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Enrico Fermi in the 1940s.

Enrico Fermi (September 29, 1901 – November 28, 1954) was an Italian-born physicist of United States citizenship most noted for his work on beta decay, the development of the first nuclear reactor, and for the development of quantum theory. Fermi won the 1938 Nobel Prize in Physics for his work on induced radioactivity.

Early years and education

Enrico Fermi was born in Rome, Italy in 1901. When his brother Giulio died during a minor surgery in 1915, 14-year-old Enrico threw himself into the study of physics as a way of coping with his grief. According to his later recollection, he would walk each day in front of the hospital where Giulio had died, until he could look back at the event with detachment.

A friend of the family, Adolfo Amidei, guided the young Fermi's study of algebra, trigonometry, analytic geometry, calculus and theoretical mechanics. Amidei also suggested Fermi attend not a university in Rome but to apply to the prestigious "Scuola Normale Superiore" of Pisa, a special university-college for selected gifted students in 1918. Fermi did especially well, and the examiner at the Scuola Normale thought the 17-year-old Fermi's competition essay worthy of a doctoral exam. He graduated with a doctorate in 1922, and the next year left for the University of Göttingen, then the center of the quantum physics world. Fermi became unhappy, though, with what he saw as an excessively formal theoretical style under the influence of Max Born, and so after six months left for the University of Leiden, Netherlands, to work with Paul Ehrenfest. While there, he also met Albert Einstein.

Physics in Rome

Fermi took a professorship in Rome (the first for theoretical physics in Italy, created for him by professor Orso Maria Corbino, director of the Institute of Physics). Corbino worked a lot to help Fermi in selecting his team, which soon was joined by notable minds like Edoardo Amaldi, Bruno Pontecorvo, Franco Rasetti and Emilio Segrè. For the theoretical studies only, Ettore Majorana also took part in what was soon nicknamed "the Via Panisperna boys" (after the name of the road in which the Institute had its labs).

The group went on with its now famous experiments, but in 1933 Rasetti left Italy for Canada and the United States, Pontecorvo went to France, Segrè left to teach in Palermo.

During their time in Rome, Fermi and his group made important contributions to many practical and theoretical aspects of physics. Some of these include Fermi-Dirac statistics, the theory of beta decay, and the discovery of slow neutrons, which was to prove pivotal for the working of nuclear reactors.

Nobel prize and the Manhattan Project

Fermi remained in Rome until 1938.

In 1938, Fermi won the Nobel Prize in Physics for his "demonstrations of the existence of new radioactive elements produced by neutron irradiation, and for his related discovery of nuclear reactions brought about by slow neutrons".

Fermi (bottom left), Szilárd (second from right on bottom), and the rest of the pile team.

After Fermi received the prize in Stockholm, he, his wife Laura, and their children emigrated to New York. By this time, the Fascist government in Italy had instituted anti-Semitic laws, and Fermi's wife, Laura Capon, was Jewish. Soon after his arrival in New York, Fermi began working at Columbia University.

Laura Fermi, Fermilab

At Columbia, Fermi verified the initial nuclear fission experiment of Hahn and Fritz Strassman (with the help of Booth and Dunning). Fermi then began studies that led to the construction of the first nuclear pile.

Fermi recalled the beginning of the project in a speech given in 1954 when he retired as President of the American Physical Society:

"I remember very vividly the first month, January, 1939, that I started working at the Pupin Laboratories because things began happening very fast. In that period, Niels Bohr was on a lecture engagement at the Princeton University and I remember one afternoon Willis Lamb came back very excited and said that Bohr had leaked out great news. The great news that had leaked out was the discovery of fission and at least the outline of its interpretation. Then, somewhat later that same month, there was a meeting in Washington where the possible importance of the newly discovered phenomenon of fission was first discussed in semi-jocular earnest as a possible source of nuclear power."

Fermi's ID badge photo from Los Alamos.

After the famous letter signed by Albert Einstein (transcribed by Leó Szilárd) to President Franklin D. Roosevelt in 1939, the Navy awarded Columbia University the first Atomic Energy funding of US$ 6,000. The money was used in studies which led to the first nuclear reactor — Chicago Pile-1, a massive "pile" of graphite bricks and uranium fuel which went critical on December 2, 1942, at the University of Chicago. This experiment was a landmark in the quest for energy, and it was typical of Fermi's brilliance. Every step had been carefully planned, every calculation meticulously done by him. When man first achieved the first self sustained nuclear chain reaction, a coded phone call was made to one of the leaders of the Manhattan Project, James Conant: 'The Italian navigator has landed in the new world... The natives were very friendly'. The chain-reacting pile was important not only for its help in assessing the properties of fission — needed for understanding the internal workings of an atomic bomb — but because it would serve as a pilot plant for the massive reactors which would be created in Hanford, Washington, which would then be used to "breed" the plutonium needed for the bombs used at the Trinity test and Nagasaki. Eventually Fermi and Szilárd's reactor work was folded into the Manhattan Project.

He became a naturalized citizen of the United States of America in 1944.

Post-war work

In Fermi's 1954 address to the APS he also said, "Well, this brings us to Pearl Harbor. That is the time when I left Columbia University, and after a few months of commuting between Chicago and New York, eventually moved to Chicago to keep up the work there, and from then on, with a few notable exceptions, the work at Columbia was concentrated on the isotope separation phase of the atomic energy project, initiated by Booth, Dunning and Urey about 1940".

Fermi was one of the few physicists of the twentieth century who excelled both theoretically and experimentally (see link below in 'References'). The well-known historian of physics, C. P. Snow, says about him, "If Fermi had been born a few years earlier, one could well imagine him discovering Rutherford's atomic nucleus, and then developing Bohr's theory of the hydrogen atom. If this sounds like hyperbole, anything about Fermi is likely to sound like hyperbole". Fermi's ability and success stemmed as much from his appraisal of the art of the possible, as from his innate skill and intelligence. He disliked complicated theories, and while he had great mathematical ability, he would never use it when the job could be done much more simply. He was famous for getting quick and accurate answers to problems which would stump other people. An instance of this was seen during the first atomic bomb test in New Mexico on July 16, 1945. As the blast wave reached him, Fermi dropped bits of paper. By measuring the distance they were blown, he could compare to a previously computed table and thus estimate the bomb energy yield. He estimated 10 kilotons of TNT, the measured result was 18.6. (Rhodes, page 674). Later on, this method of getting approximate and quick answers through back of the envelope calculations became informally known as the 'Fermi method'.

Fermi's most disarming trait was his great modesty, and his ability to do any kind of work, whether creative or routine. It was this quality that made him popular and liked among people of all strata, from other Nobel Laureates to technicians. Henry DeWolf Smyth, who was Chairman of the Princeton Physics department, had once invited Fermi over to do some experiments with the Princeton cyclotron. Walking into the lab one day, Smyth saw the distinguished scientist helping a graduate student move a table, under another student's directions! Another time, a Du Pont executive made a visit to see him at Columbia. Not finding him either in his lab or his office, the executive was surprised to find the Nobel Laureate in the machine shop, cutting sheets of tin with a big pair of shears.

When he submitted his famous paper on beta decay to the prestigious journal Nature, the journal's editor turned it down because "it contained speculations which were too remote from reality". Thus, Fermi saw the theory published in Italian and in German before it was published in English.

He never forgot this experience of being ahead of his time, and used to tell his protégés: "Never be first; try to be second".

On November 28, 1954, Fermi died at the age of 53 of stomach cancer in Chicago, Illinois and was interred there in Oak Woods Cemetery. As Eugene Wigner wrote: "Ten days before Fermi had passed away he told me, 'I hope it won't take long.' He had reconciled himself perfectly to his fate".

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