Is scientific research only for the young?
One of the myths of the sciences holds that research is a young person's game. It ain't necessarily so. Astronomer Virginia Trimble of the University of California at Irvine has found what she calls ''surprises'' in statistics gathered by Helmut Abt, editor of The Astrophysical Journal. Among astronomers, at least, outstanding scientists tend to remain productive throughout long careers, which often extend well beyond nominal retirement.
Abt compiled records of scientific papers published by 115 PhD astronomers who earned their degrees in the United States between 1945 and 1960. He also assembled the so-called citation records of 22 astronomers whose careers were largely completed by 1970. One indication of the influence of a scientist's work - as opposed to sheer volume of output - is the number of times other scientists cite his or her papers in their own publications.
Both studies show that neither age nor the supposed distractions of administrative responsibilities have necessarily held down the productivity of the leading astronomers.
Taken as a group, half the citations to the nearly 1,000 papers of the 22 astronomers covered by the citation survey referenced the work of authors 58 years old and older. Four of the astronomers were in their 70s, and 6 were in their 60s, when they wrote their most cited papers. And there were 82 citations of papers published by 5 of the group when they were over 80.
This recalls the 75-year career of the late Joel Hildebrand. When he retired from the University of California at Berkeley in 1952, he had long been considered one of the 20th century's greatest and most productive chemists. Yet he continued working vigorously for another three decades, during which he produced half of his scientific papers.
Returning to the astronomers who began postdoctoral careers between 1945 and 1960, here, too, there is continued productivity. But this also points up the importance of individual motivation and mental outlook.
The group as a whole has maintained a steady output. Yet 9 percent of the group published little after getting the doctoral degree. The group has also suffered an annual 1.5 percent attrition, as far as publishing is concerned. On the other hand, the 13 most productive members of the group account for 65 percent of the publications.
Analyzing these studies in Nature, Virginia Trimble notes Helmut Abt's conclusion that productive astronomers are largely self-motivated and do not allow administration, committee work, or other circumstances to curb their productivity.
She herself concludes that ''. . . we can apparently expect to go on producing work that our colleagues will consider worth publishing and referencing for as long as we remain motivated to try.''
What's true for astronomers is true for other scientists - indeed for people generally. Productivity in creative work has more to do with motivation and mental outlook than with myths about aging.
One of the mysteries of this century has been the cause of the blast that devastated several hundred square kilometers of central Siberia. Now debris of the cosmic object which exploded June 30, 1908, has been found in Antarctica.
According to Ramachandran Ganapathy of the J.T. Baker Chemical Company, this indicates that the debris penetrated the stratosphere and spread widely around the world.
The event has been called the Tunguska Explosion, because the object exploded in the air over the Podkamennaya Tunguska River basin. Trees were knocked down over several hundred square kilometers, although there was no crater. Soviet scientists have recovered microscopic black and shiny metallic spheres from the Tunguska soil.
Ganapathy has studied eight of these spheres. He reports in Science that their composition shows them to be from the Tunguska object and not part of the general meteoritic material falling on Earth. This indicates that the explosion was powerful enough to vaporize the object.
Ganapathy also reports that analysis of an ice core from the South Pole shows a sharp excess of the element iridium in the layer corresponding to the time of the Tunguska event. Iridium is a telltale marker of cosmic material. Extrapolating from the amount of iridium, Ganapathy estimates that some 7 million tons of Tunguska debris were distributed globally. He further estimates that the object must have been at least 0.16 kilometers in diameter to inject that much debris into the stratospere.
Ganapathy says his findings, taken together, confirm that a sizable cosmic body did indeed explode in the air. Some scientists have suggested it was a comet. Ganapathy says it could just as well have been a stony meteorite.
More must be known about the chemical composition of comets to settle the question. Perhaps the needed knowledge will be gained from the multinational study planned for Halley's Comet. Life at 482 F.
Bacteria from the eastern Pacific have proved the biologist's truism that the upper temperature limit for organic life has yet to be defined. These bacteria thrive at 250 degrees C. (482 F.) and hotter.
The microbes come from vents in the deep sea floor. They live at depths of 2, 500 meters and under a pressure of 265 atmospheres. John A. Baross of Oregon State University and Jody W. Deming of Johns Hopkins University reported recently in Nature that they have confirmed this by laboratory tests that simulate the deep sea conditions.
They note that ''these findings open the possibility that bacteria may exist and grow within the Earth's crust at temperatures exceeding 250 C.'' They add that this shows that ''microbial growth is limited not by temperature but by the existence of liquid water.'' It opens new possibilities for life on other worlds as well.