More than seventy years ago, American forces exploded the first atomic bombs over the Japanese cities of Hiroshima and Nagasaki, causing great physical and human destruction. The young scientists at Los Alamos who developed the bombs, which were nicknamed Little Boy and Fat Man, were introduced to the basic principles and goals of the project in March 1943, at a crash course in new weapons technology. The lecturer was physicist Robert Serber, J. Robert Oppenheimer’s protégé, and the scient...