But this is a false assumption in the case of Reichstein, who at age 95 is still publishing. Reichstein, who shared the 1950 Nobel Prize in physiology or medicine for discoveries relating to the hormones of the adrenal cortex, is still hard at work at the Institute of Organic Chemistry at the University of Basel, Switzerland, actively participating in international collaborations.
His 1992 paper "The phloroglucinols of Dryopteris stenolepis" (C.J. Widen, P. Ayras, T. Reichstein, Annales Botancici Fennici, 29:41-54), for example, was coauthored with Finnish researchers from the University of Helsinki and the University of Turku. In the United States, a change in a federal law may make nonagenerian researchers like Reichstein more common on university campuses. January 1 of this year marked the end of the exemption for university faculty to the Age Discrimination in Employment Act, which in essence will prohibit mandatory retirement for professors (see story on page 1).
Now that U.S. faculty members don't have to retire at age 70--the mandatory age at many schools before the law went into effect--they can continue to work indefinitely. And, indeed, scientists who are remaining vital and active into their 90s can already be found on American soil. It's hardly surprising; scientists, after all, possess a boundless curiosity. Their quest for new knowledge is timeless.
New Providence, N.J.-based R.R. Bowker Co.'s directory American Men and Women of Science lists more than 350 scientists who are 90 years old or older and living in North America. Many are no longer actively involved in their profession. Many are in poor health. But a select few continue to defy time.
While most interviewed for this article acknowledge that they don't quite get around the way they used to--they rarely attend conferences or give lectures, for example--they all agree that they continue to work because they love what they do.
"I'm a scientist, and I keep working because I enjoy it," says ornithologist and evolutionary biologist Ernst Mayr, the Alexander Agazziz Professor of Zoology, Emeritus, at Harvard University's Museum of Comparative Zoology, who will turn 90 in July. "I'm interested in science, in finding new things out, and in communicating with the public. Why shouldn't I continue to work?"
Their continued high productivity notwithstanding, many of these active nonagenarians approve of a mandatory retirement age. They contend that scientists can continue their work in other venues, and that retiring is often necessary to allow younger researchers and scholars the opportunity to make their own marks.
Take Mayr, for example. His official university retirement in 1975 "has been a godsend" to him, he says. He's busier than ever lecturing, consulting, and writing. In fact, says Mayr--who received the National Medal of Science in 1969 and is a member of the National Academy of Sciences (NAS)--since age 64 he's published nine books, and he has two more that will go to the publisher this year. He still writes some five to 10 scientific papers a year.
This past January, Mayr spent the month as a visiting scientist at the Archbold Biological Station in Lake Placid, Fla.
"I have a very active mind," says Mayr. "Any person worth his salt should know what to do when he retires; if he doesn't, he probably wasn't any good in the job to begin with. People should retire so young people can have opportunities."
Mayr has written some 17 books. His latest, One Long Argument (Harvard University Press, 1991), focuses on the philosophical founda- tions of Charles Darwin's theories of evolution.
Few scientists' careers rival that of 93-year-old Linus Pauling, winner of two Nobel Prizes (for chemistry in 1954 and for peace in 1962). His 1970 book, Vitamin C and the Common Cold (New York, W.H. Freeman & Co.), helped make him a household name. When he was 73, he founded the Linus Pauling Institute of Science and Medicine in Palo Alto, Calif., where he has continued studying vitamins and disease. He maintains a rigorous schedule, despite having been diagnosed with prostate cancer two years ago.
"I don't lecture much anymore, but I continue to write and collaborate with colleagues at the institute on their research on vitamins," says Pauling, speaking from his ranch at Big Sur, some 200 miles from the Palo Alto institute, where he spends most of his time. He likes to devote two or three weeks of "high energy" at a time to a project.
Last year, he published the second edition of his book Cancer and Vitamin C (Philadelphia, Camino Books), and he's currently collaborating on a second edition of his 1986 book, How to Live Longer and Feel Better (New York, W.H. Freeman & Co.).
"Age 70 may be too early for people to retire, with people living longer and healthier," Pauling says. "The previous policy seemed a good one. But a professor who is retired at one university is occasionally offered a job by another university . . . the rule never prevented another university from hiring you.
"Professors who were handicapped by age could retire; others, if they were healthy and wanted to continue to work, could [do so]," Pauling says. He retired from Stanford University when he was 73 rather than further abuse the university's retirement policy, he says.
"There was no pressure on the administrators that way." Why does Pauling continue to work? He has few financial worries; he's paid a salary from the institute under a lifetime appointment. He also receives a pension from his days on university faculties at the California Institute of Technology, Stanford, and the University of California, San Diego.
Pauling, an NAS member, contends there's little left for him to do, save visiting with family. "I've always been interested in learning new things, and have always liked research," he says. "I've always taken pleasure in discovering something new and thinking of something that no one had."
Today, he keeps up with major scientific journals; in February, he published a "Technical Comment" in Science ("Triethylsilyl cations," Science, 263:983). He continues to be interested in the fields of atomic structure and nuclear physics.
John T. Edsall, 91, a professor, emeritus, of biochemistry at Harvard University, still walks to work daily in Cambridge, Mass., weather permitting. But when the biochemist-physician officially retired in 1973 from teaching at Harvard, he decided not to continue his bench research. "I had seen other people who continued their research into their old age, but it inevitably was less significant than in their youth," says Edsall.
Edsall's retirement from the classroom hardly seems to have slowed him down. He has turned to the history of science, an old interest of his. Edsall also has written extensively on the history of the study of blood and hemoglobin. His latest publication came out this past December: a review of a biography of Nobel laureate Hans Krebs for Nature (366:417-8).
Like Pauling, Edsall has been deeply involved in social issues. In 1973, the American Association for the Advancement of Science asked him to help develop its proposed Committee on Scientific Freedom and Responsibility, which he later chaired. Edsall, an NAS member, also serves on the academy's committee that addresses human rights violations.
Edsall's expertise is in the chemistry and structure of blood and muscle proteins. During the 1940s, he and his colleagues helped develop new uses of blood plasma proteins and blood fractionation processes in medicine and surgery.
Edsall says he's "somewhat concerned" about the abolition of mandatory faculty retirement. "Older faculty may want to hang on," he worries. "There may be too many holding on and not enough opportunities for young people."
Mathematician Dirk J. Struik, who will turn 100 in September, has little doubt he could still teach a college class in calculus. However, he no longer does mathematical research. Though early in his career he focused on tensor analysis and differential geometry, in the 1960s he turned to the history and sociology of mathematics and science. "Creative mathematics is for the young," he says, "but historical insight can last till the end."
Struik, an emeritus professor of mathematics at the Massachusetts Institute of Technology, taught at MIT from 1926 to his retirement in 1960, save the five-year period during the McCarthy era when he was accused of subversive activities and suspended from the faculty.
Struik continues to work every day, "perhaps three hours, answering calls from colleagues and students, writing letters or articles and book reviews, as well as some biographical notes" for a planned autobiography. He remains an associate to the history of science department at Harvard.
"Tons of people can do good work after age 70 or 75," says Struik. "I didn't necessarily want to retire when I did, but I had to. Of course, it goes the other way, too. There are those who should retire at age 50."
"We spend a lifetime in a career doing something [we] like, and you don't just give that up," says Ernest R. Hilgard, a professor, emeritus, of psychology and education at Stanford who will turn 90 in July.
Hilgard, who retired from teaching in 1969, continued an active research program for another decade. Today he attends a conference every so often and lectures on occasion. His most recent books include a history of psychology in the United States, which was published in 1987 (Psychology in America: A Historical Survey, San Diego, Harcourt Brace Jovanovich Inc.).
Hilgard, a member of both NAS and the American Philosophical Society, sees nothing wrong with mandatory retirement. "If you want to continue to work, the university will almost always let you," he says. "I liked the option of a formal retirement. That way the administration doesn't have to make the decision."
Pioneering plant physiologist Paul J. Kramer, James B. Duke Professor of Botany, Emeritus, at Duke University, who will celebrate his 90th birthday in May, believes that the ending of mandatory retirement will "create an embarrassing situation" for university administrations.
"It was easy for administrations; once you turned 70, they could say it's time to retire," he says. "Now they will have to give a great deal of thought to this."
Kramer, an NAS member and one of the founders and past presidents of the American Institute of Biological Sciences, currently is collaborating on a fourth edition of his 1949 textbook Water Relations of Plants (New York, McGraw-Hill Inc.).
Meanwhile, in Canada, Gerhard Herzberg believes that retirement should be left to the individual, although, he says, "it's perfectly acceptable to have an age of retirement--say, 65 or 70." Herz-berg is Distinguished Research Scientist at the Herzberg Institute of Astrophysics in Ottawa, which is a member institute of the National Research Council of Canada. He won the Nobel Prize in chemistry in 1971 for his pioneering work in spectral analysis and molecular structure.
Herzberg plans to retire when he turns 90, on Christmas Day. Although there is no longer a mandatory retirement age for Canadian government workers, there was a mandatory age of 65 at the time of Herzberg's 65th birthday. (In Ontario, university faculty currently must retire at age 65, though other provinces may differ.) The mandatory age notwithstanding, Herzberg has kept on working past his 65th year. He was still discovering new molecules when he was 75.
"There should be allowances in special circumstances for some people to continue working," says Herzberg. In his own case, the Nobel Prize was just the ticket.
Steven Benowitz is a science and medical writer for Penn State University's Milton S. Hershey Medical Center in Hershey, Pa.