History of the Atomic Bombs

History of the Atomic Bombing 

of Hiroshima and Nagasaki

Leo Szilard

• In 1939, Leo Szilard, one of the world's top physicists, had heard that German scientists had split the Uranium-235 atom.
• Worried that the Nazis were working on an atomic bomb, Szilard convinced Albert Einstein to send a letter drafted by Szilard to President Roosevelt warning him about "extremely powerful bombs of a new type..."
• Roosevelt set up a scientific committee to study the issue, and the committee met up with British scientists who had already been working on the atomic bomb.
• The Manhattan Project: the American program to build the atomic bomb
• Headed by Leslie R. Groves
• The atomic bomb was built at a secret laboratory in Los Alamos, New Mexico
• Led by J. Robert Oppenheimer
• On December 7, 1941, the day which shall live in infamy, a US naval station, Pearl Harbor, was bombed by the Japanese in Hawaii.



This bomb was used during the Trinity Test, the experiment
in which the first atomic bomb was detonated.



The Manhattan Project Team


• Allowed the US to even contemplate using the atomic bomb
• After World War II ended in 1945, the US still felt aggression towards Japan and the Manhattan Project was underway.
• On July 26th, 1945, the US, United Kingdom and the Republic of China demanded the surrender of Japan in the Potsdam Declaration under the threat of "prompt and utter destruction"
• On August 6th, 1945, the United States dropped "Little Boy" on Hiroshima
• B-29 bomber named the Enola Gay
• 8:15 a.m.
• Destroyed 76,000 buildings
• 80,000-120,00 people died instantly
• On August 9th, 1945, the United States dropped "Fat Man" on Nagasaki
• 35,000-74,000 people died
• August 15th, 1945, V-J Day, Japan surrendered