BECAUSE A HOT DEBATE delayed the announcement of this year's Nobel Prize in medicine for over an hour, the public got a rare glimpse into the politics of the selection process.Apparently the Nobel Assembly split over whether the prize should be awarded for advances in basic research, as it generally has been, or for discoveries with direct application to medicine. Because there is no separate Nobel Prize in biology and biochemistry, the great majority of the prizes in medicine over the past two decades have gone for fundamental insights into the nature of the genetic code and the mechanisms that control its expression. While these have undoubtedly been the most exciting developments in the life sciences during this period, they are advances not in medicine, but in molecular biology.

Judging from a few of the recent Nobel awards and from this year's prize -- given for the development of the CAT scanner, an X-ray device that has revolutionized the diagnosis of many diseases in the brain -- this trend has generated a backlash among some members of the Nobel Assembly who feel medicine has been neglected. Whether the development of the CAT scanner is worthy of a prize generally reserved for the development of major new ideas on the frontiers of science is already the source of considerable debate among scientists.

This year's prize in chemistry is one of the relatively rare Nobels that is given for a lifetime's contribution to the field rather than for a single idea or experiment. The prize went to two chemist whose work, while not of great theoretical interest, has enormous practical application, opening up vast new possibilities in the field of organic chemistry. Organic chemists attempt to synthesize complex molecules -- including those found in living things -- in the lab. Their discoveries make possible huge industries -- drugs, dyes, plastics, petrochemicals and petroleum refining and more. In no other field of science would one be likely to find a Nobel Prize winner who is already a millionaire because of the patents that have emerged from his research.

Unlike either medicine or chemistry, this year's physics prize recognized work that has led to a fundamentally new understanding of natural principles. A central thrust of modern physics has been the search for a new theory that would demonstrate that the four basic physical forces -- gravitation, electromagnetism, the strong atomic interaction and the weak atomic interaction -- are in fact different manifestations of a single, more basic force. The three winners of this year's prize (two of whom were high school classmates) elaborated a theory, since confirmed by experiment, showing that two of these forces -- electromagnetism and the weak atomic force -- are indeed the same phenomenon. Their work lends new impetus to the continuing search for the "unified field theory," the single framework that would show that all four forces are one. What does that mean? Achieving proof of this theory would affect our understanding of the physical universe as profoundly as did Einstein's discovery of relatively.