Enrico Fermi Enrico Fermi ( ; 29 September 1901 – 28 November 1954 ) was an Italian physicist , best known for his work on Chicago Pile - 1 ( the first nuclear reactor ) , and for his contributions to the development of quantum theory , nuclear and particle physics , and statistical mechanics . He is one of the men referred to as the " father of the atomic bomb " . Fermi held several patents related to the use of nuclear power , and was awarded the 1938 Nobel Prize in Physics for his work on induced radioactivity by neutron bombardment and the discovery of transuranic elements . He was widely regarded as one of the very few physicists to excel both theoretically and experimentally . Fermi ' s first major contribution was to statistical mechanics . After Wolfgang Pauli announced 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 " fermion s " . Later Pauli postulated the existence of an uncharged invisible particle emitted along with an electron during beta decay , to satisfy the law of conservation of energy . Fermi took up this idea , developing a model that incorporated the postulated particle , which he named the " neutrino " . His theory , later referred to as Fermi ' s interaction and still later as weak interaction , described one of the four fundamental forces of nature . Through experiments inducing radioactivity with recently discovered neutrons , Fermi discovered that slow neutron s were more easily captured than fast ones , and developed the Fermi age equation to describe this . After bombarding thorium and uranium with slow neutrons , he concluded that he had created new elements ; although he was awarded the Nobel Prize for this discovery , the new elements were subsequently revealed to be fission products . Fermi left Italy in 1938 to escape new Italian Racial Laws that affected his Jewish wife Laura . He emigrated to the United States where he worked on the Manhattan Project during World War II . Fermi led the team that designed and built Chicago Pile - 1 , that went critical on 2 December 1942 , demonstrating the first artificial self - sustaining nuclear chain reaction . He was on hand when the X - 10 Graphite Reactor at Oak Ridge , Tennessee went critical in 1943 , and when the B Reactor at the Hanford Site did so the next year . At Los Alamos he headed F Division , part of which worked on Edward Teller ' s thermonuclear " Super " bomb . He was present at the Trinity test on 16 July 1945 , where he used his Fermi method to estimate the bomb ' s yield . After the war , Fermi served under Oppenheimer on the influential General Advisory Committee , which advised the Atomic Energy Commission on nuclear matters and policy . Following the detonation of the first Soviet fission bomb in August 1949 , he strongly opposed the development of a hydrogen bomb on both moral and technical grounds . He was among the scientists who testified on Oppenheimer ' s behalf at the 1954 hearing that resulted in the denial of the latter ' s security clearance . Fermi did important work in particle physics , especially related to pion s and muons , and he speculated that cosmic rays arose through material being accelerated by magnetic fields in interstellar space . Many awards , concepts , and institutions are named after Fermi , including the Enrico Fermi Award , the Enrico Fermi Institute , the Fermi National Accelerator Laboratory , the Fermi Gamma - ray Space Telescope , the Enrico Fermi Nuclear Generating Station , and the synthetic element fermium . Early life . Enrico Fermi was born in Rome on 29 September 1901 . He was the third child of Alberto Fermi , a division head ( " " ) in the Ministry of Railways , and Ida de Gattis , an elementary school teacher . His only sister , Maria , was two years older than him , and his brother , Giulio , was a year older . After the two boys were sent to a rural community to be wet nurse d , Enrico rejoined his family in Rome when he was two and a half . While he came from a Roman Catholic family and was baptized in accord with his grandparents ' wishes , the family was not religious , and Fermi was an agnostic throughout his adult life . As a young boy he shared his interests with his brother Giulio . They built electric motors and played with electrical and mechanical toys . Giulio died during the administration of anesthesia for an operation on a throat abscess in 1915 . One of Fermi ' s 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 from 1840 , " Elementorum physicae mathematicae " , was written in Latin by Jesuit Father Andrea Caraffa , a professor at the Collegio Romano . It covered mathematics , classical mechanics , astronomy , optics , and acoustics , to the extent that they were understood when it was written . Fermi befriended another scientifically inclined student , 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 his father ' s colleague Adolfo Amidei , who gave him several books on physics and mathematics that he read and assimilated quickly . " Scuola Normale Superiore " in Pisa . Fermi graduated from high school in July 1918 and , at Amidei ' s urging , applied to the " Scuola Normale Superiore " in Pisa . Having lost one son , his parents were reluctant to let him move away from home for four years while attending the Sapienza University of Rome , but in the end they acquiesced . The school provided free lodging for students , but candidates had to take a difficult entrance exam that included an essay . The given theme was " Specific characteristics of Sounds " . The 17 - year - old Fermi chose to derive and solve the partial differential equation for a vibrating rod , applying Fourier analysis in the solution . The examiner , Professor Giuseppe Pittarelli from the Sapienza University of Rome , interviewed Fermi and concluded that his entry would have been commendable even for a doctoral degree . 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 would indulge in light - hearted pranks and who would later become Fermi ' s close friend and collaborator . In Pisa , Fermi was advised by the director of the physics laboratory , Luigi Puccianti , who acknowledged that there was little that he could teach Fermi , and frequently asked Fermi to teach him something instead . Fermi ' s knowledge of quantum physics reached such a high level that Puccianti asked him to organize seminars on the topic . During this time Fermi learned tensor calculus , a mathematical technique invented by Gregorio Ricci and Tullio Levi - Civita that was needed to demonstrate the principles of general relativity . Fermi initially chose mathematics as his major , but soon switched to physics . He remained largely self - taught , studying general relativity , quantum mechanics , and atomic physics . In September 1920 , Fermi was admitted to the Physics department . Since there were only three students in the department — Fermi , Rasetti , and Nello Carrara — Puccianti let them freely use the laboratory for whatever purposes they chose . Fermi decided that they should research X - ray crystallography , and the three worked to produce a Laue photograph — an X - ray photograph of a crystal . During 1921 , his third year at the university , Fermi published his first scientific works in the Italian journal " Nuovo Cimento " . The first was entitled " On the dynamics of a rigid system of electrical charges in translational motion " ( ) . A sign of things to come was that the mass was expressed as a tensor — a mathematical construct commonly used to describe something moving and changing in three - dimensional space . In classical mechanics , mass is a scalar quantity , but in relativity it changes with velocity . The second paper was " On the electrostatics of a uniform gravitational field of electromagnetic charges and on the weight of electromagnetic charges " ( ) . Using general relativity , Fermi showed that a charge has a weight equal to U / c , where U was the electrostatic energy of the system , and c is the speed of light . The first paper seemed to point out a contradiction between the electrodynamic theory and the relativistic one concerning the calculation of the electromagnetic masses , as the former predicted a value of 4 / 3 U / c . Fermi addressed this the next year in a paper " Concerning a contradiction between electrodynamic and the relativistic theory of electromagnetic mass " in which he showed that the apparent contradiction was a consequence of relativity . This paper was sufficiently well - regarded that it was translated into German and published in the German scientific journal " Physikalische Zeitschrift " in 1922 . That year , Fermi submitted his article " On the phenomena occurring near a world line " ( ) to the Italian journal " I Rendiconti dell ' Accademia dei Lincei " . In this article he examined the Principle of Equivalence , and introduced the so - called " Fermi coordinates " . He proved that on a world line close to the time line , space behaves as if it were a Euclidean space . Fermi submitted his thesis , " A theorem on probability and some of its applications " ( ) , to the " Scuola Normale Superiore " in July 1922 , and received his laurea at the unusually young age of 21 . The thesis was on X - ray diffraction images . Theoretical physics was not yet considered a discipline in Italy , and the only thesis that would have been accepted was one on experimental physics . For this reason , Italian physicists were slow in embracing the new ideas like relativity coming from Germany . Since Fermi was quite at home in the lab doing experimental work , this did not pose insurmountable problems for him . While writing the appendix for the Italian edition of the book " The Mathematical Theory of Relativity " by August Kopff in 1923 , Fermi was the first to point out that hidden inside the famous Einstein equation ( ) was an enormous amount of nuclear potential energy to be exploited . " It does not seem possible , at least in the near future " , he wrote , " to find a way to release these dreadful amounts of energy — which is all to the good because the first effect of an explosion of such a dreadful amount of energy would be to smash into smithereens the physicist who had the misfortune to find a way to do it . " Fermi decided to travel abroad , and spent a semester studying under Max Born at the University of Göttingen , where he met Werner Heisenberg and Pascual Jordan . Fermi then studied in Leiden with Paul Ehrenfest from September to December 1924 on a fellowship from the Rockefeller Foundation obtained through the intercession of the mathematician Vito Volterra . Here Fermi met Hendrik Lorentz and Albert Einstein , and became good friends with Samuel Goudsmit and Jan Tinbergen . From January 1925 to late 1926 , Fermi taught mathematical physics and theoretical mechanics at the University of Florence , where he teamed up with Rasetti to conduct a series of experiments on the effects of magnetic fields on mercury vapour . He also participated in seminars at the Sapienza University of Rome , giving lectures on quantum mechanics and solid state physics . After Wolfgang Pauli announced his exclusion principle in 1925 , Fermi responded with a paper " On the quantisation of the perfect monoatomic gas " ( ) , in which he applied the exclusion principle to an ideal gas . The paper was especially notable for Fermi ' s statistical formulation , which describes the distribution of particles in systems of many identical particles that obey the exclusion principle . This was independently developed soon after by the British physicist Paul Dirac , who also showed how it was related to the Bose – Einstein statistics . Accordingly , it is now known as Fermi – Dirac statistics . Following Dirac , particles that obey the exclusion principle are today called " fermion s " , while those that do not are called " boson s " . Professor in Rome . Professorships in Italy were granted by competition ( ) 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 favour 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 " ( ) , 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 " ( ) . 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 : In January 1934 , Irène Joliot - Curie and Frédéric Joliot announced that they had bombarded elements with alpha particle s and induced radioactivity in them . By March , Fermi ' s assistant Gian - Carlo Wick had provided a theoretical explanation using Fermi ' s theory of beta decay . Fermi decided to switch to experimental physics , using the neutron , which James Chadwick had discovered in 1932 . In March 1934 , Fermi wanted to see if he could induce radioactivity with Rasetti ' s polonium - beryllium neutron source . Neutrons , which had no electric charge , and so would not be deflected by the positively charged nucleus . This meant that they needed much less energy to penetrate the nucleus than charged particles , and so would not require a particle accelerator , which the Via Panisperna boys did not have . Fermi had the idea to resort to replacing Rasetti ' s polonium - beryllium neutron source with a radon - beryllium neutron source , which he created by filling a glass bulb with beryllium powder , evacuating the air , and then adding 50 m Ci of radon gas , supplied by Giulio Cesare Trabacchi . This created a much stronger neutron source , the effectiveness of which declined with the 3 . 8 - day half - life of radon . He knew that this source would also emit gamma rays , but , on the basis of his theory , he believed that this would not affect the results of the experiment . He started by bombarding platinum , an element with a high atomic number that was readily available , without success . He turned to aluminium , which emitted an alpha particle and produced sodium , which then decayed into magnesium by beta particle emission . He tried lead , without success , and then fluorine in the form of calcium fluoride , which emitted an alpha particle and produced nitrogen , decaying into oxygen by beta particle emission . In all , he induced radioactivity in 22 different elements . Fermi rapidly reported the discovery of neutron - induced radioactivity in the Italian journal " La Ricerca Scientifica " on 25 March 1934 . The natural radioactivity of thorium and uranium made it hard to determine what was happening when these elements were bombarded with neutrons but , after correctly eliminating the presence of elements lighter than uranium but heavier than lead , Fermi concluded that they had created new elements , which he called hesperium and ausonium . The chemist Ida Noddack criticised this work , suggesting that some of the experiments could have produced lighter elements than lead rather than new , heavier elements . Her suggestion was not taken seriously at the time because her team had not carried out any experiments with uranium , and its claim to have discovered masurium ( technetium ) was disputed . At that time , fission was thought to be improbable if not impossible on theoretical grounds . While physicists expected elements with higher atomic numbers to form from neutron bombardment of lighter elements , nobody expected neutrons to have enough energy to split a heavier atom into two light element fragments in the manner that Noddack suggested . The Via Panisperna boys also noticed some unexplained effects . The experiment seemed to work better on a wooden table than a marble table top . Fermi remembered that Joliot - Curie and Chadwick had noted that paraffin wax was effective at slowing neutrons , so he decided to try that . When neutrons were passed through paraffin wax , they induced a hundred times as much radioactivity in silver compared with when it was bombarded without the paraffin . Fermi guessed that this was due to the hydrogen atoms in the paraffin . Those in wood similarly explained the difference between the wooden and the marble table tops . This was confirmed by repeating the effect with water . He concluded that collisions with hydrogen atoms slowed the neutrons . The lower the atomic number of the nucleus it collides with , the more energy a neutron loses per collision , and therefore the less collisions that are required to slow a neutron down by a given amount . Fermi realised that this induced more radioactivity because slow neutron s were more easily captured than fast ones . He developed a diffusion equation to describe this , which became known as the Fermi age equation . In 1938 Fermi received the Nobel Prize in Physics at the age of 37 for his " demonstrations of the existence of new radioactive elements produced by neutron irradiation , and for his related discovery of nuclear reaction s brought about by slow neutrons " . After Fermi received the prize in Stockholm , he did not return home to Italy , but rather continued on to New York City along with his family , where they applied for permanent residency . The decision to move to America and become American citizens was primarily a result of the racial laws in Italy . Manhattan Project . Soon after Fermi ' s arrival in New York City on 2 January 1939 , he was offered five different chairs , and chose to work at Columbia University , where he had already given summer lectures in 1936 . He received the news that in December 1938 , the German chemists Otto Hahn and Fritz Strassmann had detected the element barium after bombarding uranium with neutrons , which Lise Meitner and her nephew Otto Frisch correctly interpreted as the result of nuclear fission . Frisch confirmed this experimentally on 13 January 1939 . The news of Meitner and Frisch ' s interpretation of Hahn and Strassmann ' s discovery crossed the Atlantic with Niels Bohr , who was to lecture at Princeton University . Isidor Isaac Rabi and Willis Lamb , two Columbia University physicists working at Princeton , found out about it and carried it back to Columbia . Rabi said he told Enrico Fermi , but Fermi later gave the credit to Lamb : Noddack was proven right after all . Fermi had dismissed the possibility of fission on the basis of his calculations , but he had not taken into account the binding energy that would appear when a nuclide with an odd number of neutrons absorbed an extra neutron . For Fermi , the news came as a profound embarrassment , as the transuranic elements that he had partly been awarded the Nobel Prize for discovering had not been transuranic elements at all , but fission products . He added a footnote to this effect to his Nobel Prize acceptance speech . The scientists at Columbia decided that they should try to detect the energy released in the nuclear fission of uranium when bombarded by neutrons . On 25 January 1939 , Fermi was a member of the experimental team at Columbia University which conducted the first nuclear fission experiment in the United States , in the basement of Pupin Hall ; the other members of the team were Herbert L . Anderson , Eugene T . Booth , John R . Dunning , G . Norris Glasoe , and Francis G . Slack . The next day , the Fifth Washington Conference on Theoretical Physics began in Washington , D . C . under the joint auspices of The George Washington University and the Carnegie Institution of Washington . There , the news on nuclear fission was spread even further , which fostered many more experimental demonstrations . Few weeks after French scientists Hans von Halban , Lew Kowarski and Frédéric Joliot - Curie , Fermi and Anderson demonstrated that uranium bombarded by neutrons emitted more neutrons than it absorbed . Leó Szilárd obtained of uranium oxide from Canadian radium producer Eldorado Gold Mines Limited , allowing Fermi and Herbert L . Anderson to conduct experiments with fission on a much larger scale . Fermi and Szilárd collaborated on a design of a device to achieve a self - sustaining nuclear reaction — a nuclear reactor . Due to the rate of absorption of neutrons by the hydrogen in water , it was unlikely that a self - sustaining reaction could be achieved with natural uranium and water as a neutron moderator . Fermi suggested , based on his work with neutrons , that uranium oxide could be used in the form of blocks , with graphite as a moderator instead of water . This would reduce the rate of capture of the neutrons , and make it theoretically possible to achieve a self - sustaining chain reaction . Szilárd then came up with what proved to be a workable design , a pile of uranium oxide blocks surrounded by graphite bricks . Szilárd , Anderson and Fermi jointly published a paper on " Neutron Production in Uranium " but their work habits and personalities were different , and Fermi had trouble working with Szilárd . Fermi was the first to warn military leaders about the potential impact of nuclear energy , giving a lecture on the subject at the Navy Department on 18 March 1939 . The response fell short of what he had hoped for , although the Navy agreed to provide $ 1 , 500 towards further research at Columbia . In August 1939 , three Hungarian physicists — Szilárd , Eugene Wigner and Edward Teller — prepared the Einstein – Szilárd letter , which they persuaded Einstein to sign , warning President Franklin D . Roosevelt of the probability that Germany was planning to build an atomic bomb . Because of the German invasion of Poland on 1 September , it was October before they could arrange for the letter to be personally delivered . Roosevelt was sufficiently concerned that he assembled the S - 1 Uranium Committee to investigate the matter . The S - 1 Uranium Committee provided money for Fermi to buy graphite , and he built a pile of graphite bricks on the seventh floor of the Pupin laboratory . By August 1941 , he had six tons of uranium oxide and thirty tons of graphite , which he used to build a still larger pile in the Schermerhorn Hall at Columbia . When the S - 1 Uranium Committee next met on 18 December 1941 , there was a heightened sense of urgency in the wake of the attack on Pearl Harbor and the subsequent United States entry into World War II . While most of the effort thus far had been directed at three different processes for producing enriched uranium , S - 1 Uranium Committee member Arthur Compton determined that plutonium was a feasible alternative which could be mass - produced in nuclear reactors by the end of 1944 . To achieve this , he decided to concentrate the plutonium work at the University of Chicago . Fermi reluctantly moved , and his team became part of the new Metallurgical Laboratory there . Given the number of unknown factors involved in creating a self - sustaining nuclear reaction , it seemed inadvisable to do so in a densely populated area . Compton arranged with Colonel Kenneth Nichols , the head of the Army ' s Manhattan District , for land to be acquired in the Argonne Forest about from Chicago , and Stone & Webster was contracted to develop the site . This work was halted by an industrial dispute . Fermi then persuaded Compton that he could build a reactor in the squash court under Stagg Field at the University of Chicago . Construction of the pile began on 6 November 1942 , and Chicago Pile - 1 went critical on 2 December . The shape of the pile was intended to be roughly spherical , but as work proceeded Fermi calculated that criticality could be achieved without finishing the entire pile as planned . This experiment was a landmark in the quest for energy , and it was typical of Fermi ' s approach . Every step was carefully planned , every calculation meticulously done . When the first self - sustained nuclear chain reaction was achieved , Compton made a coded phone call to James B . Conant , the chairman of the National Defense Research Committee . To continue the research where it would not pose a public health hazard , the reactor was disassembled and moved to the Argonne site , where Fermi directed research on reactors and other fundamental sciences , revelling in the myriad of research opportunities that the reactor provided by an abundance of neutrons . The laboratory soon branched out from physics and engineering into using the reactor for biological and medical research . Initially , Argonne was run by Fermi as part of the University of Chicago , but it became a separate entity with Fermi as its director in May 1944 . Just in case something went wrong , Fermi was on hand at Oak Ridge to witness the air - cooled X - 10 Graphite Reactor go critical on 4 November 1943 . The technicians woke him early so that he could see it happen . Getting X - 10 operational was another milestone in the plutonium project . It provided data on reactor design , training for DuPont staff in reactor operation , and produced the first small quantities of reactor - bred plutonium . Fermi became an American citizen in July 1944 , the earliest date the law allowed . In September 1944 , Fermi inserted the first uranium fuel slug into the B Reactor at the Hanford Site , the production reactor designed to breed plutonium in large quantities . Like X - 10 , it had been designed by Fermi ' s team at the Metallurgical Laboratory , and built by DuPont , but it was much larger , and was water - cooled . Over the next few days , 838 tubes were loaded , and the reactor went critical . Shortly after midnight on 27 September , the operators began to withdraw the control rod s to initiate production . At first all appeared to be well , but around 03 : 00 , the power level started to drop and by 06 : 30 the reactor had shut down completely . The Army and DuPont turned to Fermi ' s team for answers . The cooling water was investigated to see if there was a leak or contamination . The next day the reactor suddenly started up again , only to shut down once more a few hours later . The problem was traced to neutron poison ing from xenon - 135 , a fission product with a half - life of 9 . 2 hours . Fortunately , DuPont had deviated from the Metallurgical Laboratory ' s original design in which the reactor had 1 , 500 tubes arranged in a circle , and had added an additional 504 tubes to fill in the corners . The scientists had originally considered this over - engineering a waste of time and money , but Fermi realized that by loading all 2 , 004 tubes , the reactor could reach the required power level and efficiently produce plutonium . In mid - 1944 , Robert Oppenheimer persuaded Fermi to join his Project Y in Los Alamos , New Mexico . Arriving in September , Fermi was appointed an associate director of the laboratory , with broad responsibility for nuclear and theoretical physics , and was placed in charge of F Division , which was named after him . F Division consisted of four branches : the F - 1 Super and General Theory under Teller , which was responsible for the development of a thermonuclear " Super " bomb ; the F - 2 Water Boiler under L . D . P . King , which looked after the " water boiler " research reactor ; F - 3 Super Experimentation under Egon Bretscher ; and the F - 4 Fission Studies under Anderson . Fermi observed the Trinity test on 16 July 1945 , and conducted an experiment dropping strips of paper to estimate the bomb ' s yield . He simply measured how far they were blown by the explosion using his paces , and came up with a figure of ten kilotons of TNT ; the actual yield was about 18 . 6 kilotons . Along with Oppenheimer , Compton and Ernest Lawrence , Fermi was part of the scientific panel that advised the Interim Committee on target selection . The panel agreed with the committee that atomic bombs be used without warning against an industrial target . Like others at the Los Alamos Laboratory , Fermi found out about the atomic bombings of Hiroshima and Nagasaki from the public address system in the technical area . Fermi did not believe that atomic bombs would scare people into not starting wars , nor did he think that the time was ripe for world government . He therefore did not join the Association of Los Alamos Scientists . Post - war work . Fermi became a professor at the University of Chicago on 1 July 1945 , although he did not depart the Los Alamos Laboratory with his family until 31 December 1945 . The Metallurgical Laboratory became the Argonne National Laboratory on 1 July 1946 , the first of the national laboratories established by the Manhattan Project . The short distance between Chicago and Argonne allowed Fermi to work at both places . At Argonne he continued experimental physics , investigating neutron scattering with Leona Marshall . He also discussed theoretical physics with Maria Mayer , helping her develop insights into spin – orbit coupling that would lead to her receiving the Nobel Prize . The Manhattan Project was replaced by Atomic Energy Commission ( AEC ) on 1 January 1947 . Fermi served on the AEC General Advisory Committee , an influential scientific committee chaired by Robert Oppenheimer . He also liked to spend a few weeks of each year at the Los Alamos National Laboratory , where he collaborated with Nicholas Metropolis , and with John von Neumann on Rayleigh – Taylor instability , the science of what occurs at the border between two fluids of different densities . Following the detonation of the first Soviet fission bomb in August 1949 , Fermi , along with Isidor Rabi , wrote a strongly worded report for the committee , opposing the development of a hydrogen bomb on moral and technical grounds . Nonetheless , Fermi continued to participate in work on the hydrogen bomb at Los Alamos as a consultant . Along with Stanislaw Ulam , he calculated that not only would the amount of tritium needed for Teller ' s model of a thermonuclear weapon be prohibitive , but a fusion reaction could still not be assured to propagate even with this large quantity of tritium . Fermi was among the scientists who testified on Oppenheimer ' s behalf at the Oppenheimer security hearing in 1954 that resulted in denial of Oppenheimer ' s security clearance . In his later years , Fermi continued teaching at the University of Chicago . His PhD students in the post - war period included Owen Chamberlain , Geoffrey Chew , Jerome Friedman , Marvin Goldberger , Tsung - Dao Lee , Arthur Rosenfeld and Sam Treiman . Jack Steinberger was a graduate student . Fermi conducted important research in particle physics , especially related to pion s and muons . He made the first predictions of pion - nucleon resonance , relying on statistical methods , since he reasoned that exact answers were not required when the theory was wrong anyway . In a paper co - authored with Chen Ning Yang , he speculated that pions might actually be composite particles . The idea was elaborated by Shoichi Sakata . It has since been supplanted by the quark model , in which the pion is made up of quarks , which completed Fermi ' s model , and vindicated his approach . Fermi wrote a paper " On the Origin of Cosmic Radiation " in which he proposed that cosmic rays arose through material being accelerated by magnetic fields in interstellar space , which led to a difference of opinion with Teller . Fermi examined the issues surrounding magnetic fields in the arms of a spiral galaxy . He mused about what is now referred to as the " Fermi paradox " : the contradiction between the presumed probability of the existence of extraterrestrial life and the fact that contact has not been made . Toward the end of his life , Fermi questioned his faith in society at large to make wise choices about nuclear technology . He said : Fermi died at age 53 of stomach cancer in his home in Chicago , and was interred at Oak Woods Cemetery . Impact and legacy . Legacy . Fermi received numerous awards in recognition of his achievements , including the Matteucci Medal in 1926 , the Nobel Prize for Physics in 1938 , the Hughes Medal in 1942 , the Franklin Medal in 1947 , and the Rumford Prize in 1953 . He was awarded the Medal for Merit in 1946 for his contribution to the Manhattan Project . In 1999 , " Time magazine " named Fermi on its list of the top 100 persons of the twentieth century . Fermi was widely regarded as an unusual case of a 20th - century physicist who excelled both theoretically and experimentally . The historian of physics , C . P . Snow , wrote that " 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 was known as an inspiring teacher , and was noted for his attention to detail , simplicity , and careful preparation of his lectures . Later , his lecture notes were transcribed into books . His papers and notebooks are today in the University of Chicago . Victor Weisskopf noted how Fermi " always managed to find the simplest and most direct approach , with the minimum of complication and sophistication . " 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 that would stump other people . Later on , his method of getting approximate and quick answers through back - of - the - envelope calculations became informally known as the " Fermi method " , and is widely taught . Fermi was fond of pointing out that Alessandro Volta , working in his laboratory , could have had no idea where the study of electricity would lead . Fermi is generally remembered for his work on nuclear power and nuclear weapons , especially the creation of the first nuclear reactor , and the development of the first atomic and hydrogen bombs . His scientific work has stood the test of time . This includes his theory of beta decay , his work with non - linear systems , his discovery of the effects of slow neutrons , his study of pion - nucleon collisions , and his Fermi – Dirac statistics . His speculation that a pion was not a fundamental particle pointed the way towards the study of quark s and lepton s . Things named after Fermi . Many things have been named in Fermi ' s honour . These include the Fermilab particle accelerator and physics lab in Batavia , Illinois , which was renamed in his honour in 1974 , and the Fermi Gamma - ray Space Telescope , which was named after him in 2008 , in recognition of his work on cosmic rays . Three nuclear reactor installations have been named after him : the Fermi 1 and Fermi 2 nuclear power plants in Newport , Michigan , the Enrico Fermi Nuclear Power Plant at Trino Vercellese in Italy , and the RA - 1 Enrico Fermi research reactor in Argentina . A synthetic element isolated from the debris of the 1952 Ivy Mike nuclear test was named fermium , in honour of Fermi ' s contributions to the scientific community . It follows the element einsteinium , which was discovered with it . Since 1956 , the United States Atomic Energy Commission has named its highest honour , the Fermi Award , after him . Recipients of the award include well - known scientists like Otto Hahn , Robert Oppenheimer , Edward Teller and Hans Bethe . Bibliography . For a full list of his papers , see pages 75 – 78 in