Chapter Three—
The Education of a Physicist (1922–1928):
Scent of Roman Hay and Alpine Snow

 . . . chè non fa scienza,
sanza lo ritenere, aver inteso.

( . . . for knowledge none can vaunt
who retains not, though he have understood.)
Dante, Paradiso 5.41–42 (trans. Laurence Binyon)

The end of high school materially changed my studies, which were still my primary occupation. No longer was I forced to study subjects in which I was not interested, and neither was I subject to pedagogues whom I often could not admire. At the university I found several teachers who were universally known as eminent in their fields, and who obviously dominated their subjects. What I learned was new to me; interesting and challenging, it stimulated me to think further about what I heard, which had only rarely happened in high school. I was much freer in organizing my time and chosing my friends. I did a fair amount of fencing at first, but later I became an enthusiastic mountaineer and skier. Love, girls, and sex also came to the forefront.

I finished high school in July 1922, matriculating in engineering by a process of elimination. The first two introductory years of study were common to engineering, physics, and mathematics. I knew, from a practical point of view, that my father would give me a job in the paper mill or find me work in some other industry. The idea of a career as a physicist seemed farfetched because it offered little hope of finding any employment.

I and my parents certainly favored a university career, but to try for this was very risky because at the time there were very few openings in Italy—in total about twenty chairs in physics, all of them occupied. Perhaps one position became available each year because of retirements and deaths. Furthermore, I had some misgivings about whether physics was up to date in Italy. I do not know from where I got that idea. Possibly in reading Reiche's book I had noted that hardly any Italians were mentioned, and even in the old Ganot, there were few Italians. In any case the choice of the preparatory biennial course postponed making a final decision, so I registered for it.

In my first year at university, I studied algebra under Professor Francesco Severi, geometry with Professor Guido Castelnuovo, and chemistry with Professor Nicola Parravano. I also took a drafting course. Severi gave excellent lectures, and I was pleased by the change of level from high school; here there was real intellectual stimulus and a challenge to understand; perhaps even to try to invent something new. Castelnuovo was a paragon of clarity, and in spite of his monotonous voice, which induced sleep, one learned new and interesting things. I soon came to suspect, however, that the chemist, Parravano, did not always know what he was talking about. At home I had found a treatise on physico-chemistry by Walther Nernst,^[1] and comparing what I had learned from it with what Professor Parravano taught, I concluded that he had misunderstood several things, or at least that he understood them differently from me. The professors' assistants were more accessible than the great men, and one of Severi's explained Fourier series to us in a startling and profound way, which gave much food for thought.

In my second year, Severi taught us analysis; Senator O. M. Corbino, the head of the department, physics (in practice only dealing with electricity); Pittarelli, descriptive geometry; and Tullio Levi-Civita, rational mechanics. In my first two years at university, nobody taught us any thermal physics or optics, let alone more modern subjects.

Levi-Civita's course on rational mechanics was poorly attended, although the professor was famous and the lectures were good, even if slightly verbose.^[2] Levi-Civita was very short and also short-sighted;

nevertheless, he strove to reach the top of the blackboard, putting his nose very close to it, raising his arm, and writing blind. In this position, he was once struck on the back of the head by a missile from the peashooter of some nasty student. Levi-Civita turned around and, with the most innocent expression, asked: "Have I written a wrong sign?" His candor and good faith were so obvious that nobody laughed, and no peashooter ever dared disturb him again. For many months we heard the simplifications that occur in mechanics if F × dP is a total differential without the professor ever explaining what a total differential was, and without us ever asking. Levi-Civita trusted our analytical competence, but unfortunately Severi had not mentioned total differentials.

No less important than the courses were my new fellow students. Among them Giovanni Ferro-Luzzi was the closest to me. We came from the same high school, but from different sections. Soon we started studying together. We liked to compete in solving problems and we quizzed each other on the theory.

I also discovered that there was a very great advantage in studying steadily during the year, avoiding a cramming period before the examinations. Good, paternal Professor Castelnuovo had warned us on this subject; I was surprised in discovering the pertinence of his advice. I found that I needed time for digesting many new ideas and that a steady diet nourished infinitely more than occasional feasts (and bouts of indigestion). I believe that the discipline of steady work helped me immensely then and later in life.

Ettore Majorana, who subsequently acquired a well-deserved reputation as a mathematical genius, was another of my fellow students.^[3] Once, not having sufficiently prepared a lecture, Severi started a proof of a theorem the wrong way. Majorana immediately whispered that he would soon be in trouble, so we all anticipated what was to come. After a minute or two, Severi's face reddened, and it became obvious that he did not know how to proceed. Some voices then murmured: "Majorana predicted it." Severi did not know who Majorana was, but said haughtily, "Then let Mr. Majorana come forward." Ettore was pushed to the blackboard, where he erased what Severi had written and gave the correct proof. It is noteworthy that Severi neither complimented him

in any way nor made any effort to become acquainted with him. On a different occasion, while I was waiting to be called to an oral examination, Majorana gave me a synthetic proof for the existence of Villarceau's circles on a torus. I did not fully understand it, but memorized it on the spot. As I entered the examination room, Professor Pittarelli asked me, as was his wont, whether I had prepared a special topic. "Yes, on Villarceau's circles," I said, and I proceeded immediately to repeat Majorana's words before I forgot them. The professor was impressed and congratulated me on such an elegant proof, which was new to him.

My friend Giovanni Ferro-Luzzi and I prepared for examinations on a bench in the marvelous Palatine gardens, near the house of the superintendent of the diggings at the Roman Forum, the humanist and archaeologist Giacomo Boni (1859–1925). It was an extraordinary location, quiet and evocative, with laurel thickets and Italian gardens. On the days of ancient Roman festivals, somebody put up rich festoons of flowers and fruits, hanging them in appropriate places.

In the fall, Ferro-Luzzi and I repaired to Tivoli for concentrated, undisturbed study, as I was later to do with Edoardo Amaldi. My parents' housekeeper there fed us excellently; after studying we went for hikes under the olive trees or on the Viale Carciano, as I had done since my childhood. If by chance it rained, the rain was followed by the clear, cool, scented air of the beginning of autumn.

Mountaineering became a serious avocation with me, and every summer I and some friend went to the Alps for rock or ice climbing; during the winter we practiced cross-country skiing, often in the Abruzzi. In the Dolomites I climbed the Vajolet Towers, and, all alone, the Cinque Dita, and many other mountains in the vicinity of Cortina d'Ampezzo, in the Pale di San Martino group, and elsewhere. Our climbs reached today's fourth class and would now be deemed easy, but in the 1920s they were thought fairly difficult. We always went without a guide, for sport as well as to save money.

My active mountaineering lasted until about 1930. Later physics absorbed my summers too, and still later, after my marriage, I discovered

that while I still liked hiking, camping, and outdoor activities a lot, I had no more stomach for difficult climbs.

In my third year at university, I transferred to the Engineering School, where I found the courses much less interesting than in the preparatory biennium, except for one by Professor U. Bordoni, who taught us thermodynamics according to Clausius, emphasizing all its subtleties. The other professors taught ordinary engineering practice, at a low technical level and without imagination. To refresh myself, I attended a mathematics course on the theory of functions of a complex variable, given by Professor Ugo Amaldi, the father of my future friend Edoardo. The lectures were at 1 P.M. , not exactly a pleasant hour in Rome, but the teacher presented the material in a fascinating way. The exposition resembled a soap opera, and at the end of each lecture I asked myself what the next would bring: new singularities? new power series developments?

At about this time, my fellow student and mountain-climbing companion Giovanni Enriques told me that he had heard from his father that there was at Rome a sort of genius, a certain Enrico Fermi, who had recently got his physics degree in Pisa. When I went to hear Fermi speak at a mathematics seminar,^[4] I soon realized that the rumor was not exaggerated; at last here was somebody fully conversant with modern physics. However, I did not approach Fermi at that time. At other meetings of the same seminar, I heard E. Landau, whose talk confirmed my conviction that pure mathematics was not my cup of tea. Another time a professor from Bologna spoke for an unconscionably long time. For some reason, the light went out for a few minutes; when it came back on, the room was almost empty.

In my third or fourth year in engineering, why I do not remember, or perhaps never grasped, I grew a Charlie Chaplin moustache and started going to school wearing a bowler hat and kid gloves, carrying a cane. This lasted for several months and provoked a certain amount of mockery among my fellow students, to which I responded with haughty disdain.

In 1927 my mother had the happy idea of giving me a Fiat 509 au-

tomobile. I suspect she may have thought it was the simplest way of getting me a girlfriend. If she had any such idea, however, she never even hinted at it to me.

Cars were then still relatively uncommon in Rome, and the 509 made big changes in my life. It ranked me as affluent among my fellow students, and everybody wanted to use my car. It also greatly facilitated mountain trips. On the other hand, it did not have great success in procuring me a girlfriend. My friends and I took several girls of a good family background to the seashore or to places in the vicinity of Rome, but always within the limits of strict decorum and prevailing Italian rules. Often we went in a party of four: Giovanni Enriques and I with two girls, whom we may have liked even more than we let on. To give an idea of the difficulties we faced, once at the seashore at Castel Fusano, about twenty miles from Rome, we lost the ignition key. We were supposed to return before nightfall, and being late would have caused a scandal. By combining all our technical ingenuity, we succeeded in bypassing the ignition switch and starting the car. This shows how restricted we were; a simple accident would not have excused us for a few hours' delay in getting back.

In those days, the surroundings of Rome were of an unsurpassed beauty, now almost entirely vanished. In springtime, places such as the Pratoni di Nemi, a plateau at about 3,000 feet in the volcanic Alban Hills, overflowed with wild jonquils and violets; Pratica di Mare, almost unknown except to a few cognoscenti, resembled a Pacific island, with palms, tropical vegetation, and wild buffaloes wallowing in the mud; Veio's Etruscan ruins, covered with scented honeysuckle, were interspersed with green meadows, on which I would lie for hours talking to my girlfriend. It was hard to tell which was more exciting: her perfume or the scent of the hay and of the wildflowers. Even Ostia and Fregene, still sparsely populated, were true gems.

In the beginning of the 1920s, I had carefully toured Rome, often together with my cousin Fausta, who came visiting from Turin and stayed with us. She had rather romantic tastes, and with the help of the Touring Club Italiano guidebook, knew where to go and at what time of the day. Little wonder that two young people under such con-

ditions should develop tender feelings; however as time went on, friendship prevailed over love, and endured solidly until Fausta's death in 1982.

At home, Marco, after attempting some deals on his own, in which he lost money to an impostor, had accepted a job in the paper mill, and he expected, in due course, to succeed my father. Father told me openly that there could be only one person in command of the paper mill, and that he would help me start a different business for myself or find a job elsewhere, according to my preference.

In the meantime my distaste for engineering studies steadily increased. Luck had it that in the spring of 1927, Giovanni Enriques introduced me to Corbino's newly arrived assistant, Franco Rasetti.^[5] Rasetti, who was then about twenty-five, was a close friend of Fermi's; he had studied with Fermi at Pisa, had followed him to Florence, and had been hired by Corbino on Fermi's suggestion when Fermi was appointed professor of theoretical physics at Rome. In addition to being an excellent physicist, Rasetti was a skier, a mountain climber, an insect collector, and in general a person of the most diverse interests.

My car allowed us to go to places that were otherwise rather inaccessible, and at the end of May 1927, Enriques, Rasetti, and I went to Castel del Monte in the Abruzzi. From there, we followed a long ridge to the Gran Sasso, the highest mountain in the Apennines. It was a hike of a couple of days, requiring us to sleep in the open. These conditions helped create a fast friendship between us, and soon thereafter Rasetti introduced me to Fermi.

The two of them were looking for physics students to educate, and I was looking for teachers, so we suited each other. At the end of July, I went with Rasetti to the Pizzo d'Eta from the valley of the river Liri in central Italy, a lengthy and very beautiful excursion. The long, deep valleys of this isolated and rarely visited part of the country, with their well-preserved ash, oak, and maple woods, preserved the aspect of Italy before its deforestation in recent centuries. Near the top of the mountain, Rasetti started looking for some tiny insects of the genus Bythinus, which lived under the bark of trees. He sucked them into a small glass container he had brought with him and saved them for his famous

collection of coleoptera. At the same time, speaking very loudly, he taught me the principles of statistical mechanics and Boltzmann's distribution. He asserted that except for Fermi and himself, there was no physics professor in the Italian universities conversant with such theories. On the Pizzo d'Eta, I also learned some calculus of variations and analytical mechanics. I greatly enjoyed these strange lectures and on my return home made notes on them.

A few weeks later I went to Ostia with Fermi, Rasetti, and other young men and women. Fermi started talking physics and asked me what I knew. He challenged me to calculate the vibrations of a heavy rope dangling vertically, which I did to his satisfaction. Thus started our friendship.

In the summer of 1927, always in my car, we went to the Val d'Herens, in the Alps. I stopped on the Riviera near Genoa, to say hello to Renata J., a great and unhappy love of mine, who was spending her vacations there. Our company consisted of Giovanni Enriques, Rasetti, FerroLuzzi, Piero Franchetti (Enriques's cousin) and myself. We settled in a very primitive refuge and from there started several rather difficult climbs: Dents des Bouquetins, Dent d'Herens, and others. I had with me a guidebook and carefully studied the itineraries. It was a sensible thing to do, but I was rather pedantic, and my friends teased me because I would say things like: "Here according to the book we should find the plaque marking the spot where X lost his life." However, recognizing landmarks and critical spots on the climb helped us achieve our goal. Once we were caught in an electrical storm. The sight of the sparks coming out of our ice axes and of our hair standing on end was truly spectacular, and scary.

That summer I experienced for the first time a strange, almost pathological, peculiarity of Rasetti's. Whenever he saw a chance of ditching his companions, whether because of darkness or fog or any other reason, he took it. Later he rejoiced in having done so as though it had been a funny joke. A psychologist could have a field day with such behavior.

From the Val d'Herens, we passed to Val Tournanche and from there on August 14, 1927, we climbed the Matterhorn. The weather foiled a

first attempt, but the next day, taking advantage of a clear spell, we bounced back from Breuil, slept at the Luigi Amedeo di Savoia Hut and, after a very cold and windy climb, reached the top. We descended from the Swiss side, sleeping at the Solvay Hut. That year the ice and snow conditions on the mountain were difficult, and ours had not been an easy enterprise. During our stay at Breuil, we met the duca degli Abruzzi, a cousin of the king of Italy and a noted explorer, as well as the famous writer and mountain climber Guido Rey. The latter invited us for tea at his villa and gave me some pictures. The Breuil too has been disfigured by much new construction and automobile traffic since World War II. In our day, the easiest access was by a mule trail from Val Tournanche.

After the Matterhorn climb, I met my uncle Claudio in Aosta, where he happened to be attending a geological meeting. I accompanied him on a field trip and he showed me the landscape through the eyes of a geologist. It was a revelation and a fascinating lesson; I do not know why my uncle had never taken me on a field trip before. Unfortunately, it was also the last possible chance. At Aosta, while we were together, Uncle Claudio suffered a small stroke; it did not seem serious at first, and he recovered fast, but after his return to Rome, more strokes, of increasing gravity followed, and on March 18, 1928, he died. He was the first person dear to me that I saw dead, and the sight affected me deeply. From what I have written about him, it should be clear what a loss it was for me.

From Aosta I went to Como, where an International Physics Conference was held that September to commemorate the hundredth anniversary of the death of Alessandro Volta in 1827.^[6] Needless to say, I was not invited. I was not even a physics student, but I thought, with some impudence, that by tailing Rasetti, who in turn was tailing Fermi, I might be able to attend some of the lectures and see what was going on. Indeed, this came to pass. Besides going to the lectures, I collected several free publications that were given to those attending the conference, and in particular an excellent series of articles on modern physics, written by K. K. Darrow of the Bell Telephone Company. I read them carefully during the conference.

Many great physicists were present; among them Max Planck, Ernest Rutherford, Niels Bohr, Robert Millikan, Wolfgang Pauli, and Werner Heisenberg. Einstein was not there because he did not want to enter Fascist Italy. Corbino, Quirino Majorana (Ettore's uncle), Fermi, and a few others represented Italy, and it was easy to see that Fermi was the only Italian who counted in the eyes of the foreign participants. The organizers offered lavish receptions and excursions on a lordly scale. Corbino privately commented that Italy should have exhibited more physics and less hospitality and that it should not deceive itself that sponsoring a conference was a substitute for scientific achievement. From Como, the participants in the conference went to Rome, where Mussolini received them.

What I had seen at the conference tipped the scales in my decision to switch from engineering to physics. I had been brooding over the idea since the spring, when my meetings with Rasetti and Fermi had convinced me that a unique opportunity for seriously learning and practicing physics had arrived. The young professors, who were only slightly older than I was, treated me not as a mere freshman but as a future colleague. They were prepared to let me have immediate access to the laboratory of the physics department, to show me what they were doing, and to give me an opportunity of helping them in their work. What more could have I wished for?

On my return to Rome, I started going regularly to the lab in the Physics Institute at Via Panisperna 89a, where I found my mentors dressed in none-too-clean gray smocks, so much so that my olfactory memory can still evoke the characteristic slight smell of those garments. They explained to me the purpose and the techniques of the experiments they were performing and the results they expected.^[7]

At the time, having read much physics privately, I was acquainted with classical physics at an intermediate level. My mathematical preparation was pretty good and derived mainly from the excellent university courses I had attended. I also knew some chemistry and had worked in a good analytical laboratory at the Engineering School. My practical experience derived from amateurish experiments and appa-

ratus; I had built a crystal radio receiver and played with a Ruhmkorff coil. All told, I knew how to use my hands and simple tools.

Fermi started tutoring me privately almost from the outset. At about 6.30 P.M. he would call me to his office and there, mostly with Rasetti also in attendance, he would explain to me whatever came to mind, or whatever I proposed. I listened, when I did not understand I asked questions, and then at home I wrote down what I had learned, with the help of sheets of paper that Fermi had filled with formulae as he progressed in this cross between a lecture and an informal conversation. I did this work mostly the day after the lecture, and I included some problem proposed by Fermi or, more frequently, of my own invention. Here are some samples of the subjects treated, according to my extant notes: light diffraction from a slit; mean free path in gases; fluctuations; classical theory of light resonance; molecular rotatory power; diffusion vacuum pumps; X-ray diffraction according to Max yon Laue and to W. H. Bragg. This was possibly the most influential "class" teaching I ever had. A little later Edoardo Amaldi joined the "class."

Rasetti showed us how to perform spectroscopic experiments using interferometers, spectrographs, and simple techniques. Fermi thought that one could teach theory, but that the only way of learning experimentation was a laboratory apprenticeship. Furthermore, it was his rule that beginners should study theory and experiment equally; specialization would come only later. He used the same teaching method again and again, particularly in Chicago.^[8] The subjects too, even after many years, were often the same as in Rome, almost stereotyped. In fact, they were the methods and results that seemed important to Fermi. I was able to retrace them to an extent even in notebooks of his own studies at Pisa or earlier. Some of these notebooks, which are astounding for the unerring choice of materials, are deposited in Chicago among Fermi's papers. I saw them only after his death.

Fermi did not give himself airs; he was very simple in his manner, courteous, and easily accessible. These outward appearances nonetheless concealed great reserve. Outside of physics, he was much more inclined to listen than to speak and refrained from private confidences.

Although we spent many hours together every day, and ostensibly on a footing of equality, I do not believe there was the same degree of intimacy with him as with the other members of our group. Perhaps his manifest scientific superiority contributed to this situation, but its main cause was Fermi's disposition and the care with which he set reason over feelings. With the passing of time and given the special circumstances that obtained later during the war, Fermi's reserve increased rather than decreased. This was contrary to what one might have expected; relative differences in age and scientific standing tended to diminish with time. Although affable, Fermi always inspired a certain awe, and perhaps more so in those who knew him best than in those who had only a cursory acquaintance.

Under Fermi's ministrations, we rapidly gained an incredible enthusiasm for science. We loved physics with an intensity comparable to that of physical human love; we thought and talked only about physics. Rapid progress followed, which further enhanced our passion. We spent all our available time at the Physics Institute—that is, according to the holy Italian schedule, from 8 A.M. to 1 P.M. and from 3 P.M. to 8 P.M. , Monday to Friday and on Saturday mornings. We never went to work after dinner and very seldom on Sunday. The institute closed on a regular schedule, and none of us had a key to the door.

Saturday was a very interesting day because we frequently devoted Saturday mornings to planning future work. On Sunday we usually went on hikes with friends of both sexes, including many nonphysicists, but the physicists often formed a separate group after a while and started talking shop. Under the influence of our common life, we developed some strange tics, such as the habit of speaking with an intonation or cadence characteristic of Fermi. It was not a pose, only mimicry.^[9]

Everything was going well for me, but I was still registered at the Engineering School and not in the physics department. Any mention of the fact that I was inclined to switch met with distinct coldness at home. Uncle Claudio, who was already ill, wanted me to get my engineering degree first; my parents said that as an engineer I would easily be able to find a job, but that as a physicist, if I did not obtain a university

chair, I would have to make a living as a high school teacher, a dim prospect.

Rasetti and Fermi had rapidly convinced me that they were supermen (not a totally erroneous opinion, merely exaggerated), and that whoever associated with them would become one too. They were positive they were the only up-to-date physicists in Italy (with the possible exception of their students) and the only ones that counted scientifically.

In the beginning I tried to keep up with both engineering and physics, but I soon realized that this was not possible. Studying physics with the intensity and dedication I desired, and that was necessary if I was to meet Fermi's expectations, did not leave time or energy for anything else. In the meantime I had been introduced to Corbino, who in spite of his benevolent cordiality inspired me with considerable awe too.^[10] This feeling paradoxically manifested itself in my often acting as if I did not see him, or in my being curt with him. I always regretted not having been more open with him, as I desired and as he deserved.

Finally, I decided I had to burn my bridges and transfer to physics. Unexpectedly, I met with a bureaucratic difficulty. Because I had not taken a required laboratory course in practical physics, I stood to lose a year. It was then that I really saw Corbino in action for the first time. He telephoned a relative of his who was registrar at the Engineering School and told him: "Segrè wants to register in physics, but in the certificate you have given him there is no mention of the exam in practical physics. How come? He passed it in my institute last year and got a grade of 30/30." The registrar apologized and corrected the "error," and I did not waste the year. The following year, however, Corbino assigned me to teach that course, and now, sixty years later, it dawns on me that perhaps it was not just by chance. I repeatedly saw Corbino circumventing obnoxious regulations or managing some wellplanned scheme, but never without a clear justification from a higher point of view. He was a master at overcoming obstacles standing in the way of raising the level of physics in Italy. Ultimately, he succeeded brilliantly.

A few months after I transferred to physics, I spoke to Ettore Majorana about doing so, encouraging him to follow my example. I told

him that the Engineering School was not for him, just as it was not for me, and that the present situation in the physics department offered a unique opportunity. Ettore listened and then decided to come to see in person. At the institute, he found Fermi calculating the function central to the Thomas-Fermi statistical method for calculating atomic properties,^[11] cranking a small Brunsviga adding machine by hand. With its help, in about a week of work, he had obtained a numerical table of the function. Majorana informed himself in detail about the mathematical problem and went home without further comment. At home, he transformed Fermi's nonlinear equation into a Riccati equation and solved it numerically using his brain as calculating machine. After a few days he returned to the physics department and asked Fermi to show him his numerical results. He compared them with his own and verified that they agreed. "Surprisingly, Fermi has made no errors," he said. After this experience, he too converted to physics, but being mathematically vastly superior to all of us, and in some respects even to Fermi, he did not come regularly to our instructional sessions, although he participated in many of our conversations and discussions. He never tried experimental work.

In the early days of our informal Rome group, Giovanni Gentile, Jr., son of the philosopher, powerful senator, minister, and Fascist bigwig of the same name, often came to the institute. He had recently graduated from the Scuola normale in Pisa and, possibly because of their common Sicilian roots, became very close to Majorana and wrote a few papers with him. Gentile remained our friend and occasionally visited the institute, but never became a regular member of our group.

Already in the fall of 1927 we had a new recruit, Edoardo Amaldi.^[12] "In the present state of rapid change now prevailing in physics all over Europe, and with Fermi's appointment at Rome, an exceptional period has opened up for young people who have already shown sufficient ability and are willing to make an exceptional effort in theoretical and experimental study," Corbino had announced in one of his lectures to the second-year students. Amaldi was the only one who answered the appeal and joined our group. He was the youngest, and seemed even

younger than he was because of his rosy complexion, so he was often called "the little boy" (il fanciulletto ).

Jokingly, we assumed nicknames that originated from a ribald poem popular at the Scuola normale at Pisa, where it had been transmitted orally for a long period. Fermi and Rasetti knew by heart long excerpts from this poem and occasionally quoted it. Another origin of the nicknames was a parody of the offices of the Vatican Curia. Corbino was the Heavenly Father; Fermi, the Pope; Rasetti, the Cardinal Vicar; I, the Prefect of the Libraries, because I was interested in the library and knew the physics literature; however, I was also the Basilisk, because I was supposed to spit fire when mad; Majorana's extremely critical attitude earned him the title of Grand Inquisitor.

Amaldi had the most common sense and was also by nature and upbringing warmer and more humane than the rest of us. Majorana, with his profound skepticism and pessimism and his ironic bent, was not always easily accessible. Rasetti was pure brains, with childish forms of selfishness fostered by his mother, but in spite of his peculiarities, he was easily approachable. Of Fermi I have already spoken. All in all, they were excellent friends, loyal, generous, and honest. There were, however, differences in the degree of intimacy prevailing among us. Amaldi, Rasetti, and I could speak of anything with one another, including girls, love, politics, and career; with Fermi or Majorana, there was more reserve.

In that period, or shortly before it, I fell desperately, but unfortunately platonically, in love with Renata J. In the famous 509, we went to the most romantic spots in the vicinity of Rome, where she deployed much detachment. A high school friend whom I still saw occasionally told me stories aimed at inflaming my jealousy and sufferings. Many years later I learned astounding things about that period from Renata; had I known them around 1927, they might have changed my life. Both Renata and I were victims of our upbringing in a world where there was no pill, and where girls married as virgins (at least most of them). I still see myself trying to adjust the fringes of an interferometer while thinking of and sighing for her.

I was registered as a physics student only for one year. I registered in the fall of 1927 and obtained my doctorate on July 14, 1928. Because I had already studied engineering for four years, Corbino and Fermi shortened my formal study period in physics as much as possible. The most important subject I studied in class that year was theoretical physics with Fermi. His course followed his book Introduzione alla fisica atomica , which he had recently written. The book was not yet published, but Fermi gave me a set of proofs. It is an elementary book, still treating the atom in terms of the semiclassical Bohr-Sommerfeld approach. Only in the last chapter is there brief mention of the recent novelty "quantum mechanics." I studied the book thoroughly and soon supplemented it with information from Erwin Schrödinger's memoirs, which Fermi had explained to us privately as they appeared.

I was required to pass also an examination in "Higher Physics" as taught by Professor Antonino Lo Surdo. He was Fermi's avowed enemy, and his feelings were reciprocated. He had opposed Fermi's call to the Rome chair, stating that such a call was a personal slight to him. Scientifically, the man was badly out of date. He knew Drude's optics and J. J. Thomson's gas discharge book, but he was about thirty years behind his time, both in his teaching and in his anemic research. In class he showed beautiful experiments, but his lectures did not convey anything of vital import. Since he could no longer fight Fermi, he took it out on me. As the Italian saying goes, "He beats the donkey, being unable to hit the master."

As a third required course, I attended the lectures on mathematical physics given by Vito Volterra. I should add that the subsequent year I again attended his course, because he changed subject every year and from him one learned interesting notions of classical mathematical physics. Volterra's lectures were well organized and the subject matter was skillfully chosen (as I realized later), but his delivery, in a thin and slightly high-pitched or nasal voice, tended to put me to sleep. There were no textbooks, and one had to take notes; I therefore asked Amaldi to write for both of us, since he wrote faster than I, and also to wake me up if I fell asleep. Volterra used to close his eyes while

lecturing and somebody said that this was because, being kindhearted, he did not want to see the students' sufferings. Except for these superficial shortcomings, the lectures were profitable. One learned the mysteries of the Laplacian, Green's functions, Poisson brackets, and similar topics. It seemed sometimes that Volterra did not want to reveal the physics underlying the equations and the analogies between different theories. After taking a course on elasticity and one on analytical mechanics, I passed the exam with the highest grades. I remember that to show my proficiency I mentioned the analogy between some elasticity coefficients and the capacity coefficients of electrostatics. I should not have done it. Volterra cut me short, remarking that he had not mentioned this in his lectures, almost as if he disliked my revealing a secret.

Volterra always treated me very kindly. I visited him in his residence in a palazzo at the center of Rome. He received me in his magnificent library and gave me some reprints of his papers on the applications of mathematics to biological population problems; later he helped me to secure a Rockefeller fellowship. He was, however, far removed from current physics, which did not seem to interest him. Corbino, in one of his sharp remarks, once said that mathematical physics as practiced in Italy was the "theoretical physics of 1830."

University rules required preliminary discussion within the department of one's doctoral dissertation prior to the final public examination. I presented a modest piece of experimental work on anomalous dispersion in mercury and in lithium vapor.^[13] It was certainly no great shakes, but it was above the average then prevailing at Rome. When I went for the discussion, I found a committee composed of Fermi, Rasetti, and Lo Surdo. Lo Surdo immediately swamped me with questions on all possible types of interferometers, which I did not know, although, of course, I had mastered the ins and outs of the Jamin interferometer I had used. He then passed to optical features of crystalline quartz, although my own apparatus had an optics of amorphous fused quartz. I correctly told him that my work was not affected by the properties of crystalline quartz. Lo Surdo concluded, however, that I

did not know what I was doing, that I was superficial and ignorant. This behavior was peculiar and unprecedented. I was furious, and after the examination I waited until Lo Surdo had left the building and then went to his office, where I found just what I had expected. Piled on his desk lay a couple of big German treatises, open at the pages dealing with interferometers. The good man had prepared for the occasion in order to make a fool of me.

A few weeks later, on July 9th, the formal discussion of my thesis took place, with eleven professors in attendance, among them Severi, Levi-Civita, Volterra, Fermi, and the young Beniamino Segre, subsequently a well-known mathematician. Corbino was absent. I discussed as a subordinate subject, given to me by Volterra, some properties of partial differential equations of the second order, which are much more profound than I realized at the time. Finally, I was excused and left the room, but I overheard the following exchange:

I must say that the exchange I heard compensated me for the laurels I missed. Fifty years later, Beniamino Segre, by then a famous president of the Accademia dei Lincei, still chuckled when reminding me of the scene.

After completing my doctorate, I had to satisfy the military obligations prescribed by law, which I did at a recently instituted army officers' training school in Spoleto, an ancient town in Umbria, now best known for its summer festivals. Not long before I went there, I met Lo Surdo in the street one day. He stopped me, inquired what I was doing, and commented: "So; you will go to serve in the army.

Well, you will forget everything. Ordinarily it is a fatal interruption in one's scientific career. After your discharge it would be better for you to look for another profession." I thanked him for the friendly advice and touched wood (Italian style one touches something else). In our love for the gentleman, we had given him a reputation of casting the evil eye, and we had ample corroboration of this—for example, of an apparatus blowing up with catastrophical consequences as soon as he looked at it.

Lo Surdo occupied a wing of the physics building on the same floor as us; he also had an assistant, usually an insignificant fellow. He treated him in a way no scientist, even a beginner, would have tolerated. Lo Surdo's research is insignificant, with the exception of a method for observing the splitting of spectral lines when the source is in an electric field. The phenomenon is the electric analog of the magnetic Zeeman effect and is usually called the Stark effect. It is likely that Lo Surdo had observed it before Stark, but certainly he did not understand what he saw, possibly confusing it with a Doppler effect. When, a couple of months later, Stark announced his discovery, Lo Surdo was deeply disappointed at having missed the boat and tried to establish his priority on shaky grounds. Corbino had favored Lo Surdo's call to Rome hoping he would help to raise the level of the place. His expectations came to nothing, and several years later Corbino bet on Fermi with the same aim. He was disgusted by the jealousy shown by Lo Surdo and on further provocation gave him a memorable lesson.^[14]

On Corbino's death in 1937, Lo Surdo was appointed director of the Physics Institute in preference to Fermi. I do not know how he wangled the appointment. After the promulgation of the infamous racial laws, he showed unusual and unnecessary anti-Semitic zeal. For instance, he locked the venerable Professor Castelnuovo, his colleague for many years, out of the library of the physics department. He earned Edoardo Amaldi's gratitude, however, by helping him to return from military service in Libya during World War II.

At the end of the war, Lo Surdo was dismissed from the Accademia

dei Lincei and experienced some retribution for his fascist zeal. When I returned to Italy for the first time in 1947, he asked to see me. The undignified and servile manner in which he greeted me did not improve my opinion of him. I told him coolly that I knew how he had behaved during the war, that I had a good memory, and that he did not need to pay his respects to me. He died about a year later. Let him rest in peace. He had been generous to me in letting me use his spectroscopes at the beginning of my career.