaped a generation of instruction,” spotlighted a few cases in which various stakehold- Richard Hunt when, in fact, few students have had a real ers felt this balanced approach was missing. Regard- senior pRODUCTION EDITOR, npg: Michelle Wright opportunity to try a fully committed in- ing fractions: the issue is not that people “do not quiry-based curriculum as envisioned by want students” to learn to add fractions but whether PRODUCTION MANAGER: Christina Hippeli the NCTM. or not they are actually teaching them to do so. ADVERTISING PRODUCTION MANAGER: Traditional math is the status quo in Carl Cherebin ■■ PREPRESS AND QUALITY MANAGER: U.S. schools and predominates in U.S. Plasma Display Silvia De Santis textbooks. The most egregious distortion Michael Moyer’s “Fusion’s False Dawn” CUSTOM PU BLISHING MANAGER: is when Baker writes, “Instead of having might give the impression that informed Madelyn Keyes-Milch PRODUCTION coordinatoR, npg: Lisa Headley students memorize formulas and compute scientists have become skeptical about fu- problems such as adding fractions, advo- sion. This impression is incorrect. Fusion cates of reform math encouraged students scientists consider their goal to be more Letters to the Editor to develop their own visual representations tractable and relevant than ever before— Scientific American of math concepts and use calculators to and every one of several recently commis- 75 Varick Street, 9th Floor, New York, NY 10013-1917 solve numerical tasks.” sioned expert review committees has con- or [email protected] In my 40 years of interacting with math- curred, concluding that fusion energy

Letters may be edited for length and clarity. ematics education professionals, I have should be actively pursued. Magnetic fu- We regret that we cannot answer each one. never met a single one who does not want sion devices have already in 1997 produced Post a comment on any article at students to learn to add fractions. In fact, 16 million watts of fusion power. The chal- www.ScientificAmerican.com/ sciammag math education researchers around the lenges of plasma physics have been suffi- world and here in the U.S. agree on the ciently met that we can confidently design

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BOS73175A_Q7866.indd 1 4/12/10 12:59:07 PM Letters devices that will make copious fusion reac- can produce H 2S from cysteine in the brain tions. ITER is one such device that will en- and that H S facilitates the induction of 2 ® able study of high-energy-gain plasma hippocampal long-term potentiation by en- physics. Fusion researchers worldwide are hancing receptor activity. discussing facilities from specialized exper- Wang also claims that “we decided to Established 1845 iments to a demonstration power plant to look at an enzyme called cystathionine take on our next issues of materials, power gamma-lyase (CSE) ... no one knew wheth- pRESIDENT: Steven Inchcoombe executive Vice president: Michael Florek extraction and tritium production in a reli- er CSE existed in blood vessels.” In 1997 VIC E PRESI DE NT, operations and able, continuously operating system. Rumiko Hosoki, Norio Matsuki and I had Administration: Frances Newburg Richard Hazeltine already published our second paper on Professor of physics, University of Texas at Austin H2S, in which we demonstrated that CSE managing DIRECTOR, consu mer mark eting : Miklos Porkolab is expressed in the thoracic aorta, the ile- Christian Dorbandt associate DIRECTOR, consu mer mark eting : Director, Plasma Science and Fusion Center, um and the portal vein and produces H S 2 Anne Marie O’Keefe Massachusetts Institute of Technology from cysteine. We also showed that H2S Senior Marketing Manager/Retention: Stewart Prager relaxes these smooth muscles. Wang knew Catherine Bussey Director, Princeton Plasma Physics Laboratory about this work, because he cited our pa- Senior Marketing Manager/Acquisition: Patricia Elliott Ronald Stambaugh pers in 2001—four years after ours. Vice president, Magnetic Fusion Energy Program, Hideo Kimura VIC E PRESIDENT AND PU BLISHER: General Atomics National Institute of Neuroscience, Tokyo Bruce Brandfon vice president, marketing and ■■ Where Credit Is Due WANG REPLIES: My article was not intended to be a sales development: Michael Voss DI REC TOR , global media solu tions: Having published on the biology of hy- complete academic chronicle of the discovery of the Jeremy A. Abbate drogen sulfide (H 2S) since 1987, we believe biological effects of H2S. Many important milestones manager, integrated media sales: Stan Schmidt that Rui Wang’s “Toxic Gas, Lifesaver” were not mentioned, but I by no means meant to SALES DEVELOPMENT MANAGER: David Tirpack PROMOTION MANAGER: Diane Schube had substantial factual inaccuracies and deny or disregard these contributions, including Marketing research Director: Rick Simone omissions. Studies by our group from as those of Kimura. Bearing in mind the severe space SALES REPRESENTATIVES: Jeffrey Crennan, early as 1987 had already described some constraints and general audience of Scientific Amer- Chantel Arroyo of the neurochemical effects of NaHS, an ican, I described how my personal interest in this H2S precursor. By 1990 we had reported topic evolved, and the article truthfully reflected DIRECTOR, ANCILLARY PRODUCTS: Diane McGarvey the presence of detectable endogenous lev- that. Nevertheless, some important descriptions els of H2S in tissue and discussed the pos- were lost during the editing process. For example, How to Contact Us sibility that chronic exposure to sublethal shortly before the article went to press, I specifically subscriptions concentrations of NaHS may have biologi- corrected the text to say [revision in bold], “Some For new subscriptions, renewals, gifts, payments, cal effects, including the regulation of ami- earlier studies by Hideo Kimura in Japan sug- and changes of address: U.S. and Canada, 800-333-1199; outside North America, 515-248-7684 no acid neurotransmitter levels. At that gested that H2S is a neuromodulator, making neural or www.ScientificAmerican.com time, we had already raised the possibility circuits more or less responsive to stimuli.” Unfortu- of neuroprotection by H2S. Wang was cer- nately, I was told that there was no space for the SUBMISSIONS tainly aware of this work, because he cited change to be made. To submit article proposals, follow the guidelines at www.ScientificAmerican.com. Click on “Contact Us.” several of these papers in a review he wrote As to Kimura’s concern about the statement re- We cannot return and are not responsible for in 2002. At about the time, another group, garding the presence of CSE in blood vessels, in a materials delivered to our office. led by Sheldon Roth of the University of revision sent to my editor, I wrote, “But no one knew reprints Calgary, was also studying the effects of whether the same CSE existed in blood vessels. Sure To order bulk reprints of articles (minimum of 1,000 copies): Reprint Department, Scientific American, H2S on the respiratory system. enough, we found the enzyme there and cloned it.” 75 Varick Street, 9th Floor, New York, NY 10013-1917; Samuel B. Kombian These words in bold are important for stating our 212-451-8877; [email protected]. Faculty of Pharmacy, Kuwait University unique contribution, but they were omitted from the For single copies of back issues: 800-333-1199. William F. Colmers text because of a misunderstanding between the edi- permissions Professor of pharmacology, tor and me. Indeed, Kimura and his colleagues showed For permission to copy or reuse material: Permissions Department, Scientific American, 75 Varick Street, University of Alberta previously that H2S relaxes blood vessels, but that did 9th Floor, New York, NY 10013-1917; randp@SciAm. not prevent us or anyone else from reasoning that H2S com; www.ScientificAmerican.com/permissions. Please allow three to six weeks for processing. Wang suggests that he started the H2S might have a similar effect to nitric oxide. studies based on his own ideas, which is advertising simply not true. In 1996 Kazuho Abe and I ERRATUM In “Fusion’s False Dawn,” Michael Moyer www.ScientificAmerican.com has electronic had already published the first paper on the referred to William Thompson as the name of the contact information for sales representatives of Scientific American in all regions of the U.S. positive biological effects of H 2S and dem- physicist better known as Lord Kelvin. The correct and in other countries. onstrated that cystathionine beta-synthase spelling of his name is Thomson.

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Friday & Saturday, May 6–7 (optional) Scientometrics will permit the forecasting of science developments, and help increase our Friday, May 6, 2011 — We’ll travel to the ability to advocate for science. Then we’re o to New York Hall of Science in Queens. Initially a Manhattan, for a late afternoon social reception pavilion for the 1964 World’s Fair, the Hall of with Scienti c American sta ers. Science is now NYC’s science and tech center. We’ll speak with resident experts on the emerging Saturday, May 7, 2011 — Wake up in the eld of scientometrics, the science of science. city that never sleeps, and we’ll meet midday at the Rose Center (left) for Earth and Space at the American Museum of Natural History. Get the inside scoop on research being done at the Rose Center, take a journey to the stars in the Hayden Planetarium, and get a new perspective on space with the Scales of the Universe. After our astronomy sojourn, we’ll reconvene in mid-town Manhattan for an early evening social reception.

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sa09_1pg_4_19_10_v2.indd 1 4/20/10 1:49 PM 50, 100 & 150 years ago Innovation and discovery as chronicled in Scientific American

Live Births ■ Dangerous Skies ■ King of Beers Compiled by Daniel C. Schlenoff

JULY 1960 consider methods for counteracting the in- thinks that three or four will do twice as INFANT MORTALITY—“The death rate of fluence such craft will have in future wars. much. This is not the case at all. The only U.S. infants, after a long and precipitous Two 1909 Cadillac ‘30s’ were purchased English patients I have ever known to refuse decline, has leveled off in the last few years, by the Northwestern Military Academy in tea, have been typhus cases; and the first according to a study by Iwao M. Moriya- the spring of 1910. These automobiles of sign of their getting better was their crav- ma of the National Office of Vital Statis- stock chassis are made to seat four cadets, ing again for tea. —Florence Nightingale” tics. In some states it has even risen slight- and mount a Colt automatic rapid fire gun ly, after reaching an all-time low of 26 per over the engine [see illustration]. The guns LAGER BIER—“There are thousands of peo- 1,000 live births in 1956. Most of the re- of .30 caliber deliver automatically 480 ple in New York who seem to have quite duction in mortality of children under one shots a minute, having a sighted range of forgotten the use of plain water as a bever- year of age is attributable to control of infectious diseases, primarily influenza and MILITARY AUTOMOBILE: A weapon against a fledgling threat from the air, 1910 pneumonia. In 1946, when penicillin became available to the public, the death from infectious diseases dropped about 30 per cent. However, infectious diseases still account for about half of the deaths among infants between one month and one year old. The death rate for younger infants re- flects the heavy toll taken by noninfectious conditions such as congenital malforma- tions, birth injuries, postnatal asphyxia and premature births.”

JULY 1910 ELEGANT FLIGHT—“The most important fact established by the Rheims aeronauti- cal meet was the unquestionable superior- ity of the monoplane. Its success must be particularly gratifying to the French peo- 2 ,000 yards. Results of experiments clear- age. In certain quarters of the city, ‘lager’ ple. They seem to have realized that if its ly demonstrate the rapidity of fire would be is the main staple of life, being for sale in inherent fragility, as compared with the such that military automobiles must be almost every house, and the drink and strong bridge-like form of the biplane, reckoned with as weapons against airships even the food, of all the men, women and could be overcome, there were many ad- and aeroplanes.” children. Lager is king! Lager is one of vantages in the way of simplicity, reduc- our most modern institutions. Ten years tion of head resistance, and small weight. ago it was only a vulgar German word of Furthermore, the monoplane is attractive, JULY 1860 unknown import; then it was looked upon both because it approximates so closely in NOTES ON NURSING—“When you see the as an insipid Dutch beer; but finally, a ma- appearance the form and structure of the natural and almost universal craving in jority, perhaps, will vote that it is ‘the peo- birds, and because its simple and graceful English sick for their ‘tea,’ you cannot but ple’s nectar.’ Certain witnesses have testi- lines give it a decided artistic advantage— feel that nature knows what she is about. fied and courts have decided that lager is this last being a strong recommendation But a little tea or coffee restores them quite not intoxicating; but in view of the fact

to a people so aesthetic as the French.” as much as a great deal; and a great deal of that a pint of lager contains as much alco- 1910 30, JULY 5; NO. CIII, VOL. tea, and especially of coffee, impairs the hol as an ordinary glass of brandy, it might THREAT FROM ABOVE—“With the rapid little power of digestion they have. Yet the be suspected that those witnesses had strides made in aerial navigation, it is emi- nurse, because she sees how one or two indeed been indulging in lager just at the

nently necessary that the army seriously cups of tea or coffee restores her patients, time they needed their sober judgment.” AMERICAN, SCIENTIFIC

14 Scientific American July 2010 © 2010 Scientific American www.diako.ir It’s not the advice you’d expect. Learning by complete immersion. Our award- a new language seems formidable,, What’s the fastest way winning, computer-based method does as we recall from years of combat to learn a language? just that. with grammar and translations in Dynamic Immersion® unlocks the school. Yet infants begin at birth. eyy innate language-learning ability you communicate at eighteen months and acquired before birth and mastered speak the language uently before theyy as a child. go to school. And they never battle translations or grammar explanations ACT By recreating the immersion context in along the way. which you learned your rst language, you understand, speak, read and write Born into a veritable language jam-- your new language with con dence and boree, children figure out language accuracy from the beginning—without purely from the sounds, objects and LIKE A translations and explanations. interactions around them. At every step and in every skill, you receive eir senses re up neural circuits that instant, actionable feedback, including send the stimuli to di erent language speech recognition and analysis tech- areas in the brain. Meanings fuse to nologies that prepare you for everyday words. Words string into structures.. BABY. conversations. And Adaptive Recall® And language erupts. brings back material just when you need it to reinforce and perfect your learning. Three characteristics of the child’s’ language-learning l l i process are crucial for success: Every act of learning is an act of play for children and there’s First, and most importantly, a child’s natural language-learning no reason it should be di erent for learners of any age. With ability emerges only in a speech-soaked, immersion environment Rosetta Stone® programs, you rediscover the joy of learning free of translations and explanations of grammar. language. Clever, puzzle-like activities produce sudden “Aha!” moments and astonishing language discoveries. Second, a child’s language learning is dramatically accelerated by constant feedback from family and friends. Positive correction Your “language brain” remembers. and persistent reinforcement nurture the child’s language and We see it all the time. language skills into full communicative expression. A slow smile sneaks across the learner’s face a er just a few screens. It’s a smile of recognition, as though the brain suddenly ird, children learn through play, whether it’s the arm-waving recalls what it was like to learn language as a child, as though it balancing act that announces their rst step or the spluttering realizes, “Aha! I’ve done this before.” preamble to their rst words. All the conversational chatter skittering through young children’s play with parents and Act like a baby? You bet. Visit our website and nd out how you playmates—“…what’s this…” “…clap, clap your hands…” can reactivate your own innate, language-learning ability with “…my ball…”—helps children develop language skills that Rosetta Stone. It’s the fastest way to learn a language. Guaranteed.® connect them to the world. SAVE 10% TODAY WHEN YOU ORDER Adults possess this same powerful language-learning ability Version 3 Personal Edition CD-ROM products. that orchestrated our language success as children. Sadly, our clashes with vocabulary drills and grammar explanations force Level 1 Reg. $229 $206 us to conclude it’s hopeless. We simply don’t have “the language Level 1,2,&3 Reg. $539 $485 learning gene.” Level 1,2,3,4,&5 Reg. $699 $629 At Rosetta Stone, we know otherwise. You can recover your More than 30 languages available. native language-learning ability as an adult by prompting your WIN/MAC compatible. brain to learn language the way it’s wired to learn language: SIX-MONTH, NO-RISK, MONEY-BACK GUARANTEE.*

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www.diako.ir N E W S S C A N Insights and Analysis about Science and Technology LastingE nergy & Enviro nMenacement Gulf oil-spill disaster likely to exert environmental harm for decades BY DAVID BIELLO m o r e t h a n 20 y e a r s after the Exxon Valdez foundered off the coast of Alaska, sea otters still dig up oil in their hunt for clams in Prince William Sound. Nearly 25 years after an oil storage tank ruptured near mangrove swamps and coral reefs of Bahia Las Minas in Panama, oil slicks still form in the water. And some 40 years after the fuel-oil barge Florida ran aground off Cape Cod, the muck beneath the marsh grasses makes the area smell like a gas station. Similar damage may be in store for the U.S. Gulf coast, given that millions of gallons of light sweet crude spewed from BP’s broken well 1,500 meters down and approximately 65 kilometers off the Louisiana coast. Its oil-drilling rig Deepwater Horizon ex- ploded on April 20, and efforts to cap the flow—estimated to be 200,000 to a few million gallons a day during the weeks right after the accident—suffered setbacks and delays. All the oil released, which could ultimately exceed the Valdez spill several times over, could compromise wildlife and local livelihoods for years. The toxic compounds in oil vary, but the most worrisome are polycyclic aromatic hydrocarbons (PAHs), such as napthalenes, benzene, toluene and xylenes. All can sicken humans, animals and plants. “These hydrocarbons are particularly relevant if in- haled or ingested,” says environmental toxicologist Ronald J. Kendall of Texas Tech University. “In the bodies of organisms such as mammals or birds, these aromatic hydrocarbons can be transformed into even more toxic products, which can affect DNA.” The mutations that might result could lead to reduced fertility, cancer and other problems. Not all the PAHs become an environmental threat, though. Thanks to evaporation, oil that reaches the surface loses at least 20 to 40 percent of the original hydrocarbons. “Evaporation is good; it selectively removes a lot of compounds we’d rather not SEA SICKNESS: Vast oil slicks have formed in the Gulf of Mexico after have in the water,” says marine chemist Christopher M. Reddy the explosion of BP’s Deepwater Horizon drilling rig. The oil’s toxic of the Woods Hole Oceanographic Institution. The oil also emul- hydrocarbons could pose environmental health risks for decades. sifies, forming mousse—a frothy mix of hydrocarbons and water—or clumps into so-called tar balls. of the National Oceanic and Atmospheric Administration, at a But to scientists’ surprise, plumes of oil extending several ki- May 12 press conference on the spill. lometers were floating roughly 1,000 meters beneath the surface, In the area by the spill itself, “anything that’s in the upper wa- where the toxic compounds are literally washing off the oil and ter column is going to be exposed” to oil chemicals, Shirley says. contaminating the water. Those components “can be more per- That’s bad news for the millions of zooplankton out there, and vasive in finding ways to infiltrate a salt marsh” and impact wild- the contamination could ultimately end up having cascading ef- life, Reddy says. And there’s a lot of wildlife to impact: some fects up the food chain. “If you start removing pieces of this big 16,000 species of plants and animals live in the Gulf of Mexico, food web out there, what’s going to happen?” Shirley asks. “We according to marine biologist Thomas Shirley of Texas A&M don’t really know, but probably not good things.”

University. Many of their habitats “are at risk of being affected, In regard to long-term damage, researchers worry most about Getty Images but we don’t have any direct way to know which ones or in what landfall. “Once the oil, because of high tides or high winds, gets

amount,” remarked marine biologist Jane Lubchenco, director into the coastal wetland, it gets trapped in the sediment,” notes JoeRaedle

DEEPWATER HORIZON, EXXON VALDEZ, 1989 IXTOC 1, 1979 GULF WAR, 1991 Average annual spillage from 2010 natural seeps and regular human activities such as transportation

April 20–May 13 1 billion gallons Global: 380 million gallons released overall 4.6 million gallons (BP estimate)

11 million gallons U.S. waters: 97 million gallons 140 million 76 million gallons (Other scientists’ estimate) gallons At least 250 million into Persian Gulf CRUDE ESTIMATES: Among recent major oil-spill disasters, the ciences Deepwater Horizon may be on par with Ixtoc 1, off Mexico. cademy of S Héctor M. Guzmán of the Smithsonian weather. Rough seas would swamp the grade the oil than in the spill at Prince Tropical Research Institute in Panama, booms keeping oil off the coast. “A hurri- William Sound. And early on workers ational A who studied the effects of the 1986 spill off cane or even just a tropical depression used hundreds of thousands of gallons of

Panama. “Then for decades you continue could be catastrophic,” Kendall empha- chemical dispersants to help break up the and N to see oil coming back out.” Particularly sizes. “It will push oil into places that it’s slick. The dispersants themselves carry critical are marshes, which are nurseries for difficult to clean up.” their own risks and toxicity, which have ces: BP, NOAA wildlife ranging from fish to birds; contam- Of course, everyone hopes that the oil many environmentalists concerned about r ou ination there could damage embryos and can be removed or dissipated before that their potential impact. Given the choices, affect a species for generations. happens. Certainly the warmer conditions noaa’s Lubchenco probably summed it up istiansen; S Whether the oil can be kept out of the of the Gulf of Mexico will help bacteria best: “When an oil spill occurs, there are r en ch wetlands comes down to one thing: the and other natural forces more quickly de- no good outcomes.” j Our researc hInner & discovery Neandertal Genome analysis indicates Neandertals and modern humans interbred BY KATE WONG u p t o 4 percent of the DNA of people today who live outside which is distinct from the much longer DNA sequence that re- Africa came from Neandertals, the result of interbreeding be- sides in the cell’s nucleus. Their analysis revealed that Neander- tween Neandertals and early modern humans. That conclusion tals had not made any contributions to modern mitochondrial comes from scientists led by Svante Pääbo of the Max Planck In- DNA. Yet because mitochondrial DNA represents only a tiny stitute for Evolutionary Anthropology in Leipzig, Germany, fraction of an individual’s genetic makeup, the possibility re- who pieced together the first draft of the Neandertal genome— mained that Neandertal nuclear DNA might tell a different sto- which represents about 60 percent of the entire genome—using ry. Still, additional genetic analyses have typically led research- DNA obtained from three Neandertal bones that come from ers to conclude that Homo sapiens arose in Africa and replaced Vindija cave in Croatia and are more than 38,000 years old. the archaic humans it encountered as it spread out from its birth- The evidence that Neandertals contributed DNA to modern place without mingling with them—the Out of Africa replace- humans came as a shock to the investigators, who published ment scenario, as it is known. their findings in the May 7Science. “First I thought it was some But mingle they apparently did. When Pääbo’s team looked at kind of statistical fluke,” Pääbo remarked during a press tele- patterns of nuclear genome variation in present-day humans, it conference on May 5. The finding contrasts sharply with his pre- identified 12 genome regions where non-Africans exhibited vari- vious work. In 1997 he and his colleagues sequenced the first ants that were not seen in Africans and that were thus candidates Neandertal mitochondrial DNA. Mitochondria are the cell’s en- for being derived from the Neandertals, who lived not in Africa ergy-generating organelles, and they have their own DNA, but Eurasia. Comparing those regions with the same regions in

FRIENDSfriends ANDand LOVERS? DNA analysis shows that anatomically modern humans (top) mated with Neandertals (bottom). Some geneticists suspect that they may have interbred with other archaic humans, such as Homo erectus, as well.

the newly assembled Neandertal sequence, the researchers found 10 matches, meaning 10 of these 12 variants in non-Africans came from Neandertals. The contributions do not seem to encode anything partic-particularly important from a functional standpoint, however. Intriguingly, the researchers failed to detect a special affinity to Eu-Eu- ropeans—a link that might have been expected given that Neandertals seem to have persisted in Europe longer than anywhere else before dis-dis- ) ) appearing around 28,000 years ago. Rather the Neandertal sequence was equally close to sequences from present-day people from France, Papua New Guinea and China. By way of explanation, the investiga-investigators suggest that the interbreeding occurred in the Middle East be-between 50,000 and 80,000 years ago, before moderns fanned out to human and Neandertal skulls Neandertal and human human and Neandertal skulls Neandertal and human . ( . ( other parts of the Old World and split into different groups. Intermixing does not surprise paleoanthropologists who have long argued on the basis of fossils that archaic humans, such as the Neander-Neander- tals in Eurasia and H. erectus in East Asia, mated with early moderns Photo Researchers, Inc Photo Researchers, Inc and can be counted among our ancestors—the so-called multiregional evolution theory of modern human origins. The detection of Neander-Neander-

egginger tal DNA in present-day people thus comes as welcome news to these sci- D tal DNA in present-day people thus comes as welcome news to these sci- . . R . . E. R. DEGGINGER R. E. E entists. “It is important evidence for multiregional evolution,” com-com- © 2010 Scientific American

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Untitled-2 1 5/24/10 12:12:20 PM N E W S S C A N

ments Milford H. Wolpoff of the University of Michigan at Ann Arbor, the leading proponent of the theory. Under Threat, Women Bond and In a prepared statement, Out of Africa theorist Christo- Men Withdraw pher B. Stringer of the Natural History Museum in London acknowledged that the genome results show that “many of Under stress, we fight or flee, or so scientists have long preached. But us outside of Africa have some [Neandertal] inheritance.” this response may really be just a guy thing. New evidence shows how, But Stringer maintains that the origin of our species is most- unlike men, women under stress “tend and befriend,” engaging in nur- turing and social networking. ly an Out of Africa story. Population geneticist Laurent Ex- At the Cognitive Neuroscience Society 2010 annual meeting in Montre- coffier of the University of Bern in Switzerland agrees, not- al, psychologist Mara Mather of the University of Southern California and ing that the alleged admixture did not continue as moderns her colleagues asked male and female volunteers to place their hand in ice moved into Europe. “In all scenarios of speciation, there is water, which makes the stress hormone cortisol shoot up. Then they a time during which two diverging species remain interfer- looked at angry or neutral faces while lying inside a brain scanner. Men showed less activity in a key face-processing region of the brain tile,” he explains. than the unstressed men did, suggesting that their ability In addition to illuminating how early humans interacted, to evaluate facial expressions declined. In con- the Neandertal genome is helping to indicate which parts of trast, the region was more active in stressed the modern human genome separate us from all other crea- women. Moreover, these women showed great- tures. Thus far Pääbo’s group has identified a number of er activity in the brain circuit that enables people to understand the emotions of others. The modern human genome regions containing sequence varia- enhanced ability of stressed women to read tion that is not seen in Neandertals and that may have helped faces and empathize could underlie the pro- modern humans adapt. Some of these regions are involved in pensity to bond under trying circumstanc- cognitive development, sperm movement and the physiology es, which may have evolved as a way to of the skin. But exactly how these slight changes to the mod- protect offspring. —Ingrid Wickelgren ern human sequence affected the functioning of these ge- READY TO BOND? Stressed women have nome regions remains to be determined. Says Pääbo: “This greater activity in the areas of the is just the beginning of the exploration of human uniqueness brain that are involved in empathy. that is now possible.”

Damp Rocks from Space ) woman Icy discovery bolsters view that asteroids delivered water to Earth BY JOHN MATSON ( a n a s t e r o i d c i r c l i n g the sun between solar system. The finding supports the no- tist at the nasa Ames Research Center.

Mars and Jupiter harbors water ice and tion that asteroids could have provided The asteroid is intriguing in part because GettyImages eahy

organic compounds on its surface—the early Earth with water for its oceans as it occupies a similar orbit to so-called main- L d first time such components have been dis- well as some of the prebiotic compounds belt comets—and likely stems from the covered on asteroids. Those traits had that allowed life to develop. same parent body. Main-belt comets reside Davi); been associated with comets, which spring Two teams reported complementary in the asteroid belt but feature cometlike asteroid ( from colder, more distant reservoirs in the observations of the 200-kilometer-wide tails thought to arise from sublimating ice. asteroid, known as 24 Themis, in the These newly discovered main-belt comets, April 29 Nature. (Scientific American and now Themis, “are very interesting ob- is part of Nature Publishing Group.) Both jects and potentially one of the sources of groups saw infrared absorption features Earth’s oceans,” Cruikshank says. indicating a thin coating of frost, along University of Central Florida astrono- with unidentified organic compounds. mer Humberto Campins, a co-author of “They have found something that a lot of one of the studies, says other asteroids people, including myself, have been chas- may harbor ice as well. “Or it could be ing in the solar system for a long time,” unique to Themis,” Campins says. “We says Dale Cruikshank, a planetary scien- don’t know.” ServicioMultimedia, Instituto Astrofisicade Canarias, de Tenerife

ICE on THE ROCK: Artist’s conception depicts asteroid 24 Themis alongside two smaller bodies, one of which is a comet that orbits within the asteroid belt. Measurements indicate that

Themis harbors water ice, supporting the idea that asteroids seeded the Earth’s oceans. Gabriel Pérez

20 Scientific American © 2010 Scientific American July 2010 www.diako.ir www.diako.ir NEWSN E W S SCAN S C A N -HBQNRBNOHB�'H@MSRMicroscopic� Giants Mat of microbes the size of Greece discovered on seafloor BY KATHERINE HARMON FORGETf o r g e t GARGANTUANg a r g a n t u a n WHALESw h a l e s and hefty cling nutrients in the ocean. But little is cephalopods—the real marine mam-mam- known about these creatures’ suscepti-suscepti- moths may be the mighty microbes. They bility to shifts in temperatures, dissolved constitute at least half, and perhaps up to gases and acidity, which are predicted to 90 percent, of the oceans’ total biomass, occur with climate change. Researchers according to data gathered by the decade- will present the full census in October in long Census of Marine Life project. London. The estimate comes courtesy of high- throughput DNA sequencing, which suggests that there might be as many as Eye-Candy 100 times more microbe genera than Solar Science previously assumed. The increase in ge-ge- nus and species also raises the estimate A new sun-studying satellite had its of individual microbes. A single liter of coming-out party in April, with the release of early imagery and videos. The Solar seawater, once thought to contain about Dynamics Observatory, launched by NASA 100,000 microbes, can actually hold in February, returns 16-megapixel images more than one billion, the census scien-scien- of the sun on a nearly continuous basis, tists reported in April. splits the sun’s emissions into its individual wavelengths, tracks the propagation of waves across the sun’s

); surface and maps the ever shifting solar ); magnetic field. The photograph here is an microbe SUBSCRIBE extreme ultraviolet image of the sun taken microbe on March 30. False colors trace different gas temperatures: reds are relatively cool (about 60,000 degrees); blues and greens NOW! are hotter (at least one million degrees). ensus of Marine Life ( Life Marine of ensus C esearch/ ) ) R sun sun ( NASA OCEAN’S ABUNDANCE: Microbe called Culex-Culex- y/ iregiloricus trichiscalida was discovered on mbl sse A

the seafloor off the coast of Africa by the g in g

ongoing Census of Marine Life project. a enter for Marine Biodiversity Biodiversity Marine for enter C The tiny creatures can join together to ospheric Im an m an m t

create some of the largest masses of life A / on the planet. Census scientists found one such seafloor mat off the Pacific coast SERVATORY B

of South America that is roughly the size O ICS of Greece. With all that information, scientists M

Despite their small individual size, think that the observatory could do DYNA AR microbes play a big role in the planet’s for heliophysics what the Hubble Space L Telescope has done for astrophysics SO

www.ScientificAmerican.com/MindSale climate. They help to turn atmospheric OF in general. —John Matson carbon dioxide into usable carbon, as courtesy of Gunnar Gad/Marco Buntzow/Ger Gad/Marco Gunnar of courtesy COURTESY COURTESYGUNNAROF GAD/MARCO BUNTZOW/GERMAN CENTER FORMARINE BIODIVERSITY RESEARCH/CENSUS MARINEOF LIFE( well as oxygenating sediment and cy-cy- COURTESY OF SOLAR DYNAMICS OBSERVATORY/ATMOSPHERIC IMAGING ASSEMBLY/NASA (

22_Sciam07.indd 1 5/24/10 12:19:52 PM NEWS SCAN

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22_Sciam07.indd 1 5/24/10 12:27:18 PM NEWSN E W S SCAN S C A N 21 st Century and they became less sensitized to the blocking sleep aids may facilitate more Shaker stimulant than controls did, even with natural slumber than current sleeping repeated doses. Sensitized neurons grow pills, which depress brain activity gener-gener- extra receptors for the craved drug, de-de- ally and therefore have to fight “wake” manding more of it to achieve stimula-stimula- signals, including orexin. tion, thereby fueling a cycle that leads to Stimulant drugs may produce a simi-simi- addiction. larly unnatural imitation of normal stim-stim- John J. Renger and his colleagues at uli, Renger speculates, which could ex-ex- Merck also showed that a different ex-explain why orexins play a role in facilitat-facilitat- perimental orexin blocker, administered ing the dopamine-driven learning and with amphetamine to rats, prevented reward processes that lead to addiction. sensitization. In the same study, the com-com- The animal studies indicate that admin-admin- pany’s dual orexin-receptor antagonist istering orexin blockers with a stimulant (DORA), administered along with nico-nico- drug could facilitate unlearning the ad-ad- tine to rats that were previously addicted diction, too. to nicotine, prevented the animals from The companies have not announced relapsing. plans to develop orexin blockers for sub-sub- “What we showed was not that orex-orex- stance abuse treatment, but Renger notes ins are a target of amphetamine,” Renger that once the sleep aids reach the market, explains, “because we know amphet-amphet- they may help toward that end just by fa-fa- amine targets dopamine.” The brain’s re-re- cilitating a good night’s sleep. “There’s lease of orexins in response to the stimu-stimu- evidence out there that one of the major lants, however, enhances dopamine’s reasons for alcoholics to relapse is in-in- downstream activities that lead to sensi-sensi- somnia,” he explains, “because they re-re- tization and addiction. “Orexin sets the lied on it to help them get to sleep.” The tone,” Renger says, that enables those orexin-blocking sleeping pills might pro-pro- brain changes to occur. vide a better-quality sleep than alcohol- As narcolepsy illustrates in the ex-ex- induced unconsciousness. Whether they treme, a lack of orexin removes a barrier are the first sleeping pills guaranteed not to sleep. For that reason, the new orexin- to be addictive remains to be seen. (D@QSATQM�(D@C@BGDHeartburn� Headache

Overuse of a popular acid blocker poses health risks BY MELINDA WENNER MOYER

INin 2008 AMERICANSa m e r i c a n s spent more than $14 enzyme system in the stomach’s cells essen-essen- billion on heartburn treatments called tial for pumping out acid. Although they proton pump inhibitors—such as Nexium, are meant to treat only gastroesophageal Prevacid and Protonix—making them sec-sec- reflux and peptic ulcer disease, “a number ond only to lipid regulators as the best- of people who have gastrointestinal symp-symp- AT: selling drug class in the country. But re-re- toms that are not due to acid are given !$ " cent research suggests that the popularity PPIs,” perhaps because of misdiagnoses or ! % of these drugs in part results from unnec-unnec- because “the physician didn’t have any bet-bet- & !! essary prescriptions that may be putting ter alternative,” says Colin W. Howden, a ! & " $& millions of people at risk. Long-term use gastroenterologist at the Northwestern " !# has been linked to withdrawal symp-symp- University School of Medicine. toms, an increased risk of bacterial infec-infec- Doctors also give PPIs to hospital pa-pa- tion, hip fracture and even possibly nutri-nutri- tients who have serious injuries to prevent tional deficiencies. gastrointestinal bleeding and stress ul-ul- Proton pump inhibitors, or PPIs, work cers. But not only are such prescriptions just as their name implies: they block an questionable—only one intensive care pa-pa-

22_Sciam07.indd 1 5/24/10 12:24:31 PM NEWS SCAN

tient is saved from serious bleeding for evev-- orders. And approximately one third of subjects (although the overall risk is low). ery 900 treated—they are also frequently patients who start taking the drugs refill And in March researchers reported in given to patients who do not need them, their prescriptions without needing to. Clinical Gastroenterology and HepatolHepatol-- despite the fact that the American Society “We know that people are put on them ogy that half the subjects taking PPIs at of Health System Pharmacists released and left on them; we know it costs somesome-- an Italian hospital, compared with only 6 guidelines in 1999 delineating who specifspecif-- thing; and we know it’s not without risk,” percent of healthy subjects not taking the ically to treat. “This spilled out into, ‘Let’s Heidelbaugh says. drugs, suffered from an infection of the do this for all or most of our hospitalized Indeed, multiple studies suggest that small intestine caused by bacteria from patients,’ ” explains Joel Heidelbaugh, an long-term use of PPIs can cause problems. the colon. The condition can trigger diardiar-- associate professor of family medicine at A 2006 study in the Journal of the AmerAmer-- rhea and impede nutrient absorption. the University of Michigan at Ann Arbor. ican Medical Association reported that Most worrisome, long-term use of PPIs He co-authored a 2006 study reporting people taking long-term, high-dose propro-- may cause the very symptoms the drugs that his university’s health system annuannu-- ton pump inhibitors are 2.65 times as are designed to treat. In a 2009 study pubpub-- ally spends about $110,000 on unnecesunneces-- likely as controls to experience hip fracfrac-- lished in Gastroenterology, researchers sary PPI prescriptions. A more recent tures, possibly because the drugs inhibit split 120 healthy patients into two groups. 2009 study published in the American calcium absorption. By increasing the pH Half received a placebo for 12 weeks, Journal of Medicine concluded that up to of the stomach, PPIs also boost the risk of while the other half received a PPI for eight 60 percent of PPI prescriptions for hospihospi-- infection: studies published in JAMA in weeks, followed by a placebo for the last talized patients are unnecessary. 2004 and 2005 reported that subjects on four weeks. At the end of the trial, 22 perper-- Bizarrely, Heidelbaugh has also found acid-suppressing drugs are nearly twice as cent of subjects who had taken the drugs that people admitted to hospitals for gasgas-- likely to develop pneumonia, and nearly reported suffering from heartburn and trointestinal symptoms are less likely to be three times as likely to acquire a potenpoten-- acid reflux, compared with only 2 percent put on PPIs than people admitted for othoth-- tially deadly infection from the bacterium of those who had never taken the drugs. er problems, such as rheumatological disdis-- Clostridium difficile, as unmedicated Howden points out that because the tritri--

Untitled-2 1 5/24/10 12:16:01 PM N E W S S C A N

al was conducted in healthy subjects, from heartburn.” And if that’s true, then $100,000 in annual drug costs after set- knowing whether PPIs would worsen no wonder PPIs are so popular, he says: ting such guidelines, and a similar move symptoms in patients with existing acid they may well be addictive. by St. Paul’s Hospital in Vancouver cut problems is impossible. But “there is no Currently no national move exists to daily medication costs nearly in half with- reason to believe that this should not be the curb PPI overuse, but “there are many ef- out worsening clinical outcomes. case,” says trial co-author Peter Bytzer, a forts, mostly specific to institutions, to professor of medicine at the University of raise awareness about this issue and to try Melinda Wenner Moyer, based in New Copenhagen in Denmark. “I would even to limit nonjudicious PPI use,” Heidel- York City, writes about health and medi- anticipate that the effects might be more baugh says. The Carolinas Medical Cen- cine. She described the heart risk from pronounced in patients who already suffer ter in Charlotte, N.C., saved about refined carbohydrates in the May issue. technologyManipulation of the Crowd New concerns about the trustworthiness of online ratings BY MICHAEL MOYER w e b s i t e s s u c h a s Amazon, TripAdvisor and Yelp have long de- judgment gap; as in modern politics, only the loudest voices at pended on customers to rate books, hotels and restaurants. The the furthest ends of the spectrum seem to get heard. philosophy behind this so-called crowdsourcing strategy holds This self-selection process manifests itself in other ways. In a that the truest and most accurate evaluations will come from ag- 2009 study of more than 20,000 items on Amazon, Vassilis Ko- gregating the opinions of a large and diverse group of people. Yet stakos, a computer scientist at the University of Madeira in Portu- a closer look reveals that the wisdom of crowds may neither be gal, found that a small percentage of users accounted for a huge wise nor necessarily made by a crowd. Its judgments are inaccu- majority of the reviews. These super-reviewers—often celebrated rate at best, fraudulent at worst. with “Top Reviewer” badges and ranked against one another to According to Eric K. Clemons, a professor of operations and encourage their participation—each contribute thousands of re- systems management at the Wharton School of the University of views, ultimately drowning out the voices of more typical users Pennsylvania, online ranking systems suffer from a number of (95 percent of Amazon reviewers have rated fewer than eight inherent biases. The first is deceptively obvious: people who rate products). “There is nothing to say that these people are good at purchases have already made the purchase. Therefore, they are what they do,” Kostakos says. “They just do a lot of it.” What ap- disposed to like the product. “I happen to love Larry Niven nov- pears to be a wise crowd is just an oligarchy of the enthusiastic. els,” Clemons says. “So whenever Larry Niven has a novel out, I The existence of super-reviewers has one unassailable advan- buy it. Other fans do, too, and so the initial reviews are very tage, though: they are rarely shills. The deliberate manipulation high—five stars.” The high ratings draw people who would nev- of review sites by people directly involved with a product—the er have considered a science-fiction novel. And if they hate it, author of the book, say—is one of the oldest and most difficult their spite could lead to an overcorrection, with a spate of one- problems for online-rating communities to solve. star ratings. Some sites attempt to remove suspect posts using automated Such negativity exposes another, filters that search for extremely posi- more pernicious bias: people tend not tive or negative language, especially ) to review things they find merely sat- when the review comes from some- computer isfactory. They evangelize what they one with a short résumé. But this ( love and trash things they hate. These lack of transparency can breed mis- feelings lead to a lot of one- and five- trust—or worse. Getty Images star reviews of the same product. Consider the case of the local- A controlled offline survey of business review site Yelp, which fil- some of these supposedly polarizing ters out suspect reviews. Its CEO products revealed that individuals’ and co-founder Jeremy Stoppelman Jeffrey; Coolidge hands)

true opinions fit a bell-shaped defends the practice by pointing to ( curve—ratings cluster around three classified advertisements placed by or four, with fewer scores of two and business owners offering payment almost no ones and fives. Self-select- for positive reviews. Yet some busi- Getty Images

ed online voting creates an artificial USER-GENERATED RATINGS are ripe for manipulation. nesses suspect more sinister forces at Johner

26 Scientific American © 2010 Scientific American July 2010 www.diako.ir Our roots in local communities go back 100 years. And throughout all those years, you’ve been able to depend on the people of CITGO to get you where you need to go. For busy families, for neighborhood businesses and organizations, CITGO ensures a reliable supply of quality fuel to help communities around the country succeed.

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work. Earlier this year a coalition of local refused to divulge how its filters operate, uated hundreds or thousands of times. business owners sued Yelp, accusing the lest unscrupulous users employ that infor- The voluminous data set is virtually ma- company of running what amounted to a mation to game the system. This lack of nipulation-proof, and the site’s passionate digital extortion racket. The lawsuit transparency has led to the perception users tend to post on all beers they try— claims that sales representatives from Yelp that the company itself might be manipu- not just ones they love or hate. would call businesses and make a simple lating the playing field. Of course, reviewing 1,000 beers is offer: advertise with us, and we’ll make The system is not beyond repair, how- easier (and cheaper) than rating the same negative reviews disappear. ever. Clemons points to RateBeer.com, number of restaurants or hotel rooms. Un- The company vigorously denies the al- which has attracted some 3,000 members til other sites amass the same amount of legations and claims that any cuts are au- who have rated at least 100 beers each; all quality data, an old truism could be con- tomated and coincidental. Still, Yelp has but the most obscure beers have been eval- sumers’ best advice: buyer beware. Patent Still Pending Green tech wilts under Patent Office scrutiny BY LARRY GREENEMEIER l a s t d e c e m b e r the U.S. Patent and Trade- But it has been difficult to define what mark Office began a pilot program to constitutes a patentable invention in this speed the emergence of green technology. area. Most of the technology being devel- The goal was to shave a year off the 40 oped to improve (or at least not harm) the months it typically took to evaluate a pat- environment is little more than an incre- ent application. Yet the agency has ap- mental change in devices already in use, proved only about one third of the requests says Eric P. Raciti, a partner at the Cam- it has received, disappointing inventors and bridge, Mass., law firm of Finnegan, Hen- even the Patent Office itself. The program’s derson, Farabow, Garrett & Dunner. acceptance rate is “less than I would have Whereas anything that creates energy and expected,” says Robert L. Stoll, the agen- reduces reliance on fossil fuels could be cy’s commissioner for patents. considered green, the actual technology As of early May, only 335 of the 943 that does the job often draws on an inter- flower power UNPLUGGED? A fast-track applications filed under the agency’s Green disciplinary set of components from other patent-approval system to encourage green Technology pilot program had qualified areas, explains Raciti, who worked for technology is lagging, suggesting that its to jump to the front of the patent exami- five years as anUSPTO patent examiner. green-tech definitions may need rethinking. nation line. Applicants have been “aggres- The program to fast-track green pat- sive” in their hopes of taking advantage of ents “won’t have a big impact” on the de- that we’re fast-tracked means that some- the fast-track program without necessar- velopment of green technology, because so thing is interesting here,” says Tim Keat- ily meeting the program’s requirements, many of these technologies have already ing, vice president of marketing and field Stoll explains. been patented, agrees Mark Bünger, a re- operations at Skyline Solar, a maker of In defining the requirements in the De- search director at Lux Research, a New high-gain solar arrays in Mountain View, cember 8, 2009, Federal Register, the York–based technology consulting firm. Calif. “That certainly makes investors USPTO stated that it is looking for inven- “I wouldn’t oversell the importance of the more comfortable, which means you get tions that fit into a number of broad buck- green patent fast track,” he states. The your money for a cheaper price and you ets—addressing environmental quality, technologies that companies are trying to spend less of your time raising that energy conservation, development of re- patent as green are typically only a small money.” newable energy, and greenhouse gas emis- part of a larger process or project that may Whether the fast-track program con- sions reduction. It also listed 79 very spe- cut fossil-fuel consumption or otherwise tinues beyond its yearlong pilot phase will cific classifications. Stoll acknowledges, help the environment, Bünger says, adding depend on several measures, Stoll says. however, that if the office is approving that “there will never be something like a They include how enthusiastic inventors only one third of applications, “maybe we killer app in clean technology” that stands are about using that program (the number

need to eliminate the class and subclass completely on its own. of applications), how often inventors file g es designations to open up the definition for Not all have given up hope, especially legitimate green-tech applications, and

green tech.” start-up companies. “The ability to say the public’s perception of the program. ImaGetty

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Terminate the Terminators Robots are now a fact of war, but the prospect of androids that can hunt and kill on their own should give us all pause by the editors

When U.S. forces invaded Iraq in 2003, they fought a traditional war of main a legal combatant—in other words, a legitimate enemy tar- human on human. Since then, robots have joined the fight. Both get—on the trip after work to Walmart or to a daughter’s soccer there and in Afghanistan, thousands of “unmanned” systems match? Would an increasingly sketchy line between warrior and dismantle roadside IEDs, take that first peek around the corner civilian invite attacks on U.S. soil against homes and schools? at a sniper’s lair and launch missiles at Taliban hideouts. Robots Remote-controlled robots are here to stay, and rules can be are pouring onto battlefields as if a new species of mechanotronic worked out to regulate their use. But the more serious threat alien had just landed on our planet. comes from semiautonomous machines over which humans re- It is not the first time that the technology of warfare has ad- tain nothing more than last-ditch veto power. These systems are vanced more rapidly than the body of international law that seeks only a software upgrade away from fully self-sufficient operation. to restrain its use. During World War I, cannons shot chemical The prospect of androids that hunt down and kill on their own weapons at and airplanes dropped bombs on unsuspecting cities. accord (shades of Terminator) should give us all pause. An auto- Only later did nations reach a verdict on whether it was accept- matic pilot that makes its own calls about whom to shoot violates able to target a munitions factory next to a primary school. the “human” part of international Something similar is happening today with potentially humanitarian law, the one that even more profound and disturbing conse- recognizes that some weapons quences. As Brookings Institution analyst are so abhorrent that they just P. W. Singer describes in “War of the Ma- should be eliminated. chines,” starting on page 56, the rise of ro- Some might call a ban on au- bots leads to the frightening prospect of tonomous robots naive or com- making obsolete the rule book by which na- plain that it would tie the hands tions go to war. Armed conflict be- of soldiers faced with irregular tween nation states is brutal, but at warfare. But although robots have least it proceeds according to a set of clear tactical advantages, they rules grounded both in international carry a heavy strategic price. law and in the demands of military The laws of war are an act not discipline. It is not true that anything of charity but of self-interest; the goes in the heat of battle. “Such rules U.S. would be weakened, not strengthened, if chemical and bio- are certainly not always followed, but their very existence logical weapons were widespread, and the same is true of robots. is what separates killing in war from murder and what distin- They are a cheap way to offset conventional military strength, and guishes soldiers from criminals,” writes Singer in Wired for War, other nations and groups such as Hezbollah in Lebanon are al- his recent popular book on the military robotic revolution. ready deploying them. The U.S. may not always be the leader in Those rules are stretched to their breaking point when robots this technology and would be well advised to negotiate restric- go to war. The legal and ethical questions abound. Who is actions on their use from a position of strength. We can never put countable when a Predator’s missile hits the wrong target? Mis- the genie back into the bottle, but putting a hold on further devel- siles from errant drones have already killed as many as 1,000 ci- opment of this technology could limit the damage. vilians in Iraq, Afghanistan and Pakistan. Does responsibility The organization best placed to work toward a ban is the reside with a field commander in the Middle East where spotters International Committee of the Red Cross, the guardian of the identified the “target of interest”? Or should blame be appor- Geneva Conventions. A good starting point would be to convene tioned to the “remote pilot” stationed at a military base near Las a summit to consider armed, autonomous robots in the same Vegas who launched the strike from 7,000 miles away? And what framework as chemical and biological agents. The scientific com- about a software engineer who might have committed a program- munity at large should get involved with this issue much as the ming error that caused a misfire? Pugwash movement has worked toward nuclear arms control. Considering rules of engagement for war-at-a-distance raises Now is the time to take steps to ensure that a war of the machines

a surreal set of questions. Does the remote operator in Nevada re- remains nothing more than a science-fiction nightmare. ■ collins Matt

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Note: GovMint.com. is a private distributor of worldwide government coin issues and is not affiliated with the ® United States government. Prices and availability subject to change without notice. ©GovMint.com, 2010 www.diako.ir 32 blunts the short-term stimulus effects of the deficits. Households Households deficits. the of effects stimulus short-term the blunts at least increases tax and cuts spending require eventually will the economy. awareness that Furthermore, today’s budget deficits the costs of the servicing extra debt remain and will distort will deficitis then cuts andreduced through increases, spending tax 2011, from around 37 percent to 70 percent. Even if the budget and 2007 between ble dou roughly will GDP to debt U.S. of ratio of national income. The rise sharply as a percent that the public debt will mean today deficits Large wise. be not might borrowing large-scale spending, bank inflation. will stoke deficits central offuture financing that but bankruptcy not is case that in fear where the course, Of them. provides Reserve Federal gov U.S. the currency: euros, the of as long as out of dollars out run really cannot national run ernment can own its in government Greek the borrows as U.S. the Greece, the U.K. including countries, for other European various to same do the 2010in early threatened and by Greece nancing fi new on door the slammed markets bond the Consequently, future. the in lowerspending and taxes higher of combination some through debts those service to ability governments’ to ly will markets most recently Potential Greece. investors looked ahead skeptical financial the that presumes thebuy readily stimulus. bonds to government thinking finance Keynesian sary. neces considered was cuts tax by spending private stimulating offsetting the decline through higher government spending or by was falling, spending consumer column). Because 2009 March in keeping with Keynesian ideas (which I cautioned about in my adopted fiscal stimulus imbalances. packages of peacetime spending increases and tax unprecedented cuts these with dealing for SACHS D. JEFFREY BY Sus Nations need to curb their public debt to avoid stifling future growth future stifling avoid to debt public their curb to need Nations Get Get Serious about Budget Deficits Yet even if the markets agree to finance deficit deficit finance to agree markets the if Yeteven Unlike touched. similarly been not has U.S. the far So countries, European smaller many for overoptimistic proved It In the wake of the financial panicin late 2008, mosteconomies

SCIENTIFIC AMERICAN tainable tainable development and the financial markets that they have a plan plan havea they that markets financial the and publics their show must governments their and 10around or ofincome larger, percent national deficits budget have Europe countries and Several nances. U.S. the in crisis debate the over public fi sharpening quickly is economic continuing The - www.diako.ir

get, get, which now stands at around 5 percent of GDP and finances cuts in the budget for simple waste. removing are anathema, but contrary to common belief, there are few easy deep political division over the role of government. Tax increases mayany in dampen boost spending. deficits private investment by budget caused rates interest higher And rising. are taxes ture fu that grounds on the cuts tax any spend may savethan rather Jeffrey D. Sachs is director of the Earth Institute at Columbia Columbia at Institute Earth the University of (www.earth.columbia.edu). director is Sachs D. Jeffrey perhaps 1 ofpercent or budget total even spending less. which do earmarks, disparaged distort the budget, only constitute rather than underfunded laden chronically with waste. The much more and development global education, higher structure, Med Medicare, discretionary civilian spending Security, Social on food is stamps and other mandated programs. Many categories of which of bulk the ing, exists. outlays military of reduction sharp a on consensus overpriced service contracts and weapons systems. Yet no publicand bases, military overseas of hundreds wars, expensive two The biggest waste, I would suggest, lies in the Pentagon bud Pentagon the in lies I would suggest, waste, biggest The America’s budget deficit challenge is worsened bythe country’s Still less will there be an agreement on cutting civilian spend civilian on cutting be an agreement there will less Still The wealthiest 1 The wealthiest percent of households U.S. now take home double their roughly 10 percent share around 1980. The rich than more income, household all of percent 20 than more We ofneed to atlookthe superrich. taxation again higher est 0.01 percent of households brings home around 5 home around per of0.01 est brings percent households www.Scientific at is available of essay this version An extended cent of total household income. household total of cent ed tax cuts during the past 30 years. Their increased ed the past cuts increased tax during 30 Their years. tax contribution will not will the tax contribution to be balance sufficient books. We will also need to look at higher gasoline gasoline to at look higher need also We will books. taxes, carbon-emissions levies and perhaps even a even perhaps and levies carbon-emissions taxes, The superrich households have also enjoyed repeat enjoyed also have households superrich The A merican.com/jul2010 — sustainable energy, sustainable R&D, infra national value-added value-added national es back in order. order. in back es get our public financ right place to begin to the are households tax. Yet the superrich July 2010 i — caid, caid, are are

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52646_sciamer2.indd 1 5/11/10 2:44 PM Skeptic

When Scientists Sin Fraud, deception and lies in research reveal how science is (mostly) self-correcting By Michael Shermer

In his 1974 commencement speech at the California work properly; and 3. Were working in a field where individual Institute of Technology, Nobel laureate physicist experiments are not expected to be precisely reproducible.” Richard P. Feynman articulated the foundation To detect fraud, we must first define it, and Goodstein does: of scientific integrity: “The first principle is that “Research misconduct is defined as fabrication, falsification, or you must not fool yourself—and you are the easi- plagiarism in proposing, performing, or reviewing research, or est person to fool.... After you’ve not fooled in reporting research results.” Next there must “be significant yourself, it’s easy not to fool other scientists. You just have to be departure from accepted practices of the scientific community.” honest in a conventional way after that.” Then, the misconduct must be “committed intentionally, or Unfortunately, says Feynman’s Caltech colleague David knowingly, or in reckless disregard of accepted practices,” and Goodstein in his new book On Fact and Fraud: Cautionary finally, as in any court of law, the fraud charge must be proved Tales from the Front Lines of Science (Princeton University by a preponderance of evidence. Press, 2010), some scientists do try to fool their colleagues, and Clear-cut cases of fraud include the twin studies of British psy- believing that everyone is conventionally honest may make a per- chologist Cyril L. Burt (who faked so many twins that he had to son more likely to be duped by deliberate fraud. Nature may be fabricate additional twin researchers), the Sloan-Kettering Insti- subtle, but she does not intentionally lie. People do. Why some tute cancer researcher William Summerlin’s experiments on in- scientists lie is what Goodstein wants to understand. He begins ducing healthy black skin grafts on white mice (which he was by debunking myths about science such as: “A scientist should caught enhancing with a black felt-tipped pen), physicist Victor never be motivated to do science for personal gain, advancement Ninov’s alleged discovery of element 118 or other rewards.” “Scientists should always be objective and im- (predicted by others so he faked data for partial when gathering data.” “Scientists must never believe dog- its existence), and of course the famous matically in an idea or use rhetorical exaggeration in promot- Piltdown Man hoax (which turned out ing it.” “Scientists should never permit their to be the jaw of an orangutan dyed to judgments to be affected by authority.” These look old). Other cases are not so clear. and many other maxims just do not reflect Martin Fleischmann and Stanley Pons’s how science works in practice. “discovery” of cold fusion, Goodstein Knowing that scientists are highly concludes, was most likely a case of scientists motivated by status and rewards, that who “convince themselves that they are in the posses- they are no more objective than pro- sion of knowledge that does not in fact exist.” This self- fessionals in other fields, that deception is distinctly different from deliberate deception. they can dogmatically defend an So some scientists sin, it’s true. Given the fiercely com- idea no less vehemently than petitive nature of research funding and the hardscrabble ideologues and that they can intensity of scientific status seeking, it is fall sway to the pull of author- surprising that fraud isn’t more rampant. ity allows us to understand that, in Goodstein’s assessment, “in- The reason that it is so rare (compared with, say, corruption in jecting falsehoods into the body of science is rarely, if ever, the politics) is that science is designed to detect deception (of one’s purpose of those who perpetrate fraud. They almost always be- self and others) through colleague collaboration, graduate stu- lieve that they are injecting a truth into the scientific record.” dent mentoring, peer review, experimental corroboration and re- Goodstein should know because his job as the vice provost of sults replication. The general environment of openness and hon- Caltech was to investigate allegations of scientific misconduct. esty, though mythic in its idealized form, nonetheless exists and From his investigations Goodstein found three risk factors pres- in the long run weeds out the cheats and exposes frauds and ent in nearly all cases of scientific fraud. The perpetrators, he hoaxes, as history has demonstrated. ■ h by brad swonetz; illustration by matt collins writes, “1. Were under career pressure; 2. Knew, or thought they p knew, what the answer to the problem they were considering Michael Shermer is publisher of Skeptic magazine

would turn out to be if they went to all the trouble of doing the (www.skeptic.com) and author of The Mind of the Market. Photogra

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No Country Is an Island Whether volcanic or nuclear, disasters anywhere in our interconnected world affect us all By LaWrence m. Krauss

This spring I was stranded in Europe for a week, a a remote part of the world where natural disasters might be more minor victim of Mother Nature, as most airports easily and habitually ignored. on the continent were closed after the eruption of The studies conclude that a regional nuclear conflict between the Eyjafjallajökull volcano in Iceland. This re- India and Pakistan that detonated merely 100 Hiroshima-size mote natural event did not result in a huge human weapons (which are far smaller than many of those in current death toll but still caused hundreds of millions of nuclear arsenals) not only could produce as many fatalities as dollars of lost revenue for almost all the world’s major airlines. World War II but also would drastically disrupt the planet’s cli- More important, it disrupted millions of people’s lives. mate for at least a decade. Up to five million tons of smoke would Such is the nature of our modern interconnected society, rise above cloud level and within days form a global stratospher- where a catastrophe in one corner of the world can nonetheless ic smoke layer, which would for years block 7 to 10 percent of affect almost immediately the livelihood and well-being of peo- sunlight reaching the earth. Average surface temperatures could ple around the globe. drop lower than they have at any time in the past millennium, The Icelandic eruption took on additional significance, follow- significantly shortening growing seasons and reducing the aver- ing as it did the Nuclear Security Summit that President Barack age global precipitation. Obama convened in Washington, D.C., to help be- To grasp the true magnitude of the human ca- gin to secure nuclear materials and to work toward tastrophe from such a use of nuclear weapons, combating global nuclear proliferation. For 40 it is perhaps easiest to return to the situation years the world was focused on the possibil- in Europe after the Eyjafjallajökull eruption. ity of mutually assured destruction and Estimates I have gleaned from various sourc- global annihilation, with literally thou- es suggest that the volcano spewed per- sands of nuclear weapons on hair- haps a million tons of particulate mat- trigger alert, ready to be launched on ter into the atmosphere, only slightly the mere warning of an attack. smaller in magnitude than the amount But the dangers facing the mod- predicted to result from a limited nu- ern world are far more complex. The clear weapons exchange. But the par- president has emphasized the devastat- ticles of soot from the intense fires ig- ing global economic and social impact nited by nuclear explosions are much that the explosion of even a single nu- smaller and therefore rise higher into the clear weapon in a major metropolis atmosphere. They also reflect more light than would have, beyond of course the tragic the larger silicon particles emitted by volcanoes. loss of human life. Moreover, as more countries The net result is that this soot would remain in in regions with rising geopolitical tensions seek to the atmosphere far longer and have a much greater cli- possess nuclear weapons, the likelihood of both nu- mate-changing effect, affecting agriculture worldwide. clear terrorism and regional nuclear conflicts only A small volcano in Iceland that was able to paralyze continues to increase. commerce and travel for hundreds of millions of people As the event in Iceland makes abundantly clear, “re- around the world sends a chilling message: even a limited and gional” is an illusion in the modern world. A recent set of remote use of nuclear weapons anywhere will be devastating scientific studies by Alan Robock of Rutgers University, on a global scale. Airline cancellations would be the least of Owen B. Toon of the University of Colorado at Boulder and our worries. ■ oswell; illustration by matt collins their colleagues—reported on in journals ranging from Sci- ence to Scientific American(see the January 2010 issue) — Lawrence M. Krauss, a theoretical physicist and science h by john B demonstrates a more pernicious impact from even commentator, is Foundation Professor and director p a limited nuclear exchange in what, for of the Origins Initiative at Arizona State Uni-

North Americans, would seem to be versity (www.krauss.faculty.asu.edu). Photogra

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Is the Universe Leaking Energy? Total energy must be conserved. Every student of physics learns this fundamental law. The trouble is, it does not apply to the universe as a whole By Tamara M. Davis

n e r g y c a n n e i t h e r b e c r e a t e d form of light, and one of light’s key features is nor destroyed. This principle, called that it gets redshifted —its electromagnetic waves Key Concepts conservation of energy, is one of get stretched—as it travels from distant galax- ■ ■ As the universe expands and our most cherished laws of physics. ies through our ever expanding universe, in ac- distant galaxies recede from us, It governs every part of our lives: cordance with Albert Einstein’s general theory their light gets redshifted, thus the heat it takes to warm up a cup of relativity. But the longer the wavelength, the becoming less energetic. of coffee; the chemical reactions that lower the energy. Thus, inquisitive minds ask: produce oxygen in the leaves of trees; the orbit When light is redshifted by the expansion of the ■ ■ This seeming violation of the principle of conservation of Eof Earth around the sun; the food we need to universe, where does its energy go? Is it lost, in energy is actually not in keep our hearts beating. We cannot live without violation of the conservation principle? contradiction with accepted eating, cars do not run without fuel, and perpet- Modern physics has shown that when we physical laws. ual-motion machines are just a mirage. So when move far from the comfort of our everyday lives an experiment seems to violate the law of ener- to explore the extremes of time and space, many ■ ■ According to the author, the proper interpretation shows gy conservation, we are rightfully suspicious. of our basic assumptions start to crumble. We that the energy of individual What happens when our observations seem to know from Einstein that simultaneity is an illu- photons is conserved. And contradict one of science’s most deeply held no- sion that changes based on the observer’s per- phenomena taking place tions: that energy is always conserved? spective and that notions of distance and dura- inside the galaxy generally Skip for a moment outside our Earthly sphere tion are also relative. We now also suspect that conserve energy. and consider the wider universe. Almost all of the apparent continuity of time and space may —The Editors mark hooper mark our information about outer space comes in the be as illusory as the deceptively smooth appear-

www.ScientificAmerican.com SCIENTIFIC AMERICAN 39 www.diako.ir© 2010 Scientific American [ the problem, part 1 ] Why Energy Seems To Disappear Those who argue that the universe is losing energy base their conclusion in part on the redshift of light. The universe appears to be expanding, as if space itself were getting stretched out. In consequence, the electromagnetic waves that compose light get stretched as well, shifting, in the case of visible light, toward the red part of the spectrum (below). Photons of longer wavelength have lower energy, so logic dictates that each photon must become less energetic as it travels toward us. But does the universe as a whole lose energy? The total energy of the photons in the universe cannot be calculated, but one can in principle calculate the energy contained within an imaginary membrane that expands in concert with Photons the universe (at right, the region inside a membrane is repre- sented as two-dimensional). Photons can enter or exit through the membrane, but the uniform density of space tells us that the number of photons in the enclosed region will roughly stay constant. Because each photon in the region becomes less energetic as space Expanded expands, this calculation suggests that the total amount of photon membrane energy in the region and, by implication, in the rest of the universe must be going down.

Electromagnetic waves get longer . . .

Time

Initial membrane enclosing region of space nergy declines nergy Space stretches Space E

. . . yet the NUMBER OF PHOTONS stays the same; energy appears to be lost

ance of matter. What is there in physics that we becomes a subtle concept indeed, and that is can rely on? Which of our deeply held principles where things start to get interesting. is pulling the wool over our mind’s eye and blind- ing us to the deeper truths? We physicists spend Symmetry and Conservation our days challenging what is known and striving n o t o n l y h a s conservation of energy been to discover where our knowledge is inadequate empirically validated many times over, but sci- or just plain wrong. And history is littered with entists also have good theoretical reasons to the debris of discarded misconceptions. Is conser- believe it. Our confidence comes from German vation of energy one of those misguided ideas? mathematician Emmy Noether, who put conser- It is not. On the scale of individual photons, vation of energy on a secure footing nearly 100 energy is always conserved, even as light gets red- years ago, when she discovered that all conser- shifted. Likewise, for phenomena that take place vation laws are based on symmetries of nature. within our galaxy, violations are virtually impos- Usually you think of symmetry as something sible and our cherished law remains on a sound you see in a mirror, a reflection of some kind or

foundation. But on a cosmological scale, energy a rotation perhaps. An equilateral triangle is design moonrunner

40 Scientific American July 2010 www.diako.ir© 2010 Scientific American symmetric because you can flip it sideways or light we are seeing has been traveling for bil- rotate it one third of the way around, and you lions of years, and in all that time, the first thing The metaphor end up with exactly the same shape. A square it has hit is the mirror of our telescope. The wave- of the universe also has symmetry, but you need rotate it only lengths of that light are our key to assessing one fourth of the way around to find an identi- conservation. as an expanding cal configuration. The most symmetric of the In the 1920s Edwin Hubble discovered that two-dimensional objects is the circle, because the light of most galaxies is redshifted: he found rubber balloon you can rotate it any amount and reflect it over that the wavelengths of photons that were should be taken any axis through its center, and it remains ex- emitted or absorbed by atoms (such as by hy actly the same—it displays what is called con- drogen) in all but the nearest galaxies to us with a grain tinuous symmetry. appear, when they reach us, to be stretched rel Physical laws, too, can be symmetric. The ative to the wavelengths emitted by the same of salt. passage of time does not change the laws of na- atoms at home —stretching roughly in proportion ture; if you repeat an experiment many times— with the galaxies’ distance. In fact, ever since the for example, making billiard balls collide at a discovery of this phenomenon, whenever astron given angle—the result is always the same. This omers cannot measure a galaxy’s distance more quality is known as time symmetry. The laws of directly they instead give an estimate using its nature do not change depending on where you redshift as a proxy. are—so we have spatial symmetry. Nor do the Redshifts (and blueshifts) also happen all the laws of nature change depending on the direc- time here on Earth. ��Imagine driving past a po- tion in which you look (rotational symmetry). lice radar. As your car approached, the electro- Sure, the scenery may change depending on magnetic waves from the radar would look where you are standing, when you are standing slightly shrunk to you—if you could see them— there and the direction you are looking, but the when they reached you. But after you passed, fundamental underlying laws of physics that the waves would look a bit stretched. This is the dictate how that scenery behaves are indepen- Doppler effect: it is the electromagnetic equiva- dent of your location, orientation and time. lent of the familiar change in acoustical pitch When a law remains unchanged regardless of you would hear in a siren as it passes by. (The the situation, it, like the circle, is said to be con- police officer can tell if you are speeding by tinuously symmetric. measuring a Doppler shift in the reflection of What Noether discovered is that whenever the radar.) Although in this case the waves are nature displays a continuous symmetry, a conser- not in the visible spectrum, physicists still call vation law comes along for the ride, and vice ver- the stretching and shrinking of the waves red- sa. In particular, spatial symmetry dictates that shift and blueshift, respectively. momentum is conserved; rotational symmetry Cosmological redshifts, however, are general ensures angular momentum is conserved; and ly considered to be different from the Doppler time symmetry means that energy is conserved. effect. Doppler shifts are caused by relative So, saying that energy is conserved is as sol- motion. In that case, the photons are not losing id as saying that the laws of physics are the or gaining energy; they just look different to you same now as they were in the past and will be than they do to the emitter. In contrast, most in the future. On the other hand, were time general relativity or cosmology textbooks say symmetry to break down, conservation of en- cosmological redshifts happen because as light ergy would fail. As we will see, this is where en- travels, the very space it travels in gets stretched ergy conservation may start to get in trouble in like the surface of an inflating rubber balloon. Einstein’s universe. In fact, cosmological redshifts can happen even when there seems to be no relative motion at Go with the Flow all, as the following thought experiment shows. t h e r e is n o b e t t e r w a y to test whether the Imagine a galaxy far, far away but connected to present matches the past, and thus to see if ener- ours by a long tether. Relative to us, the galaxy is gy is conserved in the universe, than to watch not moving, even as other galaxies in its vicinity the past in full live action through an astrono- recede from us. Yet standard calculations show mer’s telescope. Our telescopes are now so pow- that the light reaching us from the tethered erful that we are able to see back to when the galaxy will still be redshifted (though not quite first galaxies were forming and beyond to the as strongly as the light from the galaxies in its piping-hot afterglow of the big bang itself. The vicinity, which have not been pulled out of the www.ScientificAmerican.com SCIENTIFIC AMERICAN 41 www.diako.ir© 2010 Scientific American [ The problem, part 2 ] A matter of changing geometry Conservation laws are intimately tied to symmetries of nature. In particular, energy is conserved when the laws of nature have “time symmetry.” Time symmetry is said to occur if any experiment gives the same results regardless of when it is performed. But if experiments can give different results at different times, energy may not be conserved. An example is playing a bank shot on a pool table that has a changing geometry. At cosmological scales, our universe has a changing geometry, which once again implies that energy may not be conserved.

CURVED POOL TABLE EVOLVING GEOMETRY To play on a table that has curved, or “non-Euclidean,” geometry, you have If the pool table has a geometry that changes in time, however, the shots that to adjust your shots to the geometry. Still, if the geometry is fixed, the same worked in the past may not work again—therefore, time symmetry is broken. exact shot will work again in the future. Because of this time symmetry, in Something similar can happen in the universe, because according to general a universe with fixed geometry energy would be conserved. relativity the motion of matter and energy changes the geometry of space. Under these conditions, energy need not be conserved.

Later shot

First shot

flow of the expansion). This redshift is usually culiar velocity is small compared with their re- attributed to the stretching of the space through cession. At the largest scales, the distribution of [ The Author ] which light travels. galaxies is uniform, so local effects are negligible and galaxies are essentially comoving. They can Peculiar Physics be regarded as the dots on the balloon, that is, as so p h o t o n s t r a v e l i n g in an expanding uni- flag posts of the expanding fabric of space. verse appear to lose energy. What about matter? A comoving frame of reference such as that Does it lose energy, too? When we describe the defined by galaxies is very handy: for example, motion of matter in the universe, we distinguish it gives a universal convention for time, so that between two different types. An object can just everyone in every comoving galaxy would agree

be receding with the general flow of the universe’s on how long ago the big bang happened. ) Tamara M. Davis earned a Ph.D. at the expansion, just like dots painted on our balloon If an intergalactic traveler drifts for billions Davis University of New South Wales in 2004 and is a research fellow at the University would recede from one another as the balloon of light-years, he or she will pass many of these of Queensland in Brisbane, Australia, and inflates. In cosmology, such an object is called flag-post galaxies. But because the universe is ndrei Linde ( A an associate professor at the University comoving. But an object can also have its own expanding, the flag posts are moving away from f of Copenhagen. She works with large motion on top of the motion caused by the expan- one another, and our traveler appears to be go- astrophysical data sets to discover what sion. This second type is called peculiar motion, ing slower and slower relative to each subse- cosmology can teach us about funda- ); Courtesy o mental physics—for example, about the and it takes place when something is dragged out quent galaxy he or she passes. So the traveler ap- nature of dark energy and dark matter. of the smooth flow of the expansion by local pears to slow down. She has won the Astronomical Society of effects, such as the gravitational pull of a nearby Thus, much as light loses energy by increas- illustration Australia’s early career researcher award galaxy or the thrust of a rocket. ing in wavelength, matter loses energy by slow- and the L’Oréal-UNESCO Women in Galaxies themselves always have at least a bit ing down. At first sight those behaviors appear Science Award for Australia. Davis has also played on Australia’s and on Den- of peculiar motion, but for distant galaxies— to be very different. But, interestingly, quantum

mark’s national ultimate Frisbee teams. which recede faster than near ones do—the pe- mechanics unifies the two. In the quantum- ( design moonrunner

42 Scientific American July 2010 www.diako.ir© 2010 Scientific American mechanical view of matter, particles that have A first problem they would face is that the uni- mass also have wavelike properties. French phys- verse may be infinitely large and contain an infi- icist Louis de Broglie found that the larger the nite amount of matter and energy. Thus, the ac- momentum of a particle, the smaller its wave- countants would need to take a shortcut. They length and the greater its energy—and he won would draw an imaginary membrane around a the Nobel Prize in 1929 for his discovery. region of the universe and add up the energy in- Particles of matter can have high momentum side [see box on page 40]. They then would let the by having high mass or high velocity, or both. membrane expand as the universe does, so that That feature explains, for example, why a base- comoving galaxies stay inside the membrane. ball does not appear to wiggle about in wavelike Light and matter can pass in and out of the mem- motions after it leaves the pitcher’s glove. Base- brane, but because the universe is homogeneous, balls are enormously massive in quantum terms, the same amount leaves as enters, so the amount and at the typical speed of a major-league fast- inside the membrane stays roughly constant. Our ball pitch (about 145 kilometers an hour) a base- accountants know that the whole universe can be ball has a wavelength of 10 -34 meter—not some- constructed from a series of such volumes. If the thing a batter will have to worry about. On the energy in the universe is to be conserved as a other hand, an electron traveling at the same whole, therefore, it is enough to show that the en- speed has a wavelength of 18 microns: still ergy in any one of those volumes is conserved. small, but 29 orders of magnitude larger than a The calculation is easy to do for matter that baseball’s, and very noticeable when it comes to is at rest—just chilling out and going with the the behavior of electrons. flow of the expansion. Its only energy in this When you calculate how much relative veloc- case comes from its mass, and because no mat- ity massive particles lose as they pass by their re- ter leaves or enters the membrane, we know the ceding neighbors, you find that the de Broglie mass is conserved. But things are a bit more wavelength of the particles increases by exactly complicated for light, as we have seen, and for the same proportion as a photon’s wavelength matter that has peculiar velocity. Although the More Cosmic does. Thus, light and matter seem to behave in ex- number of photons or of matter particles within Puzzles actly the same way when it comes to energy loss the membrane does not change, over time pho- Is space within our galaxy in the expanding universe, and in both cases it ton energy is lowered, as is the kinetic energy of expanding? looks as if energy conservation is being violated. the peculiarly moving matter. Therefore, the to- No. Cosmic-scale expansion does not In the case of matter, the paradox is explained by tal energy in the membrane goes down. affect the dynamics inside a galaxy. the fact that we are measuring velocity in differ- The situation would be even more compli- Once local gravitational effects cause a galaxy to form, the expansion has — ent frames of reference that is, relative to the re- cated if the accountants were to count dark en- no power to pull the galaxy apart. ceding galaxies. As we will see, something simi- ergy, which is what is causing the universe’s ex- lar happens with photons. pansion to accelerate. The nature and proper- Do photons from distant galaxies get ties of dark energy are still a complete mystery, redshifted because the universe’s Creative Accounting but it appears that dark energy does not dilute density has been decreasing? After all, photons get redshifted when they w e r e cosmological accountants to verify as the universe expands. Thus, as the volume in climb up a gravitational gradient. that the universe is losing energy, they might our membrane increases, the amount of energy True, but at any given time, the attempt to tally up all the energy in the universe, in that volume increases as well, with the addi- universe was uniform, so the density rather than focusing on one object at a time. tional energy seemingly coming out of nowhere! of matter was the same behind They might first add up all the energy contained One might think that the increase in dark ener- a photon as it was in front of it. Thus, photons had no gravitational simply in the mass of the matter in the universe gy could balance out the losses in all other forms gradient to climb out of. (mass m and energy E are equivalent following of energy, but that is not the case. Even if we Einstein’s E = mc 2, where c represents the speed take dark energy into account, the total energy Is entropy compatible with of light). Then they would add in the kinetic within the membrane is not conserved. time symmetry? energy related to the matter’s peculiar motion. How do our accountants reconcile these Yes. In complex interactions of particles, such as the breaking of an To that sum, they would have to add the energy changing energies with Noether’s theorem? In egg, we can tell which way a movie of light as well and then get to the complex job fact, they would soon realize that there is no of the process is being played—the of counting the energy in all the gravitational reason why Noether’s theorem should apply to direction in which entropy increases, fields around planets, stars and galaxies, plus our changing universe. According to general which is the direction of increasing the energy contained in chemical bonds and in relativity, matter and energy curve space, and disorder. Nevertheless, any single one of the interactions between the nuclei of atoms. (Sound and heat are just the as matter and energy move (or spread out in an particles could happen forward or motion of particles, so they have already been expanding space) the shape of space changes backward, as far as the laws of accounted for.) accordingly. In everyday life, these effects are physics are concerned.

www.ScientificAmerican.com SCIENTIFIC AMERICAN 43 © 2010 Scientific American www.diako.ir© 2010 Scientific American www.diako.ir www.diako.ir [ a solution ] How photon energy is conserved after all The redshift we see in distant galaxies is usually attributed to the stretching by but that also affects the wavelengths of photons—for example, those of space, but it can also be interpreted as an effect of the receding motion of from the car’s emergency lights (below). In the case of the police car, energy the galaxies with respect to the observer. It is therefore similar to the familiar is conserved; similarly, calculating galaxy redshift as a Doppler shift (oppo- Doppler effect, which one can hear in the siren of a police car that is passing site page) shows that photons from a distant galaxy also do not lose energy.

Blueshifted light Redshifted light

Car’s relative velocity (in space) Observer

ORDINARY DOPPLER SHIFT Doppler shifts arise from relative motion. The lights flashing from the top stronger the effect will be. But the occurrence of the Doppler shift does not of a police cruiser appear redshifted or blueshifted—though imperceptibly mean that photons change color (nor that they lose energy) along the way; to human eyes—depending on whether the car is moving away from you they just have different colors as seen from an observer’s point of view or toward you. The larger the car’s velocity relative to an observer, the than they have from the car’s own point of view.

essentially too small to detect, but at cosmic spective does not pertain to any observer in the scales they can be relevant. universe. In particular, they do not take into This malleability of space implies that the be- account the energy of comoving galaxies’ mo havior of the universe is not time-symmetric. tion with respect to one another, so to them, the The easiest way to visualize this fact is to go galaxies appear to have no kinetic energy. An back to the example of the billiard balls. If we other issue is the gravitational energy associated watched several movies of a particular shot be- with the galaxies’ mutual attraction. A well- ing played on a pool table of changing geome- known problem with general relativity is that in try—for example, one that starts flat and warps the theory one cannot always unambiguously with time—each movie would look different define gravitational energy in a way that applies from the others; you could tell when and in what to the universe as a whole. order each movie was taken. Time symmetry Thus, the total energy of the universe is nei- would be broken [see box on page 42]. ther conserved nor lost—it is just undefinable. We have come to the limit of our cherished On the other hand, if we abandon the godlike conservation principles: when time and space point of view and instead focus on one particle themselves are mutable, time symmetry is lost, at a time, we can find what many cosmologists and conservation of energy need no longer hold. believe is a more natural way of thinking of the journey of a photon from a distant galaxy. In Cosmic Semantics this interpretation, the photon does not lose en- e v e n if c u rvat u r e does not change, however, ergy after all. The point is that our metaphor of trying to tally up the energy of the universe is a the expanding rubber balloon, though useful to

futile exercise: our accountants’ godlike per- visualize the expansion, should be taken with a design moonrunner

Observer’s velocity in spacetime

Space in the present

Photon’s trajectory in spacetime

Galaxy’s velocity in spacetime

Space at the time of photon emission

Galaxy REDSHIFT as a Doppler shift A galaxy’s redshift is identical to the Doppler shift an observer would see emitted the photon (purple arrow) with the velocity of the observer at the when watching a police car recede at the same relative velocity as the time when the photon was received (green arrow) and then—using the galaxy—as long as “relative velocity” is interpreted in the appropriate appropriate math derived from general relativity—calculate the relative way. First, one must trace the trajectories of the galaxy and of the observer velocity. The Doppler shift calculated from this relative velocity coincides not in space but in spacetime. (In the schematic view here, space is an with the galaxy’s redshift, suggesting that the galaxy’s redshift can be evolving two-dimensional surface; spacetime trajectories cut through it.) interpreted as the result of relative motion, rather than of the expansion Second, one must compare the velocity of the galaxy at the time when it of space. Therefore, no energy is lost.

grain of salt: empty space does not have a physi- So we can think of the light as making many cal reality. As galaxies recede from one another, tiny little Doppler shifts along its trajectory. we are free to consider this relative motion as And just as in the case of the police car—where “expansion of space” or as “movement through it would not even occur to us to think that pho- space”; the difference is mostly semantics. tons are gaining or losing energy—here, too, the Cosmological redshift is usually described as relative motion of the emitter and observer a consequence of the expansion of space. But in means that they see photons from different per- Einstein’s general relativity, space is relative, spectives and not that the photons have lost en- More To Explore and what really matters is a galaxy’s history— ergy along the way. the trajectory it describes in spacetime. Thus, In the end, therefore, there is no mystery to Spacetime and Geometry: An we should calculate the relative velocity of the the energy loss of photons: the energies are be- Introduction to General Relativity. Sean M. Carroll. Addison-Wesley, 2003. distant galaxy with respect to us by comparing ing measured by galaxies that are receding from its trajectory in spacetime and ours. The amount each other, and the drop in energy is just a mat- Misconceptions about the Big of redshift seen in the galaxy turns out to be ter of perspective and relative motion. Bang. Charles H. Lineweaver and identical to the Doppler shift the observer would Still, when we tried to understand whether Tamara M. Davis in Scientific American, see in a car that is receding at the same relative the universe as a whole conserves energy we Vol. 292, No. 3, pages 36–45; March 2005. velocity [see box above]. faced a fundamental limitation, because there is This happens because in small enough re- no unique value we can ever attribute to some- The Kinematic Origin of the gions the universe makes a pretty good approx- thing called the energy of the universe. Cosmological Redshift. Emory F. imation of flat spacetime. But in flat spacetime Thus, the universe does not violate the con- Bunn and David W. Hogg in American there is no gravity and no stretching of waves, servation of energy; rather it lies outside that Journal of Physics, Vol. 77, No. 8, pages 688–694; August 2009. and any redshift must just be a Doppler effect. law’s jurisdiction. ■

DNA Drugs Come of Age After years of false starts, a new generation of vaccines and medicines for HIV, influenza and other stubborn illnesses is now in clinical trials By Matthew P. Morrow and David B. Weiner

n a h e a d -t o -h e a d competition held 10 proteins or no response at all, whereas recipi- years ago, scientists at the National Insti- ents of the adenovirus-based vaccine had robust tutes of Health tested two promising new reactions. To academic and pharmaceutical types of vaccine to see which might offer company researchers, adenoviruses clearly the strongest protection against one of the looked like the stronger candidates to take for- Ideadliest viruses on earth, the human immuno- ward in developing HIV vaccines. deficiency virus (HIV) that causes AIDS. One To DNA vaccine investigators, the results vaccine consisted of DNA rings called plasmids, were not entirely surprising, because poor re- each carrying a gene for one of five HIV pro- sponses had been seen in some previous trials. teins. Its goal was to get the recipient’s own cells Still, the failures were disappointing because we Key Concepts to make the viral proteins in the hope they had good reasons for expecting the plasmid vac- ■ ■ Vaccines and therapies contain- would provoke protective reactions by immune cine to be both safe and powerful. Convinced ing DNA rings called plasmids cells. Instead of plasmids, the second vaccine that the original concept was still strong, scien- have long held promise for used another virus called an adenovirus as a tists went back to the drawing board to find treating and preventing dis- carrier for a single HIV gene encoding a viral ways to boost the effectiveness of the technolo- ease, but the plasmids made a protein. The rationale for this combination was gy. Now these efforts are beginning to pay off. weak showing in early tests. to employ a “safe” virus to catch the attention A new generation of plasmid-based vaccines is ■ ■ Improvements to the plasmids of immune cells while getting them to direct proving in human and animal trials that it can and new methods for deliver- their responses against the HIV protein. produce the desired responses while retaining ing them have dramatically One of us (Weiner) had already been work- the safety and other benefits that make DNA so enhanced their potency. ing on DNA vaccines for eight years and was appealing. The same DNA-based technology is ■ ■ DNA vaccines and therapies hoping for a major demonstration of the plas- also now expanding to other forms of immune now used in animals or in late- mids’ ability to induce immunity against a therapy and the direct delivery of medicines. In stage human trials demonstrate dreaded pathogen. Instead the test results dealt their mature form, such DNA-based vaccines that plasmids are reaching a major blow to believers in this first generation and treatments are poised to become a success their potential. of DNA vaccines. The DNA recipients displayed story by addressing several conditions that now —The Editors

stuart bradshaw stuart only weak immune responses to the five HIV lack effective treatments.

www.ScientificAmerican.com SCIENTIFIC AMERICAN 49 © 2010 Scientific American www.diako.ir© 2010 Scientific American [ BASICS ] Virus infected, prompting long-term immune recogni- How Dna Drugs Work tion and responses against the foreign protein. Whether intended to treat or to prevent disease, DNA drugs are Just introducing a DNA ring carrying one gene made of plasmids—tiny rings of DNA—designed to ferry a se- could thereby induce immunity that protects Viral genes Selected gene lected gene into cells. Once plasmids are inside, the cells manu- against an entire pathogen. facture the protein encoded by the gene. In the case of an antivi- In addition to their safety and simplicity, DNA ral DNA vaccine (illustration), the resulting viral proteins elicit an vaccines offer a number of advantages over other immune response that prevents future infection by that virus. types of vaccine. Their manufacture is consider- Plasmid ably faster than some traditional vaccines, such Making the Vaccine proteins as those for influenza that require handling and A DNA vaccine delivered into the skin enters, or “transfects,” local skin cells and some immune cells. The transfected cells make cultivating “live” viruses and a minimum four- the plasmid-encoded viral protein, called an antigen. Still more to six-month production process. DNA is inher- immune cells engulf the antigen proteins as they are exiting cells. ently stable at room temperature (luckily for our cells), so DNA vaccines should not require con- Antigen Vaccine stant refrigeration, which is a concern during the plasmids transportation and storage of many vaccines. From the standpoint of a vaccine designer, DNA has another plus, which in recent years Lymph node played an important role in reopening the door Skin cell Immune to this technology. The immune system does not cells perceive the plasmids as foreign material—after Transfected cells all, they are made of DNA—so the vaccine itself Immune technically does not provoke any immune re- cells sponse. Only the protein encoded by the plasmid Antigen- gene, once manufactured by cells, garners the at- presenting cell Immune cells respond tention of immune sentinels, meaning that plas- Antibodies Immune cells carrying mids can be used over and over in the same re- antigen—known as antigen- cipient to deliver a variety of genes without fear presenting cells—travel to lymph nodes, where inter that the body will develop immunity to the DNA actions with other immune carrier and attack the vaccine itself. cells yield antibody molecules and killer T cells tailored to Killer T cells Unfortunately, in the early DNA vaccine tests recognize the viral protein the problem of weak immune responses was a and to attack any virus significant pitfall. The main reasons for those bearing it in the future. Blocked viruses failures seemed to be that vaccine plasmids were not getting into enough cells and, where they did A Good Idea, Then and Now penetrate, the cells were not producing enough w h e n t h e c o n c e p t of using DNA to immunize of the encoded proteins. As a result, the immune people began to gain traction in the early 1990s, system was not being sufficiently stimulated. its elegant simplicity was immediately apparent. The rival technology would ultimately face a The core components of the vaccine—the plas- bigger problem, however. In 2007 pharmaceu- mids constructed to carry genes encoding one or tical company Merck initiated a large trial of an more proteins from a pathogen—would induce HIV vaccine that used an adenovirus called the recipient’s cells to make those proteins but AdHu5 to deliver HIV viral genes. In light of the would not carry instructions for making the potent immune responses seen in previous ex- entire pathogen, so the vaccine could not give rise periments with adenoviruses, great hope and to the pathogen itself. excitement surrounded the beginning of this When the plasmids enter a host cell, known test, known as the STEP trial. In all, about as transfection, the machinery that normally de- 3,000 HIV-negative individuals received the codes DNA starts reading the plasmid’s gene and vaccine or a placebo shot. makes the desired protein, which is eventually As the trial progressed, though, a disturbing released from the cell, much the way virus par- difference between the two groups began to ticles would be. Outside the cell the pathogen- emerge: people who got the vaccine were no bet- specific proteins are recognized by immune cells ter protected than those who received the pla- as foreign to the body. The immune system cebo, and eventually they appeared to be more

should thus be tricked into thinking the body is vulnerable to being infected by HIV. An early graphics precision

50 Scientific American July 2010 www.diako.ir© 2010 Scientific American tally found that 49 out of 914 men in the vaccine late it more efficiently than the others. Choosing group became HIV-positive, whereas 33 out of optimal codons thus increases the cell’s produc- 922 men in the placebo group did. With this re- tion of the desired protein. Additional revisions alization, in the summer of 2009 the STEP trial to the gene sequence can improve the stability was halted. The data are still being analyzed for and accuracy of the messenger RNA gene tran- clues to what happened, but some evidence is scripts that the cell actually reads to make the pointing to the AdHu5 carrier as one possible protein and can speed protein manufacture. confounding factor. In people with preexisting A so-called leader sequence near the start of immunity to AdHu5, a common cold virus, the each gene is the first to be translated by the cell immune system may have attacked the vaccine into the beginnings of a protein molecule, and itself. Why some vaccine recipients seemed more optimizing a gene’s leader sequence can improve susceptible to HIV infection remains unclear. the stability of the final protein molecules. Cer- tain leader sequences can even mark a protein The Rebirth of DNA as one that the cell should secrete, which is de- d u r i n g t h e y e a r s leading up to the STEP trial, sirable because it allows immune cells to en- researchers still convinced of the DNA platform’s counter the foreign proteins both inside trans- potential had been working hard to develop solu- fected cells and outside them. The two situa- tions for the complex issues that handicapped the tions provoke slightly different types of immune first generation of plasmid vaccines. These efforts focused on boosting all aspects of the plasmids’ [ PROGRESS ] activity, including new methods of getting them into cells, new ways of increasing protein produc- boosting dna’s power tion once they were inside, and additions to the Technologies that increase the effectiveness of plasmid-based vaccines and therapies vaccines that enhance immune system responses have renewed hope for the success of the DNA approach. The improvements raise cells’ to the vaccine-encoded proteins. uptake of plasmids, augment their production of plasmid-encoded proteins and intensi- New vaccine delivery methods are among the fy immune system responses to those proteins. most significant accomplishments to come out of this work, because they get considerably more Enhanced Delivery cells—including immune cells themselves—to Needle-free injection Electroporation device take up the plasmids. For instance, transdermal High uptake by cells patches and other needle-free systems, such as Immune cell Gene Gun and Bioject that use pressurized air to inject vaccine, deliver plasmids into the skin, where immune sentries called antigen-present- Skin cells ing cells are highly concentrated. These methods also physically force plasmids into more cells than needle injection would do. To achieve a Skin cells similar result with vaccines delivered by needle Muscle cells into muscle or skin, the injection can be followed High uptake Temporary pore by electroporation, a series of electrical pulses by cells that cause cell membranes to temporarily open pores that allow plasmids to enter more easily. Needle-free injection systems deliver vaccine into Mild electrical stimulation called electroporation the skin, where immune cells are concentrated. can boost cells’ uptake of plasmids delivered by Electroporation can increase cells’ uptake of The injectors push more plasmids directly into skin needle injection. The electrical pulses cause cells plasmids by as much as 1,000-fold. and immune cells than needle injections would. to briefly open pores that admit the plasmids. The plasmid-gene constructs themselves have also been improved through several types of re- Best gene sequence Optimized Plasmid Design finements to the DNA sequences of the genes they Instructions for making a protein encoded by a plasmid gene can be spelled out using various sequences of DNA “letters,” but choosing carry. Codon optimization, for instance, involves High protein spelling out the gene’s instructions in a way the certain sequences can raise the amount of protein a cell generates. production cell will execute most readily. In the genetic code, Adjuvant Antigen the amino acid building blocks of proteins are gene gene specified by sets of three DNA “letters” that Improved Immune Stimulation Immune cell–stimulating substances called adjuvants make up a codon. Certain amino acids are desig- can be encoded by genes added to plasmids. The nated by more than one codon, but cells typically adjuvants manufactured alongside the antigens enhance immune responses to the vaccine antigens. precision graphics precision favor one of these synonymous codons and trans- Enhanced immune response to antigen

www.ScientificAmerican.com SCIENTIFIC AMERICAN 51 www.diako.ir© 2010 Scientific American response, and the combination enhances the cellular genome or even remain permanently in overall immunity generated by the vaccine. cells, which avoids complications that have ham- A final important improvement involves sub- pered progress in gene therapies. stances called adjuvants, which are typically As is often the case with new technologies, added to traditional vaccines to boost immune the earliest successes in plasmid-based therapies system responses. In some cases, an adjuvant can have been in animals. One example already li- even steer the immune system toward one form censed for use in pigs is designed to prevent fetal of response over another if desired, for instance, loss. Administered to pregnant sows along with favoring greater production of T cells, which electroporation, the plasmid enters the sow’s seek out and kill pathogen-infected cells in the cells, which then make a hormone (growth hor- body, as opposed to greater production of anti- mone –releasing hormone) that supports the ges- body proteins, which attempt to block patho- tating fetuses’ survival. The success of this treat- gens from entering cells. A chemical compound ment is exciting in part because it requires only called Vaxfectin, for example, has been shown a single injection to work in such a large animal, to increase antibody responses to a DNA vaccine which bodes well for human therapies. against influenza 200-fold. Another adjuvant— Various large clinical trials for human DNA Resiquimod—is used with some DNA vaccines therapies are now under way [see table on oppo- to provoke a strong immune reaction that in- site page], including one that delivers genes for cludes both T cells and antibodies. proteins called growth factors that mobilize Another compelling aspect of the DNA-based stem cells to treat congestive heart failure. An- technology is that instead of adding adjuvants to other employs a plasmid encoding a growth fac- the final vaccine formulation, which sometimes tor called IGF-1 to treat growth failure in pa- creates concerns about maintaining proper emul- tients with the disorder X-linked severe com- sification or stability of the formula, designers can bined immunodeficiency. A third trial addresses incorporate the gene for an adjuvant molecule di- a circulatory problem that can be notoriously rectly into a vaccine plasmid. Cells that take up the hard to treat, called critical limb ischemia. This plasmids will then manufacture the encoded adju- therapy delivers plasmid-encoded factors that vant alongside the vaccine proteins. When gene- induce new blood vessels to grow, in the hope of encoded adjuvants are added to DNA vaccines, preventing the need for amputation. even when the plasmid has already been optimized, A different category of treatments, known as as described earlier, the adjuvant can further in- DNA biological immunotherapy, combines the crease immune responses by fivefold or more. best aspects of DNA therapies and vaccines by These designer plasmid vaccines are a far cry delivering a gene that induces the body to mount from the simple protein-encoding constructs of an immune response to an existing disease, such the early years of the DNA platform. With opti- as a tumor or a chronic viral infection. One ear- [ The Authors ] mized plasmids and improved delivery methods, ly trial uses DNA encoding viral proteins to in- the technology was ready to make a comeback duce immune cell attacks on tumors caused by by the start of the STEP trial. What is more, the the human papillomavirus (HPV), for example.

DNA approach has begun to show promise for Initial results from this trial show that half of re- )

uses beyond classical vaccination, including cipients muster T cell responses to the HPV pro- Weiner ( plasmid delivery of some medications and of im- teins and that more than 90 percent generate

mune therapies targeted at cancers. high levels of antibodies. Another current trial . WEINER B ID

is testing a DNA immunotherapy against the V Matthew P. Morrow and David B. A Multipurpose Technology hepatitis C virus. Encouraging preliminary re- DA Weiner collaborate at the University of OF Pennsylvania, where Morrow is a post- t h e a b i l i t y t o s a f e l y deliver genes into cells sults in both these trials are significant because doctoral research fellow. Investigating and get those cells to efficiently manufacture the no effective immune therapies currently exist for HIV for nearly 10 years led to his current encoded proteins opens avenues to a host of either HPV tumors or hepatitis C. ); COURTESY focus on DNA vaccines and immune

potential treatments. Indeed, many of these In this arena, veterinary applications are once Morrow therapies. Weiner, a professor of pathol- ogy and medicine, is chair of the univer- DNA-based therapies are ahead of DNA vac- again even more advanced than human studies, sity’s Gene Therapy and Vaccines gradu- cines in the race to widespread clinical use. and a successful DNA-based therapy for mela- . Morrow ( ate program. A pioneer of DNA vaccine Unlike classical drugs that often take the form noma in dogs is exciting researchers who study technology, he brought the first plasmid- of small chemical molecules, DNA therapies human cancer. The dog melanoma treatment, based vaccines to clinical trials and has deliver a gene to treat an ailment. Unlike tradi- made by Merial, increases the median survival been a consultant to the FDA and to many vaccine and pharmaceutical com- tional gene therapy, however, the plasmid does time of dogs with advanced melanoma by six- ourtesy of Matthew P panies pursuing plasmid-based drugs. not integrate permanently into the recipient’s fold compared with untreated dogs. This DNA C

52 Scientific American July 2010 www.diako.ir© 2010 Scientific American demonstrating the potential of dna Plasmid-based vaccines and therapies are under study in humans for a wide range of disorders, and some are already approved for animals. The table below lists a selection of the disorders targeted by products in human clinical trials or already marketed for animals.

product disorder targeted in human trials disorder targeted in animals

Vaccines to ■ HIV (3 vaccines) ■ West Nile virus (horses) prevent disease ■ Influenza (2 vaccines) ■ Infectious hematopoietic necrosis virus (farmed salmon)

Immune-stimulating ■ Hepatitis C ■ Melanoma (dogs) treatments for ■ HIV existing diseases ■ Human papillomavirus-induced tumors ■ Liver cancer ■ Melanoma

Therapies that give rise ■ Congestive heart failure ■ Fetal loss (pigs) to needed proteins ■ Growth failure from X-linked severe combined immunodeficiency disorder ■ Limb circulatory disorders (3 treatments) ■ Melanoma

biological immunotherapy attests to the poten- able. It is now in early human trials with encour- tial of the new-generation DNA platforms to aging results. succeed where previous approaches have not. The potential power of DNA vaccines and therapies to target diseases that have no other ef- Back to the Future fective alternatives has also brought DNA back d o z e n s o f h u m a n clinical trials of DNA ther- into the HIV vaccine race. One vaccine now in apies and vaccines have been conducted in the human trials, Pennvax-B, contains three HI V vi- past 10 years or are currently ongoing. Plasmid ral genes plus genes encoding adjuvant mole- versions of flu vaccines exemplify some of the cules and is delivered with electroporation. Two

Photo Researchers, Inc. benefits the DNA approach has already demon- more vaccines are being tested in a strategy that strated. A flu vaccine our research group devel- uses plasmids to prime immune cells to recog- eissner m oped, now in early human trials, was shown in nize the HIV proteins followed by administra- sch

e G animals to protect against common flu strains tion of another vaccine type to boost the early v te S ; and against the highly lethal H5N1 avian flu immune response to higher levels. One of these, More To Explore that has infected several hundred people. The GeoVax, is being given along with a vaccine vaccine is able to provide this broad protection based on a virus called modified vaccinia Anka- DNA Vaccines for HIV: Challenges and Opportunities. David A. Hokey because its plasmids contain so-called consensus ra as the boost. And in an amusing irony, the and David B. Weiner in Springer sequences of flu virus genes, meaning the result- NIH Vaccine Research Center is now testing a Seminars in Immunopathology, Photo Researchers, Inc. ing viral proteins resemble those of many differ- different DNA-based HIV vaccine with one of Vol. 28, No. 3, pages 267–279; allini

v November 2006.

a ent flu strains. Such vaccines might spell an end two adenovirus-based HIV vaccines as boosts.

es C to mismatches between seasonal flu vaccines and The fact that several DNA vaccines and ther- m DNA Vaccines: Precision Tools for Ja ; the flu strains that emerge every year. apies are already used in animals and are in large, Activating Effective Immunity Of course, the novel H1N1 flu strain that ap- late-stage human trials involving hard-to-treat against Cancer. Jason Rice et al. in peared last year to produce a global pandemic ailments attests to how far the plasmid technol- Nature Reviews Cancer, Vol. 8, No. 2, highlights the urgent need for a new vaccine ap- ogy has come. Dramatic progress in the field over pages 108–120; February 2008.

Photo Researchers, Inc. proach. An experimental DNA version of an the past decade has brought some of the most cre- Electroporation of Synthetic DNA H1N1 vaccine made by the pharmaceutical ative vaccines and therapeutics yet to clinical oller Antigens Offers Protection in B company Vical was completed in just two weeks testing for human benefit. In this regard, those of Nonhuman Primates Challenged

: Klaus: in May 2009. Had it been tested and licensed in us who have nursed this technology since its in- with Highly Pathogenic Avian m advance, such a vaccine could have been manu- fancy cannot help but feel proud to see that it has Influenza Virus.Dominick J. Laddy factured in large amounts at least two months emerged from a difficult childhood and can look et al. in Journal of Virology, Vol. 83, No. 9, pages 4624–4630; May 2009. ■ top to bottotopto sooner than the standard vaccines became avail- forward to a bright future.

4. NEW YORK 5. NEW ENGLAND 6. MID-ATLANTIC The Dirty 67.2% OIL 4.5% OIL 2.4% OIL 29.4% NATURAL GAS 70.3% NATURAL GAS 60.6% NATURAL GAS Truth about 3.4% COAL 15.5% COAL 37.0% COAL 9.7% RENEWABLE Plug-in Hybrids 4.3% –1.2% –11.4% How green is that electric car? Depends on where you plug it in By Michael Moyer 19.0% 6.1% –17.4% –8.6% –45.4% –44.3% n the months after Nissan’s announcement last year that it would power sources –10.9% –95.9% soon introduce the Leaf, the world’s first mass-market electric vehicle, –93.5% Where does your electricity come from? The answer depends on the time of day, day the company embarked on a 24-city “zero-emission tour” to show off of week and where you live. To determine the sources of energy that will power the the technology. The Leaf’s electric motor draws its energy from a coming fleet of electric vehicles, researchers modeled the additional strain that a fleet battery pack that plugs into an outlet in your garage. It has no engine, of electrics would place on the grid. They found that the added demand will likely be 2. GREATER ILLINOIS 3. GREATER OHIO no gas tank and no tailpipe. And during the time the car is on the road, it met by plants burning fossil fuels. In fact, in the six regions whose numbers are high- 24.6% NATURAL GAS 32.8% NATURAL GAS I lighted in yellow, heavy contributions from coal mean that plug-in cars will emit at 75.4% COAL 65.7% COAL is truly a zero-emission machine. But at night, in your garage, that bat- least as much in the way of greenhouse gases as would an ordinary hybrid. 1.5% RENEWABLE tery pack must refill the energy lost to the day’s driving with fresh elec- 11.7% 7.8% trons culled from a nearby power plant. And zero emission it ain’t. THE COAL IN YOUR CAR 1. UPPER MIDWEST 36.0% 27.0% The Leaf should be the first all-electric car off the starting grid, but Here we represent the carbon intensity of 47.6% NATURAL GAS –46.5% followers are whirring hot behind it. Chevrolet is introducing the Volt, an the electricity that will power plug-in cars by 46.0% COAL –46.6% –98.6% electric car supplemented with a small internal-combustion engine that height and color—dirtier regions are darker 6.3% RENEWABLE and taller. Boxes detail how a plug-in car will –98.7% 5 keeps the battery charged. Ford will come out with an electric version of its compare to an ordinary hybrid in terms of car- –0.8% Focus in 2011, followed by models from Toyota, Volvo, Audi and Hyundai. bon emissions and petroleum consumption. 7.2% A true accounting of the environmental consequences of these cars HOW DIRTY IS YOUR REGION? –46.7% would have to include the emissions of the power plants that supply their 4 energy. When Department of Energy researchers carried out such an –99.0% 6 In taller and darker regions, the electricity used analysis, they found that the results vary considerably with geography. to power plug-in cars is responsible for 3 The researchers split the continental U.S. into 13 regions defined by the higher carbon dioxide emissions. North American Electric Reliability Corporation and examined the mix of PER-MILE COMPARISON TO ORDINARY HYBRID: power sources within each region—generally, a combination of coal, natural 2 gas and nuclear energy, with a smattering of renewable energy thrown in. LESS MORE than a hybrid 1 They then looked at how a new fleet of electric cars would alter that supply. Carbon emitted by ... Gasoline consumed by ... Nuclear and renewables, which together account for less than a quarter of Plug-in hybrid Plug-in hybrid the U.S. electricity supply, are “always on” sources. Their energy gets used All-electric All-electric up quickly for routine tasks, leaving little to no green energy left over to help charge a burgeoning fleet of electric vehicles. In practical terms, 8 this means that even if you live down the street from a wind farm, 7 its energy is already spoken for before you plug in your plug-in. 10 With nuclear and renewables taken out of the equation, the 13 researchers concluded that power for the fleets will have to come primarily from coal and natural gas. If you live in a place where natural gas is dominant, electric vehicles will reduce carbon dioxide emissions—in some 7. FLORIDA cases by as much as 40 percent below that of an ordinary hybrid. In regions 11 9 2.4% OIL powered mostly by coal—a much dirtier fuel—electric vehicles will lead to 96.1% NATURAL GAS an increase in the amount of carbon dioxide released into the atmosphere. 1.5% RENEWABLE The zero-emission tour may have ended this spring, but the controversy over 12 –14.8% what zero really means is just getting under way. –25.3% –45.6%  The greenest Leafs will be in –96.4% the Northwest.

11. SOUTHWEST 10. LOWER MIDWEST 9. TEXAS 8. SOUTHEAST 13. NORTHWEST 12. CALIFORNIA 83.6% NATURAL GAS 88.6% NATURAL GAS 100.0% NATURAL GAS 44.9% NATURAL GAS 84.3% NATURAL GAS 99.0% NATURAL GAS 16.1% COAL 11.4% COAL 51.9% COAL 15.7% NUCLEAR 1.0% RENEWABLE 0.3% RENEWABLE –15.0% 3.2% RENEWABLE –11.0% –20.0% –15.3% –9.4% –25.7% 2.4% –16.4% –37.2% –26.5% –12.8% –47.0% 14.4% –46.9% –47.0% –47.0% –46.9% –99.6% –46.7% –99.4% –99.6% –99.6% –99.4% –98.9%

July 2010 www.diako.ir© 2010 Scientific American 4. NEW YORK 5. NEW ENGLAND 6. MID-ATLANTIC Three Flavors 67.2% OIL 4.5% OIL 2.4% OIL of Electric Cars 29.4% NATURAL GAS 70.3% NATURAL GAS 60.6% NATURAL GAS 3.4% COAL 15.5% COAL 37.0% COAL 9.7% RENEWABLE Plug-in Hybrids 4.3% –1.2% –11.4% All-Electric 6.1% 19.0% With no gasoline engine, cars such –17.4% –8.6% –45.4% as the Nissan Leaf run exclusively –44.3% on battery power. This limits their –10.9% –95.9% range to about 100 miles before –93.5% they require a charge.

3. GREATER OHIO 2. GREATER ILLINOIS Plug-in Hybrid 24.6% NATURAL GAS 32.8% NATURAL GAS Vehicles such as the Chevrolet 75.4% COAL 65.7% COAL Volt plug into the grid like 1.5% RENEWABLE all-electric cars, but they also 11.7% 7.8% include a small internal-combus- THE COAL IN YOUR CAR 1. UPPER MIDWEST 36.0% tion engine that can be used to 27.0% charge the batteries. 47.6% NATURAL GAS –46.5% 46.0% COAL –46.6% 6.3% RENEWABLE –98.6% –98.7% 5 –0.8% Hybrid 7.2% Cars such as the Toyota Prius do not connect to the grid. An HOW DIRTY IS YOUR REGION? –46.7% electric motor powers the car at 4 low speeds, while an internal- –99.0% 6 combustion engine takes over In taller and darker regions, the electricity used at high speeds. to power plug-in cars is responsible for 3 higher carbon dioxide emissions.

PER-MILE COMPARISON TO ORDINARY HYBRID: 2 LESS MORE than a hybrid 1 Carbon emitted by ... Gasoline consumed by ... Plug-in hybrid Plug-in hybrid All-electric All-electric

8 7 10 13

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of War the Machines Robots on and above the battlefield are bringing about the most profound transformation of warfare since the advent of the atom bomb By P. W. Singer

56 Scientific American July 2010

©www.diako.ir 2010 Scientific American © 2010 Scientific American a c k in t h e e a r l y 1970s, and organizations from 55 countries. a handful of scientists, engi The growth happened so fast, in fact, neers, defense contractors and that it found itself in something of an U.S. Air Force officers got identity crisis. At one of its meetings in together to form a profession San Diego, it even hired a “master sto Key Concepts B al group. They were essentially trying to ryteller” to help the group pull together ■ ■ The U.S. military once shunned solve the same problem: how to build the narrative of the amazing changes in robots as obstacles to tradi- machines that can operate on their own robotic technology. As one attendee tional soldiering. without human control and to figure summed up, “Where have we come ■ ■ “Unmanned” systems have out ways to convince both the public from? Where are we? And where should proliferated in conflicts in the and a reluctant Pentagon brass that ro we—and where do we want to—go?” Middle East, either helping to bots on the battlefield are a good idea. What prompted the group’s soul- negotiate the urban labyrinth For decades they met once or twice a searching is one of the most profound of streets and alleyways or act- year, in relative obscurity, to talk over changes in modern warfare since the ing as scouts in remote villages. technical issues, exchange gossip and advent of gunpowder or the airplane: ■ ■ As robots do more on their renew old friendships. This once cozy an astonishingly rapid rise in the use of own, they continue to raise a group, the Association for Unmanned robots on the battlefield. Not a single host of ethical and legal issues. Systems International, now encompass robot accompanied the U.S. advance —The Editors es more than 1,500 member companies from Kuwait toward Baghdad in 2003.

REMOTE CONTROL in high-tech warfare has begun to extend to robots involved in surveillance, troop supply and even the firing of powerful weapons. www.ScientificAmerican.com SCIENTIFIC AMERICAN 57

©www.diako.ir 2010 Scientific American 58 then moves the actuators. the that through hydraulic system adrives pump that sends oil coursing Power supplied from an engine ENGINE tors to adjust leg position. actua to command a send to velocity and acceleration and calculate to processor the Inputs from sensors enable CO ( locator from the received universal coordinates by determined are The whereabouts robot’s GLOBAL all the while toting ammunition or another supply load weighing hundreds of pounds. a pack-animal-like quadruped will traverse terrain too steep, rutted, rocky, muddy or snowy for vehicles that move on wheels or tracks, Neither human soldiers nor ordinary machines will match the capabilities of the newest military robots now in development. BigDog, A [

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of warfare and whether these technologies technologies these whether and warfare of ethical questions about the fundamental nature and legal political, deep raises also robots of of out harm’s soldiers way may save Moving lives, but the growing battle. use in machines of ever using more autonomous and intelligent implications the about arguments contentious of set a initiated have also they but fought, is hav only not ing are a big effect on how systems this new type of warfare robotic These crowd. the into back blends then and phones cell with war a ir explosions remote an triggers that enemy regular embraced combating of now means a as have machines the of culture, warrior their which once eschewed robots as to unbecoming stan. The world’s bombing to most powerful fighting forces, snipers out al of hideouts the seeking from range that U.S. military inventory, entrusted with missions havevehicles ground entered the other 12,000 Since then, 7,000 and aircraft an “unmanned” ext-Gene - www.diako.ir Qaeda higher Qaeda © 2010 Scientific American r ation Ro ation - ups in Paki in ups b ot machines built to operate in a “sense a in operate to built machines ting our demise. In the simplest terms, robots are wood “remote or manned” ues today in contin that fiction science of staple a is control don’t want to doassuming but ultimately then we work the on taking robots of theme re This had who 1800s. the peasants in landowners rich against volted “robotniks,” the to linked historically “slave,” for word Slavic older the rived from the Czech word for “servitude” and de it because meaning, with packed was word tually rise up against their human masters. The even that servants mechanical describe to bot” Karel writer Czech play 1921 the to back hark start. to easier wars make inadvertently could paradigm. That is, they have sensors that gather gather that sensors have they is, That paradigm. Today invoke roboticists the “un descriptors arguably story this of threads earliest The - fueled visions of machines that are plot are that machines of visions fueled Servo valve Servo The Terminator The Terminator survey immediate surroundings. surroundings. immediate survey and a machine-vision LIDAR module called radar or form A ELECTRONIC Position Position sensor to the desired placement. pistons) that moves the leg an (a with actuator cylinder that opens to let oil flow valve into servo a to signal a sends all four the legs, computer data sensor from integrating the on acting forces it. After the of position the leg and computer information about robot’s the to relay Sensors SENSORS Force Force sensor Capek ˆ - AND operated” to avoid Holly avoid to operated”

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preceding pages: joe zeff design; Mansour Ali Photography Getty Images (background); this page: bryan christie design information about the world. Those data are as one promotion puts it, the U.S. Navy is “work then relayed to computer processors, and per ing every day to unman the front lines.” haps artificial-intelligence software, that use When teens do join the military, exposure to them to make appropriate decisions. Finally, automated systems is integral to their experi based on that information, mechanical systems ence, from induction to discharge. They use the known as effectors carry out some physical ac latest virtual-training software to learn how to tion on the world around them. Robots do not operate a particular weapons system. After have to be anthropomorphic, as is the other Hol training, they may well operate a lawnmower- lywood trope of a man in a metal suit. The size size PackBot or a TALON ground robot that can and shape of the systems that are beginning to defuse bombs or peek over the top of a ridge in carry out these actions vary widely and rarely the hunt for insurgents in Iraq or Afghanistan. evoke the image of C-3PO or the Terminator. If they end up at sea, they may well serve on BRING YOUR OWN DRONE: The ScanEagle provided an airborne The Global Positioning Satellite system, video- an Aegis-class destroyer or Littoral Combat security camera for U.S. Marines in game-like remote controls and a host of other Ship, which operate as mother ships for a range Iraq’s Al Anbar province by hovering technologies have made robots both useful and of systems, from Fire Scout unmanned helicop over remote tracts for hours on end. usable on the battlefield during the past decade. ters to Protector robotic sentry motorboats. If The increased ability to observe, pinpoint and their career takes them into submarines, they then attack targets in hostile settings without could end up controlling unmanned underwater having to expose the human operator to danger vehicles such as the REMUS (Remote Environ became a priority after the 9/11 attacks, and mental Monitoring Units, a torpedo-shaped ro each new use of the systems on the ground creat bot sub originally developed by the Woods Hole ed a success story that had broader repercussions. Oceanographic Institution) to detect mines or to As an example, in the first few months of the Af conduct surveillance of unfriendly coastlines. If ghan campaign in 2001, a prototype of the Pack they become aviators, they may “fly” Predator Bot, now used extensively to defuse bombs, was or Global Hawk drones over Central Asia, while sent into the field for testing. The soldiers liked it never physically leaving the continental U.S. so much that they would not return it to its man ufacturer, iRobot, which has since gone on to sell The War Bots of Tomorrow thousands. Similarly, another robotics company s u c h technologies are billed in a recruiting executive recounts that before 9/11, he could not ad as part of today’s military, while “seeming get his calls returned by the Pentagon. Afterward, like science fiction.” In reality, they are merely he was told: “Make ’em as fast as you can.” the first generation, a suggestion of more to This accelerating acceptance of military ro come. That is, today’s PackBot robot hunting botics became apparent as the Iraq War played roadside bombs and the Predator drones flying out. When U.S. forces went into Iraq in 2003, over Afghanistan represent the equivalent of the the ground invasion force had no unmanned sys Model T Ford and the Wright brothers’ Flyer. tems. By the end of 2004 the number had risen Prototypes for the next generation reveal three to 150 or so. A year later it had reached 2,400. key ways that robots will change how we con Today the overall U.S. military inventory is more duct warfare. than 12,000. The same trend occurred with air The idea of robots as mere “unmanned sys weaponry: the U.S. military went from having tems”—identical to any other machine, except a handful of unmanned aerial vehicles support without the presence of a human operator in ing the invasion force to more than 7,000 now. side—is beginning to fade. The evolution recapit And this progression is just the start. One U.S. ulates the trajectory of automotive history: think Air Force three-star general forecasts that the ing about cars as mere “horseless carriages” be next major U.S. conflict will involve not the came an artifact as designers started to consider had McMeen thousands of robots currently in the field but wholly novel forms and sizes. The similar casting gt. C “tens of thousands.” off of preconceptions about robots is leading the

unnery S The raw numbers reveal an important shift in machines to take on a wide range of shapes. As attitude by a military that just a few years ago would be expected, some models take their inspi remained dubious of its capabilities and protec ration from biology. Boston Dynamics’s BigDog, tive of the age-old warrior’s prerogative of lead for one, is a metallic, equipment-toting quadru orps photo by G ing the charge into combat. Today the U.S. Air ped. Others are hybrids, such as a Naval Post Force, Army and Navy entice teenage recruits graduate School surveillance bot that has both . Marine C S .

U through television advertising that extols how, wings and legs. But other systems in early devel

www.ScientificAmerican.com SCIENTIFIC AMERICAN 59 www.diako.ir© 2010 Scientific American opment have literally no form at all. ChemBot, a already planning to replace these planes, de creation of the University of Chicago and iRobot, ployed since 1995, with a newer generation. is a bloblike machine that shifts shape, such that The expansion of robotic intelligence and au it is able to squeeze through a hole in the wall. tonomy raises profound questions of what roles With no humans inside, the size of robots can are appropriate to outsource to machines. These range wildly. Miniaturized robots already mea decisions must be weighed on how effective the sure in millimeters and weigh in grams. Take a machines might be in battle but also on what this surveillance bot made by AeroVironment for ur shift in responsibility would mean for both their ban combat. It mimics a hummingbird in size human commanders and broader political, ethi and in its ability to hover over a target. The next cal and legal responsibility for their conduct. frontier is nanoscale robotics (structures mea The most likely outcome in the near future is for sured in billionths of a meter) that some scien robots to take on the semblance of “war fighter tists believe will become commonplace within a associates.” In this scenario, mixed teams of hu helping out: A soldier chucks a few decades. In war these machines might be mans and robots would work together, each do PackBot surveillance robot through used for roles that range from “smart dust” that ing what they do best. The human element may a window so that its onboard video cameras can provide an inside view detects the enemy to cellular-level machines in well turn out to be akin to the quarterback in a of the premises. side the human body that repair wounds or, in football game, calling plays for robotic team turn, cause them. At the other end of the scale, mates, while giving them enough autonomy to the ability to deploy a system that does not have react to changing circumstances. to take into account human bodily needs is lead ing to gigantic unmanned systems, such as Lock The Real Story heed Martin’s High-Altitude Airship, an un t h e s e r e m a r k a b l e developments may still manned blimp that carries a radar the length of not fully capture the story of where robotics is a football field, designed to fly at above 19,800 headed and what it means for our world and the meters for more than a month at a time. future of warfare. The full implications cannot be Beyond size and shape, a second key change gleaned from describing physical capabilities, just is the widening of roles these machines can per as the significance of gunpowder is not captured form in warfare. Much like the early “aeroplanes” by noting that it produced a chemical explosion in World War I, robots started out only for ob that allowed a longer trajectory for projectiles. servation and reconnaissance and have now ex Robots are one of those rare inventions that panded into new tasks. Technology development literally change the rules of the game. Such a company QinetiQ North America, maker of the “revolutionary” technology does not give one TALON, introduced the MAARS robot in 2007, side a permanent advantage, as some analysts which is armed with a machine gun and grenade mistakenly believe, because it is quickly adopted launcher and can take on sentry and sniper duty. by or adapted to by other combatants. Rather it In turn, med bots such as the U.S. Army Medi causes shake-ups, not only on the battlefield but cal Research and Materiel Command’s Robotic in the social structures surrounding it. The long Extraction Vehicle are designed to drag wound bow, for example, was not notable simply because ed soldiers to safety and then administer care. it allowed the English to beat the French at the The third key change is the robots’ ever grow Battle of Agincourt during the Hundred Years’ [ The Author ] ing intelligence and autonomy. The inexorable War; rather it let organized groups of peasants tri growth in computing power means that today’s umph over knights, ending the age of feudalism.

recently enlisted soldiers may end their careers An apt historical parallel to the current period )

witnessing robots powered by computers literally may well turn out to be World War I. Back then, Singer a billion times more capable than those currently strange, exciting new technologies that had been inger ( available. The World War II–era military did not viewed as merely science fiction just years earlier . W. S differentiate between the B-17 and B-24 bomber were introduced and then used in increasing by how smart they were, but latter-day weapons numbers on the battlefield. Indeed, it was H. G.

systems require just such distinctions. The Pred Wells’s 1903 short story “Land Ironclads” that ourtesy of P P. W. Singer directs the 21st ator series of unmanned planes, for example, has inspired Winston Churchill, then First Lord of ); C

Century Defense Initiative at the evolved from being purely remote-controlled to the Admiralty, to champion the development of soldier Brookings Institution and is author

now being able to take off and land on their own the tank. Another story, by A. A. Milne, creator obot ( of the best-selling 2009 book Wired R and track 12 targets at once; the target-recogni of the beloved Winnie-the-Pooh series, was for War: The Robotics Revolution and Conflict in the 21st Century tion software can even trace footprints back to among the first to raise the idea of using airplanes ourtesy of i

(wiredforwar.pwsinger.com). their point of origin. Even so, the U.S. military is in war, while Arthur Conan Doyle (in his 1914 C

60 Scientific American July 2010 www.diako.ir© 2010 Scientific American bryan christie design out any cost in U.S. human lives. By one measure, measure, one By They lives. with effective. highly been have human strikes comes these it U.S. in because cost any war, a out considered even not but without publicis deliberation. conflict The what we would have previously called a de “war,” no prompted ing in the media. In essence, we are engaging in Pakistan into bate at all in and Congress relatively little report strikes air robotic sovo War a mere decade ago. But unlike that thatwe launched in war, the opening round of the Ko strikes bomber ofmanned total the triple than more is number This craft. unmanned Reaper 130 air strikes into Pakistan using Predator and For example, the U.S. has carried out more than to and start may even change how we view them. the theater of conflictmay wellmake wars easier in 1979.draft the end of military the U.S. by begun already a decline sentiment, by public exerted of force) deterrent acts the remote erode Unmanned systems (and their ability to carry out survival. but state’s the very daughters and sons commitment or that serious jeopardizeda not just the lives of signified that itsinvolved public currying favor democrat citizens’for long an endeav it For war.” to nations, “go ic to meant once it what of idea Takethe robotics. military with today e w The Plo front.” “home term the to meaning new tirely en an giving populations, civilian onto raining of bombs in resulted emergence often the that bombing aerial allowing at also but distances, at troops greater and attacking only at spotting not useful proved airplanes Similarly, status. War, ultimately leading to its rise to superpowerWorld First the into America drew fight warning?) to allowed they legally be allowed to sink merchant ships were without submarines over and the tions Germany U.S. between how consequences. For differing instance, interpreta legal issues that resulted in dramatic strategic amoral and wholly raised new ofset political, they because however, important, was rines effectively. more weapon new the use to how out with their blitzkrieg tactics that they had figured mere 20 years later when proved the Germans a surmounted was example, for WorldI, War ish invention and early exploitation ofin tanks Brit fleeting. was it but edge, an had users First neered the notion use in full of war. submarines’ 1869 novel his (in Verne Jules and “Danger!”) story short www.ScientificAmerican.com This distancing of the human combatant from from combatant human the of distancing This subma and airplanes tanks, of arrival The

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(should (should ) pio www.diako.ir © 2010 Scientific American to take over tasks typically carried out by human soldiers for centuries. for soldiers human by out carried typically begun tasks have air over the take in to and land on small and big both Machines A [ i nade-launching sentry and sniper. machine and gun–carrying gre as serves a 160-kilogram MAARS n the Mena aloft for up to a month. a to up for aloft of a fieldand football remains length the radar a carries H immensely popular in Iraq. Iraq. in popular immensely proved has craft, spy like RAVEN, a model-airplane- i g h a -A ir ir ltitude its wings frenetically as its its cameras observe as a scene. frenetically wings its 7.5 centimeters and flaps measures no more than g Hummin a nd nd every

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on in the next room. next the in on spies on the goings- the wall and then in hole a through fit size to blob, morphs Chemb o t , a palm- wall [ Action at a distance ] have killed as many as 40 leaders of al-Qaeda, America’s Remote-Controlled the Taliban and allied militant groups without Air War having to send American troops or pilots into harm’s way. But the repercussions of these strikes An intricate communications network allows soldiers at U.S. domestic and overseas raise questions that are still being answered. military bases to control unmanned aircraft that fire missiles or gather intelligence What is, for one, this technology’s impact on from battlefronts in both Iraq and Afghanistan. Each base is responsible for control of one or more types of aircraft (orange lines) or for receiving intelligence data (green the “war of ideas” we are fighting against terror lines). Information moves through two U.S.-based communication centers (blue ist recruiting and propaganda? That is, how and cubes) to and from Iraq and Afghanistan. why is the reality of our painstaking efforts to act with precision emerging on the other side of the globe through a cloud of anger and mispercep tion? Whereas we use adjectives such as “precise” and “costless” to describe the technology in our mass media, a leading newspaper in Pakistan de clared the U.S. to be a “principal hate figure” and “all-purpose scapegoat” because of the strikes. Unfortunately, “drone” has become a colloquial word in Urdu, appearing in rock lyrics that ac cuse America of not fighting with honor. This issue becomes more complex when weighing who should be held accountable when things go wrong. Estimates of civilian ca sualties range from 200 to 1,000. But many of these incidents oc curred close to some of the most dangerous terrorist leaders around. Where does one draw the line? The meaning of “going to war” is also changing for IRAQ the individual warrior in AFGHANISTAN 2010. Setting off to battle has always meant that a sol dier might never come home. Achilles and Odysseus sailed off to fight Troy. My grandfa ther shipped out to fight the Jap anese after Pearl Harbor. Remote warfare has changed the enduring truth of the past 5,000 years of war. A growing number of soldiers wake up, drive to work, sit in front of computers and use robotic systems to battle insurgents 11,300 kilometers away. At the end of a day “at war,” they get back in their cars, drive home and, as one U.S. Air Force officer put it: “Within 20 minutes you are sitting at the dinner table talk ing to your kids.” The most dangerous part of their day is not the dangers of the battlefield but the commute home. Communication centers This disconnection from the battlefield also Airbases leads to a demographic change in who does what Command sent to robots in war and the issues it provokes about a soldier’s Intelligence collected identity (young enlisted troops doing jobs once by robots

limited to senior officers) or status (the techni bryan christie design

62 Scientific American July 2010 www.diako.ir© 2010 Scientific American © 2010 Scientific American cian versus the warrior) or the nature of combat Such incidents, of course, raise immense legal Despite the stress and fatigue. Remote operators may seem concerns. How should one apportion account like they are just playing video games, but they ability? What system of law can even be relied on precision experience a psychological burden of fighting for guidance? These instances demonstrate that of robotic day after day after day, with lives on the ground technology often moves faster than our social in depending on their flawless performance. Their stitutions. How do we reconcile our 20th-centu technology, commanders describe the challenges of leading ry laws of war to the new reality? the “fog of units fighting remotely as being far different and sometimes even more difficult than leading reg A New Beginning war” will ular units physically in battle. o u r definitions and understandings of war, surely persist. With each step in the growing lethality and in how it is fought and even who should fight are in telligence of robotics, the role of the “man in the great flux, driven by a remarkable new technolo loop” of decision making in war has begun to di gy that delivers immense capability. Humankind minish. For example, the pace of war is such that has been in this same kind of situation before. We only systems such as the Counter-Rocket Artil often struggle to integrate and understand new lery and Mortar, or C-RAM (which looks a bit technologies and then eventually look at what like the Star Wars robot R2-D2, with a 20-mil was once considered strange and even unaccept limeter automatic machine gun attached) can re able as completely normal. Perhaps the best act quickly enough to shoot down incoming example can be invoked from the 1400s, when rockets or missiles. The human is certainly part one French nobleman argued that guns were of the decision making but mainly in the initial tools of murder a true soldier would not deign to programming of the robot. During the actual op use. Only cowards, he wrote, “would not dare to eration of the machine, the operator really only look in the face of the men they bring down from exercises veto power, and a decision to override a distance with their wretched bullets.” a robot’s decision must be made in only half a We have “progressed” since then, but the sto second, with few willing to challenge what they ry today is much the same with robotics. Mas view as the better judgment of the machine. tery of the technology may turn out to be much Many observers argue that such a trend will easier to address than the policy dilemmas aris lower the likely mistakes in war, as well as ensure ing from the incredible capabilities of machines that the laws of war are uniformly followed, as if that can change the world around them. Indeed, they were software code in a computer processor. it is for this reason that some scientists invoke a Yet this attitude ignores the complex environ different historic parallel to where we stand now ment of war. An unmanned system may be able with robotics than the gun or airplane, instead to pick out a man carrying an AK-47 rifle from citing the atomic bomb. We are creating an ex over a kilometer away and tell whether he fired it citing technology that is pushing the frontiers of recently or not (by the weapon’s thermal signa science but raises such penetrating concerns be ture), but knowing whether that man is an insur yond the scientific realm that we may well come gent, a member of an allied militia or a simple to regret these elaborate engineering creations, shopkeeper will be as hard for the machine as it as did some designers of early nuclear warheads. is today for any human soldier. Of course, just like those inventors back in the Nor is the age-old “fog of war” being lifted by 1940s, today’s robotics developers continue technology, as former defense secretary Donald their work because it is militarily useful, highly H. Rumsfeld and other advocates for the digital profitable, as well as the cutting edge of science. More To Explore battlefield once believed. For instance, the so As Albert Einstein supposedly said, “If we knew Wired for War: The Robotics Revo- phisticated C-RAM technology reportedly once what it was we were doing, it would not be called lution and Conflict in the 21st mistook a U.S. Army helicopter for an enemy tar research, would it?” Century. P. W. Singer. Penguin, 2009. get because of a programming error. Fortunately, The real story is that what was once only fod no one was hurt. Unluckily, what an investigative der for science-fiction conventions has to be dis Bombs Away. The Economist, report described as a “software glitch” in a simi cussed seriously and not only at the Pentagon. Technology Quarterly, page 13; March 4, 2010. lar antiaircraft system in South Africa produced This narrative is of importance not solely to what a less benign outcome in 2007. Armed with a takes place at robotic trade group meetings, in The Regulation of New Warfare. 35-millimeter cannon, the weapon was supposed the research labs or on the battlefield but to how Peter W. Singer. Brookings Institution. to fire into the sky during a training exercise. In the overall tale of humanity is playing itself out. Available at www.brookings.edu/ stead it leveled and fired in a circle, killing nine Humankind had a 5,000-year monopoly on the opinions/2010/0227_defense_ regulations_singer.aspx soldiers before it ran out of ammunition. fighting of war. That monopoly has ended. ■ www.ScientificAmerican.com SCIENTIFIC AMERICAN 63 www.diako.ir© 2010 Scientific American environment

Key Concepts

■ ■ Injecting cleansed municipal wastewater into underground geothermal fields can create sources of steam for generating electricity and reduce wastewater disposal problems.

■ ■ Projects in the Santa Rosa, Calif., area are providing lessons in how best to build shallow- and deep-drilled geothermal power plants.

■ ■ Small earthquakes can be caused in the area immediately surrounding such plants— a serious complication that municipalities must consider.

—The Editors

64 Scientific American FebruaryJuly 2010 www.diako.ir© 2010 Scientific American © 2010 Scientific American Energy Clean Energy from filthy Water California cities are pumping their treated wastewater underground to create electricity By Jane Braxton Little

VAPOR rises from cooling towers at a Calpine geothermal power plant in California’s Mayacamas Mountains. www.ScientificAmerican.com SCIENTIFIC AMERICAN 65 www.diako.ir© 2010 Scientific American h e n r e s i d e n t s of Santa Rosa Pump, Don’t Dump flip a wall switch, they can take f o r s a n t a r o s a , that unique something is the a little credit for the lights that Geysers, a misnamed field of fumaroles—vents come on. In this California city, in rock formations that leak steam. The steam yesterday’s toilet flush is to- that spews out the side of the Mayacamas Moun- Wday’s electricity. tains is visible from the city, but until recently it Santa Rosa and Calpine Corporation, an offered little more than a distant backdrop. In wenergy company, are partners in the world’s 1993 Santa Rosa was facing a cease-and-desist largest geothermal wastewater-to-power proj- order and the threat of a building moratorium ect. They are using urban effluent to generate because of the city’s illegal wastewater discharg- clean energy, improving life not only for hu- es into the Russian River, important spawning mans but also for fish. For the city, the partner- grounds for endangered coho salmon and steel- russian river near Santa Rosa, ship has eliminated fines it was paying for dump- head trout. City officials were scrambling to Calif., is healthier since the city stopped discharging daily ing wastewater into the Russian River and the come up with an affordable storage and disposal wastewater there. $400-million expense of building new waste- system that would meet state environmental water storage facilities. For Calpine, the ar- requirements. On the other side of the Mayaca- rangement has revived geothermal steam fields mas, Lake County officials were under a similar that were declining from overuse. state mandate to halt illegal discharges into Clear Every day the Santa Rosa Geysers Recharge Lake, California’s largest body of freshwater. Project pumps some 12 million gallons of treat- Even treated to legal standards, the wastewater ed wastewater through a pipeline to a mountain- still contained nutrients harmful to aquatic life. top 40 miles from the city and then injects it High in the hills between the two communi- down into an aquifer a mile and a half under- ties, officials at Calpine’s geothermal operation ground. There hot rocks boil the water into were also in a quandary. Production of electric- steam, which is piped to the surface to drive elec- ity was depleting the underground resource tricity-generating turbines. A sister project in faster than it could be naturally replenished: neighboring Lake County recycles eight million Calpine’s power plants were literally running gallons of wastewater a day. Together these in- out of steam. Company officials were searching stallations generate 200 megawatts of electrici- for a source of water to inject into the steam ty—equivalent to the output of a modest-size fields to reinvigorate them. power plant—without discharging any green- The partnerships Calpine formed with Santa house gases or pollutants into the atmosphere. Rosa and Lake County fixed all three problems Some of the electricity is sent as far as San Fran- with one simple solution: moving the wastewa- cisco, 70 miles to the south. ter to where it was wanted. Today the world’s The Obama administration is touting geother- first recycled-water-to-electricity project, in

mal as a clean energy source. According to the Lake County, and the largest, in Santa Rosa, are ) U.S. Department of Energy, the technique could both poised to expand. Lake County plans to supply 10 percent of the nation’s electricity by extend its pipeline beyond Clear Lake to accept 2050, and other estimates go higher. To succeed, wastewater from Lakeport and other communi- Braxton Little lynn (

plans to expand drilling here and to start else- ties. And the neighboring town of Windsor F a h t

where will have to take into account small earth- signed a 30-year agreement in November 2008 r quakes triggered by extracting steam. Indeed, allowing it to pump 700,000 gallons of effluent

residents near the Calpine project are complain- a day into the Santa Rosa pipeline. esy of Ma t

[ The Author ] ing of increased ground shaking, and they are Officials in both counties are proud of their our

worried that an independent geothermal project project’s environmental achievements, but they ); C in the same area could exacerbate the problem. take equal satisfaction in the regulatory and fi- The benefits to Santa Rosa are many, howev- nancial stability they have brought. “These Russian River

er, says Dan Carlson, the city’s deputy director were business decisions,” Carlson says. “If we and of operations. And the partnership with Calpine could provide a cheaper solution, it would help offers a model for developing creative solutions us and Calpine.”

Jane Braxton Little is a to civic problems that seem overwhelming. Oth- pages preceding freelance writer and photographer ( ld er communities are now exploring various styles Birthplace of an Industry a based in Plumas County, California. of geothermal energy. “Every community has t h e s t o r y o f h o w the Geysers came to lose She has written for numerous magazines, including Audubon, something unique,” Carlson says. “The lesson is steam involves years of overexploitation. The Archib t hy

where she is a contributing editor. finding the right fit.” Geysers have been hissing for millennia, part of Timo

66 Scientific American July 2010 www.diako.ir© 2010 Scientific American a geothermal system east of the San Andreas Grant was building the nation’s first geothermal Calpine’s steam Fault. A large magma chamber more than five power plant at the Geysers. He completed it in miles below the surface heats a layer of rock. 1921. Pipe blowouts and well failures notwith- fields were Water trapped in this greywacke sandstone res- standing, Grant eventually produced 250 kilo- failing. But city ervoir boils into steam, which fizzes out through watts of electricity—enough to light the build- hairline fissures in the overlying rock cap. ings and streets at the Geysers Resort. By 1960 wastewater When William Bell Elliott wandered through technical advances made geothermal power could replenish in 1847 as a member of a large survey team, he commercially viable on a much larger scale. Us- dubbed the steam fields the Geysers. What he ing pipes drilled through the rock to extract the resource. found are actually fumaroles, not the spectacu- steam from its source, Pacific Gas and Electric lar eruptions of geysers shooting hot water into Company began operating an 11-megawatt the air. But Elliott’s misnomer stuck. Word of the plant. Other companies built additional plants discovery drew a steady stream of tourists that in the 1970s and 1980s. Generation at the Gey- included J. P. Morgan and presidents Ulysses S. sers peaked in 1987 at 2 ,0 0 0 megawatts, enough Grant and Theodore Roosevelt. But by the 1930s to power two million homes. Calpine entered the tourist trade had collapsed in a muddle of ho- the geothermal business in 1989 and today op- tel fires, landslides and impending war. erates 19 of the 21 Geysers power plants, spread While visitors were soaking in the steam that across 40 square miles of steep slopes pocked made some feel like “boiled angels,” John D. with hundreds of steam wells.

[ bird’s-eye view ] Three Problems, One Solution

Santa Rosa (bottom) and Lake County Lake County (top) had nowhere left to send treated wastewater. And steam fields that drive

turbines at numerous Geysers geothermal Clear Lake power plants (center) were drying from Lakeport overuse. Now, every day, the municipalities pump more than 20 million gallons of The Geysers wastewater up the Mayacamas Moun- tains to recharge the fields. Cobb Mountain

Anderson Springs

Sonoma County

Healdsburg

Middletown Russian River Windsor orin ul M

a Santa Rosa Lake County pipeline nd P

er a Santa Rosa pipeline t r Pump station Power station huck Ca C Treatment plant

www.diako.ir© 2010 Scientific American Generating Running Out of Steam three stages along the way: physical treatment a l l t h a t d r i l l i n g and pumping took a toll on in sedimentation tanks to remove grease, oil 200 megawatts the steam fields. Rainfall could not seep into the and other impurities; biological treatment to of electricity sandstone reservoir fast enough to refill the break down organic matter and remove nutri- reserves. By 1999 production had dropped sig- ents and additional compounds; and sand or ac- from wastewater nificantly, sending Calpine officials looking for tivated carbon filtration to remove remaining has displaced water to inject into the ground. The $250-mil- organic matter and parasites. The wastewater is lion Santa Rosa project presented more daunt- then exposed to ultraviolet light to kill any lin- two billion ing technical challenges than its eastside coun- gering bacteria. pounds of terpart in Lake County, which lies closer to the Calpine uses $2.5 million worth of its own elevation of the steam fields. To get wastewater geothermal electricity annually to pump the wa- greenhouse from Santa Rosa to the Geysers, a pipeline pass- ter to this peak, where it is stored before being gas emissions es underneath city streets, residential develop- injected into the steam fields east of the Maya- ments and open fields before beginning its camas crest. Beyond the tank the ground drops annually. 3,000-foot climb into the Mayacamas. through gray pines to a valley laced with pipe- Engineers made the pipeline as inconspicuous lines shining silver in the sun. At power plants as possible. “This is an environmentally con- half a mile away, steam tapped from the ground scious community, and we’re all stewards of this turns turbines, then condenses into water that system,” says Mike Sherman, Santa Rosa’s op- is cooled in funnel-shaped towers before it is re- erations coordinator for the Geysers. A drive injected into the ground. For the world’s largest along the 40-mile route from the city’s Laguna geothermal power plant, it is a surrealistic, treatment plant passes wild apple trees that give strangely bucolic panorama disturbed only by way to red-barked madrone and majestic valley the faint hum of engines in the breeze. oaks as the back roads over the pipeline wind up- ward. Much of the land is operated as a wildlife Earthquakes Raise Concern sanctuary by Audubon California. f o r r e s i d e n t s w h o l i v e within 20 miles of the A steep single-lane road leads to the pinnacle, production area, however, the scene is anything which is dominated by a dark-green three-story but pastoral. Since Calpine began injecting efflu- tank no different from any municipal water ent into the ground, local residents have experi- tank except for its contents: one million gallons enced a dramatic increase in earthquakes; activ- of wastewater. The water has been processed in ity at the Geysers is up by 60 percent since 2003.

[ how it works ] Injecting New Life Into Geothermal Power

Turbines At the Geysers, cleansed Tank Cooled Cooling towers wastewater (left) is water Steam production well injected into permeable Water vapor stone, where heat from Incoming, cleansed Natural vent magma below converts wastewater Water (fumarole) it to pressurized steam. injection A well (right) taps the steam, which turns turbines that generate electricity. The steam Caprock condenses to water, cools and is then injected back underground.

Permeable reservoir Steam

Magma don foley don

68 Scientific American July 2010 www.diako.ir© 2010 Scientific American The community of Anderson Springs, less than increase the number of jolts measuring 2.0 or a mile from the closest installation, has recorded less, but something large like a magnitude 8.0 2,562 separate jolts, including 24 with magni- earthquake needs a major fault, and the Geysers tudes greater than 4.0. Most tremors cause no area has only small fractures. In more than 30 damage, but others shake items off shelves and years of monitoring there, the largest earthquake even crack building foundations, says Hamilton recorded has been 4.5, Oppenheimer says. Hess, a retired University of San Francisco pro- The AltaRock plan caused greater concern fessor who has lived near the Geysers off and on about more powerful earthquakes, however. In since 1939. Other residents also describe the dai- July 2009 federal agencies put the project on ly jolts as more than a nuisance: “You can hear hold until a scientific review could better deter- the rumbling coming down the canyon. When it mine the risk for quakes. Facing a dubious fu- hits, it’s like an explosion under the house,” says ture, AltaRock said in December that it was Jeffrey D. Gospe, president of the Anderson abandoning the effort. In January the DOE an- Springs Community Alliance. nounced new safeguard requirements for en- In 2009 residents found themselves facing an hanced geothermal operations. even greater possibility of earthquakes from an local resident Jeffrey D. Gospe experimental project under construction outside Expanding the Benefits and fellow community activists who live near the power plants the Geysers steam fields but just two miles from b y g e n e r a t i n g 200 megawatts of electricity want geothermal operations Anderson Springs. Because no surface geother- from wastewater, Santa Rosa and Lake County changed to reduce potential dam- mal activity is present there, AltaRock Energy, have effectively reduced greenhouse gas emis- age from earthquakes, which have a Sausalito-based company, began to drill more sions by two billion pounds a year—the amount risen in frequency. than two miles down to fracture the hot bed- that a coal-burning power plant of comparable rock, inject water and tap the resulting steam. size would spew into the atmosphere. The city A similar “enhanced geothermal” project in and area towns have also stopped pouring efflu- Basel, Switzerland, triggered an earthquake mea- ent into the Russian River and Clear Lake and suring 3.4—modest by some standards but have eliminated the need to build new storage enough to cause more than $8 million in damage. and treatment facilities. And because Calpine is AltaRock officials said their Lake County project using wastewater instead of withdrawing water differed in the underlying geology and distance from Russian River tributaries—to which the from major faults. They also said they were using company has water rights—there is more fresh- technology not available in Basel. But local resi- water in the streams for fish. dents continued to protest, citing errors and ex- For entrepreneurs and scientists hoping to ex- clusions in AltaRock’s environmental analyses. pand the use of geothermal energy nationwide, Scientists have long known that extracting the Calpine project offers a wealth of experience. steam from a subterranean magma-heated res- But AltaRock’s fate could lessen interest in deep- ervoir cools it, causing the rocks to contract. To drilled enhanced geothermal systems at sites accommodate the contraction, the rocks deform with no surface activity, even though they could More To Explore through small earthquakes, explains David Op- produce more than 100,000 megawatts of elec- penheimer, a seismologist with the U.S. Geolog- tricity in the U.S., according to a study led by Jef- A Geysers Album: Five Eras of Geothermal History. Susan F. ical Survey. Spaces vacated by the steam can also ferson W. Tester, professor of sustainable energy Hodgson. California Department cave in, causing further jolts. systems at Cornell University. In May 2009 the of Conservation, Sacramento, 1997. Officials who planned the Santa Rosa waste- Obama administration made $350 million avail- water project predicted increased seismic activ- able for geothermal development, including $80 Santa Rosa Geysers Recharge ity. But the city decided to proceed, citing the million for enhanced geothermal projects. Project. California Energy Commission, 2002. Available at overriding benefits of resolving the wastewater For the many potential sites that lack an ad- www.energy.ca.gov/reports/ disposal crisis and generating clean electricity. equate supply of water to inject into the hot 2003-03-01_500-02-078V1.PDF That’s small consolation to the 500 year-round rocks, the power plants at the Geysers still serve residents who live within a 20-mile radius of the as an inspiration. They have demonstrated that The Future of Geothermal Energy: Geysers. “It’s Santa Rosa’s wastewater, and they treated effluent is a commercially viable alterna- Impact of Enhanced Geothermal Systems (EGS) on the United don’t feel the earthquakes,” Hess says. tive to freshwater for steam-generated electrici- States in the 21st Century. He and others are troubled by the expansions ty, Carlson says. Of course, safety issues require An assessment by an MIT-led ld a planned by Santa Rosa and Lake County. Will more study. But he is optimistic: “Our residents interdisciplinary panel. MIT, 2006. injecting greater volumes of water in more places are benefiting, the environment is benefiting and Available at http://geothermal.inel. gov/publications/future_of_

hy Archib t hy eventually trigger “the big one?” Not likely, Op- people all over the world can use this model to geothermal_energy.pdf ■ Timo penheimer says. Expanded production is apt to improve their own communities.”

W i nged Victory

Modern birds, long thought to have arisen only after the dinosaurs perished, turn out to have lived alongside them By Gareth Dyke

e c e m b e r in m o s c o w , and the tempera- Key Concepts ture drops under 15 degrees below zero. ■ ■ The descent of birds from small, The radiators in the bar have grown meat-eating dinosaurs is by cold, so I sit in a thick coat and gloves now established. Far less clear drinking vodka while I ponder the fos- is the origin of anatomically Dsil birds. The year is 2001, and Evgeny N. Kurochkin modern birds. of the Russian Academy of Sciences and I have just ■ ■ The conventional fossil-based spent hours at the paleontology museum as part of our thinking is that modern birds effort to survey all the avian fossils ever collected in arose only after the asteroid Mongolia by joint Soviet-Mongolian expeditions. impact that claimed the dino- Among the remains is a wing unearthed in the Gobi saurs and many other creatures Desert in 1987. Compared with the spectacularly pre- 65 million years ago. served dinosaur skeletons in the museum’s collections, ■ ■ But molecular studies and a this tiny wing—its delicate bones jumbled and crushed— smattering of equivocal fossil is decidedly unglamorous. But it offers a strong hint finds have hinted that modern that a widely held view of bird evolution is wrong. birds might have deeper roots. More than 10,000 species of birds populate the ■ ■ Recently analyzed fossils of earth today. Some are adapted to living far out on the ancient modern birds confirm open ocean, others eke out a living in arid deserts, and this earlier origin, raising the question of why these birds, side by side: Based on fossil evidence from Antarctica, but not the archaic ones, sur- this artist’s conception depicts Vegavis, an early modern bird, vived the mass extinction. foraging alongside duck-billed dinosaurs in a marine estuary —The Editors kazuhiko sano kazuhiko some 67 million years ago.

SCIENTIFIC AMERICAN 71 www.diako.ir© 2010 Scientific American still others dwell atop snow-capped mountains. [ The Author ] Deinonychus, Anchiornis and Troodon than Indeed, of all the classes of land vertebrates, the modern birds. Like those dinosaurs, early birds one comprising birds is easily the most diverse. such as Archaeopteryx and the more recently Evolutionary biologists long assumed that the discovered Jeholornis from China and Raho- ancestors of today’s birds owed their success to navis from Madagascar possessed long, bony the asteroid impact that wiped out the dino- tails, and some had sharp teeth, among other saurs and many other land vertebrates around primitive traits. Neornithines, in contrast, lack 65 million years ago. Their reasoning was sim- those characteristics and exhibit a suite of ad- ple: although birds had evolved before that ca- vanced ones. These features include fully fused tastrophe, anatomically modern varieties ap- Gareth Dyke prefers dry bones and toe bones and fingerless wings, which reduce the peared in the fossil record only after that event. flattened fossils to living birds. A paleon- weight of the skeleton, allowing more efficient The dawning of ducks, cuckoos, hummingbirds tologist at University College Dublin, he flight, and highly flexible wrists became interested in animal flight when — and other modern forms which together make he was an undergraduate student in and wings, which enhance up the neornithine (“new birds”) lineage— England. In conducting his research on maneuverability in the air. seemed to be a classic case of an evolutionary the evolution of birds and their flight, How and when the neorni- radiation in response to the clearing out of eco- he has studied and described fossils from thines acquired these traits logical niches by an extinction event. In this all over the world. When not traveling to were impossible to deter- visit museums or to do fieldwork in the case, the niches were those occupied by dino- middle of deserts, Dyke enjoys learning mine, however, thanks to an saurs, the flying reptiles known as pterosaurs about 19th-century European history. absence of fossils document- and archaic birds. He is writing a book about a Transylva- ing the transition. Over the past decade, however, mounting ev- nian dinosaur collector who was also This is not to say the fossil re- a spy for Austria-Hungary. idence from the fossil record—including that cord lacked avian remains interme- crushed wing—and from analyses of the DNA diate in age between the first birds and of living birds has revealed that neornithine the postextinction neornithines. Clearly birds probably diversified earlier than 65 mil- by the early Cretaceous, more than 100 million years ago. The findings have upended the lion years ago, birds representing a wide range traditional view of bird evolution—and sparked of flight adaptations and ecological specializa- important new questions about how these ani- tions had evolved. Some flew on wings that were mals soared to evolutionary heights. broad and wide; others had wings that were long and thin. Some lived in forests eating insects and Early Birds fruit; others made their home along lakeshores b i r d s a r e o n e of just three groups of vertebrates or in the water and subsisted on fish. This in- ever to have evolved active, flapping flight. The credible diversity persisted through the latest other two are the ill-fated pterosaurs and the bats, stages of the Cretaceous, 65 million years ago. which appeared much later and share the skies with birds to this day. For years paleontologists debated the origin of the earliest birds. One side argued that they evolved from small, meat-eating dinosaurs called theropods; the other contended Long tail that they evolved from earlier reptiles. But the discoveries over the past two decades of birdlike dinosaurs, including many with downy coats, have convinced most scientists that birds evolved from theropod dinosaurs. Pubis angled to rest of pelvis Connecting the dots between ancestral avi- ans and modern birds has proved far trickier, however. Consider Archaeopteryx, the 145-million-year-old creature from Germany that is the oldest known bird. Archaeopteryx preserves the earliest definitive evidence for wings with BIRDS EVOLVED from small, carnivorous dinosaurs. Accordingly, some of the oldest known fossil e asymmetric feathers capable of generating the birds, such as the 145-million-year-old Archaeopteryx, retain a number of primitive characteristics ynn lift required for flight—one defining character- linking them to this so-called theropod group—teeth and long tails, for instance. Modern birds ia j. w istic of the group. Yet it more closely resembles shed these features and evolved fingerless wings and highly flexible wrists, among other traits c ri t

small-bodied dinosaurs such as Velociraptor, that enhanced their flying ability. Pa

72 Scientific American July 2010 www.diako.ir© 2010 Scientific American In fact, along with my Dutch colleagues at the Molecular Clues It is funny to Natural History Museum in Maastricht, I have b y t h e 1990s, while paleontologists were still described remains of toothed birds found just looking for ancestral neornithines in the Creta- think of a robin below the geologic horizon that marks the end- ceous and coming up empty-handed, another perched on Cretaceous extinction event. But all the Creta- method of reconstructing the evolutionary his- ceous birds complete enough to classify belonged tory of organisms—one that did not involve the the back of a to lineages more ancient than neornithines, and fossil record—was gaining traction. Molecular Velociraptor or these lineages did not survive the catastrophe– biologists were sequencing the DNA of living which is why, until recently, the available evi- organisms and comparing those sequences to a duck paddling dence implied that the simplest explanation for estimate when two groups split from each other. alongside a the rise of modern birds was that they originated They can make such estimates because certain and radiated after the extinction event. parts of the genome mutate at a more or less con- Spinosaurus. stant rate, constituting the “ticking” of the so- called molecular clock. Molecular biologists had long questioned the Free fingers

Fused fingers

Teeth

No teeth

Short tail

Pubis parallel to rest of pelvis

Archaeopteryx Modern duck

SCIENTIFIC AMERICAN 73 © 2010 Scientific American www.diako.ir© 2010 Scientific American Why were classical, fossil-based view of modern bird evo- Ducks in a Row lution. So they tackled the problem using their a t l a s t, after the new millennium, paleontolo- modern birds able clock technique to estimate the divergence dates gists’ luck began to change for the better, starting to survive the for major lineages of modern birds. Among the with the tiny Mongolian wing that Evgeny and I most significant splits is the one that occurred focused on in Moscow. Back when Evgeny first asteroid impact between the large, mostly flightless paleognaths saw the fossil in 1987, he told me that he thought and its attendant (ostriches and emu and their kin) and the Gal- it looked like a member of the presbyornithids, a loanserae (which includes chickens and other group of now extinct ducklike birds related to ecological members of the Galliformes group, as well as modern ducks and geese. But at 70 million years changes when ducks and other members of the Anseriformes old, it was a Cretaceous bird, and everyone group). The DNA studies concluded that these knew—or thought they did—that there was no their more two lineages—the most primitive of the living definitive evidence for presbyornithids in the primitive avian neornithines—split from each other deep in the Cretaceous. Yet our comparisons in the museum Cretaceous. And researchers obtained similarly that cold winter in 2001 demonstrated conclu- cousins and ancient divergence dates for other lineages. sively that the wing—with its straight carpo- their fellow fliers, The findings implied that, contrary to con- metacarpus (the bone formed by the fusion of ventional paleontological wisdom, neornithines the hand bones) and details of canals, ridges and the pterosaurs, lived alongside dinosaurs. It is funny to think of muscle scars—did indeed belong to a presbyor- were not? a robin perched on the back of a Velociraptor or nithid, which, moreover, was the oldest unequiv- a duck paddling alongside a Spinosaurus. But ocal representative of any neornithine group. the molecular evidence for the contemporaneity Our finding fit the predictions of the molecular of modern birds and dinosaurs was so compel- biologists perfectly. In a 2002 paper that formal- ling that even the paleontologists—who have ly described the animal, we gave it the name typically viewed with skepticism those DNA Teviornis. findings that conflict with the fossil record—be- Before long, Teviornis was joined by a second gan to embrace it. Still, those of us who study confirmed early neornithine,Vegavis, from Ant- ancient skeletons urgently wanted fossil confir- arctica’s Vega Island. Vegavis had been found in mation of this new view of bird evolution. the 1990s only to languish in relative anonymity

[ FINDING ]

Earlier Origin Neornithines (modern birds) The traditional view of bird evolution holds that whereas archaic End-Cretaceous Extinction avian groups arose long before the mass extinction that doomed  (65 million years ago) the dinosaurs and other beasts 65 million years ago, anatomically modern birds originated after that catastrophic event, filling newly available ecological niches. But recent fossil discoveries of modern Paleognaths birds predating that mass extinction—namely, 67-million-year-old

Vegavis and 70-million-year-old Teviornis—show that this group ) evolved earlier than previously thought and, unlike their archaic duck counterparts, somehow averted elimination. and

Neoaves ostrich, hummingbird ostrich,

Enantiornithines n ( e ians Traditional View t Origin of birds Origin of neornithines hris n c

  e ); j Ornithurines Passeriformes  New Understanding sparrow Origin of neornithines and fossilbirds ( Early lineages of ornithurines d

Galloanseres n goul w sha

74 Scientific American July 2010 www.diako.ir© 2010 Scientific American for years before its true significance came to and hence gain information about the aerody- hard evidence light. In 2005 Julia A. Clarke, now at the Uni- namic capabilities of fossil birds. But so far as we Partial skeleton of Vegavis from versity of Texas at Austin, and her colleagues can tell, the wing shapes of the two groups of Antarctica’s Vega Island reveals a published a paper showing that Vegavis was an- fossil birds do not differ; in other words, we do 67-million-year-old bird with distinctly other bird from the Cretaceous that exhibits a not think that early neornithines were any bet- modern features, including a broad number of features found in modern ducks, par- ter at flying than were the enantiornithines (al- shoulder girdle and fused wing bones. ticularly in its broad shoulder girdle, pelvis, wing though both these groups were most bones and lower legs. At 66 million to 68 million likely better in the air than ear- years old, Vegavis is a little younger than Tevior- lier theropodlike birds such nis but still clearly predates the mass extinction. as Archaeopteryx). And it is a much more complete fossil, preserv- If flight ability did ing the better part of a skeleton. not give the neorni- For most paleontologists, Vegavis clinched thines an advantage the case for Cretaceous neornithines. Thus en- over their Creta- lightened, researchers have begun reexamining ceous counterparts, fossil collections from this time period, looking what did? A num- for additional examples of early modern birds. ber of paleontolo- One investigator, Sylvia Hope of the California gists, including me, Academy of Sciences in San Francisco, had been have posited that arguing for years that bird species she has identi- differences in forag- fied from fossils found in New Jersey and Wyo- ing habits might have ming that date to between 80 million and 100 conferred a competitive million years ago are modern. But the finds— edge. In support of that the- mostly single bones—had been considered by ory, I have shown in a series other researchers as too scrappy to identify con- of papers published over the past clusively. The revelations about Vegavis and Te- few years that modern birds pre- viornis suggest that she was right all along. Com- served in the immediate aftermath of the

anuary 20, 2005 parisons of Hope’s bones with more complete re- mass extinction, in rocks 60 million years old mains should prove illuminating in this regard. and younger, probably lived mostly in wet envi- More To Explore ol. 433; J ronments: coastlines, lakes, the edges of rivers , V A New Presbyornithid Bird (Aves, Flying the Coop and the deep ocean, for example. Many of the Anseriformes) from the Late Cre-

Nature r o o t i n g m o d e r n b i r d s in the Cretaceous birds that inhabit such environments today— taceous of Southern Mongolia. E. N. neatly aligned the fossil record with the DNA- ducks among them—are typically generalists, Kurochkin, G. J. Dyke and A. A. Karhu

al.,etin in American Museum Novitates, No. e based divergence dates. But it raised a vexing able to subsist on a wide variety of foods. And 3866, pages 1–12; December 27, 2002. new question, namely, Why were modern birds ducklike birds are currently the one confirmed . Clark. A able to survive the asteroid impact and its atten- lineage of modern birds we have found in the Survival in the First Hours of the ulia J dant ecological changes when their more primi- Cretaceous. The groups of Cretaceous birds that Cenozoic. Douglas S. Robertson et al. tive avian cousins and their fellow fliers, the pte- did not survive the disaster, in contrast, have in Geological Society of America ous,” by by ous,” Bulletin, Vol. 116, Nos. 5–6, pages ce rosaurs, were not? To my mind, this constitutes been collected from rocks that were formed in a 760–768; May 2004. et the single biggest remaining mystery of bird evo- many different kinds of environments—includ- Cr e h t lution. The answer is still very much up for ing seashores, inland areas, deserts and forests. DefinitiveF ossil Evidence for the grabs, and I am devoting much of my research at This ecological diversity may indicate that the Extant Avian Radiation in the ionin t ia the moment to trying to get at it. archaic birds had evolved specializations for Cretaceous. Julia A. Clarke et al. d With only a couple of confirmed Cretaceous feeding in each of these niches. Perhaps, then, in Nature, Vol. 433, pages 305–308; January 20, 2005. neornithines on record, there is not much in the the secret of early modern birds’ success was aviant ra an t way of fossil clues to go on. Insights have come simply the fact that they were less specialized The Beginnings of Birds: Recent x e e from studies of living birds, however. Using a than the other groups. Discoveries, Ongoing Arguments h t and New Directions. Luis M. or huge data set of measurements of living birds, Such flexibility might have enabled the neor- f Chiappe and Gareth J. Dyke in Major ce

n my colleagues in the U.K. and I have shown, for nithines to adapt more easily to the changing

de Transitions in Vertebrate Evolution. vi example, that the wing-bone proportions of conditions that followed the asteroid impact. It e Edited by J. S. Anderson and H.-D. primitive modern birds, including Teviornis and is an appealing idea, but these are early days.

ossil Sues. Indiana University Press, 2007. f e Vegavis, are no different from those of the ex- Only with the discovery of more fossils —wheth- iv t ini tinct enantiornithines. Comparing the fossil er in the ground or in museum drawers—will we The Inner Bird: Anatomy and ef wing-bone proportions with those of living birds be able to determine how modern birds eluded Evolution. Gary W. Kaiser. University of British Columbia Press, 2007.

From“D allows us to infer some aspects of wing shape elimination and took wing. ■

www.ScientificAmerican.com SCIENTIFIC AMERICAN 75 www.diako.ir© 2010 Scientific American psychology How Babies Think Even the youngest children know, experience and learn far more than scientists ever thought possible By Alison Gopnik Photographs by Timothy Archibald

h i r t y y e a r s a g o most psychologists, discuss in this article), you might indeed con- philosophers and psychiatrists thought clude that not much is going on. Babies, after all, that babies and young children were ir- cannot talk. And even preschoolers are not good rational, egocentric and amoral. They at reporting what they think. Ask your average believed children were locked in the three-year-old an open-ended question, and you Tconcrete here and now—unable to understand are likely to get a beautiful but incomprehensible cause and effect, imagine the experiences of oth- stream-of-consciousness monologue. Earlier er people, or appreciate the difference between researchers, such as the pioneering Swiss psy- reality and fantasy. People still often think of chologist Jean Piaget, concluded that children’s Key Concepts children as defective adults. thought itself was irrational and illogical, ego- ■ ■ Babies’ and young children’s But in the past three decades scientists have centric and “precausal”—with no concept of cognitive abilities far surpass discovered that even the youngest children know cause and effect. those that psychologists long more than we would ever have thought possible. The new science that began in the late 1970s attributed to them. They can, Moreover, studies suggest that children learn depends on techniques that look at what babies for instance, imagine another about the world in much the same way that sci- and young children do instead of just what they person’s experiences and grasp cause and effect. entists do—by conducting experiments, analyz- say. Babies look longer at novel or unexpected ing statistics, and forming intuitive theories of events than at more predictable ones, and exper- ■ ■ Children learn about the world the physical, biological and psychological realms. imenters can use this behavior to figure out what much as scientists do—in Since about 2000, researchers have started to babies expect to happen. The strongest results, effect, conducting experi- understand the underlying computational, evo- however, come from studies that observe actions ments, analyzing statistics and forming theories to ac- lutionary and neurological mechanisms that un- as well: Which objects do babies reach for or count for their observations. derpin these remarkable early abilities. These crawl to? How do babies and young children im- revolutionary findings not only change our ideas itate the actions of people around them? ■ ■ The long helplessness of babies about babies, they give us a fresh perspective on Although very young children have a hard may be an evolutionary trade- human nature itself. time telling us what they think, we can use lan- off, a necessary consequence of having brains wired for guage in more subtle ways to tease out what they prodigious feats of learning Physics for Babies know. For example, Henry Wellman of the Uni- and creativity. w h y w e r e w e so wrong about babies for so versity of Michigan at Ann Arbor has analyzed long? If you look cursorily at children who are recordings of children’s spontaneous conversa- —The Editors four years old and younger (the age range I will tions for clues to their thinking. We can give chil-

76 Scientific American July 2010 www.diako.ir© 2010 Scientific American www.ScientificAmerican.com SCIENTIFIC AMERICAN 77 © 2010 Scientific American www.diako.ir© 2010 Scientific American dren very focused questions—for instance, ask- get older. Some scientists have argued that ba- Babies look ing them to choose between just two alternatives, bies must be born knowing much of what adults longer at novel or rather than asking an open-ended question. know about how objects and people behave. Un- In the mid-1980s and through the 1990s, sci- doubtedly, newborns are far from being blank unexpected events entists using these techniques discovered that slates, but the changes in children’s knowledge than at more babies already know a great deal about the world also suggest that they are learning about the around them. That knowledge goes well beyond world from their experiences. predictable ones, concrete, here-and-now sensations. Researchers One of the greatest mysteries of psychology and experimenters such as Renée Baillargeon of the University of Il- and philosophy is how human beings learn about linois and Elizabeth S. Spelke of Harvard Uni- the world from a confusing mess of sensory data. can use this versity found that infants understand funda- Over the past decade researchers have begun to behavior to figure mental physical relations such as movement tra- understand much more about how babies and jectories, gravity and containment. They look young children can learn so much so quickly and out what babies longer at a toy car appearing to pass through a accurately. In particular, we have discovered expect to happen. solid wall than at events that fit basic principles that babies and young children have an extraor- of everyday physics. dinary ability to learn from statistical patterns. By the time they are three or four, children have elementary ideas about biology and a first The Statistics of Blickets understanding of growth, inheritance and ill- in 1996 Jenny R. Saffran, Richard N. Aslin and ness. This early biological understanding reveals Elissa L. Newport, all then at the University of that children go beyond superficial perceptual Rochester, first demonstrated this ability in stud- appearances when they reason about objects. ies of the sound patterns of language. They played Susan A. Gelman, also at Michigan, found that sequences of syllables with statistical regularities young children believe that animals and plants to some eight-month-old babies. For example, have an “essence”—an invisible core that stays “bi” might follow “ro” only one third of the the same even if outside appearances change. time, whereas “da” might always follow “bi.” For babies and young children, the most im- Then they played the babies new strings of sounds portant knowledge of all is knowledge of other that either followed these patterns or broke them. people. Andrew N. Meltzoff of the University of Babies listened longer to the statistically unusual Washington showed that newborns already un- strings. More recent studies show that babies can derstand that people are special and will imitate detect statistical patterns of musical tones and their facial expressions. visual scenes and also more abstract grammati- In 1996 Betty Repacholi (now at Washington) cal patterns. and I found that 18-month-olds can understand Babies can even understand the relation be- that I might want one thing, whereas you want tween a statistical sample and a population. In a [ The Author ] another. An experimenter showed 14- and 2008 study my University of California, Berke- 18-month-olds a bowl of raw broccoli and a bowl ley, colleague Fei Xu showed eight-month-old of goldfish crackers and then tasted some of each, babies a box full of mixed-up Ping-Pong balls: making either a disgusted face or a happy face. for instance, 80 percent white and 20 percent Then she put her hand out and asked, “Could you red. The experimenter would then take out five give me some?” The 18-month-olds gave her balls, seemingly at random. The babies were broccoli when she acted as if she liked it, even more surprised (that is, they looked longer and though they would not choose it for themselves. more intently at the scene) when the experiment- Alison Gopnik is professor of psycholo- (The 14-month-olds always gave her crackers.) er pulled four red balls and one white one out of gy and affiliate professor of philosophy at So even at this very young age, children are not the box—an improbable outcome—than when the University of California, Berkeley. She completely egocentric—they can take the per- she pulled out four white balls and one red one. has done groundbreaking research into spective of another person, at least in a simple Detecting statistical patterns is just the first how children develop a “theory of mind,” way. By age four, their understanding of every- step in scientific discovery. Even more impres- the ability to understand that other people have minds and may believe or want day psychology is even more refined. They can sively, children (like scientists) use those statistics different things than they do. She helped explain, for instance, if a person is acting oddly to draw conclusions about the world. In a version to formulate the “theory theory,” the because he believes something that is not true. of the Ping-Pong ball study with 20-month-old idea that children learn in the same way By the end of the 20th century experiments babies using toy green frogs and yellow ducks, that scientists do. Investigations of chil- had thus charted impressively abstract and so- the experimenter would take five toys from the dren’s minds, she argues, could help us resolve deep philosophical questions phisticated knowledge in babies and the equally box and then ask the child to give her a toy from

such as the mystery of consciousness. impressive growth of that knowledge as children some that were on the table. The children showed Courtesy of Kathleen King

78 Scientific American July 2010 www.diako.ir© 2010 Scientific American no preference between the colors if the experimenter had taken mostly green frogs from the box of mostly green toys. Yet they specifically gave her a duck if she had taken mostly ducks from the box—apparently the children thought her statistically unlikely selection meant that she was not acting randomly and that she must prefer ducks. In my laboratory we have been investigating how young children use statistical evidence and experimentation to figure out cause and effect, and we find their thinking is far from being “precausal.” We introduce them to a device we call “the blicket detector,” a machine that lights up and plays music when you put some things on it but not others. Then we can give children patterns of evidence about the detector and see what causal conclusions they draw. Which objects are the blickets? In 2007 Tamar Kushnir, now at Cornell Uni- versity, and I discovered that preschoolers can use probabilities to learn how the machine works. We repeatedly put one of two blocks on the machine. The machine lit up two out of three times with the yellow block but only two out of six times for the blue one. Then we gave the children the blocks and asked them to light up the machine. These children, who could not yet add or subtract, were more likely to put the high- moved the yellow gear and turned the switch, Statistician probability yellow block on the machine. nothing happened. We asked the children to pick at Work They still chose correctly when we waved the the picture that matched how the toy worked. high-probability block over the machine, acti- Four-year-olds were amazingly good at ascer- Babies are skillful statistical analysts. Experiments showed that eight- vating it without touching it. Although they taining how the toy worked based on the pattern month-olds notice if an improbable thought this kind of “action at a distance” was of evidence that we presented to them. More- number of red Ping-Pong balls are unlikely at the start of the experiment (we asked over, when other children were just left alone taken out of a collection that is them), these children could use probability to with the machine, they played with the gears in mostly white. Variations of the experiments (such as swapping the discover brand-new and surprising facts about ways that helped them learn how it worked—as role of red and white) control against the world. if they were experimenting. alternative explanations (such as In another experiment Laura Schulz, now at Another study by Schulz used a toy that had having a greater interest in red the Massachusetts Institute of Technology, and two levers and a duck and a puppet that popped objects). Twenty-month-olds tested I showed four-year-olds a toy with a switch and up. One group of preschoolers was shown that with green and yellow toys inferred two gears, one blue and one yellow, on top. The the duck appeared when you pressed one lever that a person taking an unusually large number of the rare color would gears turn when you flip the switch. This simple and that the puppet popped up when you pressed prefer to be given a toy of that toy can work in many ways. Perhaps the switch the other one. The second group saw that when color. Thus, babies and young chil- makes both gears turn at once, or perhaps the you pressed both levers at once, both toys popped dren learn about the world like switch turns the blue gear, which turns the yel- up, but they never got a chance to see what the scientists—by detecting statistical low one, and so on. We showed the children pic- levers did separately. Then the experimenter had patterns and drawing conclusions from them. tures illustrating each of these possibilities—the the children play with the toy. Children from the yellow gear would be depicted pushing the blue first group played with the toy much less than one, for instance. Then we showed them toys those from the second group. They already knew that worked in one or the other of these ways how it worked and were less interested in explor- and gave them rather complex evidence about ing it. The second group faced a mystery, and how each toy worked. For example, the children they spontaneously played with the toy, soon un- who got the “causal chain toy” saw that if you covering which lever did what. removed the blue gear and turned the switch, the These studies suggested that when children yellow gear would still turn but that if you re- play spontaneously (“getting into everything”)

www.ScientificAmerican.com SCIENTIFIC AMERICAN 79 © 2010 Scientific American www.diako.ir© 2010 Scientific American they are also exploring cause and effect and do- the computers in children’s heads might work. ing experiments—the most effective way to dis- Probabilistic models combine two basic ideas. cover how the world works. First, they use mathematics to describe the hypotheses that children might have about things, The Baby Computer people or words. For example, we can represent o b v i o u s l y c h i l d r e n a r e n o t doing experi- a child’s causal knowledge as a map of the caus- Natural ments or analyzing statistics in the self-con- al relations between events. An arrow could experimenters scious way that adult scientists do. The chil- point from “press blue lever” to “duck pops up” Four-year-olds are adept at interpret- dren’s brains, however, must be unconsciously to represent that hypothesis. ing evidence to learn about cause and processing information in a way that parallels Second, the programs systematically relate effect, such as determining if one cog the methods of scientific discovery. The central the hypotheses to the probability of different pat- on a machine is turning another — (below). Some even carried out the idea of cognitive science is that the brain is a kind terns of events the kind of patterns that emerge correct experiments (and drew the of computer designed by evolution and pro- from experimentation and statistical analysis in right conclusion) while freely “play- grammed by experience. science. Hypotheses that fit the data better being” with the toy. Research involving Computer scientists and philosophers have become more likely. I have argued that children’s a “blicket detector” (opposite page), gun to use mathematical ideas about probability brains may relate hypotheses about the world to which is more likely to light up for some combinations of blocks than for to understand the powerful learning abilities of patterns of probability in a similar way. Children others, found that four-year-olds scientists—and children. A whole new approach reason in complex and subtle ways that cannot could use statistics to learn how the to developing computer programs for machine be explained by simple associations or rules. machine worked, even when it learning uses what are called probabilistic mod- Furthermore, when children unconsciously showed new, unexpected behavior. els, also known as Bayesian models or Bayes nets. use this Bayesian statistical analysis, they may Indeed, they were more open-minded than adults when faced with evidence The programs can unravel complex gene expres- actually be better than adults at considering un- that the machine responded to blocks sion problems or help understand climate change. usual possibilities. In a study to be presented at in an unusual way. The approach has also led to new ideas about how a conference later this year, my colleagues and I showed four-year-olds and adults a blicket detector that worked in an odd way, requiring two blocks on it together to make it go. The four- year-olds were better than the adults at grasping this unusual causal structure. The adults seemed to rely more on their prior knowledge that things usually do not work that way, even though the evidence implied otherwise for the machine in front of them. In other recent research my group found that young children who think they are being in- structed modify their statistical analysis and may become less creative as a result. The experimenter showed four-year-olds a toy that would play music if you performed the right sequence of actions on it, such as pulling a handle and then squeezing a bulb. For some children, the experimenter said, “I don’t know how this toy works— let’s figure it out.” She proceeded to try out various longer action sequences for the children, some that ended with the short sequence and made music and some that did not. When she asked the children to make the toy work, many of them tried the correct short sequence, astutely omitting actions that were probably superfluous based on the statistics of what they had seen. With other children, the experimenter said that she would teach them how the toy worked by showing them sequences that did and did not produce music, and then she acted on the toy in exactly the same way. When asked to make the

80 Scientific American July 2010 www.diako.ir© 2010 Scientific American toy work, these children never tried a shortcut. Instead they mimicked the entire sequence of actions. Were these children ignoring the statistics of what they saw? Perhaps not—their behavior is accurately described by a Bayesian model in which the “teacher” is expected to choose the most instructive sequences. In simple terms: if she knew shorter sequences worked, she would not have shown them the unnecessary actions.

Evolution and Neurology if t h e b r a i n is a computer designed by evolution, we can also ask about the evolutionary jus- tification and neurological basis for the extraor- dinary learning abilities we see in very young children. Recent biological thinking is in close accord with what we see in the psychology lab. From an evolutionary perspective, one of the most striking things about human beings is our long period of immaturity. We have a much longer childhood than any other species. Why make babies so helpless for so long and thus require adults to put so much work and care into keep- The brain region called the prefrontal cortex ing their babies alive? is distinctive to humans and takes an especially Across the animal kingdom, the intelligence long time to mature. The adult capacities for fo- and flexibility of adults are correlated with the cus, planning and efficient action that are gov- immaturity of babies. “Precocial” species such erned by this brain area depend on the long as chickens rely on highly specific innate capaci- learning that occurs in childhood. This area’s ties adapted to one particular environmental wiring may not be complete until the mid-20s. niche, and so they mature quickly. “Altricial” The lack of prefrontal control in young chil- species (those whose offspring need care and dren naturally seems like a huge handicap, but it feeding by parents) rely on learning instead. may actually be tremendously helpful for learn- Crows, for instance, can take a new object, such ing. The prefrontal area inhibits irrelevant More To Explore as a piece of wire, and work out how to turn it thoughts or actions. But being uninhibited may The Scientist in the Crib: Minds, into a tool, but young crows depend on their par- help babies and young children to explore freely. Brains, and How Children Learn. ents for much longer than chickens. There is a trade-off between the ability to ex- Alison Gopnik, Andrew N. Meltzoff A learning strategy has many advantages, but plore creatively and learn flexibly, like a child, and Patricia K. Kuhl. William Morrow until learning takes place, you are helpless. Evo- and the ability to plan and act effectively, like an and Company, 1999. lution solves this problem with a division of la- adult. The very qualities needed to act efficient- Bayesian Networks, Bayesian bor between babies and adults. Babies get a pro- ly—such as swift automatic processing and a Learning and Cognitive tected time to learn about their environment, highly pruned brain network—may be intrinsi- Development. Special section without having to actually do anything. When cally antithetical to the qualities that are useful in Developmental Science, Vol. 10, they grow up, they can use what they have for learning, such as flexibility. No. 3, pages 281–364; May 2007. learned to be better at surviving and reproduc- A new picture of childhood and human na- Causal Learning: Psychology, ing—and taking care of the next generation. ture emerges from the research of the past de- Philosophy, and Computation. Fundamentally, babies are designed to learn. cade. Far from being mere unfinished adults, ba- Edited by Alison Gopnik and Laura Neuroscientists have started to understand bies and young children are exquisitely designed Schulz. Oxford University Press, 2007. some of the brain mechanisms that allow all this by evolution to change and create, to learn and learning to occur. Baby brains are more flexible explore. Those capacities, so intrinsic to what it The Philosophical Baby: What Children’s Minds Tell Us about than adult brains. They have far more connec- means to be human, appear in their purest forms Truth, Love, and the Meaning tions between neurons, none of them particular- in the earliest years of our lives. Our most valu- of Life. Alison Gopnik. Farrar, Straus ly efficient, but over time they prune out unused able human accomplishments are possible be- and Giroux, 2009. connections and strengthen useful ones. Baby cause we were once helpless dependent children brains also have a high level of the chemicals that and not in spite of it. Childhood, and caregiving, Alison Gopnik’s Web site: alisongopnik.com make brains change connections easily. is fundamental to our humanity. ■ www.ScientificAmerican.com SCIENTIFIC AMERICAN 81 www.diako.ir© 2010 Scientific American environment

The Drillers Are Coming Companies and regulators are squaring off over a controversial technique that yields natural gas but threatens to pollute water supplies By Mark Fischetti

s i n g l e , v a s t s h a l e d e p o s i t — the rush is on to capture as much Marcellus gas as Marcellus formation, stretching possible. Drilling is expanding fastest in Penn- from Tennessee to New York— sylvania’s extensive reserve. Only two Marcellus might contain enough natural gas to wells were drilled in that state in 2005, but 210 supply the U.S. for more than 40 were drilled in 2008, and 768 were drilled in Ayears at today’s consumption rates, according to 2009, according to the Pennsylvania Depart- recent estimates. Thousands of vertical wells ment of Environmental Protection (DEP). And have exploited the shale’s easy-to-reach deposits. every year the portion of drilling permits for But newer technology and improved procedures horizontal wells has increased significantly, ac- are making horizontal drilling cost-effective, counting for 75 percent in 2009 and 87 percent greatly expanding the amount of gas that can be so far in 2010. Fewer than 3,000 Marcellus drill- extracted economically. ing permits were approved from 2005 through Political pressure is increasing to achieve en- 2009, yet “we expect about 5,000 applications ergy independence from overseas suppliers and in 2010,” says John Hanger, secretary of the to use cleaner sources such as natural gas to cre- DEP. Horizontal drilling is spreading rapidly ate electricity, which emits 40 percent less car- across Europe as well. awk bon dioxide than burning coal. In response, the Concern is growing, too: scientists, politi- H cians and public advocates are claiming with in- ight to L creasing urgency that the horizontal process— s Key Concepts known as slickwater hydraulic fracturing, or ■ ■ The Marcellus shale could potentially supply the fracking—poses a threat to the environment and ecial thank p country’s natural gas needs for 40 years. people’s health. Enormous volumes of freshwa- ■ ■ Critics claim the hydraulic fracturing process that taps ter and chemicals are forced down the wells to the gas can contaminate drinking water supplies, break the rock and free the gas, and large quan- enry Fair; S prompting regulators to propose tough controls. tities of fouled water flow back up.

■ ■ Full disclosure of chemicals injected into the earth Residents in states where fracking has been h by © 2010 J. H during the fracking process could ease tensions. practiced for years have charged that gas pro- p duction has contaminated air and drinking wa- —The Editors

ter. Investigations by state or federal agencies in Photogra

82 Scientific American July 2010 www.diako.ir© 2010 Scientific American Texas, Colorado and Wyoming have raised anx- iety. An August 2009 air-quality study in Dish, Tex., by the state’s Commission on Environmen- tal Quality found that benzene, xylene and other toxins exceeded legal limits. Isolated incidents do not constitute scientific proof that gas production is systemically perilous. On the other hand, the recent oil disaster in the Gulf of Mex- ico makes an eloquent case for caution. Does fracking pose too big of a threat? The answer is not clear.

Heightened Scrutiny s a f e t y disagreements between industry and citizen groups boiled over into national news earlier this year. Because the Marcellus formation underlies the watersheds that supply more than nine million people in the New York City area and another 200,000 upstate in Syracuse, the New York Department of Environmental Conservation announced in April that it would require drilling applicants to meet tough, site- specific environmental reviews—procedures that would be so time-consuming and costly that industry would walk away. “We’re not going to go to New York because of that,” acknowledges Mark D. Whitley, a senior vice president at Range Resources in Fort Worth, Tex., one of the biggest Marcellus drillers. A month before the New York announcement was made, the U.S. Environmental Protection Agency had begun a two-year study of the horizontal drilling process, from site selection to the disposal of fracking fluids. In e-mail responses to questions from Scientific American, the agency writes that anecdotal evidence indicates potential adverse impacts on drinking water, but “there is a lack of scientific information to verify these concerns.” The study, the EPA notes, is intended “to resolve the scientific uncertainties.” Some legislators have said the pace of land leasing and drilling should slow down until such examinations are completed. But Kathryn Z. Klaber, president of the Marcellus Shale Coali- tion, an industry group in Pennsylvania, says drillers will not ease up, other than possibly in New York. Whitley adds, “I don’t see the EPA study having any impact” on expansion plans.

drill rig bores a hole Down the Hole down to the Marcellus c o n c e r n s s t e m l a r g e l y from chemicals used shale under Dimock, in the fracking process. After four or five acres of Pa. Drilling fluid and land are cleared, a well is drilled to the shale lay- cuttings are sprayed er, typically 3,000 to 8,000 feet below the sur- into a retention pond. face. The layer is usually only a few hundred feet www.ScientificAmerican.com SCIENTIFIC AMERICAN 83 www.diako.ir© 2010 Scientific American Catskill and Delaware [ the resource ] watersheds MA sounds small, that fraction of one million gal- vast supply, lons is 5,000 gallons of chemicals. NY Over time, five frackings would be done worried eye Croton CT Marcellus watershed across the mile stretch. And up to 12 horizontal shale Shale deposits considered bores may be drilled from one well over several economically worth City water years. Ten bores, each with five stages, would mining for natural gas supply PA require 50 million gallons of freshwater and New York City NJ 250,000 gallons of chemicals. Geologists say it is highly unlikely that the chemicals could find their way up to groundwater, which typically lies a few hundred feet below the surface, because the shale is below imperme-

Marcellus shale able rock. But the flowback fluid can leak at the wellhead. “The high pressures can cause mal- functions at the surface,” Pennsylvania’s Hanger says. Although the pipe is encased in cement to Utica shale prevent such leaks, “the space between the wider bore and the narrower pipe is not uniform,”

Barnett shale notes Anthony R. Ingraffea, a professor of engineering at Cornell University who has a Ph.D. in Huge underground shale formations (gold) could provide the U.S. with natural gas for years. rock fracture mechanics and whose research has But concerns that drilling into deposits could contaminate freshwater sources has prompted at times been supported by the gas industry. The New York to fight extraction in regions of the Marcellus that underlie drinking water supplies. bore intersects voids, fractures and cracks, “and sometimes cement doesn’t fill those features.” It is also unclear how long the cement will thick, so the drill bit gradually turns about 90 last. And the drilling may cross pockets of meth- degrees and continues horizontally through the ane, allowing the gas to rise up the borehole to layer for up to a mile. Steel pipe is then inserted groundwater. Another problem may involve the length of the bore and encased in cement. leaks from poorly built or lined holding ponds. Shale is fracked in stages of about 1,000 feet Up to 40 percent of the water and chemicals sent each, beginning at the far end of the pipe. For each down the hole returns in the briny flowback flu- stage, huge pumps force a million or more gallons id. “The companies are trying to do it right,” of fluid through holes in the pipe at up to 6,000 says J. Scott Roberts, deputy secretary for min- pounds per square inch, fracturing the shale. eral resources management at the DEP. “But we Subterranean pressure pushes the fracking mix- do find the occasional individual who forgets nvironmental Protection

ture back up the pipe; this “flowback fluid” picks what the priorities should be. Or a company E f up other compounds from the shale, including runs short of money and does dumb things.” salts, heavy metals and naturally radioactive ma- artment o p terials. The fluid is stored in a holding pond or Chemical Transparency e

tanks. Gas later rises through the pipe. w a r i n e s s a b o u t which chemicals are used ity D

Going down, the fluid is about 99.5 percent where stems in part from a legal maneuver that ork C

freshwater and sand and 0.5 percent chemicals. excludes fracking from having to meet the ew Y The sand props open the fractures so gas can es- “underground injection control” provisions of cape. Drilling companies use a proprietary mix the Safe Drinking Water Act, which protect tration and N

of up to 10 or 12 chemicals in a well, including underground drinking water sources from con- s

a friction reducer to help the mixture flow, a tamination. The exemption, written into the dmini scale inhibitor to prevent rust, acid to clean the 2005 Energy Policy Act, was dubbed the Halli- perforations, bactericides to kill microorgan- burton loophole because it was supported by ormation A f

isms that can inhibit some chemical actions, and then vice president Dick Cheney, former CEO n more. Among the dozen “fracturing solutions” of Halliburton. In 2009 New York State Repre- nergy I

used by Halliburton, one of the nation’s largest sentative Maurice Hinchey introduced the : E s fracking companies, are hydrochloric acid, eth- FRAC Act to repeal the exemption. As of May, ylene glycol and the bacteria killer glutaralde- the act was in committee, with no timetable for

hyde. BJ Services’s list includes methanol and pe- action. Klaber says the legislation is pointless, oley; Source

troleum distillate blend. Although 0.5 percent “a solution that doesn’t have a problem.” don f

84 Scientific American July 2010 www.diako.ir© 2010 Scientific American [ how it works ] The Occupational Safety and Health Admin- istration requires a company to list on-site chem- frack, baby, frack icals on a “material safety data sheet” that must Hydraulic fracturing, or fracking, releases natural gas from shales. A borehole is drilled down be available to first responders, so if an accident to and through the shale, a pipe is inserted and a cement slurry is injected around the pipe to encase it. The drill rig is then removed, and rock is fractured in several occurs they can evaluate possible injuries. But stages (one of which is shown, bottom right). Josh Fox, who produced the 2010 documen- Drill rig tary Gasland, about potential health prob- Pump truck lems experienced by residents across the U.S., says in the film that gas companies refused to tell him, and abutting home- Pressurized Holding pond owners, which chemicals were used at fluid Pipeline particular sites. Fluid and gas Klaber says local regulators can obtain flow back the data sheets and can disclose that information to the public. The sheets do not list the con- Freshwater

centrations of the chemicals, which the EPA notes Pressurized “are necessary to determine toxicity.” The DEP’s fluid Roberts says the sheets do not disclose “the rec- After the rig is removed, Fluid and gas ipe” of how chemicals are mixed or used: “That’s fracking fluid is pumped flow back down the pipe; when considered intellectual property.” One issue is it returns, it is stored Shale whether mixing of chemicals or their reactions in a holding pond or tanks. Later, gas will Pressurized fluid with compounds down in the shale create other flow through a well- fractures rock compounds that could be harmful. head (not shown) into Even unmixed, the chemicals may be toxic. a pipeline. The River Reporter, an advocacy group in Nar- Fluid and gas flow back rowsburg, N.Y., sent a list of 54 data-sheet chem- supplies for Pittsburgh.” Hanger concurs: “Both Shale icals to the Endocrine Disruption Exchange for sides are trying to win a position, and truth can analysis. The exchange, led by Theo Colborn, a be a casualty.” former EPA science adviser, determined that the The EPA study, due in 2012, could add scien- For each stage, a gun blasts chemicals fell into 14 categories of potential tific clarity. Also, in July the EPA plans to an- perforations through the cement-encased pipe. A health concerns, including possible damage to nounce results of an investigation into contami- mixture of water, sand and the lungs, liver, kidneys, blood and brain. nation of residential wells in Pavillion, Wyo. chemicals is forced through the holes at high pressure, breaking the rock. The Groundwater Contamination Going Full Bore fluid, and later the gas, i n d u s t r y l e a d e r s , including Range Resources’s r e g a r d l e s s o f w h a t the EPA reports say, flows back up the well. Whitley, point out that no cases of groundwater fracking seems destined to increase. In May, for contamination due to the fracking process have instance, Statoil Natural Gas signed an agree- ever been documented. Some regulators agree. ment to send up to 113 billion cubic feet of Mar- Critics say that phrasing refers only to injected cellus gas a year, for 20 years, from Ellisburg, More To Explore fluids rising back to groundwater level. They note Pa., to Toronto. Ironically, in March, Statoil Riverkeeper’s watchdog Industrial that when the entire fracking operation is consid- also agreed to pipe gas to New York City. Gas Drilling Reporters, covering ered, including wastewater holding ponds, hun- Tension over fracking will likely continue. At action in New York State and Penn dreds of contamination incidents have been doc- a May 3 forum at Duquesne University, Hanger sylvania, can be downloaded at umented. In Dimock, Pa., for example, the DEP called for a severance tax on producers to cover www.riverkeeper.org/campaigns/ safeguard/gas-drilling cited Houston-based Cabot Oil & Gas for spill- the cost of sealing wells that might be abandoned ing fracking fluid and diesel. and to remediate other damage. Operators pay Information from the Marcellus Shale Most violations cited by regulators do not in- severance taxes in 28 states. Klaber warned that Coalition is available at volve fracking chemicals, however. Both the in- too many impediments could discourage more www.pamarcellus.com dustry and the critics “are being a bit disingenu- drilling in Pennsylvania, which she said created A video of Anthony R. Ingraffea ous” in their statements, says Terry Engelder, 107,000 jobs in the prior year. The industry, she explaining fracking can be seen at professor of geosciences at Pennsylvania State says, does not want to “miss an opportunity as a www.mefeedia.com/ University, whose research is also in part sup- country to reap the benefits that come with do- watch/28577813 ported by the gas industry. “New York, in par- mestic natural gas.” The country certainly needs To track the documentary Gasland,

f oley ticular, is being hypocritical; they are happy to energy. It also needs drinking water. Whether it go to www.gaslandthemovie.com don don heat with natural gas drilled around the water can have both remains an open question. ■

Earth sans Ice Caps ■ Biomimetics ■ Immortality By kate wong

■➜ Bulletproof Feathers: How Science Uses Nature’s Secrets ALSO NOTABLE to Design Cutting-Edge Technology edited by Robert Allen. University of Chicago Press, 2010 ($35) NONFICTION ➜➜ Long for This World: Researchers are increasingly turning to nature The Strange Science of Immortality for design inspiration. This book surveys by Jonathan Weiner. Ecco, examples from the field 2010 ($27.99) of biomimetics—from ➜➜ Colossus: Hoover Dam and the Making of the self-cleaning surfaces American Century based on the lotus leaf by Michael Hiltzik. Free Press, 2010 ($30) to fishery echo sounders ➜➜ Spider Silk: Evolution and 400 Million that aim to simulate Years of Spinning, Waiting, Snagging, and Mating dolphin sonar (right). by Leslie Brunetta and Catherine L. Craig. Yale University Press, 2010 ($30) ➜➜ Drawing the Map of Life: Inside the Excerpt Human Genome Project ■➜ The Flooded Earth: Our Future in a World without Ice Caps by Victor K. McElheny. Basic Books, 2010 ($28) ➜➜ by Peter D. Ward. Basic Books, 2010 ($25.95) The Last Tortoise: A Tale of Extinction in Our Lifetime by Craig B. Stanford. Harvard University Press, Earth scientist Peter D. Ward of the University of Washington imagines 2010 ($23.95) how Earth and its inhabitants will change in the next 1,000 years as ➜➜ What’s Luck Got to Do with It?: The History, the ice caps melt and the seas rise. Here he describes northern Mathematics, and Psychology of the Gambler’s Illusion California in the year 2135. by Joseph Mazur. Princeton University Press, “The [Great Valley of California] had once been one of the richest 2010 ($29.95) agricultural areas on the planet. It had been divided roughly in half by ➜➜ A Little Book of Language by David Crystal. Yale University Press, the Sacramento River Delta and the low marshes west of Sacramento. 2010 ($25) Its northern half had been farmed for fruit, olives, nuts, cotton, and especially rice, ➜➜ Parasites: Tales of Humanity’s while the southern valley was once the largest vegetable-producing area on the planet. Most Unwelcome Guests by Rosemary Drisdelle. University of California Now the Great Valley was bisected by the long extension of San Francisco Bay, which Press, 2010 ($27.50) stretched all the way to Sacramento. Salt water from that enormous extension of the sea ➜➜ Leonardo’s Legacy: How Da Vinci had gradually worked its way into the many aquifers that had once been necessary for Reimagined the World irrigation, and every year the sea encroached both north and south into the major rivers by Stefan Klein. Da Capo Press, 2010 ($26) of the Valley. Now, despite the intense engineering efforts Californians had put forth, most of those aquifers contained salt. But even that would not have been so bad had FICTION ➜➜ The Bradbury Report the climate continued to allow snow to fall prodigiously on the Sierras. Because the by Steven Polansky. Weinstein Books, precipitation now came entirely as rain, there was no snowpack to melt and provide 2010 ($24.95) spring runoff just in time for sowing and watering new crops, or give budding trees a ➜➜ Ancestor good drink in the first spell of hot weather. by Scott Sigler. Crown, 2010 ($24.99) “That heat used to arrive in April, but now there was no winter here at all. In one respect it was a blessing—no longer did the characteristic and deadly early-morning fogs cause numerous fatal accidents on Interstate 5, the major north-south freeway through KID-FRIENDLY California, as drivers rear-ended others in the pea soup. There was no fog at all now, ➜➜ Honey Bees: Letters from the Hive by Stephen Buchmann. because the tropical temperatures of the Valley never rose to the dew point. But the lack of Delacorte Press, 2010 ($16.99) Getty Images fog was of little importance to drivers, because there were none on the freeway except for ➜➜ The Bumper Book of

truckers. Personal automobiles had been outlawed some decades before, in a vain effort to Nature: A User’s Guide to fonov the Great Outdoors save some of the word’s oil. Yet goods still needed to be moved from place to place, and by Stephen Moss. Harmony, nder S a nder people needed to travel as well, thus swelling the freeways with buses and trucks.” 2010 ($29.99) a Alex

Abraham Lincoln once said, “Let us have faith that right makes might.” Do you have that kind of faith? Or do you think that idealistic principles are outdated and impossible to achieve? Read Richard W. Wetherill’s book RIGHT IS MIGHT to discover why right really is might, and Richard W. Wetherill how the natural laws of the universe make it so. 1906-1989

During his lifetime, Wetherill was often described A reader might ask, “What did they do?” as a person who was scores of years ahead of his time. Following Wetherill’s suggestions they recognized Now former members of his research and study group the challenges of life and met life head on; squared think that his day has finally come. Increasingly, more themselves with their consciences; did what could be and more people understand that to succeed they must done to improve conditions; and made sure that every be rational and honest. personal decision was completely honest. In 1929, Wetherill identified a natural law con- People who do that do not fear the future. They know trolling people’s personal and interpersonal behavior. that the key to every virtue is honesty, so they wage an The law states that people are required to think, say, intentional campaign of unwavering honesty. and do what is right in order to get a right result. It Adopting that dynamic formula for success benefits further states that when people have personal problems everybody on earth. It will benefit posterity. Before it or trouble, something is wrong about their thinking, benefits others, the person who adopts it is the first to conversation, and behavior. benefit. Rational, honest thoughts and behavior is a for- In his book Wetherill explains the outcome that re- mula not open to abuse. Nobody can cause trouble for sults from attempted violation or disregard for nature’s others or for himself by using it. Not using that formula behavioral law. As with all natural laws, this law is also causes trouble for everybody. self-enforcing. Persons who deviate from what is right The last paragraph of RIGHT IS MIGHT reminds install in the recesses of their minds the wrong think- us, “It is helpful to recognize that what is wrong in ing that was used to justify such behavior. life is based on emotional unreality and is tempo- While Wetherill’s book RIGHT IS MIGHT was writ- rary. What is right in life is part of the reality that ten in 1950, its contents are as applicable in 2010 as unfailingly endures, establishing the principle that they were sixty years ago—perhaps even more so—and RIGHT IS MIGHT.” because Wetherill could not find a publisher willing to Visit our Website www.alphapub.com where essays go out on a limb for honesty and right action in 1950, and books (including Right Is Might) describe chang- the manuscript was simply filed. es called for by whoever or whatever created natural After his death in 1989, the manuscript was found laws. Read, download, and/or print the material free! among his papers, and it was carefully edited to delete Press a button to hear site pages read aloud, except some dated material, but the principles of right behavior for the texts of the seven books. that he put into words are ageless. They are all preserved. This message is from a self-financed, nonprofit group RIGHT IS MIGHT tells the reader how honesty and of former students of the late Richard W. Wetherill. By rightness are achieved in a person’s private and public May of 2010 our Website had over 50,000 American and life. It also describes the exciting developments in worldwide visitors. We invite your help to direct others to the lives of persons who had applied the formula for alphapub.com to learn how to find the examined life that is successful living well worth living.

www.diako.ir 88 By Steve Mir Steve By fingerprints.” in the audience shouted, “It’s easy to get rid of the glare with the ing at a mywatching while video.”nostrils To which some wag of look tired “I’m reflection: and screen’s iPad the glare edged acknowl manager, product AppleScript Soghoian, Sal issues. oppressed other with hobnob members.” minority to just cruise expensive an for pay rized them: “You speak As who are enough nuts about enough. your Apple proof stuff to was ship er the David on Pogue, tech for columnist the presence their truth, in ters, based on a show of hands, already owned an iPad. Although, so about Book, that wouldn’t the that talks device be lost on me. sail to decided featured numerous talks on the maximizing iPhone experience, I hand. So when the curriculum cruise left my to attached permanently become since has Which iPhone. I bought my first Apple product,the ter being soaked in a thunderstorm, cruddy-photos died last af summer that-just-calls-people-and-takes- geekcruises.com. their URL: opera, featuring astronomy and sojourns as quilting. well as Hence outings, se sight also puts together the Mac Horizons Bright ries produced by Insight Cruises. In American Scientific 2009 I also sailed, but as a speaker in the to Bermuda in the first week ofMay. In 2008 and ship cruise America 10. MacMania called faithful, the of sea at gathering weeklong Windows a was truly I what for out me scoped have might assembled anti gravity Shipping out with people who love a certain kind of MacHine of kind certain a love who people with out Shipping An An Apple a Day for a Week quarter-of-a-century adherent to PCs that ran DOS and and DOS ran that PCs to adherent quarter-of-a-century Despite their love their Despite of pomology, some to could admit certain quar three some that Apple to devoted so were classmates My When my old regular cell-phone- One hundred two Macphiles and I were onboard the Holland

SCIENTIFIC AMERICAN — and thrown me overboard. For I was attending a attending was I For overboard. me thrown and — MacBook. The computer was brand-new, brand-new, was the for Otherwise, purchased very purpose. this computer The MacBook. lap my in fealty of sign another balancing in my one talisman left hand holding quietly, sat I lectern. the approached T on on my own dime this time and with the new Mac s he classroom gently rocked as the speaker speaker the as rocked gently classroom he ky Veendam, Veendam,

“You have to have bigger pants.” bigger have to have “You is gone.” The same is true for the iPad, as although, Pogue said, drew the phone across his pant leg, “and it is spotless. All the oil is. this greasy Ihow do one see wipe on a piece can of “Youclothing,” at which he audience. the to screen messy his showed then He oil.” repels meaning No, yodelers. of afraid meaning of course, Oleophobic, oleophobic coating. this “It has iPhone, ly if you do waters. it in international ipso sic loquitur tyrannis semper then use, personal for own your strictly iPhone have copied said movie and put the of party the firstpart on your movie some legal scholars think that if you have purchased a DVD an Digital of industry the group, the says that using Snell, the to software is illegal. movies Although is illegal. And the according Motion copy to Picture software Association see, writing that ofsays You Act America, Copyright Ds. Millennium DV from movies copy Forhow example, to things. a useful many day meals I learned iPad wipes. for suitable pants to lead also would Which weight.” the gain one at wears presentations, name, his be hallowed Jobs, Steve that shirt same-style for the prob brief a had computer), Mac old an of chassis the from made aquarium real (a Macquarium the of inventor and columnist Ihnatko, Andy when revealed was Trifles with fingerprints aside, the audience’s true zealotry zealotry true audience’s the aside, fingerprints with Trifles the of explained Pogue as but real, is issue fingerprint The It is easy to gain weight on a cruise ship, but between the six six the between but ship, cruise a on weight gain to easy is It And Justice And for Justice All simply “programmer-sized.” Greedy Greedy “programmer-sized.” simply which wear called Soghoian a XXXL,

or or logo to anybody who could reasonably offered a golf shirt Snell featuring the Jason director editorial zine’s apparel. for logoed desire their was MacManiacs the of joshing. just course, of was, he clear it made not Ihnatko “Tipmuttered, one, get a Windows 7 with the ship’s audiovisual system. He to interface MacBook his lem getting some might have rushed the stage had than a Mac.” Lusty boos erupted, and machine 12 Angry 12 Men Angry attendee yelled out, “I’m willing to yelled out, “I’m attendee willing Another example of the true love love true the of example Another you’re within the law. Especial law. the within you’re —

they give you less trouble trouble less you give they Chicago Sun-Times Sun-Times Chicago or or The Firm, The Firm, Macworld prima facie res facie prima July 2010 and and you maga Apple tech tech ■ - - -

Photograph by flynn larsen; illustration by matt collins Technology is the only way to solve the really big problems.

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