Robert Oppenheimer (1904–1967)

A professor of physics at the University of California-Berkeley, Robert Oppenheimer has been called the father of the atomic bomb for his work on the Manhattan Project, established in 1942 during World War II at Los Alamos, New Mexico, to develop nuclear weapons. When General Leslie Groves Jr. who headed the Manhattan Project tapped him to head the lab that would develop the atomic bomb, the choice was a surprise. While the debate continues today about whether Dr. Oppenheimer was a Communist, there can be no doubt that many of his friends and relatives were and that he shared many political convictions with them. Was he a Communist? He had been “a member of just about every Communist Front organization on the West Coast,” he wrote when he completed his security clearance paperwork, although he later claimed that he was just joking. There can be no debate, however, that Dr. Oppenheimer was brilliant and knowledgeable in a wide range of scientific subjects beyond his specialty of theoretical physics. He had a phenomenal memory and the ability to understand broad concepts without getting bogged down in details. General Groves considered him a genius. “Why, Oppenheimer knows more about everything. He can talk to you about anything you bring up. Well, not exactly. I guess there are a few things he doesn’t know about. He doesn’t know anything about sports.”

There were two sides to Dr. Oppenheimer’s personality. His students revered him; many adopted his mannerisms, expressions, and even style of walking. On the other hand, he could be cutting and harsh, belittling anyone who asked what he considered to be a foolish question. Dr. Oppenheimer suffered with bouts of depression and psychological issues. Nevertheless, his grasp of complex ideas was renowned, and his research led him into quantum mechanics, theoretical astronomy, nuclear physics, cosmic rays, quantum electrodynamics, and more.

Dr. Oppenheimer, a first-generation American, was born to well-to-do family. His father was a textile importer, his mother an artist. Living in an apartment in a wealthy part of Manhattan overlooking the Hudson River, their apartment was decorated with Picassos, van Goghs, and other artists.

Young Robert Oppenheimer was educated at the Ethical Culture Society School. He entered Harvard when he was 18, graduating in three years summa cum laude. From Harvard he went to Cambridge and then on to the Gottingen University where he earned a PhD in theoretical physics under Max Born. On his return to the United States, he received a National Research Council Fellowship and split his time between Caltech and Harvard. The next year found him at the University of Leiden giving lectures to students in Dutch. Returning once again to the United States, Dr. Oppenheimer accepted a position at the University of California at Berkeley, but again split his time there with Caltech. He left his name on such arcane principles as the Born–Oppenheimer Approximation, the Oppenheimer–Phillips Process, and the Tolman–Oppenheimer–Volkoff Limit.

Robert Oppenheimer has been called the father of the atomic bomb for his role in the Manhattan Project, which developed nuclear weapons.

Robert Oppenheimer has been called the “father of the atomic bomb” for his role in the Manhattan Project, which developed nuclear weapons. (National Archives)

The Nazi mistreatment of the Jews was Dr. Oppenheimer’s political wake-up call. He was frank about his lack of interest in worldly affairs. By his own admission, he knew nothing of the 1929 Wall Street crash until well after the event. He never voted until 1936, but beginning in 1934 he was sending money to help physicists escape from Germany. He supported the republican side of the Spanish Civil War and hosted fund-raisers for numerous “left-wing” and Communist causes. Dr. Oppenheimer was never a member of the Communist Party. However, his brother and sister-in-law, his companion, Jean Tatlock, and many students and associates were members. Dr. Oppenheimer ended his relationship with Tatlock and married Kitty Harrison, who was a former Communist married to a Communist who was killed in the Spanish Revolution. He was under observation by the FBI as early as 1940 and was on its Custodial Detention List; he would be arrested in the event of a national emergency.

In 1939, reports surfaced that Germany had been able to split the atom, the first step in making a bomb. So President Roosevelt authorized the Manhattan Project under Dr. Arthur H. Compton, and in 1942 responsibility for the bomb-building project was given to the Army. In spite of his political background, Dr. Oppenheimer was given a security clearance and tapped to head the team to develop the atomic bomb. The location selected was a boys’ school, Los Alamos Ranch School, near Santa Fe, New Mexico. The laboratory was administered by the University of California under contract with the War Department. Plans to commission Dr. Oppenheimer and his colleagues fell through; he flunked the physical when Army doctors concluded that he was underweight (128 pounds) and that his cough was caused by tuberculosis. Other scientists objected to military enlistment. Many of the scientists that Dr. Oppenheimer recruited were colleagues and former students—people whose talent he knew and respected. Unfortunately, many had radical or Communist inclinations, creating a problem that would surface years later.

Although he had no managerial experience, Dr. Oppenheimer soon proved himself. With his quick mind and extensive knowledge of varied disciplines, he proved to all that General Groves’s choice was a good one. Balancing the govern-ment’s demand for complete and total secrecy with the inclination of scientists to share information freely was a challenge that Dr. Oppenheimer managed successfully. He sometimes went without eating when he threw himself at his work; at one point his weight dropped to 115 pounds.

In spite of his performance, Dr. Oppenheimer was subjected to round-the-clock surveillance. After he made a trip back to Berkeley to recruit scientists and spent the night with his old girlfriend, the security officer recommended that he be terminated. General Groves refused, believing that he would be more likely to share secrets with the Soviets if he were fired.

Research and development of the bomb progressed at a feverish pace. What had started as a small cadre numbered in the thousands by the time the bomb was ready to test in 1945. At 5:29:45 a.m. on July 16, 1945, the bomb code-named Trinity exploded at Alamogordo, New Mexico. Years later, Dr. Oppenheimer reflected on the moment. “We knew the world would not be the same. A few people laughed, a few people cried. Most people were silent. I remembered the line from the Hindu scripture, the Bhagavad-Gita; Vishnu is trying to persuade the Prince that he should do his duty and to impress him, takes his multi-armed form and says, ‘Now I am Death, the destroyer of worlds.’ I suppose we all thought that, one way or another.”

With the explosions at Hiroshima and Nagasaki, there was no longer any secrecy about the Manhattan Project. In November 1945, Dr. Oppenheimer returned to Caltech but he did not stay. Lewis Strauss offered him a position as director of the Institute for Advanced Studies at Princeton, a think tank for scientists. While he was there, he helped write the Acheson–Lilienthal Report, which led to the Baruch Plan of 1946, advocating international regulation over atomic energy, an idea that the U.S. Senate rejected. When the Atomic Energy Commission was formed in 1947, Dr. Oppenheimer was appointed chairman of the General Advisory Committee.

Like many scientists, Dr. Oppenheimer became embroiled in scientific disputes. In his case, the technical disputes were magnified by politics. Edward Teller, a physicist at Los Alamos, and Robert Oppenheimer had been respectful of each oth-er’s talents. One observer at the start of the Manhattan Project had noted that they were like buddies. During the development of the atomic bomb (based on nuclear fission), Dr. Oppenheimer had been in favor of building a hydrogen bomb (based on nuclear fusion). After the conclusion of the Manhattan Project, he changed his mind. Dr. Teller wanted to proceed with it, while Dr. Oppenheimer opposed it on the grounds that the technology to build it was incomplete and that it would be a weapon of mass destruction against civilians. Where Dr. Oppenheimer favored an arsenal with many tactical nuclear weapons, Dr. Teller sided with the newly created Air Force, which could deliver long-range strategic weapons. He tried to enlist Dr. Oppenheimer to come to his newly established lab but was turned down. Failing there, he requested Dr. Oppenheimer’s help in recruiting other scientists. Whether that help was forthcoming was uncertain; whether he dissuaded scientists was also speculation. Later, when the technology proved capable of building the bomb, Dr. Oppenheimer reversed his opinion, but these questions would arise at the hearing four years later when his security clearance was revoked.

There was another event, the “Chevalier Affair,” prior to Los Alamos, which would come back to haunt Dr. Oppenheimer in later years. Just before his departure to New Mexico, a friend and fellow professor at Berkeley, Haakon Chevalier, told Dr. Oppenheimer that a mutual acquaintance, George C. Eltenton, was asking him to pass information to a Soviet diplomat in San Francisco. Dr. Oppenheimer, offended by the request, refused. Some months later at Los Alamos, he mentioned the incident to the security officer, citing three encounters, not one, and refusing to divulge the name of the person involved. When pressed for more information, he denied that the incident ever occurred. Years later when he testified before the committee, he stated that he had lied only to protect his friend, Chevalier.

Questions about his loyalty continued to dog Dr. Oppenheimer. While he was awarded the Presidential Medal of Merit for his work, surveillance continued. In 1949, he testified before the House Un-American Activities Committee, acknowledging that students and family members had Communist affiliations. Dr. Oppenheimer’s relationship with Strauss, which had once been cordial, began to deteriorate. As chairman of the Atomic Energy Commission, Strauss was in a position of power. The FBI was more than willing to provide him with the information they had about Dr. Oppenheimer’s political views and connections.

More “evidence” accumulated against Dr. Oppenheimer. Paul and Sylvia Crouch, former Communist Party members, testified to the California State Senate Un-American Activities Committee in 1950 that Robert Oppenheimer had once hosted a Communist Party meeting in his Berkeley home. Dr. Oppenheimer denied it and had witnesses to prove that he was at his New Mexico ranch at the time of the alleged meeting. “I have never been a member of the Communist Party. I never assembled any such group of people for any such purpose in my home or anywhere else.” But Dr. Oppenheimer could not shake the Communist mantle.

Lewis Strauss allowed William Borden, formerly with the Joint Atomic Energy Committee, to see Dr. Oppenheimer’s top secret personnel file. In a three-and-a-half-page letter to FBI director J. Edgar Hoover dated November 7, 1953, Borden outlined his case against Dr. Oppenheimer, concluding that “more probably than not J. Robert Oppenheimer is an agent of the Soviet Union.” On November 27, Hoover forwarded copies of the letter to Strauss, the president, and the secretary of defense.

Events moved quickly. Within days President Eisenhower ordered a wall “erected immediately between this individual and any information of a sensitive or classified character.” On December 21, 1953, Lewis Strauss informed Dr. Oppenheimer that his security clearance had been suspended. He had a choice: accept it or request a hearing. Dr. Oppenheimer requested the latter.

The hearing was held the next year. An array of scientists testified to Dr. Oppenheimer’s character. Dr. Arthur Compton, who headed the atomic bomb project before it became the Manhattan Project, testified that Dr. Oppenheimer “had looked carefully into Communist activities and rejected them.” General Groves reaffirmed his decision stating that “history has fully justified my choice.” The Board of Trustees of the Institute for Advanced Studies at Princeton supported their director. Several past AEC commissioners spoke on his behalf.

The “Chevalier Affair” was discussed. Dr. Teller testified that Dr. Oppen-heimer’s judgment was questionable. His reservations about the hydrogen bomb were discussed. All of his past associations were reviewed, and in the end Robert Oppenheimer was stripped of his security clearance.

In the years after his removal from scientific power, Dr. Oppenheimer wrote, gave speeches, and traveled. The scientific community regarded him as a victim of McCarthyism. Recognition of his achievements continued. He was made an officer in the French Legion of Honor and a foreign member of the British Royal Society. In December 1963, President Johnson presented him the AEC’s Enrico Fermi Award, a $50,000 tax-free grant “for contributions to theoretical physics as a teacher and originator of ideas, and for leadership of the Los Alamos Laboratory and the atomic energy program during critical years.” Dr. Oppenheimer replied, “I think it is just possible, Mr. President, that it has taken some charity and some courage for you to make this award today.” It had taken nine years for the AEC to reverse its opinion. Although he was nominated three times, Dr. Oppenheimer was never awarded a Nobel Prize, probably because of his association with the atomic bomb.

A heavy smoker all of his adult life, Dr. Oppenheimer was diagnosed with throat cancer in 1965. Treatment was ineffective and he died on February 18, 1967.

—Tom and Gena Metcalf


Bernstein, Jeremy. Oppenheimer: Portrait of an Enigma. Chicago, IL: Ivan R. Dee, 2004.

Bird, Kai and Martin J. Sherwin. American Prometheus: The Triumph and Tragedy of J. Robert Oppenheimer. New York: Vintage Books, 2005.

Stern, Phillip. The Oppenheimer Case. New York: Harper and Row, 1969.