Scientific American February 1992 [antikvár]

_ LETTERS TO THE EDITORS Tomorrow's World Today The September 1991 special issue of Scientific American, "Communications, Computers and Networks," is wonderful. There hasn't been anything in print that comes close to the quality of material that you assembled to cover these critical teclmologies and how they have the potential to change our lives. I'm reluctant to suggest that it's incomplete, but I can't help making some related observations. During the past few decades, rapid Improvements in mass communications and transportation have taken place, but personal commimications has not kept pace. Moreover, the changes in mass communications and transportation have disrupted or destroyed many vital community structures. Entertainment and information have become entities tfiat separate people emotionally, while transportation has separated them physically. Improvements in personal communications, such as answering machines and call waiUng, have not helped re-create communities. Powerful commimications systems based on networking and computer technologies can address social issues. They can help with the problem of latchkey children, for example, by allowing parents to work from home in the afternoon when their children return from school. The network can also be a mediator of communication among teachers, parents and stadents. Nick Arnett Multimedia Computing Corporation Santa Clara, Calif. In "Infrastructure for the Global Village" [SciENTinc American, September 1991], Senator Al Gore calls for a national "data superhighway," by analogy with the national transportation infrastructure. But private concerns built the first successful mrnpikes in both England and America, and the examples of the Great Northern railroad and commercial airlines demonstrate that the free market can succeed in any transportation sphere. Government involvement, on die other hand, brings characteristic problems; public subsidy of highways has helped the trucking industry at the expense of rail transportation and has contributed to urban sprawl and pollution by shifting real costs away from drivers. Now Senator Gore wants to do the same thing to high-speed data communications, despite abundant evidence that the private sector is solving the problem on its own. Steven B. Harris Los Angeles Senator Gore's technopopulist vision of a supercomputing Route 66 would be appealing except that I operate a motor vehicle in Massachusetts. I imagine this digital interstate backed up for miles, its attendant bureaucracy perpetuating itself ad infinitum through obscure bond issues and a network of fiber-optic tollbooths, its body of regulations so vast, oblique and shrouded in cryptic jargon that only the lawyers who wrote it would understand it. John Gateey Luz Newton, Mass. Austroneslan Origins Peter Bellwood's description of the expansion of Austronesian from the mainland of Southeast Asia into the remote Pacific is very plausible indeed, but only if one leaves out the people ["The Austronesian Dispersal and the Origin of Languages," Scientific American, July 1991]. Analyses of die skeletons of living and prehistoric inhabitants of the area show that the modem Polynesians and Micronesians are closely related to the Jomon pottery makers, the people who inhabited prehistoric Japan. Even recent work on mitochondrial DNA shows that Polynesians are closer to the remaining preagricultural people of the Philippines than to anyone on the Asian mainland. If Austronesian has its roots in mainland Southeast Asia and the modern Polynesians have their biological roots in post-Pleistocene Japan, then the movement into the Pacific has to include an account of how the people who came from one place acquired a language that arose in another. Although that idea may sound implausible at first, it is not at all impossible. C. Loring Brace Museum of Anthropology University of Michigan at Ann Arbor Bellwood replies: I agree that Jomon Japanese, Polynesians and Micronesians might have shared a common origin. But why in Japan instead of coastal China? Biological anthropologists, including Professor Brace and others who have claimed an equally unlikely origin for Polynesians in Pleistocene Melanesia, are obliged to do their calculations without the benefit of an absolutely crucial set of data: there are no large and measurable skeletal series from around 4,000 years ago in the PhiMppines, eastern Indonesia and coastal China south of the Yangtze River. I claim those areas were the overall homeland region. Have the biological patterns in south China and Southeast Asia really been frozen for the past 4,000 years? Or have populations there changed over time, just as they have in other regions, such as Japan and Melanesia? Overlooked among the Ions I would like to rectify an omission in my recent article, "Focused Ion Beams" (SciENTinc American, October 1991]. While discussing work on optoelectronic devices with focused ion beams, I neglected to mention an important participant. Joe Puretz, who was then a sm-dent at the Oregon Graduate Institate, was instrumental in the success of the work and, with Richard DeFreez, did much of the experimental design, execution and analysis. He was also one of the primary authors on many of the subsequent papers. I profoundly regret that I did not give Dr. Puretz the credit he deserves; his contribution to the success of that work was certainly greater than my own. Jon Orloff Department of Applied Physics and Electrical Engineering Oregon Graduate Institute of Science & Technology errata Photo credits for figures appearing on page 45 of the October 1991 issue were omitted. Figure e was provided by Nick Butterfield of Harvard University. Figure f was provided by Richard Jenkins of the University of Adelaide. SciENTmc American febraao'j 992 5