this atomic weapon, code-named Little Boy, detonated over Hiroshima at an altitude of 1,900 feet—an airburst, as it’s known. This was the first nuclear weapon used in battle. Its burst height was based on a figure that had been precisely calculated by the American defense scientist John von Neumann, whose assigned task was to figure out a way to kill the most people possible on the ground below with this single atomic bomb.
