During the first few decades of the twentieth century, the world made huge advances in the understanding of physics. These advances included the discovery of the nucleus, the concept of radiation and the fact that the splitting of a number of atomic nuclei in a chain reaction could lead to a huge release of energy. This is now known as nuclear fission.
Call to Attention of the Nuclear Threat from Germany
In October 1939, President Franklin D. Roosevelt received a letter from the German mathematician and physicist Albert Einstein. The letter discussed the possibility of making extremely powerful weapons was possible following new research. The use of chain reactions utilizing uranium could create enough energy to cause devastating effect in a weapon form. The letter also urged Roosevelt to act so that the allies had nuclear capabilities before the German's, who were reportedly working on the development of their own nuclear weapons.
The British, who had made significant theoretical contributions at the start of the war did not have the resources to pursue a serious atomic bomb research program, so they sent many of their top scientists to help the United States.
The Manhattan Project
Roosevelt appointed Lyman J. Briggs to be head of the Advisory Commission on Uranium which met for the first time on 21 October 1939. They agreed the need to fund a number of projects focussing on different parts of atomic and nuclear physics.
Finally, in June 1942, the US initiated The Manhattan Project which was directed by Leslie R. Groves, the Chief of Construction of the US Army Corps of Engineers. Meanwhile, at the University of Chicago scientists were expanding the knowledge of atomic theory and on 2 December 1942, the first controlled nuclear reaction occurred.
Now that it was known that it was possible to harness nuclear energy, scientists realised the need for fuel to power the nuclear reactors with Uranium and Plutonium being the only suitable substances known at the time.
The project scientists did not know which would be best to use, so they decided to produce both at two locations, Oak Ridge, Tennessee and Hanford, Washington.
Los Alamos, New Mexico
J. Robert Oppenheimer was one of the scientists working on the project and he and Groves chose the site of Los Alamos, New Mexico to be the site where the first atomic bombs were to be designed and built. The site contained a boys schools which the project bought and used as a base for the project.
Over the next few years, the scientists at the Los Alamos site carried out hundreds of tests before they finally developed a serious prototype.
The first nuclear weapons test, which was code named Trinity, was conducted on 16 July 1945 at the Los Alamos site. The project scientists had bets on how successful and powerful the bomb test would be. Estimates ranged from no explosion at all, to the destruction of New Mexico and also the destruction of the atmosphere which would lead in the incineration of the world.
The weapon worked by setting of a nuclear fission reaction within a bomb casing which, when set off, creates a huge amount of energy which caused devastating effect.
The test was successful and lead to the immediate development of the Little Boy and Fat Man atomic bombs which were dropped on the Japanese cities of Hiroshima and Nagasaki respectively in August 1945, which lead to Japan surrendering.
