On this day, Enrico Fermi, the Italian-born Nobel Prize-winning physicist, directs and controls the first nuclear chain reaction in his laboratory beneath the bleachers of Stagg Field at the University of Chicago, ushering in the nuclear age. Upon succesful completion of the experiment, a coded message was transmitted to President Roosevelt: “The Italian navigator has landed in the new world.”
Following on England’s Sir James Chadwick’s discovery of the neutron and the Curies’ production of artificial radioactivity, Fermi, a full-time professor of physics at the University of Florence, focused his work on producing radioactivity by manipulating the speed of neutrons derived from radioactive beryllium. Further similar experimentation with other elements, including uranium 92, produced new radioactive substances; Fermi’s colleagues believed he had created a new “transuranic” element with an atomic number of 93, the result of uranium 92 capturing a neuron while under bombardment, thus increasing its atomic weight. Fermi remained skeptical about his discovery, despite the enthusiasm of his fellow physicists. He became a believer in 1938, when he was awarded the Nobel Prize in physics for “his identification of new radioactive elements.” Although travel was restricted for men whose work was deemed vital to national security, Fermi was given permission to leave Italy and go to Sweden to receive his prize. He and his wife, Laura, who was Jewish, never returned; both feared and despised Mussolini’s fascist regime.
Fermi immigrated to New York City–Columbia University, specifically, where he recreated many of his experiments with Niels Bohr, the Danish-born physicist, who suggested the possibility of a nuclear chain reaction. Fermi and others saw the possible military applications of such an explosive power, and quickly composed a letter warning President Roosevelt of the perils of a German atomic bomb. The letter was signed and delivered to the president by Albert Einstein on October 11, 1939. The Manhattan Project, the American program to create its own atomic bomb, was the result.
It fell to Fermi to produce the first nuclear chain reaction, without which such a bomb was impossible. He created a jury-rigged laboratory with the necessary equipment, which he called an “atomic pile,” in a squash court in the basement of Stagg Field at the University of Chicago. With colleagues and other physicists looking on, Fermi produced the first self-sustaining nuclear chain reaction and the “new world” of nuclear power was born.
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