The Research Before December 7, 1941     The idea that nuclear fission could be a significant producer of electrical power and a powerful military weapon occurred to many physicists, engineers and scientist around the world. Due to the escalating conflict in Europe, many scientist no longer published their discoveries and advancements for fear of it aiding enemy scientist. There was one difficulty encountered early on in the development of Manhattan Project, this problem was the difficulty of mining or creating the proper uranium isotope. Uranium-235 was the only isotope of uranium that underwent fission and only 0.7% of the uranium found in nature was of this isotope. More commonly uranium-238 was found, which actually inhibited the nuclear chain reaction. There were however several techniques which will be mentioned later for enriching the uranium. Do to how rare and expensive uranium-235 was it was first necessary to determine how much would be needed to create fission reactor or bomb.     A group of Hungarian Jewish refugee physicists named, Leo Szillard, Edward Teller, and Eugene Wigner initiated the movement towards developing a program to analyze and determine whether a weapon could be created using nuclear fission. They sought the help of Albert Einstein, who was at the time possibly the worlds most famous physicist. Albert Einstein and Leo Szilard then proceeded to write the Einstein-Szilard letter on August 2, 1939, warning president Franklin D. Roosevelt, that a powerful bomb could be created and that the Germans may have already begun development of such a bomb. The letter then urged the President to allocate some funds to further the research in the United States to determine if creating such a weapon was possible. Roosevelt authorized the creation of the Uranium Committee which began research programs in 1939 at the Naval Research Laboratory in Washington. More research was being done by Enrico Fermi, at Columbia University, where he was making prototype nuclear reactors by basically piling a mixture of graphite and uranium. However, research proceeded at a relatively slow rate because the United States had not yet entered the war.     While the research was conducted at a leisurely pace in the United States, the United Kingdom was conducting research at an accelerated rate. Then in the United Kingdom a breakthrough was made in March of 1940 as Austrian physicists, Otto Frisch and German Rudolf Peierls calculated that an atomic weapon would only need 1 kilogram of uranium-235. This was far less than an initial calculation of 130 tons or uranium-235 that German physicists Werner Heisenberg calculated. Later the British MAUD Committee confirmed that a uranium would work with just 25 pounds of enriched uranium and would produce an explosion equal to that of 1,800 tons of TNT. This information was sent to the Uranium Committee in the United States but was ignored by the Lyman Briggs, chairman of the committee, had ignored this information and kept it secret from the other members. When members of the MAUD Committee in Britain found out about this an effort was made to take control of the weapons research in the United States out of Briggs hands. Then following a meeting with Roosevelt in October of 1941 in November of 1941 a full-scale effort was authorized by the President to develop a nuclear weapon. Ironically, the first meeting of the new committee formed with this acceleration of research took place on December 6, 1941 the day before Pearl Harbor and the United States entering World War II.