In 1943 Robert Oppenheimer left the University of California at Berkeley to become director of the Los Alamos Laboratory in New Mexico, where the first atom bomb was built. He maintained a connection with the university for several more years but never really returned. Instead, he became director of Princeton’s Center for Advanced Study and a consultant to the government on issues raised by atomic weapons. After his political “disgrace” for supposed disloyalty in 1954, he devoted himself to writing, producing essays and books, notably Science and the Common Understanding. President Kennedy cleared his name and “rehabilitated” him in 1963.
The foregoing hardly suggests Oppenheimer’s historical importance. It is unlikely that anyone else could have performed his role at Los Alamos so successfully. Many of his colleagues considered him, more than any other individual, responsible for the creation of the atomic bomb during World War II. If he had not been there, they believe the atom bomb would not have been developed until after the war.
Two atom bombs ended the war abruptly and made a profound difference in how the subsequent Russian-American rivalry played out. Because they knew what atom bombs can do, the leaders of the superpowers resisted the perpetual temptation to treat the bombs as just another weapon. The devastation of Hiroshima and Nagasaki caused American and Russian leaders to hold back from the ultimate confrontation. Oppenheimer, who had worked so passionately and with such tunnel vision to create the bombs, came to believe we faced the possibility of nuclear annihilation.
This extraordinary man was born into a wealthy Jewish family in New York city in 1904. His parents, members of the non-sectarian Ethical Culture Society, sent him to the Society’s school in 1911. His teachers recognized him as a gifted polymath who studied mineralogy and composed poetry with equal enthusiasm. His friendship with the literary critic Francis Fergusson began at the Ethical Culture School.
Oppenheimer continued writing poetry for many years but after he came under the influence of Professor Percy Bridgman, science became his primary interest. He wrote of Bridgman as “a wonderful teacher because he was never really quite reconciled to things being the way they were... He was a man to whom one wanted to be an apprentice.”
Oppenheimer’s letters show that his personality was clearly developed by the time he graduated from Harvard. He cultivated a wide range of interests in science and the arts. He had a real gift for friendship, but would speak with wounding sarcasm to people who failed to measure up to his standards. He made close friends and permanent enemies. Physically, he had endurance which enabled him to work hard for extended periods of time. Professor Bridgman described him as a “well set-up young man, with a rather engaging diffidence of manner.”
When Oppenheimer decided to study physics in Europe, Bridgman recommended him to Sir Ernest Rutherford. Urging the English scientist to find a spot for him at the Cavendish Laboratory, Bridgman wrote, “It appears to me that it is a bit of a gamble as to whether Oppenheimer will ever make any real contributions of an important character, but if he does make good at all, I believe that he will be a very unusual success... .”
His experience at Cavendish taught Oppenheimer that he had a vocation for physics but not for laboratory work. His problems with experimental equipment appear to have driven him to the edge of a nervous breakdown that manifested itself in erratic behavior. But Rutherford introduced him to Niels Bohr and Max Born. Bohr inspired Oppenheimer, as he wrote, “to learn the trade of being a theoretical physicist.” And Born gave him the opportunity by inviting him to study in Germany at the University of Gottingen.
Germany was simultaneously liberating and disquieting for Oppenheimer. He recovered his balance and completed his Ph.D. in 1927. He also met Werner Heisenberg and other young German scientists, acquiring real respect for their work. He fell in love with Charlotte Riefenstahl, a fellow student, and courted her unsuccessfully. (Thinking him too self-absorbed, she turned down his proposals and married another physicist instead.) He also encountered the Nazi Party. Its presence at Gottingen gave him personal experience of Nazism long before most Americans ever heard of it. His anger at the Nazis became a constant; he described it as a “smoldering fury.”
Oppenheimer was living and learning in the midst of some of the most astonishing political and scientific developments of the 20th century. Percy Bridgman, Ernest Rutherford, Niels Bohr, Max Born and Werner Heisenberg—and others of his acquaintance—all won Nobel Prizes. By the time he left Europe he knew “it was an unusual time, that great things were afoot.”
In the spring of 1929 he traveled to his family’s ranch in New Mexico to recover from tuberculosis. He actually enjoyed his convalescence, finding the desert awesomely beautiful. He wrote, “I have two loves, physics and the desert. It troubles me that I don’t see any way of bringing them together.”
He began teaching in Berkeley in 1930. Of the university he said, “There was no theoretical physics [there] and I thought it would be nice to try to start something.” Within a few years, he turned Cal into the major American center for the study of theoretical physics. When he taught graduate students, Wendell Furry wrote, he “transmitted ... a feeling of the beauty of the logical structure of physics and an excitement in the development of the science ... His students emulated him as best they could. They copied his gestures, his mannerisms, his intonations. He truly influenced their lives.”
Oppenheimer and Ernest O. Lawrence, the inventor of the cyclotron, became close friends. They formed the habit of taking long walks together and discussing problems in physics, casually bridging the gap that separated many theoretical and experimental physicists. Lawrence came to rely on Oppenheimer’s judgment on theoretical questions; in turn, he helped Oppenheimer to a better grasp of applied physics. According to David Sloan, Oppenheimer “learned to see the apparatus and to get a feeling for its experimental limitations.... When you couldn’t carry it any farther, you could count on him to understand and to be thinking about the next thing you might want to try.” Oppenheimer’s own studies concerned the theory of nuclear structure, the quantum theory of electrons, collapsing suns, and cosmic ray showers. Jeremy Bernstein considers him to have been a physicist of the highest caliber who, if he had lived longer, might well have been awarded his own Nobel Prize.
In 1933 Hitler began driving non-Aryan scientists out of Germany and actively persecuting the Jews. Oppenheimer’s personal response was to begin contributing to a fund for the benefit of displaced German scientists. He also began working to get his relatives out of Germany.
Oppenheimer began a serious relationship with Jean Tatlock in 1936. They came close to marriage but realized they were not temperamentally suited and ended their affair in 1939. A member of the Communist Party, she introduced him to other Berkeley people with left wing sympathies, and he began to make regular contributions to Spanish War Relief and similar causes. In November 1940, he married Katherine Harrison. Looking back on this period of his life many years later, Oppenheimer said, “I liked the new sense of companionship, and at the same time felt I was coming to be part of the life of my time and country.”
Along with other physicists, Oppenheimer was alarmed by the discovery of nuclear fission in 1938. He realized it made the development of atomic weapons inevitable, and he feared what would happen if the Nazis got them first. In 1939 he began to make rough calculations of critical mass (the amount of uranium necessary to cause an atomic explosion). After the collapse of the Spanish Republic he began looking for a way to defeat fascism that would succeed.
In 1941 he accepted an invitation from Arthur Compton, the director of the government’s nuclear research project, to attend a special meeting of the National Academy of Sciences at which the military applications of atomic energy would be discussed. Afterward Compton asked him to direct a small program to plan, for the first time as a practical problem, how to produce an atom bomb.
In the summer of 1942 Oppenheimer and a group of scientists met secretly in Le Conte Hall on the Cal campus. Edward Teller later said Oppenheimer “showed a refined, sure, informal touch” in leading the group’s deliberations. They concluded that “the development of a fission bomb would require a major scientific and technical effort.” An unanticipated problem arose when some of Teller’s calculations indicated that a nuclear explosion might burn up the planet’s atmosphere.
This was so alarming that Oppenheimer traveled across the country by train to confer with Arthur Compton about it. Compton wrote of their meeting, “We agreed there could be only one answer. Oppenheimer’s team must go ahead with their calculations. Unless they came up with a firm and reliable conclusion that our atomic bombs could not explode the air or the sea, these bombs must never be made.” Further work by Hans Bethe convinced the physicists that an atomic explosion would not destroy the world.
So the work resumed. Oppenheimer’s involvement increased and, when production was ready to begin, he suggested Los Alamos as the site for the atomic bomb laboratory. His immensely hard work there culminated in the successful test of a bomb at Alamogordo. Thus, he brought his love of physics and the desert together. But in the sober aftermath of the war, while he was still being saluted as a national hero, he said, “I felt as though I had blood on my hands.”