“We’re all sons of bitches now.” J. Robert Oppenheimer, in the white hat, and Gen. Leslie Groves, military commander of the Manhattan Project, examine the twisted wreckage that is all that remains of a 100-foot tower, winch and shack that held the first nuclear weapon before its July 16, 1945, detonation. On the far right is Victor Weisskopf of the Manhattan Project’s Theoretical Division.