particularly persuasive; he had interrogated Oppenheimer over the Chevalier incident in 1943, and strongly supported him. On August 11, 1947, the AEC unanimously voted to grant Oppenheimer a Q clearance. At the first meeting of the GAC on January 3, 1947, Oppenheimer was unanimously elected its chairman. Postwar conflicts The FBI was willing to furnish Oppenheimer's political enemies with incriminating evidence about Communist ties. These included Lewis Strauss, an AEC commissioner who resented Oppenheimer for his humiliation before Congress regarding opposition to the export of radioactive isotopes to other nations, which Strauss believed had military applications. As GAC chairman, Oppenheimer was called before the Joint Committee on Atomic Energy (JCAE) over the issue in June 1949. The other four AEC commissioners had opposed Strauss, so he had gone to the JCAE in an attempt to get the decision overturned. The result was a stunning humiliation for the thin-skinned Strauss. Oppenheimer testified that: This came on the heels of controversies about whether some of Oppenheimer's students, including David Bohm, Ross Lomanitz and Bernard Peters, had been Communists at the time they had worked with him at Berkeley. Oppenheimer was called to testify in front of the House Un-American Activities Committee, where he admitted that he had associations with the Communist Party in the 1930s, and named some of his students as being Communists or closely associated with them. Bohm and Peters eventually left the country, while Lomanitz was forced to work as a laborer. Frank Oppenheimer was fired from his university position, and could not find work in physics for a decade. He and his wife Jackie became cattle ranchers in Colorado. Their reputations were rehabilitated in 1959, and they founded the San Francisco Exploratorium in 1969. David Kaiser noted that: From 1949 to 1953, Oppenheimer had also found himself in the middle of a controversy over the development of the "Super". In 1949, the Soviet Union detonated an atomic bomb. This came as a shock to many Americans, and it fell to Oppenheimer to play a leading role in checking the evidence and confirming that the explosion had taken place. In response, Strauss recommended that the United States retain nuclear superiority by developing the "Super". This had been under consideration at Los Alamos for several years. Brigadier General James McCormack told the AEC commissioners that while thermonuclear weapons could potentially be thousands of times as powerful as fission weapons, as