Scientific American Magazine
Cover; June 1998; Scientific American Magazine; by Staff Editor; 1 Page(s)
Table of Contents; June 1998; Scientific American Magazine; by Staff Editor; 2 Page(s)
From the Editors, including Masthead; June 1998; Scientific American Magazine; by Rennie; 1 Page(s)
Letters to the Editors; June 1998; Scientific American Magazine; by Staff Editor; 2 Page(s)
50, 100 and 150 Years Ago; June 1998; Scientific American Magazine; by Staff Editor; 1 Page(s)
JUNE 1948 FUNGUS INFECTION--Histoplasmosis, in 1944, was thought to be extremely rare; even its name was unknown to most physicians. However, since then a new skin test was used in a large-scale survey of thousands of student nurses. The results were astonishing: almost one fourth of all the students reacted positively to the test. It is now thought that millions of Americans are afflicted. Little is known about this ominous fungus. Histoplasma capsulatum appears in nature in two varieties, one harmless, the other parasitic and responsible for causing histoplasmosis in man. The parasitic type is believed to be insect-borne, but the method by which the disease is spread is unknown.[Editors¿ note: The fungus is associated with bird or bat droppings.]
OLD AGE--Within the last 10 years scientific interest in problems of aging has gained momentum. This interest comes in the nick of time, for such disorders as arthritis, nephritis, and cardiovascular disease have become a tremendous problem. As medicine copes more effectively with the diseases of childhood and early maturity, the percentage of our population in older age groups has been mounting steadily. How far deterioration and natural death can be pushed back is still a matter of debate. Conservative physiologists would grant that health and vigor can last to the age of 100. The enthusiastic Russians, who have been probing the secrets of age with great energy, would set the limit above 150.
In Focus: Culturing New Life; June 1998; Scientific American Magazine; by Beardsley; 2 Page(s)
Many killer diseases involve irreversible degeneration of some crucial cell type or tissue: islet cells of the pancreas in diabetes, neurons of the brain in Parkinson¿s disease, Huntington¿s disease and other neurological conditions. Researchers have long dreamed of culturing in the laboratory human cells that could colonize and regenerate failing tissue. But biology has been uncooperative. Cancer cells readily grow in a bottle, but healthy, normal ones soon stop propagating outside the body.
Recent discoveries point to a solution. Investigators have been able to identify and culture for many months rare "stem cells" from various crucial tissues. These cells, when implanted in the appropriate type of tissue, can regenerate the range of cells normally found there. Stem cells have been discovered in the nervous system, muscle, cartilage and bone and probably exist in pancreatic islet cells and the liver. More remarkable still, unpublished work has convinced moneyed entrepreneurs that special cells derived originally from a fetus could produce a wide variety of tissue-specific cells.
Lupus in Limbo; June 1998; Scientific American Magazine; by McKinsey; 1 Page(s)
This past March the U.S. Fish and Wildlife Service released 11 captive-bred Mexican gray wolves into the Apache National Forest, a tract of greenery extending through eastern Arizona. Extinct from the Southwest for the past two decades, the wolves that were reintroduced received the "nonessential experimental" designation under the Endangered Species Act. This label was meant to appease ranchers; it allows them to defend their livestock against the reintroduced wolves. With the label, the reintroduced animals have less federal protection than the wild ones, which cannot be legally harmed. But that creates a practical problem for ranchers, who can¿t always distinguish reintroduced wolves from wild ones. Now legal action by the ranchers is challenging the effectiveness of the label and could threaten the future of the program.
Conservationists got their first lesson on the legal quandaries created by the labeling from the controversy surrounding another nonessential experimental animal: the reintroduced gray wolves, Canis lupus, of Yellowstone National Park. In the early 1990s the Fish and Wildlife Service trapped wild gray wolves in western Canada and released them in the park. Listed as endangered since 1967, the gray wolf was exterminated from the American Rockies in the early 1900s to quell the fears of ranchers. But populations were allowed to thrive in parts of Canada.
Good News for the Greenhouse; June 1998; Scientific American Magazine; by Schneider; 1 Page(s)
Last December¿s climate talks in Kyoto, Japan, helped to keep the world¿s attention firmly focused on the threat of greenhouse warming posed by emissions of carbon dioxide. And to good effect: if industrial nations can meet the targets they established, the heat-trapping veil of carbon dioxide should thicken less swiftly. But another, more subtle, event occurred last December that might also bode well for future climate. Researchers from the National Oceanic and Atmospheric Administration (NOAA) and the University of Colorado reported that methane, another potent greenhouse gas, appears to be accumulating in the atmosphere more slowly than anticipated. If this trend continues, the concentration of methane might soon stabilize, miraculously stemming some 20 percent of the burgeoning greenhouse problem.
This news from NOAA¿s Edward J. Dlugokencky and his colleagues (delivered at the last meeting of the American Geophysical Union) represents a departure from previous conceptions. Researchers had known that the growth of atmospheric methane had been ebbing since comprehensive measurements began in the early 1980s. And they were aware of an abrupt decrease in the rising tide of methane and several other trace gases that occurred in 1992. But many, including members of the influential Intergovernmental Panel on Climate Change (IPCC), regarded that sudden downturn as a short-term "anomaly." After all, the main sources of methane--wetlands, rice paddies and livestock--had not gone away. According to their best guesses, the 1992 decline was caused, perhaps, by the drop in natural gas production (and, presumably, methane leakage from pipes) in the former Soviet Union. Or it came from the eruption of Mount Pinatubo the previous year, which reduced stratospheric ozone and allowed more ultraviolet light to reach the lower atmosphere, where it breaks up methane.
Mesozoic Mystery Tour; June 1998; Scientific American Magazine; by Zorpette; 2 Page(s)
Flatlands, Brooklyn, is not the kind of place to which one generally travels to reflect, awestruck, on an indescribably ancient natural pageant. But this is exactly what I did last year, on a breezy evening when the moon was full, and the summer solstice was only a day away.
Every year horseshoe crabs and their evolutionary ancestors have crawled shoreward in a mating ritual that is perhaps 400 million years old. The procession starts out on the continental shelves, where the creatures subsist on mussels, worms and other bottom dwellers. Once during their lives, in spring or early summer, the females trek in to shore to lay in the intertidal region. The coupling is best viewed during the unusually high tides of a full or new moon, when the females creep to the edge of the waterline, each with a male clinging to her posterior in the tenacious copulative embrace known as amplexus. In Florida the migration peaks in March and April; in Delaware Bay the traffic is usually heaviest around April and May; in the northeast U.S., June and July is generally the best time to view the spectacle.
In Brief; June 1998; Scientific American Magazine; by Leutwyler; 3 Page(s)
Basmati Battle Ricetec, an American company based in Texas, has patented basmati rice, a staple grain in southern Asia, and has trademarked the word "basmati" as well. Longtime foes India and Pakistan are working together to challenge Ricetec. They argue that nowhere in the U.S. can you grow what is ordinarily called basmati, so that Ricetec has no right to label the product "Kasmati, Indian style Basmati." India and Pakistan maintain that the U.S. Patent Office would not have awarded Ricetec the rights if they had known more about the prior art and use of basmati. Southern Asians are not the only ones worried: Central and South American groups have also protested a patent awarded to a U.S. company for one of their native plants.
The Man on Mars In 1976 NASA¿s Viking spacecraft snapped a photograph of a feature on Mars that was startlingly familiar to earthlings: part of the rocky surface looked just like a face. Most interpreted this Martian Mount Rushmore as a trick of light and shadow, but others credited it to alien artisans. Now the 22- year-old mystery is settled once and for all. Last month the Mars Global Surveyor took images of the same spot, and this time, the geologic formations there resembled a footprint.
The Blight is Back; June 1998; Scientific American Magazine; by Nelson; 2 Page(s)
In 1845 a plant disease called late blight swept through potato farms in Europe, causing the historic potato famine and ultimately the starvation of more than one million people in Ireland. Now, 150 years later, aggressive new strains of Phytophthora infestans, the fungus responsible for late blight, are rapidly spreading around the world. The strains are so virulent that they not only can destroy a potato field in a matter of days, but they are also resistant to metalaxyl, the only fungicide effective in slowing established infestation.
The fungus, which originated from Mexico¿s Toluca Valley, comes in two types, called A1 and A2. For reasons not clearly understood, only A1 migrated from Mexico in the mid-19th century, probably on a plant specimen. Late blight became controllable through a combination of fungicides and integrated pest management, a system that combines biological, cultural, physical and chemical tools. But in the early 1980s Europe reported a sharp increase in P. infestans¿related crop losses. Whereas only the A1 mating type had been previously reported in Europe, investigators are now finding new strains consisting of both mating types.
By the Numbers: U.S. Wetlands; June 1998; Scientific American Magazine; by Doyle; 2 Page(s)
Swamps, marshes, bogs and similar watery tracts have long been thought of as dismal, unhealthy places that should be removed in the name of progress. In recent years, however, this view has changed radically as scientists realized that wetlands perform many vital functions. They protect shorelines and remove pesticides and other pollutants from surface waters. They provide a refuge for one half of the fish, one third of the bird and one sixth of the mammal species on the U.S. threatened and endangered lists. By acting as reservoirs for rainfall and runoff, they help to extend stream flow during droughts and to prevent floods. The loss of wetlands contributed to the great floods of 1993 on the upper Mississippi and Missouri rivers, the worst in modern U.S. history.
Wetlands take many forms, including salt marshes, forested swamps, floodplains, peat bogs and prairie potholes (the depressions left after the retreat of the last glacier). The large map shows areas that have been predominantly wetlands since the early 1990s. (Also shown are lakes, which serve some of the same functions as wetlands, such as storage of water and species protection.)
The Prevention Pill; June 1998; Scientific American Magazine; by Gibbs; 2 Page(s)
The news in April that tamoxifen, a drug prescribed since the 1970s to treat breast cancer, can also prevent the disease caught many oncologists by surprise. Not least among them were the researchers at the National Cancer Institute (NCI) and the National Surgical Adjuvant Breast and Bowel Project (NSABP) whose six-year clinical trial produced the good news.
The results were not supposed to be announced until 1999. But when scientists took a regularly scheduled peek this past March at how the 13,388 women in the experiment were coming along, they discovered that "the effect [of the drug] was much stronger than we had expected," recounts Joseph P. Costantino, a biostatistician with the NSABP.
Anti Gravity: Greatness Thrust upon it; June 1998; Scientific American Magazine; by Mirsky; 1 Page(s)
Things that were great, but only briefly: the Florida Marlins; Saturday Night Live; Lake Champlain. Take the Marlins. They won the World Series last year, then sold or traded most of their best players and ran off 11 straight losses in April. Take Saturday Night Live. Please. Finally, take Lake Champlain, a long and lovely seam of freshwater that separates Vermont from upstate New York. On March 6, President Bill Clinton signed a bill containing a bon mot inserted by Vermont Senator Patrick J. Leahy: "The term ¿Great Lakes¿ includes Lake Champlain."
Yes, money was involved. The bill, the National Sea Grant Program Reauthorization Act of 1998, frees up money for research on oceans, coasts or the Great Lakes. Formerly, Vermont colleges interested in researching Lake Champlain were ineligible for a piece of the more than $50 million up for grabs. The Leahy redesignation instantly enabled Vermont schools to compete, because their lake was Great, too.
Profile: Where the Bodies Lie; June 1998; Scientific American Magazine; by Stix; 2 Page(s)
Joel Schwartz is the antithesis of the epidemiologist as public accountant of the medical profession--the cautious record keeper who never goes beyond highly qualified statements about plausible statistical association between pollutant exposure and disease. His method of employing high-powered statistical techniques to find ties between fine combustion particles and premature deaths is coupled with an activist¿s sensibility. "If you think that all a public health professional should do is to publish papers and pad a CV, then you should get another job," Schwartz says.
Schwartz is one of the scientists most closely associated with the research that led to new Environmental Protection Agency regulations last year to reduce levels of microscopic particles measuring 2. 5 microns in diameter or less. These "fine" particles are by-products of combustion from industrial plants, woodstoves and motor vehicles. During the multiyear debate over new rules, the outspoken qualities of the tall, intense figure with the salt-and-pepper beard made him a lightning rod for industry officials who have attacked particulate research as "junk science."
Star Warned; June 1998; Scientific American Magazine; by Dupont; 1 Page(s)
This year marks the 15th anniversary of the Strategic Defense Initiative, which President Ronald Reagan hoped would one day protect the U.S. from Soviet missiles. Whereas Reagan¿s vision of a space-based shield has largely faded in the aftermath of the cold war, missile defense remains alive and well funded. A Republican Congress has added more than $2 billion to the Ballistic Missile Defense Organization (BMDO) budget since 1996, and this year the Pentagon plans more tests of so-called Star Wars systems than in any prior year.
But 1998 has also brought renewed criticism of the technology. In February a team of former Pentagon officials, led by one-time Air Force chief of staff Gen. Larry Welch, issued a scathing evaluation of current efforts. Warning of a "rush to failure," the group cautioned that a "perceived" threat was driving the Pentagon to hurry the development of missile defense systems without first proving that they work.
Running on MMT?; June 1998; Scientific American Magazine; by McKinsey; 1 Page(s)
The auto industry despises it, the petroleum industry is avoiding it, the U.S. government was forced to legalize it, and animal studies suggest that its key ingredient can damage health. Yet MMT, a fuel additive that increases octane and reduces oxide emissions, is marketed worldwide as safe, effective and efficient. Its manufacturer, Ethyl Corporation, based in Richmond, Va., is so sure of MMT that it is now suing the Canadian government, which in April 1997 banned for health concerns the import and interprovince trade of MMT, after 20 years of use.
At issue is MMT¿s main component, manganese. Small amounts in the diet are beneficial and necessary, and large amounts pose no threat because the liver can rid the body of any excess. But inhaled manganese is a different story. Epidemiologist Ellen K. Silbergeld of the University of Maryland points to studies of monkeys that show the dose reaching the brain is consistently higher than when ingested and can cause neurological disorders similar to Parkinson¿s disease. She cites studies suggesting that airborne metals can travel up the olfactory nerve to the brain. The fear is that vapors of MMT-enhanced gasoline-- which does not have to be labeled in the U.S.--might enter the atmosphere.
Millennium Bug Zapper; June 1998; Scientific American Magazine; by Hayashi; 1 Page(s)
Like the late Jonas Salk¿s return to prominence to combat HIV, Bob Bemer¿s emergence from semiretirement to solve the "Year 2000" computer problem evokes nostalgia. A pioneer in the digital world, Bemer is the man who, among other accomplishments, helped to define ASCII characteristics, which allow otherwise incompatible computers to exchange text. But critics say Bemer¿s solution, though ingenious, may be too much too late.
The Year 2000, or "Y2K," problem arises from the widespread use of twodigit date fields, which leaves computers confused whether "00" refers to the year 1900 or 2000. According to detailed estimates, fixing this pervasive "bug" will cost companies and governments around the world hundreds of billions of dollars. One brute-force solution calls for finding every instance of a two-digit year and then rewriting the computer code to expand each field to accommodate four digits. This hellishly tedious process has led a cottage industry of vendors to create software tools that help to automate the procedure.
Confidentially Yours; June 1998; Scientific American Magazine; by Eisenberg; 2 Page(s)
Anew technique to send confidential messages may finally scotch government policies restricting the export of encryption technology. The method--called chaffing and winnowing--was devised by Ronald L. Rivest, a Massachusetts Institute of Technology computer scientist and the "R" in RSA encryption, the popular commercial data-scrambling scheme developed in the 1970s by Rivest and his then colleagues Adi Shamir and Leonard M. Adleman.
Rivest¿s new scheme depends not on encryption but on authentication, or proofs of the source of the message and its unaltered contents. As such, Rivest says, "it has no decryption key as its back door. The standard arguments for key recovery don¿t apply." At present, Clinton administration officials want surreptitious access to the text of encrypted documents, usually by means of a decryption key.
Eye in the Sky; June 1998; Scientific American Magazine; by Beardsley; 1 Page(s)
Politicians strive tirelessly to find what George Bush, famously but inarticulately, called the "vision thing." Presidentialcandidate- in-waiting Al Gore recently had a vision that would-- literally--encompass the whole earth and has persuaded the National Aeronautics and Space Administration to make it happen.
The veep wants NASA to launch a spacecraft whose principal (and probably only) purpose would be to beam back to Internetworked earthlings an image of the globe floating in the blackness of space. The satellite, according to NASA, is to be "a natural beacon for environmental awareness and science education." Agency scientists are now scratching their heads trying to decide how much the venture would cost and whether any nonpolitical rationale can be found to bolster its questionable scientific mission.
Cyber View; June 1998; Scientific American Magazine; by Gibbs; 1 Page(s)
Imagine lifting up a page arriving from the World Wide Web to watch the computers beneath negotiate their transfers over the Internet. You would see them conversing in four distinct languages. Three of those four tongues are extremely terse and rigid; they are spoken only by machines. It is the fourth one, HyperText Markup Language (HTML), that has made the Web such a phenomenon. HTML is similar enough to English that masses of people have learned to use it to annotate documents so that almost any kind of computer can display them. But HTML is still rigid; a committee must approve every new addition to its narrow vocabulary.
In February a fifth language was approved for use on the Web--one that could have consequences nearly as profound as the development of HTML did seven years ago. Extensible Markup Language (XML), like HTML, is surprisingly easy for humans to read and write, considering that it was developed by an international group of 60 engineers. But XML is much more flexible than HTML; anyone can create words for the language. More than that, devices that can understand XML (within a few years, probably almost all the machines hooked to the Internet) will be able to do more intelligent things than simply display the information on Web pages. XML gives computers the ability to comprehend, in some sense, what they read on the Web.
The Neurobiology of Depression; June 1998; Scientific American Magazine; by Nemeroff; 8 Page(s)
In his 1990 memoir Darkness Visible, the American novelist William Styron--author of The Confessions of Nat Turner and Sophie¿s Choice-- chillingly describes his state of mind during a period of depression:
He [a psychiatrist] asked me if I was suicidal, and I reluctantly told him yes. I did not particularize--since there seemed no need to--did not tell him that in truth many of the artifacts of my house had become potential devices for my own destruction: the attic rafters (and an outside maple or two) a means to hang myself, the garage a place to inhale carbon monoxide, the bathtub a vessel to receive the flow from my opened arteries. The kitchen knives in their drawers had but one purpose for me. Death by heart attack seemed particularly inviting, absolving me as it would of active responsibility, and I had toyed with the idea of self-induced pneumonia--a long frigid, shirt-sleeved hike through the rainy woods. Nor had I overlooked an ostensible accident, ¿ la Randall Jarrell, by walking in front of a truck on the highway nearby.... Such hideous fantasies, which cause well people to shudder, are to the deeply depressed mind what lascivious daydreams are to persons of robust sexuality.
A New Look at Quasars; June 1998; Scientific American Magazine; by Disney; 6 Page(s)
Quasars are the most luminous objects in the universe. They give off hundreds of times as much radiation as a giant galaxy like our own Milky Way, which is itself as luminous as 10 billion suns. Nevertheless, by astrophysical standards, quasars are minute objects, no more than a few light-days in diameter, as compared with the tens of thousands of light-years across a typical galaxy. How in heaven can they generate so much energy in such tiny volumes? What are they, and can they be explained by the ordinary laws of physics? To answer these questions, astronomers are training their most advanced instruments--the Hubble Space Telescope in particular--on these celestial superstars.
The first quasar was discovered in 1962, when Cyril Hazard, a young astronomer at the University of Sydney, began to study a powerful source of radio waves in the Virgo constellation. Hazard could not pinpoint the source, because the radio telescopes of the time were not precise enough, but he realized that the moon would occult the unknown object when it passed through Virgo. So he and John Bolton, the director of a newly built radio telescope in Parkes, Australia, pointed the instrument¿s giant dish toward the radio source and waited for the moon to block it out. By timing the disappearance and reappearance of the signal, they would be able to pinpoint the source of radio emissions and identify it with a visible object in the sky. Unfortunately, by the time the moon arrived the great dish was tipped so far over that it was running into its safety stops. Apparently unperturbed by the risk, Bolton sheared off the stops so that the telescope could follow the occultation downward until the rim of the dish almost touched the ground.
Shrimp Aquaculture and the Environment; June 1998; Scientific American Magazine; by Boyd, Clay; 8 Page(s)
Shrimp aquaculture, or farming, first became profitable during the 1970s and has since mushroomed into a widespread enterprise throughout the tropical world. Thailand, Indonesia, China, India and other Asian nations now host about 1.2 million hectares (three million acres) of shrimp ponds on their soil, and nearly 200,000 hectares of coastline in the Western Hemisphere have been similarly transformed. Though rare in the U.S., where fewer than 1,000 hectares are devoted to shrimp farming, at least 130,000 hectares of Ecuador are covered with shrimp ponds. The seafood produced in this fashion ends up almost exclusively on plates in the U.S., Europe or Japan.
Hailed as the "blue revolution" a quarter century ago, raising shrimp, like many other forms of aquaculture, appeared to offer a way to reduce the pressure that overfishing brought to bear on wild populations. Shrimp farming also promised to limit massive collateral damage that trawling for these creatures did to other marine species, 10 kilograms of marine life being caught routinely for each kilogram of shrimp taken from the sea. Unfortunately, neither of these benefits has, as of yet, fully materialized. And as the record of the past two decades of shrimp farming clearly shows, aquaculture often creates its own set of environmental problems.
Quantum Computing with Molecules; June 1998; Scientific American Magazine; by Gershenfeld, Chuang; 6 Page(s)
Factoring a number with 400 digits-- a numerical feat needed to break some security codes-- would take even the fastest supercomputer in existence billions of years. But a newly conceived type of computer, one that exploits quantum-mechanical interactions, might complete the task in a year or so, thereby defeating many of the most sophisticated encryption schemes in use. Sensitive data are safe for the time being, because no one has been able to build a practical quantum computer. But researchers have now demonstrated the feasibility of this approach. Such a computer would look nothing like the machine that sits on your desk; surprisingly, it might resemble the cup of coffee at its side.
We and several other research groups believe quantum computers based on the molecules in a liquid might one day overcome many of the limits facing conventional computers. Roadblocks to improving conventional computers will ultimately arise from the fundamental physical bounds to miniaturization (for example, because transistors and electrical wiring cannot be made slimmer than the width of an atom). Or they may come about for practical reasons--most likely because the facilities for fabricating still more powerful microchips will become prohibitively expensive. Yet the magic of quantum mechanics might solve both these problems.
Gravity Gradiometry; June 1998; Scientific American Magazine; by Bell; 6 Page(s)
During the cold war, submarine crews from both sides of the iron curtain were faced with the problem of guiding their vessels through the dark reaches of the ocean. Although they could always switch on their sonars to sense obstacles ahead or the depth of water below the keel, that act would send out acoustic signals, loud "pings," which would quickly reveal their presence to enemies-- something right-thinking submariners hesitate to do.
In an effort to devise more stealthy aids to underwater navigation, U. S. and Soviet navies designed sensitive instruments that could measure tiny variations in the pull of gravity caused by underwater ridges or mountains. Yet with the exception of Tom Clancy¿s fictional submarine Red October, no Soviet vessel actually carried such elaborate gear. Only the U. S. ballistic-missile submarines benefited from these sophisticated devices, called gravity gradiometers. This equipment was a well-kept military secret for many years, but now I and other civilian geologists are making use of similar gravity gradiometers to pinpoint the location of oil and gas deposits deep underground.
Alcohol in the Western World; June 1998; Scientific American Magazine; by Vallee; 6 Page(s)
Asubstance, like a person, may have distinct and even contradictory aspects to its personality. Today ethyl alcohol, the drinkable species of alcohol, is a multifaceted entity; it may be social lubricant, sophisticated dining companion, cardiovascular health benefactor or agent of destruction. Throughout most of Western civilization¿s history, however, alcohol had a far different role. For most of the past 10 millennia, alcoholic beverages may have been the most popular and common daily drinks, indispensable sources of fluids and calories. In a world of contaminated and dangerous water supplies, alcohol truly earned the title granted it in the Middle Ages: aqua vitae, the "water of life." Potent evidence exists to open a window into a societal relationship with alcohol that is simply unimaginable today. Consider this statement, issued in 1777 by Prussia¿s Frederick the Great, whose economic strategy was threatened by importation of coffee: "It is disgusting to notice the increase in the quantity of coffee used by my subjects, and the amount of money that goes out of the country as a consequence. Everybody is using coffee; this must be prevented. His Majesty was brought up on beer, and so were both his ancestors and officers. Many battles have been fought and won by soldiers nourished on beer, and the King does not believe that coffee-drinking soldiers can be relied upon to endure hardships in case of another war."
Surely a modern leader who urged alcohol consumption over coffee, especially by the military, would have his or her mental competence questioned. But only an eyeblink ago in historical time, a powerful head of government could describe beer in terms that make it sound like mother¿s milk. And indeed, that nurturing role may be the one alcohol played from the infancy of the West to the advent of safe water supplies for the masses only within the past century.
Defibrillation: The Spark of Life; June 1998; Scientific American Magazine; by Eisenberg; 6 Page(s)
The operation had gone well. There was a brief period of fast heart rate, when the ether was given, but that was easily controlled with digitalis. The two-hour surgery had been technically demanding. The 14- year-old boy¿s congenitally deformed chest allowed respiration only 30 percent of normal. The task of the attending surgeon, Claude S. Beck, was to separate the ribs along the breastbone and repair nature¿s botched work. Beck relaxed as the easy part began. But as the 15-inch wound was being closed, triumph abruptly turned to crisis: the boy¿s heart stopped. Beck grabbed a scalpel, sliced through his sutures, enveloped the heart in his hand and rhythmically squeezed. He could feel the heart¿s ineffective quivering and knew at once that it had gone into the fatal rhythm called ventricular fibrillation. In 1947 no one survived this rhythm disturbance, but that did not deter Beck.
He called for epinephrine and digitalis to be administered and calmly asked for an electrocardiograph and a defibrillator, all the while continuing to massage the boy¿s heart. It took 35 minutes to obtain an electrocardiogram, which-- wavering and totally disorganized--con- firmed the distinctive appearance of ventricular fibrillation. Ten minutes later assistants wheeled in an experimental defibrillator from Beck¿s research lab adjoining the University Hospitals of Cleveland. Beck positioned the machine and placed its two metal paddles directly on the boy¿s heart. The surgical team watched the heart spasm as 1,500 volts of electricity crossed its muscle fibers. Beck held his breath and hoped.
The Amateur Scientist; June 1998; Scientific American Magazine; by Carlson; 3 Page(s)
Depending on where you live, you may already contemplate humidity more than you care to. In the U.S., for instance, the hot summer air across the Southeast is thick and oppressive, whereas in the western deserts it is so dry that it greedily soaks up all moisture. The differences in the wildlife inhabiting these two regions shows that humidity has deeper consequences than just the daily weather. The water content in the atmosphere has shaped evolution every bit as much as the water content in the ground, which suggests many fascinating avenues for exploration by amateur scientists.
But whether your interests are in meteorology or biology, to undertake amateur investigations of humidity you'll need some means to measure it. This column describes a way to monitor relative humidity, which is the ratio of the amount of water actually present in the atmosphere to the maximum amount that it could support at the prevailing temperature and pressure.
Mathematical Recreations; June 1998; Scientific American Magazine; by Stewart; 2 Page(s)
Some years ago a friend of mine was on his honeymoon, camping in a remote part of Ireland. He and his wife were walking along a deserted beach when in the distance they saw two people coming toward them. The other couple turned out to be my friend¿s boss and his new wife. Neither couple knew of the other¿s plans: it was a coincidence. Such a striking coincidence, in fact, that it always makes a good story.
People seem endlessly fascinated by coincidences, but should we be impressed by these fluky events, especially when they seem to happen to everyone? Robert Matthews, a British journalist and mathematician whose work has been noted in this column before ("The Anthropomurphic Principle," December 1995; "The Interrogator¿s Fallacy," September 1996) , thinks not. In a recent issue of Teaching Statistics (Spring 1998), he and co-author Fiona Stones examine one of the most common types of coincidence: people who share the same birthday. Their conclusion is that we are too impressed by coincident birthdays because we have a very poor intuition of how likely such events are.
Reviews; June 1998; Scientific American Magazine; by May; 2 Page(s)
Edward O. Wilson¿s first "big book" was a slim volume, The Theory of Island Biogeography, written in collaboration with Robert H. MacArthur and published in 1967. It is one of the canonical texts of theoretical ecology. It helped to push the study of populations, communities and ecosystems from a foundation of largely descriptive studies to today¿s richer mixture of descriptive natural history, manipulative experiments in the field and laboratory, and mathematical analyses (often of complicated nonlinear systems).
Sadly, cancer killed MacArthur a few years later. In 1973 a group of his friends and colleagues gathered in Princeton, N. J., for a memorial meeting. At that time, Wilson was about to send the manuscript of Sociobiology to his publisher. Wilson, Richard Levins and Richard C. Lewontin were staying in the overlarge house that I, recently arrived, was renting from Princeton University, and as we and others walked back to dinner there someone asked Wilson, "What is this sociobiology all about?" Dick Lewontin enthusiastically answered something like: "It is a big book, bringing a lot together, and defining sociobiology as whatever is in Ed¿s book."
Commentary: Wonders - Where Fiction Became Ancient Fact; June 1998; Scientific American Magazine; by Morrison; 2 Page(s)
Alank sunburnt person in tweeds with a yellow-brown hatchet face and one faded blue eye," the explorer Gordon-Nasmyth appeared before London tycoon Ponderevo, to tempt him into a faintly illegal venture. "Fifteen hundred percent on your money in a year...Sir...the most radioactive stuff in the world...a festering mass of earths and heavy metals, polonium, radium...as if some young creator had been playing about...in a sort of rotting sand...the world for miles about it is blasted and scorched...You can have it for the getting...worth three pounds an ounce, if it¿s worth a penny."
So runs a vivid scene in H. G. Wells¿s novel of 1909, named for Mr. Ponderevo¿s miracle tonic, Tono-Bungay. The scientist-narrator soon sails furtively to West Africa, amid whitened mangroves "within the thunderbelt of Atlantic surf." A dozen ship hands spend a few toilsome weeks loading tons of a sand dune worth its weight in gold. On the homeward journey, their laden old brig begins to leak "everywhere" and promptly sinks, its "ligneous fibers destroyed" by radiation. The entire flotilla of the too daring Ponderevo enterprises founders soon enough on the stock exchanges. Our hero and crew are picked up at sea, enabling the story to climax with the final voyage of the bankrupt promoter, an airborne fugitive on a blimp of the narrator¿s design.
Commentary: Connections - Scribble, Scribble; June 1998; Scientific American Magazine; by Burke; 2 Page(s)
One of the real pains about the kind of historical research I get involved with is that when you go to primary sources, much of the time you have to read somebody¿s scribble if he or she lived back before the typewriter was invented. You know: research notes, letters, diaries, that stuff. And most of the time, comprehension- wise, it¿s double Dutch. Recently, in my case, just that.
Which is why what little I know about a 19th-century scientist from Holland named Christoph Buys Ballot is strictly secondary source material. In more senses than one, given that his primary work produced a law that says the angle between the wind and the pressure gradient is a right angle. What I found more intriguing involved Buys Ballot¿s riding with a trainload of brass players, on a railroad out of Utrecht, Holland, in 1845. The task of these traveling trumpeters was to blow a steady note as the train approached (and then passed) a group of Buys Ballot¿s pals. Who then confirmed that they had heard the note rise as the train neared them and then fall as it moved away down the track.
Working Knowledge; June 1998; Scientific American Magazine; by McCreary; 1 Page(s)
At the heart of any digital camera is a light-sensing semiconductor array, the camera¿s endlessly reusable "film." The most commonly used light sensors are charge-coupled devices (CCDs), which were developed in the early 1970s and are also incorporated in such products as video cameras, facsimile machines and desktop scanners. CCD-based cameras make it possible to capture images that can be instantly transmitted, for example, from a photojournalist in the field or from a reconnaissance satellite in space.
A CCD is an array of light-sensitive picture elements, or pixels, each measuring five to 25 microns across. The camera¿s lens focuses the scene onto this pixel array. Just as the resolution of conventional photographic film is related to the size of the grain, the resolution of a CCD chip is measured by the number of pixels in the array. A digital still camera intended mainly for nonprofessional use has an array of, typically, 640 by 480 pixels; a top-of-the-line professional camera would have an array of millions of pixels.