The 100 Most Influential Scientists of All Time (37 page)

The joint effort of outstanding scientists at Los Alamos culminated in the first nuclear explosion on July 16, 1945, at the Trinity Site near Alamogordo, New Mexico, after the surrender of Germany. In October of the same year, Oppenheimer resigned his post. In 1947 he became head of the Institute for Advanced Study and served from 1947 until 1952 as chairman of the General Advisory Committee of the Atomic Energy Commission, which in October 1949 opposed development of the hydrogen bomb.

On December 21, 1953, he was notified of a military security report unfavourable to him and was accused of having associated with Communists in the past, of delaying the naming of Soviet agents, and of opposing the building of the hydrogen bomb. A security hearing declared him not guilty of treason but ruled that he should not have access to military secrets. As a result, his contract as adviser to the Atomic Energy Commission was cancelled. The Federation of American Scientists immediately came to his defense with a protest against the trial. Oppenheimer was made the worldwide symbol of the scientist, who, while trying to resolve the moral problems that arise from scientific discovery, becomes the victim of a witch-hunt. He spent the last years of his life working out ideas on the relationship between science and society.

In 1963 President Lyndon B. Johnson presented Oppenheimer with the Enrico Fermi Award of the Atomic Energy Commission. Oppenheimer retired from the
Institute for Advanced Study in 1966 and died of throat cancer the following year.

(b. July 2, 1906, Strassburg, Ger. [now Strasbourg, France]—d. March 6, 2005, Ithaca, N.Y., U.S.)

G
erman-born American theoretical physicist Hans Albrecht Bethe helped shape quantum physics and increased the understanding of the atomic processes responsible for the properties of matter and of the forces governing the structures of atomic nuclei. He received the Nobel Prize for Physics in 1967 for his work on the production of energy in stars. Moreover, he was a leader in emphasizing the social responsibility of science.

Bethe wrote two book-length reviews in the 1933
Handbuch der Physik
—the first with German physicist Arnold Sommerfeld on solid-state physics and the second on the quantum theory of one- and two-electron systems—that exhibited his remarkable powers of synthesis. Along with a review on nuclear physics in
Reviews of Modern Physics
(1936–37), these works were instant classics. All of Bethe's reviews were syntheses of the fields under review, giving them coherence and unity while charting the paths to be taken in addressing new problems. They usually contained much new material that Bethe had worked out in their preparation.

In the fall of 1932, Bethe obtained an appointment at the University of Tübingen as an acting assistant professor of theoretical physics. In April 1933, after Adolf Hitler's accession to power, he was dismissed because his
maternal grandparents were Jews. Sommerfeld was able to help him by awarding him a fellowship for the summer of 1933, and he got William Lawrence Bragg to invite him to the University of Manchester, Eng., for the following academic year. Bethe then went to the University of Bristol for the 1934 fall semester before accepting a position at Cornell University, Ithaca, N.Y. He arrived at Cornell in February 1935, and he stayed there for the rest of his life.

Bethe came to the United States at a time when the American physics community was undergoing enormous growth. The Washington Conferences on Theoretical Physics were paradigmatic of the meetings organized to assimilate the insights quantum mechanics was giving to many fields, especially atomic and molecular physics and the emerging field of nuclear physics. Bethe attended the 1935 and 1937 Washington Conferences, but he agreed to participate in the 1938 conference on stellar energy generation only after repeated urgings by Edward Teller. As a result of what he learned at the latter conference, Bethe was able to give definitive answers to the problem of energy generation in stars. By stipulating and analyzing the nuclear reactions responsible for the phenomenon, he explained how stars could continue to burn for billions of years. His 1939
Physical Review
paper on energy generation in stars created the field of nuclear astrophysics and led to his being awarded the Nobel Prize.

During World War II Bethe first worked on problems in radar, spending a year at the Radiation Laboratory at the Massachusetts Institute of Technology. In 1943 he joined
the Los Alamos Laboratory (now the Los Alamos National Laboratory) in New Mexico as the head of its theoretical division. He and the division were part of the Manhattan Project, and they made crucial contributions to the feasibility and design of the uranium and the plutonium atomic bombs. The years at Los Alamos changed his life.

In the aftermath of the development of these fission weapons, Bethe became deeply involved with investigating the feasibility of developing fusion bombs, hoping to prove that no terrestrial mechanism could accomplish the task. He believed their development to be immoral. When the Teller-Ulam mechanism for igniting a fusion reaction was advanced in 1951 and the possibility of a hydrogen bomb, or H-bomb, became a reality, Bethe helped to design it. He believed that the Soviets would likewise be able to build one and that only a balance of terror would prevent their use.

As a result of these activities, Bethe became deeply occupied with what he called “political physics,” the attempt to educate the public and politicians about the consequences of the existence of nuclear weapons. He became a relentless champion of nuclear arms control, writing many essays (collected in
The Road from Los Alamos
[1991]). He also became deeply committed to making peaceful applications of nuclear power economical and safe. Throughout his life, Bethe was a staunch advocate of nuclear power, defending it as an answer to the inevitable exhaustion of fossil fuels.

In 1972 Bethe's cogent and persuasive arguments helped prevent the deployment of antiballistic missile systems. He was influential in opposing President Ronald Reagan's Strategic Defense Initiative, arguing that a space-based laser defense system could be easily countered and that it would lead to further arms escalation. By
virtue of these activities, and his general comportment, Bethe became the science community's conscience. It was indicative of Bethe's constant grappling with moral issues that in 1995 he urged fellow scientists to collectively take a “Hippocratic oath” not to work on designing new nuclear weapons.

Throughout the political activism that marked his later life, Bethe never abandoned his scientific researches. Until well into his 90s, he made important contributions at the frontiers of physics and astrophysics. He helped elucidate the properties of neutrinos and explained the observed rate of neutrino emission by the Sun. With the American physicist Gerald Brown, he worked to understand why massive old stars can suddenly become supernovas.

(b. June 28, 1906, Kattowitz, Ger. [now Katowice, Pol.]—d. Feb. 20, 1972, San Diego, Calif., U.S.)

G
erman-born American physicist Maria Goeppert Mayer (née Maria Goeppert) shared one-half of the 1963 Nobel Prize for Physics with J. Hans D. Jensen of West Germany for their proposal of the shell nuclear model. (The other half of the prize was awarded to Eugene P. Wigner of the United States for unrelated work.)

Maria Goeppert studied physics at the University of Göttingen (Ph.D., 1930) under a committee of three Nobel Prize winners. In 1930 she married the American chemical physicist Joseph E. Mayer, and a short time later she accompanied him to Johns Hopkins University in Baltimore, Maryland. Over the next nine years she was associated with Johns Hopkins as a volunteer associate. During that time she collaborated with Karl Herzfeld and her husband in the study of organic molecules. She
became a U.S. citizen in 1933. In 1939 she and her husband both received appointments in chemistry at Columbia University, where Maria Mayer worked on the separation of uranium isotopes for the atomic bomb project. The Mayers published
Statistical Mechanics
in 1940. Although they remained at Columbia throughout World War II, Maria Mayer also lectured at Sarah Lawrence College (1942–45).

After the war Mayer's interests centred increasingly on nuclear physics, and in 1945 she became a volunteer professor of physics in the Enrico Fermi Institute for Nuclear Studies at the University of Chicago. She received a regular appointment as full professor in 1959. From 1948 to 1949 Mayer published several papers concerning the stability and configuration of protons and neutrons that constitute the atomic nucleus. She developed a theory that the nucleus consists of several shells, or orbital levels, and that the distribution of protons and neutrons among these shells produces the characteristic degree of stability of each species of nucleus. A similar theory was developed at the same time in Germany by J. Hans D. Jensen, with whom she subsequently collaborated on
Elementary Theory of Nuclear Shell Structure
(1955). The work established her as a leading authority in the field. Also noted for her work in quantum electrodynamics and spectroscopy, Mayer accepted an appointment at the University of California at San Diego in 1960, as did her husband.

(b. May 27, 1907, Springdale, Pa., U.S.—d. April 14, 1964, Silver Spring, Md.)

A
merican biologist Rachel Carson was well known for her writings on environmental pollution and the
natural history of the sea. Carson early developed a deep interest in the natural world. She entered Pennsylvania College for Women with the intention of becoming a writer but soon changed her major field of study from English to biology. After taking her bachelor's degree in 1929, she did graduate work at Johns Hopkins University (M.A., 1932) and in 1931 joined the faculty of the University of Maryland, where she taught for five years. From 1929 to 1936 she also taught in the Johns Hopkins summer school and pursued postgraduate studies at the Marine Biological Laboratory in Woods Hole, Mass.

In 1936 Carson took a position as aquatic biologist with the U.S. Bureau of Fisheries (from 1940 the U.S. Fish and Wildlife Service), where she remained until 1952, the last three years as editor in chief of the service's publications. An article in
The Atlantic Monthly
in 1937 served as the basis for her first book,
Under the Sea-Wind
, published in 1941. It was widely praised, as were all her books, for its remarkable combination of scientific accuracy and thoroughness with an elegant and lyrical prose style.
The Sea Around Us
(1951) became a national
best-seller, won a National Book Award, and was eventually translated into 30 languages. Her third book,
The Edge of the Sea
, was published in 1955.

Carson's prophetic
Silent Spring
(1962) was first serialized in
The New Yorker
and then became a best-seller, creating worldwide awareness of the dangers of environmental pollution. The vision of the environmental movement of the 1960s and early '70s was generally pessimistic, reflecting a pervasive sense of “civilization malaise” and a conviction that the Earth's long-term prospects were bleak. Carson's
Silent Spring
suggested that the planetary ecosystem was reaching the limits of what it could sustain. Carson stood behind her warnings of the consequences of indiscriminate pesticide use, despite the threat of lawsuits from the chemical industry and accusations that she engaged in “emotionalism” and “gross distortion.” Some critics even claimed that she was a communist. Carson died before she could see any substantive results from her work on this issue, but she left behind some of the most influential environmental writing ever published.

(b. June 11, 1910, Saint-André-de-Cubzac, France—d. June 25, 1997, Paris)

F
rench naval officer and ocean explorer Jacques-Yves Cousteau was known for his extensive underseas investigations. Not formally trained as a scientist, Cousteau was drawn to undersea exploration by his love both of the ocean and of diving. After graduating from France's naval academy in 1933, he was commissioned a second lieutenant. His plans to become a navy pilot were undermined by an almost fatal automobile accident in which both of his arms were broken.

In 1943 Cousteau and the French engineer Émile Gagnan developed the first fully automatic compressed-air Aqua-Lung. Cousteau helped to invent many other tools useful to oceanographers, including the diving saucer, a small, easily maneuverable submarine for seafloor exploration, and a number of underwater cameras.