George Cowan’s Interview (1993)
George Cowan was a physical chemist who joined the Manhattan Project in 1942. In this interview, Cowan discusses the Soviet atomic program and their effort to build a nuclear bomb. In 1949, he helped convince U.S. government officials that the radiochemistry of air samples taken from the atmosphere proved that the Soviets had detonated their own atomic bomb, rather than what many assumed was just a peaceful nuclear reactor problem. Cowan also discusses Operation Crossroads, where he helped take air samples during atomic tests at Eniwetok Atoll in 1946.