Martin Kamen

Martin Kamen was a chemist, musician, and participant in the political and scientific life surrounding J. Robert Oppenheimer at Berkeley, California. His story links a major discovery in nuclear science with the intimate networks of a university laboratory—and with the consequences of suspicion that followed him long after his work there. Kamen was not a Communist, but his presence at an organizing meeting in Oppenheimer’s home placed him at the intersection of scientific work, labor politics, and security concerns.

Identity and Arrival at Berkeley

Kamen had trained as a chemist and completed a doctoral dissertation in Chicago on a problem in nuclear physics. In early 1937, he followed a girlfriend to Berkeley, where Ernest Lawrence hired him to work in the Berkeley Radiation Laboratory for $1,000 a year. Kamen later remembered the place as “like Mecca”: Lawrence’s cyclotron had drawn scientists toward a new means of probing the atom, and the laboratory offered Kamen a place within that fast-growing enterprise.

His work there soon acquired lasting scientific importance. In 1940, Kamen and fellow chemist Sam Ruben used Lawrence’s cyclotron to discover the radioactive isotope carbon-14. The discovery became part of a longer scientific history: Willard Libby later developed carbon dating, for which he received the 1960 Nobel Prize in chemistry. Kamen’s own achievement was thus both a laboratory result and a contribution whose significance expanded through later research.

A Scientific and Personal Circle

Kamen became one of Oppenheimer’s close associates between his arrival in 1937 and the outbreak of war. His connection with Oppenheimer was not limited to physics. Kamen was a serious musician; he played violin with Frank Oppenheimer, and the two men also shared conversations about literature and music. Kamen thought Oppenheimer valued this range of interests, recalling, “I think he took a shine to me,” because they could talk about subjects beyond physics.

Kamen admired Oppenheimer’s brilliance but also registered the contradictions in his manner. He recalled that people regarded the physicist affectionately as “sort of nuts,” and described him as brilliant yet superficial, with the air of a dilettante. Kamen sometimes wondered whether Oppenheimer’s eccentricities were partly performance. At a New Year’s Eve party at Estelle Caen’s home, Oppenheimer remembered the street but not the house number, only that it was divisible by seven. The pair drove up and down until they found number 3528. Looking back, Kamen wondered whether Oppenheimer had been pulling everyone’s leg; he remembered in him an overwhelming temptation to “snow you.” The anecdote captures the mixture of intimacy and uncertainty Kamen experienced: Oppenheimer drew people close, but could leave them unsure how much of what they saw was spontaneous.

Kamen also accompanied Oppenheimer on the Berkeley cocktail circuit, attending fundraisers for the Joint Anti-Fascist Refugee Committee and Russian War Relief. That participation did not make him a left-wing activist or a Communist; the account explicitly distinguishes him from both. His social proximity to Oppenheimer’s political activities coexisted with his own reservations, a distinction that became especially clear when he was asked to take part in a union campaign.

The Union Meeting at Eagle Hill

The organizing effort began amid a labor dispute at Shell Development Company in nearby Emeryville. The company employed many white-collar workers, engineers, and chemists, including Ph.D.s from Berkeley. The Congress of Industrial Organizations–sponsored Federation of Architects, Engineers, Chemists and Technicians was organizing workers, while Shell management encouraged employees to join a company union. David Adelson, a Shell chemist who belonged to a professional unit of the Alameda County Communist Party, asked Oppenheimer to lend his prestige to the organizing drive. Oppenheimer agreed and gave a union-sponsored talk at the Berkeley home of his former graduate student Herve Voge, then a Shell employee. More than fifteen people listened as Oppenheimer discussed the possibility that the United States might enter the war.

In autumn 1941, Oppenheimer agreed to host an organizing meeting at his Eagle Hill home and invited Kamen. Kamen was uneasy: Radiation Laboratory employees were effectively working for the United States Army and had signed security pledges, and he doubted they could independently join a controversial union without Lawrence’s permission. He attended nonetheless. Fifteen people sat in a circle in Oppenheimer’s living room, among them Oppenheimer’s friend Ernest Hilgard, Berkeley chemist Joel Hildebrand, and George C. Eltenton, a British chemical engineer employed by Shell. As the others responded favorably to Oppenheimer’s pitch, Kamen interrupted to ask whether anyone had consulted Lawrence and insisted that the laboratory’s employees had no independence in the matter.

The objection unsettled Oppenheimer, who had expected unanimous support. The two-hour meeting ended without it. A couple of days later, Oppenheimer told Kamen he might have done the wrong thing and explained that he had spoken to Lawrence. Lawrence had reacted furiously to a Communist-backed union organizing in his laboratory. When Lawrence demanded to know who was behind the effort, Oppenheimer refused to identify them, saying they would have to come forward themselves. Kamen’s intervention had made the conflict tangible: for him, the issue was not simply whether a union was desirable, but whether laboratory workers under Army security rules could make that choice without their director’s approval.

The argument exposed a broader divide between the two physicists. Lawrence, increasingly conservative, objected both to union organizing and to Oppenheimer’s continuing involvement in left-wing causes. Oppenheimer defended the responsibility of scientists to help society’s underdogs. Lawrence had repeatedly rebuked what he called Oppenheimer’s leftward activities; on this occasion, he complained to Kamen that if Oppenheimer would stop them, he might be brought onto the bomb project, but the Army would not accept him as things stood. Kamen thus witnessed a personal and political dispute that also bore on Oppenheimer’s professional future.

Accusations and Aftermath

Kamen’s career at the Radiation Laboratory later ended amid a series of misunderstandings that led authorities to suspect he had acted as a Soviet spy. The evidence does not establish that his departure resulted from the union episode, and the two developments should not be conflated. It does establish that the false allegations followed him for years and became a source of severe distress. In 1951, Senator Bourke B. Hickenlooper accused him of being an “atom spy.”

Depressed and beleaguered, Kamen attempted suicide, but survived and recovered. He then sued the Chicago Tribune for libel and eventually won, receiving $7,500 in compensatory damages. The sequence gives his story a stark reversal: a chemist whose research helped establish carbon-14’s scientific importance was later publicly branded a spy, then fought the accusation in court. His life in the account is defined not by a single political label, but by the difficult distance between his scientific contribution, his cautious response to workplace politics, and the suspicion that came to overshadow his career.