| Popis: |
THE HUMAN ENTERPRISE of science consists of several components, of which the initial one is usually the observation of natural phenomena. Persons who make such observations often feel the need to classify and interpret their observations. But though we like to think of science as a free and unfettered search for the truth, it is intriguing to note the extent to which each of the steps of the scientific process reflects current attitudes and biases of scientists and their contemporaries. Comparisons may be facile but false; interpretations often reflect current fads. For science does have its fads. Those of us who have been around for awhile can easily remember that the conquest of disease, for example, which was once thought to lie in witch doctors or faith, supposedly achieved the scientific final answer first with immunizations, then antibiotics, then vitamins and minerals. At the moment, we seem determined to solve all of our problems with prostaglandins, which are claimed to cure everything from dandruff to cancer. A consequence of this dependency.on mental sets is the reward that often awaits the scientist-most frequently the neophyte unburdened with cant and dogma-who rejects the "obvious" and "accepted" and who notes that the facile explanation really glosses over difficulties or explains the facts inadequately. Nevertheless, it is astonishing how often facts have been bent to fit explanations instead of the reverse. D. Ivanovsky is usually credited with being the discoverer of viruses. He set about identifying the infectious agent of tobacco mosaic disease with the preconceived idea that it must be a bacterium. In that decade, the last of the nineteenth century, the majority of the bacterial agents of disease were being discovered; since tobacco mosaic disease is "transmissible," it was "obviously" bacterial in origin. But Ivanovsky observed that the infectious juice contained no bacterial cells that could be detected with his microscope. Moreover, his attempts to cultivate the bacteria in the usual laboratory media failed. Finally, the juice retained its infectivity even after passage through a filter that was designed to remove bacteria. In the face of these observations, did Ivanovsky abandon his preconceptions? Not at all. Instead, he seemed only to feel that his experimental results were curious. It is well known to scientists that nature is similar to an onion peeled away layer by layer; even the most satisfying of explanations often merely conceals a more fundamental layer of theory. Thus, when science is working at its best, each theory falls to more subtle interpretation. The cell as the unit of life became at least partially understandable in terms of the molecules that make up the cell. Molecules require an understanding of atoms, which in turn led to the idea of nucleus and electrons; the nucleus required protons and neutrons, and study of these particles revealed a bewildering complex of additional particles and interactions. Matters are now so complex that surely we are ready for another great simplification. An explanation that is "obvious" may conceal a further level of truth, but it may also lead to a blind alley. It can be a statement so wrong that discovery of the truth requires backtracking and rejection of the "obvious," not because the explanation was too simple but because it was 180? wrongor at least 180? removed from different explanations advanced later. Every branch of science can provide such examples of accepted "facts" and "theories" that challenge the scien |
