page_title: Enrico Fermi
section_title: Professor in Rome
hierarchical_section_title: Enrico Fermi / Professor in Rome
caption_attribution_description: English: The Italian scientists Franco Rasetti, Enrico Fermi and Emilio Segrè in academic dress
context_page_description: Enrico Fermi was an Italian physicist and the creator of the world's first nuclear reactor, the Chicago Pile-1. He has been called the "architect of the nuclear age" and the "architect of the atomic bomb". He was one of very few physicists to excel in both theoretical physics and experimental physics. Fermi was awarded the 1938 Nobel Prize in Physics for his work on induced radioactivity by neutron bombardment and for the discovery of transuranium elements. With his colleagues, Fermi filed several patents related to the use of nuclear power, all of which were taken over by the US government. He made significant contributions to the development of statistical mechanics, quantum theory, and nuclear and particle physics.
  Fermi's first major contribution involved the field of statistical mechanics. After Wolfgang Pauli formulated his exclusion principle in 1925, Fermi followed with a paper in which he applied the principle to an ideal gas, employing a statistical formulation now known as Fermi–Dirac statistics. Today, particles that obey the exclusion principle are called "fermions".
context_section_description: Professorships in Italy were granted by competition (concorso) for a vacant chair, the applicants being rated on their publications by a committee of professors. Fermi applied for a chair of mathematical physics at the University of Cagliari on Sardinia, but was narrowly passed over in favor of Giovanni Giorgi. In 1926, at the age of 24, he applied for a professorship at the Sapienza University of Rome. This was a new chair, one of the first three in theoretical physics in Italy, that had been created by the Minister of Education at the urging of Professor Orso Mario Corbino, who was the University's professor of experimental physics, the Director of the Institute of Physics, and a member of Benito Mussolini's cabinet. Corbino, who also chaired the selection committee, hoped that the new chair would raise the standard and reputation of physics in Italy. The committee chose Fermi ahead of Enrico Persico and Aldo Pontremoli, and Corbino helped Fermi recruit his team, which was soon joined by notable students such as Edoardo Amaldi, Bruno Pontecorvo, Ettore Majorana and Emilio Segrè, and by Franco Rasetti, whom Fermi had appointed as his assistant. They were soon nicknamed the "Via Panisperna boys" after the street where the Institute of Physics was located.
  Fermi married Laura Capon, a science student at the University, on 19 July 1928. They had two children: Nella, born in January 1931, and Giulio, born in February 1936. On 18 March 1929, Fermi was appointed a member of the Royal Academy of Italy by  Mussolini, and on 27 April he joined the Fascist Party. He later opposed Fascism when the 1938 racial laws were promulgated by Mussolini in order to bring Italian Fascism ideologically closer to German National Socialism. These laws threatened Laura, who was Jewish, and put many of Fermi's research assistants out of work.
  During their time in Rome, Fermi and his group made important contributions to many practical and theoretical aspects of physics. In 1928, he published his Introduction to Atomic Physics (Introduzione alla fisica atomica), which provided Italian university students with an up-to-date and accessible text. Fermi also conducted public lectures and wrote popular articles for scientists and teachers in order to spread knowledge of the new physics as widely as possible. Part of his teaching method was to gather his colleagues and graduate students together at the end of the day and go over a problem, often from his own research. A sign of success was that foreign students now began to come to Italy. The most notable of these was the German physicist Hans Bethe, who came to Rome as a Rockefeller Foundation fellow, and collaborated with Fermi on a 1932 paper "On the Interaction between Two Electrons" (German: Über die Wechselwirkung von Zwei Elektronen).
  At this time, physicists were puzzled by beta decay, in which an electron was emitted from the atomic nucleus. To satisfy the law of conservation of energy, Pauli postulated the existence of an invisible particle with no charge and little or no mass that was also emitted at the same time. Fermi took up this idea, which he developed in a tentative paper in 1933, and then a longer paper the next year that incorporated the postulated particle, which Fermi called a "neutrino". His theory, later referred to as Fermi's interaction, and still later as the theory of the weak interaction, described one of the four fundamental forces of nature. The neutrino was detected after his death, and his interaction theory showed why it was so difficult to detect. When he submitted his paper to the British journal Nature, that journal's editor turned it down because it contained speculations which were "too remote from physical reality to be of interest to readers". Thus Fermi saw the theory published in Italian and German before it was published in English.
  
  In the introduction to the 1968 English translation, physicist Fred L. Wilson noted that:
  Fermi's theory, aside from bolstering Pauli's proposal of the neutrino, has a special significance in the history of modern physics. One mus
caption: Enrico Fermi between Franco Rasetti (left) and Emilio Segrè in academic dress
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