Oppenheimer, J. Robert

views updated May 23 2018


(b. New York, N.Y., 22 April 1904; d. Princeton, New Jersey, 18 February 1967)

theoretical physics.

Robert Oppenheimer achieved great distinction in four very different ways: through his personal research, as a teacher, as director of Los Alamos, and as the elder statesman of postwar physics. These different activities belong to different periods, except that his role as teacher overlaps in time with several of these periods. We may therefore review these different contributions separately, while following a chronological order.

J. Robert Oppenheimer was the son of Julius Oppenheimer, who had immigrated as a young man from Germany.1 The fither was a successful businessman, and the family was well-to-do. His mother, the former Ella Freedman, was a painter of near professional standard, and both parents had taste for art and music.

As a boy Oppenheimer showed a wide curiosity and the ability to learn quickly. He went to the Ethical Culture School in New York, a school with high academic standards and liberal ideas. He went as a student to Harvard in 1922, and in spite of following a very broad curriculum, which included classical languages as well as chemistry and physics, he completed the four-year undergraduate course in three years and graduated summa cum laude in 1925.

With all the breadth of his interests, Oppenheimer was quite clear that his own subject was physics. During his undergraduate course he profited much from the contact with Percy Bridgman, an eminent physicist who himself had wide-ranging interests and whose publications dealt with topics far beyond the field of his own experiments; they included philosophical questions.

After graduating, Oppenheimer went to Europe; and during his four years of travel he established himself as a theoretical physicist.

Research in Quantum Mechanics. The year 1925 marked the beginning of an exhilarating period in theoretical physics. During that year Heisenberg’s first paper on the new quantum mechanics appeared, and Dirac started to develop his own version of Heisenberg’s theory in a paper which appeared in the same year. Schrödinger’s first paper on his wave equation was published early in 1926. Up to that time the principles of the quantum theory had been grafted onto the classical equations of mechanics, with which they were not consistent. The resulting rules sometimes gave unique predictions which agreed with observation; sometimes the answers were ambiguous; and sometimes the rules could not be applied at all. The new ideas showed the way of obtaining a logically consistent and mathematically clear description, and it looked as if all the old paradoxes of atomic theory would resolve themselves.

This started a period of intense activity, during which all atomic phenomena had to be reexamined in the light of the new ideas. Oppenheimer’s quickness in grasping new ideas helped him to play a part in this process. His first paper was submitted for publication in May 1926, less than four years from his entering Harvard and less than a year after Heisenherg’s first paper on quantum mechanics.2 It shows him in full command of the new methods, with which he showed that the frequencies and intensities of molecular band spectra could be obtained unambiguously from the new mechanics. A second paper, submitted in July, is concerned with the hydrogen atom;3 by this time he was making use of the full apparatus of matrix mechanics developed by Born. Heisenherg, and F. P. Jordan, of the alternative techniques of Dirac, and of Schrödinger’s wave mechanics. These two papers were written in Cambridge, and he acknowledged help from Ralph H. Fowler and Paul Dirac.

In the second paper Oppenheimer raises the question of the continuous spectrum and discusses the question of how to formulate the normalization of the wave functions for that case. This was the beginning of his interest in a range of problems which were to occupy him for some time.

In 1926 Max horn invited Oppenheimer to come to Göttingen, where he continued his work on transitions in the continuous spectrum, leading to his first calculations of the emission of X rays. He also developed, jointly with Born, the method for handling the electronic, vibrational, and rotational degrees of freedom of molecules, now one of the classical parts of quantum theory, referred to as the “Born-Oppenheimer method.”4 He obtained his Ph.D. degree in the spring of 1927.

Oppenheimer remained in Europe until 1929, spending some time with Paul Ehrenfest in Leiden and with Wolfgang Pauli in Zurich; the influence of both these men helped further to deepen his understanding of the subject. He continued with the work on radiative effects in the continuous spectrum. which he recognized as one of the important and difficult problems of the time, and found ways of improving the approximations used, which still serve as a pattern for work in this field. Among his minor papers, one deals with electron pickup by ions, a problem which requires the use of nonorthogonal wave functions.5

In 1929 Oppenheimer accepted academic positions both at the University of California, Berkeley, and at the California Institute of Technology; and between 1929 and 1942 he divided his time between these two institutions. The list of his papers during this period might almost serve as a guide to what was important in physics at that time. He was now at the top of his form in research work, and he knew what was important, so that he did not waste his time on pedantic detail. In some of these papers Oppenheimer struggled with key problems which were not yet ripe for solution, such as the difficulties of the electromagnetic self-energy, or the paradox of the “wrong” statistics of the nitrogen nucleus (wrong because, before the discovery of the neutron, nuclei were believed to consist of protons and electrons).6 But on others he was able to take important steps forward. He saw the importance of Dirac’s idea to avoid the difficulty of negative energy states for electrons by assuming them all filled except for a few holes, which were then positively charged particles. He showed, however, that Dirac could not be right in identifying these as protons, since they would have to have the same mass as electrons.7 Thus he practically predicted the positron three years before its discovery by Carl Anderson.

When cosmic-ray experiments showed serious contradiction with theory, Oppenheimer studied the possibility that this might indicate a breakdown of the accepted quantum theory of radiation.8 When the discovery of the meson resolved the paradox, he took great interest in the properties of the new particle. He also developed, in a paper with J. F. Carlson, an elegant method for investigating electron-photon showers in cosmic rays.9 In the 1930’s the cyclotron and other accelerators opened up the atomic nucleus to serious study, and Oppenheimer participated in asking important questions and in answering some of them. His paper with G. Volkoff shows a very early interest in stars with massive neutron cores.10

During the California period Oppenheimer proved to be an outstanding teacher of theoretical physics. He attracted many pupils, both graduate students and more senior collaborators, many of whom, under his inspiration, became first-rate scholars. His important qualities as a teacher were those which characterized his research: his flair for the key question, his quick understanding, and his readiness to admit ignorance and to invite others to share his struggle for the answer. His influence on his pupils was enhanced by his perceptive interest in people and by his habit of informal and charming hospitality. After his marriage in 1940 his wife, the former Katherine Harrison, helped maintain this easy and warm hospitality.

Oppenheimer still maintained a great breadth of interests, adding even Sanskrit to the languages he could, and did, read. At first his interests were exclusively academic: and he showed little interest in political questions, or in the national and world events of the day. But in the mid-1930’s he became acutely aware of the disturbing state of the world—unemployment at home, Hitler, Mussolini, and the Spanish Civil War in Europe. He became interested in politics and, like many liberal intellectuals of the day, became for a time involved with the ideas of left-wing groups.

The list of publications by Oppenheimer and his group shows a break in 1941, and this marks almost the end of his personal research (the exception being three papers published after the war) but by no means of his influence on the development of physics.

Atomic Energy: Los Alamos . The change was the result of Oppenheimer’s involvement with atomic energy. After the discovery of fission he, like many others, had started thinking about the possibility of the practical release of nuclear energy. With his quick perception he was aware of the importance of fast neutrons for any possible bomb. In 1940 and 1941 the idea of releasing nuclear energy was beginning to be taken seriously. A number of groups in different universities were working on the feasibility of a nuclear reactor, and others on methods for separating uranium isotopes. The latter would ultimately lead to the production of the light isotope (U235) in nearly pure form, and this is capable of sustaining a chain reaction with last neutrons. The reactor work led to the production of plutonium, which can be used for the same purpose. While these efforts were well under way by the beginning of 1942, there was no coordinated work on the design of an atomic weapon, its critical size, methods of detonating it, and so on. Oppenheimer had attended some meetings at which such matters were discussed, and early in 1942 he was asked to take charge of the work on fast neutrons and on the problem of the atomic bomb.

On the theoretical side Oppenheimer assembled at Berkeley a conference of first-rate theoreticians, including Edward Teller, who on that occasion first suggested the possibility of a thermonuclear explosion. The work continued in a theoretical group led by Oppenheimer at Berkeley. The experimental determination of the relevant nuclear data was divided between a large number of small nuclear physics laboratories; this hampered progress, since it was difficult for these groups to maintain adequate contact, particularly in view of the secrecy with which the whole project had to he treated.

When, therefore, the United States government brought the atomic energy work under the auspices of the army and put Colonel (later General) Leslie Groves in charge of the project under the code name “Manhattan District,” Oppenheimer suggested to Groves that the weapon development be concentrated in a single laboratory. This should include the theory and the nuclear physics work as well as the chemical, metallurgical, and ordnance aspects of the project. In this way the different groups could work together effectively.

Groves accepted the proposal, and on Oppenheimer’s advice chose the site of a boys’ boarding school at Los Alamos, New Mexico, a region Oppenheimer knew and loved—he had a ranch there. The remoteness of the site made access and transport problems difficult but seemed to have an advantage in reducing contacts with the outside—and therefore the risk of leakage of information.

Groves not only followed Oppenheimer’s advice in the creation and location of the laboratory, but he selected Oppenheimer as its director. This was a bold decision, since Oppenheimer was a theoretician with no experience of administration or of organizing experimental work. Events proved Groves right, and the work of the laboratory was extremely effective. In the view of most of the wartime members of Los Alamos, its success owed much to Oppenheimer’s leadership.

He attracted a strong team of first-rate scientists, who came because of their respect for Oppenheimer as a scientist and because of his evident sense of purpose. Inside the laboratory he was able to maintain completely free exchange of information between its scientific members; in other words, in exchange for the isolation of the laboratory and the restrictions on travel which its members had to accept, there was none of the “compartmentalization” favored in other atomic energy laboratories for the sake of security. Oppenheimer was able to delegate responsibility and to make people feel they were being trusted. At the same time his quick perception enabled him to remain in touch with all phases of the work. When there were major problems or major decisions to be taken, he guided the discussions of the people concerned in the same spirit of a joint search for the answer in which he had guided the discussions with his students. In the work he did not spare himself, and in response he obtained a sustained effort from all his staff.

It seems that the laboratory was set up just in time, because when the design of the plutonium bomb was ready, enough plutonium was available for the first bomb, The plutonium bomb required a greater design and development effort than the uranium bomb, since the more intense neutron background required a much more rapid assembly from subcritical conditions to the final, highly critical configuration. Failing this, a stray neutron is likely to set off the chain reaction when the assembly is only just critical, giving an explosion of very poor efficiency.

When the test of the first bomb at Alamogordo demonstrated the power of the new weapon, all spectators felt a terrified awe of the new power, mixed with pride and satisfaction at the success of their endeavors. Initially some were more conscious of the one emotion, some of the other. Oppenheimer, whose attitude to his own faults was as unmerciful as to those of others, if not more so, admitted later that he could not resist feeling satisfaction with the key part he had played in the work. Many accounts have quoted the verses from his Sanskrit studies of the Bhagavad-Gita which went through his mind at the time of the test, the first referring to the “radiance of a thousand suns” and the other saying, “I am become Death, the destroyer of worlds.” Besides the awareness of the technical achievement, Oppenheimer clearly did not lose sight of the seriousness of the implications.

None of this was public knowledge until 6 August 1945, when the first uranium bomb was dropped on Hiroshima. The implications of the decision to use the bomb to destroy a city will continue to occupy historians for a long time. Oppenheimer played some part in this decision: he was one of a panel of four scientists (the others being A. H. Compton, E. Fermi, and E. O. Lawrence) who were asked in May 1945 to discuss the case for the military use of the bomb on Japan. They were told that it would he impossible to cancel or delay the planned invasion of Japan, which was sure to be very costly in lives, unless Japan surrendered beforehand. Their opinion, which Oppenheimer supported, was that a demonstration on an uninhabited island would not he effective, and that the only way in which the atom bomb could be used to end the war was by actual use on a “military” target in a populated area. Today, in retrospect, many people, including many scientists, deplore this advice and the use of the bomb. Oppenheimer commented in 1962: “I believe there was very little deliberation ... The actual military plans at that time… were clearly much more terrible in every way and for everyone concerned than the use of the bomb. Nevertheless, my own feeling is that if the bombs were to he used there could have been more effective warning and much less wanton killing.…”11 lie remained for the rest of his life acutely conscious of the responsibility he bore for his part in developing the weapon and in the decision to use it.

The Aftermath of the Bomb: Princeton . At the end of 1945 Oppenheimer returned to California. This did not mean, however, returning to an ivory tower. He was by now a national figure, and his advice much in demand; he was also very seriously concerned with the issues raised by the invention of atomic weapons. He took part in the drafting of the “AchesonLilienthal Report,” which proposed the international control of atomic energy. Most of the language of this report is undoubtedly Oppenheimer’s and so, probably, are many of its ideas. The authors of this report wrote it in a generous spirit: international control of the new weapons would be used to ensure peace and to prevent any nation’s threatening another with the formidable new weapons. It probably never had much chance of becoming a political reality. A proposal embodying the outline of the report, but hardly its spirit, was presented to the United Nations by Bernard Baruch as the “Baruch Plan,” but nothing came of it.

In 1946 the Atomic Energy Commission was set up under the McMahon Act, which provided for civilian control of atomic energy. The first proposal, the May-Johnson Bill, which would have led to military control, was defeated very largely because of the opposition from scientists, although Oppenheimer was prepared to accept it. The commission appointed a General Advisory Committee, with Oppenheimer as chairman; and he served in that capacity until 1952. The committee did more than give technical advice; it had great influence on the policy of the commission. Oppenheimer’s role as chairman was not to dominate opinion but to clarify the issues and to formulate people’s thoughts. In addition to the General Advisory Committee, he served on numerous other committees concerned with policy questions relating to atomic weapons and defense.

In October 1947, Oppenheimer moved to Princeton, New Jersey, to become director of the Institute for Advanced Study. Until then the Institute had been a kind of retreat for great scientists and scholars who wanted to get on with their studies in peace. Under Oppenheimer’s regime the population of the Institute grew in number, and it included many young scientists, mostly as short-term members for a year or two. They included many visitors from other countries. Oppenheimer was an active member of the physics department and usually presided at seminar meetings.

Under Oppenheimer’s influence the physics group became one of the centers at which the current problems of modern physics were most clearly understood. Many colleagues came to discuss their ideas with Oppenheimer, and to do so meant exposing one’s thoughts to penetrating scrutiny and sometimes to withering criticism. Oppenheimer now had less time for physics than in the prewar days, and he had to form his judgments more rapidly. He was fallible, and there were occasions when he violently and effectively attacked some unfortunate speaker whose ideas were perhaps not proved hut were worth debating: there were other instances when he hailed as very promising ideas which later proved barren.

The early Princeton years were a time when there was again a buoyant optimism in physics. The theory of electrons and their electromagnetic field had been stagnant for many years because of the infinities predicted by quantum theory for the field energy of a point charge. The discovery of the “Lamb shift” in the hydrogen spectrum showed that there were some questions to which theoretical answers were needed, and the attempts to find the answers showed how one could bypass the troublesome infinities. S. Tomonaga, J. Schwinger. R. P. Feynman, and F. J. Dyson developed consistent formulations for the new form of the theory, and it was hoped that they could be extended to the proton and neutron and their interactions with the newly discovered meson field. It was a time of intense debte and discussion, and much of this took place at small ad hoc meetings of theoreticians, at which Oppenheimer was at his best in guiding discussion and in helping people to understand each other (and sometimes themselves). The phrase he used in an interview to describe the work at the Institute, “What we do not know we try to explain to each other,“ is very appropriate for these sessions. He had always had a remarkable gift for finding the right phrase, and he had now become an absolute master of the epigram.

While he did not resume personal research on any substantial scale (he was coauthor of three papers on physics after the war, one of them being a criticism of somebody else’s theory), Oppenheimer’s participation in meetings at the Institute and elsewhere was still a major factor in the development of ideas in physics.

As director of the institute, Oppenheimer was responsible also for the policy in other fields, including pure mathematics and history. Here the breadth of his knowledge was a unique qualification, lie did not, of course, take part in the work of the other groups as he did in physics, hut he could understand what was being done and could comment in a manner respected by the experts.

Throughout the postwar period Oppenheimer wrote and lectured much. At first the subject was predominantly atomic energy and its implications, and the scheme for its international control. Later he became more concerned with the relations between the scientist and society and, from this, with the problem of conveying an adequate understanding of science to the layman. In his Reith lectures on the B.B.C., “Science and the Common Understanding,” he attempted to set out what science is about.12 The language of such lectures was probably not easily followed in detail by the nonscientist, hut it had a poetic quality which to many listeners brought the subject closer.

The “Oppenheimer Case.” In December 1953, Oppenheimer was informed that his security clearance—that is, his access to secret information—was being withdrawn, because of accusations that his loyalty was in doubt. He exerted his right to ask for hearings, and he was exposed to the grueling experience of over three weeks’ quasi-judicial hearings, in which all his past was exposed to detailed scrutiny. The charges were in part his opposition in 1949 to a crash program for developing the hydrogen bomb, and in part his contacts or associations in the late 1930’s and early 1940’s with Communists and fellow travelers, contacts which had been known to the A.E.C. many years before and had then not been considered sufficiently derogatory to impede his clearance.

It is impossible to understand how these charges could he raised without remembering the atmosphere of hysterical fear of Communism of the Joseph McCarthy era and also without noting that Oppenheimer had made many enemies, who were delighted at this opportunity of curbing his influence. Some of these enemies were people he had bested in public debate, whom his devastating logic had not only shown to be wrong but also made to appear ridiculous. Others were people interested in military policy who feared his influence, which could act contrary to their interests.

The hearings before the three-man Personnel Security Board were originally intended to be confidential, but eventually the transcript was published.13 It remains an interesting historical document. The board found that Oppenheimer was “a loyal citizen” but, by a two-to-one majority, that he was to blame for opposing the hydrogen-bomb program and later was lacking in enthusiasm for it.

The report of the board went to the Atomic Energy Commission. The commissioners did not uphold the board’s (majority) decision censuring Oppenheimer for his views on the hydrogen bomb—this would have caused a powerful reaction in the scientific community—but confirmed the withdrawal of his clearance, in a majority verdict, mainly on grounds of “defects of character.” This was opposed by one of the commissioners, the physicist Henry Smyth, who wrote a minority report in favor of Oppenheimer and criticizing the arguments of his colleagues.14

Oppenheimer continued as director of the Institute and with his writing and lecturing. On many occasions audiences at his lectures gave him ovations clearly intended to express their sympathy for him and their indignation at the treatment he had received.

In 1963, when the McCarthy era was an embarrassing memory, when many of the people who had conducted the Oppenheimer investigation and made decisions had been succeeded by others, and when tempers had cooled, it was decided to make a gesture of reconciliation. Oppenheimer was given the Enrico Fermi Award for 1963, a prize of high prestige awarded by the Atomic Energy Commission. The award is usually conferred by the president, and John F. Kennedy had the intention of doing so when he was assassinated. It was then conferred by Lyndon Johnson, and Oppenheimer acknowledged it with the words he had intended to say to President Kennedy: “I think it is just possible... that it has taken some charity and some courage for you to make this award today.”

Oppenheimer knew for almost a year that he had throat cancer, and he could contemplate this fact and talk about it as lucidly as about a conclusion in physics.


1. There has been controversy whether in “J. Robert” the “J” stood for “’Julius,” P. M. Stern (footnote at the beginning of ch. 2 of the book cited in the bibliography) quotes evidence that this was the case. We use the style Oppenheimer used, with the explanation that the letter J “stood for nothing”.

2. Oppenheimer, “On the Quantum Theory of Vibration-Rotation Bands’ in Proceedings of the Cambridge Philosophical Society, 23 (1926), 327-335.

3. Oppenheimer, “On the Quantum Theory of the Problem of the Two Bodies,” ibid., 422-431.

4. Max Born and Oppenheimer, “Zur Quantentheorie der Molekeln” in Annalen der Physik, 4th ser., 84 (1927), 457-484.

5. Oppenheimer, “On the Quantum Theory of the Capture of I Electrons” in Physical Review,31 (1928), 349-356.

6. Oppenheimer, “Note on the Theory of the Interaction of Field and Matter,” ibid.. 35 (1930), 461-477; P. Ehrenfest and Oppenheimer, “Note on the Statistics of Nuclei” ibid., 37 (1931), 333-338.

7. Oppenheimer, “On the Theory of Electrons and Protons” ibid., 35 (1930). 562-563.

8. Oppenheimer, “Are the Formulas for the Absorption of High Energy Radiation Valid?“ ibid., 47 (1935), 44-52.

9. Oppenheimer and J. F. Carlson, “On Multiplicative Showers,” ibid, 51 (1937), 220-231.

10. Oppenheimer and G. Volkolf, “On Massive Neutron Cores” ibid., 55 (1937), 374-381.

11. Oppenheimer,The Flying Trapeze, the Whidden lectures for 1962 (London, 1964), pp. 59-60.

12. Oppenheimer, Science and the Common Understanding, Reith lectures, British Broadcasting Corporation, Nov. 1953 (New York, 1953; London, 1954).

13. United States Atomic Energy Commission, In the Matter of J. Robert Oppenheimer. Transcript of Hearings Before the Personnel Security Board(Washington, D.C., 1954).

14. United States Atomic Energy Commission, In the Matter of J. Robert Oppenheimer. Text of Principal Documents (Washington, D.C., 1954).


I Original Works. A full list of Oppenheimer’s writings can be found in the article by H. A. Bethe, in Biographical Memoirs of Fellows of the Royal Society, 14 (1968), 391-416.

II. Secondary Literature. There is as yet no booklength biography of Oppenheimer. Among his obituary notices the most important are the one by Bethe, cited above, and the record of speeches at a memorial meeting by R. Serber, V. F. Weisskopf, A. Pais, and G. T. Seaborg, inPhysics Today, 20 , no. 10 (Oct. 1967), 34-53. The dual biography by Nuel Pharr Davis, Lawrence and Oppenheimer (New York, 1968), has been strongly criticized by many reviewers—for instance, F. Oppenheimer, in Physics Today, 22 , no. 2 (Feb. 1969), 77-80.

Numerous books are primarily concerned with the “Oppenheimer case“ but bring in much biographical material. The most scholarly of these is P. M. Stern, The Oppenheimer Case; Security on Trial (New York, 1969). In addition there are C. P. Curtis, The Oppenheimer Case. The Trial of a Security System (New York, 1955); and J. Major, The Oppenheimer Hearing (London, 1971). H. Chevalier, Oppenheimer, The Story of a Friendship (New York, 1965), criticizes Oppenheimer for his conduct when questioned on security; it also contains many interesting facets of Oppenheimer’s life at Berkeley.

There is also a considerable literature on the history of the Manhattan Project, including Oppenheimer’s part in it. The official record is A History of the United States Atomic Energy Commission, 1, R. G. Hewlett and D. E. Anderson, Jr., The New World (University Park, Pa., 1962), II, R. G. Hewlett and F. Duncan, Atomic Shield (University Park, Pa., 1969). Other examples are Leslie R. Groves, Now It Can Be To Id (New York, 1962); Lewis L. Strauss, Men and Decisions (New York, 1962); D. E. Lilienthal, Journals, II, The Atomic Energy Years 1945-1950 (New York, 1964), and III, The Venturesome Years 1950-1955 (New York, 1966); and L. Givoanetti and F. Freed, The Decision to Drop the Bomb (New York, 1965).

Rudolf Peierls

Oppenheimer, J. Robert

views updated Jun 27 2018

J. Robert Oppenheimer

Born August 22, 1904
New York, New York
Died February 18, 1967
Princeton, New Jersey

Physicist and developer of the
U.S. atomic bomb

A t 5:30 a.m. on July 16, 1945, the United States successfully detonated the world's first atomic bomb. The scientist in charge of the U.S. project to develop the bomb was J. Robert Oppenheimer. A brilliant physicist, Oppenheimer watched in amazement as the New Mexico sky and landscape lit up brighter than a hundred sunrises. That moment marked the dawning of the nuclear age. Nuclear weapons developed and manufactured for decades thereafter influenced Cold War (1945–91) politics more than any other single issue after 1945. Oppenheimer's part in the Cold War would be a push for arms control and turning nuclear power into a benefit for mankind.

The Cold War was a prolonged conflict for world dominance between the two superpowers, the democratic, capitalist United States and the communist Soviet Union. Communism was a political and economic system, in which the Communist Party controlled all aspects of citizens' lives, as well as all economic policies. Private ownership of property was banned. Communism was not compatible with America's democratic way of life. The Cold War was a war of mutual fear and distrust. The scorecard was kept by the number of nuclear weapons each superpower possessed and had pointed at the other.

Young Oppenheimer

On August 22, 1904, J. Robert Oppenheimer was born to Julius and Ella Oppenheimer at their home on West Ninety-fourth Street in New York City. Many surmised the "J" in Oppenheimer's name stood for Julius, but apparently it was simply a "J," tying him to his father without making him a "junior." A partner in a fabric importing business, Oppenheimer's father immigrated to America from Germany in 1888 at the age of seventeen. He reportedly thrived on intellectual challenges concerning many topics, such as philosophy, religious freedom, and the art world. Oppenheimer's mother, an artist with German heritage from Baltimore, Maryland, gave her son her enthusiasm and her time—reading with him and listening to his thoughts.

Just before Oppenheimer's brother Frank was born in 1912, the family moved to a spacious upscale apartment over-looking the city and the Hudson River. The family lived comfortably, had a summer house on Long Island, took trips to Europe, and sent the boys to the private Ethical Culture School through high school. The Oppenheimers were of Jewish descent but were not members of a temple. Instead, they belonged to the Society for Ethical Culture, which was based on ethics, not religion, and undertook social reform campaigns.

As a child, Oppenheimer received from his grandfather in Germany a small mineral collection. Young Robert was fascinated with the rocks, their crystalline structure, and avidly added to the collection throughout his teen years. He became the youngest member ever of the New York Mineralogical Club, where he delivered a paper at the age of twelve. Oppenheimer, shy and awkward among his peers, was clearly brilliant in the classroom. Before long, his parents suspected he was a genius. He could easily identify obscure pieces of classical music, had a keen interest in scientific subjects, and could learn foreign languages with ease. Both parents created a home environment where the young Oppenheimer's independence and intellectual talent was nurtured.

Two teachers at his Ethical Culture High School had a lifelong influence on Oppenheimer. The first was Herbert Smith, who had just completed a master's degree in English at Harvard when he came to the school. Oppenheimer was in Smith's homeroom all four years, and they developed a lasting friendship. The second was Augustus Klock, a highly skilled physics and chemistry teacher. In the book Robert Oppenheimer, Letters and Reflections, Oppenheimer explained that he first took physics and the next year chemistry from Klock, and he felt "a great sense of indebtedness to him … he was a remarkably good teacher." Francis Ferguson, a student from New Mexico, entered Smith's homeroom his senior year and also became another lifelong friend of Oppenheimer's.

Graduating from Ethical Culture in 1921, both Oppenheimer and Ferguson expected to attend Harvard University that fall. However, Oppenheimer, on a family trip to Europe, became very ill and had to spend the 1921–22 school year recuperating. Doctors advised that Oppenheimer be removed from the cold, damp winter in New York. His parents asked Smith to accompany Oppenheimer on a trip to New Mexico—to the Page Dude ranch near Cowles, and to visit with Ferguson and his family in Albuquerque.

The New Mexico high country of western mountains and plateaus enthralled Oppenheimer. He became an expert horseman, exploring the Sangre de Cristo Mountains region northeast of Santa Fe. During these explorations, Oppenheimer first came upon the Pajarito Plateau and the boys school, Los Alamos Ranch School. Twenty years later, this would be the site recommended by Oppenheimer for the laboratory of the Manhattan Project, the U.S. wartime project to build an atomic bomb.

Harvard, September 1922 to June 1925

In September 1922, Oppenheimer entered Harvard, where he thrived. Years later, he looked back to say how exciting his Harvard years were, how much he loved the unlimited opportunity to learn. Having taken advanced studies at Ethical Culture High School, he entered Harvard as a sophomore. During his second year, he took seven required classes, several electives, and still found spare time to read classics and literature from around the world. He also developed a sense of humor and a bit of a social life. He majored in chemistry, but his passion soon became physics, figuring out concepts and equations before professors finished presenting problems. Oppenheimer graduated summa cum laude (with highest honors) in June 1925 at the age of twenty-one.

Cambridge and Göttingen

In September 1925, Oppenheimer entered Cambridge University to study at the prominent Cavendish Laboratory, where many of the world's most forward-thinking physicists researched. There, Oppenheimer was immersed in the "new" physics—the theory of relativity from Albert Einstein (1879–1955) and the quantum theory, to which Oppenheimer would make significant contributions. In September 1927, Oppenheimer continued his graduate study in Germany at the University of Göttingen. On May 11, 1927, Oppenheimer took and passed all his oral exams for his doctorate degree. Oppenheimer had completed his Ph.D. only two years after leaving Harvard.

Oppenheimer returned to the United States near the end of the summer of 1927. Due to his outstanding reputation in Europe, he was soon offered teaching positions at about ten of America's finest universities. He spent part of the 1927–28 school year at Harvard and part at the California Institute of Technology, known as Cal Tech, in Pasadena. Then, in the fall of 1928, he returned for one more time to study and work with physicists in Europe, first at the University of Leiden in the Netherlands, then in Zurich, Switzerland. Between 1926 and 1929, Oppenheimer authored sixteen papers on quantum theory.

Research, teaching, and marriage

From fall 1929 to 1942, Oppenheimer's days were spent teaching and researching at both the University of California at Berkeley and Cal Tech in Pasadena. For Oppenheimer, the social upheavals of the 1930s—involving the stock market crash and the Great Depression (1929–41), the worst financial crisis in American history—had little meaning. He remained immersed in his research and teaching, conveying to his students the new physics and the beauty of its patterns. However, a sad time for Oppenheimer came in 1931, when his mother died, then his father in 1937.

By 1937, Oppenheimer finally awakened to the social hardships and unrest caused by the economic woes of the Depression. Some of his students had no money to continue in school. Others could find no work upon graduation. Oppenheimer became interested in communism, as did many American intellectuals of the time. To many young intellectuals, it seemed to be a perfectly logical way to organize society and solve social problems. However, Oppenheimer had nagging suspicions that were confirmed in 1938, when he met three physicists who had just returned from Russia. They all reported a suffering society that endured murder and terror at the hands of Soviet dictator Joseph Stalin (1879–1953; see entry). As a result, Oppenheimer completely turned his back on communist thought.

In 1938, word came that German scientists had successfully carried out nuclear fission, the splitting of an atom. Oppenheimer's mind began to race even faster than usual. The lab at Berkeley, where Oppenheimer headed up the staff, was known as the University of California Radiation Laboratory. Immediately, tests were set up to check the validity of the German experiments. Fears abounded that Germany would use the knowledge to build an atomic bomb, enabling them to hold the rest of the world hostage under threat of its use.

Meanwhile, Oppenheimer's brother Frank had married in 1937 and was scheduled to receive his doctorate in physics in the summer of 1939 at Cal Tech. Oppenheimer went to Pasadena for the occasion. There, he met Katherine (Kitty) Puening Harrison. The two were married in late 1940 and had their first child, Peter, on May 12, 1941. In August 1941, the Oppenheimers bought a home in Berkeley and settled there. They would have a daughter, Katherine (called Toni), in 1944 and would be married for twenty-seven years until Oppenheimer's death.

The Manhattan Project

On December 7, 1941, the Japanese bombed Pearl Harbor in Hawaii, and the United States entered World War II (1939–45). Earlier in 1941, the National Academy of Sciences had proposed an all-out effort to build an atomic bomb before the Germans did. No one realized that the Germans, wrapped up in the war in Europe, had halted all work toward the bomb. U.S. efforts centered at the University of Chicago's Metallurgical Laboratory with Enrico Fermi (1901–1954) as principal investigator; at the University of California at Berkeley's Radiation Laboratory, where Oppenheimer researched; and at Columbia University's physics department. Fermi, a Nobel Prize–winning Italian physicist, had fled his native country a few years earlier.

Beginning in 1942, General Leslie R. Groves (1896–1970), who was in charge of carrying out the atomic bomb project, established two large engineering production centers at remote sites for manufacture of material needed to make atomic bombs: the Clinton Engineer Works in Oak Ridge, Tennessee (siteZ), and the Hanford Engineer Works in eastern Washington State (site W), near the town of Richland. By mid-1942, research on the bomb project occurred at several universities across the country. Oppenheimer realized that one central site was needed to bring scientists together to design a bomb using material being manufactured at Oak Ridge and Hanford. Oppenheimer suggested to Groves that a site might be located in a remote area of New Mexico. They chose a site 100 miles (160 kilometers) north of Albuquerque that was once the Los Alamos Ranch School that Oppenheimer had visited on horseback as a teenager.

In November 1942, Groves selected Oppenheimer to be scientific director of the Manhattan Project at the new Los Alamos laboratory. Oppenheimer would lead his team of physicists to success in only two-and-a-half years. On Monday, July 16, 1945, the world's first atomic bomb was successfully detonated. The test's code name was Trinity (see box). One atomic bomb was dropped on Hiroshima, Japan, on August 6, and another on Nagasaki, Japan, on August 9. The Japanese surrendered, and World War II came to an end.

Oppenheimer became known as the "father of the atom bomb." It was a title he continually tried to correct by saying he was not the "father" but the director of the laboratory where the bomb was developed. In the book The Story of J. Robert Oppenheimer, Denise Royal reported that Oppenheimer had some misgivings about the accomplishment, stating, "I'm a little scared of what we built … [but] a scientist cannot hold back progress because he fears what the world will do with his discoveries."

A national figure

Oppenheimer resigned as director of the Los Alamos Laboratory in October 1945 and returned to university life at Cal Tech. A year later he resumed teaching at Berkeley. Oppenheimer soon realized he had become a national figure, and a quiet life of university teaching would not be possible. On January 12, 1946, President Harry S. Truman (1884–1972; served 1945–53; see entry) awarded Oppenheimer the "United States of America Medal of Merit" for his leadership on the Manhattan Project. Oppenheimer graciously accepted, but he had by that time devoted himself to seeing that atomic energy became an instrument of peace, for mankind's benefit. Correctly predicting that international control of the new atomic weapons technology would prove difficult, he dedicated the rest of his life to that goal.

In 1946, Oppenheimer played an active role developing the U.S. congressional report, the Acheson-Lilienthal Report, calling for an international authority to control all atomic energy research. Bernard Baruch (1870–1965), the U.S. representative to the United Nations (UN), delivered the report to the UN. The Soviets completely rejected the suggestions in the report because they were deeply involved in the development of their own atomic bomb. They feared that the United States would use its monopoly in atomic weapons to attempt to gain influence over the Soviet Union and the communist countries of Eastern Europe under Soviet control. The Soviets were not about to turn over their atomic research to international control before they caught up with the United States.

On August 29, 1949, the Soviets succeeded in detonating an atomic bomb. Atomic weapons became a focal point of the Cold War. The United States and the Soviet Union would continuously attempt to one-up the other in nuclear weaponry.

The H-bomb debate

Becoming a familiar person in Washington, D.C., from 1947 to 1953 Oppenheimer served on many goverment

committees, traveling to meeting after meeting. Most importantly, he began a six-year term on the General Advisory Committee (GAC) within the U.S. Atomic Energy Commission (AEC). AEC was the governmental agency in charge of the nation's nuclear program (the terms atomic and nuclear were used interchangeably, but nuclear soon became the more updated term). GAC was composed of prestigious scientists who had been with Oppenheimer at the Manhattan Project. Those scientists included Fermi, James B. Conant (1893–1978), and I. I. Rabi (1898–1998).

From the time Moscow tested its first atomic bomb in 1949, the national debate over arms control turned almost exclusively to whether or not to develop the thermonuclear or hydrogen bomb (H-bomb). The H-bomb was many times more powerful than the atomic bombs dropped on Japan. Its development had been considered at the start of the Manhattan Project, but too many technical problems pushed it to the background. The H-bomb was the special interest of physicist Edward Teller (1908–2003).

The highly influential GAC was asked to report on Hbomb debate. The report was delivered on October 30, 1949. Oppenheimer at that time was chairman of the GAC. Recognizing there was no nuclear arms control treaty on the horizon between the United States and the Soviet Union, the GAC called for intensified efforts to develop nuclear weapons for defensive purposes. They also recommended conducting further research in the thermonuclear process that involved nuclear fusion (combining nuclei of atoms), as opposed to nuclear fission (splitting nuclei) that had been used in the already developed atomic weapons. However, most importantly, the report opposed using the fusion process to develop a very powerful and destructive bomb. The GAC objected on moral grounds that its only use would be to exterminate civilians. Oppenheimer's stand against the H-bomb would not be forgotten.

Three of the five AEC commissioners agreed with the GAC report. Nevertheless, President Truman authorized development of the H-bomb in January 1950. Teller became the lead scientist. Technical problems were overcome, and the United States successfully tested its first H-bomb on November 1,1952. A year later, not to be left behind, the Soviets tested an H-bomb on August 12, 1953. Andrey Sakharov (1921–1989; see entry) was the chief developer of the Soviet H-bomb.

Oppenheimer caught in Red Scare

Oppenheimer had moved, in 1947, from California to Princeton, New Jersey, and become director of the Institute for Advanced Study. During Oppenheimer's service on the GAC and at the Institute, a communist scare, called the "Red Scare," was sweeping America. Influenced greatly by U.S. senator Joseph R. McCarthy (1908–1957; see entry) of Wisconsin, the government and American public began to see "red" everywhere. ("Red" was another word for communist.) Hundreds of innocent Americans were accused of being involved in communist plots to overthrow the U.S. democratic way of life.

Suddenly in early 1953, Lewis Strauss (1896–1974), chairman of the AEC, ordered the removal of classified documents from Oppenheimer's safe. Apparently, Strauss had been greatly angered by Oppenheimer's opposition to development of the H-bomb. Nothing more came of it until November, when J. Edgar Hoover (1895–1972; see entry), director of the Federal Bureau of Investigation (FBI), received a letter from William L. Borden, who had been secretary of the Joint Congressional Committee on Atomic Energy. In the letter, after pointing out the access Oppenheimer had to national security issues, Borden accused Oppenheimer of being a Soviet spy. Hoover drew up a report on Oppenheimer. Strauss then met with President Dwight D. Eisenhower (1890–1969; served 1953–61; see entry), who decided to withdraw Oppenheimer's security clearance. Oppenheimer met with Strauss on December 21, 1953, and looked over the twenty-four points against him. Amazingly, twenty-two dealt with his left-wing political associations back in the 1930s, one with his association with French physicist and friend Haakon Chevalier (1901–1985), and the twenty-fourth with his opposition to the H-bomb development.

The Red Scare, or communist witch-hunt, had reached all the way to the developer of America's atomic bomb. Hearings on the accusations against Oppenheimer were held in April and May 1954 before the AEC's Personnel Security Board. On June 29, 1954, Oppenheimer's security clearance was not renewed. Oppenheimer emerged from the hearings a changed man. His energy seemed drained, and as noted by former students and fellow scientists who visited him back at the Institute, he appeared old and frail, even though he was just fifty years old.

Oppenheimer was strongly backed by the scientific community and reappointed as director of the Institute. Strauss, who was on the Institute's board of directors, approved, saying security was not a problem in the job. However, in the minds of the American public, Oppenheimer appeared to have been a communist or a subversive, one who attempts to overthrow or undermine an established political system.


While maintaining his position at the Institute, Oppenheimer devoted the rest of his life to the advancement of physics, traveling, lecturing, and writing. In 1958, the French government awarded him the Legion d'honneur (Legion of Honor). He was invited to participate in the Organization of American States (OAS) Professorship Program and traveled to Mexico and South America in 1961. The OAS was an organization of Central and South American countries that sought to maintain political stability in the region by providing a means to resolve disputes. Oppenheimer continued to travel and lecture throughout the world. He spent the last thirteen years of his life speaking on the need for the people of the world to communicate and understand one another.

In the early 1960s, President John F. Kennedy (1917–1963; served 1961–63; see entry) invited Oppenheimer to the White House for a dinner honoring Nobel Prize winners. Some Americans saw this as a step toward an apology for the government's wrongdoing against Oppenheimer in 1954. Before Kennedy's assassination in November 1963, the president approved Oppenheimer for the AEC's Enrico Fermi Award, in honor of the late Italian-born physicist who had initiated the atomic age with his first controlled nuclear chain reaction at the University of Chicago in 1942. Oppenheimer and Fermi had worked together on the Manhattan Project. The award included a citation, gold medal, and $50,000. President LyndonB. Johnson (1908–1973; served 1963–69; see entry) presented the award to the fifty-nine-year-old Oppenheimer on December 2, 1963, in the White House Cabinet Room. Oppenheimer grasped his wife's hand as Johnson made the presentation, and in a thank you he acknowledged that it must have taken some courage for the president to make the award.

In 1964, Oppenheimer and his wife made a nostalgic trip back to Los Alamos. Returning to the Institute, Oppenheimer focused on the building and the development of a new library. A lifelong chain smoker, Oppenheimer was diagnosed with cancer of the larynx in March 1966. He retired from the directorship of the Institute in mid-1966 but in the fall served as senior professor of physics, a position Albert Einstein once held. He continued going to his office until just before he died on February 18, 1967.

For More Information


Isaacs, Jeremy, and Taylor Downing. Cold War: An Illustrated History, 1945–1991. Boston: Little, Brown and Company, 1998.

Michelmore, Peter. The Swift Years: The Robert Oppenheimer Story. New York: Dodd, Mead & Company, 1969.

Rabi, I. I., Robert Serber, Victor F. Weisskopf, Abraham Pais, and Glenn T. Seaborg. Oppenheimer. New York: Charles Scribner's Sons, 1969.

Royal, Denise. The Story of J. Robert Oppenheimer. New York: St. Martin's Press, 1969.

Smith, Alice K., and Charles Weiner, eds. Robert Oppenheimer: Letters and Recollections. Cambridge, MA: Harvard University Press, 1980.

Web Sites

Los Alamos National Laboratory.http://www.lanl.gov/worldview/ (accessed on July 18, 2003).

U.S. Department of Energy, Office of Scientific and Technical Information. "Historical Records of the Atomic Energy Commission." Open-Net.http://www.osti.gov/opennet/nsi_desc.html (accessed on September 13, 2003).


The location of the actual test site of the United States' first atomic bomb detonation was near the northwest corner of the Alamogordo Air Base in New Mexico. J. Robert Oppenheimer, scientific head of the bomb project, gave the code name "Trinity" to the test. The name came from one of his favorite poems by John Donne (1572–1631).

On Saturday, July 14, 1945, the "gadget," as the bomb was called, was placed at the top of a 100-foot (30.5-meter) steel tower, where it would be detonated. The test was set for 4:00 a.m. Monday morning, July 16. Thunder rumbled, and rain poured down Sunday night and in the early hours of Monday morning. Oppenheimer and General Leslie R. Groves, military head of the project, popped out of their dugout every few minutes to check the weather. The tension during those early hours was high. The weather finally began clearing by 4:00 a.m., and Trinity was a go for 5:30 a.m.

The moment before detonation, no one breathed. As noted on the Los Alamos National Laboratory Web site, Groves remembered he could only think what he would do if the count went to zero and nothing happened. But at exactly 5:29:45 a.m., the gadget exploded. The tension in Oppenheimer's face relaxed immediately. General Thomas Farrell, deputy to Groves, later wrote that the force of the gadget, equivalent to 21,000 tons (19,000 metric tons) of TNT, lit up the country "with the intensity many times that of midday sun.… It lighted every peak, crevasse, and ridge of the nearby mountain range with a clarity and beauty that cannot be described but must be imagined. Seconds after the explosion came first the air blast pressing hard against the people, to be followed almost immediately by the strong, sustained awesome roar that warned of doomsday and made us feel we puny things were blasphemous to dare tamper with the forces heretofore reserved for the Almighty." Oppenheimer quoted a line from the Bhagavad Gita, an ancient Hindu sacred text: "I am become Death, the destroyer of worlds."

World War II would be over in a few weeks. On August 6, 1945, the first atomic bomb, named "Little Boy," was dropped on Hiroshima, Japan. On August 9, 1945, the second atomic bomb, "Fat Man," was dropped on Nagasaki. Japan surrendered unconditionally on August 14, 1945.

For the Benefit of Mankind

Igor Kurchatov (1903–1960; see entry) successfully directed the Soviet atomic bomb project, holding the same position in the Soviet project as Oppenheimer had in the Manhattan Project. However, following detonation of the Soviet atomic bomb, Kurchatov, just like Oppenheimer, devoted the rest of his life to stressing the peaceful uses of the atom for the benefit of human society.

J. Robert Oppenheimer

views updated Jun 27 2018

Oppenheimer, J. Robert

Born April 22, 1904
New York, New York
Died February 18, 1967

Princeton, New Jersey
American physicist

J. Robert Oppenheimer's brilliant research in the field of quantum mechanics (the study of the energy of atomic particles) led to his selection as the director of the weapons laboratory at Los Alamos, New Mexico. There, scientists from all over the world worked secretly to develop a powerful atomic bomb that, it was hoped, would end World War II. Oppenheimer was known not only for the important role he played in the Manhattan Project, but also for his work as a researcher and teacher. After the war, he advised the government on how best to use nuclear energy and weapons.

A bright and curious boy

Oppenheimer was born into a wealthy, cultured family. His father, Julius Oppenheimer, had emigrated from Germany as a young man and had built a successful textile importing company. His mother, Ella Friedman, was a painter who loved art and music. The family lived in a large apartment in New York City, but spent their summers on nearby Long Island.

Oppenheimer's great intelligence and curiosity were obvious early in his life. By the time he was eleven he had put together a huge rock collection and became the youngest member ever admitted to the New York Mineralogical Society; at twelve, he presented a paper to the society. Oppenheimer attended the liberal, academically challenging Ethical Culture School in New York City. After graduating he went to Europe for the summer, but there he contracted dysentery (a severe intestinal illness) and had to spend the next year recovering.

A young star in the world of physics

In 1922, Oppenheimer entered Harvard University, where, he later said (as quoted in Current Biography) he "lived in the [library] stacks, just raided the place intellectually." He studied a wide range of subjects—including science and foreign languages—but he was most drawn to physics, and that became his major. Oppenheimer graduated summa cum laude (with highest honors) in only three years.

Oppenheimer graduated from college at a very exciting time in the field of physics, when many discoveries were being made. He decided to go to Europe to continue his study of theoretical physics. He started at the Cavendish Laboratory at Cambridge University in England. In his first paper as a graduate student, Oppenheimer explained aspects of the behavior of the molecule (the smallest part of a substance that has all the properties of that substance and is made up of one or more atoms). In 1926, Oppenheimer moved to the University of Göttingen in Germany, where he worked with a famous physicist, Max Born, to develop the "Born-Oppenheimer Theory" of molecular activity.

Oppenheimer earned his doctorate in 1927, and went on to conduct more research in Leiden, Holland, and Zurich, Switzerland. In Switzerland he worked closely with another famous scientist, Wolfgang Pauli. During these years of study, Oppenheimer showed how quickly he could grasp and analyze ideas and how well he could draw connections between theories and detect problems.

A popular, inspiring teacher

On his return from Europe, ten universities offered Oppenheimer teaching positions. In 1928 he accepted two of them, the University of California at Berkeley and the California Institute of Technology (Cal Tech) at Pasadena. For the next thirteen years he divided his time between these two schools, doing his own research as well as teaching. During this period he established Berkeley as a major American center for the study of quantum physics (the study of the energy of atomic particles).

Oppenheimer also gained a reputation as an excellent teacher. His classes moved at a rapid pace, as he stood at the blackboard with his ever-present cigarette in one hand and a piece of chalk in the other. He sparked many students' interest in theoretical physics, and some of them admired him so much that they imitated his mannerisms (such as his habit, developed during his time in Germany, of saying "Ja! Ja! Ja!" to encourage discussion) and followed him from one campus to another, sometimes repeating courses they'd already taken.

Although Oppenheimer continued to have a wide range of interests, including the other sciences, literature, and art, he lived a sheltered life (he had no telephone, did not read newspapers, and did not even vote) until the middle of the 1930s. Then some developments in the world, such as the hard economic times many people were experiencing and the rise of harsh dictators around the world, began to catch his notice. He became involved with several groups working for social reform, including some that had ties to the Communist Party. Oppenheimer, however, never became a Communist.

The world moves toward war

As World War II loomed, science made discoveries that would change the face of warfare. In 1934, Italian physicist Enrico Fermi had devised a way to bombard uranium (a radioactive metallic element) with neutrons (a particle from the nucleus or center of an atom) to create a reaction called nuclear fission. Many scientists believed that if a large enough amount of uranium—called a "critical mass"—could be used, a chain reaction would occur, instantly setting off a huge explosion of energy. Various physics laboratories were studying the possibility of using this reaction in a military weapon—an atomic bomb.

After the United States had entered World War II on December 7, 1941, Allied intelligence operations (spying activities of the countries fighting together against Germany, Japan, and Italy, including the United States, Great Britain, and the Soviet Union) learned that the Germans were also working on an atomic bomb. President Franklin D. Roosevelt (1882-1945; see entry) decided that the United States must immediately start its own atomic research program, which would be called the Manhattan Project.

The Manhattan Project takes off

Oppenheimer was recruited for the program not because he was particularly interested in it but because he was widely recognized as a brilliant, pioneering physicist. He took part in some of the first meetings to discuss the possible use of an atomic bomb, and in early 1942 he was asked to direct research on the bomb at Berkeley. Soon the government put the project under the control of the U.S. Army, and Colonel (later General) Leslie Groves was put in charge.

Development of the bomb took place at a number of laboratories in different places. Oppenheimer recommended that a single lab be set up, where scientists could work more closely and in secret. It was Groves who decided that Oppenheimer—despite his lack of administrative and management experience—should direct the lab; he told his doubtful colleagues, "we (are) not going to find a better man."

Oppenheimer suggested that the laboratory be built at Los Alamos, New Mexico, near an area where he had often vacationed. The area was geographically isolated and transportation was difficult, but this would help ensure the secrecy the project required. Oppenheimer supervised the construction of the huge complex (which, by the end of World War II, housed 5,000 workers) and the collection of equipment needed for research. He had to put together a team of leading scientists, all with different, sometimes difficult personalities, and get them to work together in harmony. And he had to convince them to bring their families to Los Alamos and stay until the war was over.

Oppenheimer accomplished all these things, establishing at Los Alamos an atmosphere of hard work and a free exchange of information. He also opened up his own home as an informal social center, where he and his wife, Katherine (whom he had married in 1940), often entertained the laboratory's scientists and staff.

Creating and testing an atomic bomb

The biggest problem the Los Alamos physicists had to solve was how to achieve critical mass—how to bring two pieces of uranium together quickly enough to create a chain reaction and produce an explosion. Another stumbling block was the length of time it took to refine uranium to the required purity; this process took place in two factories in Oak Ridge, Tennessee, and Hanford, Washington, but production was moving more slowly than expected.

By the summer of 1945, the technical problems had finally been resolved, and the atomic bomb was ready for testing. The test took place on July 16 on the Alamogordo Bombing Range. At 5:30 A.M. the bomb was detonated, setting off a flood of white light and a loud roaring noise, and causing a ball of fire to raise an immense cloud of sand and debris 40,000 feet into the air.

"The Shatterer of Worlds"

Watching the tremendous explosion from five miles away, Oppenheimer was reminded of two lines from the Bhagavad-Gita, the Hindu sacred text that he had read in its original Sanskrit (one of eight languages he could read). One line referred to the "radiance of a thousand suns," and the other said, "I am become death, the Shatterer of Worlds." Like others present at the test, Oppenheimer's feelings were a mixture of pride in the success of their efforts, terror at the bomb's immense destructive power, and anxiety about what it meant for the future.

By this time, Germany had already surrendered and the war in Europe was over. But it seemed that Japan, despite major losses and very bleak prospects, would continue no matter the odds. Oppenheimer met with three other scientists (Ernest Lawrence, Enrico Fermi, and Arthur Compton) to discuss whether the United States should use the atomic bomb against Japan. The only alternative to the bomb, the U.S. government asserted, was to invade Japan, which would cost many American lives. On the other hand, the bomb could be dropped on a military target but would undoubtedly kill many Japanese civilians.

Although Oppenheimer would later regret his decision (claiming that the killing of civilians could and should have been avoided), he and the other scientists recommended that the United States use the atomic bomb against Japan. The final decision was made by President Harry S. Truman (1884-1975; see entry), who gave the plan his approval.

On August 6, 1945, the first bomb, nicknamed "Little Boy," was dropped on Hiroshima. Instantly, the city was destroyed: from 78,000 to 80,000 people were killed and 60,000 buildings were demolished. Over the next weeks and months, thousands more people would die of the sickness caused by the radioactive particles released by the explosion. On August 9, a second bomb ("Fat Man") was dropped on Nagasaki, killing between 25,000 and 40,000 people that day and many more later, as radiation sickness again took its toll. Japan surrendered on August 14, ending World War II.

Advisor on atomic energy and weapons

The existence of the atomic bomb had been kept secret until the Hiroshima bombing. News of the bomb made Oppenheimer famous as the so-called "Father of the A-Bomb." secretary of war Henry Stimson claimed that "the development of the bomb has been largely due to his genius and the inspiration and leadership he has given to his associates." Yet Oppenheimer himself had very serious concerns about the bomb, and wanted to make sure it was properly controlled and used only to prevent wars.

After the war, Oppenheimer was asked to advise the government on how to control and manage atomic energy and weapons. In 1947 he was appointed to serve on the General Advisory Committee of the Atomic Energy Commission, which had been established the previous year when it was decided that atomic energy should be under civilian, rather than military, control. Oppenheimer served in this position until 1952.

Building a research center

In 1947, Oppenheimer became the director of the Institute for Advanced Study at Princeton University, overseeing its development into a first-rate physics research center. Under his leadership the institute's population grew, attracting many young scientists who enjoyed the lively atmosphere in which new ideas were discussed and tested. In describing the institute's work, Oppenheimer commented, "What we do not know we try to explain to each other."

During this period, Oppenheimer wrote and lectured on atomic energy, and also on the relationship between the scientist and society. His interest in how to make science understandable to those with little background in it was the topic of his 1954 book, Science and the Common Understanding.

Security clearance withdrawn

Despite the praise Oppenheimer received for his job as director of the Manhattan Project, he had made some enemies during his career. His opposition to the H-bomb (a much more powerful weapon than the atomic bomb that uses hydrogen instead of uranium or plutonium) had angered the scientists who backed it, especially its developer, Robert Teller. Oppenheimer believed the United States should focus not on building a bigger bomb but on arms treaties. The United States and the Soviet Union were, he said, like "two scorpions in a bottle, each capable of killing the other but only at the risk of its own life."

During the mid-1950s, anti-Communist (communism is the political system that features communal or group ownership of property) fever was sweeping the country. Senator Joseph McCarthy and others crusaded to rid the government of those they considered Communist sympathizers. In 1954, Oppenheimer was informed that his security clearance was being withdrawn. He asked for a hearing so that he could defend himself. At the three-week hearing, Oppenheimer's past connections with communist-related groups were brought up to discredit him, and his failure to support the H-bomb program was criticized. The final result was that even though he was undoubtedly a "loyal citizen," his security clearance would still be canceled.

The scientific community was outraged by what had happened to Oppenheimer, and they openly supported and praised him. Although he never again worked for the government, he continued his work at Princeton. In 1963, the Atomic Energy Commission gave Oppenheimer the important Enrico Fermi Award, which came with a $50,000 prize. Presented to him by President Johnson, the award was seen by many as the government's way of making amends with Oppenheimer. Four years later, he died of cancer at age sixty-two.

Where to Learn More


Driemen, J.E. Atomic Dawn: A Biography of Robert Oppenheimer. Minneapolis, MN: Dillon Press, 1989.

Goodchild, Peter. J. Robert Oppenheimer: Shatterer of Worlds. New York:Fromm International, 1985.

Kunetka, James W. Oppenheimer: The Years of Risk. Englewood Cliffs, NJ:Prentice-Hall, 1982.

Larsen, Rebecca. Oppenheimer and the Atomic Bomb. New York: Franklin Watts, 1988.


"Brotherhood of the Bomb: Two Flinty Physicists Struggle Over Their Terrifying Legacy." U.S. News & World Report Special Report: Masters of Discovery: The Great Inventions of the 20th Century (August 17, 1998): 64.

J. Robert Oppenheimer headed the Manhattan Project—the successful effort by a group of scientists to build the first atomic bomb, which would bring the war to a swift close when used against the Japanese.

A World-Famous Physicist Joins the Manhattan Project

One of the most famous scientists to take in the Manhattan Project was the Italian physicist Enrico Fermi, who had defected (to abandon one's country to become a citizen of a new country) to the United States after winning the Nobel Prize in 1938.

Born in Rome, Italy on September 29, 1901, Fermi grew into a talented, bright teenager who learned more about physics while he was still in high school than many university graduate students. He earned his Ph.D. in physics in Italy when he was only 21, then went on to study at the German universities of Göttingen and Leiden. In 1924 he came back to Italy and became a professor at the University of Florence.

While teaching in Florence, Fermi wrote an important paper about the actions of subatomic particles. Now recognized as a leader in physics, Fermi was named to the newly created chair of theoretical physics at the University of Rome, where he worked over the next six years with a number of leading physicists and brilliant students.

During the early 1930s, while studying the atomic nucleus, Fermi discovered a new kind of particle called a "neutrino" and a new kind of force called "weak force." Later he experimented with bombarding atoms in various chemical elements with neutrons, showing that this process could produce radioactive forms (unstable atoms that give off particles and energy). Later he discovered that if a uranium atom was bombarded with neutrons it would split, producing a reaction called nuclear fission that releases huge amounts of energy.

In 1938 Fermi was awarded the Nobel Prize for his work with neutron bombardment, and after accepting his award in Sweden he and his family didn't return to Italy but went to the United States. His own country's Fascist dictator Benito Mussolini (1883-1945; see entry) was an ally of Germany's dictator Adolf Hitler, who had begun harsh measures against Jews, and Fermi's wife was Jewish. Fermi now became a professor of physics at Columbia University in New York City.

In August 1939 President Franklin D. Roosevelt (1882-1945; see entry) received a letter from Hungarian-American physicist Leo Szilard and world-renowned physicist Albert Einstein warning that nuclear weapons (which would make use of the powerful energy released by nuclear fission) were going to be developed and used by Germany. Roosevelt's response was to set up the Manhattan Project so that American scientists could explore the possibility of making an atomic bomb.

Working in his lab under Columbia's squash courts on December 2, 1942, Fermi produced the world's first self-sustaining nuclear chain reaction. He continued his work on nuclear fission at a Chicago laboratory for two years, but in 1944 he and his wife (both new citizens of the United States) moved to Los Alamos, New Mexico, so that Fermi could join the scientists working under the direction of Robert Oppenheimer.

Fermi was put in charge of his own division, which was assigned to resolve any special problems that might arise as work on the first atomic bombs continued. The bombs were finally tested and dropped on Japan, effectively ending the war in Asia. Fermi returned to the University of Chicago, where he remained as a professor and researcher for the rest of his life. He received the Civilian Medal of Merit in 1946 for his work on the Manhattan Project. After his death in 1954, the U.S. Atomic Energy Commission named Fermi the first recipient of its Enrico Fermi Award.

Oppenheimer, J. Robert

views updated Jun 27 2018


(b. New York, New York, 22 April 1904; d. Princeton, New Jersey, 18 February 1967)

theoretical physics. For the original article on Oppenheimer see DSB, vol. 10.

The important aspects of Oppenheimer’s life were accurately and perceptively highlighted in Rudolf Peierls’s 1970 DSB entry. Since its writing, many of the details of Oppenheimer’s life have come into much sharper focus by virtue of the publication by Alice Kimball Smith and Charles Weiner of many of the letters he wrote before 1945 to his teachers, to his brother, and to his friends; and by virtue of the availability of his extensive Nachlass in the archives of the Library of Congress.

The detailed investigations and analyses by historians of the Ethical Culture Society and of its school; of the Sanskrit texts Oppenheimer studied and their canonical meaning; of the organizational structure of Los Alamos and of the technical work carried out there; of Oppenheimer’s directorship of Los Alamos, and later of the Institute for Advanced Study; of the details of his governmental advisory activities after World War II, by which time he had become a Cold Warrior; of the illegal behind-the-scene activities of J. Edgar Hoover and his Federal Bureau of Investigation (FBI), and the plotting of Lewis Strauss before the special Atomic Energy Commission (AEC) board was set up to inquire as to Oppenheimer’s suitability for a security clearance; of the machinations and illegal actions carried out by the prosecution during the “inquiry” that terminated with the revocation of his clearance in 1954; and of his subsequent activities as a public intellectual and an influential member of the Congress for Cultural Freedom, have resulted in a much more nuanced, context-dependent, and questioning portrait of the man.

Biographical Advances . Since 2000, five biographies have been published that have perceptively described all aspects of his life. All devote some chapters to a depiction of the familial, educational, social, and psychological circumstances that resulted in the precocious, brilliant, arrogant, emotionally immature, privileged Oppenheimer entering adulthood with an almost pathologically “splintered personality,” as Isador Rabi had put it.

For their biography of Oppenheimer, Kai Bird and Martin J. Sherwood unraveled the deep crisis Oppenheimer underwent during 1925–1926, the academic year he spent at Cambridge after his graduation from Harvard. Oppenheimer’s frustration in his work with Joseph John Thomson at the Cavendish, his general unhappiness with the Cambridge culture, anxieties caused by some sexual encounters, and the cooling of his friendship with some of his Harvard classmates because of their getting married, were catalysts in the breakdown. He became deeply depressed, and jealous of the success of some of the people around him, in particular of Patrick Blackett, a young experimental physicist at the Cavendish some three years his senior who had become his tutor and something of a mentor to him. Sometime in the fall of 1925 he actually left a “poisoned apple” on Blackett’s desk, an apple laced with some chemical, possibly cyanide, that might well have caused Blackett great harm. Fortunately, his deed was discovered and Blackett did not eat the apple. But Oppenheimer was hauled before the university authorities and nearly expelled. Only the intervention of his parents, and the promise that he would seek psychiatric help prevented his expulsion. He recovered, immersed himself in the work of Werner Heisenberg, Paul Dirac, and Erwin Schrödinger, and wrote two papers on the application of quantum mechanics to the vibrational and rotational spectra of molecules before leaving Cambridge in late summer 1926 to accept Max Born’s invitation to come work with him in Göttingen.

Historians now also have a much better account of all of Oppenheimer’s scientific activities during the 1930s, including his astrophysical researches that culminated with his investigations of the formation of what are now known as black holes, the final state of massive stars once they have exhausted their nuclear fuel and implode under gravitational attraction. And they also have a more deeply probing assessment of his involvement with left-wing politics during the 1930s, with such causes as the Spanish Republicans, the California Farm Workers, and the American Federation of Teachers, a branch of which he helped found at Berkeley. Oppenheimer was a member of a group that met regularly to discuss issues of the day. Three out of the four members of that group, which evidently was a secret cell of the Communist Party, were members of the Party. Many of his close friends; his brother and sister-inlaw; the woman who had introduced him to left-wing politics and to whom he considered himself engaged for a while, Jean Tatlock; his wife, Katherine “Kitty” Puening Harrison; all had been or were members of the Communist Party. There is no proof that Oppenheimer ever became a card-carrying member of the party or that he accepted party discipline, though he supported many of its activities through Party channels. The possibility that he had been a Communist during the late 1930s, and might even have perjured himself in denying this, has been raised by respected and knowledgeable historians. The issue is not likely to be resolved as it hinges on what various people thought at the time on the basis of his participation of various Communist Party–supported or Party-initiated activities. On the question of perjury, it surely hinges on what Oppenheimer believed. If he thought that signing a card or paying dues_____. both of which he made it a point never to do_____. were the key criteria for membership, then his denial that he ever was a member would not be perjury, regardless of what other people thought.

Los Alamos . In his fine “sociological biography” Charles Thorpe makes clear the dynamics involved in the construction of the complex organization of Los Alamos and the simultaneous molding of Oppenheimer’s role and authority as its charismatic director. It was a recursive process. The organizational order, the assignment of authority, Oppenheimer’s charismatic role and identity were emergent properties of the social and professional interactions of scientists, technicians, military personnel and all the other people that had been brought together to accomplish the military mission of building an atomic bomb and of Oppenheimer’s interaction with them. Thorpe also highlights the complementary roles at Los Alamos of Oppenheimer and Gen. Leslie Grove and the nature of their relationship and interactions.

This greater insight into the actions and character of Oppenheimer is the result of recent scholarship that has provided a much better understanding of the context in which his actions took place: scientists as political activists in the United States during the 1930s; the prewar Berkeley milieu; Los Alamos; the post–World War II loyalty-security regime; McCarthyism; the Cold War regime and its impact on intellectuals in the United States and in Europe. Oppenheimer’s staunch anticommunism and his deep distrust of the Soviet Union after World War II have been documented by meticulous research. How these views affected his political stand relating to the international control of nuclear energy and nuclear weapons after the rejection of the Acheson-Lilienthal plan by Bernard

Baruch, a close advisor of President Harry S. Truman, and the Soviet’s rejection of the Baruch proposal have been clarified by the researches of James Hershberg and others. Similarly, Priscilla McMillan has written a careful and sensitive chronicle and analysis of the deliberate campaign to destroy Oppenheimer that led to the “inquiry” he underwent_____. a campaign that was responsible for initiating the nuclear arms race between the United States and the Soviet Union that plagued the world for fifty years. Finally, Charles Thorpe’s investigation of Oppenheimer’s activities in the Congress for Cultural Freedom has revealed an important facet of his life in the aftermath of the revocation of his clearance.

All this recent scholarship corroborates what Cathryn Carson states in the Introduction to Reappraising Oppenheimer, the book which she and David Hollinger edited and which is the best entry into recent scholarship on Oppenheimer: “If we can see Oppenheimer in his complexity as something more than a singular individual_____. as a man mirroring and responding to a panoply of contradictory forces_____. then we may come closer to capturing his sense that the life he lived had significance beyond its individual confines” (Carson and Hollinger, p. 9).


Oppenheimer’s papers are located in the Manuscript Division of the Library of Congress. His papers relating to his directorship of the Institute of Advanced Study (IAS) are located at the IAS. A useful short bibliography compiled on the occasion of a Centennial Conference at Berkeley is available from http://ohst.berkeley.edu/oppenheimer/biblio.html.


Robert Oppenheimer: Letters and Recollections. Edited by Alice Kimball Smith and Charles Weiner. Cambridge, MA: Harvard University Press. 1980. Many of his pre-1945 letters and a list of his scientific and other published papers.


Biographical Works Bernstein, Jeremy. Oppenheimer: Portrait of an Enigma. Chicago: Ivan R. Dee, 2004. Provides perspectives on Oppenheimer’s strengths as a physicist, written by a member of the contemporary physics community.

Bird, Kai, and Martin J. Sherwin. American Prometheus: The Triumph and Tragedy of J. Robert Oppenheimer. New York: Knopf, 2005. Full of detail, the result of almost twenty-five years of scholarship and more than two hundred interviews with Oppenheimer’s students, associates, friends, and family.

Carson, Cathryn, and David A. Hollinger, eds. Reappraising Oppenheimer: Centennial Studies and Reflections. Berkeley: Office for History of Science and Technology, University of California, Berkeley, 2005. The best entry into the writings on J. Robert Oppenheimer. The book also gives a valuable reassessment of Oppenheimer’s place in the history of the United States during the twentieth century.

Cassidy, David C. J. Robert Oppenheimer and the American Century. New York: Pi Press, 2005. Good description of the changing relationship between science and government.

Herken, Gregg. Brotherhood of the Bomb: The Tangled Lives and Loyalties of Robert Oppenheimer, Ernest Lawrence, and Edward Teller. New York: Henry Holt, 2002. Describes rivalries and cooperation among physicists.

Pais, Abraham, with supplemental material by Robert P. Crease. J. Robert Oppenheimer: A Life. New York: Oxford University Press, 2006. By a physicist who was also Oppenheimer’s neighbor.

Schweber, S. S. In the Shadow of the Bomb: Bethe, Oppenheimer, and the Moral Responsibility of the Scientist. Princeton, NJ: Princeton University Press, 2000. Describes the role of Bethe and Oppenheimer in their roles as advisers to the government and emphasizes the moral dilemmas faced by these scientists.

Thorpe, Charles. Oppenheimer: The Tragic Intellect. Chicago: University of Chicago Press, 2006. Covers Oppenheimer’s activities at Los Alamos and as a public intellectual after World War II.

Directorship of Los Alamos

Rhodes, Richard. The Making of the Atomic Bomb. New York: Simon and Schuster, 1986.

Hoddeson, Lillian, P. W. Henriksen, R. A. Meade, et al. Critical Assembly: A Technical History of Los Alamos during the Oppenheimer Years, 1943–1945. Cambridge, U.K.: Cambridge University Press, 1993.

Hughes, Jeff. The Manhattan Project: Big Science and the Atom Bomb. New York: Columbia University Press, 2003.

Thorpe, Charles, and S. Shapin. “Who Was J. Robert Oppenheimer: Charisma and Complex Organization.” Social Studies of Science30 (2000): 545–590.

Development of H-Bombs and Revocation of Clearance

Galison, Peter, and Barton Bernstein. “In Any Light: Scientists and the Decision to Build the Superbomb, 1942–1954.” Historical Studies in the Physical and Biological Sciences19, no. 2 (1989): 266–347.

McMillan, Priscilla Johnson. The Ruin of J. Robert Oppenheimer, and the Birth of the Modern Arms Race. New York: Viking, 2005.

Rhodes, Richard. Dark Sun: The Making of the Hydrogen Bomb. New York: Simon and Schuster, 1995.

York, Herbert F. The Advisors: Oppenheimer, Teller, and the Superbomb. San Francisco: W. H. Freeman, 1976. Reprint, Stanford, CA: Stanford University Press, 1989.

AEC Inquiry into Security Clearance

Polenberg, Richard, ed. In the Matter of J. Robert Oppenheimer: The Security Clearance Hearing. Ithaca, NY: Cornell University Press, 2002.

U.S. Atomic Energy Commission. In the Matter of J. Robert Oppenheimer: Transcript of Hearing before Personnel Security Board and Texts of Principal Documents and Letters. Cambridge, MA: MIT Press. 1971. Covers the 1954 AEC inquiry into Oppenheimer’’’s security clearance.


Adams, John, and Peter Sellars. Doctor Atomic. An opera by the contemporary minimalist American composer John Adams, with libretto by Peter Sellars. It premiered at the San Francisco Opera on 1 October 2005.

Else, Jon, and KTEH-TV (San Jose, California). The Day after Trinity: J. Robert Oppenheimer and the Atomic Bomb. A film by Jon Else. Santa Monica, CA: Pyramid Films, 1981.

Kipphardt, Heinar. In the Matter of J. Robert Oppenheimer: A Play Freely Adapted on the Basis of the Documents by Heinar Kipphardt. New York: Hill and Wang, 1968.

Silvan Schweber

Oppenheimer, J. Robert

views updated May 21 2018


J(ulius) Robert Oppenheimer (1904–1967) was born in New York City on April 22 of a privileged, assimilated German-Jewish family. Known widely as the "father of the atomic bomb," Oppenheimer also thought that physicists had special responsibilities as a result of their contributions to this development. He argued for international control of nuclear weapons and against the U.S. development of the hydrogen bomb. He died of throat cancer in Princeton, New Jersey, on February 18.

Education and Career

Oppenheimer received a liberal and wide-ranging education in New York City, at Harvard University, and at several leading scientific centers in Europe, receiving his Ph.D. under Max Born in 1927. His most creative scientific work was performed in the period 1927–1942, first at Göttingen, Germany, with Born, and then at the California Institute of Technology and, primarily, at the University of California Berkeley. His first major contribution was the Born-Oppenheimer approximation, a seminal recipe for dealing with molecular interactions. He subsequently published important papers on nuclear and particle physics. He also studied astrophysical phenomena, involving general relativity, neutron stars, and gravitational collapse.

At Berkeley Oppenheimer became arguably the most important and certainly the most charismatic American-born physics theorist. His close association with Ernest O. Lawrence helped spread his fame as a theoretical physicist capable of understanding and working with the most advanced high energy experiments. In 1942 he became scientific director of the Los Alamos center of the Manhattan Project, where the atomic weapons of World War II were designed, built, and finally delivered for use over Japan in August 1945. Resigning from Los Alamos after the war, he became director of the Institute for Advanced Studies at Princeton, where he once again demonstrated his talents as an organizer and scientific leader.

Politics and Ethics

As a result of his spectacular accomplishment with the atomic bomb, Oppenheimer was elevated to a position of extraordinary prestige and power in both the scientific and the political worlds. He became an international celebrity and governmental adviser, raising questions of conscience for the scientific community and arguing for United Nations (UN) control of nuclear weapons. In 1947, at the Massachusetts Institute of Technology, he gave a talk in which he made the comment that as a result of their development of the atomic bomb physicists had known sin and thus had a responsibility to help educate other scientists, politicians, and the public about the devastating power of these new weapons.

Early in his Berkeley years Oppenheimer became involved in political activities. He supported many organizations and interest groups that could be identified as leftist. Such activities and associations later caused Oppenheimer difficulty during the period of intense anti-communist sentiments that gripped the United States in the early days of the Cold War, and an Atomic Energy Commission (AEC) hearing resulted in the removal of his secret security clearance in 1954.

The denial of Oppenheimer's clearance was based on several factors. One was his unswerving opposition to the efforts of the U.S. government to develop a hydrogen bomb. Another was his past associations with left wing and pro-Soviet groups, and also the fact that at one time in 1943 he did not reveal a discussion with Haakon Chevalier, a friend and French professor at Berkeley, about the possibility of personal contacts between American and Soviet scientists outside official channels. The reason for not reporting this incident may have been his unwillingness to betray a friend, whom he felt was innocent of venal motive. As for his opposition to the hydrogen bomb, in retrospect Oppenheimer appears to have been punished for a dissenting view on a controversial topic, a state of affairs that is part of the normal democratic decision making process. In any case President John F Kennedy ordered what amounted to his rehabilitation in 1963 by awarding him the Enrico Fermi prize, the highest honor granted by the AEC.

Oppenheimer was an aesthete; a consummate scholar of languages, ancient cultures, and literature; as well as an accomplished physicist. He had refined tastes, supported by his inherited wealth. He was a self-proclaimed lover of the common man, exemplified in his espousal of liberal and leftist causes. Yet he worked on military weapons and projects. He did not oppose research on the hydrogen bomb, only on its development as a deliverable weapon. In telling testimony before the U.S. Congress, he once commented that such development was so sweet technically that it could not but be tried. Although known for acerbic remarks at scientific presentations, he was admired, even loved, by students and junior colleagues. Although loyal to friends, in the Chevalier case he caused irreparable damage to a career when he did belatedly describe their conversation. While his scientific productivity was outstanding, he missed producing any single contribution that would have placed him in the first ranks. In sum he was a scientist, teacher, scientific administrator, and public figure, whose flaws prevented him from achieving the highest level in the intellectual pantheon, and yet who raised important ethical issues for the scientific community and public.


SEE ALSO Atomic Bomb;Oppenheimer, Frank;Science Policy.


Herken, Gregg. (2002). Brotherhood of the Bomb. New York: Henry Holt and Company.

Schweber, Silvan S. (2000). In the Shadow of the Bomb: Bethe, Oppenheimer, and the Moral Responsibility of the Scientist. Princeton, NJ: Princeton University Press.


Bethe, Hans A. "Biographical Memoirs: J. Robert Oppenheimer." National Academy of Sciences. Available from http://nap.edu/html/biomems/joppenheimer.html.

J. Robert Oppenheimer

views updated Jun 08 2018

J. Robert Oppenheimer

The American physicist J. Robert Oppenheimer (1904-1967) made fundamental contributions to theoretical physics and was director of the atomic energy research project at Los Alamos, N.Mex.

On April 22, 1904, J. Robert Oppenheimer, whose father was a German immigrant and wealthy textile importer, was born in New York City. After attending the Ethical Culture School in New York, where his lifelong devotion to literature, the arts, and science was nurtured, he entered Harvard University in 1922 and completed his bachelor's degree in 3 years. He required only 2 additional years of study at Cambridge University and the University of Göttingen to complete his doctoral degree in 1927.

Following 2 years of postdoctoral study at home and abroad on fellowships, Oppenheimer became associate professor of physics at the California Institute of Technology in Pasadena. Almost immediately, however, he began spending part of each academic year at the University of California at Berkeley, and he simultaneously rose through the academic ranks at both institutions. His teaching and research abilities were so exceptional and his personal magnetism was so great that many of his students followed him in his annual Berkeley-Pasadena pilgrimages, often willingly repeating the courses he offered. In general, by attracting and training an unusually large number of highly competent physicists, Oppenheimer, more than any other individual, was responsible for moving theoretical physics in America from a position of obscurity into one of preeminence in the world.

Oppenheimer's own researches between 1926 and 1942 took root in his extremely insightful exploitation of the recently discovered quantum mechanics of Werner Heisenberg, Erwin Schrödinger, Paul Dirac, Max Born, and others. With Born he developed a now-standard quantum theoretical understanding of molecules and their spectra. He undertook extensive investigations on processes involving transitions to the continuous spectrum, showing, for example, how to understand the photoelectric effect quantum-mechanically. He explored electron capture and exchange processes, as well as electron-atom collision processes. In 1930 he presented a cogent symmetry argument that was later recognized to be tantamount to the prediction of the positive electron, or positron. He studied the production of cosmic-ray showers. He explored various problems in quantum electrodynamics, as well as the properties and role of the meson in nuclear forces. He helped develop the so-called Oppenheimer-Phillips interpretation of deuteronnuclear reactions, which eventually led to great insight into the structure of the nucleus. In all of these theoretical investigations—and many more could be cited— Oppenheimer displayed his genius in implementing Wolfgang Pauli's conviction that a physicist should concern himself first and foremost with those problems on the very frontiers of current knowledge.

To the general public, Oppenheimer, as a scientist, is best known for his role in directing the development of the atomic bomb at Los Alamos, the laboratory high on a New Mexican mesa at a site he chose. Many of America's foremost physicists were persuaded to come with their families to this isolated laboratory to beat the Germans in the development of the most awesome weapon of destruction in human history. When all of the huge and unique problems were solved, and the test bomb was exploded on July 16, 1945, in the desert near Alamogordo, N. Mex., Oppenheimer was deeply shaken. He thought of the words from the Bhagavad-Gita: "If the radiance of a thousands suns/ Were to burst into the sky/That would be like/The splendor of the Mighty One…./Iam become Death, the shatterer of worlds." Not much later Hiroshima and Nagasaki were obliterated.

Oppenheimer was a complex man, one who could inspire distrust as well as utter devotion, and one who could commit indiscretions as well as be a scientist of faultless integrity. After the war, his early left-wing sympathies, inflated by Senator Joseph McCarthy and his coterie of witch-hunters, made Oppenheimer the defendant in perhaps the most celebrated trial since the time of Galileo. In spite of the fact that Oppenheimer's past associations had aroused no undue concern earlier—he had received the coveted Presidential Medal of Merit in 1946 and had been serving on the highest policy-making committees—his security clearance was revoked, deeply shocking the vast majority of his fellow scientists. Not until 1961, when President John F. Kennedy made the decision to give the Fermi Award to Oppenheimer (it was actually presented in 1963 by President Lyndon B. Johnson), was a significant attempt made to publicly clear Oppenheimer's name. In the interim, Oppenheimer had been serving as the director of the Institute for Advanced Study in Princeton, giving his splendid administrative and technical talents to the young group of highly gifted physicists who had gathered there.

Oppenheimer will remain a subject of study, discussion, controversy, and admiration for years to come. His profound concern for uniting the intellectual community, and humanity in general, is evident from the vast number of lectures and articles he devoted to the subject. He died of cancer in Princeton on Feb. 18, 1967.

Further Reading

The most complete obituary notice of Oppenheimer is by H. A. Bethe in the Royal Society of London, Biographical Memoirs of Fellows of the Royal Society, vol. 14 (1968). Considerable biographical information, along with selected writings of Oppenheimer included as an addendum, is in a study of his scientific contributions to atomic theory: Michel Rouze, Robert Oppenheimer: The Man and His Theories, translated by Patrick Evans (1964). See also Peter Michelmore, The Swift Years: The Robert Oppenheimer Story (1969).

A number of works deal with the dramatic and controversial investigation of Oppenheimer's security status. The reports of the U.S. Atomic Energy Commission in 1954-1955, published as In the Matter of J. Robert Oppenheimer, constitute the official record of his trial. Haakon Chevalier, Oppenheimer: The Story of a Friendship (1965), is a personal account of the still obscure events of the 1940s. Other books on this aspect of Oppenheimer's life are Joseph and Stewart Alsop, We Accuse! (1954); Cushing Strout, ed., Conscience, Science and Security: The Case of Dr. J. Robert Oppenheimer (1963); and Philip M. Stern and Harold P. Green, The Oppenheimer Case: Security on Trial (1969).

For Oppenheimer's work on atomic energy see J. Alvin Kugelmass, J. Robert Oppenheimer and the Atomic Story (1953); Richard G. Hewlett and Oscar E. Anderson, Jr., A History of the United States Atomic Energy Commission (2 vols., 1962-1969); and Nuel Pharr Davis, Lawrence and Oppenheimer (1968). □

Oppenheimer, Robert

views updated Jun 11 2018

Oppenheimer, Robert


The son of a wealthy New York City textile importer (Julius) and a painter (Elle Friedman), Julius Robert Oppenheimer enjoyed an affluent childhood. He graduated from the Ethical Culture School of New York at the top of his class in 1921 and summa cum laude from Harvard in 1925. He then studied at the Cavendish Laboratory in Cambridge, England, and with Max Born at the University of Göttingen, in Germany, where he earned a doctorate in 1927. Although a rising star, he often was plagued by deep self-doubts and dark moods.

In 1929 Oppenheimer moved to California and for many years taught at both the California Institute of Technology (Caltech) and the University of California, Berkeley. He made several contributions to subatomic physics, including (with his former mentor) the BornOppenheimer approximation, which posited that the spin and vibration of protons could be ignored in theoretical calculations. Thin, wiry, enigmatic, and charismatic, Oppenheimer was associated with several leftist groups, which he helped fund. In 1940 he married biologist Katherine Harrison, a former member of the Communist Party.

Oppenheimer declared his leftist ties severed soon after he joined a secret group of elite scientists working with Ernest O. Lawrence at Berkeley's radiation laboratory to develop an atomic bomb. In spite of continuing suspicions about his loyalty, the U.S. Army appointed him director of the bomb design unit in October 1942. Oppenheimer's team of hundreds of gifted young scientists was secluded at a facility in Los Alamos, New Mexico. One of the brightest, Edward Teller, became a disaffected rival of Oppenheimer, but most found him a brilliant and inspiring leader.

Pushing the boundaries of theoretical physics , Oppenheimer's Los Alamos scientists followed two technological paths simultaneously. One was a "gun assembly" designed to fire two masses of uranium at each other to initiate a chain reaction. But because fissionable uranium was exceedingly difficult to refine, other scientists worked on a design using more readily available but less stable plutonium, imploding a hollow sphere of the fuel with high explosives. Both designs worked, and they were used against Japana uranium bomb was dropped over Hiroshima, a plutonium one over Nagasakiin early August 1945 to end World War II.

Initially, Oppenheimer was elated over these technical achievements, but he quickly be came regretful and despondent about a nuclear future. As director of the prestigious Center for Advanced Study at Princeton (19471952) and chair of the General Advisory Committee of the Atomic Energy Commission (AEC), he was an outspoken advocate for the international sharing of nuclear technology and for international arms control, and he opposed further development of the hydrogen bomb. After a 1954 hearing, the AEC security board affirmed his loyalty but revoked his security clearance. Although there is little hard evidence that Oppenheimer ever passed atomic secrets to the former Soviet Union, the controversy surrounding this claim continues. Oppenheimer spent his final years sailing in the Virgin Islands and writing about science and Western culture. He died in Princeton, New Jersey, on February 18, 1967.

EDWARD TELLER (19082003)

Edward Teller was a physical chemist and an important, if controversial, voice in the politics of nuclear science. His work contributed to an understanding of both fusion and fission bombs. Regarded as the "father of the H-bomb," he was an ardent anticommunist and cold war warrior and he staunchly advocated the development and stockpiling of nuclear weapons. He opposed treaties limiting nuclear arsenals and testing, and he supported the development of space-based weapons.

Valerie Borek

see also Lawrence, Ernest; Manhattan Project.

David B. Sicilia


Herken, Gregg (2002). Brotherhood of the Bomb: The Tangled Lives and Loyalties of Robert Oppenheimer, Ernest Lawrence, and Edward Teller. New York: Henry Holt and Co.

Rhodes, Richard (1986). The Making of the Atomic Bomb. New York: Simon & Schuster.

Rhodes, Richard (1995). Dark Sun: The Making of the Hydrogen Bomb. New York: Simon & Schuster.

J. Robert Oppenheimer

views updated May 23 2018

J. Robert Oppenheimer


American Physicist

J. Robert Oppenheimer led the team that developed the first atomic bomb. Between 1943 and 1945, he directed the laboratory in Los Alamos, New Mexico, where the bomb was designed and built.

Oppenheimer was born in New York City on April 22, 1904, the indulged first child of a prosperous family. At Harvard, he majored in chemistry, but an advanced course on thermodynamics attracted him to physics. He began his postgraduate work in atomic physics at the Cavendish Laboratory at Cambridge University in England. Graduate students at Cavendish were assigned much of the work involved in setting up experiments. Although Oppenheimer excelled at theoretical analysis, he was almost entirely helpless when it came to handling mechanical equipment. Being a perfectionist, these difficulties bothered him a great deal. He was therefore delighted to accept a 1926 offer from Max Born (1882-1970) to join the Institute for Theoretical Physics at Gottingen, Germany. He received his Ph.D. there the next year.

In 1929, Oppenheimer began teaching physics at the University of California at Berkeley and at the California Institute of Technology. He liked the idea of splitting his time between the two institutions, the dry air of the West was good for his rather delicate health, and he enjoyed being closer to the ranch his family eventually purchased in New Mexico.

Events of the 1930s caused Oppenheimer to take an interest in politics for the first time. The Nazis took power in Germany, and Oppenheimer attempted to orchestrate escape plans for his relatives there as well as for Jewish scientists and teachers. He also donated money to the Spanish Loyalists fighting against the Fascist military leader Francisco Franco. Closer to home, he was troubled by the poverty and suffering brought on by the Depression, and became attracted to the ideas of socialism. However, unlike many other intellectuals of the time, he did not join the Communist Party, being afraid that the organization might attempt to take advantage of his work in nuclear physics research. In 1940 he married Katherine "Kitty" Puening, a Caltech graduate student. They soon started a family, and Oppenheimer began to lose interest in radical causes.

By the end of 1941, the United States was involved in World War II. President Roosevelt was persuaded by Albert Einstein (1879-1955) and other physicists to begin the Manhattan Project to build an atomic bomb, lest Hitler obtain such a bomb and be unopposed. At first the project was decentralized, and Oppenheimer participated by making calculations in his Berkeley office. Eventually more organization was required, and Oppenheimer was chosen to head the project's main laboratory. He suggested it be located in Los Alamos, New Mexico, near the White Sands missile range and only 60 mi (95.6 km) from his beloved desert ranch. He recruited many eminent scientists, including Enrico Fermi (1901-1954) and Niels Bohr (1885-1962).

The first atomic bomb was exploded in a test on July 16, 1945. Germany had surrendered two months before. The scientists were relieved that the project had succeeded, but many had deep reservations about the power that had been unleashed. Oppenheimer was moved to quote from the Hindu scriptures, "I am become Death, the Destroyer of Worlds." Three weeks later an atomic bomb was dropped on the Japanese city of Hiroshima and, three days later, on Nagasaki. The ancient cultural center of Kyoto had been the first intended target, but was spared when Oppenheimer objected.

After the war, Oppenheimer became the director of the Institute for Advanced Study in Princeton. He also remained an important government advisor on nuclear issues, and helped draft the policies of the U.S. Atomic Energy Commission (AEC). However, in the early 1950s, Oppenheimer's patriotism was questioned, in part because of his suggestions about international cooperation in the control of nuclear energy. In the toxic atmosphere of the "McCarthy Era," old friendships from the 1930s were cited as evidence of Communist associations. A rival scientist, Edward Teller (1908- ), testified against him. An AEC security panel failed to find any evidence of disloyalty, but decided nonetheless to bar him from further access to classified information. This injustice was very hard on Oppenheimer and his family.

In 1963, with the old enmities fading, the AEC, including Teller, voted unanimously to bestow upon Oppenheimer the Enrico Fermi Award for "outstanding contributions to the development, use or control of atomic energy." Oppenheimer remained at the Institute for Advanced Study until he retired in 1966. He died of throat cancer on February 18, 1967, at his New Jersey home.


Oppenheimer, J. Robert

views updated May 18 2018

J. Robert Oppenheimer

J. Robert Oppenheimer is known as the father of the atomic bomb . A highly talented physicist, teacher, and administrator, Oppenheimer made significant scientific discoveries and headed the U.S. project that created the bomb that America used against Japan in World War II (1939–45). His interest in communism early in life and his opposition to nuclear weapons after World War II led to trouble with the U.S. government during the Red Scare of the 1950s.

Early life

Julius Robert Oppenheimer was born in New York City on April 22, 1904. His parents were Julius S. Oppenheimer, a German emigrant who became wealthy importing textiles in America, and Ella Friedman, a painter. Oppenheimer's one sibling was Frank, who was eight years younger and also became a physicist.

Oppenheimer showed intellectual talent as a boy, joining the New York Mineralogical Society at eleven years old and delivering a paper to the organization at twelve. He attended the Ethical Culture School in New York and then completed his undergraduate degree in three years at Harvard University, graduating in 1925. In just two more years, he earned a doctoral degree in Europe, where he also conducted postdoctoral studies.

Teaching and research

Oppenheimer became a professor of physics at both the California Institute of Technology and the University of California at Berkeley. His courses were demanding but popular, and he rose through the academic ranks at both institutions.

Between 1926 and 1942, Oppenheimer conducted research that led to many significant discoveries in theoretical physics, especially in particle physics, which is the study of the elementary particles of matter, and quantum mechanics, the science of the energy of particles.

The Manhattan Project

With U.S. participation in World War II on the horizon, physicists were working on how to split the nucleus of an atom to release its energy. By October 1941, Oppenheimer had calculated that a critical mass of 220 pounds (100 kilograms) of pure uranium would enable a massive explosion.

Early in 1942, Oppenheimer headed a group of theoretical physicists hired by the U.S. government to work at a secret location near Los Alamos, New Mexico . Their task—named the Manhattan Project —was to develop an atomic bomb for use in the war. Using plutonium as the radioactive material, the physicists first tested an atomic bomb in a remote New Mexico desert on the morning of July 16, 1945. Oppenheimer later wrote that on seeing the explosion, he thought of the line “I am become death, the Shatterer of Worlds” from the Hindu text the Bhagavad Gita.

Oppenheimer served on a panel of four physicists assigned to help the military consider whether to begin an armed invasion of Japan or launch an atomic attack. The invasion would cost many American lives, while the atomic attack would kill many Japanese civilians. The panel recommended the atomic attack. Oppenheimer later regretted the advice, feeling it was wrong to kill so many civilians.

Later life and career

After the war, Oppenheimer continued to serve the U.S. government, including as an advisor to the Atomic Energy Commission. Oppenheimer personally opposed a nuclear arms race. He was against developing the hydrogen bomb and in favor of international treaties limiting nuclear arms.

Oppenheimer's opinions made him enemies in Washington, D.C. The 1950s were the time of the Red Scare, when fear of Soviet Union communism gripped much of the country. In the 1930s, Oppenheimer had been affiliated with communist organizations. U.S. officials, angered by Oppenheimer's stance against nuclear weapons, used this to hold a hearing in 1954 to revoke his security clearance to work on secret federal projects. The panel in charge of the hearing found Oppenheimer to be a loyal citizen, but revoked his clearance due to “defects of character.”

Oppenheimer worked as a physicist for the remainder of his life. In 1963, he received the prestigious Enrico Fermi Award from President John F. Kennedy (1917–1963; served 1961–63). It was awarded to Oppenheimer in recognition of his life's work and to try to mend relations between him and the U.S. government. A lifelong smoker, Oppenheimer died of throat cancer on February 18, 1967.

Oppenheimer, J. Robert

views updated May 11 2018

Oppenheimer, J. Robert (1904–1967), physicist.Perhaps the most controversial scientist of this century, J. Robert Oppenheimer was awarded kudos in the 1940s for his contributions to the war effort and censure for allegedly betraying the country of his birth. Born in New York City and educated at Harvard and Görringen, Oppenheimer earned his Ph.D. in 1927 and quickly became recognized as a leader in theoretical physics, simultaneously rising through the academic ranks at the California Institute of Technology and the University of California at Berkeley, and gathering large numbers of the best scientific minds in the United States to his seminars and laboratories. In so doing, he became the catalyst for the emergence of American theoretical physics as preeminent in the world.

At the National Academy of Scientists in 1941, Oppenheimer led a group of scientists in theoretical discussions of nuclear bombs. Although intensely ambivalent about the creation of such weapons of mass destruction, he was concerned that the Nazis might produce one first, so he accepted an offer from Gen. Leslie Groves to serve as director of a highly classified U.S.‐led effort to build an atomic bomb. This effort, the Manhattan Project, was headquartered at Los Alamos, New Mexico. Many atomic scientists gathered there between 1942 and the first detonation of an atomic bomb on 16 July 1945.

Even though the dropping of atomic bombs on Hiroshima and Nagasaki ended World War II and kept the Russians from invading Japan, Oppenheimer was overwhelmed by the devastation he had wrought. He called for a cessation of atomic research or for international guidelines on the use of atomic weaponry. Both during the war and later he became associated with Communist Party members and others with strong leftist political positions. Although no clear violations of security were ever proven, there had been instances of negligence and indiscretion. During the McCarthy investigations and purges of alleged Communists in the U.S. government in the 1950s, Oppenheimer lost his security clearance and was forced to resign from the seven atomic committees he chaired. He became director of the Institute for Advanced Study in Princeton and was later at least partially vindicated when President Lyndon B. Johnson presented him with the Enrico Fermi Award in 1963.
[See also Cold War: Domestic Course.]


Michel Rouze , Robert Oppenheimer: The Man and His Theories, trans. Patrick Evans, 1962.
Peter Michelmore , The Swift Years: The Robert Oppenheimer Story, 1969.
Peter Goodchild , J. Robert Oppenheimer: Shatterer of Worlds, 1981.

Peter J. McNelis