Hiroshima & the End of WWII

On the morning of July 16, 1945, the sky over the Jornada del Muerto desert in New Mexico turned white. Then it turned orange. Then a shock wave flattened the scrub brush for miles, and a mushroom cloud climbed 40,000 feet into the atmosphere. J. Robert Oppenheimer, the physicist who had directed the effort, later said he thought of a line from the Bhagavad Gita: "Now I am become Death, the destroyer of worlds." Kenneth Bainbridge, the test director, was more concise. He turned to Oppenheimer and said: "Now we are all sons of bitches."

The Trinity test was the culmination of the A secret U.S. government research program (1942-1945) that developed the first nuclear weapons. Employing over 125,000 people across more than 30 sites, the project cost nearly $2 billion (roughly $30 billion in today's dollars). It was led by physicist J. Robert Oppenheimer and Army General Leslie Groves. Most of the workers did not know what they were building., a three-year crash program to build an atomic weapon before Nazi Germany could. The project employed 125,000 people at its peak, spread across secret facilities in Oak Ridge, Tennessee; Hanford, Washington; and Los Alamos, New Mexico. Most of these workers had no idea what they were making. Compartmentalization was the rule. Machinists shaped uranium components without knowing their purpose. Secretaries typed reports with code names and blanked-out paragraphs.

The bomb existed because physics allowed it. In 1938, German chemists Otto Hahn and Fritz Strassmann had demonstrated nuclear fission, the splitting of a uranium atom's nucleus. Physicists immediately understood the implication: if a chain reaction could be sustained, the energy released would dwarf any conventional explosive by orders of magnitude. A single kilogram of uranium-235, fully fissioned, releases the energy equivalent of about 17,000 tons of TNT.