Robert Serber was an American physicist. He was recruited by J. Robert Oppenheimer to work on the Manhattan Project. Serber was tasked with explaining the basic principles and goals of the project to all incoming scientific staff. Moving to Los Alamos in 1943, he gave lectures to members of the Manhattan Project about the design and construction of the atomic bomb; these lectures came to be known as the “Los Alamos Primer.” In this interview with Martin Sherwin, Serber talks about Oppenheimer and the physics community at Berkeley before the war. He recalls Oppenheimer’s relationships with his graduate students, and his own friendship with Oppie. Serber also gives his thoughts on Oppenheimer’s relationship with Jean Tatlock and Tatlock’s psychological issues.