During World War II, when his only daughter was a little girl, John von Neumann helped decide which Japanese civilian populations would be targeted for atomic bombing. But far more revealing is that it was von Neumann who performed the precise calculations that determined at what altitude over Hiroshima and Nagasaki the atomic bombs had to explode in order to achieve the maximum kill rate of civilians on the ground. He determined the height to be 1,800 feet.
