Working Knowledge

March 1997
Scientific American Magazine

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Cover; March 1997; Scientific American Magazine; by Staff Editor; 1 Page(s)

Table of Contents; March 1997; Scientific American Magazine; by Staff Editor; 2 Page(s)

From the Editors; March 1997; Scientific American Magazine; by Rennie; 1 Page(s)

"Conan the Librarian"? No, that doesn't fit the profile. Librarians are mousy, bespectacled fussbudgets, as faintly musty as the books they curate, at least in the popular stereotype. They certainly aren't the sort who should be trying to conquer a bold new frontier. For that job, one wants fearlessly independent explorers and tough, two-fisted cowboys in the John Wayne mold, fair but quick on the draw. You can count on them to tame badlands and carve out a safe niche for the simple, civilized townsfolk.

Cowboys, in the persons of hackers, crackers and other members of the plugged-in elite, have been among the most colorful occupants of cyberspace ever since people other than researchers and defense wonks began roaming the Internet. With the invention of e-mail, and later of the World Wide Web, the value of networked communications on a global scale became clear and attractive to masses of humanity. Many of the Net's early denizens, however, who love the terrain's wild beauties, are not happy to see the throngs of newcomers arriving in their Winnebagos. They correctly see the encroachment of civilization as spelling the end of their fun.

Letters to the Editors; March 1997; Scientific American Magazine; by Staff Editor; 1 Page(s)

A question immediately sprang to mind after reading "Quantum Seeing in the Dark," by Paul Kwiat, Harald Weinfurter and Anton Zeilinger [November]: Don't the findings presented in the article contradict the Heisenberg uncertainty principle? I always thought the uncertainty principle meant that, at an atomic level, it is impossible to measure something without interacting with it. Yet the authors' clever techniques seem to get around this theory.

Kwiat, Weinfurter and Zeilinger write that interaction-free measurements can take place when a mirror "pebble" is placed in a photon's path during an Elitzur-Vaidman experiment. It may be true that the photon received at the detector did not reflect off the pebble, but it is not accurate to say that there has been no interaction. The interaction is evidenced by the collapse of the photon's wave function when it begins behaving like a particle. In effect, the pebble takes a measurement of the photon.

50, 100 and 150 Years Ago; March 1997; Scientific American Magazine; by Staff Editor; 1 Page(s)

MARCH 1947 The problem of giving automatically reproduced form letters that individually typed look has found a solution in a device called the Flexowriter Automatic Letter Writer. Operated by means of a perforated paper tape 7/8-inch wide, it consists of an electric typewriter, an automatic perforator and an automatic writer. In preparing the form letter, the operator types manually the date and the name and address of the recipient. Then a switch is thrown, and the automatic writer takes over, controlled by the previously prepared tape.

Fouling of lenses and other optical parts of instruments used in the tropics was until recently a serious problem, particularly in the Pacific areas. The way this hindrance was checked has now been revealed. Metal foil is treated with radium compounds to give it an alpha-ray emission equivalent to about 15 micrograms of radium per square inch, and narrow strips of the foil are mounted around the lenses.

In Focus: Computer Bombs; March 1997; Scientific American Magazine; by Gibbs; 2 Page(s)

To those who handle nuclear weapons--and to anyone within several hundred kilometers of them-- two questions are paramount. First, will a warhead, having been trucked around from one stockpile to another for 20 years, go off accidentally? Second, will it explode as intended when used in anger? The physicists at the U.S. Department of Energy¿s weapons laboratories responsible for certifying that hydrogen bombs are both safe and reliable have not been able, since 1992, to check their calculations by either damaging or detonating one underground. If the Senate rati- fies, and India reverses its opposition to, the Comprehensive Test Ban Treaty signed by the U.S. last September, they may never be able to do so again. How will they know for certain?

The DOE¿s answer, a plan called science-based stockpile stewardship, is to use the fastest supercomputers yet devised to simulate nuclear explosions along with all the important changes that occur to weapons as they age. The plan has stirred vigorous debate among arms-control advocates, military strategists and, most recently, university researchers, over whether the approach is cost-effective, feasible and wise.

Suicide Prevention; March 1997; Scientific American Magazine; by Leutwyler; 2 Page(s)

Anumber of known factors can, under certain circumstances, compel someone to attempt suicide. Mental illness, family history and life events often contribute signifi- cantly. Mere opportunity, too, increases the risk: for every firearm death attributed to self-protection, there are some 37 suicides. Even so, individual suicides are exceedingly difficult to predict. Indeed, a recent survey showed that although roughly half of all suicide victims visit clinicians during the 90 days preceding their death, only a quarter receive any psychiatric treatment.

To remedy that situation--and prevent tens of thousands of deaths each year-- neuroscientists are now actively searching for the biological triggers behind suicidal behavior. So far their findings point to mixed-up chemical messengers in the prefrontal cortex, an area of the brain involved in processing emotions and inhibitions. "New research indicates that suicide is not a normal response to severe distress," says J. John Mann of Columbia University and the New York State Psychiatric Institute, "but [is] the response of a person with a vulnerability to act on powerful feelings"

Field Notes: Amphibians On-line; March 1997; Scientific American Magazine; by Nemecek; 1 Page(s)

It¿s no secret why conferences are typically held in places like New Orleans or Sun Valley. In between the long talks, people want to wander around the French Quarter or take a few runs down the slope. So, of course, I¿m curious to check out the "Field Trips" listing in the guide to the third annual meeting of the North American Amphibian Monitoring Project (NAAMP). I¿m a bit shocked to see "Exotic Dancers" as an option, but I take a peek anyway. Dancing frogs? Where am I?

In Brief; March 1997; Scientific American Magazine; by Leutwyler; 3 Page(s)

Clues from Scleroderma New results have shed light on why the body sometimes attacks its own tissues: Antony Rosen and colleagues at Johns Hopkins University developed novel means for tracking the biochemistry behind scleroderma, an autoimmune disorder that damages the arteries, joints and internal organs. They found that toxic oxygen products, caused by an irregular blood supply, break apart common tissue molecules when high levels of metals are present. The fragmented molecules then present unfamiliar facades to the immune system, which produces antibodies against them.

Rapid-Fire Gamma Rays Four gamma-ray bursts, recorded by NASA instruments over two days last October, have shot down several key theories. Astrophysicists long thought that whatever caused the high-energy events, which usually occur at random throughout the sky, might well be destroyed in the making. But this new series appeared too quickly, and too close together, to support that idea.

Where Do Turtles Go?; March 1997; Scientific American Magazine; by Garcia; 2 Page(s)

The first time that paleontologist Olivier Rieppel presented his findings on turtles, before 200 people at a meeting last year sponsored by the Society of Vertebrate Paleontology, a presenter prefaced his talk with, "And now everybody may hiss as much as you like." Venomous commentary did not ensue, but a bit of a murmur must have lingered as Rieppel announced that he believed turtles had been classified in the wrong branch of the reptile family tree.

Rieppel, from the Field Museum in Chicago, and Ph.D. student Michael deBraga of Erindale College in Ontario, knew they were proposing a maverick theory. Turtles had long been deemed to be "living fossils," the only surviving member of a primitive reptile subclass, the anapsids, which originated some 325 million years ago in the Paleozoic era. Now these two researchers were proposing that turtles belonged to the modern reptilian lot--the diapsids, which first emerged about 230 million years ago in the Triassic and include present-day lizards, snakes and crocodiles.

A Matter of Language; March 1997; Scientific American Magazine; by Gibbs; 3 Page(s)

On December 18 the board of education in Oakland, Calif., unanimously adopted a policy stating that most of the 26,000 black students in its district do not speak English as their primary language but rather speak "West and Niger-Congo African Language Systems," which the directive also calls "Ebonics." "Numerous validated scholarly studies," the policy asserts, have demonstrated that "African Language Systems are genetically based and not a dialect of English." (In January the board deleted the phrase "genetically based" from its policy.)

The policy does not order schools to teach Ebonics--until recently, a rarely used term for the variety of English spoken by many urban blacks in the U.S. Linguists more commonly refer to the variety as black English vernacular (BEV). Oakland¿s policy does insist, however, that teachers should understand BEV and use it to help black students learn educated English.

Anti Gravity: Body Blow; March 1997; Scientific American Magazine; by Mirsky; 1 Page(s)

As Julius Caesar might have put it, all of the galling things that can happen to the human body can be divided into three parts. There are the ordinary adversities, when the body falls victim to common disease or accident. Then there are the vapid calamities, such as when the body hoists a few and decides to take a midnight stroll along some train tracks, in which case the body itself may be divided into three parts. Finally, there exist those rare misadventures that would have forced Hamlet to up his estimate to 1,001 for the number of shocks the body¿s flesh is heir to. The story of the young man and the balloons belongs in this last category.

"A 24-year-old previously healthy, nonsmoker presented with a 48-hour history of a sensation of crackling under the skin," wrote attending physician Stuart Elborn, then at the University Hospital of Wales, in a recent issue of the British Medical Journal. His examination turned up pockets of air trapped under the skin on the man¿s shoulders, chest, neck, abdomen, back, arms, legs and, providing a built-in whoopiecushion effect, derriere.

By the Numbers: Global Fertility and Population; March 1997; Scientific American Magazine; by Doyle; 1 Page(s)

Historically, fertility has varied widely, but beginning in 19th-century Europe and America, it has generally declined as parents came to favor smaller families. According to the latest United Nations projections, this trend will continue, stabilizing the world population early in the 23rd century at somewhat under 11 billion, compared with about 5.8 billion today.

The map shows the total fertility rate, which indicates the total number of children the average woman will bear in a lifetime based on the experience of all women in a given year, in this case, 1996. A rate of less than 2.11 children per woman will eventually result in a declining population for a country, assuming no immigration. (The extra 0.11 allows for deaths of children before they reach reproductive age.) A dip below this rate does not lead to a declining population until about seven decades or so later, when all those living at the time the replacement level is reached have died. Such a case is illustrated by Japan, which arrived at the replacement level in the 1950s, well before other industrial nations. The Japanese population will probably level off or decline in the second decade of the next century.

Profile: Ronald L. Graham; March 1997; Scientific American Magazine; by Horgan; 2 Page(s)

Ronald L. Graham, chief scientist at AT&T Labs-Research, begins with two balls, flipping them into the air with one hand while casually chatting with a visitor. He grabs another ball off a counter, and another, while noting that the world record for juggling is nine balls. He can do six consistently, seven "playing around." Nodding at a photograph on the wall showing himself juggling 12 balls, he reveals that it is an illusion generated by his daughter, Ch¿, a photographer who specializes in digital doctoring.

Settling into a chair to give himself more vertical room, Graham juggles five balls, occasionally shifting the pattern, his hands a blur. His ground-level office here in Murray Hill, N.J.--adorned with a tabletop rock garden through which a minuscule stream burbles, a sheet of Chinese ideograms, a print of M. C. Escher¿s Night into Day--has too low a ceiling for six.

Memories Are Made Of . . .; March 1997; Scientific American Magazine; by Beardsley; 2 Page(s)

To be healthy, a human being needs a memory that works well--but not too well. The fading remembrances of a patient with Alzheimer¿s disease slowly erode the victim¿s personal identity. A traumatized war veteran, in contrast, is shattered by too vivid a recall as he cowers when a car backfires nearby.

Biologists have been zeroing in on molecular events that underlie the creation of memories. Developments are suggesting how drugs might be designed to enhance or suppress learning and remembering. Cortex Pharmaceuticals in Irvine, Calif., has already found a molecule that seems to improve the performance of volunteers in memory tests. The founders of Helicon Therapeutics in Cold Spring Harbor, N.Y., have discovered that a protein found in many animals seems to be a crucial player in forming long-term memories. The company plans to screen for drugs that will enhance or suppress the protein¿s action.

China Syndrome; March 1997; Scientific American Magazine; by Beardsley; 2 Page(s)

Eugenics produced some of the worst horrors of the century, so geneticists get jumpy when their expertise is used to coerce. Scientists are now trying to decide how to respond to a law that came into force in China in 1995 and seems unabashedly eugenic.

In most of the world, choosing to have a baby is a private matter for two people. The Chinese Law on Maternal and Infant Health Care, however, stipulates that if a married couple in childbearing years suffers from a genetic disease "of a serious nature," the couple "shall take measures in accordance with...medical advice." Other provisions make plain what measures might be appropriate. Couples with unspecified genetic diseases "considered to be inappropriate for childbearing" may be married only if both agree to practice long-term contraception or to be sterilized.

A Mirror, Cheaply; March 1997; Scientific American Magazine; by Powell; 1 Page(s)

Who would build a giant telescope that cannot move up and down? A consortium led by the University of Texas at Austin and Pennsylvania State University, that¿s who. The contradiction between observers¿ ever more ambitious plans and harsh fiscal realities encouraged the universities to back the Hobby- Eberly Telescope (HET) at the Mc- Donald Observatory in Texas. The telescope¿s stripped-down design offers high performance at a bargain price. Its lightgathering mirror stretches 11 meters across, the world¿s largest, but its $13.5- million construction budget is a mere fraction of that of other giant telescopes.

HET was dreamed up in the recession years of the early 1980s by Lawrence W. Ramsey and Daniel Weedman of Penn State. In their quest for efficiency, they reconsidered almost everything that one typically associates with a telescope--including the ability to point in any direction. The telescope¿s gaze is permanently tipped 35 degrees from vertical, although it can rotate on its base. A small, movable focusing instrument above the main mirror tracks astronomical images across the sky. Reduced mobility means a much simpler, cheaper telescope. "We¿re getting 70 percent of the sky for 15 percent of the price," Ramsey says.

Better Red Than Dead; March 1997; Scientific American Magazine; by Zorpette; 1 Page(s)

In the eternal struggle between humans and microbes, certain toxic strains of Escherichia coli are the special forces of the bacteria world. Swift and potentially deadly, they produce toxins that cause intense intestinal distress, severe dehydration and internal bleeding. No treatment has been proved consistently effective against the disease, public health officials say. And at present, no specific, convenient test is routinely used to detect the bacteria, which kill as many as 200 people every year in the U.S. alone. To test for the bacteria, samples that have been taken from food or from a patient who may be afflicted must be cultured for 24 or more hours, after which the harmful organisms can be detected with microscopes or special dyes.

An invention at Lawrence Berkeley National Laboratory promises to change all that. Researchers in the lab¿s Biomolecular Materials Program have created an advanced thin-film biomaterial that functions as a litmus test for the bacteria. The plastic strips, which researchers say could be produced for less than a penny apiece, instantly change from blue to red in the presence of any toxic strain of E. coli. "It could change the rules of the game," asserts Jeffery Kahn, a laboratory spokesperson.

Cyber View; March 1997; Scientific American Magazine; by Eisenberg; 1 Page(s)

In the past year only a trickle of money on the World Wide Web has actually made its way toward consumer goods such as books, flowers and airline tickets. But the Web has actually produced a bona fide financial hit--intranets. These systems are networks that are generally accessible only to select users and that rely on the rules of the Internet that permit computers to "talk" to one another. Unlike their rambunctious, flashy Internet cousins, intranets (and extranets, or networks extended to branches and business partners) are the emerging bourgeoisie--stable, productive money earners, the economic bedrock of cyberspace.

Convinced that they will increase profits, U.S. companies are ready to pay for the Web technology to create them. The market for intranets is estimated to reach at least $9 billion by 2000 or perhaps even more: Zona Research, a consulting firm in Redwood City, Calif., thinks annual spending on intranets will exceed $13 billion by 1999. Netscape, Sun Microsystems and Lotus/IBM are already competing fiercely for this enormous market, and so, too, looming over them all, is the Godzilla of Redmond, Wash., Microsoft.

SOHO Reveals the Secrets of the Sun; March 1997; Scientific American Magazine; by Lang; 8 Page(s)

From afar, the sun does not look very complex. To the casual observer, it is just a smooth, uniform ball of gas. Close inspection, however, shows that the star is in constant turmoil--a fact that fuels many fundamental mysteries. For instance, scientists do not understand how the sun generates its magnetic fields, which are responsible for most solar activity, including unpredictable explosions that cause magnetic storms and power blackouts here on the earth. Nor do they know why this magnetism is concentrated into so-called sunspots, dark islands on the sun¿s surface that are as large as the earth and thousands of times more magnetic. Furthermore, physicists cannot explain why the sun¿s magnetic activity varies dramatically, waning and intensifying again every 11 years or so.

To solve such puzzles--and better predict the sun¿s impact on our planet--the European Space Agency and the National Aeronautics and Space Administration launched the two-ton Solar and Heliospheric Observatory (SOHO, for short) on December 2, 1995. The spacecraft reached its permanent strategic position--which is called the inner Lagrangian point and is about 1 percent of the way to the sun--on February 14, 1996. There SOHO is balanced between the pull of the earth¿s gravity and the sun¿s gravity and so orbits the sun together with the earth. Earlier spacecraft studying the sun orbited the earth, which would regularly obstruct their view. In contrast, SOHO monitors the sun continuously: 12 instruments examine the sun in unprecedented detail. They downlink several thousand images a day through NASA¿s Deep Space Network antennae to SOHO¿s Experimenters¿ Operations Facility at the NASA Goddard Space Flight Center in Greenbelt, Md.

The Internet; March 1997; Scientific American Magazine; by Staff Editor; 1 Page(s)

Fulfilling the Promise

The Internet: Bringing Order From Chaos; March 1997; Scientific American Magazine; by Staff Editors; 2 Page(s)

The Internet, as everybody with a modem now knows, has fallen victim to its own success. In a few short years, it has gone from being the communications province of scientists and engineers to a primary route of information exchange for everyone from financial analysts to fashion designers. So much clutter and traffic snarl the computer networks that the Clinton administration has announced its intention to build a new, separate system--the Internet II--just so that scientists can get some work done again.

Putting the Net to work for the rest of us will be the real challenge in the years ahead. Electronic mail and even videoconferencing are already entrenched, but those applications do not cut to the heart of what the World Wide Web and the rest of the Internet constitute a gigantic storehouses of raw information and analysis, the database of all databases. Worries about the future of the Net usually center on the delays and access limitations caused by its overburdened hardware infrastructure. Those may be no more than growing pains, however. The more serious, longer-range obstacle is that much of the information on the Internet is quirky, transient and chaotically "shelved."

Searching the Internet; March 1997; Scientific American Magazine; by Lynch; 5 Page(s)

One sometimes hears the Internet characterized as the world¿s library for the digital age. This description does not stand up under even casual examination. The Internet-- and particularly its collection of multimedia resources known as the World Wide Web--was not designed to support the organized publication and retrieval of information, as libraries are. It has evolved into what might be thought of as a chaotic repository for the collective output of the world¿s digital "printing presses." This storehouse of information contains not only books and papers but raw scientific data, menus, meeting minutes, advertisements, video and audio recordings, and transcripts of interactive conversations. The ephemeral mixes everywhere with works of lasting importance.

In short, the Net is not a digital library. But if it is to continue to grow and thrive as a new means of communication, something very much like traditional library services will be needed to organize, access and preserve networked information. Even then, the Net will not resemble a traditional library, because its contents are more widely dispersed than a standard collection. Consequently, the librarian¿s classification and selection skills must be complemented by the computer scientist¿s ability to automate the task of indexing and storing information. Only a synthesis of the differing perspectives brought by both professions will allow this new medium to remain viable.

Going Digital; March 1997; Scientific American Magazine; by Lesk; 3 Page(s)

Smack in the middle of Paris, hugging the bank of the Seine, four enormous highrises stand ready, with 395 kilometers of shelf space, to receive up to 22 million books. The French national library¿s new Tolbiac tower complex may be both the last and the first of its kind. Last because most major cities can no longer afford to construct such ambitious public works. But first because the Biblioth¿que Nationale de France will complete its move with a pi¿ce de r¿sistance: hundreds of computer workstations providing ready electronic access to the full text of 110,000 volumes covering much of French history and culture.

All over the world, libraries have begun the Herculean task of making faithful digital copies of the books, images and recordings that preserve the intellectual effort of humankind. For armchair scholars, the work promises to bring such a wealth of information to the desktop that the present Internet may seem amateurish in retrospect. But many technical, economic and legal obstacles still make that promise an uncertain one.

Filtering Information On The Internet; March 1997; Scientific American Magazine; by Resnick; 3 Page(s)

To steer clear of the most obviously offensive, dangerous or just boring neighborhoods, users can employ some mechanical filtering techniques that identify easily definable risks. One technique is to analyze the contents of on-line material. Thus, virus-detection software searches for code fragments that it knows are common in virus programs. Services such as AltaVista and Lycos can either highlight or exclude World Wide Web documents containing particular words. My colleagues and I have been at work on another filtering technique based on electronic labels that can be added to Web sites to describe digital works. These labels can convey characteristics that require human judgment-- whether the Web page is funny or offensive-- as well as information not readily apparent from the words and graphics, such as the Web site¿s policies about the use or resale of personal data.

Interfaces For Searching the Web; March 1997; Scientific American Magazine; by Hearst; 5 Page(s)

How does anyone find anything among the millions of pages linked together in unpredictable tangles on the World Wide Web? Retrieving certain kinds of popular and crisply defined information, such as telephone numbers and stock prices, is not hard; many Web sites offer these services. What makes the Internet so exciting is its potential to transcend geography to bring information on myriad topics directly to the desktop. Yet without any consistent organization, cyberspace is growing increasingly muddled. Using the tools now available for searching the Web to locate the document in Oregon, the catalogue in Britain or the image in Japan that is most relevant for your purposes can be slow and frustrating.

More sophisticated algorithms for ranking the relevance of search results may help, but the answer is more likely to arrive in the form of new user interfaces. Today software designed to analyze text and to manipulate large hierarchies of data can provide better ways to look at the contents of the Internet or other large text collections. True, the page metaphor used by most Web sites is familiar and simple. From the perspective of user interface design, however, the page is unnecessarily restrictive. In the future, it will be superseded by more powerful alternatives that allow users to see information on the Web from several perspectives simultaneously.

Websurfing Without a Monitor; March 1997; Scientific American Magazine; by Raman; 1 Page(s)

When I hook up to the Internet to check out the news on CNN, to peruse a colleague¿s latest paper or to see how Adobe¿s stock price is doing, I leave the display on my laptop turned off. The batteries last much longer that way. Besides, because I cannot see, a monitor is of no use to me.

That a blind person can navigate the Internet just as efficiently and effectively as any sighted person attests to the profound potential of digital documents to improve human communication. Printed documents are fixed snapshots of changing ideas; they limit the means of communication to the paper on which they are stored. But in electronic form, documents can become raw material for computers that can extract, catalogue and rearrange the ideas in them. Used properly, technology can separate the message from the medium so that we can access information wherever, whenever and in whatever form we want.

Multilingualism on the Internet; March 1997; Scientific American Magazine; by Oudet; 2 Page(s)

In recent years, American culture has increased its worldwide influence through international trade and Hollywood productions. As the Internet reaches into ever more remote corners of the globe, an obvious question arises: Will it amplify this trend, so that English is used everywhere? Or will a diversity of languages enrich the on-line universe? Some observers predict that local languages will not survive on-line: English will rule.

Such a sweeping dominance will have drawbacks. Most people use English as a second language, and their grasp of it may be quite rudimentary--sufficient only for understanding basic information such as the weather report, and sometimes not even that. For more indepth discussions, almost everyone tends to fall back on his or her native language. If the Internet does not allow multilingual conversations, its role as a facilitator of international communication will be severely limited. Mistakes and misunderstandings will become rampant, and many users will be cut out of the tremendous opportunities that international communication has to offer.

Trusted Systems; March 1997; Scientific American Magazine; by Stefik; 4 Page(s)

Everyday experience with computers has led many people to believe that anything digital is ripe for copying--computer programs, digital books, newspapers, music and video. Some digital-age pundits have gone so far as to proclaim that the ease of duplicating data heralds an end to copyright: information "wants to be free," they assert. It is impossible to thwart the spread of information, so the argument goes. Anything that can be reduced to bits can be copied.

This provocative notion undermines the dream behind the creation of the Internet: the possibility of universal access in a digital age--where any author¿s work could be available to anyone, anywhere, anytime. The experience of most people, however, is not that the Net contains great works and crucial research information. Instead most of what is there is perceived to be of low value.

Preserving the Internet; March 1997; Scientific American Magazine; by Kahle; 2 Page(s)

Manuscripts from the library of Alexandria in ancient Egypt disappeared in a fire. The early printed books decayed into unrecognizable shreds. Many of the oldest cinematic films were recycled for their silver content. Unfortunately, history may repeat itself in the evolution of the Internet-- and its World Wide Web.

No one has tried to capture a comprehensive record of the text and images contained in the documents that appear on the Web. The history of print and film is a story of loss and partial reconstruction. But this scenario need not be repeated for the Web, which has increasingly evolved into a storehouse of valuable scientific, cultural and historical information.

Psychiatry's Global Challenge; March 1997; Scientific American Magazine; by Kleinman, Cohen; 4 Page(s)

Over the past 50 years, the health and living conditions of people in developing nations have improved dramatically. Average life expectancy in Egypt and India, among other countries, has risen from around 40 to 66 years. Smallpox, which once killed millions annually, has been completely eradicated, and infant mortality has fallen from about 28 to 10 percent of live births. Real average incomes more than doubled, and the percentage of rural families with access to safe water increased from less than 10 to almost 60 percent.

Unfortunately, this remarkable progress in physical well-being has been accompanied by a deterioration in mental health. In many areas outside North America and western Europe, schizophrenia, dementia and other forms of mental illness are on the rise. For example, schizophrenia--one of the most debilitating of mental illnesses, in which thoughts and emotions are sometimes disconnected or distorted by delusions-- is expected to afflict 24.4 million people in low-income societies by the year 2000, a 45 percent increase over the number afflicted in 1985.

Discovering Genes for New Medicines; March 1997; Scientific American Magazine; by Haseltine; 6 Page(s)

Most readers of this magazine are probably familiar with the idea of a gene as something that transmits inherited traits from one generation to the next. Less well appreciated is that malfunctioning genes are deeply involved in most diseases, not only inherited ones. Cancer, atherosclerosis, osteoporosis, arthritis and Alzheimer¿s disease, for example, are all characterized by specific changes in the activities of genes. Even infectious disease usually provokes the activation of identifiable genes in a patient¿s immune system. Moreover, accumulated damage to genes from a lifetime of exposure to ionizing radiation and injurious chemicals probably underlies some of the changes associated with aging.

A few years ago I and some likeminded colleagues decided that knowing where and when different genes are switched on in the human body would lead to far-reaching advances in our ability to predict, prevent, treat and cure disease. When a gene is active, or as a geneticist would say, "expressed," the sequence of the chemical units, or bases, in its DNA is used as a blueprint to produce a specific protein. Proteins direct, in various ways, all of a cell¿s functions. They serve as structural components, as catalysts that carry out the multiple chemical processes of life and as control elements that regulate cell reproduction, cell specialization and physiological activity at all levels. The development of a human from fertilized egg to mature adult is, in fact, the consequence of an orderly change in the pattern of gene expression in different tissues.

Heike Kamerlingh Onne's Discovery of Superconductivity; March 1997; Scientific American Magazine; by de Bruyn Ouboter; 6 Page(s)

Superconductivity--the disappearance of resistance in an electric current--is one of nature¿s stranger phenomena. Ten years ago this month, in what some called the "Woodstock of physics," hundreds of scientists crowded into a ballroom at the New York City Hilton to receive hurried reports of superconductivity at much higher temperatures than ever previously reported. Thirty years before that, John Bardeen, Leon N. Cooper and J. Robert Schrieffer established the theoretical foundations that best explained superconductivity. Almost forgotten in the search for theory, and for materials that superconduct at ever higher temperatures, is the work of the brilliant experimental physicist Heike Kamerlingh Onnes, superconductivity¿s discoverer.

Onnes was a man attracted to cold, which no doubt added to his enjoyment of the December day in Stockholm in 1913 when he received the Nobel Prize for Physics. His primary research goal was to quantify the behavior of gases at extremely low temperatures; the experimental program that allowed him to reach ever lower temperatures also led to the discovery of superconductivity.

Plants That Warm Themselves; March 1997; Scientific American Magazine; by Seymour; 6 Page(s)

In the spring of 1972 George A. Bartholomew, a leader in the study of animal physiology, invited a group of his students and co-workers from the University of California at Los Angeles to a dinner party. Among his guests was Daniel K. Odell, now of Sea World in Florida. En route to the affair, Dan noticed some striking flowers. They consisted of a rather phallic projection that was about nine inches long and partly enveloped by a leaflike structure. Intrigued, he picked one to show the other partygoers. When he handed the cutting to Kenneth A. Nagy and me, we were astonished to find it was warm. What is more, the flower grew hotter as the evening progressed, appearing to become warmer than the human body. As zoologists, we were dumbfounded. How could a mere plant heat itself more than the pinnacle of organic evolution--the warm-blooded animal?

From that moment on, I have hunted for and analyzed hot plants whenever I could steal time from my research into animals. I continue to be amazed by what my colleagues and I--and several other researchers--have found. Among our discoveries is that some plants produce as much heat for their weight as birds and insects in flight, the greatest heat producers of all. And a few plants actually thermoregulate, almost as if they were birds or mammals: they not only generate warmth, they alter their heat production to keep their temperature surprisingly constant in fluctuating air temperatures.

The Rising Seas; March 1997; Scientific American Magazine; by Schneider; 6 Page(s)

Many people were awakened by the air-raid sirens. Others heard church bells sounding. Some probably sensed only a distant, predawn ringing and returned to sleep. But before the end of that day-- February 1, 1953--more than a million Dutch citizens would learn for whom these bells tolled and why. In the middle of the night, a deadly combination of winds and tides had raised the level of the North Sea to the brim of the Netherlands¿ protective dikes, and the ocean was beginning to pour in.

As nearby Dutch villagers slept, water rushing over the dikes began to eat away at these earthen bulwarks from the back side. Soon the sea had breached the perimeter, and water freely flooded the land, eventually extending the sea inward as far as 64 kilometers from the former coast. In all, more than 200,000 hectares of farmland were inundated, some 2,000 people died, and roughly 100,000 were left homeless. One sixth of the Netherlands was covered in seawater.

Mathematical Recreations; March 1997; Scientific American Magazine; by Stewart; 3 Page(s)

About a year ago Ian Porteous, a mathematician at the University of Liverpool, told me about an elegant game. His son, Richard Porteous, invented it to teach children about multiplication and division. The game is called Juniper Green, after the school at which Richard taught. It is fun to play, and the search for a winning strategy is quite challenging.

To play Juniper Green, you should make 100 cards, numbered 1 through 100. Lay them face up on the table in numerical order, say, 10 rows of 10 cards each, so that it will be easy for players to locate the desired card.

The Amateur Scientist; March 1997; Scientific American Magazine; by Carlson; 3 Page(s)

I used to spend my days (and I do mean my days) hunting for supernovae. The astrophysics group I worked for dusted off an old 30-inch telescope, then used only for teaching, and converted it into a fully automated research instrument. When night arrived, this computer-controlled marvel woke up, checked its systems and set about the business of discovery. On clear nights it scanned hundreds of galaxies, searching for objects that appeared as bright stars not detected in earlier images. Sometimes it found them.

It was wonderful! And I didn't feel too guilty about not freezing all night in a remote observatory. I had toiled in cyberhell for months teaching the telescope's computer how to decide which galaxies to image and in what order it should observe them. Because large excursions from horizon to horizon sent the telescope's 40-year-old drive system into shock, it was vital that the feeble old veteran be moved as little as possible. That meant ordering the galaxies into a sequence that, totaled over the whole night, required the telescope to move through the smallest possible angle. Computer aficionados will recognize my galaxy conundrum as a variant of the classic traveling salesman problem, in which a huckster seeks an itinerary that will let him travel the smallest possible distance through a list of cities.

Reviews; March 1997; Scientific American Magazine; by da F. Costa, Wallich, Powell, Goldsmith; 5 Page(s)

Second to no machine in its performance, human vision is--or at least seems to be--comprehensive, effortless and instantaneous. There is a tendency to consider it pure in its simplicity, to think of the image we see as a direct impression of the world outside ourselves. Yet vision is an elaborate process that demands about half the overall capacity of the primate brain¿s cortex. And even with that complexity (indeed, often because of it), vision is in fact limited in many aspects. The dynamic and often contradictory nature of seeing is the organizing theme of this interesting, but sometimes gloomy book, which covers many issues not usually considered in texts on visual science.

James Elkins, an art historian by training, sets out by denying the popular concept of vision as a passive activity--that we are "just looking." In reality, our eyes are constantly and actively seeking something, whether we are visiting an art museum or just watching the clouds roll by. Furthermore, seeing is not entirely under our control. When and where our gaze settles next is to a great extent determined by our surroundings and by what we had been looking at before.

Commentary: Wonders Molecular Crayons and Mustard Seed Avalanches; March 1997; Scientific American Magazine; by Morrison, Morrison; 2 Page(s)

Hardly a week passes without bringing its dramatic image of some molecular scene. One recent tour de force of the modern nano-scene studios was an atomic abacus, the counting beads ranked in parallel grooves, and the entire device built of neatly distinct molecules and atoms. Such images are the product of a scanning probe microscope. It uses no focused beam of photons or particles; instead direct physical contacts are mapped as atom after atom is probed in turn. The brightness or darkness of each picture element depends on the strength of an interaction between an atom and the probe end; it may be a tiny current tunneling between the two or the localized force between the surfaces as the probe delicately taps away. Such pictures magnify distances within the minuscule scene by a few million times.

It took us a while to realize that images so made are not unknown at our own scale. Who has not seen an ancient relief carving in stone beautifully rendered in black on flat paper, the highlights and recesses felt out and recorded by rubbing a suitable crayon over the whole scene? The atomic images popular today are a kind of atomic rubbing, made with a fine crayon indeed.

Commentary: Connections - Revolutionary Stuff; March 1997; Scientific American Magazine; by Burke; 2 Page(s)

Iwas enjoying a recent partial solar eclipse in London and thinking about how after Copernicus came out with De revolutionibus orbium coelestium, in which he made the shocking assertion that the earth moved in orbit just like the other planets, it really was for his contemporaries, as they often said, that "the world turned upside down." Because if you put the sun instead of the earth at the center of everything, you rocked the entire boat: the old "fixed" order of things (and the church that said so); man as the center of the universe (and the church that said so); the heavens that were beyond investigation (and the church that said so).

No wonder Andreas Osiander (Lutheran mathematician and religious fanatic) tried to persuade Copernicus to write a smoke-and-mirror preface saying it was all just astronomers¿ mathematical fiction. Otherwise, Osiander said, there was a good chance Copernicus would be in deep and potentially fatal doo-doo with Rome. But since Copernicus was dying anyway, what did he care? In the event, while Copernicus¿s editor, Rheticus, was out of town (Nuremberg, where the work was being printed), Osiander, temporary replacement editor, slipped in his own preface, with the "fiction" message. By the time the thing blew up (Rheticus went ballistic), it was too late. And De Revolutionibus was off the hook enough to survive the censor. More or less.

Working Knowledge; March 1997; Scientific American Magazine; by Scott; 1 Page(s)

There is no such thing as a bulletproof vest. For more than 3,000 years, soldiers have attempted to stop pointed objects from penetrating the skin. But a sharp-enough point made of a hard-enough material delivered at high-enough velocity will defeat the most intricate chain mail or a weave of the most high-technology fiber.

Polymer chemistry, however, has achieved a measure of success in making materials that can stop many of the bullets found in the most common handguns. At the same time, the wearer of garments made from such plastics no longer need feel like a knight in armor: the materials weigh little enough to be fashioned into an overcoat or a dress jacket. Until the mid-1970s, clothes that could resist bullets required so many layers of nylon, silk, leather or metallic materials that their bulkiness often caused police to avoid them.