The Manhattan Project was the name given to the operation carried out by the United States government during World War II whose aim was to develop the first nuclear bomb, due to a threat from Nazi Germany.
During the Second World War the United States government had began to hear rumours that the Nazi’s were carrying out research which would lead them to develop a nuclear bomb. In response to this Franklin D. Roosevelt, the American President, started a similar project to the Nazi’s as he realised that the first person to develop the bomb would win the war. Much work towards the atomic theory had already begun by scientists such as John Crockroft and Ernest Walton, who in 1932 managed to split the atom. This would be the bases for the atomic bomb. Though now that the Nazi’s had began work on their atomic bomb Roosevelt felt they needed to up their game. So During June 1942 The Manhattan Project went underway.
Scientists progressed quickly before and after the beginning of the Manhattan Projiect, constantly improving their knowledge of the inner workings of the atom. In 1934 Enrico Fermi decided to bombard elements with neutrons instead of protons as was the initial way. This idea came about by James Chadwick saying particles of no charge will pass through into the nucleus with no resistance whereas before the reactions very rarely hit the nucleus so no effects occurred.
This idea dominated and Albert Einsteins equation E=mc2 was focused upon. Atoms that split had very little nucleus change but the uranium atom upon impact split into to new atoms of equal size, barium. The equation showed that there was loss of mass and so there must have been a great amount converted to energy and so a new unseen process was discovered by Otto Frisch and Lise Meitner called fission.
Fission is a chain reaction, the uranium splits by bombardment of neutrons which releases energy and more neutrons, these then cause more reactions of uranium and so even more energy is expelled. In some fission reactions plutonium is used instead, this is because it is easier to obtain than uranium. An important point of fission is the Critical Mass, chain reactions would not occur if the material is not close together,(subcritical mass) in an atomic bomb the uranium or plutonium must be close together.
One of the main objectors to the atomic bomb was Szilárd, Szilárd contributed heavily to the development of the atomic bomb; however he never wanted the bomb to be used on humans. He felt that the bomb should only be used as a threat to force the Japanese into surrender. He made the Szilárd petition, its main aim was to stop the bomb being used on humans, He managed to get over 150 scientists to sign the petition and he then sent it to the president. However the petition never made it to the president and was only made public in 1961, which meant that the petition was completely unsuccessful.
There were two detonation ideas for the bomb, one is the ‘gun-triggered’ method, and the other the ‘implosion’ method.
Two bombs were dropped, the Little Boy and the Fat Man, using the ‘gun-triggered’ and ‘implosion’ methods respectively.
The ‘gun-triggered’ was long and how a barrel. It used uranium as fuel and in two places. A small amount was used as a ‘bullet’ that was fired down the barrel hitting the larger piece and causing the explosion. This bomb was used against Hiroshima and produced a 14.5 kiloton yield.
The ‘implosion’ method used plutonium instead of uranium as fuel and although used in the second bomb it was also used in the testing of the bomb at Trinity Test site. The ‘implosion’ type concentrates the explosion at the centre of the bomb by having explosives surround the core which contains the plutonium, this creates a more efficient bomb producing 23 kilotons yield and was used against Nagasaki.
Oppenheimer, who was nicknamed the father of the atomic bomb, was reported to say when seeing the test Bomb go off “I am become death, destroyer of worlds”.
Perhaps Einstien had other ideas for the control of the atom. With such power harnessed we will be able to overcome later problems when oil becomes short.
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