25 июня - 2 июля 2002 г.
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Новости науки и техники в "Scientific American"
25 июня - 2 июля 2002 г. |
BOOKSTORE: THE ENIGMA OF THE WORLD'S UNDECIPHERED SCRIPTS by Andrew RobinsonIt is baffling and humbling to confront an incomprehensible form of writing, such as Chinese for most Westerners. People who try to decipher the scripts of lost languages face an even sterner challenge, because there are no contemporary speakers or writers to help. That is the challenge depicted learnedly and fascinatingly by Robinson, literary editor of the Times Higher Education Supplement in London. He sets the stage by describing the hard work that went into the "three great decipherments": Egyptian hieroglyphs, Linear B of Crete, and Mayan glyphs. Then he poses the problems presented by nine undeciphered scripts, among them the languages of the Etruscans and the people of Easter Island. Success at deciphering, Robinson writes, requires "fanatical perseverance and devotion to detail and wide linguistic and cultural knowledge." The book's many illustrations of the enigmatic scripts make vivid the difficulty of the decipherer's task.STUDY SHOWS HOW FAR GM POLLEN SPREADSFor years, debates have raged over the use of genetically modified crops in commercial agriculture. Many believe that GM crops will spread their altered genes to weeds and other unintended targets. The fear persists that many undesirable plants could become resistant to certain herbicides because they have altered genes. To that end,new findings may alleviate some concerns while fueling others. Recent studies tested how far pollen of herbicide-resistant canola traveled from the area in which it was planted. The researchers found that while pollen from resistant plants spread widely, the extent to which it populated adjacent fields remained low.DOUBT CAST ON CELL FROM HELL'S ROLE IN FISH KILLSDuring the 1990s, massive fish kills plagued bays and estuaries along the East Coast of the U.S. People living near and working on these waters also complained of memory loss, headaches and other physical ailments. Scientists blamed these frightening phenomena on a microorganism named Pfiesteria piscicida, often referred to as the "cell from hell" in media coverage of the disturbing events. Studies indicated that the diminutive creature, which belongs to a group of free-living marine organisms known as dinoflagellates, had as many as 24 life-cycle stages, some extremely toxic. Now, however, new research suggests that Pfiesteria's life cycle is much simpler than originally thought - and that the organism is actually nontoxic.HEAT SWITCHES NEW GLUE'S STICKINESS ON AND OFFScientists have succeeded in creating a glue with fickle stickiness. Formed from synthetic rubber and an oxidizing agent, the smart adhesive becomes less clingy at higher temperatures and regains its sticking power as it cools.COMPUTER PROGRAM SPEEDS SEARCH FOR NOVEL ALLOYSHundreds of thousands of possible metal alloy combinations can be formed from a relatively small number of elements. As a result, finding new metal blends with desirable qualities (such as rust resistance or heat conductivity) can be an arduous task. Now a team of Danish physicists has developed a novel approach to this treasure hunt, using a computer algorithm that borrows from evolutionary theory to test which compounds hold the most promise for resisting high temperatures and corrosion.CAFFEINE KEEPS GARDEN PESTS AT BAYA mocha latte might be your favorite way to start the day, but the same cannot be said for slugs and snails. New research shows that caffeine solutions sprayed onto plants can deter and even kill the pesky mollusks. Farmers must often tolerate these destructive creatures because most pesticides are deemed too toxic for use on crops. The U.S. Food and Drug Administration classifies caffeine as "safe," however, prompting optimism that the substance could form the basis for an acceptable crop pesticide.PEERING OVER EINSTEIN'S SHOULDERSAfter a century, Einstein's special theory of relativity, which describes the motion of particles moving at close to the speed of light, has held up remarkably well. But as scientists probe the edges of the current knowledge of physics with new tests, they may find effects that require modifications to the venerable theory. Indeed, several current theories, designed to encompass the behavior of black holes, the big bang and the fabric of the universe itself, could lead to violations of special relativity.RESEARCHERS DESIGN FASTER, CHEAPER METHOD FOR MAKING MICROCHIPSMoore's Law holds that every 18 months, semiconductor companies can put twice the amount of transistors on a microchip. But each time the industry squeezes in more transistors, the process becomes more costly and difficult. The challenges are so great that Moore's Law is threatened because of soaring costs and the inability of the technology to make smaller circuit features. Photolithography, today's standard for fabricating microchips, has difficulty making features any smaller than 130 nanometers on a side. Now researchers have designed a new technique, called LADI, or laser-assisted direct imprint, that may be able to print faster and more cheaply at a smaller scale.HUMAN FECAL BACTERIUM CAUSING CARIBBEAN CORAL DISEASESince 1996, a disease known as whitepox has been decimating populations of coral, particularly in the Florida Keys. Now scientists report that a bacterium commonly found in human feces may be to blame. Although the source of the coral-killing bacteria remains unconfirmed, the findings suggest that maintaining high standards of water quality is crucial to saving the reefs' remaining coral.SEXY TV PROGRAMMING STYMIES VIEWERS' RECALL OF COMMERCIALSTelevision advertisers will pay immense sums of money to ensure a captive audience. A 30-second spot during the Super Bowl, for example, can cost upward of $2 million, but it may be viewed by more than 130 million potential buyers. If viewers don't remember the commercial, however, it is not money well spent. With that in mind, new research suggests that advertisers may want to rethink where they place their spots. Viewers of TV shows with sexually explicit subject matter, it seems, are less likely to recall commercials than are people who watch programming devoid of sexual content.EYEDROPS DELAY ONSET OF GLAUCOMAA simple regimen of eyedrops could delay or prevent the onset of one of the leading causes of blindness in the U.S. According to the results of a new study, drops that reduce eye pressure slow the development of glaucoma.ASK THE EXPERTS: IF THERE IS NO GRAVITY IN SPACE, WHY DO "SHOOTING STARS" FALL?Rich Schuler of the University of Missouri in St. Louis explains.ASK THE EXPERTS: WHY DO SOME PEOPLE GET MORE CAVITIES THAN OTHERS DO?Joel Berg, president of the American Academy of Pediatric Dentistry Foundation and VP of Clinical Affairs for Philips Oral Healthcare, explains.