At 8:15 on the morning of August 6, 1945, a person sat on a flight of stone stairs leading up to the entrance of the Sumitomo Bank in Hiroshima, Japan. Seconds later, an atomic bomb detonated just 800 feet away, and the person sitting on the stairs was instantly incinerated. Gone like that. But not without leaving a mark. By a flash of the heat rays with temperatures well over a 1,000 degrees or possibly...