Timeline: HIstory Of the Manhattan Project

Feb 12, 1932

Neutron is Discovered

The exsistence of neutrons is discoverd by Sir James Chadwick

Sep 12, 1932

Leo Szilard generates the idea of an atomic bomb

More than six years before the discovery of fission, Leo Szilard comes up with of creating an atomic bomb with a controlled release of atomic power through a multiplying neutron chain reaction.

Jul 4, 1934

Leo Szilard patents his idea of an atomic bomb.

Leo Szilard files a patent application for the atomic bomb, the patent was granted and thus making him the legal inventor of the atomic bomb.

Oct 8, 1935

British War Office accepts Mr. Szilard's deal to keep the atomic bomb a secret

Mr. Szilard did not want to patent the idea for himself, but to keep the atomic bomb away from the wrong hands. So he gave the idea away to the British military for free so they could keep it a secret.

Dec 21, 1938

Nuclear Fission is discovered

Otto Hahn and Fritz Strassmann are the first scientists to officially acknoledge nuclear fission by splitting a uranium atom.

Jan 29, 1939

Robert Oppenheimer realizes the possibility of building an atomic bomb

After the discovery of fission in 1938, Oppenheimer saw that with the excess neutrons formed by fission it was possible to build a bomb.

Feb 5, 1939

NIels Bohr discovers crucial insight on the principles of fission

Bohr discovers that U-238 could be fissioned by fast neutrons but not slow ones, and that U-235 accounted for observed slow fission in uranium.

Mar 1, 1939

Fermi and Herbert Anderson determine that there are about two neutrons produced for every one consumed in fission

Jul 3, 1939

Szilard comes up with the idea of using graphite to make a chain reaction

Szilard writes to Fermi describing the idea of using a uranium lattice in carbon (graphite) to create a chain reaction. This is the first proposal of the graphite moderated reactor concept.

Aug 31, 1939

Bohr and John A. Wheeler publish a theoretical analysis of fission

This theory implies U-235 is more fissile than U-238, and that the undiscovered element 94-239 is also very fissile. These implications are not immediately recognized though.

Sep 1, 1939

Start of WWII

Germany invades Poland.

Oct 11, 1939

The Einstein Letter

Leo Szilard and Albert Einstein work together to write a letter informing FDR of the possibliblity of the construction of nuclear weapons.

Feb 1, 1940

Possibility of fast fission and ideas for bomb design

Physicists Otto Frisch and Rudolf Peierls, living in the UK prepared a theoretical analysis of the possibility of fast fission in U-235. They also begin to generate ideas for bomb design, this becomes the roadmap for fission weapon development.

Feb 26, 1940

Plutonium

Glenn Seaborg and Arthur Wahl discover plutonium

Jul 1, 1941

Plutonium is found to be extremly fissle

Plutonium was demostrated to be a superior fissle material

Sep 17, 1942

Creation of the Manhattan Project

The Manhattan project is started after Col. Leslie Richard Groves was notified at 10:30 a.m. by Gen. Brehon Somervell that his assignment overseas had been cancelled. Col. Leslie took complete charge over the project afterwards.

Oct 15, 1942

Dr. J. Robert Oppenheimer is asked to head Project Y

Project Y is now being headed by Dr. J Oppenheimer. Project Y is the new central laboratory for weapon physics research and design.

Nov 16, 1942

Project Y location

Los Alamos, New Mexico is decided to be chosen as the location for Project Y.

Dec 1, 1942

Chicago Pile 1 Reactor built

After 17 days of round-the-clock work Fermi's group completed CP-1.This was sooner than planned. It contained 36.6 metric tons of uranium oxide, 5.6 metric tons of uranium metal, and 350 metric tons of graphite.

Dec 2, 1942