The+History+of+the+Atomic+Bomb

On August 2nd 1939, just before the beginning of World War II, Albert Einstein wrote to then President Franklin D. Roosevelt. Einstein and several other scientists told Roosevelt of efforts in Nazi Germany to purify U-235 with which might in turn be used to build an atomic bomb. It was shortly thereafter that the United States Government began the serious undertaking known only then as the Manhattan Project. Simply put, the Manhattan Project was committed to expedient research and production that would produce a viable atomic bomb.

The most complicated issue to be addressed was the production of ample amounts of `enriched' uranium to sustain a chain reaction. At the time, Uranium-235 was very hard to extract. In fact, the ratio of conversion from Uranium ore to Uranium metal is 500:1. An additional drawback is that the 1 part of Uranium that is finally refined from the ore consists of over 99% Uranium-238, which is practically useless for an atomic bomb. To make it even more difficult, U-235 and U-238 are precisely similar in their chemical makeup. This proved to be as much of a challenge as separating a solution of sucrose from a solution of glucose. No ordinary chemical extraction could separate the two isotopes. Only mechanical methods could effectively separate U-235 from U-238. Several scientists at Columbia University managed to solve this dilemma.

