The Atom Bomb
The atom bomb is one of the most important discoveries in modern day science. Countless scientists worked relentlessly on the project and their efforts opened the door for present and future exploration of the atom.
Just before the beginning of World War II, Albert Einstein wrote a letter to President Franklin D. Roosevelt. Urged by Hungarian-born physicists Leo Szilard, Eugene Wingner, and Edward Teller, Einstein told Roosevelt about Nazi German efforts to purify Uranium-235 which might be used to build an atomic bomb. Shortly after that the United States Government began work on the Manhattan Project. The Manhattan Project was the code name for the United States effort to develop the atomic bomb before the Germans did. "The first successful experiments in splitting a uranium atom had been carried out in the autumn of 1938 at the Kaiser Wilhelm Institute in Berlin" Just after Einstein wrote his letter. So the race was on. Major General Wilhelm D. Styer called the Manhattan Project "the most important job in the war . . . an all-out effort to build an atomic bomb." It turned out to be the biggest development in warfare and science's biggest development this century.
The most complicated issue to be addressed by the scientists working on the Manhattan Project was the production of ample amounts of enriched uranium to sustain a chain reaction. At the time, Uranium-235 was hard to extract. Of the Uranium ore mined, only about 1/500th of it ended up as Uranium metal. The Uranium metal is relatively rare, occurring in Uranium at a ratio of 1 to 139.
Separating the one part Uranium-235 proved to be a challenge. No ordinary chemical extraction could separate the two isotopes. Only mechanical methods could effectively separate U-235 from U-238. Scientists at Columbia University solved this difficult problem.
A massive enrichment plant was built at Oak Ridge, Tennessee. H. C. Urey and his associates and colleagues at Columbia University designed a system that worked on the principle of gaseous diffusion. After this process was completed, Ernest O. Lawrence from the university of California in Berkeley implemented a process i nvolving magnetic separation of the two isotopes. Finally, a gas centrifuge was used to further separate the Uranium-235 from the Uranium-238. The Uranium-238 is forced to the bottom because it had more mass than the Uranium-235. This Uranium was then transported to a laboratory headed by J. Robert Oppenheimer. Oppenheimer was the major force behind the Manhattan Project. He literally ran the show and saw to it that all of the great minds working on this project made their brainstorms work. He oversaw the entire project from its conception to its completion. Once the purified Uranium reached New Mexico, it was made into the components of a gun-type atomic weapon. The scientists were so confident that the gun-type atomic bomb would work that no test was conducted and it was first employed in military action over Hiroshima, Japan, on Aug. 6, 1945.
Once again the University of Chicago, under Enrico Fermi's direction built the first reactor. This led to the construction of five large reactors at Hanford, Wash., where U-238 was irradiated with neutrons and changed into plutonium. The plutonium was sent to Los Alamos.
There was a debate at Los Alamos about whether to test the new plutonium 'implosion' bomb before it was actually dropped. "Harvard explosives expert George B. Kistiakowsky and Oppenheimer both argued for such a test, but initially Groves was opposed. He was afraid that if the test failed, the precious plutonium would be scattered all across the countryside."(Szasz 26) Brigadier General Leslie R. Groves, the man the army placed in charge, was eventually persuaded. Hanford's plutonium production was increasing fast enough so that a test would cause little delay in time. They feared that if they dropped the untested plutonium bomb and it failed to work, "the enemy would find themselves owners of a 'gift' atomic weapon."(Szasz 26) The final agreement for the test was that the bomb would be placed in "a gigantic, 214-ton, cylinder-shaped tank (called 'Jumbo')."(Szasz 26) If the plutonium correctly fissioned, the tank would be vaporized. If it did not work correctly, the conventional explosives would be contained in the tank and the plutonium would