On the morning of August 6, 1945, a B-29 bomber named Enola Gay flew over the industrial city of Hiroshima, Japan and dropped the first atomic bomb ever known to this world. In result of the immense power withheld in the twenty thousand tons of TNT Hiroshima went up in flames. For the United States government the project was a success. The Atomic Bomb ended World War II, but began serious controversies concerning its power and destructive potential. In this paper the question of what led to the development and use of the A-bomb will be answered.
The Manhattan Project became the code name for the Top Secret US effort to produce an atomic bomb during WWII. It was named after the Manhattan engineer district of the US army, because a large amount of the early research for the bomb was done in New York City. According to The first idea for the bomb came from the discovery of nuclear fission in 1938 by German Scientists, when many US scientists became fearful with the idea that Hitler might attempt to build a fission bomb. (The Manhattan Project, P. 24) Upset by the idea that Germany would be farther advanced than the US, in the building of a bomb, Leo Szilard wrote a letter to Albert Einstein. The idea was for Einstein to use his influences in Science to write a letter to the president of the United States, Franklin D. Roosevelt. In the letter Einstein pleaded for the support to further the research on the power of nuclear fission. The letters were completely successful, and President Roosevelt granted funding to begin the Manhattan Project. (Day of the Bomb, Pgs. 26-30)
On October 21, 1939, just 10 days after FDR received the letter about the idea for the A-bomb, the first advisory meeting of the Briggs Uranium Committee was held in Washington DC upon President Roosevelt?s order. But once the meeting took place the interest in the idea slowly diminished in the US. (URL, The Manhattan Project. P.2) So most of the further research was held in the UK. In February of 1940 two physicists living in the UK, developed an analysis for fast fission. Their names were Otto Frisch and Rudolf Peierls. These two men came to new ideas in developing an Atomic Bomb. Upon their presentation they discovered the mass, efficiency and other strong ideas for the design and construction that would be the best for the U-235. Their report spread quickly to scientists and top officials who had been appointed to building the atomic bomb. These two men changed the whole idea of the Atomic Bomb. Once their report had reached the Briggs Committee, the committee was so persuaded that they again started to work on the A-Bomb project. (URL, The Manhattan Project. P.2)
On April 10, 1940 the highest levels of government formed a new committee, in regards to the convincing report that Frisch and Peierls had given. They named the Committee MAUD. (Day of the Bomb P.62) This committee decided upon the idea of using gaseous diffusion as the most promising component for Uranium enrichment. (URL, The Manhattan Project. P.2) Between April of 1940 and 1941 work in the US increased immensely for the Manhattan Project. In 1941 Philip Abelson and Arthur Wahl developed new systems for uranium and plutonium development. With these new ideas it enabled Peierls to calculate the first estimated mass of the U-235, which was 10 lb when surrounded by a reflector. In testing these men found that Plutonium demonstrated itself to be the most useful component for fissile material. (URL, The Manhattan Project. P.2) Once all of the ideas and testing had been put together the MAUD committee completed a report describing the building and project ideas needed to build an atomic bomb.
The Second World War erupted right as the promise of atomic energy had progressed from being just an idea, to becoming a physical structure. On June 18, 1942 Col. James Marshall was ordered to organize an army corps of the engineers district to take over the highly top-secret atomic bomb development. On September 18, three months after the team of engineers had been put together by Col. Marshall, he appointed Colonel Leslie R. Groves to head the project. Col. Groves had worked in the Pentagon and went into heading the project with a strong sense of leadership. He immediately ordered twelve hundred and fifty tons of Uranium ore to be stored on the Staten Island base. Groves took the position of heading the project with full force beliefs for order in every branch of the Manhattan Project. This quick action started the physical process for building the Atomic bomb.
Col. Groves chose J. Robert Oppenheimer to hold the title of Scientific director for the bomb project. He was a theoretical mathematician who was sent to the isolated area of Los Alamos, New Mexico. Among Oppenheimer were a group of people hired to design and help build the atomic bomb. The group included the brightest and most talented individuals from the military and other Academic scholars who held jobs in scientific math. Almost every person was unknowingly sent to an isolated mountain in New Mexico to develop The Manhattan Project.
The atomic bomb was a nuclear explosion caused by the release of energy upon the splitting of the nuclei, from the elements of Plutonium or Uranium. The neutron then strikes the nucleus atom of the isotopes U235 or Plutonium-239, and it causes them to split into two fragments releasing thermal energy and Gamma Rays. Under force the neutrons will strike making fission surround the Uranium Nuclei, which let out more neutrons to split more nuclei. This series of chain reactions is what generates the explosion for the atomic bomb. (Britannica: atomic Bomb. URL) So in order to build this bomb the staff needed a heavy supply of Fissile materials. Col. Groves had ordered twelve hundred and fifty tons of Uranium ore to be stored. The most complicated issue addressed by the scientists working on the Manhattan Project was “the production of ample amounts of enriched uranium to sustain a chain reaction.”(The Manhattan Project p.79) At the time, Uranium-235 was hard to produce. Of the Uranium ore mined, only about 1/500th of the original ore ended up being used as Uranium metal. (URL, The Manhattan Project. P.2)
The Construction of the bomb was held like a roller coaster. One day the project would be running fine, and the next day the twelve hundred thousand tons of graphite used for the bomb, would be cooled by water. Problems were presented left and right to the building staff. By February 1944 the bomb was only half built and leaks from the metal binding were sprung everyday. (Britannica: Manhattan Project. URL) In 1944 the work was proceeded to three fronts. There were weapon development, Fissile material production and combat delivery preparations. The first two ideas held many problems. The materials and production ran everyway but smoothly.
On July 4, 1944 Oppenheimer revealed an idea to the staff that was a turning point for the project. The production of plutonium was too high for regular gun assembly to work, and the fission rate in the Hanford plutonium from the bomb would be a hundred times higher still. (Britannica. Atomic Bomb. URL) With only having 12 months until the weapon was to be delivered, a new idea of explosive shaping had to be invented. The crisis ran the project. Day and Night scientists worked until the new idea was found. The scientists found a way to lower the level of plutonium needed to run the fission rate of the bomb. The bomb became finished, and was delivered just a few days after its expected date.
For President Truman, the Decision to drop the atomic bomb was never ending. FDR had died on April 12, three months before the first successful Trinity test. The responsibilities were soon placed upon Truman, the next president. Truman knew nothing about the bomb for it had been kept secret even from him. He decided to send the bomb to Japan. Considering Germany was no longer a target with the war. Szilard initiated a petition, for he felt a responsibility to stop what he had once helped to build. The petition
was sent to the president. Szilard gave the opinion that the bomb should be used only if Japan refused to surrender, because the US was extremely susceptible to Atomic warfare due to the Large Metropolitan Areas. (No High Ground, P.99-100)
Two different types of bombs were sent to Hiroshima and Nagasaki. The Hiroshima bomb was known as a gun-barrel-type atomic bomb. It was assembled August 1st. (No High Ground, p.130) Due to its long and narrow shape, the Hiroshima model was called “Thin Man” at first, but during the manufacturing process the original plans were modified, shortening the length and giving rise to the name “Little Boy.” It weighed around ten thousand pounds. The energy released from the Hiroshima A-bomb was thought to be equivalent to the destructive power of twenty thousand tons of TNT. (No High Ground, p.229) This bomb was tested on July 16, 1945 at a sight in New Mexico. When the bomb was dropped upon Hiroshima Aug 6, 1945 it devastated 10 miles. Sixty-six thousand people died instantly, sixty-nine thousand were injured. (Britannica: Atomic Bomb) The next bomb was sent to Nagasaki, Japan. The fissionable material used in the Nagasaki bomb was plutonium 239. The plutonium 239 was divided into below-critical-mass units and packed into a spherical case. (Brittanica: Atomic Bomb) The Nagasaki bomb was shaped like a teardrop. (No High Ground, P.84-85) The Nagasaki model is known as an implosion-type atomic bomb. Compared to the Hiroshima A-bomb, the one used in Nagasaki was larger in diameter and rounder so it was called “Fat Man.” (No High Ground, P.84-85) This bomb was sent Aug. 9, 1945. It was larger than the U-235, and it produced a blast equal to twenty-one thousand tons of TNT. Thirty-nine thousand people were killed, and Twenty-five thousand people were injured. (Britannica: Atomic Bomb) The next day the Japanese army surrendered.
Just after the bomb was sent to Hiroshima President addressed the nation with a speech. ? Sixteen hours ago an American airplane dropped one bomb on Hiroshima, an important Japanese Army base. That bomb had more power than twenty thousand tons of T.N.T. It had more than two thousand times the blast power of the British ?Grand Slam? which is the largest bomb ever yet used in the history of welfare. The Japanese began the war from the air at Pear Harbor. They have been repaid many fold. And the end is not yet… It is an Atomic Bomb. It is harnessing of the basic power of the universe. The force from which the sun draws its power has been loosed against those who brought war to the far east…..It was to spare the Japanese people from utter destruction that the Ultimatum of July 26 was issued at Potsdam. Their Leaders promptly rejected that ultimatum. If they do not now accept our terms they may expect a rain a ruin from the air, the like which had never been seen o!
n this earth….(No High Ground, P. 231)
Even though this speech was stated fifty years ago, President Truman is still remembered through these words.
The bombs were sent over to Japan in order to end the war. The US had to prove they held a power out of reach to any other country. The bomb killed one hundred thousand, wounded one hundred thousand and destroyed over ninety percent of Hiroshima. President Truman hailed the bomb as ?the greatest thing in History.? (Higher Ground, P. 231) But many people, including the scientists themselves who developed the bomb, opposed the bombings. They felt it was immoral to kill that many people just to get an influence over the war. But isnt that what war is about Doing what you can to push the world one way or another. The Manhattan Project was one of the most important parts of American History. Its use has effected our world, and because of this man made weapon we have changed the way we live today.