J. Robert Oppenheimer was an American theoretical physicist, best known for his role as the scientific director of the Manhattan Project, the World War II effort to develop the first nuclear weapons, at the secret Los Alamos laboratory in New Mexico. Known colloquially as "the father of the atomic bomb", Oppenheimer lamented the weapon's killing power after it was used to destroy the Japanese cities of Hiroshima and Nagasaki.

After the war, he was a chief advisor to the newly created Atomic Energy Commission and used that position to lobby for international control of atomic energy and to avert the nuclear arms race with the Soviet Union. After invoking the ire of many politicians and scientists with his outspoken political opinions during the Red Scare, he had his security clearance revoked in a much-publicized and politicized hearing in 1954.

Though stripped of his direct political influence, Oppenheimer continued to lecture, write, and work in physics. A decade later, President John F. Kennedy awarded him the Enrico Fermi Award as a gesture of rehabilitation. As a scientist, Oppenheimer is remembered most for being a chief founder of the American school of theoretical physics while at the University of California, Berkeley.

Early life and education
Robert Oppenheimer was born in New York City on April 22, 1904 to Julius S. Oppenheimer (a wealthy textile importer who had immigrated to the United States from Germany in 1888) and Ella Friedman, a painter. He studied at the Ethical Culture Society School (whose physics laboratory has since been named for him) where, in addition to mathematics and science, he was exposed to a variety of subjects ranging from Greek to French literature, and met with success at the school's particular form of ethical training, based on the secular Judaism of its founder, Felix Adler (the Oppenheimers were of Jewish descent but they did not observe the religious traditions).

Throughout his life, he remained a versatile scholar, proficient in science as well as the humanities. He entered Harvard University one year late due to an attack of colitis. During the interim, he went with a former English teacher to recuperate in New Mexico, where he fell in love with horseback riding and the mountains and plateau of the Southwest. He returned reinvigorated, flourishing with ten courses at once each term in as vast topics beyond science as Greek, architecture, classics, art, and literature, and made up for the delay by graduating summa cum laude in just three years with a major in chemistry.

Europe
When at Harvard, after being admitted to graduate standing in physics in his first year as an undergraduate on the basis of independent study, Oppenheimer was introduced to experimental physics during a course on thermodynamics taught by Percy Bridgman, and was encouraged to go to Europe for future study, as a world-class education in the subject could not then be obtained in the United States.

He was accepted for postgraduate work at Ernest Rutherford's famed Cavendish Laboratory in Cambridge, working under the eminent but aging J.J. Thomson. Oppenheimer's clumsiness in the laboratory made it apparent that his forte was theoretical, not experimental, physics, so he left in 1926 for the University of Göttingen to study under Max Born. Göttingen was one of the top centers for theoretical physics in Europe, and Oppenheimer made a number of friends who would go on to great success, such as Paul Dirac, Wolfgang Pauli, and Werner Heisenberg, before he obtained his Ph.D. at the young age of 22.

After the oral exam for his Ph.D., the professor administering it is reported to have said, "Phew, I'm glad that's over. He was on the point of questioning me." At Göttingen, Oppenheimer was known for being a quick study. However, he was also known for being too enthusiastic in discussions, sometimes to the point of taking over seminar sessions, a fact that used to irritate a few of Born's pupils.

At Göttingen, Oppenheimer published many important contributions to the then newly developed quantum theory, most notably a famous paper on the so-called Born-Oppenheimer approximation, which separates nuclear motion from electronic motion in the mathematical treatment of molecules. In September 1927, he returned to Harvard as a young maven of mathematical physics and a National Research Council Fellow, having published more than a dozen articles, and in early 1928 he studied at the California Institute of Technology.

Here he received numerous invitations for teaching positions, and accepted an assistant professorship in physics at the University of California, Berkeley. In his words, "it was a desert", yet paradoxically a fertile place of opportunity. He maintained a joint appointment with Caltech, where he spent every spring term in order to avoid isolation from mainstream research. At Caltech, Oppenheimer struck a close friendship with Linus Pauling and they planned to mount a joint attack on the nature of the chemical bond, a field in which Pauling was a pioneer—apparently Oppenheimer would supply the mathematics and Pauling would interpret the results.

However, this relationship was nipped in the bud when Pauling began to suspect that the theorist was becoming too close to his wife, Ava Helen; once when Pauling was at work, Oppenheimer had come to their place and blurted out an invitation to Ava Helen to join him on a tryst in Mexico. She flatly refused and reported this incident to Pauling. This, and her apparent nonchalance about the incident, disquieted him, and he immediately cut off his relationship with the Berkeley professor, leading to a coolness between them that would last their lives, although Oppenheimer did invite Pauling to be the head of the Chemistry Division of the atomic bomb project (Pauling refused, saying that he was a pacifist).

In the Autumn of 1928, Oppenheimer visited Paul Ehrenfest's institute at the University of Leiden, the Netherlands, where he impressed those there by giving lectures in Dutch despite his little experience with the language. There he was given the nickname of "Opje", which was later Anglicised by his students as "Oppie". From Leiden he continued on to Zurich, Switzerland, to work with Wolfgang Pauli on problems relating to quantum theory and the continuous spectrum, before heading back to the United States. Oppenheimer highly respected and liked Pauli, and some of his own style and his critical approach to problems was said to be inspired by Pauli. His time with both Ehrenfest and Pauli gave Oppenheimer a chance to polish his mathematical skills.

California
Before his Berkeley professorship began, Oppenheimer was diagnosed with a mild case of tuberculosis, and with his brother Frank, spent some weeks at a ranch in New Mexico, which he leased and eventually purchased. (When he heard the ranch was available for lease, he exclaimed, "Hot dog!"—and since it was in New Mexico, the Oppenheimer brothers named it "Perro Caliente", the literal Spanish translation of this exclamation.

Later, Oppenheimer used to say that 'physics and desert country' were his two great loves, loves that would be improbably combined when he directed the atomic bomb project at Los Alamos in New Mexico. He recovered from his tuberculosis and returned to Berkeley, where he prospered as an advisor and collaborator to a generation of physicists who admired him for his intellectual virtuosity and broad interests. Nobel Prize winner Hans Bethe later said about him:

Probably the most important ingredient Oppenheimer brought to his teaching was his exquisite taste. He always knew what were the important problems, as shown by his choice of subjects. He truly lived with those problems, struggling for a solution, and he communicated his concern to the group.

He also worked closely with (and became good friends with) Nobel Prize winner experimental physicist Ernest O. Lawrence and his cyclotron pioneers, helping the experimentalists understand the new data their machines were producing at the Lawrence's Radiation Laboratory.

Oppenheimer became credited with being a founding father of the American school of theoretical physics, and developed a reputation for his erudition in physics, his eclecticism, his interest in languages and Eastern philosophy, and the eloquence and clarity with which he thought. But he was also troubled throughout his life, and professed to experiencing periods of depression. "I need physics more than friends," he once informed his brother. A tall, thin chain smoker who often neglected to eat during periods of intellectual discomfort and concentration, Oppenheimer was marked by many of his friends as having a self-destructive tendency, and during numerous periods of his life worried his colleagues and associates with his melancholy and insecurity.

When he was studying in Cambridge and had taken a vacation to meet up with his friend Francis Ferguson in Paris, a disturbing event had taken place. During a conversation in which Oppenheimer was narrating his frustration with experimental physics to Ferguson, he had suddenly leapt up and tried to strangle him. Although Ferguson easily fended off the attack, the episode had convinced Ferguson of his friend's deep psychological troubles. Oppenheimer developed numerous affectations, seemingly in an attempt to convince those around him—or possibly himself—of his self-worth.

He was said to be mesmerizing, hypnotic in private interaction but often frigid in more public settings. His associates fell into two camps: one which saw him as an aloof and impressive genius and an aesthete; another which saw him as a pretentious and insecure poseur. His students almost always fell into the former category, adopting "Oppie's" affectations, from his way of walking to talking and beyond — even trying to replicate his inclination for reading entire texts in their originally transcribed languages.

Oppenheimer did important research in theoretical astrophysics (especially as it relates to general relativity and nuclear theory), nuclear physics, spectroscopy, and quantum field theory (including its extension into quantum electrodynamics). The formalism of relativistic quantum mechanics also attracted his attention. His best-known contribution, made as a graduate student, is the Born-Oppenheimer approximation mentioned above.

He also made important contributions to the theory of cosmic ray showers, and did work which led eventually toward descriptions of quantum tunneling. His work on the Oppenheimer-Phillips process, involved in artificial radioactivity under bombardment by deuterons, has served as an important step in nuclear physics. In the late 1930s, he was the first to write papers suggesting the existence of what we today call black holes. In these papers, he demonstrated that there was a size limit (the so called Oppenheimer-Volkoff limit) to stars beyond which they would not remain stable as neutron stars, and would undergo gravitational collapse.

After the Born-Oppenheimer approximation paper, these papers remain his most cited ones, and they were key in the rejuvenation of astrophysical research in the United States in the 1950s, mainly by John Wheeler. As early as 1930, he also wrote a paper essentially predicting the existence of the positron (which had been postulated by Paul Dirac), a formulation that he however did not carry to its natural outcome, because of his skepticism about the validity of the Dirac equation.

As evidenced above, his work predicts many later finds which include, further, the neutron, meson, and neutron star. Even beyond the immense abstruseness of the topics he was expert in, Oppenheimer's papers were considered difficult to understand. Oppenheimer was very fond of using elegant, if extremely complex, mathematical techniques to demonstrate physical principles, though he was sometimes criticized for making mathematical mistakes, presumably out of haste.

Many people thought that Oppenheimer's discoveries and research were not commensurate with his inherent abilities and talents. They still considered him an outstanding physicist, but they did not place him at the very top rank of theorists who fundamentally challenged the frontiers of knowledge. One reason for this could have been his diverse interests, which kept him from completely focusing on any individual topic for long enough to bring it to full fruition. His close confidant and colleague, Nobel Prize winner Isidor Rabi, later gave his own interpretation:

Oppenheimer was overeducated in those fields which lie outside the scientific tradition, such as his interest in religion, in the Hindu religion in particular, which resulted in a feeling of mystery of the universe that surrounded him like a fog. He saw physics clearly, looking toward what had already been done, but at the border he tended to feel there was much more of the mysterious and novel than there actually was...he turned away from the hard, crude methods of theoretical physics into a mystical realm of broad intuition.

In spite of this, some people (such as the Nobel Prize winner physicist Luis Alvarez) have suggested that if he had lived long enough to see his predictions substantiated by experiment, Oppenheimer might have won a Nobel Prize for his work on gravitational collapse, concerning neutron stars and black holes.

Radical politics
During the 1920s, Oppenheimer kept himself aloof of worldly matters, and claimed to have not learned of the Stock Market Crash of 1929 until some time after the fact (Oppenheimer himself had little worry regarding financial matters, as his family inheritance provided him with ample funding). It was not until he became involved with Jean Tatlock, the daughter of a Berkeley literature professor, in 1936, that he showed any interest in politics.

Like many young intellectuals in the 1930s he became a supporter of Communist ideas, and having much more money than most professors (he inherited over $300,000, a massive sum at the time, after his father's death in 1937) was able to bankroll many left-wing efforts. The majority of his radical work consisted of hosting fund-raisers for the Republican cause in the Spanish Civil War and other anti-Fascist activity.

He never openly joined the Communist Party (his brother Frank, however, did, against Robert's advice), though the historian Gregg Herken has recently claimed to have evidence that Oppenheimer did interact with the Communist Party during the 1930s and early 1940s. In November 1940, he married Katherine Puening Harrison, a radical Berkeley student, and by May 1941 they had their first child, Peter.

The Manhattan Project
When World War II started, Oppenheimer eagerly became involved in the efforts to develop an atomic bomb which were already taking up much of the time and facilities of Lawrence's Radiation Laboratory at Berkeley. In 1941, Lawrence, Vannevar Bush, Arthur Compton, and James Conant were trying to wrest the bomb project from the Uranium Committee established by President Franklin D. Roosevelt in 1939, because they felt it was proceeding too slowly.

Oppenheimer was invited to take over work on fast neutron calculations, a task which he threw himself into with full vigor, renouncing what he called his "left-wing wanderings" to abandon himself to his responsibilities (though many of his friends and students were still quite radical). When the U.S. Army was given jurisdiction over the bomb effort, now called the Manhattan Project, project director General Leslie R. Groves (who had just finished directing the construction of the Pentagon) appointed, to the surprise of many, Oppenheimer as its scientific director. Groves knew of Oppenheimer's potential security problems, but thought that Oppenheimer was the best man to direct a diverse team of scientists and would be unaffected by his past political leanings.

Los Alamos
One of Oppenheimer's first acts was to host a summer school for bomb theory at his building in Berkeley. The mix of European physicists and his own students—a group including Robert Serber, Emil Konopinski, Felix Bloch, Hans Bethe, and Edward Teller—busied themselves calculating what needed to be done, and in what order, to make the bomb. When Teller put forward the remote possibility that the bomb would generate enough heat to ignite the atmosphere (an event that was soon shown to be impossible by Bethe), Oppenheimer nevertheless was concerned enough to meet up with Arthur Compton in Michigan to discuss the situation.

At the time, research for the project was going on at many different universities and laboratories across the country, presenting a problem for both security and cohesion. Oppenheimer and Groves decided that they needed a centralized, secret research laboratory. Scouting for a site, Oppenheimer was drawn to New Mexico, not far from his ranch. On a flat mesa near Santa Fe, New Mexico, the Los Alamos laboratory was hastily built, a rag-tag collection of barracks and mud. There Oppenheimer coaxed and collected a group of the most brilliant physicists of his day, which he referred to as the "luminaries", including Enrico Fermi, Richard Feynman, Robert R. Wilson, and Victor Weisskopf, as well as Bethe and Teller. His wife gave birth there to their second child, Katherine (called Toni), in 1944.

Oppenheimer was noted for his mastery of all scientific aspects of the project and for his efforts to control the inevitable cultural conflicts between scientists and the military. He was an iconic figure to his fellow scientists, as much a figurehead of what they were working towards as a scientific director. Victor Weisskopf put it thus:

"He did not direct from the head office. He was intellectually and even physically present at each decisive step. He was present in the laboratory or in the seminar rooms, when a new effect was measured, when a new idea was conceived. It was not that he contributed so many ideas or suggestions; he did so sometimes, but his main influence came from something else. It was his continuous and intense presence, which produced a sense of direct participation in all of us; it created that unique atmosphere of enthusiasm and challenge that pervaded the place throughout its time."

All the while, Oppenheimer was under investigation by both the FBI and the Manhattan Project's internal security arm for his past left-wing associations. He was also followed by an FBI agent during an unannounced trip to California in 1943 to meet his former girlfriend, Jean Tatlock. In August 1943, Oppenheimer told Manhattan Project security agents that three of his students had been solicited for nuclear secrets by a friend of his with Communist connections. When pressed on the issue in later interviews with General Groves and security agents, he identified the friend as Haakon Chevalier, a Berkeley professor of French literature.

Oppenheimer would be asked for interviews related to the "Chevalier incident", and he often gave contradictory and equivocating statements, telling Groves that only one person had actually been approached, and that that person was his brother Frank. But Groves still thought Oppenheimer too important to the ultimate Allied goals to oust him over this suspicious behavior.

Trinity
The joint work of the scientists at Los Alamos resulted in the first nuclear explosion near Alamogordo on July 16, 1945, the site of which Oppenheimer named "Trinity", Oppenheimer later said this name was from one of John Donne's Holy Sonnets. According to the historian Gregg Herken, this naming could have been an allusion to Jean Tatlock (who had introduced him to Donne when they had dated in the 1930s), who had committed suicide a few months previously. He later recalled that while witnessing the explosion he thought of a verse from the Hindu holy book, the Bhagavad Gita:

If the radiance of a thousand suns were to burst at once into the sky, that would be like the splendor of the mighty one...
Years later he would explain that another verse had also entered his head at that time:

"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 on his multi-armed form and says, 'Now, I am become Death, the destroyer of worlds.' I suppose we all thought that one way or another."
According to his brother, at the time he simply exclaimed, "It worked." News of the successful test was rushed to President Harry S. Truman, who would try to use it as leverage at the upcoming Potsdam Conference on the fate of post-war Europe.

Japan
Main article: Atomic bombings of Hiroshima and Nagasaki
Though the initial impetus for the development of the bomb—a perceived arms race with Nazi Germany—had been shown unnecessary (when the German program was discovered to be stillborn by the Manhattan Project's Alsos investigation), Oppenheimer and his scientists pressed on.

The scientist-administrators were divided on whether and how to use the now-tested weapon. Lawrence initially favored not using the weapon on a live target, arguing that a demonstration alone would be enough to convince the Japanese government of the futility of continuing the war. Oppenheimer and many of the military advisors strongly disagreed with this assessment. Oppenheimer feared that if it were announced where such a demonstration might occur, the enemy might move American POWs or other human shields into the region.

To other physicists, including Teller and Leo Szilard, using the weapon on a civilian area would be a moral horror. A petition was circulated at the labs in Los Alamos and Oak Ridge pleading that use of the bomb against civilians would be immoral and unnecessary. Oppenheimer opposed the petition and warned Szilard and Teller not to impede the project. It is uncertain how much stock the American government and military put in the opinions of the scientists on the weapon they had created.

On August 6, 1945, the "Little Boy" uranium bomb was dropped on the city of Hiroshima, Japan. Three days later, the "Fat Man" plutonium bomb was dropped on Nagasaki. The bombs killed tens of thousands of civilians immediately and many more over time. The bombs hastened the end of the war, which came after Japanese surrender on August 15. (Allied military casualties of the planned invasion of Japan, Operation Downfall, were estimated to number approximately 268,000 by Admiral William D. Leahy in a June 18, 1945 briefing to President Truman; Japanese military and civilian deaths would have potentially numbered in the millions, based on experience with Japanese civilians on Okinawa.)

Many people, including many of the scientists involved in the bomb project, were shocked by the devastation that the bombs produced, reports of which filtered into the United States over time. The pride which Oppenheimer had felt after the successful "Trinity" test was soon replaced by guilt and horror. "In some sort of crude sense which no vulgarity, no humor, no overstatement can quite extinguish," he later famously said, "the physicists have known sin; and this is a knowledge which they cannot lose." Los Alamos was awarded the Army-Navy "Excellence" Award shortly thereafter, and in his acceptance speech for the lab, Oppenheimer warned that:

"If atomic bombs are to be added as new weapons to the arsenals of a warring world, or to the arsenals of the nations preparing for war, then the time will come when mankind will curse the names of Los Alamos and Hiroshima. The people of this world must unite or they will perish."
He never said that he regretted making the weapon. During his only visit to postwar Japan in 1960, he was asked by a reporter whether he felt any guilt on developing the bomb. Oppenheimer quipped, "It's not that I don't feel bad about it. It's just that I don't feel worse today than what I felt yesterday."

Postwar activities
Overnight, Oppenheimer became a national spokesman for science, and emblematic of a new type of technocratic power. Nuclear physics became a powerful force as all governments of the world began to realize the strategic and political power which came with nuclear weapons and their horrific implications. Like many scientists of his generation, he felt that security from atomic bombs would come only from some form of transnational organization (such as the newly formed United Nations) which could institute a program to stifle a nuclear arms race.

Atomic Energy Commission
After the Atomic Energy Commission (AEC) was created in 1946, as a civilian agency in control of nuclear research and weapons issues, Oppenheimer was immediately appointed as the Chairman of its General Advisory Committee (GAC) and left the directorship of Los Alamos. From this position he advised on a number of nuclear-related issues, including project funding, laboratory construction, and even international policy—though the GAC's advice was not always implemented.

The Baruch Plan of 1946, which called for the internationalization of atomic energy, was derived in part from his opinions, though to his dismay it included many additional provisions which made it clear that its goal was simply to prevent the USSR from gaining its own bomb, rather than promoting a lasting international mechanism for control. The plan was rejected by the USSR to no surprise of observers, and it became clear to Oppenheimer that an arms race was unavoidable, due to the mutual distrust of the U.S. and the USSR.

In 1947, he left Berkeley, citing difficulties with the administration during the war, and took up the directorship of the Institute for Advanced Study at Princeton, New Jersey. He later held Albert Einstein's old position of senior professor of theoretical physics.

While still Chairman of the GAC, Oppenheimer lobbied vigorously for international arms control and funding for basic science, and attempted to influence policy away from a heated arms race. When the government questioned whether to pursue a crash program to develop an atomic weapon based on nuclear fusion—the hydrogen bomb—Oppenheimer initially recommended against it, though he had been in favor of developing such a weapon in the early days of the Manhattan Project.

He was motivated partly by ethical concerns, feeling that such a weapon could only be used strategically against civilian targets, resulting in millions of deaths. But he was also motivated by practical concerns; as at the time there was no workable design for a hydrogen bomb, Oppenheimer felt that resources would be better spent creating a large force of fission weapons. He was overridden by President Harry Truman, who announced a crash program after the Soviet Union tested their first atomic bomb in 1949. Oppenheimer and other GAC opponents of the project, especially James Conant, felt personally shunned and considered retiring from the committee. They stayed on, though their views on the hydrogen bomb were well known.

In 1951, however, Edward Teller and mathematician Stanislaw Ulam developed what became known as the Teller-Ulam design for a hydrogen bomb. This new design seemed technically feasible, and Oppenheimer changed his opinion about developing the weapon. As he later recalled:

“The program we had in 1949 was a tortured thing that you could well argue did not make a great deal of technical sense. It was therefore possible to argue that you did not want it even if you could have it. The program in 1951 was technically so sweet that you could not argue about that. The issues became purely the military, the political, and the humane problems of what you were going to do about it once you had it.“

Oppenheimer's critics have accused him of equivocating between 1949—when he opposed the development of the hydrogen bomb—and 1951, when he supported it, and some have made this a case for reinforcing their opinions about his moral inconsistency. Historian Priscilla McMillan has argued, however, that if Oppenheimer has been accused of being morally inconsistent, then so should Rabi and Fermi, who had also opposed the program in 1949.

Most of the GAC members were against a crash hydrogen bomb development program then, and in fact, Conant, Fermi and Rabi had submitted even more strongly worded reports against it than Oppenheimer. McMillan's argument is that because the hydrogen bomb appeared to be well within reach in 1951, everybody had to assume that the Russians could also do it, and that was the main reason why they changed their stance in favour of developing it. Thus this change in opinion should not be viewed as a change in morality, but a change in opinions purely based on technical possibilities.

The first true hydrogen bomb, dubbed "Ivy Mike", was tested in 1952 with a yield of 10.4 megatons—more than 650 times the strength of the weapons developed by Oppenheimer during World War II.

Security hearings
In his role as a political advisor, Oppenheimer made numerous enemies. The FBI under J. Edgar Hoover had been following his activities since before the war, when he showed Communist sympathies as a radical professor. They were willing to furnish Oppenheimer's political enemies with incriminating evidence about Communist ties. These enemies included Lewis Strauss, an AEC commissioner who had long harbored resentment against Oppenheimer both for his activity in opposing the hydrogen bomb and for his humiliation of Strauss before Congress some years earlier.

Strauss and Senator Brien McMahon, author of the 1946 Atomic Energy Act, pushed President Eisenhower to revoke Oppenheimer's security clearance. This came following controversies about whether some of Oppenheimer's students, including David Bohm, Joseph Weinberg, and Bernard Peters, had been Communists at the time they had worked with him at Berkeley. Oppenheimer's brother, Frank Oppenheimer, was forced to testify in front of the House Un-American Activities Committee, where he admitted that he had been a member of the Communist Party in the 1930s, but he refused to name other members. Frank was subsequently fired from his university position, could not find work in physics, and became instead a cattle rancher in Colorado.

In 1953, Oppenheimer was accused of being a security risk and President Dwight D. Eisenhower asked him to resign. Oppenheimer refused and requested a hearing to assess his loyalty, and in the meantime his security clearance was suspended. The public hearing which followed focused on Oppenheimer's past Communist ties and his association during the Manhattan Project with suspected disloyal or Communist scientists. One of the key elements in this hearing was Oppenheimer's earlier testimony about his friend Haakon Chevalier, something which he himself confessed he had fabricated.

In fact, Oppenheimer had never told Chevalier about this, and the testimony had led to Chevalier losing his job. Edward Teller, with whom Oppenheimer had disagreed on the hydrogen bomb, testified against him, leading to outrage by the scientific community and Teller's virtual expulsion from academic science. Many top scientists, as well as government and military figures, testified on Oppenheimer's behalf. Inconsistencies in his testimony and his erratic behavior on the stand convinced some that he was unreliable and a possible security risk. Oppenheimer's clearance was revoked.

During his hearing, Oppenheimer testified willingly on the left-wing behavior of many of his scientific colleagues. Cornell University historian Richard Polenberg has speculated that if Oppenheimer's clearance had not been stripped (it would have expired in a matter of days anyhow), he would have been remembered as someone who had "named names" to save his own reputation. As it happened, Oppenheimer was seen by most of the scientific community as a martyr to McCarthyism, an eclectic liberal who was unjustly attacked by warmongering enemies, symbolic of the shift of scientific creativity from academia into the military.

Institute for Advanced Study
Deprived of political power, Oppenheimer continued to lecture, write, and work on physics. He toured Europe and Japan, giving talks about the history of science, the role of science in society, and the nature of the universe. In 1963, at the urging of many of Oppenheimer's political friends who had ascended to power, President John F. Kennedy awarded Oppenheimer the Enrico Fermi Award as a gesture of political rehabilitation.

Edward Teller, the winner of the previous year's award, had also recommended Oppenheimer receive it. A little over a week after Kennedy's assassination, his successor, President Lyndon Johnson, presented Oppenheimer with the award, "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".

Oppenheimer told Johnson: "I think it is just possible, Mr. President, that it has taken some charity and some courage for you to make this award today. That would seem a good augury for all our futures". The rehabilitation implied by the award was only symbolic, as Oppenheimer still lacked a security clearance and could have no effect on official policy, but the award came with a $50,000 stipend.

In his final years, Oppenheimer continued his work at the Institute for Advanced Study, bringing together intellectuals at the height of their powers and from a variety of disciplines to solve the most pertinent questions of the current age. His lectures in America, Europe, and Canada were published in a number of books. Still, he thought the effort had minimal effect on actual policy.

Final years
After the 1954 Security hearings, Oppenheimer is reported to have been "like a wounded animal", and he started to retreat to a simpler life. In 1957, he purchased a piece of land on Gibney Beach in the island of St John in the Virgin Islands. He built a spartan vacation home on the beach, where he would spend holidays, usually months at a time, with his wife Kitty. Oppenheimer also spent a considerable amount of time sailing with his wife.

Upon their death, the property was inherited by their daughter Toni, who then left it to "the people of St. John for a public park and recreation area." Today, the Virgin Islands Government created a Community Center there, which can be rented out. The beach is colloquially known to this day as "Oppenheimer Beach".

Robert Oppenheimer died of throat cancer in Princeton, New Jersey, in 1967. His funeral was attended by many of his scientific, political, and military associates. His ashes were spread over the Virgin Islands.

Legacy
Robert Oppenheimer's life is usually seen to highlight a number of cultural and historical trends in the transformation of science from the 1920s through the 1950s.

As a scientist, Oppenheimer is remembered by his students and colleagues as being a brilliant researcher and engaging teacher, the founder of modern theoretical physics in the United States. Many have asked why Oppenheimer never won a Nobel Prize. Scholars respond that his scientific attentions often changed rapidly and he never worked long enough on any one topic to achieve enough headway to merit the Nobel Prize.

His lack of a Prize would not be odd—most scientists do not win Nobel Prizes—had not so many of his associates (Einstein, Fermi, Bethe, Lawrence, Dirac, Rabi, Feynman, etc.) won them. Some scientists and historians have speculated that his investigations towards black holes may have warranted the Nobel, had he lived long enough to see them brought into fruition by later astrophysicists.

As an advisor, Oppenheimer delineates a shift in the interactions between science and the military. During World War II, scientists became involved in military research to an unprecedented degree (some research of this sort had occurred during World War I, but it was far smaller in scope). Because of the threat Fascism posed to Western civilization, scientists volunteered in great numbers both for technological and organizational assistance to the Allied effort, resulting in such powerful tools as radar, the proximity fuze, and operations research.

As a cultured, intellectual, theoretical physicist who became a disciplined military organizer, Oppenheimer represented the shift away from the idea that scientists had their "head in the clouds" and that knowledge on such previously esoteric subjects as the composition of the atomic nucleus had no "real-world" applications. He also represented for many the new form of technocrat who would guide the emergence of what later became known as "Big Science." When Oppenheimer was ejected from his position of political influence in 1954, he symbolized for many the folly of scientists thinking they could control how others would use their research. Oppenheimer has been seen as symbolizing the dilemmas involving the moral responsibility of the scientist in the nuclear world.

Most popular depictions of Oppenheimer, notably German playwright Heinar Kipphardt's 1964 play on his trial, portray his security struggles as a confrontation between right-wing militarists (symbolized by Edward Teller) and left-wing intellectuals (symbolized by Oppenheimer) over the moral question of weapons of mass destruction. Many historians have contested this as an over-simplification: the trial, while very political, was undertaken as much for personal reasons as any political agenda, and Oppenheimer's opinion on nuclear weapons was too inconsistent to brand him as a pacifist.

While popular moralizations depict Oppenheimer as against the bomb for moral reasons, a more complete look shows him opposing it primarily for technical reasons. Once these were resolved, he supported the bomb, on the grounds that the Soviet Union too would inevitably construct one.

Even Oppenheimer himself had difficulty with this portrayal—after reading a transcript of Kipphardt's play soon after it began to be performed, Oppenheimer told an interviewer:

The whole damn thing [his security hearing] was a farce, and these people are trying to make a tragedy out of it. ... I had never said that I had regretted participating in a responsible way in the making of the bomb. I said that perhaps he [Kipphardt] had forgotten Guernica, Coventry, Hamburg, Dresden, Dachau, Warsaw, and Tokyo; but I had not, and that if he found it so difficult to understand, he should write a play about something else.

Despite Oppenheimer's apparently remorseful attitudes, Oppenheimer was a vocal supporter of using the first atomic weapons on "built-up areas" in the days before the bombings of Hiroshima and Nagasaki. Rather than consistently opposing the "Red-baiting" of the late 1940s and early 1950s, he had testified against many of his former colleagues and students, both before and during his hearing. In one incident, Oppenheimer's damning testimony against former student Bernard Peters was selectively leaked to the press.

Historians have interpreted this as an attempt by Oppenheimer to please his colleagues in the government (and perhaps to avert attention from his own previous left-wing ties and especially from those of his brother, who had earlier been a target of the anti-Red lobby). In the end it became a liability: under cross-examination, it became clear that if Oppenheimer had really doubted Peters' loyalty, then his recommending him for the Manhattan Project was reckless, or at least contradictory.

The removal of his security clearance was probably as much related to his inconsistent testimony, and his open admission of telling lies to intelligence agents, as to the left-wing views he shared with many intellectuals and scientists in the wake of the Great Depression and the rise of Fascism. Nevertheless, the trope of Oppenheimer as a martyr has proven indelible, and to speak of Oppenheimer has often been to speak of the limits of science and politics, however more complicated the actual history.

The question of the scientists' responsibility towards humanity, so manifest in the dropping of the atomic bombs and Oppenheimer's public questioning, inspired Bertolt Brecht's drama Galileo (from 1955), left its imprint on Friedrich Dürrenmatt's Die Physiker, and is the basis of the opera Doctor Atomic, which portrays Oppenheimer as a modern Faustus.