Scientific American December 2002 [antikvár]

] SA Perspectives In Science We Trust As a year for science, 2002 was marked by many wonderful accomplishments, and our inaugural listing of the Scientific American 50, beginning on page 23, celebrates dozens. But much of the public may also remember the year for blemishes on the scientific record: prominently among them, the fraud of a physicist working on semiconductor technology, the withdrawn discovery of element 118, a reversal on the wisdom of hormone replacement therapy for many postmenopausal women, and conflicting recommendations about dietary fat. Flip-flops, scandals and overblown headlines can erode confidence in science's authority as a source of truthful information. Society, as much as research, suffers when citizens and policymakers start discounting the good science along with the bad. Inevitably, scientists will sometimes be just plain wrong—they make mistakes. Interpretation of evidence leaves room for error. Moreover, scientists aren't saints. They can be swayed by careerism, by money, by ego. Biases and prejudices can blind them. As individuals, they are no more or less flawed than those from any other walk of life. Over time, however, science rises above narrow interests and corrects itself more reliably than any other institution through such practices as the open publication of results and methods. All scientific knowledge is provisional. Everything that science "knows," even the most mundane facts and long-established theories, is subject to reexamination as new information comes in. The latest ideas and data are the most provisional of all. Some recantations will be unavoidable. This is not a weakness of science; this is its glory. No endeavor rivals science in its incremental progress toward a more complete understanding of the observable world. Announcements of discoveries in professional journals always qualify and quantify their certainty; announcements in the general media often do not, because nonspecialists usually lack the background to interpret them. To the extent that researchers or journalists imply that news represents unchanging truth, we are to blame for the public's confusion over scientific reversals. But caveat lector, too: sensible readers must recognize that summaries of science will leave out potentially important details. Unfortunately, the job of educating the public is made all the harder by those looking to exploit the holes in science. "You see?" they argue. "These scientists don't really know what they're talking about. They're pushing a self-serving agenda. They don't even really agree among themselves, so you are free to believe what you like." Thus, global-warming skeptics write off the consensus of climate research investigators, emphasizing the uncertainties in others' reasoning but not in their own. Anti-evolutionists harrumph about the incompleteness of the fossil record, but the handful of neo-creationist academics they praise have only wisps of evidence and incoherent theories. How should the public weigh the recommendations of scientists? The greatest mistake is to wait for 100 percent scientific certainty or agreement, because it will never materialize. Conclusions vetted by the professional community might turn out to be wrong, but they generally represent the best-supported views currently available. People are free to disregard those views, but they shouldn't delude themselves that they are being more reasonable by doing so. Perfect certainty belongs only to the gods. The rest of us have to make do with science, imperfections and all. THE EDITORS [email protected]