The Manhattan Project: Making the Atomic Bomb

Part V: The Atomic Bomb and American Strategy

The Dawn of the Atomic Age

At precisely 5:30 a.m. on Monday, July 16, 1945, the atomic age began. While Manhattan staff members watched anxiously, the device exploded over the New Mexico desert, vaporizing the tower and turning asphalt around the base of the tower to green sand. The bomb released approximately 18.6 kilotons of power, and the New Mexico sky was suddenly brighter than many suns. Some observers suffered temporary blindness even though they looked at the brilliant light through smoked glass. Seconds after the explosion came a huge blast, sending searing heat across the desert and knocking some observers to the ground. A steel container weighing over 200 tons, standing a half-mile from ground zero, was knocked ajar. (Nicknamed Jumbo, the huge container had been ordered for the plutonium test and transported to the test site but eliminated during final planning). As the orange and yellow fireball stretched up and spread, a second column, narrower than the first, rose and flattened into a mushroom shape, thus providing the atomic age with a visual image that has become imprinted on the human consciousness as a symbol of power and awesome destruction. 49

At base camp, Bush, Conant, and Groves shook hands. Oppenheimer reported later that the experience called to his mind the legend of Prometheus, punished by Zeus for giving man fire. He also thought fleetingly of Alfred Nobel's vain hope that dynamite would end wars. The terrifying destructive power of atomic weapons and the uses to which they might be put were to haunt many of the Manhattan Project scientists for the remainder of their lives.50 The success of the Trinity test meant that a second type of atomic bomb could be readied for use against Japan. In addition to the uranium gun model, which was not tested prior to being used in combat, the plutonium implosion device detonated at Trinity now figured in American Far Eastern strategy. In the end Little Boy, the untested uranium bomb, was dropped first at Hiroshima on August 6, 1945, while the plutonium weapon Fat Man followed three days later at Nagasaki on August 9.

Remains of Trinity Test Tower Footings. Oppenheimer and Groves at Center
Remains of Trinity Test Tower Footings. Oppenheimer and Groves at Center