Cover; August 2004; Scientific American Magazine; by Staff Editor; 1 Page(s)

Table of Contents; August 2004; Scientific American Magazine; by Staff Editor; 2 Page(s)

SA Perspectives: The Green Gene Revolution; August 2004; Scientific American Magazine; by Staff Editor; 1 Page(s)

As millions of people in Zambia and Zimbabwe faced famine in 2002, their governments rejected corn donated by the United Nations, calling it "poison" because it contained some genetically modified kernels. Similar scorn sounded this past June outside a Biotechnology Industry Organization meeting in San Francisco. There protesters blockaded the street, shouting predictions that GM crops would devastate human health, the environment and the welfare of small farmers.

Yet only a month earlier the U.N. Food and Agricultural Organization (FAO) - traditionally a champion of the small farmer - had concluded that the ongoing "war of rhetoric" about agricultural biotechnology may pose a greater threat than the technology itself does. One of the worst things about GM crops, the FAO argued, is that too few farmers are planting them.

How to Contact Us and On the Web; August 2004; Scientific American Magazine; by Staff Editor; 1 Page(s)

Letters to the Editors; August 2004; Scientific American Magazine; by Staff Editor; 2 Page(s)

In "The Tyranny of Choice" [April], Barry Schwartz wrote of the challenges inherent in making multitudes of decisions in a modern world. His article resonated with many letter writers. One of the choicest reactions came from Grant Ritchey of Olathe, Kan.: "On the same day I received your magazine with Schwartz's article, I purchased his book The Paradox of Choice. I was faced with a tough choice: Should I begin reading his book or his article? After pondering the matter carefully, I arrived at a decision with which I was satisficed. I immediately read Michael Shermer's great Skeptic column." Want to read more letters about the April issue? It's up to you.

I beg to differ with the assertion that the need to choose is a hallmark of modern life ["The Tyranny of Choice," by Barry Schwartz]. Our ancestors had to pick whether to rise from sleep now or later, to go to sleep here or there, and practically endless options in between. That people who have difficulties with decisions tend to be less happy can be explained by the difficulties being a result, not the cause: people with gloomier dispositions are more likely to dwell on negative thoughts, including agonizing over selections. Being a careful evaluator could actually confer an evolutionary advantage over being happy.

50, 100 and 150 Years Ago; August 2004; Scientific American Magazine; by Staff Editor; 1 Page(s)

COLD WAR CASUALTY - "By a four to one vote the Atomic Energy Commission held J. Robert Oppenheimer to be a security risk and unemployable for any further atomic work in the national defense. In the Commission, dissent came from the scientist member of the jury. Henry D. Smyth asserted that Oppenheimer's continued employment would 'not endanger the common defense and security,' but on the contrary would 'continue to strengthen the United States.' His opinion presented in sharp focus the disagreement between scientists and the national administration over the present security system. The four members who condemned Oppenheimer based their decision on 'fundamental defects in his character,' and on his Communist associations, which they found 'have extended far beyond the tolerable limits of prudence and self-restraint' expected of a man in his position."

ORIGIN OF LIFE - "It is still true that with almost negligible exceptions all the organic matter we know is the product of living organisms. The almost negligible exceptions, however, are very important. It is now recognized that constant, slow production of organic molecules occurs without the agency of living things. If the origin of life is within the realm of natural phenomena, that is to imply that on other planets like the earth, life probably exists - life as we know it. - George Wald" [Editors note: Wald won the 1967 Nobel Prize for Physiology or Medicine.]

The Darkening Earth; August 2004; Scientific American Magazine; by David Appell; 2 Page(s)

Much to their surprise, scientists have found that less sunlight has been reaching the earth's surface in recent decades. The sun isn't going dark; rather clouds, air pollution and aerosols are getting in the way. Researchers are learning that the phenomenon can interact with global warming in ways that had not been appreciated.

"This is something that people haven't been aware of," says Shabtai Cohen of the Institute of Soil, Water and Environmental Sciences in Bet Dagan, Israel. "And it's taken a long time to gain supporters in the scientific world." Cohen's colleague Gerald Stanhill first published his solar dimming results 15 years ago.

Bumpy Flying; August 2004; Scientific American Magazine; by Steven Ashley; 2 Page(s)

One day in the early 1980s Frank E. Fish noticed a small statue of a humpback whale in a Boston sculpture gallery. On closer examination, he saw that the creature's large, winglike pectoral flippers were studded with evenly spaced bumps along their leading edges. Fish was taken by surprise. As a specialist in the hydrodynamics of vertebrate swimming, he knew of no cetacean flippers, fish fins or avian wings that bore such odd features - all of those have smooth front edges. He mentioned this to his wife and conjectured aloud that the artist must have made a mistake. The storeowner, overhearing Fish's comments and knowing the sculptor's meticulous attention to detail, soon produced a photograph that clearly showed the humpback's lumpy flippers. Fish marked down the unusual protuberances for future research.

After intermittent study over the next two decades - involving in one instance the sawing off of three-meter-long flippers from a rotting, beached humpback - the biology professor at Pennsylvania's West Chester University and several colleagues have recently shown that the whale's knobby side appendages in some ways trump the more conventional sleek designs of both human and nature.

Anonymous Trust; August 2004; Scientific American Magazine; by Wendy M. Grossman; 3 Page(s)

Under pressure to battle incessant hacker attacks, viruses and identity theft, Microsoft in 2002 came up with a scheme dubbed Palladium, which would rely on special computer hardware that would refuse to run malicious programming code or betray users' secrets. A form of "trusted computing," the idea drew several objections - chief among them, it would enable remote organizations to track what users do with their machines. Now a technology based on a decade-old idea promises better-protected machines and transactions while removing the fear of monitoring.

The strategy is called direct anonymous attestation (DAA). The plan is that computers will have a secure mode in which they will run only applications that have been authenticated by remote trusted certification authorities ("attested"); moreover, these authorities would not necessarily be able identify them or their owners. A security chip on a computer motherboard or embedded in other devices would perform such gatekeeping tasks, functioning according to specifications laid down by the Trusted Computing Group, a consortium that includes Microsoft, Hewlett-Packard, Intel and IBM.

Sloshing in Space; August 2004; Scientific American Magazine; by Govert Schilling; 2 Page(s)

What would you think the Dutch are launching into space this fall? Tulips? Wooden shoes? A van Gogh painting? No, it's water. The small European country that uses dikes to keep the ocean out is now sending water into Earth orbit. Carried aloft as a secondary payload by an Ariane 5 rocket in late September, the diminutive Dutch satellite Sloshsat FLEVO will study the sloshing behavior of water in weightlessness for two weeks.

Spending eight million euros ($9.6 million) to launch a couple of buckets' worth of water might seem excessive. But the work is "of international significance," states project manager Koos Prins of the Dutch National Aerospace Laboratory NLR. NASA's asteroid probe NEAR-Shoemaker, for instance, experienced a 13-month delay after the spacecraft unexpectedly put itself into safe mode in December 1998, possibly as a result of propellant slosh. "A better slosh model is needed for future missions," according to the report of an investigation committee. Sloshing liquid, be it propellant or drinking water, may also hamper docking maneuvers of unmanned cargo vehicles servicing the International Space Station.

Outsourcing Drug Work; August 2004; Scientific American Magazine; by Gunjan Sinha; 2 Page(s)

Girish Virkar doesn't sleep much these days. "I've got a lot to do," he laments, as he settles into a 6 A.M. flight from Frankfurt to Milan. His mission: to drum up business for his company and cash in on the latest trend in outsourcing to India - drug research and clinical trials.

Virkar is CEO of the Mumbai-based D&O Clinical Research Organization - a firm that has been manufacturing precursor drug compounds for foreign pharmaceutical companies for more than a decade. Just this year, however, D&O expanded its services to include support for clinical trials, specifically, coordinating the studies and managing data. The expansion is intended to corral more clients as Indias business climate heats up. As part of a World Trade Organization agreement that India signed in 1995, starting next year the country will honor product patents. Pharmaceutical corporations, once fearful of drug pirates, can hardly wait to move in.

A Plan for Water; August 2004; Scientific American Magazine; by Elizabeth Querna; 2 Page(s)

Ocean policy and management have not attracted much national attention during the past few decades, but that may be changing. A recent federal report brings together years of research and comes to the long-standing yet little heeded conclusion that the oceans are in trouble. Almost everyone, including conservationists, environmental groups, state officials and industry representatives, applauds the report for taking major steps toward improving management of the oceans. But there is still concern, especially among some U.S. states, that the recommendations will not be fully funded and that they may encourage offshore oil and gas drilling, an activity some states have fought to restrict.

The 450-page report of the U.S. Commission on Ocean Policy, a 16-member presidential committee, is the first federal study since 1969 to take a broad look at the health of the nation's oceans, and it propounds an overhaul of ocean policy. Among its proposals are a shift in wildlife management from an approach based on a single species to one based on ecosystems; the creation of a National Oceans Council within the executive branch; and a doubling of federal money allocated to ocean research, from $650 million to $1.3 billion (the amount has fallen from 7 percent of the national budget 25 years ago to just 3.5 percent today). "Given our power and enormous wealth, for us not to pay attention to our oceans is unconscionable. We have to lead by example, and we're not doing that now," says William D. Ruckelshaus, a member of the commission and a former administrator of the Environmental Protection Agency.

By the Numbers: Middle of the Country; August 2004; Scientific American Magazine; by Rodger Doyle; 1 Page(s)

Politically dominant until the early 1900s, rural America plunged into hard times by midcentury. Sociologists and others predicted that many areas would be depopulated and that, with improving communication and transport, urban values would overwhelm small-town civic spirit. Such changes, they hypothesized, would lead to a weakening of local community standards and, ultimately, to widespread alienation.

Studies underwritten by the U.S. Department of Agriculture in the early 1940s reinforced the notion. The agency focused on six representative communities, which all revealed a pattern of decline, depopulation and instability reflecting the effect of urban industrial expansion and the Great Depression. The economic turmoil continued in the subsequent decades for various reasons. Harmony (Putnam County), Ga., suffered from depopulation and racial divisions. Landaff, N.H., saw a nearly complete disappearance of its dairy farms over the next 40 years. Irwin, Iowa, suffered from a dramatic decrease in the number of farms, the withering of local businesses, and an aging population.

News Scan Briefs; August 2004; Scientific American Magazine; by Charles Choi, JR Minkel; 1 Page(s)

Traffic in Colombia's capital city of Bogotá consists of more than a million cars, trucks and buses, but the city's packed highways still keep more cars cruising than other major cities do, say physicists Jose Daniel Muñoz and Luis Eduardo Olmos of the National University of Colombia. They videotaped a car as it drove and then constructed rules for acceleration and braking in a cellular automaton traffic model, in which cars are points on a grid responding to neighboring points. According to the model, the key is aggressive driving - getting nearly bumper-to-bumper before slowing down. The toll for that higher flow: car accidents cause at least one in six violent deaths in Colombia, the researchers say in a paper submitted to the International Journal of Modern Physics C. But that rate is actually lower than some traffic-laden U.S. cities, such as Atlanta.

Genetically engineered salmon can grow more than seven times larger than native counterparts, raising concerns that the supersizing fish would outcompete their wild cousins if they escaped from their farms. In lab experiments, researchers at the government organization Fisheries and Oceans Canada found that the threat occurs when food is scarce. Engineered fish became aggressive over food - in fact, they grew larger than engineered fish given a sufficient diet. Meanwhile the nonengineered salmon in mixed tanks suffered in size compared with their counterparts in tanks without the super salmon. Under low-ration conditions, wild salmon alone in tanks survived and even put on weight. But tanks containing either mixed or engineered-only populations ultimately experienced population crashes and total extinctions, apparently because of malnutrition or cannibalism. The scientists, who published their findings online June 7 in the Proceedings of the National Academy of Sciences USA, cautioned that their lab study might not reflect what might happen in more complex natural ecosystems.

Innovations: Penny-wise Smart Labels; August 2004; Scientific American Magazine; by Steven Ashley; 2 Page(s)

Suppose you could go to the supermarket, fill the shopping cart with goods, and then just walk out the door without having to stand on a checkout line. Like an automated highway-toll collection system, an electronic reader at the store's exit would interrogate radio-based smart labels affixed to each item in the basket and ring up the purchases on a networked computer. Sometime later you would receive the grocery bill, perhaps by e-mail.

Smart labels, or what engineers call radio-frequency identification (RFID) tags, today cost from 30 to 50 cents each, an expense that makes attaching them to most consumer products uneconomical. If that price could be reduced to one cent a tag, however, retailers and many other businesses could implement large-scale, even globe-spanning RFID systems that eventually could save everyone - consumers and producers alike - considerable time and money. Penny smart tags would permit manufacturers to track perhaps billions of goods efficiently throughout the entire supply chain, from warehouse to store to purchaser, and maybe even all the way to the dump.

Skeptic: Miracle on Probability Street; August 2004; Scientific American Magazine; by Michael Shermer; 1 Page(s)

Because I am often introduced as a "professional skeptic," people feel compelled to challenge me with stories about highly improbable events. The implication is that if I cannot offer a satisfactory natural explanation for that particular event, the general principle of supernaturalism is preserved. A common story is the one about having a dream or thought about the death of a friend or relative and then receiving a phone call five minutes later about the unexpected death of that very person.

I cannot always explain such specific incidents, but a principle of probability called the Law of Large Numbers shows that an event with a low probability of occurrence in a small number of trials has a high probability of occurrence in a large number of trials. Events with million-to-one odds happen 295 times a day in America.

Insights: From Finish to Start; August 2004; Scientific American Magazine; by W. Wayt Gibbs; 2 Page(s)

Late this past February, with less than three weeks remaining before the first ever long-distance race for robotic vehicles, William "Red" Whittaker left Carnegie Mellon University to spend a weekend in the Mojave east of Carson City, Nev. Desert testing of the autonomous humvee that Whittaker's "Red Team" was building had begun there 18 days before.

"Yesterday the vehicle drove itself at 32 miles per hour for eight miles along the old Pony Express trail," Whittaker said proudly as he showed off the humvee, named Sandstorm, to a sponsor he had brought with him from Pittsburgh. By the normal standards of mobile robotics, that would be a culminating demonstration for a research project. But to Whittaker, an eight-mile test was just a baby step. The Grand Challenge race would be 142 miles of perilous mountain switchbacks and rough, sandy trails.

Back to the Future of Cereals; August 2004; Scientific American Magazine; by Stephen A. Goff and John M. Salmeron; 8 Page(s)

For thousands of years, farmers have surveyed their fields and eyed the sky, hoping for good weather and a bumper crop. And when they found particular plants that fared well even in bad weather, were especially prolific, or resisted disease that destroyed neighboring crops, they naturally tried to capture those desirable traits by crossbreeding them into other plants. But it has always been a game of hit or miss. Unable to look inside the plants and know exactly what was producing their favorable characteristics, one could only mix and match plants and hope for the best.

Despite the method's inherent randomness, it has worked remarkably well. When our hunter-gatherer ancestors started settling down some 10,000 years ago, their development of agriculture allowed human society to undergo a population explosion. It is still expanding, demanding continual increases in agricultural productivity.

Electrodynamic Tethers in Space; August 2004; Scientific American Magazine; by Enrico Lorenzini and Juan Sanmart¿n; 8 Page(s)

There are no filling stations in space. Every spacecraft on every mission has to carry all the energy sources required to get its job done, typically in the form of chemical propellants, photovoltaic arrays or nuclear reactors.

The sole alternative--delivery service--can be formidably expensive. The International Space Station, for example, will need an estimated 77 metric tons of booster propellant over its anticipated 10-year life span just to keep itself from gradually falling out of orbit. Even assuming a minimal price of $7,000 a pound (dirt cheap by current standards) to get fuel up to the station's 360-kilometer altitude, that is $1.2 billion simply to maintain the orbital status quo. The problems are compounded for exploration of outer planets such as Jupiter, where distance from the sun makes photovoltaic generation less effective and where every gram of fuel has to be transported hundreds of millions of kilometers.

Virtual-Reality Therapy; August 2004; Scientific American Magazine; by Hunter G. Hoffman; 8 Page(s)

In the science-fiction thriller The Matrix, the heroes "plugged in" to a virtual world. While their bodies rested in reclining chairs, their minds fought martial-arts battles, dodged bullets and drove motorcycles in an elaborately constructed software program. This cardinal virtue of virtual reality - the ability to give users the sense that they are "somewhere else" - can be of great value in a medical setting. Researchers are finding that some of the best applications of the software focus on therapy rather than entertainment. In essence, virtual reality can ease pain, both physical and psychological.

For the past several years, I have worked with David R. Patterson, a pain expert at the University of Washington School of Medicine, to determine whether severely burned patients, who often face unbearable pain, can relieve their discomfort by engaging in a virtual-reality program during wound treatment. The results have been so promising that a few hospitals are now preparing to explore the use of virtual reality as a tool for pain control. In other projects, my colleagues and I are using virtual-reality applications to help phobic patients overcome their irrational fear of spiders and to treat post-traumatic stress disorder (PTSD) in survivors of terrorist attacks.

Nuclear Bunker Buster Bombs; August 2004; Scientific American Magazine; by Michael Levi; 8 Page(s)

Potential opponents of the U.S. armed forces learned an important lesson during the first Gulf War. As smart bombs rained down with pinpoint precision on Iraqi command centers, weapons storage depots and other facilities, it became clear that fixed military assets on the surface were extremely vulnerable to American aerial assault. To survive, key operational bases and weapons caches would have to be situated underground in fortified concrete bunkers or inside hard-rock mountains.

In the years following Operation Desert Storm, U.S. military strategists debated the best way to destroy such "hardened" and deeply buried targets, knowing full well that attacks on subterranean bunkers or weapons stockpiles would face uncertain chances of success. Worse, they could inadvertently disperse any buried chemical or biological agents into the surrounding areas - with lethal effect.

Next Stretch for Plastic Electronics; August 2004; Scientific American Magazine; by Graham P. Collins; 8 Page(s)

Strong, flexible, lightweight and cheap, plastics have acquired an additional attribute in recent years: the ability to function as semiconductors, forming diodes and transistors in plastic integrated circuits. Now, as the first plastic electronics products are hitting the market in displays that use organic light-emitting diodes, the stage is set for a new era of pervasive computing with polymers. Plastics may never match the sheer processing speed and miniaturization of silicon, but they will be able to go places that silicon cannot reach: ultracheap radio-frequency identification tags; low-end, high-volume data storage; displays that are inexpensive, even disposable, or that can be wrapped around a wall column; and wearable computing. Other uses for conductive plastics include photocells, chemical sensors and pressure-sensitive materials.

A key advantage of organic transistors over silicon is their ease of fabrication. Building a state-of-the-art silicon chip takes weeks of work using complex and expensive processes such as photolithography and vacuum deposition, carried out under high temperatures in ultraclean rooms. In comparison, organic transistors can be made using faster, cheaper processes under less carefully controlled conditions. Finally, there is the promise of "roll-to-roll" fabrication similar to the continuous printing presses that revolutionized publishing.

Questions That Plague Physics; August 2004; Scientific American Magazine; by Claudia Dreifus; 4 Page(s)

Chair of the physics department at Case Western Reserve University, Lawrence M. Krauss is famed in the research community for his prescient suggestion that a still mysterious entity called dark energy might be the key to understanding the beginnings of the universe. He is also an outspoken social critic and in February was among 60 prominent scientists who signed a letter entitled "Restoring Scientific Integrity in Policymaking," complaining of the Bush administration's misuse of science. The public, though, might know him best as an op-ed writer and author of books with mass appeal. His 1995 work, The Physics of Star Trek, became a best-seller, translated into 15 languages. He is now finishing his seventh popular title, Hiding in the Mirror: The Mysterious Allure of Extra Dimensions, which he describes as "an exploration of our long-standing literary, artistic and scientific love affair with the idea that there are hidden universes out there." Krauss recently discussed his many scientific and social passions with writer Claudia Dreifus.

SCIENTIFIC AMERICAN: What are the top questions bedeviling physicists today?
LAWRENCE KRAUSS: Three that I find fascinating are: What is the nature of dark energy? How can we reconcile black hole evaporation with quantum mechanics? And, finally, do extra dimensions exist? They are all connected. And they are all going to require some new insights into quantum gravity. But someone is going to have to come up with a totally new and remarkable idea. And it's hard to predict when that is going to happen. In 1904 you couldn't have predicted that Albert Einstein would come up with a remarkable idea in 1905.

Arsenic Crisis in Bangladesh; August 2004; Scientific American Magazine; by A. Mushtaque R. Chowdhury; 6 Page(s)

A cold, clear, sparkling flow gushes from the tubewell where Pinjra Begum used to collect drinking water for her family. Married at age 15 to a millworker, she had made a pretty bride. Soon, however, her skin began to turn blotchy, then ultimately gangrenous and repulsive. Her husband remarried. In 2000 she died of cancer, at 26 years of age, leaving three children.

Pinjra Begum was poisoned by the beautiful water she had faithfully pumped. In the 1970s and 1980s the Bangladesh government, along with international aid agencies spearheaded by UNICEF, undertook an ambitious project to bring clean water to the nation's villages. Too many children were dying of diarrhea from drinking surface water contaminated with bacteria. The preferred solution was a tubewell: a simple, hardy, hand-operated pump that sucks water, through a pipe, from a shallow underground aquifer. The well-to-do could afford them, and with easy loans from nongovernmental agencies, many of the poor also installed the contraptions in their courtyards. A tubewell became a prized possession: it lessened the burden on women, who no longer had to trek long distances with their pots and pails; it reduced the dependence on better-off neighbors; and most important, it provided pathogen-free water to drink. By the early 1990s 95 percent of Bangladesh's population had access to "safe" water, virtually all of it through the country's more than 10 million tubewells - a rare success story in the otherwise impoverished nation.

Working Knowledge: Seeing Inside; August 2004; Scientific American Magazine; by Mark Fischetti; 2 Page(s)

Medical imaging helps doctors see injuries and disease directly, so they don't have to rely on external exams or exploratory surgeries. Several tomography techniques have spread widely. In each case, a patient lies on a bed inside a doughnut-shaped machine. Hardware takes images of numerous two-dimensional slices of the person's body, and a computer assembles them into a three-dimensional picture.

Computed tomography (CT), which creates images with x-rays, is good at showing sharp contrasts in bone and tissue density, indicating broken bones, blood clots and kidney stones. Early machines of the 1970s required five minutes to render a slice 10 millimeters across; today resolution is one millimeter, and a slice takes only one second. If machine cost and speed improve only a bit further, CT could also take over most standard x-ray procedures, says C. Carl Jaffe, professor of internal medicine at Yale University.

Technicalities: Crippled but Not Crashed; August 2004; Scientific American Magazine; by Mike Corder; 2 Page(s)

On July 19, 1989, as United Airlines flight 232 cruised over Iowa, the fan disk of the tail engine on the DC-10 broke apart, and the debris cut through all three of the plane's hydraulic lines. Because the pilots could not move any of the jet's control surfaces - the ailerons on the wings and the elevators and rudder on the tail - a horrific crash seemed inevitable. But by carefully adjusting power to the two remaining engines, the crew managed to maneuver the plane to the Sioux City airport. Although the jet flipped over and caught fire after hitting the runway, 184 of the 296 passengers and crew members survived.

The pilots of flight 232 proved that it was possible to control a modern airliner using only the engines. And this discovery led some innovative engineers to wonder if they could program flight computers to achieve the same feat, making it easier for a crew to safely land a heavily damaged aircraft. This research has been gradually progressing over the past 15 years, and the technology could be incorporated into commercial and military planes in the not too distant future. To judge how well these computer-controlled flight systems perform, I decided to see if they could enable a moderately experienced pilot like myself to fly a crippled jet.

Reviews: Speaking for the Animals; August 2004; Scientific American Magazine; by Madhusree Mukerjee, Staff Editors; 2 Page(s)

The one time I saw the inside of an animal laboratory, at a prestigious university, the veterinarian who showed me around was subsequently fired for that transgression. So it is little surprise that Larry Carbone, a laboratory animal veterinarian, gives us few peeks behind the door: the book has virtually no anecdotes. Instead he takes off the lab's roof to offer a bird's-eye view - distant, measured and worded with sometimes excruciating care - of the battles raging within.

A veterinarian's oath binds her to "the benefit of society through the protection of animal health, the relief of animal suffering, the conservation of animal resources, the promotion of public health, and the advancement of medical knowledge." It imposes contradictory tasks on the laboratory animal veterinarian. "So you keep them healthy until the scientists can make them sick," Carbone quotes a skeptic as saying. A lab animal vet can please no one, it seems - certainly not the animal lover, who suspects her split loyalties, nor the animal researcher, who resents her attempts to oversee not just animal care but also experimental practice.

Anti Gravity: One Hundred Years of Magnitude; August 2004; Scientific American Magazine; by Steve Mirsky; 1 Page(s)

This month marks the publication of a new book, What Makes Biology Unique? (Cambridge University Press, 2004). Such philosophizing about science is inherently fascinating but in this case may be less interesting than the philosopher. The book is the 25th by Ernst Mayr, who was scheduled to add another significant achievement to his already prolific list shortly before this issue of Scientific American hit the newsstands: July 5 was Mayr's 100th birthday.

On May 10 the Museum of Comparative Zoology (MCZ) at Harvard University, Mayr's research home for the past 50 years, held a symposium/slightly prematurebirthday bash in his honor. I arrived early and found the Geology Lecture Hall still mostly empty. A few minutes later an exceedingly elderly gent, not Ernst, slowly ambled in and did a cost-benefit analysis on the available seats. I overheard him say to no one in particular, "I need a place close enough so I can hear but not so close that I'll be a distraction when I fall asleep." This éminence grise was later introduced to the crowd as one of Mayr's former students.

Ask the Experts; August 2004; Scientific American Magazine; by Staff Editor; 1 Page(s)

Scientists have an incomplete understanding of what causes hiccups; they also do not know what purpose hiccups serve. A long list of medical disorders seems to be associated with hiccups. By far the most common are distension of the stomach and the resulting reflux of stomach acid into the esophagus. A disease or an irritation in the chest could be to blame. Hiccups may arise from a variety of neurological abnormalities, many of them involving the brain stem. Metabolic and other disorders, as well as medications that cause acid reflux, have also been linked to hiccups.

Several things happen in quick succession when a person experiences a hiccup. First the roof of the mouth lifts, as does the back of the tongue, often accompanied by a burp. Then the diaphragm and the entire set of muscles used for inhaling come together in a sudden, strong contraction. Just after that contraction begins, the vocal chords clamp shut, making the "hic" sound. The heart slows a bit. Hiccups tend to recur every few seconds, sometimes continuing for hours.