Why the Manhattan Project was Born

Logan Panchot
November 27, 2019

Submitted as coursework for PH241, Stanford University, Winter 2019

The Discovery that Changed Everything: Fission

Fig. 1: This is a photograph of the letter that was sent to Roosevelt by Szilard and Wigner to communicate the possible danger of new weapons being made by enemies. Albert Einstein also signed the letter. (Source: Wikimedia Commons)

In early 1939, German scientists Otto Hahn and Fritz Strassmann published a research paper describing how they split uranium into barium by exposing it to a large number of neutrons. [1] Soon after, Lise Meitner and Otto R. Frisch came out with a publication that used Neils Bohr's model of the atom to explain the aforementioned division. [1] They called this process fission. Fission would prove to be a discovery that changed the course of not only World War II, but also modern warfare. This discovery would lead to the creation of weapons that can cause catastrophic destruction.

The process of fission was proven to release large amounts of energy and also to release neutrons. These extra neutrons released were able to cause a chain reaction by colliding with other atoms. [2] A controlled version of this chain reaction can be used to create large amounts of energy, and an uncontrolled version can create an explosion of destructive magnitude. [2]

Using Fission for Weapons

During the time of these groundbreaking scientific discoveries, due to the political state of Germany caused by the election of Hitler, many scientists, including Lise Meitner, fled the country because they did not want the information they understood to get in the wrong hands. [2] Enrico Fermi, an Italian Scientist who won the 1938 Nobel Prize for Physics was another notable scientists who left his country and never returned due to fascists rule. [3] Fermi would be a key figure in the nuclear research that would take place in the United States.

After further developments, prominent American nuclear scientists Leo Szilard, Eugene Wigner, and Albert Einstein wrote a letter to warn the United States government that it was a possibility that the Germans were using fission for military purposes. These purposes were feared to be the creation of a weapon more powerful than anything else the world had seen before. [4] Szilard, Wigner, and Einstein felt that the matter was of the utmost importance and needed to be communicated to the leaders of the United States. While the United States was still at peace, Roosevelt, the president at the time of these events, took the warning seriously. The president chose trusted individuals to make a team to look into the possibility of making destructive weapons from uranium. [1] These individuals participated in a project that would research the possibilities of using fission to create a large energy release that could power a bomb of unforeseen proportions.

Roosevelt Approves Action

In October 1939, Roosevelt approved the creation of an advisory board concerning nuclear developments. [3] Soon after he approved action, the committee reported back to Roosevelt that uranium processes were capable of providing a weapon that was much more destructive than any of the current weapons they knew of. In 1940, this advisory board became the National Research Defense Council headed by Vannevar Bush. [1] A further division was soon put in place by the Army Corps of Engineers that could handle the construction and creation of an atomic bomb. This division would become what is now known as the Manhattan Project. [1]

Overview of the Project

The Manhattan Project was a project that was led by the United States and supported by Canada and the United Kingdom during World War 2. [5] The purpose of this project was to create and ready the United States and its allies to use atomic weapons. This project officially began in 1939. At the time of conception, the project had 1,000 employees, but by the time the project gained maximum momentum, it employed over 130,000 people and had a budget of about $2 billion US dollars. [3] A large portion of this budget was dedicated to building factories to create fissile material and only 10% of the budget was allocated to actually building the atomic weapons. The Manhattan Project proved to be a catalytic project that altered World War II and the way wars are now carried out.

© Logan Panchot. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.

References

[1] O. Hahn, "The Discovery of Fission," Scientific American 198, No. 2, 6 (February, 1958).

[2] J. Lee, "The Manhattan Project," Physics 240, Stanford University, Fall 2012.

[3] J. Hughes, The Manhattan Project (Columbia University Press, 2002).

[4] J. Belanger, "The Manhattan Project," Physics 241, Stanford University, Winter 2013.

[5] L. R. Groves, Now It Can Be Told: The Story of the Manhattan Project (Da Capo Press, 1983).