Enrico Fermi was a Nobel Prize winning physicist who worked on the Manhattan project. Among his many contributions, his most important was a demonstration that a fission reaction could be sustained.Enrico-Fermi.jpg
Enrico Fermi was originally a German scientist, but when Hitler took power, he used an opportunity, winning a Nobel Prize in Switzerland, to escape to America. There, he took up residence at Stanford. ("The Manhattan Project")
In 1940, Fermi was informed of Szilard and Einstein’s goal of developing an atomic weapon before the Germans. Their first step was to create a sustained nuclear reaction. Fermi was tasked with this job.
Initially, Fermi had wanted to use Cook County Forest Preserve, close to Chicago, but when that site proved untenable, Fermi decided to use abandoned squash courts under Chicago’s campus. The dean of UChicago did not grant Fermi permission to conduct such a dangerous experiment, fearing massive death. However, due to the importance of the experiment, Fermi was instructed by the government to continue without permission anyways. ("The Manhattan Project")
On December 2, 1942, Fermi entered the court to begin the first attempted sustained reaction. In front of him stood the world’s first “reactor”, consisting of a five hundred ton pile of graphite, in which cubes of uranium had been inserted.
40 scientists watched as he ordered the experiment to begin. It was generally accepted that if there was a catastrophic meltdown, they would be the first of many casualties. Luckily, the experiment went without a hitch, and Fermi was able to announce at 3:53 pm that “the pile has gone critical”, meaning it could have sustained a reaction. Control rods were reinserted, and the scientists dissipated. ("The Manhattan Project")