When they went badly, the results could be catastrophic. Even when things went as planned, early atmospheric tests threw fallout into the atmosphere that could wind up hundreds of miles away or more. Other countries and even non-state actors could choose to build covert nuclear programs.” On the firing line

“Nuclear technology is only getting easier,” said Melissa Hanham, deputy director of the Open Nuclear Network. It was the equivalent of detonating 15,000 tons of TNT, according to Los Alamos National Laboratory calculations. Only 1.09 kg of the 64 kg of uranium in Little Boy became energy. The concept was simple: driving together enough uranium or plutonium at high enough speeds will create a “critical mass” so quickly that it will start an uncontrolled, nearly instantaneous chain reaction of neutrons knocking apart atomic nuclei.Įach atom’s lost mass is converted to energy at a staggering exchange rate. And it was tested only once-an event so momentous that one of the bomb’s chief scientists, Robert Oppenheimer, said it brought to mind words from Hindu scripture: “Now I am become death, destroyer of worlds.” “Little Boy,” as it was known, was the endpoint of years of research, wrangling a physics theory into a mechanism to release the energy that binds together atoms. 6, 1945, killed tens of thousands and flattened the Japanese city in an instant. The atomic bomb that the United States dropped on Hiroshima on Aug.

Fission device