Robert Oppenheimer lecturing Edward R. Murrow on physics, Princeton, 1954

Why another book about Robert Oppenheimer? Many books have been written and widely read, ranging from the impressionistic Lawrence and Oppenheimer of Nuel Pharr Davis to the scholarly American Prometheus of Kai Bird and Martin Sherwin. Ray Monk says he wrote his book because the others gave too much weight to Oppenheimer’s politics and too little weight to his science. Monk restores the balance by describing in detail the activities that occupied most of Oppenheimer’s life: learning and exploring and teaching science.

The subtitle, “A Life Inside the Center,” calls attention to a rarer skill in which Oppenheimer excelled. He had a unique ability to put himself at the places and times at which important things were happening. Four times in his life, he was at the center of important events. In 1926 he was at Göttingen, where his teacher Max Born was one of the leaders of the quantum revolution that transformed our view of the subatomic world. In 1929 he was at Berkeley, where his friend Ernest Lawrence was building the first cyclotron, and with Lawrence he created in Berkeley an American school of sub-atomic physics that took the leadership away from Europe. In 1943 he was at Los Alamos building the first nuclear weapons. In 1947 he was in Washington as chairman of the General Advisory Committee of the United States Atomic Energy Commission, giving advice to political and military leaders at the highest levels of government. He was driven by an irresistible ambition to play a leading part in historic events. In each case, when he was present at the center of action, he rose to the occasion and took charge of the situation with unexpected competence.

It is often helpful to have several books covering the same territory. Since different writers have different viewpoints, each book will do better in some areas and worse in others. The most valuable contribution of Monk’s book is to give a detailed picture of two groups of people who played an important role in Oppenheimer’s life: the tightly knit society of wealthy German New York Jews to which his parents belonged, and the small army of security officers who monitored his social and political activities when he was engaged in secret work in Berkeley and Los Alamos.

Monk brings these two groups vividly to life. He puts the German Jews into their historical setting. Many of them were liberal idealists who failed to achieve their dreams of social reform in Germany and came to America with an intense commitment to the American dream of a free society. He begins his account by quoting a line, “America, thou hast it better,” from a poem by Goethe extolling America as the land of liberation from the knights, robbers, and ghosts of old Europe. This poetic German vision of America made Oppenheimer more passionately patriotic than most of his scientist friends. His father was a close friend of Felix Adler, the founder of the Ethical Culture Society, an institution that embodied the liberal ideals of the German Jewish community. Oppenheimer was educated at the Ethical Culture School, also founded by Felix Adler, from age seven to age seventeen. The purpose of the school was to raise children with a lifelong dedication to ethical principles, detached from any religious belief or ritual. The school seems to have been successful in molding Oppenheimer’s character.

Unlike the other books, which portray the security officers at Berkeley and Los Alamos as mindless bureaucrats or paranoid witch-hunters, Monk portrays them as real people with real problems. The four officers who had the thankless job of extracting information from Oppenheimer were Boris Pash, Peer de Silva, John Lansdale, and Lyall Johnson. They were trying conscientiously to protect the secrecy of the bomb project and to keep potential spies out of it.

We now know that their efforts were unsuccessful. They did not succeed in identifying the real spies. But they were aware that Soviet intelligence agents were actively seeking information about the project; they suspected that several of Oppenheimer’s Communist friends and students might be spying; and they were frustrated by Oppenheimer’s evasive answers to their questions. They were told by General Leslie Groves, commander-in-chief of the bomb project, that Oppenheimer’s leadership was essential to it, and yet Oppenheimer disregarded the security rules that they were trying to enforce. In their eyes, the essential question was whether the security rules that applied to everyone else on the project should also apply to Oppenheimer. Should he be exempt from the rules just because he was famous? Lansdale answered yes to this question. Pash, de Silva, and Johnson answered no.

Monk begins his book with a preface discussing the other Oppenheimer books and explaining why he finds them deficient. Unfortunately he does not mention the book that I found the most illuminating, Reappraising Oppenheimer: Centennial Studies and Reflections, edited by Cathryn Carson and David Hollinger.* This work does not appear in Monk’s bibliography. It is a volume of essays by various authors, most of them professional historians. I summarize here three of the essays that provide factual information about aspects of Oppenheimer’s life that Monk does not explore.


David Cassidy gives us a complete list of Oppenheimer’s graduate students with the titles of their dissertations. This list shows us what Oppenheimer was thinking about when he was a young professor in Berkeley, and how he was training the next generation of physicists. It reveals the modest foundation out of which his legendary reputation as a teacher grew. There were twenty-five students altogether, only six of them finishing in the ten years between 1929 and 1939. Two subjects are predominant in their dissertations: mesons and cosmic rays. Cosmic rays are the gentle rain of high-energy particles that constantly bombard the earth from outer space. Mesons are particles that were discovered among the cosmic rays and found to have weird and incomprehensible behavior, sometimes exploding into showers of secondary particles, and sometimes passing through matter without interaction.

Oppenheimer knew that the cosmic rays were his best clue to the understanding of nature in the wild, with energies vastly greater than Ernest Lawrence could reach with his particle accelerators. A majority of his students worked on cosmic rays in one way or another, trying to understand a mass of confusing observations by comparing them with a mass of equally confusing theories. This intense intellectual effort succeeded in educating gifted students who went on to become scientific leaders, but it failed to solve the mysteries of cosmic rays and mesons.

David Holloway gives us a chapter entitled “Parallel Lives? Oppenheimer and Khariton,” comparing Oppenheimer with his Russian counterpart. Yulii Khariton was remarkably similar to Oppenheimer in many ways, born in the same year into a cultured Jewish family, fluent in three languages, with a strong interest in art and literature, working as a student at the Cavendish Laboratory in England just after Oppenheimer left, and unexpectedly becoming the successful leader of a Soviet program to build bombs. His boss, Lavrenty Beria, was a notoriously harsh KGB official, but Khariton succeeded in working with Beria as harmoniously as Oppenheimer did with General Groves. Khariton never became a controversial public figure like Oppenheimer. His close friend and colleague Andrei Sakharov, who was for many years his deputy, played that part in the Soviet Union.

Karl Hufbauer contributes a chapter, “J. Robert Oppenheimer’s Path to Black Holes,” discussing what I consider the outstanding mystery of Oppenheimer’s life. In 1939 Oppenheimer published with his student Hartland Snyder a paper, “On Continued Gravitational Contraction,” only four pages long, which is in my opinion Oppenheimer’s one and only revolutionary contribution to science. In that paper, Oppenheimer and Snyder invented the concept of black holes; they proved that every star significantly more massive than the sun must end its life as a black hole, and deduced that black holes must exist as real objects in the sky around us. They showed that Einstein’s theory of general relativity compels any massive star that has exhausted its supply of nuclear fuel to enter a state of permanent free fall. Permanent free fall was a new idea, counterintuitive and profoundly important. It allows a massive star to keep falling permanently into a black hole without ever reaching the bottom.

Einstein never imagined and never accepted this consequence of his theory. Oppenheimer imagined it and accepted it. As a direct result of Oppenheimer’s work, we now know that black holes have played and are playing a decisive part in the evolution of the universe. That is the historical fact. The mystery is Oppenheimer’s failure to grasp the importance of his own discovery. He lived for twenty-seven years after the discovery, never spoke about it, and never came back to work on it. Several times, I asked him why he did not come back to it. He never answered my question, but always changed the conversation to some other subject.

It is true, as Monk demonstrates, that Oppenheimer’s ruling passion was to be a leader in pure science. He considered his excursions into bomb-making and nuclear politics to be temporary interruptions. My interactions with Oppenheimer confirm Monk’s picture of him. I worked at the Institute for Advanced Study for almost twenty years while Oppenheimer was director. He rarely talked about politics and almost never about bombs, but talked incessantly about the latest discoveries and puzzles in pure science.

Twice I had a reason to talk with him about bombs. The first occasion came in 1958, when I asked for a leave of absence from the institute to work on a project in California aimed at building a nuclear bomb–propelled spaceship. I told him how happy I was to be putting his bombs to better use than murdering people. He did not share my enthusiasm. He considered the spaceship project to be an exercise in applied science, unworthy of the attention of an institute professor. The only activity worthy of an institute professor was to think deep thoughts about pure science. He grudgingly gave me a leave of absence for one year, making it clear that if I stayed away for longer than a year I would not be coming back.


The second occasion for me to talk with Oppenheimer about bombs came a few years later, when I was chairman of the Federation of American Scientists, a political organization of scientists concerned with weapons and arms control. The federation was opposing the US deployment of tactical nuclear weapons in exposed positions in Europe and Asia. We considered these deployments to be unacceptably dangerous, because nuclear-armed troops involved in local fighting could start a nuclear war that would quickly get out of control. When we examined the history of tactical weapons, we learned that Oppenheimer himself had flown to Paris in 1951 to persuade General Eisenhower, then in command of American forces in Europe, that the United States Army needed tactical nuclear weapons to defend Western Europe against a Soviet invasion. Oppenheimer had been enthusiastically promoting the production and deployment of tactical weapons.



The young Robert Oppenheimer, right, playing with blocks, circa 1910

After learning this, I went to see Oppenheimer and asked him directly why he had thought that tactical nuclear weapons were a good idea. This time, he answered my question. He said, “To understand why I advocated tactical weapons, you would have to see the Air Force war plan that we had then. That was the God-damnedest thing I ever saw. It was a mindless obliteration of cities and populations. Anything, even a major ground war fought with nuclear weapons, was better than that.”

I understood then how it happened that Oppenheimer came to grief. He was caught in a battle between the Army and the Air Force. The Army wanted small bombs to destroy invading armies. The Air Force wanted big bombs to destroy whole countries. The Army wanted fission bombs and the Air Force wanted hydrogen bombs. Oppenheimer was on the side of the Army. That was why he promoted tactical weapons. That was why he opposed the development of the hydrogen bomb.

The Air Force took its revenge on the Army by helping to drive Oppenheimer out of the government. Air Force General Roscoe Charles Wilson was one of the witnesses against Oppenheimer at the security hearing. General Wilson said, “I felt compelled to go to the Director of Intelligence to express my concern over what I felt was a pattern of action [on Oppenheimer’s part] that was simply not helpful to national defense.” In the eyes of the Air Force, anyone who opposed the hydrogen bomb was opposing national defense. The Air Force won the battle, and Oppenheimer’s friends in the Army could not help him. The hydrogen bomb development rushed ahead with the highest priority. But in the end, both the Air Force and the Army got all the bombs that they wanted.

Two facts about Oppenheimer stand out clearly from the public record. He was astonishingly effective as leader of the Los Alamos project. And he never regretted his role as the chief architect of the bomb. In the memoirs of people who worked at Los Alamos, we find many descriptions of his ability to oversee a huge variety of technical jobs, to find the appropriate tools for each pair of hands, and to keep an army of prima donnas working harmoniously together. General Groves talked with many of the leading scientists before choosing one of them to be the director of the project. He chose Oppenheimer because he was the only one with a burning ambition to get the job done. Oppenheimer understood that the project was not scientific but military. Late in 1944, when some of the Los Alamos scientists seemed to be more interested in scientific experiments than in weaponry, Oppenheimer wrote in a memorandum to Groves: “The laboratory is operating under a directive to produce weapons. This directive has been and will be rigorously adhered to.”

Oppenheimer continued for the rest of his life to be proud of his achievement at Los Alamos. We know this because he protested vigorously in 1964 when the German playwright Heinar Kipphardt wrote a play portraying him as a tragic hero regretting his actions. Oppenheimer threatened to sue Kipphardt and the producers of the play if they continued to misrepresent him. The producers cut out the offending passages from the play, and the case never went to court. Oppenheimer continued to block later attempts to produce the play in London and New York. The play was mostly based on the security hearings of 1954. Oppenheimer said in a public statement about the hearings to a Washington Post reporter, “The whole damn thing was a farce, and these people are trying to make a tragedy out of it.”

Oppenheimer particularly objected to some passages in the play that made him appear anti-American. Monk expresses his opinion, with which I agree, that Oppenheimer’s anger arose from his deep loyalty to America. For him, expressing regret for what he had done for his country would have meant joining his country’s enemies.

Oppenheimer was above all a good soldier. That is why he worked so well with General Groves, and that is why Groves trusted him. I have a vivid memory of the ice-cold February day in 1967 when we held a memorial service for Oppenheimer at Princeton. Because of the extreme cold, attendance at the service was sparse. But General Groves, old and frail, came all the way from his home to pay his respects to his friend.

I often wondered how it happened that Oppenheimer changed his character so suddenly, from the left-wing bohemian intellectual at Berkeley to the good soldier at Los Alamos. I believe that an important clue to this change is the story of Joe Dallet. In his autobiographical statement at the security hearings, Oppenheimer said:

It was in the summer of 1939 in Pasadena that I first met my wife…. I learned of her earlier marriage to Joe Dallet, and of his death fighting in Spain…. When I met her I found in her a deep loyalty to her former husband.

After Oppenheimer married Kitty in 1940, they continued to live with the ghost of Joe Dallet. Later I learned from the historian Richard Polenberg some facts about Joe Dallet’s life and death.

Dallet was unlike the majority of the left-wing intellectuals who flocked to Spain to fight for the republic. Dallet took soldiering seriously. He believed in discipline. He quickly became an expert on the repair, maintenance, and use of machine guns. He drilled his troops with old-fashioned thoroughness, making sure that they knew how to take care of their weapons and how to use them effectively. In an anarchic situation, his unit was conspicuously well organized. His men caught from him the habit of competence, the pride of a steelworker who knew how to handle machinery. At moments of relaxation, he talked mostly about his beloved machine guns. This was the image of Joe that Joe’s friends brought to Kitty in Paris when they came to see her after his death. This was the image that Kitty brought to Oppenheimer when she married him.

From Spain to Los Alamos was a short step. Oppenheimer was as proud of his bombs as Joe Dallet had been proud of his guns. Oppenheimer became the good soldier that Kitty loved and admired. Through the Los Alamos years and for twenty years afterward, the spirit of Joe Dallet lived on in Robert Oppenheimer.

The real tragedy of Oppenheimer’s life was not the loss of his security clearance but his failure to be a great scientist. For forty years he put his heart and soul into thinking about deep scientific problems. With the single exception of the collapse of massive stars at the end of their lives, he did not solve any of these problems. Why did he not succeed in scientific research as brilliantly as he succeeded in soldiering and administration? I believe the main reason why he failed was a lack of Sitzfleisch. Sitzfleisch is a German word with no equivalent in English. The literal translation is “Sitflesh.” It means the ability to sit still and work quietly. He could never sit still long enough to do a difficult calculation. His calculations were always done hastily and often full of mistakes. In a letter to my parents quoted by Monk, I described Oppenheimer as I saw him in seminars:

He is moving around nervously all the time, never stops smoking, and I believe that his impatience is largely beyond his control.

In addition to his restlessness, Oppenheimer had another quality, emphasized by Monk in the subtitle of his book. He always wanted to be at the center. This quality is good for soldiers and politicians but bad for original thinkers. He paid too much attention to famous people working on fashionable topics, while ignoring less famous people working away from the mainstream of science. He had abundant opportunities to learn from two unfashionable geniuses, Fritz Zwicky and John Wheeler. Zwicky was working at the California Institute of Technology throughout the thirteen years when Oppenheimer was a regular visitor. Wheeler was working at Princeton University throughout the twenty years when Oppenheimer was living in Princeton. Zwicky was the discoverer of dark matter, the mysterious invisible stuff that outweighs the visible universe, and he was also a pioneer in the study of supernova explosions and neutron stars. Wheeler was the leading expert on black holes, and the founder of the field of science now known as relativistic astrophysics.

Although Oppenheimer lived close to each of them for many years and knew what they were doing, he did not take their work seriously. He seems to have considered them unworthy of his attention because they were out of the mainstream. Karl Hufbauer reports that Oppenheimer disliked Zwicky and for that reason never used Zwicky’s name “neutron star” for the collapsed remnant of a supernova explosion. Wheeler was one of the most enthusiastic proponents of the hydrogen bomb, and Oppenheimer never used Wheeler’s name “black hole” for the remnant of a nonexplosive gravitational collapse. In his attitude to Zwicky and Wheeler, personal antipathy was combined with professional misjudgment. As a result, he failed to grasp the opportunities that a closer contact with Zwicky or Wheeler would have provided to make revolutionary discoveries in areas of science ignored by the fashionable mandarins.

Late in Oppenheimer’s life, when he was sick and depressed, his wife Kitty came to me with a cry for help. She implored me to collaborate with Robert in a piece of technical scientific work. She said Robert was desperate because he was no longer doing science, and he needed a collaborator to get him started. I agreed with Kitty’s diagnosis, but I had to tell her that it was too late. I told her that I would like to sit quietly with Robert and hold his hand. His days as a scientist were over. It was too late to cure his anguish with equations.