Enrico Fermi (29 September 1901 – 28 November 1954) was an Italian physicist particularly known for his work on the development of the first nuclear reactor, Chicago Pile-1, and for his contributions to the development of quantum theory, nuclear and particle physics, and statistical mechanics. He was awarded the 1938 Nobel Prize in Physics for his work on induced radioactivity.
Fermi is widely regarded as one of the leading scientists of the 20th century, highly accomplished in both theory and experiment. Along with J. Robert Oppenheimer, he is frequently referred to as "the father of the atomic bomb". He also held several patents related to the use of nuclear power.
Several awards, concepts, and institutions are named after Fermi, such as the Enrico Fermi Award, the Enrico Fermi Institute, the Fermi National Accelerator Lab, the Fermi Gamma-ray Space Telescope, the Enrico Fermi Nuclear Generating Station, a type of particles called fermions, the synthetic element Fermium, and many more.
Enrico Fermi was born in Rome, Italy, to Alberto Fermi, a Chief Inspector of the Ministry of Communications, and Ida de Gattis, an elementary school teacher who built her own pressure cooker. As a young boy, he shared his interests with his older brother, Giulio. They dismantled small engines and other parts. When Giulio died unexpectedly of a throat abscess in 1915, Enrico was distraught, and immersed himself in scientific study to distract himself. According to his own account, each day he would walk in front of the hospital where Giulio died until he became inured to the pain.
One of the first sources for the study of physics was a book found at the local market of Campo de' Fiori in Roma. The 900 page book, entitled Elementorum physicae mathematicae, was written in Latin by Jesuit Father Andrea Caraffa, a professor at the Collegio Romano, covered subjects like mathematics, classical mechanics, astronomy, optics, and acoustics. Notes found in the book indicate that Fermi studied it intensely. Later, Enrico befriended another scientifically inclined student named Enrico Persico, and the two worked together on scientific projects such as building gyroscopes, and measuring the Earth's magnetic field. Fermi's interest in physics was further encouraged by a friend of his father, Adolfo Amidei, who gave him several books on physics and mathematics, which he read and assimilated quickly.
In 1918 Fermi enrolled at the Scuola Normale Superiore in Pisa, where he was later to receive his undergraduate and doctoral degree. In order to enter the Institute, candidates had to take an entrance exam which included an essay. For his essay on the given theme Characteristics of Sound, 17-year-old Fermi chose to derive and solve the Fourier analysis based partial differential equation for waves on a string. The examiner, Prof. Giulio Pittato, interviewed Fermi and concluded that his essay would have been commendable even for a doctoral degree. Enrico Fermi achieved first place in the classification of the entrance exam. During his years at the Scuola Normale Superiore, Fermi teamed up with a fellow student named Franco Rasetti with whom he used to indulge in light-hearted pranks. Later, Rasetti became Fermi's close friend and collaborator. Besides attending the classes, Enrico Fermi found the time to work on his extracurricular activities, particularly with the help of his friend Enrico Persico, who remained in Rome to attend the university. Between 1919 and 1923 Fermi studied general relativity, quantum mechanics and atomic physics.
His knowledge of quantum physics reached such a high level that the head of the Physics Institute, Prof. Luigi Puccianti, asked him to organize seminars about that topic. During this time he learned tensor calculus, a mathematical instrument invented by Gregorio Ricci and Tullio Levi-Civita, and needed to demonstrate the principles of general relativity. In 1921, his third year at the university, he published his first scientific works in the Italian journal Nuovo Cimento: the first was entitled: "On the dynamics of a solid system of electrical charges in transient conditions"; the second: "On the electrostatics of a uniform gravitational field of electromagnetic charges and on the weight of electromagnetic charges". At first glance, the first paper seemed to point out a contradiction between the electrodynamic theory and the relativistic one concerning the calculation of the electromagnetic masses. After one year with a work entitled "Correction of severe discrepancy between electrodynamic theory and the relativistic one of electromagnetic charges. Inertia and weight of electricity", Enrico Fermi showed the correctness of his paper. This last publication was so successful that it was translated into German and published in the famous German scientific journal Physikalische Zeitschrift.
In 1922 he published his first important scientific work in the Italian journal I Rendiconti dell'Accademia dei Lincei entitled "On the phenomena that happen close to the line of time", where he introduces for the first time the so-called "Fermi coordinates", and proves that when close to the time line, space behaves as a euclidean one. In 1922 Fermi graduated from Scuola Normale Superiore.
In 1923, while writing the appendix for the Italian edition of the book The Mathematical Theory of Relativity by A. Kopff, Enrico Fermi pointed out, for the first time, that hidden inside the famous Einstein equation (E = mc2), there was an enormous amount of nuclear energy to be exploited.
Fermi's Ph.D advisor was Luigi Puccianti. In 1924 Fermi spent a semester at the University of Göttingen, and then stayed for a few months in Leiden with Paul Ehrenfest. From January 1925 to the autumn of 1926, he stayed at the University of Florence. In this period he wrote his work on the Fermi–Dirac statistics.
Aged 24, Fermi took a professorship at the University of Rome (first in atomic physics in Italy) which he won in a competition held by Professor Orso Mario Corbino, director of the Institute of Physics. Corbino helped 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 and 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. These include the theory of beta decay, with the inclusion of the neutrino postulated in 1930 by Wolfgang Pauli, and the discovery of slow neutrons, which was to prove pivotal for the working of nuclear reactors. His group systematically bombarded elements with slow neutrons, and during their experiments with uranium, narrowly missed observing nuclear fission. At that time, fission was thought to be improbable if not impossible, mostly on theoretical grounds. While people expected elements with higher atomic number to form from neutron bombardment of lighter elements, nobody expected neutrons to have enough energy to actually split a heavier atom into two light element fragments. However, the chemist Ida Noddack had criticised Fermi's work and had suggested that some of his experiments could have produced lighter elements. At the time, Fermi dismissed this possibility on the basis of calculations.
Fermi was well-known for his simplicity in solving problems. He began his inquiries with the simplest lines of mathematical reasoning, then later produced complete solutions to the problems he deemed worth pursuing. His abilities as a great scientist, combining theoretical and applied nuclear physics, were acknowledged by all. He influenced many physicists who worked with him, such as Hans Bethe, who spent two semesters working with Fermi in the early 1930s. From the time he was a boy, Fermi meticulously recorded his calculations in notebooks, and later used them to solve many new problems that he encountered based on these earlier known problems.
When Fermi 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. Nature eventually did publish Fermi's report on beta decay on January 16, 1939.
Fermi remained in Rome until 1938.