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To Fermi ~ with Love – Part 1

Manhattan Project Locations:

A collection of remembrances of Manhattan Project physicist Enrico Fermi, narrated by the late Chicago radio host Jay Andres. The audio recordings are drawn from the archives of the Argonne National Laboratory, the United States Atomic Energy Commission, and the American Institute of Physics. In Part I, Fermi’s close friend and colleague Emilio Segrè describes Fermi’s scientific discoveries, motivations, and personality in detail. Fermi’s wife, Laura Capon Fermi, also offers some of her recollections of life with her husband and his decision to come to the United States. The narrator discusses Fermi’s childhood and genius.

Date of Interview:
September 12, 1971
Location of the Interview:


[Thanks to Ronald K. Smeltzer for donating the record “To Fermi with Love” to the Atomic Heritage Foundation.]

Enrico Fermi: The event that took place in this room ten years ago would not have seemed in any way spectacular to a casual observer. You would have seen a large black graphite structure, of which there is a scale model, supported in part by a scaffolding of wooden beams. You would have seen a number of people reading instruments and recording their results. Perhaps you might not even have noticed many signs of excitement in their faces because the experiment in which the first self-sustaining chain reaction was obtained had been preceded by a great number of other tries.

Narrator: It is December 2, 1952. The voice is that of Enrico Fermi speaking before a gathering that is commemorating the tenth anniversary of the first controlled nuclear chain reaction. We are in the very same racquets court under the west stands of Stagg Field. It was here that Fermi and his colleagues ushered in the nuclear age.

Fermi: The war lasted almost three more years after December 2, 1942 and throughout this period, the task of producing an effective atomic bomb was the one on which the scientists concentrated.

Narrator: In less than two years, November 29, 1954, Fermi would be dead of stomach cancer at the age of fifty-three. The Italian navigator’s scientific voyage came to an end while he was still at the height of his mental powers. The world of physics had lost a giant, a man of extraordinary intelligence and mental brilliance, the only physicist of the Twentieth Century to excel in both theory and experiment. The most durable monument to Fermi has been his own work. The author of many scientific papers, winner of the Nobel Prize in Physics, a guiding genius of the Manhattan Project—his honors have been numerous, his legacy profound. But somewhere in the flourish of all his scientific endeavor is the untold story of Enrico Fermi, the story of his humility, his uncanny physical intuition, his clear thinking, his unpretentious nature. Much of this story is voiced by the many people who knew and worked with Fermi during his lifetime. Men like John Wheeler of Princeton University.

John Wheeler: The idea of Fermi was somehow always to get on top of the scene, on top of the picture. I can remember the climbs in days in the State of Washington out in the countryside on a Sunday, and Fermi was always pushing ahead to get to the top first. On another occasion, in an irrigation canal that we were swimming in and a fast stream of water down this concrete ditch with the steep sloping sides. We had a bar across downstream so that if any of us was carried too far, he could grab hold and save himself. We then raised the question with each other—there were about eight of us out on this picnic—what would we do if we lost the bar and could not get hold? Could we save ourselves?

Fermi resolved to prove that he could. So here he was, being carried downstream by the water, and all the time fighting to climb up the steep side of this concrete wall. At last he did make it with his shins bleeding and his fingers a bit torn, but he made it. I never saw a better illustration of his drive to make any idea that he had go through.

Narrator: Why Fermi? What in his nature contributed so widely to the admiration and respect he received from people in all walks of life? There was Gus Knuth, a carpenter who worked on the Manhattan Project.

Gus Knuth: Fermi? That man, I liked him and he liked me. Let me tell you, we just got along like that.

Narrator: There was Otto Hillig, an emigrant machinist from Denmark who worked with Fermi.

Otto Hillig: Fermi, he was a wonderful guy. One thing he told me, he built everything up himself and he would stick it together with Scotch Tape. He told me once, “What can science do without Scotch Tape?”

Narrator: From the testimony of technicians to the Board Chairman of the DuPont Company, Crawford Greenewalt.

Crawford Greenewalt: The person that really impresses me most among all the people that I met there was Fermi himself. It seemed to me he was really an extraordinary man. I happen to believe that what you do in life is as much a matter of chance as it is of any direction on your part, and that great ability can manifest itself in many different ways. Fermi, I think, was an ideal case. He happened to be a physicist but I think he could have gone into any profession, whether by accident or by design, and done extraordinarily well at it. He was really a very able man, a brilliant man, and a very cultured man. And I think there is not very little doubt about it that on the physics side of it, on the experimental work aimed at determining whether a chain reaction would go or not, Fermi was the key individual.

Narrator: Fermi combined a supreme ability as a theoretical and experimental physicist. George Weil remembers.

George Weil: Fermi was an all-around scientist. He was not only a great theoretical physicist. He contributed to practically every field in physics. He was a great experimental physicist and he could brush aside details that other people would just get bogged down in.

Narrator: One scientist who knew him longest and worked with him intimately day after day was Herb Anderson.

Herb Anderson: Well, of course it was a very important part of my life. It represented, well, from 1939 to 1954—fifteen years. I had almost daily contact with an extremely brilliant man and had a very great influence on my life. Well, we got a lot of things done together, and much more than I have been able to accomplish since. I have not been able to be nearly as effective after the death of Fermi as I was when he was alive.

Narrator: Enrico Fermi was born in Rome, Italy on September 29, 1901. The house was near the railroad station at the villa Gaeta, Number 19. He was the third and last child born to Alberto and Ida Fermi. There was Marie, his older sister, and Giulio, his older brother. Enrico’s father was employed in the Administration of the Italian Railroads. His mother was an elementary school teacher. Only three years separated the three children and Mrs. Fermi was unable to attend to young Enrico. For the first two and a half years of his life, he lived with nurses in the Italian countryside, a common practice at the time.

As a young boy, Enrico displayed an all-consuming curiosity about the world around him. This innate curiosity fired his ambition. He was a model student, consistently achieving good marks. He had a prodigious memory for poems. Still, he once confessed that when he was ten, he had to struggle to understand why a circle was represented by the equation x2 + y2 = r2. But it was mathematics that first claimed his attention at age thirteen.

His genius was recognized first by Adolfo Amidei, an engineer who was a friend of the Fermi family. He encouraged Enrico, lent him books on science, and guided his math and physics studies between the ages of thirteen and seventeen. In 1915, tragedy struck. Enrico’s older brother, Giulio, died of a throat abscess before anesthesia could be administered for surgery. He was only fifteen.

Giulio’s sudden death left a deep mark on young Enrico, whose introverted and mute sorrow never really conveyed his true feeling of loss. To fill the void, young Fermi struck up a childhood relationship with Enrico Persico. The two boys had mutual scientific interests. They whiled away their idle time at the Campo de’ Fiori, an outdoor flea market comparable to Chicago’s Maxwell Street. Swept up in their scientific curiosity, the two youngsters determined the density of Rome tap water, as well as the Earth’s magnetic field. It was a rewarding, lasting friendship.

At the age of seventeen, under the urging of Amidei, Enrico entered competition for a scholarship to the Reale Scuola Normale Superiore di Pisa. He wrote an essay entitled, “Distinctive Character of Sound”. When picked as the winner of the competition, it meant four years of education with no cost to the Fermi family. It was November 1918.

The school, established in 1810 by Napoleon, was in Pisa, birthplace and home of the great Italian astronomer Galileo. Here, Fermi struck up a friendship with Franco Rasetti. The two young physics students made long Sunday excursions on the Alpi Apuane on the Apennines north of Pisa. It was a relationship that would last their entire lifetime. Enrico received his Ph.D. in Physics from the University of Pisa in 1922 graduating magna cum laude. When he returned to Rome, Enrico went to talk with Orso Mario Corbino, Director of the Physics Laboratory at the University of Rome. Their meeting reflected a mutual desire to develop a revival of Italian physics.

For seven months in 1923, Fermi studied in Göttingen, Germany on a fellowship from the Italian Ministry of Public Industry. He worked with a great German physicist, Max Born. The experience never proved satisfying to Fermi. Later, he returned to Rome to teach an elementary course in mathematics for chemists and science students.

About this time, another countryman, Emilio Segrè, came into the picture. Segrè was the son of a paper mill owner near Rome and was an engineering student went he first heard of Fermi.

Emilio Segrè: I had heard Fermi talk, say around 1923 or ’24, when he was not yet enrolled. He was known among a small circle. I mean it was known that he was an extraordinary man. He had just gotten his Ph.D. and he was invited to give some talk in a seminar of mathematicians. I was a student of engineering. I was interested in in physics and so on, so I went to hear him. But I did not talk to him; I just heard him first.

Narrator: It was 1924. The Fermi family was again shaken by tragedy when Mrs. Fermi died on May 8. She had never really recovered from the sudden death of Giulio nine years before. While still in mourning for his mother, young Fermi happened to make the casual acquaintance of a sixteen year-old girl, Laura Capon. He and other friends spent that Sunday afternoon playing soccer along the banks of the Tiber River. It was a very casual meeting for the 22-year-old Fermi, one that would lead to more deliberate meetings at street corners.

Laura Capon was the daughter of a highly cultured and respected Jewish family in Rome. Her father was an Admiral in the Italian Navy. In typical scientific fashion, Fermi was soon off again. This time under the urging of Dutch physicist George Uhlenbeck, Fermi went to the University of Leiden. He had won a fellowship from the International Education Board to study under the great teacher, Paul Ehrenfest.

For three months in the fall of 1924, Fermi worked side by side with Ehrenfest. It was an example of the international character of European science. It led to Fermi’s many summer trips to America in the early 1930s. He finished his study at Leiden and returned to Florence. Emilio Segrè recalls the atmosphere.

Segrè: Fermi was in Florence for about two years as a professor, as what you would say, a non-tenured professor. He won a competition and came to Rome in 1927. He brought into Rome Rasetti, who was his schoolmate, friend, and so on. Fermi tried to find some other people to form a school to get some other persons for the physics laboratory and so on. At that time I met first Rasetti and then immediately thereafter, through Rasetti, Fermi.

Narrator: The 26-year-old Fermi was appointed Professor of Theoretical Physics at the University of Rome by Professor Corbino. His arrival signaled the beginning of the golden age of physics at the university. The 21-year-old Segrè sensed the excitement.

Segrè: It was clear that Fermi was going to bring a revival and so I transferred from engineering to physics. And I joined the Physics Department in the fall of ’27 with a new scholastic year. By the beginning of ’27, there was Rasetti, who was already an Assistant Professor. There was myself as a student, [Edoardo] Amaldi, and [Ettore] Majorana, and then later other people came. This was the first nucleus of a very active group that stuck together for many years. There was not much difference of age and we became very good friends.

Narrator: Seven years separated the oldest from the youngest in the group, which came to be called “Corbino’s Boys”. It was a time of great scientific activity in the physics building on the Via Panisperna. The hours were from 9:00 until 12:30 and from 3:00 until 7:00 p.m. In the center of this revival was Fermi, whose profound insight and simplicity of approach marked him as a great teacher. It was Segrè who named him The Pope.

Segrè: Fermi taught us physics essentially by private instruction and this went on for two or three years. We were very well set for theory because Fermi was as good a theoretician as any; we had no problems in being completely up to date in theory. But in experiment, it was another story. It was much more complicated.

Narrator: Fermi’s first major contribution to physics came in 1926 when he discovered the statistics valid for particles obeying Pauli’s Exclusion Principle. They are now universally known as Fermi–Dirac statistics. He also contributed important work on nuclear spectroscopy. In 1927, one day less than three years after his mother’s death, Fermi’s father died. In a span of thirteen short years, three members of the Fermi family had passed away.

A year later, on July 19, 1928, at the age of twenty-six, Fermi married Laura Capon, now twenty-one. It was a hot day, 104 degrees in the shade. Enrico was late for the ceremony because of a need to shorten the sleeves of his wedding shirt. The honeymoon began from the Fiumicino Airport west of Rome. The young couple crowded into a two-engine C-plane and flew along the Tyrrhenian Sea to Genoa. The last advice of the bride’s mother to a 21-year-old daughter was, “See that your husband stops wearing hazelnut suits. They do not become him.”

Research and experiment continued at a steady pace at the University of Rome. Fermi and his colleagues contributed to an understanding of gas theory, how electrons and metals conduct electricity, why electrons do not contribute to the specific heat of substance. In 1929 Fermi was one of the first thirty members named to the Royal Academy of Italy, the only physicist named to the group. Fermi, who hated to be conspicuous, showed great displeasure every time he had to wear the peacock uniform of the Royal Academy.

In the summer of 1930, Enrico and his wife spent two months in the United States. He was lecturing on quantum theory of radiation at the University of Michigan. During these annual conferences on theoretical physics, Fermi compared ideas with some of the great minds of the scientific world. He returned to the United States for four more summers in 1933, ’35, ’36 and ’37. Laura Fermi expresses some of Enrico’s reasons for coming to these conferences.

Laura Fermi: Enrico had thought he would like America and he would come in the summer. They would make him an offer for later on and he would accept it. Then he would start working in Italy with his people and his group and so at the moment of leaving, there was something going on. He could not leave and let down the younger people. Well I had been here only once because I would stay in Italy and Enrico would come in summers.

Narrator: Six months after her return from America, Mrs. Fermi gave birth to her first child, Nella, on January 31, 1931. Five years later, she blessed Enrico with Giulio, a son named after Fermi’s deceased brother. In late 1933, Fermi demonstrated the reach of his great analytical mind. He developed the theory of beta decay emission based on Pauli’s idea of the neutrino. Emilio Segrè underscores the paper’s importance.

Segrè: This was a very, very important paper, which he wrote in the last months of ’33 and Fermi put this on a quantitative basis. He made a real theory, which would predict things on the basis of Pauli’s hypothesis It was one of his major contributions to theory and to nuclear physics; this paper on beta decay is really one of the major discoveries.

Narrator: 1934 was the year Fermi and his colleagues performed the bombardment experiments that led to his Nobel Prize. It was also the true beginning of Fermi’s long road to the development of the first nuclear chain reaction. Corbino’s Boys had stumbled upon experimental evidence of the effect of slow neutrons. Emilio Segrè recalls the moment.

Segrè: When Fermi, in 1934, read of the discovery of artificial radioactivity by Curie and Joliot, he immediately recognized that by replacing the projectile’s alpha particles with neutrons, one would create the possibility of making many more radioactive isotopes. With characteristic vigor, Fermi grabbed this opportunity. Recognizing the magnitude of the enterprise, he asked his former pupil Amaldi, Rasetti, myself, to help in the work. Later we were joined by [Oscar] D’Agostino and still later by [Bruno] Pontecorvo.

Narrator: The Italian group had bombarded uranium with neutrons and produced several radioactive substances, one of which they could not identify. Perhaps it was a new element. The new substance did not fit into the periodic table near uranium. It was a science puzzle that would last for four more years. Much later, Fermi related that they were not imaginative enough to think of uranium’s unique disintegration process. He also felt that not enough was known of separation chemistry at the time. The new element, in reality, proved to be a mixture of disintegration products that belonged back in the middle of the periodic table.

The middle Thirties in central Europe may have been an active time of scientific research, but it also was a time that ushered in the dark forces of tyranny that were fast sweeping through Europe. Emilio Segrè and Mrs. Fermi recall the period.

Laura Fermi: Up to 1938, it looked as if the Italians were on top and then from the beginning of 1938 it was the Germans who were on top and there was no doubt of that. From then on, it looked bad.

Segrè: There was Hitler always grabbing more territory and becoming a bigger and bigger menace. Early summer of ’38, Italy joined Germany, but Italy became more and more a vassal state of Germany. This started the anti-Semitic legislation that started to follow Hitler. This made an intolerable situation because while Fermi personally was not affected, his wife is Jewish. The children could not go to school, or maybe they could have gone to school but with some handicap, I do not know. He decided that there was nothing he could do anymore and he had to quit.

Laura Fermi: Then in the summer of ’38, Italy started to promulgate racial legislation, and I am Jewish. Although that did not make too much difference, especially in Italy, we could have stayed and so on, but it was some kind of last straw. So we decided to leave at about that time.

Argonne National Laboratory