Dr. Harold Edgerton developed the Rapatronic Photographic technique in the 1940s. It was able to record very early times of a nuclear explosion’s fireball growth on camera. The exposures were as short as 10 nanoseconds.
Each rapatronic camera would take just one picture. A group of four to ten cameras were arranged at test sites to shoot different intervals of the nuclear explosion to see the increase in fireball growth.
Early bomb light passed through the cell, which precisely gated the inbound light stream for exposure on the photographic film. Nuclear weapons were designed on two principles, fission and fusion. Both reactions release large quantities of energy from small amounts of matter.
The first atomic bomb released the same amount of energy as 20,000 tons of TNT. The first thermonuclear or hydrogen bomb released the same amount of energy as 10,000,000 tons of TNT. A modern thermonuclear weapon weighs only 2,400 pounds.