18 июня 2002 г.
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Новости науки и техники в "Scientific American"
18 июня 2002 г. |
NEWLY DISCOVERED PLANET-SUN PAIRING LOOKS FAMILIARAfter 15 years of searching, scientists have found a planet-star pairing that looks a lot like part of our own solar system. A team of astronomers recently announced the discovery of 15 new planets outside our solar system, including one orbiting the star 55 Cancri at a distance close to that separating Jupiter and our sun.SCIENTISTS FASHION FIRST SINGLE-MOLECULE TRANSISTORSA well-known axiom of technology states that every 18 to 24 months, advancements produce computers that process information twice as quickly as their speediest predecessors. At some point, however, limiting factors such as space on a silicon chip and heat generated by intense electrical activity will prevent further computational acceleration. Luckily, researchers working in the field of nanotechnology have been investigating another way to transmit information through the hardware of a computer: atoms. If these fundamental building blocks could themselves act as transistors to control the flow of electricity, many more circuits could be integrated on a silicon chip, resulting in exponential increases in computing speed. To that end, new findings show that creating such single-molecule transistors is indeed possible.BOOK OF THE MONTH: A BRAIN FOR ALL SEASONS: HUMAN EVOLUTION AND ABRUPT CLIMATE CHANGE By William H. CalvinImagine going to the first meeting of a course you'd long waited to enroll in. You sit down at your computer, open an e-mail message from your professor, in this case the author William H. Calvin, and get your first lesson. Your professor is thousands of miles away. In fact, he's at 51.4oN, 0.1oE. Where? Why, Charles Darwin's home in Kent, England, of course, the famous Down House.FIBBING COMMON IN EVERYDAY CONVERSATIONSo begins Calvin's journey through evolution, particularly human evolution, as he leads his "class" from the home of the man many would call the father of evolution to various locales that provide fodder for his ultimate message: human evolution, like that of other organisms, is not a gradual transformation of form and behavior over time. Rather, like the shifts in the environments in which organisms find themselves, evolutionary change is abrupt, even catastrophic.
Meeting new people can spark nervousness and dread in some individuals; it can elicit eagerness and enthusiasm in others. Most of these folks share a surprising trait, however: they lie. According to the results of a new study, 60 percent of the participants lied at least once during a 10-minute conversation, and most fibbed two or three times. Furthermore, when confronted with their falsehoods, many subjects did not even realize that they had been telling tall tales.LANDSCAPE REVEALS MASSIVE LAVA FIELD TIED TO MASS EXTINCTIONThe cause of the largest known mass extinction event, at the end of the Permian period 250 million years ago, remains elusive. The leading candidates for the chaos that killed close to 95 percent of marine species and 70 percent of those on land include dramatic fluctuations in climate or sea level, severe volcanism or an impact with an asteroid or comet. Now new findings are adding further fuel to the debate. Scientists have discovered that the surge of magma that occurred at the time of the Permian extinction was at least twice as extensive as previously believed.BEES BOOST COFFEE CROP YIELDUsually the only buzz associated with coffee comes from the jolt of caffeine it delivers. But scientists have discovered that a buzz of a different kind - one originating from bees - can increase coffee yields by as much as 50 percent.ASK THE EXPERTS: WHAT IS SYNESTHESIA?Thomas J. Palmeri, Randolph B. Blake and Renй Marois of the psychology department and the Center for Integrative and Cognitive Neuroscience at Vanderbilt University explain.