The history of the Manhattan Project
Who designed the first nuclear bomb?
General Leslie Groves was not your typical army general. He believed that the country with the technological edge would win World War II.
German scientists were well aware that nuclear fission was a possibility as early as 1934. By 1939, at the urging of Albert Einstein in letters to President Roosevelt, a scientific investigation began to look at nuclear reactions. In 1942 there were multiple groups working on the nuclear reaction problem, but General Groves was put in charge of building a team to coordinate the research activity.
Coordinating the Project
The project started in Manhattan, New York. The original name was "Laboratory for the Development of Substitute Materials," but Groves changed it to "The Manhattan Engineer District." He thought that the original name gave away too much information. It then became known as the Manhattan Project.
The history of the Manhattan Project shows there were multiple locations throughout the country. Oak Ridge, Tennessee was the site that produced the enriched uranium U-235 and plutonium production research. Other locations in Hanford, Washington produced plutonium. The Metallurgical Laboratory in Chicago was involved in reactor development. The Ames Laboratory in Iowa was involved in raw uranium production.
Robert J. Oppenheimer Takes the Lead
General Groves knew that he had to get all of the facilities under one controlling authority as well as supervising scientific geniuses. Groves appointed Dr. Robert Oppenheimer to head the project.
One of the first things that Oppenheimer did was to have a central location where all of the research scientists could work without outside interference. He chose Los Alamos. The Los Alamos lab in New Mexico was involved in nuclear bomb research.
Nuclear Weapons Research
As the war progressed, Los Alamos scientists were under pressure to work fast fearing that their German counterparts were ahead of them. Oppenheimer created various units to focus on different aspects of the problem. Research proceeded in two different directions. A uranium bomb would be designed; the other was a plutonium bomb.
The Uranium Bomb
The uranium bomb was a gun-type fission weapon. This was the type used on Hiroshima. A 'bullet' of U-235, a uranium isotope, was fired down a gun barrel into another mass of U-235. This then accumulates and forms a critical mass resulting in a chain reaction, then an explosion.
Oppenheimer was convinced that this method would work, so much so that no test was even carried out before the bomb was dropped over Hiroshima. The technical difficulties in producing the isotope U-235 also meant that there were limited quantities; this fact also entered into why there was no test prior to the drop.
The Plutonium Bomb
The other nuclear bomb developed at Los Alamos was a plutonium bomb. The technical issues were very different this time. In this bomb a perfectly symmetrical implosion around the plutonium was created. The uranium isotope 238 decays into a mass of plutonium 239. So it was easier to produce the plutonium. This time there was more than enough material so a test explosion was planned.
Trinity (Alamogordo, New Mexico)
In July 16,1945 at the test site named Trinity in the desert in Alamogordo, New Mexico the first nuclear bomb was successfully exploded. Since it was early in the morning and still dark when the explosion occurred it lit up the night sky.
Quoting from the Bhagavad Gita, Oppenheimer said upon seeing the fury he helped unleash, "If the radiance of a thousand suns were to burst at once into the sky, that would be like the splendor of the mighty one. Now I am become Death, the destroyer of worlds."
On Monday, August 6, 1945, flying on the B-29 "Enola Gay" the uranium bomb called "Little Boy" was dropped over Hiroshima. Over 140,000 civilians were killed and the city was devastated. The U.S. asked Japan to surrender.
Three days after the bombing of Hiroshima when the Japanese did not surrender, "Fat Man," the plutonium bomb, was dropped from the B-29 named "Bockscar" on the city of Nagasaki. This was not the original target, but the city of Kokura was covered by clouds so the secondary target was chosen. Over 80,000 people died from the explosion.
After the War
The United States Atomic Energy Commission took over the authority to produce and develop nuclear weapons after the war. This removed the military control of the Manhattan Project and put nuclear device development under civilian control.
Also, in a move of extreme irony and political sabotage, Oppenheimer had his security clearance revoked in 1954 because he would not lead the development of a hydrogen bomb and his political opinions during the 'red' scare irritated politicians. He was accused of being a communist.
This history of the Manhattan Project shows how determination, fear and scientific energy helped produce the most awesome weapon in the history of man.