10 сентября 2002 г.
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Новости науки и техники в "Scientific American"
10 сентября 2002 г. |
LONG-LOST REMAINS OF NEANDERTAL NEWBORN RECOVEREDA nearly complete skeleton of a Neandertal individual, which was missing for more than 80 years, has been rediscovered in a French museum.The fossils, dubbed Le Moustier 2, come from a four-month-old baby that died more than 40,000 years ago.BABIES' BABBLES LINKED TO BRAIN'S LANGUAGE CENTERJust a few minutes around a newborn is enough to get anyone babbling like, well, a baby. But just what drives an infant's babbles remains a matter of much debate. Some scientists posit that the sounds result from a baby's attempts to gain control over his mouth, tongue and lips and, therefore, are not related to language. A second hypothesis holds that babbling instead represents a key step on the way to speaking real words. Recent research further supports the latter theory - scientists say they have linked baby babbling to the brain's language-center.BOOKSTORE: THE FIRST AMERICANS: IN PURSUIT OF ARCHAEOLOGY'S GREATEST MYSTERY By J.M. AdovasioWhen did the first humans reach North America? Archaeologist Adovasio's answer is, thousands of years earlier than the Clovis people of 11,200 to 10,500 years ago (9200 to 8500 B.C.), who are held by "a tenet of archaeology" to have been the pioneers. He first advanced that argument in 1974, after charcoal taken from two fire pits in a shallow cave at Meadowcroft Rockshelter in western Pennsylvania revealed through radiocarbon dating "that humans had been there using these two hearths in about 13,000 B.C.," some 4,000 years "before any human being was supposed to have set foot anywhere in this hemisphere." Now five pre-Clovis sites are known in the Americas, all displaying very different technologies. The existence of so much cultural diversity "strongly suggests that there were multiple incursions into this hemisphere by people who were probably diverse genetically." In telling this story, Adovasio - founder and director of the Mercyhurst Archaeological Institute - and science writer Page give the general reader a fine grounding in what is known of human migration.SMART' SILICON DUST COULD HELP SCREEN FOR CHEMICAL WEAPONSOne of the largest obstacles to successfully responding to an attack with biological or chemical weapons is detecting the offending agent in time to stop its propagation. To that end, new research could help. Scientists have reported the development of dust-size silicon particles that could be used to detect chemical and biological agents from a distance using a laser light source.AFTER THE FALLOne year after the devastating attacks on New York City's 110-story, 1,365-foot-high World Trade Center towers, questions linger concerning the future of skyscrapers. The assault has led engineers, architects and safety specialists to rethink high-rise design. How will security concerns govern the shape of skyscrapers to come?SCIENTISTS DEVELOP NEW METHOD OF MANUFACTURING SUPERCONDUCTING MAGNESIUM BORIDELess than two years ago, scientists discovered that magnesium diboride--a relatively simple and readily available metallic compound--can conduct electricity with next to no resistance. Moreover, its superconductivity occurs at temperatures around 39 degrees Kelvin, which is much higher than those required for similar superconductors. But efforts to make superconducting circuits out of the compound have so far met with limited success. Now a new technique may pave the way to fabricating magnesium diboride-based devices.ASK THE EXPERTS: HOW DO YOU GET A COMPUTER VIRUS?Geoff Kuenning, an assistant professor of computer science at Harvey Mudd College, explains.